Re: [v2 PATCH 0/3] arch: mm, vdso: consolidate PAGE_SIZE definition
On Wed, Mar 06 2024 at 15:14, Arnd Bergmann wrote: > From: Arnd Bergmann > > Naresh noticed that the newly added usage of the PAGE_SIZE macro in > include/vdso/datapage.h introduced a build regression. I had an older > patch that I revived to have this defined through Kconfig rather than > through including asm/page.h, which is not allowed in vdso code. > > The vdso patch series now has a temporary workaround, but I still want to > get this into v6.9 so we can place the hack with CONFIG_PAGE_SIZE > in the vdso. Thank you for cleaning this up! tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH v2 3/3] arch: define CONFIG_PAGE_SIZE_*KB on all architectures
On Wed, Mar 06 2024 at 15:14, Arnd Bergmann wrote: > From: Arnd Bergmann > > Most architectures only support a single hardcoded page size. In order > to ensure that each one of these sets the corresponding Kconfig symbols, > change over the PAGE_SHIFT definition to the common one and allow > only the hardware page size to be selected. > > Acked-by: Guo Ren > Acked-by: Heiko Carstens > Acked-by: Stafford Horne > Acked-by: Johannes Berg > Signed-off-by: Arnd Bergmann Reviewed-by: Thomas Gleixner ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH v2 2/3] arch: simplify architecture specific page size configuration
On Wed, Mar 06 2024 at 15:14, Arnd Bergmann wrote: > From: Arnd Bergmann > > arc, arm64, parisc and powerpc all have their own Kconfig symbols > in place of the common CONFIG_PAGE_SIZE_4KB symbols. Change these > so the common symbols are the ones that are actually used, while > leaving the arhcitecture specific ones as the user visible > place for configuring it, to avoid breaking user configs. > > Reviewed-by: Christophe Leroy (powerpc32) > Acked-by: Catalin Marinas > Acked-by: Helge Deller # parisc > Signed-off-by: Arnd Bergmann Reviewed-by: Thomas Gleixner ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH v2 1/3] arch: consolidate existing CONFIG_PAGE_SIZE_*KB definitions
On Wed, Mar 06 2024 at 15:14, Arnd Bergmann wrote: > From: Arnd Bergmann > > These four architectures define the same Kconfig symbols for configuring > the page size. Move the logic into a common place where it can be shared > with all other architectures. > > Signed-off-by: Arnd Bergmann Reviewed-by: Thomas Gleixner ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH tty v1 00/74] serial: wrappers for uart port lock
On Thu, Sep 14 2023 at 20:01, Maciej W. Rozycki wrote: > On Thu, 14 Sep 2023, John Ogness wrote: > >> Patches 2-74 switch all uart port locking call sites to use the new >> wrappers. These patches were automatically generated using coccinelle. > > Hmm, no need to do this for drivers/tty/serial/zs.c? zs.c does not use port lock at all. It has like a couple of other drivers a local homebrewn spinlock. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V3 10/37] ARM: highmem: Switch to generic kmap atomic
Marek, On Thu, Nov 12 2020 at 09:10, Marek Szyprowski wrote: > On 03.11.2020 10:27, Thomas Gleixner wrote: > > I can do more tests to help fixing this issue. Just let me know what to do. Just sent out the fix before I saw your report. https://lore.kernel.org/r/87y2j6n8mj@nanos.tec.linutronix.de Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V3 22/37] highmem: High implementation details and document API
On Tue, Nov 03 2020 at 09:48, Linus Torvalds wrote: > I have no complaints about the patch, but it strikes me that if people > want to actually have much better debug coverage, this is where it > should be (I like the "every other address" thing too, don't get me > wrong). > > In particular, instead of these PageHighMem(page) tests, I think > something like this would be better: > >#ifdef CONFIG_DEBUG_HIGHMEM > #define page_use_kmap(page) ((page),1) >#else > #define page_use_kmap(page) PageHighMem(page) >#endif > > adn then replace those "if (!PageHighMem(page))" tests with "if > (!page_use_kmap())" instead. > > IOW, in debug mode, it would _always_ remap the page, whether it's > highmem or not. That would really stress the highmem code and find any > fragilities. Yes, that makes a lot of sense. We just have to avoid that for the architectures with aliasing issues. > Anyway, this is all sepatrate from the series, which still looks fine > to me. Just a reaction to seeing the patch, and Thomas' earlier > mention that the highmem debugging doesn't actually do much. Right, forcing it for both kmap and kmap_local is straight forward. I'll cook a patch on top for that. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch V4 24/37] sched: highmem: Store local kmaps in task struct
Instead of storing the map per CPU provide and use per task storage. That
prepares for local kmaps which are preemptible.
The context switch code is preparatory and not yet in use because
kmap_atomic() runs with preemption disabled. Will be made usable in the
next step.
The context switch logic is safe even when an interrupt happens after
clearing or before restoring the kmaps. The kmap index in task struct is
not modified so any nesting kmap in an interrupt will use unused indices
and on return the counter is the same as before.
Also add an assert into the return to user space code. Going back to user
space with an active kmap local is a nono.
Signed-off-by: Thomas Gleixner
---
V4: Use the version which actually compiles and works
V3: Handle the debug case correctly
---
include/linux/highmem-internal.h | 10 +++
include/linux/sched.h|9 +++
kernel/entry/common.c|2
kernel/fork.c|1
kernel/sched/core.c | 18 +++
mm/highmem.c | 99 +++
6 files changed, 129 insertions(+), 10 deletions(-)
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -9,6 +9,16 @@
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
void kunmap_local_indexed(void *vaddr);
+void kmap_local_fork(struct task_struct *tsk);
+void __kmap_local_sched_out(void);
+void __kmap_local_sched_in(void);
+static inline void kmap_assert_nomap(void)
+{
+ DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
+}
+#else
+static inline void kmap_local_fork(struct task_struct *tsk) { }
+static inline void kmap_assert_nomap(void) { }
#endif
#ifdef CONFIG_HIGHMEM
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -34,6 +34,7 @@
#include
#include
#include
+#include
/* task_struct member predeclarations (sorted alphabetically): */
struct audit_context;
@@ -629,6 +630,13 @@ struct wake_q_node {
struct wake_q_node *next;
};
+struct kmap_ctrl {
+#ifdef CONFIG_KMAP_LOCAL
+ int idx;
+ pte_t pteval[KM_MAX_IDX];
+#endif
+};
+
struct task_struct {
#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
@@ -1294,6 +1302,7 @@ struct task_struct {
unsigned intsequential_io;
unsigned intsequential_io_avg;
#endif
+ struct kmap_ctrlkmap_ctrl;
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
unsigned long task_state_change;
#endif
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -2,6 +2,7 @@
#include
#include
+#include
#include
#include
@@ -194,6 +195,7 @@ static void exit_to_user_mode_prepare(st
/* Ensure that the address limit is intact and no locks are held */
addr_limit_user_check();
+ kmap_assert_nomap();
lockdep_assert_irqs_disabled();
lockdep_sys_exit();
}
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -930,6 +930,7 @@ static struct task_struct *dup_task_stru
account_kernel_stack(tsk, 1);
kcov_task_init(tsk);
+ kmap_local_fork(tsk);
#ifdef CONFIG_FAULT_INJECTION
tsk->fail_nth = 0;
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4053,6 +4053,22 @@ static inline void finish_lock_switch(st
# define finish_arch_post_lock_switch()do { } while (0)
#endif
+static inline void kmap_local_sched_out(void)
+{
+#ifdef CONFIG_KMAP_LOCAL
+ if (unlikely(current->kmap_ctrl.idx))
+ __kmap_local_sched_out();
+#endif
+}
+
+static inline void kmap_local_sched_in(void)
+{
+#ifdef CONFIG_KMAP_LOCAL
+ if (unlikely(current->kmap_ctrl.idx))
+ __kmap_local_sched_in();
+#endif
+}
+
/**
* prepare_task_switch - prepare to switch tasks
* @rq: the runqueue preparing to switch
@@ -4075,6 +4091,7 @@ prepare_task_switch(struct rq *rq, struc
perf_event_task_sched_out(prev, next);
rseq_preempt(prev);
fire_sched_out_preempt_notifiers(prev, next);
+ kmap_local_sched_out();
prepare_task(next);
prepare_arch_switch(next);
}
@@ -4141,6 +4158,7 @@ static struct rq *finish_task_switch(str
finish_lock_switch(rq);
finish_arch_post_lock_switch();
kcov_finish_switch(current);
+ kmap_local_sched_in();
fire_sched_in_preempt_notifiers(current);
/*
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -365,8 +365,6 @@ EXPORT_SYMBOL(kunmap_high);
#include
-static DEFINE_PER_CPU(int, __kmap_local_idx);
-
/*
* With DEBUG_HIGHMEM the stack depth is doubled and every second
* slot is unused which acts as a guard page
@@ -379,23 +377,21 @@ static DEFINE_PER_CPU(int, __kmap_local_
static inline int kmap_local_idx_push(void)
{
- int idx = __this_cpu_add_return(__kmap_local_idx, KM_INCR) - 1;
-
WARN_ON_ONCE(in_irq() &
Re: [patch V3 24/37] sched: highmem: Store local kmaps in task struct
On Tue, Nov 03 2020 at 10:27, Thomas Gleixner wrote:
> +struct kmap_ctrl {
> +#ifdef CONFIG_KMAP_LOCAL
> + int idx;
> + pte_t pteval[KM_TYPE_NR];
I'm a moron. Fixed it on the test machine ...
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[patch V3 04/37] sh/highmem: Remove all traces of unused cruft
For whatever reasons SH has highmem bits all over the place but does
not enable it via Kconfig. Remove the bitrot.
Signed-off-by: Thomas Gleixner
---
arch/sh/include/asm/fixmap.h |8
arch/sh/include/asm/kmap_types.h | 15 ---
arch/sh/mm/init.c|8
3 files changed, 31 deletions(-)
--- a/arch/sh/include/asm/fixmap.h
+++ b/arch/sh/include/asm/fixmap.h
@@ -13,9 +13,6 @@
#include
#include
#include
-#ifdef CONFIG_HIGHMEM
-#include
-#endif
/*
* Here we define all the compile-time 'special' virtual
@@ -53,11 +50,6 @@ enum fixed_addresses {
FIX_CMAP_BEGIN,
FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS) - 1,
-#ifdef CONFIG_HIGHMEM
- FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
- FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
-#endif
-
#ifdef CONFIG_IOREMAP_FIXED
/*
* FIX_IOREMAP entries are useful for mapping physical address
--- a/arch/sh/include/asm/kmap_types.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __SH_KMAP_TYPES_H
-#define __SH_KMAP_TYPES_H
-
-/* Dummy header just to define km_type. */
-
-#ifdef CONFIG_DEBUG_HIGHMEM
-#define __WITH_KM_FENCE
-#endif
-
-#include
-
-#undef __WITH_KM_FENCE
-
-#endif
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -362,9 +362,6 @@ void __init mem_init(void)
mem_init_print_info(NULL);
pr_info("virtual kernel memory layout:\n"
"fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
-#ifdef CONFIG_HIGHMEM
- "pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
-#endif
"vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
"lowmem : 0x%08lx - 0x%08lx (%4ld MB) (cached)\n"
#ifdef CONFIG_UNCACHED_MAPPING
@@ -376,11 +373,6 @@ void __init mem_init(void)
FIXADDR_START, FIXADDR_TOP,
(FIXADDR_TOP - FIXADDR_START) >> 10,
-#ifdef CONFIG_HIGHMEM
- PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
- (LAST_PKMAP*PAGE_SIZE) >> 10,
-#endif
-
(unsigned long)VMALLOC_START, VMALLOC_END,
(VMALLOC_END - VMALLOC_START) >> 20,
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[patch V3 03/37] fs: Remove asm/kmap_types.h includes
Historical leftovers from the time where kmap() had fixed slots. Signed-off-by: Thomas Gleixner Cc: Alexander Viro Cc: Benjamin LaHaise Cc: linux-fsde...@vger.kernel.org Cc: linux-...@kvack.org Cc: Chris Mason Cc: Josef Bacik Cc: David Sterba Cc: linux-bt...@vger.kernel.org --- fs/aio.c |1 - fs/btrfs/ctree.h |1 - 2 files changed, 2 deletions(-) --- a/fs/aio.c +++ b/fs/aio.c @@ -43,7 +43,6 @@ #include #include -#include #include #include --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -17,7 +17,6 @@ #include #include #include -#include #include #include #include ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch V3 35/37] drm/nouveau/device: Replace io_mapping_map_atomic_wc()
Neither fbmem_peek() nor fbmem_poke() require to disable pagefaults and
preemption as a side effect of io_mapping_map_atomic_wc().
Use io_mapping_map_local_wc() instead.
Signed-off-by: Thomas Gleixner
Cc: Ben Skeggs
Cc: David Airlie
Cc: Daniel Vetter
Cc: dri-de...@lists.freedesktop.org
Cc: nouv...@lists.freedesktop.org
---
V3: New patch
---
drivers/gpu/drm/nouveau/nvkm/subdev/devinit/fbmem.h |8
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/devinit/fbmem.h
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/devinit/fbmem.h
@@ -60,19 +60,19 @@ fbmem_fini(struct io_mapping *fb)
static inline u32
fbmem_peek(struct io_mapping *fb, u32 off)
{
- u8 __iomem *p = io_mapping_map_atomic_wc(fb, off & PAGE_MASK);
+ u8 __iomem *p = io_mapping_map_local_wc(fb, off & PAGE_MASK);
u32 val = ioread32(p + (off & ~PAGE_MASK));
- io_mapping_unmap_atomic(p);
+ io_mapping_unmap_local(p);
return val;
}
static inline void
fbmem_poke(struct io_mapping *fb, u32 off, u32 val)
{
- u8 __iomem *p = io_mapping_map_atomic_wc(fb, off & PAGE_MASK);
+ u8 __iomem *p = io_mapping_map_local_wc(fb, off & PAGE_MASK);
iowrite32(val, p + (off & ~PAGE_MASK));
wmb();
- io_mapping_unmap_atomic(p);
+ io_mapping_unmap_local(p);
}
static inline bool
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[patch V3 00/37] mm/highmem: Preemptible variant of kmap_atomic & friends
Following up to the discussion in: https://lore.kernel.org/r/20200914204209.256266...@linutronix.de and the second version of this: https://lore.kernel.org/r/20201029221806.189523...@linutronix.de this series provides a preemptible variant of kmap_atomic & related interfaces. This is achieved by: - Removing the RT dependency from migrate_disable/enable() - Consolidating all kmap atomic implementations in generic code including a useful version of the CONFIG_DEBUG_HIGHMEM which provides guard pages between the individual maps instead of just increasing the map size. - Switching from per CPU storage of the kmap index to a per task storage - Adding a pteval array to the per task storage which contains the ptevals of the currently active temporary kmaps - Adding context switch code which checks whether the outgoing or the incoming task has active temporary kmaps. If so, the outgoing task's kmaps are removed and the incoming task's kmaps are restored. - Adding new interfaces k[un]map_local*() which are not disabling preemption and can be called from any context (except NMI). Contrary to kmap() which provides preemptible and "persistant" mappings, these interfaces are meant to replace the temporary mappings provided by kmap_atomic*() today. This allows to get rid of conditional mapping choices and allows to have preemptible short term mappings on 64bit which are today enforced to be non-preemptible due to the highmem constraints. It clearly puts overhead on the highmem users, but highmem is slow anyway. This is not a wholesale conversion which makes kmap_atomic magically preemptible because there might be usage sites which rely on the implicit preempt disable. So this needs to be done on a case by case basis and the call sites converted to kmap_local(). Note, that this is only tested on X86 and completely untested on all other architectures (at least it compiles except on csky which does not compile with the newest cross tools from kernel.org independent of this change). The lot is available from git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git highmem It is based on Peter Zijlstras migrate disable branch which is close to be merged into the tip tree, but still not finalized: git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/migrate-disable The series has the following parts: Patches 1 - 22: Consolidation work which is independent of the scheduler changes 79 files changed, 595 insertions(+), 1296 deletions(-) Patch 23: Needs to be folded back into the sched/migrate-disable Patches 24 - 26: The preemptible kmap_local() implementation 9 files changed, 283 insertions(+), 57 deletions(-) Patches 27 - 37: Cleanup of the less common kmap/io_map_atomic users 19 files changed, 114 insertions(+), 256 deletions(-) Vs. merging this pile: If everyone agrees, I'd like to take the first part (1-22) through tip so that the preemptible implementation can be sorted in tip once the scheduler prerequisites are there. The initial cleanups (27-37) might have to wait if there are conflicts vs. the drm/gpu tree. We'll see. >From what I can tell kmap_atomic() can be removed all together and completly replaced by kmap_local(). Most of the usage sites are trivial and just doing memcpy(), memset() or trivial operations on the temporarily mapped page. The interesting ones are those which do either conditional stuff or have copy_.*_user_inatomic() inside. As shown with the crash and drm/gpu cleanups this allows to simplify the code quite a bit. Changes vs. V2: - Remove the migrate disable from kmap_local and only issue that when the there is an actual highmem mapping. (Linus) - Reordered the series so the consolidation is upfront - Get rid of kmap_types.h and the associated cruft - Fixup documentation and add function documentation for kmap_* - Splitout the internal implementation into a seperate header - More cleanups - removal of unused functions - Replace a few of the less frequently used kmap_atomic and io_mapping_map_atomic variants and remove those interfaces. Thanks, tglx --- arch/alpha/include/asm/kmap_types.h | 15 arch/arc/include/asm/kmap_types.h | 14 arch/arm/include/asm/kmap_types.h | 10 arch/arm/mm/highmem.c | 121 --- arch/ia64/include/asm/kmap_types.h| 13 arch/microblaze/mm/highmem.c | 78 arch/mips/include/asm/kmap_types.h| 13 arch/nds32/mm/highmem.c | 48 -- arch/parisc/include/asm/kmap_types.h | 13 arch/powerpc/include/asm/kmap_types.h | 13 arch/powerpc/mm/highmem.c | 67 arch/sh/include/as
[patch V3 08/37] x86/mm/highmem: Use generic kmap atomic implementation
Convert X86 to the generic kmap atomic implementation and make the
iomap_atomic() naming convention consistent while at it.
Signed-off-by: Thomas Gleixner
Cc: x...@kernel.org
---
V3: Remove the kmap_types cruft
---
arch/x86/Kconfig |3 +
arch/x86/include/asm/fixmap.h |5 +-
arch/x86/include/asm/highmem.h| 13 +--
arch/x86/include/asm/iomap.h | 18 +-
arch/x86/include/asm/kmap_types.h | 13 ---
arch/x86/include/asm/paravirt_types.h |1
arch/x86/mm/highmem_32.c | 59 --
arch/x86/mm/init_32.c | 15
arch/x86/mm/iomap_32.c| 59 ++
include/linux/highmem.h |2 -
include/linux/io-mapping.h|2 -
mm/highmem.c |2 -
12 files changed, 31 insertions(+), 161 deletions(-)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -14,10 +14,11 @@ config X86_32
select ARCH_WANT_IPC_PARSE_VERSION
select CLKSRC_I8253
select CLONE_BACKWARDS
+ select GENERIC_VDSO_32
select HAVE_DEBUG_STACKOVERFLOW
+ select KMAP_LOCAL
select MODULES_USE_ELF_REL
select OLD_SIGACTION
- select GENERIC_VDSO_32
config X86_64
def_bool y
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -31,7 +31,7 @@
#include
#ifdef CONFIG_X86_32
#include
-#include
+#include
#else
#include
#endif
@@ -94,7 +94,7 @@ enum fixed_addresses {
#endif
#ifdef CONFIG_X86_32
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
- FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
+ FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#ifdef CONFIG_PCI_MMCONFIG
FIX_PCIE_MCFG,
#endif
@@ -151,7 +151,6 @@ extern void reserve_top_address(unsigned
extern int fixmaps_set;
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -23,7 +23,6 @@
#include
#include
-#include
#include
#include
#include
@@ -58,11 +57,17 @@ extern unsigned long highstart_pfn, high
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
-void *kmap_atomic_pfn(unsigned long pfn);
-void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
-
#define flush_cache_kmaps()do { } while (0)
+#definearch_kmap_local_post_map(vaddr, pteval) \
+ arch_flush_lazy_mmu_mode()
+
+#definearch_kmap_local_post_unmap(vaddr) \
+ do {\
+ flush_tlb_one_kernel((vaddr)); \
+ arch_flush_lazy_mmu_mode(); \
+ } while (0)
+
extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn);
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -9,19 +9,21 @@
#include
#include
#include
+#include
#include
#include
-void __iomem *
-iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
+void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
-void
-iounmap_atomic(void __iomem *kvaddr);
+static inline void iounmap_atomic(void __iomem *vaddr)
+{
+ kunmap_local_indexed((void __force *)vaddr);
+ pagefault_enable();
+ preempt_enable();
+}
-int
-iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
+int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
-void
-iomap_free(resource_size_t base, unsigned long size);
+void iomap_free(resource_size_t base, unsigned long size);
#endif /* _ASM_X86_IOMAP_H */
--- a/arch/x86/include/asm/kmap_types.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_X86_KMAP_TYPES_H
-#define _ASM_X86_KMAP_TYPES_H
-
-#if defined(CONFIG_X86_32) && defined(CONFIG_DEBUG_HIGHMEM)
-#define __WITH_KM_FENCE
-#endif
-
-#include
-
-#undef __WITH_KM_FENCE
-
-#endif /* _ASM_X86_KMAP_TYPES_H */
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -41,7 +41,6 @@
#ifndef __ASSEMBLY__
#include
-#include
#include
#include
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,65 +4,6 @@
#include /* for totalram_pages */
#include
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- BUG_ON(!pte_none(*(kmap_pte-idx)));
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- arch_flush_lazy_mmu
[patch V3 16/37] sparc/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: "David S. Miller"
Cc: sparcli...@vger.kernel.org
---
V3: Remove the kmap types cruft
---
arch/sparc/Kconfig |1
arch/sparc/include/asm/highmem.h|8 +-
arch/sparc/include/asm/kmap_types.h | 11 ---
arch/sparc/include/asm/vaddrs.h |4 -
arch/sparc/mm/Makefile |3
arch/sparc/mm/highmem.c | 115
arch/sparc/mm/srmmu.c |2
7 files changed, 8 insertions(+), 136 deletions(-)
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -139,6 +139,7 @@ config MMU
config HIGHMEM
bool
default y if SPARC32
+ select KMAP_LOCAL
config ZONE_DMA
bool
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -24,7 +24,6 @@
#include
#include
#include
-#include
#include
/* declarations for highmem.c */
@@ -33,8 +32,6 @@ extern unsigned long highstart_pfn, high
#define kmap_prot __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE)
extern pte_t *pkmap_page_table;
-void kmap_init(void) __init;
-
/*
* Right now we initialize only a single pte table. It can be extended
* easily, subsequent pte tables have to be allocated in one physical
@@ -53,6 +50,11 @@ void kmap_init(void) __init;
#define flush_cache_kmaps()flush_cache_all()
+/* FIXME: Use __flush_tlb_one(vaddr) instead of flush_cache_all() -- Anton */
+#define arch_kmap_local_post_map(vaddr, pteval)flush_cache_all()
+#define arch_kmap_local_post_unmap(vaddr) flush_cache_all()
+
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/sparc/include/asm/kmap_types.h
+++ /dev/null
@@ -1,11 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_KMAP_TYPES_H
-#define _ASM_KMAP_TYPES_H
-
-/* Dummy header just to define km_type. None of this
- * is actually used on sparc. -DaveM
- */
-
-#include
-
-#endif
--- a/arch/sparc/include/asm/vaddrs.h
+++ b/arch/sparc/include/asm/vaddrs.h
@@ -32,13 +32,13 @@
#define SRMMU_NOCACHE_ALCRATIO 64 /* 256 pages per 64MB of system RAM */
#ifndef __ASSEMBLY__
-#include
+#include
enum fixed_addresses {
FIX_HOLE,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN,
- FIX_KMAP_END = (KM_TYPE_NR * NR_CPUS),
+ FIX_KMAP_END = (KM_MAX_IDX * NR_CPUS),
#endif
__end_of_fixed_addresses
};
--- a/arch/sparc/mm/Makefile
+++ b/arch/sparc/mm/Makefile
@@ -15,6 +15,3 @@ obj-$(CONFIG_SPARC32) += leon_mm.o
# Only used by sparc64
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
-
-# Only used by sparc32
-obj-$(CONFIG_HIGHMEM) += highmem.o
--- a/arch/sparc/mm/highmem.c
+++ /dev/null
@@ -1,115 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * Provides kernel-static versions of atomic kmap functions originally
- * found as inlines in include/asm-sparc/highmem.h. These became
- * needed as kmap_atomic() and kunmap_atomic() started getting
- * called from within modules.
- * -- Tomas Szepe , September 2002
- *
- * But kmap_atomic() and kunmap_atomic() cannot be inlined in
- * modules because they are loaded with btfixup-ped functions.
- */
-
-/*
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need it.
- *
- * XXX This is an old text. Actually, it's good to use atomic kmaps,
- * provided you remember that they are atomic and not try to sleep
- * with a kmap taken, much like a spinlock. Non-atomic kmaps are
- * shared by CPUs, and so precious, and establishing them requires IPI.
- * Atomic kmaps are lightweight and we may have NCPUS more of them.
- */
-#include
-#include
-#include
-
-#include
-#include
-#include
-
-static pte_t *kmap_pte;
-
-void __init kmap_init(void)
-{
- unsigned long address = __fix_to_virt(FIX_KMAP_BEGIN);
-
-/* cache the first kmap pte */
-kmap_pte = virt_to_kpte(address);
-}
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- long idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-
-/* XXX Fix - Anton */
-#if 0
- __flush_cache_one(vaddr);
-#else
- flush_cache_all();
-#endif
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte-idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
-/* XXX Fix - Anton */
-#if 0
- __flush_tlb_one(vaddr);
-#else
- flush_tlb_all();
-#endif
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type;
-
- if (vaddr < FIXADDR_START)
[patch V3 12/37] microblaze/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture.
Signed-off-by: Thomas Gleixner
Cc: Michal Simek
---
V3: Remove the kmap types cruft
---
arch/microblaze/Kconfig |1
arch/microblaze/include/asm/fixmap.h |4 -
arch/microblaze/include/asm/highmem.h |6 ++
arch/microblaze/mm/Makefile |1
arch/microblaze/mm/highmem.c | 78 --
arch/microblaze/mm/init.c |6 --
6 files changed, 8 insertions(+), 88 deletions(-)
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -155,6 +155,7 @@ config XILINX_UNCACHED_SHADOW
config HIGHMEM
bool "High memory support"
depends on MMU
+ select KMAP_LOCAL
help
The address space of Microblaze processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
--- a/arch/microblaze/include/asm/fixmap.h
+++ b/arch/microblaze/include/asm/fixmap.h
@@ -20,7 +20,7 @@
#include
#ifdef CONFIG_HIGHMEM
#include
-#include
+#include
#endif
#define FIXADDR_TOP((unsigned long)(-PAGE_SIZE))
@@ -47,7 +47,7 @@ enum fixed_addresses {
FIX_HOLE,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
- FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * num_possible_cpus()) - 1,
+ FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * num_possible_cpus()) - 1,
#endif
__end_of_fixed_addresses
};
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -25,7 +25,6 @@
#include
#include
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@@ -52,6 +51,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps(){ flush_icache(); flush_dcache(); }
+#define arch_kmap_local_post_map(vaddr, pteval)\
+ local_flush_tlb_page(NULL, vaddr);
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_page(NULL, vaddr);
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/microblaze/mm/Makefile
+++ b/arch/microblaze/mm/Makefile
@@ -6,4 +6,3 @@
obj-y := consistent.o init.o
obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
--- a/arch/microblaze/mm/highmem.c
+++ /dev/null
@@ -1,78 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * PowerPC version, stolen from the i386 version.
- *
- * Used in CONFIG_HIGHMEM systems for memory pages which
- * are not addressable by direct kernel virtual addresses.
- *
- * Copyright (C) 1999 Gerhard Wichert, Siemens AG
- * gerhard.wich...@pdb.siemens.de
- *
- *
- * Redesigned the x86 32-bit VM architecture to deal with
- * up to 16 Terrabyte physical memory. With current x86 CPUs
- * we now support up to 64 Gigabytes physical RAM.
- *
- * Copyright (C) 1999 Ingo Molnar
- *
- * Reworked for PowerPC by various contributors. Moved from
- * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
- */
-
-#include
-#include
-
-/*
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need
- * it.
- */
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
-
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte-idx)));
-#endif
- set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
- local_flush_tlb_page(NULL, vaddr);
-
- return (void *) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type;
- unsigned int idx;
-
- if (vaddr < __fix_to_virt(FIX_KMAP_END))
- return;
-
- type = kmap_atomic_idx();
-
- idx = type + KM_TYPE_NR * smp_processor_id();
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-#endif
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_page(NULL, vaddr);
-
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -49,17 +49,11 @@ unsigned long lowmem_size;
EXPORT_SYMBOL(min_low_pfn);
EXPORT_SYMBOL(max_low_pfn);
-#ifdef CONFIG_HIGHMEM
-pte_t *kmap_pte;
-EXPORT_SYMBOL(kmap_pte);
-
static void __init highmem_init(void)
{
pr_debug("%x\n", (u32)PKMAP_BASE);
map_page(PKMAP_BASE, 0, 0);
[patch V3 10/37] ARM: highmem: Switch to generic kmap atomic
No reason having the same code in every architecture.
Signed-off-by: Thomas Gleixner
Cc: Russell King
Cc: Arnd Bergmann
Cc: linux-arm-ker...@lists.infradead.org
---
V3: Remove the kmap types cruft
---
arch/arm/Kconfig |1
arch/arm/include/asm/fixmap.h |4 -
arch/arm/include/asm/highmem.h| 33 +++---
arch/arm/include/asm/kmap_types.h | 10 ---
arch/arm/mm/Makefile |1
arch/arm/mm/highmem.c | 121 --
6 files changed, 26 insertions(+), 144 deletions(-)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1498,6 +1498,7 @@ config HAVE_ARCH_PFN_VALID
config HIGHMEM
bool "High Memory Support"
depends on MMU
+ select KMAP_LOCAL
help
The address space of ARM processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
--- a/arch/arm/include/asm/fixmap.h
+++ b/arch/arm/include/asm/fixmap.h
@@ -7,14 +7,14 @@
#define FIXADDR_TOP(FIXADDR_END - PAGE_SIZE)
#include
-#include
+#include
enum fixed_addresses {
FIX_EARLYCON_MEM_BASE,
__end_of_permanent_fixed_addresses,
FIX_KMAP_BEGIN = __end_of_permanent_fixed_addresses,
- FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
+ FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
/* Support writing RO kernel text via kprobes, jump labels, etc. */
FIX_TEXT_POKE0,
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -2,7 +2,7 @@
#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H
-#include
+#include
#define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE)
#define LAST_PKMAP PTRS_PER_PTE
@@ -46,19 +46,32 @@ extern pte_t *pkmap_page_table;
#ifdef ARCH_NEEDS_KMAP_HIGH_GET
extern void *kmap_high_get(struct page *page);
-#else
+
+static inline void *arch_kmap_local_high_get(struct page *page)
+{
+ if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !cache_is_vivt())
+ return NULL;
+ return kmap_high_get(page);
+}
+#define arch_kmap_local_high_get arch_kmap_local_high_get
+
+#else /* ARCH_NEEDS_KMAP_HIGH_GET */
static inline void *kmap_high_get(struct page *page)
{
return NULL;
}
-#endif
+#endif /* !ARCH_NEEDS_KMAP_HIGH_GET */
-/*
- * The following functions are already defined by
- * when CONFIG_HIGHMEM is not set.
- */
-#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_pfn(unsigned long pfn);
-#endif
+#define arch_kmap_local_post_map(vaddr, pteval)
\
+ local_flush_tlb_kernel_page(vaddr)
+
+#define arch_kmap_local_pre_unmap(vaddr) \
+do { \
+ if (cache_is_vivt())\
+ __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); \
+} while (0)
+
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_kernel_page(vaddr)
#endif
--- a/arch/arm/include/asm/kmap_types.h
+++ /dev/null
@@ -1,10 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ARM_KMAP_TYPES_H
-#define __ARM_KMAP_TYPES_H
-
-/*
- * This is the "bare minimum". AIO seems to require this.
- */
-#define KM_TYPE_NR 16
-
-#endif
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -19,7 +19,6 @@ obj-$(CONFIG_MODULES) += proc-syms.o
obj-$(CONFIG_DEBUG_VIRTUAL)+= physaddr.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM_PV_FIXUP) += pv-fixup-asm.o
--- a/arch/arm/mm/highmem.c
+++ /dev/null
@@ -1,121 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * arch/arm/mm/highmem.c -- ARM highmem support
- *
- * Author: Nicolas Pitre
- * Created:september 8, 2008
- * Copyright: Marvell Semiconductors Inc.
- */
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include "mm.h"
-
-static inline void set_fixmap_pte(int idx, pte_t pte)
-{
- unsigned long vaddr = __fix_to_virt(idx);
- pte_t *ptep = virt_to_kpte(vaddr);
-
- set_pte_ext(ptep, pte, 0);
- local_flush_tlb_kernel_page(vaddr);
-}
-
-static inline pte_t get_fixmap_pte(unsigned long vaddr)
-{
- pte_t *ptep = virt_to_kpte(vaddr);
-
- return *ptep;
-}
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned int idx;
- unsigned long vaddr;
- void *kmap;
- int type;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- /*
-* There is no cache coherency issue when non VIVT, so force the
-* dedicated kmap usage for better debugging purposes in that case.
-*/
- if (!cache_is_vivt())
- kmap = NULL;
- else
-#endif
- kmap = kmap_high_get(page);
- if (kmap)
-
[patch V3 06/37] highmem: Provide generic variant of kmap_atomic*
The kmap_atomic* interfaces in all architectures are pretty much the same
except for post map operations (flush) and pre- and post unmap operations.
Provide a generic variant for that.
Signed-off-by: Thomas Gleixner
Cc: Andrew Morton
Cc: linux...@kvack.org
---
V3: Do not reuse the kmap_atomic_idx pile and use kmap_size.h right away
V2: Address review comments from Christoph (style and EXPORT variant)
---
include/linux/highmem.h | 82 ++-
mm/Kconfig |3 +
mm/highmem.c| 144 +++-
3 files changed, 211 insertions(+), 18 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -31,9 +31,16 @@ static inline void invalidate_kernel_vma
#include
+/*
+ * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
+ */
+#ifdef CONFIG_KMAP_LOCAL
+void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
+void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
+void kunmap_local_indexed(void *vaddr);
+#endif
+
#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-extern void kunmap_atomic_high(void *kvaddr);
#include
#ifndef ARCH_HAS_KMAP_FLUSH_TLB
@@ -81,6 +88,11 @@ static inline void kunmap(struct page *p
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
+
+#ifndef CONFIG_KMAP_LOCAL
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
+void kunmap_atomic_high(void *kvaddr);
+
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
@@ -89,7 +101,38 @@ static inline void *kmap_atomic_prot(str
return page_address(page);
return kmap_atomic_high_prot(page, prot);
}
-#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot)
+
+static inline void __kunmap_atomic(void *vaddr)
+{
+ kunmap_atomic_high(vaddr);
+}
+#else /* !CONFIG_KMAP_LOCAL */
+
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ preempt_disable();
+ pagefault_disable();
+ return __kmap_local_page_prot(page, prot);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ preempt_disable();
+ pagefault_disable();
+ return __kmap_local_pfn_prot(pfn, kmap_prot);
+}
+
+static inline void __kunmap_atomic(void *addr)
+{
+ kunmap_local_indexed(addr);
+}
+
+#endif /* CONFIG_KMAP_LOCAL */
+
+static inline void *kmap_atomic(struct page *page)
+{
+ return kmap_atomic_prot(page, kmap_prot);
+}
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
@@ -147,25 +190,33 @@ static inline void *kmap_atomic(struct p
pagefault_disable();
return page_address(page);
}
-#define kmap_atomic_prot(page, prot) kmap_atomic(page)
-static inline void kunmap_atomic_high(void *addr)
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ return kmap_atomic(page);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ return kmap_atomic(pfn_to_page(pfn));
+}
+
+static inline void __kunmap_atomic(void *addr)
{
/*
* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
-* handles re-enabling faults + preemption
+* handles re-enabling faults and preemption
*/
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(addr);
#endif
}
-#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
-
#define kmap_flush_unused()do {} while(0)
#endif /* CONFIG_HIGHMEM */
+#if !defined(CONFIG_KMAP_LOCAL)
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
DECLARE_PER_CPU(int, __kmap_atomic_idx);
@@ -196,22 +247,21 @@ static inline void kmap_atomic_idx_pop(v
__this_cpu_dec(__kmap_atomic_idx);
#endif
}
-
+#endif
#endif
/*
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
*/
-#define kunmap_atomic(addr) \
-do {\
- BUILD_BUG_ON(__same_type((addr), struct page *)); \
- kunmap_atomic_high(addr); \
- pagefault_enable(); \
- preempt_enable(); \
+#define kunmap_atomic(__addr) \
+do { \
+ BUILD_BUG_ON(__same_type((__addr), struct page *)); \
+ __kunmap_atomic(__addr);\
+ pagefault_enable(); \
+ preempt_enable(); \
} while (0)
-
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
#ifndef clear_user_highpage
static inline void clear_user_highpage
[patch V3 17/37] xtensa/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: Chris Zankel
Cc: Max Filippov
Cc: linux-xte...@linux-xtensa.org
---
V3: Remove the kmap types cruft
---
arch/xtensa/Kconfig |1
arch/xtensa/include/asm/fixmap.h |4 +--
arch/xtensa/include/asm/highmem.h | 12 -
arch/xtensa/mm/highmem.c | 46 --
4 files changed, 18 insertions(+), 45 deletions(-)
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -666,6 +666,7 @@ endchoice
config HIGHMEM
bool "High Memory Support"
depends on MMU
+ select KMAP_LOCAL
help
Linux can use the full amount of RAM in the system by
default. However, the default MMUv2 setup only maps the
--- a/arch/xtensa/include/asm/fixmap.h
+++ b/arch/xtensa/include/asm/fixmap.h
@@ -16,7 +16,7 @@
#ifdef CONFIG_HIGHMEM
#include
#include
-#include
+#include
#endif
/*
@@ -39,7 +39,7 @@ enum fixed_addresses {
/* reserved pte's for temporary kernel mappings */
FIX_KMAP_BEGIN,
FIX_KMAP_END = FIX_KMAP_BEGIN +
- (KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1,
+ (KM_MAX_IDX * NR_CPUS * DCACHE_N_COLORS) - 1,
#endif
__end_of_fixed_addresses
};
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -16,9 +16,8 @@
#include
#include
#include
-#include
-#define PKMAP_BASE ((FIXADDR_START - \
+#define PKMAP_BASE ((FIXADDR_START - \
(LAST_PKMAP + 1) * PAGE_SIZE) & PMD_MASK)
#define LAST_PKMAP (PTRS_PER_PTE * DCACHE_N_COLORS)
#define LAST_PKMAP_MASK(LAST_PKMAP - 1)
@@ -68,6 +67,15 @@ static inline void flush_cache_kmaps(voi
flush_cache_all();
}
+enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn);
+#define arch_kmap_local_map_idxkmap_local_map_idx
+
+enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr);
+#define arch_kmap_local_unmap_idx kmap_local_unmap_idx
+
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)
+
void kmap_init(void);
#endif
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -12,8 +12,6 @@
#include
#include
-static pte_t *kmap_pte;
-
#if DCACHE_WAY_SIZE > PAGE_SIZE
unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
@@ -33,59 +31,25 @@ static inline void kmap_waitqueues_init(
static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
{
- return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS +
+ return (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS +
color;
}
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
+enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn)
{
- enum fixed_addresses idx;
- unsigned long vaddr;
-
- idx = kmap_idx(kmap_atomic_idx_push(),
- DCACHE_ALIAS(page_to_phys(page)));
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte + idx)));
-#endif
- set_pte(kmap_pte + idx, mk_pte(page, prot));
-
- return (void *)vaddr;
+ return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT));
}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-void kunmap_atomic_high(void *kvaddr)
+enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr)
{
- if (kvaddr >= (void *)FIXADDR_START &&
- kvaddr < (void *)FIXADDR_TOP) {
- int idx = kmap_idx(kmap_atomic_idx(),
- DCACHE_ALIAS((unsigned long)kvaddr));
-
- /*
-* Force other mappings to Oops if they'll try to access this
-* pte without first remap it. Keeping stale mappings around
-* is a bad idea also, in case the page changes cacheability
-* attributes or becomes a protected page in a hypervisor.
-*/
- pte_clear(&init_mm, kvaddr, kmap_pte + idx);
- local_flush_tlb_kernel_range((unsigned long)kvaddr,
-(unsigned long)kvaddr + PAGE_SIZE);
-
- kmap_atomic_idx_pop();
- }
+ return kmap_idx(type, DCACHE_ALIAS(addr));
}
-EXPORT_SYMBOL(kunmap_atomic_high);
void __init kmap_init(void)
{
- unsigned long kmap_vstart;
-
/* Check if this memory layout is broken because PKMAP overlaps
* page table.
*/
BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
- /* cache the first kmap pte */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = v
[patch V3 13/37] mips/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: Thomas Bogendoerfer
Cc: linux-m...@vger.kernel.org
---
V3: Remove the kmap types cruft
---
arch/mips/Kconfig |1
arch/mips/include/asm/fixmap.h |4 -
arch/mips/include/asm/highmem.h|6 +-
arch/mips/include/asm/kmap_types.h | 13 --
arch/mips/mm/highmem.c | 77 -
arch/mips/mm/init.c|4 -
6 files changed, 6 insertions(+), 99 deletions(-)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2719,6 +2719,7 @@ config WAR_MIPS34K_MISSED_ITLB
config HIGHMEM
bool "High Memory Support"
depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM &&
!CPU_MIPS32_3_5_EVA
+ select KMAP_LOCAL
config CPU_SUPPORTS_HIGHMEM
bool
--- a/arch/mips/include/asm/fixmap.h
+++ b/arch/mips/include/asm/fixmap.h
@@ -17,7 +17,7 @@
#include
#ifdef CONFIG_HIGHMEM
#include
-#include
+#include
#endif
/*
@@ -52,7 +52,7 @@ enum fixed_addresses {
#ifdef CONFIG_HIGHMEM
/* reserved pte's for temporary kernel mappings */
FIX_KMAP_BEGIN = FIX_CMAP_END + 1,
- FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
+ FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
__end_of_fixed_addresses
};
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -24,7 +24,7 @@
#include
#include
#include
-#include
+#include
/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;
@@ -48,11 +48,11 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps()BUG_ON(cpu_has_dc_aliases)
-extern void kmap_init(void);
+#define arch_kmap_local_post_map(vaddr, pteval)
local_flush_tlb_one(vaddr)
+#define arch_kmap_local_post_unmap(vaddr) local_flush_tlb_one(vaddr)
#endif /* __KERNEL__ */
--- a/arch/mips/include/asm/kmap_types.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_KMAP_TYPES_H
-#define _ASM_KMAP_TYPES_H
-
-#ifdef CONFIG_DEBUG_HIGHMEM
-#define __WITH_KM_FENCE
-#endif
-
-#include
-
-#undef __WITH_KM_FENCE
-
-#endif
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -8,8 +8,6 @@
#include
#include
-static pte_t *kmap_pte;
-
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@@ -17,78 +15,3 @@ void kmap_flush_tlb(unsigned long addr)
flush_tlb_one(addr);
}
EXPORT_SYMBOL(kmap_flush_tlb);
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte - idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- local_flush_tlb_one((unsigned long)vaddr);
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type __maybe_unused;
-
- if (vaddr < FIXADDR_START)
- return;
-
- type = kmap_atomic_idx();
-#ifdef CONFIG_DEBUG_HIGHMEM
- {
- int idx = type + KM_TYPE_NR * smp_processor_id();
-
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_one(vaddr);
- }
-#endif
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- unsigned long vaddr;
- int idx, type;
-
- preempt_disable();
- pagefault_disable();
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
- flush_tlb_one(vaddr);
-
- return (void*) vaddr;
-}
-
-void __init kmap_init(void)
-{
- unsigned long kmap_vstart;
-
- /* cache the first kmap pte */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = virt_to_kpte(kmap_vstart);
-}
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -36,7 +36,6 @@
#include
#include
#include
-#include
#include
#include
#include
@@ -402,9 +401,6 @@ void __
[patch V3 20/37] io-mapping: Cleanup atomic iomap
Switch the atomic iomap implementation over to kmap_local and stick the
preempt/pagefault mechanics into the generic code similar to the
kmap_atomic variants.
Rename the x86 map function in preparation for a non-atomic variant.
Signed-off-by: Thomas Gleixner
---
V2: New patch to make review easier
---
arch/x86/include/asm/iomap.h |9 +
arch/x86/mm/iomap_32.c |6 ++
include/linux/io-mapping.h |8 ++--
3 files changed, 9 insertions(+), 14 deletions(-)
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -13,14 +13,7 @@
#include
#include
-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
-
-static inline void iounmap_atomic(void __iomem *vaddr)
-{
- kunmap_local_indexed((void __force *)vaddr);
- pagefault_enable();
- preempt_enable();
-}
+void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -44,7 +44,7 @@ void iomap_free(resource_size_t base, un
}
EXPORT_SYMBOL_GPL(iomap_free);
-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot)
+void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
{
/*
* For non-PAT systems, translate non-WB request to UC- just in
@@ -60,8 +60,6 @@ void __iomem *iomap_atomic_pfn_prot(unsi
/* Filter out unsupported __PAGE_KERNEL* bits: */
pgprot_val(prot) &= __default_kernel_pte_mask;
- preempt_disable();
- pagefault_disable();
return (void __force __iomem *)__kmap_local_pfn_prot(pfn, prot);
}
-EXPORT_SYMBOL_GPL(iomap_atomic_pfn_prot);
+EXPORT_SYMBOL_GPL(__iomap_local_pfn_prot);
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -69,13 +69,17 @@ io_mapping_map_atomic_wc(struct io_mappi
BUG_ON(offset >= mapping->size);
phys_addr = mapping->base + offset;
- return iomap_atomic_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
+ preempt_disable();
+ pagefault_disable();
+ return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
}
static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
- iounmap_atomic(vaddr);
+ kunmap_local_indexed((void __force *)vaddr);
+ pagefault_enable();
+ preempt_enable();
}
static inline void __iomem *
___
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[patch V3 37/37] io-mapping: Remove io_mapping_map_atomic_wc()
No more users. Get rid of it and remove the traces in documentation.
Signed-off-by: Thomas Gleixner
---
V3: New patch
---
Documentation/driver-api/io-mapping.rst | 22 +---
include/linux/io-mapping.h | 42 +---
2 files changed, 9 insertions(+), 55 deletions(-)
--- a/Documentation/driver-api/io-mapping.rst
+++ b/Documentation/driver-api/io-mapping.rst
@@ -21,19 +21,15 @@ mappable, while 'size' indicates how lar
enable. Both are in bytes.
This _wc variant provides a mapping which may only be used with
-io_mapping_map_atomic_wc(), io_mapping_map_local_wc() or
-io_mapping_map_wc().
+io_mapping_map_local_wc() or io_mapping_map_wc().
With this mapping object, individual pages can be mapped either temporarily
or long term, depending on the requirements. Of course, temporary maps are
-more efficient. They come in two flavours::
+more efficient.
void *io_mapping_map_local_wc(struct io_mapping *mapping,
unsigned long offset)
- void *io_mapping_map_atomic_wc(struct io_mapping *mapping,
- unsigned long offset)
-
'offset' is the offset within the defined mapping region. Accessing
addresses beyond the region specified in the creation function yields
undefined results. Using an offset which is not page aligned yields an
@@ -50,9 +46,6 @@ io_mapping_map_local_wc() has a side eff
migration to make the mapping code work. No caller can rely on this side
effect.
-io_mapping_map_atomic_wc() has the side effect of disabling preemption and
-pagefaults. Don't use in new code. Use io_mapping_map_local_wc() instead.
-
Nested mappings need to be undone in reverse order because the mapping
code uses a stack for keeping track of them::
@@ -65,11 +58,10 @@ Nested mappings need to be undone in rev
The mappings are released with::
void io_mapping_unmap_local(void *vaddr)
- void io_mapping_unmap_atomic(void *vaddr)
-'vaddr' must be the value returned by the last io_mapping_map_local_wc() or
-io_mapping_map_atomic_wc() call. This unmaps the specified mapping and
-undoes the side effects of the mapping functions.
+'vaddr' must be the value returned by the last io_mapping_map_local_wc()
+call. This unmaps the specified mapping and undoes eventual side effects of
+the mapping function.
If you need to sleep while holding a mapping, you can use the regular
variant, although this may be significantly slower::
@@ -77,8 +69,8 @@ If you need to sleep while holding a map
void *io_mapping_map_wc(struct io_mapping *mapping,
unsigned long offset)
-This works like io_mapping_map_atomic/local_wc() except it has no side
-effects and the pointer is globaly visible.
+This works like io_mapping_map_local_wc() except it has no side effects and
+the pointer is globaly visible.
The mappings are released with::
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -60,28 +60,7 @@ io_mapping_fini(struct io_mapping *mappi
iomap_free(mapping->base, mapping->size);
}
-/* Atomic map/unmap */
-static inline void __iomem *
-io_mapping_map_atomic_wc(struct io_mapping *mapping,
-unsigned long offset)
-{
- resource_size_t phys_addr;
-
- BUG_ON(offset >= mapping->size);
- phys_addr = mapping->base + offset;
- preempt_disable();
- pagefault_disable();
- return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
-}
-
-static inline void
-io_mapping_unmap_atomic(void __iomem *vaddr)
-{
- kunmap_local_indexed((void __force *)vaddr);
- pagefault_enable();
- preempt_enable();
-}
-
+/* Temporary mappings which are only valid in the current context */
static inline void __iomem *
io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset)
{
@@ -163,24 +142,7 @@ io_mapping_unmap(void __iomem *vaddr)
{
}
-/* Atomic map/unmap */
-static inline void __iomem *
-io_mapping_map_atomic_wc(struct io_mapping *mapping,
-unsigned long offset)
-{
- preempt_disable();
- pagefault_disable();
- return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
-}
-
-static inline void
-io_mapping_unmap_atomic(void __iomem *vaddr)
-{
- io_mapping_unmap(vaddr);
- pagefault_enable();
- preempt_enable();
-}
-
+/* Temporary mappings which are only valid in the current context */
static inline void __iomem *
io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset)
{
___
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[patch V3 11/37] csky/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture.
Signed-off-by: Thomas Gleixner
Cc: linux-c...@vger.kernel.org
---
V3: Does not compile with gcc 10
---
arch/csky/Kconfig |1
arch/csky/include/asm/fixmap.h |4 +-
arch/csky/include/asm/highmem.h |6 ++-
arch/csky/mm/highmem.c | 75
4 files changed, 8 insertions(+), 78 deletions(-)
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -286,6 +286,7 @@ config NR_CPUS
config HIGHMEM
bool "High Memory Support"
depends on !CPU_CK610
+ select KMAP_LOCAL
default y
config FORCE_MAX_ZONEORDER
--- a/arch/csky/include/asm/fixmap.h
+++ b/arch/csky/include/asm/fixmap.h
@@ -8,7 +8,7 @@
#include
#ifdef CONFIG_HIGHMEM
#include
-#include
+#include
#endif
enum fixed_addresses {
@@ -17,7 +17,7 @@ enum fixed_addresses {
#endif
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN,
- FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
+ FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
__end_of_fixed_addresses
};
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -9,7 +9,7 @@
#include
#include
#include
-#include
+#include
#include
/* undef for production */
@@ -32,10 +32,12 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps() do {} while (0)
+#define arch_kmap_local_post_map(vaddr, pteval)kmap_flush_tlb(vaddr)
+#define arch_kmap_local_post_unmap(vaddr) kmap_flush_tlb(vaddr)
+
extern void kmap_init(void);
#endif /* __KERNEL__ */
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -9,8 +9,6 @@
#include
#include
-static pte_t *kmap_pte;
-
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@@ -19,67 +17,7 @@ void kmap_flush_tlb(unsigned long addr)
}
EXPORT_SYMBOL(kmap_flush_tlb);
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte - idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- flush_tlb_one((unsigned long)vaddr);
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int idx;
-
- if (vaddr < FIXADDR_START)
- return;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
-
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- pte_clear(&init_mm, vaddr, kmap_pte - idx);
- flush_tlb_one(vaddr);
-#else
- (void) idx; /* to kill a warning */
-#endif
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- unsigned long vaddr;
- int idx, type;
-
- pagefault_disable();
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
- flush_tlb_one(vaddr);
-
- return (void *) vaddr;
-}
-
-static void __init kmap_pages_init(void)
+void __init kmap_init(void)
{
unsigned long vaddr;
pgd_t *pgd;
@@ -96,14 +34,3 @@ static void __init kmap_pages_init(void)
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
}
-
-void __init kmap_init(void)
-{
- unsigned long vaddr;
-
- kmap_pages_init();
-
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
-
- kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
-}
___
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[patch V3 21/37] Documentation/io-mapping: Remove outdated blurb
The implementation details in the documentation are outdated and not really helpful. Remove them. Signed-off-by: Thomas Gleixner --- V3: New patch --- Documentation/driver-api/io-mapping.rst | 22 -- 1 file changed, 22 deletions(-) --- a/Documentation/driver-api/io-mapping.rst +++ b/Documentation/driver-api/io-mapping.rst @@ -73,25 +73,3 @@ for pages mapped with io_mapping_map_wc. At driver close time, the io_mapping object must be freed:: void io_mapping_free(struct io_mapping *mapping) - -Current Implementation -== - -The initial implementation of these functions uses existing mapping -mechanisms and so provides only an abstraction layer and no new -functionality. - -On 64-bit processors, io_mapping_create_wc calls ioremap_wc for the whole -range, creating a permanent kernel-visible mapping to the resource. The -map_atomic and map functions add the requested offset to the base of the -virtual address returned by ioremap_wc. - -On 32-bit processors with HIGHMEM defined, io_mapping_map_atomic_wc uses -kmap_atomic_pfn to map the specified page in an atomic fashion; -kmap_atomic_pfn isn't really supposed to be used with device pages, but it -provides an efficient mapping for this usage. - -On 32-bit processors without HIGHMEM defined, io_mapping_map_atomic_wc and -io_mapping_map_wc both use ioremap_wc, a terribly inefficient function which -performs an IPI to inform all processors about the new mapping. This results -in a significant performance penalty. ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch V3 14/37] nds32/mm/highmem: Switch to generic kmap atomic
The mapping code is odd and looks broken. See FIXME in the comment.
Also fix the harmless off by one in the FIX_KMAP_END define.
Signed-off-by: Thomas Gleixner
Cc: Nick Hu
Cc: Greentime Hu
Cc: Vincent Chen
---
V3: Remove the kmap types cruft
---
arch/nds32/Kconfig.cpu |1
arch/nds32/include/asm/fixmap.h |4 +--
arch/nds32/include/asm/highmem.h | 22 +
arch/nds32/mm/Makefile |1
arch/nds32/mm/highmem.c | 48 ---
5 files changed, 19 insertions(+), 57 deletions(-)
--- a/arch/nds32/Kconfig.cpu
+++ b/arch/nds32/Kconfig.cpu
@@ -157,6 +157,7 @@ config HW_SUPPORT_UNALIGNMENT_ACCESS
config HIGHMEM
bool "High Memory Support"
depends on MMU && !CPU_CACHE_ALIASING
+ select KMAP_LOCAL
help
The address space of Andes processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
--- a/arch/nds32/include/asm/fixmap.h
+++ b/arch/nds32/include/asm/fixmap.h
@@ -6,7 +6,7 @@
#ifdef CONFIG_HIGHMEM
#include
-#include
+#include
#endif
enum fixed_addresses {
@@ -14,7 +14,7 @@ enum fixed_addresses {
FIX_KMAP_RESERVED,
FIX_KMAP_BEGIN,
#ifdef CONFIG_HIGHMEM
- FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS),
+ FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
FIX_EARLYCON_MEM_BASE,
__end_of_fixed_addresses
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -5,7 +5,6 @@
#define _ASM_HIGHMEM_H
#include
-#include
#include
/*
@@ -45,11 +44,22 @@ extern pte_t *pkmap_page_table;
extern void kmap_init(void);
/*
- * The following functions are already defined by
- * when CONFIG_HIGHMEM is not set.
+ * FIXME: The below looks broken vs. a kmap_atomic() in task context which
+ * is interupted and another kmap_atomic() happens in interrupt context.
+ * But what do I know about nds32. -- tglx
*/
-#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_pfn(unsigned long pfn);
-#endif
+#define arch_kmap_local_post_map(vaddr, pteval)\
+ do {\
+ __nds32__tlbop_inv(vaddr); \
+ __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN); \
+ __nds32__tlbop_rwr(pteval); \
+ __nds32__isb(); \
+ } while (0)
+
+#define arch_kmap_local_pre_unmap(vaddr) \
+ do {\
+ __nds32__tlbop_inv(vaddr); \
+ __nds32__isb(); \
+ } while (0)
#endif
--- a/arch/nds32/mm/Makefile
+++ b/arch/nds32/mm/Makefile
@@ -3,7 +3,6 @@ obj-y := extable.o tlb.o fault.o init
mm-nds32.o cacheflush.o proc.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_proc.o = $(CC_FLAGS_FTRACE)
--- a/arch/nds32/mm/highmem.c
+++ /dev/null
@@ -1,48 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned int idx;
- unsigned long vaddr, pte;
- int type;
- pte_t *ptep;
-
- type = kmap_atomic_idx_push();
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- pte = (page_to_pfn(page) << PAGE_SHIFT) | prot;
- ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
- set_pte(ptep, pte);
-
- __nds32__tlbop_inv(vaddr);
- __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
- __nds32__tlbop_rwr(pte);
- __nds32__isb();
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- if (kvaddr >= (void *)FIXADDR_START) {
- unsigned long vaddr = (unsigned long)kvaddr;
- pte_t *ptep;
- kmap_atomic_idx_pop();
- __nds32__tlbop_inv(vaddr);
- __nds32__isb();
- ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
- set_pte(ptep, 0);
- }
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
___
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[patch V3 25/37] mm/highmem: Provide kmap_local*
Now that the kmap atomic index is stored in task struct provide a
preemptible variant. On context switch the maps of an outgoing task are
removed and the map of the incoming task are restored. That's obviously
slow, but highmem is slow anyway.
The kmap_local.*() functions can be invoked from both preemptible and
atomic context. kmap local sections disable migration to keep the resulting
virtual mapping address correct, but disable neither pagefaults nor
preemption.
A wholesale conversion of kmap_atomic to be fully preemptible is not
possible because some of the usage sites might rely on the preemption
disable for serialization or on the implicit pagefault disable. Needs to be
done on a case by case basis.
Signed-off-by: Thomas Gleixner
---
V3: Move migrate disable into the actual highmem mapping code so it only
affects real highmem mappings.
V2: Make it more consistent and add commentry
---
include/linux/highmem-internal.h | 48 +++
include/linux/highmem.h | 43 +-
mm/highmem.c |6
3 files changed, 81 insertions(+), 16 deletions(-)
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -69,6 +69,26 @@ static inline void kmap_flush_unused(voi
__kmap_flush_unused();
}
+static inline void *kmap_local_page(struct page *page)
+{
+ return __kmap_local_page_prot(page, kmap_prot);
+}
+
+static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
+{
+ return __kmap_local_page_prot(page, prot);
+}
+
+static inline void *kmap_local_pfn(unsigned long pfn)
+{
+ return __kmap_local_pfn_prot(pfn, kmap_prot);
+}
+
+static inline void __kunmap_local(void *vaddr)
+{
+ kunmap_local_indexed(vaddr);
+}
+
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
@@ -141,6 +161,28 @@ static inline void kunmap(struct page *p
#endif
}
+static inline void *kmap_local_page(struct page *page)
+{
+ return page_address(page);
+}
+
+static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
+{
+ return kmap_local_page(page);
+}
+
+static inline void *kmap_local_pfn(unsigned long pfn)
+{
+ return kmap_local_page(pfn_to_page(pfn));
+}
+
+static inline void __kunmap_local(void *addr)
+{
+#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+ kunmap_flush_on_unmap(addr);
+#endif
+}
+
static inline void *kmap_atomic(struct page *page)
{
preempt_disable();
@@ -182,4 +224,10 @@ do {
\
__kunmap_atomic(__addr);\
} while (0)
+#define kunmap_local(__addr) \
+do { \
+ BUILD_BUG_ON(__same_type((__addr), struct page *)); \
+ __kunmap_local(__addr); \
+} while (0)
+
#endif
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -60,24 +60,22 @@ static inline struct page *kmap_to_page(
static inline void kmap_flush_unused(void);
/**
- * kmap_atomic - Atomically map a page for temporary usage
+ * kmap_local_page - Map a page for temporary usage
* @page: Pointer to the page to be mapped
*
* Returns: The virtual address of the mapping
*
- * Side effect: On return pagefaults and preemption are disabled.
- *
* Can be invoked from any context.
*
* Requires careful handling when nesting multiple mappings because the map
* management is stack based. The unmap has to be in the reverse order of
* the map operation:
*
- * addr1 = kmap_atomic(page1);
- * addr2 = kmap_atomic(page2);
+ * addr1 = kmap_local_page(page1);
+ * addr2 = kmap_local_page(page2);
* ...
- * kunmap_atomic(addr2);
- * kunmap_atomic(addr1);
+ * kunmap_local(addr2);
+ * kunmap_local(addr1);
*
* Unmapping addr1 before addr2 is invalid and causes malfunction.
*
@@ -88,10 +86,26 @@ static inline void kmap_flush_unused(voi
* virtual address of the direct mapping. Only real highmem pages are
* temporarily mapped.
*
- * While it is significantly faster than kmap() it comes with restrictions
- * about the pointer validity and the side effects of disabling page faults
- * and preemption. Use it only when absolutely necessary, e.g. from non
- * preemptible contexts.
+ * While it is significantly faster than kmap() for the higmem case it
+ * comes with restrictions about the pointer validity. Only use when really
+ * necessary.
+ *
+ * On HIGHMEM enabled systems mapping a highmem page has the side effect of
+ * disabling migration in order to keep the virtual address stable across
+ * preemption. No caller of kmap_local_page() can rely on this side effect.
+ */
+static inline void *kmap_local_page(struct page *page);
+
+/**
+ * kmap_atomic - Atomically map a page for temporary usage - Deprecated!
+ * @page: Pointer to the page
[patch V3 09/37] arc/mm/highmem: Use generic kmap atomic implementation
Adopt the map ordering to match the other architectures and the generic
code. Also make the maximum entries limited and not dependend on the number
of CPUs. With the original implementation did the following calculation:
nr_slots = mapsize >> PAGE_SHIFT;
The results in either 512 or 1024 total slots depending on
configuration. The total slots have to be divided by the number of CPUs to
get the number of slots per CPU (former KM_TYPE_NR). ARC supports up to 4k
CPUs, so this just falls apart in random ways depending on the number of
CPUs and the actual kmap (atomic) nesting. The comment in highmem.c:
* - fixmap anyhow needs a limited number of mappings. So 2M kvaddr == 256 PTE
* slots across NR_CPUS would be more than sufficient (generic code defines
* KM_TYPE_NR as 20).
is just wrong. KM_TYPE_NR (now KM_MAX_IDX) is the number of slots per CPU
because kmap_local/atomic() needs to support nested mappings (thread,
softirq, interrupt). While KM_MAX_IDX might be overestimated, the above
reasoning is just wrong and clearly the highmem code was never tested with
any system with more than a few CPUs.
Use the default number of slots and fail the build when it does not
fit. Randomly failing at runtime is not a really good option.
Signed-off-by: Thomas Gleixner
Cc: Vineet Gupta
Cc: linux-snps-arc@lists.infradead.org
---
V3: Make it actually more correct.
---
arch/arc/Kconfig |1
arch/arc/include/asm/highmem.h| 26 ++
arch/arc/include/asm/kmap_types.h | 14 -
arch/arc/mm/highmem.c | 54 +++---
4 files changed, 26 insertions(+), 69 deletions(-)
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -507,6 +507,7 @@ config LINUX_RAM_BASE
config HIGHMEM
bool "High Memory Support"
select ARCH_DISCONTIGMEM_ENABLE
+ select KMAP_LOCAL
help
With ARC 2G:2G address split, only upper 2G is directly addressable by
kernel. Enable this to potentially allow access to rest of 2G and PAE
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -9,17 +9,29 @@
#ifdef CONFIG_HIGHMEM
#include
-#include
+#include
+
+#define FIXMAP_SIZEPGDIR_SIZE
+#define PKMAP_SIZE PGDIR_SIZE
/* start after vmalloc area */
#define FIXMAP_BASE(PAGE_OFFSET - FIXMAP_SIZE - PKMAP_SIZE)
-#define FIXMAP_SIZEPGDIR_SIZE /* only 1 PGD worth */
-#define KM_TYPE_NR ((FIXMAP_SIZE >> PAGE_SHIFT)/NR_CPUS)
-#define FIXMAP_ADDR(nr)(FIXMAP_BASE + ((nr) << PAGE_SHIFT))
+
+#define FIX_KMAP_SLOTS (KM_MAX_IDX * NR_CPUS)
+#define FIX_KMAP_BEGIN (0UL)
+#define FIX_KMAP_END ((FIX_KMAP_BEGIN + FIX_KMAP_SLOTS) - 1)
+
+#define FIXADDR_TOP(FIXMAP_BASE + (FIX_KMAP_END << PAGE_SHIFT))
+
+/*
+ * This should be converted to the asm-generic version, but of course this
+ * is needlessly different from all other architectures. Sigh - tglx
+ */
+#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
+#define __virt_to_fix(x) (((FIXADDR_TOP - ((x) & PAGE_MASK))) >>
PAGE_SHIFT)
/* start after fixmap area */
#define PKMAP_BASE (FIXMAP_BASE + FIXMAP_SIZE)
-#define PKMAP_SIZE PGDIR_SIZE
#define LAST_PKMAP (PKMAP_SIZE >> PAGE_SHIFT)
#define LAST_PKMAP_MASK(LAST_PKMAP - 1)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
@@ -29,11 +41,13 @@
extern void kmap_init(void);
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)
+
static inline void flush_cache_kmaps(void)
{
flush_cache_all();
}
-
#endif
#endif
--- a/arch/arc/include/asm/kmap_types.h
+++ /dev/null
@@ -1,14 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2015 Synopsys, Inc. (www.synopsys.com)
- */
-
-#ifndef _ASM_KMAP_TYPES_H
-#define _ASM_KMAP_TYPES_H
-
-/*
- * We primarily need to define KM_TYPE_NR here but that in turn
- * is a function of PGDIR_SIZE etc.
- * To avoid circular deps issue, put everything in asm/highmem.h
- */
-#endif
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -36,9 +36,8 @@
* This means each only has 1 PGDIR_SIZE worth of kvaddr mappings, which
means
* 2M of kvaddr space for typical config (8K page and 11:8:13 traversal
split)
*
- * - fixmap anyhow needs a limited number of mappings. So 2M kvaddr == 256 PTE
- * slots across NR_CPUS would be more than sufficient (generic code defines
- * KM_TYPE_NR as 20).
+ * - The fixed KMAP slots for kmap_local/atomic() require KM_MAX_IDX slots per
+ * CPU. So the number of CPUs sharing a single PTE page is limited.
*
* - pkmap being preemptible, in theory could do with more than 256 concurrent
* mappings. However, generic pkmap code: map_new_virtu
[patch V3 19/37] mm/highmem: Remove the old kmap_atomic cruft
All users gone.
Signed-off-by: Thomas Gleixner
---
include/linux/highmem.h | 63 +++-
mm/highmem.c|7 -
2 files changed, 5 insertions(+), 65 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -86,31 +86,16 @@ static inline void kunmap(struct page *p
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
-
-#ifndef CONFIG_KMAP_LOCAL
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-void kunmap_atomic_high(void *kvaddr);
-
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
- return kmap_atomic_high_prot(page, prot);
-}
-
-static inline void __kunmap_atomic(void *vaddr)
-{
- kunmap_atomic_high(vaddr);
+ return __kmap_local_page_prot(page, prot);
}
-#else /* !CONFIG_KMAP_LOCAL */
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+static inline void *kmap_atomic(struct page *page)
{
- preempt_disable();
- pagefault_disable();
- return __kmap_local_page_prot(page, prot);
+ return kmap_atomic_prot(page, kmap_prot);
}
static inline void *kmap_atomic_pfn(unsigned long pfn)
@@ -125,13 +110,6 @@ static inline void __kunmap_atomic(void
kunmap_local_indexed(addr);
}
-#endif /* CONFIG_KMAP_LOCAL */
-
-static inline void *kmap_atomic(struct page *page)
-{
- return kmap_atomic_prot(page, kmap_prot);
-}
-
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;
@@ -212,41 +190,8 @@ static inline void __kunmap_atomic(void
#define kmap_flush_unused()do {} while(0)
-#endif /* CONFIG_HIGHMEM */
-
-#if !defined(CONFIG_KMAP_LOCAL)
-#if defined(CONFIG_HIGHMEM)
-
-DECLARE_PER_CPU(int, __kmap_atomic_idx);
-
-static inline int kmap_atomic_idx_push(void)
-{
- int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(in_irq() && !irqs_disabled());
- BUG_ON(idx >= KM_TYPE_NR);
-#endif
- return idx;
-}
-
-static inline int kmap_atomic_idx(void)
-{
- return __this_cpu_read(__kmap_atomic_idx) - 1;
-}
-static inline void kmap_atomic_idx_pop(void)
-{
-#ifdef CONFIG_DEBUG_HIGHMEM
- int idx = __this_cpu_dec_return(__kmap_atomic_idx);
-
- BUG_ON(idx < 0);
-#else
- __this_cpu_dec(__kmap_atomic_idx);
-#endif
-}
-#endif
-#endif
+#endif /* CONFIG_HIGHMEM */
/*
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -31,12 +31,6 @@
#include
#include
-#ifndef CONFIG_KMAP_LOCAL
-#ifdef CONFIG_HIGHMEM
-DEFINE_PER_CPU(int, __kmap_atomic_idx);
-#endif
-#endif
-
/*
* Virtual_count is not a pure "count".
* 0 means that it is not mapped, and has not been mapped
@@ -410,6 +404,7 @@ static inline void kmap_local_idx_pop(vo
#ifndef arch_kmap_local_post_map
# define arch_kmap_local_post_map(vaddr, pteval) do { } while (0)
#endif
+
#ifndef arch_kmap_local_pre_unmap
# define arch_kmap_local_pre_unmap(vaddr) do { } while (0)
#endif
___
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[patch V3 28/37] mips/crashdump: Simplify copy_oldmem_page()
Replace kmap_atomic_pfn() with kmap_local_pfn() which is preemptible and
can take page faults.
Remove the indirection of the dump page and the related cruft which is not
longer required.
Signed-off-by: Thomas Gleixner
Cc: Thomas Bogendoerfer
Cc: linux-m...@vger.kernel.org
---
V3: New patch
---
arch/mips/kernel/crash_dump.c | 42 +++---
1 file changed, 7 insertions(+), 35 deletions(-)
--- a/arch/mips/kernel/crash_dump.c
+++ b/arch/mips/kernel/crash_dump.c
@@ -5,8 +5,6 @@
#include
#include
-static void *kdump_buf_page;
-
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
@@ -17,51 +15,25 @@ static void *kdump_buf_page;
* @userbuf: if set, @buf is in user address space, use copy_to_user(),
* otherwise @buf is in kernel address space, use memcpy().
*
- * Copy a page from "oldmem". For this page, there is no pte mapped
+ * Copy a page from "oldmem". For this page, there might be no pte mapped
* in the current kernel.
- *
- * Calling copy_to_user() in atomic context is not desirable. Hence first
- * copying the data to a pre-allocated kernel page and then copying to user
- * space in non-atomic context.
*/
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-size_t csize, unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
+unsigned long offset, int userbuf)
{
void *vaddr;
if (!csize)
return 0;
- vaddr = kmap_atomic_pfn(pfn);
+ vaddr = kmap_local_pfn(pfn);
if (!userbuf) {
- memcpy(buf, (vaddr + offset), csize);
- kunmap_atomic(vaddr);
+ memcpy(buf, vaddr + offset, csize);
} else {
- if (!kdump_buf_page) {
- pr_warn("Kdump: Kdump buffer page not allocated\n");
-
- return -EFAULT;
- }
- copy_page(kdump_buf_page, vaddr);
- kunmap_atomic(vaddr);
- if (copy_to_user(buf, (kdump_buf_page + offset), csize))
- return -EFAULT;
+ if (copy_to_user(buf, vaddr + offset, csize))
+ csize = -EFAULT;
}
return csize;
}
-
-static int __init kdump_buf_page_init(void)
-{
- int ret = 0;
-
- kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!kdump_buf_page) {
- pr_warn("Kdump: Failed to allocate kdump buffer page\n");
- ret = -ENOMEM;
- }
-
- return ret;
-}
-arch_initcall(kdump_buf_page_init);
___
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[patch V3 27/37] x86/crashdump/32: Simplify copy_oldmem_page()
Replace kmap_atomic_pfn() with kmap_local_pfn() which is preemptible and
can take page faults.
Remove the indirection of the dump page and the related cruft which is not
longer required.
Signed-off-by: Thomas Gleixner
---
V3: New patch
---
arch/x86/kernel/crash_dump_32.c | 48
1 file changed, 10 insertions(+), 38 deletions(-)
--- a/arch/x86/kernel/crash_dump_32.c
+++ b/arch/x86/kernel/crash_dump_32.c
@@ -13,8 +13,6 @@
#include
-static void *kdump_buf_page;
-
static inline bool is_crashed_pfn_valid(unsigned long pfn)
{
#ifndef CONFIG_X86_PAE
@@ -41,15 +39,11 @@ static inline bool is_crashed_pfn_valid(
* @userbuf: if set, @buf is in user address space, use copy_to_user(),
* otherwise @buf is in kernel address space, use memcpy().
*
- * Copy a page from "oldmem". For this page, there is no pte mapped
- * in the current kernel. We stitch up a pte, similar to kmap_atomic.
- *
- * Calling copy_to_user() in atomic context is not desirable. Hence first
- * copying the data to a pre-allocated kernel page and then copying to user
- * space in non-atomic context.
+ * Copy a page from "oldmem". For this page, there might be no pte mapped
+ * in the current kernel.
*/
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
- size_t csize, unsigned long offset, int userbuf)
+ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
+unsigned long offset, int userbuf)
{
void *vaddr;
@@ -59,38 +53,16 @@ ssize_t copy_oldmem_page(unsigned long p
if (!is_crashed_pfn_valid(pfn))
return -EFAULT;
- vaddr = kmap_atomic_pfn(pfn);
+ vaddr = kmap_local_pfn(pfn);
if (!userbuf) {
- memcpy(buf, (vaddr + offset), csize);
- kunmap_atomic(vaddr);
+ memcpy(buf, vaddr + offset, csize);
} else {
- if (!kdump_buf_page) {
- printk(KERN_WARNING "Kdump: Kdump buffer page not"
- " allocated\n");
- kunmap_atomic(vaddr);
- return -EFAULT;
- }
- copy_page(kdump_buf_page, vaddr);
- kunmap_atomic(vaddr);
- if (copy_to_user(buf, (kdump_buf_page + offset), csize))
- return -EFAULT;
+ if (copy_to_user(buf, vaddr + offset, csize))
+ csize = -EFAULT;
}
- return csize;
-}
+ kunmap_local(vaddr);
-static int __init kdump_buf_page_init(void)
-{
- int ret = 0;
-
- kdump_buf_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!kdump_buf_page) {
- printk(KERN_WARNING "Kdump: Failed to allocate kdump buffer"
-" page\n");
- ret = -ENOMEM;
- }
-
- return ret;
+ return csize;
}
-arch_initcall(kdump_buf_page_init);
___
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[patch V3 22/37] highmem: High implementation details and document API
Move the gory details of kmap & al into a private header and only document
the interfaces which are usable by drivers.
Signed-off-by: Thomas Gleixner
---
V3: New patch
---
include/linux/highmem-internal.h | 174 +
include/linux/highmem.h | 270 ++-
mm/highmem.c | 11 -
3 files changed, 276 insertions(+), 179 deletions(-)
--- /dev/null
+++ b/include/linux/highmem-internal.h
@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_HIGHMEM_INTERNAL_H
+#define _LINUX_HIGHMEM_INTERNAL_H
+
+/*
+ * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
+ */
+#ifdef CONFIG_KMAP_LOCAL
+void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
+void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
+void kunmap_local_indexed(void *vaddr);
+#endif
+
+#ifdef CONFIG_HIGHMEM
+#include
+
+#ifndef ARCH_HAS_KMAP_FLUSH_TLB
+static inline void kmap_flush_tlb(unsigned long addr) { }
+#endif
+
+#ifndef kmap_prot
+#define kmap_prot PAGE_KERNEL
+#endif
+
+void *kmap_high(struct page *page);
+void kunmap_high(struct page *page);
+void __kmap_flush_unused(void);
+struct page *__kmap_to_page(void *addr);
+
+static inline void *kmap(struct page *page)
+{
+ void *addr;
+
+ might_sleep();
+ if (!PageHighMem(page))
+ addr = page_address(page);
+ else
+ addr = kmap_high(page);
+ kmap_flush_tlb((unsigned long)addr);
+ return addr;
+}
+
+static inline void kunmap(struct page *page)
+{
+ might_sleep();
+ if (!PageHighMem(page))
+ return;
+ kunmap_high(page);
+}
+
+static inline struct page *kmap_to_page(void *addr)
+{
+ return __kmap_to_page(addr);
+}
+
+static inline void kmap_flush_unused(void)
+{
+ __kmap_flush_unused();
+}
+
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ preempt_disable();
+ pagefault_disable();
+ return __kmap_local_page_prot(page, prot);
+}
+
+static inline void *kmap_atomic(struct page *page)
+{
+ return kmap_atomic_prot(page, kmap_prot);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ preempt_disable();
+ pagefault_disable();
+ return __kmap_local_pfn_prot(pfn, kmap_prot);
+}
+
+static inline void __kunmap_atomic(void *addr)
+{
+ kunmap_local_indexed(addr);
+ pagefault_enable();
+ preempt_enable();
+}
+
+unsigned int __nr_free_highpages(void);
+extern atomic_long_t _totalhigh_pages;
+
+static inline unsigned int nr_free_highpages(void)
+{
+ return __nr_free_highpages();
+}
+
+static inline unsigned long totalhigh_pages(void)
+{
+ return (unsigned long)atomic_long_read(&_totalhigh_pages);
+}
+
+static inline void totalhigh_pages_inc(void)
+{
+ atomic_long_inc(&_totalhigh_pages);
+}
+
+static inline void totalhigh_pages_add(long count)
+{
+ atomic_long_add(count, &_totalhigh_pages);
+}
+
+#else /* CONFIG_HIGHMEM */
+
+static inline struct page *kmap_to_page(void *addr)
+{
+ return virt_to_page(addr);
+}
+
+static inline void *kmap(struct page *page)
+{
+ might_sleep();
+ return page_address(page);
+}
+
+static inline void kunmap_high(struct page *page) { }
+static inline void kmap_flush_unused(void) { }
+
+static inline void kunmap(struct page *page)
+{
+#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+ kunmap_flush_on_unmap(page_address(page));
+#endif
+}
+
+static inline void *kmap_atomic(struct page *page)
+{
+ preempt_disable();
+ pagefault_disable();
+ return page_address(page);
+}
+
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ return kmap_atomic(page);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ return kmap_atomic(pfn_to_page(pfn));
+}
+
+static inline void __kunmap_atomic(void *addr)
+{
+#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+ kunmap_flush_on_unmap(addr);
+#endif
+ pagefault_enable();
+ preempt_enable();
+}
+
+static inline unsigned int nr_free_highpages(void) { return 0; }
+static inline unsigned long totalhigh_pages(void) { return 0UL; }
+
+#endif /* CONFIG_HIGHMEM */
+
+/*
+ * Prevent people trying to call kunmap_atomic() as if it were kunmap()
+ * kunmap_atomic() should get the return value of kmap_atomic, not the page.
+ */
+#define kunmap_atomic(__addr) \
+do { \
+ BUILD_BUG_ON(__same_type((__addr), struct page *)); \
+ __kunmap_atomic(__addr);\
+} while (0)
+
+#endif
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -11,199 +11,125 @@
#include
-#ifndef ARCH_HAS_FLUSH_ANON_PAGE
-static inline void flush_anon_page(struct vm_area_struct *vma, struct page
*page, unsigned long vmaddr)
-{
-}
-#endif
+#include "highmem-internal.h"
-#ifndef ARCH_HA
[patch V3 32/37] drm/vmgfx: Replace kmap_atomic()
There is no reason to disable pagefaults and preemption as a side effect of
kmap_atomic_prot().
Use kmap_local_page_prot() instead and document the reasoning for the
mapping usage with the given pgprot.
Remove the NULL pointer check for the map. These functions return a valid
address for valid pages and the return was bogus anyway as it would have
left preemption and pagefaults disabled.
Signed-off-by: Thomas Gleixner
Cc: VMware Graphics
Cc: Roland Scheidegger
Cc: David Airlie
Cc: Daniel Vetter
Cc: dri-de...@lists.freedesktop.org
---
V3: New patch
---
drivers/gpu/drm/vmwgfx/vmwgfx_blit.c | 30 --
1 file changed, 12 insertions(+), 18 deletions(-)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
@@ -375,12 +375,12 @@ static int vmw_bo_cpu_blit_line(struct v
copy_size = min_t(u32, copy_size, PAGE_SIZE - src_page_offset);
if (unmap_src) {
- kunmap_atomic(d->src_addr);
+ kunmap_local(d->src_addr);
d->src_addr = NULL;
}
if (unmap_dst) {
- kunmap_atomic(d->dst_addr);
+ kunmap_local(d->dst_addr);
d->dst_addr = NULL;
}
@@ -388,12 +388,8 @@ static int vmw_bo_cpu_blit_line(struct v
if (WARN_ON_ONCE(dst_page >= d->dst_num_pages))
return -EINVAL;
- d->dst_addr =
- kmap_atomic_prot(d->dst_pages[dst_page],
-d->dst_prot);
- if (!d->dst_addr)
- return -ENOMEM;
-
+ d->dst_addr =
kmap_local_page_prot(d->dst_pages[dst_page],
+ d->dst_prot);
d->mapped_dst = dst_page;
}
@@ -401,12 +397,8 @@ static int vmw_bo_cpu_blit_line(struct v
if (WARN_ON_ONCE(src_page >= d->src_num_pages))
return -EINVAL;
- d->src_addr =
- kmap_atomic_prot(d->src_pages[src_page],
-d->src_prot);
- if (!d->src_addr)
- return -ENOMEM;
-
+ d->src_addr =
kmap_local_page_prot(d->src_pages[src_page],
+ d->src_prot);
d->mapped_src = src_page;
}
diff->do_cpy(diff, d->dst_addr + dst_page_offset,
@@ -436,8 +428,10 @@ static int vmw_bo_cpu_blit_line(struct v
*
* Performs a CPU blit from one buffer object to another avoiding a full
* bo vmap which may exhaust- or fragment vmalloc space.
- * On supported architectures (x86), we're using kmap_atomic which avoids
- * cross-processor TLB- and cache flushes and may, on non-HIGHMEM systems
+ *
+ * On supported architectures (x86), we're using kmap_local_prot() which
+ * avoids cross-processor TLB- and cache flushes. kmap_local_prot() will
+ * either map a highmem page with the proper pgprot on HIGHMEM=y systems or
* reference already set-up mappings.
*
* Neither of the buffer objects may be placed in PCI memory
@@ -500,9 +494,9 @@ int vmw_bo_cpu_blit(struct ttm_buffer_ob
}
out:
if (d.src_addr)
- kunmap_atomic(d.src_addr);
+ kunmap_local(d.src_addr);
if (d.dst_addr)
- kunmap_atomic(d.dst_addr);
+ kunmap_local(d.dst_addr);
return ret;
}
___
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[patch V3 36/37] drm/i915: Replace io_mapping_map_atomic_wc()
None of these mapping requires the side effect of disabling pagefaults and
preemption.
Use io_mapping_map_local_wc() instead, and clean up gtt_user_read() and
gtt_user_write() to use a plain copy_from_user() as the local maps are not
disabling pagefaults.
Signed-off-by: Thomas Gleixner
Cc: Jani Nikula
Cc: Joonas Lahtinen
Cc: Rodrigo Vivi
Cc: David Airlie
Cc: Daniel Vetter
Cc: intel-...@lists.freedesktop.org
Cc: dri-de...@lists.freedesktop.org
---
V3: New patch
---
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c |7 +---
drivers/gpu/drm/i915/i915_gem.c| 40 -
drivers/gpu/drm/i915/selftests/i915_gem.c |4 +-
drivers/gpu/drm/i915/selftests/i915_gem_gtt.c |8 ++---
4 files changed, 22 insertions(+), 37 deletions(-)
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1081,7 +1081,7 @@ static void reloc_cache_reset(struct rel
struct i915_ggtt *ggtt = cache_to_ggtt(cache);
intel_gt_flush_ggtt_writes(ggtt->vm.gt);
- io_mapping_unmap_atomic((void __iomem *)vaddr);
+ io_mapping_unmap_local((void __iomem *)vaddr);
if (drm_mm_node_allocated(&cache->node)) {
ggtt->vm.clear_range(&ggtt->vm,
@@ -1147,7 +1147,7 @@ static void *reloc_iomap(struct drm_i915
if (cache->vaddr) {
intel_gt_flush_ggtt_writes(ggtt->vm.gt);
- io_mapping_unmap_atomic((void __force __iomem *)
unmask_page(cache->vaddr));
+ io_mapping_unmap_local((void __force __iomem *)
unmask_page(cache->vaddr));
} else {
struct i915_vma *vma;
int err;
@@ -1195,8 +1195,7 @@ static void *reloc_iomap(struct drm_i915
offset += page << PAGE_SHIFT;
}
- vaddr = (void __force *)io_mapping_map_atomic_wc(&ggtt->iomap,
-offset);
+ vaddr = (void __force *)io_mapping_map_local_wc(&ggtt->iomap, offset);
cache->page = page;
cache->vaddr = (unsigned long)vaddr;
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -379,22 +379,15 @@ gtt_user_read(struct io_mapping *mapping
char __user *user_data, int length)
{
void __iomem *vaddr;
- unsigned long unwritten;
+ bool fail = false;
/* We can use the cpu mem copy function because this is X86. */
- vaddr = io_mapping_map_atomic_wc(mapping, base);
- unwritten = __copy_to_user_inatomic(user_data,
- (void __force *)vaddr + offset,
- length);
- io_mapping_unmap_atomic(vaddr);
- if (unwritten) {
- vaddr = io_mapping_map_wc(mapping, base, PAGE_SIZE);
- unwritten = copy_to_user(user_data,
-(void __force *)vaddr + offset,
-length);
- io_mapping_unmap(vaddr);
- }
- return unwritten;
+ vaddr = io_mapping_map_local_wc(mapping, base);
+ if (copy_to_user(user_data, (void __force *)vaddr + offset, length))
+ fail = true;
+ io_mapping_unmap_local(vaddr);
+
+ return fail;
}
static int
@@ -557,21 +550,14 @@ ggtt_write(struct io_mapping *mapping,
char __user *user_data, int length)
{
void __iomem *vaddr;
- unsigned long unwritten;
+ bool fail = false;
/* We can use the cpu mem copy function because this is X86. */
- vaddr = io_mapping_map_atomic_wc(mapping, base);
- unwritten = __copy_from_user_inatomic_nocache((void __force *)vaddr +
offset,
- user_data, length);
- io_mapping_unmap_atomic(vaddr);
- if (unwritten) {
- vaddr = io_mapping_map_wc(mapping, base, PAGE_SIZE);
- unwritten = copy_from_user((void __force *)vaddr + offset,
- user_data, length);
- io_mapping_unmap(vaddr);
- }
-
- return unwritten;
+ vaddr = io_mapping_map_local_wc(mapping, base);
+ if (copy_from_user((void __force *)vaddr + offset, user_data, length))
+ fail = true;
+ io_mapping_unmap_local(vaddr);
+ return fail;
}
/**
--- a/drivers/gpu/drm/i915/selftests/i915_gem.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem.c
@@ -57,12 +57,12 @@ static void trash_stolen(struct drm_i915
ggtt->vm.insert_page(&ggtt->vm, dma, slot, I915_CACHE_NONE, 0);
- s = io_mapping_map_atomic_wc(&ggtt->iomap, slot);
+ s = io_mapping_map_local_wc(&ggtt->iomap, slot);
for (x = 0; x < PAGE_SIZE / sizeof(u32); x++) {
[patch V3 31/37] drm/ttm: Replace kmap_atomic() usage
There is no reason to disable pagefaults and preemption as a side effect of kmap_atomic_prot(). Use kmap_local_page_prot() instead and document the reasoning for the mapping usage with the given pgprot. Remove the NULL pointer check for the map. These functions return a valid address for valid pages and the return was bogus anyway as it would have left preemption and pagefaults disabled. Signed-off-by: Thomas Gleixner Cc: Christian Koenig Cc: Huang Rui Cc: David Airlie Cc: Daniel Vetter Cc: dri-de...@lists.freedesktop.org --- V3: New patch --- drivers/gpu/drm/ttm/ttm_bo_util.c | 20 1 file changed, 12 insertions(+), 8 deletions(-) --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -181,13 +181,15 @@ static int ttm_copy_io_ttm_page(struct t return -ENOMEM; src = (void *)((unsigned long)src + (page << PAGE_SHIFT)); - dst = kmap_atomic_prot(d, prot); - if (!dst) - return -ENOMEM; + /* +* Ensure that a highmem page is mapped with the correct +* pgprot. For non highmem the mapping is already there. +*/ + dst = kmap_local_page_prot(d, prot); memcpy_fromio(dst, src, PAGE_SIZE); - kunmap_atomic(dst); + kunmap_local(dst); return 0; } @@ -203,13 +205,15 @@ static int ttm_copy_ttm_io_page(struct t return -ENOMEM; dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT)); - src = kmap_atomic_prot(s, prot); - if (!src) - return -ENOMEM; + /* +* Ensure that a highmem page is mapped with the correct +* pgprot. For non highmem the mapping is already there. +*/ + src = kmap_local_page_prot(s, prot); memcpy_toio(dst, src, PAGE_SIZE); - kunmap_atomic(src); + kunmap_local(src); return 0; } ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch V3 30/37] highmem: Remove kmap_atomic_pfn()
No more users.
Signed-off-by: Thomas Gleixner
---
V3: New patch
---
include/linux/highmem-internal.h | 12
1 file changed, 12 deletions(-)
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -99,13 +99,6 @@ static inline void *kmap_atomic(struct p
return kmap_atomic_prot(page, kmap_prot);
}
-static inline void *kmap_atomic_pfn(unsigned long pfn)
-{
- preempt_disable();
- pagefault_disable();
- return __kmap_local_pfn_prot(pfn, kmap_prot);
-}
-
static inline void __kunmap_atomic(void *addr)
{
kunmap_local_indexed(addr);
@@ -193,11 +186,6 @@ static inline void *kmap_atomic_prot(str
return kmap_atomic(page);
}
-static inline void *kmap_atomic_pfn(unsigned long pfn)
-{
- return kmap_atomic(pfn_to_page(pfn));
-}
-
static inline void __kunmap_atomic(void *addr)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
___
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[patch V3 34/37] drm/qxl: Replace io_mapping_map_atomic_wc()
None of these mapping requires the side effect of disabling pagefaults and
preemption.
Use io_mapping_map_local_wc() instead, rename the related functions
accordingly and clean up qxl_process_single_command() to use a plain
copy_from_user() as the local maps are not disabling pagefaults.
Signed-off-by: Thomas Gleixner
Cc: Dave Airlie
Cc: Gerd Hoffmann
Cc: David Airlie
Cc: Daniel Vetter
Cc: virtualizat...@lists.linux-foundation.org
Cc: spice-de...@lists.freedesktop.org
---
V3: New patch
---
drivers/gpu/drm/qxl/qxl_image.c | 18 +-
drivers/gpu/drm/qxl/qxl_ioctl.c | 27 +--
drivers/gpu/drm/qxl/qxl_object.c | 12 ++--
drivers/gpu/drm/qxl/qxl_object.h |4 ++--
drivers/gpu/drm/qxl/qxl_release.c |4 ++--
5 files changed, 32 insertions(+), 33 deletions(-)
--- a/drivers/gpu/drm/qxl/qxl_image.c
+++ b/drivers/gpu/drm/qxl/qxl_image.c
@@ -124,12 +124,12 @@ qxl_image_init_helper(struct qxl_device
wrong (check the bitmaps are sent correctly
first) */
- ptr = qxl_bo_kmap_atomic_page(qdev, chunk_bo, 0);
+ ptr = qxl_bo_kmap_local_page(qdev, chunk_bo, 0);
chunk = ptr;
chunk->data_size = height * chunk_stride;
chunk->prev_chunk = 0;
chunk->next_chunk = 0;
- qxl_bo_kunmap_atomic_page(qdev, chunk_bo, ptr);
+ qxl_bo_kunmap_local_page(qdev, chunk_bo, ptr);
{
void *k_data, *i_data;
@@ -143,7 +143,7 @@ qxl_image_init_helper(struct qxl_device
i_data = (void *)data;
while (remain > 0) {
- ptr = qxl_bo_kmap_atomic_page(qdev, chunk_bo,
page << PAGE_SHIFT);
+ ptr = qxl_bo_kmap_local_page(qdev, chunk_bo,
page << PAGE_SHIFT);
if (page == 0) {
chunk = ptr;
@@ -157,7 +157,7 @@ qxl_image_init_helper(struct qxl_device
memcpy(k_data, i_data, size);
- qxl_bo_kunmap_atomic_page(qdev, chunk_bo, ptr);
+ qxl_bo_kunmap_local_page(qdev, chunk_bo, ptr);
i_data += size;
remain -= size;
page++;
@@ -175,10 +175,10 @@ qxl_image_init_helper(struct qxl_device
page_offset =
offset_in_page(out_offset);
size = min((int)(PAGE_SIZE -
page_offset), remain);
- ptr = qxl_bo_kmap_atomic_page(qdev,
chunk_bo, page_base);
+ ptr = qxl_bo_kmap_local_page(qdev,
chunk_bo, page_base);
k_data = ptr + page_offset;
memcpy(k_data, i_data, size);
- qxl_bo_kunmap_atomic_page(qdev,
chunk_bo, ptr);
+ qxl_bo_kunmap_local_page(qdev,
chunk_bo, ptr);
remain -= size;
i_data += size;
out_offset += size;
@@ -189,7 +189,7 @@ qxl_image_init_helper(struct qxl_device
qxl_bo_kunmap(chunk_bo);
image_bo = dimage->bo;
- ptr = qxl_bo_kmap_atomic_page(qdev, image_bo, 0);
+ ptr = qxl_bo_kmap_local_page(qdev, image_bo, 0);
image = ptr;
image->descriptor.id = 0;
@@ -212,7 +212,7 @@ qxl_image_init_helper(struct qxl_device
break;
default:
DRM_ERROR("unsupported image bit depth\n");
- qxl_bo_kunmap_atomic_page(qdev, image_bo, ptr);
+ qxl_bo_kunmap_local_page(qdev, image_bo, ptr);
return -EINVAL;
}
image->u.bitmap.flags = QXL_BITMAP_TOP_DOWN;
@@ -222,7 +222,7 @@ qxl_image_init_helper(struct qxl_device
image->u.bitmap.palette = 0;
image->u.bitmap.data = qxl_bo_physical_address(qdev, chunk_bo, 0);
- qxl_bo_kunmap_atomic_page(qdev, image_bo, ptr);
+ qxl_bo_kunmap_local_page(qdev, image_bo, ptr);
return 0;
}
--- a/drivers/gpu/drm/qxl/qxl_ioctl.c
+++ b/drivers/gpu/drm/qxl/qxl_ioctl.c
@@ -89,11 +89,11 @@ apply_reloc(struct qxl_device *qdev, str
{
void *reloc_page;
- reloc_page = qxl_bo_kmap_atomic_page(qdev, info->dst_bo,
info->dst_offset & PAGE_MASK);
+ reloc_page = qxl_bo_kmap_local_page(qdev, info->dst_bo,
info->dst_offset & PAGE_MASK);
*(uint64_t *)(reloc_page + (info->dst_offset & ~PAGE_MASK)) =
qxl_bo_physical_address(qdev,
info->src_bo,
[patch V3 18/37] highmem: Get rid of kmap_types.h
The header is not longer used and on alpha, ia64, openrisc, parisc and um it was completely unused anyway as these architectures have no highmem support. Signed-off-by: Thomas Gleixner --- V3: New patch --- arch/alpha/include/asm/kmap_types.h | 15 --- arch/ia64/include/asm/kmap_types.h | 13 - arch/openrisc/mm/init.c |1 - arch/openrisc/mm/ioremap.c |1 - arch/parisc/include/asm/kmap_types.h | 13 - arch/um/include/asm/fixmap.h |1 - arch/um/include/asm/kmap_types.h | 13 - include/asm-generic/Kbuild |1 - include/asm-generic/kmap_types.h | 11 --- include/linux/highmem.h |2 -- 10 files changed, 71 deletions(-) --- a/arch/alpha/include/asm/kmap_types.h +++ /dev/null @@ -1,15 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_KMAP_TYPES_H -#define _ASM_KMAP_TYPES_H - -/* Dummy header just to define km_type. */ - -#ifdef CONFIG_DEBUG_HIGHMEM -#define __WITH_KM_FENCE -#endif - -#include - -#undef __WITH_KM_FENCE - -#endif --- a/arch/ia64/include/asm/kmap_types.h +++ /dev/null @@ -1,13 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_IA64_KMAP_TYPES_H -#define _ASM_IA64_KMAP_TYPES_H - -#ifdef CONFIG_DEBUG_HIGHMEM -#define __WITH_KM_FENCE -#endif - -#include - -#undef __WITH_KM_FENCE - -#endif /* _ASM_IA64_KMAP_TYPES_H */ --- a/arch/openrisc/mm/init.c +++ b/arch/openrisc/mm/init.c @@ -33,7 +33,6 @@ #include #include #include -#include #include #include #include --- a/arch/openrisc/mm/ioremap.c +++ b/arch/openrisc/mm/ioremap.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include #include --- a/arch/parisc/include/asm/kmap_types.h +++ /dev/null @@ -1,13 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_KMAP_TYPES_H -#define _ASM_KMAP_TYPES_H - -#ifdef CONFIG_DEBUG_HIGHMEM -#define __WITH_KM_FENCE -#endif - -#include - -#undef __WITH_KM_FENCE - -#endif --- a/arch/um/include/asm/fixmap.h +++ b/arch/um/include/asm/fixmap.h @@ -3,7 +3,6 @@ #define __UM_FIXMAP_H #include -#include #include #include #include --- a/arch/um/include/asm/kmap_types.h +++ /dev/null @@ -1,13 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Copyright (C) 2002 Jeff Dike (jd...@karaya.com) - */ - -#ifndef __UM_KMAP_TYPES_H -#define __UM_KMAP_TYPES_H - -/* No more #include "asm/arch/kmap_types.h" ! */ - -#define KM_TYPE_NR 14 - -#endif --- a/include/asm-generic/Kbuild +++ b/include/asm-generic/Kbuild @@ -30,7 +30,6 @@ mandatory-y += irq.h mandatory-y += irq_regs.h mandatory-y += irq_work.h mandatory-y += kdebug.h -mandatory-y += kmap_types.h mandatory-y += kmap_size.h mandatory-y += kprobes.h mandatory-y += linkage.h --- a/include/asm-generic/kmap_types.h +++ /dev/null @@ -1,11 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_GENERIC_KMAP_TYPES_H -#define _ASM_GENERIC_KMAP_TYPES_H - -#ifdef __WITH_KM_FENCE -# define KM_TYPE_NR 41 -#else -# define KM_TYPE_NR 20 -#endif - -#endif --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -29,8 +29,6 @@ static inline void invalidate_kernel_vma } #endif -#include - /* * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft. */ ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch V3 33/37] highmem: Remove kmap_atomic_prot()
No more users.
Signed-off-by: Thomas Gleixner
---
V3: New patch
---
include/linux/highmem-internal.h | 14 ++
1 file changed, 2 insertions(+), 12 deletions(-)
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -87,16 +87,11 @@ static inline void __kunmap_local(void *
kunmap_local_indexed(vaddr);
}
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+static inline void *kmap_atomic(struct page *page)
{
preempt_disable();
pagefault_disable();
- return __kmap_local_page_prot(page, prot);
-}
-
-static inline void *kmap_atomic(struct page *page)
-{
- return kmap_atomic_prot(page, kmap_prot);
+ return __kmap_local_page_prot(page, kmap_prot);
}
static inline void __kunmap_atomic(void *addr)
@@ -181,11 +176,6 @@ static inline void *kmap_atomic(struct p
return page_address(page);
}
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
- return kmap_atomic(page);
-}
-
static inline void __kunmap_atomic(void *addr)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
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[patch V3 23/37] sched: Make migrate_disable/enable() independent of RT
Now that the scheduler can deal with migrate disable properly, there is no
real compelling reason to make it only available for RT.
There are quite some code pathes which needlessly disable preemption in
order to prevent migration and some constructs like kmap_atomic() enforce
it implicitly.
Making it available independent of RT allows to provide a preemptible
variant of kmap_atomic() and makes the code more consistent in general.
FIXME: Rework the comment in preempt.h
Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Juri Lelli
Cc: Vincent Guittot
Cc: Dietmar Eggemann
Cc: Steven Rostedt
Cc: Ben Segall
Cc: Mel Gorman
Cc: Daniel Bristot de Oliveira
---
include/linux/kernel.h | 21 ++---
include/linux/preempt.h | 38 +++---
include/linux/sched.h |2 +-
kernel/sched/core.c | 45 +++--
kernel/sched/sched.h|4 ++--
lib/smp_processor_id.c |2 +-
6 files changed, 56 insertions(+), 56 deletions(-)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -204,6 +204,7 @@ extern int _cond_resched(void);
extern void ___might_sleep(const char *file, int line, int preempt_offset);
extern void __might_sleep(const char *file, int line, int preempt_offset);
extern void __cant_sleep(const char *file, int line, int preempt_offset);
+extern void __cant_migrate(const char *file, int line);
/**
* might_sleep - annotation for functions that can sleep
@@ -227,6 +228,18 @@ extern void __cant_sleep(const char *fil
# define cant_sleep() \
do { __cant_sleep(__FILE__, __LINE__, 0); } while (0)
# define sched_annotate_sleep()(current->task_state_change = 0)
+
+/**
+ * cant_migrate - annotation for functions that cannot migrate
+ *
+ * Will print a stack trace if executed in code which is migratable
+ */
+# define cant_migrate()
\
+ do {\
+ if (IS_ENABLED(CONFIG_SMP)) \
+ __cant_migrate(__FILE__, __LINE__); \
+ } while (0)
+
/**
* non_block_start - annotate the start of section where sleeping is prohibited
*
@@ -251,6 +264,7 @@ extern void __cant_sleep(const char *fil
int preempt_offset) { }
# define might_sleep() do { might_resched(); } while (0)
# define cant_sleep() do { } while (0)
+# define cant_migrate()do { } while (0)
# define sched_annotate_sleep() do { } while (0)
# define non_block_start() do { } while (0)
# define non_block_end() do { } while (0)
@@ -258,13 +272,6 @@ extern void __cant_sleep(const char *fil
#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
-#ifndef CONFIG_PREEMPT_RT
-# define cant_migrate()cant_sleep()
-#else
- /* Placeholder for now */
-# define cant_migrate()do { } while (0)
-#endif
-
/**
* abs - return absolute value of an argument
* @x: the value. If it is unsigned type, it is converted to signed type
first.
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -322,7 +322,7 @@ static inline void preempt_notifier_init
#endif
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT)
+#ifdef CONFIG_SMP
/*
* Migrate-Disable and why it is undesired.
@@ -382,43 +382,11 @@ static inline void preempt_notifier_init
extern void migrate_disable(void);
extern void migrate_enable(void);
-#elif defined(CONFIG_PREEMPT_RT)
+#else
static inline void migrate_disable(void) { }
static inline void migrate_enable(void) { }
-#else /* !CONFIG_PREEMPT_RT */
-
-/**
- * migrate_disable - Prevent migration of the current task
- *
- * Maps to preempt_disable() which also disables preemption. Use
- * migrate_disable() to annotate that the intent is to prevent migration,
- * but not necessarily preemption.
- *
- * Can be invoked nested like preempt_disable() and needs the corresponding
- * number of migrate_enable() invocations.
- */
-static __always_inline void migrate_disable(void)
-{
- preempt_disable();
-}
-
-/**
- * migrate_enable - Allow migration of the current task
- *
- * Counterpart to migrate_disable().
- *
- * As migrate_disable() can be invoked nested, only the outermost invocation
- * reenables migration.
- *
- * Currently mapped to preempt_enable().
- */
-static __always_inline void migrate_enable(void)
-{
- preempt_enable();
-}
-
-#endif /* CONFIG_SMP && CONFIG_PREEMPT_RT */
+#endif /* CONFIG_SMP */
#endif /* __LINUX_PREEMPT_H */
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -715,7 +715,7 @@ struct task_struct {
const cpumask_t *cpus_ptr;
cpumask_t cpus_mask;
void*migration_pending;
-#if defined(CONFIG_SMP) && defined(CONFIG_PRE
[patch V3 24/37] sched: highmem: Store local kmaps in task struct
Instead of storing the map per CPU provide and use per task storage. That
prepares for local kmaps which are preemptible.
The context switch code is preparatory and not yet in use because
kmap_atomic() runs with preemption disabled. Will be made usable in the
next step.
The context switch logic is safe even when an interrupt happens after
clearing or before restoring the kmaps. The kmap index in task struct is
not modified so any nesting kmap in an interrupt will use unused indices
and on return the counter is the same as before.
Also add an assert into the return to user space code. Going back to user
space with an active kmap local is a nono.
Signed-off-by: Thomas Gleixner
---
V3: Handle the debug case correctly
---
include/linux/highmem-internal.h | 10 +++
include/linux/sched.h|9 +++
kernel/entry/common.c|2
kernel/fork.c|1
kernel/sched/core.c | 18 +++
mm/highmem.c | 99 +++
6 files changed, 129 insertions(+), 10 deletions(-)
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -9,6 +9,16 @@
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
void kunmap_local_indexed(void *vaddr);
+void kmap_local_fork(struct task_struct *tsk);
+void __kmap_local_sched_out(void);
+void __kmap_local_sched_in(void);
+static inline void kmap_assert_nomap(void)
+{
+ DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
+}
+#else
+static inline void kmap_local_fork(struct task_struct *tsk) { }
+static inline void kmap_assert_nomap(void) { }
#endif
#ifdef CONFIG_HIGHMEM
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -34,6 +34,7 @@
#include
#include
#include
+#include
/* task_struct member predeclarations (sorted alphabetically): */
struct audit_context;
@@ -629,6 +630,13 @@ struct wake_q_node {
struct wake_q_node *next;
};
+struct kmap_ctrl {
+#ifdef CONFIG_KMAP_LOCAL
+ int idx;
+ pte_t pteval[KM_TYPE_NR];
+#endif
+};
+
struct task_struct {
#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
@@ -1294,6 +1302,7 @@ struct task_struct {
unsigned intsequential_io;
unsigned intsequential_io_avg;
#endif
+ struct kmap_ctrlkmap_ctrl;
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
unsigned long task_state_change;
#endif
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -2,6 +2,7 @@
#include
#include
+#include
#include
#include
@@ -194,6 +195,7 @@ static void exit_to_user_mode_prepare(st
/* Ensure that the address limit is intact and no locks are held */
addr_limit_user_check();
+ kmap_assert_nomap();
lockdep_assert_irqs_disabled();
lockdep_sys_exit();
}
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -930,6 +930,7 @@ static struct task_struct *dup_task_stru
account_kernel_stack(tsk, 1);
kcov_task_init(tsk);
+ kmap_local_fork(tsk);
#ifdef CONFIG_FAULT_INJECTION
tsk->fail_nth = 0;
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4053,6 +4053,22 @@ static inline void finish_lock_switch(st
# define finish_arch_post_lock_switch()do { } while (0)
#endif
+static inline void kmap_local_sched_out(void)
+{
+#ifdef CONFIG_KMAP_LOCAL
+ if (unlikely(current->kmap_ctrl.idx))
+ __kmap_local_sched_out();
+#endif
+}
+
+static inline void kmap_local_sched_in(void)
+{
+#ifdef CONFIG_KMAP_LOCAL
+ if (unlikely(current->kmap_ctrl.idx))
+ __kmap_local_sched_in();
+#endif
+}
+
/**
* prepare_task_switch - prepare to switch tasks
* @rq: the runqueue preparing to switch
@@ -4075,6 +4091,7 @@ prepare_task_switch(struct rq *rq, struc
perf_event_task_sched_out(prev, next);
rseq_preempt(prev);
fire_sched_out_preempt_notifiers(prev, next);
+ kmap_local_sched_out();
prepare_task(next);
prepare_arch_switch(next);
}
@@ -4141,6 +4158,7 @@ static struct rq *finish_task_switch(str
finish_lock_switch(rq);
finish_arch_post_lock_switch();
kcov_finish_switch(current);
+ kmap_local_sched_in();
fire_sched_in_preempt_notifiers(current);
/*
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -365,8 +365,6 @@ EXPORT_SYMBOL(kunmap_high);
#include
-static DEFINE_PER_CPU(int, __kmap_local_idx);
-
/*
* With DEBUG_HIGHMEM the stack depth is doubled and every second
* slot is unused which acts as a guard page
@@ -379,23 +377,21 @@ static DEFINE_PER_CPU(int, __kmap_local_
static inline int kmap_local_idx_push(void)
{
- int idx = __this_cpu_add_return(__kmap_local_idx, KM_INCR) - 1;
-
WARN_ON_ONCE(in_irq() && !irqs_disabled());
- BUG_ON(idx >= KM_MAX_I
[patch V3 29/37] ARM: mm: Replace kmap_atomic_pfn()
There is no requirement to disable pagefaults and preemption for these
cache management mappings.
Replace kmap_atomic_pfn() with kmap_local_pfn(). This allows to remove
kmap_atomic_pfn() in the next step.
Signed-off-by: Thomas Gleixner
Cc: Russell King
Cc: linux-arm-ker...@lists.infradead.org
---
V3: New patch
---
arch/arm/mm/cache-feroceon-l2.c |6 +++---
arch/arm/mm/cache-xsc3l2.c |4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)
--- a/arch/arm/mm/cache-feroceon-l2.c
+++ b/arch/arm/mm/cache-feroceon-l2.c
@@ -49,9 +49,9 @@ static inline unsigned long l2_get_va(un
* we simply install a virtual mapping for it only for the
* TLB lookup to occur, hence no need to flush the untouched
* memory mapping afterwards (note: a cache flush may happen
-* in some circumstances depending on the path taken in kunmap_atomic).
+* in some circumstances depending on the path taken in kunmap_local).
*/
- void *vaddr = kmap_atomic_pfn(paddr >> PAGE_SHIFT);
+ void *vaddr = kmap_local_pfn(paddr >> PAGE_SHIFT);
return (unsigned long)vaddr + (paddr & ~PAGE_MASK);
#else
return __phys_to_virt(paddr);
@@ -61,7 +61,7 @@ static inline unsigned long l2_get_va(un
static inline void l2_put_va(unsigned long vaddr)
{
#ifdef CONFIG_HIGHMEM
- kunmap_atomic((void *)vaddr);
+ kunmap_local((void *)vaddr);
#endif
}
--- a/arch/arm/mm/cache-xsc3l2.c
+++ b/arch/arm/mm/cache-xsc3l2.c
@@ -59,7 +59,7 @@ static inline void l2_unmap_va(unsigned
{
#ifdef CONFIG_HIGHMEM
if (va != -1)
- kunmap_atomic((void *)va);
+ kunmap_local((void *)va);
#endif
}
@@ -75,7 +75,7 @@ static inline unsigned long l2_map_va(un
* in place for it.
*/
l2_unmap_va(prev_va);
- va = (unsigned long)kmap_atomic_pfn(pa >> PAGE_SHIFT);
+ va = (unsigned long)kmap_local_pfn(pa >> PAGE_SHIFT);
}
return va + (pa_offset >> (32 - PAGE_SHIFT));
#else
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[patch V3 07/37] highmem: Make DEBUG_HIGHMEM functional
For some obscure reason when CONFIG_DEBUG_HIGHMEM is enabled the stack
depth is increased from 20 to 41. But the only thing DEBUG_HIGHMEM does is
to enable a few BUG_ON()'s in the mapping code.
That's a leftover from the historical mapping code which had fixed entries
for various purposes. DEBUG_HIGHMEM inserted guard mappings between the map
types. But that got all ditched when kmap_atomic() switched to a stack
based map management. Though the WITH_KM_FENCE magic survived without being
functional. All the thing does today is to increase the stack depth.
Add a working implementation to the generic kmap_local* implementation.
Signed-off-by: Thomas Gleixner
---
V3: New patch
---
mm/highmem.c | 14 --
1 file changed, 12 insertions(+), 2 deletions(-)
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -374,9 +374,19 @@ EXPORT_SYMBOL(kunmap_high);
static DEFINE_PER_CPU(int, __kmap_local_idx);
+/*
+ * With DEBUG_HIGHMEM the stack depth is doubled and every second
+ * slot is unused which acts as a guard page
+ */
+#ifdef CONFIG_DEBUG_HIGHMEM
+# define KM_INCR 2
+#else
+# define KM_INCR 1
+#endif
+
static inline int kmap_local_idx_push(void)
{
- int idx = __this_cpu_inc_return(__kmap_local_idx) - 1;
+ int idx = __this_cpu_add_return(__kmap_local_idx, KM_INCR) - 1;
WARN_ON_ONCE(in_irq() && !irqs_disabled());
BUG_ON(idx >= KM_MAX_IDX);
@@ -390,7 +400,7 @@ static inline int kmap_local_idx(void)
static inline void kmap_local_idx_pop(void)
{
- int idx = __this_cpu_dec_return(__kmap_local_idx);
+ int idx = __this_cpu_sub_return(__kmap_local_idx, KM_INCR);
BUG_ON(idx < 0);
}
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[patch V3 26/37] io-mapping: Provide iomap_local variant
Similar to kmap local provide a iomap local variant which only disables migration, but neither disables pagefaults nor preemption. Signed-off-by: Thomas Gleixner --- V3: Restrict migrate disable to the 32bit mapping case and update documentation. V2: Split out from the large combo patch and add the !IOMAP_ATOMIC variants --- Documentation/driver-api/io-mapping.rst | 76 +++- include/linux/io-mapping.h | 30 +++- 2 files changed, 74 insertions(+), 32 deletions(-) --- a/Documentation/driver-api/io-mapping.rst +++ b/Documentation/driver-api/io-mapping.rst @@ -20,55 +20,71 @@ as it would consume too much of the kern mappable, while 'size' indicates how large a mapping region to enable. Both are in bytes. -This _wc variant provides a mapping which may only be used -with the io_mapping_map_atomic_wc or io_mapping_map_wc. +This _wc variant provides a mapping which may only be used with +io_mapping_map_atomic_wc(), io_mapping_map_local_wc() or +io_mapping_map_wc(). + +With this mapping object, individual pages can be mapped either temporarily +or long term, depending on the requirements. Of course, temporary maps are +more efficient. They come in two flavours:: -With this mapping object, individual pages can be mapped either atomically -or not, depending on the necessary scheduling environment. Of course, atomic -maps are more efficient:: + void *io_mapping_map_local_wc(struct io_mapping *mapping, + unsigned long offset) void *io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) -'offset' is the offset within the defined mapping region. -Accessing addresses beyond the region specified in the -creation function yields undefined results. Using an offset -which is not page aligned yields an undefined result. The -return value points to a single page in CPU address space. - -This _wc variant returns a write-combining map to the -page and may only be used with mappings created by -io_mapping_create_wc +'offset' is the offset within the defined mapping region. Accessing +addresses beyond the region specified in the creation function yields +undefined results. Using an offset which is not page aligned yields an +undefined result. The return value points to a single page in CPU address +space. -Note that the task may not sleep while holding this page -mapped. +This _wc variant returns a write-combining map to the page and may only be +used with mappings created by io_mapping_create_wc() -:: +Temporary mappings are only valid in the context of the caller. The mapping +is not guaranteed to be globaly visible. - void io_mapping_unmap_atomic(void *vaddr) +io_mapping_map_local_wc() has a side effect on X86 32bit as it disables +migration to make the mapping code work. No caller can rely on this side +effect. + +io_mapping_map_atomic_wc() has the side effect of disabling preemption and +pagefaults. Don't use in new code. Use io_mapping_map_local_wc() instead. -'vaddr' must be the value returned by the last -io_mapping_map_atomic_wc call. This unmaps the specified -page and allows the task to sleep once again. +Nested mappings need to be undone in reverse order because the mapping +code uses a stack for keeping track of them:: -If you need to sleep while holding the lock, you can use the non-atomic -variant, although they may be significantly slower. + addr1 = io_mapping_map_local_wc(map1, offset1); + addr2 = io_mapping_map_local_wc(map2, offset2); + ... + io_mapping_unmap_local(addr2); + io_mapping_unmap_local(addr1); -:: +The mappings are released with:: + + void io_mapping_unmap_local(void *vaddr) + void io_mapping_unmap_atomic(void *vaddr) + +'vaddr' must be the value returned by the last io_mapping_map_local_wc() or +io_mapping_map_atomic_wc() call. This unmaps the specified mapping and +undoes the side effects of the mapping functions. + +If you need to sleep while holding a mapping, you can use the regular +variant, although this may be significantly slower:: void *io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) -This works like io_mapping_map_atomic_wc except it allows -the task to sleep while holding the page mapped. - +This works like io_mapping_map_atomic/local_wc() except it has no side +effects and the pointer is globaly visible. -:: +The mappings are released with:: void io_mapping_unmap(void *vaddr) -This works like io_mapping_unmap_atomic, except it is used -for pages mapped with io_mapping_map_wc. +Use for pages mapped with io_mapping_map_wc(). At driver close time, the io_mapping object must be freed:: --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -83,6 +83,21 @@ io_mapping_unmap_atomic(void __iomem *va } static inline void __iomem * +io_ma
[patch V3 15/37] powerpc/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: Michael Ellerman
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: linuxppc-...@lists.ozlabs.org
---
V3: Remove the kmap types cruft
---
arch/powerpc/Kconfig |1
arch/powerpc/include/asm/fixmap.h |4 +-
arch/powerpc/include/asm/highmem.h|7 ++-
arch/powerpc/include/asm/kmap_types.h | 13 --
arch/powerpc/mm/Makefile |1
arch/powerpc/mm/highmem.c | 67 --
arch/powerpc/mm/mem.c |7 ---
7 files changed, 8 insertions(+), 92 deletions(-)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -409,6 +409,7 @@ menu "Kernel options"
config HIGHMEM
bool "High memory support"
depends on PPC32
+ select KMAP_LOCAL
source "kernel/Kconfig.hz"
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -20,7 +20,7 @@
#include
#ifdef CONFIG_HIGHMEM
#include
-#include
+#include
#endif
#ifdef CONFIG_KASAN
@@ -55,7 +55,7 @@ enum fixed_addresses {
FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+(ALIGN(SZ_128K,
PAGE_SIZE)/PAGE_SIZE)-1,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
- FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
+ FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
#endif
#ifdef CONFIG_PPC_8xx
/* For IMMR we need an aligned 512K area */
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -24,12 +24,10 @@
#ifdef __KERNEL__
#include
-#include
#include
#include
#include
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@@ -60,6 +58,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps()flush_cache_all()
+#define arch_kmap_local_post_map(vaddr, pteval)\
+ local_flush_tlb_page(NULL, vaddr)
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_page(NULL, vaddr)
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/powerpc/include/asm/kmap_types.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-#ifndef _ASM_POWERPC_KMAP_TYPES_H
-#define _ASM_POWERPC_KMAP_TYPES_H
-
-#ifdef __KERNEL__
-
-/*
- */
-
-#define KM_TYPE_NR 16
-
-#endif /* __KERNEL__ */
-#endif /* _ASM_POWERPC_KMAP_TYPES_H */
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -16,7 +16,6 @@ obj-$(CONFIG_NEED_MULTIPLE_NODES) += num
obj-$(CONFIG_PPC_MM_SLICES)+= slice.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_PPC_COPRO_BASE) += copro_fault.o
obj-$(CONFIG_PPC_PTDUMP) += ptdump/
obj-$(CONFIG_KASAN)+= kasan/
--- a/arch/powerpc/mm/highmem.c
+++ /dev/null
@@ -1,67 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * PowerPC version, stolen from the i386 version.
- *
- * Used in CONFIG_HIGHMEM systems for memory pages which
- * are not addressable by direct kernel virtual addresses.
- *
- * Copyright (C) 1999 Gerhard Wichert, Siemens AG
- * gerhard.wich...@pdb.siemens.de
- *
- *
- * Redesigned the x86 32-bit VM architecture to deal with
- * up to 16 Terrabyte physical memory. With current x86 CPUs
- * we now support up to 64 Gigabytes physical RAM.
- *
- * Copyright (C) 1999 Ingo Molnar
- *
- * Reworked for PowerPC by various contributors. Moved from
- * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
- */
-
-#include
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- WARN_ON(IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !pte_none(*(kmap_pte -
idx)));
- __set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
- local_flush_tlb_page(NULL, vaddr);
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr < __fix_to_virt(FIX_KMAP_END))
- return;
-
- if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
- int type = kmap_atomic_idx();
- unsigned int idx;
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr,
[patch V3 01/37] mm/highmem: Un-EXPORT __kmap_atomic_idx()
Nothing in modules can use that.
Signed-off-by: Thomas Gleixner
Reviewed-by: Christoph Hellwig
Cc: Andrew Morton
Cc: linux...@kvack.org
---
mm/highmem.c |2 --
1 file changed, 2 deletions(-)
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -108,8 +108,6 @@ static inline wait_queue_head_t *get_pkm
atomic_long_t _totalhigh_pages __read_mostly;
EXPORT_SYMBOL(_totalhigh_pages);
-EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
-
unsigned int nr_free_highpages (void)
{
struct zone *zone;
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[patch V3 02/37] highmem: Remove unused functions
Nothing uses totalhigh_pages_dec() and totalhigh_pages_set().
Signed-off-by: Thomas Gleixner
---
V3: New patch
---
include/linux/highmem.h | 10 --
1 file changed, 10 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -104,21 +104,11 @@ static inline void totalhigh_pages_inc(v
atomic_long_inc(&_totalhigh_pages);
}
-static inline void totalhigh_pages_dec(void)
-{
- atomic_long_dec(&_totalhigh_pages);
-}
-
static inline void totalhigh_pages_add(long count)
{
atomic_long_add(count, &_totalhigh_pages);
}
-static inline void totalhigh_pages_set(long val)
-{
- atomic_long_set(&_totalhigh_pages, val);
-}
-
void kmap_flush_unused(void);
struct page *kmap_to_page(void *addr);
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[patch V3 05/37] asm-generic: Provide kmap_size.h
kmap_types.h is a misnomer because the old atomic MAP based array does not exist anymore and the whole indirection of architectures including kmap_types.h is inconinstent and does not allow to provide guard page debugging for this misfeature. Add a common header file which defines the mapping stack size for all architectures. Will be used when converting architectures over to a generic kmap_local/atomic implementation. The array size is chosen with the following constraints in mind: - The deepest nest level in one context is 3 according to code inspection. - The worst case nesting for the upcoming reemptible version would be: 2 maps in task context and a fault inside 2 maps in the fault handler 3 maps in softirq 2 maps in interrupt So a total of 16 is sufficient and probably overestimated. Signed-off-by: Thomas Gleixner --- V3: New patch --- include/asm-generic/Kbuild |1 + include/asm-generic/kmap_size.h | 12 2 files changed, 13 insertions(+) --- a/include/asm-generic/Kbuild +++ b/include/asm-generic/Kbuild @@ -31,6 +31,7 @@ mandatory-y += irq_regs.h mandatory-y += irq_work.h mandatory-y += kdebug.h mandatory-y += kmap_types.h +mandatory-y += kmap_size.h mandatory-y += kprobes.h mandatory-y += linkage.h mandatory-y += local.h --- /dev/null +++ b/include/asm-generic/kmap_size.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_KMAP_SIZE_H +#define _ASM_GENERIC_KMAP_SIZE_H + +/* For debug this provides guard pages between the maps */ +#ifdef CONFIG_DEBUG_HIGHMEM +# define KM_MAX_IDX33 +#else +# define KM_MAX_IDX16 +#endif + +#endif ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Thu, Oct 29 2020 at 23:18, Thomas Gleixner wrote: > > There is also a still to be investigated question from Linus on the initial > posting versus the per cpu / per task mapping stack depth which might need > to be made larger due to the ability to take page faults within a mapping > region. I looked deeper into that and we have a stack depth of 20. That's plenty and I couldn't find a way to get above 10 nested ones including faults, interrupts, softirqs. With some stress testing I was not able to get over a maximum of 6 according to the traceprintk I added. For some obscure reason when CONFIG_DEBUG_HIGHMEM is enabled the stack depth is increased from 20 to 41. But the only thing DEBUG_HIGHMEM does is to enable a few BUG_ON()'s in the mapping code. That's a leftover from the historical mapping code which had fixed entries for various purposes. DEBUG_HIGHMEM inserted guard mappings between the map types. But that got all ditched when kmap_atomic() switched to a stack based map management. Though the WITH_KM_FENCE magic survived without being functional. All the thing does today is to increase the stack depth. I just made that functional again by keeping the stack depth increase and utilizing every second slot. That should catch Willy's mapping problem nicely if he bothers to test on 32bit :) Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Sat, Oct 31 2020 at 00:26, Thomas Gleixner wrote: > On Fri, Oct 30 2020 at 15:46, Linus Torvalds wrote: >> On Fri, Oct 30, 2020 at 3:26 PM Thomas Gleixner wrote: >> To me, your patch series has two big advantages: >> >> - more common code >> >> - kmap_local() becomes more of a no-op >> >> and the last thing we want is to expand on kmap. > > Happy to go with that. > > While trying to document the mess, I just stumbled over the abuse of > kmap_atomic_prot() in > > drivers/gpu/drm/ttm/ttm_bo_util.c: dst = kmap_atomic_prot(d, prot); > drivers/gpu/drm/ttm/ttm_bo_util.c: src = kmap_atomic_prot(s, prot); > drivers/gpu/drm/vmwgfx/vmwgfx_blit.c: > kmap_atomic_prot(d->dst_pages[dst_page], > drivers/gpu/drm/vmwgfx/vmwgfx_blit.c: > kmap_atomic_prot(d->src_pages[src_page], > > For !HIGHMEM kmap_atomic_prot() just ignores the 'prot' argument and > returns the page address. > > Moar patches to be written ... Sigh! Or not. This is actually correct by some definition of correct. For the non highmem case pgprot is set via the set_memory_*() functions and this just handles the highmem case. Comments are overrrated... ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Fri, Oct 30 2020 at 15:46, Linus Torvalds wrote: > On Fri, Oct 30, 2020 at 3:26 PM Thomas Gleixner wrote: > To me, your patch series has two big advantages: > > - more common code > > - kmap_local() becomes more of a no-op > > and the last thing we want is to expand on kmap. Happy to go with that. While trying to document the mess, I just stumbled over the abuse of kmap_atomic_prot() in drivers/gpu/drm/ttm/ttm_bo_util.c: dst = kmap_atomic_prot(d, prot); drivers/gpu/drm/ttm/ttm_bo_util.c: src = kmap_atomic_prot(s, prot); drivers/gpu/drm/vmwgfx/vmwgfx_blit.c: kmap_atomic_prot(d->dst_pages[dst_page], drivers/gpu/drm/vmwgfx/vmwgfx_blit.c: kmap_atomic_prot(d->src_pages[src_page], For !HIGHMEM kmap_atomic_prot() just ignores the 'prot' argument and returns the page address. Moar patches to be written ... Sigh! Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Fri, Oct 30 2020 at 13:28, Linus Torvalds wrote:
> On Fri, Oct 30, 2020 at 2:39 AM Thomas Gleixner wrote:
>>
>> But then we really should not name it kmap_local. 'local' suggests
>> locality, think local_irq*, local_bh* ... kmap_task would be more
>> accurate then.
>
> So the main reason I'd like to see it is because I think on a
> non-highmem machine, the new kmap should be a complete no-op. IOW,
> we'd make sure that there are no costs, no need to increment any
> "restrict migration" counts etc.
Fair enough.
> It's been a bit of a pain to have kmap_atomic() have magical side
> semantics that people might then depend on.
kmap_atomic() will still have the side semantics :)
> I think "local" could still work as a name, because it would have to
> be thread-local (and maybe we'd want a debug mode where that gets
> verified, as actual HIGHMEM machines are getting rare).
>
> I'd avoid "task", because that implies (to me, at least) that it
> wouldn't be good for interrupts etc that don't have a task context.
>
> I think the main issue is that it has to be released in the same
> context as it was created (ie no passing those things around to other
> contexts). I think "local" is fine for that, but I could imagine other
> names. The ones that come to mind are somewhat cumbersome, though
> ("shortterm" or "local_ctx" or something along those lines).
Yeah, not really intuitive either.
Let's stick with _local and add proper function documentation which
clearly says, that the side effect of non-migratability applies only for
the 32bit highmem case in order to make it work at all.
So code which needs CPU locality cannot rely on it and we have enough
debug stuff to catch something like:
kmap_local()
this_cpu_write()
kunmap_local()
Let me redo the pile.
While at it I might have a look at that debug request from Willy in the
other end of this thread. Any comment on that?
https://lore.kernel.org/r/87k0v7mrrd@nanos.tec.linutronix.de
Thanks,
tglx
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Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Fri, Oct 30 2020 at 13:06, Matthew Wilcox wrote: > On Thu, Oct 29, 2020 at 11:18:06PM +0100, Thomas Gleixner wrote: >> This series provides kmap_local.* iomap_local variants which only disable >> migration to keep the virtual mapping address stable accross preemption, >> but do neither disable pagefaults nor preemption. The new functions can be >> used in any context, but if used in atomic context the caller has to take >> care of eventually disabling pagefaults. > > Could I ask for a CONFIG_KMAP_DEBUG which aliases all the kmap variants > to vmap()? I think we currently have a problem in iov_iter on HIGHMEM > configs: For kmap() that would work, but for kmap_atomic() not so much when it is called in non-preemptible context because vmap() might sleep. > copy_page_to_iter() calls page_copy_sane() which checks: > > head = compound_head(page); > if (likely(n <= v && v <= page_size(head))) > return true; > > but then: > > void *kaddr = kmap_atomic(page); > size_t wanted = copy_to_iter(kaddr + offset, bytes, i); > kunmap_atomic(kaddr); > > so if offset to offset+bytes is larger than PAGE_SIZE, this is going to > work for lowmem pages and fail miserably for highmem pages. I suggest > vmap() because vmap has a PAGE_SIZE gap between each allocation. On 32bit highmem the kmap_atomic() case is easy: Double the number of mapping slots and only use every second one, which gives you a guard page between the maps. For 64bit we could do something ugly: Enable the highmem kmap_atomic() crud and enforce an alias mapping (at least on the architectures where this is reasonable). Then you get the same as for 32bit. > Alternatively if we could have a kmap_atomic_compound(), that would > be awesome, but probably not realistic to implement. I've more > or less resigned myself to having to map things one page at a time. That might be horribly awesome on 32bit :) Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Fri, Oct 30 2020 at 00:41, Thomas Gleixner wrote: > On Thu, Oct 29 2020 at 16:11, Linus Torvalds wrote: > No, you're not misreading it, but doing it conditionally would be a > complete semantical disaster. kmap_atomic*() also disables preemption > and pagefaults unconditionaly. If that wouldn't be the case then every > caller would have to have conditionals like 'if (CONFIG_HIGHMEM)' or > worse 'if (PageHighMem(page)'. > > Let's not go there. > > Migrate disable is a less horrible plague than preempt and pagefault > disable even if the scheduler people disagree due to the lack of theory > backing that up :) > > The charm of the new interface is that users still can rely on per > cpuness independent of being on a highmem plagued system. For non > highmem systems the extra migrate disable/enable is really a minor > nuissance. thinking about it some more after having sleep and coffee, we actually could hide the migrate disable in the actual highmem part. But then we really should not name it kmap_local. 'local' suggests locality, think local_irq*, local_bh* ... kmap_task would be more accurate then. Toughts? tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Fri, Oct 30 2020 at 08:25, Christoph Hellwig wrote: > On Thu, Oct 29, 2020 at 11:18:06PM +0100, Thomas Gleixner wrote: >> - Consolidating all kmap atomic implementations in generic code > > I think the consolidation is a winner no matter where we go next. Maybe > split it out in a prep series so we can get it in ASAP? Yes, patch 2-15 can just go without any dependency. The only thing which needs a bit of thought is naming. See the other reply to Linus. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
On Thu, Oct 29 2020 at 16:11, Linus Torvalds wrote: > On Thu, Oct 29, 2020 at 3:32 PM Thomas Gleixner wrote: >> >> Though I wanted to share the current state of affairs before investigating >> that further. If there is consensus in going forward with this, I'll have a >> deeper look into this issue. > > Me likee. I think this looks like the right thing to do. > > I didn't actually apply the patches, but just from reading them it > _looks_ to me like you do the migrate_disable() unconditionally, even > if it's not a highmem page.. > > That sounds like it might be a good thing for debugging, but not > necessarily great in general. > > Or am I misreading things? No, you're not misreading it, but doing it conditionally would be a complete semantical disaster. kmap_atomic*() also disables preemption and pagefaults unconditionaly. If that wouldn't be the case then every caller would have to have conditionals like 'if (CONFIG_HIGHMEM)' or worse 'if (PageHighMem(page)'. Let's not go there. Migrate disable is a less horrible plague than preempt and pagefault disable even if the scheduler people disagree due to the lack of theory backing that up :) The charm of the new interface is that users still can rely on per cpuness independent of being on a highmem plagued system. For non highmem systems the extra migrate disable/enable is really a minor nuissance. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch V2 12/18] sparc/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: "David S. Miller"
Cc: sparcli...@vger.kernel.org
---
arch/sparc/Kconfig |1
arch/sparc/include/asm/highmem.h |7 +-
arch/sparc/mm/Makefile |3 -
arch/sparc/mm/highmem.c | 115 ---
arch/sparc/mm/srmmu.c|2
5 files changed, 6 insertions(+), 122 deletions(-)
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -139,6 +139,7 @@ config MMU
config HIGHMEM
bool
default y if SPARC32
+select KMAP_LOCAL
config ZONE_DMA
bool
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -33,8 +33,6 @@ extern unsigned long highstart_pfn, high
#define kmap_prot __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE)
extern pte_t *pkmap_page_table;
-void kmap_init(void) __init;
-
/*
* Right now we initialize only a single pte table. It can be extended
* easily, subsequent pte tables have to be allocated in one physical
@@ -53,6 +51,11 @@ void kmap_init(void) __init;
#define flush_cache_kmaps()flush_cache_all()
+/* FIXME: Use __flush_tlb_one(vaddr) instead of flush_cache_all() -- Anton */
+#define arch_kmap_local_post_map(vaddr, pteval)flush_cache_all()
+#define arch_kmap_local_post_unmap(vaddr) flush_cache_all()
+
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/sparc/mm/Makefile
+++ b/arch/sparc/mm/Makefile
@@ -15,6 +15,3 @@ obj-$(CONFIG_SPARC32) += leon_mm.o
# Only used by sparc64
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
-
-# Only used by sparc32
-obj-$(CONFIG_HIGHMEM) += highmem.o
--- a/arch/sparc/mm/highmem.c
+++ /dev/null
@@ -1,115 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * Provides kernel-static versions of atomic kmap functions originally
- * found as inlines in include/asm-sparc/highmem.h. These became
- * needed as kmap_atomic() and kunmap_atomic() started getting
- * called from within modules.
- * -- Tomas Szepe , September 2002
- *
- * But kmap_atomic() and kunmap_atomic() cannot be inlined in
- * modules because they are loaded with btfixup-ped functions.
- */
-
-/*
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need it.
- *
- * XXX This is an old text. Actually, it's good to use atomic kmaps,
- * provided you remember that they are atomic and not try to sleep
- * with a kmap taken, much like a spinlock. Non-atomic kmaps are
- * shared by CPUs, and so precious, and establishing them requires IPI.
- * Atomic kmaps are lightweight and we may have NCPUS more of them.
- */
-#include
-#include
-#include
-
-#include
-#include
-#include
-
-static pte_t *kmap_pte;
-
-void __init kmap_init(void)
-{
- unsigned long address = __fix_to_virt(FIX_KMAP_BEGIN);
-
-/* cache the first kmap pte */
-kmap_pte = virt_to_kpte(address);
-}
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- long idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-
-/* XXX Fix - Anton */
-#if 0
- __flush_cache_one(vaddr);
-#else
- flush_cache_all();
-#endif
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte-idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
-/* XXX Fix - Anton */
-#if 0
- __flush_tlb_one(vaddr);
-#else
- flush_tlb_all();
-#endif
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type;
-
- if (vaddr < FIXADDR_START)
- return;
-
- type = kmap_atomic_idx();
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- {
- unsigned long idx;
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
-
- /* XXX Fix - Anton */
-#if 0
- __flush_cache_one(vaddr);
-#else
- flush_cache_all();
-#endif
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- /* XXX Fix - Anton */
-#if 0
- __flush_tlb_one(vaddr);
-#else
- flush_tlb_all();
-#endif
- }
-#endif
-
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -971,8 +971,6 @@ void __init srmmu_paging_init(void)
[patch V2 13/18] xtensa/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: Chris Zankel
Cc: Max Filippov
Cc: linux-xte...@linux-xtensa.org
---
arch/xtensa/Kconfig |1
arch/xtensa/include/asm/highmem.h |9 +++
arch/xtensa/mm/highmem.c | 44 +++---
3 files changed, 14 insertions(+), 40 deletions(-)
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -666,6 +666,7 @@ endchoice
config HIGHMEM
bool "High Memory Support"
depends on MMU
+select KMAP_LOCAL
help
Linux can use the full amount of RAM in the system by
default. However, the default MMUv2 setup only maps the
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -68,6 +68,15 @@ static inline void flush_cache_kmaps(voi
flush_cache_all();
}
+enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn);
+#define arch_kmap_local_map_idxkmap_local_map_idx
+
+enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr);
+#define arch_kmap_local_unmap_idx kmap_local_unmap_idx
+
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)
+
void kmap_init(void);
#endif
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -12,8 +12,6 @@
#include
#include
-static pte_t *kmap_pte;
-
#if DCACHE_WAY_SIZE > PAGE_SIZE
unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
@@ -37,55 +35,21 @@ static inline enum fixed_addresses kmap_
color;
}
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
+enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn)
{
- enum fixed_addresses idx;
- unsigned long vaddr;
-
- idx = kmap_idx(kmap_atomic_idx_push(),
- DCACHE_ALIAS(page_to_phys(page)));
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte + idx)));
-#endif
- set_pte(kmap_pte + idx, mk_pte(page, prot));
-
- return (void *)vaddr;
+ return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT);
}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-void kunmap_atomic_high(void *kvaddr)
+enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr)
{
- if (kvaddr >= (void *)FIXADDR_START &&
- kvaddr < (void *)FIXADDR_TOP) {
- int idx = kmap_idx(kmap_atomic_idx(),
- DCACHE_ALIAS((unsigned long)kvaddr));
-
- /*
-* Force other mappings to Oops if they'll try to access this
-* pte without first remap it. Keeping stale mappings around
-* is a bad idea also, in case the page changes cacheability
-* attributes or becomes a protected page in a hypervisor.
-*/
- pte_clear(&init_mm, kvaddr, kmap_pte + idx);
- local_flush_tlb_kernel_range((unsigned long)kvaddr,
-(unsigned long)kvaddr + PAGE_SIZE);
-
- kmap_atomic_idx_pop();
- }
+ return kmap_idx(type, DCACHE_ALIAS(addr));
}
-EXPORT_SYMBOL(kunmap_atomic_high);
void __init kmap_init(void)
{
- unsigned long kmap_vstart;
-
/* Check if this memory layout is broken because PKMAP overlaps
* page table.
*/
BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
- /* cache the first kmap pte */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = virt_to_kpte(kmap_vstart);
kmap_waitqueues_init();
}
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[patch V2 15/18] io-mapping: Cleanup atomic iomap
Switch the atomic iomap implementation over to kmap_local and stick the
preempt/pagefault mechanics into the generic code similar to the
kmap_atomic variants.
Rename the x86 map function in preparation for a non-atomic variant.
Signed-off-by: Thomas Gleixner
---
V2: New patch to make review easier
---
arch/x86/include/asm/iomap.h |9 +
arch/x86/mm/iomap_32.c |6 ++
include/linux/io-mapping.h |8 ++--
3 files changed, 9 insertions(+), 14 deletions(-)
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -13,14 +13,7 @@
#include
#include
-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
-
-static inline void iounmap_atomic(void __iomem *vaddr)
-{
- kunmap_local_indexed((void __force *)vaddr);
- pagefault_enable();
- preempt_enable();
-}
+void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -44,7 +44,7 @@ void iomap_free(resource_size_t base, un
}
EXPORT_SYMBOL_GPL(iomap_free);
-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot)
+void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
{
/*
* For non-PAT systems, translate non-WB request to UC- just in
@@ -60,8 +60,6 @@ void __iomem *iomap_atomic_pfn_prot(unsi
/* Filter out unsupported __PAGE_KERNEL* bits: */
pgprot_val(prot) &= __default_kernel_pte_mask;
- preempt_disable();
- pagefault_disable();
return (void __force __iomem *)__kmap_local_pfn_prot(pfn, prot);
}
-EXPORT_SYMBOL_GPL(iomap_atomic_pfn_prot);
+EXPORT_SYMBOL_GPL(__iomap_local_pfn_prot);
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -69,13 +69,17 @@ io_mapping_map_atomic_wc(struct io_mappi
BUG_ON(offset >= mapping->size);
phys_addr = mapping->base + offset;
- return iomap_atomic_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
+ preempt_disable();
+ pagefault_disable();
+ return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
}
static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
- iounmap_atomic(vaddr);
+ kunmap_local_indexed((void __force *)vaddr);
+ pagefault_enable();
+ preempt_enable();
}
static inline void __iomem *
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[patch V2 17/18] mm/highmem: Provide kmap_local*
Now that the kmap atomic index is stored in task struct provide a
preemptible variant. On context switch the maps of an outgoing task are
removed and the map of the incoming task are restored. That's obviously
slow, but highmem is slow anyway.
The kmap_local.*() functions can be invoked from both preemptible and
atomic context. kmap local sections disable migration to keep the resulting
virtual mapping address correct, but disable neither pagefaults nor
preemption.
A wholesale conversion of kmap_atomic to be fully preemptible is not
possible because some of the usage sites might rely on the preemption
disable for serialization or on the implicit pagefault disable. Needs to be
done on a case by case basis.
Signed-off-by: Thomas Gleixner
---
V2: Make it more consistent and add commentry
---
include/linux/highmem.h | 115 +---
1 file changed, 100 insertions(+), 15 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -86,17 +86,56 @@ static inline void kunmap(struct page *p
}
/*
- * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
- * no global lock is needed and because the kmap code must perform a global TLB
- * invalidation when the kmap pool wraps.
- *
- * However when holding an atomic kmap it is not legal to sleep, so atomic
- * kmaps are appropriate for short, tight code paths only.
- *
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need
- * it.
+ * For highmem systems it is required to temporarily map pages
+ * which reside in the portion of memory which is not covered
+ * by the permanent kernel mapping.
+ *
+ * This comes in three flavors:
+ *
+ * 1) kmap/kunmap:
+ *
+ *An interface to acquire longer term mappings with no restrictions
+ *on preemption and migration. This comes with an overhead as the
+ *mapping space is restricted and protected by a global lock. It
+ *also requires global TLB invalidation when the kmap pool wraps.
+ *
+ *kmap() might block when the mapping space is fully utilized until a
+ *slot becomes available. Only callable from preemptible thread
+ *context.
+ *
+ * 2) kmap_local.*()/kunmap_local.*()
+ *
+ *An interface to acquire short term mappings. Can be invoked from any
+ *context including interrupts. The mapping is per thread, CPU local
+ *and not globaly visible. It can only be used in the context which
+ *acquried the mapping. Nesting kmap_local.*() and kmap_atomic.*()
+ *mappings is allowed to a certain extent (up to KMAP_TYPE_NR).
+ *
+ *Nested kmap_local.*() and kunmap_local.*() invocations have to be
+ *strictly ordered because the map implementation is stack based.
+ *
+ *kmap_local.*() disables migration, but keeps preemption enabled. It's
+ *valid to take pagefaults in a kmap_local region unless the context in
+ *which the local kmap is acquired does not allow it for other reasons.
+ *
+ *If a task holding local kmaps is preempted, the maps are removed on
+ *context switch and restored when the task comes back on the CPU. As
+ *the maps are strictly CPU local it is guaranteed that the task stays
+ *on the CPU and the CPU cannot be unplugged until the local kmaps are
+ *released.
+ *
+ * 3) kmap_atomic.*()/kunmap_atomic.*()
+ *
+ *Based on the same mechanism as kmap local. Atomic kmap disables
+ *preemption and pagefaults. Only use if absolutely required, use
+ *the corresponding kmap_local variant if possible.
+ *
+ * Local and atomic kmaps are faster than kmap/kunmap, but impose
+ * restrictions. Only use them when required.
+ *
+ * For !HIGHMEM enabled systems the kmap flavours are not doing any mapping
+ * operation and kmap() won't sleep, but the kmap local and atomic variants
+ * still disable migration resp. pagefaults and preemption.
*/
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
@@ -122,6 +161,28 @@ static inline void __kunmap_atomic(void
kunmap_local_indexed(addr);
}
+static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
+{
+ migrate_disable();
+ return __kmap_local_page_prot(page, prot);
+}
+
+static inline void *kmap_local_page(struct page *page)
+{
+ return kmap_local_page_prot(page, kmap_prot);
+}
+
+static inline void *kmap_local_pfn(unsigned long pfn)
+{
+ migrate_disable();
+ return __kmap_local_pfn_prot(pfn, kmap_prot);
+}
+
+static inline void __kunmap_local(void *vaddr)
+{
+ kunmap_local_indexed(vaddr);
+}
+
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;
@@ -201,10 +262,27 @@ static inline void *kmap_atomic_pfn(unsi
static inline void __kunmap_atomic(void *addr)
{
- /*
-* Mostly nothi
[patch V2 11/18] powerpc/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: Michael Ellerman
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: linuxppc-...@lists.ozlabs.org
---
arch/powerpc/Kconfig |1
arch/powerpc/include/asm/highmem.h |6 ++-
arch/powerpc/mm/Makefile |1
arch/powerpc/mm/highmem.c | 67 -
arch/powerpc/mm/mem.c |7 ---
5 files changed, 6 insertions(+), 76 deletions(-)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -409,6 +409,7 @@ menu "Kernel options"
config HIGHMEM
bool "High memory support"
depends on PPC32
+select KMAP_LOCAL
source "kernel/Kconfig.hz"
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -29,7 +29,6 @@
#include
#include
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@@ -60,6 +59,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps()flush_cache_all()
+#define arch_kmap_local_post_map(vaddr, pteval)\
+ local_flush_tlb_page(NULL, vaddr)
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_page(NULL, vaddr)
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -16,7 +16,6 @@ obj-$(CONFIG_NEED_MULTIPLE_NODES) += num
obj-$(CONFIG_PPC_MM_SLICES)+= slice.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_PPC_COPRO_BASE) += copro_fault.o
obj-$(CONFIG_PPC_PTDUMP) += ptdump/
obj-$(CONFIG_KASAN)+= kasan/
--- a/arch/powerpc/mm/highmem.c
+++ /dev/null
@@ -1,67 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * PowerPC version, stolen from the i386 version.
- *
- * Used in CONFIG_HIGHMEM systems for memory pages which
- * are not addressable by direct kernel virtual addresses.
- *
- * Copyright (C) 1999 Gerhard Wichert, Siemens AG
- * gerhard.wich...@pdb.siemens.de
- *
- *
- * Redesigned the x86 32-bit VM architecture to deal with
- * up to 16 Terrabyte physical memory. With current x86 CPUs
- * we now support up to 64 Gigabytes physical RAM.
- *
- * Copyright (C) 1999 Ingo Molnar
- *
- * Reworked for PowerPC by various contributors. Moved from
- * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
- */
-
-#include
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- WARN_ON(IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !pte_none(*(kmap_pte -
idx)));
- __set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
- local_flush_tlb_page(NULL, vaddr);
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr < __fix_to_virt(FIX_KMAP_END))
- return;
-
- if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
- int type = kmap_atomic_idx();
- unsigned int idx;
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_page(NULL, vaddr);
- }
-
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -61,11 +61,6 @@
unsigned long long memory_limit;
bool init_mem_is_free;
-#ifdef CONFIG_HIGHMEM
-pte_t *kmap_pte;
-EXPORT_SYMBOL(kmap_pte);
-#endif
-
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
@@ -235,8 +230,6 @@ void __init paging_init(void)
map_kernel_page(PKMAP_BASE, 0, __pgprot(0));/* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
-
- kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
#endif /* CONFIG_HIGHMEM */
printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
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[patch V2 18/18] io-mapping: Provide iomap_local variant
Similar to kmap local provide a iomap local variant which only disables
migration, but neither disables pagefaults nor preemption.
Signed-off-by: Thomas Gleixner
---
V2: Split out from the large combo patch and add the !IOMAP_ATOMIC variants
---
include/linux/io-mapping.h | 34 --
1 file changed, 32 insertions(+), 2 deletions(-)
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -83,6 +83,23 @@ io_mapping_unmap_atomic(void __iomem *va
}
static inline void __iomem *
+io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset)
+{
+ resource_size_t phys_addr;
+
+ BUG_ON(offset >= mapping->size);
+ phys_addr = mapping->base + offset;
+ migrate_disable();
+ return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
+}
+
+static inline void io_mapping_unmap_local(void __iomem *vaddr)
+{
+ kunmap_local_indexed((void __force *)vaddr);
+ migrate_enable();
+}
+
+static inline void __iomem *
io_mapping_map_wc(struct io_mapping *mapping,
unsigned long offset,
unsigned long size)
@@ -101,7 +118,7 @@ io_mapping_unmap(void __iomem *vaddr)
iounmap(vaddr);
}
-#else
+#else /* HAVE_ATOMIC_IOMAP */
#include
@@ -166,7 +183,20 @@ io_mapping_unmap_atomic(void __iomem *va
preempt_enable();
}
-#endif /* HAVE_ATOMIC_IOMAP */
+static inline void __iomem *
+io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset)
+{
+ migrate_disable();
+ return io_mapping_map_wc(mapping, offset, PAGE_SIZE);
+}
+
+static inline void io_mapping_unmap_local(void __iomem *vaddr)
+{
+ io_mapping_unmap(vaddr);
+ migrate_enable();
+}
+
+#endif /* !HAVE_ATOMIC_IOMAP */
static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base,
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[patch V2 14/18] mm/highmem: Remove the old kmap_atomic cruft
All users gone.
Signed-off-by: Thomas Gleixner
---
include/linux/highmem.h | 61 ++--
mm/highmem.c| 28 ++
2 files changed, 27 insertions(+), 62 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -88,31 +88,16 @@ static inline void kunmap(struct page *p
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
-
-#ifndef CONFIG_KMAP_LOCAL
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-void kunmap_atomic_high(void *kvaddr);
-
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
- return kmap_atomic_high_prot(page, prot);
-}
-
-static inline void __kunmap_atomic(void *vaddr)
-{
- kunmap_atomic_high(vaddr);
+ return __kmap_local_page_prot(page, prot);
}
-#else /* !CONFIG_KMAP_LOCAL */
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+static inline void *kmap_atomic(struct page *page)
{
- preempt_disable();
- pagefault_disable();
- return __kmap_local_page_prot(page, prot);
+ return kmap_atomic_prot(page, kmap_prot);
}
static inline void *kmap_atomic_pfn(unsigned long pfn)
@@ -127,13 +112,6 @@ static inline void __kunmap_atomic(void
kunmap_local_indexed(addr);
}
-#endif /* CONFIG_KMAP_LOCAL */
-
-static inline void *kmap_atomic(struct page *page)
-{
- return kmap_atomic_prot(page, kmap_prot);
-}
-
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;
@@ -226,39 +204,6 @@ static inline void __kunmap_atomic(void
#endif /* CONFIG_HIGHMEM */
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
-
-DECLARE_PER_CPU(int, __kmap_atomic_idx);
-
-static inline int kmap_atomic_idx_push(void)
-{
- int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(in_irq() && !irqs_disabled());
- BUG_ON(idx >= KM_TYPE_NR);
-#endif
- return idx;
-}
-
-static inline int kmap_atomic_idx(void)
-{
- return __this_cpu_read(__kmap_atomic_idx) - 1;
-}
-
-static inline void kmap_atomic_idx_pop(void)
-{
-#ifdef CONFIG_DEBUG_HIGHMEM
- int idx = __this_cpu_dec_return(__kmap_atomic_idx);
-
- BUG_ON(idx < 0);
-#else
- __this_cpu_dec(__kmap_atomic_idx);
-#endif
-}
-
-#endif
-
/*
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -32,10 +32,6 @@
#include
#include
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
-DEFINE_PER_CPU(int, __kmap_atomic_idx);
-#endif
-
/*
* Virtual_count is not a pure "count".
* 0 means that it is not mapped, and has not been mapped
@@ -370,6 +366,30 @@ EXPORT_SYMBOL(kunmap_high);
#endif /* CONFIG_HIGHMEM */
#ifdef CONFIG_KMAP_LOCAL
+
+static DEFINE_PER_CPU(int, __kmap_atomic_idx);
+
+static inline int kmap_atomic_idx_push(void)
+{
+ int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
+
+ WARN_ON_ONCE(in_irq() && !irqs_disabled());
+ BUG_ON(idx >= KM_TYPE_NR);
+ return idx;
+}
+
+static inline int kmap_atomic_idx(void)
+{
+ return __this_cpu_read(__kmap_atomic_idx) - 1;
+}
+
+static inline void kmap_atomic_idx_pop(void)
+{
+ int idx = __this_cpu_dec_return(__kmap_atomic_idx);
+
+ BUG_ON(idx < 0);
+}
+
#ifndef arch_kmap_local_post_map
# define arch_kmap_local_post_map(vaddr, pteval) do { } while (0)
#endif
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[patch V2 09/18] mips/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture
Signed-off-by: Thomas Gleixner
Cc: Thomas Bogendoerfer
Cc: linux-m...@vger.kernel.org
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 8f328298f8cc..ed6b3de944a8 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2654,6 +2654,7 @@ config MIPS_CRC_SUPPORT
config HIGHMEM
bool "High Memory Support"
depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM &&
!CPU_MIPS32_3_5_EVA
+ select KMAP_LOCAL
config CPU_SUPPORTS_HIGHMEM
bool
diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h
index f1f788b57166..cb2e0fb8483b 100644
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -48,11 +48,11 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps()BUG_ON(cpu_has_dc_aliases)
-extern void kmap_init(void);
+#define arch_kmap_local_post_map(vaddr, pteval)
local_flush_tlb_one(vaddr)
+#define arch_kmap_local_post_unmap(vaddr) local_flush_tlb_one(vaddr)
#endif /* __KERNEL__ */
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index 5fec7f45d79a..57e2f08f00d0 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -8,8 +8,6 @@
#include
#include
-static pte_t *kmap_pte;
-
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@@ -17,78 +15,3 @@ void kmap_flush_tlb(unsigned long addr)
flush_tlb_one(addr);
}
EXPORT_SYMBOL(kmap_flush_tlb);
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte - idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- local_flush_tlb_one((unsigned long)vaddr);
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type __maybe_unused;
-
- if (vaddr < FIXADDR_START)
- return;
-
- type = kmap_atomic_idx();
-#ifdef CONFIG_DEBUG_HIGHMEM
- {
- int idx = type + KM_TYPE_NR * smp_processor_id();
-
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_one(vaddr);
- }
-#endif
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- unsigned long vaddr;
- int idx, type;
-
- preempt_disable();
- pagefault_disable();
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
- flush_tlb_one(vaddr);
-
- return (void*) vaddr;
-}
-
-void __init kmap_init(void)
-{
- unsigned long kmap_vstart;
-
- /* cache the first kmap pte */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = virt_to_kpte(kmap_vstart);
-}
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 6c7bbfe35ba3..e5de8e9c2ede 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -402,9 +402,6 @@ void __init paging_init(void)
pagetable_init();
-#ifdef CONFIG_HIGHMEM
- kmap_init();
-#endif
#ifdef CONFIG_ZONE_DMA
max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
#endif
___
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[patch V2 16/18] sched: highmem: Store local kmaps in task struct
Instead of storing the map per CPU provide and use per task storage. That
prepares for local kmaps which are preemptible.
The context switch code is preparatory and not yet in use because
kmap_atomic() runs with preemption disabled. Will be made usable in the
next step.
The context switch logic is safe even when an interrupt happens after
clearing or before restoring the kmaps. The kmap index in task struct is
not modified so any nesting kmap in an interrupt will use unused indices
and on return the counter is the same as before.
Also add an assert into the return to user space code. Going back to user
space with an active kmap local is a nono.
Signed-off-by: Thomas Gleixner
---
include/linux/highmem.h | 10 +
include/linux/sched.h |9
kernel/entry/common.c |2 +
kernel/fork.c |1
kernel/sched/core.c | 18 +
mm/highmem.c| 96 +---
6 files changed, 123 insertions(+), 13 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -38,6 +38,16 @@ static inline void invalidate_kernel_vma
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
void kunmap_local_indexed(void *vaddr);
+void kmap_local_fork(struct task_struct *tsk);
+void __kmap_local_sched_out(void);
+void __kmap_local_sched_in(void);
+static inline void kmap_assert_nomap(void)
+{
+ DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
+}
+#else
+static inline void kmap_local_fork(struct task_struct *tsk) { }
+static inline void kmap_assert_nomap(void) { }
#endif
#ifdef CONFIG_HIGHMEM
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -34,6 +34,7 @@
#include
#include
#include
+#include
/* task_struct member predeclarations (sorted alphabetically): */
struct audit_context;
@@ -629,6 +630,13 @@ struct wake_q_node {
struct wake_q_node *next;
};
+struct kmap_ctrl {
+#ifdef CONFIG_KMAP_LOCAL
+ int idx;
+ pte_t pteval[KM_TYPE_NR];
+#endif
+};
+
struct task_struct {
#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
@@ -1294,6 +1302,7 @@ struct task_struct {
unsigned intsequential_io;
unsigned intsequential_io_avg;
#endif
+ struct kmap_ctrlkmap_ctrl;
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
unsigned long task_state_change;
#endif
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -2,6 +2,7 @@
#include
#include
+#include
#include
#include
@@ -194,6 +195,7 @@ static void exit_to_user_mode_prepare(st
/* Ensure that the address limit is intact and no locks are held */
addr_limit_user_check();
+ kmap_assert_nomap();
lockdep_assert_irqs_disabled();
lockdep_sys_exit();
}
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -930,6 +930,7 @@ static struct task_struct *dup_task_stru
account_kernel_stack(tsk, 1);
kcov_task_init(tsk);
+ kmap_local_fork(tsk);
#ifdef CONFIG_FAULT_INJECTION
tsk->fail_nth = 0;
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4053,6 +4053,22 @@ static inline void finish_lock_switch(st
# define finish_arch_post_lock_switch()do { } while (0)
#endif
+static inline void kmap_local_sched_out(void)
+{
+#ifdef CONFIG_KMAP_LOCAL
+ if (unlikely(current->kmap_ctrl.idx))
+ __kmap_local_sched_out();
+#endif
+}
+
+static inline void kmap_local_sched_in(void)
+{
+#ifdef CONFIG_KMAP_LOCAL
+ if (unlikely(current->kmap_ctrl.idx))
+ __kmap_local_sched_in();
+#endif
+}
+
/**
* prepare_task_switch - prepare to switch tasks
* @rq: the runqueue preparing to switch
@@ -4075,6 +4091,7 @@ prepare_task_switch(struct rq *rq, struc
perf_event_task_sched_out(prev, next);
rseq_preempt(prev);
fire_sched_out_preempt_notifiers(prev, next);
+ kmap_local_sched_out();
prepare_task(next);
prepare_arch_switch(next);
}
@@ -4141,6 +4158,7 @@ static struct rq *finish_task_switch(str
finish_lock_switch(rq);
finish_arch_post_lock_switch();
kcov_finish_switch(current);
+ kmap_local_sched_in();
fire_sched_in_preempt_notifiers(current);
/*
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -367,27 +367,24 @@ EXPORT_SYMBOL(kunmap_high);
#ifdef CONFIG_KMAP_LOCAL
-static DEFINE_PER_CPU(int, __kmap_atomic_idx);
-
-static inline int kmap_atomic_idx_push(void)
+static inline int kmap_local_idx_push(void)
{
- int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
+ int idx = current->kmap_ctrl.idx++;
WARN_ON_ONCE(in_irq() && !irqs_disabled());
BUG_ON(idx >= KM_TYPE_NR);
return idx;
}
-static inline int kmap_atomic_idx(void)
+static inline int kmap_local_idx(void)
{
- return __this_
[patch V2 06/18] ARM: highmem: Switch to generic kmap atomic
No reason having the same code in every architecture.
Signed-off-by: Thomas Gleixner
Cc: Russell King
Cc: Arnd Bergmann
Cc: linux-arm-ker...@lists.infradead.org
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e00d94b16658..410235e350cc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1499,6 +1499,7 @@ config HAVE_ARCH_PFN_VALID
config HIGHMEM
bool "High Memory Support"
depends on MMU
+ select KMAP_LOCAL
help
The address space of ARM processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 31811be38d78..99a99862c474 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -46,19 +46,32 @@ extern pte_t *pkmap_page_table;
#ifdef ARCH_NEEDS_KMAP_HIGH_GET
extern void *kmap_high_get(struct page *page);
-#else
+
+static inline void *arch_kmap_local_high_get(struct page *page)
+{
+ if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !cache_is_vivt())
+ return NULL;
+ return kmap_high_get(page);
+}
+#define arch_kmap_local_high_get arch_kmap_local_high_get
+
+#else /* ARCH_NEEDS_KMAP_HIGH_GET */
static inline void *kmap_high_get(struct page *page)
{
return NULL;
}
-#endif
+#endif /* !ARCH_NEEDS_KMAP_HIGH_GET */
-/*
- * The following functions are already defined by
- * when CONFIG_HIGHMEM is not set.
- */
-#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_pfn(unsigned long pfn);
-#endif
+#define arch_kmap_local_post_map(vaddr, pteval)
\
+ local_flush_tlb_kernel_page(vaddr)
+
+#define arch_kmap_local_pre_unmap(vaddr) \
+do { \
+ if (cache_is_vivt())\
+ __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); \
+} while (0)
+
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_kernel_page(vaddr)
#endif
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 7cb1699fbfc4..c4ce477c5261 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -19,7 +19,6 @@ obj-$(CONFIG_MODULES) += proc-syms.o
obj-$(CONFIG_DEBUG_VIRTUAL)+= physaddr.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM_PV_FIXUP) += pv-fixup-asm.o
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
deleted file mode 100644
index 187fab227b50..
--- a/arch/arm/mm/highmem.c
+++ /dev/null
@@ -1,121 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * arch/arm/mm/highmem.c -- ARM highmem support
- *
- * Author: Nicolas Pitre
- * Created:september 8, 2008
- * Copyright: Marvell Semiconductors Inc.
- */
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include "mm.h"
-
-static inline void set_fixmap_pte(int idx, pte_t pte)
-{
- unsigned long vaddr = __fix_to_virt(idx);
- pte_t *ptep = virt_to_kpte(vaddr);
-
- set_pte_ext(ptep, pte, 0);
- local_flush_tlb_kernel_page(vaddr);
-}
-
-static inline pte_t get_fixmap_pte(unsigned long vaddr)
-{
- pte_t *ptep = virt_to_kpte(vaddr);
-
- return *ptep;
-}
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned int idx;
- unsigned long vaddr;
- void *kmap;
- int type;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- /*
-* There is no cache coherency issue when non VIVT, so force the
-* dedicated kmap usage for better debugging purposes in that case.
-*/
- if (!cache_is_vivt())
- kmap = NULL;
- else
-#endif
- kmap = kmap_high_get(page);
- if (kmap)
- return kmap;
-
- type = kmap_atomic_idx_push();
-
- idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
- vaddr = __fix_to_virt(idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- /*
-* With debugging enabled, kunmap_atomic forces that entry to 0.
-* Make sure it was indeed properly unmapped.
-*/
- BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
-#endif
- /*
-* When debugging is off, kunmap_atomic leaves the previous mapping
-* in place, so the contained TLB flush ensures the TLB is updated
-* with the new mapping.
-*/
- set_fixmap_pte(idx, mk_pte(page, prot));
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int idx, type;
-
- if (kvaddr >= (void *)FIXADDR_START) {
- type = kmap_atomic_idx();
- idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_p
[patch V2 07/18] csky/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture.
Signed-off-by: Thomas Gleixner
Acked-by: Guo Ren
Cc: linux-c...@vger.kernel.org
---
arch/csky/Kconfig |1
arch/csky/include/asm/highmem.h |4 +-
arch/csky/mm/highmem.c | 75
3 files changed, 5 insertions(+), 75 deletions(-)
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -286,6 +286,7 @@ config NR_CPUS
config HIGHMEM
bool "High Memory Support"
depends on !CPU_CK610
+ select KMAP_LOCAL
default y
config FORCE_MAX_ZONEORDER
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -32,10 +32,12 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps() do {} while (0)
+#define arch_kmap_local_post_map(vaddr, pteval)kmap_flush_tlb(vaddr)
+#define arch_kmap_local_post_unmap(vaddr) kmap_flush_tlb(vaddr)
+
extern void kmap_init(void);
#endif /* __KERNEL__ */
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -9,8 +9,6 @@
#include
#include
-static pte_t *kmap_pte;
-
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@@ -19,67 +17,7 @@ void kmap_flush_tlb(unsigned long addr)
}
EXPORT_SYMBOL(kmap_flush_tlb);
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte - idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- flush_tlb_one((unsigned long)vaddr);
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int idx;
-
- if (vaddr < FIXADDR_START)
- return;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
-
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- pte_clear(&init_mm, vaddr, kmap_pte - idx);
- flush_tlb_one(vaddr);
-#else
- (void) idx; /* to kill a warning */
-#endif
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- unsigned long vaddr;
- int idx, type;
-
- pagefault_disable();
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
- flush_tlb_one(vaddr);
-
- return (void *) vaddr;
-}
-
-static void __init kmap_pages_init(void)
+void __init kmap_init(void)
{
unsigned long vaddr;
pgd_t *pgd;
@@ -96,14 +34,3 @@ static void __init kmap_pages_init(void)
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
}
-
-void __init kmap_init(void)
-{
- unsigned long vaddr;
-
- kmap_pages_init();
-
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
-
- kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
-}
___
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[patch V2 10/18] nds32/mm/highmem: Switch to generic kmap atomic
The mapping code is odd and looks broken. See FIXME in the comment.
Signed-off-by: Thomas Gleixner
Cc: Nick Hu
Cc: Greentime Hu
Cc: Vincent Chen
diff --git a/arch/nds32/Kconfig.cpu b/arch/nds32/Kconfig.cpu
index f88a12fdf0f3..c7add11ea36e 100644
--- a/arch/nds32/Kconfig.cpu
+++ b/arch/nds32/Kconfig.cpu
@@ -157,6 +157,7 @@ config HW_SUPPORT_UNALIGNMENT_ACCESS
config HIGHMEM
bool "High Memory Support"
depends on MMU && !CPU_CACHE_ALIASING
+select KMAP_LOCAL
help
The address space of Andes processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
diff --git a/arch/nds32/include/asm/highmem.h b/arch/nds32/include/asm/highmem.h
index fe986d0e6e3f..d844c282c090 100644
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -45,11 +45,22 @@ extern pte_t *pkmap_page_table;
extern void kmap_init(void);
/*
- * The following functions are already defined by
- * when CONFIG_HIGHMEM is not set.
+ * FIXME: The below looks broken vs. a kmap_atomic() in task context which
+ * is interupted and another kmap_atomic() happens in interrupt context.
+ * But what do I know about nds32. -- tglx
*/
-#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_pfn(unsigned long pfn);
-#endif
+#define arch_kmap_local_post_map(vaddr, pteval)\
+ do {\
+ __nds32__tlbop_inv(vaddr); \
+ __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN); \
+ __nds32__tlbop_rwr(pteval); \
+ __nds32__isb(); \
+ } while (0)
+
+#define arch_kmap_local_pre_unmap(vaddr, pte) \
+ do {\
+ __nds32__tlbop_inv(vaddr); \
+ __nds32__isb(); \
+ } while (0)
#endif
diff --git a/arch/nds32/mm/Makefile b/arch/nds32/mm/Makefile
index 897ecaf5cf54..14fb2e8eb036 100644
--- a/arch/nds32/mm/Makefile
+++ b/arch/nds32/mm/Makefile
@@ -3,7 +3,6 @@ obj-y := extable.o tlb.o fault.o
init.o mmap.o \
mm-nds32.o cacheflush.o proc.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_proc.o = $(CC_FLAGS_FTRACE)
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
deleted file mode 100644
index 4284cd59e21a..
--- a/arch/nds32/mm/highmem.c
+++ /dev/null
@@ -1,48 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned int idx;
- unsigned long vaddr, pte;
- int type;
- pte_t *ptep;
-
- type = kmap_atomic_idx_push();
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- pte = (page_to_pfn(page) << PAGE_SHIFT) | prot;
- ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
- set_pte(ptep, pte);
-
- __nds32__tlbop_inv(vaddr);
- __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
- __nds32__tlbop_rwr(pte);
- __nds32__isb();
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- if (kvaddr >= (void *)FIXADDR_START) {
- unsigned long vaddr = (unsigned long)kvaddr;
- pte_t *ptep;
- kmap_atomic_idx_pop();
- __nds32__tlbop_inv(vaddr);
- __nds32__isb();
- ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
- set_pte(ptep, 0);
- }
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
___
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[patch V2 08/18] microblaze/mm/highmem: Switch to generic kmap atomic
No reason having the same code in every architecture.
Signed-off-by: Thomas Gleixner
Cc: Michal Simek
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index d262ac0c8714..186a0526564c 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -170,6 +170,7 @@ config XILINX_UNCACHED_SHADOW
config HIGHMEM
bool "High memory support"
depends on MMU
+ select KMAP_LOCAL
help
The address space of Microblaze processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
diff --git a/arch/microblaze/include/asm/highmem.h
b/arch/microblaze/include/asm/highmem.h
index 284ca8fb54c1..4418633fb163 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -25,7 +25,6 @@
#include
#include
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@@ -52,6 +51,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps(){ flush_icache(); flush_dcache(); }
+#define arch_kmap_local_post_map(vaddr, pteval)\
+ local_flush_tlb_page(NULL, vaddr);
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_page(NULL, vaddr);
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
diff --git a/arch/microblaze/mm/Makefile b/arch/microblaze/mm/Makefile
index 1b16875cea70..8ced71100047 100644
--- a/arch/microblaze/mm/Makefile
+++ b/arch/microblaze/mm/Makefile
@@ -6,4 +6,3 @@
obj-y := consistent.o init.o
obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c
deleted file mode 100644
index 92e0890416c9..
--- a/arch/microblaze/mm/highmem.c
+++ /dev/null
@@ -1,78 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * PowerPC version, stolen from the i386 version.
- *
- * Used in CONFIG_HIGHMEM systems for memory pages which
- * are not addressable by direct kernel virtual addresses.
- *
- * Copyright (C) 1999 Gerhard Wichert, Siemens AG
- * gerhard.wich...@pdb.siemens.de
- *
- *
- * Redesigned the x86 32-bit VM architecture to deal with
- * up to 16 Terrabyte physical memory. With current x86 CPUs
- * we now support up to 64 Gigabytes physical RAM.
- *
- * Copyright (C) 1999 Ingo Molnar
- *
- * Reworked for PowerPC by various contributors. Moved from
- * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
- */
-
-#include
-#include
-
-/*
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need
- * it.
- */
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
-
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte-idx)));
-#endif
- set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
- local_flush_tlb_page(NULL, vaddr);
-
- return (void *) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type;
- unsigned int idx;
-
- if (vaddr < __fix_to_virt(FIX_KMAP_END))
- return;
-
- type = kmap_atomic_idx();
-
- idx = type + KM_TYPE_NR * smp_processor_id();
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-#endif
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_page(NULL, vaddr);
-
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index 3344d4a1fe89..3f4e41787a4e 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -49,17 +49,11 @@ unsigned long lowmem_size;
EXPORT_SYMBOL(min_low_pfn);
EXPORT_SYMBOL(max_low_pfn);
-#ifdef CONFIG_HIGHMEM
-pte_t *kmap_pte;
-EXPORT_SYMBOL(kmap_pte);
-
static void __init highmem_init(void)
{
pr_debug("%x\n", (u32)PKMAP_BASE);
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
-
- kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
}
static void highmem_setup(void)
___
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[patch V2 04/18] x86/mm/highmem: Use generic kmap atomic implementation
Convert X86 to the generic kmap atomic implementation and make the
iomap_atomic() naming convention consistent while at it.
Signed-off-by: Thomas Gleixner
Cc: x...@kernel.org
---
arch/x86/Kconfig |3 +-
arch/x86/include/asm/fixmap.h |1
arch/x86/include/asm/highmem.h | 12 ++--
arch/x86/include/asm/iomap.h | 18 ++--
arch/x86/mm/highmem_32.c | 59 -
arch/x86/mm/init_32.c | 15 --
arch/x86/mm/iomap_32.c | 59 +++--
include/linux/io-mapping.h |2 -
8 files changed, 27 insertions(+), 142 deletions(-)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -14,10 +14,11 @@ config X86_32
select ARCH_WANT_IPC_PARSE_VERSION
select CLKSRC_I8253
select CLONE_BACKWARDS
+ select GENERIC_VDSO_32
select HAVE_DEBUG_STACKOVERFLOW
+ select KMAP_LOCAL
select MODULES_USE_ELF_REL
select OLD_SIGACTION
- select GENERIC_VDSO_32
config X86_64
def_bool y
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -151,7 +151,6 @@ extern void reserve_top_address(unsigned
extern int fixmaps_set;
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -58,11 +58,17 @@ extern unsigned long highstart_pfn, high
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
-void *kmap_atomic_pfn(unsigned long pfn);
-void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
-
#define flush_cache_kmaps()do { } while (0)
+#definearch_kmap_local_post_map(vaddr, pteval) \
+ arch_flush_lazy_mmu_mode()
+
+#definearch_kmap_local_post_unmap(vaddr) \
+ do {\
+ flush_tlb_one_kernel((vaddr)); \
+ arch_flush_lazy_mmu_mode(); \
+ } while (0)
+
extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn);
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -9,19 +9,21 @@
#include
#include
#include
+#include
#include
#include
-void __iomem *
-iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
+void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
-void
-iounmap_atomic(void __iomem *kvaddr);
+static inline void iounmap_atomic(void __iomem *vaddr)
+{
+ kunmap_local_indexed((void __force *)vaddr);
+ pagefault_enable();
+ preempt_enable();
+}
-int
-iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
+int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
-void
-iomap_free(resource_size_t base, unsigned long size);
+void iomap_free(resource_size_t base, unsigned long size);
#endif /* _ASM_X86_IOMAP_H */
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,65 +4,6 @@
#include /* for totalram_pages */
#include
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- BUG_ON(!pte_none(*(kmap_pte-idx)));
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- arch_flush_lazy_mmu_mode();
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- return kmap_atomic_prot_pfn(pfn, kmap_prot);
-}
-EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
- vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
- int idx, type;
-
- type = kmap_atomic_idx();
- idx = type + KM_TYPE_NR * smp_processor_id();
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-#endif
- /*
-* Force other mappings to Oops if they'll try to access this
-* pte without first remap it. Keeping stale mappings around
-* is a bad idea also, in case the page changes cacheability
-* attributes or becomes a protected page in a hypervisor.
-*/
- kpte_clear_flush(kmap_pte-idx, vaddr);
- kmap_atomic_idx_pop();
- arch_flush_lazy_mmu_mode();
- }
-
[patch V2 05/18] arc/mm/highmem: Use generic kmap atomic implementation
Adopt the map ordering to match the other architectures and the generic
code.
Signed-off-by: Thomas Gleixner
Cc: Vineet Gupta
Cc: linux-snps-arc@lists.infradead.org
---
arch/arc/Kconfig |1
arch/arc/include/asm/highmem.h |8 ++-
arch/arc/mm/highmem.c | 44 -
3 files changed, 9 insertions(+), 44 deletions(-)
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -507,6 +507,7 @@ config LINUX_RAM_BASE
config HIGHMEM
bool "High Memory Support"
select ARCH_DISCONTIGMEM_ENABLE
+ select KMAP_LOCAL
help
With ARC 2G:2G address split, only upper 2G is directly addressable by
kernel. Enable this to potentially allow access to rest of 2G and PAE
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -15,7 +15,10 @@
#define FIXMAP_BASE(PAGE_OFFSET - FIXMAP_SIZE - PKMAP_SIZE)
#define FIXMAP_SIZEPGDIR_SIZE /* only 1 PGD worth */
#define KM_TYPE_NR ((FIXMAP_SIZE >> PAGE_SHIFT)/NR_CPUS)
-#define FIXMAP_ADDR(nr)(FIXMAP_BASE + ((nr) << PAGE_SHIFT))
+
+#define FIX_KMAP_BEGIN (0)
+#define FIX_KMAP_END ((FIXMAP_SIZE >> PAGE_SHIFT) - 1)
+#define FIXADDR_TOP(FIXMAP_BASE + FIXMAP_SIZE - PAGE_SIZE)
/* start after fixmap area */
#define PKMAP_BASE (FIXMAP_BASE + FIXMAP_SIZE)
@@ -29,6 +32,9 @@
extern void kmap_init(void);
+#define arch_kmap_local_post_unmap(vaddr) \
+ local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)
+
static inline void flush_cache_kmaps(void)
{
flush_cache_all();
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -47,48 +47,6 @@
*/
extern pte_t * pkmap_page_table;
-static pte_t * fixmap_page_table;
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- int idx, cpu_idx;
- unsigned long vaddr;
-
- cpu_idx = kmap_atomic_idx_push();
- idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
- vaddr = FIXMAP_ADDR(idx);
-
- set_pte_at(&init_mm, vaddr, fixmap_page_table + idx,
- mk_pte(page, prot));
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kv)
-{
- unsigned long kvaddr = (unsigned long)kv;
-
- if (kvaddr >= FIXMAP_BASE && kvaddr < (FIXMAP_BASE + FIXMAP_SIZE)) {
-
- /*
-* Because preemption is disabled, this vaddr can be associated
-* with the current allocated index.
-* But in case of multiple live kmap_atomic(), it still relies
on
-* callers to unmap in right order.
-*/
- int cpu_idx = kmap_atomic_idx();
- int idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
-
- WARN_ON(kvaddr != FIXMAP_ADDR(idx));
-
- pte_clear(&init_mm, kvaddr, fixmap_page_table + idx);
- local_flush_tlb_kernel_range(kvaddr, kvaddr + PAGE_SIZE);
-
- kmap_atomic_idx_pop();
- }
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr)
{
@@ -113,5 +71,5 @@ void __init kmap_init(void)
pkmap_page_table = alloc_kmap_pgtable(PKMAP_BASE);
BUILD_BUG_ON(LAST_PKMAP > PTRS_PER_PTE);
- fixmap_page_table = alloc_kmap_pgtable(FIXMAP_BASE);
+ alloc_kmap_pgtable(FIXMAP_BASE);
}
___
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[patch V2 03/18] highmem: Provide generic variant of kmap_atomic*
The kmap_atomic* interfaces in all architectures are pretty much the same
except for post map operations (flush) and pre- and post unmap operations.
Provide a generic variant for that.
Signed-off-by: Thomas Gleixner
Cc: Andrew Morton
Cc: linux...@kvack.org
---
V2: Address review comments from Christoph (style and EXPORT variant)
---
include/linux/highmem.h | 79 ++--
mm/Kconfig |3 +
mm/highmem.c| 118 +++-
3 files changed, 183 insertions(+), 17 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -31,9 +31,16 @@ static inline void invalidate_kernel_vma
#include
+/*
+ * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
+ */
+#ifdef CONFIG_KMAP_LOCAL
+void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
+void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
+void kunmap_local_indexed(void *vaddr);
+#endif
+
#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-extern void kunmap_atomic_high(void *kvaddr);
#include
#ifndef ARCH_HAS_KMAP_FLUSH_TLB
@@ -81,6 +88,11 @@ static inline void kunmap(struct page *p
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
+
+#ifndef CONFIG_KMAP_LOCAL
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
+void kunmap_atomic_high(void *kvaddr);
+
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
@@ -89,7 +101,38 @@ static inline void *kmap_atomic_prot(str
return page_address(page);
return kmap_atomic_high_prot(page, prot);
}
-#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot)
+
+static inline void __kunmap_atomic(void *vaddr)
+{
+ kunmap_atomic_high(vaddr);
+}
+#else /* !CONFIG_KMAP_LOCAL */
+
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ preempt_disable();
+ pagefault_disable();
+ return __kmap_local_page_prot(page, prot);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ preempt_disable();
+ pagefault_disable();
+ return __kmap_local_pfn_prot(pfn, kmap_prot);
+}
+
+static inline void __kunmap_atomic(void *addr)
+{
+ kunmap_local_indexed(addr);
+}
+
+#endif /* CONFIG_KMAP_LOCAL */
+
+static inline void *kmap_atomic(struct page *page)
+{
+ return kmap_atomic_prot(page, kmap_prot);
+}
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
@@ -157,21 +200,28 @@ static inline void *kmap_atomic(struct p
pagefault_disable();
return page_address(page);
}
-#define kmap_atomic_prot(page, prot) kmap_atomic(page)
-static inline void kunmap_atomic_high(void *addr)
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ return kmap_atomic(page);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ return kmap_atomic(pfn_to_page(pfn));
+}
+
+static inline void __kunmap_atomic(void *addr)
{
/*
* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
-* handles re-enabling faults + preemption
+* handles re-enabling faults and preemption
*/
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(addr);
#endif
}
-#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
-
#define kmap_flush_unused()do {} while(0)
#endif /* CONFIG_HIGHMEM */
@@ -213,15 +263,14 @@ static inline void kmap_atomic_idx_pop(v
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
*/
-#define kunmap_atomic(addr) \
-do {\
- BUILD_BUG_ON(__same_type((addr), struct page *)); \
- kunmap_atomic_high(addr); \
- pagefault_enable(); \
- preempt_enable(); \
+#define kunmap_atomic(__addr) \
+do { \
+ BUILD_BUG_ON(__same_type((__addr), struct page *)); \
+ __kunmap_atomic(__addr);\
+ pagefault_enable(); \
+ preempt_enable(); \
} while (0)
-
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
#ifndef clear_user_highpage
static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -872,4 +872,7 @@ config ARCH_HAS_HUGEPD
config MAPPING_DIRTY_HELPERS
bool
+config KMAP_LOCAL
+ bool
+
endmenu
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -30,6 +30,7 @@
#include
#include
[patch V2 02/18] mm/highmem: Un-EXPORT __kmap_atomic_idx()
Nothing in modules can use that.
Signed-off-by: Thomas Gleixner
Reviewed-by: Christoph Hellwig
Cc: Andrew Morton
Cc: linux...@kvack.org
---
mm/highmem.c |2 --
1 file changed, 2 deletions(-)
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -108,8 +108,6 @@ static inline wait_queue_head_t *get_pkm
atomic_long_t _totalhigh_pages __read_mostly;
EXPORT_SYMBOL(_totalhigh_pages);
-EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
-
unsigned int nr_free_highpages (void)
{
struct zone *zone;
___
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[patch V2 01/18] sched: Make migrate_disable/enable() independent of RT
Now that the scheduler can deal with migrate disable properly, there is no
real compelling reason to make it only available for RT.
There are quite some code pathes which needlessly disable preemption in
order to prevent migration and some constructs like kmap_atomic() enforce
it implicitly.
Making it available independent of RT allows to provide a preemptible
variant of kmap_atomic() and makes the code more consistent in general.
FIXME: Rework the comment in preempt.h
Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: Ingo Molnar
Cc: Juri Lelli
Cc: Vincent Guittot
Cc: Dietmar Eggemann
Cc: Steven Rostedt
Cc: Ben Segall
Cc: Mel Gorman
Cc: Daniel Bristot de Oliveira
---
include/linux/preempt.h | 38 +++---
include/linux/sched.h |2 +-
kernel/sched/core.c | 12 ++--
kernel/sched/sched.h|2 +-
lib/smp_processor_id.c |2 +-
5 files changed, 8 insertions(+), 48 deletions(-)
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -322,7 +322,7 @@ static inline void preempt_notifier_init
#endif
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT)
+#ifdef CONFIG_SMP
/*
* Migrate-Disable and why it is undesired.
@@ -382,43 +382,11 @@ static inline void preempt_notifier_init
extern void migrate_disable(void);
extern void migrate_enable(void);
-#elif defined(CONFIG_PREEMPT_RT)
+#else
static inline void migrate_disable(void) { }
static inline void migrate_enable(void) { }
-#else /* !CONFIG_PREEMPT_RT */
-
-/**
- * migrate_disable - Prevent migration of the current task
- *
- * Maps to preempt_disable() which also disables preemption. Use
- * migrate_disable() to annotate that the intent is to prevent migration,
- * but not necessarily preemption.
- *
- * Can be invoked nested like preempt_disable() and needs the corresponding
- * number of migrate_enable() invocations.
- */
-static __always_inline void migrate_disable(void)
-{
- preempt_disable();
-}
-
-/**
- * migrate_enable - Allow migration of the current task
- *
- * Counterpart to migrate_disable().
- *
- * As migrate_disable() can be invoked nested, only the outermost invocation
- * reenables migration.
- *
- * Currently mapped to preempt_enable().
- */
-static __always_inline void migrate_enable(void)
-{
- preempt_enable();
-}
-
-#endif /* CONFIG_SMP && CONFIG_PREEMPT_RT */
+#endif /* CONFIG_SMP */
#endif /* __LINUX_PREEMPT_H */
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -715,7 +715,7 @@ struct task_struct {
const cpumask_t *cpus_ptr;
cpumask_t cpus_mask;
void*migration_pending;
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT)
+#ifdef CONFIG_SMP
unsigned short migration_disabled;
#endif
unsigned short migration_flags;
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1696,8 +1696,6 @@ void check_preempt_curr(struct rq *rq, s
#ifdef CONFIG_SMP
-#ifdef CONFIG_PREEMPT_RT
-
static void
__do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask,
u32 flags);
@@ -1772,8 +1770,6 @@ static inline bool rq_has_pinned_tasks(s
return rq->nr_pinned;
}
-#endif
-
/*
* Per-CPU kthreads are allowed to run on !active && online CPUs, see
* __set_cpus_allowed_ptr() and select_fallback_rq().
@@ -2841,7 +2837,7 @@ void sched_set_stop_task(int cpu, struct
}
}
-#else
+#else /* CONFIG_SMP */
static inline int __set_cpus_allowed_ptr(struct task_struct *p,
const struct cpumask *new_mask,
@@ -2850,10 +2846,6 @@ static inline int __set_cpus_allowed_ptr
return set_cpus_allowed_ptr(p, new_mask);
}
-#endif /* CONFIG_SMP */
-
-#if !defined(CONFIG_SMP) || !defined(CONFIG_PREEMPT_RT)
-
static inline void migrate_disable_switch(struct rq *rq, struct task_struct
*p) { }
static inline bool rq_has_pinned_tasks(struct rq *rq)
@@ -2861,7 +2853,7 @@ static inline bool rq_has_pinned_tasks(s
return false;
}
-#endif
+#endif /* !CONFIG_SMP */
static void
ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1056,7 +1056,7 @@ struct rq {
struct cpuidle_state*idle_state;
#endif
-#if defined(CONFIG_PREEMPT_RT) && defined(CONFIG_SMP)
+#if CONFIG_SMP
unsigned intnr_pinned;
#endif
unsigned intpush_busy;
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -26,7 +26,7 @@ unsigned int check_preemption_disabled(c
if (current->nr_cpus_allowed == 1)
goto out;
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT)
+#ifdef CONFIG_SMP
if (current->migration_disabled)
goto out;
#endif
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[patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends
Following up to the discussion in: https://lore.kernel.org/r/20200914204209.256266...@linutronix.de and the initial version of this: https://lore.kernel.org/r/20200919091751.06...@linutronix.de this series provides a preemptible variant of kmap_atomic & related interfaces. Now that the scheduler folks have wrapped their heads around the migration disable scheduler woes, there is not a real reason anymore to confine migration disabling to RT. As expressed in the earlier discussion by graphics and crypto folks, there is interest to get rid of their kmap_atomic* usage because they need only a temporary stable map and not all the bells and whistels of kmap_atomic*. This series provides kmap_local.* iomap_local variants which only disable migration to keep the virtual mapping address stable accross preemption, but do neither disable pagefaults nor preemption. The new functions can be used in any context, but if used in atomic context the caller has to take care of eventually disabling pagefaults. This is achieved by: - Removing the RT dependency from migrate_disable/enable() - Consolidating all kmap atomic implementations in generic code - Switching from per CPU storage of the kmap index to a per task storage - Adding a pteval array to the per task storage which contains the ptevals of the currently active temporary kmaps - Adding context switch code which checks whether the outgoing or the incoming task has active temporary kmaps. If so, the outgoing task's kmaps are removed and the incoming task's kmaps are restored. - Adding new interfaces k[un]map_temporary*() which are not disabling preemption and can be called from any context (except NMI). Contrary to kmap() which provides preemptible and "persistant" mappings, these interfaces are meant to replace the temporary mappings provided by kmap_atomic*() today. This allows to get rid of conditional mapping choices and allows to have preemptible short term mappings on 64bit which are today enforced to be non-preemptible due to the highmem constraints. It clearly puts overhead on the highmem users, but highmem is slow anyway. This is not a wholesale conversion which makes kmap_atomic magically preemptible because there might be usage sites which rely on the implicit preempt disable. So this needs to be done on a case by case basis and the call sites converted to kmap_temporary. Note, that this is only lightly tested on X86 and completely untested on all other architectures. There is also a still to be investigated question from Linus on the initial posting versus the per cpu / per task mapping stack depth which might need to be made larger due to the ability to take page faults within a mapping region. Though I wanted to share the current state of affairs before investigating that further. If there is consensus in going forward with this, I'll have a deeper look into this issue. The lot is available from git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git highmem It is based on Peter Zijlstras migrate disable branch which is close to be merged into the tip tree, but still not finalized: git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/migrate-disable Changes vs. V1: - Make it truly functional by depending on migrate disable/enable (Brown paperbag) - Rename to kmap_local.* (Linus) - Fix the sched in/out issue Linus pointed out - Fix a few style issues (Christoph) - Split a few things out into seperate patches to make review simpler - Pick up acked/reviewed tags as appropriate Thanks, tglx --- a/arch/arm/mm/highmem.c | 121 -- a/arch/microblaze/mm/highmem.c| 78 a/arch/nds32/mm/highmem.c | 48 --- a/arch/powerpc/mm/highmem.c | 67 -- a/arch/sparc/mm/highmem.c | 115 - arch/arc/Kconfig |1 arch/arc/include/asm/highmem.h|8 + arch/arc/mm/highmem.c | 44 -- arch/arm/Kconfig |1 arch/arm/include/asm/highmem.h| 31 +++- arch/arm/mm/Makefile |1 arch/csky/Kconfig |1 arch/csky/include/asm/highmem.h |4 arch/csky/mm/highmem.c| 75 --- arch/microblaze/Kconfig |1 arch/microblaze/include/asm/highmem.h |6 arch/microblaze/mm/Makefile |1 arch/microblaze/mm/init.c |6 arch/mips/Kconfig |1 arch/mips/include/asm/highmem.h |4 arch/mips/mm/highmem.c| 77 arch/mips/mm/init.c |3 arch/nds32/Kconfig.cpu|1 arch/nds32/include/asm/highmem.h | 21 ++- arch/nds32/mm/Makefile|1 arch/powerpc/Kconfig |1 arch/powerpc/include/asm/highmem.h|6 arch/powe
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Thu, Sep 24 2020 at 08:32, Steven Rostedt wrote: > On Thu, 24 Sep 2020 08:57:52 +0200 > Thomas Gleixner wrote: > >> > Now as for migration disabled nesting, at least now we would have >> > groupings of this, and perhaps the theorists can handle that. I mean, >> > how is this much different that having a bunch of tasks blocked on a >> > mutex with the owner is pinned on a CPU? >> > >> > migrate_disable() is a BKL of pinning affinity. >> >> No. That's just wrong. preempt disable is a concurrency control, > > I think you totally misunderstood what I was saying. The above wasn't about > comparing preempt_disable to migrate_disable. It was comparing > migrate_disable to a chain of tasks blocked on mutexes where the top owner > has preempt_disable set. You still have a bunch of tasks that can't move to > other CPUs. What? The top owner does not prevent any task from moving. The tasks cannot move because they are blocked on the mutex, which means they are not runnable and non runnable tasks are not migrated at all. I really don't understand what you are trying to say. >> > If we only have local_lock() available (even on !RT), then it makes >> > the blocking in groups. At least this way you could grep for all the >> > different local_locks in the system and plug that into the algorithm >> > for WCS, just like one would with a bunch of mutexes. >> >> You cannot do that on RT at all where migrate disable is substituting >> preempt disable in spin and rw locks. The result would be the same as >> with a !RT kernel just with horribly bad performance. > > Note, the spin and rwlocks already have a lock associated with them. Why > would it be any different on RT? I wasn't suggesting adding another lock > inside a spinlock. Why would I recommend THAT? I wasn't recommending > blindly replacing migrate_disable() with local_lock(). I just meant expose > local_lock() but not migrate_disable(). We already exposed local_lock() to non RT and it's for places which do preempt_disable() or local_irq_disable() without having a lock associated. But both primitives are scope less and therefore behave like CPU local BKLs. What local_lock() provides in these cases is: - Making the protection scope clear by associating a named local lock which is coverred by lockdep. - It still maps to preempt_disable() or local_irq_disable() in !RT kernels - The scope and the named lock allows RT kernels to substitute with real (recursion aware) locking primitives which keep preemption and interupts enabled, but provide the fine grained protection for the scoped critical section. So how would you substitute migrate_disable() with a local_lock()? You can't. Again migrate_disable() is NOT a concurrency control and therefore it cannot be substituted by any concurrency control primitive. >> That means the stacking problem has to be solved anyway. >> >> So why on earth do you want to create yet another special duct tape case >> for kamp_local() which proliferates inconsistency instead of aiming for >> consistency accross all preemption models? > > The idea was to help with the scheduling issue. I don't see how mixing concepts and trying to duct tape a problem which is clearly in the realm of the scheduler, i.e. load balancing and placing algorithms, is helpful. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Wed, Sep 23 2020 at 17:12, Steven Rostedt wrote: > On Wed, 23 Sep 2020 22:55:54 +0200 > Then scratch the idea of having anonymous local_lock() and just bring > local_lock in directly? Then have a kmap local lock, which would only > block those that need to do a kmap. That's still going to end up in lock ordering nightmares and you lose the ability to use kmap_local from arbitrary contexts which was again one of the goals of this exercise. Aside of that you're imposing reentrancy protections on something which does not need it in the first place. > Now as for migration disabled nesting, at least now we would have > groupings of this, and perhaps the theorists can handle that. I mean, > how is this much different that having a bunch of tasks blocked on a > mutex with the owner is pinned on a CPU? > > migrate_disable() is a BKL of pinning affinity. No. That's just wrong. preempt disable is a concurrency control, i.e. protecting against reentrancy on a given CPU. But it's a cpu global protection which means that it's not protecting a specific code path. Contrary to preempt disable, migrate disable is not protecting against reentrancy on a given CPU. It's a temporary restriction to the scheduler on placement. The fact that disabling preemption implicitely disables migration does not make them semantically equivalent. > If we only have local_lock() available (even on !RT), then it makes > the blocking in groups. At least this way you could grep for all the > different local_locks in the system and plug that into the algorithm > for WCS, just like one would with a bunch of mutexes. You cannot do that on RT at all where migrate disable is substituting preempt disable in spin and rw locks. The result would be the same as with a !RT kernel just with horribly bad performance. That means the stacking problem has to be solved anyway. So why on earth do you want to create yet another special duct tape case for kamp_local() which proliferates inconsistency instead of aiming for consistency accross all preemption models? Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Wed, Sep 23 2020 at 11:52, Steven Rostedt wrote: > On Wed, 23 Sep 2020 10:40:32 +0200 > pet...@infradead.org wrote: > >> However, with migrate_disable() we can have each task preempted in a >> migrate_disable() region, worse we can stack them all on the _same_ CPU >> (super ridiculous odds, sure). And then we end up only able to run one >> task, with the rest of the CPUs picking their nose. > > What if we just made migrate_disable() a local_lock() available for !RT? > > I mean make it a priority inheritance PER CPU lock. > > That is, no two tasks could do a migrate_disable() on the same CPU? If > one task does a migrate_disable() and then gets preempted and the > preempting task does a migrate_disable() on the same CPU, it will block > and wait for the first task to do a migrate_enable(). > > No two tasks on the same CPU could enter the migrate_disable() section > simultaneously, just like no two tasks could enter a preempt_disable() > section. > > In essence, we just allow local_lock() to be used for both RT and !RT. > > Perhaps make migrate_disable() an anonymous local_lock()? > > This should lower the SHC in theory, if you can't have stacked migrate > disables on the same CPU. I'm pretty sure this ends up in locking hell pretty fast and aside of that it's not working for scenarios like: kmap_local(); migrate_disable(); ... copy_from_user() -> #PF -> schedule() which brought us into that discussion in the first place. You would stop any other migrate disable user from running until the page fault is resolved... Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Mon, Sep 21 2020 at 21:27, Thomas Gleixner wrote: > On Mon, Sep 21 2020 at 09:24, Linus Torvalds wrote: >> On Mon, Sep 21, 2020 at 12:39 AM Thomas Gleixner wrote: >> Maybe we really *could* call this new kmap functionality something >> like "kmap_percpu()" (or maybe "local" is good enough), and make it >> act like your RT code does for spinlocks - not disable preemption, but >> only disabling CPU migration. > > I"m all for it, but the scheduler people have opinions :) I just took the latest version of migrate disable patches https://lore.kernel.org/r/20200921163557.234036...@infradead.org removed the RT dependency on top of them and adopted the kmap stuff (addressing the various comments while at it and unbreaking ARM). I'm not going to post that until there is consensus about the general availability of migrate disable, but for those who want to play with it I've pushed the resulting combo out to: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git highmem For testing I've tweaked a few places to use the new _local() variants and it survived testing so far and I've verified that there is actual preemption which means zap/restore of the thread local kmaps. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Wed, Sep 23 2020 at 10:40, peterz wrote: > Right, so I'm concerned. migrate_disable() wrecks pretty much all > Real-Time scheduler theory we have, and PREEMPRT_RT bringing it in is > somewhat ironic. It's even more ironic that the approach of PREEMPT_RT has been 'pragmatic ignorance of theory' from the very beginning and despite violating all theories it still works. :) > Yes, it allows breaking up non-preemptible regions of non-deterministic > duration, and thereby both reduce and bound the scheduling latency, the > cost for doing that is that the theory on CPU utilization/bandwidth go > out the window. I agree, that the theory goes out of the window, but does it matter in practice? I've yet to see a report of migrate disable stacking being the culprit of a missed deadline and I surely have stared at lots of reports in the past 10+ years. > To easily see this consider an SMP system with a number of tasks equal > to the number of CPUs. On a regular (preempt_disable) kernel we can > always run each task, by virtue of always having an idle CPU to take the > task. > > However, with migrate_disable() we can have each task preempted in a > migrate_disable() region, worse we can stack them all on the _same_ CPU > (super ridiculous odds, sure). And then we end up only able to run one > task, with the rest of the CPUs picking their nose. > > The end result is that, like with unbounded latency, we will still miss > our deadline, simply because we got starved for CPU. I'm well aware of that. > Now, while we could (with a _lot_ of work) rework the kernel to not rely > on the implicit per-cpu ness of things like spinlock_t, the moment we > bring in basic primitives that rely on migrate_disable() we're stuck > with it. Right, but we are stuck with per CPUness and distangling that is just infeasible IMO. > The problem is; afaict there's been no research into this problem. There is no research on a lot of things the kernel does :) > There might be scheduling (read: balancing) schemes that can > mitigate/solve this problem, or it might prove to be a 'hard' problem, > I just don't know. In practive balancing surely can take the number of preempted tasks which are in a migrate disable section into account which would be just another measure to work around the fact that the kernel is not adhering to the theories. It never did that even w/o migrate disable. > But once we start down this road, it's going to be hell to get rid of > it. Like most of the other things the kernel came up with to deal with the oddities of modern hardware :) > That's why I've been arguing (for many years) to strictly limit this to > PREEMPT_RT and only as a gap-stop, not a fundamental primitive to build > on. I know, but short of rewriting the world, I'm not seing the faintest plan to remove the stop gap. :) As we discussed not long ago we have too many inconsistent preemption models already. RT is adding yet another one. And that's worse than introducing migrate disable as a general available facility. IMO, reaching a point of consistency where our different preemption models (NONE, VOLUNTARY, PREEMPT. RT) build on each other is far more important. For !RT migrate disable is far less of an danger than for RT kernels because the amount of code which will use it is rather limited compared to code which still will disable preemption implicit through spin and rw locks. On RT converting these locks to 'sleepable spinlocks' is just possible because RT forces almost everything into task context and migrate disable is just the obvious decomposition of preempt disable which implicitely disables migration. But that means that RT is by orders of magnitude more prone to run into the scheduling trainwreck you are worried about. It just refuses to do so at least with real world work loads. I'm surely in favour of having solid theories behind implementation, but at some point you just have to bite the bullet and chose pragmatism in order to make progress. Proliferating inconsistency is not real progress, as it is violating the most fundamental engineering principles. That's by far more dangerous than violating scheduling theories which are built on perfect models and therefore enforce violation by practical implementations anyway. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Wed, Sep 23 2020 at 12:19, peterz wrote: > On Mon, Sep 21, 2020 at 09:27:57PM +0200, Thomas Gleixner wrote: >> Alternatively this could of course be solved with per CPU page tables >> which will come around some day anyway I fear. > > Previously (with PTI) we looked at making the entire kernel map per-CPU, > and that takes a 2K copy on switch_mm() (or more general, the user part > of whatever the top level directory is for architectures that have a > shared kernel/user page-table setup in the first place). > > The idea was having a fixed per-cpu kernel page-table, share a bunch of > (kernel) page-tables between all CPUs and then copy in the user part on > switch. > > I've forgotten what the plan was for ASID/PCID in that scheme. > > For x86_64 we've been fearing the performance of that 2k copy, but I > don't think we've ever actually bit the bullet and implemented it to see > how bad it really is. I actually did at some point and depending on the workload the overhead was clearly measurable. And yes, it fell apart with PCID and I could not come up with a scheme for it which did not suck horribly. So I burried the patches in the poison cabinet. Aside of that, we'd need to implement that for a eight other architectures as well... Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Mon, Sep 21 2020 at 09:24, Linus Torvalds wrote: > On Mon, Sep 21, 2020 at 12:39 AM Thomas Gleixner wrote: >> >> If a task is migrated to a different CPU then the mapping address will >> change which will explode in colourful ways. > > Right you are. > > Maybe we really *could* call this new kmap functionality something > like "kmap_percpu()" (or maybe "local" is good enough), and make it > act like your RT code does for spinlocks - not disable preemption, but > only disabling CPU migration. I"m all for it, but the scheduler people have opinions :) > That would probably be good enough for a lot of users that don't want > to expose excessive latencies, but where it's really not a huge deal > to say "stick to this CPU for a short while". > > The crypto code certainly sounds like one such case. I looked at a lot of the kmap_atomic() places and quite some of them only require migration to be disabled to keep the temporary map stable. Quite some code could be simplified significantly especially those places which need to do copy_from/to_user inside these sections. Graphics is the main example here as Daniel pointed out. Alternatively this could of course be solved with per CPU page tables which will come around some day anyway I fear. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Sun, Sep 20 2020 at 10:42, Linus Torvalds wrote: > On Sun, Sep 20, 2020 at 10:40 AM Thomas Gleixner wrote: >> >> I think the more obvious solution is to split the whole exercise: >> >> schedule() >> prepare_switch() >> unmap() >> >> switch_to() >> >> finish_switch() >> map() > > Yeah, that looks much easier to explain. Ack. So far so good, but Peter Z. just pointed out to me that I completely missed the fact that this cannot work. If a task is migrated to a different CPU then the mapping address will change which will explode in colourful ways. On RT kernels this works because we ping the task to the CPU via migrate_disable(). On a !RT kernel migrate_disable() maps to preempt_disable() which brings us back to square one. /me goes back to the drawing board. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Sun, Sep 20 2020 at 09:57, Linus Torvalds wrote:
> On Sun, Sep 20, 2020 at 1:49 AM Thomas Gleixner wrote:
> Btw, looking at the stack code, Ithink your new implementation of it
> is a bit scary:
>
>static inline int kmap_atomic_idx_push(void)
>{
> - int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
> + int idx = current->kmap_ctrl.idx++;
>
> and now that 'current->kmap_ctrl.idx' is not atomic wrt
>
> (a) NMI's (this may be ok, maybe we never do kmaps in NMIs, and with
> nesting I think it's fine anyway - the NMI will undo whatever it did)
Right. Nesting should be a non issue, but I don't think we have
kmap_atomic() in NMI context.
> (b) the prev/next switch
>
> And that (b) part worries me. You do the kmap_switch_temporary() to
> switch the entries, but you do that *separately* from actually
> switching 'current' to the new value.
>
> So kmap_switch_temporary() looks safe, but I don't think it actually
> is. Because while it first unmaps the old entries and then remaps the
> new ones, an interrupt can come in, and at that point it matters what
> is *CURRENT*.
>
> And regardless of whether 'current' is 'prev' or 'next', that
> kmap_switch_temporary() loop may be doing the wrong thing, depending
> on which one had the deeper stack. The interrupt will be using
> whatever "current->kmap_ctrl.idx" is, but that might overwrite entries
> that are in the process of being restored (if current is still 'prev',
> but kmap_switch_temporary() is in the "restore @next's kmaps" pgase),
> or it might stomp on entries that have been pte_clear()'ed by the
> 'prev' thing.
Duh yes. Never thought about that.
> Alternatively, that process counter would need about a hundred lines
> of commentary about exactly why it's safe. Because I don't think it
> is.
I think the more obvious solution is to split the whole exercise:
schedule()
prepare_switch()
unmap()
switch_to()
finish_switch()
map()
That's safe because neither the unmap() nor the map() code changes
kmap_ctrl.idx. So if there is an interrupt coming in between unmap() and
switch_to() then a kmap_local() there will use the next entry. So we
could even do the unmap() with interrupts enabled (preemption disabled).
Same for the map() part.
To explain that we need only a few lines of commentry methinks.
Thanks,
tglx
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Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Sun, Sep 20 2020 at 10:23, Daniel Vetter wrote: > On Sun, Sep 20, 2020 at 08:23:26AM +0200, Thomas Gleixner wrote: >> On Sat, Sep 19 2020 at 12:37, Daniel Vetter wrote: >> > On Sat, Sep 19, 2020 at 12:35 PM Daniel Vetter wrote: >> >> I think it should be the case, but I want to double check: Will >> >> copy_*_user be allowed within a kmap_temporary section? This would >> >> allow us to ditch an absolute pile of slowpaths. >> > >> > (coffee just kicked in) copy_*_user is ofc allowed, but if you hit a >> > page fault you get a short read/write. This looks like it would remove >> > the need to handle these in a slowpath, since page faults can now be >> > served in this new kmap_temporary sections. But this sounds too good >> > to be true, so I'm wondering what I'm missing. >> >> In principle we could allow pagefaults, but not with the currently >> proposed interface which can be called from any context. Obviously if >> called from atomic context it can't handle user page faults. > > Yeah that's clear, but does the implemention need to disable pagefaults > unconditionally? As I wrote in the other reply it's not required and the final interface will neither disable preemption nor pagefaults (except for the atomic wrapper around it). Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Sun, Sep 20 2020 at 08:41, Thomas Gleixner wrote: > On Sat, Sep 19 2020 at 10:18, Linus Torvalds wrote: >> Maybe I've missed something. Is it because the new interface still >> does "pagefault_disable()" perhaps? >> >> But does it even need the pagefault_disable() at all? Yes, the >> *atomic* one obviously needed it. But why does this new one need to >> disable page faults? > > It disables pagefaults because it can be called from atomic and > non-atomic context. That was the point to get rid of > > if (preeemptible()) > kmap(); > else > kmap_atomic(); > > If it does not disable pagefaults, then it's just a lightweight variant > of kmap() for short lived mappings. Actually most usage sites of kmap atomic do not need page faults to be disabled at all. As Daniel pointed out the implicit pagefault disable enforces copy_from_user_inatomic() even in places which are clearly preemptible task context. As we need to look at each instance anyway we can add the PF disable explicitely to the very few places which actually need it. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Sat, Sep 19 2020 at 10:18, Linus Torvalds wrote: > On Sat, Sep 19, 2020 at 2:50 AM Thomas Gleixner wrote: >> >> this provides a preemptible variant of kmap_atomic & related >> interfaces. This is achieved by: > > Ack. This looks really nice, even apart from the new capability. > > The only thing I really reacted to is that the name doesn't make sense > to me: "kmap_temporary()" seems a bit odd. Yeah. Couldn't come up with something useful. > Particularly for an interface that really is basically meant as a > better replacement of "kmap_atomic()" (but is perhaps also a better > replacement for "kmap()"). > > I think I understand how the name came about: I think the "temporary" > is there as a distinction from the "longterm" regular kmap(). So I > think it makes some sense from an internal implementation angle, but I > don't think it makes a lot of sense from an interface name. > > I don't know what might be a better name, but if we want to emphasize > that it's thread-private and a one-off, maybe "local" would be a > better naming, and make it distinct from the "global" nature of the > old kmap() interface? Right, _local or _thread would be more intuitive. > However, another solution might be to just use this new preemptible > "local" kmap(), and remove the old global one entirely. Yes, the old > global one caches the page table mapping and that sounds really > efficient and nice. But it's actually horribly horribly bad, because > it means that we need to use locking for them. Your new "temporary" > implementation seems to be fundamentally better locking-wise, and only > need preemption disabling as locking (and is equally fast for the > non-highmem case). > > So I wonder if the single-page TLB flush isn't a better model, and > whether it wouldn't be a lot simpler to just get rid of the old > complex kmap() entirely, and replace it with this? > > I agree we can't replace the kmap_atomic() version, because maybe > people depend on the preemption disabling it also implied. But what > about replacing the non-atomic kmap()? > > Maybe I've missed something. Is it because the new interface still > does "pagefault_disable()" perhaps? > > But does it even need the pagefault_disable() at all? Yes, the > *atomic* one obviously needed it. But why does this new one need to > disable page faults? It disables pagefaults because it can be called from atomic and non-atomic context. That was the point to get rid of if (preeemptible()) kmap(); else kmap_atomic(); If it does not disable pagefaults, then it's just a lightweight variant of kmap() for short lived mappings. > But apart from that question about naming (and perhaps replacing > kmap() entirely), I very much like it. I thought about it, but then I figured that kmap pointers can be handed to other contexts from the thread which sets up the mapping because it's 'permanent'. I'm not sure whether that actually happens, so we'd need to audit all kmap() users to be sure. If there is no such use case, then we surely can get of rid of kmap() completely. It's only 300+ instances to stare at and quite some of them are wrapped into other functions. Highmem sucks no matter what and the only sane solution is to remove it completely. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [patch RFC 00/15] mm/highmem: Provide a preemptible variant of kmap_atomic & friends
On Sat, Sep 19 2020 at 12:37, Daniel Vetter wrote: > On Sat, Sep 19, 2020 at 12:35 PM Daniel Vetter wrote: >> I think it should be the case, but I want to double check: Will >> copy_*_user be allowed within a kmap_temporary section? This would >> allow us to ditch an absolute pile of slowpaths. > > (coffee just kicked in) copy_*_user is ofc allowed, but if you hit a > page fault you get a short read/write. This looks like it would remove > the need to handle these in a slowpath, since page faults can now be > served in this new kmap_temporary sections. But this sounds too good > to be true, so I'm wondering what I'm missing. In principle we could allow pagefaults, but not with the currently proposed interface which can be called from any context. Obviously if called from atomic context it can't handle user page faults. In theory we could make a variant which does not disable pagefaults, but that's what kmap() already provides. Thanks, tglx ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch RFC 13/15] mm/highmem: Remove the old kmap_atomic cruft
Signed-off-by: Thomas Gleixner
---
include/linux/highmem.h | 65 ++--
mm/highmem.c| 28 +---
2 files changed, 28 insertions(+), 65 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -94,27 +94,6 @@ static inline void kunmap(struct page *p
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
-
-#ifndef CONFIG_KMAP_ATOMIC_GENERIC
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-void kunmap_atomic_high(void *kvaddr);
-
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
- return kmap_atomic_high_prot(page, prot);
-}
-
-static inline void __kunmap_atomic(void *vaddr)
-{
- kunmap_atomic_high(vaddr);
- pagefault_enable();
-}
-#else /* !CONFIG_KMAP_ATOMIC_GENERIC */
-
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
@@ -127,17 +106,14 @@ static inline void *kmap_atomic_pfn(unsi
return kmap_atomic_pfn_prot(pfn, kmap_prot);
}
-static inline void __kunmap_atomic(void *addr)
+static inline void *kmap_atomic(struct page *page)
{
- kumap_atomic_indexed(addr);
+ return kmap_atomic_prot(page, kmap_prot);
}
-
-#endif /* CONFIG_KMAP_ATOMIC_GENERIC */
-
-static inline void *kmap_atomic(struct page *page)
+static inline void __kunmap_atomic(void *addr)
{
- return kmap_atomic_prot(page, kmap_prot);
+ kumap_atomic_indexed(addr);
}
/* declarations for linux/mm/highmem.c */
@@ -233,39 +209,6 @@ static inline void __kunmap_atomic(void
#endif /* CONFIG_HIGHMEM */
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
-
-DECLARE_PER_CPU(int, __kmap_atomic_idx);
-
-static inline int kmap_atomic_idx_push(void)
-{
- int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(in_irq() && !irqs_disabled());
- BUG_ON(idx >= KM_TYPE_NR);
-#endif
- return idx;
-}
-
-static inline int kmap_atomic_idx(void)
-{
- return __this_cpu_read(__kmap_atomic_idx) - 1;
-}
-
-static inline void kmap_atomic_idx_pop(void)
-{
-#ifdef CONFIG_DEBUG_HIGHMEM
- int idx = __this_cpu_dec_return(__kmap_atomic_idx);
-
- BUG_ON(idx < 0);
-#else
- __this_cpu_dec(__kmap_atomic_idx);
-#endif
-}
-
-#endif
-
/*
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -31,10 +31,6 @@
#include
#include
-#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
-DEFINE_PER_CPU(int, __kmap_atomic_idx);
-#endif
-
/*
* Virtual_count is not a pure "count".
* 0 means that it is not mapped, and has not been mapped
@@ -380,6 +376,30 @@ static inline void kmap_high_unmap_tempo
#endif /* CONFIG_HIGHMEM */
#ifdef CONFIG_KMAP_ATOMIC_GENERIC
+
+static DEFINE_PER_CPU(int, __kmap_atomic_idx);
+
+static inline int kmap_atomic_idx_push(void)
+{
+ int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
+
+ WARN_ON_ONCE(in_irq() && !irqs_disabled());
+ BUG_ON(idx >= KM_TYPE_NR);
+ return idx;
+}
+
+static inline int kmap_atomic_idx(void)
+{
+ return __this_cpu_read(__kmap_atomic_idx) - 1;
+}
+
+static inline void kmap_atomic_idx_pop(void)
+{
+ int idx = __this_cpu_dec_return(__kmap_atomic_idx);
+
+ BUG_ON(idx < 0);
+}
+
#ifndef arch_kmap_temp_post_map
# define arch_kmap_temp_post_map(vaddr, pteval)do { } while (0)
#endif
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[patch RFC 07/15] microblaze/mm/highmem: Switch to generic kmap atomic
Signed-off-by: Thomas Gleixner
Cc: Michal Simek
---
Note: Completely untested
---
arch/microblaze/Kconfig |1
arch/microblaze/include/asm/highmem.h |6 ++
arch/microblaze/mm/Makefile |1
arch/microblaze/mm/highmem.c | 78 --
arch/microblaze/mm/init.c |6 --
5 files changed, 6 insertions(+), 86 deletions(-)
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -170,6 +170,7 @@ config XILINX_UNCACHED_SHADOW
config HIGHMEM
bool "High memory support"
depends on MMU
+ select KMAP_ATOMIC_GENERIC
help
The address space of Microblaze processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -25,7 +25,6 @@
#include
#include
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@@ -52,6 +51,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps(){ flush_icache(); flush_dcache(); }
+#define arch_kmap_temp_post_map(vaddr, pteval) \
+ local_flush_tlb_page(NULL, vaddr);
+#define arch_kmap_temp_post_unmap(vaddr) \
+ local_flush_tlb_page(NULL, vaddr);
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/microblaze/mm/Makefile
+++ b/arch/microblaze/mm/Makefile
@@ -6,4 +6,3 @@
obj-y := consistent.o init.o
obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
--- a/arch/microblaze/mm/highmem.c
+++ /dev/null
@@ -1,78 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * PowerPC version, stolen from the i386 version.
- *
- * Used in CONFIG_HIGHMEM systems for memory pages which
- * are not addressable by direct kernel virtual addresses.
- *
- * Copyright (C) 1999 Gerhard Wichert, Siemens AG
- * gerhard.wich...@pdb.siemens.de
- *
- *
- * Redesigned the x86 32-bit VM architecture to deal with
- * up to 16 Terrabyte physical memory. With current x86 CPUs
- * we now support up to 64 Gigabytes physical RAM.
- *
- * Copyright (C) 1999 Ingo Molnar
- *
- * Reworked for PowerPC by various contributors. Moved from
- * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
- */
-
-#include
-#include
-
-/*
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need
- * it.
- */
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
-
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte-idx)));
-#endif
- set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
- local_flush_tlb_page(NULL, vaddr);
-
- return (void *) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type;
- unsigned int idx;
-
- if (vaddr < __fix_to_virt(FIX_KMAP_END))
- return;
-
- type = kmap_atomic_idx();
-
- idx = type + KM_TYPE_NR * smp_processor_id();
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-#endif
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_page(NULL, vaddr);
-
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -49,17 +49,11 @@ unsigned long lowmem_size;
EXPORT_SYMBOL(min_low_pfn);
EXPORT_SYMBOL(max_low_pfn);
-#ifdef CONFIG_HIGHMEM
-pte_t *kmap_pte;
-EXPORT_SYMBOL(kmap_pte);
-
static void __init highmem_init(void)
{
pr_debug("%x\n", (u32)PKMAP_BASE);
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
-
- kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
}
static void highmem_setup(void)
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[patch RFC 08/15] mips/mm/highmem: Switch to generic kmap atomic
Signed-off-by: Thomas Gleixner
Cc: Thomas Bogendoerfer
Cc: linux-m...@vger.kernel.org
---
Note: Completely untested
---
arch/mips/Kconfig |1
arch/mips/include/asm/highmem.h |4 +-
arch/mips/mm/highmem.c | 77
arch/mips/mm/init.c |3 -
4 files changed, 3 insertions(+), 82 deletions(-)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2654,6 +2654,7 @@ config MIPS_CRC_SUPPORT
config HIGHMEM
bool "High Memory Support"
depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM &&
!CPU_MIPS32_3_5_EVA
+ select KMAP_ATOMIC_GENERIC
config CPU_SUPPORTS_HIGHMEM
bool
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -48,11 +48,11 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps()BUG_ON(cpu_has_dc_aliases)
-extern void kmap_init(void);
+#define arch_kmap_temp_post_map(vaddr, pteval) local_flush_tlb_one(vaddr)
+#define arch_kmap_temp_post_unmap(vaddr) local_flush_tlb_one(vaddr)
#endif /* __KERNEL__ */
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -8,8 +8,6 @@
#include
#include
-static pte_t *kmap_pte;
-
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@@ -17,78 +15,3 @@ void kmap_flush_tlb(unsigned long addr)
flush_tlb_one(addr);
}
EXPORT_SYMBOL(kmap_flush_tlb);
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte - idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- local_flush_tlb_one((unsigned long)vaddr);
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type __maybe_unused;
-
- if (vaddr < FIXADDR_START)
- return;
-
- type = kmap_atomic_idx();
-#ifdef CONFIG_DEBUG_HIGHMEM
- {
- int idx = type + KM_TYPE_NR * smp_processor_id();
-
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_one(vaddr);
- }
-#endif
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- unsigned long vaddr;
- int idx, type;
-
- preempt_disable();
- pagefault_disable();
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
- flush_tlb_one(vaddr);
-
- return (void*) vaddr;
-}
-
-void __init kmap_init(void)
-{
- unsigned long kmap_vstart;
-
- /* cache the first kmap pte */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = virt_to_kpte(kmap_vstart);
-}
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -402,9 +402,6 @@ void __init paging_init(void)
pagetable_init();
-#ifdef CONFIG_HIGHMEM
- kmap_init();
-#endif
#ifdef CONFIG_ZONE_DMA
max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
#endif
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[patch RFC 09/15] nds32/mm/highmem: Switch to generic kmap atomic
The mapping code is odd and looks broken. See FIXME in the comment.
Signed-off-by: Thomas Gleixner
Cc: Nick Hu
Cc: Greentime Hu
Cc: Vincent Chen
---
Note: Completely untested
---
arch/nds32/Kconfig.cpu |1
arch/nds32/include/asm/highmem.h | 21 +
arch/nds32/mm/Makefile |1
arch/nds32/mm/highmem.c | 48 ---
4 files changed, 17 insertions(+), 54 deletions(-)
--- a/arch/nds32/Kconfig.cpu
+++ b/arch/nds32/Kconfig.cpu
@@ -157,6 +157,7 @@ config HW_SUPPORT_UNALIGNMENT_ACCESS
config HIGHMEM
bool "High Memory Support"
depends on MMU && !CPU_CACHE_ALIASING
+select KMAP_ATOMIC_GENERIC
help
The address space of Andes processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -45,11 +45,22 @@ extern pte_t *pkmap_page_table;
extern void kmap_init(void);
/*
- * The following functions are already defined by
- * when CONFIG_HIGHMEM is not set.
+ * FIXME: The below looks broken vs. a kmap_atomic() in task context which
+ * is interupted and another kmap_atomic() happens in interrupt context.
+ * But what do I know about nds32. -- tglx
*/
-#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_pfn(unsigned long pfn);
-#endif
+#define arch_kmap_temp_post_map(vaddr, pteval) \
+ do {\
+ __nds32__tlbop_inv(vaddr); \
+ __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN); \
+ __nds32__tlbop_rwr(pteval); \
+ __nds32__isb(); \
+ } while (0)
+
+#define arch_kmap_temp_pre_unmap(vaddr, pte) \
+ do {\
+ __nds32__tlbop_inv(vaddr); \
+ __nds32__isb(); \
+ } while (0)
#endif
--- a/arch/nds32/mm/Makefile
+++ b/arch/nds32/mm/Makefile
@@ -3,7 +3,6 @@ obj-y := extable.o tlb.o fault.o init
mm-nds32.o cacheflush.o proc.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_proc.o = $(CC_FLAGS_FTRACE)
--- a/arch/nds32/mm/highmem.c
+++ /dev/null
@@ -1,48 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned int idx;
- unsigned long vaddr, pte;
- int type;
- pte_t *ptep;
-
- type = kmap_atomic_idx_push();
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- pte = (page_to_pfn(page) << PAGE_SHIFT) | prot;
- ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
- set_pte(ptep, pte);
-
- __nds32__tlbop_inv(vaddr);
- __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
- __nds32__tlbop_rwr(pte);
- __nds32__isb();
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- if (kvaddr >= (void *)FIXADDR_START) {
- unsigned long vaddr = (unsigned long)kvaddr;
- pte_t *ptep;
- kmap_atomic_idx_pop();
- __nds32__tlbop_inv(vaddr);
- __nds32__isb();
- ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
- set_pte(ptep, 0);
- }
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
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[patch RFC 11/15] sparc/mm/highmem: Switch to generic kmap atomic
Signed-off-by: Thomas Gleixner
Cc: "David S. Miller"
Cc: sparcli...@vger.kernel.org
---
Note: Completely untested
---
arch/sparc/Kconfig |1
arch/sparc/include/asm/highmem.h |7 +-
arch/sparc/mm/Makefile |3 -
arch/sparc/mm/highmem.c | 115 ---
arch/sparc/mm/srmmu.c|2
5 files changed, 6 insertions(+), 122 deletions(-)
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -137,6 +137,7 @@ config MMU
config HIGHMEM
bool
default y if SPARC32
+select KMAP_ATOMIC_GENERIC
config ZONE_DMA
bool
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -33,8 +33,6 @@ extern unsigned long highstart_pfn, high
#define kmap_prot __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE)
extern pte_t *pkmap_page_table;
-void kmap_init(void) __init;
-
/*
* Right now we initialize only a single pte table. It can be extended
* easily, subsequent pte tables have to be allocated in one physical
@@ -53,6 +51,11 @@ void kmap_init(void) __init;
#define flush_cache_kmaps()flush_cache_all()
+/* FIXME: Use __flush_tlb_one(vaddr) instead of flush_cache_all() -- Anton */
+#define arch_kmap_temp_post_map(vaddr, pteval) flush_cache_all()
+#define arch_kmap_temp_post_unmap(vaddr) flush_cache_all()
+
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/sparc/mm/Makefile
+++ b/arch/sparc/mm/Makefile
@@ -15,6 +15,3 @@ obj-$(CONFIG_SPARC32) += leon_mm.o
# Only used by sparc64
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
-
-# Only used by sparc32
-obj-$(CONFIG_HIGHMEM) += highmem.o
--- a/arch/sparc/mm/highmem.c
+++ /dev/null
@@ -1,115 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * Provides kernel-static versions of atomic kmap functions originally
- * found as inlines in include/asm-sparc/highmem.h. These became
- * needed as kmap_atomic() and kunmap_atomic() started getting
- * called from within modules.
- * -- Tomas Szepe , September 2002
- *
- * But kmap_atomic() and kunmap_atomic() cannot be inlined in
- * modules because they are loaded with btfixup-ped functions.
- */
-
-/*
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need it.
- *
- * XXX This is an old text. Actually, it's good to use atomic kmaps,
- * provided you remember that they are atomic and not try to sleep
- * with a kmap taken, much like a spinlock. Non-atomic kmaps are
- * shared by CPUs, and so precious, and establishing them requires IPI.
- * Atomic kmaps are lightweight and we may have NCPUS more of them.
- */
-#include
-#include
-#include
-
-#include
-#include
-#include
-
-static pte_t *kmap_pte;
-
-void __init kmap_init(void)
-{
- unsigned long address = __fix_to_virt(FIX_KMAP_BEGIN);
-
-/* cache the first kmap pte */
-kmap_pte = virt_to_kpte(address);
-}
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- long idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-
-/* XXX Fix - Anton */
-#if 0
- __flush_cache_one(vaddr);
-#else
- flush_cache_all();
-#endif
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte-idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
-/* XXX Fix - Anton */
-#if 0
- __flush_tlb_one(vaddr);
-#else
- flush_tlb_all();
-#endif
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int type;
-
- if (vaddr < FIXADDR_START)
- return;
-
- type = kmap_atomic_idx();
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- {
- unsigned long idx;
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
-
- /* XXX Fix - Anton */
-#if 0
- __flush_cache_one(vaddr);
-#else
- flush_cache_all();
-#endif
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- /* XXX Fix - Anton */
-#if 0
- __flush_tlb_one(vaddr);
-#else
- flush_tlb_all();
-#endif
- }
-#endif
-
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -971,8 +971,6 @@ void __init srmmu_paging_init(void)
sparc_context_init(num
[patch RFC 15/15] mm/highmem: Provide kmap_temporary*
Now that the kmap atomic index is stored in task struct provide a
preemptible variant. On context switch the maps of an outgoing task are
removed and the map of the incoming task are restored. That's obviously
slow, but highmem is slow anyway.
The kmap_temporary and iomap_temporary interfaces can be invoked from both
preemptible and atomic context.
A wholesale conversion of kmap_atomic to be fully preemptible is not
possible because some of the usage sites might rely on the preemption
disable for serialization or per CPUness. Needs to be done on a case by
case basis.
Signed-off-by: Thomas Gleixner
---
arch/x86/include/asm/iomap.h | 16 -
arch/x86/mm/iomap_32.c |7 +---
include/linux/highmem.h | 70 +--
mm/highmem.c | 18 +--
4 files changed, 80 insertions(+), 31 deletions(-)
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -13,11 +13,23 @@
#include
#include
-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
+void __iomem *iomap_temporary_pfn_prot(unsigned long pfn, pgprot_t prot);
+
+static inline void __iomem *iomap_atomic_pfn_prot(unsigned long pfn,
+ pgprot_t prot)
+{
+ preempt_disable();
+ return iomap_temporary_pfn_prot(pfn, prot);
+}
+
+static inline void iounmap_temporary(void __iomem *vaddr)
+{
+ kunmap_temporary_indexed((void __force *)vaddr);
+}
static inline void iounmap_atomic(void __iomem *vaddr)
{
- kunmap_atomic_indexed((void __force *)vaddr);
+ iounmap_temporary(vaddr);
preempt_enable();
}
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -44,7 +44,7 @@ void iomap_free(resource_size_t base, un
}
EXPORT_SYMBOL_GPL(iomap_free);
-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot)
+void __iomem *iomap_temporary_pfn_prot(unsigned long pfn, pgprot_t prot)
{
/*
* For non-PAT systems, translate non-WB request to UC- just in
@@ -60,7 +60,6 @@ void __iomem *iomap_atomic_pfn_prot(unsi
/* Filter out unsupported __PAGE_KERNEL* bits: */
pgprot_val(prot) &= __default_kernel_pte_mask;
- preempt_disable();
- return (void __force __iomem *)kmap_atomic_pfn_prot(pfn, prot);
+ return (void __force __iomem *)__kmap_temporary_pfn_prot(pfn, prot);
}
-EXPORT_SYMBOL_GPL(iomap_atomic_pfn_prot);
+EXPORT_SYMBOL_GPL(iomap_temporary_pfn_prot);
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -35,9 +35,9 @@ static inline void invalidate_kernel_vma
* Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
*/
#ifdef CONFIG_KMAP_ATOMIC_GENERIC
-void *kmap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
-void *kmap_atomic_page_prot(struct page *page, pgprot_t prot);
-void kunmap_atomic_indexed(void *vaddr);
+void *__kmap_temporary_pfn_prot(unsigned long pfn, pgprot_t prot);
+void *__kmap_temporary_page_prot(struct page *page, pgprot_t prot);
+void kunmap_temporary_indexed(void *vaddr);
void kmap_switch_temporary(struct task_struct *prev, struct task_struct *next);
# ifndef ARCH_NEEDS_KMAP_HIGH_GET
static inline void *arch_kmap_temporary_high_get(struct page *page)
@@ -95,16 +95,35 @@ static inline void kunmap(struct page *p
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+static inline void *kmap_temporary_page_prot(struct page *page, pgprot_t prot)
{
- preempt_disable();
- return kmap_atomic_page_prot(page, prot);
+ return __kmap_temporary_page_prot(page, prot);
}
-static inline void *kmap_atomic_pfn(unsigned long pfn)
+static inline void *kmap_temporary_page(struct page *page)
+{
+ return kmap_temporary_page_prot(page, kmap_prot);
+}
+
+static inline void *kmap_temporary_pfn_prot(unsigned long pfn, pgprot_t prot)
+{
+ return __kmap_temporary_pfn_prot(pfn, prot);
+}
+
+static inline void *kmap_temporary_pfn(unsigned long pfn)
+{
+ return kmap_temporary_pfn_prot(pfn, kmap_prot);
+}
+
+static inline void __kunmap_temporary(void *vaddr)
+{
+ kunmap_temporary_indexed(vaddr);
+}
+
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
- return kmap_atomic_pfn_prot(pfn, kmap_prot);
+ return kmap_temporary_page_prot(page, prot);
}
static inline void *kmap_atomic(struct page *page)
@@ -112,9 +131,10 @@ static inline void *kmap_atomic(struct p
return kmap_atomic_prot(page, kmap_prot);
}
-static inline void __kunmap_atomic(void *addr)
+static inline void *kmap_atomic_pfn(unsigned long pfn)
{
- kumap_atomic_indexed(addr);
+ preempt_disable();
+ return kmap_temporary_pfn_prot(pfn, kmap_prot);
}
/* declarations for linux/mm/highmem.c */
@@ -177,6 +197,22 @@ static inline void kunmap(struct page *p
#endif
}
+static in
[patch RFC 14/15] sched: highmem: Store temporary kmaps in task struct
Instead of storing the map per CPU provide and use per task storage. That
prepares for temporary kmaps which are preemptible.
The context switch code is preparatory and not yet in use because
kmap_atomic() runs with preemption disabled. Will be made usable in the
next step.
Signed-off-by: Thomas Gleixner
---
include/linux/highmem.h |1
include/linux/sched.h |9 +++
kernel/sched/core.c | 10
mm/highmem.c| 59 ++--
4 files changed, 72 insertions(+), 7 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -38,6 +38,7 @@ static inline void invalidate_kernel_vma
void *kmap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
void *kmap_atomic_page_prot(struct page *page, pgprot_t prot);
void kunmap_atomic_indexed(void *vaddr);
+void kmap_switch_temporary(struct task_struct *prev, struct task_struct *next);
# ifndef ARCH_NEEDS_KMAP_HIGH_GET
static inline void *arch_kmap_temporary_high_get(struct page *page)
{
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -34,6 +34,7 @@
#include
#include
#include
+#include
/* task_struct member predeclarations (sorted alphabetically): */
struct audit_context;
@@ -628,6 +629,13 @@ struct wake_q_node {
struct wake_q_node *next;
};
+struct kmap_ctrl {
+#ifdef CONFIG_KMAP_ATOMIC_GENERIC
+ int idx;
+ pte_t pteval[KM_TYPE_NR];
+#endif
+};
+
struct task_struct {
#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
@@ -1280,6 +1288,7 @@ struct task_struct {
unsigned intsequential_io;
unsigned intsequential_io_avg;
#endif
+ struct kmap_ctrlkmap_ctrl;
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
unsigned long task_state_change;
#endif
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3529,6 +3529,15 @@ static inline void finish_lock_switch(st
# define finish_arch_post_lock_switch()do { } while (0)
#endif
+static inline void kmap_temp_switch(struct task_struct *prev,
+ struct task_struct *next)
+{
+#ifdef CONFIG_HIGHMEM
+ if (unlikely(prev->kmap_ctrl.idx || next->kmap_ctrl.idx))
+ kmap_switch_temporary(prev, next);
+#endif
+}
+
/**
* prepare_task_switch - prepare to switch tasks
* @rq: the runqueue preparing to switch
@@ -3551,6 +3560,7 @@ prepare_task_switch(struct rq *rq, struc
perf_event_task_sched_out(prev, next);
rseq_preempt(prev);
fire_sched_out_preempt_notifiers(prev, next);
+ kmap_temp_switch(prev, next);
prepare_task(next);
prepare_arch_switch(next);
}
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -370,6 +370,7 @@ void kunmap_high(struct page *page)
if (need_wakeup)
wake_up(pkmap_map_wait);
}
+
EXPORT_SYMBOL(kunmap_high);
#else
static inline void kmap_high_unmap_temporary(unsigned long vaddr) { }
@@ -377,11 +378,9 @@ static inline void kmap_high_unmap_tempo
#ifdef CONFIG_KMAP_ATOMIC_GENERIC
-static DEFINE_PER_CPU(int, __kmap_atomic_idx);
-
static inline int kmap_atomic_idx_push(void)
{
- int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
+ int idx = current->kmap_ctrl.idx++;
WARN_ON_ONCE(in_irq() && !irqs_disabled());
BUG_ON(idx >= KM_TYPE_NR);
@@ -390,14 +389,13 @@ static inline int kmap_atomic_idx_push(v
static inline int kmap_atomic_idx(void)
{
- return __this_cpu_read(__kmap_atomic_idx) - 1;
+ return current->kmap_ctrl.idx - 1;
}
static inline void kmap_atomic_idx_pop(void)
{
- int idx = __this_cpu_dec_return(__kmap_atomic_idx);
-
- BUG_ON(idx < 0);
+ current->kmap_ctrl.idx--;
+ BUG_ON(current->kmap_ctrl.idx < 0);
}
#ifndef arch_kmap_temp_post_map
@@ -447,6 +445,7 @@ static void *__kmap_atomic_pfn_prot(unsi
pteval = pfn_pte(pfn, prot);
set_pte(kmap_pte - idx, pteval);
arch_kmap_temp_post_map(vaddr, pteval);
+ current->kmap_ctrl.pteval[kmap_atomic_idx()] = pteval;
preempt_enable();
return (void *)vaddr;
@@ -499,11 +498,57 @@ void kunmap_atomic_indexed(void *vaddr)
arch_kmap_temp_pre_unmap(addr);
pte_clear(&init_mm, addr, kmap_pte - idx);
arch_kmap_temp_post_unmap(addr);
+ current->kmap_ctrl.pteval[kmap_atomic_idx()] = __pte(0);
kmap_atomic_idx_pop();
preempt_enable();
pagefault_enable();
}
EXPORT_SYMBOL(kunmap_atomic_indexed);
+
+void kmap_switch_temporary(struct task_struct *prev, struct task_struct *next)
+{
+ pte_t *kmap_pte = kmap_get_pte();
+ int i;
+
+ /* Clear @prev's kmaps */
+ for (i = 0; i < prev->kmap_ctrl.idx; i++) {
+ pte_t pteval = prev->kmap_ctrl.pteval[i];
+ unsigned long addr;
+
[patch RFC 12/15] xtensa/mm/highmem: Switch to generic kmap atomic
Signed-off-by: Thomas Gleixner
Cc: Chris Zankel
Cc: Max Filippov
Cc: linux-xte...@linux-xtensa.org
---
Note: Completely untested
---
arch/xtensa/Kconfig |1
arch/xtensa/include/asm/highmem.h |9 +++
arch/xtensa/mm/highmem.c | 44 +++---
3 files changed, 14 insertions(+), 40 deletions(-)
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -679,6 +679,7 @@ endchoice
config HIGHMEM
bool "High Memory Support"
depends on MMU
+select KMAP_ATOMIC_GENERIC
help
Linux can use the full amount of RAM in the system by
default. However, the default MMUv2 setup only maps the
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -68,6 +68,15 @@ static inline void flush_cache_kmaps(voi
flush_cache_all();
}
+enum fixed_addresses kmap_temp_map_idx(int type, unsigned long pfn);
+#define arch_kmap_temp_map_idx kmap_temp_map_idx
+
+enum fixed_addresses kmap_temp_unmap_idx(int type, unsigned long addr);
+#define arch_kmap_temp_unmap_idx kmap_temp_unmap_idx
+
+#define arch_kmap_temp_post_unmap(vaddr) \
+ local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE)
+
void kmap_init(void);
#endif
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -12,8 +12,6 @@
#include
#include
-static pte_t *kmap_pte;
-
#if DCACHE_WAY_SIZE > PAGE_SIZE
unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
@@ -37,55 +35,21 @@ static inline enum fixed_addresses kmap_
color;
}
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
+enum fixed_addresses kmap_temp_map_idx(int type, unsigned long pfn)
{
- enum fixed_addresses idx;
- unsigned long vaddr;
-
- idx = kmap_idx(kmap_atomic_idx_push(),
- DCACHE_ALIAS(page_to_phys(page)));
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte + idx)));
-#endif
- set_pte(kmap_pte + idx, mk_pte(page, prot));
-
- return (void *)vaddr;
+ return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT);
}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-void kunmap_atomic_high(void *kvaddr)
+enum fixed_addresses kmap_temp_unmap_idx(int type, unsigned long addr)
{
- if (kvaddr >= (void *)FIXADDR_START &&
- kvaddr < (void *)FIXADDR_TOP) {
- int idx = kmap_idx(kmap_atomic_idx(),
- DCACHE_ALIAS((unsigned long)kvaddr));
-
- /*
-* Force other mappings to Oops if they'll try to access this
-* pte without first remap it. Keeping stale mappings around
-* is a bad idea also, in case the page changes cacheability
-* attributes or becomes a protected page in a hypervisor.
-*/
- pte_clear(&init_mm, kvaddr, kmap_pte + idx);
- local_flush_tlb_kernel_range((unsigned long)kvaddr,
-(unsigned long)kvaddr + PAGE_SIZE);
-
- kmap_atomic_idx_pop();
- }
+ return kmap_idx(type, DCACHE_ALIAS(addr));
}
-EXPORT_SYMBOL(kunmap_atomic_high);
void __init kmap_init(void)
{
- unsigned long kmap_vstart;
-
/* Check if this memory layout is broken because PKMAP overlaps
* page table.
*/
BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
- /* cache the first kmap pte */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = virt_to_kpte(kmap_vstart);
kmap_waitqueues_init();
}
___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch RFC 10/15] powerpc/mm/highmem: Switch to generic kmap atomic
Signed-off-by: Thomas Gleixner
Cc: Michael Ellerman
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: linuxppc-...@lists.ozlabs.org
---
Note: Completely untested
---
arch/powerpc/Kconfig |1
arch/powerpc/include/asm/highmem.h |6 ++-
arch/powerpc/mm/Makefile |1
arch/powerpc/mm/highmem.c | 67 -
arch/powerpc/mm/mem.c |7 ---
5 files changed, 6 insertions(+), 76 deletions(-)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -406,6 +406,7 @@ menu "Kernel options"
config HIGHMEM
bool "High memory support"
depends on PPC32
+select KMAP_ATOMIC_GENERIC
source "kernel/Kconfig.hz"
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -29,7 +29,6 @@
#include
#include
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
/*
@@ -60,6 +59,11 @@ extern pte_t *pkmap_page_table;
#define flush_cache_kmaps()flush_cache_all()
+#define arch_kmap_temp_post_map(vaddr, pteval) \
+ local_flush_tlb_page(NULL, vaddr)
+#define arch_kmap_temp_post_unmap(vaddr) \
+ local_flush_tlb_page(NULL, vaddr)
+
#endif /* __KERNEL__ */
#endif /* _ASM_HIGHMEM_H */
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -16,7 +16,6 @@ obj-$(CONFIG_NEED_MULTIPLE_NODES) += num
obj-$(CONFIG_PPC_MM_SLICES)+= slice.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_PPC_COPRO_BASE) += copro_fault.o
obj-$(CONFIG_PPC_PTDUMP) += ptdump/
obj-$(CONFIG_KASAN)+= kasan/
--- a/arch/powerpc/mm/highmem.c
+++ /dev/null
@@ -1,67 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * highmem.c: virtual kernel memory mappings for high memory
- *
- * PowerPC version, stolen from the i386 version.
- *
- * Used in CONFIG_HIGHMEM systems for memory pages which
- * are not addressable by direct kernel virtual addresses.
- *
- * Copyright (C) 1999 Gerhard Wichert, Siemens AG
- * gerhard.wich...@pdb.siemens.de
- *
- *
- * Redesigned the x86 32-bit VM architecture to deal with
- * up to 16 Terrabyte physical memory. With current x86 CPUs
- * we now support up to 64 Gigabytes physical RAM.
- *
- * Copyright (C) 1999 Ingo Molnar
- *
- * Reworked for PowerPC by various contributors. Moved from
- * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
- */
-
-#include
-#include
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- WARN_ON(IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !pte_none(*(kmap_pte -
idx)));
- __set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
- local_flush_tlb_page(NULL, vaddr);
-
- return (void*) vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr < __fix_to_virt(FIX_KMAP_END))
- return;
-
- if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
- int type = kmap_atomic_idx();
- unsigned int idx;
-
- idx = type + KM_TYPE_NR * smp_processor_id();
- WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- /*
-* force other mappings to Oops if they'll try to access
-* this pte without first remap it
-*/
- pte_clear(&init_mm, vaddr, kmap_pte-idx);
- local_flush_tlb_page(NULL, vaddr);
- }
-
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -60,11 +60,6 @@
unsigned long long memory_limit;
bool init_mem_is_free;
-#ifdef CONFIG_HIGHMEM
-pte_t *kmap_pte;
-EXPORT_SYMBOL(kmap_pte);
-#endif
-
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
@@ -233,8 +228,6 @@ void __init paging_init(void)
map_kernel_page(PKMAP_BASE, 0, __pgprot(0));/* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
-
- kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
#endif /* CONFIG_HIGHMEM */
printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch RFC 05/15] ARM: highmem: Switch to generic kmap atomic
Signed-off-by: Thomas Gleixner
Cc: Russell King
Cc: Arnd Bergmann
Cc: linux-arm-ker...@lists.infradead.org
---
Note: Completely untested
---
arch/arm/Kconfig |1
arch/arm/include/asm/highmem.h | 30 +++---
arch/arm/mm/Makefile |1
arch/arm/mm/highmem.c | 121 -
4 files changed, 23 insertions(+), 130 deletions(-)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1499,6 +1499,7 @@ config HAVE_ARCH_PFN_VALID
config HIGHMEM
bool "High Memory Support"
depends on MMU
+ select KMAP_ATOMIC_GENERIC
help
The address space of ARM processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -46,19 +46,33 @@ extern pte_t *pkmap_page_table;
#ifdef ARCH_NEEDS_KMAP_HIGH_GET
extern void *kmap_high_get(struct page *page);
+
+#ifdef CONFIG_DEBUG_HIGHMEM
+extern void *arch_kmap_temporary_high_get(struct page *page);
#else
+static inline void *arch_kmap_temporary_high_get(struct page *page)
+{
+ return kmap_high_get(page);
+}
+#endif /* !CONFIG_DEBUG_HIGHMEM */
+
+#else /* ARCH_NEEDS_KMAP_HIGH_GET */
static inline void *kmap_high_get(struct page *page)
{
return NULL;
}
-#endif
+#endif /* !ARCH_NEEDS_KMAP_HIGH_GET */
-/*
- * The following functions are already defined by
- * when CONFIG_HIGHMEM is not set.
- */
-#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_pfn(unsigned long pfn);
-#endif
+#define arch_kmap_temp_post_map(vaddr, pteval) \
+ local_flush_tlb_kernel_page(vaddr)
+
+#define arch_kmap_temp_pre_unmap(vaddr)
\
+do { \
+ if (cache_is_vivt())\
+ __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); \
+} while (0)
+
+#define arch_kmap_temp_post_unmap(vaddr) \
+ local_flush_tlb_kernel_page(vaddr)
#endif
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -19,7 +19,6 @@ obj-$(CONFIG_MODULES) += proc-syms.o
obj-$(CONFIG_DEBUG_VIRTUAL)+= physaddr.o
obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o
-obj-$(CONFIG_HIGHMEM) += highmem.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM_PV_FIXUP) += pv-fixup-asm.o
--- a/arch/arm/mm/highmem.c
+++ /dev/null
@@ -1,121 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * arch/arm/mm/highmem.c -- ARM highmem support
- *
- * Author: Nicolas Pitre
- * Created:september 8, 2008
- * Copyright: Marvell Semiconductors Inc.
- */
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include "mm.h"
-
-static inline void set_fixmap_pte(int idx, pte_t pte)
-{
- unsigned long vaddr = __fix_to_virt(idx);
- pte_t *ptep = virt_to_kpte(vaddr);
-
- set_pte_ext(ptep, pte, 0);
- local_flush_tlb_kernel_page(vaddr);
-}
-
-static inline pte_t get_fixmap_pte(unsigned long vaddr)
-{
- pte_t *ptep = virt_to_kpte(vaddr);
-
- return *ptep;
-}
-
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned int idx;
- unsigned long vaddr;
- void *kmap;
- int type;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- /*
-* There is no cache coherency issue when non VIVT, so force the
-* dedicated kmap usage for better debugging purposes in that case.
-*/
- if (!cache_is_vivt())
- kmap = NULL;
- else
-#endif
- kmap = kmap_high_get(page);
- if (kmap)
- return kmap;
-
- type = kmap_atomic_idx_push();
-
- idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
- vaddr = __fix_to_virt(idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- /*
-* With debugging enabled, kunmap_atomic forces that entry to 0.
-* Make sure it was indeed properly unmapped.
-*/
- BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
-#endif
- /*
-* When debugging is off, kunmap_atomic leaves the previous mapping
-* in place, so the contained TLB flush ensures the TLB is updated
-* with the new mapping.
-*/
- set_fixmap_pte(idx, mk_pte(page, prot));
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int idx, type;
-
- if (kvaddr >= (void *)FIXADDR_START) {
- type = kmap_atomic_idx();
- idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
-
- if (cache_is_vivt())
- __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON
[patch RFC 02/15] highmem: Provide generic variant of kmap_atomic*
The kmap_atomic* interfaces in all architectures are pretty much the same
except for post map operations (flush) and pre- and post unmap operations.
Provide a generic variant for that.
Signed-off-by: Thomas Gleixner
---
include/linux/highmem.h | 87 ---
mm/Kconfig |3 +
mm/highmem.c| 119 +++-
3 files changed, 192 insertions(+), 17 deletions(-)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -31,9 +31,22 @@ static inline void invalidate_kernel_vma
#include
+/*
+ * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
+ */
+#ifdef CONFIG_KMAP_ATOMIC_GENERIC
+void *kmap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
+void *kmap_atomic_page_prot(struct page *page, pgprot_t prot);
+void kunmap_atomic_indexed(void *vaddr);
+# ifndef ARCH_NEEDS_KMAP_HIGH_GET
+static inline void *arch_kmap_temporary_high_get(struct page *page)
+{
+ return NULL;
+}
+# endif
+#endif
+
#ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-extern void kunmap_atomic_high(void *kvaddr);
#include
#ifndef ARCH_HAS_KMAP_FLUSH_TLB
@@ -81,6 +94,11 @@ static inline void kunmap(struct page *p
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
+
+#ifndef CONFIG_KMAP_ATOMIC_GENERIC
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
+void kunmap_atomic_high(void *kvaddr);
+
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
preempt_disable();
@@ -89,7 +107,38 @@ static inline void *kmap_atomic_prot(str
return page_address(page);
return kmap_atomic_high_prot(page, prot);
}
-#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot)
+
+static inline void __kunmap_atomic(void *vaddr)
+{
+ kunmap_atomic_high(vaddr);
+ pagefault_enable();
+}
+#else /* !CONFIG_KMAP_ATOMIC_GENERIC */
+
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ preempt_disable();
+ return kmap_atomic_page_prot(page, prot);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ preempt_disable();
+ return kmap_atomic_pfn_prot(pfn, kmap_prot);
+}
+
+static inline void __kunmap_atomic(void *addr)
+{
+ kumap_atomic_indexed(addr);
+}
+
+
+#endif /* CONFIG_KMAP_ATOMIC_GENERIC */
+
+static inline void *kmap_atomic(struct page *page)
+{
+ return kmap_atomic_prot(page, kmap_prot);
+}
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
@@ -157,21 +206,29 @@ static inline void *kmap_atomic(struct p
pagefault_disable();
return page_address(page);
}
-#define kmap_atomic_prot(page, prot) kmap_atomic(page)
-static inline void kunmap_atomic_high(void *addr)
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ return kmap_atomic(page);
+}
+
+static inline void *kmap_atomic_pfn(unsigned long pfn)
+{
+ return kmap_atomic(pfn_to_page(pfn));
+}
+
+static inline void __kunmap_atomic(void *addr)
{
/*
* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
-* handles re-enabling faults + preemption
+* handles preemption
*/
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
kunmap_flush_on_unmap(addr);
#endif
+ pagefault_enable();
}
-#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
-
#define kmap_flush_unused()do {} while(0)
#endif /* CONFIG_HIGHMEM */
@@ -213,14 +270,12 @@ static inline void kmap_atomic_idx_pop(v
* Prevent people trying to call kunmap_atomic() as if it were kunmap()
* kunmap_atomic() should get the return value of kmap_atomic, not the page.
*/
-#define kunmap_atomic(addr) \
-do {\
- BUILD_BUG_ON(__same_type((addr), struct page *)); \
- kunmap_atomic_high(addr); \
- pagefault_enable(); \
- preempt_enable(); \
-} while (0)
-
+#define kunmap_atomic(addr)\
+ do {\
+ BUILD_BUG_ON(__same_type((addr), struct page *)); \
+ __kunmap_atomic(addr); \
+ preempt_enable(); \
+ } while (0)
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
#ifndef clear_user_highpage
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -868,4 +868,7 @@ config ARCH_HAS_HUGEPD
config MAPPING_DIRTY_HELPERS
bool
+config KMAP_ATOMIC_GENERIC
+ bool
+
endmenu
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -314,6 +314,15 @@ void *kmap_high_get(struct page *page
[patch RFC 06/15] csky/mm/highmem: Switch to generic kmap atomic
Signed-off-by: Thomas Gleixner
Cc: Guo Ren
Cc: linux-c...@vger.kernel.org
---
Note: Completely untested
---
arch/csky/Kconfig |1
arch/csky/include/asm/highmem.h |4 +-
arch/csky/mm/highmem.c | 75
3 files changed, 5 insertions(+), 75 deletions(-)
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -285,6 +285,7 @@ config NR_CPUS
config HIGHMEM
bool "High Memory Support"
depends on !CPU_CK610
+ select KMAP_ATOMIC_GENERIC
default y
config FORCE_MAX_ZONEORDER
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -32,10 +32,12 @@ extern pte_t *pkmap_page_table;
#define ARCH_HAS_KMAP_FLUSH_TLB
extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic_pfn(unsigned long pfn);
#define flush_cache_kmaps() do {} while (0)
+#define arch_kmap_temp_post_map(vaddr, pteval) kmap_flush_tlb(vaddr)
+#define arch_kmap_temp_post_unmap(vaddr) kmap_flush_tlb(vaddr)
+
extern void kmap_init(void);
#endif /* __KERNEL__ */
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -9,8 +9,6 @@
#include
#include
-static pte_t *kmap_pte;
-
unsigned long highstart_pfn, highend_pfn;
void kmap_flush_tlb(unsigned long addr)
@@ -19,67 +17,7 @@ void kmap_flush_tlb(unsigned long addr)
}
EXPORT_SYMBOL(kmap_flush_tlb);
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(!pte_none(*(kmap_pte - idx)));
-#endif
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- flush_tlb_one((unsigned long)vaddr);
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
- int idx;
-
- if (vaddr < FIXADDR_START)
- return;
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
-
- BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-
- pte_clear(&init_mm, vaddr, kmap_pte - idx);
- flush_tlb_one(vaddr);
-#else
- (void) idx; /* to kill a warning */
-#endif
- kmap_atomic_idx_pop();
-}
-EXPORT_SYMBOL(kunmap_atomic_high);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- unsigned long vaddr;
- int idx, type;
-
- pagefault_disable();
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
- flush_tlb_one(vaddr);
-
- return (void *) vaddr;
-}
-
-static void __init kmap_pages_init(void)
+void __init kmap_init(void)
{
unsigned long vaddr;
pgd_t *pgd;
@@ -96,14 +34,3 @@ static void __init kmap_pages_init(void)
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
}
-
-void __init kmap_init(void)
-{
- unsigned long vaddr;
-
- kmap_pages_init();
-
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
-
- kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
-}
___
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http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[patch RFC 03/15] x86/mm/highmem: Use generic kmap atomic implementation
Convert X86 to the generic kmap atomic implementation.
Make the iomap_atomic() naming convention consistent while at it.
Signed-off-by: Thomas Gleixner
---
arch/x86/Kconfig |3 +-
arch/x86/include/asm/fixmap.h |1
arch/x86/include/asm/highmem.h | 12 ++--
arch/x86/include/asm/iomap.h | 17 ++-
arch/x86/mm/highmem_32.c | 59 -
arch/x86/mm/init_32.c | 15 --
arch/x86/mm/iomap_32.c | 58 ++--
include/linux/io-mapping.h |2 -
8 files changed, 25 insertions(+), 142 deletions(-)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -14,10 +14,11 @@ config X86_32
select ARCH_WANT_IPC_PARSE_VERSION
select CLKSRC_I8253
select CLONE_BACKWARDS
+ select GENERIC_VDSO_32
select HAVE_DEBUG_STACKOVERFLOW
+ select KMAP_ATOMIC_GENERIC
select MODULES_USE_ELF_REL
select OLD_SIGACTION
- select GENERIC_VDSO_32
config X86_64
def_bool y
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -151,7 +151,6 @@ extern void reserve_top_address(unsigned
extern int fixmaps_set;
-extern pte_t *kmap_pte;
extern pte_t *pkmap_page_table;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -58,11 +58,17 @@ extern unsigned long highstart_pfn, high
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
-void *kmap_atomic_pfn(unsigned long pfn);
-void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
-
#define flush_cache_kmaps()do { } while (0)
+#definearch_kmap_temp_post_map(vaddr, pteval) \
+ arch_flush_lazy_mmu_mode()
+
+#definearch_kmap_temp_post_unmap(vaddr)\
+ do {\
+ flush_tlb_one_kernel((vaddr)); \
+ arch_flush_lazy_mmu_mode(); \
+ } while (0)
+
extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn);
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -9,19 +9,20 @@
#include
#include
#include
+#include
#include
#include
-void __iomem *
-iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
+void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
-void
-iounmap_atomic(void __iomem *kvaddr);
+static inline void iounmap_atomic(void __iomem *vaddr)
+{
+ kunmap_atomic_indexed((void __force *)vaddr);
+ preempt_enable();
+}
-int
-iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
+int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
-void
-iomap_free(resource_size_t base, unsigned long size);
+void iomap_free(resource_size_t base, unsigned long size);
#endif /* _ASM_X86_IOMAP_H */
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,65 +4,6 @@
#include /* for totalram_pages */
#include
-void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
-{
- unsigned long vaddr;
- int idx, type;
-
- type = kmap_atomic_idx_push();
- idx = type + KM_TYPE_NR*smp_processor_id();
- vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- BUG_ON(!pte_none(*(kmap_pte-idx)));
- set_pte(kmap_pte-idx, mk_pte(page, prot));
- arch_flush_lazy_mmu_mode();
-
- return (void *)vaddr;
-}
-EXPORT_SYMBOL(kmap_atomic_high_prot);
-
-/*
- * This is the same as kmap_atomic() but can map memory that doesn't
- * have a struct page associated with it.
- */
-void *kmap_atomic_pfn(unsigned long pfn)
-{
- return kmap_atomic_prot_pfn(pfn, kmap_prot);
-}
-EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
-
-void kunmap_atomic_high(void *kvaddr)
-{
- unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-
- if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
- vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
- int idx, type;
-
- type = kmap_atomic_idx();
- idx = type + KM_TYPE_NR * smp_processor_id();
-
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
-#endif
- /*
-* Force other mappings to Oops if they'll try to access this
-* pte without first remap it. Keeping stale mappings around
-* is a bad idea also, in case the page changes cacheability
-* attributes or becomes a protected page in a hypervisor.
-*/
- kpte_clear_flush(kmap_pte-idx, vaddr);
- kmap_atomic_idx_pop();
- arch_flush_lazy_mmu_mode();
- }
-#ifdef CONFIG_DEBUG_HIGHMEM
-
