[PATCH 13/15] swiotlb: merge swiotlb-xen initialization into swiotlb
Reuse the generic swiotlb initialization for xen-swiotlb. For ARM/ARM64
this works trivially, while for x86 xen_swiotlb_fixup needs to be passed
as the remap argument to swiotlb_init_remap/swiotlb_init_late.
Note that the lower bound of the swiotlb size is changed to the smaller
IO_TLB_MIN_SLABS based value with this patch, but that is fine as the
2MB value used in Xen before was just an optimization and is not the
hard lower bound.
Signed-off-by: Christoph Hellwig
Reviewed-by: Stefano Stabellini
---
arch/arm/xen/mm.c | 21 +++---
arch/x86/include/asm/xen/page.h | 5 --
arch/x86/kernel/pci-dma.c | 20 ++---
drivers/xen/swiotlb-xen.c | 128 +---
include/xen/arm/page.h | 1 -
include/xen/swiotlb-xen.h | 8 +-
6 files changed, 28 insertions(+), 155 deletions(-)
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index 28c2070602535..ff05a7899cb86 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -23,22 +23,20 @@
#include
#include
-unsigned long xen_get_swiotlb_free_pages(unsigned int order)
+static gfp_t xen_swiotlb_gfp(void)
{
phys_addr_t base;
- gfp_t flags = __GFP_NOWARN|__GFP_KSWAPD_RECLAIM;
u64 i;
for_each_mem_range(i, , NULL) {
if (base < (phys_addr_t)0x) {
if (IS_ENABLED(CONFIG_ZONE_DMA32))
- flags |= __GFP_DMA32;
- else
- flags |= __GFP_DMA;
- break;
+ return __GFP_DMA32;
+ return __GFP_DMA;
}
}
- return __get_free_pages(flags, order);
+
+ return GFP_KERNEL;
}
static bool hypercall_cflush = false;
@@ -140,10 +138,13 @@ static int __init xen_mm_init(void)
if (!xen_swiotlb_detect())
return 0;
- rc = xen_swiotlb_init();
/* we can work with the default swiotlb */
- if (rc < 0 && rc != -EEXIST)
- return rc;
+ if (!io_tlb_default_mem.nslabs) {
+ rc = swiotlb_init_late(swiotlb_size_or_default(),
+ xen_swiotlb_gfp(), NULL);
+ if (rc < 0)
+ return rc;
+ }
cflush.op = 0;
cflush.a.dev_bus_addr = 0;
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index e989bc2269f54..1fc67df500145 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -357,9 +357,4 @@ static inline bool xen_arch_need_swiotlb(struct device *dev,
return false;
}
-static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
-{
- return __get_free_pages(__GFP_NOWARN, order);
-}
-
#endif /* _ASM_X86_XEN_PAGE_H */
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index a705a199bf8a3..30bbe4abb5d61 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -72,15 +72,13 @@ static inline void __init pci_swiotlb_detect(void)
#endif /* CONFIG_SWIOTLB */
#ifdef CONFIG_SWIOTLB_XEN
-static bool xen_swiotlb;
-
static void __init pci_xen_swiotlb_init(void)
{
if (!xen_initial_domain() && !x86_swiotlb_enable)
return;
x86_swiotlb_enable = true;
- xen_swiotlb = true;
- xen_swiotlb_init_early();
+ x86_swiotlb_flags |= SWIOTLB_ANY;
+ swiotlb_init_remap(true, x86_swiotlb_flags, xen_swiotlb_fixup);
dma_ops = _swiotlb_dma_ops;
if (IS_ENABLED(CONFIG_PCI))
pci_request_acs();
@@ -88,14 +86,16 @@ static void __init pci_xen_swiotlb_init(void)
int pci_xen_swiotlb_init_late(void)
{
- int rc;
-
- if (xen_swiotlb)
+ if (dma_ops == _swiotlb_dma_ops)
return 0;
- rc = xen_swiotlb_init();
- if (rc)
- return rc;
+ /* we can work with the default swiotlb */
+ if (!io_tlb_default_mem.nslabs) {
+ int rc = swiotlb_init_late(swiotlb_size_or_default(),
+ GFP_KERNEL, xen_swiotlb_fixup);
+ if (rc < 0)
+ return rc;
+ }
/* XXX: this switches the dma ops under live devices! */
dma_ops = _swiotlb_dma_ops;
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index c2da3eb4826e8..df8085b50df10 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -104,7 +104,7 @@ static int is_xen_swiotlb_buffer(struct device *dev,
dma_addr_t dma_addr)
return 0;
}
-static int xen_swiotlb_fixup(void *buf, unsigned long nslabs)
+int xen_swiotlb_fixup(void *buf, unsigned long nslabs)
{
int rc;
unsigned int order = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT);
@@ -130,132 +130,6 @@ static int xen_swiotlb_fixup(void *buf, unsigned long
nslabs)
return 0;
}
-enum xen_swiotlb_err {
-
Re: [PATCH 13/15] swiotlb: merge swiotlb-xen initialization into swiotlb
On Mon, Mar 14, 2022 at 07:07:44PM -0400, Boris Ostrovsky wrote:
>> +swiotlb_init_remap(true, x86_swiotlb_flags, xen_swiotlb_fixup);
>
>
> I think we need to have SWIOTLB_ANY set in x86_swiotlb_flags here.
Yes.
> Notice that we don't do remap() after final update to nslabs. We should.
Indeed. I've pushed the fixed patches to the git tree and attached
the patches 12, 13 and 14 in case that is easier:
>From 6d72b98620281984ae778659cedeb369e82af8d8 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig
Date: Mon, 14 Mar 2022 08:02:57 +0100
Subject: swiotlb: provide swiotlb_init variants that remap the buffer
To shared more code between swiotlb and xen-swiotlb, offer a
swiotlb_init_remap interface and add a remap callback to
swiotlb_init_late that will allow Xen to remap the buffer the
buffer without duplicating much of the logic.
Signed-off-by: Christoph Hellwig
---
arch/x86/pci/sta2x11-fixup.c | 2 +-
include/linux/swiotlb.h | 5 -
kernel/dma/swiotlb.c | 36 +---
3 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
index c7e6faf59a861..7368afc039987 100644
--- a/arch/x86/pci/sta2x11-fixup.c
+++ b/arch/x86/pci/sta2x11-fixup.c
@@ -57,7 +57,7 @@ static void sta2x11_new_instance(struct pci_dev *pdev)
int size = STA2X11_SWIOTLB_SIZE;
/* First instance: register your own swiotlb area */
dev_info(>dev, "Using SWIOTLB (size %i)\n", size);
- if (swiotlb_init_late(size, GFP_DMA))
+ if (swiotlb_init_late(size, GFP_DMA, NULL))
dev_emerg(>dev, "init swiotlb failed\n");
}
list_add(>list, _instance_list);
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index ee655f2e4d28b..7b50c82f84ce9 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -36,8 +36,11 @@ struct scatterlist;
int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, unsigned int flags);
unsigned long swiotlb_size_or_default(void);
+void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
+ int (*remap)(void *tlb, unsigned long nslabs));
+int swiotlb_init_late(size_t size, gfp_t gfp_mask,
+ int (*remap)(void *tlb, unsigned long nslabs));
extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
-int swiotlb_init_late(size_t size, gfp_t gfp_mask);
extern void __init swiotlb_update_mem_attributes(void);
phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys,
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 79641c446d284..c37fd3d1c97f7 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -256,9 +256,11 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs,
* Statically reserve bounce buffer space and initialize bounce buffer data
* structures for the software IO TLB used to implement the DMA API.
*/
-void __init swiotlb_init(bool addressing_limit, unsigned int flags)
+void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
+ int (*remap)(void *tlb, unsigned long nslabs))
{
- size_t bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);
+ unsigned long nslabs = default_nslabs;
+ size_t bytes;
void *tlb;
if (!addressing_limit && !swiotlb_force_bounce)
@@ -271,12 +273,23 @@ void __init swiotlb_init(bool addressing_limit, unsigned int flags)
* allow to pick a location everywhere for hypervisors with guest
* memory encryption.
*/
+retry:
+ bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);
if (flags & SWIOTLB_ANY)
tlb = memblock_alloc(bytes, PAGE_SIZE);
else
tlb = memblock_alloc_low(bytes, PAGE_SIZE);
if (!tlb)
goto fail;
+ if (remap && remap(tlb, nslabs) < 0) {
+ memblock_free(tlb, PAGE_ALIGN(bytes));
+
+ if (nslabs <= IO_TLB_MIN_SLABS)
+ panic("%s: Failed to remap %zu bytes\n",
+ __func__, bytes);
+ nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE));
+ goto retry;
+ }
if (swiotlb_init_with_tbl(tlb, default_nslabs, flags))
goto fail_free_mem;
return;
@@ -287,12 +300,18 @@ void __init swiotlb_init(bool addressing_limit, unsigned int flags)
pr_warn("Cannot allocate buffer");
}
+void __init swiotlb_init(bool addressing_limit, unsigned int flags)
+{
+ return swiotlb_init_remap(addressing_limit, flags, NULL);
+}
+
/*
* Systems with larger DMA zones (those that don't support ISA) can
* initialize the swiotlb later using the slab allocator if needed.
* This should be just like above, but with some error catching.
*/
-int swiotlb_init_late(size_t size, gfp_t gfp_mask)
+int swiotlb_init_late(size_t size, gfp_t gfp_mask,
+ int (*remap)(void *tlb, unsigned long nslabs))
{
unsigned long nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE);
unsigned long bytes;
@@ -303,6 +322,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask)
if (swiotlb_force_disable)
return 0;
+retry:
order = get_order(nslabs << IO_TLB_SHIFT);
nslabs = SLABS_PER_PAGE << order;
bytes = nslabs << IO_TLB_SHIFT;
@@ -323,6
Re: [PATCH 13/15] swiotlb: merge swiotlb-xen initialization into swiotlb
On Mon, 14 Mar 2022, Christoph Hellwig wrote: > Reuse the generic swiotlb initialization for xen-swiotlb. For ARM/ARM64 > this works trivially, while for x86 xen_swiotlb_fixup needs to be passed > as the remap argument to swiotlb_init_remap/swiotlb_init_late. > > Signed-off-by: Christoph Hellwig For arch/arm/xen and drivers/xen/swiotlb-xen.c Reviewed-by: Stefano Stabellini ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH 13/15] swiotlb: merge swiotlb-xen initialization into swiotlb
On 3/14/22 3:31 AM, Christoph Hellwig wrote:
-
static void __init pci_xen_swiotlb_init(void)
{
if (!xen_initial_domain() && !x86_swiotlb_enable)
return;
x86_swiotlb_enable = true;
- xen_swiotlb = true;
- xen_swiotlb_init_early();
+ swiotlb_init_remap(true, x86_swiotlb_flags, xen_swiotlb_fixup);
I think we need to have SWIOTLB_ANY set in x86_swiotlb_flags here.
dma_ops = _swiotlb_dma_ops;
if (IS_ENABLED(CONFIG_PCI))
pci_request_acs();
@@ -88,14 +85,16 @@ static void __init pci_xen_swiotlb_init(void)
int pci_xen_swiotlb_init_late(void)
{
- int rc;
-
- if (xen_swiotlb)
+ if (dma_ops == _swiotlb_dma_ops)
return 0;
- rc = xen_swiotlb_init();
- if (rc)
- return rc;
+ /* we can work with the default swiotlb */
+ if (!io_tlb_default_mem.nslabs) {
+ int rc = swiotlb_init_late(swiotlb_size_or_default(),
+ GFP_KERNEL, xen_swiotlb_fixup);
This may be comment for previous patch but looking at swiotlb_init_late():
retry:
order = get_order(nslabs << IO_TLB_SHIFT);
nslabs = SLABS_PER_PAGE << order;
bytes = nslabs << IO_TLB_SHIFT;
while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
vstart = (void *)__get_free_pages(gfp_mask | __GFP_NOWARN,
order);
if (vstart)
break;
order--;
}
if (!vstart)
return -ENOMEM;
if (remap)
rc = remap(vstart, nslabs);
if (rc) {
free_pages((unsigned long)vstart, order);
/* Min is 2MB */
if (nslabs <= 1024)
return rc;
nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE));
goto retry;
}
if (order != get_order(bytes)) {
pr_warn("only able to allocate %ld MB\n",
(PAGE_SIZE << order) >> 20);
nslabs = SLABS_PER_PAGE << order; <===
}
rc = swiotlb_late_init_with_tbl(vstart, nslabs);
Notice that we don't do remap() after final update to nslabs. We should.
-boris
___
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
[PATCH 13/15] swiotlb: merge swiotlb-xen initialization into swiotlb
Reuse the generic swiotlb initialization for xen-swiotlb. For ARM/ARM64
this works trivially, while for x86 xen_swiotlb_fixup needs to be passed
as the remap argument to swiotlb_init_remap/swiotlb_init_late.
Signed-off-by: Christoph Hellwig
---
arch/arm/xen/mm.c | 21 +++---
arch/x86/include/asm/xen/page.h | 5 --
arch/x86/kernel/pci-dma.c | 19 +++--
drivers/xen/swiotlb-xen.c | 128 +---
include/xen/arm/page.h | 1 -
include/xen/swiotlb-xen.h | 8 +-
6 files changed, 27 insertions(+), 155 deletions(-)
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index 28c2070602535..ff05a7899cb86 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -23,22 +23,20 @@
#include
#include
-unsigned long xen_get_swiotlb_free_pages(unsigned int order)
+static gfp_t xen_swiotlb_gfp(void)
{
phys_addr_t base;
- gfp_t flags = __GFP_NOWARN|__GFP_KSWAPD_RECLAIM;
u64 i;
for_each_mem_range(i, , NULL) {
if (base < (phys_addr_t)0x) {
if (IS_ENABLED(CONFIG_ZONE_DMA32))
- flags |= __GFP_DMA32;
- else
- flags |= __GFP_DMA;
- break;
+ return __GFP_DMA32;
+ return __GFP_DMA;
}
}
- return __get_free_pages(flags, order);
+
+ return GFP_KERNEL;
}
static bool hypercall_cflush = false;
@@ -140,10 +138,13 @@ static int __init xen_mm_init(void)
if (!xen_swiotlb_detect())
return 0;
- rc = xen_swiotlb_init();
/* we can work with the default swiotlb */
- if (rc < 0 && rc != -EEXIST)
- return rc;
+ if (!io_tlb_default_mem.nslabs) {
+ rc = swiotlb_init_late(swiotlb_size_or_default(),
+ xen_swiotlb_gfp(), NULL);
+ if (rc < 0)
+ return rc;
+ }
cflush.op = 0;
cflush.a.dev_bus_addr = 0;
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index e989bc2269f54..1fc67df500145 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -357,9 +357,4 @@ static inline bool xen_arch_need_swiotlb(struct device *dev,
return false;
}
-static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
-{
- return __get_free_pages(__GFP_NOWARN, order);
-}
-
#endif /* _ASM_X86_XEN_PAGE_H */
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index a705a199bf8a3..dbb7b83fc3e48 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -72,15 +72,12 @@ static inline void __init pci_swiotlb_detect(void)
#endif /* CONFIG_SWIOTLB */
#ifdef CONFIG_SWIOTLB_XEN
-static bool xen_swiotlb;
-
static void __init pci_xen_swiotlb_init(void)
{
if (!xen_initial_domain() && !x86_swiotlb_enable)
return;
x86_swiotlb_enable = true;
- xen_swiotlb = true;
- xen_swiotlb_init_early();
+ swiotlb_init_remap(true, x86_swiotlb_flags, xen_swiotlb_fixup);
dma_ops = _swiotlb_dma_ops;
if (IS_ENABLED(CONFIG_PCI))
pci_request_acs();
@@ -88,14 +85,16 @@ static void __init pci_xen_swiotlb_init(void)
int pci_xen_swiotlb_init_late(void)
{
- int rc;
-
- if (xen_swiotlb)
+ if (dma_ops == _swiotlb_dma_ops)
return 0;
- rc = xen_swiotlb_init();
- if (rc)
- return rc;
+ /* we can work with the default swiotlb */
+ if (!io_tlb_default_mem.nslabs) {
+ int rc = swiotlb_init_late(swiotlb_size_or_default(),
+ GFP_KERNEL, xen_swiotlb_fixup);
+ if (rc < 0)
+ return rc;
+ }
/* XXX: this switches the dma ops under live devices! */
dma_ops = _swiotlb_dma_ops;
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index c2da3eb4826e8..df8085b50df10 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -104,7 +104,7 @@ static int is_xen_swiotlb_buffer(struct device *dev,
dma_addr_t dma_addr)
return 0;
}
-static int xen_swiotlb_fixup(void *buf, unsigned long nslabs)
+int xen_swiotlb_fixup(void *buf, unsigned long nslabs)
{
int rc;
unsigned int order = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT);
@@ -130,132 +130,6 @@ static int xen_swiotlb_fixup(void *buf, unsigned long
nslabs)
return 0;
}
-enum xen_swiotlb_err {
- XEN_SWIOTLB_UNKNOWN = 0,
- XEN_SWIOTLB_ENOMEM,
- XEN_SWIOTLB_EFIXUP
-};
-
-static const char *xen_swiotlb_error(enum xen_swiotlb_err err)
-{
- switch (err) {
- case XEN_SWIOTLB_ENOMEM:
- return "Cannot allocate Xen-SWIOTLB buffer\n";
- case XEN_SWIOTLB_EFIXUP:
-
