This patch uses the generic early_ioremap code to implement early_ioremap for ARM. The ARM-specific bits come mostly from an earlier patch from Leif Lindholm <leif.lindh...@linaro.org> here:
https://lkml.org/lkml/2013/10/3/279 Signed-off-by: Mark Salter <msal...@redhat.com> Tested-by: Leif Lindholm <leif.lindh...@linaro.org> CC: linux-arm-ker...@lists.infradead.org CC: Russell King <li...@arm.linux.org.uk> CC: Catalin Marinas <catalin.mari...@arm.com> CC: Will Deacon <will.dea...@arm.com> CC: Arnd Bergmann <a...@arndb.de> --- arch/arm/Kconfig | 11 +++++ arch/arm/include/asm/Kbuild | 1 + arch/arm/include/asm/fixmap.h | 18 +++++++++ arch/arm/include/asm/io.h | 1 + arch/arm/kernel/setup.c | 3 ++ arch/arm/mm/Makefile | 1 + arch/arm/mm/early_ioremap.c | 93 +++++++++++++++++++++++++++++++++++++++++++ arch/arm/mm/mmu.c | 2 + 8 files changed, 130 insertions(+) create mode 100644 arch/arm/mm/early_ioremap.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c1f1a7e..78a79a6a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1842,6 +1842,17 @@ config UACCESS_WITH_MEMCPY However, if the CPU data cache is using a write-allocate mode, this option is unlikely to provide any performance gain. +config EARLY_IOREMAP + depends on MMU + bool "Provide early_ioremap() support for kernel initialization." + select GENERIC_EARLY_IOREMAP + help + Provide a mechanism for kernel initialisation code to temporarily + map, in a highmem-agnostic way, memory pages in before ioremap() + and friends are available (before paging_init() has run). It uses + the same virtual memory range as kmap so all early mappings must + be unapped before paging_init() is called. + config SECCOMP bool prompt "Enable seccomp to safely compute untrusted bytecode" diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index c38b58c..49ec506 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -4,6 +4,7 @@ generic-y += auxvec.h generic-y += bitsperlong.h generic-y += cputime.h generic-y += current.h +generic-y += early_ioremap.h generic-y += emergency-restart.h generic-y += errno.h generic-y += exec.h diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index 68ea615..e92b7a4 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -21,8 +21,26 @@ enum fixed_addresses { FIX_KMAP_BEGIN, FIX_KMAP_END = (FIXADDR_TOP - FIXADDR_START) >> PAGE_SHIFT, __end_of_fixed_addresses +/* + * 224 temporary boot-time mappings, used by early_ioremap(), + * before ioremap() is functional. + * + * (P)re-using the FIXADDR region, which is used for highmem + * later on, and statically aligned to 1MB. + */ +#define NR_FIX_BTMAPS 32 +#define FIX_BTMAPS_SLOTS 7 +#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) +#define FIX_BTMAP_END FIX_KMAP_BEGIN +#define FIX_BTMAP_BEGIN (FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1) }; +#define FIXMAP_PAGE_NORMAL (L_PTE_MT_WRITEBACK | L_PTE_YOUNG | L_PTE_PRESENT) +#define FIXMAP_PAGE_IO (L_PTE_MT_DEV_NONSHARED | L_PTE_YOUNG | L_PTE_PRESENT) + +extern void __early_set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags); + #include <asm-generic/fixmap.h> #endif diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index 3c597c2..131e0ba 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -28,6 +28,7 @@ #include <asm/byteorder.h> #include <asm/memory.h> #include <asm-generic/pci_iomap.h> +#include <asm/early_ioremap.h> #include <xen/xen.h> /* diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 987a7f5..038fb75 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -36,6 +36,7 @@ #include <asm/cpu.h> #include <asm/cputype.h> #include <asm/elf.h> +#include <asm/io.h> #include <asm/procinfo.h> #include <asm/psci.h> #include <asm/sections.h> @@ -887,6 +888,8 @@ void __init setup_arch(char **cmdline_p) parse_early_param(); + early_ioremap_init(); + sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL); early_paging_init(mdesc, lookup_processor_type(read_cpuid_id())); diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index ecfe6e5..fea855e 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -15,6 +15,7 @@ endif obj-$(CONFIG_MODULES) += proc-syms.o obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o +obj-$(CONFIG_EARLY_IOREMAP) += early_ioremap.o obj-$(CONFIG_HIGHMEM) += highmem.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o diff --git a/arch/arm/mm/early_ioremap.c b/arch/arm/mm/early_ioremap.c new file mode 100644 index 0000000..c3e2bf2 --- /dev/null +++ b/arch/arm/mm/early_ioremap.c @@ -0,0 +1,93 @@ +/* + * early_ioremap() support for ARM + * + * Based on existing support in arch/x86/mm/ioremap.c + * + * Restrictions: currently only functional before paging_init() + */ + +#include <linux/init.h> +#include <linux/io.h> + +#include <asm/fixmap.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/tlbflush.h> + +#include <asm/mach/map.h> + +static pte_t bm_pte[PTRS_PER_PTE] __aligned(PTE_HWTABLE_SIZE) __initdata; + +static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) +{ + unsigned int index = pgd_index(addr); + pgd_t *pgd = cpu_get_pgd() + index; + pud_t *pud = pud_offset(pgd, addr); + pmd_t *pmd = pmd_offset(pud, addr); + + return pmd; +} + +static inline pte_t * __init early_ioremap_pte(unsigned long addr) +{ + return &bm_pte[pte_index(addr)]; +} + +void __init early_ioremap_init(void) +{ + pmd_t *pmd; + + pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); + + pmd_populate_kernel(NULL, pmd, bm_pte); + + /* + * Make sure we don't span multiple pmds. + */ + BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) + != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); + + if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { + WARN_ON(1); + pr_warn("pmd %p != %p\n", + pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); + pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", + fix_to_virt(FIX_BTMAP_BEGIN)); + pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", + fix_to_virt(FIX_BTMAP_END)); + pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); + pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); + } + + early_ioremap_setup(); +} + +void __init __early_set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *pte; + u64 desc; + + if (idx > FIX_KMAP_END) { + BUG(); + return; + } + pte = early_ioremap_pte(addr); + + if (pgprot_val(flags)) + set_pte_at(NULL, 0xfff00000, pte, + pfn_pte(phys >> PAGE_SHIFT, flags)); + else + pte_clear(NULL, addr, pte); + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + desc = *pte; +} + +void __init +early_ioremap_shutdown(void) +{ + pmd_t *pmd; + pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); + pmd_clear(pmd); +} diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 580ef2d..bef59b9 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -34,6 +34,7 @@ #include <asm/mach/arch.h> #include <asm/mach/map.h> #include <asm/mach/pci.h> +#include <asm/early_ioremap.h> #include "mm.h" #include "tcm.h" @@ -1405,6 +1406,7 @@ void __init paging_init(const struct machine_desc *mdesc) { void *zero_page; + early_ioremap_reset(); build_mem_type_table(); prepare_page_table(); map_lowmem(); -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
