From b40227fbfb1f98614e6f9bdc4cb3a54ab31d48a5 Mon Sep 17 00:00:00 2001 From: "Jonathan (Zhixiong) Zhang" Date: Fri, 7 Aug 2015 09:36:58 +0100 Subject: [PATCH] acpi, x86: Implement arch_apei_get_mem_attributes() ... to allow an arch specific implementation of getting page protection type associated with a physical address. On x86, we currently have no way to look up the EFI memory map attributes for a region in a consistent way, because the memmap is discarded after efi_free_boot_services(). So if you call efi_mem_attributes() during boot and at runtime, you could theoretically see different attributes. Since we are yet to see any x86 platforms that require anything other than PAGE_KERNEL (some arm64 platforms require the equivalent of PAGE_KERNEL_NOCACHE), return that until we know differently. Signed-off-by: Jonathan (Zhixiong) Zhang Signed-off-by: Matt Fleming Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1438936621-5215-5-git-send-email-matt@codeblueprint.co.uk [ Small fixes to spelling. ] Signed-off-by: Ingo Molnar --- arch/x86/include/asm/acpi.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h index 3a45668f6dc3..94c18ebfd68c 100644 --- a/arch/x86/include/asm/acpi.h +++ b/arch/x86/include/asm/acpi.h @@ -32,6 +32,10 @@ #include #include +#ifdef CONFIG_ACPI_APEI +# include +#endif + #ifdef CONFIG_ACPI extern int acpi_lapic; extern int acpi_ioapic; @@ -147,4 +151,23 @@ extern int x86_acpi_numa_init(void); #define acpi_unlazy_tlb(x) leave_mm(x) +#ifdef CONFIG_ACPI_APEI +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr) +{ + /* + * We currently have no way to look up the EFI memory map + * attributes for a region in a consistent way, because the + * memmap is discarded after efi_free_boot_services(). So if + * you call efi_mem_attributes() during boot and at runtime, + * you could theoretically see different attributes. + * + * Since we are yet to see any x86 platforms that require + * anything other than PAGE_KERNEL (some arm64 platforms + * require the equivalent of PAGE_KERNEL_NOCACHE), return that + * until we know differently. + */ + return PAGE_KERNEL; +} +#endif + #endif /* _ASM_X86_ACPI_H */ -- 2.20.1