[PATCH V10 2/5] x86: acpi: implement arch_apei_get_mem_attributes()
From: Jonathan (Zhixiong) Zhang <hidden>
Date: 2015-08-06 13:41:02
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: "Jonathan (Zhixiong) Zhang" <redacted> ... to allow arch specific implementation of getting page protection type associated with a physical address. On x86, we currently have no way to lookup 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 <redacted> --- arch/x86/include/asm/acpi.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 3a45668f6dc3..ffe22c6b17bd 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h@@ -32,6 +32,10 @@ #include <asm/mpspec.h> #include <asm/realmode.h> +#ifdef CONFIG_ACPI_APEI +#include <asm/pgtable_types.h> +#endif + #ifdef CONFIG_ACPI extern int acpi_lapic; extern int acpi_ioapic;
@@ -147,4 +151,24 @@ 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 lookup 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 */
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