Messages in this thread Patch in this message | | | From | Matt Fleming <> | Subject | [PATCH 1/2] arm64: apei: Implement arch_apei_get_mem_attributes() | Date | Fri, 4 Sep 2015 14:11:41 +0100 |
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From: "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>
Table 8 of UEFI 2.5 section 2.3.6.1 defines mappings from EFI memory types to MAIR attribute encodings for arm64.
If the physical address has memory attributes defined by EFI memmap as EFI_MEMORY_[UC|WC|WT], return approprate page protection type according to the UEFI spec. Otherwise, return PAGE_KERNEL.
Reviewed-by: Matt Fleming <matt.fleming@intel.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Hanjun Guo <hanjun.guo@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> --- arch/arm64/include/asm/acpi.h | 5 +++++ arch/arm64/kernel/acpi.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 406485ed110a..5aa892a12a0d 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -92,4 +92,9 @@ static inline const char *acpi_get_enable_method(int cpu) { return acpi_psci_present() ? "psci" : NULL; } + +#ifdef CONFIG_ACPI_APEI +pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr); +#endif + #endif /*_ASM_ACPI_H*/ diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 19de7537e7d3..9f083606e5bf 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -29,6 +29,11 @@ #include <asm/cpu_ops.h> #include <asm/smp_plat.h> +#ifdef CONFIG_ACPI_APEI +#include <linux/efi.h> +#include <asm/pgtable.h> +#endif + int acpi_noirq = 1; /* skip ACPI IRQ initialization */ int acpi_disabled = 1; EXPORT_SYMBOL(acpi_disabled); @@ -230,3 +235,27 @@ void __init acpi_gic_init(void) early_acpi_os_unmap_memory((char *)table, tbl_size); } + +#ifdef CONFIG_ACPI_APEI +pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr) +{ + /* + * According to "Table 8 Map: EFI memory types to AArch64 memory + * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is + * mapped to a corresponding MAIR attribute encoding. + * The EFI memory attribute advises all possible capabilities + * of a memory region. We use the most efficient capability. + */ + + u64 attr; + + attr = efi_mem_attributes(addr); + if (attr & EFI_MEMORY_WB) + return PAGE_KERNEL; + if (attr & EFI_MEMORY_WT) + return __pgprot(PROT_NORMAL_WT); + if (attr & EFI_MEMORY_WC) + return __pgprot(PROT_NORMAL_NC); + return __pgprot(PROT_DEVICE_nGnRnE); +} +#endif -- 2.1.0
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