On Sat, 08 Aug, at 10:18:52AM, Jonathan (Zhixiong) Zhang wrote:
> From: "Jonathan (Zhixiong) Zhang" <zjzh...@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: Catalin Marinas <catalin.mari...@arm.com>
> Acked-by: Hanjun Guo <hanjun....@linaro.org>
> Signed-off-by: Jonathan (Zhixiong) Zhang <zjzh...@codeaurora.org>
> ---
> arch/arm64/include/asm/acpi.h | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 614096732839..b77a2d133da9 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -19,6 +19,11 @@
> #include <asm/psci.h>
> #include <asm/smp_plat.h>
>
> +#ifdef CONFIG_ACPI_APEI
> +#include <linux/efi.h>
> +#include <asm/pgtable.h>
> +#endif
> +
> /* Macros for consistency checks of the GICC subtable of MADT */
> #define ACPI_MADT_GICC_LENGTH \
> (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
> @@ -91,4 +95,29 @@ static inline const char *acpi_get_enable_method(int cpu)
> {
> return acpi_psci_present() ? "psci" : NULL;
> }
> +
> +#ifdef CONFIG_ACPI_APEI
> +static inline 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
> + * 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
> +
> #endif /*_ASM_ACPI_H*/
Everyone happy with this change? Ard?
--
Matt Fleming, Intel Open Source Technology Center
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