From: "Jonathan (Zhixiong) Zhang" <[email protected]> If the physical address has memory attributes defined by EFI memmap as EFI_MEMORY_UC, the page protection type is PROT_DEVICE_nGnRE. Otherwise, the page protection type is PAGE_KERNEL.
Signed-off-by: Jonathan (Zhixiong) Zhang <[email protected]> --- This patch applies cleanly to efi-next-14364 of efi/next and arm64-upstream-13521 of arm64/master, but needed slight change to apply to next-20150720 of linux-next/master and pm+acpi-4.2-rc3 of linux-pm/master. The later two branches has newer arch/arm64/include/asm/acpi.h with following patch: b6cfb277378e ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro --- arch/arm64/include/asm/acpi.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 1ff9e6eb5e02..41c7623d5b84 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 + /* Basic configuration for ACPI */ #ifdef CONFIG_ACPI /* ACPI table mapping after acpi_gbl_permanent_mmap is set */ @@ -84,4 +89,25 @@ static inline const char *acpi_get_enable_method(int cpu) { return acpi_psci_present() ? "psci" : NULL; } +#ifdef CONFIG_ACPI_APEI +/* + * 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. + */ +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr) +{ + pgprot_t prot; + + prot = efi_mem_attributes(addr); + if (prot & EFI_MEMORY_UC) + return PROT_DEVICE_nGnRnE; + if (prot & EFI_MEMORY_WC) + return PROT_NORMAL_NC; + if (prot & EFI_MEMORY_WT) + return PROT_NORMAL_WT; + return PAGE_KERNEL; +} +#endif + #endif /*_ASM_ACPI_H*/ -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
