Re: [PATCH V8 4/5] arm64: apei: implement arch_apei_get_mem_attributes()

[Catalin Marinas]

On Sat, Jul 25, 2015 at 12:51:08AM +0100, Jonathan (Zhixiong) Zhang wrote:
> From: "Jonathan (Zhixiong) Zhang" <zjzhang@xxxxxxxxxxxxxx>
> 
> 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. Otherwise, return PAGE_KERNEL.
> 
> Change-Id: I7f836cae0fb3e74a34e27ac695c2637ffc4cddc6
> Acked-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@xxxxxxxxxxxxxx>

Same comment about the Change-Id.

> ---
>  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..04720f819f0a 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 +95,26 @@ 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)
> +{
> +	u64 attr;
> +
> +	attr = efi_mem_attributes(addr);
> +	if (attr & EFI_MEMORY_UC)
> +		return PROT_DEVICE_nGnRnE;
> +	if (attr & EFI_MEMORY_WC)
> +		return PROT_NORMAL_NC;
> +	if (attr & EFI_MEMORY_WT)
> +		return PROT_NORMAL_WT;

Just to match the strict mm types, please add __pgprot(PROT_*) here.

> +	return PAGE_KERNEL;

Otherwise:

Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>

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