On Thu, 30 Jul, at 02:35:06PM, Jonathan (Zhixiong) Zhang wrote:
> From: "Jonathan (Zhixiong) Zhang" <zjzhang@xxxxxxxxxxxxxx>
>
> ... 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 <zjzhang@xxxxxxxxxxxxxx>
> ---
> arch/x86/kernel/acpi/apei.c | 19 +++++++++++++++++++
> include/acpi/apei.h | 1 +
> 2 files changed, 20 insertions(+)
>
> diff --git a/arch/x86/kernel/acpi/apei.c b/arch/x86/kernel/acpi/apei.c
> index c280df6b2aa2..675bd46c4e17 100644
> --- a/arch/x86/kernel/acpi/apei.c
> +++ b/arch/x86/kernel/acpi/apei.c
> @@ -60,3 +60,22 @@ void arch_apei_flush_tlb_one(unsigned long addr)
> {
> __flush_tlb_one(addr);
> }
> +
> +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 __pgprot(PAGE_KERNEL);
> +}
> diff --git a/include/acpi/apei.h b/include/acpi/apei.h
> index 284801ac7042..64a12ce9880b 100644
> --- a/include/acpi/apei.h
> +++ b/include/acpi/apei.h
> @@ -46,6 +46,7 @@ int erst_clear(u64 record_id);
> int arch_apei_enable_cmcff(struct acpi_hest_header *hest_hdr, void *data);
> void arch_apei_report_mem_error(int sev, struct cper_sec_mem_err *mem_err);
> void arch_apei_flush_tlb_one(unsigned long addr);
> +pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);
>
> #endif
> #endif
This doesn't compile :(
/home/matt/src/kernels/efi/arch/x86/kernel/acpi/apei.c:64:24: error: static declaration of ‘arch_apei_get_mem_attribute’ follows non-static declaration
static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
^
In file included from /home/matt/src/kernels/efi/arch/x86/kernel/acpi/apei.c:15:0:
/home/matt/src/kernels/efi/include/acpi/apei.h:48:10: note: previous declaration of ‘arch_apei_get_mem_attribute’ was here
pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);
^
/home/matt/src/kernels/efi/arch/x86/kernel/acpi/apei.c: In function ‘arch_apei_get_mem_attribute’:
/home/matt/src/kernels/efi/arch/x86/kernel/acpi/apei.c:80:2: error: incompatible types when initializing type ‘long unsigned int’ using type ‘pgprot_t’
return __pgprot(PAGE_KERNEL);
--
Matt Fleming, Intel Open Source Technology Center
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