On Thu, 30 Jul, at 02:35:06PM, Jonathan (Zhixiong) Zhang wrote:
From: "Jonathan (Zhixiong) Zhang" zjzhang@codeaurora.org
... 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@codeaurora.org
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);