UEFI GetMemoryMap() uses a new attribute bit to mark mirrored memory address ranges. See UEFI 2.5 spec pages 157-158: http://www.uefi.org/sites/default/files/resources/UEFI%202_5.pdf On EFI enabled systems scan the memory map and tell memblock about any mirrored ranges. Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> --- arch/x86/kernel/setup.c | 3 +++ arch/x86/platform/efi/efi.c | 21 +++++++++++++++++++++ include/linux/efi.h | 3 +++ 3 files changed, 27 insertions(+) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d74ac33290ae..ac85a1775661 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1103,6 +1103,9 @@ void __init setup_arch(char **cmdline_p) memblock_set_current_limit(ISA_END_ADDRESS); memblock_x86_fill(); + if (efi_enabled(EFI_BOOT)) + efi_find_mirror(); + /* * The EFI specification says that boot service code won't be called * after ExitBootServices(). This is, in fact, a lie. diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 02744df576d5..31635dc5bca4 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -117,6 +117,27 @@ void efi_get_time(struct timespec *now) now->tv_nsec = 0; } +void __init efi_find_mirror(void) +{ + void *p; + unsigned long long mirror_size = 0, total_size = 0; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + efi_memory_desc_t *md = p; + unsigned long long start = md->phys_addr; + unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; + + total_size += size; + if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { + memblock_mark_mirror(start, size); + mirror_size += size; + } + } + if (mirror_size) + pr_info("Memory: %lldM/%lldM mirrored memory\n", + mirror_size>>20, total_size>>20); +} + /* * Tell the kernel about the EFI memory map. This might include * more than the max 128 entries that can fit in the e820 legacy diff --git a/include/linux/efi.h b/include/linux/efi.h index af5be0368dec..3f13903346a2 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -96,6 +96,8 @@ typedef struct { #define EFI_MEMORY_WP ((u64)0x0000000000001000ULL) /* write-protect */ #define EFI_MEMORY_RP ((u64)0x0000000000002000ULL) /* read-protect */ #define EFI_MEMORY_XP ((u64)0x0000000000004000ULL) /* execute-protect */ +#define EFI_MEMORY_MORE_RELIABLE \ + ((u64)0x0000000000010000ULL) /* higher reliability */ #define EFI_MEMORY_RUNTIME ((u64)0x8000000000000000ULL) /* range requires runtime mapping */ #define EFI_MEMORY_DESCRIPTOR_VERSION 1 @@ -864,6 +866,7 @@ extern void efi_enter_virtual_mode (void); /* switch EFI to virtual mode, if pos extern void efi_late_init(void); extern void efi_free_boot_services(void); extern efi_status_t efi_query_variable_store(u32 attributes, unsigned long size); +extern void efi_find_mirror (void); #else static inline void efi_late_init(void) {} static inline void efi_free_boot_services(void) {} -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>