From e981316f560482c001dede7f5b29259bde0b8afb Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 17 Mar 2017 21:55:11 +0300 Subject: [PATCH] x86/efi: Add 5-level paging support Allocate additional page table level and ajdust efi_sync_low_kernel_mappings() to work with additional page table level. Signed-off-by: Kirill A. Shutemov Reviewed-by: Matt Fleming Acked-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Michal Hocko Cc: Peter Zijlstra Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170317185515.8636-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/platform/efi/efi_64.c | 36 ++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-) diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 8544dae3d1b4..eb64e5b33e37 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -135,6 +135,7 @@ static pgd_t *efi_pgd; int __init efi_alloc_page_tables(void) { pgd_t *pgd; + p4d_t *p4d; pud_t *pud; gfp_t gfp_mask; @@ -147,15 +148,20 @@ int __init efi_alloc_page_tables(void) return -ENOMEM; pgd = efi_pgd + pgd_index(EFI_VA_END); + p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END); + if (!p4d) { + free_page((unsigned long)efi_pgd); + return -ENOMEM; + } - pud = pud_alloc_one(NULL, 0); + pud = pud_alloc(&init_mm, p4d, EFI_VA_END); if (!pud) { + if (CONFIG_PGTABLE_LEVELS > 4) + free_page((unsigned long) pgd_page_vaddr(*pgd)); free_page((unsigned long)efi_pgd); return -ENOMEM; } - pgd_populate(NULL, pgd, pud); - return 0; } @@ -190,6 +196,21 @@ void efi_sync_low_kernel_mappings(void) num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET); memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries); + /* + * As with PGDs, we share all P4D entries apart from the one entry + * that covers the EFI runtime mapping space. + */ + BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END)); + BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK)); + + pgd_efi = efi_pgd + pgd_index(EFI_VA_END); + pgd_k = pgd_offset_k(EFI_VA_END); + p4d_efi = p4d_offset(pgd_efi, 0); + p4d_k = p4d_offset(pgd_k, 0); + + num_entries = p4d_index(EFI_VA_END); + memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries); + /* * We share all the PUD entries apart from those that map the * EFI regions. Copy around them. @@ -197,20 +218,15 @@ void efi_sync_low_kernel_mappings(void) BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0); BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0); - pgd_efi = efi_pgd + pgd_index(EFI_VA_END); - p4d_efi = p4d_offset(pgd_efi, 0); + p4d_efi = p4d_offset(pgd_efi, EFI_VA_END); + p4d_k = p4d_offset(pgd_k, EFI_VA_END); pud_efi = pud_offset(p4d_efi, 0); - - pgd_k = pgd_offset_k(EFI_VA_END); - p4d_k = p4d_offset(pgd_k, 0); pud_k = pud_offset(p4d_k, 0); num_entries = pud_index(EFI_VA_END); memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries); - p4d_efi = p4d_offset(pgd_efi, EFI_VA_START); pud_efi = pud_offset(p4d_efi, EFI_VA_START); - p4d_k = p4d_offset(pgd_k, EFI_VA_START); pud_k = pud_offset(p4d_k, EFI_VA_START); num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START); -- 2.20.1