Commit-ID: e981316f560482c001dede7f5b29259bde0b8afb
Gitweb: http://git.kernel.org/tip/e981316f560482c001dede7f5b29259bde0b8afb
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
AuthorDate: Fri, 17 Mar 2017 21:55:11 +0300
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 27 Mar 2017 08:56:25 +0200
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 <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/20170317185515.8636-3-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
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 8544dae..eb64e5b 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;
}
@@ -191,26 +197,36 @@ void efi_sync_low_kernel_mappings(void)
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.
*/
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);
--
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