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@linux.intel.com>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
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 <mingo@kernel.org>
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 @@
int __init efi_alloc_page_tables(void)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
gfp_t gfp_mask;
@@ -147,14 +148,19 @@
return -ENOMEM;
pgd = efi_pgd + pgd_index(EFI_VA_END);
-
- pud = pud_alloc_one(NULL, 0);
- if (!pud) {
+ p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
+ if (!p4d) {
free_page((unsigned long)efi_pgd);
return -ENOMEM;
}
- pgd_populate(NULL, pgd, pud);
+ 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;
+ }
return 0;
}
@@ -191,26 +197,36 @@
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);