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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2018-02-14 14:16:53 +0300
committerIngo Molnar <mingo@kernel.org>2018-02-14 13:11:14 +0100
commitc65e774fb3f6af212641538694b9778ff9ab4300 (patch)
tree3c4da88dd0658874ea3fc7de3cc96ee27d711ef9 /arch/x86/platform/efi
parent5c7919bb1994f8dc7fed219a5db09e6bb9d473a5 (diff)
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x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable
For boot-time switching between 4- and 5-level paging we need to be able to fold p4d page table level at runtime. It requires variable PGDIR_SHIFT and PTRS_PER_P4D. The change doesn't affect the kernel image size much: text data bss dec hex filename 8628091 4734304 1368064 14730459 e0c4db vmlinux.before 8628393 4734340 1368064 14730797 e0c62d vmlinux.after Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214111656.88514-7-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/platform/efi')
-rw-r--r--arch/x86/platform/efi/efi_64.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 780460aa5ea5..d52aaa7dc088 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -257,8 +257,8 @@ void efi_sync_low_kernel_mappings(void)
* only span a single PGD entry and that the entry also maps
* other important kernel regions.
*/
- BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
- BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
+ MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
+ MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
(EFI_VA_END & PGDIR_MASK));
pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);