diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 14:16:53 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-14 13:11:14 +0100 |
| commit | c65e774fb3f6af212641538694b9778ff9ab4300 (patch) | |
| tree | 3c4da88dd0658874ea3fc7de3cc96ee27d711ef9 /arch/x86/include/asm/pgtable_64_types.h | |
| parent | 5c7919bb1994f8dc7fed219a5db09e6bb9d473a5 (diff) | |
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/include/asm/pgtable_64_types.h')
| -rw-r--r-- | arch/x86/include/asm/pgtable_64_types.h | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 903e4d054bcb..0c48d80e11d4 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -26,6 +26,9 @@ extern unsigned int pgtable_l5_enabled; #define pgtable_l5_enabled 0 #endif +extern unsigned int pgdir_shift; +extern unsigned int ptrs_per_p4d; + #endif /* !__ASSEMBLY__ */ #define SHARED_KERNEL_PMD 0 @@ -35,16 +38,17 @@ extern unsigned int pgtable_l5_enabled; /* * PGDIR_SHIFT determines what a top-level page table entry can map */ -#define PGDIR_SHIFT 48 +#define PGDIR_SHIFT pgdir_shift #define PTRS_PER_PGD 512 /* * 4th level page in 5-level paging case */ -#define P4D_SHIFT 39 -#define PTRS_PER_P4D 512 -#define P4D_SIZE (_AC(1, UL) << P4D_SHIFT) -#define P4D_MASK (~(P4D_SIZE - 1)) +#define P4D_SHIFT 39 +#define MAX_PTRS_PER_P4D 512 +#define PTRS_PER_P4D ptrs_per_p4d +#define P4D_SIZE (_AC(1, UL) << P4D_SHIFT) +#define P4D_MASK (~(P4D_SIZE - 1)) #define MAX_POSSIBLE_PHYSMEM_BITS 52 @@ -53,8 +57,9 @@ extern unsigned int pgtable_l5_enabled; /* * PGDIR_SHIFT determines what a top-level page table entry can map */ -#define PGDIR_SHIFT 39 -#define PTRS_PER_PGD 512 +#define PGDIR_SHIFT 39 +#define PTRS_PER_PGD 512 +#define MAX_PTRS_PER_P4D 1 #endif /* CONFIG_X86_5LEVEL */ |