From c65e774fb3f6af212641538694b9778ff9ab4300 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 14 Feb 2018 14:16:53 +0300 Subject: 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 Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214111656.88514-7-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- include/asm-generic/5level-fixup.h | 1 + include/asm-generic/pgtable-nop4d.h | 9 +++++---- include/linux/kasan.h | 2 +- 3 files changed, 7 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h index dfbd9d990637..9c2e0708eb82 100644 --- a/include/asm-generic/5level-fixup.h +++ b/include/asm-generic/5level-fixup.h @@ -8,6 +8,7 @@ #define P4D_SHIFT PGDIR_SHIFT #define P4D_SIZE PGDIR_SIZE #define P4D_MASK PGDIR_MASK +#define MAX_PTRS_PER_P4D 1 #define PTRS_PER_P4D 1 #define p4d_t pgd_t diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h index 8f22f55de17a..1a29b2a0282b 100644 --- a/include/asm-generic/pgtable-nop4d.h +++ b/include/asm-generic/pgtable-nop4d.h @@ -8,10 +8,11 @@ typedef struct { pgd_t pgd; } p4d_t; -#define P4D_SHIFT PGDIR_SHIFT -#define PTRS_PER_P4D 1 -#define P4D_SIZE (1UL << P4D_SHIFT) -#define P4D_MASK (~(P4D_SIZE-1)) +#define P4D_SHIFT PGDIR_SHIFT +#define MAX_PTRS_PER_P4D 1 +#define PTRS_PER_P4D 1 +#define P4D_SIZE (1UL << P4D_SHIFT) +#define P4D_MASK (~(P4D_SIZE-1)) /* * The "pgd_xxx()" functions here are trivial for a folded two-level diff --git a/include/linux/kasan.h b/include/linux/kasan.h index adc13474a53b..d6459bd1376d 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -18,7 +18,7 @@ extern unsigned char kasan_zero_page[PAGE_SIZE]; extern pte_t kasan_zero_pte[PTRS_PER_PTE]; extern pmd_t kasan_zero_pmd[PTRS_PER_PMD]; extern pud_t kasan_zero_pud[PTRS_PER_PUD]; -extern p4d_t kasan_zero_p4d[PTRS_PER_P4D]; +extern p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D]; void kasan_populate_zero_shadow(const void *shadow_start, const void *shadow_end); -- cgit v1.2.3