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 --- arch/x86/mm/dump_pagetables.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'arch/x86/mm/dump_pagetables.c') diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index a89f2dbc3531..420058b05d39 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -428,14 +428,15 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st, p4d_t addr, #define p4d_none(a) pud_none(__pud(p4d_val(a))) #endif -#if PTRS_PER_P4D > 1 - static void walk_p4d_level(struct seq_file *m, struct pg_state *st, pgd_t addr, unsigned long P) { int i; p4d_t *start, *p4d_start; pgprotval_t prot; + if (PTRS_PER_P4D == 1) + return walk_pud_level(m, st, __p4d(pgd_val(addr)), P); + p4d_start = start = (p4d_t *)pgd_page_vaddr(addr); for (i = 0; i < PTRS_PER_P4D; i++) { @@ -455,11 +456,8 @@ static void walk_p4d_level(struct seq_file *m, struct pg_state *st, pgd_t addr, } } -#else -#define walk_p4d_level(m,s,a,p) walk_pud_level(m,s,__p4d(pgd_val(a)),p) -#define pgd_large(a) p4d_large(__p4d(pgd_val(a))) -#define pgd_none(a) p4d_none(__p4d(pgd_val(a))) -#endif +#define pgd_large(a) (pgtable_l5_enabled ? pgd_large(a) : p4d_large(__p4d(pgd_val(a)))) +#define pgd_none(a) (pgtable_l5_enabled ? pgd_none(a) : p4d_none(__p4d(pgd_val(a)))) static inline bool is_hypervisor_range(int idx) { -- cgit v1.2.3