From e626e6bb0dfaca41487241d49ce0ae827716101a Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 14 Feb 2018 14:16:51 +0300 Subject: [PATCH] x86/mm: Introduce 'pgtable_l5_enabled' The new flag would indicate what paging mode we are in. 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/20180214111656.88514-5-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/boot/compressed/kaslr.c | 4 ++++ arch/x86/include/asm/pgtable_32_types.h | 2 ++ arch/x86/include/asm/pgtable_64_types.h | 6 ++++++ arch/x86/kernel/head64.c | 5 +++++ 4 files changed, 17 insertions(+) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 8199a6187251..bd69e1830fbe 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -46,6 +46,10 @@ #define STATIC #include +#ifdef CONFIG_X86_5LEVEL +unsigned int pgtable_l5_enabled __ro_after_init = 1; +#endif + extern unsigned long get_cmd_line_ptr(void); /* Simplified build-specific string for starting entropy. */ diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h index 0777e18a1d23..e3225e83db7d 100644 --- a/arch/x86/include/asm/pgtable_32_types.h +++ b/arch/x86/include/asm/pgtable_32_types.h @@ -15,6 +15,8 @@ # include #endif +#define pgtable_l5_enabled 0 + #define PGDIR_SIZE (1UL << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE - 1)) diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index a0db91ab63b8..5e2d724f8f47 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -20,6 +20,12 @@ typedef unsigned long pgprotval_t; typedef struct { pteval_t pte; } pte_t; +#ifdef CONFIG_X86_5LEVEL +extern unsigned int pgtable_l5_enabled; +#else +#define pgtable_l5_enabled 0 +#endif + #endif /* !__ASSEMBLY__ */ #define SHARED_KERNEL_PMD 0 diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index bf5c9ba63ba1..17d00d1886de 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -39,6 +39,11 @@ extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; static unsigned int __initdata next_early_pgt; pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); +#ifdef CONFIG_X86_5LEVEL +unsigned int pgtable_l5_enabled __ro_after_init = 1; +EXPORT_SYMBOL(pgtable_l5_enabled); +#endif + #ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE; EXPORT_SYMBOL(page_offset_base); -- 2.45.2