From ad3fe525b9507d8d750d60e8e5dd8e0c0836fb99 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 18 May 2018 13:35:23 +0300 Subject: [PATCH] x86/mm: Unify pgtable_l5_enabled usage in early boot code Usually pgtable_l5_enabled is defined using cpu_feature_enabled(). cpu_feature_enabled() is not available in early boot code. We use several different preprocessor tricks to get around it. It's messy. Unify them all. If cpu_feature_enabled() is not yet available, USE_EARLY_PGTABLE_L5 can be defined before all includes. It makes pgtable_l5_enabled rely on __pgtable_l5_enabled variable instead. This approach fits all early users. Signed-off-by: Kirill A. Shutemov Reviewed-by: Thomas Gleixner Cc: Hugh Dickins Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20180518103528.59260-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/boot/compressed/kaslr.c | 4 ++-- arch/x86/boot/compressed/misc.h | 6 ++---- arch/x86/include/asm/pgtable_64_types.h | 13 ++++++++++--- arch/x86/kernel/head64.c | 12 +++++------- arch/x86/mm/kasan_init_64.c | 6 ++---- 5 files changed, 21 insertions(+), 20 deletions(-) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index a0a50b91ecef..b87a7582853d 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -47,7 +47,7 @@ #include #ifdef CONFIG_X86_5LEVEL -unsigned int pgtable_l5_enabled __ro_after_init; +unsigned int __pgtable_l5_enabled; unsigned int pgdir_shift __ro_after_init = 39; unsigned int ptrs_per_p4d __ro_after_init = 1; #endif @@ -734,7 +734,7 @@ void choose_random_location(unsigned long input, #ifdef CONFIG_X86_5LEVEL if (__read_cr4() & X86_CR4_LA57) { - pgtable_l5_enabled = 1; + __pgtable_l5_enabled = 1; pgdir_shift = 48; ptrs_per_p4d = 512; } diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 9e11be4cae19..a423bdb42686 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -12,10 +12,8 @@ #undef CONFIG_PARAVIRT_SPINLOCKS #undef CONFIG_KASAN -#ifdef CONFIG_X86_5LEVEL -/* cpu_feature_enabled() cannot be used that early */ -#define pgtable_l5_enabled __pgtable_l5_enabled -#endif +/* cpu_feature_enabled() cannot be used this early */ +#define USE_EARLY_PGTABLE_L5 #include #include diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index adb47552e6bb..c14a4116a693 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -22,12 +22,19 @@ typedef struct { pteval_t pte; } pte_t; #ifdef CONFIG_X86_5LEVEL extern unsigned int __pgtable_l5_enabled; -#ifndef pgtable_l5_enabled + +#ifdef USE_EARLY_PGTABLE_L5 +/* + * cpu_feature_enabled() is not available in early boot code. + * Use variable instead. + */ +#define pgtable_l5_enabled __pgtable_l5_enabled +#else #define pgtable_l5_enabled cpu_feature_enabled(X86_FEATURE_LA57) -#endif +#endif /* USE_EARLY_PGTABLE_L5 */ #else #define pgtable_l5_enabled 0 -#endif +#endif /* CONFIG_X86_5LEVEL */ extern unsigned int pgdir_shift; extern unsigned int ptrs_per_p4d; diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 2d29e47c056e..494fea1dbd6e 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -6,6 +6,10 @@ */ #define DISABLE_BRANCH_PROFILING + +/* cpu_feature_enabled() cannot be used this early */ +#define USE_EARLY_PGTABLE_L5 + #include #include #include @@ -32,11 +36,6 @@ #include #include -#ifdef CONFIG_X86_5LEVEL -#undef pgtable_l5_enabled -#define pgtable_l5_enabled __pgtable_l5_enabled -#endif - /* * Manage page tables very early on. */ @@ -46,7 +45,6 @@ pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); #ifdef CONFIG_X86_5LEVEL unsigned int __pgtable_l5_enabled __ro_after_init; -EXPORT_SYMBOL(__pgtable_l5_enabled); unsigned int pgdir_shift __ro_after_init = 39; EXPORT_SYMBOL(pgdir_shift); unsigned int ptrs_per_p4d __ro_after_init = 1; @@ -88,7 +86,7 @@ static bool __head check_la57_support(unsigned long physaddr) if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) return false; - *fixup_int(&pgtable_l5_enabled, physaddr) = 1; + *fixup_int(&__pgtable_l5_enabled, physaddr) = 1; *fixup_int(&pgdir_shift, physaddr) = 48; *fixup_int(&ptrs_per_p4d, physaddr) = 512; *fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5; diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 980dbebd0ca7..340bb9b32e01 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -2,10 +2,8 @@ #define DISABLE_BRANCH_PROFILING #define pr_fmt(fmt) "kasan: " fmt -#ifdef CONFIG_X86_5LEVEL -/* Too early to use cpu_feature_enabled() */ -#define pgtable_l5_enabled __pgtable_l5_enabled -#endif +/* cpu_feature_enabled() cannot be used this early */ +#define USE_EARLY_PGTABLE_L5 #include #include -- 2.11.0