From ef5e94af16c0c82452e1ea5d387e1203dd2198d6 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 1 Jul 2008 16:46:36 -0700 Subject: [PATCH] x86_32: remove __PAGE_KERNEL(_EXEC) From: Jeremy Fitzhardinge Older x86-32 processors do not support global mappings (PGD), so must only use it if the processor supports it. The _PAGE_KERNEL* flags always have _PAGE_KERNEL set, since logically we always want it set. This is OK even on processors which do not support PGD, since all _PAGE flags are masked with __supported_pte_mask before being turned into a real in-pagetable pte. On 32-bit systems, __supported_pte_mask is initialized to not contain _PAGE_GLOBAL, and it is then added if the CPU is found to support it. The x86-32 code used to use __PAGE_KERNEL/__PAGE_KERNEL_EXEC for this purpose, but they're now redundant and can be removed. Signed-off-by: Jeremy Fitzhardinge Cc: Stephen Tweedie Cc: Eduardo Habkost Cc: Mark McLoughlin Signed-off-by: Ingo Molnar --- arch/x86/mm/init_32.c | 10 ++-------- include/asm-x86/pgtable.h | 10 ---------- 2 files changed, 2 insertions(+), 18 deletions(-) diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 8efe872b96..b5a0fd5f4c 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -383,11 +383,6 @@ static void __init set_highmem_pages_init(void) # define set_highmem_pages_init() do { } while (0) #endif /* CONFIG_HIGHMEM */ -pteval_t __PAGE_KERNEL = _PAGE_KERNEL; -EXPORT_SYMBOL(__PAGE_KERNEL); - -pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC; - void __init native_pagetable_setup_start(pgd_t *base) { unsigned long pfn, va; @@ -509,7 +504,7 @@ void zap_low_mappings(void) int nx_enabled; -pteval_t __supported_pte_mask __read_mostly = ~_PAGE_NX; +pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL); EXPORT_SYMBOL_GPL(__supported_pte_mask); #ifdef CONFIG_X86_PAE @@ -796,8 +791,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, /* Enable PGE if available */ if (cpu_has_pge) { set_in_cr4(X86_CR4_PGE); - __PAGE_KERNEL |= _PAGE_GLOBAL; - __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL; + __supported_pte_mask |= _PAGE_GLOBAL; } /* diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index a1c0009e81..64de07e253 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -78,19 +78,9 @@ #define PAGE_READONLY_EXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | \ _PAGE_ACCESSED) -#ifdef CONFIG_X86_32 -#define _PAGE_KERNEL_EXEC \ - (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED) -#define _PAGE_KERNEL (_PAGE_KERNEL_EXEC | _PAGE_NX) - -#ifndef __ASSEMBLY__ -extern pteval_t __PAGE_KERNEL, __PAGE_KERNEL_EXEC; -#endif /* __ASSEMBLY__ */ -#else #define __PAGE_KERNEL_EXEC \ (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL) #define __PAGE_KERNEL (__PAGE_KERNEL_EXEC | _PAGE_NX) -#endif #define __PAGE_KERNEL_RO (__PAGE_KERNEL & ~_PAGE_RW) #define __PAGE_KERNEL_RX (__PAGE_KERNEL_EXEC & ~_PAGE_RW) -- 2.39.5