From 2c3cf556b2f7ab5823195766eddec6f1a43134f5 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Tue, 9 Oct 2012 15:31:12 +0200 Subject: [PATCH] x86/mm: Introduce pte_accessible() We need pte_present to return true for _PAGE_PROTNONE pages, to indicate that the pte is associated with a page. However, for TLB flushing purposes, we would like to know whether the pte points to an actually accessible page. This allows us to skip remote TLB flushes for pages that are not actually accessible. Fill in this method for x86 and provide a safe (but slower) method on other architectures. Signed-off-by: Rik van Riel Signed-off-by: Peter Zijlstra Fixed-by: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-66p11te4uj23gevgh4j987ip@git.kernel.org [ Added Linus's review fixes. ] Signed-off-by: Ingo Molnar --- arch/x86/include/asm/pgtable.h | 6 ++++++ include/asm-generic/pgtable.h | 4 ++++ 2 files changed, 10 insertions(+) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index a1f780d45f76..5fe03aaca92e 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -407,6 +407,12 @@ static inline int pte_present(pte_t a) return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE); } +#define pte_accessible pte_accessible +static inline int pte_accessible(pte_t a) +{ + return pte_flags(a) & _PAGE_PRESENT; +} + static inline int pte_hidden(pte_t pte) { return pte_flags(pte) & _PAGE_HIDDEN; diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index b36ce40bd1c6..48fc1dc1c74b 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -219,6 +219,10 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) #define move_pte(pte, prot, old_addr, new_addr) (pte) #endif +#ifndef pte_accessible +# define pte_accessible(pte) ((void)(pte),1) +#endif + #ifndef flush_tlb_fix_spurious_fault #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address) #endif