linux/mm/pgtable-generic.c
Rik van Riel 8d1acce453 mm: Only flush the TLB when clearing an accessible pte
If ptep_clear_flush() is called to clear a page table entry that is
accessible anyway by the CPU, eg. a _PAGE_PROTNONE page table entry,
there is no need to flush the TLB on remote CPUs.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-vm3rkzevahelwhejx5uwm8ex@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-12-11 14:28:34 +00:00

173 lines
4.6 KiB
C

/*
* mm/pgtable-generic.c
*
* Generic pgtable methods declared in asm-generic/pgtable.h
*
* Copyright (C) 2010 Linus Torvalds
*/
#include <linux/pagemap.h>
#include <asm/tlb.h>
#include <asm-generic/pgtable.h>
#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
/*
* Only sets the access flags (dirty, accessed), as well as write
* permission. Furthermore, we know it always gets set to a "more
* permissive" setting, which allows most architectures to optimize
* this. We return whether the PTE actually changed, which in turn
* instructs the caller to do things like update__mmu_cache. This
* used to be done in the caller, but sparc needs minor faults to
* force that call on sun4c so we changed this macro slightly
*/
int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
pte_t entry, int dirty)
{
int changed = !pte_same(*ptep, entry);
if (changed) {
set_pte_at(vma->vm_mm, address, ptep, entry);
flush_tlb_fix_spurious_fault(vma, address);
}
return changed;
}
#endif
#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
int pmdp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp,
pmd_t entry, int dirty)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
int changed = !pmd_same(*pmdp, entry);
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
if (changed) {
set_pmd_at(vma->vm_mm, address, pmdp, entry);
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
}
return changed;
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
BUG();
return 0;
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
}
#endif
#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
int ptep_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
int young;
young = ptep_test_and_clear_young(vma, address, ptep);
if (young)
flush_tlb_page(vma, address);
return young;
}
#endif
#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
int young;
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
#else
BUG();
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
young = pmdp_test_and_clear_young(vma, address, pmdp);
if (young)
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
return young;
}
#endif
#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
pte_t *ptep)
{
pte_t pte;
pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
if (pte_accessible(pte))
flush_tlb_page(vma, address);
return pte;
}
#endif
#ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd;
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
return pmd;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd = pmd_mksplitting(*pmdp);
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
set_pmd_at(vma->vm_mm, address, pmdp, pmd);
/* tlb flush only to serialize against gup-fast */
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
{
assert_spin_locked(&mm->page_table_lock);
/* FIFO */
if (!mm->pmd_huge_pte)
INIT_LIST_HEAD(&pgtable->lru);
else
list_add(&pgtable->lru, &mm->pmd_huge_pte->lru);
mm->pmd_huge_pte = pgtable;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/* no "address" argument so destroys page coloring of some arch */
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
{
pgtable_t pgtable;
assert_spin_locked(&mm->page_table_lock);
/* FIFO */
pgtable = mm->pmd_huge_pte;
if (list_empty(&pgtable->lru))
mm->pmd_huge_pte = NULL;
else {
mm->pmd_huge_pte = list_entry(pgtable->lru.next,
struct page, lru);
list_del(&pgtable->lru);
}
return pgtable;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PMDP_INVALIDATE
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(*pmdp));
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif