![Gerald Schaefer](/assets/img/avatar_default.png)
A cow break on a hugetlbfs page with page_count > 1 will set a new pte with set_huge_pte_at(), w/o any tlb flush operation. The old pte will remain in the tlb and subsequent write access to the page will result in a page fault loop, for as long as it may take until the tlb is flushed from somewhere else. This patch introduces an architecture-specific huge_ptep_clear_flush() function, which is called before the the set_huge_pte_at() in hugetlb_cow(). ATTENTION: This is just a nop on all architectures for now, the s390 implementation will come with our large page patch later. Other architectures should define their own huge_ptep_clear_flush() if needed. Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
#ifndef _ASM_X86_HUGETLB_H
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#define _ASM_X86_HUGETLB_H
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#include <asm/page.h>
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static inline int is_hugepage_only_range(struct mm_struct *mm,
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unsigned long addr,
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unsigned long len) {
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return 0;
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}
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/*
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* If the arch doesn't supply something else, assume that hugepage
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* size aligned regions are ok without further preparation.
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*/
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static inline int prepare_hugepage_range(unsigned long addr, unsigned long len)
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{
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if (len & ~HPAGE_MASK)
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return -EINVAL;
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if (addr & ~HPAGE_MASK)
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return -EINVAL;
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return 0;
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}
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static inline void hugetlb_prefault_arch_hook(struct mm_struct *mm) {
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}
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static inline void hugetlb_free_pgd_range(struct mmu_gather **tlb,
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unsigned long addr, unsigned long end,
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unsigned long floor,
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unsigned long ceiling)
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{
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free_pgd_range(tlb, addr, end, floor, ceiling);
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}
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static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, pte_t pte)
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{
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set_pte_at(mm, addr, ptep, pte);
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}
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static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep)
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{
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return ptep_get_and_clear(mm, addr, ptep);
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}
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static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
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unsigned long addr, pte_t *ptep)
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{
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}
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#endif /* _ASM_X86_HUGETLB_H */
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