From 5cad465d7fa646bad3d677df276bfc8e2ad709e3 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 8 Sep 2015 14:58:54 -0700 Subject: [PATCH] mm: add vmf_insert_pfn_pmd() Similar to vm_insert_pfn(), but for PMDs rather than PTEs. The 'vmf_' prefix instead of 'vm_' prefix is intended to indicate that it returns a VMF_ value rather than an errno (which would only have to be converted into a VMF_ value anyway). Signed-off-by: Matthew Wilcox Cc: Hillf Danton Cc: "Kirill A. Shutemov" Cc: Theodore Ts'o Cc: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/huge_mm.h | 2 ++ mm/huge_memory.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 70587ea..f9b612f 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -33,6 +33,8 @@ extern int move_huge_pmd(struct vm_area_struct *vma, extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot, int prot_numa); +int vmf_insert_pfn_pmd(struct vm_area_struct *, unsigned long addr, pmd_t *, + unsigned long pfn, bool write); enum transparent_hugepage_flag { TRANSPARENT_HUGEPAGE_FLAG, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c426a89..3ea6f90 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -869,6 +869,49 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, flags); } +static int insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd, unsigned long pfn, pgprot_t prot, bool write) +{ + struct mm_struct *mm = vma->vm_mm; + pmd_t entry; + spinlock_t *ptl; + + ptl = pmd_lock(mm, pmd); + if (pmd_none(*pmd)) { + entry = pmd_mkhuge(pfn_pmd(pfn, prot)); + if (write) { + entry = pmd_mkyoung(pmd_mkdirty(entry)); + entry = maybe_pmd_mkwrite(entry, vma); + } + set_pmd_at(mm, addr, pmd, entry); + update_mmu_cache_pmd(vma, addr, pmd); + } + spin_unlock(ptl); + return VM_FAULT_NOPAGE; +} + +int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, + pmd_t *pmd, unsigned long pfn, bool write) +{ + pgprot_t pgprot = vma->vm_page_prot; + /* + * If we had pmd_special, we could avoid all these restrictions, + * but we need to be consistent with PTEs and architectures that + * can't support a 'special' bit. + */ + BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))); + BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == + (VM_PFNMAP|VM_MIXEDMAP)); + BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); + BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn)); + + if (addr < vma->vm_start || addr >= vma->vm_end) + return VM_FAULT_SIGBUS; + if (track_pfn_insert(vma, &pgprot, pfn)) + return VM_FAULT_SIGBUS; + return insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write); +} + int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, struct vm_area_struct *vma) -- 2.7.4