diff options
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c426a89e025c..3ea6f908a5e0 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) |