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 <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox 2015-09-08 14:58:54 -07:00 committed by Linus Torvalds
parent fc43704437
commit 5cad465d7f
2 changed files with 45 additions and 0 deletions

View File

@ -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,

View File

@ -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)