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authorJohannes Weiner <hannes@cmpxchg.org>2009-06-16 15:32:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 19:47:40 -0700
commit3b6748e2dd69906af3835db4dc9d1c8a3ee4c68c (patch)
tree5d5476844f8e29e31684ce8ccf7e163ab3182ad6 /include/linux
parent03668a4debf4f50de55c34b6e66dae63e1c73716 (diff)
mm: introduce follow_pfn()
Analoguous to follow_phys(), add a helper that looks up the PFN at a user virtual address in an IO mapping or a raw PFN mapping. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Acked-by: Magnus Damm <magnus.damm@gmail.com> Cc: Hans Verkuil <hverkuil@xs4all.nl> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/mm.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7b548e7cfbd9..c80dbd4a62c6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -792,6 +792,8 @@ int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *vma);
void unmap_mapping_range(struct address_space *mapping,
loff_t const holebegin, loff_t const holelen, int even_cows);
+int follow_pfn(struct vm_area_struct *vma, unsigned long address,
+ unsigned long *pfn);
int follow_phys(struct vm_area_struct *vma, unsigned long address,
unsigned int flags, unsigned long *prot, resource_size_t *phys);
int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,