tree 5d5476844f8e29e31684ce8ccf7e163ab3182ad6
parent 03668a4debf4f50de55c34b6e66dae63e1c73716
author Johannes Weiner <hannes@cmpxchg.org> 1245191555 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1245206860 -0700

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>