tree fb812c2d3cf5940b714d63af0b2bc26082b5855c
parent 0f6e2825ce916eed882996bb6e9148c13ecebefd
author Jan Kara <jack@suse.cz> 1436799344 -0300
committer Mauro Carvalho Chehab <mchehab@osg.samsung.com> 1439740967 -0300

[media] mm: Provide new get_vaddr_frames() helper

Provide new function get_vaddr_frames().  This function maps virtual
addresses from given start and fills given array with page frame numbers of
the corresponding pages. If given start belongs to a normal vma, the function
grabs reference to each of the pages to pin them in memory. If start
belongs to VM_IO | VM_PFNMAP vma, we don't touch page structures. Caller
must make sure pfns aren't reused for anything else while he is using
them.

This function is created for various drivers to simplify handling of
their buffers.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>