media/v4l2-core: pin_user_pages (FOLL_PIN) and put_user_page() conversion

1. Change v4l2 from get_user_pages() to pin_user_pages().

2. Because all FOLL_PIN-acquired pages must be released via
   put_user_page(), also convert the put_page() call over to
   put_user_pages_dirty_lock().

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Acked-by: Hans Verkuil <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Alex Williamson <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Björn Töpel <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Leon Romanovsky <[email protected]>
Cc: Mauro Carvalho Chehab <[email protected]>
Cc: Mike Rapoport <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 4 insertions, 7 deletions

diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c
index 28262190c3ab..162a2633b1e3 100644
--- a/drivers/media/v4l2-core/videobuf-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf-dma-sg.c
@@ -183,12 +183,12 @@ static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
 	dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n",
 		data, size, dma->nr_pages);
 
-	err = get_user_pages(data & PAGE_MASK, dma->nr_pages,
+	err = pin_user_pages(data & PAGE_MASK, dma->nr_pages,
 			     flags | FOLL_LONGTERM, dma->pages, NULL);
 
 	if (err != dma->nr_pages) {
 		dma->nr_pages = (err >= 0) ? err : 0;
-		dprintk(1, "get_user_pages: err=%d [%d]\n", err,
+		dprintk(1, "pin_user_pages: err=%d [%d]\n", err,
 			dma->nr_pages);
 		return err < 0 ? err : -EINVAL;
 	}
@@ -349,11 +349,8 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma)
 	BUG_ON(dma->sglen);
 
 	if (dma->pages) {
-		for (i = 0; i < dma->nr_pages; i++) {
-			if (dma->direction == DMA_FROM_DEVICE)
-				set_page_dirty_lock(dma->pages[i]);
-			put_page(dma->pages[i]);
-		}
+		put_user_pages_dirty_lock(dma->pages, dma->nr_pages,
+					  dma->direction == DMA_FROM_DEVICE);
 		kfree(dma->pages);
 		dma->pages = NULL;
 	}