[PATCH v3 17/23] media/v4l2-core: pin_longterm_pages (FOLL_PIN) and put_user_page() conversion

John Hubbard
2019-11-12T00:08:59Z

1. Change v4l2 from get_user_pages(FOLL_LONGTERM), to
pin_longterm_pages(), which sets both FOLL_LONGTERM and FOLL_PIN.

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().

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
drivers/media/v4l2-core/videobuf-dma-sg.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c
index 28262190c3ab..9b9c5b37bf59 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,
- flags | FOLL_LONGTERM, dma->pages, NULL);
+ err = pin_longterm_pages(data & PAGE_MASK, dma->nr_pages,
+ flags, 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_longterm_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;
}
--
2.24.0