videobuf2/videobuf2-dma-sg.c: convert to use vm_map_pages()

Convert to use vm_map_pages() to map range of kernel memory to user vma.

vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer, not as a
in-buffer offset by design and it always want to mmap a whole buffer from
its beginning.

Link: http://lkml.kernel.org/r/a953fe6b3056de1cc6eab654effdd4a22f125375.1552921225.git.jrdr.linux@gmail.com
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 16 deletions

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 270c3162fdcb..4a4c49d6085c 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -328,28 +328,18 @@ static unsigned int vb2_dma_sg_num_users(void *buf_priv)
 static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
-	unsigned long uaddr = vma->vm_start;
-	unsigned long usize = vma->vm_end - vma->vm_start;
-	int i = 0;
+	int err;
 
 	if (!buf) {
 		printk(KERN_ERR "No memory to map\n");
 		return -EINVAL;
 	}
 
-	do {
-		int ret;
-
-		ret = vm_insert_page(vma, uaddr, buf->pages[i++]);
-		if (ret) {
-			printk(KERN_ERR "Remapping memory, error: %d\n", ret);
-			return ret;
-		}
-
-		uaddr += PAGE_SIZE;
-		usize -= PAGE_SIZE;
-	} while (usize > 0);
-
+	err = vm_map_pages(vma, buf->pages, buf->num_pages);
+	if (err) {
+		printk(KERN_ERR "Remapping memory, error: %d\n", err);
+		return err;
+	}
 
 	/*
 	 * Use common vm_area operations to track buffer refcount.