[media] v4l: videobuf2: add DMA scatter/gather allocator

Add an implementation of DMA scatter/gather allocator and handling
routines for videobuf2.

For mmap operation mode it is implemented on top of
alloc_page + sg_set_page/_free_page.

For userptr operation mode it is implemented on top of
get_user_pages + sg_set_page/put_page.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/media/videobuf2-dma-sg.h b/include/media/videobuf2-dma-sg.h
new file mode 100644
index 000000000000..0038526b8ef7
--- /dev/null
+++ b/include/media/videobuf2-dma-sg.h
@@ -0,0 +1,32 @@
+/*
+ * videobuf2-dma-sg.h - DMA scatter/gather memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_DMA_SG_H
+#define _MEDIA_VIDEOBUF2_DMA_SG_H
+
+#include <media/videobuf2-core.h>
+
+struct vb2_dma_sg_desc {
+        unsigned long           size;
+        unsigned int            num_pages;
+        struct scatterlist      *sglist;
+};
+
+static inline struct vb2_dma_sg_desc *vb2_dma_sg_plane_desc(
+                struct vb2_buffer *vb, unsigned int plane_no)
+{
+        return (struct vb2_dma_sg_desc *)vb2_plane_cookie(vb, plane_no);
+}
+
+extern const struct vb2_mem_ops vb2_dma_sg_memops;
+
+#endif