[media] videobuf2-dma-sg: Replace vb2_dma_sg_desc with sg_table

Replace the private struct vb2_dma_sg_desc with the struct sg_table so
we can benefit from all the helping functions in lib/scatterlist.c for
things like allocating the sg or compacting the descriptor.
marvel-ccic and solo6x10 drivers, that use this API have been updated.

Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
[s.nawrocki@samsung.com: minor corrections of the changelog]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

4 files changed, 63 insertions, 84 deletions

diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index 5184887b155c..32fab30a9105 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -1221,16 +1221,16 @@ static int mcam_vb_sg_buf_prepare(struct vb2_buffer *vb)
 {
 	struct mcam_vb_buffer *mvb = vb_to_mvb(vb);
 	struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
-	struct vb2_dma_sg_desc *sgd = vb2_dma_sg_plane_desc(vb, 0);
+	struct sg_table *sg_table = vb2_dma_sg_plane_desc(vb, 0);
 	struct mcam_dma_desc *desc = mvb->dma_desc;
 	struct scatterlist *sg;
 	int i;
 
-	mvb->dma_desc_nent = dma_map_sg(cam->dev, sgd->sglist, sgd->num_pages,
-			DMA_FROM_DEVICE);
+	mvb->dma_desc_nent = dma_map_sg(cam->dev, sg_table->sgl,
+			sg_table->nents, DMA_FROM_DEVICE);
 	if (mvb->dma_desc_nent <= 0)
 		return -EIO;  /* Not sure what's right here */
-	for_each_sg(sgd->sglist, sg, mvb->dma_desc_nent, i) {
+	for_each_sg(sg_table->sgl, sg, mvb->dma_desc_nent, i) {
 		desc->dma_addr = sg_dma_address(sg);
 		desc->segment_len = sg_dma_len(sg);
 		desc++;
@@ -1241,9 +1241,11 @@ static int mcam_vb_sg_buf_prepare(struct vb2_buffer *vb)
 static int mcam_vb_sg_buf_finish(struct vb2_buffer *vb)
 {
 	struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
-	struct vb2_dma_sg_desc *sgd = vb2_dma_sg_plane_desc(vb, 0);
+	struct sg_table *sg_table = vb2_dma_sg_plane_desc(vb, 0);
 
-	dma_unmap_sg(cam->dev, sgd->sglist, sgd->num_pages, DMA_FROM_DEVICE);
+	if (sg_table)
+		dma_unmap_sg(cam->dev, sg_table->sgl,
+				sg_table->nents, DMA_FROM_DEVICE);
 	return 0;
 }
 
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 4999c4886898..2f860543912c 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -35,7 +35,9 @@ struct vb2_dma_sg_buf {
 	struct page			**pages;
 	int				write;
 	int				offset;
-	struct vb2_dma_sg_desc		sg_desc;
+	struct sg_table			sg_table;
+	size_t				size;
+	unsigned int			num_pages;
 	atomic_t			refcount;
 	struct vb2_vmarea_handler	handler;
 };
@@ -46,7 +48,7 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
 		gfp_t gfp_flags)
 {
 	unsigned int last_page = 0;
-	int size = buf->sg_desc.size;
+	int size = buf->size;
 
 	while (size > 0) {
 		struct page *pages;
@@ -74,12 +76,8 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
 		}
 
 		split_page(pages, order);
-		for (i = 0; i < (1 << order); i++) {
-			buf->pages[last_page] = &pages[i];
-			sg_set_page(&buf->sg_desc.sglist[last_page],
-					buf->pages[last_page], PAGE_SIZE, 0);
-			last_page++;
-		}
+		for (i = 0; i < (1 << order); i++)
+			buf->pages[last_page++] = &pages[i];
 
 		size -= PAGE_SIZE << order;
 	}
@@ -91,6 +89,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
 {
 	struct vb2_dma_sg_buf *buf;
 	int ret;
+	int num_pages;
 
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
@@ -99,17 +98,11 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
 	buf->vaddr = NULL;
 	buf->write = 0;
 	buf->offset = 0;
-	buf->sg_desc.size = size;
+	buf->size = size;
 	/* size is already page aligned */
-	buf->sg_desc.num_pages = size >> PAGE_SHIFT;
-
-	buf->sg_desc.sglist = vzalloc(buf->sg_desc.num_pages *
-				      sizeof(*buf->sg_desc.sglist));
-	if (!buf->sg_desc.sglist)
-		goto fail_sglist_alloc;
-	sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
+	buf->num_pages = size >> PAGE_SHIFT;
 
-	buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
+	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
 			     GFP_KERNEL);
 	if (!buf->pages)
 		goto fail_pages_array_alloc;
@@ -118,6 +111,11 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
 	if (ret)
 		goto fail_pages_alloc;
 
+	ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
+			buf->num_pages, 0, size, gfp_flags);
+	if (ret)
+		goto fail_table_alloc;
+
 	buf->handler.refcount = &buf->refcount;
 	buf->handler.put = vb2_dma_sg_put;
 	buf->handler.arg = buf;
@@ -125,16 +123,16 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
 	atomic_inc(&buf->refcount);
 
 	dprintk(1, "%s: Allocated buffer of %d pages\n",
-		__func__, buf->sg_desc.num_pages);
+		__func__, buf->num_pages);
 	return buf;
 
+fail_table_alloc:
+	num_pages = buf->num_pages;
+	while (num_pages--)
+		__free_page(buf->pages[num_pages]);
 fail_pages_alloc:
 	kfree(buf->pages);
-
 fail_pages_array_alloc:
-	vfree(buf->sg_desc.sglist);
-
-fail_sglist_alloc:
 	kfree(buf);
 	return NULL;
 }
@@ -142,14 +140,14 @@ fail_sglist_alloc:
 static void vb2_dma_sg_put(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
-	int i = buf->sg_desc.num_pages;
+	int i = buf->num_pages;
 
 	if (atomic_dec_and_test(&buf->refcount)) {
 		dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
-			buf->sg_desc.num_pages);
+			buf->num_pages);
 		if (buf->vaddr)
-			vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages);
-		vfree(buf->sg_desc.sglist);
+			vm_unmap_ram(buf->vaddr, buf->num_pages);
+		sg_free_table(&buf->sg_table);
 		while (--i >= 0)
 			__free_page(buf->pages[i]);
 		kfree(buf->pages);
@@ -162,7 +160,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 {
 	struct vb2_dma_sg_buf *buf;
 	unsigned long first, last;
-	int num_pages_from_user, i;
+	int num_pages_from_user;
 
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
@@ -171,56 +169,41 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	buf->vaddr = NULL;
 	buf->write = write;
 	buf->offset = vaddr & ~PAGE_MASK;
-	buf->sg_desc.size = size;
+	buf->size = size;
 
 	first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;
 	last  = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
-	buf->sg_desc.num_pages = last - first + 1;
-
-	buf->sg_desc.sglist = vzalloc(
-		buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist));
-	if (!buf->sg_desc.sglist)
-		goto userptr_fail_sglist_alloc;
+	buf->num_pages = last - first + 1;
 
-	sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
-
-	buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
+	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
 			     GFP_KERNEL);
 	if (!buf->pages)
-		goto userptr_fail_pages_array_alloc;
+		return NULL;
 
 	num_pages_from_user = get_user_pages(current, current->mm,
 					     vaddr & PAGE_MASK,
-					     buf->sg_desc.num_pages,
+					     buf->num_pages,
 					     write,
 					     1, /* force */
 					     buf->pages,
 					     NULL);
 
-	if (num_pages_from_user != buf->sg_desc.num_pages)
+	if (num_pages_from_user != buf->num_pages)
 		goto userptr_fail_get_user_pages;
 
-	sg_set_page(&buf->sg_desc.sglist[0], buf->pages[0],
-		    PAGE_SIZE - buf->offset, buf->offset);
-	size -= PAGE_SIZE - buf->offset;
-	for (i = 1; i < buf->sg_desc.num_pages; ++i) {
-		sg_set_page(&buf->sg_desc.sglist[i], buf->pages[i],
-			    min_t(size_t, PAGE_SIZE, size), 0);
-		size -= min_t(size_t, PAGE_SIZE, size);
-	}
+	if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
+			buf->num_pages, buf->offset, size, 0))
+		goto userptr_fail_alloc_table_from_pages;
+
 	return buf;
 
+userptr_fail_alloc_table_from_pages:
 userptr_fail_get_user_pages:
 	dprintk(1, "get_user_pages requested/got: %d/%d]\n",
-	       num_pages_from_user, buf->sg_desc.num_pages);
+	       num_pages_from_user, buf->num_pages);
 	while (--num_pages_from_user >= 0)
 		put_page(buf->pages[num_pages_from_user]);
 	kfree(buf->pages);
-
-userptr_fail_pages_array_alloc:
-	vfree(buf->sg_desc.sglist);
-
-userptr_fail_sglist_alloc:
 	kfree(buf);
 	return NULL;
 }
@@ -232,18 +215,18 @@ userptr_fail_sglist_alloc:
 static void vb2_dma_sg_put_userptr(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
-	int i = buf->sg_desc.num_pages;
+	int i = buf->num_pages;
 
 	dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
-	       __func__, buf->sg_desc.num_pages);
+	       __func__, buf->num_pages);
 	if (buf->vaddr)
-		vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages);
+		vm_unmap_ram(buf->vaddr, buf->num_pages);
+	sg_free_table(&buf->sg_table);
 	while (--i >= 0) {
 		if (buf->write)
 			set_page_dirty_lock(buf->pages[i]);
 		put_page(buf->pages[i]);
 	}
-	vfree(buf->sg_desc.sglist);
 	kfree(buf->pages);
 	kfree(buf);
 }
@@ -256,7 +239,7 @@ static void *vb2_dma_sg_vaddr(void *buf_priv)
 
 	if (!buf->vaddr)
 		buf->vaddr = vm_map_ram(buf->pages,
-					buf->sg_desc.num_pages,
+					buf->num_pages,
 					-1,
 					PAGE_KERNEL);
 
@@ -312,7 +295,7 @@ static void *vb2_dma_sg_cookie(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
 
-	return &buf->sg_desc;
+	return &buf->sg_table;
 }
 
 const struct vb2_mem_ops vb2_dma_sg_memops = {
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
index a4c589604b02..9a6d5c0b1339 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
@@ -346,7 +346,7 @@ static int enc_get_mpeg_dma(struct solo_dev *solo_dev, dma_addr_t dma,
 /* Build a descriptor queue out of an SG list and send it to the P2M for
  * processing. */
 static int solo_send_desc(struct solo_enc_dev *solo_enc, int skip,
-			  struct vb2_dma_sg_desc *vbuf, int off, int size,
+			  struct sg_table *vbuf, int off, int size,
 			  unsigned int base, unsigned int base_size)
 {
 	struct solo_dev *solo_dev = solo_enc->solo_dev;
@@ -359,7 +359,7 @@ static int solo_send_desc(struct solo_enc_dev *solo_enc, int skip,
 
 	solo_enc->desc_count = 1;
 
-	for_each_sg(vbuf->sglist, sg, vbuf->num_pages, i) {
+	for_each_sg(vbuf->sgl, sg, vbuf->nents, i) {
 		struct solo_p2m_desc *desc;
 		dma_addr_t dma;
 		int len;
@@ -434,7 +434,7 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
 		struct vb2_buffer *vb, struct vop_header *vh)
 {
 	struct solo_dev *solo_dev = solo_enc->solo_dev;
-	struct vb2_dma_sg_desc *vbuf = vb2_dma_sg_plane_desc(vb, 0);
+	struct sg_table *vbuf = vb2_dma_sg_plane_desc(vb, 0);
 	int frame_size;
 	int ret;
 
@@ -443,7 +443,7 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
 	if (vb2_plane_size(vb, 0) < vh->jpeg_size + solo_enc->jpeg_len)
 		return -EIO;
 
-	sg_copy_from_buffer(vbuf->sglist, vbuf->num_pages,
+	sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
 			solo_enc->jpeg_header,
 			solo_enc->jpeg_len);
 
@@ -451,12 +451,12 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
 		& ~(DMA_ALIGN - 1);
 	vb2_set_plane_payload(vb, 0, vh->jpeg_size + solo_enc->jpeg_len);
 
-	dma_map_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+	dma_map_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
 			DMA_FROM_DEVICE);
 	ret = solo_send_desc(solo_enc, solo_enc->jpeg_len, vbuf, vh->jpeg_off,
 			frame_size, SOLO_JPEG_EXT_ADDR(solo_dev),
 			SOLO_JPEG_EXT_SIZE(solo_dev));
-	dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+	dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
 			DMA_FROM_DEVICE);
 	return ret;
 }
@@ -465,7 +465,7 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
 		struct vb2_buffer *vb, struct vop_header *vh)
 {
 	struct solo_dev *solo_dev = solo_enc->solo_dev;
-	struct vb2_dma_sg_desc *vbuf = vb2_dma_sg_plane_desc(vb, 0);
+	struct sg_table *vbuf = vb2_dma_sg_plane_desc(vb, 0);
 	int frame_off, frame_size;
 	int skip = 0;
 	int ret;
@@ -475,7 +475,7 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
 
 	/* If this is a key frame, add extra header */
 	if (!vh->vop_type) {
-		sg_copy_from_buffer(vbuf->sglist, vbuf->num_pages,
+		sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
 				solo_enc->vop,
 				solo_enc->vop_len);
 
@@ -494,12 +494,12 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
 	frame_size = (vh->mpeg_size + skip + (DMA_ALIGN - 1))
 		& ~(DMA_ALIGN - 1);
 
-	dma_map_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+	dma_map_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
 			DMA_FROM_DEVICE);
 	ret = solo_send_desc(solo_enc, skip, vbuf, frame_off, frame_size,
 			SOLO_MP4E_EXT_ADDR(solo_dev),
 			SOLO_MP4E_EXT_SIZE(solo_dev));
-	dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sglist, vbuf->num_pages,
+	dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
 			DMA_FROM_DEVICE);
 	return ret;
 }
diff --git a/include/media/videobuf2-dma-sg.h b/include/media/videobuf2-dma-sg.h
index 0038526b8ef7..7b89852779af 100644
--- a/include/media/videobuf2-dma-sg.h
+++ b/include/media/videobuf2-dma-sg.h
@@ -15,16 +15,10 @@
 
 #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(
+static inline struct sg_table *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);
+	return (struct sg_table *)vb2_plane_cookie(vb, plane_no);
 }
 
 extern const struct vb2_mem_ops vb2_dma_sg_memops;