[RFC v3 07/14] vb2: dma-contig: Remove redundant sgt_base field

[Sakari Ailus <sakari.ailus@linux.intel.com>]

The struct vb2_dc_buf contains two struct sg_table fields: sgt_base and
dma_sgt. The former is used by DMA-BUF buffers whereas the latter is used
by USERPTR.

Unify the two, leaving dma_sgt.

MMAP buffers do not need cache flushing since they have been allocated
using dma_alloc_coherent().

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-dma-contig.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index a8a46a8..ddbbcf0 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -31,12 +31,13 @@ struct vb2_dc_buf {
 	unsigned long			attrs;
 	enum dma_data_direction		dma_dir;
 	struct sg_table			*dma_sgt;
-	struct frame_vector		*vec;
 
 	/* MMAP related */
 	struct vb2_vmarea_handler	handler;
 	refcount_t			refcount;
-	struct sg_table			*sgt_base;
+
+	/* USERPTR related */
+	struct frame_vector		*vec;
 
 	/* DMABUF related */
 	struct dma_buf_attachment	*db_attach;
@@ -96,7 +97,7 @@ static void vb2_dc_prepare(void *buf_priv)
 	struct sg_table *sgt = buf->dma_sgt;
 
 	/* DMABUF exporter will flush the cache for us */
-	if (!sgt || buf->db_attach)
+	if (!buf->vec)
 		return;
 
 	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
@@ -109,7 +110,7 @@ static void vb2_dc_finish(void *buf_priv)
 	struct sg_table *sgt = buf->dma_sgt;
 
 	/* DMABUF exporter will flush the cache for us */
-	if (!sgt || buf->db_attach)
+	if (!buf->vec)
 		return;
 
 	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
@@ -126,9 +127,9 @@ static void vb2_dc_put(void *buf_priv)
 	if (!refcount_dec_and_test(&buf->refcount))
 		return;
 
-	if (buf->sgt_base) {
-		sg_free_table(buf->sgt_base);
-		kfree(buf->sgt_base);
+	if (buf->dma_sgt) {
+		sg_free_table(buf->dma_sgt);
+		kfree(buf->dma_sgt);
 	}
 	dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr,
 		       buf->attrs);
@@ -239,13 +240,13 @@ static int vb2_dc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
 	/* Copy the buf->base_sgt scatter list to the attachment, as we can't
 	 * map the same scatter list to multiple attachments at the same time.
 	 */
-	ret = sg_alloc_table(sgt, buf->sgt_base->orig_nents, GFP_KERNEL);
+	ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
 	if (ret) {
 		kfree(attach);
 		return -ENOMEM;
 	}
 
-	rd = buf->sgt_base->sgl;
+	rd = buf->dma_sgt->sgl;
 	wr = sgt->sgl;
 	for (i = 0; i < sgt->orig_nents; ++i) {
 		sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
@@ -396,10 +397,10 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags)
 	exp_info.flags = flags;
 	exp_info.priv = buf;
 
-	if (!buf->sgt_base)
-		buf->sgt_base = vb2_dc_get_base_sgt(buf);
+	if (!buf->dma_sgt)
+		buf->dma_sgt = vb2_dc_get_base_sgt(buf);
 
-	if (WARN_ON(!buf->sgt_base))
+	if (WARN_ON(!buf->dma_sgt))
 		return NULL;
 
 	dbuf = dma_buf_export(&exp_info);
-- 
2.7.4