From: Douglas Anderson <[email protected]>

We do video allocation all the time and we need it to be fast.  Plus TLB
efficiency isn't terribly important for video.

That means we want to set DMA_ATTR_ALLOC_SINGLE_PAGES.

See also the previous change (commit 14d3ae2efeed "ARM: dma-mapping: Use
DMA_ATTR_ALLOC_SINGLE_PAGES hint to optimize allocation").

Signed-off-by: Douglas Anderson <[email protected]>
[mszyprow: rebased patch onto v4.9-rc1 and adapted changes to latest videbuf2
 changes, this simplifies code changes to only set proper dma attribute flag
 and comment the reason for it, added commit id of arch/arm/mm patch]
Signed-off-by: Marek Szyprowski <[email protected]>
---
 drivers/media/platform/s5p-mfc/s5p_mfc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c 
b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index 27b375e75555..a0a29194ccd1 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -851,6 +851,11 @@ static int s5p_mfc_open(struct file *file)
                ret = -ENOENT;
                goto err_queue_init;
        }
+       /*
+        * We'll do mostly sequential access, so sacrifice TLB efficiency for
+        * faster allocation.
+        */
+       q->dma_attrs = DMA_ATTR_ALLOC_SINGLE_PAGES;
        q->mem_ops = &vb2_dma_contig_memops;
        q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        ret = vb2_queue_init(q);
@@ -881,6 +886,12 @@ static int s5p_mfc_open(struct file *file)
         * will keep the value of bytesused intact.
         */
        q->allow_zero_bytesused = 1;
+
+       /*
+        * We'll do mostly sequential access, so sacrifice TLB efficiency for
+        * faster allocation.
+        */
+       q->dma_attrs = DMA_ATTR_ALLOC_SINGLE_PAGES;
        q->mem_ops = &vb2_dma_contig_memops;
        q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        ret = vb2_queue_init(q);
-- 
1.9.1

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