From d4db5eb57cab049d378fbfb7ee842857009a8679 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Thu, 14 May 2020 18:01:50 +0200 Subject: media: videobuf2: add begin/end cpu_access callbacks to dma-sg Provide begin_cpu_access() and end_cpu_access() dma_buf_ops callbacks for cache synchronisation on exported buffers. V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers. dma-sg allocates memory using the page allocator directly, so there is no memory consistency guarantee. Signed-off-by: Sergey Senozhatsky Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/common/videobuf2/videobuf2-dma-sg.c | 30 +++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'drivers/media/common/videobuf2/videobuf2-dma-sg.c') diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c index 92072a08af25..595137e358e7 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c @@ -120,6 +120,12 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs, buf->num_pages = size >> PAGE_SHIFT; buf->dma_sgt = &buf->sg_table; + /* + * NOTE: dma-sg allocates memory using the page allocator directly, so + * there is no memory consistency guarantee, hence dma-sg ignores DMA + * attributes passed from the upper layer. That means that + * V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers. + */ buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *), GFP_KERNEL | __GFP_ZERO); if (!buf->pages) @@ -469,6 +475,28 @@ static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf) vb2_dma_sg_put(dbuf->priv); } +static int +vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf, + enum dma_data_direction direction) +{ + struct vb2_dma_sg_buf *buf = dbuf->priv; + struct sg_table *sgt = buf->dma_sgt; + + dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + return 0; +} + +static int +vb2_dma_sg_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf, + enum dma_data_direction direction) +{ + struct vb2_dma_sg_buf *buf = dbuf->priv; + struct sg_table *sgt = buf->dma_sgt; + + dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + return 0; +} + static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf) { struct vb2_dma_sg_buf *buf = dbuf->priv; @@ -487,6 +515,8 @@ static const struct dma_buf_ops vb2_dma_sg_dmabuf_ops = { .detach = vb2_dma_sg_dmabuf_ops_detach, .map_dma_buf = vb2_dma_sg_dmabuf_ops_map, .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap, + .begin_cpu_access = vb2_dma_sg_dmabuf_ops_begin_cpu_access, + .end_cpu_access = vb2_dma_sg_dmabuf_ops_end_cpu_access, .vmap = vb2_dma_sg_dmabuf_ops_vmap, .mmap = vb2_dma_sg_dmabuf_ops_mmap, .release = vb2_dma_sg_dmabuf_ops_release, -- cgit v1.2.3 From a9a2c823601789e9f59ec75f13d0ef03138c04a4 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Thu, 14 May 2020 18:01:51 +0200 Subject: media: videobuf2: don't test db_attach in dma-contig prepare and finish We moved cache management decision making to the upper layer and rely on buffer's need_cache_sync flags and videobuf2 core. If the upper layer (core) has decided to invoke ->prepare() or ->finish() then we must sync. For DMABUF ->need_cache_sync_on_prepare and ->need_cache_sync_on_flush are always false so videobuf core does not call ->prepare() and ->finish() on such buffers. Additionally, scratch the DMABUF comment. Signed-off-by: Sergey Senozhatsky Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/common/videobuf2/videobuf2-dma-contig.c | 6 ++---- drivers/media/common/videobuf2/videobuf2-dma-sg.c | 8 -------- 2 files changed, 2 insertions(+), 12 deletions(-) (limited to 'drivers/media/common/videobuf2/videobuf2-dma-sg.c') diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index 4c68263c617a..a753a03bc48e 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -100,8 +100,7 @@ static void vb2_dc_prepare(void *buf_priv) struct vb2_dc_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt; - /* DMABUF exporter will flush the cache for us */ - if (!sgt || buf->db_attach) + if (!sgt) return; dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, @@ -113,8 +112,7 @@ static void vb2_dc_finish(void *buf_priv) struct vb2_dc_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt; - /* DMABUF exporter will flush the cache for us */ - if (!sgt || buf->db_attach) + if (!sgt) return; dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c index 595137e358e7..0a40e00f0d7e 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c @@ -204,10 +204,6 @@ static void vb2_dma_sg_prepare(void *buf_priv) struct vb2_dma_sg_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt; - /* DMABUF exporter will flush the cache for us */ - if (buf->db_attach) - return; - dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); } @@ -217,10 +213,6 @@ static void vb2_dma_sg_finish(void *buf_priv) struct vb2_dma_sg_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt; - /* DMABUF exporter will flush the cache for us */ - if (buf->db_attach) - return; - dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); } -- cgit v1.2.3