The desirable DMA attributes are not generic for all devices using Videobuf2 scatter-gather DMA ops. Let the drivers decide.
As a result, also the DMA-BUF exporter must provide ops for synchronising the cache. This adds begin_cpu_access and end_cpu_access ops to vb2_dc_dmabuf_ops.
Signed-off-by: Sakari Ailus sakari.ailus@linux.intel.com --- drivers/media/v4l2-core/videobuf2-dma-sg.c | 81 +++++++++++++++++++++++------- 1 file changed, 62 insertions(+), 19 deletions(-)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index 102ddb2..5662f00 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -38,6 +38,7 @@ struct vb2_dma_sg_buf { struct frame_vector *vec; int offset; enum dma_data_direction dma_dir; + unsigned long dma_attrs; struct sg_table sg_table; /* * This will point to sg_table when used with the MMAP or USERPTR @@ -114,6 +115,7 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
buf->vaddr = NULL; buf->dma_dir = dma_dir; + buf->dma_attrs = dma_attrs; buf->offset = 0; buf->size = size; /* size is already page aligned */ @@ -143,7 +145,7 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs, * prepare() memop is called. */ sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + buf->dma_dir, dma_attrs); if (!sgt->nents) goto fail_map;
@@ -181,7 +183,7 @@ static void vb2_dma_sg_put(void *buf_priv) dprintk(1, "%s: Freeing buffer of %d pages\n", __func__, buf->num_pages); dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + buf->dma_dir, buf->dma_attrs); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); sg_free_table(buf->dma_sgt); @@ -198,12 +200,13 @@ 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); + /* + * DMABUF exporter will flush the cache for us; only USERPTR + * and MMAP buffers with non-coherent memory will be flushed. + */ + if (buf->dma_attrs & DMA_ATTR_NON_CONSISTENT) + dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, + buf->dma_dir); }
static void vb2_dma_sg_finish(void *buf_priv) @@ -211,11 +214,13 @@ 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); + /* + * DMABUF exporter will flush the cache for us; only USERPTR + * and MMAP buffers with non-coherent memory will be flushed. + */ + if (buf->dma_attrs & DMA_ATTR_NON_CONSISTENT) + dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, + buf->dma_dir); }
static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr, @@ -237,6 +242,7 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr, buf->vaddr = NULL; buf->dev = dev; buf->dma_dir = dma_dir; + buf->dma_attrs = dma_attrs; buf->offset = vaddr & ~PAGE_MASK; buf->size = size; buf->dma_sgt = &buf->sg_table; @@ -260,7 +266,7 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr, * prepare() memop is called. */ sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + buf->dma_dir, dma_attrs); if (!sgt->nents) goto userptr_fail_map;
@@ -288,7 +294,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) dprintk(1, "%s: Releasing userspace buffer of %d pages\n", __func__, buf->num_pages); dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir, - DMA_ATTR_SKIP_CPU_SYNC); + buf->dma_attrs); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); sg_free_table(buf->dma_sgt); @@ -433,6 +439,7 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map( struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir) { struct vb2_dma_sg_attachment *attach = db_attach->priv; + struct vb2_dma_sg_buf *buf = db_attach->dmabuf->priv; /* stealing dmabuf mutex to serialize map/unmap operations */ struct mutex *lock = &db_attach->dmabuf->lock; struct sg_table *sgt; @@ -448,14 +455,14 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
/* release any previous cache */ if (attach->dma_dir != DMA_NONE) { - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); + dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, + attach->dma_dir, buf->dma_attrs); attach->dma_dir = DMA_NONE; }
/* mapping to the client with new direction */ - sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - dma_dir); + sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents, + dma_dir, buf->dma_attrs); if (!sgt->nents) { pr_err("failed to map scatterlist\n"); mutex_unlock(lock); @@ -488,6 +495,40 @@ static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnu return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL; }
+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; + + /* + * DMABUF exporter will flush the cache for us; only USERPTR + * and MMAP buffers with non-coherent memory will be flushed. + */ + if (buf->dma_attrs & DMA_ATTR_NON_CONSISTENT) + 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; + + /* + * DMABUF exporter will flush the cache for us; only USERPTR + * and MMAP buffers with non-coherent memory will be flushed. + */ + if (buf->dma_attrs & DMA_ATTR_NON_CONSISTENT) + 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; @@ -508,6 +549,8 @@ static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = { .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap, .kmap = vb2_dma_sg_dmabuf_ops_kmap, .kmap_atomic = vb2_dma_sg_dmabuf_ops_kmap, + .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,