The scatterlist table is needed in the vast majority of the cases. Allocate struct sg_table as part of the struct. This has the benefit of making managing the buffer data structure allocation, setup and release more simple.
Signed-off-by: Sakari Ailus sakari.ailus@linux.intel.com --- drivers/media/v4l2-core/videobuf2-dma-contig.c | 83 ++++++++++---------------- 1 file changed, 32 insertions(+), 51 deletions(-)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index 22636cd..0afc3da 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -30,6 +30,7 @@ struct vb2_dc_buf { dma_addr_t dma_addr; unsigned long attrs; enum dma_data_direction dma_dir; + struct sg_table __dma_sgt; struct sg_table *dma_sgt;
/* MMAP related */ @@ -127,10 +128,9 @@ static void vb2_dc_put(void *buf_priv) if (!refcount_dec_and_test(&buf->refcount)) return;
- if (buf->dma_sgt) { + 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); put_device(buf->dev); @@ -364,26 +364,6 @@ static struct dma_buf_ops vb2_dc_dmabuf_ops = { .release = vb2_dc_dmabuf_ops_release, };
-static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf) -{ - int ret; - struct sg_table *sgt; - - sgt = kmalloc(sizeof(*sgt), GFP_KERNEL); - if (!sgt) - return NULL; - - ret = dma_get_sgtable_attrs(buf->dev, sgt, buf->cookie, buf->dma_addr, - buf->size, buf->attrs); - if (ret < 0) { - dev_err(buf->dev, "failed to get scatterlist from DMA API\n"); - kfree(sgt); - return NULL; - } - - return sgt; -} - static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags) { struct vb2_dc_buf *buf = buf_priv; @@ -395,11 +375,19 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags) exp_info.flags = flags; exp_info.priv = buf;
- if (!buf->dma_sgt) - buf->dma_sgt = vb2_dc_get_base_sgt(buf); + if (!buf->dma_sgt) { + int ret;
- if (!buf->dma_sgt) - return NULL; + ret = dma_get_sgtable_attrs(buf->dev, &buf->__dma_sgt, + buf->cookie, buf->dma_addr, + buf->size, buf->attrs); + if (ret < 0) { + dev_err(buf->dev, "failed to get scatterlist from DMA API\n"); + return NULL; + } + + buf->dma_sgt = &buf->__dma_sgt; + }
dbuf = dma_buf_export(&exp_info); if (IS_ERR(dbuf)) @@ -435,7 +423,6 @@ static void vb2_dc_put_userptr(void *buf_priv) for (i = 0; i < frame_vector_count(buf->vec); i++) set_page_dirty_lock(pages[i]); sg_free_table(sgt); - kfree(sgt); } vb2_destroy_framevec(buf->vec); kfree(buf); @@ -481,7 +468,6 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, unsigned long offset; int n_pages, i; int ret = 0; - struct sg_table *sgt; unsigned long contig_size; unsigned long dma_align = dma_get_cache_alignment();
@@ -529,33 +515,31 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, goto out; }
- sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); - if (!sgt) { - pr_err("failed to allocate sg table\n"); - ret = -ENOMEM; - goto fail_pfnvec; - } - - ret = sg_alloc_table_from_pages(sgt, frame_vector_pages(vec), n_pages, - offset, size, GFP_KERNEL); + ret = sg_alloc_table_from_pages(&buf->__dma_sgt, + frame_vector_pages(vec), n_pages, + offset, size, GFP_KERNEL); if (ret) { pr_err("failed to initialize sg table\n"); - goto fail_sgt; + goto fail_pfnvec; }
+ buf->dma_sgt = &buf->__dma_sgt; + /* * No need to sync to the device, this will happen later when the * 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); - if (sgt->nents <= 0) { + buf->dma_sgt->nents = dma_map_sg_attrs(buf->dev, buf->dma_sgt->sgl, + buf->dma_sgt->orig_nents, + buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC); + if (buf->dma_sgt->nents <= 0) { pr_err("failed to map scatterlist\n"); ret = -EIO; goto fail_sgt_init; }
- contig_size = vb2_dc_get_contiguous_size(sgt); + contig_size = vb2_dc_get_contiguous_size(buf->dma_sgt); if (contig_size < size) { pr_err("contiguous mapping is too small %lu/%lu\n", contig_size, size); @@ -563,22 +547,19 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, goto fail_map_sg; }
- buf->dma_addr = sg_dma_address(sgt->sgl); - buf->dma_sgt = sgt; + buf->dma_addr = sg_dma_address(buf->dma_sgt->sgl); out: buf->size = size;
return buf;
fail_map_sg: - dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + dma_unmap_sg_attrs(buf->dev, buf->dma_sgt->sgl, + buf->dma_sgt->orig_nents, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC);
fail_sgt_init: - sg_free_table(sgt); - -fail_sgt: - kfree(sgt); + sg_free_table(buf->dma_sgt);
fail_pfnvec: vb2_destroy_framevec(vec);