Hi Tomasz,
Thanks for the patch.
On Wednesday 23 May 2012 15:07:34 Tomasz Stanislawski wrote:
> This patch makes use of sg_alloc_table_from_pages to simplify
> handling of sg tables.
Would you mind moving this patch before 04/12, to avoid introducing a
vb2_dc_pages_to_sgt() user only to remove it in this patch ? Otherwise this
looks good.
> Signed-off-by: Tomasz Stanislawski <t.stanislaws@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> drivers/media/video/videobuf2-dma-contig.c | 90 +++++++------------------
> 1 file changed, 25 insertions(+), 65 deletions(-)
>
> diff --git a/drivers/media/video/videobuf2-dma-contig.c
> b/drivers/media/video/videobuf2-dma-contig.c index 59ee81c..b5caf1d 100644
> --- a/drivers/media/video/videobuf2-dma-contig.c
> +++ b/drivers/media/video/videobuf2-dma-contig.c
> @@ -32,7 +32,7 @@ struct vb2_dc_buf {
> /* MMAP related */
> struct vb2_vmarea_handler handler;
> atomic_t refcount;
> - struct sg_table *sgt_base;
> + struct sg_table sgt_base;
>
> /* USERPTR related */
> struct vm_area_struct *vma;
> @@ -45,57 +45,6 @@ struct vb2_dc_buf {
> /* scatterlist table functions */
> /*********************************************/
>
> -static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages,
> - unsigned int n_pages, unsigned long offset, unsigned long size)
> -{
> - struct sg_table *sgt;
> - unsigned int chunks;
> - unsigned int i;
> - unsigned int cur_page;
> - int ret;
> - struct scatterlist *s;
> -
> - sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
> - if (!sgt)
> - return ERR_PTR(-ENOMEM);
> -
> - /* compute number of chunks */
> - chunks = 1;
> - for (i = 1; i < n_pages; ++i)
> - if (pages[i] != pages[i - 1] + 1)
> - ++chunks;
> -
> - ret = sg_alloc_table(sgt, chunks, GFP_KERNEL);
> - if (ret) {
> - kfree(sgt);
> - return ERR_PTR(-ENOMEM);
> - }
> -
> - /* merging chunks and putting them into the scatterlist */
> - cur_page = 0;
> - for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
> - unsigned long chunk_size;
> - unsigned int j;
> -
> - for (j = cur_page + 1; j < n_pages; ++j)
> - if (pages[j] != pages[j - 1] + 1)
> - break;
> -
> - chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset;
> - sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
> - size -= chunk_size;
> - offset = 0;
> - cur_page = j;
> - }
> -
> - return sgt;
> -}
> -
> -static void vb2_dc_release_sgtable(struct sg_table *sgt)
> -{
> - sg_free_table(sgt);
> - kfree(sgt);
> -}
>
> static void vb2_dc_sgt_foreach_page(struct sg_table *sgt,
> void (*cb)(struct page *pg))
> @@ -190,7 +139,7 @@ static void vb2_dc_put(void *buf_priv)
> if (!atomic_dec_and_test(&buf->refcount))
> return;
>
> - vb2_dc_release_sgtable(buf->sgt_base);
> + sg_free_table(&buf->sgt_base);
> dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr);
> kfree(buf);
> }
> @@ -254,9 +203,9 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long
> size) goto fail_pages;
> }
>
> - buf->sgt_base = vb2_dc_pages_to_sgt(pages, n_pages, 0, size);
> - if (IS_ERR(buf->sgt_base)) {
> - ret = PTR_ERR(buf->sgt_base);
> + ret = sg_alloc_table_from_pages(&buf->sgt_base,
> + pages, n_pages, 0, size, GFP_KERNEL);
> + if (ret) {
> dev_err(dev, "failed to prepare sg table\n");
> goto fail_pages;
> }
> @@ -379,13 +328,13 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
> attach->dir = dir;
>
> /* copying the buf->base_sgt to attachment */
> - ret = sg_alloc_table(sgt, buf->sgt_base->orig_nents, GFP_KERNEL);
> + ret = sg_alloc_table(sgt, buf->sgt_base.orig_nents, GFP_KERNEL);
> if (ret) {
> kfree(attach);
> return ERR_PTR(-ENOMEM);
> }
>
> - rd = buf->sgt_base->sgl;
> + rd = buf->sgt_base.sgl;
> wr = sgt->sgl;
> for (i = 0; i < sgt->orig_nents; ++i) {
> sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
> @@ -519,7 +468,8 @@ static void vb2_dc_put_userptr(void *buf_priv)
> if (!vma_is_io(buf->vma))
> vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page);
>
> - vb2_dc_release_sgtable(sgt);
> + sg_free_table(sgt);
> + kfree(sgt);
> vb2_put_vma(buf->vma);
> kfree(buf);
> }
> @@ -586,13 +536,20 @@ static void *vb2_dc_get_userptr(void *alloc_ctx,
> unsigned long vaddr, goto fail_vma;
> }
>
> - sgt = vb2_dc_pages_to_sgt(pages, n_pages, offset, size);
> - if (IS_ERR(sgt)) {
> - printk(KERN_ERR "failed to create scatterlist table\n");
> + sgt = kzalloc(sizeof *sgt, GFP_KERNEL);
> + if (!sgt) {
> + printk(KERN_ERR "failed to allocate sg table\n");
> ret = -ENOMEM;
> goto fail_get_user_pages;
> }
>
> + ret = sg_alloc_table_from_pages(sgt, pages, n_pages,
> + offset, size, GFP_KERNEL);
> + if (ret) {
> + printk(KERN_ERR "failed to initialize sg table\n");
> + goto fail_sgt;
> + }
> +
> /* pages are no longer needed */
> kfree(pages);
> pages = NULL;
> @@ -602,7 +559,7 @@ static void *vb2_dc_get_userptr(void *alloc_ctx,
> unsigned long vaddr, if (sgt->nents <= 0) {
> printk(KERN_ERR "failed to map scatterlist\n");
> ret = -EIO;
> - goto fail_sgt;
> + goto fail_sgt_init;
> }
>
> contig_size = vb2_dc_get_contiguous_size(sgt);
> @@ -622,10 +579,13 @@ static void *vb2_dc_get_userptr(void *alloc_ctx,
> unsigned long vaddr, fail_map_sg:
> dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
>
> -fail_sgt:
> +fail_sgt_init:
> if (!vma_is_io(buf->vma))
> vb2_dc_sgt_foreach_page(sgt, put_page);
> - vb2_dc_release_sgtable(sgt);
> + sg_free_table(sgt);
> +
> +fail_sgt:
> + kfree(sgt);
>
> fail_get_user_pages:
> if (pages && !vma_is_io(buf->vma))
--
Regards,
Laurent Pinchart
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