This patch makes use of sg_alloc_table_from_pages to simplify handling of sg tables.
Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- 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))