This patch makes use of sg_alloc_table_from_pages to simplify
handling of sg tables.
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))
--
1.7.9.5
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