From: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
Scatter-gather lib provides a helper functions to allocate scatter list,
so there is no need to use vmalloc for it. sg_alloc_table() splits
allocation into page size chunks and links them together into a chain.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
CC: Pawel Osciak <pawel@xxxxxxxxxx>
---
drivers/media/video/videobuf2-dma-sg.c | 54 +++++++++++++++++++------------
1 files changed, 33 insertions(+), 21 deletions(-)
diff --git a/drivers/media/video/videobuf2-dma-sg.c b/drivers/media/video/videobuf2-dma-sg.c
index 065f468..e1158f9 100644
--- a/drivers/media/video/videobuf2-dma-sg.c
+++ b/drivers/media/video/videobuf2-dma-sg.c
@@ -36,6 +36,8 @@ static void vb2_dma_sg_put(void *buf_priv);
static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size)
{
struct vb2_dma_sg_buf *buf;
+ struct sg_table sgt;
+ struct scatterlist *sl;
int i;
buf = kzalloc(sizeof *buf, GFP_KERNEL);
@@ -48,23 +50,21 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size)
buf->sg_desc.size = size;
buf->sg_desc.num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
- buf->sg_desc.sglist = vzalloc(buf->sg_desc.num_pages *
- sizeof(*buf->sg_desc.sglist));
- if (!buf->sg_desc.sglist)
+ if (sg_alloc_table(&sgt, buf->sg_desc.num_pages, GFP_KERNEL))
goto fail_sglist_alloc;
- sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
+ buf->sg_desc.sglist = sgt.sgl;
buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
GFP_KERNEL);
if (!buf->pages)
goto fail_pages_array_alloc;
- for (i = 0; i < buf->sg_desc.num_pages; ++i) {
- buf->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
+ for_each_sg(buf->sg_desc.sglist, sl, buf->sg_desc.num_pages, i) {
+ buf->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO |
+ __GFP_NOWARN);
if (NULL == buf->pages[i])
goto fail_pages_alloc;
- sg_set_page(&buf->sg_desc.sglist[i],
- buf->pages[i], PAGE_SIZE, 0);
+ sg_set_page(sl, buf->pages[i], PAGE_SIZE, 0);
}
buf->handler.refcount = &buf->refcount;
@@ -89,7 +89,7 @@ fail_pages_alloc:
kfree(buf->pages);
fail_pages_array_alloc:
- vfree(buf->sg_desc.sglist);
+ sg_free_table(&sgt);
fail_sglist_alloc:
kfree(buf);
@@ -99,6 +99,7 @@ fail_sglist_alloc:
static void vb2_dma_sg_put(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
+ struct sg_table sgt;
int i = buf->sg_desc.num_pages;
if (atomic_dec_and_test(&buf->refcount)) {
@@ -106,7 +107,9 @@ static void vb2_dma_sg_put(void *buf_priv)
buf->sg_desc.num_pages);
if (buf->vaddr)
vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages);
- vfree(buf->sg_desc.sglist);
+ sgt.sgl = buf->sg_desc.sglist;
+ sgt.orig_nents = sgt.nents = i;
+ sg_free_table(&sgt);
while (--i >= 0)
__free_page(buf->pages[i]);
kfree(buf->pages);
@@ -118,6 +121,8 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
unsigned long size, int write)
{
struct vb2_dma_sg_buf *buf;
+ struct sg_table sgt;
+ struct scatterlist *sl;
unsigned long first, last;
int num_pages_from_user, i;
@@ -134,12 +139,9 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
buf->sg_desc.num_pages = last - first + 1;
- buf->sg_desc.sglist = vzalloc(
- buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist));
- if (!buf->sg_desc.sglist)
+ if (sg_alloc_table(&sgt, buf->sg_desc.num_pages, GFP_KERNEL))
goto userptr_fail_sglist_alloc;
-
- sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
+ buf->sg_desc.sglist = sgt.sgl;
buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
GFP_KERNEL);
@@ -158,12 +160,12 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
if (num_pages_from_user != buf->sg_desc.num_pages)
goto userptr_fail_get_user_pages;
- sg_set_page(&buf->sg_desc.sglist[0], buf->pages[0],
- PAGE_SIZE - buf->offset, buf->offset);
+ sl = buf->sg_desc.sglist;
+ sg_set_page(sl, buf->pages[0], PAGE_SIZE - buf->offset, buf->offset);
size -= PAGE_SIZE - buf->offset;
for (i = 1; i < buf->sg_desc.num_pages; ++i) {
- sg_set_page(&buf->sg_desc.sglist[i], buf->pages[i],
- min_t(size_t, PAGE_SIZE, size), 0);
+ sl = sg_next(sl);
+ sg_set_page(sl, buf->pages[i], min_t(size_t, PAGE_SIZE, size), 0);
size -= min_t(size_t, PAGE_SIZE, size);
}
return buf;
@@ -176,7 +178,7 @@ userptr_fail_get_user_pages:
kfree(buf->pages);
userptr_fail_pages_array_alloc:
- vfree(buf->sg_desc.sglist);
+ sg_free_table(&sgt);
userptr_fail_sglist_alloc:
kfree(buf);
@@ -190,6 +192,8 @@ userptr_fail_sglist_alloc:
static void vb2_dma_sg_put_userptr(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
+ struct sg_table sgt;
+
int i = buf->sg_desc.num_pages;
printk(KERN_DEBUG "%s: Releasing userspace buffer of %d pages\n",
@@ -201,7 +205,9 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
set_page_dirty_lock(buf->pages[i]);
put_page(buf->pages[i]);
}
- vfree(buf->sg_desc.sglist);
+ sgt.sgl = buf->sg_desc.sglist;
+ sgt.orig_nents = sgt.nents = buf->sg_desc.num_pages;
+ sg_free_table(&sgt);
kfree(buf->pages);
kfree(buf);
}
@@ -218,6 +224,12 @@ static void *vb2_dma_sg_vaddr(void *buf_priv)
-1,
PAGE_KERNEL);
+ if (!buf->vaddr) {
+ printk(KERN_ERR "Cannot map buffer memory "
+ "into kernel address space\n");
+ return NULL;
+ }
+
/* add offset in case userptr is not page-aligned */
return buf->vaddr + buf->offset;
}
--
1.7.1.569.g6f426
--
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