This patch adds the setup of sglist list for MMAP buffers.
It is needed for buffer exporting via DMABUF mechanism.
This patch depends on dma_get_pages extension to DMA api.
Signed-off-by: Tomasz Stanislawski <t.stanisl...@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com>
---
drivers/media/video/videobuf2-dma-contig.c | 51 ++++++++++++++++++++++++++-
1 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/drivers/media/video/videobuf2-dma-contig.c
b/drivers/media/video/videobuf2-dma-contig.c
index f4df9e2..0cdcd2b 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -31,6 +31,7 @@ struct vb2_dc_buf {
/* MMAP related */
struct vb2_vmarea_handler handler;
atomic_t refcount;
+ struct sg_table *sgt_base;
/* USERPTR related */
struct vm_area_struct *vma;
@@ -189,6 +190,7 @@ static void vb2_dc_put(void *buf_priv)
if (!atomic_dec_and_test(&buf->refcount))
return;
+ vb2_dc_release_sgtable(buf->sgt_base);
dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr);
kfree(buf);
}
@@ -197,6 +199,9 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long
size)
{
struct device *dev = alloc_ctx;
struct vb2_dc_buf *buf;
+ int ret = -ENOMEM;
+ int n_pages;
+ struct page **pages = NULL;
buf = kzalloc(sizeof *buf, GFP_KERNEL);
if (!buf)
@@ -205,10 +210,41 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long
size)
buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, GFP_KERNEL);
if (!buf->vaddr) {
dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size);
- kfree(buf);
- return ERR_PTR(-ENOMEM);
+ goto fail_buf;
+ }
+
+ WARN_ON((unsigned long)buf->vaddr & ~PAGE_MASK);
+ WARN_ON(buf->dma_addr & ~PAGE_MASK);
+
+ n_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+ pages = kmalloc(n_pages * sizeof pages[0], GFP_KERNEL);
+ if (!pages) {
+ dev_err(dev, "failed to alloc page table\n");
+ goto fail_dma;
+ }
+
+ ret = dma_get_pages(dev, buf->vaddr, buf->dma_addr, pages, n_pages);
+ if (ret < 0) {
+ dev_err(dev, "failed to get buffer pages from DMA API\n");
+ goto fail_pages;
+ }
+ if (ret != n_pages) {
+ ret = -EFAULT;
+ dev_err(dev, "failed to get all pages from DMA API\n");
+ goto fail_pages;
}
+ buf->sgt_base = vb2_dc_pages_to_sgt(pages, n_pages, 0, 0);
+ if (IS_ERR(buf->sgt_base)) {
+ ret = PTR_ERR(buf->sgt_base);
+ dev_err(dev, "failed to prepare sg table\n");
+ goto fail_pages;
+ }
+
+ /* pages are no longer needed */
+ kfree(pages);
+
buf->dev = dev;
buf->size = size;
@@ -219,6 +255,17 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long
size)
atomic_inc(&buf->refcount);
return buf;
+
+fail_pages:
+ kfree(pages);
+
+fail_dma:
+ dma_free_coherent(dev, size, buf->vaddr, buf->dma_addr);
+
+fail_buf:
+ kfree(buf);
+
+ return ERR_PTR(ret);
}
static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
--
1.7.5.4
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