[PATCH 6.0 0347/1073] media: videobuf-dma-contig: use dma_mmap_coherent

Greg Kroah-Hartman
2022-12-28T15:39:10Z

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit b3dc3f8e49577840dc8ac8a365c5b3da4edb10b8 ]

dma_alloc_coherent does not return a physical address, but a DMA address,
which might be remapped or have an offset. Passing the DMA address to
vm_iomap_memory is thus broken.

Use the proper dma_mmap_coherent helper instead, and stop passing
__GFP_COMP to dma_alloc_coherent, as the memory management inside the
DMA allocator is hidden from the callers and does not require it.

With this the gfp_t argument to __videobuf_dc_alloc can be removed and
hard coded to GFP_KERNEL.

Fixes: a8f3c203e19b ("[media] videobuf-dma-contig: add cache support")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/v4l2-core/videobuf-dma-contig.c | 22 +++++++------------
1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c b/drivers/media/v4l2-core/videobuf-dma-contig.c
index 52312ce2ba05..f2c439359557 100644
--- a/drivers/media/v4l2-core/videobuf-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf-dma-contig.c
@@ -36,12 +36,11 @@ struct videobuf_dma_contig_memory {

static int __videobuf_dc_alloc(struct device *dev,
struct videobuf_dma_contig_memory *mem,
- unsigned long size, gfp_t flags)
+ unsigned long size)
{
mem->size = size;
- mem->vaddr = dma_alloc_coherent(dev, mem->size,
- &mem->dma_handle, flags);
-
+ mem->vaddr = dma_alloc_coherent(dev, mem->size, &mem->dma_handle,
+ GFP_KERNEL);
if (!mem->vaddr) {
dev_err(dev, "memory alloc size %ld failed\n", mem->size);
return -ENOMEM;
@@ -258,8 +257,7 @@ static int __videobuf_iolock(struct videobuf_queue *q,
return videobuf_dma_contig_user_get(mem, vb);

/* allocate memory for the read() method */
- if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(vb->size),
- GFP_KERNEL))
+ if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(vb->size)))
return -ENOMEM;
break;
case V4L2_MEMORY_OVERLAY:
@@ -295,22 +293,18 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
BUG_ON(!mem);
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);

- if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(buf->bsize),
- GFP_KERNEL | __GFP_COMP))
+ if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(buf->bsize)))
goto error;

- /* Try to remap memory */
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
/* the "vm_pgoff" is just used in v4l2 to find the
* corresponding buffer data structure which is allocated
* earlier and it does not mean the offset from the physical
* buffer start address as usual. So set it to 0 to pass
- * the sanity check in vm_iomap_memory().
+ * the sanity check in dma_mmap_coherent().
*/
vma->vm_pgoff = 0;
-
- retval = vm_iomap_memory(vma, mem->dma_handle, mem->size);
+ retval = dma_mmap_coherent(q->dev, vma, mem->vaddr, mem->dma_handle,
+ mem->size);
if (retval) {
dev_err(q->dev, "mmap: remap failed with error %d. ",
retval);
--
2.35.1