This is a note to let you know that I've just added the patch titled media: videobuf-dma-contig: use dma_mmap_coherent to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-videobuf-dma-contig-use-dma_mmap_coherent.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e39def8b3dde59b1b28e2c0b202ed0e98332f854 Author: Christoph Hellwig <hch@xxxxxx> Date: Wed Dec 18 11:39:07 2019 +0100 media: videobuf-dma-contig: use dma_mmap_coherent [ 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@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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);