[PATCH 1/1] V4L: videobuf, don't use dma addr as physical

[PATCH 1/1] V4L: videobuf, don't use dma addr as physical

[Jiri Slaby]

mem->dma_handle is a dma address obtained by dma_alloc_coherent which
needn't be a physical address in presence of IOMMU. So ensure we are
remapping (remap_pfn_range) the right page in __videobuf_mmap_mapper
by using virt_to_phys(mem->vaddr) and not mem->dma_handle.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
---
 drivers/media/video/videobuf-dma-contig.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/videobuf-dma-contig.c b/drivers/media/video/videobuf-dma-contig.c
index c969111..8d778aa 100644
--- a/drivers/media/video/videobuf-dma-contig.c
+++ b/drivers/media/video/videobuf-dma-contig.c
@@ -300,7 +300,7 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 	retval = remap_pfn_range(vma, vma->vm_start,
-				 mem->dma_handle >> PAGE_SHIFT,
+				 virt_to_phys(mem->vaddr) >> PAGE_SHIFT,
 				 size, vma->vm_page_prot);
 	if (retval) {
 		dev_err(q->dev, "mmap: remap failed with error %d. ", retval);
-- 
1.7.3.1

Re: [PATCH 1/1] V4L: videobuf, don't use dma addr as physical

[Konrad Rzeszutek Wilk]

On Mon, Dec 06, 2010 at 02:30:52PM +0100, Jiri Slaby wrote:
> mem->dma_handle is a dma address obtained by dma_alloc_coherent which
> needn't be a physical address in presence of IOMMU. So ensure we are

Could you use  PFN_DOWN(virt_to_phys(mem->vaddr)?
> remapping (remap_pfn_range) the right page in __videobuf_mmap_mapper
> by using virt_to_phys(mem->vaddr) and not mem->dma_handle.
> 
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
> ---
>  drivers/media/video/videobuf-dma-contig.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/media/video/videobuf-dma-contig.c b/drivers/media/video/videobuf-dma-contig.c
> index c969111..8d778aa 100644
> --- a/drivers/media/video/videobuf-dma-contig.c
> +++ b/drivers/media/video/videobuf-dma-contig.c
> @@ -300,7 +300,7 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
>  
>  	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
>  	retval = remap_pfn_range(vma, vma->vm_start,
> -				 mem->dma_handle >> PAGE_SHIFT,
> +				 virt_to_phys(mem->vaddr) >> PAGE_SHIFT,
>  				 size, vma->vm_page_prot);
>  	if (retval) {
>  		dev_err(q->dev, "mmap: remap failed with error %d. ", retval);
> -- 
> 1.7.3.1
> 
> 
> _______________________________________________
> iommu mailing list
> iommu@lists.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/iommu

[PATCH v2 1/1] V4L: videobuf, don't use dma addr as physical

[Jiri Slaby]

mem->dma_handle is a dma address obtained by dma_alloc_coherent which
needn't be a physical address in presence of IOMMU. So ensure we are
remapping (remap_pfn_range) the right page in __videobuf_mmap_mapper
by using virt_to_phys(mem->vaddr) and not mem->dma_handle.

While at it, use PFN_DOWN instead of explicit shift.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/media/video/videobuf-dma-contig.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/videobuf-dma-contig.c b/drivers/media/video/videobuf-dma-contig.c
index c969111..19d3e4a 100644
--- a/drivers/media/video/videobuf-dma-contig.c
+++ b/drivers/media/video/videobuf-dma-contig.c
@@ -300,7 +300,7 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 	retval = remap_pfn_range(vma, vma->vm_start,
-				 mem->dma_handle >> PAGE_SHIFT,
+				 PFN_DOWN(virt_to_phys(mem->vaddr))
 				 size, vma->vm_page_prot);
 	if (retval) {
 		dev_err(q->dev, "mmap: remap failed with error %d. ", retval);
-- 
1.7.3.1