diff mbox series

[v3,5/9] dma-buf: Move dma_buf_mmap_unlocked() to dynamic locking specification

Message ID 20220824102248.91964-6-dmitry.osipenko@collabora.com (mailing list archive)
State Not Applicable
Headers
Series Move all drivers to a common dma-buf locking convention |

Commit Message

Dmitry Osipenko Aug. 24, 2022, 10:22 a.m. UTC 
  Move dma_buf_mmap_unlocked() function to the dynamic locking specification
by taking the reservation lock. Neither of the today's drivers take the
reservation lock within the mmap() callback, hence it's safe to enforce
the locking.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Christian König Aug. 24, 2022, 2:01 p.m. UTC | #1 
This should work, but I'm really wondering if this makes a difference 
for somebody.

Anyway the approach is fine with me: Acked-by: Christian König 
<christian.koenig@amd.com>

Regards,
Christian.

Am 24.08.22 um 12:22 schrieb Dmitry Osipenko:
> Move dma_buf_mmap_unlocked() function to the dynamic locking specification
> by taking the reservation lock. Neither of the today's drivers take the
> reservation lock within the mmap() callback, hence it's safe to enforce
> the locking.
>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> ---
>   drivers/dma-buf/dma-buf.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
> index f358af401360..4556a12bd741 100644
> --- a/drivers/dma-buf/dma-buf.c
> +++ b/drivers/dma-buf/dma-buf.c
> @@ -1348,6 +1348,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF);
>   int dma_buf_mmap_unlocked(struct dma_buf *dmabuf, struct vm_area_struct *vma,
>   			  unsigned long pgoff)
>   {
> +	int ret;
> +
>   	if (WARN_ON(!dmabuf || !vma))
>   		return -EINVAL;
>   
> @@ -1368,7 +1370,11 @@ int dma_buf_mmap_unlocked(struct dma_buf *dmabuf, struct vm_area_struct *vma,
>   	vma_set_file(vma, dmabuf->file);
>   	vma->vm_pgoff = pgoff;
>   
> -	return dmabuf->ops->mmap(dmabuf, vma);
> +	dma_resv_lock(dmabuf->resv, NULL);
> +	ret = dmabuf->ops->mmap(dmabuf, vma);
> +	dma_resv_unlock(dmabuf->resv);
> +
> +	return ret;
>   }
>   EXPORT_SYMBOL_NS_GPL(dma_buf_mmap_unlocked, DMA_BUF);
>
diff mbox series

Patch

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index f358af401360..4556a12bd741 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1348,6 +1348,8 @@  EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF);
 int dma_buf_mmap_unlocked(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 			  unsigned long pgoff)
 {
+	int ret;
+
 	if (WARN_ON(!dmabuf || !vma))
 		return -EINVAL;
 
@@ -1368,7 +1370,11 @@  int dma_buf_mmap_unlocked(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 	vma_set_file(vma, dmabuf->file);
 	vma->vm_pgoff = pgoff;
 
-	return dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_lock(dmabuf->resv, NULL);
+	ret = dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_unlock(dmabuf->resv);
+
+	return ret;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_mmap_unlocked, DMA_BUF);