diff mbox series

[v4,21/21] dma-buf: Remove obsoleted internal lock

Message ID 20220831153757.97381-22-dmitry.osipenko@collabora.com (mailing list archive)
State Superseded
Headers show
Series Move all drivers to a common dma-buf locking convention | expand

Commit Message

Dmitry Osipenko Aug. 31, 2022, 3:37 p.m. UTC
The internal dma-buf lock isn't needed anymore because the updated
locking specification claims that dma-buf reservation must be locked
by importers, and thus, the internal data is already protected by the
reservation lock. Remove the obsoleted internal lock.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 14 ++++----------
 include/linux/dma-buf.h   |  9 ---------
 2 files changed, 4 insertions(+), 19 deletions(-)

Comments

Christian König Sept. 1, 2022, 7:46 a.m. UTC | #1
Am 31.08.22 um 17:37 schrieb Dmitry Osipenko:
> The internal dma-buf lock isn't needed anymore because the updated
> locking specification claims that dma-buf reservation must be locked
> by importers, and thus, the internal data is already protected by the
> reservation lock. Remove the obsoleted internal lock.
>
> Acked-by: Christian König <christian.koenig@amd.com>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/dma-buf/dma-buf.c | 14 ++++----------
>   include/linux/dma-buf.h   |  9 ---------
>   2 files changed, 4 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
> index 97ce884fad76..772fdd9eeed8 100644
> --- a/drivers/dma-buf/dma-buf.c
> +++ b/drivers/dma-buf/dma-buf.c
> @@ -656,7 +656,6 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
>   
>   	dmabuf->file = file;
>   
> -	mutex_init(&dmabuf->lock);
>   	INIT_LIST_HEAD(&dmabuf->attachments);
>   
>   	mutex_lock(&db_list.lock);
> @@ -1502,7 +1501,7 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
>   int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
>   {
>   	struct iosys_map ptr;
> -	int ret = 0;
> +	int ret;
>   
>   	iosys_map_clear(map);
>   
> @@ -1514,28 +1513,25 @@ int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
>   	if (!dmabuf->ops->vmap)
>   		return -EINVAL;
>   
> -	mutex_lock(&dmabuf->lock);
>   	if (dmabuf->vmapping_counter) {
>   		dmabuf->vmapping_counter++;
>   		BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
>   		*map = dmabuf->vmap_ptr;
> -		goto out_unlock;
> +		return 0;
>   	}
>   
>   	BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));
>   
>   	ret = dmabuf->ops->vmap(dmabuf, &ptr);
>   	if (WARN_ON_ONCE(ret))
> -		goto out_unlock;
> +		return ret;
>   
>   	dmabuf->vmap_ptr = ptr;
>   	dmabuf->vmapping_counter = 1;
>   
>   	*map = dmabuf->vmap_ptr;
>   
> -out_unlock:
> -	mutex_unlock(&dmabuf->lock);
> -	return ret;
> +	return 0;
>   }
>   EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
>   
> @@ -1577,13 +1573,11 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
>   	BUG_ON(dmabuf->vmapping_counter == 0);
>   	BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));
>   
> -	mutex_lock(&dmabuf->lock);
>   	if (--dmabuf->vmapping_counter == 0) {
>   		if (dmabuf->ops->vunmap)
>   			dmabuf->ops->vunmap(dmabuf, map);
>   		iosys_map_clear(&dmabuf->vmap_ptr);
>   	}
> -	mutex_unlock(&dmabuf->lock);
>   }
>   EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
>   
> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
> index f11b5bbc2f37..6fa8d4e29719 100644
> --- a/include/linux/dma-buf.h
> +++ b/include/linux/dma-buf.h
> @@ -326,15 +326,6 @@ struct dma_buf {
>   	/** @ops: dma_buf_ops associated with this buffer object. */
>   	const struct dma_buf_ops *ops;
>   
> -	/**
> -	 * @lock:
> -	 *
> -	 * Used internally to serialize list manipulation, attach/detach and
> -	 * vmap/unmap. Note that in many cases this is superseeded by
> -	 * dma_resv_lock() on @resv.
> -	 */
> -	struct mutex lock;
> -
>   	/**
>   	 * @vmapping_counter:
>   	 *
diff mbox series

Patch

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 97ce884fad76..772fdd9eeed8 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -656,7 +656,6 @@  struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 
 	dmabuf->file = file;
 
-	mutex_init(&dmabuf->lock);
 	INIT_LIST_HEAD(&dmabuf->attachments);
 
 	mutex_lock(&db_list.lock);
@@ -1502,7 +1501,7 @@  EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
 int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 {
 	struct iosys_map ptr;
-	int ret = 0;
+	int ret;
 
 	iosys_map_clear(map);
 
@@ -1514,28 +1513,25 @@  int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	if (!dmabuf->ops->vmap)
 		return -EINVAL;
 
-	mutex_lock(&dmabuf->lock);
 	if (dmabuf->vmapping_counter) {
 		dmabuf->vmapping_counter++;
 		BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
 		*map = dmabuf->vmap_ptr;
-		goto out_unlock;
+		return 0;
 	}
 
 	BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));
 
 	ret = dmabuf->ops->vmap(dmabuf, &ptr);
 	if (WARN_ON_ONCE(ret))
-		goto out_unlock;
+		return ret;
 
 	dmabuf->vmap_ptr = ptr;
 	dmabuf->vmapping_counter = 1;
 
 	*map = dmabuf->vmap_ptr;
 
-out_unlock:
-	mutex_unlock(&dmabuf->lock);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
 
@@ -1577,13 +1573,11 @@  void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	BUG_ON(dmabuf->vmapping_counter == 0);
 	BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));
 
-	mutex_lock(&dmabuf->lock);
 	if (--dmabuf->vmapping_counter == 0) {
 		if (dmabuf->ops->vunmap)
 			dmabuf->ops->vunmap(dmabuf, map);
 		iosys_map_clear(&dmabuf->vmap_ptr);
 	}
-	mutex_unlock(&dmabuf->lock);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
 
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index f11b5bbc2f37..6fa8d4e29719 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -326,15 +326,6 @@  struct dma_buf {
 	/** @ops: dma_buf_ops associated with this buffer object. */
 	const struct dma_buf_ops *ops;
 
-	/**
-	 * @lock:
-	 *
-	 * Used internally to serialize list manipulation, attach/detach and
-	 * vmap/unmap. Note that in many cases this is superseeded by
-	 * dma_resv_lock() on @resv.
-	 */
-	struct mutex lock;
-
 	/**
 	 * @vmapping_counter:
 	 *