Commit 28743e25 authored by Dmitry Osipenko's avatar Dmitry Osipenko
Browse files

dma-buf: Remove obsoleted internal lock 



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: default avatarSumit Semwal <sumit.semwal@linaro.org>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-22-dmitry.osipenko@collabora.com
parent 23543b3c

drivers/dma-buf/dma-buf.c

+4 −10
Original line number Diff line number Diff line
@@ -657,7 +657,6 @@ 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);
@@ -1503,7 +1502,7 @@ 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);
@@ -1515,28 +1514,25 @@ 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);
@@ -1583,13 +1579,11 @@ 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);

include/linux/dma-buf.h

+0 −9
Original line number Diff line number Diff line
@@ -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:

	 *