Christian König
2022-Sep-01 07:46 UTC
[PATCH v4 21/21] dma-buf: Remove obsoleted internal lock
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 K?nig <christian.koenig at amd.com> > Signed-off-by: Dmitry Osipenko <dmitry.osipenko at collabora.com>Reviewed-by: Christian K?nig <christian.koenig at 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: > *