diff options
| author | Gerd Hoffmann <kraxel@redhat.com> | 2018-05-29 15:59:18 +0200 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2018-06-01 08:59:35 +0200 |
| commit | 09ea0dfbf972c63dfea8cf46f2fb67f39e4d833b (patch) | |
| tree | 33c731ecd3febc843c2eaefd2c33002d336e925a | |
| parent | e065a8dd30af703b4794dc740c0825ee12b92efd (diff) | |
dma-buf: make map_atomic and map function pointers optional
So drivers don't need dummy functions just returning NULL.
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180529135918.19729-1-kraxel@redhat.com
| -rw-r--r-- | drivers/dma-buf/dma-buf.c | 4 | ||||
| -rw-r--r-- | include/linux/dma-buf.h | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index d78d5fc173dc..4c45e31258f0 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -872,6 +872,8 @@ void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) { WARN_ON(!dmabuf); + if (!dmabuf->ops->map_atomic) + return NULL; return dmabuf->ops->map_atomic(dmabuf, page_num); } EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); @@ -907,6 +909,8 @@ void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) { WARN_ON(!dmabuf); + if (!dmabuf->ops->map) + return NULL; return dmabuf->ops->map(dmabuf, page_num); } EXPORT_SYMBOL_GPL(dma_buf_kmap); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 085db2fee2d7..88917fa796e4 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -39,12 +39,12 @@ struct dma_buf_attachment; /** * struct dma_buf_ops - operations possible on struct dma_buf - * @map_atomic: maps a page from the buffer into kernel address + * @map_atomic: [optional] maps a page from the buffer into kernel address * space, users may not block until the subsequent unmap call. * This callback must not sleep. * @unmap_atomic: [optional] unmaps a atomically mapped page from the buffer. * This Callback must not sleep. - * @map: maps a page from the buffer into kernel address space. + * @map: [optional] maps a page from the buffer into kernel address space. * @unmap: [optional] unmaps a page from the buffer. * @vmap: [optional] creates a virtual mapping for the buffer into kernel * address space. Same restrictions as for vmap and friends apply. |