Messages in this thread | | | Subject | Re: [PATCH] dma-buf: make map_atomic and map function pointers optional | From | Oleksandr Andrushchenko <> | Date | Wed, 30 May 2018 14:36:43 +0300 |
| |
On 05/29/2018 04:59 PM, Gerd Hoffmann wrote: > So drivers don't need dummy functions just returning NULL. > > Cc: Daniel Vetter <daniel@ffwll.ch> > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> > --- > include/linux/dma-buf.h | 4 ++-- > drivers/dma-buf/dma-buf.c | 4 ++++ > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > index 085db2fee2..88917fa796 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. > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index d78d5fc173..4c45e31258 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); Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
| |