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authorGerd Hoffmann <kraxel@redhat.com>2018-05-29 15:59:18 +0200
committerGerd Hoffmann <kraxel@redhat.com>2018-06-01 08:59:35 +0200
commit09ea0dfbf972c63dfea8cf46f2fb67f39e4d833b (patch)
tree33c731ecd3febc843c2eaefd2c33002d336e925a
parente065a8dd30af703b4794dc740c0825ee12b92efd (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.c4
-rw-r--r--include/linux/dma-buf.h4
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.