dma-buf: drop dynamic_mapping flag

Instead use the pin() callback to detect dynamic DMA-buf handling.
Since amdgpu is now migrated it doesn't make much sense to keep
the extra flag.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/353997/?series=73646&rev=1

drivers/dma-buf/dma-buf.c

@@ -524,11 +524,10 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 	}
 
 	if (WARN_ON(exp_info->ops->cache_sgt_mapping &&
-		    exp_info->ops->dynamic_mapping))
+		    (exp_info->ops->pin || exp_info->ops->unpin)))
 		return ERR_PTR(-EINVAL);
 
-	if (WARN_ON(!exp_info->ops->dynamic_mapping &&
-		    (exp_info->ops->pin || exp_info->ops->unpin)))
+	if (WARN_ON(!exp_info->ops->pin != !exp_info->ops->unpin))
 		return ERR_PTR(-EINVAL);
 
 	if (!try_module_get(exp_info->owner))

drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c

@@ -364,7 +364,6 @@ static int amdgpu_dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
 }
 
 const struct dma_buf_ops amdgpu_dmabuf_ops = {
-	.dynamic_mapping = true,
 	.attach = amdgpu_dma_buf_attach,
 	.detach = amdgpu_dma_buf_detach,
 	.pin = amdgpu_dma_buf_pin,

include/linux/dma-buf.h

@@ -42,18 +42,6 @@ struct dma_buf_ops {
 	  */
 	bool cache_sgt_mapping;
 
-	/**
-	 * @dynamic_mapping:
-	 *
-	 * If true the framework makes sure that the map/unmap_dma_buf
-	 * callbacks are always called with the dma_resv object locked.
-	 *
-	 * If false the framework makes sure that the map/unmap_dma_buf
-	 * callbacks are always called without the dma_resv object locked.
-	 * Mutual exclusive with @cache_sgt_mapping.
-	 */
-	bool dynamic_mapping;
-
 	/**
 	 * @attach:
 	 *
@@ -99,7 +87,8 @@ struct dma_buf_ops {
 	 * This is called by dma_buf_pin and lets the exporter know that the
 	 * DMA-buf can't be moved any more.
 	 *
-	 * This is called with the dmabuf->resv object locked.
+	 * This is called with the dmabuf->resv object locked and is mutual
+	 * exclusive with @cache_sgt_mapping.
 	 *
 	 * This callback is optional and should only be used in limited use
 	 * cases like scanout and not for temporary pin operations.
@@ -116,7 +105,8 @@ struct dma_buf_ops {
 	 * This is called by dma_buf_unpin and lets the exporter know that the
 	 * DMA-buf can be moved again.
 	 *
-	 * This is called with the dmabuf->resv object locked.
+	 * This is called with the dmabuf->resv object locked and is mutual
+	 * exclusive with @cache_sgt_mapping.
 	 *
 	 * This callback is optional.
 	 */
@@ -455,8 +445,7 @@ static inline void get_dma_buf(struct dma_buf *dmabuf)
  */
 static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf)
 {
-	/* TODO: switch to using pin/unpin functions as indicator. */
-	return dmabuf->ops->dynamic_mapping;
+	return !!dmabuf->ops->pin;
 }
 
 /**