1 files changed, 57 insertions, 6 deletions

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index ec212cb27fdc..af73f835c51c 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -43,6 +43,18 @@ 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:
 	 *
 	 * This is called from dma_buf_attach() to make sure that a given
@@ -109,6 +121,9 @@ struct dma_buf_ops {
 	 * any other kind of sharing that the exporter might wish to make
 	 * available to buffer-users.
 	 *
+	 * This is always called with the dmabuf->resv object locked when
+	 * the dynamic_mapping flag is true.
+	 *
 	 * Returns:
 	 *
 	 * A &sg_table scatter list of or the backing storage of the DMA buffer,
@@ -267,14 +282,16 @@ struct dma_buf_ops {
  * struct dma_buf - shared buffer object
  * @size: size of the buffer
  * @file: file pointer used for sharing buffers across, and for refcounting.
- * @attachments: list of dma_buf_attachment that denotes all devices attached.
+ * @attachments: list of dma_buf_attachment that denotes all devices attached,
+ *               protected by dma_resv lock.
  * @ops: dma_buf_ops associated with this buffer object.
  * @lock: used internally to serialize list manipulation, attach/detach and
- *        vmap/unmap, and accesses to name
+ *        vmap/unmap
  * @vmapping_counter: used internally to refcnt the vmaps
  * @vmap_ptr: the current vmap ptr if vmapping_counter > 0
  * @exp_name: name of the exporter; useful for debugging.
- * @name: userspace-provided name; useful for accounting and debugging.
+ * @name: userspace-provided name; useful for accounting and debugging,
+ *        protected by @resv.
  * @owner: pointer to exporter module; used for refcounting when exporter is a
  *         kernel module.
  * @list_node: node for dma_buf accounting and debugging.
@@ -323,10 +340,12 @@ struct dma_buf {
  * struct dma_buf_attachment - holds device-buffer attachment data
  * @dmabuf: buffer for this attachment.
  * @dev: device attached to the buffer.
- * @node: list of dma_buf_attachment.
+ * @node: list of dma_buf_attachment, protected by dma_resv lock of the dmabuf.
  * @sgt: cached mapping.
  * @dir: direction of cached mapping.
  * @priv: exporter specific attachment data.
+ * @dynamic_mapping: true if dma_buf_map/unmap_attachment() is called with the
+ * dma_resv lock held.
  *
  * This structure holds the attachment information between the dma_buf buffer
  * and its user device(s). The list contains one attachment struct per device
@@ -343,6 +362,7 @@ struct dma_buf_attachment {
 	struct list_head node;
 	struct sg_table *sgt;
 	enum dma_data_direction dir;
+	bool dynamic_mapping;
 	void *priv;
 };
 
@@ -394,10 +414,40 @@ static inline void get_dma_buf(struct dma_buf *dmabuf)
 	get_file(dmabuf->file);
 }
 
+/**
+ * dma_buf_is_dynamic - check if a DMA-buf uses dynamic mappings.
+ * @dmabuf: the DMA-buf to check
+ *
+ * Returns true if a DMA-buf exporter wants to be called with the dma_resv
+ * locked for the map/unmap callbacks, false if it doesn't wants to be called
+ * with the lock held.
+ */
+static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf)
+{
+	return dmabuf->ops->dynamic_mapping;
+}
+
+/**
+ * dma_buf_attachment_is_dynamic - check if a DMA-buf attachment uses dynamic
+ * mappinsg
+ * @attach: the DMA-buf attachment to check
+ *
+ * Returns true if a DMA-buf importer wants to call the map/unmap functions with
+ * the dma_resv lock held.
+ */
+static inline bool
+dma_buf_attachment_is_dynamic(struct dma_buf_attachment *attach)
+{
+	return attach->dynamic_mapping;
+}
+
 struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
-							struct device *dev);
+					  struct device *dev);
+struct dma_buf_attachment *
+dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
+		       bool dynamic_mapping);
 void dma_buf_detach(struct dma_buf *dmabuf,
-				struct dma_buf_attachment *dmabuf_attach);
+		    struct dma_buf_attachment *attach);
 
 struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info);
 
@@ -409,6 +459,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
 					enum dma_data_direction);
 void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
 				enum dma_data_direction);
+void dma_buf_move_notify(struct dma_buf *dma_buf);
 int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
 			     enum dma_data_direction dir);
 int dma_buf_end_cpu_access(struct dma_buf *dma_buf,