1 files changed, 38 insertions, 9 deletions

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 58725f890b5b..8a327566d7f4 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -39,19 +39,21 @@ struct dma_buf_attachment;
 
 /**
  * struct dma_buf_ops - operations possible on struct dma_buf
- * @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: [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.
  * @vunmap: [optional] unmaps a vmap from the buffer
  */
 struct dma_buf_ops {
 	/**
+	  * @cache_sgt_mapping:
+	  *
+	  * If true the framework will cache the first mapping made for each
+	  * attachment. This avoids creating mappings for attachments multiple
+	  * times.
+	  */
+	bool cache_sgt_mapping;
+
+	/**
 	 * @attach:
 	 *
 	 * This is called from dma_buf_attach() to make sure that a given
@@ -205,8 +207,6 @@ struct dma_buf_ops {
 	 * to be restarted.
 	 */
 	int (*end_cpu_access)(struct dma_buf *, enum dma_data_direction);
-	void *(*map)(struct dma_buf *, unsigned long);
-	void (*unmap)(struct dma_buf *, unsigned long, void *);
 
 	/**
 	 * @mmap:
@@ -245,6 +245,31 @@ struct dma_buf_ops {
 	 */
 	int (*mmap)(struct dma_buf *, struct vm_area_struct *vma);
 
+	/**
+	 * @map:
+	 *
+	 * Maps a page from the buffer into kernel address space. The page is
+	 * specified by offset into the buffer in PAGE_SIZE units.
+	 *
+	 * This callback is optional.
+	 *
+	 * Returns:
+	 *
+	 * Virtual address pointer where requested page can be accessed. NULL
+	 * on error or when this function is unimplemented by the exporter.
+	 */
+	void *(*map)(struct dma_buf *, unsigned long);
+
+	/**
+	 * @unmap:
+	 *
+	 * Unmaps a page from the buffer. Page offset and address pointer should
+	 * be the same as the one passed to and returned by matching call to map.
+	 *
+	 * This callback is optional.
+	 */
+	void (*unmap)(struct dma_buf *, unsigned long, void *);
+
 	void *(*vmap)(struct dma_buf *);
 	void (*vunmap)(struct dma_buf *, void *vaddr);
 };
@@ -307,6 +332,8 @@ struct dma_buf {
  * @dmabuf: buffer for this attachment.
  * @dev: device attached to the buffer.
  * @node: list of dma_buf_attachment.
+ * @sgt: cached mapping.
+ * @dir: direction of cached mapping.
  * @priv: exporter specific attachment data.
  *
  * This structure holds the attachment information between the dma_buf buffer
@@ -322,6 +349,8 @@ struct dma_buf_attachment {
 	struct dma_buf *dmabuf;
 	struct device *dev;
 	struct list_head node;
+	struct sg_table *sgt;
+	enum dma_data_direction dir;
 	void *priv;
 };