1 files changed, 59 insertions, 0 deletions

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 24e0f4828711..ee7ef9990d9a 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -50,6 +50,17 @@ struct dma_buf_attachment;
  * @unmap_dma_buf: decreases usecount of buffer, might deallocate scatter
  *                 pages.
  * @release: release this buffer; to be called after the last dma_buf_put.
+ * @begin_cpu_access: [optional] called before cpu access to invalidate cpu
+ *                    caches and allocate backing storage (if not yet done)
+ *                    respectively pin the objet into memory.
+ * @end_cpu_access: [optional] called after cpu access to flush cashes.
+ * @kmap_atomic: maps a page from the buffer into kernel address
+ *               space, users may not block until the subsequent unmap call.
+ *               This callback must not sleep.
+ * @kunmap_atomic: [optional] unmaps a atomically mapped page from the buffer.
+ *                 This Callback must not sleep.
+ * @kmap: maps a page from the buffer into kernel address space.
+ * @kunmap: [optional] unmaps a page from the buffer.
  */
 struct dma_buf_ops {
         int (*attach)(struct dma_buf *, struct device *,
@@ -73,6 +84,14 @@ struct dma_buf_ops {
         /* after final dma_buf_put() */
         void (*release)(struct dma_buf *);
 
+        int (*begin_cpu_access)(struct dma_buf *, size_t, size_t,
+                                enum dma_data_direction);
+        void (*end_cpu_access)(struct dma_buf *, size_t, size_t,
+                               enum dma_data_direction);
+        void *(*kmap_atomic)(struct dma_buf *, unsigned long);
+        void (*kunmap_atomic)(struct dma_buf *, unsigned long, void *);
+        void *(*kmap)(struct dma_buf *, unsigned long);
+        void (*kunmap)(struct dma_buf *, unsigned long, void *);
 };
 
 /**
@@ -140,6 +159,14 @@ 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);
+int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t len,
+                             enum dma_data_direction dir);
+void dma_buf_end_cpu_access(struct dma_buf *dma_buf, size_t start, size_t len,
+                            enum dma_data_direction dir);
+void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long);
+void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long, void *);
+void *dma_buf_kmap(struct dma_buf *, unsigned long);
+void dma_buf_kunmap(struct dma_buf *, unsigned long, void *);
 #else
 
 static inline struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
@@ -188,6 +215,38 @@ static inline void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
         return;
 }
 
+static inline int dma_buf_begin_cpu_access(struct dma_buf *,
+                                           size_t, size_t,
+                                           enum dma_data_direction)
+{
+        return -ENODEV;
+}
+
+static inline void dma_buf_end_cpu_access(struct dma_buf *,
+                                          size_t, size_t,
+                                          enum dma_data_direction)
+{
+}
+
+static inline void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long)
+{
+        return NULL;
+}
+
+static inline void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long,
+                                         void *)
+{
+}
+
+static inline void *dma_buf_kmap(struct dma_buf *, unsigned long)
+{
+        return NULL;
+}
+
+static inline void dma_buf_kunmap(struct dma_buf *, unsigned long,
+                                  void *)
+{
+}
 #endif /* CONFIG_DMA_SHARED_BUFFER */
 
 #endif /* __DMA_BUF_H__ */