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-rw-r--r--include/linux/dma-buf.h29
1 files changed, 25 insertions, 4 deletions
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index e4a8dab2bc54..a0bd071466fc 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -39,8 +39,6 @@ struct dma_buf_attachment;
/**
* struct dma_buf_ops - operations possible on struct dma_buf
- * @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
@@ -200,8 +198,6 @@ 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:
@@ -240,6 +236,31 @@ 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);
};