1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 395704bdf5cc..92b96fe39307 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -233,6 +233,19 @@ struct hc_driver {
         int     (*urb_dequeue)(struct usb_hcd *hcd,
                                 struct urb *urb, int status);
 
+        /*
+         * (optional) these hooks allow an HCD to override the default DMA
+         * mapping and unmapping routines.  In general, they shouldn't be
+         * necessary unless the host controller has special DMA requirements,
+         * such as alignment contraints.  If these are not specified, the
+         * general usb_hcd_(un)?map_urb_for_dma functions will be used instead
+         * (and it may be a good idea to call these functions in your HCD
+         * implementation)
+         */
+        int     (*map_urb_for_dma)(struct usb_hcd *hcd, struct urb *urb,
+                                   gfp_t mem_flags);
+        void    (*unmap_urb_for_dma)(struct usb_hcd *hcd, struct urb *urb);
+
         /* hw synch, freeing endpoint resources that urb_dequeue can't */
         void    (*endpoint_disable)(struct usb_hcd *hcd,
                         struct usb_host_endpoint *ep);
@@ -329,6 +342,8 @@ extern int usb_hcd_submit_urb(struct urb *urb, gfp_t mem_flags);
 extern int usb_hcd_unlink_urb(struct urb *urb, int status);
 extern void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb,
                 int status);
+extern int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
+                gfp_t mem_flags);
 extern void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *, struct urb *);
 extern void usb_hcd_unmap_urb_for_dma(struct usb_hcd *, struct urb *);
 extern void usb_hcd_flush_endpoint(struct usb_device *udev,