1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 0b0d12ccc487..56da49f31d6c 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -22,6 +22,7 @@
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/err.h>
+#include <linux/dma-mapping.h>
 
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
@@ -49,6 +50,57 @@ static DEFINE_MUTEX(udc_lock);
 
 /* ------------------------------------------------------------------------- */
 
+int usb_gadget_map_request(struct usb_gadget *gadget,
+                struct usb_request *req, int is_in)
+{
+        if (req->length == 0)
+                return 0;
+
+        if (req->num_sgs) {
+                int     mapped;
+
+                mapped = dma_map_sg(&gadget->dev, req->sg, req->num_sgs,
+                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+                if (mapped == 0) {
+                        dev_err(&gadget->dev, "failed to map SGs\n");
+                        return -EFAULT;
+                }
+
+                req->num_mapped_sgs = mapped;
+        } else {
+                req->dma = dma_map_single(&gadget->dev, req->buf, req->length,
+                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+                if (dma_mapping_error(&gadget->dev, req->dma)) {
+                        dev_err(&gadget->dev, "failed to map buffer\n");
+                        return -EFAULT;
+                }
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_map_request);
+
+void usb_gadget_unmap_request(struct usb_gadget *gadget,
+                struct usb_request *req, int is_in)
+{
+        if (req->length == 0)
+                return;
+
+        if (req->num_mapped_sgs) {
+                dma_unmap_sg(&gadget->dev, req->sg, req->num_mapped_sgs,
+                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+                req->num_mapped_sgs = 0;
+        } else {
+                dma_unmap_single(&gadget->dev, req->dma, req->length,
+                                is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+        }
+}
+EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
+
+/* ------------------------------------------------------------------------- */
+
 /**
  * usb_gadget_start - tells usb device controller to start up
  * @gadget: The gadget we want to get started