usb: gadget: define free_ep_req as universal function

commit 079fe5a6da616891cca1a26e803e1df2a87e9ae5 upstream.

This function is shared between gadget functions, so this avoid unnecessary
duplicated code and potentially avoid memory leaks.

Reviewed-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 847f7036..d8a4b77 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -201,12 +201,6 @@
 	return alloc_ep_req(ep, length, length);
 }
 
-static void free_ep_req(struct usb_ep *ep, struct usb_request *req)
-{
-	kfree(req->buf);
-	usb_ep_free_request(ep, req);
-}
-
 static const uint8_t f_midi_cin_length[] = {
 	0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
 };
diff --git a/drivers/usb/gadget/function/f_sourcesink.c b/drivers/usb/gadget/function/f_sourcesink.c
index 9f3ced6..67b2439 100644
--- a/drivers/usb/gadget/function/f_sourcesink.c
+++ b/drivers/usb/gadget/function/f_sourcesink.c
@@ -303,12 +303,6 @@
 	return alloc_ep_req(ep, len, ss->buflen);
 }
 
-void free_ep_req(struct usb_ep *ep, struct usb_request *req)
-{
-	kfree(req->buf);
-	usb_ep_free_request(ep, req);
-}
-
 static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
 {
 	int			value;
diff --git a/drivers/usb/gadget/function/g_zero.h b/drivers/usb/gadget/function/g_zero.h
index 15f1809..5ed90b4 100644
--- a/drivers/usb/gadget/function/g_zero.h
+++ b/drivers/usb/gadget/function/g_zero.h
@@ -59,7 +59,6 @@
 int lb_modinit(void);
 
 /* common utilities */
-void free_ep_req(struct usb_ep *ep, struct usb_request *req);
 void disable_endpoints(struct usb_composite_dev *cdev,
 		struct usb_ep *in, struct usb_ep *out,
 		struct usb_ep *iso_in, struct usb_ep *iso_out);
diff --git a/drivers/usb/gadget/u_f.c b/drivers/usb/gadget/u_f.c
index c6276f0..4bc7eea 100644
--- a/drivers/usb/gadget/u_f.c
+++ b/drivers/usb/gadget/u_f.c
@@ -11,7 +11,6 @@
  * published by the Free Software Foundation.
  */
 
-#include <linux/usb/gadget.h>
 #include "u_f.h"
 
 struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len)
diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
index 1d5f0eb..4247cc0 100644
--- a/drivers/usb/gadget/u_f.h
+++ b/drivers/usb/gadget/u_f.h
@@ -16,6 +16,8 @@
 #ifndef __U_F_H__
 #define __U_F_H__
 
+#include <linux/usb/gadget.h>
+
 /* Variable Length Array Macros **********************************************/
 #define vla_group(groupname) size_t groupname##__next = 0
 #define vla_group_size(groupname) groupname##__next
@@ -45,8 +47,12 @@
 struct usb_ep;
 struct usb_request;
 
+/* Requests allocated via alloc_ep_req() must be freed by free_ep_req(). */
 struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len);
+static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
+{
+	kfree(req->buf);
+	usb_ep_free_request(ep, req);
+}
 
 #endif /* __U_F_H__ */
-
-