1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
new file mode 100644
index 000000000..e313c3b8d
--- /dev/null
+++ b/drivers/usb/gadget/u_f.h
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * u_f.h
+ *
+ * Utility definitions for USB functions
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
+ */
+
+#ifndef __U_F_H__
+#define __U_F_H__
+
+#include <linux/usb/gadget.h>
+#include <linux/overflow.h>
+
+/* Variable Length Array Macros **********************************************/
+#define vla_group(groupname) size_t groupname##__next = 0
+#define vla_group_size(groupname) groupname##__next
+
+#define vla_item(groupname, type, name, n) \
+	size_t groupname##_##name##__offset = ({			       \
+		size_t offset = 0;					       \
+		if (groupname##__next != SIZE_MAX) {			       \
+			size_t align_mask = __alignof__(type) - 1;	       \
+			size_t size = array_size(n, sizeof(type));	       \
+			offset = (groupname##__next + align_mask) &	       \
+				  ~align_mask;				       \
+			if (check_add_overflow(offset, size,		       \
+					       &groupname##__next)) {          \
+				groupname##__next = SIZE_MAX;		       \
+				offset = 0;				       \
+			}						       \
+		}							       \
+		offset;							       \
+	})
+
+#define vla_item_with_sz(groupname, type, name, n) \
+	size_t groupname##_##name##__sz = array_size(n, sizeof(type));	        \
+	size_t groupname##_##name##__offset = ({			        \
+		size_t offset = 0;						\
+		if (groupname##__next != SIZE_MAX) {				\
+			size_t align_mask = __alignof__(type) - 1;		\
+			offset = (groupname##__next + align_mask) &		\
+				  ~align_mask;					\
+			if (check_add_overflow(offset, groupname##_##name##__sz,\
+							&groupname##__next)) {	\
+				groupname##__next = SIZE_MAX;			\
+				offset = 0;					\
+			}							\
+		}								\
+		offset;								\
+	})
+
+#define vla_ptr(ptr, groupname, name) \
+	((void *) ((char *)ptr + groupname##_##name##__offset))
+
+struct usb_ep;
+struct usb_request;
+
+/**
+ * alloc_ep_req - returns a usb_request allocated by the gadget driver and
+ * allocates the request's buffer.
+ *
+ * @ep: the endpoint to allocate a usb_request
+ * @len: usb_requests's buffer suggested size
+ *
+ * In case @ep direction is OUT, the @len will be aligned to ep's
+ * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
+ * usb_requests's length (req->length) to refer to the allocated buffer size.
+ * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
+ */
+struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len);
+
+/* Frees a usb_request previously allocated by alloc_ep_req() */
+static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
+{
+	WARN_ON(req->buf == NULL);
+	kfree(req->buf);
+	req->buf = NULL;
+	usb_ep_free_request(ep, req);
+}
+
+#endif /* __U_F_H__ */