1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * u_f.h
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Utility definitions for USB functions
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Copyright (c) 2013 Samsung Electronics Co., Ltd.
8*4882a593Smuzhiyun * http://www.samsung.com
9*4882a593Smuzhiyun *
10*4882a593Smuzhiyun * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
11*4882a593Smuzhiyun */
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #ifndef __U_F_H__
14*4882a593Smuzhiyun #define __U_F_H__
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #include <linux/usb/gadget.h>
17*4882a593Smuzhiyun #include <linux/overflow.h>
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun /* Variable Length Array Macros **********************************************/
20*4882a593Smuzhiyun #define vla_group(groupname) size_t groupname##__next = 0
21*4882a593Smuzhiyun #define vla_group_size(groupname) groupname##__next
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun #define vla_item(groupname, type, name, n) \
24*4882a593Smuzhiyun size_t groupname##_##name##__offset = ({ \
25*4882a593Smuzhiyun size_t offset = 0; \
26*4882a593Smuzhiyun if (groupname##__next != SIZE_MAX) { \
27*4882a593Smuzhiyun size_t align_mask = __alignof__(type) - 1; \
28*4882a593Smuzhiyun size_t size = array_size(n, sizeof(type)); \
29*4882a593Smuzhiyun offset = (groupname##__next + align_mask) & \
30*4882a593Smuzhiyun ~align_mask; \
31*4882a593Smuzhiyun if (check_add_overflow(offset, size, \
32*4882a593Smuzhiyun &groupname##__next)) { \
33*4882a593Smuzhiyun groupname##__next = SIZE_MAX; \
34*4882a593Smuzhiyun offset = 0; \
35*4882a593Smuzhiyun } \
36*4882a593Smuzhiyun } \
37*4882a593Smuzhiyun offset; \
38*4882a593Smuzhiyun })
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun #define vla_item_with_sz(groupname, type, name, n) \
41*4882a593Smuzhiyun size_t groupname##_##name##__sz = array_size(n, sizeof(type)); \
42*4882a593Smuzhiyun size_t groupname##_##name##__offset = ({ \
43*4882a593Smuzhiyun size_t offset = 0; \
44*4882a593Smuzhiyun if (groupname##__next != SIZE_MAX) { \
45*4882a593Smuzhiyun size_t align_mask = __alignof__(type) - 1; \
46*4882a593Smuzhiyun offset = (groupname##__next + align_mask) & \
47*4882a593Smuzhiyun ~align_mask; \
48*4882a593Smuzhiyun if (check_add_overflow(offset, groupname##_##name##__sz,\
49*4882a593Smuzhiyun &groupname##__next)) { \
50*4882a593Smuzhiyun groupname##__next = SIZE_MAX; \
51*4882a593Smuzhiyun offset = 0; \
52*4882a593Smuzhiyun } \
53*4882a593Smuzhiyun } \
54*4882a593Smuzhiyun offset; \
55*4882a593Smuzhiyun })
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun #define vla_ptr(ptr, groupname, name) \
58*4882a593Smuzhiyun ((void *) ((char *)ptr + groupname##_##name##__offset))
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun struct usb_ep;
61*4882a593Smuzhiyun struct usb_request;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun /**
64*4882a593Smuzhiyun * alloc_ep_req - returns a usb_request allocated by the gadget driver and
65*4882a593Smuzhiyun * allocates the request's buffer.
66*4882a593Smuzhiyun *
67*4882a593Smuzhiyun * @ep: the endpoint to allocate a usb_request
68*4882a593Smuzhiyun * @len: usb_requests's buffer suggested size
69*4882a593Smuzhiyun *
70*4882a593Smuzhiyun * In case @ep direction is OUT, the @len will be aligned to ep's
71*4882a593Smuzhiyun * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
72*4882a593Smuzhiyun * usb_requests's length (req->length) to refer to the allocated buffer size.
73*4882a593Smuzhiyun * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
74*4882a593Smuzhiyun */
75*4882a593Smuzhiyun struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len);
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun /* Frees a usb_request previously allocated by alloc_ep_req() */
free_ep_req(struct usb_ep * ep,struct usb_request * req)78*4882a593Smuzhiyun static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
79*4882a593Smuzhiyun {
80*4882a593Smuzhiyun WARN_ON(req->buf == NULL);
81*4882a593Smuzhiyun kfree(req->buf);
82*4882a593Smuzhiyun req->buf = NULL;
83*4882a593Smuzhiyun usb_ep_free_request(ep, req);
84*4882a593Smuzhiyun }
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun #endif /* __U_F_H__ */
87