Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block
[linux-2.6-microblaze.git] / drivers / usb / gadget / u_f.h
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * u_f.h
4  *
5  * Utility definitions for USB functions
6  *
7  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
8  *              http://www.samsung.com
9  *
10  * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
11  */
12
13 #ifndef __U_F_H__
14 #define __U_F_H__
15
16 #include <linux/usb/gadget.h>
17 #include <linux/overflow.h>
18
19 /* Variable Length Array Macros **********************************************/
20 #define vla_group(groupname) size_t groupname##__next = 0
21 #define vla_group_size(groupname) groupname##__next
22
23 #define vla_item(groupname, type, name, n) \
24         size_t groupname##_##name##__offset = ({                               \
25                 size_t offset = 0;                                             \
26                 if (groupname##__next != SIZE_MAX) {                           \
27                         size_t align_mask = __alignof__(type) - 1;             \
28                         size_t size = array_size(n, sizeof(type));             \
29                         offset = (groupname##__next + align_mask) &            \
30                                   ~align_mask;                                 \
31                         if (check_add_overflow(offset, size,                   \
32                                                &groupname##__next)) {          \
33                                 groupname##__next = SIZE_MAX;                  \
34                                 offset = 0;                                    \
35                         }                                                      \
36                 }                                                              \
37                 offset;                                                        \
38         })
39
40 #define vla_item_with_sz(groupname, type, name, n) \
41         size_t groupname##_##name##__sz = array_size(n, sizeof(type));          \
42         size_t groupname##_##name##__offset = ({                                \
43                 size_t offset = 0;                                              \
44                 if (groupname##__next != SIZE_MAX) {                            \
45                         size_t align_mask = __alignof__(type) - 1;              \
46                         offset = (groupname##__next + align_mask) &             \
47                                   ~align_mask;                                  \
48                         if (check_add_overflow(offset, groupname##_##name##__sz,\
49                                                         &groupname##__next)) {  \
50                                 groupname##__next = SIZE_MAX;                   \
51                                 offset = 0;                                     \
52                         }                                                       \
53                 }                                                               \
54                 offset;                                                         \
55         })
56
57 #define vla_ptr(ptr, groupname, name) \
58         ((void *) ((char *)ptr + groupname##_##name##__offset))
59
60 struct usb_ep;
61 struct usb_request;
62
63 /**
64  * alloc_ep_req - returns a usb_request allocated by the gadget driver and
65  * allocates the request's buffer.
66  *
67  * @ep: the endpoint to allocate a usb_request
68  * @len: usb_requests's buffer suggested size
69  *
70  * In case @ep direction is OUT, the @len will be aligned to ep's
71  * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
72  * usb_requests's length (req->length) to refer to the allocated buffer size.
73  * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
74  */
75 struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len);
76
77 /* Frees a usb_request previously allocated by alloc_ep_req() */
78 static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
79 {
80         WARN_ON(req->buf == NULL);
81         kfree(req->buf);
82         req->buf = NULL;
83         usb_ep_free_request(ep, req);
84 }
85
86 #endif /* __U_F_H__ */