1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2 /*
3  *  include/linux/eventpoll.h ( Efficient event polling implementation )
4  *  Copyright (C) 2001,...,2006	 Davide Libenzi
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  Davide Libenzi <davidel@xmailserver.org>
12  *
13  */
14 
15 #ifndef _UAPI_LINUX_EVENTPOLL_H
16 #define _UAPI_LINUX_EVENTPOLL_H
17 
18 /* For O_CLOEXEC */
19 #include <linux/fcntl.h>
20 #include <linux/types.h>
21 
22 /* Flags for epoll_create1.  */
23 #define EPOLL_CLOEXEC O_CLOEXEC
24 
25 /* Valid opcodes to issue to sys_epoll_ctl() */
26 #define EPOLL_CTL_ADD 1
27 #define EPOLL_CTL_DEL 2
28 #define EPOLL_CTL_MOD 3
29 
30 /* Epoll event masks */
31 #define EPOLLIN		(__force __poll_t)0x00000001
32 #define EPOLLPRI	(__force __poll_t)0x00000002
33 #define EPOLLOUT	(__force __poll_t)0x00000004
34 #define EPOLLERR	(__force __poll_t)0x00000008
35 #define EPOLLHUP	(__force __poll_t)0x00000010
36 #define EPOLLNVAL	(__force __poll_t)0x00000020
37 #define EPOLLRDNORM	(__force __poll_t)0x00000040
38 #define EPOLLRDBAND	(__force __poll_t)0x00000080
39 #define EPOLLWRNORM	(__force __poll_t)0x00000100
40 #define EPOLLWRBAND	(__force __poll_t)0x00000200
41 #define EPOLLMSG	(__force __poll_t)0x00000400
42 #define EPOLLRDHUP	(__force __poll_t)0x00002000
43 
44 /* Set exclusive wakeup mode for the target file descriptor */
45 #define EPOLLEXCLUSIVE	((__force __poll_t)(1U << 28))
46 
47 /*
48  * Request the handling of system wakeup events so as to prevent system suspends
49  * from happening while those events are being processed.
50  *
51  * Assuming neither EPOLLET nor EPOLLONESHOT is set, system suspends will not be
52  * re-allowed until epoll_wait is called again after consuming the wakeup
53  * event(s).
54  *
55  * Requires CAP_BLOCK_SUSPEND
56  */
57 #define EPOLLWAKEUP	((__force __poll_t)(1U << 29))
58 
59 /* Set the One Shot behaviour for the target file descriptor */
60 #define EPOLLONESHOT	((__force __poll_t)(1U << 30))
61 
62 /* Set the Edge Triggered behaviour for the target file descriptor */
63 #define EPOLLET		((__force __poll_t)(1U << 31))
64 
65 /*
66  * On x86-64 make the 64bit structure have the same alignment as the
67  * 32bit structure. This makes 32bit emulation easier.
68  *
69  * UML/x86_64 needs the same packing as x86_64
70  */
71 #ifdef __x86_64__
72 #define EPOLL_PACKED __attribute__((packed))
73 #else
74 #define EPOLL_PACKED
75 #endif
76 
77 struct epoll_event {
78 	__poll_t events;
79 	__u64 data;
80 } EPOLL_PACKED;
81 
82 #ifdef CONFIG_PM_SLEEP
ep_take_care_of_epollwakeup(struct epoll_event * epev)83 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
84 {
85 	if ((epev->events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
86 		epev->events &= ~EPOLLWAKEUP;
87 }
88 #else
ep_take_care_of_epollwakeup(struct epoll_event * epev)89 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
90 {
91 	epev->events &= ~EPOLLWAKEUP;
92 }
93 #endif
94 #endif /* _UAPI_LINUX_EVENTPOLL_H */
95