xref: /linux-6.15/include/uapi/linux/eventpoll.h (revision 7fb2e072)
1 /*
2  *  include/linux/eventpoll.h ( Efficient event polling implementation )
3  *  Copyright (C) 2001,...,2006	 Davide Libenzi
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  Davide Libenzi <[email protected]>
11  *
12  */
13 
14 #ifndef _UAPI_LINUX_EVENTPOLL_H
15 #define _UAPI_LINUX_EVENTPOLL_H
16 
17 /* For O_CLOEXEC */
18 #include <linux/fcntl.h>
19 #include <linux/types.h>
20 
21 /* Flags for epoll_create1.  */
22 #define EPOLL_CLOEXEC O_CLOEXEC
23 
24 /* Valid opcodes to issue to sys_epoll_ctl() */
25 #define EPOLL_CTL_ADD 1
26 #define EPOLL_CTL_DEL 2
27 #define EPOLL_CTL_MOD 3
28 
29 /* Epoll event masks */
30 #define EPOLLIN		0x00000001
31 #define EPOLLPRI	0x00000002
32 #define EPOLLOUT	0x00000004
33 #define EPOLLERR	0x00000008
34 #define EPOLLHUP	0x00000010
35 #define EPOLLRDNORM	0x00000040
36 #define EPOLLRDBAND	0x00000080
37 #define EPOLLWRNORM	0x00000100
38 #define EPOLLWRBAND	0x00000200
39 #define EPOLLMSG	0x00000400
40 #define EPOLLRDHUP	0x00002000
41 
42 /* Set exclusive wakeup mode for the target file descriptor */
43 #define EPOLLEXCLUSIVE (1U << 28)
44 
45 /*
46  * Request the handling of system wakeup events so as to prevent system suspends
47  * from happening while those events are being processed.
48  *
49  * Assuming neither EPOLLET nor EPOLLONESHOT is set, system suspends will not be
50  * re-allowed until epoll_wait is called again after consuming the wakeup
51  * event(s).
52  *
53  * Requires CAP_BLOCK_SUSPEND
54  */
55 #define EPOLLWAKEUP (1U << 29)
56 
57 /* Set the One Shot behaviour for the target file descriptor */
58 #define EPOLLONESHOT (1U << 30)
59 
60 /* Set the Edge Triggered behaviour for the target file descriptor */
61 #define EPOLLET (1U << 31)
62 
63 /*
64  * On x86-64 make the 64bit structure have the same alignment as the
65  * 32bit structure. This makes 32bit emulation easier.
66  *
67  * UML/x86_64 needs the same packing as x86_64
68  */
69 #ifdef __x86_64__
70 #define EPOLL_PACKED __attribute__((packed))
71 #else
72 #define EPOLL_PACKED
73 #endif
74 
75 struct epoll_event {
76 	__u32 events;
77 	__u64 data;
78 } EPOLL_PACKED;
79 
80 #ifdef CONFIG_PM_SLEEP
81 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
82 {
83 	if ((epev->events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
84 		epev->events &= ~EPOLLWAKEUP;
85 }
86 #else
87 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
88 {
89 	epev->events &= ~EPOLLWAKEUP;
90 }
91 #endif
92 #endif /* _UAPI_LINUX_EVENTPOLL_H */
93