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 <davidel@xmailserver.org>
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 /*
30  * Request the handling of system wakeup events so as to prevent system suspends
31  * from happening while those events are being processed.
32  *
33  * Assuming neither EPOLLET nor EPOLLONESHOT is set, system suspends will not be
34  * re-allowed until epoll_wait is called again after consuming the wakeup
35  * event(s).
36  *
37  * Requires CAP_BLOCK_SUSPEND
38  */
39 #define EPOLLWAKEUP (1 << 29)
40 
41 /* Set the One Shot behaviour for the target file descriptor */
42 #define EPOLLONESHOT (1 << 30)
43 
44 /* Set the Edge Triggered behaviour for the target file descriptor */
45 #define EPOLLET (1 << 31)
46 
47 /*
48  * On x86-64 make the 64bit structure have the same alignment as the
49  * 32bit structure. This makes 32bit emulation easier.
50  *
51  * UML/x86_64 needs the same packing as x86_64
52  */
53 #ifdef __x86_64__
54 #define EPOLL_PACKED __attribute__((packed))
55 #else
56 #define EPOLL_PACKED
57 #endif
58 
59 struct epoll_event {
60 	__u32 events;
61 	__u64 data;
62 } EPOLL_PACKED;
63 
64 #ifdef CONFIG_PM_SLEEP
ep_take_care_of_epollwakeup(struct epoll_event * epev)65 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
66 {
67 	if ((epev->events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
68 		epev->events &= ~EPOLLWAKEUP;
69 }
70 #else
ep_take_care_of_epollwakeup(struct epoll_event * epev)71 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
72 {
73 	epev->events &= ~EPOLLWAKEUP;
74 }
75 #endif
76 #endif /* _UAPI_LINUX_EVENTPOLL_H */
77