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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 /* Set exclusive wakeup mode for the target file descriptor */
30 #define EPOLLEXCLUSIVE (1 << 28)
31 
32 /*
33  * Request the handling of system wakeup events so as to prevent system suspends
34  * from happening while those events are being processed.
35  *
36  * Assuming neither EPOLLET nor EPOLLONESHOT is set, system suspends will not be
37  * re-allowed until epoll_wait is called again after consuming the wakeup
38  * event(s).
39  *
40  * Requires CAP_BLOCK_SUSPEND
41  */
42 #define EPOLLWAKEUP (1 << 29)
43 
44 /* Set the One Shot behaviour for the target file descriptor */
45 #define EPOLLONESHOT (1 << 30)
46 
47 /* Set the Edge Triggered behaviour for the target file descriptor */
48 #define EPOLLET (1 << 31)
49 
50 /*
51  * On x86-64 make the 64bit structure have the same alignment as the
52  * 32bit structure. This makes 32bit emulation easier.
53  *
54  * UML/x86_64 needs the same packing as x86_64
55  */
56 #ifdef __x86_64__
57 #define EPOLL_PACKED __attribute__((packed))
58 #else
59 #define EPOLL_PACKED
60 #endif
61 
62 struct epoll_event {
63 	__u32 events;
64 	__u64 data;
65 } EPOLL_PACKED;
66 
67 #ifdef CONFIG_PM_SLEEP
ep_take_care_of_epollwakeup(struct epoll_event * epev)68 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
69 {
70 	if ((epev->events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
71 		epev->events &= ~EPOLLWAKEUP;
72 }
73 #else
ep_take_care_of_epollwakeup(struct epoll_event * epev)74 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
75 {
76 	epev->events &= ~EPOLLWAKEUP;
77 }
78 #endif
79 #endif /* _UAPI_LINUX_EVENTPOLL_H */
80