include/uapi/linux/eventpoll.h

   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         0x00000001
  32 #define EPOLLPRI        0x00000002
  33 #define EPOLLOUT        0x00000004
  34 #define EPOLLERR        0x00000008
  35 #define EPOLLHUP        0x00000010
  36 #define EPOLLRDNORM     0x00000040
  37 #define EPOLLRDBAND     0x00000080
  38 #define EPOLLWRNORM     0x00000100
  39 #define EPOLLWRBAND     0x00000200
  40 #define EPOLLMSG        0x00000400
  41 #define EPOLLRDHUP      0x00002000
  42
  43 /* Set exclusive wakeup mode for the target file descriptor */
  44 #define EPOLLEXCLUSIVE (1U << 28)
  45
  46 /*
  47  * Request the handling of system wakeup events so as to prevent system suspends
  48  * from happening while those events are being processed.
  49  *
  50  * Assuming neither EPOLLET nor EPOLLONESHOT is set, system suspends will not be
  51  * re-allowed until epoll_wait is called again after consuming the wakeup
  52  * event(s).
  53  *
  54  * Requires CAP_BLOCK_SUSPEND
  55  */
  56 #define EPOLLWAKEUP (1U << 29)
  57
  58 /* Set the One Shot behaviour for the target file descriptor */
  59 #define EPOLLONESHOT (1U << 30)
  60
  61 /* Set the Edge Triggered behaviour for the target file descriptor */
  62 #define EPOLLET (1U << 31)
  63
  64 /*
  65  * On x86-64 make the 64bit structure have the same alignment as the
  66  * 32bit structure. This makes 32bit emulation easier.
  67  *
  68  * UML/x86_64 needs the same packing as x86_64
  69  */
  70 #ifdef __x86_64__
  71 #define EPOLL_PACKED __attribute__((packed))
  72 #else
  73 #define EPOLL_PACKED
  74 #endif
  75
  76 struct epoll_event {
  77         __u32 events;
  78         __u64 data;
  79 } EPOLL_PACKED;
  80
  81 #ifdef CONFIG_PM_SLEEP
  82 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
  83 {
  84         if ((epev->events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
  85                 epev->events &= ~EPOLLWAKEUP;
  86 }
  87 #else
  88 static inline void ep_take_care_of_epollwakeup(struct epoll_event *epev)
  89 {
  90         epev->events &= ~EPOLLWAKEUP;
  91 }
  92 #endif
  93 #endif /* _UAPI_LINUX_EVENTPOLL_H */