LXR linux/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         (__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
  77struct epoll_event {
  78        __poll_t events;
  79        __u64 data;
  80} EPOLL_PACKED;
  81
  82#ifdef CONFIG_PM_SLEEP
  83static 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
  89static 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