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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2017 - Cambridge Greys Ltd
* Copyright (C) 2011 - 2014 Cisco Systems Inc
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <stdlib.h>
#include <errno.h>
#include <sys/epoll.h>
#include <signal.h>
#include <string.h>
#include <irq_user.h>
#include <os.h>
#include <um_malloc.h>
/* Epoll support */
static int epollfd = -1;
#define MAX_EPOLL_EVENTS 64
static struct epoll_event epoll_events[MAX_EPOLL_EVENTS];
/* Helper to return an Epoll data pointer from an epoll event structure.
* We need to keep this one on the userspace side to keep includes separate
*/
void *os_epoll_get_data_pointer(int index)
{
return epoll_events[index].data.ptr;
}
/* Helper to compare events versus the events in the epoll structure.
* Same as above - needs to be on the userspace side
*/
int os_epoll_triggered(int index, int events)
{
return epoll_events[index].events & events;
}
/* Helper to set the event mask.
* The event mask is opaque to the kernel side, because it does not have
* access to the right includes/defines for EPOLL constants.
*/
int os_event_mask(enum um_irq_type irq_type)
{
if (irq_type == IRQ_READ)
return EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP | EPOLLRDHUP;
if (irq_type == IRQ_WRITE)
return EPOLLOUT;
return 0;
}
/*
* Initial Epoll Setup
*/
int os_setup_epoll(void)
{
epollfd = epoll_create(MAX_EPOLL_EVENTS);
return epollfd;
}
/*
* Helper to run the actual epoll_wait
*/
int os_waiting_for_events_epoll(void)
{
int n, err;
n = epoll_wait(epollfd,
(struct epoll_event *) &epoll_events, MAX_EPOLL_EVENTS, 0);
if (n < 0) {
err = -errno;
if (errno != EINTR)
printk(
UM_KERN_ERR "os_waiting_for_events:"
" epoll returned %d, error = %s\n", n,
strerror(errno)
);
return err;
}
return n;
}
/*
* Helper to add a fd to epoll
*/
int os_add_epoll_fd(int events, int fd, void *data)
{
struct epoll_event event;
int result;
event.data.ptr = data;
event.events = events | EPOLLET;
result = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
if ((result) && (errno == EEXIST))
result = os_mod_epoll_fd(events, fd, data);
if (result)
printk("epollctl add err fd %d, %s\n", fd, strerror(errno));
return result;
}
/*
* Helper to mod the fd event mask and/or data backreference
*/
int os_mod_epoll_fd(int events, int fd, void *data)
{
struct epoll_event event;
int result;
event.data.ptr = data;
event.events = events;
result = epoll_ctl(epollfd, EPOLL_CTL_MOD, fd, &event);
if (result)
printk(UM_KERN_ERR
"epollctl mod err fd %d, %s\n", fd, strerror(errno));
return result;
}
/*
* Helper to delete the epoll fd
*/
int os_del_epoll_fd(int fd)
{
struct epoll_event event;
/* This is quiet as we use this as IO ON/OFF - so it is often
* invoked on a non-existent fd
*/
return epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &event);
}
void os_set_ioignore(void)
{
signal(SIGIO, SIG_IGN);
}
void os_close_epoll_fd(void)
{
/* Needed so we do not leak an fd when rebooting */
os_close_file(epollfd);
}
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