1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
4 */
5
6#include <linux/interrupt.h>
7#include <irq_kern.h>
8#include <os.h>
9#include <sigio.h>
10
11/* Protected by sigio_lock() called from write_sigio_workaround */
12static int sigio_irq_fd = -1;
13
14static irqreturn_t sigio_interrupt(int irq, void *data)
15{
16 char c;
17
18 os_read_file(sigio_irq_fd, &c, sizeof(c));
19 return IRQ_HANDLED;
20}
21
22int write_sigio_irq(int fd)
23{
24 int err;
25
26 err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
27 0, "write sigio", NULL);
28 if (err < 0) {
29 printk(KERN_ERR "write_sigio_irq : um_request_irq failed, "
30 "err = %d\n", err);
31 return -1;
32 }
33 sigio_irq_fd = fd;
34 return 0;
35}
36
37/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
38static DEFINE_MUTEX(sigio_mutex);
39
40void sigio_lock(void)
41{
42 mutex_lock(&sigio_mutex);
43}
44
45void sigio_unlock(void)
46{
47 mutex_unlock(lock: &sigio_mutex);
48}
49

source code of linux/arch/um/kernel/sigio.c