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 */
12 static int sigio_irq_fd = -1;
13 
sigio_interrupt(int irq,void * data)14 static 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 
write_sigio_irq(int fd)22 int 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) {
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. */
38 static DEFINE_SPINLOCK(sigio_spinlock);
39 
sigio_lock(void)40 void sigio_lock(void)
41 {
42 	spin_lock(&sigio_spinlock);
43 }
44 
sigio_unlock(void)45 void sigio_unlock(void)
46 {
47 	spin_unlock(&sigio_spinlock);
48 }
49