1 /*
2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
3 * Licensed under the GPL
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 reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ);
20 return IRQ_HANDLED;
21 }
22
write_sigio_irq(int fd)23 int write_sigio_irq(int fd)
24 {
25 int err;
26
27 err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
28 IRQF_DISABLED|IRQF_SAMPLE_RANDOM, "write sigio",
29 NULL);
30 if (err) {
31 printk(KERN_ERR "write_sigio_irq : um_request_irq failed, "
32 "err = %d\n", err);
33 return -1;
34 }
35 sigio_irq_fd = fd;
36 return 0;
37 }
38
39 /* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
40 static DEFINE_SPINLOCK(sigio_spinlock);
41
sigio_lock(void)42 void sigio_lock(void)
43 {
44 spin_lock(&sigio_spinlock);
45 }
46
sigio_unlock(void)47 void sigio_unlock(void)
48 {
49 spin_unlock(&sigio_spinlock);
50 }
51