File: sigio.c

package info (click to toggle)
linux 3.2.73-2
  • links: PTS, VCS
  • area: main
  • in suites: wheezy
  • size: 692,996 kB
  • sloc: ansic: 9,719,677; asm: 244,034; xml: 40,377; makefile: 23,845; perl: 16,079; python: 4,929; sh: 4,425; cpp: 3,598; yacc: 2,979; lex: 1,726; awk: 708; pascal: 231; lisp: 218; sed: 30
file content (50 lines) | stat: -rw-r--r-- 1,043 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
/*
 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
 * Licensed under the GPL
 */

#include <linux/interrupt.h>
#include "irq_kern.h"
#include "os.h"
#include "sigio.h"

/* Protected by sigio_lock() called from write_sigio_workaround */
static int sigio_irq_fd = -1;

static irqreturn_t sigio_interrupt(int irq, void *data)
{
	char c;

	os_read_file(sigio_irq_fd, &c, sizeof(c));
	reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ);
	return IRQ_HANDLED;
}

int write_sigio_irq(int fd)
{
	int err;

	err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
			     IRQF_DISABLED|IRQF_SAMPLE_RANDOM, "write sigio",
			     NULL);
	if (err) {
		printk(KERN_ERR "write_sigio_irq : um_request_irq failed, "
		       "err = %d\n", err);
		return -1;
	}
	sigio_irq_fd = fd;
	return 0;
}

/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
static DEFINE_SPINLOCK(sigio_spinlock);

void sigio_lock(void)
{
	spin_lock(&sigio_spinlock);
}

void sigio_unlock(void)
{
	spin_unlock(&sigio_spinlock);
}