linux-sg2042/arch/um/kernel/sigio.c

50 lines
1004 B
C

/*
* 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,
0, "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);
}