linux/arch/um/kernel/sigio_kern.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

64 lines
1.4 KiB
C

/*
* Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "linux/list.h"
#include "linux/slab.h"
#include "linux/signal.h"
#include "linux/interrupt.h"
#include "init.h"
#include "sigio.h"
#include "irq_user.h"
#include "irq_kern.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, struct pt_regs *unused)
{
read_sigio_fd(sigio_irq_fd);
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,
SA_INTERRUPT | SA_SAMPLE_RANDOM, "write sigio",
NULL);
if(err){
printk("write_sigio_irq : um_request_irq failed, err = %d\n",
err);
return(-1);
}
sigio_irq_fd = fd;
return(0);
}
static DEFINE_SPINLOCK(sigio_spinlock);
void sigio_lock(void)
{
spin_lock(&sigio_spinlock);
}
void sigio_unlock(void)
{
spin_unlock(&sigio_spinlock);
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/