linux/arch/um/kernel/sigio.c
Theodore Ts'o aab944606f um: remove IRQF_SAMPLE_RANDOM which is now a no-op
With the changes in the random tree, IRQF_SAMPLE_RANDOM is now a
no-op; interrupt randomness is now collected unconditionally in a very
low-overhead fashion; see commit 775f4b297b.  The IRQF_SAMPLE_RANDOM
flag was scheduled to be removed in 2009 on the
feature-removal-schedule, so this patch is preparation for the final
removal of this flag.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
2012-07-19 10:40:42 -04:00

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);
}