freebsd-src/sys/kern/subr_autoconf.c
John Baldwin 9079458ad2 Add a mutex to protect the list of interrupt config hooks. We do assume
that the only remove hook operation that can occur while processing the
hooks is to remove the currently executing hook.  This should be safe as
the existing code has assumed this already for a long time now.

Reviewed by:	scottl
MFC after:	1 week
2006-07-19 18:53:56 +00:00

134 lines
4.3 KiB
C

/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)subr_autoconf.c 8.1 (Berkeley) 6/10/93
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/systm.h>
/*
* Autoconfiguration subroutines.
*/
/*
* "Interrupt driven config" functions.
*/
static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
static struct mtx intr_config_hook_lock;
MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
/* ARGSUSED */
static void run_interrupt_driven_config_hooks(void *dummy);
static void
run_interrupt_driven_config_hooks(dummy)
void *dummy;
{
struct intr_config_hook *hook_entry, *next_entry;
mtx_lock(&intr_config_hook_lock);
TAILQ_FOREACH_SAFE(hook_entry, &intr_config_hook_list, ich_links,
next_entry) {
next_entry = TAILQ_NEXT(hook_entry, ich_links);
mtx_unlock(&intr_config_hook_lock);
(*hook_entry->ich_func)(hook_entry->ich_arg);
mtx_lock(&intr_config_hook_lock);
}
while (!TAILQ_EMPTY(&intr_config_hook_list)) {
msleep(&intr_config_hook_list, &intr_config_hook_lock, PCONFIG,
"conifhk", 0);
}
mtx_unlock(&intr_config_hook_lock);
}
SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
run_interrupt_driven_config_hooks, NULL)
/*
* Register a hook that will be called after "cold"
* autoconfiguration is complete and interrupts can
* be used to complete initialization.
*/
int
config_intrhook_establish(hook)
struct intr_config_hook *hook;
{
struct intr_config_hook *hook_entry;
mtx_lock(&intr_config_hook_lock);
TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
if (hook_entry == hook)
break;
if (hook_entry != NULL) {
mtx_unlock(&intr_config_hook_lock);
printf("config_intrhook_establish: establishing an "
"already established hook.\n");
return (1);
}
TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
mtx_unlock(&intr_config_hook_lock);
if (cold == 0)
/* XXX Sufficient for modules loaded after initial config??? */
run_interrupt_driven_config_hooks(NULL);
return (0);
}
void
config_intrhook_disestablish(hook)
struct intr_config_hook *hook;
{
struct intr_config_hook *hook_entry;
mtx_lock(&intr_config_hook_lock);
TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
if (hook_entry == hook)
break;
if (hook_entry == NULL)
panic("config_intrhook_disestablish: disestablishing an "
"unestablished hook");
TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
/* Wakeup anyone watching the list */
wakeup(&intr_config_hook_list);
mtx_unlock(&intr_config_hook_lock);
}