freebsd-dev/sys/kern/subr_autoconf.c
Robert Watson 828e07694c If run_interrupt_driven_config_hooks() waits 360 seconds and INVARIANTS
is compiled into the kernel, then panic.

MFC after:	3 days
Discussed with:	scottl
2008-07-21 20:50:49 +00:00

197 lines
5.9 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 "opt_ddb.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/linker.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);
/*
* If we wait too long for an interrupt-driven config hook to return, print
* a diagnostic.
*/
#define WARNING_INTERVAL_SECS 60
static void
run_interrupt_driven_config_hooks_warning(int warned)
{
struct intr_config_hook *hook_entry;
char namebuf[64];
long offset;
if (warned < 6) {
printf("run_interrupt_driven_hooks: still waiting after %d "
"seconds for", warned * WARNING_INTERVAL_SECS);
TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
if (linker_search_symbol_name(
(caddr_t)hook_entry->ich_func, namebuf,
sizeof(namebuf), &offset) == 0)
printf(" %s", namebuf);
else
printf(" %p", hook_entry->ich_func);
}
printf("\n");
}
KASSERT(warned < 6,
("run_interrupt_driven_config_hooks: waited too long"));
}
static void
run_interrupt_driven_config_hooks(dummy)
void *dummy;
{
struct intr_config_hook *hook_entry, *next_entry;
int warned;
mtx_lock(&intr_config_hook_lock);
TAILQ_FOREACH_SAFE(hook_entry, &intr_config_hook_list, ich_links,
next_entry) {
mtx_unlock(&intr_config_hook_lock);
(*hook_entry->ich_func)(hook_entry->ich_arg);
mtx_lock(&intr_config_hook_lock);
}
warned = 0;
while (!TAILQ_EMPTY(&intr_config_hook_list)) {
if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
PCONFIG, "conifhk", WARNING_INTERVAL_SECS * hz) ==
EWOULDBLOCK) {
mtx_unlock(&intr_config_hook_lock);
warned++;
run_interrupt_driven_config_hooks_warning(warned);
mtx_lock(&intr_config_hook_lock);
}
}
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);
}
#ifdef DDB
#include <ddb/ddb.h>
DB_SHOW_COMMAND(conifhk, db_show_conifhk)
{
struct intr_config_hook *hook_entry;
char namebuf[64];
long offset;
TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
if (linker_ddb_search_symbol_name(
(caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
&offset) == 0) {
db_printf("hook: %p at %s+%#lx arg: %p\n",
hook_entry->ich_func, namebuf, offset,
hook_entry->ich_arg);
} else {
db_printf("hook: %p at ??+?? arg %p\n",
hook_entry->ich_func, hook_entry->ich_arg);
}
}
}
#endif /* DDB */