subr_autoconf.c revision 176323 
1/*-
2 * Copyright (c) 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This software was developed by the Computer Systems Engineering group
6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7 * contributed to Berkeley.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)subr_autoconf.c	8.1 (Berkeley) 6/10/93
34 *
35 */
36
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: head/sys/kern/subr_autoconf.c 176323 2008-02-15 21:54:21Z antoine $");
39
40#include <sys/param.h>
41#include <sys/kernel.h>
42#include <sys/lock.h>
43#include <sys/mutex.h>
44#include <sys/systm.h>
45
46/*
47 * Autoconfiguration subroutines.
48 */
49
50/*
51 * "Interrupt driven config" functions.
52 */
53static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
54	TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
55static struct mtx intr_config_hook_lock;
56MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
57
58/* ARGSUSED */
59static void run_interrupt_driven_config_hooks(void *dummy);
60
61static void
62run_interrupt_driven_config_hooks(dummy)
63	void *dummy;
64{
65	struct intr_config_hook *hook_entry, *next_entry;
66
67	mtx_lock(&intr_config_hook_lock);
68	TAILQ_FOREACH_SAFE(hook_entry, &intr_config_hook_list, ich_links,
69	    next_entry) {
70		mtx_unlock(&intr_config_hook_lock);
71		(*hook_entry->ich_func)(hook_entry->ich_arg);
72		mtx_lock(&intr_config_hook_lock);
73	}
74
75	while (!TAILQ_EMPTY(&intr_config_hook_list)) {
76		msleep(&intr_config_hook_list, &intr_config_hook_lock, PCONFIG,
77		    "conifhk", 0);
78	}
79	mtx_unlock(&intr_config_hook_lock);
80}
81SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
82	run_interrupt_driven_config_hooks, NULL)
83
84/*
85 * Register a hook that will be called after "cold"
86 * autoconfiguration is complete and interrupts can
87 * be used to complete initialization.
88 */
89int
90config_intrhook_establish(hook)
91	struct intr_config_hook *hook;
92{
93	struct intr_config_hook *hook_entry;
94
95	mtx_lock(&intr_config_hook_lock);
96	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
97		if (hook_entry == hook)
98			break;
99	if (hook_entry != NULL) {
100		mtx_unlock(&intr_config_hook_lock);
101		printf("config_intrhook_establish: establishing an "
102		       "already established hook.\n");
103		return (1);
104	}
105	TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
106	mtx_unlock(&intr_config_hook_lock);
107	if (cold == 0)
108		/* XXX Sufficient for modules loaded after initial config??? */
109		run_interrupt_driven_config_hooks(NULL);
110	return (0);
111}
112
113void
114config_intrhook_disestablish(hook)
115	struct intr_config_hook *hook;
116{
117	struct intr_config_hook *hook_entry;
118
119	mtx_lock(&intr_config_hook_lock);
120	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
121		if (hook_entry == hook)
122			break;
123	if (hook_entry == NULL)
124		panic("config_intrhook_disestablish: disestablishing an "
125		      "unestablished hook");
126
127	TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
128
129	/* Wakeup anyone watching the list */
130	wakeup(&intr_config_hook_list);
131	mtx_unlock(&intr_config_hook_lock);
132}
133