subr_autoconf.c revision 139804 
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 139804 2005-01-06 23:35:40Z imp $");
39
40#include <sys/param.h>
41#include <sys/kernel.h>
42#include <sys/systm.h>
43
44/*
45 * Autoconfiguration subroutines.
46 */
47
48/*
49 * "Interrupt driven config" functions.
50 */
51static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
52	TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
53
54
55/* ARGSUSED */
56static void run_interrupt_driven_config_hooks(void *dummy);
57static void
58run_interrupt_driven_config_hooks(dummy)
59	void *dummy;
60{
61	struct intr_config_hook *hook_entry, *next_entry;
62
63	for (hook_entry = TAILQ_FIRST(&intr_config_hook_list);
64	     hook_entry != NULL;
65	     hook_entry = next_entry) {
66		next_entry = TAILQ_NEXT(hook_entry, ich_links);
67		(*hook_entry->ich_func)(hook_entry->ich_arg);
68	}
69
70	while (!TAILQ_EMPTY(&intr_config_hook_list)) {
71		tsleep(&intr_config_hook_list, PCONFIG, "conifhk", 0);
72	}
73}
74SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
75	run_interrupt_driven_config_hooks, NULL)
76
77/*
78 * Register a hook that will be called after "cold"
79 * autoconfiguration is complete and interrupts can
80 * be used to complete initialization.
81 */
82int
83config_intrhook_establish(hook)
84	struct intr_config_hook *hook;
85{
86	struct intr_config_hook *hook_entry;
87
88	for (hook_entry = TAILQ_FIRST(&intr_config_hook_list);
89	     hook_entry != NULL;
90	     hook_entry = TAILQ_NEXT(hook_entry, ich_links))
91		if (hook_entry == hook)
92			break;
93	if (hook_entry != NULL) {
94		printf("config_intrhook_establish: establishing an "
95		       "already established hook.\n");
96		return (1);
97	}
98	TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
99	if (cold == 0)
100		/* XXX Sufficient for modules loaded after initial config??? */
101		run_interrupt_driven_config_hooks(NULL);
102	return (0);
103}
104
105void
106config_intrhook_disestablish(hook)
107	struct intr_config_hook *hook;
108{
109	struct intr_config_hook *hook_entry;
110
111	for (hook_entry = TAILQ_FIRST(&intr_config_hook_list);
112	     hook_entry != NULL;
113	     hook_entry = TAILQ_NEXT(hook_entry, ich_links))
114		if (hook_entry == hook)
115			break;
116	if (hook_entry == NULL)
117		panic("config_intrhook_disestablish: disestablishing an "
118		      "unestablished hook");
119
120	TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
121	/* Wakeup anyone watching the list */
122	wakeup(&intr_config_hook_list);
123}
124