subr_autoconf.c revision 180673 
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 180673 2008-07-21 20:50:49Z rwatson $");
39
40#include "opt_ddb.h"
41
42#include <sys/param.h>
43#include <sys/kernel.h>
44#include <sys/linker.h>
45#include <sys/lock.h>
46#include <sys/mutex.h>
47#include <sys/systm.h>
48
49/*
50 * Autoconfiguration subroutines.
51 */
52
53/*
54 * "Interrupt driven config" functions.
55 */
56static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
57	TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
58static struct mtx intr_config_hook_lock;
59MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
60
61/* ARGSUSED */
62static void run_interrupt_driven_config_hooks(void *dummy);
63
64/*
65 * If we wait too long for an interrupt-driven config hook to return, print
66 * a diagnostic.
67 */
68#define	WARNING_INTERVAL_SECS	60
69static void
70run_interrupt_driven_config_hooks_warning(int warned)
71{
72	struct intr_config_hook *hook_entry;
73	char namebuf[64];
74	long offset;
75
76	if (warned < 6) {
77		printf("run_interrupt_driven_hooks: still waiting after %d "
78		    "seconds for", warned * WARNING_INTERVAL_SECS);
79		TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
80			if (linker_search_symbol_name(
81			    (caddr_t)hook_entry->ich_func, namebuf,
82			    sizeof(namebuf), &offset) == 0)
83				printf(" %s", namebuf);
84			else
85				printf(" %p", hook_entry->ich_func);
86		}
87		printf("\n");
88	}
89	KASSERT(warned < 6,
90	    ("run_interrupt_driven_config_hooks: waited too long"));
91}
92
93static void
94run_interrupt_driven_config_hooks(dummy)
95	void *dummy;
96{
97	struct intr_config_hook *hook_entry, *next_entry;
98	int warned;
99
100	mtx_lock(&intr_config_hook_lock);
101	TAILQ_FOREACH_SAFE(hook_entry, &intr_config_hook_list, ich_links,
102	    next_entry) {
103		mtx_unlock(&intr_config_hook_lock);
104		(*hook_entry->ich_func)(hook_entry->ich_arg);
105		mtx_lock(&intr_config_hook_lock);
106	}
107
108	warned = 0;
109	while (!TAILQ_EMPTY(&intr_config_hook_list)) {
110		if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
111		    PCONFIG, "conifhk", WARNING_INTERVAL_SECS * hz) ==
112		    EWOULDBLOCK) {
113			mtx_unlock(&intr_config_hook_lock);
114			warned++;
115			run_interrupt_driven_config_hooks_warning(warned);
116			mtx_lock(&intr_config_hook_lock);
117		}
118	}
119	mtx_unlock(&intr_config_hook_lock);
120}
121SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
122	run_interrupt_driven_config_hooks, NULL);
123
124/*
125 * Register a hook that will be called after "cold"
126 * autoconfiguration is complete and interrupts can
127 * be used to complete initialization.
128 */
129int
130config_intrhook_establish(hook)
131	struct intr_config_hook *hook;
132{
133	struct intr_config_hook *hook_entry;
134
135	mtx_lock(&intr_config_hook_lock);
136	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
137		if (hook_entry == hook)
138			break;
139	if (hook_entry != NULL) {
140		mtx_unlock(&intr_config_hook_lock);
141		printf("config_intrhook_establish: establishing an "
142		       "already established hook.\n");
143		return (1);
144	}
145	TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
146	mtx_unlock(&intr_config_hook_lock);
147	if (cold == 0)
148		/* XXX Sufficient for modules loaded after initial config??? */
149		run_interrupt_driven_config_hooks(NULL);
150	return (0);
151}
152
153void
154config_intrhook_disestablish(hook)
155	struct intr_config_hook *hook;
156{
157	struct intr_config_hook *hook_entry;
158
159	mtx_lock(&intr_config_hook_lock);
160	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
161		if (hook_entry == hook)
162			break;
163	if (hook_entry == NULL)
164		panic("config_intrhook_disestablish: disestablishing an "
165		      "unestablished hook");
166
167	TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
168
169	/* Wakeup anyone watching the list */
170	wakeup(&intr_config_hook_list);
171	mtx_unlock(&intr_config_hook_lock);
172}
173
174#ifdef DDB
175#include <ddb/ddb.h>
176
177DB_SHOW_COMMAND(conifhk, db_show_conifhk)
178{
179	struct intr_config_hook *hook_entry;
180	char namebuf[64];
181	long offset;
182
183	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
184		if (linker_ddb_search_symbol_name(
185		    (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
186		    &offset) == 0) {
187			db_printf("hook: %p at %s+%#lx arg: %p\n",
188			    hook_entry->ich_func, namebuf, offset,
189			    hook_entry->ich_arg);
190		} else {
191			db_printf("hook: %p at ??+?? arg %p\n",
192			    hook_entry->ich_func, hook_entry->ich_arg);
193		}
194	}
195}
196#endif /* DDB */
197