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: stable/11/sys/kern/subr_autoconf.c 323464 2017-09-11 21:32:35Z ian $"); 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/malloc.h> 47#include <sys/mutex.h> 48#include <sys/systm.h> 49 50/* 51 * Autoconfiguration subroutines. 52 */ 53 54/* 55 * "Interrupt driven config" functions. 56 */ 57static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list = 58 TAILQ_HEAD_INITIALIZER(intr_config_hook_list); 59static struct intr_config_hook *next_to_notify; 60static struct mtx intr_config_hook_lock; 61MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF); 62 63/* ARGSUSED */ 64static void run_interrupt_driven_config_hooks(void); 65 66/* 67 * Private data and a shim function for implementing config_interhook_oneshot(). 68 */ 69struct oneshot_config_hook { 70 struct intr_config_hook 71 och_hook; /* Must be first */ 72 ich_func_t och_func; 73 void *och_arg; 74}; 75 76static void 77config_intrhook_oneshot_func(void *arg) 78{ 79 struct oneshot_config_hook *ohook; 80 81 ohook = arg; 82 ohook->och_func(ohook->och_arg); 83 config_intrhook_disestablish(&ohook->och_hook); 84 free(ohook, M_DEVBUF); 85} 86 87/* 88 * If we wait too long for an interrupt-driven config hook to return, print 89 * a diagnostic. 90 */ 91#define WARNING_INTERVAL_SECS 60 92static void 93run_interrupt_driven_config_hooks_warning(int warned) 94{ 95 struct intr_config_hook *hook_entry; 96 char namebuf[64]; 97 long offset; 98 99 if (warned < 6) { 100 printf("run_interrupt_driven_hooks: still waiting after %d " 101 "seconds for", warned * WARNING_INTERVAL_SECS); 102 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) { 103 if (linker_search_symbol_name( 104 (caddr_t)hook_entry->ich_func, namebuf, 105 sizeof(namebuf), &offset) == 0) 106 printf(" %s", namebuf); 107 else 108 printf(" %p", hook_entry->ich_func); 109 } 110 printf("\n"); 111 } 112 KASSERT(warned < 6, 113 ("run_interrupt_driven_config_hooks: waited too long")); 114} 115 116static void 117run_interrupt_driven_config_hooks() 118{ 119 static int running; 120 struct intr_config_hook *hook_entry; 121 122 mtx_lock(&intr_config_hook_lock); 123 124 /* 125 * If hook processing is already active, any newly 126 * registered hooks will eventually be notified. 127 * Let the currently running session issue these 128 * notifications. 129 */ 130 if (running != 0) { 131 mtx_unlock(&intr_config_hook_lock); 132 return; 133 } 134 running = 1; 135 136 while (next_to_notify != NULL) { 137 hook_entry = next_to_notify; 138 next_to_notify = TAILQ_NEXT(hook_entry, ich_links); 139 mtx_unlock(&intr_config_hook_lock); 140 (*hook_entry->ich_func)(hook_entry->ich_arg); 141 mtx_lock(&intr_config_hook_lock); 142 } 143 144 running = 0; 145 mtx_unlock(&intr_config_hook_lock); 146} 147 148static void 149boot_run_interrupt_driven_config_hooks(void *dummy) 150{ 151 int warned; 152 153 run_interrupt_driven_config_hooks(); 154 155 /* Block boot processing until all hooks are disestablished. */ 156 mtx_lock(&intr_config_hook_lock); 157 warned = 0; 158 while (!TAILQ_EMPTY(&intr_config_hook_list)) { 159 if (msleep(&intr_config_hook_list, &intr_config_hook_lock, 160 0, "conifhk", WARNING_INTERVAL_SECS * hz) == 161 EWOULDBLOCK) { 162 mtx_unlock(&intr_config_hook_lock); 163 warned++; 164 run_interrupt_driven_config_hooks_warning(warned); 165 mtx_lock(&intr_config_hook_lock); 166 } 167 } 168 mtx_unlock(&intr_config_hook_lock); 169} 170 171SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST, 172 boot_run_interrupt_driven_config_hooks, NULL); 173 174/* 175 * Register a hook that will be called after "cold" 176 * autoconfiguration is complete and interrupts can 177 * be used to complete initialization. 178 */ 179int 180config_intrhook_establish(struct intr_config_hook *hook) 181{ 182 struct intr_config_hook *hook_entry; 183 184 mtx_lock(&intr_config_hook_lock); 185 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) 186 if (hook_entry == hook) 187 break; 188 if (hook_entry != NULL) { 189 mtx_unlock(&intr_config_hook_lock); 190 printf("config_intrhook_establish: establishing an " 191 "already established hook.\n"); 192 return (1); 193 } 194 TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links); 195 if (next_to_notify == NULL) 196 next_to_notify = hook; 197 mtx_unlock(&intr_config_hook_lock); 198 if (cold == 0) 199 /* 200 * XXX Call from a task since not all drivers expect 201 * to be re-entered at the time a hook is established. 202 */ 203 /* XXX Sufficient for modules loaded after initial config??? */ 204 run_interrupt_driven_config_hooks(); 205 return (0); 206} 207 208/* 209 * Register a hook function that is automatically unregistered after it runs. 210 */ 211void 212config_intrhook_oneshot(ich_func_t func, void *arg) 213{ 214 struct oneshot_config_hook *ohook; 215 216 ohook = malloc(sizeof(*ohook), M_DEVBUF, M_WAITOK); 217 ohook->och_func = func; 218 ohook->och_arg = arg; 219 ohook->och_hook.ich_func = config_intrhook_oneshot_func; 220 ohook->och_hook.ich_arg = ohook; 221 config_intrhook_establish(&ohook->och_hook); 222} 223 224void 225config_intrhook_disestablish(struct intr_config_hook *hook) 226{ 227 struct intr_config_hook *hook_entry; 228 229 mtx_lock(&intr_config_hook_lock); 230 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) 231 if (hook_entry == hook) 232 break; 233 if (hook_entry == NULL) 234 panic("config_intrhook_disestablish: disestablishing an " 235 "unestablished hook"); 236 237 if (next_to_notify == hook) 238 next_to_notify = TAILQ_NEXT(hook, ich_links); 239 TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links); 240 241 /* Wakeup anyone watching the list */ 242 wakeup(&intr_config_hook_list); 243 mtx_unlock(&intr_config_hook_lock); 244} 245 246#ifdef DDB 247#include <ddb/ddb.h> 248 249DB_SHOW_COMMAND(conifhk, db_show_conifhk) 250{ 251 struct intr_config_hook *hook_entry; 252 char namebuf[64]; 253 long offset; 254 255 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) { 256 if (linker_ddb_search_symbol_name( 257 (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf), 258 &offset) == 0) { 259 db_printf("hook: %p at %s+%#lx arg: %p\n", 260 hook_entry->ich_func, namebuf, offset, 261 hook_entry->ich_arg); 262 } else { 263 db_printf("hook: %p at ??+?? arg %p\n", 264 hook_entry->ich_func, hook_entry->ich_arg); 265 } 266 } 267} 268#endif /* DDB */ 269