1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)subr_autoconf.c 8.1 (Berkeley) 6/10/93 36 * 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ddb.h" 43 44 #include <sys/param.h> 45 #include <sys/kernel.h> 46 #include <sys/linker.h> 47 #include <sys/lock.h> 48 #include <sys/malloc.h> 49 #include <sys/mutex.h> 50 #include <sys/systm.h> 51 52 /* 53 * Autoconfiguration subroutines. 54 */ 55 56 /* 57 * "Interrupt driven config" functions. 58 */ 59 static STAILQ_HEAD(, intr_config_hook) intr_config_hook_list = 60 STAILQ_HEAD_INITIALIZER(intr_config_hook_list); 61 static struct intr_config_hook *next_to_notify; 62 static struct mtx intr_config_hook_lock; 63 MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF); 64 65 /* ARGSUSED */ 66 static void run_interrupt_driven_config_hooks(void); 67 68 /* 69 * Private data and a shim function for implementing config_interhook_oneshot(). 70 */ 71 struct oneshot_config_hook { 72 struct intr_config_hook 73 och_hook; /* Must be first */ 74 ich_func_t och_func; 75 void *och_arg; 76 }; 77 78 static void 79 config_intrhook_oneshot_func(void *arg) 80 { 81 struct oneshot_config_hook *ohook; 82 83 ohook = arg; 84 ohook->och_func(ohook->och_arg); 85 config_intrhook_disestablish(&ohook->och_hook); 86 free(ohook, M_DEVBUF); 87 } 88 89 /* 90 * If we wait too long for an interrupt-driven config hook to return, print 91 * a diagnostic. 92 */ 93 #define WARNING_INTERVAL_SECS 60 94 static void 95 run_interrupt_driven_config_hooks_warning(int warned) 96 { 97 struct intr_config_hook *hook_entry; 98 char namebuf[64]; 99 long offset; 100 101 if (warned < 6) { 102 printf("run_interrupt_driven_hooks: still waiting after %d " 103 "seconds for", warned * WARNING_INTERVAL_SECS); 104 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) { 105 if (linker_search_symbol_name( 106 (caddr_t)hook_entry->ich_func, namebuf, 107 sizeof(namebuf), &offset) == 0) 108 printf(" %s", namebuf); 109 else 110 printf(" %p", hook_entry->ich_func); 111 } 112 printf("\n"); 113 } 114 KASSERT(warned < 6, 115 ("run_interrupt_driven_config_hooks: waited too long")); 116 } 117 118 static void 119 run_interrupt_driven_config_hooks(void) 120 { 121 static int running; 122 struct intr_config_hook *hook_entry; 123 124 TSENTER(); 125 mtx_lock(&intr_config_hook_lock); 126 127 /* 128 * If hook processing is already active, any newly 129 * registered hooks will eventually be notified. 130 * Let the currently running session issue these 131 * notifications. 132 */ 133 if (running != 0) { 134 mtx_unlock(&intr_config_hook_lock); 135 return; 136 } 137 running = 1; 138 139 while (next_to_notify != NULL) { 140 hook_entry = next_to_notify; 141 next_to_notify = STAILQ_NEXT(hook_entry, ich_links); 142 hook_entry->ich_state = ICHS_RUNNING; 143 mtx_unlock(&intr_config_hook_lock); 144 (*hook_entry->ich_func)(hook_entry->ich_arg); 145 mtx_lock(&intr_config_hook_lock); 146 } 147 148 running = 0; 149 mtx_unlock(&intr_config_hook_lock); 150 TSEXIT(); 151 } 152 153 static void 154 boot_run_interrupt_driven_config_hooks(void *dummy) 155 { 156 int warned; 157 158 run_interrupt_driven_config_hooks(); 159 160 /* Block boot processing until all hooks are disestablished. */ 161 TSWAIT("config hooks"); 162 mtx_lock(&intr_config_hook_lock); 163 warned = 0; 164 while (!STAILQ_EMPTY(&intr_config_hook_list)) { 165 if (msleep(&intr_config_hook_list, &intr_config_hook_lock, 166 0, "conifhk", WARNING_INTERVAL_SECS * hz) == 167 EWOULDBLOCK) { 168 mtx_unlock(&intr_config_hook_lock); 169 warned++; 170 run_interrupt_driven_config_hooks_warning(warned); 171 mtx_lock(&intr_config_hook_lock); 172 } 173 } 174 mtx_unlock(&intr_config_hook_lock); 175 TSUNWAIT("config hooks"); 176 } 177 178 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST, 179 boot_run_interrupt_driven_config_hooks, NULL); 180 181 /* 182 * Register a hook that will be called after "cold" 183 * autoconfiguration is complete and interrupts can 184 * be used to complete initialization. 185 */ 186 int 187 config_intrhook_establish(struct intr_config_hook *hook) 188 { 189 struct intr_config_hook *hook_entry; 190 191 TSHOLD("config hooks"); 192 mtx_lock(&intr_config_hook_lock); 193 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) 194 if (hook_entry == hook) 195 break; 196 if (hook_entry != NULL) { 197 mtx_unlock(&intr_config_hook_lock); 198 printf("config_intrhook_establish: establishing an " 199 "already established hook.\n"); 200 return (1); 201 } 202 STAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links); 203 if (next_to_notify == NULL) 204 next_to_notify = hook; 205 hook->ich_state = ICHS_QUEUED; 206 mtx_unlock(&intr_config_hook_lock); 207 if (cold == 0) 208 /* 209 * XXX Call from a task since not all drivers expect 210 * to be re-entered at the time a hook is established. 211 */ 212 /* XXX Sufficient for modules loaded after initial config??? */ 213 run_interrupt_driven_config_hooks(); 214 return (0); 215 } 216 217 /* 218 * Register a hook function that is automatically unregistered after it runs. 219 */ 220 void 221 config_intrhook_oneshot(ich_func_t func, void *arg) 222 { 223 struct oneshot_config_hook *ohook; 224 225 ohook = malloc(sizeof(*ohook), M_DEVBUF, M_WAITOK); 226 ohook->och_func = func; 227 ohook->och_arg = arg; 228 ohook->och_hook.ich_func = config_intrhook_oneshot_func; 229 ohook->och_hook.ich_arg = ohook; 230 config_intrhook_establish(&ohook->och_hook); 231 } 232 233 static void 234 config_intrhook_disestablish_locked(struct intr_config_hook *hook) 235 { 236 struct intr_config_hook *hook_entry; 237 238 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) 239 if (hook_entry == hook) 240 break; 241 if (hook_entry == NULL) 242 panic("config_intrhook_disestablish: disestablishing an " 243 "unestablished hook"); 244 245 if (next_to_notify == hook) 246 next_to_notify = STAILQ_NEXT(hook, ich_links); 247 STAILQ_REMOVE(&intr_config_hook_list, hook, intr_config_hook, ich_links); 248 TSRELEASE("config hooks"); 249 250 /* Wakeup anyone watching the list */ 251 hook->ich_state = ICHS_DONE; 252 wakeup(&intr_config_hook_list); 253 } 254 255 void 256 config_intrhook_disestablish(struct intr_config_hook *hook) 257 { 258 mtx_lock(&intr_config_hook_lock); 259 config_intrhook_disestablish_locked(hook); 260 mtx_unlock(&intr_config_hook_lock); 261 } 262 263 int 264 config_intrhook_drain(struct intr_config_hook *hook) 265 { 266 mtx_lock(&intr_config_hook_lock); 267 268 /* 269 * The config hook has completed, so just return. 270 */ 271 if (hook->ich_state == ICHS_DONE) { 272 mtx_unlock(&intr_config_hook_lock); 273 return (ICHS_DONE); 274 } 275 276 /* 277 * The config hook hasn't started running, just call disestablish. 278 */ 279 if (hook->ich_state == ICHS_QUEUED) { 280 config_intrhook_disestablish_locked(hook); 281 mtx_unlock(&intr_config_hook_lock); 282 return (ICHS_QUEUED); 283 } 284 285 /* 286 * The config hook is running, so wait for it to complete and return. 287 */ 288 while (hook->ich_state != ICHS_DONE) { 289 if (msleep(&intr_config_hook_list, &intr_config_hook_lock, 290 0, "confhd", hz) == EWOULDBLOCK) { 291 // XXX do I whine? 292 } 293 } 294 mtx_unlock(&intr_config_hook_lock); 295 return (ICHS_RUNNING); 296 } 297 298 #ifdef DDB 299 #include <ddb/ddb.h> 300 301 DB_SHOW_COMMAND_FLAGS(conifhk, db_show_conifhk, DB_CMD_MEMSAFE) 302 { 303 struct intr_config_hook *hook_entry; 304 char namebuf[64]; 305 long offset; 306 307 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) { 308 if (linker_ddb_search_symbol_name( 309 (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf), 310 &offset) == 0) { 311 db_printf("hook: %p at %s+%#lx arg: %p\n", 312 hook_entry->ich_func, namebuf, offset, 313 hook_entry->ich_arg); 314 } else { 315 db_printf("hook: %p at ??+?? arg %p\n", 316 hook_entry->ich_func, hook_entry->ich_arg); 317 } 318 } 319 } 320 #endif /* DDB */ 321