sys/kern/subr_autoconf.c

   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("$FreeBSD$");
  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  */
  57 static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
  58         TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
  59 static struct intr_config_hook *next_to_notify;
  60 static struct mtx intr_config_hook_lock;
  61 MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
  62
  63 /* ARGSUSED */
  64 static void run_interrupt_driven_config_hooks(void);
  65
  66 /*
  67  * Private data and a shim function for implementing config_interhook_oneshot().
  68  */
  69 struct 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
  76 static void
  77 config_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
  92 static void
  93 run_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
 116 static void
 117 run_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
 148 static void
 149 boot_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
 171 SYSINIT(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  */
 179 int
 180 config_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  */
 211 void
 212 config_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
 224 void
 225 config_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
 249 DB_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 */