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