sys/kern/kern_sensors.c

   1 /* $OpenBSD: kern_sensors.c,v 1.19 2007/06/04 18:42:05 deraadt Exp $ */
   2
   3 /*
   4  * (MPSAFE)
   5  *
   6  * Copyright (c) 2005 David Gwynne <dlg@openbsd.org>
   7  * Copyright (c) 2006 Constantine A. Murenin <cnst+openbsd@bugmail.mojo.ru>
   8  *
   9  * Permission to use, copy, modify, and distribute this software for any
  10  * purpose with or without fee is hereby granted, provided that the above
  11  * copyright notice and this permission notice appear in all copies.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  15  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  19  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  20  */
  21
  22 #include <sys/param.h>
  23 #include <sys/systm.h>
  24 #include <sys/kernel.h>
  25 #include <sys/malloc.h>
  26 #include <sys/kthread.h>
  27 #include <sys/queue.h>
  28 #include <sys/types.h>
  29 #include <sys/time.h>
  30 #include <sys/spinlock.h>
  31 #include <sys/spinlock2.h>
  32 #include <sys/lock.h>
  33
  34 #include <sys/sysctl.h>
  35 #include <sys/sensors.h>
  36
  37 #include <sys/mplock2.h>
  38
  39 static struct spinlock  sensor_dev_lock =
  40     SPINLOCK_INITIALIZER(sensor_dev_lock, "sensor_dev_lock");
  41
  42 static int              sensordev_count;
  43 static SLIST_HEAD(, ksensordev) sensordev_list =
  44     SLIST_HEAD_INITIALIZER(sensordev_list);
  45
  46 static struct ksensordev *sensordev_get(int);
  47 static struct ksensor   *sensor_find(struct ksensordev *, enum sensor_type,
  48                             int);
  49
  50 struct sensor_task {
  51         void                            *arg;
  52         void                            (*func)(void *);
  53
  54         int                             period;
  55         time_t                          nextrun;        /* time_uptime */
  56         int                             running;
  57         TAILQ_ENTRY(sensor_task)        entry;
  58 };
  59
  60 static void             sensor_task_thread(void *);
  61 static void             sensor_task_schedule(struct sensor_task *);
  62
  63 static TAILQ_HEAD(, sensor_task) sensor_tasklist =
  64     TAILQ_HEAD_INITIALIZER(sensor_tasklist);
  65
  66 static struct lock      sensor_task_lock =
  67     LOCK_INITIALIZER("ksensor_task", 0, LK_CANRECURSE);
  68
  69 static void             sensor_sysctl_install(struct ksensordev *);
  70 static void             sensor_sysctl_deinstall(struct ksensordev *);
  71
  72 void
  73 sensordev_install(struct ksensordev *sensdev)
  74 {
  75         struct ksensordev *v, *nv;
  76
  77         /* mtx_lock(&Giant); */
  78         spin_lock(&sensor_dev_lock);
  79         if (sensordev_count == 0) {
  80                 sensdev->num = 0;
  81                 SLIST_INSERT_HEAD(&sensordev_list, sensdev, list);
  82         } else {
  83                 for (v = SLIST_FIRST(&sensordev_list);
  84                     (nv = SLIST_NEXT(v, list)) != NULL; v = nv)
  85                         if (nv->num - v->num > 1)
  86                                 break;
  87                 sensdev->num = v->num + 1;
  88                 SLIST_INSERT_AFTER(v, sensdev, list);
  89         }
  90         sensordev_count++;
  91         /* mtx_unlock(&Giant); */
  92         spin_unlock(&sensor_dev_lock);
  93
  94         sensor_sysctl_install(sensdev);
  95 }
  96
  97 void
  98 sensor_attach(struct ksensordev *sensdev, struct ksensor *sens)
  99 {
 100         struct ksensor *v, *nv;
 101         struct ksensors_head *sh;
 102         int i;
 103
 104         /* mtx_lock(&Giant); */
 105         spin_lock(&sensor_dev_lock);
 106         sh = &sensdev->sensors_list;
 107         if (sensdev->sensors_count == 0) {
 108                 for (i = 0; i < SENSOR_MAX_TYPES; i++)
 109                         sensdev->maxnumt[i] = 0;
 110                 sens->numt = 0;
 111                 SLIST_INSERT_HEAD(sh, sens, list);
 112         } else {
 113                 for (v = SLIST_FIRST(sh);
 114                     (nv = SLIST_NEXT(v, list)) != NULL; v = nv)
 115                         if (v->type == sens->type && (v->type != nv->type ||
 116                             (v->type == nv->type && nv->numt - v->numt > 1)))
 117                                 break;
 118                 /* sensors of the same type go after each other */
 119                 if (v->type == sens->type)
 120                         sens->numt = v->numt + 1;
 121                 else
 122                         sens->numt = 0;
 123                 SLIST_INSERT_AFTER(v, sens, list);
 124         }
 125         /* we only increment maxnumt[] if the sensor was added
 126          * to the last position of sensors of this type
 127          */
 128         if (sensdev->maxnumt[sens->type] == sens->numt)
 129                 sensdev->maxnumt[sens->type]++;
 130         sensdev->sensors_count++;
 131         spin_unlock(&sensor_dev_lock);
 132         /* mtx_unlock(&Giant); */
 133 }
 134
 135 void
 136 sensordev_deinstall(struct ksensordev *sensdev)
 137 {
 138         /* mtx_lock(&Giant); */
 139         spin_lock(&sensor_dev_lock);
 140         sensordev_count--;
 141         SLIST_REMOVE(&sensordev_list, sensdev, ksensordev, list);
 142         /* mtx_unlock(&Giant); */
 143         spin_unlock(&sensor_dev_lock);
 144
 145         sensor_sysctl_deinstall(sensdev);
 146 }
 147
 148 void
 149 sensor_detach(struct ksensordev *sensdev, struct ksensor *sens)
 150 {
 151         struct ksensors_head *sh;
 152
 153         /* mtx_lock(&Giant); */
 154         sh = &sensdev->sensors_list;
 155         sensdev->sensors_count--;
 156         SLIST_REMOVE(sh, sens, ksensor, list);
 157         /* we only decrement maxnumt[] if this is the tail
 158          * sensor of this type
 159          */
 160         if (sens->numt == sensdev->maxnumt[sens->type] - 1)
 161                 sensdev->maxnumt[sens->type]--;
 162         /* mtx_unlock(&Giant); */
 163 }
 164
 165 static struct ksensordev *
 166 sensordev_get(int num)
 167 {
 168         struct ksensordev *sd;
 169
 170         spin_lock(&sensor_dev_lock);
 171         SLIST_FOREACH(sd, &sensordev_list, list)
 172                 if (sd->num == num) {
 173                         spin_unlock(&sensor_dev_lock);
 174                         return (sd);
 175                 }
 176
 177         spin_unlock(&sensor_dev_lock);
 178         return (NULL);
 179 }
 180
 181 static struct ksensor *
 182 sensor_find(struct ksensordev *sensdev, enum sensor_type type, int numt)
 183 {
 184         struct ksensor *s;
 185         struct ksensors_head *sh;
 186
 187         spin_lock(&sensor_dev_lock);
 188         sh = &sensdev->sensors_list;
 189         SLIST_FOREACH(s, sh, list) {
 190                 if (s->type == type && s->numt == numt) {
 191                         spin_unlock(&sensor_dev_lock);
 192                         return (s);
 193                 }
 194         }
 195
 196         spin_unlock(&sensor_dev_lock);
 197         return (NULL);
 198 }
 199
 200 int
 201 sensor_task_register(void *arg, void (*func)(void *), int period)
 202 {
 203         struct sensor_task      *st;
 204
 205         st = kmalloc(sizeof(struct sensor_task), M_DEVBUF, M_NOWAIT);
 206         if (st == NULL)
 207                 return (1);
 208
 209         lockmgr(&sensor_task_lock, LK_EXCLUSIVE);
 210         st->arg = arg;
 211         st->func = func;
 212         st->period = period;
 213
 214         st->running = 1;
 215
 216         st->nextrun = 0;
 217         TAILQ_INSERT_HEAD(&sensor_tasklist, st, entry);
 218
 219         wakeup(&sensor_tasklist);
 220
 221         lockmgr(&sensor_task_lock, LK_RELEASE);
 222         return (0);
 223 }
 224
 225 void
 226 sensor_task_unregister(void *arg)
 227 {
 228         struct sensor_task      *st;
 229
 230         lockmgr(&sensor_task_lock, LK_EXCLUSIVE);
 231         TAILQ_FOREACH(st, &sensor_tasklist, entry)
 232                 if (st->arg == arg)
 233                         st->running = 0;
 234         lockmgr(&sensor_task_lock, LK_RELEASE);
 235 }
 236
 237 static void
 238 sensor_task_thread(void *arg)
 239 {
 240         struct sensor_task      *st, *nst;
 241         time_t                  now;
 242
 243         lockmgr(&sensor_task_lock, LK_EXCLUSIVE);
 244
 245         for (;;) {
 246                 while (TAILQ_EMPTY(&sensor_tasklist)) {
 247                         lksleep(&sensor_tasklist, &sensor_task_lock, 0,
 248                             "waittask", 0);
 249                 }
 250
 251                 while ((nst = TAILQ_FIRST(&sensor_tasklist))->nextrun >
 252                     (now = time_uptime)) {
 253                         lksleep(&sensor_tasklist, &sensor_task_lock, 0,
 254                             "timeout", (nst->nextrun - now) * hz);
 255                 }
 256
 257                 while ((st = nst) != NULL) {
 258                         nst = TAILQ_NEXT(st, entry);
 259
 260                         if (st->nextrun > now)
 261                                 break;
 262
 263                         /* take it out while we work on it */
 264                         TAILQ_REMOVE(&sensor_tasklist, st, entry);
 265
 266                         if (!st->running) {
 267                                 kfree(st, M_DEVBUF);
 268                                 continue;
 269                         }
 270
 271                         /* run the task */
 272                         st->func(st->arg);
 273                         /* stick it back in the tasklist */
 274                         sensor_task_schedule(st);
 275                 }
 276         }
 277
 278         lockmgr(&sensor_task_lock, LK_RELEASE);
 279 }
 280
 281 static void
 282 sensor_task_schedule(struct sensor_task *st)
 283 {
 284         struct sensor_task      *cst;
 285
 286         lockmgr(&sensor_task_lock, LK_EXCLUSIVE);
 287         st->nextrun = time_uptime + st->period;
 288
 289         TAILQ_FOREACH(cst, &sensor_tasklist, entry) {
 290                 if (cst->nextrun > st->nextrun) {
 291                         TAILQ_INSERT_BEFORE(cst, st, entry);
 292                         lockmgr(&sensor_task_lock, LK_RELEASE);
 293                         return;
 294                 }
 295         }
 296
 297         /* must be an empty list, or at the end of the list */
 298         TAILQ_INSERT_TAIL(&sensor_tasklist, st, entry);
 299         lockmgr(&sensor_task_lock, LK_RELEASE);
 300 }
 301
 302 /*
 303  * sysctl glue code
 304  */
 305 static int      sysctl_handle_sensordev(SYSCTL_HANDLER_ARGS);
 306 static int      sysctl_handle_sensor(SYSCTL_HANDLER_ARGS);
 307 static int      sysctl_sensors_handler(SYSCTL_HANDLER_ARGS);
 308
 309 SYSCTL_NODE(_hw, OID_AUTO, sensors, CTLFLAG_RD, NULL,
 310     "Hardware Sensors sysctl internal magic");
 311 SYSCTL_NODE(_hw, HW_SENSORS, _sensors, CTLFLAG_RD, sysctl_sensors_handler,
 312     "Hardware Sensors XP MIB interface");
 313
 314 static void
 315 sensor_sysctl_install(struct ksensordev *sensdev)
 316 {
 317         struct sysctl_oid_list *ol;
 318         struct sysctl_ctx_list *cl = &sensdev->clist;
 319         struct ksensor *s;
 320         struct ksensors_head *sh = &sensdev->sensors_list;
 321
 322         sysctl_ctx_init(cl);
 323         ol = SYSCTL_CHILDREN(SYSCTL_ADD_NODE(cl, (&SYSCTL_NODE_CHILDREN(_hw,
 324             sensors)), sensdev->num, sensdev->xname, CTLFLAG_RD, NULL, ""));
 325         SLIST_FOREACH(s, sh, list) {
 326                 char n[32];
 327
 328                 ksnprintf(n, sizeof(n), "%s%d", sensor_type_s[s->type], s->numt);
 329                 SYSCTL_ADD_PROC(cl, ol, OID_AUTO, n, CTLTYPE_STRUCT |
 330                     CTLFLAG_RD, s, 0, sysctl_handle_sensor, "S,sensor", "");
 331         }
 332 }
 333
 334 static void
 335 sensor_sysctl_deinstall(struct ksensordev *sensdev)
 336 {
 337         struct sysctl_ctx_list *cl = &sensdev->clist;
 338
 339         sysctl_ctx_free(cl);
 340 }
 341
 342 static int
 343 sysctl_handle_sensordev(SYSCTL_HANDLER_ARGS)
 344 {
 345         struct ksensordev *ksd = arg1;
 346         struct sensordev *usd;
 347         int error;
 348
 349         if (req->newptr)
 350                 return (EPERM);
 351
 352         /* Grab a copy, to clear the kernel pointers */
 353         usd = kmalloc(sizeof(*usd), M_TEMP, M_WAITOK | M_ZERO);
 354         usd->num = ksd->num;
 355         strlcpy(usd->xname, ksd->xname, sizeof(usd->xname));
 356         memcpy(usd->maxnumt, ksd->maxnumt, sizeof(usd->maxnumt));
 357         usd->sensors_count = ksd->sensors_count;
 358
 359         error = SYSCTL_OUT(req, usd, sizeof(struct sensordev));
 360
 361         kfree(usd, M_TEMP);
 362         return (error);
 363
 364 }
 365
 366 static int
 367 sysctl_handle_sensor(SYSCTL_HANDLER_ARGS)
 368 {
 369         struct ksensor *ks = arg1;
 370         struct sensor *us;
 371         int error;
 372
 373         if (req->newptr)
 374                 return (EPERM);
 375
 376         /* Grab a copy, to clear the kernel pointers */
 377         us = kmalloc(sizeof(*us), M_TEMP, M_WAITOK | M_ZERO);
 378         memcpy(us->desc, ks->desc, sizeof(ks->desc));
 379         us->tv = ks->tv;
 380         us->value = ks->value;
 381         us->type = ks->type;
 382         us->status = ks->status;
 383         us->numt = ks->numt;
 384         us->flags = ks->flags;
 385
 386         error = SYSCTL_OUT(req, us, sizeof(struct sensor));
 387
 388         kfree(us, M_TEMP);
 389         return (error);
 390 }
 391
 392 static int
 393 sysctl_sensors_handler(SYSCTL_HANDLER_ARGS)
 394 {
 395         int *name = arg1;
 396         u_int namelen = arg2;
 397         struct ksensordev *ksd;
 398         struct ksensor *ks;
 399         int dev, numt;
 400         enum sensor_type type;
 401
 402         if (namelen != 1 && namelen != 3)
 403                 return (ENOTDIR);
 404
 405         dev = name[0];
 406         if ((ksd = sensordev_get(dev)) == NULL)
 407                 return (ENOENT);
 408
 409         if (namelen == 1)
 410                 return (sysctl_handle_sensordev(NULL, ksd, 0, req));
 411
 412         type = name[1];
 413         numt = name[2];
 414
 415         if ((ks = sensor_find(ksd, type, numt)) == NULL)
 416                 return (ENOENT);
 417         return (sysctl_handle_sensor(NULL, ks, 0, req));
 418 }
 419
 420 static void
 421 sensor_sysinit(void *arg __unused)
 422 {
 423         int error;
 424
 425         error = kthread_create(sensor_task_thread, NULL, NULL, "sensors");
 426         if (error)
 427                 panic("sensors kthread failed: %d", error);
 428 }
 429 SYSINIT(sensor, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, sensor_sysinit, NULL);