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 int              sensordev_idmax;
  40 static TAILQ_HEAD(sensordev_list, ksensordev) sensordev_list =
  41     TAILQ_HEAD_INITIALIZER(sensordev_list);
  42
  43 static struct ksensordev *sensordev_get(int);
  44 static struct ksensor   *sensor_find(struct ksensordev *, enum sensor_type,
  45                             int);
  46
  47 struct sensor_task {
  48         void                            *arg;
  49         void                            (*func)(void *);
  50
  51         int                             period;
  52         time_t                          nextrun;        /* time_uptime */
  53         int                             running;
  54         TAILQ_ENTRY(sensor_task)        entry;
  55 };
  56
  57 static void             sensor_task_thread(void *);
  58 static void             sensor_task_schedule(struct sensor_task *);
  59
  60 static TAILQ_HEAD(, sensor_task) sensor_tasklist =
  61     TAILQ_HEAD_INITIALIZER(sensor_tasklist);
  62
  63 static struct lock      sensor_task_lock =
  64     LOCK_INITIALIZER("ksensor_task", 0, LK_CANRECURSE);
  65
  66 static void             sensordev_sysctl_install(struct ksensordev *);
  67 static void             sensordev_sysctl_deinstall(struct ksensordev *);
  68 static void             sensor_sysctl_install(struct ksensordev *,
  69                             struct ksensor *);
  70 static void             sensor_sysctl_deinstall(struct ksensordev *,
  71                             struct ksensor *);
  72
  73 void
  74 sensordev_install(struct ksensordev *sensdev)
  75 {
  76         struct ksensordev *v, *after = NULL;
  77         int num = 0;
  78
  79         SYSCTL_XLOCK();
  80
  81         TAILQ_FOREACH(v, &sensordev_list, list) {
  82                 if (v->num == num) {
  83                         ++num;
  84                         after = v;
  85                 } else if (v->num > num) {
  86                         break;
  87                 }
  88         }
  89
  90         sensdev->num = num;
  91         if (after == NULL) {
  92                 KKASSERT(sensdev->num == 0);
  93                 TAILQ_INSERT_HEAD(&sensordev_list, sensdev, list);
  94         } else {
  95                 TAILQ_INSERT_AFTER(&sensordev_list, after, sensdev, list);
  96         }
  97
  98         /* Save max sensor device id */
  99         sensordev_idmax = TAILQ_LAST(&sensordev_list, sensordev_list)->num + 1;
 100
 101         /* Install sysctl node for this sensor device */
 102         sensordev_sysctl_install(sensdev);
 103
 104         SYSCTL_XUNLOCK();
 105 }
 106
 107 void
 108 sensor_attach(struct ksensordev *sensdev, struct ksensor *sens)
 109 {
 110         struct ksensor *v, *nv;
 111         struct ksensors_head *sh;
 112         int i;
 113
 114         SYSCTL_XLOCK();
 115
 116         sh = &sensdev->sensors_list;
 117         if (sensdev->sensors_count == 0) {
 118                 for (i = 0; i < SENSOR_MAX_TYPES; i++)
 119                         sensdev->maxnumt[i] = 0;
 120                 sens->numt = 0;
 121                 SLIST_INSERT_HEAD(sh, sens, list);
 122         } else {
 123                 for (v = SLIST_FIRST(sh);
 124                     (nv = SLIST_NEXT(v, list)) != NULL; v = nv)
 125                         if (v->type == sens->type && (v->type != nv->type ||
 126                             (v->type == nv->type && nv->numt - v->numt > 1)))
 127                                 break;
 128                 /* sensors of the same type go after each other */
 129                 if (v->type == sens->type)
 130                         sens->numt = v->numt + 1;
 131                 else
 132                         sens->numt = 0;
 133                 SLIST_INSERT_AFTER(v, sens, list);
 134         }
 135         /*
 136          * We only increment maxnumt[] if the sensor was added
 137          * to the last position of sensors of this type
 138          */
 139         if (sensdev->maxnumt[sens->type] == sens->numt)
 140                 sensdev->maxnumt[sens->type]++;
 141         sensdev->sensors_count++;
 142
 143         /* Install sysctl node for this sensor */
 144         sensor_sysctl_install(sensdev, sens);
 145
 146         SYSCTL_XUNLOCK();
 147 }
 148
 149 void
 150 sensordev_deinstall(struct ksensordev *sensdev)
 151 {
 152         struct ksensordev *last;
 153
 154         SYSCTL_XLOCK();
 155
 156         TAILQ_REMOVE(&sensordev_list, sensdev, list);
 157
 158         /* Adjust max sensor device id */
 159         last = TAILQ_LAST(&sensordev_list, sensordev_list);
 160         if (last != NULL)
 161                 sensordev_idmax = last->num + 1;
 162         else
 163                 sensordev_idmax = 0;
 164
 165         /*
 166          * Deinstall sensor device's sysctl node; this also
 167          * removes all attached sensors' sysctl nodes.
 168          */
 169         sensordev_sysctl_deinstall(sensdev);
 170
 171         SYSCTL_XUNLOCK();
 172 }
 173
 174 void
 175 sensor_detach(struct ksensordev *sensdev, struct ksensor *sens)
 176 {
 177         struct ksensors_head *sh;
 178
 179         SYSCTL_XLOCK();
 180
 181         sh = &sensdev->sensors_list;
 182         sensdev->sensors_count--;
 183         SLIST_REMOVE(sh, sens, ksensor, list);
 184         /*
 185          * We only decrement maxnumt[] if this is the tail
 186          * sensor of this type
 187          */
 188         if (sens->numt == sensdev->maxnumt[sens->type] - 1)
 189                 sensdev->maxnumt[sens->type]--;
 190
 191         /* Deinstall sensor's sysctl node */
 192         sensor_sysctl_deinstall(sensdev, sens);
 193
 194         SYSCTL_XUNLOCK();
 195 }
 196
 197 static struct ksensordev *
 198 sensordev_get(int num)
 199 {
 200         struct ksensordev *sd;
 201
 202         SYSCTL_ASSERT_XLOCKED();
 203
 204         TAILQ_FOREACH(sd, &sensordev_list, list) {
 205                 if (sd->num == num)
 206                         return (sd);
 207         }
 208         return (NULL);
 209 }
 210
 211 static struct ksensor *
 212 sensor_find(struct ksensordev *sensdev, enum sensor_type type, int numt)
 213 {
 214         struct ksensor *s;
 215         struct ksensors_head *sh;
 216
 217         SYSCTL_ASSERT_XLOCKED();
 218
 219         sh = &sensdev->sensors_list;
 220         SLIST_FOREACH(s, sh, list) {
 221                 if (s->type == type && s->numt == numt)
 222                         return (s);
 223         }
 224         return (NULL);
 225 }
 226
 227 void
 228 sensor_task_register(void *arg, void (*func)(void *), int period)
 229 {
 230         struct sensor_task      *st;
 231
 232         st = kmalloc(sizeof(struct sensor_task), M_DEVBUF, M_WAITOK);
 233
 234         lockmgr(&sensor_task_lock, LK_EXCLUSIVE);
 235         st->arg = arg;
 236         st->func = func;
 237         st->period = period;
 238
 239         st->running = 1;
 240
 241         st->nextrun = 0;
 242         TAILQ_INSERT_HEAD(&sensor_tasklist, st, entry);
 243
 244         wakeup(&sensor_tasklist);
 245
 246         lockmgr(&sensor_task_lock, LK_RELEASE);
 247 }
 248
 249 void
 250 sensor_task_unregister(void *arg)
 251 {
 252         struct sensor_task      *st;
 253
 254         lockmgr(&sensor_task_lock, LK_EXCLUSIVE);
 255         TAILQ_FOREACH(st, &sensor_tasklist, entry)
 256                 if (st->arg == arg)
 257                         st->running = 0;
 258         lockmgr(&sensor_task_lock, LK_RELEASE);
 259 }
 260
 261 static void
 262 sensor_task_thread(void *arg)
 263 {
 264         struct sensor_task      *st, *nst;
 265         time_t                  now;
 266
 267         lockmgr(&sensor_task_lock, LK_EXCLUSIVE);
 268
 269         for (;;) {
 270                 while (TAILQ_EMPTY(&sensor_tasklist)) {
 271                         lksleep(&sensor_tasklist, &sensor_task_lock, 0,
 272                             "waittask", 0);
 273                 }
 274
 275                 while ((nst = TAILQ_FIRST(&sensor_tasklist))->nextrun >
 276                     (now = time_uptime)) {
 277                         lksleep(&sensor_tasklist, &sensor_task_lock, 0,
 278                             "timeout", (nst->nextrun - now) * hz);
 279                 }
 280
 281                 while ((st = nst) != NULL) {
 282                         nst = TAILQ_NEXT(st, entry);
 283
 284                         if (st->nextrun > now)
 285                                 break;
 286
 287                         /* take it out while we work on it */
 288                         TAILQ_REMOVE(&sensor_tasklist, st, entry);
 289
 290                         if (!st->running) {
 291                                 kfree(st, M_DEVBUF);
 292                                 continue;
 293                         }
 294
 295                         /* run the task */
 296                         st->func(st->arg);
 297                         /* stick it back in the tasklist */
 298                         sensor_task_schedule(st);
 299                 }
 300         }
 301
 302         lockmgr(&sensor_task_lock, LK_RELEASE);
 303 }
 304
 305 static void
 306 sensor_task_schedule(struct sensor_task *st)
 307 {
 308         struct sensor_task      *cst;
 309
 310         KASSERT(lockstatus(&sensor_task_lock, curthread) == LK_EXCLUSIVE,
 311             ("sensor task lock is not held"));
 312
 313         st->nextrun = time_uptime + st->period;
 314
 315         TAILQ_FOREACH(cst, &sensor_tasklist, entry) {
 316                 if (cst->nextrun > st->nextrun) {
 317                         TAILQ_INSERT_BEFORE(cst, st, entry);
 318                         return;
 319                 }
 320         }
 321
 322         /* must be an empty list, or at the end of the list */
 323         TAILQ_INSERT_TAIL(&sensor_tasklist, st, entry);
 324 }
 325
 326 /*
 327  * sysctl glue code
 328  */
 329 static int      sysctl_handle_sensordev(SYSCTL_HANDLER_ARGS);
 330 static int      sysctl_handle_sensor(SYSCTL_HANDLER_ARGS);
 331 static int      sysctl_sensors_handler(SYSCTL_HANDLER_ARGS);
 332
 333 SYSCTL_NODE(_hw, OID_AUTO, sensors, CTLFLAG_RD, NULL,
 334     "Hardware Sensors sysctl internal magic");
 335 SYSCTL_NODE(_hw, HW_SENSORS, _sensors, CTLFLAG_RD, sysctl_sensors_handler,
 336     "Hardware Sensors XP MIB interface");
 337
 338 SYSCTL_INT(_hw_sensors, OID_AUTO, dev_idmax, CTLFLAG_RD,
 339     &sensordev_idmax, 0, "Max sensor device id");
 340
 341 static void
 342 sensordev_sysctl_install(struct ksensordev *sensdev)
 343 {
 344         struct sysctl_ctx_list *cl = &sensdev->clist;
 345         struct ksensor *s;
 346         struct ksensors_head *sh = &sensdev->sensors_list;
 347
 348         SYSCTL_ASSERT_XLOCKED();
 349
 350         KASSERT(sensdev->oid == NULL,
 351             ("sensor device %s sysctl node already installed", sensdev->xname));
 352
 353         sysctl_ctx_init(cl);
 354         sensdev->oid = SYSCTL_ADD_NODE(cl, SYSCTL_STATIC_CHILDREN(_hw_sensors),
 355             sensdev->num, sensdev->xname, CTLFLAG_RD, NULL, "");
 356         if (sensdev->oid == NULL) {
 357                 kprintf("sensor: add sysctl tree for %s failed\n",
 358                     sensdev->xname);
 359                 return;
 360         }
 361
 362         /* Install sysctl nodes for sensors attached to this sensor device */
 363         SLIST_FOREACH(s, sh, list)
 364                 sensor_sysctl_install(sensdev, s);
 365 }
 366
 367 static void
 368 sensor_sysctl_install(struct ksensordev *sensdev, struct ksensor *sens)
 369 {
 370         char n[32];
 371
 372         SYSCTL_ASSERT_XLOCKED();
 373
 374         if (sensdev->oid == NULL) {
 375                 /* Sensor device sysctl node is not installed yet */
 376                 return;
 377         }
 378
 379         ksnprintf(n, sizeof(n), "%s%d", sensor_type_s[sens->type], sens->numt);
 380         KASSERT(sens->oid == NULL,
 381             ("sensor %s:%s sysctl node already installed", sensdev->xname, n));
 382
 383         sens->oid = SYSCTL_ADD_PROC(&sensdev->clist,
 384             SYSCTL_CHILDREN(sensdev->oid), OID_AUTO, n,
 385             CTLTYPE_STRUCT | CTLFLAG_RD, sens, 0, sysctl_handle_sensor,
 386             "S,sensor", "");
 387 }
 388
 389 static void
 390 sensordev_sysctl_deinstall(struct ksensordev *sensdev)
 391 {
 392         SYSCTL_ASSERT_XLOCKED();
 393
 394         if (sensdev->oid != NULL) {
 395                 sysctl_ctx_free(&sensdev->clist);
 396                 sensdev->oid = NULL;
 397         }
 398 }
 399
 400 static void
 401 sensor_sysctl_deinstall(struct ksensordev *sensdev, struct ksensor *sens)
 402 {
 403         SYSCTL_ASSERT_XLOCKED();
 404
 405         if (sensdev->oid != NULL && sens->oid != NULL) {
 406                 sysctl_ctx_entry_del(&sensdev->clist, sens->oid);
 407                 sysctl_remove_oid(sens->oid, 1, 0);
 408         }
 409         sens->oid = NULL;
 410 }
 411
 412 static int
 413 sysctl_handle_sensordev(SYSCTL_HANDLER_ARGS)
 414 {
 415         struct ksensordev *ksd = arg1;
 416         struct sensordev *usd;
 417         int error;
 418
 419         if (req->newptr)
 420                 return (EPERM);
 421
 422         /* Grab a copy, to clear the kernel pointers */
 423         usd = kmalloc(sizeof(*usd), M_TEMP, M_WAITOK | M_ZERO);
 424         usd->num = ksd->num;
 425         strlcpy(usd->xname, ksd->xname, sizeof(usd->xname));
 426         memcpy(usd->maxnumt, ksd->maxnumt, sizeof(usd->maxnumt));
 427         usd->sensors_count = ksd->sensors_count;
 428
 429         error = SYSCTL_OUT(req, usd, sizeof(struct sensordev));
 430
 431         kfree(usd, M_TEMP);
 432         return (error);
 433 }
 434
 435 static int
 436 sysctl_handle_sensor(SYSCTL_HANDLER_ARGS)
 437 {
 438         struct ksensor *ks = arg1;
 439         struct sensor *us;
 440         int error;
 441
 442         if (req->newptr)
 443                 return (EPERM);
 444
 445         /* Grab a copy, to clear the kernel pointers */
 446         us = kmalloc(sizeof(*us), M_TEMP, M_WAITOK | M_ZERO);
 447         memcpy(us->desc, ks->desc, sizeof(ks->desc));
 448         us->tv = ks->tv;
 449         us->value = ks->value;
 450         us->type = ks->type;
 451         us->status = ks->status;
 452         us->numt = ks->numt;
 453         us->flags = ks->flags;
 454
 455         error = SYSCTL_OUT(req, us, sizeof(struct sensor));
 456
 457         kfree(us, M_TEMP);
 458         return (error);
 459 }
 460
 461 static int
 462 sysctl_sensors_handler(SYSCTL_HANDLER_ARGS)
 463 {
 464         int *name = arg1;
 465         u_int namelen = arg2;
 466         struct ksensordev *ksd;
 467         struct ksensor *ks;
 468         int dev, numt;
 469         enum sensor_type type;
 470
 471         if (namelen != 1 && namelen != 3)
 472                 return (ENOTDIR);
 473
 474         dev = name[0];
 475         if ((ksd = sensordev_get(dev)) == NULL)
 476                 return (ENOENT);
 477
 478         if (namelen == 1)
 479                 return (sysctl_handle_sensordev(NULL, ksd, 0, req));
 480
 481         type = name[1];
 482         numt = name[2];
 483
 484         if ((ks = sensor_find(ksd, type, numt)) == NULL)
 485                 return (ENOENT);
 486         return (sysctl_handle_sensor(NULL, ks, 0, req));
 487 }
 488
 489 static void
 490 sensor_sysinit(void *arg __unused)
 491 {
 492         int error, cpu;
 493
 494         cpu = ncpus - 1; /* stick to the last CPU */
 495         error = kthread_create_cpu(sensor_task_thread, NULL, NULL, cpu,
 496             "sensors");
 497         if (error)
 498                 panic("sensors kthread on cpu%d failed: %d", cpu, error);
 499 }
 500 SYSINIT(sensor, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, sensor_sysinit, NULL);