sys/kern/kern_cpu.c

   1 /*-
   2  * Copyright (c) 2004-2007 Nate Lawson (SDG)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/bus.h>
  32 #include <sys/cpu.h>
  33 #include <sys/eventhandler.h>
  34 #include <sys/kernel.h>
  35 #include <sys/lock.h>
  36 #include <sys/malloc.h>
  37 #include <sys/module.h>
  38 #include <sys/proc.h>
  39 #include <sys/queue.h>
  40 #include <sys/sbuf.h>
  41 #include <sys/sched.h>
  42 #include <sys/smp.h>
  43 #include <sys/sysctl.h>
  44 #include <sys/systm.h>
  45 #include <sys/sx.h>
  46 #include <sys/timetc.h>
  47 #include <sys/taskqueue.h>
  48
  49 #include "cpufreq_if.h"
  50
  51 /*
  52  * Common CPU frequency glue code.  Drivers for specific hardware can
  53  * attach this interface to allow users to get/set the CPU frequency.
  54  */
  55
  56 /*
  57  * Number of levels we can handle.  Levels are synthesized from settings
  58  * so for M settings and N drivers, there may be M*N levels.
  59  */
  60 #define CF_MAX_LEVELS   64
  61
  62 struct cf_saved_freq {
  63         struct cf_level                 level;
  64         int                             priority;
  65         SLIST_ENTRY(cf_saved_freq)      link;
  66 };
  67
  68 struct cpufreq_softc {
  69         struct sx                       lock;
  70         struct cf_level                 curr_level;
  71         int                             curr_priority;
  72         SLIST_HEAD(, cf_saved_freq)     saved_freq;
  73         struct cf_level_lst             all_levels;
  74         int                             all_count;
  75         int                             max_mhz;
  76         device_t                        dev;
  77         struct sysctl_ctx_list          sysctl_ctx;
  78         struct task                     startup_task;
  79         struct cf_level                 *levels_buf;
  80 };
  81
  82 struct cf_setting_array {
  83         struct cf_setting               sets[MAX_SETTINGS];
  84         int                             count;
  85         TAILQ_ENTRY(cf_setting_array)   link;
  86 };
  87
  88 TAILQ_HEAD(cf_setting_lst, cf_setting_array);
  89
  90 #define CF_MTX_INIT(x)          sx_init((x), "cpufreq lock")
  91 #define CF_MTX_LOCK(x)          sx_xlock((x))
  92 #define CF_MTX_UNLOCK(x)        sx_xunlock((x))
  93 #define CF_MTX_ASSERT(x)        sx_assert((x), SX_XLOCKED)
  94
  95 #define CF_DEBUG(msg...)        do {            \
  96         if (cf_verbose)                         \
  97                 printf("cpufreq: " msg);        \
  98         } while (0)
  99
 100 static int      cpufreq_attach(device_t dev);
 101 static void     cpufreq_startup_task(void *ctx, int pending);
 102 static int      cpufreq_detach(device_t dev);
 103 static int      cf_set_method(device_t dev, const struct cf_level *level,
 104                     int priority);
 105 static int      cf_get_method(device_t dev, struct cf_level *level);
 106 static int      cf_levels_method(device_t dev, struct cf_level *levels,
 107                     int *count);
 108 static int      cpufreq_insert_abs(struct cpufreq_softc *sc,
 109                     struct cf_setting *sets, int count);
 110 static int      cpufreq_expand_set(struct cpufreq_softc *sc,
 111                     struct cf_setting_array *set_arr);
 112 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc,
 113                     struct cf_level *dup, struct cf_setting *set);
 114 static int      cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS);
 115 static int      cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS);
 116 static int      cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS);
 117
 118 static device_method_t cpufreq_methods[] = {
 119         DEVMETHOD(device_probe,         bus_generic_probe),
 120         DEVMETHOD(device_attach,        cpufreq_attach),
 121         DEVMETHOD(device_detach,        cpufreq_detach),
 122
 123         DEVMETHOD(cpufreq_set,          cf_set_method),
 124         DEVMETHOD(cpufreq_get,          cf_get_method),
 125         DEVMETHOD(cpufreq_levels,       cf_levels_method),
 126         {0, 0}
 127 };
 128 static driver_t cpufreq_driver = {
 129         "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc)
 130 };
 131 static devclass_t cpufreq_dc;
 132 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0);
 133
 134 static int              cf_lowest_freq;
 135 static int              cf_verbose;
 136 TUNABLE_INT("debug.cpufreq.lowest", &cf_lowest_freq);
 137 TUNABLE_INT("debug.cpufreq.verbose", &cf_verbose);
 138 static SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL,
 139     "cpufreq debugging");
 140 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 1,
 141     "Don't provide levels below this frequency.");
 142 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1,
 143     "Print verbose debugging messages");
 144
 145 static int
 146 cpufreq_attach(device_t dev)
 147 {
 148         struct cpufreq_softc *sc;
 149         struct pcpu *pc;
 150         device_t parent;
 151         uint64_t rate;
 152         int numdevs;
 153
 154         CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
 155         sc = device_get_softc(dev);
 156         parent = device_get_parent(dev);
 157         sc->dev = dev;
 158         sysctl_ctx_init(&sc->sysctl_ctx);
 159         TAILQ_INIT(&sc->all_levels);
 160         CF_MTX_INIT(&sc->lock);
 161         sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
 162         SLIST_INIT(&sc->saved_freq);
 163         /* Try to get nominal CPU freq to use it as maximum later if needed */
 164         sc->max_mhz = cpu_get_nominal_mhz(dev);
 165         /* If that fails, try to measure the current rate */
 166         if (sc->max_mhz <= 0) {
 167                 pc = cpu_get_pcpu(dev);
 168                 if (cpu_est_clockrate(pc->pc_cpuid, &rate) == 0)
 169                         sc->max_mhz = rate / 1000000;
 170                 else
 171                         sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
 172         }
 173
 174         /*
 175          * Only initialize one set of sysctls for all CPUs.  In the future,
 176          * if multiple CPUs can have different settings, we can move these
 177          * sysctls to be under every CPU instead of just the first one.
 178          */
 179         numdevs = devclass_get_count(cpufreq_dc);
 180         if (numdevs > 1)
 181                 return (0);
 182
 183         CF_DEBUG("initializing one-time data for %s\n",
 184             device_get_nameunit(dev));
 185         sc->levels_buf = malloc(CF_MAX_LEVELS * sizeof(*sc->levels_buf),
 186             M_DEVBUF, M_WAITOK);
 187         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
 188             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
 189             OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
 190             cpufreq_curr_sysctl, "I", "Current CPU frequency");
 191         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
 192             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
 193             OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
 194             cpufreq_levels_sysctl, "A", "CPU frequency levels");
 195
 196         /*
 197          * Queue a one-shot broadcast that levels have changed.
 198          * It will run once the system has completed booting.
 199          */
 200         TASK_INIT(&sc->startup_task, 0, cpufreq_startup_task, dev);
 201         taskqueue_enqueue(taskqueue_thread, &sc->startup_task);
 202
 203         return (0);
 204 }
 205
 206 /* Handle any work to be done for all drivers that attached during boot. */
 207 static void
 208 cpufreq_startup_task(void *ctx, int pending)
 209 {
 210
 211         cpufreq_settings_changed((device_t)ctx);
 212 }
 213
 214 static int
 215 cpufreq_detach(device_t dev)
 216 {
 217         struct cpufreq_softc *sc;
 218         struct cf_saved_freq *saved_freq;
 219         int numdevs;
 220
 221         CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
 222         sc = device_get_softc(dev);
 223         sysctl_ctx_free(&sc->sysctl_ctx);
 224
 225         while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) {
 226                 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
 227                 free(saved_freq, M_TEMP);
 228         }
 229
 230         /* Only clean up these resources when the last device is detaching. */
 231         numdevs = devclass_get_count(cpufreq_dc);
 232         if (numdevs == 1) {
 233                 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev));
 234                 free(sc->levels_buf, M_DEVBUF);
 235         }
 236
 237         return (0);
 238 }
 239
 240 static int
 241 cf_set_method(device_t dev, const struct cf_level *level, int priority)
 242 {
 243         struct cpufreq_softc *sc;
 244         const struct cf_setting *set;
 245         struct cf_saved_freq *saved_freq, *curr_freq;
 246         struct pcpu *pc;
 247         int error, i;
 248
 249         sc = device_get_softc(dev);
 250         error = 0;
 251         set = NULL;
 252         saved_freq = NULL;
 253
 254         /* We are going to change levels so notify the pre-change handler. */
 255         EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error);
 256         if (error != 0) {
 257                 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
 258                 return (error);
 259         }
 260
 261         CF_MTX_LOCK(&sc->lock);
 262
 263 #ifdef SMP
 264         /*
 265          * If still booting and secondary CPUs not started yet, don't allow
 266          * changing the frequency until they're online.  This is because we
 267          * can't switch to them using sched_bind() and thus we'd only be
 268          * switching the main CPU.  XXXTODO: Need to think more about how to
 269          * handle having different CPUs at different frequencies.
 270          */
 271         if (mp_ncpus > 1 && !smp_started) {
 272                 device_printf(dev, "rejecting change, SMP not started yet\n");
 273                 error = ENXIO;
 274                 goto out;
 275         }
 276 #endif /* SMP */
 277
 278         /*
 279          * If the requested level has a lower priority, don't allow
 280          * the new level right now.
 281          */
 282         if (priority < sc->curr_priority) {
 283                 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority,
 284                     sc->curr_priority);
 285                 error = EPERM;
 286                 goto out;
 287         }
 288
 289         /*
 290          * If the caller didn't specify a level and one is saved, prepare to
 291          * restore the saved level.  If none has been saved, return an error.
 292          */
 293         if (level == NULL) {
 294                 saved_freq = SLIST_FIRST(&sc->saved_freq);
 295                 if (saved_freq == NULL) {
 296                         CF_DEBUG("NULL level, no saved level\n");
 297                         error = ENXIO;
 298                         goto out;
 299                 }
 300                 level = &saved_freq->level;
 301                 priority = saved_freq->priority;
 302                 CF_DEBUG("restoring saved level, freq %d prio %d\n",
 303                     level->total_set.freq, priority);
 304         }
 305
 306         /* Reject levels that are below our specified threshold. */
 307         if (level->total_set.freq < cf_lowest_freq) {
 308                 CF_DEBUG("rejecting freq %d, less than %d limit\n",
 309                     level->total_set.freq, cf_lowest_freq);
 310                 error = EINVAL;
 311                 goto out;
 312         }
 313
 314         /* If already at this level, just return. */
 315         if (sc->curr_level.total_set.freq == level->total_set.freq) {
 316                 CF_DEBUG("skipping freq %d, same as current level %d\n",
 317                     level->total_set.freq, sc->curr_level.total_set.freq);
 318                 goto skip;
 319         }
 320
 321         /* First, set the absolute frequency via its driver. */
 322         set = &level->abs_set;
 323         if (set->dev) {
 324                 if (!device_is_attached(set->dev)) {
 325                         error = ENXIO;
 326                         goto out;
 327                 }
 328
 329                 /* Bind to the target CPU before switching. */
 330                 pc = cpu_get_pcpu(set->dev);
 331                 thread_lock(curthread);
 332                 sched_bind(curthread, pc->pc_cpuid);
 333                 thread_unlock(curthread);
 334                 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
 335                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
 336                 error = CPUFREQ_DRV_SET(set->dev, set);
 337                 thread_lock(curthread);
 338                 sched_unbind(curthread);
 339                 thread_unlock(curthread);
 340                 if (error) {
 341                         goto out;
 342                 }
 343         }
 344
 345         /* Next, set any/all relative frequencies via their drivers. */
 346         for (i = 0; i < level->rel_count; i++) {
 347                 set = &level->rel_set[i];
 348                 if (!device_is_attached(set->dev)) {
 349                         error = ENXIO;
 350                         goto out;
 351                 }
 352
 353                 /* Bind to the target CPU before switching. */
 354                 pc = cpu_get_pcpu(set->dev);
 355                 thread_lock(curthread);
 356                 sched_bind(curthread, pc->pc_cpuid);
 357                 thread_unlock(curthread);
 358                 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
 359                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
 360                 error = CPUFREQ_DRV_SET(set->dev, set);
 361                 thread_lock(curthread);
 362                 sched_unbind(curthread);
 363                 thread_unlock(curthread);
 364                 if (error) {
 365                         /* XXX Back out any successful setting? */
 366                         goto out;
 367                 }
 368         }
 369
 370 skip:
 371         /*
 372          * Before recording the current level, check if we're going to a
 373          * higher priority.  If so, save the previous level and priority.
 374          */
 375         if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
 376             priority > sc->curr_priority) {
 377                 CF_DEBUG("saving level, freq %d prio %d\n",
 378                     sc->curr_level.total_set.freq, sc->curr_priority);
 379                 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT);
 380                 if (curr_freq == NULL) {
 381                         error = ENOMEM;
 382                         goto out;
 383                 }
 384                 curr_freq->level = sc->curr_level;
 385                 curr_freq->priority = sc->curr_priority;
 386                 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link);
 387         }
 388         sc->curr_level = *level;
 389         sc->curr_priority = priority;
 390
 391         /* If we were restoring a saved state, reset it to "unused". */
 392         if (saved_freq != NULL) {
 393                 CF_DEBUG("resetting saved level\n");
 394                 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
 395                 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
 396                 free(saved_freq, M_TEMP);
 397         }
 398
 399 out:
 400         CF_MTX_UNLOCK(&sc->lock);
 401
 402         /*
 403          * We changed levels (or attempted to) so notify the post-change
 404          * handler of new frequency or error.
 405          */
 406         EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
 407         if (error && set)
 408                 device_printf(set->dev, "set freq failed, err %d\n", error);
 409
 410         return (error);
 411 }
 412
 413 static int
 414 cf_get_method(device_t dev, struct cf_level *level)
 415 {
 416         struct cpufreq_softc *sc;
 417         struct cf_level *levels;
 418         struct cf_setting *curr_set, set;
 419         struct pcpu *pc;
 420         device_t *devs;
 421         int bdiff, count, diff, error, i, n, numdevs;
 422         uint64_t rate;
 423
 424         sc = device_get_softc(dev);
 425         error = 0;
 426         levels = NULL;
 427
 428         /* If we already know the current frequency, we're done. */
 429         CF_MTX_LOCK(&sc->lock);
 430         curr_set = &sc->curr_level.total_set;
 431         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
 432                 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
 433                 goto out;
 434         }
 435         CF_MTX_UNLOCK(&sc->lock);
 436
 437         /*
 438          * We need to figure out the current level.  Loop through every
 439          * driver, getting the current setting.  Then, attempt to get a best
 440          * match of settings against each level.
 441          */
 442         count = CF_MAX_LEVELS;
 443         levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
 444         if (levels == NULL)
 445                 return (ENOMEM);
 446         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
 447         if (error) {
 448                 if (error == E2BIG)
 449                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
 450                 free(levels, M_TEMP);
 451                 return (error);
 452         }
 453         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
 454         if (error) {
 455                 free(levels, M_TEMP);
 456                 return (error);
 457         }
 458
 459         /*
 460          * Reacquire the lock and search for the given level.
 461          *
 462          * XXX Note: this is not quite right since we really need to go
 463          * through each level and compare both absolute and relative
 464          * settings for each driver in the system before making a match.
 465          * The estimation code below catches this case though.
 466          */
 467         CF_MTX_LOCK(&sc->lock);
 468         for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) {
 469                 if (!device_is_attached(devs[n]))
 470                         continue;
 471                 if (CPUFREQ_DRV_GET(devs[n], &set) != 0)
 472                         continue;
 473                 for (i = 0; i < count; i++) {
 474                         if (set.freq == levels[i].total_set.freq) {
 475                                 sc->curr_level = levels[i];
 476                                 break;
 477                         }
 478                 }
 479         }
 480         free(devs, M_TEMP);
 481         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
 482                 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
 483                 goto out;
 484         }
 485
 486         /*
 487          * We couldn't find an exact match, so attempt to estimate and then
 488          * match against a level.
 489          */
 490         pc = cpu_get_pcpu(dev);
 491         if (pc == NULL) {
 492                 error = ENXIO;
 493                 goto out;
 494         }
 495         cpu_est_clockrate(pc->pc_cpuid, &rate);
 496         rate /= 1000000;
 497         bdiff = 1 << 30;
 498         for (i = 0; i < count; i++) {
 499                 diff = abs(levels[i].total_set.freq - rate);
 500                 if (diff < bdiff) {
 501                         bdiff = diff;
 502                         sc->curr_level = levels[i];
 503                 }
 504         }
 505         CF_DEBUG("get estimated freq %d\n", curr_set->freq);
 506
 507 out:
 508         if (error == 0)
 509                 *level = sc->curr_level;
 510
 511         CF_MTX_UNLOCK(&sc->lock);
 512         if (levels)
 513                 free(levels, M_TEMP);
 514         return (error);
 515 }
 516
 517 static int
 518 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
 519 {
 520         struct cf_setting_array *set_arr;
 521         struct cf_setting_lst rel_sets;
 522         struct cpufreq_softc *sc;
 523         struct cf_level *lev;
 524         struct cf_setting *sets;
 525         struct pcpu *pc;
 526         device_t *devs;
 527         int error, i, numdevs, set_count, type;
 528         uint64_t rate;
 529
 530         if (levels == NULL || count == NULL)
 531                 return (EINVAL);
 532
 533         TAILQ_INIT(&rel_sets);
 534         sc = device_get_softc(dev);
 535         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
 536         if (error)
 537                 return (error);
 538         sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
 539         if (sets == NULL) {
 540                 free(devs, M_TEMP);
 541                 return (ENOMEM);
 542         }
 543
 544         /* Get settings from all cpufreq drivers. */
 545         CF_MTX_LOCK(&sc->lock);
 546         for (i = 0; i < numdevs; i++) {
 547                 /* Skip devices that aren't ready. */
 548                 if (!device_is_attached(devs[i]))
 549                         continue;
 550
 551                 /*
 552                  * Get settings, skipping drivers that offer no settings or
 553                  * provide settings for informational purposes only.
 554                  */
 555                 error = CPUFREQ_DRV_TYPE(devs[i], &type);
 556                 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) {
 557                         if (error == 0) {
 558                                 CF_DEBUG("skipping info-only driver %s\n",
 559                                     device_get_nameunit(devs[i]));
 560                         }
 561                         continue;
 562                 }
 563                 set_count = MAX_SETTINGS;
 564                 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count);
 565                 if (error || set_count == 0)
 566                         continue;
 567
 568                 /* Add the settings to our absolute/relative lists. */
 569                 switch (type & CPUFREQ_TYPE_MASK) {
 570                 case CPUFREQ_TYPE_ABSOLUTE:
 571                         error = cpufreq_insert_abs(sc, sets, set_count);
 572                         break;
 573                 case CPUFREQ_TYPE_RELATIVE:
 574                         CF_DEBUG("adding %d relative settings\n", set_count);
 575                         set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
 576                         if (set_arr == NULL) {
 577                                 error = ENOMEM;
 578                                 goto out;
 579                         }
 580                         bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
 581                         set_arr->count = set_count;
 582                         TAILQ_INSERT_TAIL(&rel_sets, set_arr, link);
 583                         break;
 584                 default:
 585                         error = EINVAL;
 586                 }
 587                 if (error)
 588                         goto out;
 589         }
 590
 591         /*
 592          * If there are no absolute levels, create a fake one at 100%.  We
 593          * then cache the clockrate for later use as our base frequency.
 594          */
 595         if (TAILQ_EMPTY(&sc->all_levels)) {
 596                 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
 597                         sc->max_mhz = cpu_get_nominal_mhz(dev);
 598                         /*
 599                          * If the CPU can't report a rate for 100%, hope
 600                          * the CPU is running at its nominal rate right now,
 601                          * and use that instead.
 602                          */
 603                         if (sc->max_mhz <= 0) {
 604                                 pc = cpu_get_pcpu(dev);
 605                                 cpu_est_clockrate(pc->pc_cpuid, &rate);
 606                                 sc->max_mhz = rate / 1000000;
 607                         }
 608                 }
 609                 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets));
 610                 sets[0].freq = sc->max_mhz;
 611                 sets[0].dev = NULL;
 612                 error = cpufreq_insert_abs(sc, sets, 1);
 613                 if (error)
 614                         goto out;
 615         }
 616
 617         /* Create a combined list of absolute + relative levels. */
 618         TAILQ_FOREACH(set_arr, &rel_sets, link)
 619                 cpufreq_expand_set(sc, set_arr);
 620
 621         /* If the caller doesn't have enough space, return the actual count. */
 622         if (sc->all_count > *count) {
 623                 *count = sc->all_count;
 624                 error = E2BIG;
 625                 goto out;
 626         }
 627
 628         /* Finally, output the list of levels. */
 629         i = 0;
 630         TAILQ_FOREACH(lev, &sc->all_levels, link) {
 631
 632                 /* Skip levels that have a frequency that is too low. */
 633                 if (lev->total_set.freq < cf_lowest_freq) {
 634                         sc->all_count--;
 635                         continue;
 636                 }
 637
 638                 levels[i] = *lev;
 639                 i++;
 640         }
 641         *count = sc->all_count;
 642         error = 0;
 643
 644 out:
 645         /* Clear all levels since we regenerate them each time. */
 646         while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
 647                 TAILQ_REMOVE(&sc->all_levels, lev, link);
 648                 free(lev, M_TEMP);
 649         }
 650         sc->all_count = 0;
 651
 652         CF_MTX_UNLOCK(&sc->lock);
 653         while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
 654                 TAILQ_REMOVE(&rel_sets, set_arr, link);
 655                 free(set_arr, M_TEMP);
 656         }
 657         free(devs, M_TEMP);
 658         free(sets, M_TEMP);
 659         return (error);
 660 }
 661
 662 /*
 663  * Create levels for an array of absolute settings and insert them in
 664  * sorted order in the specified list.
 665  */
 666 static int
 667 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
 668     int count)
 669 {
 670         struct cf_level_lst *list;
 671         struct cf_level *level, *search;
 672         int i;
 673
 674         CF_MTX_ASSERT(&sc->lock);
 675
 676         list = &sc->all_levels;
 677         for (i = 0; i < count; i++) {
 678                 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
 679                 if (level == NULL)
 680                         return (ENOMEM);
 681                 level->abs_set = sets[i];
 682                 level->total_set = sets[i];
 683                 level->total_set.dev = NULL;
 684                 sc->all_count++;
 685
 686                 if (TAILQ_EMPTY(list)) {
 687                         CF_DEBUG("adding abs setting %d at head\n",
 688                             sets[i].freq);
 689                         TAILQ_INSERT_HEAD(list, level, link);
 690                         continue;
 691                 }
 692
 693                 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) {
 694                         if (sets[i].freq <= search->total_set.freq) {
 695                                 CF_DEBUG("adding abs setting %d after %d\n",
 696                                     sets[i].freq, search->total_set.freq);
 697                                 TAILQ_INSERT_AFTER(list, search, level, link);
 698                                 break;
 699                         }
 700                 }
 701         }
 702         return (0);
 703 }
 704
 705 /*
 706  * Expand a group of relative settings, creating derived levels from them.
 707  */
 708 static int
 709 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
 710 {
 711         struct cf_level *fill, *search;
 712         struct cf_setting *set;
 713         int i;
 714
 715         CF_MTX_ASSERT(&sc->lock);
 716
 717         /*
 718          * Walk the set of all existing levels in reverse.  This is so we
 719          * create derived states from the lowest absolute settings first
 720          * and discard duplicates created from higher absolute settings.
 721          * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
 722          * preferable to 200 Mhz + 25% because absolute settings are more
 723          * efficient since they often change the voltage as well.
 724          */
 725         TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
 726                 /* Add each setting to the level, duplicating if necessary. */
 727                 for (i = 0; i < set_arr->count; i++) {
 728                         set = &set_arr->sets[i];
 729
 730                         /*
 731                          * If this setting is less than 100%, split the level
 732                          * into two and add this setting to the new level.
 733                          */
 734                         fill = search;
 735                         if (set->freq < 10000) {
 736                                 fill = cpufreq_dup_set(sc, search, set);
 737
 738                                 /*
 739                                  * The new level was a duplicate of an existing
 740                                  * level or its absolute setting is too high
 741                                  * so we freed it.  For example, we discard a
 742                                  * derived level of 1000 MHz/25% if a level
 743                                  * of 500 MHz/100% already exists.
 744                                  */
 745                                 if (fill == NULL)
 746                                         break;
 747                         }
 748
 749                         /* Add this setting to the existing or new level. */
 750                         KASSERT(fill->rel_count < MAX_SETTINGS,
 751                             ("cpufreq: too many relative drivers (%d)",
 752                             MAX_SETTINGS));
 753                         fill->rel_set[fill->rel_count] = *set;
 754                         fill->rel_count++;
 755                         CF_DEBUG(
 756                         "expand set added rel setting %d%% to %d level\n",
 757                             set->freq / 100, fill->total_set.freq);
 758                 }
 759         }
 760
 761         return (0);
 762 }
 763
 764 static struct cf_level *
 765 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
 766     struct cf_setting *set)
 767 {
 768         struct cf_level_lst *list;
 769         struct cf_level *fill, *itr;
 770         struct cf_setting *fill_set, *itr_set;
 771         int i;
 772
 773         CF_MTX_ASSERT(&sc->lock);
 774
 775         /*
 776          * Create a new level, copy it from the old one, and update the
 777          * total frequency and power by the percentage specified in the
 778          * relative setting.
 779          */
 780         fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
 781         if (fill == NULL)
 782                 return (NULL);
 783         *fill = *dup;
 784         fill_set = &fill->total_set;
 785         fill_set->freq =
 786             ((uint64_t)fill_set->freq * set->freq) / 10000;
 787         if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
 788                 fill_set->power = ((uint64_t)fill_set->power * set->freq)
 789                     / 10000;
 790         }
 791         if (set->lat != CPUFREQ_VAL_UNKNOWN) {
 792                 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
 793                         fill_set->lat += set->lat;
 794                 else
 795                         fill_set->lat = set->lat;
 796         }
 797         CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
 798
 799         /*
 800          * If we copied an old level that we already modified (say, at 100%),
 801          * we need to remove that setting before adding this one.  Since we
 802          * process each setting array in order, we know any settings for this
 803          * driver will be found at the end.
 804          */
 805         for (i = fill->rel_count; i != 0; i--) {
 806                 if (fill->rel_set[i - 1].dev != set->dev)
 807                         break;
 808                 CF_DEBUG("removed last relative driver: %s\n",
 809                     device_get_nameunit(set->dev));
 810                 fill->rel_count--;
 811         }
 812
 813         /*
 814          * Insert the new level in sorted order.  If it is a duplicate of an
 815          * existing level (1) or has an absolute setting higher than the
 816          * existing level (2), do not add it.  We can do this since any such
 817          * level is guaranteed use less power.  For example (1), a level with
 818          * one absolute setting of 800 Mhz uses less power than one composed
 819          * of an absolute setting of 1600 Mhz and a relative setting at 50%.
 820          * Also for example (2), a level of 800 Mhz/75% is preferable to
 821          * 1600 Mhz/25% even though the latter has a lower total frequency.
 822          */
 823         list = &sc->all_levels;
 824         KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
 825         TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
 826                 itr_set = &itr->total_set;
 827                 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
 828                         CF_DEBUG("dup set rejecting %d (dupe)\n",
 829                             fill_set->freq);
 830                         itr = NULL;
 831                         break;
 832                 } else if (fill_set->freq < itr_set->freq) {
 833                         if (fill->abs_set.freq <= itr->abs_set.freq) {
 834                                 CF_DEBUG(
 835                         "dup done, inserting new level %d after %d\n",
 836                                     fill_set->freq, itr_set->freq);
 837                                 TAILQ_INSERT_AFTER(list, itr, fill, link);
 838                                 sc->all_count++;
 839                         } else {
 840                                 CF_DEBUG("dup set rejecting %d (abs too big)\n",
 841                                     fill_set->freq);
 842                                 itr = NULL;
 843                         }
 844                         break;
 845                 }
 846         }
 847
 848         /* We didn't find a good place for this new level so free it. */
 849         if (itr == NULL) {
 850                 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
 851                     fill_set->freq);
 852                 free(fill, M_TEMP);
 853                 fill = NULL;
 854         }
 855
 856         return (fill);
 857 }
 858
 859 static int
 860 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
 861 {
 862         struct cpufreq_softc *sc;
 863         struct cf_level *levels;
 864         int best, count, diff, bdiff, devcount, error, freq, i, n;
 865         device_t *devs;
 866
 867         devs = NULL;
 868         sc = oidp->oid_arg1;
 869         levels = sc->levels_buf;
 870
 871         error = CPUFREQ_GET(sc->dev, &levels[0]);
 872         if (error)
 873                 goto out;
 874         freq = levels[0].total_set.freq;
 875         error = sysctl_handle_int(oidp, &freq, 0, req);
 876         if (error != 0 || req->newptr == NULL)
 877                 goto out;
 878
 879         /*
 880          * While we only call cpufreq_get() on one device (assuming all
 881          * CPUs have equal levels), we call cpufreq_set() on all CPUs.
 882          * This is needed for some MP systems.
 883          */
 884         error = devclass_get_devices(cpufreq_dc, &devs, &devcount);
 885         if (error)
 886                 goto out;
 887         for (n = 0; n < devcount; n++) {
 888                 count = CF_MAX_LEVELS;
 889                 error = CPUFREQ_LEVELS(devs[n], levels, &count);
 890                 if (error) {
 891                         if (error == E2BIG)
 892                                 printf(
 893                         "cpufreq: need to increase CF_MAX_LEVELS\n");
 894                         break;
 895                 }
 896                 best = 0;
 897                 bdiff = 1 << 30;
 898                 for (i = 0; i < count; i++) {
 899                         diff = abs(levels[i].total_set.freq - freq);
 900                         if (diff < bdiff) {
 901                                 bdiff = diff;
 902                                 best = i;
 903                         }
 904                 }
 905                 error = CPUFREQ_SET(devs[n], &levels[best], CPUFREQ_PRIO_USER);
 906         }
 907
 908 out:
 909         if (devs)
 910                 free(devs, M_TEMP);
 911         return (error);
 912 }
 913
 914 static int
 915 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
 916 {
 917         struct cpufreq_softc *sc;
 918         struct cf_level *levels;
 919         struct cf_setting *set;
 920         struct sbuf sb;
 921         int count, error, i;
 922
 923         sc = oidp->oid_arg1;
 924         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
 925
 926         /* Get settings from the device and generate the output string. */
 927         count = CF_MAX_LEVELS;
 928         levels = sc->levels_buf;
 929         if (levels == NULL) {
 930                 sbuf_delete(&sb);
 931                 return (ENOMEM);
 932         }
 933         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
 934         if (error) {
 935                 if (error == E2BIG)
 936                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
 937                 goto out;
 938         }
 939         if (count) {
 940                 for (i = 0; i < count; i++) {
 941                         set = &levels[i].total_set;
 942                         sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
 943                 }
 944         } else
 945                 sbuf_cpy(&sb, "0");
 946         sbuf_trim(&sb);
 947         sbuf_finish(&sb);
 948         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
 949
 950 out:
 951         sbuf_delete(&sb);
 952         return (error);
 953 }
 954
 955 static int
 956 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
 957 {
 958         device_t dev;
 959         struct cf_setting *sets;
 960         struct sbuf sb;
 961         int error, i, set_count;
 962
 963         dev = oidp->oid_arg1;
 964         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
 965
 966         /* Get settings from the device and generate the output string. */
 967         set_count = MAX_SETTINGS;
 968         sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
 969         if (sets == NULL) {
 970                 sbuf_delete(&sb);
 971                 return (ENOMEM);
 972         }
 973         error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
 974         if (error)
 975                 goto out;
 976         if (set_count) {
 977                 for (i = 0; i < set_count; i++)
 978                         sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
 979         } else
 980                 sbuf_cpy(&sb, "0");
 981         sbuf_trim(&sb);
 982         sbuf_finish(&sb);
 983         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
 984
 985 out:
 986         free(sets, M_TEMP);
 987         sbuf_delete(&sb);
 988         return (error);
 989 }
 990
 991 int
 992 cpufreq_register(device_t dev)
 993 {
 994         struct cpufreq_softc *sc;
 995         device_t cf_dev, cpu_dev;
 996
 997         /* Add a sysctl to get each driver's settings separately. */
 998         SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
 999             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1000             OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0,
1001             cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
1002
1003         /*
1004          * Add only one cpufreq device to each CPU.  Currently, all CPUs
1005          * must offer the same levels and be switched at the same time.
1006          */
1007         cpu_dev = device_get_parent(dev);
1008         if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
1009                 sc = device_get_softc(cf_dev);
1010                 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
1011                 return (0);
1012         }
1013
1014         /* Add the child device and possibly sysctls. */
1015         cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1);
1016         if (cf_dev == NULL)
1017                 return (ENOMEM);
1018         device_quiet(cf_dev);
1019
1020         return (device_probe_and_attach(cf_dev));
1021 }
1022
1023 int
1024 cpufreq_unregister(device_t dev)
1025 {
1026         device_t cf_dev, *devs;
1027         int cfcount, devcount, error, i, type;
1028
1029         /*
1030          * If this is the last cpufreq child device, remove the control
1031          * device as well.  We identify cpufreq children by calling a method
1032          * they support.
1033          */
1034         error = device_get_children(device_get_parent(dev), &devs, &devcount);
1035         if (error)
1036                 return (error);
1037         cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
1038         if (cf_dev == NULL) {
1039                 device_printf(dev,
1040         "warning: cpufreq_unregister called with no cpufreq device active\n");
1041                 free(devs, M_TEMP);
1042                 return (0);
1043         }
1044         cfcount = 0;
1045         for (i = 0; i < devcount; i++) {
1046                 if (!device_is_attached(devs[i]))
1047                         continue;
1048                 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0)
1049                         cfcount++;
1050         }
1051         if (cfcount <= 1)
1052                 device_delete_child(device_get_parent(cf_dev), cf_dev);
1053         free(devs, M_TEMP);
1054
1055         return (0);
1056 }
1057
1058 int
1059 cpufreq_settings_changed(device_t dev)
1060 {
1061
1062         EVENTHANDLER_INVOKE(cpufreq_levels_changed,
1063             device_get_unit(device_get_parent(dev)));
1064         return (0);
1065 }