The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_cpu.c

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    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: stable/9/sys/kern/kern_cpu.c 266167 2014-05-15 18:14:19Z cperciva $");
   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_active) {
  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, "");
  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, "");
  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 }

Cache object: 8077ae60b4fd0f5f2b0ac2f8640201fd


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