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: releng/8.3/sys/kern/kern_cpu.c 211578 2010-08-21 17:48:29Z avg $");
   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 SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL, "cpufreq debugging");
  139 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 1,
  140     "Don't provide levels below this frequency.");
  141 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1,
  142     "Print verbose debugging messages");
  143 
  144 static int
  145 cpufreq_attach(device_t dev)
  146 {
  147         struct cpufreq_softc *sc;
  148         struct pcpu *pc;
  149         device_t parent;
  150         uint64_t rate;
  151         int numdevs;
  152 
  153         CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
  154         sc = device_get_softc(dev);
  155         parent = device_get_parent(dev);
  156         sc->dev = dev;
  157         sysctl_ctx_init(&sc->sysctl_ctx);
  158         TAILQ_INIT(&sc->all_levels);
  159         CF_MTX_INIT(&sc->lock);
  160         sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
  161         SLIST_INIT(&sc->saved_freq);
  162         /* Try to get nominal CPU freq to use it as maximum later if needed */
  163         sc->max_mhz = cpu_get_nominal_mhz(dev);
  164         /* If that fails, try to measure the current rate */
  165         if (sc->max_mhz <= 0) {
  166                 pc = cpu_get_pcpu(dev);
  167                 if (cpu_est_clockrate(pc->pc_cpuid, &rate) == 0)
  168                         sc->max_mhz = rate / 1000000;
  169                 else
  170                         sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
  171         }
  172 
  173         /*
  174          * Only initialize one set of sysctls for all CPUs.  In the future,
  175          * if multiple CPUs can have different settings, we can move these
  176          * sysctls to be under every CPU instead of just the first one.
  177          */
  178         numdevs = devclass_get_count(cpufreq_dc);
  179         if (numdevs > 1)
  180                 return (0);
  181 
  182         CF_DEBUG("initializing one-time data for %s\n",
  183             device_get_nameunit(dev));
  184         sc->levels_buf = malloc(CF_MAX_LEVELS * sizeof(*sc->levels_buf),
  185             M_DEVBUF, M_WAITOK);
  186         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
  187             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
  188             OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
  189             cpufreq_curr_sysctl, "I", "Current CPU frequency");
  190         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
  191             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
  192             OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
  193             cpufreq_levels_sysctl, "A", "CPU frequency levels");
  194 
  195         /*
  196          * Queue a one-shot broadcast that levels have changed.
  197          * It will run once the system has completed booting.
  198          */
  199         TASK_INIT(&sc->startup_task, 0, cpufreq_startup_task, dev);
  200         taskqueue_enqueue(taskqueue_thread, &sc->startup_task);
  201 
  202         return (0);
  203 }
  204 
  205 /* Handle any work to be done for all drivers that attached during boot. */
  206 static void 
  207 cpufreq_startup_task(void *ctx, int pending)
  208 {
  209 
  210         cpufreq_settings_changed((device_t)ctx);
  211 }
  212 
  213 static int
  214 cpufreq_detach(device_t dev)
  215 {
  216         struct cpufreq_softc *sc;
  217         struct cf_saved_freq *saved_freq;
  218         int numdevs;
  219 
  220         CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
  221         sc = device_get_softc(dev);
  222         sysctl_ctx_free(&sc->sysctl_ctx);
  223 
  224         while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) {
  225                 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
  226                 free(saved_freq, M_TEMP);
  227         }
  228 
  229         /* Only clean up these resources when the last device is detaching. */
  230         numdevs = devclass_get_count(cpufreq_dc);
  231         if (numdevs == 1) {
  232                 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev));
  233                 free(sc->levels_buf, M_DEVBUF);
  234         }
  235 
  236         return (0);
  237 }
  238 
  239 static int
  240 cf_set_method(device_t dev, const struct cf_level *level, int priority)
  241 {
  242         struct cpufreq_softc *sc;
  243         const struct cf_setting *set;
  244         struct cf_saved_freq *saved_freq, *curr_freq;
  245         struct pcpu *pc;
  246         int error, i;
  247 
  248         sc = device_get_softc(dev);
  249         error = 0;
  250         set = NULL;
  251         saved_freq = NULL;
  252 
  253         /* We are going to change levels so notify the pre-change handler. */
  254         EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error);
  255         if (error != 0) {
  256                 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
  257                 return (error);
  258         }
  259 
  260         CF_MTX_LOCK(&sc->lock);
  261 
  262 #ifdef SMP
  263         /*
  264          * If still booting and secondary CPUs not started yet, don't allow
  265          * changing the frequency until they're online.  This is because we
  266          * can't switch to them using sched_bind() and thus we'd only be
  267          * switching the main CPU.  XXXTODO: Need to think more about how to
  268          * handle having different CPUs at different frequencies.  
  269          */
  270         if (mp_ncpus > 1 && !smp_active) {
  271                 device_printf(dev, "rejecting change, SMP not started yet\n");
  272                 error = ENXIO;
  273                 goto out;
  274         }
  275 #endif /* SMP */
  276 
  277         /*
  278          * If the requested level has a lower priority, don't allow
  279          * the new level right now.
  280          */
  281         if (priority < sc->curr_priority) {
  282                 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority,
  283                     sc->curr_priority);
  284                 error = EPERM;
  285                 goto out;
  286         }
  287 
  288         /*
  289          * If the caller didn't specify a level and one is saved, prepare to
  290          * restore the saved level.  If none has been saved, return an error.
  291          */
  292         if (level == NULL) {
  293                 saved_freq = SLIST_FIRST(&sc->saved_freq);
  294                 if (saved_freq == NULL) {
  295                         CF_DEBUG("NULL level, no saved level\n");
  296                         error = ENXIO;
  297                         goto out;
  298                 }
  299                 level = &saved_freq->level;
  300                 priority = saved_freq->priority;
  301                 CF_DEBUG("restoring saved level, freq %d prio %d\n",
  302                     level->total_set.freq, priority);
  303         }
  304 
  305         /* Reject levels that are below our specified threshold. */
  306         if (level->total_set.freq < cf_lowest_freq) {
  307                 CF_DEBUG("rejecting freq %d, less than %d limit\n",
  308                     level->total_set.freq, cf_lowest_freq);
  309                 error = EINVAL;
  310                 goto out;
  311         }
  312 
  313         /* If already at this level, just return. */
  314         if (CPUFREQ_CMP(sc->curr_level.total_set.freq, level->total_set.freq)) {
  315                 CF_DEBUG("skipping freq %d, same as current level %d\n",
  316                     level->total_set.freq, sc->curr_level.total_set.freq);
  317                 goto skip;
  318         }
  319 
  320         /* First, set the absolute frequency via its driver. */
  321         set = &level->abs_set;
  322         if (set->dev) {
  323                 if (!device_is_attached(set->dev)) {
  324                         error = ENXIO;
  325                         goto out;
  326                 }
  327 
  328                 /* Bind to the target CPU before switching. */
  329                 pc = cpu_get_pcpu(set->dev);
  330                 thread_lock(curthread);
  331                 sched_bind(curthread, pc->pc_cpuid);
  332                 thread_unlock(curthread);
  333                 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
  334                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
  335                 error = CPUFREQ_DRV_SET(set->dev, set);
  336                 thread_lock(curthread);
  337                 sched_unbind(curthread);
  338                 thread_unlock(curthread);
  339                 if (error) {
  340                         goto out;
  341                 }
  342         }
  343 
  344         /* Next, set any/all relative frequencies via their drivers. */
  345         for (i = 0; i < level->rel_count; i++) {
  346                 set = &level->rel_set[i];
  347                 if (!device_is_attached(set->dev)) {
  348                         error = ENXIO;
  349                         goto out;
  350                 }
  351 
  352                 /* Bind to the target CPU before switching. */
  353                 pc = cpu_get_pcpu(set->dev);
  354                 thread_lock(curthread);
  355                 sched_bind(curthread, pc->pc_cpuid);
  356                 thread_unlock(curthread);
  357                 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
  358                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
  359                 error = CPUFREQ_DRV_SET(set->dev, set);
  360                 thread_lock(curthread);
  361                 sched_unbind(curthread);
  362                 thread_unlock(curthread);
  363                 if (error) {
  364                         /* XXX Back out any successful setting? */
  365                         goto out;
  366                 }
  367         }
  368 
  369 skip:
  370         /*
  371          * Before recording the current level, check if we're going to a
  372          * higher priority.  If so, save the previous level and priority.
  373          */
  374         if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
  375             priority > sc->curr_priority) {
  376                 CF_DEBUG("saving level, freq %d prio %d\n",
  377                     sc->curr_level.total_set.freq, sc->curr_priority);
  378                 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT);
  379                 if (curr_freq == NULL) {
  380                         error = ENOMEM;
  381                         goto out;
  382                 }
  383                 curr_freq->level = sc->curr_level;
  384                 curr_freq->priority = sc->curr_priority;
  385                 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link);
  386         }
  387         sc->curr_level = *level;
  388         sc->curr_priority = priority;
  389 
  390         /* If we were restoring a saved state, reset it to "unused". */
  391         if (saved_freq != NULL) {
  392                 CF_DEBUG("resetting saved level\n");
  393                 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
  394                 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
  395                 free(saved_freq, M_TEMP);
  396         }
  397 
  398 out:
  399         CF_MTX_UNLOCK(&sc->lock);
  400 
  401         /*
  402          * We changed levels (or attempted to) so notify the post-change
  403          * handler of new frequency or error.
  404          */
  405         EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
  406         if (error && set)
  407                 device_printf(set->dev, "set freq failed, err %d\n", error);
  408 
  409         return (error);
  410 }
  411 
  412 static int
  413 cf_get_method(device_t dev, struct cf_level *level)
  414 {
  415         struct cpufreq_softc *sc;
  416         struct cf_level *levels;
  417         struct cf_setting *curr_set, set;
  418         struct pcpu *pc;
  419         device_t *devs;
  420         int count, error, i, n, numdevs;
  421         uint64_t rate;
  422 
  423         sc = device_get_softc(dev);
  424         error = 0;
  425         levels = NULL;
  426 
  427         /* If we already know the current frequency, we're done. */
  428         CF_MTX_LOCK(&sc->lock);
  429         curr_set = &sc->curr_level.total_set;
  430         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
  431                 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
  432                 goto out;
  433         }
  434         CF_MTX_UNLOCK(&sc->lock);
  435 
  436         /*
  437          * We need to figure out the current level.  Loop through every
  438          * driver, getting the current setting.  Then, attempt to get a best
  439          * match of settings against each level.
  440          */
  441         count = CF_MAX_LEVELS;
  442         levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
  443         if (levels == NULL)
  444                 return (ENOMEM);
  445         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
  446         if (error) {
  447                 if (error == E2BIG)
  448                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
  449                 free(levels, M_TEMP);
  450                 return (error);
  451         }
  452         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
  453         if (error) {
  454                 free(levels, M_TEMP);
  455                 return (error);
  456         }
  457 
  458         /*
  459          * Reacquire the lock and search for the given level.
  460          *
  461          * XXX Note: this is not quite right since we really need to go
  462          * through each level and compare both absolute and relative
  463          * settings for each driver in the system before making a match.
  464          * The estimation code below catches this case though.
  465          */
  466         CF_MTX_LOCK(&sc->lock);
  467         for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) {
  468                 if (!device_is_attached(devs[n]))
  469                         continue;
  470                 if (CPUFREQ_DRV_GET(devs[n], &set) != 0)
  471                         continue;
  472                 for (i = 0; i < count; i++) {
  473                         if (CPUFREQ_CMP(set.freq, levels[i].total_set.freq)) {
  474                                 sc->curr_level = levels[i];
  475                                 break;
  476                         }
  477                 }
  478         }
  479         free(devs, M_TEMP);
  480         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
  481                 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
  482                 goto out;
  483         }
  484 
  485         /*
  486          * We couldn't find an exact match, so attempt to estimate and then
  487          * match against a level.
  488          */
  489         pc = cpu_get_pcpu(dev);
  490         if (pc == NULL) {
  491                 error = ENXIO;
  492                 goto out;
  493         }
  494         cpu_est_clockrate(pc->pc_cpuid, &rate);
  495         rate /= 1000000;
  496         for (i = 0; i < count; i++) {
  497                 if (CPUFREQ_CMP(rate, levels[i].total_set.freq)) {
  498                         sc->curr_level = levels[i];
  499                         CF_DEBUG("get estimated freq %d\n", curr_set->freq);
  500                         goto out;
  501                 }
  502         }
  503         error = ENXIO;
  504 
  505 out:
  506         if (error == 0)
  507                 *level = sc->curr_level;
  508 
  509         CF_MTX_UNLOCK(&sc->lock);
  510         if (levels)
  511                 free(levels, M_TEMP);
  512         return (error);
  513 }
  514 
  515 static int
  516 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
  517 {
  518         struct cf_setting_array *set_arr;
  519         struct cf_setting_lst rel_sets;
  520         struct cpufreq_softc *sc;
  521         struct cf_level *lev;
  522         struct cf_setting *sets;
  523         struct pcpu *pc;
  524         device_t *devs;
  525         int error, i, numdevs, set_count, type;
  526         uint64_t rate;
  527 
  528         if (levels == NULL || count == NULL)
  529                 return (EINVAL);
  530 
  531         TAILQ_INIT(&rel_sets);
  532         sc = device_get_softc(dev);
  533         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
  534         if (error)
  535                 return (error);
  536         sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
  537         if (sets == NULL) {
  538                 free(devs, M_TEMP);
  539                 return (ENOMEM);
  540         }
  541 
  542         /* Get settings from all cpufreq drivers. */
  543         CF_MTX_LOCK(&sc->lock);
  544         for (i = 0; i < numdevs; i++) {
  545                 /* Skip devices that aren't ready. */
  546                 if (!device_is_attached(devs[i]))
  547                         continue;
  548 
  549                 /*
  550                  * Get settings, skipping drivers that offer no settings or
  551                  * provide settings for informational purposes only.
  552                  */
  553                 error = CPUFREQ_DRV_TYPE(devs[i], &type);
  554                 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) {
  555                         if (error == 0) {
  556                                 CF_DEBUG("skipping info-only driver %s\n",
  557                                     device_get_nameunit(devs[i]));
  558                         }
  559                         continue;
  560                 }
  561                 set_count = MAX_SETTINGS;
  562                 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count);
  563                 if (error || set_count == 0)
  564                         continue;
  565 
  566                 /* Add the settings to our absolute/relative lists. */
  567                 switch (type & CPUFREQ_TYPE_MASK) {
  568                 case CPUFREQ_TYPE_ABSOLUTE:
  569                         error = cpufreq_insert_abs(sc, sets, set_count);
  570                         break;
  571                 case CPUFREQ_TYPE_RELATIVE:
  572                         CF_DEBUG("adding %d relative settings\n", set_count);
  573                         set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
  574                         if (set_arr == NULL) {
  575                                 error = ENOMEM;
  576                                 goto out;
  577                         }
  578                         bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
  579                         set_arr->count = set_count;
  580                         TAILQ_INSERT_TAIL(&rel_sets, set_arr, link);
  581                         break;
  582                 default:
  583                         error = EINVAL;
  584                 }
  585                 if (error)
  586                         goto out;
  587         }
  588 
  589         /*
  590          * If there are no absolute levels, create a fake one at 100%.  We
  591          * then cache the clockrate for later use as our base frequency.
  592          */
  593         if (TAILQ_EMPTY(&sc->all_levels)) {
  594                 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
  595                         sc->max_mhz = cpu_get_nominal_mhz(dev);
  596                         /*
  597                          * If the CPU can't report a rate for 100%, hope
  598                          * the CPU is running at its nominal rate right now,
  599                          * and use that instead.
  600                          */
  601                         if (sc->max_mhz <= 0) {
  602                                 pc = cpu_get_pcpu(dev);
  603                                 cpu_est_clockrate(pc->pc_cpuid, &rate);
  604                                 sc->max_mhz = rate / 1000000;
  605                         }
  606                 }
  607                 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets));
  608                 sets[0].freq = sc->max_mhz;
  609                 sets[0].dev = NULL;
  610                 error = cpufreq_insert_abs(sc, sets, 1);
  611                 if (error)
  612                         goto out;
  613         }
  614 
  615         /* Create a combined list of absolute + relative levels. */
  616         TAILQ_FOREACH(set_arr, &rel_sets, link)
  617                 cpufreq_expand_set(sc, set_arr);
  618 
  619         /* If the caller doesn't have enough space, return the actual count. */
  620         if (sc->all_count > *count) {
  621                 *count = sc->all_count;
  622                 error = E2BIG;
  623                 goto out;
  624         }
  625 
  626         /* Finally, output the list of levels. */
  627         i = 0;
  628         TAILQ_FOREACH(lev, &sc->all_levels, link) {
  629                 /*
  630                  * Skip levels that are too close in frequency to the
  631                  * previous levels.  Some systems report bogus duplicate
  632                  * settings (i.e., for acpi_perf).
  633                  */
  634                 if (i > 0 && CPUFREQ_CMP(lev->total_set.freq,
  635                     levels[i - 1].total_set.freq)) {
  636                         sc->all_count--;
  637                         continue;
  638                 }
  639 
  640                 /* Skip levels that have a frequency that is too low. */
  641                 if (lev->total_set.freq < cf_lowest_freq) {
  642                         sc->all_count--;
  643                         continue;
  644                 }
  645 
  646                 levels[i] = *lev;
  647                 i++;
  648         }
  649         *count = sc->all_count;
  650         error = 0;
  651 
  652 out:
  653         /* Clear all levels since we regenerate them each time. */
  654         while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
  655                 TAILQ_REMOVE(&sc->all_levels, lev, link);
  656                 free(lev, M_TEMP);
  657         }
  658         sc->all_count = 0;
  659 
  660         CF_MTX_UNLOCK(&sc->lock);
  661         while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
  662                 TAILQ_REMOVE(&rel_sets, set_arr, link);
  663                 free(set_arr, M_TEMP);
  664         }
  665         free(devs, M_TEMP);
  666         free(sets, M_TEMP);
  667         return (error);
  668 }
  669 
  670 /*
  671  * Create levels for an array of absolute settings and insert them in
  672  * sorted order in the specified list.
  673  */
  674 static int
  675 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
  676     int count)
  677 {
  678         struct cf_level_lst *list;
  679         struct cf_level *level, *search;
  680         int i;
  681 
  682         CF_MTX_ASSERT(&sc->lock);
  683 
  684         list = &sc->all_levels;
  685         for (i = 0; i < count; i++) {
  686                 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
  687                 if (level == NULL)
  688                         return (ENOMEM);
  689                 level->abs_set = sets[i];
  690                 level->total_set = sets[i];
  691                 level->total_set.dev = NULL;
  692                 sc->all_count++;
  693 
  694                 if (TAILQ_EMPTY(list)) {
  695                         CF_DEBUG("adding abs setting %d at head\n",
  696                             sets[i].freq);
  697                         TAILQ_INSERT_HEAD(list, level, link);
  698                         continue;
  699                 }
  700 
  701                 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) {
  702                         if (sets[i].freq <= search->total_set.freq) {
  703                                 CF_DEBUG("adding abs setting %d after %d\n",
  704                                     sets[i].freq, search->total_set.freq);
  705                                 TAILQ_INSERT_AFTER(list, search, level, link);
  706                                 break;
  707                         }
  708                 }
  709         }
  710         return (0);
  711 }
  712 
  713 /*
  714  * Expand a group of relative settings, creating derived levels from them.
  715  */
  716 static int
  717 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
  718 {
  719         struct cf_level *fill, *search;
  720         struct cf_setting *set;
  721         int i;
  722 
  723         CF_MTX_ASSERT(&sc->lock);
  724 
  725         /*
  726          * Walk the set of all existing levels in reverse.  This is so we
  727          * create derived states from the lowest absolute settings first
  728          * and discard duplicates created from higher absolute settings.
  729          * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
  730          * preferable to 200 Mhz + 25% because absolute settings are more
  731          * efficient since they often change the voltage as well.
  732          */
  733         TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
  734                 /* Add each setting to the level, duplicating if necessary. */
  735                 for (i = 0; i < set_arr->count; i++) {
  736                         set = &set_arr->sets[i];
  737 
  738                         /*
  739                          * If this setting is less than 100%, split the level
  740                          * into two and add this setting to the new level.
  741                          */
  742                         fill = search;
  743                         if (set->freq < 10000) {
  744                                 fill = cpufreq_dup_set(sc, search, set);
  745 
  746                                 /*
  747                                  * The new level was a duplicate of an existing
  748                                  * level or its absolute setting is too high
  749                                  * so we freed it.  For example, we discard a
  750                                  * derived level of 1000 MHz/25% if a level
  751                                  * of 500 MHz/100% already exists.
  752                                  */
  753                                 if (fill == NULL)
  754                                         break;
  755                         }
  756 
  757                         /* Add this setting to the existing or new level. */
  758                         KASSERT(fill->rel_count < MAX_SETTINGS,
  759                             ("cpufreq: too many relative drivers (%d)",
  760                             MAX_SETTINGS));
  761                         fill->rel_set[fill->rel_count] = *set;
  762                         fill->rel_count++;
  763                         CF_DEBUG(
  764                         "expand set added rel setting %d%% to %d level\n",
  765                             set->freq / 100, fill->total_set.freq);
  766                 }
  767         }
  768 
  769         return (0);
  770 }
  771 
  772 static struct cf_level *
  773 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
  774     struct cf_setting *set)
  775 {
  776         struct cf_level_lst *list;
  777         struct cf_level *fill, *itr;
  778         struct cf_setting *fill_set, *itr_set;
  779         int i;
  780 
  781         CF_MTX_ASSERT(&sc->lock);
  782 
  783         /*
  784          * Create a new level, copy it from the old one, and update the
  785          * total frequency and power by the percentage specified in the
  786          * relative setting.
  787          */
  788         fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
  789         if (fill == NULL)
  790                 return (NULL);
  791         *fill = *dup;
  792         fill_set = &fill->total_set;
  793         fill_set->freq =
  794             ((uint64_t)fill_set->freq * set->freq) / 10000;
  795         if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
  796                 fill_set->power = ((uint64_t)fill_set->power * set->freq)
  797                     / 10000;
  798         }
  799         if (set->lat != CPUFREQ_VAL_UNKNOWN) {
  800                 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
  801                         fill_set->lat += set->lat;
  802                 else
  803                         fill_set->lat = set->lat;
  804         }
  805         CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
  806 
  807         /*
  808          * If we copied an old level that we already modified (say, at 100%),
  809          * we need to remove that setting before adding this one.  Since we
  810          * process each setting array in order, we know any settings for this
  811          * driver will be found at the end.
  812          */
  813         for (i = fill->rel_count; i != 0; i--) {
  814                 if (fill->rel_set[i - 1].dev != set->dev)
  815                         break;
  816                 CF_DEBUG("removed last relative driver: %s\n",
  817                     device_get_nameunit(set->dev));
  818                 fill->rel_count--;
  819         }
  820 
  821         /*
  822          * Insert the new level in sorted order.  If it is a duplicate of an
  823          * existing level (1) or has an absolute setting higher than the
  824          * existing level (2), do not add it.  We can do this since any such
  825          * level is guaranteed use less power.  For example (1), a level with
  826          * one absolute setting of 800 Mhz uses less power than one composed
  827          * of an absolute setting of 1600 Mhz and a relative setting at 50%.
  828          * Also for example (2), a level of 800 Mhz/75% is preferable to
  829          * 1600 Mhz/25% even though the latter has a lower total frequency.
  830          */
  831         list = &sc->all_levels;
  832         KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
  833         TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
  834                 itr_set = &itr->total_set;
  835                 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
  836                         CF_DEBUG("dup set rejecting %d (dupe)\n",
  837                             fill_set->freq);
  838                         itr = NULL;
  839                         break;
  840                 } else if (fill_set->freq < itr_set->freq) {
  841                         if (fill->abs_set.freq <= itr->abs_set.freq) {
  842                                 CF_DEBUG(
  843                         "dup done, inserting new level %d after %d\n",
  844                                     fill_set->freq, itr_set->freq);
  845                                 TAILQ_INSERT_AFTER(list, itr, fill, link);
  846                                 sc->all_count++;
  847                         } else {
  848                                 CF_DEBUG("dup set rejecting %d (abs too big)\n",
  849                                     fill_set->freq);
  850                                 itr = NULL;
  851                         }
  852                         break;
  853                 }
  854         }
  855 
  856         /* We didn't find a good place for this new level so free it. */
  857         if (itr == NULL) {
  858                 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
  859                     fill_set->freq);
  860                 free(fill, M_TEMP);
  861                 fill = NULL;
  862         }
  863 
  864         return (fill);
  865 }
  866 
  867 static int
  868 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
  869 {
  870         struct cpufreq_softc *sc;
  871         struct cf_level *levels;
  872         int count, devcount, error, freq, i, n;
  873         device_t *devs;
  874 
  875         devs = NULL;
  876         sc = oidp->oid_arg1;
  877         levels = sc->levels_buf;
  878 
  879         error = CPUFREQ_GET(sc->dev, &levels[0]);
  880         if (error)
  881                 goto out;
  882         freq = levels[0].total_set.freq;
  883         error = sysctl_handle_int(oidp, &freq, 0, req);
  884         if (error != 0 || req->newptr == NULL)
  885                 goto out;
  886 
  887         /*
  888          * While we only call cpufreq_get() on one device (assuming all
  889          * CPUs have equal levels), we call cpufreq_set() on all CPUs.
  890          * This is needed for some MP systems.
  891          */
  892         error = devclass_get_devices(cpufreq_dc, &devs, &devcount);
  893         if (error)
  894                 goto out;
  895         for (n = 0; n < devcount; n++) {
  896                 count = CF_MAX_LEVELS;
  897                 error = CPUFREQ_LEVELS(devs[n], levels, &count);
  898                 if (error) {
  899                         if (error == E2BIG)
  900                                 printf(
  901                         "cpufreq: need to increase CF_MAX_LEVELS\n");
  902                         break;
  903                 }
  904                 for (i = 0; i < count; i++) {
  905                         if (CPUFREQ_CMP(levels[i].total_set.freq, freq)) {
  906                                 error = CPUFREQ_SET(devs[n], &levels[i],
  907                                     CPUFREQ_PRIO_USER);
  908                                 break;
  909                         }
  910                 }
  911                 if (i == count) {
  912                         error = EINVAL;
  913                         break;
  914                 }
  915         }
  916 
  917 out:
  918         if (devs)
  919                 free(devs, M_TEMP);
  920         return (error);
  921 }
  922 
  923 static int
  924 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
  925 {
  926         struct cpufreq_softc *sc;
  927         struct cf_level *levels;
  928         struct cf_setting *set;
  929         struct sbuf sb;
  930         int count, error, i;
  931 
  932         sc = oidp->oid_arg1;
  933         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
  934 
  935         /* Get settings from the device and generate the output string. */
  936         count = CF_MAX_LEVELS;
  937         levels = sc->levels_buf;
  938         if (levels == NULL) {
  939                 sbuf_delete(&sb);
  940                 return (ENOMEM);
  941         }
  942         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
  943         if (error) {
  944                 if (error == E2BIG)
  945                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
  946                 goto out;
  947         }
  948         if (count) {
  949                 for (i = 0; i < count; i++) {
  950                         set = &levels[i].total_set;
  951                         sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
  952                 }
  953         } else
  954                 sbuf_cpy(&sb, "");
  955         sbuf_trim(&sb);
  956         sbuf_finish(&sb);
  957         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
  958 
  959 out:
  960         sbuf_delete(&sb);
  961         return (error);
  962 }
  963 
  964 static int
  965 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
  966 {
  967         device_t dev;
  968         struct cf_setting *sets;
  969         struct sbuf sb;
  970         int error, i, set_count;
  971 
  972         dev = oidp->oid_arg1;
  973         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
  974 
  975         /* Get settings from the device and generate the output string. */
  976         set_count = MAX_SETTINGS;
  977         sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
  978         if (sets == NULL) {
  979                 sbuf_delete(&sb);
  980                 return (ENOMEM);
  981         }
  982         error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
  983         if (error)
  984                 goto out;
  985         if (set_count) {
  986                 for (i = 0; i < set_count; i++)
  987                         sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
  988         } else
  989                 sbuf_cpy(&sb, "");
  990         sbuf_trim(&sb);
  991         sbuf_finish(&sb);
  992         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
  993 
  994 out:
  995         free(sets, M_TEMP);
  996         sbuf_delete(&sb);
  997         return (error);
  998 }
  999 
 1000 int
 1001 cpufreq_register(device_t dev)
 1002 {
 1003         struct cpufreq_softc *sc;
 1004         device_t cf_dev, cpu_dev;
 1005 
 1006         /* Add a sysctl to get each driver's settings separately. */
 1007         SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
 1008             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
 1009             OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0,
 1010             cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
 1011 
 1012         /*
 1013          * Add only one cpufreq device to each CPU.  Currently, all CPUs
 1014          * must offer the same levels and be switched at the same time.
 1015          */
 1016         cpu_dev = device_get_parent(dev);
 1017         if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
 1018                 sc = device_get_softc(cf_dev);
 1019                 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
 1020                 return (0);
 1021         }
 1022 
 1023         /* Add the child device and possibly sysctls. */
 1024         cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1);
 1025         if (cf_dev == NULL)
 1026                 return (ENOMEM);
 1027         device_quiet(cf_dev);
 1028 
 1029         return (device_probe_and_attach(cf_dev));
 1030 }
 1031 
 1032 int
 1033 cpufreq_unregister(device_t dev)
 1034 {
 1035         device_t cf_dev, *devs;
 1036         int cfcount, devcount, error, i, type;
 1037 
 1038         /*
 1039          * If this is the last cpufreq child device, remove the control
 1040          * device as well.  We identify cpufreq children by calling a method
 1041          * they support.
 1042          */
 1043         error = device_get_children(device_get_parent(dev), &devs, &devcount);
 1044         if (error)
 1045                 return (error);
 1046         cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
 1047         if (cf_dev == NULL) {
 1048                 device_printf(dev,
 1049         "warning: cpufreq_unregister called with no cpufreq device active\n");
 1050                 return (0);
 1051         }
 1052         cfcount = 0;
 1053         for (i = 0; i < devcount; i++) {
 1054                 if (!device_is_attached(devs[i]))
 1055                         continue;
 1056                 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0)
 1057                         cfcount++;
 1058         }
 1059         if (cfcount <= 1)
 1060                 device_delete_child(device_get_parent(cf_dev), cf_dev);
 1061         free(devs, M_TEMP);
 1062 
 1063         return (0);
 1064 }
 1065 
 1066 int
 1067 cpufreq_settings_changed(device_t dev)
 1068 {
 1069 
 1070         EVENTHANDLER_INVOKE(cpufreq_levels_changed,
 1071             device_get_unit(device_get_parent(dev)));
 1072         return (0);
 1073 }

Cache object: 37ff0fd659bf6cbc43e88dc1ac81b921


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