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) 2004-2005 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/sched.h>
   41 #include <sys/sysctl.h>
   42 #include <sys/systm.h>
   43 #include <sys/sbuf.h>
   44 #include <sys/sx.h>
   45 #include <sys/timetc.h>
   46 
   47 #include "cpufreq_if.h"
   48 
   49 /*
   50  * Common CPU frequency glue code.  Drivers for specific hardware can
   51  * attach this interface to allow users to get/set the CPU frequency.
   52  */
   53 
   54 /*
   55  * Number of levels we can handle.  Levels are synthesized from settings
   56  * so for M settings and N drivers, there may be M*N levels.
   57  */
   58 #define CF_MAX_LEVELS   64
   59 
   60 struct cf_saved_freq {
   61         struct cf_level                 level;
   62         int                             priority;
   63         SLIST_ENTRY(cf_saved_freq)      link;
   64 };
   65 
   66 struct cpufreq_softc {
   67         struct sx                       lock;
   68         struct cf_level                 curr_level;
   69         int                             curr_priority;
   70         SLIST_HEAD(, cf_saved_freq)     saved_freq;
   71         struct cf_level_lst             all_levels;
   72         int                             all_count;
   73         int                             max_mhz;
   74         device_t                        dev;
   75         struct sysctl_ctx_list          sysctl_ctx;
   76 };
   77 
   78 struct cf_setting_array {
   79         struct cf_setting               sets[MAX_SETTINGS];
   80         int                             count;
   81         TAILQ_ENTRY(cf_setting_array)   link;
   82 };
   83 
   84 TAILQ_HEAD(cf_setting_lst, cf_setting_array);
   85 
   86 #define CF_MTX_INIT(x)          sx_init((x), "cpufreq lock")
   87 #define CF_MTX_LOCK(x)          sx_xlock((x))
   88 #define CF_MTX_UNLOCK(x)        sx_xunlock((x))
   89 #define CF_MTX_ASSERT(x)        sx_assert((x), SX_XLOCKED)
   90 
   91 #define CF_DEBUG(msg...)        do {            \
   92         if (cf_verbose)                         \
   93                 printf("cpufreq: " msg);        \
   94         } while (0)
   95 
   96 static int      cpufreq_attach(device_t dev);
   97 static int      cpufreq_detach(device_t dev);
   98 static void     cpufreq_evaluate(void *arg);
   99 static int      cf_set_method(device_t dev, const struct cf_level *level,
  100                     int priority);
  101 static int      cf_get_method(device_t dev, struct cf_level *level);
  102 static int      cf_levels_method(device_t dev, struct cf_level *levels,
  103                     int *count);
  104 static int      cpufreq_insert_abs(struct cpufreq_softc *sc,
  105                     struct cf_setting *sets, int count);
  106 static int      cpufreq_expand_set(struct cpufreq_softc *sc,
  107                     struct cf_setting_array *set_arr);
  108 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc,
  109                     struct cf_level *dup, struct cf_setting *set);
  110 static int      cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS);
  111 static int      cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS);
  112 static int      cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS);
  113 
  114 static device_method_t cpufreq_methods[] = {
  115         DEVMETHOD(device_probe,         bus_generic_probe),
  116         DEVMETHOD(device_attach,        cpufreq_attach),
  117         DEVMETHOD(device_detach,        cpufreq_detach),
  118 
  119         DEVMETHOD(cpufreq_set,          cf_set_method),
  120         DEVMETHOD(cpufreq_get,          cf_get_method),
  121         DEVMETHOD(cpufreq_levels,       cf_levels_method),
  122         {0, 0}
  123 };
  124 static driver_t cpufreq_driver = {
  125         "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc)
  126 };
  127 static devclass_t cpufreq_dc;
  128 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0);
  129 
  130 static eventhandler_tag cf_ev_tag;
  131 
  132 static int              cf_lowest_freq;
  133 static int              cf_verbose;
  134 TUNABLE_INT("debug.cpufreq.lowest", &cf_lowest_freq);
  135 TUNABLE_INT("debug.cpufreq.verbose", &cf_verbose);
  136 SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL, "cpufreq debugging");
  137 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 1,
  138     "Don't provide levels below this frequency.");
  139 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1,
  140     "Print verbose debugging messages");
  141 
  142 static int
  143 cpufreq_attach(device_t dev)
  144 {
  145         struct cpufreq_softc *sc;
  146         device_t parent;
  147         int numdevs;
  148 
  149         CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
  150         sc = device_get_softc(dev);
  151         parent = device_get_parent(dev);
  152         sc->dev = dev;
  153         sysctl_ctx_init(&sc->sysctl_ctx);
  154         TAILQ_INIT(&sc->all_levels);
  155         CF_MTX_INIT(&sc->lock);
  156         sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
  157         SLIST_INIT(&sc->saved_freq);
  158         sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
  159 
  160         /*
  161          * Only initialize one set of sysctls for all CPUs.  In the future,
  162          * if multiple CPUs can have different settings, we can move these
  163          * sysctls to be under every CPU instead of just the first one.
  164          */
  165         numdevs = devclass_get_count(cpufreq_dc);
  166         if (numdevs > 1)
  167                 return (0);
  168 
  169         CF_DEBUG("initializing one-time data for %s\n",
  170             device_get_nameunit(dev));
  171         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
  172             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
  173             OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
  174             cpufreq_curr_sysctl, "I", "Current CPU frequency");
  175         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
  176             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
  177             OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
  178             cpufreq_levels_sysctl, "A", "CPU frequency levels");
  179         cf_ev_tag = EVENTHANDLER_REGISTER(cpufreq_changed, cpufreq_evaluate,
  180             NULL, EVENTHANDLER_PRI_ANY);
  181 
  182         return (0);
  183 }
  184 
  185 static int
  186 cpufreq_detach(device_t dev)
  187 {
  188         struct cpufreq_softc *sc;
  189         struct cf_saved_freq *saved_freq;
  190         int numdevs;
  191 
  192         CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
  193         sc = device_get_softc(dev);
  194         sysctl_ctx_free(&sc->sysctl_ctx);
  195 
  196         while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) {
  197                 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
  198                 free(saved_freq, M_TEMP);
  199         }
  200 
  201         /* Only clean up these resources when the last device is detaching. */
  202         numdevs = devclass_get_count(cpufreq_dc);
  203         if (numdevs == 1) {
  204                 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev));
  205                 EVENTHANDLER_DEREGISTER(cpufreq_changed, cf_ev_tag);
  206         }
  207 
  208         return (0);
  209 }
  210 
  211 static void
  212 cpufreq_evaluate(void *arg)
  213 {
  214         /* TODO: Re-evaluate when notified of changes to drivers. */
  215 }
  216 
  217 static int
  218 cf_set_method(device_t dev, const struct cf_level *level, int priority)
  219 {
  220         struct cpufreq_softc *sc;
  221         const struct cf_setting *set;
  222         struct cf_saved_freq *saved_freq, *curr_freq;
  223         struct pcpu *pc;
  224         int error, i;
  225         static int once;
  226 
  227         sc = device_get_softc(dev);
  228         error = 0;
  229         set = NULL;
  230         saved_freq = NULL;
  231 
  232         /*
  233          * Check that the TSC isn't being used as a timecounter.
  234          * If it is, then return EBUSY and refuse to change the
  235          * clock speed.
  236          */
  237         if (strcmp(timecounter->tc_name, "TSC") == 0) {
  238                 if (!once) {
  239                         printf("cpufreq: frequency change with timecounter"
  240                                 " TSC not allowed, see cpufreq(4)\n");
  241                         once = 1;
  242                 }
  243                 return (EBUSY);
  244         }
  245 
  246         CF_MTX_LOCK(&sc->lock);
  247 
  248         /*
  249          * If the requested level has a lower priority, don't allow
  250          * the new level right now.
  251          */
  252         if (priority < sc->curr_priority) {
  253                 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority,
  254                     sc->curr_priority);
  255                 error = EPERM;
  256                 goto out;
  257         }
  258 
  259         /*
  260          * If the caller didn't specify a level and one is saved, prepare to
  261          * restore the saved level.  If none has been saved, return an error.
  262          */
  263         if (level == NULL) {
  264                 saved_freq = SLIST_FIRST(&sc->saved_freq);
  265                 if (saved_freq == NULL) {
  266                         CF_DEBUG("NULL level, no saved level\n");
  267                         error = ENXIO;
  268                         goto out;
  269                 }
  270                 level = &saved_freq->level;
  271                 priority = saved_freq->priority;
  272                 CF_DEBUG("restoring saved level, freq %d prio %d\n",
  273                     level->total_set.freq, priority);
  274         }
  275 
  276         /* Reject levels that are below our specified threshold. */
  277         if (level->total_set.freq < cf_lowest_freq) {
  278                 CF_DEBUG("rejecting freq %d, less than %d limit\n",
  279                     level->total_set.freq, cf_lowest_freq);
  280                 error = EINVAL;
  281                 goto out;
  282         }
  283 
  284         /* If already at this level, just return. */
  285         if (CPUFREQ_CMP(sc->curr_level.total_set.freq, level->total_set.freq)) {
  286                 CF_DEBUG("skipping freq %d, same as current level %d\n",
  287                     level->total_set.freq, sc->curr_level.total_set.freq);
  288                 goto skip;
  289         }
  290 
  291         /* First, set the absolute frequency via its driver. */
  292         set = &level->abs_set;
  293         if (set->dev) {
  294                 if (!device_is_attached(set->dev)) {
  295                         error = ENXIO;
  296                         goto out;
  297                 }
  298 
  299                 /* Bind to the target CPU before switching. */
  300                 pc = cpu_get_pcpu(set->dev);
  301                 mtx_lock_spin(&sched_lock);
  302                 sched_bind(curthread, pc->pc_cpuid);
  303                 mtx_unlock_spin(&sched_lock);
  304                 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
  305                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
  306                 error = CPUFREQ_DRV_SET(set->dev, set);
  307                 mtx_lock_spin(&sched_lock);
  308                 sched_unbind(curthread);
  309                 mtx_unlock_spin(&sched_lock);
  310                 if (error) {
  311                         goto out;
  312                 }
  313         }
  314 
  315         /* Next, set any/all relative frequencies via their drivers. */
  316         for (i = 0; i < level->rel_count; i++) {
  317                 set = &level->rel_set[i];
  318                 if (!device_is_attached(set->dev)) {
  319                         error = ENXIO;
  320                         goto out;
  321                 }
  322 
  323                 /* Bind to the target CPU before switching. */
  324                 pc = cpu_get_pcpu(set->dev);
  325                 mtx_lock_spin(&sched_lock);
  326                 sched_bind(curthread, pc->pc_cpuid);
  327                 mtx_unlock_spin(&sched_lock);
  328                 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
  329                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
  330                 error = CPUFREQ_DRV_SET(set->dev, set);
  331                 mtx_lock_spin(&sched_lock);
  332                 sched_unbind(curthread);
  333                 mtx_unlock_spin(&sched_lock);
  334                 if (error) {
  335                         /* XXX Back out any successful setting? */
  336                         goto out;
  337                 }
  338         }
  339 
  340 skip:
  341         /*
  342          * Before recording the current level, check if we're going to a
  343          * higher priority.  If so, save the previous level and priority.
  344          */
  345         if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
  346             priority > sc->curr_priority) {
  347                 CF_DEBUG("saving level, freq %d prio %d\n",
  348                     sc->curr_level.total_set.freq, sc->curr_priority);
  349                 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT);
  350                 if (curr_freq == NULL) {
  351                         error = ENOMEM;
  352                         goto out;
  353                 }
  354                 curr_freq->level = sc->curr_level;
  355                 curr_freq->priority = sc->curr_priority;
  356                 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link);
  357         }
  358         sc->curr_level = *level;
  359         sc->curr_priority = priority;
  360 
  361         /* If we were restoring a saved state, reset it to "unused". */
  362         if (saved_freq != NULL) {
  363                 CF_DEBUG("resetting saved level\n");
  364                 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
  365                 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
  366                 free(saved_freq, M_TEMP);
  367         }
  368 
  369 out:
  370         CF_MTX_UNLOCK(&sc->lock);
  371         if (error && set)
  372                 device_printf(set->dev, "set freq failed, err %d\n", error);
  373         return (error);
  374 }
  375 
  376 static int
  377 cf_get_method(device_t dev, struct cf_level *level)
  378 {
  379         struct cpufreq_softc *sc;
  380         struct cf_level *levels;
  381         struct cf_setting *curr_set, set;
  382         struct pcpu *pc;
  383         device_t *devs;
  384         int count, error, i, n, numdevs;
  385         uint64_t rate;
  386 
  387         sc = device_get_softc(dev);
  388         error = 0;
  389         levels = NULL;
  390 
  391         /* If we already know the current frequency, we're done. */
  392         CF_MTX_LOCK(&sc->lock);
  393         curr_set = &sc->curr_level.total_set;
  394         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
  395                 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
  396                 goto out;
  397         }
  398         CF_MTX_UNLOCK(&sc->lock);
  399 
  400         /*
  401          * We need to figure out the current level.  Loop through every
  402          * driver, getting the current setting.  Then, attempt to get a best
  403          * match of settings against each level.
  404          */
  405         count = CF_MAX_LEVELS;
  406         levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
  407         if (levels == NULL)
  408                 return (ENOMEM);
  409         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
  410         if (error) {
  411                 if (error == E2BIG)
  412                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
  413                 free(levels, M_TEMP);
  414                 return (error);
  415         }
  416         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
  417         if (error) {
  418                 free(levels, M_TEMP);
  419                 return (error);
  420         }
  421 
  422         /*
  423          * Reacquire the lock and search for the given level.
  424          *
  425          * XXX Note: this is not quite right since we really need to go
  426          * through each level and compare both absolute and relative
  427          * settings for each driver in the system before making a match.
  428          * The estimation code below catches this case though.
  429          */
  430         CF_MTX_LOCK(&sc->lock);
  431         for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) {
  432                 if (!device_is_attached(devs[n]))
  433                         continue;
  434                 if (CPUFREQ_DRV_GET(devs[n], &set) != 0)
  435                         continue;
  436                 for (i = 0; i < count; i++) {
  437                         if (CPUFREQ_CMP(set.freq, levels[i].total_set.freq)) {
  438                                 sc->curr_level = levels[i];
  439                                 break;
  440                         }
  441                 }
  442         }
  443         free(devs, M_TEMP);
  444         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
  445                 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
  446                 goto out;
  447         }
  448 
  449         /*
  450          * We couldn't find an exact match, so attempt to estimate and then
  451          * match against a level.
  452          */
  453         pc = cpu_get_pcpu(dev);
  454         if (pc == NULL) {
  455                 error = ENXIO;
  456                 goto out;
  457         }
  458         cpu_est_clockrate(pc->pc_cpuid, &rate);
  459         rate /= 1000000;
  460         for (i = 0; i < count; i++) {
  461                 if (CPUFREQ_CMP(rate, levels[i].total_set.freq)) {
  462                         sc->curr_level = levels[i];
  463                         CF_DEBUG("get estimated freq %d\n", curr_set->freq);
  464                         goto out;
  465                 }
  466         }
  467         error = ENXIO;
  468 
  469 out:
  470         if (error == 0)
  471                 *level = sc->curr_level;
  472 
  473         CF_MTX_UNLOCK(&sc->lock);
  474         if (levels)
  475                 free(levels, M_TEMP);
  476         return (error);
  477 }
  478 
  479 static int
  480 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
  481 {
  482         struct cf_setting_array *set_arr;
  483         struct cf_setting_lst rel_sets;
  484         struct cpufreq_softc *sc;
  485         struct cf_level *lev;
  486         struct cf_setting *sets;
  487         struct pcpu *pc;
  488         device_t *devs;
  489         int error, i, numdevs, set_count, type;
  490         uint64_t rate;
  491 
  492         if (levels == NULL || count == NULL)
  493                 return (EINVAL);
  494 
  495         TAILQ_INIT(&rel_sets);
  496         sc = device_get_softc(dev);
  497         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
  498         if (error)
  499                 return (error);
  500         sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
  501         if (sets == NULL) {
  502                 free(devs, M_TEMP);
  503                 return (ENOMEM);
  504         }
  505 
  506         /* Get settings from all cpufreq drivers. */
  507         CF_MTX_LOCK(&sc->lock);
  508         for (i = 0; i < numdevs; i++) {
  509                 /* Skip devices that aren't ready. */
  510                 if (!device_is_attached(devs[i]))
  511                         continue;
  512 
  513                 /*
  514                  * Get settings, skipping drivers that offer no settings or
  515                  * provide settings for informational purposes only.
  516                  */
  517                 error = CPUFREQ_DRV_TYPE(devs[i], &type);
  518                 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) {
  519                         if (error == 0) {
  520                                 CF_DEBUG("skipping info-only driver %s\n",
  521                                     device_get_nameunit(devs[i]));
  522                         }
  523                         continue;
  524                 }
  525                 set_count = MAX_SETTINGS;
  526                 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count);
  527                 if (error || set_count == 0)
  528                         continue;
  529 
  530                 /* Add the settings to our absolute/relative lists. */
  531                 switch (type & CPUFREQ_TYPE_MASK) {
  532                 case CPUFREQ_TYPE_ABSOLUTE:
  533                         error = cpufreq_insert_abs(sc, sets, set_count);
  534                         break;
  535                 case CPUFREQ_TYPE_RELATIVE:
  536                         CF_DEBUG("adding %d relative settings\n", set_count);
  537                         set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
  538                         if (set_arr == NULL) {
  539                                 error = ENOMEM;
  540                                 goto out;
  541                         }
  542                         bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
  543                         set_arr->count = set_count;
  544                         TAILQ_INSERT_TAIL(&rel_sets, set_arr, link);
  545                         break;
  546                 default:
  547                         error = EINVAL;
  548                 }
  549                 if (error)
  550                         goto out;
  551         }
  552 
  553         /*
  554          * If there are no absolute levels, create a fake one at 100%.  We
  555          * then cache the clockrate for later use as our base frequency.
  556          *
  557          * XXX This assumes that the first time through, if we only have
  558          * relative drivers, the CPU is currently running at 100%.
  559          */
  560         if (TAILQ_EMPTY(&sc->all_levels)) {
  561                 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
  562                         pc = cpu_get_pcpu(dev);
  563                         cpu_est_clockrate(pc->pc_cpuid, &rate);
  564                         sc->max_mhz = rate / 1000000;
  565                 }
  566                 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets));
  567                 sets[0].freq = sc->max_mhz;
  568                 sets[0].dev = NULL;
  569                 error = cpufreq_insert_abs(sc, sets, 1);
  570                 if (error)
  571                         goto out;
  572         }
  573 
  574         /* Create a combined list of absolute + relative levels. */
  575         TAILQ_FOREACH(set_arr, &rel_sets, link)
  576                 cpufreq_expand_set(sc, set_arr);
  577 
  578         /* If the caller doesn't have enough space, return the actual count. */
  579         if (sc->all_count > *count) {
  580                 *count = sc->all_count;
  581                 error = E2BIG;
  582                 goto out;
  583         }
  584 
  585         /* Finally, output the list of levels. */
  586         i = 0;
  587         TAILQ_FOREACH(lev, &sc->all_levels, link) {
  588                 /* Skip levels that have a frequency that is too low. */
  589                 if (lev->total_set.freq < cf_lowest_freq) {
  590                         sc->all_count--;
  591                         continue;
  592                 }
  593 
  594                 levels[i] = *lev;
  595                 i++;
  596         }
  597         *count = sc->all_count;
  598         error = 0;
  599 
  600 out:
  601         /* Clear all levels since we regenerate them each time. */
  602         while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
  603                 TAILQ_REMOVE(&sc->all_levels, lev, link);
  604                 free(lev, M_TEMP);
  605         }
  606         sc->all_count = 0;
  607 
  608         CF_MTX_UNLOCK(&sc->lock);
  609         while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
  610                 TAILQ_REMOVE(&rel_sets, set_arr, link);
  611                 free(set_arr, M_TEMP);
  612         }
  613         free(devs, M_TEMP);
  614         free(sets, M_TEMP);
  615         return (error);
  616 }
  617 
  618 /*
  619  * Create levels for an array of absolute settings and insert them in
  620  * sorted order in the specified list.
  621  */
  622 static int
  623 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
  624     int count)
  625 {
  626         struct cf_level_lst *list;
  627         struct cf_level *level, *search;
  628         int i;
  629 
  630         CF_MTX_ASSERT(&sc->lock);
  631 
  632         list = &sc->all_levels;
  633         for (i = 0; i < count; i++) {
  634                 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
  635                 if (level == NULL)
  636                         return (ENOMEM);
  637                 level->abs_set = sets[i];
  638                 level->total_set = sets[i];
  639                 level->total_set.dev = NULL;
  640                 sc->all_count++;
  641 
  642                 if (TAILQ_EMPTY(list)) {
  643                         CF_DEBUG("adding abs setting %d at head\n",
  644                             sets[i].freq);
  645                         TAILQ_INSERT_HEAD(list, level, link);
  646                         continue;
  647                 }
  648 
  649                 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) {
  650                         if (sets[i].freq <= search->total_set.freq) {
  651                                 CF_DEBUG("adding abs setting %d after %d\n",
  652                                     sets[i].freq, search->total_set.freq);
  653                                 TAILQ_INSERT_AFTER(list, search, level, link);
  654                                 break;
  655                         }
  656                 }
  657         }
  658         return (0);
  659 }
  660 
  661 /*
  662  * Expand a group of relative settings, creating derived levels from them.
  663  */
  664 static int
  665 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
  666 {
  667         struct cf_level *fill, *search;
  668         struct cf_setting *set;
  669         int i;
  670 
  671         CF_MTX_ASSERT(&sc->lock);
  672 
  673         /*
  674          * Walk the set of all existing levels in reverse.  This is so we
  675          * create derived states from the lowest absolute settings first
  676          * and discard duplicates created from higher absolute settings.
  677          * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
  678          * preferable to 200 Mhz + 25% because absolute settings are more
  679          * efficient since they often change the voltage as well.
  680          */
  681         TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
  682                 /* Add each setting to the level, duplicating if necessary. */
  683                 for (i = 0; i < set_arr->count; i++) {
  684                         set = &set_arr->sets[i];
  685 
  686                         /*
  687                          * If this setting is less than 100%, split the level
  688                          * into two and add this setting to the new level.
  689                          */
  690                         fill = search;
  691                         if (set->freq < 10000) {
  692                                 fill = cpufreq_dup_set(sc, search, set);
  693 
  694                                 /*
  695                                  * The new level was a duplicate of an existing
  696                                  * level or its absolute setting is too high
  697                                  * so we freed it.  For example, we discard a
  698                                  * derived level of 1000 MHz/25% if a level
  699                                  * of 500 MHz/100% already exists.
  700                                  */
  701                                 if (fill == NULL)
  702                                         break;
  703                         }
  704 
  705                         /* Add this setting to the existing or new level. */
  706                         KASSERT(fill->rel_count < MAX_SETTINGS,
  707                             ("cpufreq: too many relative drivers (%d)",
  708                             MAX_SETTINGS));
  709                         fill->rel_set[fill->rel_count] = *set;
  710                         fill->rel_count++;
  711                         CF_DEBUG(
  712                         "expand set added rel setting %d%% to %d level\n",
  713                             set->freq / 100, fill->total_set.freq);
  714                 }
  715         }
  716 
  717         return (0);
  718 }
  719 
  720 static struct cf_level *
  721 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
  722     struct cf_setting *set)
  723 {
  724         struct cf_level_lst *list;
  725         struct cf_level *fill, *itr;
  726         struct cf_setting *fill_set, *itr_set;
  727         int i;
  728 
  729         CF_MTX_ASSERT(&sc->lock);
  730 
  731         /*
  732          * Create a new level, copy it from the old one, and update the
  733          * total frequency and power by the percentage specified in the
  734          * relative setting.
  735          */
  736         fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
  737         if (fill == NULL)
  738                 return (NULL);
  739         *fill = *dup;
  740         fill_set = &fill->total_set;
  741         fill_set->freq =
  742             ((uint64_t)fill_set->freq * set->freq) / 10000;
  743         if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
  744                 fill_set->power = ((uint64_t)fill_set->power * set->freq)
  745                     / 10000;
  746         }
  747         if (set->lat != CPUFREQ_VAL_UNKNOWN) {
  748                 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
  749                         fill_set->lat += set->lat;
  750                 else
  751                         fill_set->lat = set->lat;
  752         }
  753         CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
  754 
  755         /*
  756          * If we copied an old level that we already modified (say, at 100%),
  757          * we need to remove that setting before adding this one.  Since we
  758          * process each setting array in order, we know any settings for this
  759          * driver will be found at the end.
  760          */
  761         for (i = fill->rel_count; i != 0; i--) {
  762                 if (fill->rel_set[i - 1].dev != set->dev)
  763                         break;
  764                 CF_DEBUG("removed last relative driver: %s\n",
  765                     device_get_nameunit(set->dev));
  766                 fill->rel_count--;
  767         }
  768 
  769         /*
  770          * Insert the new level in sorted order.  If it is a duplicate of an
  771          * existing level (1) or has an absolute setting higher than the
  772          * existing level (2), do not add it.  We can do this since any such
  773          * level is guaranteed use less power.  For example (1), a level with
  774          * one absolute setting of 800 Mhz uses less power than one composed
  775          * of an absolute setting of 1600 Mhz and a relative setting at 50%.
  776          * Also for example (2), a level of 800 Mhz/75% is preferable to
  777          * 1600 Mhz/25% even though the latter has a lower total frequency.
  778          */
  779         list = &sc->all_levels;
  780         KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
  781         TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
  782                 itr_set = &itr->total_set;
  783                 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
  784                         CF_DEBUG("dup set rejecting %d (dupe)\n",
  785                             fill_set->freq);
  786                         itr = NULL;
  787                         break;
  788                 } else if (fill_set->freq < itr_set->freq) {
  789                         if (fill->abs_set.freq <= itr->abs_set.freq) {
  790                                 CF_DEBUG(
  791                         "dup done, inserting new level %d after %d\n",
  792                                     fill_set->freq, itr_set->freq);
  793                                 TAILQ_INSERT_AFTER(list, itr, fill, link);
  794                                 sc->all_count++;
  795                         } else {
  796                                 CF_DEBUG("dup set rejecting %d (abs too big)\n",
  797                                     fill_set->freq);
  798                                 itr = NULL;
  799                         }
  800                         break;
  801                 }
  802         }
  803 
  804         /* We didn't find a good place for this new level so free it. */
  805         if (itr == NULL) {
  806                 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
  807                     fill_set->freq);
  808                 free(fill, M_TEMP);
  809                 fill = NULL;
  810         }
  811 
  812         return (fill);
  813 }
  814 
  815 static int
  816 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
  817 {
  818         struct cpufreq_softc *sc;
  819         struct cf_level *levels;
  820         int count, devcount, error, freq, i, n;
  821         device_t *devs;
  822 
  823         devs = NULL;
  824         sc = oidp->oid_arg1;
  825         levels = malloc(CF_MAX_LEVELS * sizeof(*levels), M_TEMP, M_NOWAIT);
  826         if (levels == NULL)
  827                 return (ENOMEM);
  828 
  829         error = CPUFREQ_GET(sc->dev, &levels[0]);
  830         if (error)
  831                 goto out;
  832         freq = levels[0].total_set.freq;
  833         error = sysctl_handle_int(oidp, &freq, 0, req);
  834         if (error != 0 || req->newptr == NULL)
  835                 goto out;
  836 
  837         /*
  838          * While we only call cpufreq_get() on one device (assuming all
  839          * CPUs have equal levels), we call cpufreq_set() on all CPUs.
  840          * This is needed for some MP systems.
  841          */
  842         error = devclass_get_devices(cpufreq_dc, &devs, &devcount);
  843         if (error)
  844                 goto out;
  845         for (n = 0; n < devcount; n++) {
  846                 count = CF_MAX_LEVELS;
  847                 error = CPUFREQ_LEVELS(devs[n], levels, &count);
  848                 if (error) {
  849                         if (error == E2BIG)
  850                                 printf(
  851                         "cpufreq: need to increase CF_MAX_LEVELS\n");
  852                         break;
  853                 }
  854                 for (i = 0; i < count; i++) {
  855                         if (CPUFREQ_CMP(levels[i].total_set.freq, freq)) {
  856                                 error = CPUFREQ_SET(devs[n], &levels[i],
  857                                     CPUFREQ_PRIO_USER);
  858                                 break;
  859                         }
  860                 }
  861                 if (i == count) {
  862                         error = EINVAL;
  863                         break;
  864                 }
  865         }
  866 
  867 out:
  868         if (devs)
  869                 free(devs, M_TEMP);
  870         if (levels)
  871                 free(levels, M_TEMP);
  872         return (error);
  873 }
  874 
  875 static int
  876 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
  877 {
  878         struct cpufreq_softc *sc;
  879         struct cf_level *levels;
  880         struct cf_setting *set;
  881         struct sbuf sb;
  882         int count, error, i;
  883 
  884         sc = oidp->oid_arg1;
  885         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
  886 
  887         /* Get settings from the device and generate the output string. */
  888         count = CF_MAX_LEVELS;
  889         levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
  890         if (levels == NULL)
  891                 return (ENOMEM);
  892         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
  893         if (error) {
  894                 if (error == E2BIG)
  895                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
  896                 goto out;
  897         }
  898         if (count) {
  899                 for (i = 0; i < count; i++) {
  900                         set = &levels[i].total_set;
  901                         sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
  902                 }
  903         } else
  904                 sbuf_cpy(&sb, "");
  905         sbuf_trim(&sb);
  906         sbuf_finish(&sb);
  907         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
  908 
  909 out:
  910         free(levels, M_TEMP);
  911         sbuf_delete(&sb);
  912         return (error);
  913 }
  914 
  915 static int
  916 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
  917 {
  918         device_t dev;
  919         struct cf_setting *sets;
  920         struct sbuf sb;
  921         int error, i, set_count;
  922 
  923         dev = oidp->oid_arg1;
  924         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
  925 
  926         /* Get settings from the device and generate the output string. */
  927         set_count = MAX_SETTINGS;
  928         sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
  929         if (sets == NULL)
  930                 return (ENOMEM);
  931         error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
  932         if (error)
  933                 goto out;
  934         if (set_count) {
  935                 for (i = 0; i < set_count; i++)
  936                         sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
  937         } else
  938                 sbuf_cpy(&sb, "");
  939         sbuf_trim(&sb);
  940         sbuf_finish(&sb);
  941         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
  942 
  943 out:
  944         free(sets, M_TEMP);
  945         sbuf_delete(&sb);
  946         return (error);
  947 }
  948 
  949 int
  950 cpufreq_register(device_t dev)
  951 {
  952         struct cpufreq_softc *sc;
  953         device_t cf_dev, cpu_dev;
  954 
  955         /* Add a sysctl to get each driver's settings separately. */
  956         SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
  957             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
  958             OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0,
  959             cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
  960 
  961         /*
  962          * Add only one cpufreq device to each CPU.  Currently, all CPUs
  963          * must offer the same levels and be switched at the same time.
  964          */
  965         cpu_dev = device_get_parent(dev);
  966         if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
  967                 sc = device_get_softc(cf_dev);
  968                 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
  969                 return (0);
  970         }
  971 
  972         /* Add the child device and possibly sysctls. */
  973         cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1);
  974         if (cf_dev == NULL)
  975                 return (ENOMEM);
  976         device_quiet(cf_dev);
  977 
  978         return (device_probe_and_attach(cf_dev));
  979 }
  980 
  981 int
  982 cpufreq_unregister(device_t dev)
  983 {
  984         device_t cf_dev, *devs;
  985         int cfcount, devcount, error, i, type;
  986 
  987         /*
  988          * If this is the last cpufreq child device, remove the control
  989          * device as well.  We identify cpufreq children by calling a method
  990          * they support.
  991          */
  992         error = device_get_children(device_get_parent(dev), &devs, &devcount);
  993         if (error)
  994                 return (error);
  995         cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
  996         if (cf_dev == NULL) {
  997                 device_printf(dev,
  998         "warning: cpufreq_unregister called with no cpufreq device active\n");
  999                 return (0);
 1000         }
 1001         cfcount = 0;
 1002         for (i = 0; i < devcount; i++) {
 1003                 if (!device_is_attached(devs[i]))
 1004                         continue;
 1005                 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0)
 1006                         cfcount++;
 1007         }
 1008         if (cfcount <= 1)
 1009                 device_delete_child(device_get_parent(cf_dev), cf_dev);
 1010         free(devs, M_TEMP);
 1011 
 1012         return (0);
 1013 }

Cache object: 92e913579f7be3523cabc8efa4f3559f


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