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: releng/6.0/sys/kern/kern_cpu.c 149821 2005-09-06 18:01:44Z njl $");
   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 cpufreq_softc {
   61         struct sx                       lock;
   62         struct cf_level                 curr_level;
   63         int                             curr_priority;
   64         struct cf_level                 saved_level;
   65         int                             saved_priority;
   66         struct cf_level_lst             all_levels;
   67         int                             all_count;
   68         int                             max_mhz;
   69         device_t                        dev;
   70         struct sysctl_ctx_list          sysctl_ctx;
   71 };
   72 
   73 struct cf_setting_array {
   74         struct cf_setting               sets[MAX_SETTINGS];
   75         int                             count;
   76         TAILQ_ENTRY(cf_setting_array)   link;
   77 };
   78 
   79 TAILQ_HEAD(cf_setting_lst, cf_setting_array);
   80 
   81 #define CF_MTX_INIT(x)          sx_init((x), "cpufreq lock")
   82 #define CF_MTX_LOCK(x)          sx_xlock((x))
   83 #define CF_MTX_UNLOCK(x)        sx_xunlock((x))
   84 #define CF_MTX_ASSERT(x)        sx_assert((x), SX_XLOCKED)
   85 
   86 #define CF_DEBUG(msg...)        do {            \
   87         if (cf_verbose)                         \
   88                 printf("cpufreq: " msg);        \
   89         } while (0)
   90 
   91 static int      cpufreq_attach(device_t dev);
   92 static int      cpufreq_detach(device_t dev);
   93 static void     cpufreq_evaluate(void *arg);
   94 static int      cf_set_method(device_t dev, const struct cf_level *level,
   95                     int priority);
   96 static int      cf_get_method(device_t dev, struct cf_level *level);
   97 static int      cf_levels_method(device_t dev, struct cf_level *levels,
   98                     int *count);
   99 static int      cpufreq_insert_abs(struct cpufreq_softc *sc,
  100                     struct cf_setting *sets, int count);
  101 static int      cpufreq_expand_set(struct cpufreq_softc *sc,
  102                     struct cf_setting_array *set_arr);
  103 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc,
  104                     struct cf_level *dup, struct cf_setting *set);
  105 static int      cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS);
  106 static int      cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS);
  107 static int      cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS);
  108 
  109 static device_method_t cpufreq_methods[] = {
  110         DEVMETHOD(device_probe,         bus_generic_probe),
  111         DEVMETHOD(device_attach,        cpufreq_attach),
  112         DEVMETHOD(device_detach,        cpufreq_detach),
  113 
  114         DEVMETHOD(cpufreq_set,          cf_set_method),
  115         DEVMETHOD(cpufreq_get,          cf_get_method),
  116         DEVMETHOD(cpufreq_levels,       cf_levels_method),
  117         {0, 0}
  118 };
  119 static driver_t cpufreq_driver = {
  120         "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc)
  121 };
  122 static devclass_t cpufreq_dc;
  123 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0);
  124 
  125 static eventhandler_tag cf_ev_tag;
  126 
  127 static int              cf_lowest_freq;
  128 static int              cf_verbose;
  129 TUNABLE_INT("debug.cpufreq.lowest", &cf_lowest_freq);
  130 TUNABLE_INT("debug.cpufreq.verbose", &cf_verbose);
  131 SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL, "cpufreq debugging");
  132 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 1,
  133     "Don't provide levels below this frequency.");
  134 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1,
  135     "Print verbose debugging messages");
  136 
  137 static int
  138 cpufreq_attach(device_t dev)
  139 {
  140         struct cpufreq_softc *sc;
  141         device_t parent;
  142         int numdevs;
  143 
  144         CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
  145         sc = device_get_softc(dev);
  146         parent = device_get_parent(dev);
  147         sc->dev = dev;
  148         sysctl_ctx_init(&sc->sysctl_ctx);
  149         TAILQ_INIT(&sc->all_levels);
  150         CF_MTX_INIT(&sc->lock);
  151         sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
  152         sc->saved_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
  153         sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
  154 
  155         /*
  156          * Only initialize one set of sysctls for all CPUs.  In the future,
  157          * if multiple CPUs can have different settings, we can move these
  158          * sysctls to be under every CPU instead of just the first one.
  159          */
  160         numdevs = devclass_get_count(cpufreq_dc);
  161         if (numdevs > 1)
  162                 return (0);
  163 
  164         CF_DEBUG("initializing one-time data for %s\n",
  165             device_get_nameunit(dev));
  166         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
  167             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
  168             OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
  169             cpufreq_curr_sysctl, "I", "Current CPU frequency");
  170         SYSCTL_ADD_PROC(&sc->sysctl_ctx,
  171             SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
  172             OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
  173             cpufreq_levels_sysctl, "A", "CPU frequency levels");
  174         cf_ev_tag = EVENTHANDLER_REGISTER(cpufreq_changed, cpufreq_evaluate,
  175             NULL, EVENTHANDLER_PRI_ANY);
  176 
  177         return (0);
  178 }
  179 
  180 static int
  181 cpufreq_detach(device_t dev)
  182 {
  183         struct cpufreq_softc *sc;
  184         int numdevs;
  185 
  186         CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
  187         sc = device_get_softc(dev);
  188         sysctl_ctx_free(&sc->sysctl_ctx);
  189 
  190         /* Only clean up these resources when the last device is detaching. */
  191         numdevs = devclass_get_count(cpufreq_dc);
  192         if (numdevs == 1) {
  193                 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev));
  194                 EVENTHANDLER_DEREGISTER(cpufreq_changed, cf_ev_tag);
  195         }
  196 
  197         return (0);
  198 }
  199 
  200 static void
  201 cpufreq_evaluate(void *arg)
  202 {
  203         /* TODO: Re-evaluate when notified of changes to drivers. */
  204 }
  205 
  206 static int
  207 cf_set_method(device_t dev, const struct cf_level *level, int priority)
  208 {
  209         struct cpufreq_softc *sc;
  210         const struct cf_setting *set;
  211         struct pcpu *pc;
  212         int cpu_id, error, i;
  213 
  214         sc = device_get_softc(dev);
  215         error = 0;
  216         set = NULL;
  217 
  218         /*
  219          * Check that the TSC isn't being used as a timecounter.
  220          * If it is, then return EBUSY and refuse to change the
  221          * clock speed.
  222          */
  223         if (strcmp(timecounter->tc_name, "TSC") == 0)
  224                 return (EBUSY);
  225 
  226         /*
  227          * If the caller didn't specify a level and one is saved, prepare to
  228          * restore the saved level.  If none has been saved, return an error.
  229          * If they did specify one, but the requested level has a lower
  230          * priority, don't allow the new level right now.
  231          */
  232         CF_MTX_LOCK(&sc->lock);
  233         if (level == NULL) {
  234                 if (sc->saved_level.total_set.freq != CPUFREQ_VAL_UNKNOWN) {
  235                         level = &sc->saved_level;
  236                         priority = sc->saved_priority;
  237                         CF_DEBUG("restoring saved level, freq %d prio %d\n",
  238                             level->total_set.freq, priority);
  239                 } else {
  240                         CF_DEBUG("NULL level, no saved level\n");
  241                         error = ENXIO;
  242                         goto out;
  243                 }
  244         } else if (priority < sc->curr_priority) {
  245                 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority,
  246                     sc->curr_priority);
  247                 error = EPERM;
  248                 goto out;
  249         }
  250 
  251         /* Reject levels that are below our specified threshold. */
  252         if (level->total_set.freq < cf_lowest_freq) {
  253                 CF_DEBUG("rejecting freq %d, less than %d limit\n",
  254                     level->total_set.freq, cf_lowest_freq);
  255                 error = EINVAL;
  256                 goto out;
  257         }
  258 
  259         /* If already at this level, just return. */
  260         if (CPUFREQ_CMP(sc->curr_level.total_set.freq, level->total_set.freq)) {
  261                 CF_DEBUG("skipping freq %d, same as current level %d\n",
  262                     level->total_set.freq, sc->curr_level.total_set.freq);
  263                 goto out;
  264         }
  265 
  266         /* First, set the absolute frequency via its driver. */
  267         set = &level->abs_set;
  268         if (set->dev) {
  269                 if (!device_is_attached(set->dev)) {
  270                         error = ENXIO;
  271                         goto out;
  272                 }
  273 
  274                 /* Bind to the target CPU before switching, if necessary. */
  275                 cpu_id = PCPU_GET(cpuid);
  276                 pc = cpu_get_pcpu(set->dev);
  277                 if (cpu_id != pc->pc_cpuid) {
  278                         mtx_lock_spin(&sched_lock);
  279                         sched_bind(curthread, pc->pc_cpuid);
  280                         mtx_unlock_spin(&sched_lock);
  281                 }
  282                 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
  283                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
  284                 error = CPUFREQ_DRV_SET(set->dev, set);
  285                 if (cpu_id != pc->pc_cpuid) {
  286                         mtx_lock_spin(&sched_lock);
  287                         sched_unbind(curthread);
  288                         mtx_unlock_spin(&sched_lock);
  289                 }
  290                 if (error) {
  291                         goto out;
  292                 }
  293         }
  294 
  295         /* Next, set any/all relative frequencies via their drivers. */
  296         for (i = 0; i < level->rel_count; i++) {
  297                 set = &level->rel_set[i];
  298                 if (!device_is_attached(set->dev)) {
  299                         error = ENXIO;
  300                         goto out;
  301                 }
  302 
  303                 /* Bind to the target CPU before switching, if necessary. */
  304                 cpu_id = PCPU_GET(cpuid);
  305                 pc = cpu_get_pcpu(set->dev);
  306                 if (cpu_id != pc->pc_cpuid) {
  307                         mtx_lock_spin(&sched_lock);
  308                         sched_bind(curthread, pc->pc_cpuid);
  309                         mtx_unlock_spin(&sched_lock);
  310                 }
  311                 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
  312                     device_get_nameunit(set->dev), PCPU_GET(cpuid));
  313                 error = CPUFREQ_DRV_SET(set->dev, set);
  314                 if (cpu_id != pc->pc_cpuid) {
  315                         mtx_lock_spin(&sched_lock);
  316                         sched_unbind(curthread);
  317                         mtx_unlock_spin(&sched_lock);
  318                 }
  319                 if (error) {
  320                         /* XXX Back out any successful setting? */
  321                         goto out;
  322                 }
  323         }
  324 
  325         /* If we were restoring a saved state, reset it to "unused". */
  326         if (level == &sc->saved_level) {
  327                 CF_DEBUG("resetting saved level\n");
  328                 sc->saved_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
  329                 sc->saved_priority = 0;
  330         }
  331 
  332         /*
  333          * Before recording the current level, check if we're going to a
  334          * higher priority and have not saved a level yet.  If so, save the
  335          * previous level and priority.
  336          */
  337         if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
  338             sc->saved_level.total_set.freq == CPUFREQ_VAL_UNKNOWN &&
  339             priority > sc->curr_priority) {
  340                 CF_DEBUG("saving level, freq %d prio %d\n",
  341                     sc->curr_level.total_set.freq, sc->curr_priority);
  342                 sc->saved_level = sc->curr_level;
  343                 sc->saved_priority = sc->curr_priority;
  344         }
  345         sc->curr_level = *level;
  346         sc->curr_priority = priority;
  347         error = 0;
  348 
  349 out:
  350         CF_MTX_UNLOCK(&sc->lock);
  351         if (error && set)
  352                 device_printf(set->dev, "set freq failed, err %d\n", error);
  353         return (error);
  354 }
  355 
  356 static int
  357 cf_get_method(device_t dev, struct cf_level *level)
  358 {
  359         struct cpufreq_softc *sc;
  360         struct cf_level *levels;
  361         struct cf_setting *curr_set, set;
  362         struct pcpu *pc;
  363         device_t *devs;
  364         int count, error, i, numdevs;
  365         uint64_t rate;
  366 
  367         sc = device_get_softc(dev);
  368         error = 0;
  369         levels = NULL;
  370 
  371         /* If we already know the current frequency, we're done. */
  372         CF_MTX_LOCK(&sc->lock);
  373         curr_set = &sc->curr_level.total_set;
  374         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
  375                 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
  376                 goto out;
  377         }
  378         CF_MTX_UNLOCK(&sc->lock);
  379 
  380         /*
  381          * We need to figure out the current level.  Loop through every
  382          * driver, getting the current setting.  Then, attempt to get a best
  383          * match of settings against each level.
  384          */
  385         count = CF_MAX_LEVELS;
  386         levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
  387         if (levels == NULL)
  388                 return (ENOMEM);
  389         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
  390         if (error) {
  391                 if (error == E2BIG)
  392                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
  393                 free(levels, M_TEMP);
  394                 return (error);
  395         }
  396         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
  397         if (error) {
  398                 free(levels, M_TEMP);
  399                 return (error);
  400         }
  401 
  402         /*
  403          * Reacquire the lock and search for the given level.
  404          *
  405          * XXX Note: this is not quite right since we really need to go
  406          * through each level and compare both absolute and relative
  407          * settings for each driver in the system before making a match.
  408          * The estimation code below catches this case though.
  409          */
  410         CF_MTX_LOCK(&sc->lock);
  411         for (i = 0; i < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; i++) {
  412                 if (!device_is_attached(devs[i]))
  413                         continue;
  414                 error = CPUFREQ_DRV_GET(devs[i], &set);
  415                 if (error)
  416                         continue;
  417                 for (i = 0; i < count; i++) {
  418                         if (CPUFREQ_CMP(set.freq, levels[i].total_set.freq)) {
  419                                 sc->curr_level = levels[i];
  420                                 break;
  421                         }
  422                 }
  423         }
  424         free(devs, M_TEMP);
  425         if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
  426                 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
  427                 goto out;
  428         }
  429 
  430         /*
  431          * We couldn't find an exact match, so attempt to estimate and then
  432          * match against a level.
  433          */
  434         pc = cpu_get_pcpu(dev);
  435         if (pc == NULL) {
  436                 error = ENXIO;
  437                 goto out;
  438         }
  439         cpu_est_clockrate(pc->pc_cpuid, &rate);
  440         rate /= 1000000;
  441         for (i = 0; i < count; i++) {
  442                 if (CPUFREQ_CMP(rate, levels[i].total_set.freq)) {
  443                         sc->curr_level = levels[i];
  444                         CF_DEBUG("get estimated freq %d\n", curr_set->freq);
  445                         break;
  446                 }
  447         }
  448 
  449 out:
  450         if (error == 0)
  451                 *level = sc->curr_level;
  452 
  453         CF_MTX_UNLOCK(&sc->lock);
  454         if (levels)
  455                 free(levels, M_TEMP);
  456         return (error);
  457 }
  458 
  459 static int
  460 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
  461 {
  462         struct cf_setting_array *set_arr;
  463         struct cf_setting_lst rel_sets;
  464         struct cpufreq_softc *sc;
  465         struct cf_level *lev;
  466         struct cf_setting *sets;
  467         struct pcpu *pc;
  468         device_t *devs;
  469         int error, i, numdevs, set_count, type;
  470         uint64_t rate;
  471 
  472         if (levels == NULL || count == NULL)
  473                 return (EINVAL);
  474 
  475         TAILQ_INIT(&rel_sets);
  476         sc = device_get_softc(dev);
  477         error = device_get_children(device_get_parent(dev), &devs, &numdevs);
  478         if (error)
  479                 return (error);
  480         sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
  481         if (sets == NULL) {
  482                 free(devs, M_TEMP);
  483                 return (ENOMEM);
  484         }
  485 
  486         /* Get settings from all cpufreq drivers. */
  487         CF_MTX_LOCK(&sc->lock);
  488         for (i = 0; i < numdevs; i++) {
  489                 /* Skip devices that aren't ready. */
  490                 if (!device_is_attached(devs[i]))
  491                         continue;
  492 
  493                 /*
  494                  * Get settings, skipping drivers that offer no settings or
  495                  * provide settings for informational purposes only.
  496                  */
  497                 error = CPUFREQ_DRV_TYPE(devs[i], &type);
  498                 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) {
  499                         if (error == 0) {
  500                                 CF_DEBUG("skipping info-only driver %s\n",
  501                                     device_get_nameunit(devs[i]));
  502                         }
  503                         continue;
  504                 }
  505                 set_count = MAX_SETTINGS;
  506                 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count);
  507                 if (error || set_count == 0)
  508                         continue;
  509 
  510                 /* Add the settings to our absolute/relative lists. */
  511                 switch (type & CPUFREQ_TYPE_MASK) {
  512                 case CPUFREQ_TYPE_ABSOLUTE:
  513                         error = cpufreq_insert_abs(sc, sets, set_count);
  514                         break;
  515                 case CPUFREQ_TYPE_RELATIVE:
  516                         CF_DEBUG("adding %d relative settings\n", set_count);
  517                         set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
  518                         if (set_arr == NULL) {
  519                                 error = ENOMEM;
  520                                 goto out;
  521                         }
  522                         bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
  523                         set_arr->count = set_count;
  524                         TAILQ_INSERT_TAIL(&rel_sets, set_arr, link);
  525                         break;
  526                 default:
  527                         error = EINVAL;
  528                 }
  529                 if (error)
  530                         goto out;
  531         }
  532 
  533         /*
  534          * If there are no absolute levels, create a fake one at 100%.  We
  535          * then cache the clockrate for later use as our base frequency.
  536          *
  537          * XXX This assumes that the first time through, if we only have
  538          * relative drivers, the CPU is currently running at 100%.
  539          */
  540         if (TAILQ_EMPTY(&sc->all_levels)) {
  541                 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
  542                         pc = cpu_get_pcpu(dev);
  543                         cpu_est_clockrate(pc->pc_cpuid, &rate);
  544                         sc->max_mhz = rate / 1000000;
  545                 }
  546                 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets));
  547                 sets[0].freq = sc->max_mhz;
  548                 sets[0].dev = NULL;
  549                 error = cpufreq_insert_abs(sc, sets, 1);
  550                 if (error)
  551                         goto out;
  552         }
  553 
  554         /* Create a combined list of absolute + relative levels. */
  555         TAILQ_FOREACH(set_arr, &rel_sets, link)
  556                 cpufreq_expand_set(sc, set_arr);
  557 
  558         /* If the caller doesn't have enough space, return the actual count. */
  559         if (sc->all_count > *count) {
  560                 *count = sc->all_count;
  561                 error = E2BIG;
  562                 goto out;
  563         }
  564 
  565         /* Finally, output the list of levels. */
  566         i = 0;
  567         TAILQ_FOREACH(lev, &sc->all_levels, link) {
  568                 /* Skip levels that have a frequency that is too low. */
  569                 if (lev->total_set.freq < cf_lowest_freq) {
  570                         sc->all_count--;
  571                         continue;
  572                 }
  573 
  574                 levels[i] = *lev;
  575                 i++;
  576         }
  577         *count = sc->all_count;
  578         error = 0;
  579 
  580 out:
  581         /* Clear all levels since we regenerate them each time. */
  582         while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
  583                 TAILQ_REMOVE(&sc->all_levels, lev, link);
  584                 free(lev, M_TEMP);
  585         }
  586         sc->all_count = 0;
  587 
  588         CF_MTX_UNLOCK(&sc->lock);
  589         while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
  590                 TAILQ_REMOVE(&rel_sets, set_arr, link);
  591                 free(set_arr, M_TEMP);
  592         }
  593         free(devs, M_TEMP);
  594         free(sets, M_TEMP);
  595         return (error);
  596 }
  597 
  598 /*
  599  * Create levels for an array of absolute settings and insert them in
  600  * sorted order in the specified list.
  601  */
  602 static int
  603 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
  604     int count)
  605 {
  606         struct cf_level_lst *list;
  607         struct cf_level *level, *search;
  608         int i;
  609 
  610         CF_MTX_ASSERT(&sc->lock);
  611 
  612         list = &sc->all_levels;
  613         for (i = 0; i < count; i++) {
  614                 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
  615                 if (level == NULL)
  616                         return (ENOMEM);
  617                 level->abs_set = sets[i];
  618                 level->total_set = sets[i];
  619                 level->total_set.dev = NULL;
  620                 sc->all_count++;
  621 
  622                 if (TAILQ_EMPTY(list)) {
  623                         CF_DEBUG("adding abs setting %d at head\n",
  624                             sets[i].freq);
  625                         TAILQ_INSERT_HEAD(list, level, link);
  626                         continue;
  627                 }
  628 
  629                 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) {
  630                         if (sets[i].freq <= search->total_set.freq) {
  631                                 CF_DEBUG("adding abs setting %d after %d\n",
  632                                     sets[i].freq, search->total_set.freq);
  633                                 TAILQ_INSERT_AFTER(list, search, level, link);
  634                                 break;
  635                         }
  636                 }
  637         }
  638         return (0);
  639 }
  640 
  641 /*
  642  * Expand a group of relative settings, creating derived levels from them.
  643  */
  644 static int
  645 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
  646 {
  647         struct cf_level *fill, *search;
  648         struct cf_setting *set;
  649         int i;
  650 
  651         CF_MTX_ASSERT(&sc->lock);
  652 
  653         /*
  654          * Walk the set of all existing levels in reverse.  This is so we
  655          * create derived states from the lowest absolute settings first
  656          * and discard duplicates created from higher absolute settings.
  657          * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
  658          * preferable to 200 Mhz + 25% because absolute settings are more
  659          * efficient since they often change the voltage as well.
  660          */
  661         TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
  662                 /* Add each setting to the level, duplicating if necessary. */
  663                 for (i = 0; i < set_arr->count; i++) {
  664                         set = &set_arr->sets[i];
  665 
  666                         /*
  667                          * If this setting is less than 100%, split the level
  668                          * into two and add this setting to the new level.
  669                          */
  670                         fill = search;
  671                         if (set->freq < 10000) {
  672                                 fill = cpufreq_dup_set(sc, search, set);
  673 
  674                                 /*
  675                                  * The new level was a duplicate of an existing
  676                                  * level or its absolute setting is too high
  677                                  * so we freed it.  For example, we discard a
  678                                  * derived level of 1000 MHz/25% if a level
  679                                  * of 500 MHz/100% already exists.
  680                                  */
  681                                 if (fill == NULL)
  682                                         break;
  683                         }
  684 
  685                         /* Add this setting to the existing or new level. */
  686                         KASSERT(fill->rel_count < MAX_SETTINGS,
  687                             ("cpufreq: too many relative drivers (%d)",
  688                             MAX_SETTINGS));
  689                         fill->rel_set[fill->rel_count] = *set;
  690                         fill->rel_count++;
  691                         CF_DEBUG(
  692                         "expand set added rel setting %d%% to %d level\n",
  693                             set->freq / 100, fill->total_set.freq);
  694                 }
  695         }
  696 
  697         return (0);
  698 }
  699 
  700 static struct cf_level *
  701 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
  702     struct cf_setting *set)
  703 {
  704         struct cf_level_lst *list;
  705         struct cf_level *fill, *itr;
  706         struct cf_setting *fill_set, *itr_set;
  707         int i;
  708 
  709         CF_MTX_ASSERT(&sc->lock);
  710 
  711         /*
  712          * Create a new level, copy it from the old one, and update the
  713          * total frequency and power by the percentage specified in the
  714          * relative setting.
  715          */
  716         fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
  717         if (fill == NULL)
  718                 return (NULL);
  719         *fill = *dup;
  720         fill_set = &fill->total_set;
  721         fill_set->freq =
  722             ((uint64_t)fill_set->freq * set->freq) / 10000;
  723         if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
  724                 fill_set->power = ((uint64_t)fill_set->power * set->freq)
  725                     / 10000;
  726         }
  727         if (set->lat != CPUFREQ_VAL_UNKNOWN) {
  728                 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
  729                         fill_set->lat += set->lat;
  730                 else
  731                         fill_set->lat = set->lat;
  732         }
  733         CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
  734 
  735         /*
  736          * If we copied an old level that we already modified (say, at 100%),
  737          * we need to remove that setting before adding this one.  Since we
  738          * process each setting array in order, we know any settings for this
  739          * driver will be found at the end.
  740          */
  741         for (i = fill->rel_count; i != 0; i--) {
  742                 if (fill->rel_set[i - 1].dev != set->dev)
  743                         break;
  744                 CF_DEBUG("removed last relative driver: %s\n",
  745                     device_get_nameunit(set->dev));
  746                 fill->rel_count--;
  747         }
  748 
  749         /*
  750          * Insert the new level in sorted order.  If it is a duplicate of an
  751          * existing level (1) or has an absolute setting higher than the
  752          * existing level (2), do not add it.  We can do this since any such
  753          * level is guaranteed use less power.  For example (1), a level with
  754          * one absolute setting of 800 Mhz uses less power than one composed
  755          * of an absolute setting of 1600 Mhz and a relative setting at 50%.
  756          * Also for example (2), a level of 800 Mhz/75% is preferable to
  757          * 1600 Mhz/25% even though the latter has a lower total frequency.
  758          */
  759         list = &sc->all_levels;
  760         KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
  761         TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
  762                 itr_set = &itr->total_set;
  763                 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
  764                         CF_DEBUG("dup set rejecting %d (dupe)\n",
  765                             fill_set->freq);
  766                         itr = NULL;
  767                         break;
  768                 } else if (fill_set->freq < itr_set->freq) {
  769                         if (fill->abs_set.freq <= itr->abs_set.freq) {
  770                                 CF_DEBUG(
  771                         "dup done, inserting new level %d after %d\n",
  772                                     fill_set->freq, itr_set->freq);
  773                                 TAILQ_INSERT_AFTER(list, itr, fill, link);
  774                                 sc->all_count++;
  775                         } else {
  776                                 CF_DEBUG("dup set rejecting %d (abs too big)\n",
  777                                     fill_set->freq);
  778                                 itr = NULL;
  779                         }
  780                         break;
  781                 }
  782         }
  783 
  784         /* We didn't find a good place for this new level so free it. */
  785         if (itr == NULL) {
  786                 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
  787                     fill_set->freq);
  788                 free(fill, M_TEMP);
  789                 fill = NULL;
  790         }
  791 
  792         return (fill);
  793 }
  794 
  795 static int
  796 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
  797 {
  798         struct cpufreq_softc *sc;
  799         struct cf_level *levels;
  800         int count, devcount, error, freq, i, n;
  801         device_t *devs;
  802 
  803         devs = NULL;
  804         sc = oidp->oid_arg1;
  805         levels = malloc(CF_MAX_LEVELS * sizeof(*levels), M_TEMP, M_NOWAIT);
  806         if (levels == NULL)
  807                 return (ENOMEM);
  808 
  809         error = CPUFREQ_GET(sc->dev, &levels[0]);
  810         if (error)
  811                 goto out;
  812         freq = levels[0].total_set.freq;
  813         error = sysctl_handle_int(oidp, &freq, 0, req);
  814         if (error != 0 || req->newptr == NULL)
  815                 goto out;
  816 
  817         /*
  818          * While we only call cpufreq_get() on one device (assuming all
  819          * CPUs have equal levels), we call cpufreq_set() on all CPUs.
  820          * This is needed for some MP systems.
  821          */
  822         error = devclass_get_devices(cpufreq_dc, &devs, &devcount);
  823         if (error)
  824                 goto out;
  825         for (n = 0; n < devcount; n++) {
  826                 count = CF_MAX_LEVELS;
  827                 error = CPUFREQ_LEVELS(devs[n], levels, &count);
  828                 if (error) {
  829                         if (error == E2BIG)
  830                                 printf(
  831                         "cpufreq: need to increase CF_MAX_LEVELS\n");
  832                         break;
  833                 }
  834                 for (i = 0; i < count; i++) {
  835                         if (CPUFREQ_CMP(levels[i].total_set.freq, freq)) {
  836                                 error = CPUFREQ_SET(devs[n], &levels[i],
  837                                     CPUFREQ_PRIO_USER);
  838                                 break;
  839                         }
  840                 }
  841                 if (i == count) {
  842                         error = EINVAL;
  843                         break;
  844                 }
  845         }
  846 
  847 out:
  848         if (devs)
  849                 free(devs, M_TEMP);
  850         if (levels)
  851                 free(levels, M_TEMP);
  852         return (error);
  853 }
  854 
  855 static int
  856 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
  857 {
  858         struct cpufreq_softc *sc;
  859         struct cf_level *levels;
  860         struct cf_setting *set;
  861         struct sbuf sb;
  862         int count, error, i;
  863 
  864         sc = oidp->oid_arg1;
  865         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
  866 
  867         /* Get settings from the device and generate the output string. */
  868         count = CF_MAX_LEVELS;
  869         levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
  870         if (levels == NULL)
  871                 return (ENOMEM);
  872         error = CPUFREQ_LEVELS(sc->dev, levels, &count);
  873         if (error) {
  874                 if (error == E2BIG)
  875                         printf("cpufreq: need to increase CF_MAX_LEVELS\n");
  876                 goto out;
  877         }
  878         if (count) {
  879                 for (i = 0; i < count; i++) {
  880                         set = &levels[i].total_set;
  881                         sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
  882                 }
  883         } else
  884                 sbuf_cpy(&sb, "");
  885         sbuf_trim(&sb);
  886         sbuf_finish(&sb);
  887         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
  888 
  889 out:
  890         free(levels, M_TEMP);
  891         sbuf_delete(&sb);
  892         return (error);
  893 }
  894 
  895 static int
  896 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
  897 {
  898         device_t dev;
  899         struct cf_setting *sets;
  900         struct sbuf sb;
  901         int error, i, set_count;
  902 
  903         dev = oidp->oid_arg1;
  904         sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
  905 
  906         /* Get settings from the device and generate the output string. */
  907         set_count = MAX_SETTINGS;
  908         sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
  909         if (sets == NULL)
  910                 return (ENOMEM);
  911         error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
  912         if (error)
  913                 goto out;
  914         if (set_count) {
  915                 for (i = 0; i < set_count; i++)
  916                         sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
  917         } else
  918                 sbuf_cpy(&sb, "");
  919         sbuf_trim(&sb);
  920         sbuf_finish(&sb);
  921         error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
  922 
  923 out:
  924         free(sets, M_TEMP);
  925         sbuf_delete(&sb);
  926         return (error);
  927 }
  928 
  929 int
  930 cpufreq_register(device_t dev)
  931 {
  932         struct cpufreq_softc *sc;
  933         device_t cf_dev, cpu_dev;
  934 
  935         /* Add a sysctl to get each driver's settings separately. */
  936         SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
  937             SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
  938             OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0,
  939             cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
  940 
  941         /*
  942          * Add only one cpufreq device to each CPU.  Currently, all CPUs
  943          * must offer the same levels and be switched at the same time.
  944          */
  945         cpu_dev = device_get_parent(dev);
  946         if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
  947                 sc = device_get_softc(cf_dev);
  948                 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
  949                 return (0);
  950         }
  951 
  952         /* Add the child device and possibly sysctls. */
  953         cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1);
  954         if (cf_dev == NULL)
  955                 return (ENOMEM);
  956         device_quiet(cf_dev);
  957 
  958         return (device_probe_and_attach(cf_dev));
  959 }
  960 
  961 int
  962 cpufreq_unregister(device_t dev)
  963 {
  964         device_t cf_dev, *devs;
  965         int cfcount, devcount, error, i, type;
  966 
  967         /*
  968          * If this is the last cpufreq child device, remove the control
  969          * device as well.  We identify cpufreq children by calling a method
  970          * they support.
  971          */
  972         error = device_get_children(device_get_parent(dev), &devs, &devcount);
  973         if (error)
  974                 return (error);
  975         cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
  976         if (cf_dev == NULL) {
  977                 device_printf(dev,
  978         "warning: cpufreq_unregister called with no cpufreq device active\n");
  979                 return (0);
  980         }
  981         cfcount = 0;
  982         for (i = 0; i < devcount; i++) {
  983                 if (!device_is_attached(devs[i]))
  984                         continue;
  985                 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0)
  986                         cfcount++;
  987         }
  988         if (cfcount <= 1)
  989                 device_delete_child(device_get_parent(cf_dev), cf_dev);
  990         free(devs, M_TEMP);
  991 
  992         return (0);
  993 }

Cache object: 11ec21a97923994651c95ad5111649ad


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