FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_cpu.c
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 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: aaacbcdaf56801b32a1e007d056e17ca
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