1 /*-
2 * Copyright (c) 2004-2007 Nate Lawson (SDG)
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/cpu.h>
33 #include <sys/eventhandler.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/proc.h>
39 #include <sys/queue.h>
40 #include <sys/sbuf.h>
41 #include <sys/sched.h>
42 #include <sys/smp.h>
43 #include <sys/sysctl.h>
44 #include <sys/systm.h>
45 #include <sys/sx.h>
46 #include <sys/timetc.h>
47 #include <sys/taskqueue.h>
48
49 #include "cpufreq_if.h"
50
51 /*
52 * Common CPU frequency glue code. Drivers for specific hardware can
53 * attach this interface to allow users to get/set the CPU frequency.
54 */
55
56 /*
57 * Number of levels we can handle. Levels are synthesized from settings
58 * so for M settings and N drivers, there may be M*N levels.
59 */
60 #define CF_MAX_LEVELS 64
61
62 struct cf_saved_freq {
63 struct cf_level level;
64 int priority;
65 SLIST_ENTRY(cf_saved_freq) link;
66 };
67
68 struct cpufreq_softc {
69 struct sx lock;
70 struct cf_level curr_level;
71 int curr_priority;
72 SLIST_HEAD(, cf_saved_freq) saved_freq;
73 struct cf_level_lst all_levels;
74 int all_count;
75 int max_mhz;
76 device_t dev;
77 struct sysctl_ctx_list sysctl_ctx;
78 struct task startup_task;
79 struct cf_level *levels_buf;
80 };
81
82 struct cf_setting_array {
83 struct cf_setting sets[MAX_SETTINGS];
84 int count;
85 TAILQ_ENTRY(cf_setting_array) link;
86 };
87
88 TAILQ_HEAD(cf_setting_lst, cf_setting_array);
89
90 #define CF_MTX_INIT(x) sx_init((x), "cpufreq lock")
91 #define CF_MTX_LOCK(x) sx_xlock((x))
92 #define CF_MTX_UNLOCK(x) sx_xunlock((x))
93 #define CF_MTX_ASSERT(x) sx_assert((x), SX_XLOCKED)
94
95 #define CF_DEBUG(msg...) do { \
96 if (cf_verbose) \
97 printf("cpufreq: " msg); \
98 } while (0)
99
100 static int cpufreq_attach(device_t dev);
101 static void cpufreq_startup_task(void *ctx, int pending);
102 static int cpufreq_detach(device_t dev);
103 static int cf_set_method(device_t dev, const struct cf_level *level,
104 int priority);
105 static int cf_get_method(device_t dev, struct cf_level *level);
106 static int cf_levels_method(device_t dev, struct cf_level *levels,
107 int *count);
108 static int cpufreq_insert_abs(struct cpufreq_softc *sc,
109 struct cf_setting *sets, int count);
110 static int cpufreq_expand_set(struct cpufreq_softc *sc,
111 struct cf_setting_array *set_arr);
112 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc,
113 struct cf_level *dup, struct cf_setting *set);
114 static int cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS);
115 static int cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS);
116 static int cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS);
117
118 static device_method_t cpufreq_methods[] = {
119 DEVMETHOD(device_probe, bus_generic_probe),
120 DEVMETHOD(device_attach, cpufreq_attach),
121 DEVMETHOD(device_detach, cpufreq_detach),
122
123 DEVMETHOD(cpufreq_set, cf_set_method),
124 DEVMETHOD(cpufreq_get, cf_get_method),
125 DEVMETHOD(cpufreq_levels, cf_levels_method),
126 {0, 0}
127 };
128 static driver_t cpufreq_driver = {
129 "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc)
130 };
131 static devclass_t cpufreq_dc;
132 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0);
133
134 static int cf_lowest_freq;
135 static int cf_verbose;
136 static SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL,
137 "cpufreq debugging");
138 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RWTUN, &cf_lowest_freq, 1,
139 "Don't provide levels below this frequency.");
140 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RWTUN, &cf_verbose, 1,
141 "Print verbose debugging messages");
142
143 static int
cpufreq_attach(device_t dev)144 cpufreq_attach(device_t dev)
145 {
146 struct cpufreq_softc *sc;
147 struct pcpu *pc;
148 device_t parent;
149 uint64_t rate;
150 int numdevs;
151
152 CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
153 sc = device_get_softc(dev);
154 parent = device_get_parent(dev);
155 sc->dev = dev;
156 sysctl_ctx_init(&sc->sysctl_ctx);
157 TAILQ_INIT(&sc->all_levels);
158 CF_MTX_INIT(&sc->lock);
159 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
160 SLIST_INIT(&sc->saved_freq);
161 /* Try to get nominal CPU freq to use it as maximum later if needed */
162 sc->max_mhz = cpu_get_nominal_mhz(dev);
163 /* If that fails, try to measure the current rate */
164 if (sc->max_mhz <= 0) {
165 pc = cpu_get_pcpu(dev);
166 if (cpu_est_clockrate(pc->pc_cpuid, &rate) == 0)
167 sc->max_mhz = rate / 1000000;
168 else
169 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
170 }
171
172 /*
173 * Only initialize one set of sysctls for all CPUs. In the future,
174 * if multiple CPUs can have different settings, we can move these
175 * sysctls to be under every CPU instead of just the first one.
176 */
177 numdevs = devclass_get_count(cpufreq_dc);
178 if (numdevs > 1)
179 return (0);
180
181 CF_DEBUG("initializing one-time data for %s\n",
182 device_get_nameunit(dev));
183 sc->levels_buf = malloc(CF_MAX_LEVELS * sizeof(*sc->levels_buf),
184 M_DEVBUF, M_WAITOK);
185 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
186 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
187 OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
188 cpufreq_curr_sysctl, "I", "Current CPU frequency");
189 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
190 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
191 OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
192 cpufreq_levels_sysctl, "A", "CPU frequency levels");
193
194 /*
195 * Queue a one-shot broadcast that levels have changed.
196 * It will run once the system has completed booting.
197 */
198 TASK_INIT(&sc->startup_task, 0, cpufreq_startup_task, dev);
199 taskqueue_enqueue(taskqueue_thread, &sc->startup_task);
200
201 return (0);
202 }
203
204 /* Handle any work to be done for all drivers that attached during boot. */
205 static void
cpufreq_startup_task(void * ctx,int pending)206 cpufreq_startup_task(void *ctx, int pending)
207 {
208
209 cpufreq_settings_changed((device_t)ctx);
210 }
211
212 static int
cpufreq_detach(device_t dev)213 cpufreq_detach(device_t dev)
214 {
215 struct cpufreq_softc *sc;
216 struct cf_saved_freq *saved_freq;
217 int numdevs;
218
219 CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
220 sc = device_get_softc(dev);
221 sysctl_ctx_free(&sc->sysctl_ctx);
222
223 while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) {
224 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
225 free(saved_freq, M_TEMP);
226 }
227
228 /* Only clean up these resources when the last device is detaching. */
229 numdevs = devclass_get_count(cpufreq_dc);
230 if (numdevs == 1) {
231 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev));
232 free(sc->levels_buf, M_DEVBUF);
233 }
234
235 return (0);
236 }
237
238 static int
cf_set_method(device_t dev,const struct cf_level * level,int priority)239 cf_set_method(device_t dev, const struct cf_level *level, int priority)
240 {
241 struct cpufreq_softc *sc;
242 const struct cf_setting *set;
243 struct cf_saved_freq *saved_freq, *curr_freq;
244 struct pcpu *pc;
245 int error, i;
246
247 sc = device_get_softc(dev);
248 error = 0;
249 set = NULL;
250 saved_freq = NULL;
251
252 /* We are going to change levels so notify the pre-change handler. */
253 EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error);
254 if (error != 0) {
255 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
256 return (error);
257 }
258
259 CF_MTX_LOCK(&sc->lock);
260
261 #ifdef SMP
262 /*
263 * If still booting and secondary CPUs not started yet, don't allow
264 * changing the frequency until they're online. This is because we
265 * can't switch to them using sched_bind() and thus we'd only be
266 * switching the main CPU. XXXTODO: Need to think more about how to
267 * handle having different CPUs at different frequencies.
268 */
269 if (mp_ncpus > 1 && !smp_started) {
270 device_printf(dev, "rejecting change, SMP not started yet\n");
271 error = ENXIO;
272 goto out;
273 }
274 #endif /* SMP */
275
276 /*
277 * If the requested level has a lower priority, don't allow
278 * the new level right now.
279 */
280 if (priority < sc->curr_priority) {
281 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority,
282 sc->curr_priority);
283 error = EPERM;
284 goto out;
285 }
286
287 /*
288 * If the caller didn't specify a level and one is saved, prepare to
289 * restore the saved level. If none has been saved, return an error.
290 */
291 if (level == NULL) {
292 saved_freq = SLIST_FIRST(&sc->saved_freq);
293 if (saved_freq == NULL) {
294 CF_DEBUG("NULL level, no saved level\n");
295 error = ENXIO;
296 goto out;
297 }
298 level = &saved_freq->level;
299 priority = saved_freq->priority;
300 CF_DEBUG("restoring saved level, freq %d prio %d\n",
301 level->total_set.freq, priority);
302 }
303
304 /* Reject levels that are below our specified threshold. */
305 if (level->total_set.freq < cf_lowest_freq) {
306 CF_DEBUG("rejecting freq %d, less than %d limit\n",
307 level->total_set.freq, cf_lowest_freq);
308 error = EINVAL;
309 goto out;
310 }
311
312 /* If already at this level, just return. */
313 if (sc->curr_level.total_set.freq == level->total_set.freq) {
314 CF_DEBUG("skipping freq %d, same as current level %d\n",
315 level->total_set.freq, sc->curr_level.total_set.freq);
316 goto skip;
317 }
318
319 /* First, set the absolute frequency via its driver. */
320 set = &level->abs_set;
321 if (set->dev) {
322 if (!device_is_attached(set->dev)) {
323 error = ENXIO;
324 goto out;
325 }
326
327 /* Bind to the target CPU before switching. */
328 pc = cpu_get_pcpu(set->dev);
329 thread_lock(curthread);
330 sched_bind(curthread, pc->pc_cpuid);
331 thread_unlock(curthread);
332 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
333 device_get_nameunit(set->dev), PCPU_GET(cpuid));
334 error = CPUFREQ_DRV_SET(set->dev, set);
335 thread_lock(curthread);
336 sched_unbind(curthread);
337 thread_unlock(curthread);
338 if (error) {
339 goto out;
340 }
341 }
342
343 /* Next, set any/all relative frequencies via their drivers. */
344 for (i = 0; i < level->rel_count; i++) {
345 set = &level->rel_set[i];
346 if (!device_is_attached(set->dev)) {
347 error = ENXIO;
348 goto out;
349 }
350
351 /* Bind to the target CPU before switching. */
352 pc = cpu_get_pcpu(set->dev);
353 thread_lock(curthread);
354 sched_bind(curthread, pc->pc_cpuid);
355 thread_unlock(curthread);
356 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
357 device_get_nameunit(set->dev), PCPU_GET(cpuid));
358 error = CPUFREQ_DRV_SET(set->dev, set);
359 thread_lock(curthread);
360 sched_unbind(curthread);
361 thread_unlock(curthread);
362 if (error) {
363 /* XXX Back out any successful setting? */
364 goto out;
365 }
366 }
367
368 skip:
369 /*
370 * Before recording the current level, check if we're going to a
371 * higher priority. If so, save the previous level and priority.
372 */
373 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
374 priority > sc->curr_priority) {
375 CF_DEBUG("saving level, freq %d prio %d\n",
376 sc->curr_level.total_set.freq, sc->curr_priority);
377 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT);
378 if (curr_freq == NULL) {
379 error = ENOMEM;
380 goto out;
381 }
382 curr_freq->level = sc->curr_level;
383 curr_freq->priority = sc->curr_priority;
384 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link);
385 }
386 sc->curr_level = *level;
387 sc->curr_priority = priority;
388
389 /* If we were restoring a saved state, reset it to "unused". */
390 if (saved_freq != NULL) {
391 CF_DEBUG("resetting saved level\n");
392 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
393 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
394 free(saved_freq, M_TEMP);
395 }
396
397 out:
398 CF_MTX_UNLOCK(&sc->lock);
399
400 /*
401 * We changed levels (or attempted to) so notify the post-change
402 * handler of new frequency or error.
403 */
404 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
405 if (error && set)
406 device_printf(set->dev, "set freq failed, err %d\n", error);
407
408 return (error);
409 }
410
411 static int
cf_get_method(device_t dev,struct cf_level * level)412 cf_get_method(device_t dev, struct cf_level *level)
413 {
414 struct cpufreq_softc *sc;
415 struct cf_level *levels;
416 struct cf_setting *curr_set, set;
417 struct pcpu *pc;
418 device_t *devs;
419 int bdiff, count, diff, error, i, n, numdevs;
420 uint64_t rate;
421
422 sc = device_get_softc(dev);
423 error = 0;
424 levels = NULL;
425
426 /* If we already know the current frequency, we're done. */
427 CF_MTX_LOCK(&sc->lock);
428 curr_set = &sc->curr_level.total_set;
429 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
430 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
431 goto out;
432 }
433 CF_MTX_UNLOCK(&sc->lock);
434
435 /*
436 * We need to figure out the current level. Loop through every
437 * driver, getting the current setting. Then, attempt to get a best
438 * match of settings against each level.
439 */
440 count = CF_MAX_LEVELS;
441 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
442 if (levels == NULL)
443 return (ENOMEM);
444 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
445 if (error) {
446 if (error == E2BIG)
447 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
448 free(levels, M_TEMP);
449 return (error);
450 }
451 error = device_get_children(device_get_parent(dev), &devs, &numdevs);
452 if (error) {
453 free(levels, M_TEMP);
454 return (error);
455 }
456
457 /*
458 * Reacquire the lock and search for the given level.
459 *
460 * XXX Note: this is not quite right since we really need to go
461 * through each level and compare both absolute and relative
462 * settings for each driver in the system before making a match.
463 * The estimation code below catches this case though.
464 */
465 CF_MTX_LOCK(&sc->lock);
466 for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) {
467 if (!device_is_attached(devs[n]))
468 continue;
469 if (CPUFREQ_DRV_GET(devs[n], &set) != 0)
470 continue;
471 for (i = 0; i < count; i++) {
472 if (set.freq == levels[i].total_set.freq) {
473 sc->curr_level = levels[i];
474 break;
475 }
476 }
477 }
478 free(devs, M_TEMP);
479 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
480 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
481 goto out;
482 }
483
484 /*
485 * We couldn't find an exact match, so attempt to estimate and then
486 * match against a level.
487 */
488 pc = cpu_get_pcpu(dev);
489 if (pc == NULL) {
490 error = ENXIO;
491 goto out;
492 }
493 cpu_est_clockrate(pc->pc_cpuid, &rate);
494 rate /= 1000000;
495 bdiff = 1 << 30;
496 for (i = 0; i < count; i++) {
497 diff = abs(levels[i].total_set.freq - rate);
498 if (diff < bdiff) {
499 bdiff = diff;
500 sc->curr_level = levels[i];
501 }
502 }
503 CF_DEBUG("get estimated freq %d\n", curr_set->freq);
504
505 out:
506 if (error == 0)
507 *level = sc->curr_level;
508
509 CF_MTX_UNLOCK(&sc->lock);
510 if (levels)
511 free(levels, M_TEMP);
512 return (error);
513 }
514
515 static int
cf_levels_method(device_t dev,struct cf_level * levels,int * count)516 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
517 {
518 struct cf_setting_array *set_arr;
519 struct cf_setting_lst rel_sets;
520 struct cpufreq_softc *sc;
521 struct cf_level *lev;
522 struct cf_setting *sets;
523 struct pcpu *pc;
524 device_t *devs;
525 int error, i, numdevs, set_count, type;
526 uint64_t rate;
527
528 if (levels == NULL || count == NULL)
529 return (EINVAL);
530
531 TAILQ_INIT(&rel_sets);
532 sc = device_get_softc(dev);
533 error = device_get_children(device_get_parent(dev), &devs, &numdevs);
534 if (error)
535 return (error);
536 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
537 if (sets == NULL) {
538 free(devs, M_TEMP);
539 return (ENOMEM);
540 }
541
542 /* Get settings from all cpufreq drivers. */
543 CF_MTX_LOCK(&sc->lock);
544 for (i = 0; i < numdevs; i++) {
545 /* Skip devices that aren't ready. */
546 if (!device_is_attached(devs[i]))
547 continue;
548
549 /*
550 * Get settings, skipping drivers that offer no settings or
551 * provide settings for informational purposes only.
552 */
553 error = CPUFREQ_DRV_TYPE(devs[i], &type);
554 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) {
555 if (error == 0) {
556 CF_DEBUG("skipping info-only driver %s\n",
557 device_get_nameunit(devs[i]));
558 }
559 continue;
560 }
561 set_count = MAX_SETTINGS;
562 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count);
563 if (error || set_count == 0)
564 continue;
565
566 /* Add the settings to our absolute/relative lists. */
567 switch (type & CPUFREQ_TYPE_MASK) {
568 case CPUFREQ_TYPE_ABSOLUTE:
569 error = cpufreq_insert_abs(sc, sets, set_count);
570 break;
571 case CPUFREQ_TYPE_RELATIVE:
572 CF_DEBUG("adding %d relative settings\n", set_count);
573 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
574 if (set_arr == NULL) {
575 error = ENOMEM;
576 goto out;
577 }
578 bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
579 set_arr->count = set_count;
580 TAILQ_INSERT_TAIL(&rel_sets, set_arr, link);
581 break;
582 default:
583 error = EINVAL;
584 }
585 if (error)
586 goto out;
587 }
588
589 /*
590 * If there are no absolute levels, create a fake one at 100%. We
591 * then cache the clockrate for later use as our base frequency.
592 */
593 if (TAILQ_EMPTY(&sc->all_levels)) {
594 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
595 sc->max_mhz = cpu_get_nominal_mhz(dev);
596 /*
597 * If the CPU can't report a rate for 100%, hope
598 * the CPU is running at its nominal rate right now,
599 * and use that instead.
600 */
601 if (sc->max_mhz <= 0) {
602 pc = cpu_get_pcpu(dev);
603 cpu_est_clockrate(pc->pc_cpuid, &rate);
604 sc->max_mhz = rate / 1000000;
605 }
606 }
607 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets));
608 sets[0].freq = sc->max_mhz;
609 sets[0].dev = NULL;
610 error = cpufreq_insert_abs(sc, sets, 1);
611 if (error)
612 goto out;
613 }
614
615 /* Create a combined list of absolute + relative levels. */
616 TAILQ_FOREACH(set_arr, &rel_sets, link)
617 cpufreq_expand_set(sc, set_arr);
618
619 /* If the caller doesn't have enough space, return the actual count. */
620 if (sc->all_count > *count) {
621 *count = sc->all_count;
622 error = E2BIG;
623 goto out;
624 }
625
626 /* Finally, output the list of levels. */
627 i = 0;
628 TAILQ_FOREACH(lev, &sc->all_levels, link) {
629
630 /* Skip levels that have a frequency that is too low. */
631 if (lev->total_set.freq < cf_lowest_freq) {
632 sc->all_count--;
633 continue;
634 }
635
636 levels[i] = *lev;
637 i++;
638 }
639 *count = sc->all_count;
640 error = 0;
641
642 out:
643 /* Clear all levels since we regenerate them each time. */
644 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
645 TAILQ_REMOVE(&sc->all_levels, lev, link);
646 free(lev, M_TEMP);
647 }
648 sc->all_count = 0;
649
650 CF_MTX_UNLOCK(&sc->lock);
651 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
652 TAILQ_REMOVE(&rel_sets, set_arr, link);
653 free(set_arr, M_TEMP);
654 }
655 free(devs, M_TEMP);
656 free(sets, M_TEMP);
657 return (error);
658 }
659
660 /*
661 * Create levels for an array of absolute settings and insert them in
662 * sorted order in the specified list.
663 */
664 static int
cpufreq_insert_abs(struct cpufreq_softc * sc,struct cf_setting * sets,int count)665 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
666 int count)
667 {
668 struct cf_level_lst *list;
669 struct cf_level *level, *search;
670 int i;
671
672 CF_MTX_ASSERT(&sc->lock);
673
674 list = &sc->all_levels;
675 for (i = 0; i < count; i++) {
676 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
677 if (level == NULL)
678 return (ENOMEM);
679 level->abs_set = sets[i];
680 level->total_set = sets[i];
681 level->total_set.dev = NULL;
682 sc->all_count++;
683
684 if (TAILQ_EMPTY(list)) {
685 CF_DEBUG("adding abs setting %d at head\n",
686 sets[i].freq);
687 TAILQ_INSERT_HEAD(list, level, link);
688 continue;
689 }
690
691 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) {
692 if (sets[i].freq <= search->total_set.freq) {
693 CF_DEBUG("adding abs setting %d after %d\n",
694 sets[i].freq, search->total_set.freq);
695 TAILQ_INSERT_AFTER(list, search, level, link);
696 break;
697 }
698 }
699 }
700 return (0);
701 }
702
703 /*
704 * Expand a group of relative settings, creating derived levels from them.
705 */
706 static int
cpufreq_expand_set(struct cpufreq_softc * sc,struct cf_setting_array * set_arr)707 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
708 {
709 struct cf_level *fill, *search;
710 struct cf_setting *set;
711 int i;
712
713 CF_MTX_ASSERT(&sc->lock);
714
715 /*
716 * Walk the set of all existing levels in reverse. This is so we
717 * create derived states from the lowest absolute settings first
718 * and discard duplicates created from higher absolute settings.
719 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
720 * preferable to 200 Mhz + 25% because absolute settings are more
721 * efficient since they often change the voltage as well.
722 */
723 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
724 /* Add each setting to the level, duplicating if necessary. */
725 for (i = 0; i < set_arr->count; i++) {
726 set = &set_arr->sets[i];
727
728 /*
729 * If this setting is less than 100%, split the level
730 * into two and add this setting to the new level.
731 */
732 fill = search;
733 if (set->freq < 10000) {
734 fill = cpufreq_dup_set(sc, search, set);
735
736 /*
737 * The new level was a duplicate of an existing
738 * level or its absolute setting is too high
739 * so we freed it. For example, we discard a
740 * derived level of 1000 MHz/25% if a level
741 * of 500 MHz/100% already exists.
742 */
743 if (fill == NULL)
744 break;
745 }
746
747 /* Add this setting to the existing or new level. */
748 KASSERT(fill->rel_count < MAX_SETTINGS,
749 ("cpufreq: too many relative drivers (%d)",
750 MAX_SETTINGS));
751 fill->rel_set[fill->rel_count] = *set;
752 fill->rel_count++;
753 CF_DEBUG(
754 "expand set added rel setting %d%% to %d level\n",
755 set->freq / 100, fill->total_set.freq);
756 }
757 }
758
759 return (0);
760 }
761
762 static struct cf_level *
cpufreq_dup_set(struct cpufreq_softc * sc,struct cf_level * dup,struct cf_setting * set)763 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
764 struct cf_setting *set)
765 {
766 struct cf_level_lst *list;
767 struct cf_level *fill, *itr;
768 struct cf_setting *fill_set, *itr_set;
769 int i;
770
771 CF_MTX_ASSERT(&sc->lock);
772
773 /*
774 * Create a new level, copy it from the old one, and update the
775 * total frequency and power by the percentage specified in the
776 * relative setting.
777 */
778 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
779 if (fill == NULL)
780 return (NULL);
781 *fill = *dup;
782 fill_set = &fill->total_set;
783 fill_set->freq =
784 ((uint64_t)fill_set->freq * set->freq) / 10000;
785 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
786 fill_set->power = ((uint64_t)fill_set->power * set->freq)
787 / 10000;
788 }
789 if (set->lat != CPUFREQ_VAL_UNKNOWN) {
790 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
791 fill_set->lat += set->lat;
792 else
793 fill_set->lat = set->lat;
794 }
795 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
796
797 /*
798 * If we copied an old level that we already modified (say, at 100%),
799 * we need to remove that setting before adding this one. Since we
800 * process each setting array in order, we know any settings for this
801 * driver will be found at the end.
802 */
803 for (i = fill->rel_count; i != 0; i--) {
804 if (fill->rel_set[i - 1].dev != set->dev)
805 break;
806 CF_DEBUG("removed last relative driver: %s\n",
807 device_get_nameunit(set->dev));
808 fill->rel_count--;
809 }
810
811 /*
812 * Insert the new level in sorted order. If it is a duplicate of an
813 * existing level (1) or has an absolute setting higher than the
814 * existing level (2), do not add it. We can do this since any such
815 * level is guaranteed use less power. For example (1), a level with
816 * one absolute setting of 800 Mhz uses less power than one composed
817 * of an absolute setting of 1600 Mhz and a relative setting at 50%.
818 * Also for example (2), a level of 800 Mhz/75% is preferable to
819 * 1600 Mhz/25% even though the latter has a lower total frequency.
820 */
821 list = &sc->all_levels;
822 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
823 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
824 itr_set = &itr->total_set;
825 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
826 CF_DEBUG("dup set rejecting %d (dupe)\n",
827 fill_set->freq);
828 itr = NULL;
829 break;
830 } else if (fill_set->freq < itr_set->freq) {
831 if (fill->abs_set.freq <= itr->abs_set.freq) {
832 CF_DEBUG(
833 "dup done, inserting new level %d after %d\n",
834 fill_set->freq, itr_set->freq);
835 TAILQ_INSERT_AFTER(list, itr, fill, link);
836 sc->all_count++;
837 } else {
838 CF_DEBUG("dup set rejecting %d (abs too big)\n",
839 fill_set->freq);
840 itr = NULL;
841 }
842 break;
843 }
844 }
845
846 /* We didn't find a good place for this new level so free it. */
847 if (itr == NULL) {
848 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
849 fill_set->freq);
850 free(fill, M_TEMP);
851 fill = NULL;
852 }
853
854 return (fill);
855 }
856
857 static int
cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)858 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
859 {
860 struct cpufreq_softc *sc;
861 struct cf_level *levels;
862 int best, count, diff, bdiff, devcount, error, freq, i, n;
863 device_t *devs;
864
865 devs = NULL;
866 sc = oidp->oid_arg1;
867 levels = sc->levels_buf;
868
869 error = CPUFREQ_GET(sc->dev, &levels[0]);
870 if (error)
871 goto out;
872 freq = levels[0].total_set.freq;
873 error = sysctl_handle_int(oidp, &freq, 0, req);
874 if (error != 0 || req->newptr == NULL)
875 goto out;
876
877 /*
878 * While we only call cpufreq_get() on one device (assuming all
879 * CPUs have equal levels), we call cpufreq_set() on all CPUs.
880 * This is needed for some MP systems.
881 */
882 error = devclass_get_devices(cpufreq_dc, &devs, &devcount);
883 if (error)
884 goto out;
885 for (n = 0; n < devcount; n++) {
886 count = CF_MAX_LEVELS;
887 error = CPUFREQ_LEVELS(devs[n], levels, &count);
888 if (error) {
889 if (error == E2BIG)
890 printf(
891 "cpufreq: need to increase CF_MAX_LEVELS\n");
892 break;
893 }
894 best = 0;
895 bdiff = 1 << 30;
896 for (i = 0; i < count; i++) {
897 diff = abs(levels[i].total_set.freq - freq);
898 if (diff < bdiff) {
899 bdiff = diff;
900 best = i;
901 }
902 }
903 error = CPUFREQ_SET(devs[n], &levels[best], CPUFREQ_PRIO_USER);
904 }
905
906 out:
907 if (devs)
908 free(devs, M_TEMP);
909 return (error);
910 }
911
912 static int
cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)913 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
914 {
915 struct cpufreq_softc *sc;
916 struct cf_level *levels;
917 struct cf_setting *set;
918 struct sbuf sb;
919 int count, error, i;
920
921 sc = oidp->oid_arg1;
922 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
923
924 /* Get settings from the device and generate the output string. */
925 count = CF_MAX_LEVELS;
926 levels = sc->levels_buf;
927 if (levels == NULL) {
928 sbuf_delete(&sb);
929 return (ENOMEM);
930 }
931 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
932 if (error) {
933 if (error == E2BIG)
934 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
935 goto out;
936 }
937 if (count) {
938 for (i = 0; i < count; i++) {
939 set = &levels[i].total_set;
940 sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
941 }
942 } else
943 sbuf_cpy(&sb, "0");
944 sbuf_trim(&sb);
945 sbuf_finish(&sb);
946 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
947
948 out:
949 sbuf_delete(&sb);
950 return (error);
951 }
952
953 static int
cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)954 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
955 {
956 device_t dev;
957 struct cf_setting *sets;
958 struct sbuf sb;
959 int error, i, set_count;
960
961 dev = oidp->oid_arg1;
962 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
963
964 /* Get settings from the device and generate the output string. */
965 set_count = MAX_SETTINGS;
966 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
967 if (sets == NULL) {
968 sbuf_delete(&sb);
969 return (ENOMEM);
970 }
971 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
972 if (error)
973 goto out;
974 if (set_count) {
975 for (i = 0; i < set_count; i++)
976 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
977 } else
978 sbuf_cpy(&sb, "0");
979 sbuf_trim(&sb);
980 sbuf_finish(&sb);
981 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
982
983 out:
984 free(sets, M_TEMP);
985 sbuf_delete(&sb);
986 return (error);
987 }
988
989 int
cpufreq_register(device_t dev)990 cpufreq_register(device_t dev)
991 {
992 struct cpufreq_softc *sc;
993 device_t cf_dev, cpu_dev;
994
995 /* Add a sysctl to get each driver's settings separately. */
996 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
997 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
998 OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0,
999 cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
1000
1001 /*
1002 * Add only one cpufreq device to each CPU. Currently, all CPUs
1003 * must offer the same levels and be switched at the same time.
1004 */
1005 cpu_dev = device_get_parent(dev);
1006 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
1007 sc = device_get_softc(cf_dev);
1008 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
1009 return (0);
1010 }
1011
1012 /* Add the child device and possibly sysctls. */
1013 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1);
1014 if (cf_dev == NULL)
1015 return (ENOMEM);
1016 device_quiet(cf_dev);
1017
1018 return (device_probe_and_attach(cf_dev));
1019 }
1020
1021 int
cpufreq_unregister(device_t dev)1022 cpufreq_unregister(device_t dev)
1023 {
1024 device_t cf_dev, *devs;
1025 int cfcount, devcount, error, i, type;
1026
1027 /*
1028 * If this is the last cpufreq child device, remove the control
1029 * device as well. We identify cpufreq children by calling a method
1030 * they support.
1031 */
1032 error = device_get_children(device_get_parent(dev), &devs, &devcount);
1033 if (error)
1034 return (error);
1035 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
1036 if (cf_dev == NULL) {
1037 device_printf(dev,
1038 "warning: cpufreq_unregister called with no cpufreq device active\n");
1039 free(devs, M_TEMP);
1040 return (0);
1041 }
1042 cfcount = 0;
1043 for (i = 0; i < devcount; i++) {
1044 if (!device_is_attached(devs[i]))
1045 continue;
1046 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0)
1047 cfcount++;
1048 }
1049 if (cfcount <= 1)
1050 device_delete_child(device_get_parent(cf_dev), cf_dev);
1051 free(devs, M_TEMP);
1052
1053 return (0);
1054 }
1055
1056 int
cpufreq_settings_changed(device_t dev)1057 cpufreq_settings_changed(device_t dev)
1058 {
1059
1060 EVENTHANDLER_INVOKE(cpufreq_levels_changed,
1061 device_get_unit(device_get_parent(dev)));
1062 return (0);
1063 }
1064