1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004-2007 Nate Lawson (SDG)
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/param.h>
30 #include <sys/bus.h>
31 #include <sys/cpu.h>
32 #include <sys/eventhandler.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/proc.h>
38 #include <sys/queue.h>
39 #include <sys/sbuf.h>
40 #include <sys/sched.h>
41 #include <sys/smp.h>
42 #include <sys/sysctl.h>
43 #include <sys/systm.h>
44 #include <sys/sx.h>
45 #include <sys/timetc.h>
46 #include <sys/taskqueue.h>
47
48 #include "cpufreq_if.h"
49
50 /*
51 * Common CPU frequency glue code. Drivers for specific hardware can
52 * attach this interface to allow users to get/set the CPU frequency.
53 */
54
55 /*
56 * Number of levels we can handle. Levels are synthesized from settings
57 * so for M settings and N drivers, there may be M*N levels.
58 */
59 #define CF_MAX_LEVELS 256
60
61 struct cf_saved_freq {
62 struct cf_level level;
63 int priority;
64 SLIST_ENTRY(cf_saved_freq) link;
65 };
66
67 struct cpufreq_softc {
68 struct sx lock;
69 struct cf_level curr_level;
70 int curr_priority;
71 SLIST_HEAD(, cf_saved_freq) saved_freq;
72 struct cf_level_lst all_levels;
73 int all_count;
74 int max_mhz;
75 device_t dev;
76 device_t cf_drv_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
129 static driver_t cpufreq_driver = {
130 "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc)
131 };
132
133 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, 0, 0);
134
135 static int cf_lowest_freq;
136 static int cf_verbose;
137 static SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
138 "cpufreq debugging");
139 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RWTUN, &cf_lowest_freq, 1,
140 "Don't provide levels below this frequency.");
141 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RWTUN, &cf_verbose, 1,
142 "Print verbose debugging messages");
143
144 /*
145 * This is called as the result of a hardware specific frequency control driver
146 * calling cpufreq_register. It provides a general interface for system wide
147 * frequency controls and operates on a per cpu basis.
148 */
149 static int
cpufreq_attach(device_t dev)150 cpufreq_attach(device_t dev)
151 {
152 struct cpufreq_softc *sc;
153 struct pcpu *pc;
154 device_t parent;
155 uint64_t rate;
156
157 CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
158 sc = device_get_softc(dev);
159 parent = device_get_parent(dev);
160 sc->dev = dev;
161 sysctl_ctx_init(&sc->sysctl_ctx);
162 TAILQ_INIT(&sc->all_levels);
163 CF_MTX_INIT(&sc->lock);
164 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
165 SLIST_INIT(&sc->saved_freq);
166 /* Try to get nominal CPU freq to use it as maximum later if needed */
167 sc->max_mhz = cpu_get_nominal_mhz(dev);
168 /* If that fails, try to measure the current rate */
169 if (sc->max_mhz <= 0) {
170 CF_DEBUG("Unable to obtain nominal frequency.\n");
171 pc = cpu_get_pcpu(dev);
172 if (cpu_est_clockrate(pc->pc_cpuid, &rate) == 0)
173 sc->max_mhz = rate / 1000000;
174 else
175 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
176 }
177
178 CF_DEBUG("initializing one-time data for %s\n",
179 device_get_nameunit(dev));
180 sc->levels_buf = malloc(CF_MAX_LEVELS * sizeof(*sc->levels_buf),
181 M_DEVBUF, M_WAITOK);
182 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
183 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
184 OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
185 sc, 0, cpufreq_curr_sysctl, "I", "Current CPU frequency");
186 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
187 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
188 OID_AUTO, "freq_levels",
189 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, sc, 0,
190 cpufreq_levels_sysctl, "A", "CPU frequency levels");
191
192 /*
193 * Queue a one-shot broadcast that levels have changed.
194 * It will run once the system has completed booting.
195 */
196 TASK_INIT(&sc->startup_task, 0, cpufreq_startup_task, dev);
197 taskqueue_enqueue(taskqueue_thread, &sc->startup_task);
198
199 return (0);
200 }
201
202 /* Handle any work to be done for all drivers that attached during boot. */
203 static void
cpufreq_startup_task(void * ctx,int pending)204 cpufreq_startup_task(void *ctx, int pending)
205 {
206
207 cpufreq_settings_changed((device_t)ctx);
208 }
209
210 static int
cpufreq_detach(device_t dev)211 cpufreq_detach(device_t dev)
212 {
213 struct cpufreq_softc *sc;
214 struct cf_saved_freq *saved_freq;
215
216 CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
217 sc = device_get_softc(dev);
218 sysctl_ctx_free(&sc->sysctl_ctx);
219
220 while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) {
221 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
222 free(saved_freq, M_TEMP);
223 }
224
225 free(sc->levels_buf, M_DEVBUF);
226
227 return (0);
228 }
229
230 static int
cf_set_method(device_t dev,const struct cf_level * level,int priority)231 cf_set_method(device_t dev, const struct cf_level *level, int priority)
232 {
233 struct cpufreq_softc *sc;
234 const struct cf_setting *set;
235 struct cf_saved_freq *saved_freq, *curr_freq;
236 struct pcpu *pc;
237 int error, i;
238 u_char pri;
239
240 sc = device_get_softc(dev);
241 error = 0;
242 set = NULL;
243 saved_freq = NULL;
244
245 /* We are going to change levels so notify the pre-change handler. */
246 EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error);
247 if (error != 0) {
248 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
249 return (error);
250 }
251
252 CF_MTX_LOCK(&sc->lock);
253
254 #ifdef SMP
255 #ifdef EARLY_AP_STARTUP
256 MPASS(mp_ncpus == 1 || smp_started);
257 #else
258 /*
259 * If still booting and secondary CPUs not started yet, don't allow
260 * changing the frequency until they're online. This is because we
261 * can't switch to them using sched_bind() and thus we'd only be
262 * switching the main CPU. XXXTODO: Need to think more about how to
263 * handle having different CPUs at different frequencies.
264 */
265 if (mp_ncpus > 1 && !smp_started) {
266 device_printf(dev, "rejecting change, SMP not started yet\n");
267 error = ENXIO;
268 goto out;
269 }
270 #endif
271 #endif /* SMP */
272
273 /*
274 * If the requested level has a lower priority, don't allow
275 * the new level right now.
276 */
277 if (priority < sc->curr_priority) {
278 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority,
279 sc->curr_priority);
280 error = EPERM;
281 goto out;
282 }
283
284 /*
285 * If the caller didn't specify a level and one is saved, prepare to
286 * restore the saved level. If none has been saved, return an error.
287 */
288 if (level == NULL) {
289 saved_freq = SLIST_FIRST(&sc->saved_freq);
290 if (saved_freq == NULL) {
291 CF_DEBUG("NULL level, no saved level\n");
292 error = ENXIO;
293 goto out;
294 }
295 level = &saved_freq->level;
296 priority = saved_freq->priority;
297 CF_DEBUG("restoring saved level, freq %d prio %d\n",
298 level->total_set.freq, priority);
299 }
300
301 /* Reject levels that are below our specified threshold. */
302 if (level->total_set.freq < cf_lowest_freq) {
303 CF_DEBUG("rejecting freq %d, less than %d limit\n",
304 level->total_set.freq, cf_lowest_freq);
305 error = EINVAL;
306 goto out;
307 }
308
309 /* If already at this level, just return. */
310 if (sc->curr_level.total_set.freq == level->total_set.freq) {
311 CF_DEBUG("skipping freq %d, same as current level %d\n",
312 level->total_set.freq, sc->curr_level.total_set.freq);
313 goto skip;
314 }
315
316 /* First, set the absolute frequency via its driver. */
317 set = &level->abs_set;
318 if (set->dev) {
319 if (!device_is_attached(set->dev)) {
320 error = ENXIO;
321 goto out;
322 }
323
324 /* Bind to the target CPU before switching. */
325 pc = cpu_get_pcpu(set->dev);
326
327 /* Skip settings if CPU is not started. */
328 if (pc == NULL) {
329 error = 0;
330 goto out;
331 }
332 thread_lock(curthread);
333 pri = curthread->td_priority;
334 sched_prio(curthread, PRI_MIN);
335 sched_bind(curthread, pc->pc_cpuid);
336 thread_unlock(curthread);
337 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
338 device_get_nameunit(set->dev), PCPU_GET(cpuid));
339 error = CPUFREQ_DRV_SET(set->dev, set);
340 thread_lock(curthread);
341 sched_unbind(curthread);
342 sched_prio(curthread, pri);
343 thread_unlock(curthread);
344 if (error) {
345 goto out;
346 }
347 }
348
349 /* Next, set any/all relative frequencies via their drivers. */
350 for (i = 0; i < level->rel_count; i++) {
351 set = &level->rel_set[i];
352 if (!device_is_attached(set->dev)) {
353 error = ENXIO;
354 goto out;
355 }
356
357 /* Bind to the target CPU before switching. */
358 pc = cpu_get_pcpu(set->dev);
359 thread_lock(curthread);
360 pri = curthread->td_priority;
361 sched_prio(curthread, PRI_MIN);
362 sched_bind(curthread, pc->pc_cpuid);
363 thread_unlock(curthread);
364 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
365 device_get_nameunit(set->dev), PCPU_GET(cpuid));
366 error = CPUFREQ_DRV_SET(set->dev, set);
367 thread_lock(curthread);
368 sched_unbind(curthread);
369 sched_prio(curthread, pri);
370 thread_unlock(curthread);
371 if (error) {
372 /* XXX Back out any successful setting? */
373 goto out;
374 }
375 }
376
377 skip:
378 /*
379 * Before recording the current level, check if we're going to a
380 * higher priority. If so, save the previous level and priority.
381 */
382 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
383 priority > sc->curr_priority) {
384 CF_DEBUG("saving level, freq %d prio %d\n",
385 sc->curr_level.total_set.freq, sc->curr_priority);
386 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT);
387 if (curr_freq == NULL) {
388 error = ENOMEM;
389 goto out;
390 }
391 curr_freq->level = sc->curr_level;
392 curr_freq->priority = sc->curr_priority;
393 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link);
394 }
395 sc->curr_level = *level;
396 sc->curr_priority = priority;
397
398 /* If we were restoring a saved state, reset it to "unused". */
399 if (saved_freq != NULL) {
400 CF_DEBUG("resetting saved level\n");
401 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
402 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
403 free(saved_freq, M_TEMP);
404 }
405
406 out:
407 CF_MTX_UNLOCK(&sc->lock);
408
409 /*
410 * We changed levels (or attempted to) so notify the post-change
411 * handler of new frequency or error.
412 */
413 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
414 if (error && set)
415 device_printf(set->dev, "set freq failed, err %d\n", error);
416
417 return (error);
418 }
419
420 static int
cpufreq_get_frequency(device_t dev)421 cpufreq_get_frequency(device_t dev)
422 {
423 struct cf_setting set;
424
425 if (CPUFREQ_DRV_GET(dev, &set) != 0)
426 return (-1);
427
428 return (set.freq);
429 }
430
431 /* Returns the index into *levels with the match */
432 static int
cpufreq_get_level(device_t dev,struct cf_level * levels,int count)433 cpufreq_get_level(device_t dev, struct cf_level *levels, int count)
434 {
435 int i, freq;
436
437 if ((freq = cpufreq_get_frequency(dev)) < 0)
438 return (-1);
439 for (i = 0; i < count; i++)
440 if (freq == levels[i].total_set.freq)
441 return (i);
442
443 return (-1);
444 }
445
446 /*
447 * Used by the cpufreq core, this function will populate *level with the current
448 * frequency as either determined by a cached value sc->curr_level, or in the
449 * case the lower level driver has set the CPUFREQ_FLAG_UNCACHED flag, it will
450 * obtain the frequency from the driver itself.
451 */
452 static int
cf_get_method(device_t dev,struct cf_level * level)453 cf_get_method(device_t dev, struct cf_level *level)
454 {
455 struct cpufreq_softc *sc;
456 struct cf_level *levels;
457 struct cf_setting *curr_set;
458 struct pcpu *pc;
459 int bdiff, count, diff, error, i, type;
460 uint64_t rate;
461
462 sc = device_get_softc(dev);
463 error = 0;
464 levels = NULL;
465
466 /*
467 * If we already know the current frequency, and the driver didn't ask
468 * for uncached usage, we're done.
469 */
470 CF_MTX_LOCK(&sc->lock);
471 curr_set = &sc->curr_level.total_set;
472 error = CPUFREQ_DRV_TYPE(sc->cf_drv_dev, &type);
473 if (error == 0 && (type & CPUFREQ_FLAG_UNCACHED)) {
474 struct cf_setting set;
475
476 /*
477 * If the driver wants to always report back the real frequency,
478 * first try the driver and if that fails, fall back to
479 * estimating.
480 */
481 if (CPUFREQ_DRV_GET(sc->cf_drv_dev, &set) == 0) {
482 sc->curr_level.total_set = set;
483 CF_DEBUG("get returning immediate freq %d\n",
484 curr_set->freq);
485 goto out;
486 }
487 } else if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
488 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
489 error = 0;
490 goto out;
491 }
492 CF_MTX_UNLOCK(&sc->lock);
493
494 /*
495 * We need to figure out the current level. Loop through every
496 * driver, getting the current setting. Then, attempt to get a best
497 * match of settings against each level.
498 */
499 count = CF_MAX_LEVELS;
500 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
501 if (levels == NULL)
502 return (ENOMEM);
503 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
504 if (error) {
505 if (error == E2BIG)
506 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
507 free(levels, M_TEMP);
508 return (error);
509 }
510
511 /*
512 * Reacquire the lock and search for the given level.
513 *
514 * XXX Note: this is not quite right since we really need to go
515 * through each level and compare both absolute and relative
516 * settings for each driver in the system before making a match.
517 * The estimation code below catches this case though.
518 */
519 CF_MTX_LOCK(&sc->lock);
520 i = cpufreq_get_level(sc->cf_drv_dev, levels, count);
521 if (i >= 0)
522 sc->curr_level = levels[i];
523 else
524 CF_DEBUG("Couldn't find supported level for %s\n",
525 device_get_nameunit(sc->cf_drv_dev));
526
527 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
528 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
529 goto out;
530 }
531
532 /*
533 * We couldn't find an exact match, so attempt to estimate and then
534 * match against a level.
535 */
536 pc = cpu_get_pcpu(dev);
537 if (pc == NULL) {
538 error = ENXIO;
539 goto out;
540 }
541 cpu_est_clockrate(pc->pc_cpuid, &rate);
542 rate /= 1000000;
543 bdiff = 1 << 30;
544 for (i = 0; i < count; i++) {
545 diff = abs(levels[i].total_set.freq - rate);
546 if (diff < bdiff) {
547 bdiff = diff;
548 sc->curr_level = levels[i];
549 }
550 }
551 CF_DEBUG("get estimated freq %d\n", curr_set->freq);
552
553 out:
554 if (error == 0)
555 *level = sc->curr_level;
556
557 CF_MTX_UNLOCK(&sc->lock);
558 if (levels)
559 free(levels, M_TEMP);
560 return (error);
561 }
562
563 /*
564 * Either directly obtain settings from the cpufreq driver, or build a list of
565 * relative settings to be integrated later against an absolute max.
566 */
567 static int
cpufreq_add_levels(device_t cf_dev,struct cf_setting_lst * rel_sets)568 cpufreq_add_levels(device_t cf_dev, struct cf_setting_lst *rel_sets)
569 {
570 struct cf_setting_array *set_arr;
571 struct cf_setting *sets;
572 device_t dev;
573 struct cpufreq_softc *sc;
574 int type, set_count, error;
575
576 sc = device_get_softc(cf_dev);
577 dev = sc->cf_drv_dev;
578
579 /* Skip devices that aren't ready. */
580 if (!device_is_attached(cf_dev))
581 return (0);
582
583 /*
584 * Get settings, skipping drivers that offer no settings or
585 * provide settings for informational purposes only.
586 */
587 error = CPUFREQ_DRV_TYPE(dev, &type);
588 if (error != 0 || (type & CPUFREQ_FLAG_INFO_ONLY)) {
589 if (error == 0) {
590 CF_DEBUG("skipping info-only driver %s\n",
591 device_get_nameunit(cf_dev));
592 }
593 return (error);
594 }
595
596 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
597 if (sets == NULL)
598 return (ENOMEM);
599
600 set_count = MAX_SETTINGS;
601 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
602 if (error != 0 || set_count == 0)
603 goto out;
604
605 /* Add the settings to our absolute/relative lists. */
606 switch (type & CPUFREQ_TYPE_MASK) {
607 case CPUFREQ_TYPE_ABSOLUTE:
608 error = cpufreq_insert_abs(sc, sets, set_count);
609 break;
610 case CPUFREQ_TYPE_RELATIVE:
611 CF_DEBUG("adding %d relative settings\n", set_count);
612 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
613 if (set_arr == NULL) {
614 error = ENOMEM;
615 goto out;
616 }
617 bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
618 set_arr->count = set_count;
619 TAILQ_INSERT_TAIL(rel_sets, set_arr, link);
620 break;
621 default:
622 error = EINVAL;
623 }
624
625 out:
626 free(sets, M_TEMP);
627 return (error);
628 }
629
630 static int
cf_levels_method(device_t dev,struct cf_level * levels,int * count)631 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
632 {
633 struct cf_setting_array *set_arr;
634 struct cf_setting_lst rel_sets;
635 struct cpufreq_softc *sc;
636 struct cf_level *lev;
637 struct pcpu *pc;
638 int error, i;
639 uint64_t rate;
640
641 if (levels == NULL || count == NULL)
642 return (EINVAL);
643
644 TAILQ_INIT(&rel_sets);
645 sc = device_get_softc(dev);
646
647 CF_MTX_LOCK(&sc->lock);
648 error = cpufreq_add_levels(sc->dev, &rel_sets);
649 if (error)
650 goto out;
651
652 /*
653 * If there are no absolute levels, create a fake one at 100%. We
654 * then cache the clockrate for later use as our base frequency.
655 */
656 if (TAILQ_EMPTY(&sc->all_levels)) {
657 struct cf_setting set;
658
659 CF_DEBUG("No absolute levels returned by driver\n");
660
661 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
662 sc->max_mhz = cpu_get_nominal_mhz(dev);
663 /*
664 * If the CPU can't report a rate for 100%, hope
665 * the CPU is running at its nominal rate right now,
666 * and use that instead.
667 */
668 if (sc->max_mhz <= 0) {
669 pc = cpu_get_pcpu(dev);
670 cpu_est_clockrate(pc->pc_cpuid, &rate);
671 sc->max_mhz = rate / 1000000;
672 }
673 }
674 memset(&set, CPUFREQ_VAL_UNKNOWN, sizeof(set));
675 set.freq = sc->max_mhz;
676 set.dev = NULL;
677 error = cpufreq_insert_abs(sc, &set, 1);
678 if (error)
679 goto out;
680 }
681
682 /* Create a combined list of absolute + relative levels. */
683 TAILQ_FOREACH(set_arr, &rel_sets, link)
684 cpufreq_expand_set(sc, set_arr);
685
686 /* If the caller doesn't have enough space, return the actual count. */
687 if (sc->all_count > *count) {
688 *count = sc->all_count;
689 error = E2BIG;
690 goto out;
691 }
692
693 /* Finally, output the list of levels. */
694 i = 0;
695 TAILQ_FOREACH(lev, &sc->all_levels, link) {
696 /* Skip levels that have a frequency that is too low. */
697 if (lev->total_set.freq < cf_lowest_freq) {
698 sc->all_count--;
699 continue;
700 }
701
702 levels[i] = *lev;
703 i++;
704 }
705 *count = sc->all_count;
706 error = 0;
707
708 out:
709 /* Clear all levels since we regenerate them each time. */
710 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
711 TAILQ_REMOVE(&sc->all_levels, lev, link);
712 free(lev, M_TEMP);
713 }
714 sc->all_count = 0;
715
716 CF_MTX_UNLOCK(&sc->lock);
717 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
718 TAILQ_REMOVE(&rel_sets, set_arr, link);
719 free(set_arr, M_TEMP);
720 }
721 return (error);
722 }
723
724 /*
725 * Create levels for an array of absolute settings and insert them in
726 * sorted order in the specified list.
727 */
728 static int
cpufreq_insert_abs(struct cpufreq_softc * sc,struct cf_setting * sets,int count)729 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
730 int count)
731 {
732 struct cf_level_lst *list;
733 struct cf_level *level, *search;
734 int i, inserted;
735
736 CF_MTX_ASSERT(&sc->lock);
737
738 list = &sc->all_levels;
739 for (i = 0; i < count; i++) {
740 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
741 if (level == NULL)
742 return (ENOMEM);
743 level->abs_set = sets[i];
744 level->total_set = sets[i];
745 level->total_set.dev = NULL;
746 sc->all_count++;
747 inserted = 0;
748
749 if (TAILQ_EMPTY(list)) {
750 CF_DEBUG("adding abs setting %d at head\n",
751 sets[i].freq);
752 TAILQ_INSERT_HEAD(list, level, link);
753 continue;
754 }
755
756 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link)
757 if (sets[i].freq <= search->total_set.freq) {
758 CF_DEBUG("adding abs setting %d after %d\n",
759 sets[i].freq, search->total_set.freq);
760 TAILQ_INSERT_AFTER(list, search, level, link);
761 inserted = 1;
762 break;
763 }
764
765 if (inserted == 0) {
766 TAILQ_FOREACH(search, list, link)
767 if (sets[i].freq >= search->total_set.freq) {
768 CF_DEBUG("adding abs setting %d before %d\n",
769 sets[i].freq, search->total_set.freq);
770 TAILQ_INSERT_BEFORE(search, level, link);
771 break;
772 }
773 }
774 }
775
776 return (0);
777 }
778
779 /*
780 * Expand a group of relative settings, creating derived levels from them.
781 */
782 static int
cpufreq_expand_set(struct cpufreq_softc * sc,struct cf_setting_array * set_arr)783 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
784 {
785 struct cf_level *fill, *search;
786 struct cf_setting *set;
787 int i;
788
789 CF_MTX_ASSERT(&sc->lock);
790
791 /*
792 * Walk the set of all existing levels in reverse. This is so we
793 * create derived states from the lowest absolute settings first
794 * and discard duplicates created from higher absolute settings.
795 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
796 * preferable to 200 Mhz + 25% because absolute settings are more
797 * efficient since they often change the voltage as well.
798 */
799 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
800 /* Add each setting to the level, duplicating if necessary. */
801 for (i = 0; i < set_arr->count; i++) {
802 set = &set_arr->sets[i];
803
804 /*
805 * If this setting is less than 100%, split the level
806 * into two and add this setting to the new level.
807 */
808 fill = search;
809 if (set->freq < 10000) {
810 fill = cpufreq_dup_set(sc, search, set);
811
812 /*
813 * The new level was a duplicate of an existing
814 * level or its absolute setting is too high
815 * so we freed it. For example, we discard a
816 * derived level of 1000 MHz/25% if a level
817 * of 500 MHz/100% already exists.
818 */
819 if (fill == NULL)
820 break;
821 }
822
823 /* Add this setting to the existing or new level. */
824 KASSERT(fill->rel_count < MAX_SETTINGS,
825 ("cpufreq: too many relative drivers (%d)",
826 MAX_SETTINGS));
827 fill->rel_set[fill->rel_count] = *set;
828 fill->rel_count++;
829 CF_DEBUG(
830 "expand set added rel setting %d%% to %d level\n",
831 set->freq / 100, fill->total_set.freq);
832 }
833 }
834
835 return (0);
836 }
837
838 static struct cf_level *
cpufreq_dup_set(struct cpufreq_softc * sc,struct cf_level * dup,struct cf_setting * set)839 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
840 struct cf_setting *set)
841 {
842 struct cf_level_lst *list;
843 struct cf_level *fill, *itr;
844 struct cf_setting *fill_set, *itr_set;
845 int i;
846
847 CF_MTX_ASSERT(&sc->lock);
848
849 /*
850 * Create a new level, copy it from the old one, and update the
851 * total frequency and power by the percentage specified in the
852 * relative setting.
853 */
854 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
855 if (fill == NULL)
856 return (NULL);
857 *fill = *dup;
858 fill_set = &fill->total_set;
859 fill_set->freq =
860 ((uint64_t)fill_set->freq * set->freq) / 10000;
861 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
862 fill_set->power = ((uint64_t)fill_set->power * set->freq)
863 / 10000;
864 }
865 if (set->lat != CPUFREQ_VAL_UNKNOWN) {
866 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
867 fill_set->lat += set->lat;
868 else
869 fill_set->lat = set->lat;
870 }
871 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
872
873 /*
874 * If we copied an old level that we already modified (say, at 100%),
875 * we need to remove that setting before adding this one. Since we
876 * process each setting array in order, we know any settings for this
877 * driver will be found at the end.
878 */
879 for (i = fill->rel_count; i != 0; i--) {
880 if (fill->rel_set[i - 1].dev != set->dev)
881 break;
882 CF_DEBUG("removed last relative driver: %s\n",
883 device_get_nameunit(set->dev));
884 fill->rel_count--;
885 }
886
887 /*
888 * Insert the new level in sorted order. If it is a duplicate of an
889 * existing level (1) or has an absolute setting higher than the
890 * existing level (2), do not add it. We can do this since any such
891 * level is guaranteed use less power. For example (1), a level with
892 * one absolute setting of 800 Mhz uses less power than one composed
893 * of an absolute setting of 1600 Mhz and a relative setting at 50%.
894 * Also for example (2), a level of 800 Mhz/75% is preferable to
895 * 1600 Mhz/25% even though the latter has a lower total frequency.
896 */
897 list = &sc->all_levels;
898 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
899 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
900 itr_set = &itr->total_set;
901 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
902 CF_DEBUG("dup set rejecting %d (dupe)\n",
903 fill_set->freq);
904 itr = NULL;
905 break;
906 } else if (fill_set->freq < itr_set->freq) {
907 if (fill->abs_set.freq <= itr->abs_set.freq) {
908 CF_DEBUG(
909 "dup done, inserting new level %d after %d\n",
910 fill_set->freq, itr_set->freq);
911 TAILQ_INSERT_AFTER(list, itr, fill, link);
912 sc->all_count++;
913 } else {
914 CF_DEBUG("dup set rejecting %d (abs too big)\n",
915 fill_set->freq);
916 itr = NULL;
917 }
918 break;
919 }
920 }
921
922 /* We didn't find a good place for this new level so free it. */
923 if (itr == NULL) {
924 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
925 fill_set->freq);
926 free(fill, M_TEMP);
927 fill = NULL;
928 }
929
930 return (fill);
931 }
932
933 static int
cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)934 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
935 {
936 struct cpufreq_softc *sc;
937 struct cf_level *levels;
938 int best, count, diff, bdiff, devcount, error, freq, i, n;
939 device_t *devs;
940
941 devs = NULL;
942 sc = oidp->oid_arg1;
943 levels = sc->levels_buf;
944
945 error = CPUFREQ_GET(sc->dev, &levels[0]);
946 if (error)
947 goto out;
948 freq = levels[0].total_set.freq;
949 error = sysctl_handle_int(oidp, &freq, 0, req);
950 if (error != 0 || req->newptr == NULL)
951 goto out;
952
953 /*
954 * While we only call cpufreq_get() on one device (assuming all
955 * CPUs have equal levels), we call cpufreq_set() on all CPUs.
956 * This is needed for some MP systems.
957 */
958 error = devclass_get_devices(devclass_find("cpufreq"), &devs, &devcount);
959 if (error)
960 goto out;
961 for (n = 0; n < devcount; n++) {
962 count = CF_MAX_LEVELS;
963 error = CPUFREQ_LEVELS(devs[n], levels, &count);
964 if (error) {
965 if (error == E2BIG)
966 printf(
967 "cpufreq: need to increase CF_MAX_LEVELS\n");
968 break;
969 }
970 best = 0;
971 bdiff = 1 << 30;
972 for (i = 0; i < count; i++) {
973 diff = abs(levels[i].total_set.freq - freq);
974 if (diff < bdiff) {
975 bdiff = diff;
976 best = i;
977 }
978 }
979 error = CPUFREQ_SET(devs[n], &levels[best], CPUFREQ_PRIO_USER);
980 }
981
982 out:
983 if (devs)
984 free(devs, M_TEMP);
985 return (error);
986 }
987
988 static int
cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)989 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
990 {
991 struct cpufreq_softc *sc;
992 struct cf_level *levels;
993 struct cf_setting *set;
994 struct sbuf sb;
995 int count, error, i;
996
997 sc = oidp->oid_arg1;
998 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
999
1000 /* Get settings from the device and generate the output string. */
1001 count = CF_MAX_LEVELS;
1002 levels = sc->levels_buf;
1003 if (levels == NULL) {
1004 sbuf_delete(&sb);
1005 return (ENOMEM);
1006 }
1007 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
1008 if (error) {
1009 if (error == E2BIG)
1010 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
1011 goto out;
1012 }
1013 if (count) {
1014 for (i = 0; i < count; i++) {
1015 set = &levels[i].total_set;
1016 sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
1017 }
1018 } else
1019 sbuf_cpy(&sb, "0");
1020 sbuf_trim(&sb);
1021 sbuf_finish(&sb);
1022 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1023
1024 out:
1025 sbuf_delete(&sb);
1026 return (error);
1027 }
1028
1029 static int
cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)1030 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
1031 {
1032 device_t dev;
1033 struct cf_setting *sets;
1034 struct sbuf sb;
1035 int error, i, set_count;
1036
1037 dev = oidp->oid_arg1;
1038 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
1039
1040 /* Get settings from the device and generate the output string. */
1041 set_count = MAX_SETTINGS;
1042 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
1043 if (sets == NULL) {
1044 sbuf_delete(&sb);
1045 return (ENOMEM);
1046 }
1047 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
1048 if (error)
1049 goto out;
1050 if (set_count) {
1051 for (i = 0; i < set_count; i++)
1052 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
1053 } else
1054 sbuf_cpy(&sb, "0");
1055 sbuf_trim(&sb);
1056 sbuf_finish(&sb);
1057 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1058
1059 out:
1060 free(sets, M_TEMP);
1061 sbuf_delete(&sb);
1062 return (error);
1063 }
1064
1065 static void
cpufreq_add_freq_driver_sysctl(device_t cf_dev)1066 cpufreq_add_freq_driver_sysctl(device_t cf_dev)
1067 {
1068 struct cpufreq_softc *sc;
1069
1070 sc = device_get_softc(cf_dev);
1071 SYSCTL_ADD_CONST_STRING(&sc->sysctl_ctx,
1072 SYSCTL_CHILDREN(device_get_sysctl_tree(cf_dev)), OID_AUTO,
1073 "freq_driver", CTLFLAG_RD, device_get_nameunit(sc->cf_drv_dev),
1074 "cpufreq driver used by this cpu");
1075 }
1076
1077 int
cpufreq_register(device_t dev)1078 cpufreq_register(device_t dev)
1079 {
1080 struct cpufreq_softc *sc;
1081 device_t cf_dev, cpu_dev;
1082 int error;
1083
1084 /* Add a sysctl to get each driver's settings separately. */
1085 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
1086 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1087 OID_AUTO, "freq_settings",
1088 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, dev, 0,
1089 cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
1090
1091 /*
1092 * Add only one cpufreq device to each CPU. Currently, all CPUs
1093 * must offer the same levels and be switched at the same time.
1094 */
1095 cpu_dev = device_get_parent(dev);
1096 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
1097 sc = device_get_softc(cf_dev);
1098 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
1099 MPASS(sc->cf_drv_dev != NULL);
1100 return (0);
1101 }
1102
1103 /* Add the child device and possibly sysctls. */
1104 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", device_get_unit(cpu_dev));
1105 if (cf_dev == NULL)
1106 return (ENOMEM);
1107 device_quiet(cf_dev);
1108
1109 error = device_probe_and_attach(cf_dev);
1110 if (error)
1111 return (error);
1112
1113 sc = device_get_softc(cf_dev);
1114 sc->cf_drv_dev = dev;
1115 cpufreq_add_freq_driver_sysctl(cf_dev);
1116 return (error);
1117 }
1118
1119 int
cpufreq_unregister(device_t dev)1120 cpufreq_unregister(device_t dev)
1121 {
1122 device_t cf_dev;
1123 struct cpufreq_softc *sc __diagused;
1124
1125 /*
1126 * If this is the last cpufreq child device, remove the control
1127 * device as well. We identify cpufreq children by calling a method
1128 * they support.
1129 */
1130 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
1131 if (cf_dev == NULL) {
1132 device_printf(dev,
1133 "warning: cpufreq_unregister called with no cpufreq device active\n");
1134 return (0);
1135 }
1136 sc = device_get_softc(cf_dev);
1137 MPASS(sc->cf_drv_dev == dev);
1138 device_delete_child(device_get_parent(cf_dev), cf_dev);
1139
1140 return (0);
1141 }
1142
1143 int
cpufreq_settings_changed(device_t dev)1144 cpufreq_settings_changed(device_t dev)
1145 {
1146
1147 EVENTHANDLER_INVOKE(cpufreq_levels_changed,
1148 device_get_unit(device_get_parent(dev)));
1149 return (0);
1150 }
1151