FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_cpu.c
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 TUNABLE_INT("debug.cpufreq.lowest", &cf_lowest_freq);
137 TUNABLE_INT("debug.cpufreq.verbose", &cf_verbose);
138 static SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL,
139 "cpufreq debugging");
140 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 1,
141 "Don't provide levels below this frequency.");
142 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1,
143 "Print verbose debugging messages");
144
145 static int
146 cpufreq_attach(device_t dev)
147 {
148 struct cpufreq_softc *sc;
149 struct pcpu *pc;
150 device_t parent;
151 uint64_t rate;
152 int numdevs;
153
154 CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
155 sc = device_get_softc(dev);
156 parent = device_get_parent(dev);
157 sc->dev = dev;
158 sysctl_ctx_init(&sc->sysctl_ctx);
159 TAILQ_INIT(&sc->all_levels);
160 CF_MTX_INIT(&sc->lock);
161 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
162 SLIST_INIT(&sc->saved_freq);
163 /* Try to get nominal CPU freq to use it as maximum later if needed */
164 sc->max_mhz = cpu_get_nominal_mhz(dev);
165 /* If that fails, try to measure the current rate */
166 if (sc->max_mhz <= 0) {
167 pc = cpu_get_pcpu(dev);
168 if (cpu_est_clockrate(pc->pc_cpuid, &rate) == 0)
169 sc->max_mhz = rate / 1000000;
170 else
171 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
172 }
173
174 /*
175 * Only initialize one set of sysctls for all CPUs. In the future,
176 * if multiple CPUs can have different settings, we can move these
177 * sysctls to be under every CPU instead of just the first one.
178 */
179 numdevs = devclass_get_count(cpufreq_dc);
180 if (numdevs > 1)
181 return (0);
182
183 CF_DEBUG("initializing one-time data for %s\n",
184 device_get_nameunit(dev));
185 sc->levels_buf = malloc(CF_MAX_LEVELS * sizeof(*sc->levels_buf),
186 M_DEVBUF, M_WAITOK);
187 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
188 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
189 OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
190 cpufreq_curr_sysctl, "I", "Current CPU frequency");
191 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
192 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
193 OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
194 cpufreq_levels_sysctl, "A", "CPU frequency levels");
195
196 /*
197 * Queue a one-shot broadcast that levels have changed.
198 * It will run once the system has completed booting.
199 */
200 TASK_INIT(&sc->startup_task, 0, cpufreq_startup_task, dev);
201 taskqueue_enqueue(taskqueue_thread, &sc->startup_task);
202
203 return (0);
204 }
205
206 /* Handle any work to be done for all drivers that attached during boot. */
207 static void
208 cpufreq_startup_task(void *ctx, int pending)
209 {
210
211 cpufreq_settings_changed((device_t)ctx);
212 }
213
214 static int
215 cpufreq_detach(device_t dev)
216 {
217 struct cpufreq_softc *sc;
218 struct cf_saved_freq *saved_freq;
219 int numdevs;
220
221 CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
222 sc = device_get_softc(dev);
223 sysctl_ctx_free(&sc->sysctl_ctx);
224
225 while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) {
226 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
227 free(saved_freq, M_TEMP);
228 }
229
230 /* Only clean up these resources when the last device is detaching. */
231 numdevs = devclass_get_count(cpufreq_dc);
232 if (numdevs == 1) {
233 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev));
234 free(sc->levels_buf, M_DEVBUF);
235 }
236
237 return (0);
238 }
239
240 static int
241 cf_set_method(device_t dev, const struct cf_level *level, int priority)
242 {
243 struct cpufreq_softc *sc;
244 const struct cf_setting *set;
245 struct cf_saved_freq *saved_freq, *curr_freq;
246 struct pcpu *pc;
247 int error, i;
248
249 sc = device_get_softc(dev);
250 error = 0;
251 set = NULL;
252 saved_freq = NULL;
253
254 /* We are going to change levels so notify the pre-change handler. */
255 EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error);
256 if (error != 0) {
257 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
258 return (error);
259 }
260
261 CF_MTX_LOCK(&sc->lock);
262
263 #ifdef SMP
264 /*
265 * If still booting and secondary CPUs not started yet, don't allow
266 * changing the frequency until they're online. This is because we
267 * can't switch to them using sched_bind() and thus we'd only be
268 * switching the main CPU. XXXTODO: Need to think more about how to
269 * handle having different CPUs at different frequencies.
270 */
271 if (mp_ncpus > 1 && !smp_active) {
272 device_printf(dev, "rejecting change, SMP not started yet\n");
273 error = ENXIO;
274 goto out;
275 }
276 #endif /* SMP */
277
278 /*
279 * If the requested level has a lower priority, don't allow
280 * the new level right now.
281 */
282 if (priority < sc->curr_priority) {
283 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority,
284 sc->curr_priority);
285 error = EPERM;
286 goto out;
287 }
288
289 /*
290 * If the caller didn't specify a level and one is saved, prepare to
291 * restore the saved level. If none has been saved, return an error.
292 */
293 if (level == NULL) {
294 saved_freq = SLIST_FIRST(&sc->saved_freq);
295 if (saved_freq == NULL) {
296 CF_DEBUG("NULL level, no saved level\n");
297 error = ENXIO;
298 goto out;
299 }
300 level = &saved_freq->level;
301 priority = saved_freq->priority;
302 CF_DEBUG("restoring saved level, freq %d prio %d\n",
303 level->total_set.freq, priority);
304 }
305
306 /* Reject levels that are below our specified threshold. */
307 if (level->total_set.freq < cf_lowest_freq) {
308 CF_DEBUG("rejecting freq %d, less than %d limit\n",
309 level->total_set.freq, cf_lowest_freq);
310 error = EINVAL;
311 goto out;
312 }
313
314 /* If already at this level, just return. */
315 if (sc->curr_level.total_set.freq == level->total_set.freq) {
316 CF_DEBUG("skipping freq %d, same as current level %d\n",
317 level->total_set.freq, sc->curr_level.total_set.freq);
318 goto skip;
319 }
320
321 /* First, set the absolute frequency via its driver. */
322 set = &level->abs_set;
323 if (set->dev) {
324 if (!device_is_attached(set->dev)) {
325 error = ENXIO;
326 goto out;
327 }
328
329 /* Bind to the target CPU before switching. */
330 pc = cpu_get_pcpu(set->dev);
331 thread_lock(curthread);
332 sched_bind(curthread, pc->pc_cpuid);
333 thread_unlock(curthread);
334 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
335 device_get_nameunit(set->dev), PCPU_GET(cpuid));
336 error = CPUFREQ_DRV_SET(set->dev, set);
337 thread_lock(curthread);
338 sched_unbind(curthread);
339 thread_unlock(curthread);
340 if (error) {
341 goto out;
342 }
343 }
344
345 /* Next, set any/all relative frequencies via their drivers. */
346 for (i = 0; i < level->rel_count; i++) {
347 set = &level->rel_set[i];
348 if (!device_is_attached(set->dev)) {
349 error = ENXIO;
350 goto out;
351 }
352
353 /* Bind to the target CPU before switching. */
354 pc = cpu_get_pcpu(set->dev);
355 thread_lock(curthread);
356 sched_bind(curthread, pc->pc_cpuid);
357 thread_unlock(curthread);
358 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
359 device_get_nameunit(set->dev), PCPU_GET(cpuid));
360 error = CPUFREQ_DRV_SET(set->dev, set);
361 thread_lock(curthread);
362 sched_unbind(curthread);
363 thread_unlock(curthread);
364 if (error) {
365 /* XXX Back out any successful setting? */
366 goto out;
367 }
368 }
369
370 skip:
371 /*
372 * Before recording the current level, check if we're going to a
373 * higher priority. If so, save the previous level and priority.
374 */
375 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
376 priority > sc->curr_priority) {
377 CF_DEBUG("saving level, freq %d prio %d\n",
378 sc->curr_level.total_set.freq, sc->curr_priority);
379 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT);
380 if (curr_freq == NULL) {
381 error = ENOMEM;
382 goto out;
383 }
384 curr_freq->level = sc->curr_level;
385 curr_freq->priority = sc->curr_priority;
386 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link);
387 }
388 sc->curr_level = *level;
389 sc->curr_priority = priority;
390
391 /* If we were restoring a saved state, reset it to "unused". */
392 if (saved_freq != NULL) {
393 CF_DEBUG("resetting saved level\n");
394 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
395 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
396 free(saved_freq, M_TEMP);
397 }
398
399 out:
400 CF_MTX_UNLOCK(&sc->lock);
401
402 /*
403 * We changed levels (or attempted to) so notify the post-change
404 * handler of new frequency or error.
405 */
406 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
407 if (error && set)
408 device_printf(set->dev, "set freq failed, err %d\n", error);
409
410 return (error);
411 }
412
413 static int
414 cf_get_method(device_t dev, struct cf_level *level)
415 {
416 struct cpufreq_softc *sc;
417 struct cf_level *levels;
418 struct cf_setting *curr_set, set;
419 struct pcpu *pc;
420 device_t *devs;
421 int bdiff, count, diff, error, i, n, numdevs;
422 uint64_t rate;
423
424 sc = device_get_softc(dev);
425 error = 0;
426 levels = NULL;
427
428 /* If we already know the current frequency, we're done. */
429 CF_MTX_LOCK(&sc->lock);
430 curr_set = &sc->curr_level.total_set;
431 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
432 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
433 goto out;
434 }
435 CF_MTX_UNLOCK(&sc->lock);
436
437 /*
438 * We need to figure out the current level. Loop through every
439 * driver, getting the current setting. Then, attempt to get a best
440 * match of settings against each level.
441 */
442 count = CF_MAX_LEVELS;
443 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
444 if (levels == NULL)
445 return (ENOMEM);
446 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
447 if (error) {
448 if (error == E2BIG)
449 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
450 free(levels, M_TEMP);
451 return (error);
452 }
453 error = device_get_children(device_get_parent(dev), &devs, &numdevs);
454 if (error) {
455 free(levels, M_TEMP);
456 return (error);
457 }
458
459 /*
460 * Reacquire the lock and search for the given level.
461 *
462 * XXX Note: this is not quite right since we really need to go
463 * through each level and compare both absolute and relative
464 * settings for each driver in the system before making a match.
465 * The estimation code below catches this case though.
466 */
467 CF_MTX_LOCK(&sc->lock);
468 for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) {
469 if (!device_is_attached(devs[n]))
470 continue;
471 if (CPUFREQ_DRV_GET(devs[n], &set) != 0)
472 continue;
473 for (i = 0; i < count; i++) {
474 if (set.freq == levels[i].total_set.freq) {
475 sc->curr_level = levels[i];
476 break;
477 }
478 }
479 }
480 free(devs, M_TEMP);
481 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
482 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
483 goto out;
484 }
485
486 /*
487 * We couldn't find an exact match, so attempt to estimate and then
488 * match against a level.
489 */
490 pc = cpu_get_pcpu(dev);
491 if (pc == NULL) {
492 error = ENXIO;
493 goto out;
494 }
495 cpu_est_clockrate(pc->pc_cpuid, &rate);
496 rate /= 1000000;
497 bdiff = 1 << 30;
498 for (i = 0; i < count; i++) {
499 diff = abs(levels[i].total_set.freq - rate);
500 if (diff < bdiff) {
501 bdiff = diff;
502 sc->curr_level = levels[i];
503 }
504 }
505 CF_DEBUG("get estimated freq %d\n", curr_set->freq);
506
507 out:
508 if (error == 0)
509 *level = sc->curr_level;
510
511 CF_MTX_UNLOCK(&sc->lock);
512 if (levels)
513 free(levels, M_TEMP);
514 return (error);
515 }
516
517 static int
518 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
519 {
520 struct cf_setting_array *set_arr;
521 struct cf_setting_lst rel_sets;
522 struct cpufreq_softc *sc;
523 struct cf_level *lev;
524 struct cf_setting *sets;
525 struct pcpu *pc;
526 device_t *devs;
527 int error, i, numdevs, set_count, type;
528 uint64_t rate;
529
530 if (levels == NULL || count == NULL)
531 return (EINVAL);
532
533 TAILQ_INIT(&rel_sets);
534 sc = device_get_softc(dev);
535 error = device_get_children(device_get_parent(dev), &devs, &numdevs);
536 if (error)
537 return (error);
538 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
539 if (sets == NULL) {
540 free(devs, M_TEMP);
541 return (ENOMEM);
542 }
543
544 /* Get settings from all cpufreq drivers. */
545 CF_MTX_LOCK(&sc->lock);
546 for (i = 0; i < numdevs; i++) {
547 /* Skip devices that aren't ready. */
548 if (!device_is_attached(devs[i]))
549 continue;
550
551 /*
552 * Get settings, skipping drivers that offer no settings or
553 * provide settings for informational purposes only.
554 */
555 error = CPUFREQ_DRV_TYPE(devs[i], &type);
556 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) {
557 if (error == 0) {
558 CF_DEBUG("skipping info-only driver %s\n",
559 device_get_nameunit(devs[i]));
560 }
561 continue;
562 }
563 set_count = MAX_SETTINGS;
564 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count);
565 if (error || set_count == 0)
566 continue;
567
568 /* Add the settings to our absolute/relative lists. */
569 switch (type & CPUFREQ_TYPE_MASK) {
570 case CPUFREQ_TYPE_ABSOLUTE:
571 error = cpufreq_insert_abs(sc, sets, set_count);
572 break;
573 case CPUFREQ_TYPE_RELATIVE:
574 CF_DEBUG("adding %d relative settings\n", set_count);
575 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
576 if (set_arr == NULL) {
577 error = ENOMEM;
578 goto out;
579 }
580 bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
581 set_arr->count = set_count;
582 TAILQ_INSERT_TAIL(&rel_sets, set_arr, link);
583 break;
584 default:
585 error = EINVAL;
586 }
587 if (error)
588 goto out;
589 }
590
591 /*
592 * If there are no absolute levels, create a fake one at 100%. We
593 * then cache the clockrate for later use as our base frequency.
594 */
595 if (TAILQ_EMPTY(&sc->all_levels)) {
596 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
597 sc->max_mhz = cpu_get_nominal_mhz(dev);
598 /*
599 * If the CPU can't report a rate for 100%, hope
600 * the CPU is running at its nominal rate right now,
601 * and use that instead.
602 */
603 if (sc->max_mhz <= 0) {
604 pc = cpu_get_pcpu(dev);
605 cpu_est_clockrate(pc->pc_cpuid, &rate);
606 sc->max_mhz = rate / 1000000;
607 }
608 }
609 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets));
610 sets[0].freq = sc->max_mhz;
611 sets[0].dev = NULL;
612 error = cpufreq_insert_abs(sc, sets, 1);
613 if (error)
614 goto out;
615 }
616
617 /* Create a combined list of absolute + relative levels. */
618 TAILQ_FOREACH(set_arr, &rel_sets, link)
619 cpufreq_expand_set(sc, set_arr);
620
621 /* If the caller doesn't have enough space, return the actual count. */
622 if (sc->all_count > *count) {
623 *count = sc->all_count;
624 error = E2BIG;
625 goto out;
626 }
627
628 /* Finally, output the list of levels. */
629 i = 0;
630 TAILQ_FOREACH(lev, &sc->all_levels, link) {
631
632 /* Skip levels that have a frequency that is too low. */
633 if (lev->total_set.freq < cf_lowest_freq) {
634 sc->all_count--;
635 continue;
636 }
637
638 levels[i] = *lev;
639 i++;
640 }
641 *count = sc->all_count;
642 error = 0;
643
644 out:
645 /* Clear all levels since we regenerate them each time. */
646 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
647 TAILQ_REMOVE(&sc->all_levels, lev, link);
648 free(lev, M_TEMP);
649 }
650 sc->all_count = 0;
651
652 CF_MTX_UNLOCK(&sc->lock);
653 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
654 TAILQ_REMOVE(&rel_sets, set_arr, link);
655 free(set_arr, M_TEMP);
656 }
657 free(devs, M_TEMP);
658 free(sets, M_TEMP);
659 return (error);
660 }
661
662 /*
663 * Create levels for an array of absolute settings and insert them in
664 * sorted order in the specified list.
665 */
666 static int
667 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
668 int count)
669 {
670 struct cf_level_lst *list;
671 struct cf_level *level, *search;
672 int i;
673
674 CF_MTX_ASSERT(&sc->lock);
675
676 list = &sc->all_levels;
677 for (i = 0; i < count; i++) {
678 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
679 if (level == NULL)
680 return (ENOMEM);
681 level->abs_set = sets[i];
682 level->total_set = sets[i];
683 level->total_set.dev = NULL;
684 sc->all_count++;
685
686 if (TAILQ_EMPTY(list)) {
687 CF_DEBUG("adding abs setting %d at head\n",
688 sets[i].freq);
689 TAILQ_INSERT_HEAD(list, level, link);
690 continue;
691 }
692
693 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) {
694 if (sets[i].freq <= search->total_set.freq) {
695 CF_DEBUG("adding abs setting %d after %d\n",
696 sets[i].freq, search->total_set.freq);
697 TAILQ_INSERT_AFTER(list, search, level, link);
698 break;
699 }
700 }
701 }
702 return (0);
703 }
704
705 /*
706 * Expand a group of relative settings, creating derived levels from them.
707 */
708 static int
709 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
710 {
711 struct cf_level *fill, *search;
712 struct cf_setting *set;
713 int i;
714
715 CF_MTX_ASSERT(&sc->lock);
716
717 /*
718 * Walk the set of all existing levels in reverse. This is so we
719 * create derived states from the lowest absolute settings first
720 * and discard duplicates created from higher absolute settings.
721 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
722 * preferable to 200 Mhz + 25% because absolute settings are more
723 * efficient since they often change the voltage as well.
724 */
725 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
726 /* Add each setting to the level, duplicating if necessary. */
727 for (i = 0; i < set_arr->count; i++) {
728 set = &set_arr->sets[i];
729
730 /*
731 * If this setting is less than 100%, split the level
732 * into two and add this setting to the new level.
733 */
734 fill = search;
735 if (set->freq < 10000) {
736 fill = cpufreq_dup_set(sc, search, set);
737
738 /*
739 * The new level was a duplicate of an existing
740 * level or its absolute setting is too high
741 * so we freed it. For example, we discard a
742 * derived level of 1000 MHz/25% if a level
743 * of 500 MHz/100% already exists.
744 */
745 if (fill == NULL)
746 break;
747 }
748
749 /* Add this setting to the existing or new level. */
750 KASSERT(fill->rel_count < MAX_SETTINGS,
751 ("cpufreq: too many relative drivers (%d)",
752 MAX_SETTINGS));
753 fill->rel_set[fill->rel_count] = *set;
754 fill->rel_count++;
755 CF_DEBUG(
756 "expand set added rel setting %d%% to %d level\n",
757 set->freq / 100, fill->total_set.freq);
758 }
759 }
760
761 return (0);
762 }
763
764 static struct cf_level *
765 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
766 struct cf_setting *set)
767 {
768 struct cf_level_lst *list;
769 struct cf_level *fill, *itr;
770 struct cf_setting *fill_set, *itr_set;
771 int i;
772
773 CF_MTX_ASSERT(&sc->lock);
774
775 /*
776 * Create a new level, copy it from the old one, and update the
777 * total frequency and power by the percentage specified in the
778 * relative setting.
779 */
780 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
781 if (fill == NULL)
782 return (NULL);
783 *fill = *dup;
784 fill_set = &fill->total_set;
785 fill_set->freq =
786 ((uint64_t)fill_set->freq * set->freq) / 10000;
787 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
788 fill_set->power = ((uint64_t)fill_set->power * set->freq)
789 / 10000;
790 }
791 if (set->lat != CPUFREQ_VAL_UNKNOWN) {
792 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
793 fill_set->lat += set->lat;
794 else
795 fill_set->lat = set->lat;
796 }
797 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
798
799 /*
800 * If we copied an old level that we already modified (say, at 100%),
801 * we need to remove that setting before adding this one. Since we
802 * process each setting array in order, we know any settings for this
803 * driver will be found at the end.
804 */
805 for (i = fill->rel_count; i != 0; i--) {
806 if (fill->rel_set[i - 1].dev != set->dev)
807 break;
808 CF_DEBUG("removed last relative driver: %s\n",
809 device_get_nameunit(set->dev));
810 fill->rel_count--;
811 }
812
813 /*
814 * Insert the new level in sorted order. If it is a duplicate of an
815 * existing level (1) or has an absolute setting higher than the
816 * existing level (2), do not add it. We can do this since any such
817 * level is guaranteed use less power. For example (1), a level with
818 * one absolute setting of 800 Mhz uses less power than one composed
819 * of an absolute setting of 1600 Mhz and a relative setting at 50%.
820 * Also for example (2), a level of 800 Mhz/75% is preferable to
821 * 1600 Mhz/25% even though the latter has a lower total frequency.
822 */
823 list = &sc->all_levels;
824 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
825 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
826 itr_set = &itr->total_set;
827 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
828 CF_DEBUG("dup set rejecting %d (dupe)\n",
829 fill_set->freq);
830 itr = NULL;
831 break;
832 } else if (fill_set->freq < itr_set->freq) {
833 if (fill->abs_set.freq <= itr->abs_set.freq) {
834 CF_DEBUG(
835 "dup done, inserting new level %d after %d\n",
836 fill_set->freq, itr_set->freq);
837 TAILQ_INSERT_AFTER(list, itr, fill, link);
838 sc->all_count++;
839 } else {
840 CF_DEBUG("dup set rejecting %d (abs too big)\n",
841 fill_set->freq);
842 itr = NULL;
843 }
844 break;
845 }
846 }
847
848 /* We didn't find a good place for this new level so free it. */
849 if (itr == NULL) {
850 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
851 fill_set->freq);
852 free(fill, M_TEMP);
853 fill = NULL;
854 }
855
856 return (fill);
857 }
858
859 static int
860 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
861 {
862 struct cpufreq_softc *sc;
863 struct cf_level *levels;
864 int best, count, diff, bdiff, devcount, error, freq, i, n;
865 device_t *devs;
866
867 devs = NULL;
868 sc = oidp->oid_arg1;
869 levels = sc->levels_buf;
870
871 error = CPUFREQ_GET(sc->dev, &levels[0]);
872 if (error)
873 goto out;
874 freq = levels[0].total_set.freq;
875 error = sysctl_handle_int(oidp, &freq, 0, req);
876 if (error != 0 || req->newptr == NULL)
877 goto out;
878
879 /*
880 * While we only call cpufreq_get() on one device (assuming all
881 * CPUs have equal levels), we call cpufreq_set() on all CPUs.
882 * This is needed for some MP systems.
883 */
884 error = devclass_get_devices(cpufreq_dc, &devs, &devcount);
885 if (error)
886 goto out;
887 for (n = 0; n < devcount; n++) {
888 count = CF_MAX_LEVELS;
889 error = CPUFREQ_LEVELS(devs[n], levels, &count);
890 if (error) {
891 if (error == E2BIG)
892 printf(
893 "cpufreq: need to increase CF_MAX_LEVELS\n");
894 break;
895 }
896 best = 0;
897 bdiff = 1 << 30;
898 for (i = 0; i < count; i++) {
899 diff = abs(levels[i].total_set.freq - freq);
900 if (diff < bdiff) {
901 bdiff = diff;
902 best = i;
903 }
904 }
905 error = CPUFREQ_SET(devs[n], &levels[best], CPUFREQ_PRIO_USER);
906 }
907
908 out:
909 if (devs)
910 free(devs, M_TEMP);
911 return (error);
912 }
913
914 static int
915 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
916 {
917 struct cpufreq_softc *sc;
918 struct cf_level *levels;
919 struct cf_setting *set;
920 struct sbuf sb;
921 int count, error, i;
922
923 sc = oidp->oid_arg1;
924 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
925
926 /* Get settings from the device and generate the output string. */
927 count = CF_MAX_LEVELS;
928 levels = sc->levels_buf;
929 if (levels == NULL) {
930 sbuf_delete(&sb);
931 return (ENOMEM);
932 }
933 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
934 if (error) {
935 if (error == E2BIG)
936 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
937 goto out;
938 }
939 if (count) {
940 for (i = 0; i < count; i++) {
941 set = &levels[i].total_set;
942 sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
943 }
944 } else
945 sbuf_cpy(&sb, "");
946 sbuf_trim(&sb);
947 sbuf_finish(&sb);
948 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
949
950 out:
951 sbuf_delete(&sb);
952 return (error);
953 }
954
955 static int
956 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
957 {
958 device_t dev;
959 struct cf_setting *sets;
960 struct sbuf sb;
961 int error, i, set_count;
962
963 dev = oidp->oid_arg1;
964 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
965
966 /* Get settings from the device and generate the output string. */
967 set_count = MAX_SETTINGS;
968 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
969 if (sets == NULL) {
970 sbuf_delete(&sb);
971 return (ENOMEM);
972 }
973 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
974 if (error)
975 goto out;
976 if (set_count) {
977 for (i = 0; i < set_count; i++)
978 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
979 } else
980 sbuf_cpy(&sb, "");
981 sbuf_trim(&sb);
982 sbuf_finish(&sb);
983 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
984
985 out:
986 free(sets, M_TEMP);
987 sbuf_delete(&sb);
988 return (error);
989 }
990
991 int
992 cpufreq_register(device_t dev)
993 {
994 struct cpufreq_softc *sc;
995 device_t cf_dev, cpu_dev;
996
997 /* Add a sysctl to get each driver's settings separately. */
998 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
999 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1000 OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0,
1001 cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
1002
1003 /*
1004 * Add only one cpufreq device to each CPU. Currently, all CPUs
1005 * must offer the same levels and be switched at the same time.
1006 */
1007 cpu_dev = device_get_parent(dev);
1008 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
1009 sc = device_get_softc(cf_dev);
1010 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
1011 return (0);
1012 }
1013
1014 /* Add the child device and possibly sysctls. */
1015 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1);
1016 if (cf_dev == NULL)
1017 return (ENOMEM);
1018 device_quiet(cf_dev);
1019
1020 return (device_probe_and_attach(cf_dev));
1021 }
1022
1023 int
1024 cpufreq_unregister(device_t dev)
1025 {
1026 device_t cf_dev, *devs;
1027 int cfcount, devcount, error, i, type;
1028
1029 /*
1030 * If this is the last cpufreq child device, remove the control
1031 * device as well. We identify cpufreq children by calling a method
1032 * they support.
1033 */
1034 error = device_get_children(device_get_parent(dev), &devs, &devcount);
1035 if (error)
1036 return (error);
1037 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
1038 if (cf_dev == NULL) {
1039 device_printf(dev,
1040 "warning: cpufreq_unregister called with no cpufreq device active\n");
1041 free(devs, M_TEMP);
1042 return (0);
1043 }
1044 cfcount = 0;
1045 for (i = 0; i < devcount; i++) {
1046 if (!device_is_attached(devs[i]))
1047 continue;
1048 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0)
1049 cfcount++;
1050 }
1051 if (cfcount <= 1)
1052 device_delete_child(device_get_parent(cf_dev), cf_dev);
1053 free(devs, M_TEMP);
1054
1055 return (0);
1056 }
1057
1058 int
1059 cpufreq_settings_changed(device_t dev)
1060 {
1061
1062 EVENTHANDLER_INVOKE(cpufreq_levels_changed,
1063 device_get_unit(device_get_parent(dev)));
1064 return (0);
1065 }
Cache object: 8077ae60b4fd0f5f2b0ac2f8640201fd
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