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: releng/8.1/sys/kern/kern_cpu.c 202815 2010-01-22 17:03:49Z brueffer $");
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 };
80
81 struct cf_setting_array {
82 struct cf_setting sets[MAX_SETTINGS];
83 int count;
84 TAILQ_ENTRY(cf_setting_array) link;
85 };
86
87 TAILQ_HEAD(cf_setting_lst, cf_setting_array);
88
89 #define CF_MTX_INIT(x) sx_init((x), "cpufreq lock")
90 #define CF_MTX_LOCK(x) sx_xlock((x))
91 #define CF_MTX_UNLOCK(x) sx_xunlock((x))
92 #define CF_MTX_ASSERT(x) sx_assert((x), SX_XLOCKED)
93
94 #define CF_DEBUG(msg...) do { \
95 if (cf_verbose) \
96 printf("cpufreq: " msg); \
97 } while (0)
98
99 static int cpufreq_attach(device_t dev);
100 static void cpufreq_startup_task(void *ctx, int pending);
101 static int cpufreq_detach(device_t dev);
102 static int cf_set_method(device_t dev, const struct cf_level *level,
103 int priority);
104 static int cf_get_method(device_t dev, struct cf_level *level);
105 static int cf_levels_method(device_t dev, struct cf_level *levels,
106 int *count);
107 static int cpufreq_insert_abs(struct cpufreq_softc *sc,
108 struct cf_setting *sets, int count);
109 static int cpufreq_expand_set(struct cpufreq_softc *sc,
110 struct cf_setting_array *set_arr);
111 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc,
112 struct cf_level *dup, struct cf_setting *set);
113 static int cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS);
114 static int cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS);
115 static int cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS);
116
117 static device_method_t cpufreq_methods[] = {
118 DEVMETHOD(device_probe, bus_generic_probe),
119 DEVMETHOD(device_attach, cpufreq_attach),
120 DEVMETHOD(device_detach, cpufreq_detach),
121
122 DEVMETHOD(cpufreq_set, cf_set_method),
123 DEVMETHOD(cpufreq_get, cf_get_method),
124 DEVMETHOD(cpufreq_levels, cf_levels_method),
125 {0, 0}
126 };
127 static driver_t cpufreq_driver = {
128 "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc)
129 };
130 static devclass_t cpufreq_dc;
131 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0);
132
133 static int cf_lowest_freq;
134 static int cf_verbose;
135 TUNABLE_INT("debug.cpufreq.lowest", &cf_lowest_freq);
136 TUNABLE_INT("debug.cpufreq.verbose", &cf_verbose);
137 SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL, "cpufreq debugging");
138 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 1,
139 "Don't provide levels below this frequency.");
140 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1,
141 "Print verbose debugging messages");
142
143 static int
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 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
184 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
185 OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
186 cpufreq_curr_sysctl, "I", "Current CPU frequency");
187 SYSCTL_ADD_PROC(&sc->sysctl_ctx,
188 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)),
189 OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, 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
204 cpufreq_startup_task(void *ctx, int pending)
205 {
206
207 cpufreq_settings_changed((device_t)ctx);
208 }
209
210 static int
211 cpufreq_detach(device_t dev)
212 {
213 struct cpufreq_softc *sc;
214 struct cf_saved_freq *saved_freq;
215 int numdevs;
216
217 CF_DEBUG("shutdown %s\n", device_get_nameunit(dev));
218 sc = device_get_softc(dev);
219 sysctl_ctx_free(&sc->sysctl_ctx);
220
221 while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) {
222 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
223 free(saved_freq, M_TEMP);
224 }
225
226 /* Only clean up these resources when the last device is detaching. */
227 numdevs = devclass_get_count(cpufreq_dc);
228 if (numdevs == 1) {
229 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev));
230 }
231
232 return (0);
233 }
234
235 static int
236 cf_set_method(device_t dev, const struct cf_level *level, int priority)
237 {
238 struct cpufreq_softc *sc;
239 const struct cf_setting *set;
240 struct cf_saved_freq *saved_freq, *curr_freq;
241 struct pcpu *pc;
242 int error, i;
243
244 sc = device_get_softc(dev);
245 error = 0;
246 set = NULL;
247 saved_freq = NULL;
248
249 /* We are going to change levels so notify the pre-change handler. */
250 EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error);
251 if (error != 0) {
252 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
253 return (error);
254 }
255
256 CF_MTX_LOCK(&sc->lock);
257
258 #ifdef SMP
259 /*
260 * If still booting and secondary CPUs not started yet, don't allow
261 * changing the frequency until they're online. This is because we
262 * can't switch to them using sched_bind() and thus we'd only be
263 * switching the main CPU. XXXTODO: Need to think more about how to
264 * handle having different CPUs at different frequencies.
265 */
266 if (mp_ncpus > 1 && !smp_active) {
267 device_printf(dev, "rejecting change, SMP not started yet\n");
268 error = ENXIO;
269 goto out;
270 }
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 (CPUFREQ_CMP(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 thread_lock(curthread);
327 sched_bind(curthread, pc->pc_cpuid);
328 thread_unlock(curthread);
329 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq,
330 device_get_nameunit(set->dev), PCPU_GET(cpuid));
331 error = CPUFREQ_DRV_SET(set->dev, set);
332 thread_lock(curthread);
333 sched_unbind(curthread);
334 thread_unlock(curthread);
335 if (error) {
336 goto out;
337 }
338 }
339
340 /* Next, set any/all relative frequencies via their drivers. */
341 for (i = 0; i < level->rel_count; i++) {
342 set = &level->rel_set[i];
343 if (!device_is_attached(set->dev)) {
344 error = ENXIO;
345 goto out;
346 }
347
348 /* Bind to the target CPU before switching. */
349 pc = cpu_get_pcpu(set->dev);
350 thread_lock(curthread);
351 sched_bind(curthread, pc->pc_cpuid);
352 thread_unlock(curthread);
353 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq,
354 device_get_nameunit(set->dev), PCPU_GET(cpuid));
355 error = CPUFREQ_DRV_SET(set->dev, set);
356 thread_lock(curthread);
357 sched_unbind(curthread);
358 thread_unlock(curthread);
359 if (error) {
360 /* XXX Back out any successful setting? */
361 goto out;
362 }
363 }
364
365 skip:
366 /*
367 * Before recording the current level, check if we're going to a
368 * higher priority. If so, save the previous level and priority.
369 */
370 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN &&
371 priority > sc->curr_priority) {
372 CF_DEBUG("saving level, freq %d prio %d\n",
373 sc->curr_level.total_set.freq, sc->curr_priority);
374 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT);
375 if (curr_freq == NULL) {
376 error = ENOMEM;
377 goto out;
378 }
379 curr_freq->level = sc->curr_level;
380 curr_freq->priority = sc->curr_priority;
381 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link);
382 }
383 sc->curr_level = *level;
384 sc->curr_priority = priority;
385
386 /* If we were restoring a saved state, reset it to "unused". */
387 if (saved_freq != NULL) {
388 CF_DEBUG("resetting saved level\n");
389 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
390 SLIST_REMOVE_HEAD(&sc->saved_freq, link);
391 free(saved_freq, M_TEMP);
392 }
393
394 out:
395 CF_MTX_UNLOCK(&sc->lock);
396
397 /*
398 * We changed levels (or attempted to) so notify the post-change
399 * handler of new frequency or error.
400 */
401 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error);
402 if (error && set)
403 device_printf(set->dev, "set freq failed, err %d\n", error);
404
405 return (error);
406 }
407
408 static int
409 cf_get_method(device_t dev, struct cf_level *level)
410 {
411 struct cpufreq_softc *sc;
412 struct cf_level *levels;
413 struct cf_setting *curr_set, set;
414 struct pcpu *pc;
415 device_t *devs;
416 int count, error, i, n, numdevs;
417 uint64_t rate;
418
419 sc = device_get_softc(dev);
420 error = 0;
421 levels = NULL;
422
423 /* If we already know the current frequency, we're done. */
424 CF_MTX_LOCK(&sc->lock);
425 curr_set = &sc->curr_level.total_set;
426 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
427 CF_DEBUG("get returning known freq %d\n", curr_set->freq);
428 goto out;
429 }
430 CF_MTX_UNLOCK(&sc->lock);
431
432 /*
433 * We need to figure out the current level. Loop through every
434 * driver, getting the current setting. Then, attempt to get a best
435 * match of settings against each level.
436 */
437 count = CF_MAX_LEVELS;
438 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
439 if (levels == NULL)
440 return (ENOMEM);
441 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
442 if (error) {
443 if (error == E2BIG)
444 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
445 free(levels, M_TEMP);
446 return (error);
447 }
448 error = device_get_children(device_get_parent(dev), &devs, &numdevs);
449 if (error) {
450 free(levels, M_TEMP);
451 return (error);
452 }
453
454 /*
455 * Reacquire the lock and search for the given level.
456 *
457 * XXX Note: this is not quite right since we really need to go
458 * through each level and compare both absolute and relative
459 * settings for each driver in the system before making a match.
460 * The estimation code below catches this case though.
461 */
462 CF_MTX_LOCK(&sc->lock);
463 for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) {
464 if (!device_is_attached(devs[n]))
465 continue;
466 if (CPUFREQ_DRV_GET(devs[n], &set) != 0)
467 continue;
468 for (i = 0; i < count; i++) {
469 if (CPUFREQ_CMP(set.freq, levels[i].total_set.freq)) {
470 sc->curr_level = levels[i];
471 break;
472 }
473 }
474 }
475 free(devs, M_TEMP);
476 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) {
477 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq);
478 goto out;
479 }
480
481 /*
482 * We couldn't find an exact match, so attempt to estimate and then
483 * match against a level.
484 */
485 pc = cpu_get_pcpu(dev);
486 if (pc == NULL) {
487 error = ENXIO;
488 goto out;
489 }
490 cpu_est_clockrate(pc->pc_cpuid, &rate);
491 rate /= 1000000;
492 for (i = 0; i < count; i++) {
493 if (CPUFREQ_CMP(rate, levels[i].total_set.freq)) {
494 sc->curr_level = levels[i];
495 CF_DEBUG("get estimated freq %d\n", curr_set->freq);
496 goto out;
497 }
498 }
499 error = ENXIO;
500
501 out:
502 if (error == 0)
503 *level = sc->curr_level;
504
505 CF_MTX_UNLOCK(&sc->lock);
506 if (levels)
507 free(levels, M_TEMP);
508 return (error);
509 }
510
511 static int
512 cf_levels_method(device_t dev, struct cf_level *levels, int *count)
513 {
514 struct cf_setting_array *set_arr;
515 struct cf_setting_lst rel_sets;
516 struct cpufreq_softc *sc;
517 struct cf_level *lev;
518 struct cf_setting *sets;
519 struct pcpu *pc;
520 device_t *devs;
521 int error, i, numdevs, set_count, type;
522 uint64_t rate;
523
524 if (levels == NULL || count == NULL)
525 return (EINVAL);
526
527 TAILQ_INIT(&rel_sets);
528 sc = device_get_softc(dev);
529 error = device_get_children(device_get_parent(dev), &devs, &numdevs);
530 if (error)
531 return (error);
532 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT);
533 if (sets == NULL) {
534 free(devs, M_TEMP);
535 return (ENOMEM);
536 }
537
538 /* Get settings from all cpufreq drivers. */
539 CF_MTX_LOCK(&sc->lock);
540 for (i = 0; i < numdevs; i++) {
541 /* Skip devices that aren't ready. */
542 if (!device_is_attached(devs[i]))
543 continue;
544
545 /*
546 * Get settings, skipping drivers that offer no settings or
547 * provide settings for informational purposes only.
548 */
549 error = CPUFREQ_DRV_TYPE(devs[i], &type);
550 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) {
551 if (error == 0) {
552 CF_DEBUG("skipping info-only driver %s\n",
553 device_get_nameunit(devs[i]));
554 }
555 continue;
556 }
557 set_count = MAX_SETTINGS;
558 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count);
559 if (error || set_count == 0)
560 continue;
561
562 /* Add the settings to our absolute/relative lists. */
563 switch (type & CPUFREQ_TYPE_MASK) {
564 case CPUFREQ_TYPE_ABSOLUTE:
565 error = cpufreq_insert_abs(sc, sets, set_count);
566 break;
567 case CPUFREQ_TYPE_RELATIVE:
568 CF_DEBUG("adding %d relative settings\n", set_count);
569 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT);
570 if (set_arr == NULL) {
571 error = ENOMEM;
572 goto out;
573 }
574 bcopy(sets, set_arr->sets, set_count * sizeof(*sets));
575 set_arr->count = set_count;
576 TAILQ_INSERT_TAIL(&rel_sets, set_arr, link);
577 break;
578 default:
579 error = EINVAL;
580 }
581 if (error)
582 goto out;
583 }
584
585 /*
586 * If there are no absolute levels, create a fake one at 100%. We
587 * then cache the clockrate for later use as our base frequency.
588 */
589 if (TAILQ_EMPTY(&sc->all_levels)) {
590 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) {
591 sc->max_mhz = cpu_get_nominal_mhz(dev);
592 /*
593 * If the CPU can't report a rate for 100%, hope
594 * the CPU is running at its nominal rate right now,
595 * and use that instead.
596 */
597 if (sc->max_mhz <= 0) {
598 pc = cpu_get_pcpu(dev);
599 cpu_est_clockrate(pc->pc_cpuid, &rate);
600 sc->max_mhz = rate / 1000000;
601 }
602 }
603 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets));
604 sets[0].freq = sc->max_mhz;
605 sets[0].dev = NULL;
606 error = cpufreq_insert_abs(sc, sets, 1);
607 if (error)
608 goto out;
609 }
610
611 /* Create a combined list of absolute + relative levels. */
612 TAILQ_FOREACH(set_arr, &rel_sets, link)
613 cpufreq_expand_set(sc, set_arr);
614
615 /* If the caller doesn't have enough space, return the actual count. */
616 if (sc->all_count > *count) {
617 *count = sc->all_count;
618 error = E2BIG;
619 goto out;
620 }
621
622 /* Finally, output the list of levels. */
623 i = 0;
624 TAILQ_FOREACH(lev, &sc->all_levels, link) {
625 /*
626 * Skip levels that are too close in frequency to the
627 * previous levels. Some systems report bogus duplicate
628 * settings (i.e., for acpi_perf).
629 */
630 if (i > 0 && CPUFREQ_CMP(lev->total_set.freq,
631 levels[i - 1].total_set.freq)) {
632 sc->all_count--;
633 continue;
634 }
635
636 /* Skip levels that have a frequency that is too low. */
637 if (lev->total_set.freq < cf_lowest_freq) {
638 sc->all_count--;
639 continue;
640 }
641
642 levels[i] = *lev;
643 i++;
644 }
645 *count = sc->all_count;
646 error = 0;
647
648 out:
649 /* Clear all levels since we regenerate them each time. */
650 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) {
651 TAILQ_REMOVE(&sc->all_levels, lev, link);
652 free(lev, M_TEMP);
653 }
654 sc->all_count = 0;
655
656 CF_MTX_UNLOCK(&sc->lock);
657 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
658 TAILQ_REMOVE(&rel_sets, set_arr, link);
659 free(set_arr, M_TEMP);
660 }
661 free(devs, M_TEMP);
662 free(sets, M_TEMP);
663 return (error);
664 }
665
666 /*
667 * Create levels for an array of absolute settings and insert them in
668 * sorted order in the specified list.
669 */
670 static int
671 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
672 int count)
673 {
674 struct cf_level_lst *list;
675 struct cf_level *level, *search;
676 int i;
677
678 CF_MTX_ASSERT(&sc->lock);
679
680 list = &sc->all_levels;
681 for (i = 0; i < count; i++) {
682 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
683 if (level == NULL)
684 return (ENOMEM);
685 level->abs_set = sets[i];
686 level->total_set = sets[i];
687 level->total_set.dev = NULL;
688 sc->all_count++;
689
690 if (TAILQ_EMPTY(list)) {
691 CF_DEBUG("adding abs setting %d at head\n",
692 sets[i].freq);
693 TAILQ_INSERT_HEAD(list, level, link);
694 continue;
695 }
696
697 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) {
698 if (sets[i].freq <= search->total_set.freq) {
699 CF_DEBUG("adding abs setting %d after %d\n",
700 sets[i].freq, search->total_set.freq);
701 TAILQ_INSERT_AFTER(list, search, level, link);
702 break;
703 }
704 }
705 }
706 return (0);
707 }
708
709 /*
710 * Expand a group of relative settings, creating derived levels from them.
711 */
712 static int
713 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
714 {
715 struct cf_level *fill, *search;
716 struct cf_setting *set;
717 int i;
718
719 CF_MTX_ASSERT(&sc->lock);
720
721 /*
722 * Walk the set of all existing levels in reverse. This is so we
723 * create derived states from the lowest absolute settings first
724 * and discard duplicates created from higher absolute settings.
725 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is
726 * preferable to 200 Mhz + 25% because absolute settings are more
727 * efficient since they often change the voltage as well.
728 */
729 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) {
730 /* Add each setting to the level, duplicating if necessary. */
731 for (i = 0; i < set_arr->count; i++) {
732 set = &set_arr->sets[i];
733
734 /*
735 * If this setting is less than 100%, split the level
736 * into two and add this setting to the new level.
737 */
738 fill = search;
739 if (set->freq < 10000) {
740 fill = cpufreq_dup_set(sc, search, set);
741
742 /*
743 * The new level was a duplicate of an existing
744 * level or its absolute setting is too high
745 * so we freed it. For example, we discard a
746 * derived level of 1000 MHz/25% if a level
747 * of 500 MHz/100% already exists.
748 */
749 if (fill == NULL)
750 break;
751 }
752
753 /* Add this setting to the existing or new level. */
754 KASSERT(fill->rel_count < MAX_SETTINGS,
755 ("cpufreq: too many relative drivers (%d)",
756 MAX_SETTINGS));
757 fill->rel_set[fill->rel_count] = *set;
758 fill->rel_count++;
759 CF_DEBUG(
760 "expand set added rel setting %d%% to %d level\n",
761 set->freq / 100, fill->total_set.freq);
762 }
763 }
764
765 return (0);
766 }
767
768 static struct cf_level *
769 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
770 struct cf_setting *set)
771 {
772 struct cf_level_lst *list;
773 struct cf_level *fill, *itr;
774 struct cf_setting *fill_set, *itr_set;
775 int i;
776
777 CF_MTX_ASSERT(&sc->lock);
778
779 /*
780 * Create a new level, copy it from the old one, and update the
781 * total frequency and power by the percentage specified in the
782 * relative setting.
783 */
784 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT);
785 if (fill == NULL)
786 return (NULL);
787 *fill = *dup;
788 fill_set = &fill->total_set;
789 fill_set->freq =
790 ((uint64_t)fill_set->freq * set->freq) / 10000;
791 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) {
792 fill_set->power = ((uint64_t)fill_set->power * set->freq)
793 / 10000;
794 }
795 if (set->lat != CPUFREQ_VAL_UNKNOWN) {
796 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN)
797 fill_set->lat += set->lat;
798 else
799 fill_set->lat = set->lat;
800 }
801 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq);
802
803 /*
804 * If we copied an old level that we already modified (say, at 100%),
805 * we need to remove that setting before adding this one. Since we
806 * process each setting array in order, we know any settings for this
807 * driver will be found at the end.
808 */
809 for (i = fill->rel_count; i != 0; i--) {
810 if (fill->rel_set[i - 1].dev != set->dev)
811 break;
812 CF_DEBUG("removed last relative driver: %s\n",
813 device_get_nameunit(set->dev));
814 fill->rel_count--;
815 }
816
817 /*
818 * Insert the new level in sorted order. If it is a duplicate of an
819 * existing level (1) or has an absolute setting higher than the
820 * existing level (2), do not add it. We can do this since any such
821 * level is guaranteed use less power. For example (1), a level with
822 * one absolute setting of 800 Mhz uses less power than one composed
823 * of an absolute setting of 1600 Mhz and a relative setting at 50%.
824 * Also for example (2), a level of 800 Mhz/75% is preferable to
825 * 1600 Mhz/25% even though the latter has a lower total frequency.
826 */
827 list = &sc->all_levels;
828 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set"));
829 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) {
830 itr_set = &itr->total_set;
831 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) {
832 CF_DEBUG("dup set rejecting %d (dupe)\n",
833 fill_set->freq);
834 itr = NULL;
835 break;
836 } else if (fill_set->freq < itr_set->freq) {
837 if (fill->abs_set.freq <= itr->abs_set.freq) {
838 CF_DEBUG(
839 "dup done, inserting new level %d after %d\n",
840 fill_set->freq, itr_set->freq);
841 TAILQ_INSERT_AFTER(list, itr, fill, link);
842 sc->all_count++;
843 } else {
844 CF_DEBUG("dup set rejecting %d (abs too big)\n",
845 fill_set->freq);
846 itr = NULL;
847 }
848 break;
849 }
850 }
851
852 /* We didn't find a good place for this new level so free it. */
853 if (itr == NULL) {
854 CF_DEBUG("dup set freeing new level %d (not optimal)\n",
855 fill_set->freq);
856 free(fill, M_TEMP);
857 fill = NULL;
858 }
859
860 return (fill);
861 }
862
863 static int
864 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS)
865 {
866 struct cpufreq_softc *sc;
867 struct cf_level *levels;
868 int count, devcount, error, freq, i, n;
869 device_t *devs;
870
871 devs = NULL;
872 sc = oidp->oid_arg1;
873 levels = malloc(CF_MAX_LEVELS * sizeof(*levels), M_TEMP, M_NOWAIT);
874 if (levels == NULL)
875 return (ENOMEM);
876
877 error = CPUFREQ_GET(sc->dev, &levels[0]);
878 if (error)
879 goto out;
880 freq = levels[0].total_set.freq;
881 error = sysctl_handle_int(oidp, &freq, 0, req);
882 if (error != 0 || req->newptr == NULL)
883 goto out;
884
885 /*
886 * While we only call cpufreq_get() on one device (assuming all
887 * CPUs have equal levels), we call cpufreq_set() on all CPUs.
888 * This is needed for some MP systems.
889 */
890 error = devclass_get_devices(cpufreq_dc, &devs, &devcount);
891 if (error)
892 goto out;
893 for (n = 0; n < devcount; n++) {
894 count = CF_MAX_LEVELS;
895 error = CPUFREQ_LEVELS(devs[n], levels, &count);
896 if (error) {
897 if (error == E2BIG)
898 printf(
899 "cpufreq: need to increase CF_MAX_LEVELS\n");
900 break;
901 }
902 for (i = 0; i < count; i++) {
903 if (CPUFREQ_CMP(levels[i].total_set.freq, freq)) {
904 error = CPUFREQ_SET(devs[n], &levels[i],
905 CPUFREQ_PRIO_USER);
906 break;
907 }
908 }
909 if (i == count) {
910 error = EINVAL;
911 break;
912 }
913 }
914
915 out:
916 if (devs)
917 free(devs, M_TEMP);
918 if (levels)
919 free(levels, M_TEMP);
920 return (error);
921 }
922
923 static int
924 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS)
925 {
926 struct cpufreq_softc *sc;
927 struct cf_level *levels;
928 struct cf_setting *set;
929 struct sbuf sb;
930 int count, error, i;
931
932 sc = oidp->oid_arg1;
933 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
934
935 /* Get settings from the device and generate the output string. */
936 count = CF_MAX_LEVELS;
937 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT);
938 if (levels == NULL) {
939 sbuf_delete(&sb);
940 return (ENOMEM);
941 }
942 error = CPUFREQ_LEVELS(sc->dev, levels, &count);
943 if (error) {
944 if (error == E2BIG)
945 printf("cpufreq: need to increase CF_MAX_LEVELS\n");
946 goto out;
947 }
948 if (count) {
949 for (i = 0; i < count; i++) {
950 set = &levels[i].total_set;
951 sbuf_printf(&sb, "%d/%d ", set->freq, set->power);
952 }
953 } else
954 sbuf_cpy(&sb, "");
955 sbuf_trim(&sb);
956 sbuf_finish(&sb);
957 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
958
959 out:
960 free(levels, M_TEMP);
961 sbuf_delete(&sb);
962 return (error);
963 }
964
965 static int
966 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS)
967 {
968 device_t dev;
969 struct cf_setting *sets;
970 struct sbuf sb;
971 int error, i, set_count;
972
973 dev = oidp->oid_arg1;
974 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND);
975
976 /* Get settings from the device and generate the output string. */
977 set_count = MAX_SETTINGS;
978 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT);
979 if (sets == NULL) {
980 sbuf_delete(&sb);
981 return (ENOMEM);
982 }
983 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count);
984 if (error)
985 goto out;
986 if (set_count) {
987 for (i = 0; i < set_count; i++)
988 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power);
989 } else
990 sbuf_cpy(&sb, "");
991 sbuf_trim(&sb);
992 sbuf_finish(&sb);
993 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
994
995 out:
996 free(sets, M_TEMP);
997 sbuf_delete(&sb);
998 return (error);
999 }
1000
1001 int
1002 cpufreq_register(device_t dev)
1003 {
1004 struct cpufreq_softc *sc;
1005 device_t cf_dev, cpu_dev;
1006
1007 /* Add a sysctl to get each driver's settings separately. */
1008 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
1009 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
1010 OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0,
1011 cpufreq_settings_sysctl, "A", "CPU frequency driver settings");
1012
1013 /*
1014 * Add only one cpufreq device to each CPU. Currently, all CPUs
1015 * must offer the same levels and be switched at the same time.
1016 */
1017 cpu_dev = device_get_parent(dev);
1018 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) {
1019 sc = device_get_softc(cf_dev);
1020 sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
1021 return (0);
1022 }
1023
1024 /* Add the child device and possibly sysctls. */
1025 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1);
1026 if (cf_dev == NULL)
1027 return (ENOMEM);
1028 device_quiet(cf_dev);
1029
1030 return (device_probe_and_attach(cf_dev));
1031 }
1032
1033 int
1034 cpufreq_unregister(device_t dev)
1035 {
1036 device_t cf_dev, *devs;
1037 int cfcount, devcount, error, i, type;
1038
1039 /*
1040 * If this is the last cpufreq child device, remove the control
1041 * device as well. We identify cpufreq children by calling a method
1042 * they support.
1043 */
1044 error = device_get_children(device_get_parent(dev), &devs, &devcount);
1045 if (error)
1046 return (error);
1047 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1);
1048 if (cf_dev == NULL) {
1049 device_printf(dev,
1050 "warning: cpufreq_unregister called with no cpufreq device active\n");
1051 return (0);
1052 }
1053 cfcount = 0;
1054 for (i = 0; i < devcount; i++) {
1055 if (!device_is_attached(devs[i]))
1056 continue;
1057 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0)
1058 cfcount++;
1059 }
1060 if (cfcount <= 1)
1061 device_delete_child(device_get_parent(cf_dev), cf_dev);
1062 free(devs, M_TEMP);
1063
1064 return (0);
1065 }
1066
1067 int
1068 cpufreq_settings_changed(device_t dev)
1069 {
1070
1071 EVENTHANDLER_INVOKE(cpufreq_levels_changed,
1072 device_get_unit(device_get_parent(dev)));
1073 return (0);
1074 }
Cache object: d41750fef35612377bac39e44b20b9c2
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