Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_cpu.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/cpu.h> 35 #include <sys/eventhandler.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/module.h> 40 #include <sys/proc.h> 41 #include <sys/queue.h> 42 #include <sys/sbuf.h> 43 #include <sys/sched.h> 44 #include <sys/smp.h> 45 #include <sys/sysctl.h> 46 #include <sys/systm.h> 47 #include <sys/sx.h> 48 #include <sys/timetc.h> 49 #include <sys/taskqueue.h> 50 51 #include "cpufreq_if.h" 52 53 /* 54 * Common CPU frequency glue code. Drivers for specific hardware can 55 * attach this interface to allow users to get/set the CPU frequency. 56 */ 57 58 /* 59 * Number of levels we can handle. Levels are synthesized from settings 60 * so for M settings and N drivers, there may be M*N levels. 61 */ 62 #define CF_MAX_LEVELS 256 63 64 struct cf_saved_freq { 65 struct cf_level level; 66 int priority; 67 SLIST_ENTRY(cf_saved_freq) link; 68 }; 69 70 struct cpufreq_softc { 71 struct sx lock; 72 struct cf_level curr_level; 73 int curr_priority; 74 SLIST_HEAD(, cf_saved_freq) saved_freq; 75 struct cf_level_lst all_levels; 76 int all_count; 77 int max_mhz; 78 device_t dev; 79 struct sysctl_ctx_list sysctl_ctx; 80 struct task startup_task; 81 struct cf_level *levels_buf; 82 }; 83 84 struct cf_setting_array { 85 struct cf_setting sets[MAX_SETTINGS]; 86 int count; 87 TAILQ_ENTRY(cf_setting_array) link; 88 }; 89 90 TAILQ_HEAD(cf_setting_lst, cf_setting_array); 91 92 #define CF_MTX_INIT(x) sx_init((x), "cpufreq lock") 93 #define CF_MTX_LOCK(x) sx_xlock((x)) 94 #define CF_MTX_UNLOCK(x) sx_xunlock((x)) 95 #define CF_MTX_ASSERT(x) sx_assert((x), SX_XLOCKED) 96 97 #define CF_DEBUG(msg...) do { \ 98 if (cf_verbose) \ 99 printf("cpufreq: " msg); \ 100 } while (0) 101 102 static int cpufreq_attach(device_t dev); 103 static void cpufreq_startup_task(void *ctx, int pending); 104 static int cpufreq_detach(device_t dev); 105 static int cf_set_method(device_t dev, const struct cf_level *level, 106 int priority); 107 static int cf_get_method(device_t dev, struct cf_level *level); 108 static int cf_levels_method(device_t dev, struct cf_level *levels, 109 int *count); 110 static int cpufreq_insert_abs(struct cpufreq_softc *sc, 111 struct cf_setting *sets, int count); 112 static int cpufreq_expand_set(struct cpufreq_softc *sc, 113 struct cf_setting_array *set_arr); 114 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc, 115 struct cf_level *dup, struct cf_setting *set); 116 static int cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS); 117 static int cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS); 118 static int cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS); 119 120 static device_method_t cpufreq_methods[] = { 121 DEVMETHOD(device_probe, bus_generic_probe), 122 DEVMETHOD(device_attach, cpufreq_attach), 123 DEVMETHOD(device_detach, cpufreq_detach), 124 125 DEVMETHOD(cpufreq_set, cf_set_method), 126 DEVMETHOD(cpufreq_get, cf_get_method), 127 DEVMETHOD(cpufreq_levels, cf_levels_method), 128 {0, 0} 129 }; 130 static driver_t cpufreq_driver = { 131 "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc) 132 }; 133 static devclass_t cpufreq_dc; 134 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0); 135 136 static int cf_lowest_freq; 137 static int 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_RWTUN, &cf_lowest_freq, 1, 141 "Don't provide levels below this frequency."); 142 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RWTUN, &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 u_char pri; 249 250 sc = device_get_softc(dev); 251 error = 0; 252 set = NULL; 253 saved_freq = NULL; 254 255 /* We are going to change levels so notify the pre-change handler. */ 256 EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error); 257 if (error != 0) { 258 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error); 259 return (error); 260 } 261 262 CF_MTX_LOCK(&sc->lock); 263 264 #ifdef SMP 265 #ifdef EARLY_AP_STARTUP 266 MPASS(mp_ncpus == 1 || smp_started); 267 #else 268 /* 269 * If still booting and secondary CPUs not started yet, don't allow 270 * changing the frequency until they're online. This is because we 271 * can't switch to them using sched_bind() and thus we'd only be 272 * switching the main CPU. XXXTODO: Need to think more about how to 273 * handle having different CPUs at different frequencies. 274 */ 275 if (mp_ncpus > 1 && !smp_started) { 276 device_printf(dev, "rejecting change, SMP not started yet\n"); 277 error = ENXIO; 278 goto out; 279 } 280 #endif 281 #endif /* SMP */ 282 283 /* 284 * If the requested level has a lower priority, don't allow 285 * the new level right now. 286 */ 287 if (priority < sc->curr_priority) { 288 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority, 289 sc->curr_priority); 290 error = EPERM; 291 goto out; 292 } 293 294 /* 295 * If the caller didn't specify a level and one is saved, prepare to 296 * restore the saved level. If none has been saved, return an error. 297 */ 298 if (level == NULL) { 299 saved_freq = SLIST_FIRST(&sc->saved_freq); 300 if (saved_freq == NULL) { 301 CF_DEBUG("NULL level, no saved level\n"); 302 error = ENXIO; 303 goto out; 304 } 305 level = &saved_freq->level; 306 priority = saved_freq->priority; 307 CF_DEBUG("restoring saved level, freq %d prio %d\n", 308 level->total_set.freq, priority); 309 } 310 311 /* Reject levels that are below our specified threshold. */ 312 if (level->total_set.freq < cf_lowest_freq) { 313 CF_DEBUG("rejecting freq %d, less than %d limit\n", 314 level->total_set.freq, cf_lowest_freq); 315 error = EINVAL; 316 goto out; 317 } 318 319 /* If already at this level, just return. */ 320 if (sc->curr_level.total_set.freq == level->total_set.freq) { 321 CF_DEBUG("skipping freq %d, same as current level %d\n", 322 level->total_set.freq, sc->curr_level.total_set.freq); 323 goto skip; 324 } 325 326 /* First, set the absolute frequency via its driver. */ 327 set = &level->abs_set; 328 if (set->dev) { 329 if (!device_is_attached(set->dev)) { 330 error = ENXIO; 331 goto out; 332 } 333 334 /* Bind to the target CPU before switching. */ 335 pc = cpu_get_pcpu(set->dev); 336 337 /* Skip settings if CPU is not started. */ 338 if (pc == NULL) { 339 error = 0; 340 goto out; 341 } 342 thread_lock(curthread); 343 pri = curthread->td_priority; 344 sched_prio(curthread, PRI_MIN); 345 sched_bind(curthread, pc->pc_cpuid); 346 thread_unlock(curthread); 347 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq, 348 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 349 error = CPUFREQ_DRV_SET(set->dev, set); 350 thread_lock(curthread); 351 sched_unbind(curthread); 352 sched_prio(curthread, pri); 353 thread_unlock(curthread); 354 if (error) { 355 goto out; 356 } 357 } 358 359 /* Next, set any/all relative frequencies via their drivers. */ 360 for (i = 0; i < level->rel_count; i++) { 361 set = &level->rel_set[i]; 362 if (!device_is_attached(set->dev)) { 363 error = ENXIO; 364 goto out; 365 } 366 367 /* Bind to the target CPU before switching. */ 368 pc = cpu_get_pcpu(set->dev); 369 thread_lock(curthread); 370 pri = curthread->td_priority; 371 sched_prio(curthread, PRI_MIN); 372 sched_bind(curthread, pc->pc_cpuid); 373 thread_unlock(curthread); 374 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq, 375 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 376 error = CPUFREQ_DRV_SET(set->dev, set); 377 thread_lock(curthread); 378 sched_unbind(curthread); 379 sched_prio(curthread, pri); 380 thread_unlock(curthread); 381 if (error) { 382 /* XXX Back out any successful setting? */ 383 goto out; 384 } 385 } 386 387 skip: 388 /* 389 * Before recording the current level, check if we're going to a 390 * higher priority. If so, save the previous level and priority. 391 */ 392 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN && 393 priority > sc->curr_priority) { 394 CF_DEBUG("saving level, freq %d prio %d\n", 395 sc->curr_level.total_set.freq, sc->curr_priority); 396 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT); 397 if (curr_freq == NULL) { 398 error = ENOMEM; 399 goto out; 400 } 401 curr_freq->level = sc->curr_level; 402 curr_freq->priority = sc->curr_priority; 403 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link); 404 } 405 sc->curr_level = *level; 406 sc->curr_priority = priority; 407 408 /* If we were restoring a saved state, reset it to "unused". */ 409 if (saved_freq != NULL) { 410 CF_DEBUG("resetting saved level\n"); 411 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; 412 SLIST_REMOVE_HEAD(&sc->saved_freq, link); 413 free(saved_freq, M_TEMP); 414 } 415 416 out: 417 CF_MTX_UNLOCK(&sc->lock); 418 419 /* 420 * We changed levels (or attempted to) so notify the post-change 421 * handler of new frequency or error. 422 */ 423 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error); 424 if (error && set) 425 device_printf(set->dev, "set freq failed, err %d\n", error); 426 427 return (error); 428 } 429 430 static int 431 cf_get_method(device_t dev, struct cf_level *level) 432 { 433 struct cpufreq_softc *sc; 434 struct cf_level *levels; 435 struct cf_setting *curr_set, set; 436 struct pcpu *pc; 437 device_t *devs; 438 int bdiff, count, diff, error, i, n, numdevs; 439 uint64_t rate; 440 441 sc = device_get_softc(dev); 442 error = 0; 443 levels = NULL; 444 445 /* If we already know the current frequency, we're done. */ 446 CF_MTX_LOCK(&sc->lock); 447 curr_set = &sc->curr_level.total_set; 448 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 449 CF_DEBUG("get returning known freq %d\n", curr_set->freq); 450 goto out; 451 } 452 CF_MTX_UNLOCK(&sc->lock); 453 454 /* 455 * We need to figure out the current level. Loop through every 456 * driver, getting the current setting. Then, attempt to get a best 457 * match of settings against each level. 458 */ 459 count = CF_MAX_LEVELS; 460 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT); 461 if (levels == NULL) 462 return (ENOMEM); 463 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 464 if (error) { 465 if (error == E2BIG) 466 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 467 free(levels, M_TEMP); 468 return (error); 469 } 470 error = device_get_children(device_get_parent(dev), &devs, &numdevs); 471 if (error) { 472 free(levels, M_TEMP); 473 return (error); 474 } 475 476 /* 477 * Reacquire the lock and search for the given level. 478 * 479 * XXX Note: this is not quite right since we really need to go 480 * through each level and compare both absolute and relative 481 * settings for each driver in the system before making a match. 482 * The estimation code below catches this case though. 483 */ 484 CF_MTX_LOCK(&sc->lock); 485 for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) { 486 if (!device_is_attached(devs[n])) 487 continue; 488 if (CPUFREQ_DRV_GET(devs[n], &set) != 0) 489 continue; 490 for (i = 0; i < count; i++) { 491 if (set.freq == levels[i].total_set.freq) { 492 sc->curr_level = levels[i]; 493 break; 494 } 495 } 496 } 497 free(devs, M_TEMP); 498 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 499 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq); 500 goto out; 501 } 502 503 /* 504 * We couldn't find an exact match, so attempt to estimate and then 505 * match against a level. 506 */ 507 pc = cpu_get_pcpu(dev); 508 if (pc == NULL) { 509 error = ENXIO; 510 goto out; 511 } 512 cpu_est_clockrate(pc->pc_cpuid, &rate); 513 rate /= 1000000; 514 bdiff = 1 << 30; 515 for (i = 0; i < count; i++) { 516 diff = abs(levels[i].total_set.freq - rate); 517 if (diff < bdiff) { 518 bdiff = diff; 519 sc->curr_level = levels[i]; 520 } 521 } 522 CF_DEBUG("get estimated freq %d\n", curr_set->freq); 523 524 out: 525 if (error == 0) 526 *level = sc->curr_level; 527 528 CF_MTX_UNLOCK(&sc->lock); 529 if (levels) 530 free(levels, M_TEMP); 531 return (error); 532 } 533 534 static int 535 cf_levels_method(device_t dev, struct cf_level *levels, int *count) 536 { 537 struct cf_setting_array *set_arr; 538 struct cf_setting_lst rel_sets; 539 struct cpufreq_softc *sc; 540 struct cf_level *lev; 541 struct cf_setting *sets; 542 struct pcpu *pc; 543 device_t *devs; 544 int error, i, numdevs, set_count, type; 545 uint64_t rate; 546 547 if (levels == NULL || count == NULL) 548 return (EINVAL); 549 550 TAILQ_INIT(&rel_sets); 551 sc = device_get_softc(dev); 552 error = device_get_children(device_get_parent(dev), &devs, &numdevs); 553 if (error) 554 return (error); 555 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT); 556 if (sets == NULL) { 557 free(devs, M_TEMP); 558 return (ENOMEM); 559 } 560 561 /* Get settings from all cpufreq drivers. */ 562 CF_MTX_LOCK(&sc->lock); 563 for (i = 0; i < numdevs; i++) { 564 /* Skip devices that aren't ready. */ 565 if (!device_is_attached(devs[i])) 566 continue; 567 568 /* 569 * Get settings, skipping drivers that offer no settings or 570 * provide settings for informational purposes only. 571 */ 572 error = CPUFREQ_DRV_TYPE(devs[i], &type); 573 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) { 574 if (error == 0) { 575 CF_DEBUG("skipping info-only driver %s\n", 576 device_get_nameunit(devs[i])); 577 } 578 continue; 579 } 580 set_count = MAX_SETTINGS; 581 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count); 582 if (error || set_count == 0) 583 continue; 584 585 /* Add the settings to our absolute/relative lists. */ 586 switch (type & CPUFREQ_TYPE_MASK) { 587 case CPUFREQ_TYPE_ABSOLUTE: 588 error = cpufreq_insert_abs(sc, sets, set_count); 589 break; 590 case CPUFREQ_TYPE_RELATIVE: 591 CF_DEBUG("adding %d relative settings\n", set_count); 592 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT); 593 if (set_arr == NULL) { 594 error = ENOMEM; 595 goto out; 596 } 597 bcopy(sets, set_arr->sets, set_count * sizeof(*sets)); 598 set_arr->count = set_count; 599 TAILQ_INSERT_TAIL(&rel_sets, set_arr, link); 600 break; 601 default: 602 error = EINVAL; 603 } 604 if (error) 605 goto out; 606 } 607 608 /* 609 * If there are no absolute levels, create a fake one at 100%. We 610 * then cache the clockrate for later use as our base frequency. 611 */ 612 if (TAILQ_EMPTY(&sc->all_levels)) { 613 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) { 614 sc->max_mhz = cpu_get_nominal_mhz(dev); 615 /* 616 * If the CPU can't report a rate for 100%, hope 617 * the CPU is running at its nominal rate right now, 618 * and use that instead. 619 */ 620 if (sc->max_mhz <= 0) { 621 pc = cpu_get_pcpu(dev); 622 cpu_est_clockrate(pc->pc_cpuid, &rate); 623 sc->max_mhz = rate / 1000000; 624 } 625 } 626 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets)); 627 sets[0].freq = sc->max_mhz; 628 sets[0].dev = NULL; 629 error = cpufreq_insert_abs(sc, sets, 1); 630 if (error) 631 goto out; 632 } 633 634 /* Create a combined list of absolute + relative levels. */ 635 TAILQ_FOREACH(set_arr, &rel_sets, link) 636 cpufreq_expand_set(sc, set_arr); 637 638 /* If the caller doesn't have enough space, return the actual count. */ 639 if (sc->all_count > *count) { 640 *count = sc->all_count; 641 error = E2BIG; 642 goto out; 643 } 644 645 /* Finally, output the list of levels. */ 646 i = 0; 647 TAILQ_FOREACH(lev, &sc->all_levels, link) { 648 649 /* Skip levels that have a frequency that is too low. */ 650 if (lev->total_set.freq < cf_lowest_freq) { 651 sc->all_count--; 652 continue; 653 } 654 655 levels[i] = *lev; 656 i++; 657 } 658 *count = sc->all_count; 659 error = 0; 660 661 out: 662 /* Clear all levels since we regenerate them each time. */ 663 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) { 664 TAILQ_REMOVE(&sc->all_levels, lev, link); 665 free(lev, M_TEMP); 666 } 667 sc->all_count = 0; 668 669 CF_MTX_UNLOCK(&sc->lock); 670 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) { 671 TAILQ_REMOVE(&rel_sets, set_arr, link); 672 free(set_arr, M_TEMP); 673 } 674 free(devs, M_TEMP); 675 free(sets, M_TEMP); 676 return (error); 677 } 678 679 /* 680 * Create levels for an array of absolute settings and insert them in 681 * sorted order in the specified list. 682 */ 683 static int 684 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets, 685 int count) 686 { 687 struct cf_level_lst *list; 688 struct cf_level *level, *search; 689 int i, inserted; 690 691 CF_MTX_ASSERT(&sc->lock); 692 693 list = &sc->all_levels; 694 for (i = 0; i < count; i++) { 695 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO); 696 if (level == NULL) 697 return (ENOMEM); 698 level->abs_set = sets[i]; 699 level->total_set = sets[i]; 700 level->total_set.dev = NULL; 701 sc->all_count++; 702 inserted = 0; 703 704 if (TAILQ_EMPTY(list)) { 705 CF_DEBUG("adding abs setting %d at head\n", 706 sets[i].freq); 707 TAILQ_INSERT_HEAD(list, level, link); 708 continue; 709 } 710 711 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) 712 if (sets[i].freq <= search->total_set.freq) { 713 CF_DEBUG("adding abs setting %d after %d\n", 714 sets[i].freq, search->total_set.freq); 715 TAILQ_INSERT_AFTER(list, search, level, link); 716 inserted = 1; 717 break; 718 } 719 720 if (inserted == 0) { 721 TAILQ_FOREACH(search, list, link) 722 if (sets[i].freq >= search->total_set.freq) { 723 CF_DEBUG("adding abs setting %d before %d\n", 724 sets[i].freq, search->total_set.freq); 725 TAILQ_INSERT_BEFORE(search, level, link); 726 break; 727 } 728 } 729 } 730 731 return (0); 732 } 733 734 /* 735 * Expand a group of relative settings, creating derived levels from them. 736 */ 737 static int 738 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr) 739 { 740 struct cf_level *fill, *search; 741 struct cf_setting *set; 742 int i; 743 744 CF_MTX_ASSERT(&sc->lock); 745 746 /* 747 * Walk the set of all existing levels in reverse. This is so we 748 * create derived states from the lowest absolute settings first 749 * and discard duplicates created from higher absolute settings. 750 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is 751 * preferable to 200 Mhz + 25% because absolute settings are more 752 * efficient since they often change the voltage as well. 753 */ 754 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) { 755 /* Add each setting to the level, duplicating if necessary. */ 756 for (i = 0; i < set_arr->count; i++) { 757 set = &set_arr->sets[i]; 758 759 /* 760 * If this setting is less than 100%, split the level 761 * into two and add this setting to the new level. 762 */ 763 fill = search; 764 if (set->freq < 10000) { 765 fill = cpufreq_dup_set(sc, search, set); 766 767 /* 768 * The new level was a duplicate of an existing 769 * level or its absolute setting is too high 770 * so we freed it. For example, we discard a 771 * derived level of 1000 MHz/25% if a level 772 * of 500 MHz/100% already exists. 773 */ 774 if (fill == NULL) 775 break; 776 } 777 778 /* Add this setting to the existing or new level. */ 779 KASSERT(fill->rel_count < MAX_SETTINGS, 780 ("cpufreq: too many relative drivers (%d)", 781 MAX_SETTINGS)); 782 fill->rel_set[fill->rel_count] = *set; 783 fill->rel_count++; 784 CF_DEBUG( 785 "expand set added rel setting %d%% to %d level\n", 786 set->freq / 100, fill->total_set.freq); 787 } 788 } 789 790 return (0); 791 } 792 793 static struct cf_level * 794 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup, 795 struct cf_setting *set) 796 { 797 struct cf_level_lst *list; 798 struct cf_level *fill, *itr; 799 struct cf_setting *fill_set, *itr_set; 800 int i; 801 802 CF_MTX_ASSERT(&sc->lock); 803 804 /* 805 * Create a new level, copy it from the old one, and update the 806 * total frequency and power by the percentage specified in the 807 * relative setting. 808 */ 809 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT); 810 if (fill == NULL) 811 return (NULL); 812 *fill = *dup; 813 fill_set = &fill->total_set; 814 fill_set->freq = 815 ((uint64_t)fill_set->freq * set->freq) / 10000; 816 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) { 817 fill_set->power = ((uint64_t)fill_set->power * set->freq) 818 / 10000; 819 } 820 if (set->lat != CPUFREQ_VAL_UNKNOWN) { 821 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN) 822 fill_set->lat += set->lat; 823 else 824 fill_set->lat = set->lat; 825 } 826 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq); 827 828 /* 829 * If we copied an old level that we already modified (say, at 100%), 830 * we need to remove that setting before adding this one. Since we 831 * process each setting array in order, we know any settings for this 832 * driver will be found at the end. 833 */ 834 for (i = fill->rel_count; i != 0; i--) { 835 if (fill->rel_set[i - 1].dev != set->dev) 836 break; 837 CF_DEBUG("removed last relative driver: %s\n", 838 device_get_nameunit(set->dev)); 839 fill->rel_count--; 840 } 841 842 /* 843 * Insert the new level in sorted order. If it is a duplicate of an 844 * existing level (1) or has an absolute setting higher than the 845 * existing level (2), do not add it. We can do this since any such 846 * level is guaranteed use less power. For example (1), a level with 847 * one absolute setting of 800 Mhz uses less power than one composed 848 * of an absolute setting of 1600 Mhz and a relative setting at 50%. 849 * Also for example (2), a level of 800 Mhz/75% is preferable to 850 * 1600 Mhz/25% even though the latter has a lower total frequency. 851 */ 852 list = &sc->all_levels; 853 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set")); 854 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) { 855 itr_set = &itr->total_set; 856 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) { 857 CF_DEBUG("dup set rejecting %d (dupe)\n", 858 fill_set->freq); 859 itr = NULL; 860 break; 861 } else if (fill_set->freq < itr_set->freq) { 862 if (fill->abs_set.freq <= itr->abs_set.freq) { 863 CF_DEBUG( 864 "dup done, inserting new level %d after %d\n", 865 fill_set->freq, itr_set->freq); 866 TAILQ_INSERT_AFTER(list, itr, fill, link); 867 sc->all_count++; 868 } else { 869 CF_DEBUG("dup set rejecting %d (abs too big)\n", 870 fill_set->freq); 871 itr = NULL; 872 } 873 break; 874 } 875 } 876 877 /* We didn't find a good place for this new level so free it. */ 878 if (itr == NULL) { 879 CF_DEBUG("dup set freeing new level %d (not optimal)\n", 880 fill_set->freq); 881 free(fill, M_TEMP); 882 fill = NULL; 883 } 884 885 return (fill); 886 } 887 888 static int 889 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS) 890 { 891 struct cpufreq_softc *sc; 892 struct cf_level *levels; 893 int best, count, diff, bdiff, devcount, error, freq, i, n; 894 device_t *devs; 895 896 devs = NULL; 897 sc = oidp->oid_arg1; 898 levels = sc->levels_buf; 899 900 error = CPUFREQ_GET(sc->dev, &levels[0]); 901 if (error) 902 goto out; 903 freq = levels[0].total_set.freq; 904 error = sysctl_handle_int(oidp, &freq, 0, req); 905 if (error != 0 || req->newptr == NULL) 906 goto out; 907 908 /* 909 * While we only call cpufreq_get() on one device (assuming all 910 * CPUs have equal levels), we call cpufreq_set() on all CPUs. 911 * This is needed for some MP systems. 912 */ 913 error = devclass_get_devices(cpufreq_dc, &devs, &devcount); 914 if (error) 915 goto out; 916 for (n = 0; n < devcount; n++) { 917 count = CF_MAX_LEVELS; 918 error = CPUFREQ_LEVELS(devs[n], levels, &count); 919 if (error) { 920 if (error == E2BIG) 921 printf( 922 "cpufreq: need to increase CF_MAX_LEVELS\n"); 923 break; 924 } 925 best = 0; 926 bdiff = 1 << 30; 927 for (i = 0; i < count; i++) { 928 diff = abs(levels[i].total_set.freq - freq); 929 if (diff < bdiff) { 930 bdiff = diff; 931 best = i; 932 } 933 } 934 error = CPUFREQ_SET(devs[n], &levels[best], CPUFREQ_PRIO_USER); 935 } 936 937 out: 938 if (devs) 939 free(devs, M_TEMP); 940 return (error); 941 } 942 943 static int 944 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS) 945 { 946 struct cpufreq_softc *sc; 947 struct cf_level *levels; 948 struct cf_setting *set; 949 struct sbuf sb; 950 int count, error, i; 951 952 sc = oidp->oid_arg1; 953 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 954 955 /* Get settings from the device and generate the output string. */ 956 count = CF_MAX_LEVELS; 957 levels = sc->levels_buf; 958 if (levels == NULL) { 959 sbuf_delete(&sb); 960 return (ENOMEM); 961 } 962 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 963 if (error) { 964 if (error == E2BIG) 965 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 966 goto out; 967 } 968 if (count) { 969 for (i = 0; i < count; i++) { 970 set = &levels[i].total_set; 971 sbuf_printf(&sb, "%d/%d ", set->freq, set->power); 972 } 973 } else 974 sbuf_cpy(&sb, ""); 975 sbuf_trim(&sb); 976 sbuf_finish(&sb); 977 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 978 979 out: 980 sbuf_delete(&sb); 981 return (error); 982 } 983 984 static int 985 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS) 986 { 987 device_t dev; 988 struct cf_setting *sets; 989 struct sbuf sb; 990 int error, i, set_count; 991 992 dev = oidp->oid_arg1; 993 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 994 995 /* Get settings from the device and generate the output string. */ 996 set_count = MAX_SETTINGS; 997 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT); 998 if (sets == NULL) { 999 sbuf_delete(&sb); 1000 return (ENOMEM); 1001 } 1002 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count); 1003 if (error) 1004 goto out; 1005 if (set_count) { 1006 for (i = 0; i < set_count; i++) 1007 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power); 1008 } else 1009 sbuf_cpy(&sb, ""); 1010 sbuf_trim(&sb); 1011 sbuf_finish(&sb); 1012 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 1013 1014 out: 1015 free(sets, M_TEMP); 1016 sbuf_delete(&sb); 1017 return (error); 1018 } 1019 1020 int 1021 cpufreq_register(device_t dev) 1022 { 1023 struct cpufreq_softc *sc; 1024 device_t cf_dev, cpu_dev; 1025 1026 /* Add a sysctl to get each driver's settings separately. */ 1027 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), 1028 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 1029 OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0, 1030 cpufreq_settings_sysctl, "A", "CPU frequency driver settings"); 1031 1032 /* 1033 * Add only one cpufreq device to each CPU. Currently, all CPUs 1034 * must offer the same levels and be switched at the same time. 1035 */ 1036 cpu_dev = device_get_parent(dev); 1037 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) { 1038 sc = device_get_softc(cf_dev); 1039 sc->max_mhz = CPUFREQ_VAL_UNKNOWN; 1040 return (0); 1041 } 1042 1043 /* Add the child device and possibly sysctls. */ 1044 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1); 1045 if (cf_dev == NULL) 1046 return (ENOMEM); 1047 device_quiet(cf_dev); 1048 1049 return (device_probe_and_attach(cf_dev)); 1050 } 1051 1052 int 1053 cpufreq_unregister(device_t dev) 1054 { 1055 device_t cf_dev, *devs; 1056 int cfcount, devcount, error, i, type; 1057 1058 /* 1059 * If this is the last cpufreq child device, remove the control 1060 * device as well. We identify cpufreq children by calling a method 1061 * they support. 1062 */ 1063 error = device_get_children(device_get_parent(dev), &devs, &devcount); 1064 if (error) 1065 return (error); 1066 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1); 1067 if (cf_dev == NULL) { 1068 device_printf(dev, 1069 "warning: cpufreq_unregister called with no cpufreq device active\n"); 1070 free(devs, M_TEMP); 1071 return (0); 1072 } 1073 cfcount = 0; 1074 for (i = 0; i < devcount; i++) { 1075 if (!device_is_attached(devs[i])) 1076 continue; 1077 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0) 1078 cfcount++; 1079 } 1080 if (cfcount <= 1) 1081 device_delete_child(device_get_parent(cf_dev), cf_dev); 1082 free(devs, M_TEMP); 1083 1084 return (0); 1085 } 1086 1087 int 1088 cpufreq_settings_changed(device_t dev) 1089 { 1090 1091 EVENTHANDLER_INVOKE(cpufreq_levels_changed, 1092 device_get_unit(device_get_parent(dev))); 1093 return (0); 1094 }
Cache object: c8b9a6afada497026c0576071b4096ae
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