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: releng/12.0/sys/kern/kern_cpu.c 336477 2018-07-19 11:28:14Z manu $"); 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 thread_lock(curthread); 337 pri = curthread->td_priority; 338 sched_prio(curthread, PRI_MIN); 339 sched_bind(curthread, pc->pc_cpuid); 340 thread_unlock(curthread); 341 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq, 342 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 343 error = CPUFREQ_DRV_SET(set->dev, set); 344 thread_lock(curthread); 345 sched_unbind(curthread); 346 sched_prio(curthread, pri); 347 thread_unlock(curthread); 348 if (error) { 349 goto out; 350 } 351 } 352 353 /* Next, set any/all relative frequencies via their drivers. */ 354 for (i = 0; i < level->rel_count; i++) { 355 set = &level->rel_set[i]; 356 if (!device_is_attached(set->dev)) { 357 error = ENXIO; 358 goto out; 359 } 360 361 /* Bind to the target CPU before switching. */ 362 pc = cpu_get_pcpu(set->dev); 363 thread_lock(curthread); 364 pri = curthread->td_priority; 365 sched_prio(curthread, PRI_MIN); 366 sched_bind(curthread, pc->pc_cpuid); 367 thread_unlock(curthread); 368 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq, 369 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 370 error = CPUFREQ_DRV_SET(set->dev, set); 371 thread_lock(curthread); 372 sched_unbind(curthread); 373 sched_prio(curthread, pri); 374 thread_unlock(curthread); 375 if (error) { 376 /* XXX Back out any successful setting? */ 377 goto out; 378 } 379 } 380 381 skip: 382 /* 383 * Before recording the current level, check if we're going to a 384 * higher priority. If so, save the previous level and priority. 385 */ 386 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN && 387 priority > sc->curr_priority) { 388 CF_DEBUG("saving level, freq %d prio %d\n", 389 sc->curr_level.total_set.freq, sc->curr_priority); 390 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT); 391 if (curr_freq == NULL) { 392 error = ENOMEM; 393 goto out; 394 } 395 curr_freq->level = sc->curr_level; 396 curr_freq->priority = sc->curr_priority; 397 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link); 398 } 399 sc->curr_level = *level; 400 sc->curr_priority = priority; 401 402 /* If we were restoring a saved state, reset it to "unused". */ 403 if (saved_freq != NULL) { 404 CF_DEBUG("resetting saved level\n"); 405 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; 406 SLIST_REMOVE_HEAD(&sc->saved_freq, link); 407 free(saved_freq, M_TEMP); 408 } 409 410 out: 411 CF_MTX_UNLOCK(&sc->lock); 412 413 /* 414 * We changed levels (or attempted to) so notify the post-change 415 * handler of new frequency or error. 416 */ 417 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error); 418 if (error && set) 419 device_printf(set->dev, "set freq failed, err %d\n", error); 420 421 return (error); 422 } 423 424 static int 425 cf_get_method(device_t dev, struct cf_level *level) 426 { 427 struct cpufreq_softc *sc; 428 struct cf_level *levels; 429 struct cf_setting *curr_set, set; 430 struct pcpu *pc; 431 device_t *devs; 432 int bdiff, count, diff, error, i, n, numdevs; 433 uint64_t rate; 434 435 sc = device_get_softc(dev); 436 error = 0; 437 levels = NULL; 438 439 /* If we already know the current frequency, we're done. */ 440 CF_MTX_LOCK(&sc->lock); 441 curr_set = &sc->curr_level.total_set; 442 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 443 CF_DEBUG("get returning known freq %d\n", curr_set->freq); 444 goto out; 445 } 446 CF_MTX_UNLOCK(&sc->lock); 447 448 /* 449 * We need to figure out the current level. Loop through every 450 * driver, getting the current setting. Then, attempt to get a best 451 * match of settings against each level. 452 */ 453 count = CF_MAX_LEVELS; 454 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT); 455 if (levels == NULL) 456 return (ENOMEM); 457 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 458 if (error) { 459 if (error == E2BIG) 460 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 461 free(levels, M_TEMP); 462 return (error); 463 } 464 error = device_get_children(device_get_parent(dev), &devs, &numdevs); 465 if (error) { 466 free(levels, M_TEMP); 467 return (error); 468 } 469 470 /* 471 * Reacquire the lock and search for the given level. 472 * 473 * XXX Note: this is not quite right since we really need to go 474 * through each level and compare both absolute and relative 475 * settings for each driver in the system before making a match. 476 * The estimation code below catches this case though. 477 */ 478 CF_MTX_LOCK(&sc->lock); 479 for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) { 480 if (!device_is_attached(devs[n])) 481 continue; 482 if (CPUFREQ_DRV_GET(devs[n], &set) != 0) 483 continue; 484 for (i = 0; i < count; i++) { 485 if (set.freq == levels[i].total_set.freq) { 486 sc->curr_level = levels[i]; 487 break; 488 } 489 } 490 } 491 free(devs, M_TEMP); 492 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 493 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq); 494 goto out; 495 } 496 497 /* 498 * We couldn't find an exact match, so attempt to estimate and then 499 * match against a level. 500 */ 501 pc = cpu_get_pcpu(dev); 502 if (pc == NULL) { 503 error = ENXIO; 504 goto out; 505 } 506 cpu_est_clockrate(pc->pc_cpuid, &rate); 507 rate /= 1000000; 508 bdiff = 1 << 30; 509 for (i = 0; i < count; i++) { 510 diff = abs(levels[i].total_set.freq - rate); 511 if (diff < bdiff) { 512 bdiff = diff; 513 sc->curr_level = levels[i]; 514 } 515 } 516 CF_DEBUG("get estimated freq %d\n", curr_set->freq); 517 518 out: 519 if (error == 0) 520 *level = sc->curr_level; 521 522 CF_MTX_UNLOCK(&sc->lock); 523 if (levels) 524 free(levels, M_TEMP); 525 return (error); 526 } 527 528 static int 529 cf_levels_method(device_t dev, struct cf_level *levels, int *count) 530 { 531 struct cf_setting_array *set_arr; 532 struct cf_setting_lst rel_sets; 533 struct cpufreq_softc *sc; 534 struct cf_level *lev; 535 struct cf_setting *sets; 536 struct pcpu *pc; 537 device_t *devs; 538 int error, i, numdevs, set_count, type; 539 uint64_t rate; 540 541 if (levels == NULL || count == NULL) 542 return (EINVAL); 543 544 TAILQ_INIT(&rel_sets); 545 sc = device_get_softc(dev); 546 error = device_get_children(device_get_parent(dev), &devs, &numdevs); 547 if (error) 548 return (error); 549 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT); 550 if (sets == NULL) { 551 free(devs, M_TEMP); 552 return (ENOMEM); 553 } 554 555 /* Get settings from all cpufreq drivers. */ 556 CF_MTX_LOCK(&sc->lock); 557 for (i = 0; i < numdevs; i++) { 558 /* Skip devices that aren't ready. */ 559 if (!device_is_attached(devs[i])) 560 continue; 561 562 /* 563 * Get settings, skipping drivers that offer no settings or 564 * provide settings for informational purposes only. 565 */ 566 error = CPUFREQ_DRV_TYPE(devs[i], &type); 567 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) { 568 if (error == 0) { 569 CF_DEBUG("skipping info-only driver %s\n", 570 device_get_nameunit(devs[i])); 571 } 572 continue; 573 } 574 set_count = MAX_SETTINGS; 575 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count); 576 if (error || set_count == 0) 577 continue; 578 579 /* Add the settings to our absolute/relative lists. */ 580 switch (type & CPUFREQ_TYPE_MASK) { 581 case CPUFREQ_TYPE_ABSOLUTE: 582 error = cpufreq_insert_abs(sc, sets, set_count); 583 break; 584 case CPUFREQ_TYPE_RELATIVE: 585 CF_DEBUG("adding %d relative settings\n", set_count); 586 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT); 587 if (set_arr == NULL) { 588 error = ENOMEM; 589 goto out; 590 } 591 bcopy(sets, set_arr->sets, set_count * sizeof(*sets)); 592 set_arr->count = set_count; 593 TAILQ_INSERT_TAIL(&rel_sets, set_arr, link); 594 break; 595 default: 596 error = EINVAL; 597 } 598 if (error) 599 goto out; 600 } 601 602 /* 603 * If there are no absolute levels, create a fake one at 100%. We 604 * then cache the clockrate for later use as our base frequency. 605 */ 606 if (TAILQ_EMPTY(&sc->all_levels)) { 607 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) { 608 sc->max_mhz = cpu_get_nominal_mhz(dev); 609 /* 610 * If the CPU can't report a rate for 100%, hope 611 * the CPU is running at its nominal rate right now, 612 * and use that instead. 613 */ 614 if (sc->max_mhz <= 0) { 615 pc = cpu_get_pcpu(dev); 616 cpu_est_clockrate(pc->pc_cpuid, &rate); 617 sc->max_mhz = rate / 1000000; 618 } 619 } 620 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets)); 621 sets[0].freq = sc->max_mhz; 622 sets[0].dev = NULL; 623 error = cpufreq_insert_abs(sc, sets, 1); 624 if (error) 625 goto out; 626 } 627 628 /* Create a combined list of absolute + relative levels. */ 629 TAILQ_FOREACH(set_arr, &rel_sets, link) 630 cpufreq_expand_set(sc, set_arr); 631 632 /* If the caller doesn't have enough space, return the actual count. */ 633 if (sc->all_count > *count) { 634 *count = sc->all_count; 635 error = E2BIG; 636 goto out; 637 } 638 639 /* Finally, output the list of levels. */ 640 i = 0; 641 TAILQ_FOREACH(lev, &sc->all_levels, link) { 642 643 /* Skip levels that have a frequency that is too low. */ 644 if (lev->total_set.freq < cf_lowest_freq) { 645 sc->all_count--; 646 continue; 647 } 648 649 levels[i] = *lev; 650 i++; 651 } 652 *count = sc->all_count; 653 error = 0; 654 655 out: 656 /* Clear all levels since we regenerate them each time. */ 657 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) { 658 TAILQ_REMOVE(&sc->all_levels, lev, link); 659 free(lev, M_TEMP); 660 } 661 sc->all_count = 0; 662 663 CF_MTX_UNLOCK(&sc->lock); 664 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) { 665 TAILQ_REMOVE(&rel_sets, set_arr, link); 666 free(set_arr, M_TEMP); 667 } 668 free(devs, M_TEMP); 669 free(sets, M_TEMP); 670 return (error); 671 } 672 673 /* 674 * Create levels for an array of absolute settings and insert them in 675 * sorted order in the specified list. 676 */ 677 static int 678 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets, 679 int count) 680 { 681 struct cf_level_lst *list; 682 struct cf_level *level, *search; 683 int i, inserted; 684 685 CF_MTX_ASSERT(&sc->lock); 686 687 list = &sc->all_levels; 688 for (i = 0; i < count; i++) { 689 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO); 690 if (level == NULL) 691 return (ENOMEM); 692 level->abs_set = sets[i]; 693 level->total_set = sets[i]; 694 level->total_set.dev = NULL; 695 sc->all_count++; 696 inserted = 0; 697 698 if (TAILQ_EMPTY(list)) { 699 CF_DEBUG("adding abs setting %d at head\n", 700 sets[i].freq); 701 TAILQ_INSERT_HEAD(list, level, link); 702 continue; 703 } 704 705 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) 706 if (sets[i].freq <= search->total_set.freq) { 707 CF_DEBUG("adding abs setting %d after %d\n", 708 sets[i].freq, search->total_set.freq); 709 TAILQ_INSERT_AFTER(list, search, level, link); 710 inserted = 1; 711 break; 712 } 713 714 if (inserted == 0) { 715 TAILQ_FOREACH(search, list, link) 716 if (sets[i].freq >= search->total_set.freq) { 717 CF_DEBUG("adding abs setting %d before %d\n", 718 sets[i].freq, search->total_set.freq); 719 TAILQ_INSERT_BEFORE(search, level, link); 720 break; 721 } 722 } 723 } 724 725 return (0); 726 } 727 728 /* 729 * Expand a group of relative settings, creating derived levels from them. 730 */ 731 static int 732 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr) 733 { 734 struct cf_level *fill, *search; 735 struct cf_setting *set; 736 int i; 737 738 CF_MTX_ASSERT(&sc->lock); 739 740 /* 741 * Walk the set of all existing levels in reverse. This is so we 742 * create derived states from the lowest absolute settings first 743 * and discard duplicates created from higher absolute settings. 744 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is 745 * preferable to 200 Mhz + 25% because absolute settings are more 746 * efficient since they often change the voltage as well. 747 */ 748 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) { 749 /* Add each setting to the level, duplicating if necessary. */ 750 for (i = 0; i < set_arr->count; i++) { 751 set = &set_arr->sets[i]; 752 753 /* 754 * If this setting is less than 100%, split the level 755 * into two and add this setting to the new level. 756 */ 757 fill = search; 758 if (set->freq < 10000) { 759 fill = cpufreq_dup_set(sc, search, set); 760 761 /* 762 * The new level was a duplicate of an existing 763 * level or its absolute setting is too high 764 * so we freed it. For example, we discard a 765 * derived level of 1000 MHz/25% if a level 766 * of 500 MHz/100% already exists. 767 */ 768 if (fill == NULL) 769 break; 770 } 771 772 /* Add this setting to the existing or new level. */ 773 KASSERT(fill->rel_count < MAX_SETTINGS, 774 ("cpufreq: too many relative drivers (%d)", 775 MAX_SETTINGS)); 776 fill->rel_set[fill->rel_count] = *set; 777 fill->rel_count++; 778 CF_DEBUG( 779 "expand set added rel setting %d%% to %d level\n", 780 set->freq / 100, fill->total_set.freq); 781 } 782 } 783 784 return (0); 785 } 786 787 static struct cf_level * 788 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup, 789 struct cf_setting *set) 790 { 791 struct cf_level_lst *list; 792 struct cf_level *fill, *itr; 793 struct cf_setting *fill_set, *itr_set; 794 int i; 795 796 CF_MTX_ASSERT(&sc->lock); 797 798 /* 799 * Create a new level, copy it from the old one, and update the 800 * total frequency and power by the percentage specified in the 801 * relative setting. 802 */ 803 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT); 804 if (fill == NULL) 805 return (NULL); 806 *fill = *dup; 807 fill_set = &fill->total_set; 808 fill_set->freq = 809 ((uint64_t)fill_set->freq * set->freq) / 10000; 810 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) { 811 fill_set->power = ((uint64_t)fill_set->power * set->freq) 812 / 10000; 813 } 814 if (set->lat != CPUFREQ_VAL_UNKNOWN) { 815 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN) 816 fill_set->lat += set->lat; 817 else 818 fill_set->lat = set->lat; 819 } 820 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq); 821 822 /* 823 * If we copied an old level that we already modified (say, at 100%), 824 * we need to remove that setting before adding this one. Since we 825 * process each setting array in order, we know any settings for this 826 * driver will be found at the end. 827 */ 828 for (i = fill->rel_count; i != 0; i--) { 829 if (fill->rel_set[i - 1].dev != set->dev) 830 break; 831 CF_DEBUG("removed last relative driver: %s\n", 832 device_get_nameunit(set->dev)); 833 fill->rel_count--; 834 } 835 836 /* 837 * Insert the new level in sorted order. If it is a duplicate of an 838 * existing level (1) or has an absolute setting higher than the 839 * existing level (2), do not add it. We can do this since any such 840 * level is guaranteed use less power. For example (1), a level with 841 * one absolute setting of 800 Mhz uses less power than one composed 842 * of an absolute setting of 1600 Mhz and a relative setting at 50%. 843 * Also for example (2), a level of 800 Mhz/75% is preferable to 844 * 1600 Mhz/25% even though the latter has a lower total frequency. 845 */ 846 list = &sc->all_levels; 847 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set")); 848 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) { 849 itr_set = &itr->total_set; 850 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) { 851 CF_DEBUG("dup set rejecting %d (dupe)\n", 852 fill_set->freq); 853 itr = NULL; 854 break; 855 } else if (fill_set->freq < itr_set->freq) { 856 if (fill->abs_set.freq <= itr->abs_set.freq) { 857 CF_DEBUG( 858 "dup done, inserting new level %d after %d\n", 859 fill_set->freq, itr_set->freq); 860 TAILQ_INSERT_AFTER(list, itr, fill, link); 861 sc->all_count++; 862 } else { 863 CF_DEBUG("dup set rejecting %d (abs too big)\n", 864 fill_set->freq); 865 itr = NULL; 866 } 867 break; 868 } 869 } 870 871 /* We didn't find a good place for this new level so free it. */ 872 if (itr == NULL) { 873 CF_DEBUG("dup set freeing new level %d (not optimal)\n", 874 fill_set->freq); 875 free(fill, M_TEMP); 876 fill = NULL; 877 } 878 879 return (fill); 880 } 881 882 static int 883 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS) 884 { 885 struct cpufreq_softc *sc; 886 struct cf_level *levels; 887 int best, count, diff, bdiff, devcount, error, freq, i, n; 888 device_t *devs; 889 890 devs = NULL; 891 sc = oidp->oid_arg1; 892 levels = sc->levels_buf; 893 894 error = CPUFREQ_GET(sc->dev, &levels[0]); 895 if (error) 896 goto out; 897 freq = levels[0].total_set.freq; 898 error = sysctl_handle_int(oidp, &freq, 0, req); 899 if (error != 0 || req->newptr == NULL) 900 goto out; 901 902 /* 903 * While we only call cpufreq_get() on one device (assuming all 904 * CPUs have equal levels), we call cpufreq_set() on all CPUs. 905 * This is needed for some MP systems. 906 */ 907 error = devclass_get_devices(cpufreq_dc, &devs, &devcount); 908 if (error) 909 goto out; 910 for (n = 0; n < devcount; n++) { 911 count = CF_MAX_LEVELS; 912 error = CPUFREQ_LEVELS(devs[n], levels, &count); 913 if (error) { 914 if (error == E2BIG) 915 printf( 916 "cpufreq: need to increase CF_MAX_LEVELS\n"); 917 break; 918 } 919 best = 0; 920 bdiff = 1 << 30; 921 for (i = 0; i < count; i++) { 922 diff = abs(levels[i].total_set.freq - freq); 923 if (diff < bdiff) { 924 bdiff = diff; 925 best = i; 926 } 927 } 928 error = CPUFREQ_SET(devs[n], &levels[best], CPUFREQ_PRIO_USER); 929 } 930 931 out: 932 if (devs) 933 free(devs, M_TEMP); 934 return (error); 935 } 936 937 static int 938 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS) 939 { 940 struct cpufreq_softc *sc; 941 struct cf_level *levels; 942 struct cf_setting *set; 943 struct sbuf sb; 944 int count, error, i; 945 946 sc = oidp->oid_arg1; 947 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 948 949 /* Get settings from the device and generate the output string. */ 950 count = CF_MAX_LEVELS; 951 levels = sc->levels_buf; 952 if (levels == NULL) { 953 sbuf_delete(&sb); 954 return (ENOMEM); 955 } 956 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 957 if (error) { 958 if (error == E2BIG) 959 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 960 goto out; 961 } 962 if (count) { 963 for (i = 0; i < count; i++) { 964 set = &levels[i].total_set; 965 sbuf_printf(&sb, "%d/%d ", set->freq, set->power); 966 } 967 } else 968 sbuf_cpy(&sb, ""); 969 sbuf_trim(&sb); 970 sbuf_finish(&sb); 971 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 972 973 out: 974 sbuf_delete(&sb); 975 return (error); 976 } 977 978 static int 979 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS) 980 { 981 device_t dev; 982 struct cf_setting *sets; 983 struct sbuf sb; 984 int error, i, set_count; 985 986 dev = oidp->oid_arg1; 987 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 988 989 /* Get settings from the device and generate the output string. */ 990 set_count = MAX_SETTINGS; 991 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT); 992 if (sets == NULL) { 993 sbuf_delete(&sb); 994 return (ENOMEM); 995 } 996 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count); 997 if (error) 998 goto out; 999 if (set_count) { 1000 for (i = 0; i < set_count; i++) 1001 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power); 1002 } else 1003 sbuf_cpy(&sb, ""); 1004 sbuf_trim(&sb); 1005 sbuf_finish(&sb); 1006 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 1007 1008 out: 1009 free(sets, M_TEMP); 1010 sbuf_delete(&sb); 1011 return (error); 1012 } 1013 1014 int 1015 cpufreq_register(device_t dev) 1016 { 1017 struct cpufreq_softc *sc; 1018 device_t cf_dev, cpu_dev; 1019 1020 /* Add a sysctl to get each driver's settings separately. */ 1021 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), 1022 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 1023 OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0, 1024 cpufreq_settings_sysctl, "A", "CPU frequency driver settings"); 1025 1026 /* 1027 * Add only one cpufreq device to each CPU. Currently, all CPUs 1028 * must offer the same levels and be switched at the same time. 1029 */ 1030 cpu_dev = device_get_parent(dev); 1031 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) { 1032 sc = device_get_softc(cf_dev); 1033 sc->max_mhz = CPUFREQ_VAL_UNKNOWN; 1034 return (0); 1035 } 1036 1037 /* Add the child device and possibly sysctls. */ 1038 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1); 1039 if (cf_dev == NULL) 1040 return (ENOMEM); 1041 device_quiet(cf_dev); 1042 1043 return (device_probe_and_attach(cf_dev)); 1044 } 1045 1046 int 1047 cpufreq_unregister(device_t dev) 1048 { 1049 device_t cf_dev, *devs; 1050 int cfcount, devcount, error, i, type; 1051 1052 /* 1053 * If this is the last cpufreq child device, remove the control 1054 * device as well. We identify cpufreq children by calling a method 1055 * they support. 1056 */ 1057 error = device_get_children(device_get_parent(dev), &devs, &devcount); 1058 if (error) 1059 return (error); 1060 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1); 1061 if (cf_dev == NULL) { 1062 device_printf(dev, 1063 "warning: cpufreq_unregister called with no cpufreq device active\n"); 1064 free(devs, M_TEMP); 1065 return (0); 1066 } 1067 cfcount = 0; 1068 for (i = 0; i < devcount; i++) { 1069 if (!device_is_attached(devs[i])) 1070 continue; 1071 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0) 1072 cfcount++; 1073 } 1074 if (cfcount <= 1) 1075 device_delete_child(device_get_parent(cf_dev), cf_dev); 1076 free(devs, M_TEMP); 1077 1078 return (0); 1079 } 1080 1081 int 1082 cpufreq_settings_changed(device_t dev) 1083 { 1084 1085 EVENTHANDLER_INVOKE(cpufreq_levels_changed, 1086 device_get_unit(device_get_parent(dev))); 1087 return (0); 1088 }
Cache object: 000ff2ee7d5edea28003256e9087e406
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