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 device_t cf_drv_dev; 80 struct sysctl_ctx_list sysctl_ctx; 81 struct task startup_task; 82 struct cf_level *levels_buf; 83 }; 84 85 struct cf_setting_array { 86 struct cf_setting sets[MAX_SETTINGS]; 87 int count; 88 TAILQ_ENTRY(cf_setting_array) link; 89 }; 90 91 TAILQ_HEAD(cf_setting_lst, cf_setting_array); 92 93 #define CF_MTX_INIT(x) sx_init((x), "cpufreq lock") 94 #define CF_MTX_LOCK(x) sx_xlock((x)) 95 #define CF_MTX_UNLOCK(x) sx_xunlock((x)) 96 #define CF_MTX_ASSERT(x) sx_assert((x), SX_XLOCKED) 97 98 #define CF_DEBUG(msg...) do { \ 99 if (cf_verbose) \ 100 printf("cpufreq: " msg); \ 101 } while (0) 102 103 static int cpufreq_attach(device_t dev); 104 static void cpufreq_startup_task(void *ctx, int pending); 105 static int cpufreq_detach(device_t dev); 106 static int cf_set_method(device_t dev, const struct cf_level *level, 107 int priority); 108 static int cf_get_method(device_t dev, struct cf_level *level); 109 static int cf_levels_method(device_t dev, struct cf_level *levels, 110 int *count); 111 static int cpufreq_insert_abs(struct cpufreq_softc *sc, 112 struct cf_setting *sets, int count); 113 static int cpufreq_expand_set(struct cpufreq_softc *sc, 114 struct cf_setting_array *set_arr); 115 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc, 116 struct cf_level *dup, struct cf_setting *set); 117 static int cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS); 118 static int cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS); 119 static int cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS); 120 121 static device_method_t cpufreq_methods[] = { 122 DEVMETHOD(device_probe, bus_generic_probe), 123 DEVMETHOD(device_attach, cpufreq_attach), 124 DEVMETHOD(device_detach, cpufreq_detach), 125 126 DEVMETHOD(cpufreq_set, cf_set_method), 127 DEVMETHOD(cpufreq_get, cf_get_method), 128 DEVMETHOD(cpufreq_levels, cf_levels_method), 129 {0, 0} 130 }; 131 static driver_t cpufreq_driver = { 132 "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc) 133 }; 134 static devclass_t cpufreq_dc; 135 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0); 136 137 static int cf_lowest_freq; 138 static int cf_verbose; 139 static SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 140 "cpufreq debugging"); 141 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RWTUN, &cf_lowest_freq, 1, 142 "Don't provide levels below this frequency."); 143 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RWTUN, &cf_verbose, 1, 144 "Print verbose debugging messages"); 145 146 /* 147 * This is called as the result of a hardware specific frequency control driver 148 * calling cpufreq_register. It provides a general interface for system wide 149 * frequency controls and operates on a per cpu basis. 150 */ 151 static int 152 cpufreq_attach(device_t dev) 153 { 154 struct cpufreq_softc *sc; 155 struct pcpu *pc; 156 device_t parent; 157 uint64_t rate; 158 159 CF_DEBUG("initializing %s\n", device_get_nameunit(dev)); 160 sc = device_get_softc(dev); 161 parent = device_get_parent(dev); 162 sc->dev = dev; 163 sysctl_ctx_init(&sc->sysctl_ctx); 164 TAILQ_INIT(&sc->all_levels); 165 CF_MTX_INIT(&sc->lock); 166 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; 167 SLIST_INIT(&sc->saved_freq); 168 /* Try to get nominal CPU freq to use it as maximum later if needed */ 169 sc->max_mhz = cpu_get_nominal_mhz(dev); 170 /* If that fails, try to measure the current rate */ 171 if (sc->max_mhz <= 0) { 172 CF_DEBUG("Unable to obtain nominal frequency.\n"); 173 pc = cpu_get_pcpu(dev); 174 if (cpu_est_clockrate(pc->pc_cpuid, &rate) == 0) 175 sc->max_mhz = rate / 1000000; 176 else 177 sc->max_mhz = CPUFREQ_VAL_UNKNOWN; 178 } 179 180 CF_DEBUG("initializing one-time data for %s\n", 181 device_get_nameunit(dev)); 182 sc->levels_buf = malloc(CF_MAX_LEVELS * sizeof(*sc->levels_buf), 183 M_DEVBUF, M_WAITOK); 184 SYSCTL_ADD_PROC(&sc->sysctl_ctx, 185 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)), 186 OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 187 sc, 0, cpufreq_curr_sysctl, "I", "Current CPU frequency"); 188 SYSCTL_ADD_PROC(&sc->sysctl_ctx, 189 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)), 190 OID_AUTO, "freq_levels", 191 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, sc, 0, 192 cpufreq_levels_sysctl, "A", "CPU frequency levels"); 193 194 /* 195 * Queue a one-shot broadcast that levels have changed. 196 * It will run once the system has completed booting. 197 */ 198 TASK_INIT(&sc->startup_task, 0, cpufreq_startup_task, dev); 199 taskqueue_enqueue(taskqueue_thread, &sc->startup_task); 200 201 return (0); 202 } 203 204 /* Handle any work to be done for all drivers that attached during boot. */ 205 static void 206 cpufreq_startup_task(void *ctx, int pending) 207 { 208 209 cpufreq_settings_changed((device_t)ctx); 210 } 211 212 static int 213 cpufreq_detach(device_t dev) 214 { 215 struct cpufreq_softc *sc; 216 struct cf_saved_freq *saved_freq; 217 218 CF_DEBUG("shutdown %s\n", device_get_nameunit(dev)); 219 sc = device_get_softc(dev); 220 sysctl_ctx_free(&sc->sysctl_ctx); 221 222 while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) { 223 SLIST_REMOVE_HEAD(&sc->saved_freq, link); 224 free(saved_freq, M_TEMP); 225 } 226 227 free(sc->levels_buf, M_DEVBUF); 228 229 return (0); 230 } 231 232 static int 233 cf_set_method(device_t dev, const struct cf_level *level, int priority) 234 { 235 struct cpufreq_softc *sc; 236 const struct cf_setting *set; 237 struct cf_saved_freq *saved_freq, *curr_freq; 238 struct pcpu *pc; 239 int error, i; 240 u_char pri; 241 242 sc = device_get_softc(dev); 243 error = 0; 244 set = NULL; 245 saved_freq = NULL; 246 247 /* We are going to change levels so notify the pre-change handler. */ 248 EVENTHANDLER_INVOKE(cpufreq_pre_change, level, &error); 249 if (error != 0) { 250 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error); 251 return (error); 252 } 253 254 CF_MTX_LOCK(&sc->lock); 255 256 #ifdef SMP 257 #ifdef EARLY_AP_STARTUP 258 MPASS(mp_ncpus == 1 || smp_started); 259 #else 260 /* 261 * If still booting and secondary CPUs not started yet, don't allow 262 * changing the frequency until they're online. This is because we 263 * can't switch to them using sched_bind() and thus we'd only be 264 * switching the main CPU. XXXTODO: Need to think more about how to 265 * handle having different CPUs at different frequencies. 266 */ 267 if (mp_ncpus > 1 && !smp_started) { 268 device_printf(dev, "rejecting change, SMP not started yet\n"); 269 error = ENXIO; 270 goto out; 271 } 272 #endif 273 #endif /* SMP */ 274 275 /* 276 * If the requested level has a lower priority, don't allow 277 * the new level right now. 278 */ 279 if (priority < sc->curr_priority) { 280 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority, 281 sc->curr_priority); 282 error = EPERM; 283 goto out; 284 } 285 286 /* 287 * If the caller didn't specify a level and one is saved, prepare to 288 * restore the saved level. If none has been saved, return an error. 289 */ 290 if (level == NULL) { 291 saved_freq = SLIST_FIRST(&sc->saved_freq); 292 if (saved_freq == NULL) { 293 CF_DEBUG("NULL level, no saved level\n"); 294 error = ENXIO; 295 goto out; 296 } 297 level = &saved_freq->level; 298 priority = saved_freq->priority; 299 CF_DEBUG("restoring saved level, freq %d prio %d\n", 300 level->total_set.freq, priority); 301 } 302 303 /* Reject levels that are below our specified threshold. */ 304 if (level->total_set.freq < cf_lowest_freq) { 305 CF_DEBUG("rejecting freq %d, less than %d limit\n", 306 level->total_set.freq, cf_lowest_freq); 307 error = EINVAL; 308 goto out; 309 } 310 311 /* If already at this level, just return. */ 312 if (sc->curr_level.total_set.freq == level->total_set.freq) { 313 CF_DEBUG("skipping freq %d, same as current level %d\n", 314 level->total_set.freq, sc->curr_level.total_set.freq); 315 goto skip; 316 } 317 318 /* First, set the absolute frequency via its driver. */ 319 set = &level->abs_set; 320 if (set->dev) { 321 if (!device_is_attached(set->dev)) { 322 error = ENXIO; 323 goto out; 324 } 325 326 /* Bind to the target CPU before switching. */ 327 pc = cpu_get_pcpu(set->dev); 328 329 /* Skip settings if CPU is not started. */ 330 if (pc == NULL) { 331 error = 0; 332 goto out; 333 } 334 thread_lock(curthread); 335 pri = curthread->td_priority; 336 sched_prio(curthread, PRI_MIN); 337 sched_bind(curthread, pc->pc_cpuid); 338 thread_unlock(curthread); 339 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq, 340 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 341 error = CPUFREQ_DRV_SET(set->dev, set); 342 thread_lock(curthread); 343 sched_unbind(curthread); 344 sched_prio(curthread, pri); 345 thread_unlock(curthread); 346 if (error) { 347 goto out; 348 } 349 } 350 351 /* Next, set any/all relative frequencies via their drivers. */ 352 for (i = 0; i < level->rel_count; i++) { 353 set = &level->rel_set[i]; 354 if (!device_is_attached(set->dev)) { 355 error = ENXIO; 356 goto out; 357 } 358 359 /* Bind to the target CPU before switching. */ 360 pc = cpu_get_pcpu(set->dev); 361 thread_lock(curthread); 362 pri = curthread->td_priority; 363 sched_prio(curthread, PRI_MIN); 364 sched_bind(curthread, pc->pc_cpuid); 365 thread_unlock(curthread); 366 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq, 367 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 368 error = CPUFREQ_DRV_SET(set->dev, set); 369 thread_lock(curthread); 370 sched_unbind(curthread); 371 sched_prio(curthread, pri); 372 thread_unlock(curthread); 373 if (error) { 374 /* XXX Back out any successful setting? */ 375 goto out; 376 } 377 } 378 379 skip: 380 /* 381 * Before recording the current level, check if we're going to a 382 * higher priority. If so, save the previous level and priority. 383 */ 384 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN && 385 priority > sc->curr_priority) { 386 CF_DEBUG("saving level, freq %d prio %d\n", 387 sc->curr_level.total_set.freq, sc->curr_priority); 388 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT); 389 if (curr_freq == NULL) { 390 error = ENOMEM; 391 goto out; 392 } 393 curr_freq->level = sc->curr_level; 394 curr_freq->priority = sc->curr_priority; 395 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link); 396 } 397 sc->curr_level = *level; 398 sc->curr_priority = priority; 399 400 /* If we were restoring a saved state, reset it to "unused". */ 401 if (saved_freq != NULL) { 402 CF_DEBUG("resetting saved level\n"); 403 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; 404 SLIST_REMOVE_HEAD(&sc->saved_freq, link); 405 free(saved_freq, M_TEMP); 406 } 407 408 out: 409 CF_MTX_UNLOCK(&sc->lock); 410 411 /* 412 * We changed levels (or attempted to) so notify the post-change 413 * handler of new frequency or error. 414 */ 415 EVENTHANDLER_INVOKE(cpufreq_post_change, level, error); 416 if (error && set) 417 device_printf(set->dev, "set freq failed, err %d\n", error); 418 419 return (error); 420 } 421 422 static int 423 cpufreq_get_frequency(device_t dev) 424 { 425 struct cf_setting set; 426 427 if (CPUFREQ_DRV_GET(dev, &set) != 0) 428 return (-1); 429 430 return (set.freq); 431 } 432 433 /* Returns the index into *levels with the match */ 434 static int 435 cpufreq_get_level(device_t dev, struct cf_level *levels, int count) 436 { 437 int i, freq; 438 439 if ((freq = cpufreq_get_frequency(dev)) < 0) 440 return (-1); 441 for (i = 0; i < count; i++) 442 if (freq == levels[i].total_set.freq) 443 return (i); 444 445 return (-1); 446 } 447 448 /* 449 * Used by the cpufreq core, this function will populate *level with the current 450 * frequency as either determined by a cached value sc->curr_level, or in the 451 * case the lower level driver has set the CPUFREQ_FLAG_UNCACHED flag, it will 452 * obtain the frequency from the driver itself. 453 */ 454 static int 455 cf_get_method(device_t dev, struct cf_level *level) 456 { 457 struct cpufreq_softc *sc; 458 struct cf_level *levels; 459 struct cf_setting *curr_set; 460 struct pcpu *pc; 461 int bdiff, count, diff, error, i, type; 462 uint64_t rate; 463 464 sc = device_get_softc(dev); 465 error = 0; 466 levels = NULL; 467 468 /* 469 * If we already know the current frequency, and the driver didn't ask 470 * for uncached usage, we're done. 471 */ 472 CF_MTX_LOCK(&sc->lock); 473 curr_set = &sc->curr_level.total_set; 474 error = CPUFREQ_DRV_TYPE(sc->cf_drv_dev, &type); 475 if (error == 0 && (type & CPUFREQ_FLAG_UNCACHED)) { 476 struct cf_setting set; 477 478 /* 479 * If the driver wants to always report back the real frequency, 480 * first try the driver and if that fails, fall back to 481 * estimating. 482 */ 483 if (CPUFREQ_DRV_GET(sc->cf_drv_dev, &set) == 0) { 484 sc->curr_level.total_set = set; 485 CF_DEBUG("get returning immediate freq %d\n", 486 curr_set->freq); 487 goto out; 488 } 489 } else if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 490 CF_DEBUG("get returning known freq %d\n", curr_set->freq); 491 error = 0; 492 goto out; 493 } 494 CF_MTX_UNLOCK(&sc->lock); 495 496 /* 497 * We need to figure out the current level. Loop through every 498 * driver, getting the current setting. Then, attempt to get a best 499 * match of settings against each level. 500 */ 501 count = CF_MAX_LEVELS; 502 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT); 503 if (levels == NULL) 504 return (ENOMEM); 505 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 506 if (error) { 507 if (error == E2BIG) 508 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 509 free(levels, M_TEMP); 510 return (error); 511 } 512 513 /* 514 * Reacquire the lock and search for the given level. 515 * 516 * XXX Note: this is not quite right since we really need to go 517 * through each level and compare both absolute and relative 518 * settings for each driver in the system before making a match. 519 * The estimation code below catches this case though. 520 */ 521 CF_MTX_LOCK(&sc->lock); 522 i = cpufreq_get_level(sc->cf_drv_dev, levels, count); 523 if (i >= 0) 524 sc->curr_level = levels[i]; 525 else 526 CF_DEBUG("Couldn't find supported level for %s\n", 527 device_get_nameunit(sc->cf_drv_dev)); 528 529 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 530 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq); 531 goto out; 532 } 533 534 /* 535 * We couldn't find an exact match, so attempt to estimate and then 536 * match against a level. 537 */ 538 pc = cpu_get_pcpu(dev); 539 if (pc == NULL) { 540 error = ENXIO; 541 goto out; 542 } 543 cpu_est_clockrate(pc->pc_cpuid, &rate); 544 rate /= 1000000; 545 bdiff = 1 << 30; 546 for (i = 0; i < count; i++) { 547 diff = abs(levels[i].total_set.freq - rate); 548 if (diff < bdiff) { 549 bdiff = diff; 550 sc->curr_level = levels[i]; 551 } 552 } 553 CF_DEBUG("get estimated freq %d\n", curr_set->freq); 554 555 out: 556 if (error == 0) 557 *level = sc->curr_level; 558 559 CF_MTX_UNLOCK(&sc->lock); 560 if (levels) 561 free(levels, M_TEMP); 562 return (error); 563 } 564 565 /* 566 * Either directly obtain settings from the cpufreq driver, or build a list of 567 * relative settings to be integrated later against an absolute max. 568 */ 569 static int 570 cpufreq_add_levels(device_t cf_dev, struct cf_setting_lst *rel_sets) 571 { 572 struct cf_setting_array *set_arr; 573 struct cf_setting *sets; 574 device_t dev; 575 struct cpufreq_softc *sc; 576 int type, set_count, error; 577 578 sc = device_get_softc(cf_dev); 579 dev = sc->cf_drv_dev; 580 581 /* Skip devices that aren't ready. */ 582 if (!device_is_attached(cf_dev)) 583 return (0); 584 585 /* 586 * Get settings, skipping drivers that offer no settings or 587 * provide settings for informational purposes only. 588 */ 589 error = CPUFREQ_DRV_TYPE(dev, &type); 590 if (error != 0 || (type & CPUFREQ_FLAG_INFO_ONLY)) { 591 if (error == 0) { 592 CF_DEBUG("skipping info-only driver %s\n", 593 device_get_nameunit(cf_dev)); 594 } 595 return (error); 596 } 597 598 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT); 599 if (sets == NULL) 600 return (ENOMEM); 601 602 set_count = MAX_SETTINGS; 603 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count); 604 if (error != 0 || set_count == 0) 605 goto out; 606 607 /* Add the settings to our absolute/relative lists. */ 608 switch (type & CPUFREQ_TYPE_MASK) { 609 case CPUFREQ_TYPE_ABSOLUTE: 610 error = cpufreq_insert_abs(sc, sets, set_count); 611 break; 612 case CPUFREQ_TYPE_RELATIVE: 613 CF_DEBUG("adding %d relative settings\n", set_count); 614 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT); 615 if (set_arr == NULL) { 616 error = ENOMEM; 617 goto out; 618 } 619 bcopy(sets, set_arr->sets, set_count * sizeof(*sets)); 620 set_arr->count = set_count; 621 TAILQ_INSERT_TAIL(rel_sets, set_arr, link); 622 break; 623 default: 624 error = EINVAL; 625 } 626 627 out: 628 free(sets, M_TEMP); 629 return (error); 630 } 631 632 static int 633 cf_levels_method(device_t dev, struct cf_level *levels, int *count) 634 { 635 struct cf_setting_array *set_arr; 636 struct cf_setting_lst rel_sets; 637 struct cpufreq_softc *sc; 638 struct cf_level *lev; 639 struct pcpu *pc; 640 int error, i; 641 uint64_t rate; 642 643 if (levels == NULL || count == NULL) 644 return (EINVAL); 645 646 TAILQ_INIT(&rel_sets); 647 sc = device_get_softc(dev); 648 649 CF_MTX_LOCK(&sc->lock); 650 error = cpufreq_add_levels(sc->dev, &rel_sets); 651 if (error) 652 goto out; 653 654 /* 655 * If there are no absolute levels, create a fake one at 100%. We 656 * then cache the clockrate for later use as our base frequency. 657 */ 658 if (TAILQ_EMPTY(&sc->all_levels)) { 659 struct cf_setting set; 660 661 CF_DEBUG("No absolute levels returned by driver\n"); 662 663 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) { 664 sc->max_mhz = cpu_get_nominal_mhz(dev); 665 /* 666 * If the CPU can't report a rate for 100%, hope 667 * the CPU is running at its nominal rate right now, 668 * and use that instead. 669 */ 670 if (sc->max_mhz <= 0) { 671 pc = cpu_get_pcpu(dev); 672 cpu_est_clockrate(pc->pc_cpuid, &rate); 673 sc->max_mhz = rate / 1000000; 674 } 675 } 676 memset(&set, CPUFREQ_VAL_UNKNOWN, sizeof(set)); 677 set.freq = sc->max_mhz; 678 set.dev = NULL; 679 error = cpufreq_insert_abs(sc, &set, 1); 680 if (error) 681 goto out; 682 } 683 684 /* Create a combined list of absolute + relative levels. */ 685 TAILQ_FOREACH(set_arr, &rel_sets, link) 686 cpufreq_expand_set(sc, set_arr); 687 688 /* If the caller doesn't have enough space, return the actual count. */ 689 if (sc->all_count > *count) { 690 *count = sc->all_count; 691 error = E2BIG; 692 goto out; 693 } 694 695 /* Finally, output the list of levels. */ 696 i = 0; 697 TAILQ_FOREACH(lev, &sc->all_levels, link) { 698 /* Skip levels that have a frequency that is too low. */ 699 if (lev->total_set.freq < cf_lowest_freq) { 700 sc->all_count--; 701 continue; 702 } 703 704 levels[i] = *lev; 705 i++; 706 } 707 *count = sc->all_count; 708 error = 0; 709 710 out: 711 /* Clear all levels since we regenerate them each time. */ 712 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) { 713 TAILQ_REMOVE(&sc->all_levels, lev, link); 714 free(lev, M_TEMP); 715 } 716 sc->all_count = 0; 717 718 CF_MTX_UNLOCK(&sc->lock); 719 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) { 720 TAILQ_REMOVE(&rel_sets, set_arr, link); 721 free(set_arr, M_TEMP); 722 } 723 return (error); 724 } 725 726 /* 727 * Create levels for an array of absolute settings and insert them in 728 * sorted order in the specified list. 729 */ 730 static int 731 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets, 732 int count) 733 { 734 struct cf_level_lst *list; 735 struct cf_level *level, *search; 736 int i, inserted; 737 738 CF_MTX_ASSERT(&sc->lock); 739 740 list = &sc->all_levels; 741 for (i = 0; i < count; i++) { 742 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO); 743 if (level == NULL) 744 return (ENOMEM); 745 level->abs_set = sets[i]; 746 level->total_set = sets[i]; 747 level->total_set.dev = NULL; 748 sc->all_count++; 749 inserted = 0; 750 751 if (TAILQ_EMPTY(list)) { 752 CF_DEBUG("adding abs setting %d at head\n", 753 sets[i].freq); 754 TAILQ_INSERT_HEAD(list, level, link); 755 continue; 756 } 757 758 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) 759 if (sets[i].freq <= search->total_set.freq) { 760 CF_DEBUG("adding abs setting %d after %d\n", 761 sets[i].freq, search->total_set.freq); 762 TAILQ_INSERT_AFTER(list, search, level, link); 763 inserted = 1; 764 break; 765 } 766 767 if (inserted == 0) { 768 TAILQ_FOREACH(search, list, link) 769 if (sets[i].freq >= search->total_set.freq) { 770 CF_DEBUG("adding abs setting %d before %d\n", 771 sets[i].freq, search->total_set.freq); 772 TAILQ_INSERT_BEFORE(search, level, link); 773 break; 774 } 775 } 776 } 777 778 return (0); 779 } 780 781 /* 782 * Expand a group of relative settings, creating derived levels from them. 783 */ 784 static int 785 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr) 786 { 787 struct cf_level *fill, *search; 788 struct cf_setting *set; 789 int i; 790 791 CF_MTX_ASSERT(&sc->lock); 792 793 /* 794 * Walk the set of all existing levels in reverse. This is so we 795 * create derived states from the lowest absolute settings first 796 * and discard duplicates created from higher absolute settings. 797 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is 798 * preferable to 200 Mhz + 25% because absolute settings are more 799 * efficient since they often change the voltage as well. 800 */ 801 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) { 802 /* Add each setting to the level, duplicating if necessary. */ 803 for (i = 0; i < set_arr->count; i++) { 804 set = &set_arr->sets[i]; 805 806 /* 807 * If this setting is less than 100%, split the level 808 * into two and add this setting to the new level. 809 */ 810 fill = search; 811 if (set->freq < 10000) { 812 fill = cpufreq_dup_set(sc, search, set); 813 814 /* 815 * The new level was a duplicate of an existing 816 * level or its absolute setting is too high 817 * so we freed it. For example, we discard a 818 * derived level of 1000 MHz/25% if a level 819 * of 500 MHz/100% already exists. 820 */ 821 if (fill == NULL) 822 break; 823 } 824 825 /* Add this setting to the existing or new level. */ 826 KASSERT(fill->rel_count < MAX_SETTINGS, 827 ("cpufreq: too many relative drivers (%d)", 828 MAX_SETTINGS)); 829 fill->rel_set[fill->rel_count] = *set; 830 fill->rel_count++; 831 CF_DEBUG( 832 "expand set added rel setting %d%% to %d level\n", 833 set->freq / 100, fill->total_set.freq); 834 } 835 } 836 837 return (0); 838 } 839 840 static struct cf_level * 841 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup, 842 struct cf_setting *set) 843 { 844 struct cf_level_lst *list; 845 struct cf_level *fill, *itr; 846 struct cf_setting *fill_set, *itr_set; 847 int i; 848 849 CF_MTX_ASSERT(&sc->lock); 850 851 /* 852 * Create a new level, copy it from the old one, and update the 853 * total frequency and power by the percentage specified in the 854 * relative setting. 855 */ 856 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT); 857 if (fill == NULL) 858 return (NULL); 859 *fill = *dup; 860 fill_set = &fill->total_set; 861 fill_set->freq = 862 ((uint64_t)fill_set->freq * set->freq) / 10000; 863 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) { 864 fill_set->power = ((uint64_t)fill_set->power * set->freq) 865 / 10000; 866 } 867 if (set->lat != CPUFREQ_VAL_UNKNOWN) { 868 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN) 869 fill_set->lat += set->lat; 870 else 871 fill_set->lat = set->lat; 872 } 873 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq); 874 875 /* 876 * If we copied an old level that we already modified (say, at 100%), 877 * we need to remove that setting before adding this one. Since we 878 * process each setting array in order, we know any settings for this 879 * driver will be found at the end. 880 */ 881 for (i = fill->rel_count; i != 0; i--) { 882 if (fill->rel_set[i - 1].dev != set->dev) 883 break; 884 CF_DEBUG("removed last relative driver: %s\n", 885 device_get_nameunit(set->dev)); 886 fill->rel_count--; 887 } 888 889 /* 890 * Insert the new level in sorted order. If it is a duplicate of an 891 * existing level (1) or has an absolute setting higher than the 892 * existing level (2), do not add it. We can do this since any such 893 * level is guaranteed use less power. For example (1), a level with 894 * one absolute setting of 800 Mhz uses less power than one composed 895 * of an absolute setting of 1600 Mhz and a relative setting at 50%. 896 * Also for example (2), a level of 800 Mhz/75% is preferable to 897 * 1600 Mhz/25% even though the latter has a lower total frequency. 898 */ 899 list = &sc->all_levels; 900 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set")); 901 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) { 902 itr_set = &itr->total_set; 903 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) { 904 CF_DEBUG("dup set rejecting %d (dupe)\n", 905 fill_set->freq); 906 itr = NULL; 907 break; 908 } else if (fill_set->freq < itr_set->freq) { 909 if (fill->abs_set.freq <= itr->abs_set.freq) { 910 CF_DEBUG( 911 "dup done, inserting new level %d after %d\n", 912 fill_set->freq, itr_set->freq); 913 TAILQ_INSERT_AFTER(list, itr, fill, link); 914 sc->all_count++; 915 } else { 916 CF_DEBUG("dup set rejecting %d (abs too big)\n", 917 fill_set->freq); 918 itr = NULL; 919 } 920 break; 921 } 922 } 923 924 /* We didn't find a good place for this new level so free it. */ 925 if (itr == NULL) { 926 CF_DEBUG("dup set freeing new level %d (not optimal)\n", 927 fill_set->freq); 928 free(fill, M_TEMP); 929 fill = NULL; 930 } 931 932 return (fill); 933 } 934 935 static int 936 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS) 937 { 938 struct cpufreq_softc *sc; 939 struct cf_level *levels; 940 int best, count, diff, bdiff, devcount, error, freq, i, n; 941 device_t *devs; 942 943 devs = NULL; 944 sc = oidp->oid_arg1; 945 levels = sc->levels_buf; 946 947 error = CPUFREQ_GET(sc->dev, &levels[0]); 948 if (error) 949 goto out; 950 freq = levels[0].total_set.freq; 951 error = sysctl_handle_int(oidp, &freq, 0, req); 952 if (error != 0 || req->newptr == NULL) 953 goto out; 954 955 /* 956 * While we only call cpufreq_get() on one device (assuming all 957 * CPUs have equal levels), we call cpufreq_set() on all CPUs. 958 * This is needed for some MP systems. 959 */ 960 error = devclass_get_devices(cpufreq_dc, &devs, &devcount); 961 if (error) 962 goto out; 963 for (n = 0; n < devcount; n++) { 964 count = CF_MAX_LEVELS; 965 error = CPUFREQ_LEVELS(devs[n], levels, &count); 966 if (error) { 967 if (error == E2BIG) 968 printf( 969 "cpufreq: need to increase CF_MAX_LEVELS\n"); 970 break; 971 } 972 best = 0; 973 bdiff = 1 << 30; 974 for (i = 0; i < count; i++) { 975 diff = abs(levels[i].total_set.freq - freq); 976 if (diff < bdiff) { 977 bdiff = diff; 978 best = i; 979 } 980 } 981 error = CPUFREQ_SET(devs[n], &levels[best], CPUFREQ_PRIO_USER); 982 } 983 984 out: 985 if (devs) 986 free(devs, M_TEMP); 987 return (error); 988 } 989 990 static int 991 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS) 992 { 993 struct cpufreq_softc *sc; 994 struct cf_level *levels; 995 struct cf_setting *set; 996 struct sbuf sb; 997 int count, error, i; 998 999 sc = oidp->oid_arg1; 1000 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 1001 1002 /* Get settings from the device and generate the output string. */ 1003 count = CF_MAX_LEVELS; 1004 levels = sc->levels_buf; 1005 if (levels == NULL) { 1006 sbuf_delete(&sb); 1007 return (ENOMEM); 1008 } 1009 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 1010 if (error) { 1011 if (error == E2BIG) 1012 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 1013 goto out; 1014 } 1015 if (count) { 1016 for (i = 0; i < count; i++) { 1017 set = &levels[i].total_set; 1018 sbuf_printf(&sb, "%d/%d ", set->freq, set->power); 1019 } 1020 } else 1021 sbuf_cpy(&sb, ""); 1022 sbuf_trim(&sb); 1023 sbuf_finish(&sb); 1024 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 1025 1026 out: 1027 sbuf_delete(&sb); 1028 return (error); 1029 } 1030 1031 static int 1032 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS) 1033 { 1034 device_t dev; 1035 struct cf_setting *sets; 1036 struct sbuf sb; 1037 int error, i, set_count; 1038 1039 dev = oidp->oid_arg1; 1040 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 1041 1042 /* Get settings from the device and generate the output string. */ 1043 set_count = MAX_SETTINGS; 1044 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT); 1045 if (sets == NULL) { 1046 sbuf_delete(&sb); 1047 return (ENOMEM); 1048 } 1049 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count); 1050 if (error) 1051 goto out; 1052 if (set_count) { 1053 for (i = 0; i < set_count; i++) 1054 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power); 1055 } else 1056 sbuf_cpy(&sb, ""); 1057 sbuf_trim(&sb); 1058 sbuf_finish(&sb); 1059 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 1060 1061 out: 1062 free(sets, M_TEMP); 1063 sbuf_delete(&sb); 1064 return (error); 1065 } 1066 1067 static void 1068 cpufreq_add_freq_driver_sysctl(device_t cf_dev) 1069 { 1070 struct cpufreq_softc *sc; 1071 1072 sc = device_get_softc(cf_dev); 1073 SYSCTL_ADD_CONST_STRING(&sc->sysctl_ctx, 1074 SYSCTL_CHILDREN(device_get_sysctl_tree(cf_dev)), OID_AUTO, 1075 "freq_driver", CTLFLAG_RD, device_get_nameunit(sc->cf_drv_dev), 1076 "cpufreq driver used by this cpu"); 1077 } 1078 1079 int 1080 cpufreq_register(device_t dev) 1081 { 1082 struct cpufreq_softc *sc; 1083 device_t cf_dev, cpu_dev; 1084 int error; 1085 1086 /* Add a sysctl to get each driver's settings separately. */ 1087 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), 1088 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 1089 OID_AUTO, "freq_settings", 1090 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, dev, 0, 1091 cpufreq_settings_sysctl, "A", "CPU frequency driver settings"); 1092 1093 /* 1094 * Add only one cpufreq device to each CPU. Currently, all CPUs 1095 * must offer the same levels and be switched at the same time. 1096 */ 1097 cpu_dev = device_get_parent(dev); 1098 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) { 1099 sc = device_get_softc(cf_dev); 1100 sc->max_mhz = CPUFREQ_VAL_UNKNOWN; 1101 MPASS(sc->cf_drv_dev != NULL); 1102 return (0); 1103 } 1104 1105 /* Add the child device and possibly sysctls. */ 1106 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", device_get_unit(cpu_dev)); 1107 if (cf_dev == NULL) 1108 return (ENOMEM); 1109 device_quiet(cf_dev); 1110 1111 error = device_probe_and_attach(cf_dev); 1112 if (error) 1113 return (error); 1114 1115 sc = device_get_softc(cf_dev); 1116 sc->cf_drv_dev = dev; 1117 cpufreq_add_freq_driver_sysctl(cf_dev); 1118 return (error); 1119 } 1120 1121 int 1122 cpufreq_unregister(device_t dev) 1123 { 1124 device_t cf_dev; 1125 struct cpufreq_softc *sc; 1126 1127 /* 1128 * If this is the last cpufreq child device, remove the control 1129 * device as well. We identify cpufreq children by calling a method 1130 * they support. 1131 */ 1132 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1); 1133 if (cf_dev == NULL) { 1134 device_printf(dev, 1135 "warning: cpufreq_unregister called with no cpufreq device active\n"); 1136 return (0); 1137 } 1138 sc = device_get_softc(cf_dev); 1139 MPASS(sc->cf_drv_dev == dev); 1140 device_delete_child(device_get_parent(cf_dev), cf_dev); 1141 1142 return (0); 1143 } 1144 1145 int 1146 cpufreq_settings_changed(device_t dev) 1147 { 1148 1149 EVENTHANDLER_INVOKE(cpufreq_levels_changed, 1150 device_get_unit(device_get_parent(dev))); 1151 return (0); 1152 }
Cache object: b03d490dcb20a933c703754ee94ef883
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