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 * Copyright (c) 2004-2005 Nate Lawson (SDG) 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD: releng/6.4/sys/kern/kern_cpu.c 178881 2008-05-09 19:03:55Z jhb $"); 29 30 #include <sys/param.h> 31 #include <sys/bus.h> 32 #include <sys/cpu.h> 33 #include <sys/eventhandler.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/malloc.h> 37 #include <sys/module.h> 38 #include <sys/proc.h> 39 #include <sys/queue.h> 40 #include <sys/sched.h> 41 #include <sys/sysctl.h> 42 #include <sys/systm.h> 43 #include <sys/sbuf.h> 44 #include <sys/sx.h> 45 #include <sys/timetc.h> 46 47 #include "cpufreq_if.h" 48 49 /* 50 * Common CPU frequency glue code. Drivers for specific hardware can 51 * attach this interface to allow users to get/set the CPU frequency. 52 */ 53 54 /* 55 * Number of levels we can handle. Levels are synthesized from settings 56 * so for M settings and N drivers, there may be M*N levels. 57 */ 58 #define CF_MAX_LEVELS 64 59 60 struct cf_saved_freq { 61 struct cf_level level; 62 int priority; 63 SLIST_ENTRY(cf_saved_freq) link; 64 }; 65 66 struct cpufreq_softc { 67 struct sx lock; 68 struct cf_level curr_level; 69 int curr_priority; 70 SLIST_HEAD(, cf_saved_freq) saved_freq; 71 struct cf_level_lst all_levels; 72 int all_count; 73 int max_mhz; 74 device_t dev; 75 struct sysctl_ctx_list sysctl_ctx; 76 }; 77 78 struct cf_setting_array { 79 struct cf_setting sets[MAX_SETTINGS]; 80 int count; 81 TAILQ_ENTRY(cf_setting_array) link; 82 }; 83 84 TAILQ_HEAD(cf_setting_lst, cf_setting_array); 85 86 #define CF_MTX_INIT(x) sx_init((x), "cpufreq lock") 87 #define CF_MTX_LOCK(x) sx_xlock((x)) 88 #define CF_MTX_UNLOCK(x) sx_xunlock((x)) 89 #define CF_MTX_ASSERT(x) sx_assert((x), SX_XLOCKED) 90 91 #define CF_DEBUG(msg...) do { \ 92 if (cf_verbose) \ 93 printf("cpufreq: " msg); \ 94 } while (0) 95 96 static int cpufreq_attach(device_t dev); 97 static int cpufreq_detach(device_t dev); 98 static void cpufreq_evaluate(void *arg); 99 static int cf_set_method(device_t dev, const struct cf_level *level, 100 int priority); 101 static int cf_get_method(device_t dev, struct cf_level *level); 102 static int cf_levels_method(device_t dev, struct cf_level *levels, 103 int *count); 104 static int cpufreq_insert_abs(struct cpufreq_softc *sc, 105 struct cf_setting *sets, int count); 106 static int cpufreq_expand_set(struct cpufreq_softc *sc, 107 struct cf_setting_array *set_arr); 108 static struct cf_level *cpufreq_dup_set(struct cpufreq_softc *sc, 109 struct cf_level *dup, struct cf_setting *set); 110 static int cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS); 111 static int cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS); 112 static int cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS); 113 114 static device_method_t cpufreq_methods[] = { 115 DEVMETHOD(device_probe, bus_generic_probe), 116 DEVMETHOD(device_attach, cpufreq_attach), 117 DEVMETHOD(device_detach, cpufreq_detach), 118 119 DEVMETHOD(cpufreq_set, cf_set_method), 120 DEVMETHOD(cpufreq_get, cf_get_method), 121 DEVMETHOD(cpufreq_levels, cf_levels_method), 122 {0, 0} 123 }; 124 static driver_t cpufreq_driver = { 125 "cpufreq", cpufreq_methods, sizeof(struct cpufreq_softc) 126 }; 127 static devclass_t cpufreq_dc; 128 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0); 129 130 static eventhandler_tag cf_ev_tag; 131 132 static int cf_lowest_freq; 133 static int cf_verbose; 134 TUNABLE_INT("debug.cpufreq.lowest", &cf_lowest_freq); 135 TUNABLE_INT("debug.cpufreq.verbose", &cf_verbose); 136 SYSCTL_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL, "cpufreq debugging"); 137 SYSCTL_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 1, 138 "Don't provide levels below this frequency."); 139 SYSCTL_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1, 140 "Print verbose debugging messages"); 141 142 static int 143 cpufreq_attach(device_t dev) 144 { 145 struct cpufreq_softc *sc; 146 device_t parent; 147 int numdevs; 148 149 CF_DEBUG("initializing %s\n", device_get_nameunit(dev)); 150 sc = device_get_softc(dev); 151 parent = device_get_parent(dev); 152 sc->dev = dev; 153 sysctl_ctx_init(&sc->sysctl_ctx); 154 TAILQ_INIT(&sc->all_levels); 155 CF_MTX_INIT(&sc->lock); 156 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; 157 SLIST_INIT(&sc->saved_freq); 158 sc->max_mhz = CPUFREQ_VAL_UNKNOWN; 159 160 /* 161 * Only initialize one set of sysctls for all CPUs. In the future, 162 * if multiple CPUs can have different settings, we can move these 163 * sysctls to be under every CPU instead of just the first one. 164 */ 165 numdevs = devclass_get_count(cpufreq_dc); 166 if (numdevs > 1) 167 return (0); 168 169 CF_DEBUG("initializing one-time data for %s\n", 170 device_get_nameunit(dev)); 171 SYSCTL_ADD_PROC(&sc->sysctl_ctx, 172 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)), 173 OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0, 174 cpufreq_curr_sysctl, "I", "Current CPU frequency"); 175 SYSCTL_ADD_PROC(&sc->sysctl_ctx, 176 SYSCTL_CHILDREN(device_get_sysctl_tree(parent)), 177 OID_AUTO, "freq_levels", CTLTYPE_STRING | CTLFLAG_RD, sc, 0, 178 cpufreq_levels_sysctl, "A", "CPU frequency levels"); 179 cf_ev_tag = EVENTHANDLER_REGISTER(cpufreq_changed, cpufreq_evaluate, 180 NULL, EVENTHANDLER_PRI_ANY); 181 182 return (0); 183 } 184 185 static int 186 cpufreq_detach(device_t dev) 187 { 188 struct cpufreq_softc *sc; 189 struct cf_saved_freq *saved_freq; 190 int numdevs; 191 192 CF_DEBUG("shutdown %s\n", device_get_nameunit(dev)); 193 sc = device_get_softc(dev); 194 sysctl_ctx_free(&sc->sysctl_ctx); 195 196 while ((saved_freq = SLIST_FIRST(&sc->saved_freq)) != NULL) { 197 SLIST_REMOVE_HEAD(&sc->saved_freq, link); 198 free(saved_freq, M_TEMP); 199 } 200 201 /* Only clean up these resources when the last device is detaching. */ 202 numdevs = devclass_get_count(cpufreq_dc); 203 if (numdevs == 1) { 204 CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev)); 205 EVENTHANDLER_DEREGISTER(cpufreq_changed, cf_ev_tag); 206 } 207 208 return (0); 209 } 210 211 static void 212 cpufreq_evaluate(void *arg) 213 { 214 /* TODO: Re-evaluate when notified of changes to drivers. */ 215 } 216 217 static int 218 cf_set_method(device_t dev, const struct cf_level *level, int priority) 219 { 220 struct cpufreq_softc *sc; 221 const struct cf_setting *set; 222 struct cf_saved_freq *saved_freq, *curr_freq; 223 struct pcpu *pc; 224 int error, i; 225 static int once; 226 227 sc = device_get_softc(dev); 228 error = 0; 229 set = NULL; 230 saved_freq = NULL; 231 232 /* 233 * Check that the TSC isn't being used as a timecounter. 234 * If it is, then return EBUSY and refuse to change the 235 * clock speed. 236 */ 237 if (strcmp(timecounter->tc_name, "TSC") == 0) { 238 if (!once) { 239 printf("cpufreq: frequency change with timecounter" 240 " TSC not allowed, see cpufreq(4)\n"); 241 once = 1; 242 } 243 return (EBUSY); 244 } 245 246 CF_MTX_LOCK(&sc->lock); 247 248 /* 249 * If the requested level has a lower priority, don't allow 250 * the new level right now. 251 */ 252 if (priority < sc->curr_priority) { 253 CF_DEBUG("ignoring, curr prio %d less than %d\n", priority, 254 sc->curr_priority); 255 error = EPERM; 256 goto out; 257 } 258 259 /* 260 * If the caller didn't specify a level and one is saved, prepare to 261 * restore the saved level. If none has been saved, return an error. 262 */ 263 if (level == NULL) { 264 saved_freq = SLIST_FIRST(&sc->saved_freq); 265 if (saved_freq == NULL) { 266 CF_DEBUG("NULL level, no saved level\n"); 267 error = ENXIO; 268 goto out; 269 } 270 level = &saved_freq->level; 271 priority = saved_freq->priority; 272 CF_DEBUG("restoring saved level, freq %d prio %d\n", 273 level->total_set.freq, priority); 274 } 275 276 /* Reject levels that are below our specified threshold. */ 277 if (level->total_set.freq < cf_lowest_freq) { 278 CF_DEBUG("rejecting freq %d, less than %d limit\n", 279 level->total_set.freq, cf_lowest_freq); 280 error = EINVAL; 281 goto out; 282 } 283 284 /* If already at this level, just return. */ 285 if (CPUFREQ_CMP(sc->curr_level.total_set.freq, level->total_set.freq)) { 286 CF_DEBUG("skipping freq %d, same as current level %d\n", 287 level->total_set.freq, sc->curr_level.total_set.freq); 288 goto skip; 289 } 290 291 /* First, set the absolute frequency via its driver. */ 292 set = &level->abs_set; 293 if (set->dev) { 294 if (!device_is_attached(set->dev)) { 295 error = ENXIO; 296 goto out; 297 } 298 299 /* Bind to the target CPU before switching. */ 300 pc = cpu_get_pcpu(set->dev); 301 mtx_lock_spin(&sched_lock); 302 sched_bind(curthread, pc->pc_cpuid); 303 mtx_unlock_spin(&sched_lock); 304 CF_DEBUG("setting abs freq %d on %s (cpu %d)\n", set->freq, 305 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 306 error = CPUFREQ_DRV_SET(set->dev, set); 307 mtx_lock_spin(&sched_lock); 308 sched_unbind(curthread); 309 mtx_unlock_spin(&sched_lock); 310 if (error) { 311 goto out; 312 } 313 } 314 315 /* Next, set any/all relative frequencies via their drivers. */ 316 for (i = 0; i < level->rel_count; i++) { 317 set = &level->rel_set[i]; 318 if (!device_is_attached(set->dev)) { 319 error = ENXIO; 320 goto out; 321 } 322 323 /* Bind to the target CPU before switching. */ 324 pc = cpu_get_pcpu(set->dev); 325 mtx_lock_spin(&sched_lock); 326 sched_bind(curthread, pc->pc_cpuid); 327 mtx_unlock_spin(&sched_lock); 328 CF_DEBUG("setting rel freq %d on %s (cpu %d)\n", set->freq, 329 device_get_nameunit(set->dev), PCPU_GET(cpuid)); 330 error = CPUFREQ_DRV_SET(set->dev, set); 331 mtx_lock_spin(&sched_lock); 332 sched_unbind(curthread); 333 mtx_unlock_spin(&sched_lock); 334 if (error) { 335 /* XXX Back out any successful setting? */ 336 goto out; 337 } 338 } 339 340 skip: 341 /* 342 * Before recording the current level, check if we're going to a 343 * higher priority. If so, save the previous level and priority. 344 */ 345 if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN && 346 priority > sc->curr_priority) { 347 CF_DEBUG("saving level, freq %d prio %d\n", 348 sc->curr_level.total_set.freq, sc->curr_priority); 349 curr_freq = malloc(sizeof(*curr_freq), M_TEMP, M_NOWAIT); 350 if (curr_freq == NULL) { 351 error = ENOMEM; 352 goto out; 353 } 354 curr_freq->level = sc->curr_level; 355 curr_freq->priority = sc->curr_priority; 356 SLIST_INSERT_HEAD(&sc->saved_freq, curr_freq, link); 357 } 358 sc->curr_level = *level; 359 sc->curr_priority = priority; 360 361 /* If we were restoring a saved state, reset it to "unused". */ 362 if (saved_freq != NULL) { 363 CF_DEBUG("resetting saved level\n"); 364 sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; 365 SLIST_REMOVE_HEAD(&sc->saved_freq, link); 366 free(saved_freq, M_TEMP); 367 } 368 369 out: 370 CF_MTX_UNLOCK(&sc->lock); 371 if (error && set) 372 device_printf(set->dev, "set freq failed, err %d\n", error); 373 return (error); 374 } 375 376 static int 377 cf_get_method(device_t dev, struct cf_level *level) 378 { 379 struct cpufreq_softc *sc; 380 struct cf_level *levels; 381 struct cf_setting *curr_set, set; 382 struct pcpu *pc; 383 device_t *devs; 384 int count, error, i, n, numdevs; 385 uint64_t rate; 386 387 sc = device_get_softc(dev); 388 error = 0; 389 levels = NULL; 390 391 /* If we already know the current frequency, we're done. */ 392 CF_MTX_LOCK(&sc->lock); 393 curr_set = &sc->curr_level.total_set; 394 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 395 CF_DEBUG("get returning known freq %d\n", curr_set->freq); 396 goto out; 397 } 398 CF_MTX_UNLOCK(&sc->lock); 399 400 /* 401 * We need to figure out the current level. Loop through every 402 * driver, getting the current setting. Then, attempt to get a best 403 * match of settings against each level. 404 */ 405 count = CF_MAX_LEVELS; 406 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT); 407 if (levels == NULL) 408 return (ENOMEM); 409 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 410 if (error) { 411 if (error == E2BIG) 412 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 413 free(levels, M_TEMP); 414 return (error); 415 } 416 error = device_get_children(device_get_parent(dev), &devs, &numdevs); 417 if (error) { 418 free(levels, M_TEMP); 419 return (error); 420 } 421 422 /* 423 * Reacquire the lock and search for the given level. 424 * 425 * XXX Note: this is not quite right since we really need to go 426 * through each level and compare both absolute and relative 427 * settings for each driver in the system before making a match. 428 * The estimation code below catches this case though. 429 */ 430 CF_MTX_LOCK(&sc->lock); 431 for (n = 0; n < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; n++) { 432 if (!device_is_attached(devs[n])) 433 continue; 434 if (CPUFREQ_DRV_GET(devs[n], &set) != 0) 435 continue; 436 for (i = 0; i < count; i++) { 437 if (CPUFREQ_CMP(set.freq, levels[i].total_set.freq)) { 438 sc->curr_level = levels[i]; 439 break; 440 } 441 } 442 } 443 free(devs, M_TEMP); 444 if (curr_set->freq != CPUFREQ_VAL_UNKNOWN) { 445 CF_DEBUG("get matched freq %d from drivers\n", curr_set->freq); 446 goto out; 447 } 448 449 /* 450 * We couldn't find an exact match, so attempt to estimate and then 451 * match against a level. 452 */ 453 pc = cpu_get_pcpu(dev); 454 if (pc == NULL) { 455 error = ENXIO; 456 goto out; 457 } 458 cpu_est_clockrate(pc->pc_cpuid, &rate); 459 rate /= 1000000; 460 for (i = 0; i < count; i++) { 461 if (CPUFREQ_CMP(rate, levels[i].total_set.freq)) { 462 sc->curr_level = levels[i]; 463 CF_DEBUG("get estimated freq %d\n", curr_set->freq); 464 goto out; 465 } 466 } 467 error = ENXIO; 468 469 out: 470 if (error == 0) 471 *level = sc->curr_level; 472 473 CF_MTX_UNLOCK(&sc->lock); 474 if (levels) 475 free(levels, M_TEMP); 476 return (error); 477 } 478 479 static int 480 cf_levels_method(device_t dev, struct cf_level *levels, int *count) 481 { 482 struct cf_setting_array *set_arr; 483 struct cf_setting_lst rel_sets; 484 struct cpufreq_softc *sc; 485 struct cf_level *lev; 486 struct cf_setting *sets; 487 struct pcpu *pc; 488 device_t *devs; 489 int error, i, numdevs, set_count, type; 490 uint64_t rate; 491 492 if (levels == NULL || count == NULL) 493 return (EINVAL); 494 495 TAILQ_INIT(&rel_sets); 496 sc = device_get_softc(dev); 497 error = device_get_children(device_get_parent(dev), &devs, &numdevs); 498 if (error) 499 return (error); 500 sets = malloc(MAX_SETTINGS * sizeof(*sets), M_TEMP, M_NOWAIT); 501 if (sets == NULL) { 502 free(devs, M_TEMP); 503 return (ENOMEM); 504 } 505 506 /* Get settings from all cpufreq drivers. */ 507 CF_MTX_LOCK(&sc->lock); 508 for (i = 0; i < numdevs; i++) { 509 /* Skip devices that aren't ready. */ 510 if (!device_is_attached(devs[i])) 511 continue; 512 513 /* 514 * Get settings, skipping drivers that offer no settings or 515 * provide settings for informational purposes only. 516 */ 517 error = CPUFREQ_DRV_TYPE(devs[i], &type); 518 if (error || (type & CPUFREQ_FLAG_INFO_ONLY)) { 519 if (error == 0) { 520 CF_DEBUG("skipping info-only driver %s\n", 521 device_get_nameunit(devs[i])); 522 } 523 continue; 524 } 525 set_count = MAX_SETTINGS; 526 error = CPUFREQ_DRV_SETTINGS(devs[i], sets, &set_count); 527 if (error || set_count == 0) 528 continue; 529 530 /* Add the settings to our absolute/relative lists. */ 531 switch (type & CPUFREQ_TYPE_MASK) { 532 case CPUFREQ_TYPE_ABSOLUTE: 533 error = cpufreq_insert_abs(sc, sets, set_count); 534 break; 535 case CPUFREQ_TYPE_RELATIVE: 536 CF_DEBUG("adding %d relative settings\n", set_count); 537 set_arr = malloc(sizeof(*set_arr), M_TEMP, M_NOWAIT); 538 if (set_arr == NULL) { 539 error = ENOMEM; 540 goto out; 541 } 542 bcopy(sets, set_arr->sets, set_count * sizeof(*sets)); 543 set_arr->count = set_count; 544 TAILQ_INSERT_TAIL(&rel_sets, set_arr, link); 545 break; 546 default: 547 error = EINVAL; 548 } 549 if (error) 550 goto out; 551 } 552 553 /* 554 * If there are no absolute levels, create a fake one at 100%. We 555 * then cache the clockrate for later use as our base frequency. 556 * 557 * XXX This assumes that the first time through, if we only have 558 * relative drivers, the CPU is currently running at 100%. 559 */ 560 if (TAILQ_EMPTY(&sc->all_levels)) { 561 if (sc->max_mhz == CPUFREQ_VAL_UNKNOWN) { 562 pc = cpu_get_pcpu(dev); 563 cpu_est_clockrate(pc->pc_cpuid, &rate); 564 sc->max_mhz = rate / 1000000; 565 } 566 memset(&sets[0], CPUFREQ_VAL_UNKNOWN, sizeof(*sets)); 567 sets[0].freq = sc->max_mhz; 568 sets[0].dev = NULL; 569 error = cpufreq_insert_abs(sc, sets, 1); 570 if (error) 571 goto out; 572 } 573 574 /* Create a combined list of absolute + relative levels. */ 575 TAILQ_FOREACH(set_arr, &rel_sets, link) 576 cpufreq_expand_set(sc, set_arr); 577 578 /* If the caller doesn't have enough space, return the actual count. */ 579 if (sc->all_count > *count) { 580 *count = sc->all_count; 581 error = E2BIG; 582 goto out; 583 } 584 585 /* Finally, output the list of levels. */ 586 i = 0; 587 TAILQ_FOREACH(lev, &sc->all_levels, link) { 588 /* Skip levels that have a frequency that is too low. */ 589 if (lev->total_set.freq < cf_lowest_freq) { 590 sc->all_count--; 591 continue; 592 } 593 594 levels[i] = *lev; 595 i++; 596 } 597 *count = sc->all_count; 598 error = 0; 599 600 out: 601 /* Clear all levels since we regenerate them each time. */ 602 while ((lev = TAILQ_FIRST(&sc->all_levels)) != NULL) { 603 TAILQ_REMOVE(&sc->all_levels, lev, link); 604 free(lev, M_TEMP); 605 } 606 sc->all_count = 0; 607 608 CF_MTX_UNLOCK(&sc->lock); 609 while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) { 610 TAILQ_REMOVE(&rel_sets, set_arr, link); 611 free(set_arr, M_TEMP); 612 } 613 free(devs, M_TEMP); 614 free(sets, M_TEMP); 615 return (error); 616 } 617 618 /* 619 * Create levels for an array of absolute settings and insert them in 620 * sorted order in the specified list. 621 */ 622 static int 623 cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets, 624 int count) 625 { 626 struct cf_level_lst *list; 627 struct cf_level *level, *search; 628 int i; 629 630 CF_MTX_ASSERT(&sc->lock); 631 632 list = &sc->all_levels; 633 for (i = 0; i < count; i++) { 634 level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO); 635 if (level == NULL) 636 return (ENOMEM); 637 level->abs_set = sets[i]; 638 level->total_set = sets[i]; 639 level->total_set.dev = NULL; 640 sc->all_count++; 641 642 if (TAILQ_EMPTY(list)) { 643 CF_DEBUG("adding abs setting %d at head\n", 644 sets[i].freq); 645 TAILQ_INSERT_HEAD(list, level, link); 646 continue; 647 } 648 649 TAILQ_FOREACH_REVERSE(search, list, cf_level_lst, link) { 650 if (sets[i].freq <= search->total_set.freq) { 651 CF_DEBUG("adding abs setting %d after %d\n", 652 sets[i].freq, search->total_set.freq); 653 TAILQ_INSERT_AFTER(list, search, level, link); 654 break; 655 } 656 } 657 } 658 return (0); 659 } 660 661 /* 662 * Expand a group of relative settings, creating derived levels from them. 663 */ 664 static int 665 cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr) 666 { 667 struct cf_level *fill, *search; 668 struct cf_setting *set; 669 int i; 670 671 CF_MTX_ASSERT(&sc->lock); 672 673 /* 674 * Walk the set of all existing levels in reverse. This is so we 675 * create derived states from the lowest absolute settings first 676 * and discard duplicates created from higher absolute settings. 677 * For instance, a level of 50 Mhz derived from 100 Mhz + 50% is 678 * preferable to 200 Mhz + 25% because absolute settings are more 679 * efficient since they often change the voltage as well. 680 */ 681 TAILQ_FOREACH_REVERSE(search, &sc->all_levels, cf_level_lst, link) { 682 /* Add each setting to the level, duplicating if necessary. */ 683 for (i = 0; i < set_arr->count; i++) { 684 set = &set_arr->sets[i]; 685 686 /* 687 * If this setting is less than 100%, split the level 688 * into two and add this setting to the new level. 689 */ 690 fill = search; 691 if (set->freq < 10000) { 692 fill = cpufreq_dup_set(sc, search, set); 693 694 /* 695 * The new level was a duplicate of an existing 696 * level or its absolute setting is too high 697 * so we freed it. For example, we discard a 698 * derived level of 1000 MHz/25% if a level 699 * of 500 MHz/100% already exists. 700 */ 701 if (fill == NULL) 702 break; 703 } 704 705 /* Add this setting to the existing or new level. */ 706 KASSERT(fill->rel_count < MAX_SETTINGS, 707 ("cpufreq: too many relative drivers (%d)", 708 MAX_SETTINGS)); 709 fill->rel_set[fill->rel_count] = *set; 710 fill->rel_count++; 711 CF_DEBUG( 712 "expand set added rel setting %d%% to %d level\n", 713 set->freq / 100, fill->total_set.freq); 714 } 715 } 716 717 return (0); 718 } 719 720 static struct cf_level * 721 cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup, 722 struct cf_setting *set) 723 { 724 struct cf_level_lst *list; 725 struct cf_level *fill, *itr; 726 struct cf_setting *fill_set, *itr_set; 727 int i; 728 729 CF_MTX_ASSERT(&sc->lock); 730 731 /* 732 * Create a new level, copy it from the old one, and update the 733 * total frequency and power by the percentage specified in the 734 * relative setting. 735 */ 736 fill = malloc(sizeof(*fill), M_TEMP, M_NOWAIT); 737 if (fill == NULL) 738 return (NULL); 739 *fill = *dup; 740 fill_set = &fill->total_set; 741 fill_set->freq = 742 ((uint64_t)fill_set->freq * set->freq) / 10000; 743 if (fill_set->power != CPUFREQ_VAL_UNKNOWN) { 744 fill_set->power = ((uint64_t)fill_set->power * set->freq) 745 / 10000; 746 } 747 if (set->lat != CPUFREQ_VAL_UNKNOWN) { 748 if (fill_set->lat != CPUFREQ_VAL_UNKNOWN) 749 fill_set->lat += set->lat; 750 else 751 fill_set->lat = set->lat; 752 } 753 CF_DEBUG("dup set considering derived setting %d\n", fill_set->freq); 754 755 /* 756 * If we copied an old level that we already modified (say, at 100%), 757 * we need to remove that setting before adding this one. Since we 758 * process each setting array in order, we know any settings for this 759 * driver will be found at the end. 760 */ 761 for (i = fill->rel_count; i != 0; i--) { 762 if (fill->rel_set[i - 1].dev != set->dev) 763 break; 764 CF_DEBUG("removed last relative driver: %s\n", 765 device_get_nameunit(set->dev)); 766 fill->rel_count--; 767 } 768 769 /* 770 * Insert the new level in sorted order. If it is a duplicate of an 771 * existing level (1) or has an absolute setting higher than the 772 * existing level (2), do not add it. We can do this since any such 773 * level is guaranteed use less power. For example (1), a level with 774 * one absolute setting of 800 Mhz uses less power than one composed 775 * of an absolute setting of 1600 Mhz and a relative setting at 50%. 776 * Also for example (2), a level of 800 Mhz/75% is preferable to 777 * 1600 Mhz/25% even though the latter has a lower total frequency. 778 */ 779 list = &sc->all_levels; 780 KASSERT(!TAILQ_EMPTY(list), ("all levels list empty in dup set")); 781 TAILQ_FOREACH_REVERSE(itr, list, cf_level_lst, link) { 782 itr_set = &itr->total_set; 783 if (CPUFREQ_CMP(fill_set->freq, itr_set->freq)) { 784 CF_DEBUG("dup set rejecting %d (dupe)\n", 785 fill_set->freq); 786 itr = NULL; 787 break; 788 } else if (fill_set->freq < itr_set->freq) { 789 if (fill->abs_set.freq <= itr->abs_set.freq) { 790 CF_DEBUG( 791 "dup done, inserting new level %d after %d\n", 792 fill_set->freq, itr_set->freq); 793 TAILQ_INSERT_AFTER(list, itr, fill, link); 794 sc->all_count++; 795 } else { 796 CF_DEBUG("dup set rejecting %d (abs too big)\n", 797 fill_set->freq); 798 itr = NULL; 799 } 800 break; 801 } 802 } 803 804 /* We didn't find a good place for this new level so free it. */ 805 if (itr == NULL) { 806 CF_DEBUG("dup set freeing new level %d (not optimal)\n", 807 fill_set->freq); 808 free(fill, M_TEMP); 809 fill = NULL; 810 } 811 812 return (fill); 813 } 814 815 static int 816 cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS) 817 { 818 struct cpufreq_softc *sc; 819 struct cf_level *levels; 820 int count, devcount, error, freq, i, n; 821 device_t *devs; 822 823 devs = NULL; 824 sc = oidp->oid_arg1; 825 levels = malloc(CF_MAX_LEVELS * sizeof(*levels), M_TEMP, M_NOWAIT); 826 if (levels == NULL) 827 return (ENOMEM); 828 829 error = CPUFREQ_GET(sc->dev, &levels[0]); 830 if (error) 831 goto out; 832 freq = levels[0].total_set.freq; 833 error = sysctl_handle_int(oidp, &freq, 0, req); 834 if (error != 0 || req->newptr == NULL) 835 goto out; 836 837 /* 838 * While we only call cpufreq_get() on one device (assuming all 839 * CPUs have equal levels), we call cpufreq_set() on all CPUs. 840 * This is needed for some MP systems. 841 */ 842 error = devclass_get_devices(cpufreq_dc, &devs, &devcount); 843 if (error) 844 goto out; 845 for (n = 0; n < devcount; n++) { 846 count = CF_MAX_LEVELS; 847 error = CPUFREQ_LEVELS(devs[n], levels, &count); 848 if (error) { 849 if (error == E2BIG) 850 printf( 851 "cpufreq: need to increase CF_MAX_LEVELS\n"); 852 break; 853 } 854 for (i = 0; i < count; i++) { 855 if (CPUFREQ_CMP(levels[i].total_set.freq, freq)) { 856 error = CPUFREQ_SET(devs[n], &levels[i], 857 CPUFREQ_PRIO_USER); 858 break; 859 } 860 } 861 if (i == count) { 862 error = EINVAL; 863 break; 864 } 865 } 866 867 out: 868 if (devs) 869 free(devs, M_TEMP); 870 if (levels) 871 free(levels, M_TEMP); 872 return (error); 873 } 874 875 static int 876 cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS) 877 { 878 struct cpufreq_softc *sc; 879 struct cf_level *levels; 880 struct cf_setting *set; 881 struct sbuf sb; 882 int count, error, i; 883 884 sc = oidp->oid_arg1; 885 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 886 887 /* Get settings from the device and generate the output string. */ 888 count = CF_MAX_LEVELS; 889 levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT); 890 if (levels == NULL) 891 return (ENOMEM); 892 error = CPUFREQ_LEVELS(sc->dev, levels, &count); 893 if (error) { 894 if (error == E2BIG) 895 printf("cpufreq: need to increase CF_MAX_LEVELS\n"); 896 goto out; 897 } 898 if (count) { 899 for (i = 0; i < count; i++) { 900 set = &levels[i].total_set; 901 sbuf_printf(&sb, "%d/%d ", set->freq, set->power); 902 } 903 } else 904 sbuf_cpy(&sb, ""); 905 sbuf_trim(&sb); 906 sbuf_finish(&sb); 907 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 908 909 out: 910 free(levels, M_TEMP); 911 sbuf_delete(&sb); 912 return (error); 913 } 914 915 static int 916 cpufreq_settings_sysctl(SYSCTL_HANDLER_ARGS) 917 { 918 device_t dev; 919 struct cf_setting *sets; 920 struct sbuf sb; 921 int error, i, set_count; 922 923 dev = oidp->oid_arg1; 924 sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND); 925 926 /* Get settings from the device and generate the output string. */ 927 set_count = MAX_SETTINGS; 928 sets = malloc(set_count * sizeof(*sets), M_TEMP, M_NOWAIT); 929 if (sets == NULL) 930 return (ENOMEM); 931 error = CPUFREQ_DRV_SETTINGS(dev, sets, &set_count); 932 if (error) 933 goto out; 934 if (set_count) { 935 for (i = 0; i < set_count; i++) 936 sbuf_printf(&sb, "%d/%d ", sets[i].freq, sets[i].power); 937 } else 938 sbuf_cpy(&sb, ""); 939 sbuf_trim(&sb); 940 sbuf_finish(&sb); 941 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 942 943 out: 944 free(sets, M_TEMP); 945 sbuf_delete(&sb); 946 return (error); 947 } 948 949 int 950 cpufreq_register(device_t dev) 951 { 952 struct cpufreq_softc *sc; 953 device_t cf_dev, cpu_dev; 954 955 /* Add a sysctl to get each driver's settings separately. */ 956 SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev), 957 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 958 OID_AUTO, "freq_settings", CTLTYPE_STRING | CTLFLAG_RD, dev, 0, 959 cpufreq_settings_sysctl, "A", "CPU frequency driver settings"); 960 961 /* 962 * Add only one cpufreq device to each CPU. Currently, all CPUs 963 * must offer the same levels and be switched at the same time. 964 */ 965 cpu_dev = device_get_parent(dev); 966 if ((cf_dev = device_find_child(cpu_dev, "cpufreq", -1))) { 967 sc = device_get_softc(cf_dev); 968 sc->max_mhz = CPUFREQ_VAL_UNKNOWN; 969 return (0); 970 } 971 972 /* Add the child device and possibly sysctls. */ 973 cf_dev = BUS_ADD_CHILD(cpu_dev, 0, "cpufreq", -1); 974 if (cf_dev == NULL) 975 return (ENOMEM); 976 device_quiet(cf_dev); 977 978 return (device_probe_and_attach(cf_dev)); 979 } 980 981 int 982 cpufreq_unregister(device_t dev) 983 { 984 device_t cf_dev, *devs; 985 int cfcount, devcount, error, i, type; 986 987 /* 988 * If this is the last cpufreq child device, remove the control 989 * device as well. We identify cpufreq children by calling a method 990 * they support. 991 */ 992 error = device_get_children(device_get_parent(dev), &devs, &devcount); 993 if (error) 994 return (error); 995 cf_dev = device_find_child(device_get_parent(dev), "cpufreq", -1); 996 if (cf_dev == NULL) { 997 device_printf(dev, 998 "warning: cpufreq_unregister called with no cpufreq device active\n"); 999 return (0); 1000 } 1001 cfcount = 0; 1002 for (i = 0; i < devcount; i++) { 1003 if (!device_is_attached(devs[i])) 1004 continue; 1005 if (CPUFREQ_DRV_TYPE(devs[i], &type) == 0) 1006 cfcount++; 1007 } 1008 if (cfcount <= 1) 1009 device_delete_child(device_get_parent(cf_dev), cf_dev); 1010 free(devs, M_TEMP); 1011 1012 return (0); 1013 }
Cache object: 0bf3c60cc3091c05863ecda64171d600
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