1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/drivers/cpufreq/cpufreq.c 4 * 5 * Copyright (C) 2001 Russell King 6 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> 7 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> 8 * 9 * Oct 2005 - Ashok Raj <ashok.raj@intel.com> 10 * Added handling for CPU hotplug 11 * Feb 2006 - Jacob Shin <jacob.shin@amd.com> 12 * Fix handling for CPU hotplug -- affected CPUs 13 */ 14 15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 16 17 #include <linux/cpu.h> 18 #include <linux/cpufreq.h> 19 #include <linux/cpu_cooling.h> 20 #include <linux/delay.h> 21 #include <linux/device.h> 22 #include <linux/init.h> 23 #include <linux/kernel_stat.h> 24 #include <linux/module.h> 25 #include <linux/mutex.h> 26 #include <linux/pm_qos.h> 27 #include <linux/slab.h> 28 #include <linux/string_choices.h> 29 #include <linux/suspend.h> 30 #include <linux/syscore_ops.h> 31 #include <linux/tick.h> 32 #include <linux/units.h> 33 #include <trace/events/power.h> 34 35 static LIST_HEAD(cpufreq_policy_list); 36 37 /* Macros to iterate over CPU policies */ 38 #define for_each_suitable_policy(__policy, __active) \ 39 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \ 40 if ((__active) == !policy_is_inactive(__policy)) 41 42 #define for_each_active_policy(__policy) \ 43 for_each_suitable_policy(__policy, true) 44 #define for_each_inactive_policy(__policy) \ 45 for_each_suitable_policy(__policy, false) 46 47 /* Iterate over governors */ 48 static LIST_HEAD(cpufreq_governor_list); 49 #define for_each_governor(__governor) \ 50 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) 51 52 static char default_governor[CPUFREQ_NAME_LEN]; 53 54 /* 55 * The "cpufreq driver" - the arch- or hardware-dependent low 56 * level driver of CPUFreq support, and its spinlock. This lock 57 * also protects the cpufreq_cpu_data array. 58 */ 59 static struct cpufreq_driver *cpufreq_driver; 60 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); 61 static DEFINE_RWLOCK(cpufreq_driver_lock); 62 63 static DEFINE_STATIC_KEY_FALSE(cpufreq_freq_invariance); 64 bool cpufreq_supports_freq_invariance(void) 65 { 66 return static_branch_likely(&cpufreq_freq_invariance); 67 } 68 69 /* Flag to suspend/resume CPUFreq governors */ 70 static bool cpufreq_suspended; 71 72 static inline bool has_target(void) 73 { 74 return cpufreq_driver->target_index || cpufreq_driver->target; 75 } 76 77 bool has_target_index(void) 78 { 79 return !!cpufreq_driver->target_index; 80 } 81 82 /* internal prototypes */ 83 static unsigned int __cpufreq_get(struct cpufreq_policy *policy); 84 static int cpufreq_init_governor(struct cpufreq_policy *policy); 85 static void cpufreq_exit_governor(struct cpufreq_policy *policy); 86 static void cpufreq_governor_limits(struct cpufreq_policy *policy); 87 static int cpufreq_set_policy(struct cpufreq_policy *policy, 88 struct cpufreq_governor *new_gov, 89 unsigned int new_pol); 90 static bool cpufreq_boost_supported(void); 91 static int cpufreq_boost_trigger_state(int state); 92 93 /* 94 * Two notifier lists: the "policy" list is involved in the 95 * validation process for a new CPU frequency policy; the 96 * "transition" list for kernel code that needs to handle 97 * changes to devices when the CPU clock speed changes. 98 * The mutex locks both lists. 99 */ 100 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); 101 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list); 102 103 static int off __read_mostly; 104 static int cpufreq_disabled(void) 105 { 106 return off; 107 } 108 void disable_cpufreq(void) 109 { 110 off = 1; 111 } 112 static DEFINE_MUTEX(cpufreq_governor_mutex); 113 114 bool have_governor_per_policy(void) 115 { 116 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); 117 } 118 EXPORT_SYMBOL_GPL(have_governor_per_policy); 119 120 static struct kobject *cpufreq_global_kobject; 121 122 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) 123 { 124 if (have_governor_per_policy()) 125 return &policy->kobj; 126 else 127 return cpufreq_global_kobject; 128 } 129 EXPORT_SYMBOL_GPL(get_governor_parent_kobj); 130 131 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) 132 { 133 struct kernel_cpustat kcpustat; 134 u64 cur_wall_time; 135 u64 idle_time; 136 u64 busy_time; 137 138 cur_wall_time = jiffies64_to_nsecs(get_jiffies_64()); 139 140 kcpustat_cpu_fetch(&kcpustat, cpu); 141 142 busy_time = kcpustat.cpustat[CPUTIME_USER]; 143 busy_time += kcpustat.cpustat[CPUTIME_SYSTEM]; 144 busy_time += kcpustat.cpustat[CPUTIME_IRQ]; 145 busy_time += kcpustat.cpustat[CPUTIME_SOFTIRQ]; 146 busy_time += kcpustat.cpustat[CPUTIME_STEAL]; 147 busy_time += kcpustat.cpustat[CPUTIME_NICE]; 148 149 idle_time = cur_wall_time - busy_time; 150 if (wall) 151 *wall = div_u64(cur_wall_time, NSEC_PER_USEC); 152 153 return div_u64(idle_time, NSEC_PER_USEC); 154 } 155 156 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) 157 { 158 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); 159 160 if (idle_time == -1ULL) 161 return get_cpu_idle_time_jiffy(cpu, wall); 162 else if (!io_busy) 163 idle_time += get_cpu_iowait_time_us(cpu, wall); 164 165 return idle_time; 166 } 167 EXPORT_SYMBOL_GPL(get_cpu_idle_time); 168 169 /* 170 * This is a generic cpufreq init() routine which can be used by cpufreq 171 * drivers of SMP systems. It will do following: 172 * - validate & show freq table passed 173 * - set policies transition latency 174 * - policy->cpus with all possible CPUs 175 */ 176 void cpufreq_generic_init(struct cpufreq_policy *policy, 177 struct cpufreq_frequency_table *table, 178 unsigned int transition_latency) 179 { 180 policy->freq_table = table; 181 policy->cpuinfo.transition_latency = transition_latency; 182 183 /* 184 * The driver only supports the SMP configuration where all processors 185 * share the clock and voltage and clock. 186 */ 187 cpumask_setall(policy->cpus); 188 } 189 EXPORT_SYMBOL_GPL(cpufreq_generic_init); 190 191 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) 192 { 193 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); 194 195 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL; 196 } 197 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw); 198 199 unsigned int cpufreq_generic_get(unsigned int cpu) 200 { 201 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); 202 203 if (!policy || IS_ERR(policy->clk)) { 204 pr_err("%s: No %s associated to cpu: %d\n", 205 __func__, policy ? "clk" : "policy", cpu); 206 return 0; 207 } 208 209 return clk_get_rate(policy->clk) / 1000; 210 } 211 EXPORT_SYMBOL_GPL(cpufreq_generic_get); 212 213 /** 214 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy. 215 * @cpu: CPU to find the policy for. 216 * 217 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment 218 * the kobject reference counter of that policy. Return a valid policy on 219 * success or NULL on failure. 220 * 221 * The policy returned by this function has to be released with the help of 222 * cpufreq_cpu_put() to balance its kobject reference counter properly. 223 */ 224 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) 225 { 226 struct cpufreq_policy *policy = NULL; 227 unsigned long flags; 228 229 if (WARN_ON(cpu >= nr_cpu_ids)) 230 return NULL; 231 232 /* get the cpufreq driver */ 233 read_lock_irqsave(&cpufreq_driver_lock, flags); 234 235 if (cpufreq_driver) { 236 /* get the CPU */ 237 policy = cpufreq_cpu_get_raw(cpu); 238 if (policy) 239 kobject_get(&policy->kobj); 240 } 241 242 read_unlock_irqrestore(&cpufreq_driver_lock, flags); 243 244 return policy; 245 } 246 EXPORT_SYMBOL_GPL(cpufreq_cpu_get); 247 248 /** 249 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy. 250 * @policy: cpufreq policy returned by cpufreq_cpu_get(). 251 */ 252 void cpufreq_cpu_put(struct cpufreq_policy *policy) 253 { 254 kobject_put(&policy->kobj); 255 } 256 EXPORT_SYMBOL_GPL(cpufreq_cpu_put); 257 258 /********************************************************************* 259 * EXTERNALLY AFFECTING FREQUENCY CHANGES * 260 *********************************************************************/ 261 262 /** 263 * adjust_jiffies - Adjust the system "loops_per_jiffy". 264 * @val: CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. 265 * @ci: Frequency change information. 266 * 267 * This function alters the system "loops_per_jiffy" for the clock 268 * speed change. Note that loops_per_jiffy cannot be updated on SMP 269 * systems as each CPU might be scaled differently. So, use the arch 270 * per-CPU loops_per_jiffy value wherever possible. 271 */ 272 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) 273 { 274 #ifndef CONFIG_SMP 275 static unsigned long l_p_j_ref; 276 static unsigned int l_p_j_ref_freq; 277 278 if (ci->flags & CPUFREQ_CONST_LOOPS) 279 return; 280 281 if (!l_p_j_ref_freq) { 282 l_p_j_ref = loops_per_jiffy; 283 l_p_j_ref_freq = ci->old; 284 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", 285 l_p_j_ref, l_p_j_ref_freq); 286 } 287 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { 288 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, 289 ci->new); 290 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", 291 loops_per_jiffy, ci->new); 292 } 293 #endif 294 } 295 296 /** 297 * cpufreq_notify_transition - Notify frequency transition and adjust jiffies. 298 * @policy: cpufreq policy to enable fast frequency switching for. 299 * @freqs: contain details of the frequency update. 300 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. 301 * 302 * This function calls the transition notifiers and adjust_jiffies(). 303 * 304 * It is called twice on all CPU frequency changes that have external effects. 305 */ 306 static void cpufreq_notify_transition(struct cpufreq_policy *policy, 307 struct cpufreq_freqs *freqs, 308 unsigned int state) 309 { 310 int cpu; 311 312 BUG_ON(irqs_disabled()); 313 314 if (cpufreq_disabled()) 315 return; 316 317 freqs->policy = policy; 318 freqs->flags = cpufreq_driver->flags; 319 pr_debug("notification %u of frequency transition to %u kHz\n", 320 state, freqs->new); 321 322 switch (state) { 323 case CPUFREQ_PRECHANGE: 324 /* 325 * Detect if the driver reported a value as "old frequency" 326 * which is not equal to what the cpufreq core thinks is 327 * "old frequency". 328 */ 329 if (policy->cur && policy->cur != freqs->old) { 330 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", 331 freqs->old, policy->cur); 332 freqs->old = policy->cur; 333 } 334 335 srcu_notifier_call_chain(&cpufreq_transition_notifier_list, 336 CPUFREQ_PRECHANGE, freqs); 337 338 adjust_jiffies(CPUFREQ_PRECHANGE, freqs); 339 break; 340 341 case CPUFREQ_POSTCHANGE: 342 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); 343 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new, 344 cpumask_pr_args(policy->cpus)); 345 346 for_each_cpu(cpu, policy->cpus) 347 trace_cpu_frequency(freqs->new, cpu); 348 349 srcu_notifier_call_chain(&cpufreq_transition_notifier_list, 350 CPUFREQ_POSTCHANGE, freqs); 351 352 cpufreq_stats_record_transition(policy, freqs->new); 353 policy->cur = freqs->new; 354 } 355 } 356 357 /* Do post notifications when there are chances that transition has failed */ 358 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, 359 struct cpufreq_freqs *freqs, int transition_failed) 360 { 361 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); 362 if (!transition_failed) 363 return; 364 365 swap(freqs->old, freqs->new); 366 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); 367 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); 368 } 369 370 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, 371 struct cpufreq_freqs *freqs) 372 { 373 374 /* 375 * Catch double invocations of _begin() which lead to self-deadlock. 376 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core 377 * doesn't invoke _begin() on their behalf, and hence the chances of 378 * double invocations are very low. Moreover, there are scenarios 379 * where these checks can emit false-positive warnings in these 380 * drivers; so we avoid that by skipping them altogether. 381 */ 382 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) 383 && current == policy->transition_task); 384 385 wait: 386 wait_event(policy->transition_wait, !policy->transition_ongoing); 387 388 spin_lock(&policy->transition_lock); 389 390 if (unlikely(policy->transition_ongoing)) { 391 spin_unlock(&policy->transition_lock); 392 goto wait; 393 } 394 395 policy->transition_ongoing = true; 396 policy->transition_task = current; 397 398 spin_unlock(&policy->transition_lock); 399 400 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); 401 } 402 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); 403 404 void cpufreq_freq_transition_end(struct cpufreq_policy *policy, 405 struct cpufreq_freqs *freqs, int transition_failed) 406 { 407 if (WARN_ON(!policy->transition_ongoing)) 408 return; 409 410 cpufreq_notify_post_transition(policy, freqs, transition_failed); 411 412 arch_set_freq_scale(policy->related_cpus, 413 policy->cur, 414 arch_scale_freq_ref(policy->cpu)); 415 416 spin_lock(&policy->transition_lock); 417 policy->transition_ongoing = false; 418 policy->transition_task = NULL; 419 spin_unlock(&policy->transition_lock); 420 421 wake_up(&policy->transition_wait); 422 } 423 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); 424 425 /* 426 * Fast frequency switching status count. Positive means "enabled", negative 427 * means "disabled" and 0 means "not decided yet". 428 */ 429 static int cpufreq_fast_switch_count; 430 static DEFINE_MUTEX(cpufreq_fast_switch_lock); 431 432 static void cpufreq_list_transition_notifiers(void) 433 { 434 struct notifier_block *nb; 435 436 pr_info("Registered transition notifiers:\n"); 437 438 mutex_lock(&cpufreq_transition_notifier_list.mutex); 439 440 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next) 441 pr_info("%pS\n", nb->notifier_call); 442 443 mutex_unlock(&cpufreq_transition_notifier_list.mutex); 444 } 445 446 /** 447 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy. 448 * @policy: cpufreq policy to enable fast frequency switching for. 449 * 450 * Try to enable fast frequency switching for @policy. 451 * 452 * The attempt will fail if there is at least one transition notifier registered 453 * at this point, as fast frequency switching is quite fundamentally at odds 454 * with transition notifiers. Thus if successful, it will make registration of 455 * transition notifiers fail going forward. 456 */ 457 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy) 458 { 459 lockdep_assert_held(&policy->rwsem); 460 461 if (!policy->fast_switch_possible) 462 return; 463 464 mutex_lock(&cpufreq_fast_switch_lock); 465 if (cpufreq_fast_switch_count >= 0) { 466 cpufreq_fast_switch_count++; 467 policy->fast_switch_enabled = true; 468 } else { 469 pr_warn("CPU%u: Fast frequency switching not enabled\n", 470 policy->cpu); 471 cpufreq_list_transition_notifiers(); 472 } 473 mutex_unlock(&cpufreq_fast_switch_lock); 474 } 475 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); 476 477 /** 478 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. 479 * @policy: cpufreq policy to disable fast frequency switching for. 480 */ 481 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) 482 { 483 mutex_lock(&cpufreq_fast_switch_lock); 484 if (policy->fast_switch_enabled) { 485 policy->fast_switch_enabled = false; 486 if (!WARN_ON(cpufreq_fast_switch_count <= 0)) 487 cpufreq_fast_switch_count--; 488 } 489 mutex_unlock(&cpufreq_fast_switch_lock); 490 } 491 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); 492 493 static unsigned int __resolve_freq(struct cpufreq_policy *policy, 494 unsigned int target_freq, 495 unsigned int min, unsigned int max, 496 unsigned int relation) 497 { 498 unsigned int idx; 499 500 target_freq = clamp_val(target_freq, min, max); 501 502 if (!policy->freq_table) 503 return target_freq; 504 505 idx = cpufreq_frequency_table_target(policy, target_freq, min, max, relation); 506 policy->cached_resolved_idx = idx; 507 policy->cached_target_freq = target_freq; 508 return policy->freq_table[idx].frequency; 509 } 510 511 /** 512 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported 513 * one. 514 * @policy: associated policy to interrogate 515 * @target_freq: target frequency to resolve. 516 * 517 * The target to driver frequency mapping is cached in the policy. 518 * 519 * Return: Lowest driver-supported frequency greater than or equal to the 520 * given target_freq, subject to policy (min/max) and driver limitations. 521 */ 522 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, 523 unsigned int target_freq) 524 { 525 unsigned int min = READ_ONCE(policy->min); 526 unsigned int max = READ_ONCE(policy->max); 527 528 /* 529 * If this function runs in parallel with cpufreq_set_policy(), it may 530 * read policy->min before the update and policy->max after the update 531 * or the other way around, so there is no ordering guarantee. 532 * 533 * Resolve this by always honoring the max (in case it comes from 534 * thermal throttling or similar). 535 */ 536 if (unlikely(min > max)) 537 min = max; 538 539 return __resolve_freq(policy, target_freq, min, max, CPUFREQ_RELATION_LE); 540 } 541 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); 542 543 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy) 544 { 545 unsigned int latency; 546 547 if (policy->transition_delay_us) 548 return policy->transition_delay_us; 549 550 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC; 551 if (latency) 552 /* Give a 50% breathing room between updates */ 553 return latency + (latency >> 1); 554 555 return USEC_PER_MSEC; 556 } 557 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us); 558 559 /********************************************************************* 560 * SYSFS INTERFACE * 561 *********************************************************************/ 562 static ssize_t show_boost(struct kobject *kobj, 563 struct kobj_attribute *attr, char *buf) 564 { 565 return sysfs_emit(buf, "%d\n", cpufreq_driver->boost_enabled); 566 } 567 568 static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr, 569 const char *buf, size_t count) 570 { 571 bool enable; 572 573 if (kstrtobool(buf, &enable)) 574 return -EINVAL; 575 576 if (cpufreq_boost_trigger_state(enable)) { 577 pr_err("%s: Cannot %s BOOST!\n", 578 __func__, str_enable_disable(enable)); 579 return -EINVAL; 580 } 581 582 pr_debug("%s: cpufreq BOOST %s\n", 583 __func__, str_enabled_disabled(enable)); 584 585 return count; 586 } 587 define_one_global_rw(boost); 588 589 static ssize_t show_local_boost(struct cpufreq_policy *policy, char *buf) 590 { 591 return sysfs_emit(buf, "%d\n", policy->boost_enabled); 592 } 593 594 static int policy_set_boost(struct cpufreq_policy *policy, bool enable) 595 { 596 int ret; 597 598 if (policy->boost_enabled == enable) 599 return 0; 600 601 policy->boost_enabled = enable; 602 603 ret = cpufreq_driver->set_boost(policy, enable); 604 if (ret) 605 policy->boost_enabled = !policy->boost_enabled; 606 607 return ret; 608 } 609 610 static ssize_t store_local_boost(struct cpufreq_policy *policy, 611 const char *buf, size_t count) 612 { 613 int ret; 614 bool enable; 615 616 if (kstrtobool(buf, &enable)) 617 return -EINVAL; 618 619 if (!cpufreq_driver->boost_enabled) 620 return -EINVAL; 621 622 if (!policy->boost_supported) 623 return -EINVAL; 624 625 ret = policy_set_boost(policy, enable); 626 if (!ret) 627 return count; 628 629 return ret; 630 } 631 632 static struct freq_attr local_boost = __ATTR(boost, 0644, show_local_boost, store_local_boost); 633 634 static struct cpufreq_governor *find_governor(const char *str_governor) 635 { 636 struct cpufreq_governor *t; 637 638 for_each_governor(t) 639 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) 640 return t; 641 642 return NULL; 643 } 644 645 static struct cpufreq_governor *get_governor(const char *str_governor) 646 { 647 struct cpufreq_governor *t; 648 649 mutex_lock(&cpufreq_governor_mutex); 650 t = find_governor(str_governor); 651 if (!t) 652 goto unlock; 653 654 if (!try_module_get(t->owner)) 655 t = NULL; 656 657 unlock: 658 mutex_unlock(&cpufreq_governor_mutex); 659 660 return t; 661 } 662 663 static unsigned int cpufreq_parse_policy(char *str_governor) 664 { 665 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) 666 return CPUFREQ_POLICY_PERFORMANCE; 667 668 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) 669 return CPUFREQ_POLICY_POWERSAVE; 670 671 return CPUFREQ_POLICY_UNKNOWN; 672 } 673 674 /** 675 * cpufreq_parse_governor - parse a governor string only for has_target() 676 * @str_governor: Governor name. 677 */ 678 static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor) 679 { 680 struct cpufreq_governor *t; 681 682 t = get_governor(str_governor); 683 if (t) 684 return t; 685 686 if (request_module("cpufreq_%s", str_governor)) 687 return NULL; 688 689 return get_governor(str_governor); 690 } 691 692 /* 693 * cpufreq_per_cpu_attr_read() / show_##file_name() - 694 * print out cpufreq information 695 * 696 * Write out information from cpufreq_driver->policy[cpu]; object must be 697 * "unsigned int". 698 */ 699 700 #define show_one(file_name, object) \ 701 static ssize_t show_##file_name \ 702 (struct cpufreq_policy *policy, char *buf) \ 703 { \ 704 return sysfs_emit(buf, "%u\n", policy->object); \ 705 } 706 707 show_one(cpuinfo_min_freq, cpuinfo.min_freq); 708 show_one(cpuinfo_max_freq, cpuinfo.max_freq); 709 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); 710 show_one(scaling_min_freq, min); 711 show_one(scaling_max_freq, max); 712 713 __weak int arch_freq_get_on_cpu(int cpu) 714 { 715 return -EOPNOTSUPP; 716 } 717 718 static inline bool cpufreq_avg_freq_supported(struct cpufreq_policy *policy) 719 { 720 return arch_freq_get_on_cpu(policy->cpu) != -EOPNOTSUPP; 721 } 722 723 static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) 724 { 725 ssize_t ret; 726 int freq; 727 728 freq = IS_ENABLED(CONFIG_CPUFREQ_ARCH_CUR_FREQ) 729 ? arch_freq_get_on_cpu(policy->cpu) 730 : 0; 731 732 if (freq > 0) 733 ret = sysfs_emit(buf, "%u\n", freq); 734 else if (cpufreq_driver->setpolicy && cpufreq_driver->get) 735 ret = sysfs_emit(buf, "%u\n", cpufreq_driver->get(policy->cpu)); 736 else 737 ret = sysfs_emit(buf, "%u\n", policy->cur); 738 return ret; 739 } 740 741 /* 742 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access 743 */ 744 #define store_one(file_name, object) \ 745 static ssize_t store_##file_name \ 746 (struct cpufreq_policy *policy, const char *buf, size_t count) \ 747 { \ 748 unsigned long val; \ 749 int ret; \ 750 \ 751 ret = kstrtoul(buf, 0, &val); \ 752 if (ret) \ 753 return ret; \ 754 \ 755 ret = freq_qos_update_request(policy->object##_freq_req, val);\ 756 return ret >= 0 ? count : ret; \ 757 } 758 759 store_one(scaling_min_freq, min); 760 store_one(scaling_max_freq, max); 761 762 /* 763 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware 764 */ 765 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, 766 char *buf) 767 { 768 unsigned int cur_freq = __cpufreq_get(policy); 769 770 if (cur_freq) 771 return sysfs_emit(buf, "%u\n", cur_freq); 772 773 return sysfs_emit(buf, "<unknown>\n"); 774 } 775 776 /* 777 * show_cpuinfo_avg_freq - average CPU frequency as detected by hardware 778 */ 779 static ssize_t show_cpuinfo_avg_freq(struct cpufreq_policy *policy, 780 char *buf) 781 { 782 int avg_freq = arch_freq_get_on_cpu(policy->cpu); 783 784 if (avg_freq > 0) 785 return sysfs_emit(buf, "%u\n", avg_freq); 786 return avg_freq != 0 ? avg_freq : -EINVAL; 787 } 788 789 /* 790 * show_scaling_governor - show the current policy for the specified CPU 791 */ 792 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) 793 { 794 if (policy->policy == CPUFREQ_POLICY_POWERSAVE) 795 return sysfs_emit(buf, "powersave\n"); 796 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) 797 return sysfs_emit(buf, "performance\n"); 798 else if (policy->governor) 799 return sysfs_emit(buf, "%s\n", policy->governor->name); 800 return -EINVAL; 801 } 802 803 /* 804 * store_scaling_governor - store policy for the specified CPU 805 */ 806 static ssize_t store_scaling_governor(struct cpufreq_policy *policy, 807 const char *buf, size_t count) 808 { 809 char str_governor[CPUFREQ_NAME_LEN]; 810 int ret; 811 812 ret = sscanf(buf, "%15s", str_governor); 813 if (ret != 1) 814 return -EINVAL; 815 816 if (cpufreq_driver->setpolicy) { 817 unsigned int new_pol; 818 819 new_pol = cpufreq_parse_policy(str_governor); 820 if (!new_pol) 821 return -EINVAL; 822 823 ret = cpufreq_set_policy(policy, NULL, new_pol); 824 } else { 825 struct cpufreq_governor *new_gov; 826 827 new_gov = cpufreq_parse_governor(str_governor); 828 if (!new_gov) 829 return -EINVAL; 830 831 ret = cpufreq_set_policy(policy, new_gov, 832 CPUFREQ_POLICY_UNKNOWN); 833 834 module_put(new_gov->owner); 835 } 836 837 return ret ? ret : count; 838 } 839 840 /* 841 * show_scaling_driver - show the cpufreq driver currently loaded 842 */ 843 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) 844 { 845 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); 846 } 847 848 /* 849 * show_scaling_available_governors - show the available CPUfreq governors 850 */ 851 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, 852 char *buf) 853 { 854 ssize_t i = 0; 855 struct cpufreq_governor *t; 856 857 if (!has_target()) { 858 i += sysfs_emit(buf, "performance powersave"); 859 goto out; 860 } 861 862 mutex_lock(&cpufreq_governor_mutex); 863 for_each_governor(t) { 864 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) 865 - (CPUFREQ_NAME_LEN + 2))) 866 break; 867 i += sysfs_emit_at(buf, i, "%s ", t->name); 868 } 869 mutex_unlock(&cpufreq_governor_mutex); 870 out: 871 i += sysfs_emit_at(buf, i, "\n"); 872 return i; 873 } 874 875 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) 876 { 877 ssize_t i = 0; 878 unsigned int cpu; 879 880 for_each_cpu(cpu, mask) { 881 i += sysfs_emit_at(buf, i, "%u ", cpu); 882 if (i >= (PAGE_SIZE - 5)) 883 break; 884 } 885 886 /* Remove the extra space at the end */ 887 i--; 888 889 i += sysfs_emit_at(buf, i, "\n"); 890 return i; 891 } 892 EXPORT_SYMBOL_GPL(cpufreq_show_cpus); 893 894 /* 895 * show_related_cpus - show the CPUs affected by each transition even if 896 * hw coordination is in use 897 */ 898 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) 899 { 900 return cpufreq_show_cpus(policy->related_cpus, buf); 901 } 902 903 /* 904 * show_affected_cpus - show the CPUs affected by each transition 905 */ 906 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) 907 { 908 return cpufreq_show_cpus(policy->cpus, buf); 909 } 910 911 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, 912 const char *buf, size_t count) 913 { 914 unsigned int freq = 0; 915 unsigned int ret; 916 917 if (!policy->governor || !policy->governor->store_setspeed) 918 return -EINVAL; 919 920 ret = kstrtouint(buf, 0, &freq); 921 if (ret) 922 return ret; 923 924 policy->governor->store_setspeed(policy, freq); 925 926 return count; 927 } 928 929 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) 930 { 931 if (!policy->governor || !policy->governor->show_setspeed) 932 return sysfs_emit(buf, "<unsupported>\n"); 933 934 return policy->governor->show_setspeed(policy, buf); 935 } 936 937 /* 938 * show_bios_limit - show the current cpufreq HW/BIOS limitation 939 */ 940 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) 941 { 942 unsigned int limit; 943 int ret; 944 ret = cpufreq_driver->bios_limit(policy->cpu, &limit); 945 if (!ret) 946 return sysfs_emit(buf, "%u\n", limit); 947 return sysfs_emit(buf, "%u\n", policy->cpuinfo.max_freq); 948 } 949 950 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); 951 cpufreq_freq_attr_ro(cpuinfo_avg_freq); 952 cpufreq_freq_attr_ro(cpuinfo_min_freq); 953 cpufreq_freq_attr_ro(cpuinfo_max_freq); 954 cpufreq_freq_attr_ro(cpuinfo_transition_latency); 955 cpufreq_freq_attr_ro(scaling_available_governors); 956 cpufreq_freq_attr_ro(scaling_driver); 957 cpufreq_freq_attr_ro(scaling_cur_freq); 958 cpufreq_freq_attr_ro(bios_limit); 959 cpufreq_freq_attr_ro(related_cpus); 960 cpufreq_freq_attr_ro(affected_cpus); 961 cpufreq_freq_attr_rw(scaling_min_freq); 962 cpufreq_freq_attr_rw(scaling_max_freq); 963 cpufreq_freq_attr_rw(scaling_governor); 964 cpufreq_freq_attr_rw(scaling_setspeed); 965 966 static struct attribute *cpufreq_attrs[] = { 967 &cpuinfo_min_freq.attr, 968 &cpuinfo_max_freq.attr, 969 &cpuinfo_transition_latency.attr, 970 &scaling_min_freq.attr, 971 &scaling_max_freq.attr, 972 &affected_cpus.attr, 973 &related_cpus.attr, 974 &scaling_governor.attr, 975 &scaling_driver.attr, 976 &scaling_available_governors.attr, 977 &scaling_setspeed.attr, 978 NULL 979 }; 980 ATTRIBUTE_GROUPS(cpufreq); 981 982 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) 983 #define to_attr(a) container_of(a, struct freq_attr, attr) 984 985 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) 986 { 987 struct cpufreq_policy *policy = to_policy(kobj); 988 struct freq_attr *fattr = to_attr(attr); 989 990 if (!fattr->show) 991 return -EIO; 992 993 guard(cpufreq_policy_read)(policy); 994 995 if (likely(!policy_is_inactive(policy))) 996 return fattr->show(policy, buf); 997 998 return -EBUSY; 999 } 1000 1001 static ssize_t store(struct kobject *kobj, struct attribute *attr, 1002 const char *buf, size_t count) 1003 { 1004 struct cpufreq_policy *policy = to_policy(kobj); 1005 struct freq_attr *fattr = to_attr(attr); 1006 1007 if (!fattr->store) 1008 return -EIO; 1009 1010 guard(cpufreq_policy_write)(policy); 1011 1012 if (likely(!policy_is_inactive(policy))) 1013 return fattr->store(policy, buf, count); 1014 1015 return -EBUSY; 1016 } 1017 1018 static void cpufreq_sysfs_release(struct kobject *kobj) 1019 { 1020 struct cpufreq_policy *policy = to_policy(kobj); 1021 pr_debug("last reference is dropped\n"); 1022 complete(&policy->kobj_unregister); 1023 } 1024 1025 static const struct sysfs_ops sysfs_ops = { 1026 .show = show, 1027 .store = store, 1028 }; 1029 1030 static const struct kobj_type ktype_cpufreq = { 1031 .sysfs_ops = &sysfs_ops, 1032 .default_groups = cpufreq_groups, 1033 .release = cpufreq_sysfs_release, 1034 }; 1035 1036 static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu, 1037 struct device *dev) 1038 { 1039 if (unlikely(!dev)) 1040 return; 1041 1042 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus)) 1043 return; 1044 1045 dev_dbg(dev, "%s: Adding symlink\n", __func__); 1046 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq")) 1047 dev_err(dev, "cpufreq symlink creation failed\n"); 1048 } 1049 1050 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu, 1051 struct device *dev) 1052 { 1053 dev_dbg(dev, "%s: Removing symlink\n", __func__); 1054 sysfs_remove_link(&dev->kobj, "cpufreq"); 1055 cpumask_clear_cpu(cpu, policy->real_cpus); 1056 } 1057 1058 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) 1059 { 1060 struct freq_attr **drv_attr; 1061 int ret = 0; 1062 1063 /* Attributes that need freq_table */ 1064 if (policy->freq_table) { 1065 ret = sysfs_create_file(&policy->kobj, 1066 &cpufreq_freq_attr_scaling_available_freqs.attr); 1067 if (ret) 1068 return ret; 1069 1070 if (cpufreq_boost_supported()) { 1071 ret = sysfs_create_file(&policy->kobj, 1072 &cpufreq_freq_attr_scaling_boost_freqs.attr); 1073 if (ret) 1074 return ret; 1075 } 1076 } 1077 1078 /* set up files for this cpu device */ 1079 drv_attr = cpufreq_driver->attr; 1080 while (drv_attr && *drv_attr) { 1081 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); 1082 if (ret) 1083 return ret; 1084 drv_attr++; 1085 } 1086 if (cpufreq_driver->get) { 1087 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); 1088 if (ret) 1089 return ret; 1090 } 1091 1092 if (cpufreq_avg_freq_supported(policy)) { 1093 ret = sysfs_create_file(&policy->kobj, &cpuinfo_avg_freq.attr); 1094 if (ret) 1095 return ret; 1096 } 1097 1098 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); 1099 if (ret) 1100 return ret; 1101 1102 if (cpufreq_driver->bios_limit) { 1103 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); 1104 if (ret) 1105 return ret; 1106 } 1107 1108 if (cpufreq_boost_supported()) { 1109 ret = sysfs_create_file(&policy->kobj, &local_boost.attr); 1110 if (ret) 1111 return ret; 1112 } 1113 1114 return 0; 1115 } 1116 1117 static int cpufreq_init_policy(struct cpufreq_policy *policy) 1118 { 1119 struct cpufreq_governor *gov = NULL; 1120 unsigned int pol = CPUFREQ_POLICY_UNKNOWN; 1121 int ret; 1122 1123 if (has_target()) { 1124 /* Update policy governor to the one used before hotplug. */ 1125 gov = get_governor(policy->last_governor); 1126 if (gov) { 1127 pr_debug("Restoring governor %s for cpu %d\n", 1128 gov->name, policy->cpu); 1129 } else { 1130 gov = get_governor(default_governor); 1131 } 1132 1133 if (!gov) { 1134 gov = cpufreq_default_governor(); 1135 __module_get(gov->owner); 1136 } 1137 1138 } else { 1139 1140 /* Use the default policy if there is no last_policy. */ 1141 if (policy->last_policy) { 1142 pol = policy->last_policy; 1143 } else { 1144 pol = cpufreq_parse_policy(default_governor); 1145 /* 1146 * In case the default governor is neither "performance" 1147 * nor "powersave", fall back to the initial policy 1148 * value set by the driver. 1149 */ 1150 if (pol == CPUFREQ_POLICY_UNKNOWN) 1151 pol = policy->policy; 1152 } 1153 if (pol != CPUFREQ_POLICY_PERFORMANCE && 1154 pol != CPUFREQ_POLICY_POWERSAVE) 1155 return -ENODATA; 1156 } 1157 1158 ret = cpufreq_set_policy(policy, gov, pol); 1159 if (gov) 1160 module_put(gov->owner); 1161 1162 return ret; 1163 } 1164 1165 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) 1166 { 1167 int ret = 0; 1168 1169 /* Has this CPU been taken care of already? */ 1170 if (cpumask_test_cpu(cpu, policy->cpus)) 1171 return 0; 1172 1173 guard(cpufreq_policy_write)(policy); 1174 1175 if (has_target()) 1176 cpufreq_stop_governor(policy); 1177 1178 cpumask_set_cpu(cpu, policy->cpus); 1179 1180 if (has_target()) { 1181 ret = cpufreq_start_governor(policy); 1182 if (ret) 1183 pr_err("%s: Failed to start governor\n", __func__); 1184 } 1185 1186 return ret; 1187 } 1188 1189 void refresh_frequency_limits(struct cpufreq_policy *policy) 1190 { 1191 if (!policy_is_inactive(policy)) { 1192 pr_debug("updating policy for CPU %u\n", policy->cpu); 1193 1194 cpufreq_set_policy(policy, policy->governor, policy->policy); 1195 } 1196 } 1197 EXPORT_SYMBOL(refresh_frequency_limits); 1198 1199 static void handle_update(struct work_struct *work) 1200 { 1201 struct cpufreq_policy *policy = 1202 container_of(work, struct cpufreq_policy, update); 1203 1204 pr_debug("handle_update for cpu %u called\n", policy->cpu); 1205 1206 guard(cpufreq_policy_write)(policy); 1207 1208 refresh_frequency_limits(policy); 1209 } 1210 1211 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq, 1212 void *data) 1213 { 1214 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min); 1215 1216 schedule_work(&policy->update); 1217 return 0; 1218 } 1219 1220 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq, 1221 void *data) 1222 { 1223 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max); 1224 1225 schedule_work(&policy->update); 1226 return 0; 1227 } 1228 1229 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) 1230 { 1231 struct kobject *kobj; 1232 struct completion *cmp; 1233 1234 scoped_guard(cpufreq_policy_write, policy) { 1235 cpufreq_stats_free_table(policy); 1236 kobj = &policy->kobj; 1237 cmp = &policy->kobj_unregister; 1238 } 1239 kobject_put(kobj); 1240 1241 /* 1242 * We need to make sure that the underlying kobj is 1243 * actually not referenced anymore by anybody before we 1244 * proceed with unloading. 1245 */ 1246 pr_debug("waiting for dropping of refcount\n"); 1247 wait_for_completion(cmp); 1248 pr_debug("wait complete\n"); 1249 } 1250 1251 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) 1252 { 1253 struct cpufreq_policy *policy; 1254 struct device *dev = get_cpu_device(cpu); 1255 int ret; 1256 1257 if (!dev) 1258 return NULL; 1259 1260 policy = kzalloc(sizeof(*policy), GFP_KERNEL); 1261 if (!policy) 1262 return NULL; 1263 1264 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) 1265 goto err_free_policy; 1266 1267 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) 1268 goto err_free_cpumask; 1269 1270 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) 1271 goto err_free_rcpumask; 1272 1273 init_completion(&policy->kobj_unregister); 1274 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, 1275 cpufreq_global_kobject, "policy%u", cpu); 1276 if (ret) { 1277 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret); 1278 /* 1279 * The entire policy object will be freed below, but the extra 1280 * memory allocated for the kobject name needs to be freed by 1281 * releasing the kobject. 1282 */ 1283 kobject_put(&policy->kobj); 1284 goto err_free_real_cpus; 1285 } 1286 1287 freq_constraints_init(&policy->constraints); 1288 1289 policy->nb_min.notifier_call = cpufreq_notifier_min; 1290 policy->nb_max.notifier_call = cpufreq_notifier_max; 1291 1292 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN, 1293 &policy->nb_min); 1294 if (ret) { 1295 dev_err(dev, "Failed to register MIN QoS notifier: %d (CPU%u)\n", 1296 ret, cpu); 1297 goto err_kobj_remove; 1298 } 1299 1300 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX, 1301 &policy->nb_max); 1302 if (ret) { 1303 dev_err(dev, "Failed to register MAX QoS notifier: %d (CPU%u)\n", 1304 ret, cpu); 1305 goto err_min_qos_notifier; 1306 } 1307 1308 INIT_LIST_HEAD(&policy->policy_list); 1309 init_rwsem(&policy->rwsem); 1310 spin_lock_init(&policy->transition_lock); 1311 init_waitqueue_head(&policy->transition_wait); 1312 INIT_WORK(&policy->update, handle_update); 1313 1314 return policy; 1315 1316 err_min_qos_notifier: 1317 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN, 1318 &policy->nb_min); 1319 err_kobj_remove: 1320 cpufreq_policy_put_kobj(policy); 1321 err_free_real_cpus: 1322 free_cpumask_var(policy->real_cpus); 1323 err_free_rcpumask: 1324 free_cpumask_var(policy->related_cpus); 1325 err_free_cpumask: 1326 free_cpumask_var(policy->cpus); 1327 err_free_policy: 1328 kfree(policy); 1329 1330 return NULL; 1331 } 1332 1333 static void cpufreq_policy_free(struct cpufreq_policy *policy) 1334 { 1335 unsigned long flags; 1336 int cpu; 1337 1338 /* 1339 * The callers must ensure the policy is inactive by now, to avoid any 1340 * races with show()/store() callbacks. 1341 */ 1342 if (unlikely(!policy_is_inactive(policy))) 1343 pr_warn("%s: Freeing active policy\n", __func__); 1344 1345 /* Remove policy from list */ 1346 write_lock_irqsave(&cpufreq_driver_lock, flags); 1347 list_del(&policy->policy_list); 1348 1349 for_each_cpu(cpu, policy->related_cpus) 1350 per_cpu(cpufreq_cpu_data, cpu) = NULL; 1351 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 1352 1353 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX, 1354 &policy->nb_max); 1355 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN, 1356 &policy->nb_min); 1357 1358 /* Cancel any pending policy->update work before freeing the policy. */ 1359 cancel_work_sync(&policy->update); 1360 1361 if (policy->max_freq_req) { 1362 /* 1363 * Remove max_freq_req after sending CPUFREQ_REMOVE_POLICY 1364 * notification, since CPUFREQ_CREATE_POLICY notification was 1365 * sent after adding max_freq_req earlier. 1366 */ 1367 blocking_notifier_call_chain(&cpufreq_policy_notifier_list, 1368 CPUFREQ_REMOVE_POLICY, policy); 1369 freq_qos_remove_request(policy->max_freq_req); 1370 } 1371 1372 freq_qos_remove_request(policy->min_freq_req); 1373 kfree(policy->min_freq_req); 1374 1375 cpufreq_policy_put_kobj(policy); 1376 free_cpumask_var(policy->real_cpus); 1377 free_cpumask_var(policy->related_cpus); 1378 free_cpumask_var(policy->cpus); 1379 kfree(policy); 1380 } 1381 1382 static int cpufreq_policy_online(struct cpufreq_policy *policy, 1383 unsigned int cpu, bool new_policy) 1384 { 1385 unsigned long flags; 1386 unsigned int j; 1387 int ret; 1388 1389 guard(cpufreq_policy_write)(policy); 1390 1391 policy->cpu = cpu; 1392 policy->governor = NULL; 1393 1394 if (!new_policy && cpufreq_driver->online) { 1395 /* Recover policy->cpus using related_cpus */ 1396 cpumask_copy(policy->cpus, policy->related_cpus); 1397 1398 ret = cpufreq_driver->online(policy); 1399 if (ret) { 1400 pr_debug("%s: %d: initialization failed\n", __func__, 1401 __LINE__); 1402 goto out_exit_policy; 1403 } 1404 } else { 1405 cpumask_copy(policy->cpus, cpumask_of(cpu)); 1406 1407 /* 1408 * Call driver. From then on the cpufreq must be able 1409 * to accept all calls to ->verify and ->setpolicy for this CPU. 1410 */ 1411 ret = cpufreq_driver->init(policy); 1412 if (ret) { 1413 pr_debug("%s: %d: initialization failed\n", __func__, 1414 __LINE__); 1415 goto out_clear_policy; 1416 } 1417 1418 /* 1419 * The initialization has succeeded and the policy is online. 1420 * If there is a problem with its frequency table, take it 1421 * offline and drop it. 1422 */ 1423 ret = cpufreq_table_validate_and_sort(policy); 1424 if (ret) 1425 goto out_offline_policy; 1426 1427 /* related_cpus should at least include policy->cpus. */ 1428 cpumask_copy(policy->related_cpus, policy->cpus); 1429 } 1430 1431 /* 1432 * affected cpus must always be the one, which are online. We aren't 1433 * managing offline cpus here. 1434 */ 1435 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); 1436 1437 if (new_policy) { 1438 for_each_cpu(j, policy->related_cpus) { 1439 per_cpu(cpufreq_cpu_data, j) = policy; 1440 add_cpu_dev_symlink(policy, j, get_cpu_device(j)); 1441 } 1442 1443 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req), 1444 GFP_KERNEL); 1445 if (!policy->min_freq_req) { 1446 ret = -ENOMEM; 1447 goto out_destroy_policy; 1448 } 1449 1450 ret = freq_qos_add_request(&policy->constraints, 1451 policy->min_freq_req, FREQ_QOS_MIN, 1452 FREQ_QOS_MIN_DEFAULT_VALUE); 1453 if (ret < 0) { 1454 /* 1455 * So we don't call freq_qos_remove_request() for an 1456 * uninitialized request. 1457 */ 1458 kfree(policy->min_freq_req); 1459 policy->min_freq_req = NULL; 1460 goto out_destroy_policy; 1461 } 1462 1463 /* 1464 * This must be initialized right here to avoid calling 1465 * freq_qos_remove_request() on uninitialized request in case 1466 * of errors. 1467 */ 1468 policy->max_freq_req = policy->min_freq_req + 1; 1469 1470 ret = freq_qos_add_request(&policy->constraints, 1471 policy->max_freq_req, FREQ_QOS_MAX, 1472 FREQ_QOS_MAX_DEFAULT_VALUE); 1473 if (ret < 0) { 1474 policy->max_freq_req = NULL; 1475 goto out_destroy_policy; 1476 } 1477 1478 blocking_notifier_call_chain(&cpufreq_policy_notifier_list, 1479 CPUFREQ_CREATE_POLICY, policy); 1480 } else { 1481 ret = freq_qos_update_request(policy->max_freq_req, policy->max); 1482 if (ret < 0) 1483 goto out_destroy_policy; 1484 } 1485 1486 if (cpufreq_driver->get && has_target()) { 1487 policy->cur = cpufreq_driver->get(policy->cpu); 1488 if (!policy->cur) { 1489 ret = -EIO; 1490 pr_err("%s: ->get() failed\n", __func__); 1491 goto out_destroy_policy; 1492 } 1493 } 1494 1495 /* 1496 * Sometimes boot loaders set CPU frequency to a value outside of 1497 * frequency table present with cpufreq core. In such cases CPU might be 1498 * unstable if it has to run on that frequency for long duration of time 1499 * and so its better to set it to a frequency which is specified in 1500 * freq-table. This also makes cpufreq stats inconsistent as 1501 * cpufreq-stats would fail to register because current frequency of CPU 1502 * isn't found in freq-table. 1503 * 1504 * Because we don't want this change to effect boot process badly, we go 1505 * for the next freq which is >= policy->cur ('cur' must be set by now, 1506 * otherwise we will end up setting freq to lowest of the table as 'cur' 1507 * is initialized to zero). 1508 * 1509 * We are passing target-freq as "policy->cur - 1" otherwise 1510 * __cpufreq_driver_target() would simply fail, as policy->cur will be 1511 * equal to target-freq. 1512 */ 1513 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) 1514 && has_target()) { 1515 unsigned int old_freq = policy->cur; 1516 1517 /* Are we running at unknown frequency ? */ 1518 ret = cpufreq_frequency_table_get_index(policy, old_freq); 1519 if (ret == -EINVAL) { 1520 ret = __cpufreq_driver_target(policy, old_freq - 1, 1521 CPUFREQ_RELATION_L); 1522 1523 /* 1524 * Reaching here after boot in a few seconds may not 1525 * mean that system will remain stable at "unknown" 1526 * frequency for longer duration. Hence, a BUG_ON(). 1527 */ 1528 BUG_ON(ret); 1529 pr_info("%s: CPU%d: Running at unlisted initial frequency: %u kHz, changing to: %u kHz\n", 1530 __func__, policy->cpu, old_freq, policy->cur); 1531 } 1532 } 1533 1534 if (new_policy) { 1535 ret = cpufreq_add_dev_interface(policy); 1536 if (ret) 1537 goto out_destroy_policy; 1538 1539 cpufreq_stats_create_table(policy); 1540 1541 write_lock_irqsave(&cpufreq_driver_lock, flags); 1542 list_add(&policy->policy_list, &cpufreq_policy_list); 1543 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 1544 1545 /* 1546 * Register with the energy model before 1547 * em_rebuild_sched_domains() is called, which will result 1548 * in rebuilding of the sched domains, which should only be done 1549 * once the energy model is properly initialized for the policy 1550 * first. 1551 * 1552 * Also, this should be called before the policy is registered 1553 * with cooling framework. 1554 */ 1555 if (cpufreq_driver->register_em) 1556 cpufreq_driver->register_em(policy); 1557 } 1558 1559 ret = cpufreq_init_policy(policy); 1560 if (ret) { 1561 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", 1562 __func__, cpu, ret); 1563 goto out_destroy_policy; 1564 } 1565 1566 return 0; 1567 1568 out_destroy_policy: 1569 for_each_cpu(j, policy->real_cpus) 1570 remove_cpu_dev_symlink(policy, j, get_cpu_device(j)); 1571 1572 out_offline_policy: 1573 if (cpufreq_driver->offline) 1574 cpufreq_driver->offline(policy); 1575 1576 out_exit_policy: 1577 if (cpufreq_driver->exit) 1578 cpufreq_driver->exit(policy); 1579 1580 out_clear_policy: 1581 cpumask_clear(policy->cpus); 1582 1583 return ret; 1584 } 1585 1586 static int cpufreq_online(unsigned int cpu) 1587 { 1588 struct cpufreq_policy *policy; 1589 bool new_policy; 1590 int ret; 1591 1592 pr_debug("%s: bringing CPU%u online\n", __func__, cpu); 1593 1594 /* Check if this CPU already has a policy to manage it */ 1595 policy = per_cpu(cpufreq_cpu_data, cpu); 1596 if (policy) { 1597 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus)); 1598 if (!policy_is_inactive(policy)) 1599 return cpufreq_add_policy_cpu(policy, cpu); 1600 1601 /* This is the only online CPU for the policy. Start over. */ 1602 new_policy = false; 1603 } else { 1604 new_policy = true; 1605 policy = cpufreq_policy_alloc(cpu); 1606 if (!policy) 1607 return -ENOMEM; 1608 } 1609 1610 ret = cpufreq_policy_online(policy, cpu, new_policy); 1611 if (ret) { 1612 cpufreq_policy_free(policy); 1613 return ret; 1614 } 1615 1616 kobject_uevent(&policy->kobj, KOBJ_ADD); 1617 1618 /* Callback for handling stuff after policy is ready */ 1619 if (cpufreq_driver->ready) 1620 cpufreq_driver->ready(policy); 1621 1622 /* Register cpufreq cooling only for a new policy */ 1623 if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver)) 1624 policy->cdev = of_cpufreq_cooling_register(policy); 1625 1626 /* 1627 * Let the per-policy boost flag mirror the cpufreq_driver boost during 1628 * initialization for a new policy. For an existing policy, maintain the 1629 * previous boost value unless global boost is disabled. 1630 */ 1631 if (cpufreq_driver->set_boost && policy->boost_supported && 1632 (new_policy || !cpufreq_boost_enabled())) { 1633 ret = policy_set_boost(policy, cpufreq_boost_enabled()); 1634 if (ret) { 1635 /* If the set_boost fails, the online operation is not affected */ 1636 pr_info("%s: CPU%d: Cannot %s BOOST\n", __func__, policy->cpu, 1637 str_enable_disable(cpufreq_boost_enabled())); 1638 } 1639 } 1640 1641 pr_debug("initialization complete\n"); 1642 1643 return 0; 1644 } 1645 1646 /** 1647 * cpufreq_add_dev - the cpufreq interface for a CPU device. 1648 * @dev: CPU device. 1649 * @sif: Subsystem interface structure pointer (not used) 1650 */ 1651 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 1652 { 1653 struct cpufreq_policy *policy; 1654 unsigned cpu = dev->id; 1655 int ret; 1656 1657 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); 1658 1659 if (cpu_online(cpu)) { 1660 ret = cpufreq_online(cpu); 1661 if (ret) 1662 return ret; 1663 } 1664 1665 /* Create sysfs link on CPU registration */ 1666 policy = per_cpu(cpufreq_cpu_data, cpu); 1667 if (policy) 1668 add_cpu_dev_symlink(policy, cpu, dev); 1669 1670 return 0; 1671 } 1672 1673 static void __cpufreq_offline(unsigned int cpu, struct cpufreq_policy *policy) 1674 { 1675 int ret; 1676 1677 if (has_target()) 1678 cpufreq_stop_governor(policy); 1679 1680 cpumask_clear_cpu(cpu, policy->cpus); 1681 1682 if (!policy_is_inactive(policy)) { 1683 /* Nominate a new CPU if necessary. */ 1684 if (cpu == policy->cpu) 1685 policy->cpu = cpumask_any(policy->cpus); 1686 1687 /* Start the governor again for the active policy. */ 1688 if (has_target()) { 1689 ret = cpufreq_start_governor(policy); 1690 if (ret) 1691 pr_err("%s: Failed to start governor\n", __func__); 1692 } 1693 1694 return; 1695 } 1696 1697 if (has_target()) 1698 strscpy(policy->last_governor, policy->governor->name, 1699 CPUFREQ_NAME_LEN); 1700 else 1701 policy->last_policy = policy->policy; 1702 1703 if (has_target()) 1704 cpufreq_exit_governor(policy); 1705 1706 /* 1707 * Perform the ->offline() during light-weight tear-down, as 1708 * that allows fast recovery when the CPU comes back. 1709 */ 1710 if (cpufreq_driver->offline) { 1711 cpufreq_driver->offline(policy); 1712 return; 1713 } 1714 1715 if (cpufreq_driver->exit) 1716 cpufreq_driver->exit(policy); 1717 1718 policy->freq_table = NULL; 1719 } 1720 1721 static int cpufreq_offline(unsigned int cpu) 1722 { 1723 struct cpufreq_policy *policy; 1724 1725 pr_debug("%s: unregistering CPU %u\n", __func__, cpu); 1726 1727 policy = cpufreq_cpu_get_raw(cpu); 1728 if (!policy) { 1729 pr_debug("%s: No cpu_data found\n", __func__); 1730 return 0; 1731 } 1732 1733 guard(cpufreq_policy_write)(policy); 1734 1735 __cpufreq_offline(cpu, policy); 1736 1737 return 0; 1738 } 1739 1740 /* 1741 * cpufreq_remove_dev - remove a CPU device 1742 * 1743 * Removes the cpufreq interface for a CPU device. 1744 */ 1745 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) 1746 { 1747 unsigned int cpu = dev->id; 1748 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); 1749 1750 if (!policy) 1751 return; 1752 1753 scoped_guard(cpufreq_policy_write, policy) { 1754 if (cpu_online(cpu)) 1755 __cpufreq_offline(cpu, policy); 1756 1757 remove_cpu_dev_symlink(policy, cpu, dev); 1758 1759 if (!cpumask_empty(policy->real_cpus)) 1760 return; 1761 1762 /* 1763 * Unregister cpufreq cooling once all the CPUs of the policy 1764 * are removed. 1765 */ 1766 if (cpufreq_thermal_control_enabled(cpufreq_driver)) { 1767 cpufreq_cooling_unregister(policy->cdev); 1768 policy->cdev = NULL; 1769 } 1770 1771 /* We did light-weight exit earlier, do full tear down now */ 1772 if (cpufreq_driver->offline && cpufreq_driver->exit) 1773 cpufreq_driver->exit(policy); 1774 } 1775 1776 cpufreq_policy_free(policy); 1777 } 1778 1779 /** 1780 * cpufreq_out_of_sync - Fix up actual and saved CPU frequency difference. 1781 * @policy: Policy managing CPUs. 1782 * @new_freq: New CPU frequency. 1783 * 1784 * Adjust to the current frequency first and clean up later by either calling 1785 * cpufreq_update_policy(), or scheduling handle_update(). 1786 */ 1787 static void cpufreq_out_of_sync(struct cpufreq_policy *policy, 1788 unsigned int new_freq) 1789 { 1790 struct cpufreq_freqs freqs; 1791 1792 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", 1793 policy->cur, new_freq); 1794 1795 freqs.old = policy->cur; 1796 freqs.new = new_freq; 1797 1798 cpufreq_freq_transition_begin(policy, &freqs); 1799 cpufreq_freq_transition_end(policy, &freqs, 0); 1800 } 1801 1802 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update) 1803 { 1804 unsigned int new_freq; 1805 1806 new_freq = cpufreq_driver->get(policy->cpu); 1807 if (!new_freq) 1808 return 0; 1809 1810 /* 1811 * If fast frequency switching is used with the given policy, the check 1812 * against policy->cur is pointless, so skip it in that case. 1813 */ 1814 if (policy->fast_switch_enabled || !has_target()) 1815 return new_freq; 1816 1817 if (policy->cur != new_freq) { 1818 /* 1819 * For some platforms, the frequency returned by hardware may be 1820 * slightly different from what is provided in the frequency 1821 * table, for example hardware may return 499 MHz instead of 500 1822 * MHz. In such cases it is better to avoid getting into 1823 * unnecessary frequency updates. 1824 */ 1825 if (abs(policy->cur - new_freq) < KHZ_PER_MHZ) 1826 return policy->cur; 1827 1828 cpufreq_out_of_sync(policy, new_freq); 1829 if (update) 1830 schedule_work(&policy->update); 1831 } 1832 1833 return new_freq; 1834 } 1835 1836 /** 1837 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur 1838 * @cpu: CPU number 1839 * 1840 * This is the last known freq, without actually getting it from the driver. 1841 * Return value will be same as what is shown in scaling_cur_freq in sysfs. 1842 */ 1843 unsigned int cpufreq_quick_get(unsigned int cpu) 1844 { 1845 struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL; 1846 unsigned long flags; 1847 1848 read_lock_irqsave(&cpufreq_driver_lock, flags); 1849 1850 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { 1851 unsigned int ret_freq = cpufreq_driver->get(cpu); 1852 1853 read_unlock_irqrestore(&cpufreq_driver_lock, flags); 1854 1855 return ret_freq; 1856 } 1857 1858 read_unlock_irqrestore(&cpufreq_driver_lock, flags); 1859 1860 policy = cpufreq_cpu_get(cpu); 1861 if (policy) 1862 return policy->cur; 1863 1864 return 0; 1865 } 1866 EXPORT_SYMBOL(cpufreq_quick_get); 1867 1868 /** 1869 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU 1870 * @cpu: CPU number 1871 * 1872 * Just return the max possible frequency for a given CPU. 1873 */ 1874 unsigned int cpufreq_quick_get_max(unsigned int cpu) 1875 { 1876 struct cpufreq_policy *policy __free(put_cpufreq_policy); 1877 1878 policy = cpufreq_cpu_get(cpu); 1879 if (policy) 1880 return policy->max; 1881 1882 return 0; 1883 } 1884 EXPORT_SYMBOL(cpufreq_quick_get_max); 1885 1886 /** 1887 * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU 1888 * @cpu: CPU number 1889 * 1890 * The default return value is the max_freq field of cpuinfo. 1891 */ 1892 __weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu) 1893 { 1894 struct cpufreq_policy *policy __free(put_cpufreq_policy); 1895 1896 policy = cpufreq_cpu_get(cpu); 1897 if (policy) 1898 return policy->cpuinfo.max_freq; 1899 1900 return 0; 1901 } 1902 EXPORT_SYMBOL(cpufreq_get_hw_max_freq); 1903 1904 static unsigned int __cpufreq_get(struct cpufreq_policy *policy) 1905 { 1906 if (unlikely(policy_is_inactive(policy))) 1907 return 0; 1908 1909 return cpufreq_verify_current_freq(policy, true); 1910 } 1911 1912 /** 1913 * cpufreq_get - get the current CPU frequency (in kHz) 1914 * @cpu: CPU number 1915 * 1916 * Get the CPU current (static) CPU frequency 1917 */ 1918 unsigned int cpufreq_get(unsigned int cpu) 1919 { 1920 struct cpufreq_policy *policy __free(put_cpufreq_policy); 1921 1922 policy = cpufreq_cpu_get(cpu); 1923 if (!policy) 1924 return 0; 1925 1926 guard(cpufreq_policy_read)(policy); 1927 1928 if (cpufreq_driver->get) 1929 return __cpufreq_get(policy); 1930 1931 return 0; 1932 } 1933 EXPORT_SYMBOL(cpufreq_get); 1934 1935 static struct subsys_interface cpufreq_interface = { 1936 .name = "cpufreq", 1937 .subsys = &cpu_subsys, 1938 .add_dev = cpufreq_add_dev, 1939 .remove_dev = cpufreq_remove_dev, 1940 }; 1941 1942 /* 1943 * In case platform wants some specific frequency to be configured 1944 * during suspend.. 1945 */ 1946 int cpufreq_generic_suspend(struct cpufreq_policy *policy) 1947 { 1948 int ret; 1949 1950 if (!policy->suspend_freq) { 1951 pr_debug("%s: suspend_freq not defined\n", __func__); 1952 return 0; 1953 } 1954 1955 pr_debug("%s: Setting suspend-freq: %u\n", __func__, 1956 policy->suspend_freq); 1957 1958 ret = __cpufreq_driver_target(policy, policy->suspend_freq, 1959 CPUFREQ_RELATION_H); 1960 if (ret) 1961 pr_err("%s: unable to set suspend-freq: %u. err: %d\n", 1962 __func__, policy->suspend_freq, ret); 1963 1964 return ret; 1965 } 1966 EXPORT_SYMBOL(cpufreq_generic_suspend); 1967 1968 /** 1969 * cpufreq_suspend() - Suspend CPUFreq governors. 1970 * 1971 * Called during system wide Suspend/Hibernate cycles for suspending governors 1972 * as some platforms can't change frequency after this point in suspend cycle. 1973 * Because some of the devices (like: i2c, regulators, etc) they use for 1974 * changing frequency are suspended quickly after this point. 1975 */ 1976 void cpufreq_suspend(void) 1977 { 1978 struct cpufreq_policy *policy; 1979 1980 if (!cpufreq_driver) 1981 return; 1982 1983 if (!has_target() && !cpufreq_driver->suspend) 1984 goto suspend; 1985 1986 pr_debug("%s: Suspending Governors\n", __func__); 1987 1988 for_each_active_policy(policy) { 1989 if (has_target()) { 1990 scoped_guard(cpufreq_policy_write, policy) { 1991 cpufreq_stop_governor(policy); 1992 } 1993 } 1994 1995 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) 1996 pr_err("%s: Failed to suspend driver: %s\n", __func__, 1997 cpufreq_driver->name); 1998 } 1999 2000 suspend: 2001 cpufreq_suspended = true; 2002 } 2003 2004 /** 2005 * cpufreq_resume() - Resume CPUFreq governors. 2006 * 2007 * Called during system wide Suspend/Hibernate cycle for resuming governors that 2008 * are suspended with cpufreq_suspend(). 2009 */ 2010 void cpufreq_resume(void) 2011 { 2012 struct cpufreq_policy *policy; 2013 int ret; 2014 2015 if (!cpufreq_driver) 2016 return; 2017 2018 if (unlikely(!cpufreq_suspended)) 2019 return; 2020 2021 cpufreq_suspended = false; 2022 2023 if (!has_target() && !cpufreq_driver->resume) 2024 return; 2025 2026 pr_debug("%s: Resuming Governors\n", __func__); 2027 2028 for_each_active_policy(policy) { 2029 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { 2030 pr_err("%s: Failed to resume driver: %s\n", __func__, 2031 cpufreq_driver->name); 2032 } else if (has_target()) { 2033 scoped_guard(cpufreq_policy_write, policy) { 2034 ret = cpufreq_start_governor(policy); 2035 } 2036 2037 if (ret) 2038 pr_err("%s: Failed to start governor for CPU%u's policy\n", 2039 __func__, policy->cpu); 2040 } 2041 } 2042 } 2043 2044 /** 2045 * cpufreq_driver_test_flags - Test cpufreq driver's flags against given ones. 2046 * @flags: Flags to test against the current cpufreq driver's flags. 2047 * 2048 * Assumes that the driver is there, so callers must ensure that this is the 2049 * case. 2050 */ 2051 bool cpufreq_driver_test_flags(u16 flags) 2052 { 2053 return !!(cpufreq_driver->flags & flags); 2054 } 2055 2056 /** 2057 * cpufreq_get_current_driver - Return the current driver's name. 2058 * 2059 * Return the name string of the currently registered cpufreq driver or NULL if 2060 * none. 2061 */ 2062 const char *cpufreq_get_current_driver(void) 2063 { 2064 if (cpufreq_driver) 2065 return cpufreq_driver->name; 2066 2067 return NULL; 2068 } 2069 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); 2070 2071 /** 2072 * cpufreq_get_driver_data - Return current driver data. 2073 * 2074 * Return the private data of the currently registered cpufreq driver, or NULL 2075 * if no cpufreq driver has been registered. 2076 */ 2077 void *cpufreq_get_driver_data(void) 2078 { 2079 if (cpufreq_driver) 2080 return cpufreq_driver->driver_data; 2081 2082 return NULL; 2083 } 2084 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); 2085 2086 /********************************************************************* 2087 * NOTIFIER LISTS INTERFACE * 2088 *********************************************************************/ 2089 2090 /** 2091 * cpufreq_register_notifier - Register a notifier with cpufreq. 2092 * @nb: notifier function to register. 2093 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER. 2094 * 2095 * Add a notifier to one of two lists: either a list of notifiers that run on 2096 * clock rate changes (once before and once after every transition), or a list 2097 * of notifiers that ron on cpufreq policy changes. 2098 * 2099 * This function may sleep and it has the same return values as 2100 * blocking_notifier_chain_register(). 2101 */ 2102 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) 2103 { 2104 int ret; 2105 2106 if (cpufreq_disabled()) 2107 return -EINVAL; 2108 2109 switch (list) { 2110 case CPUFREQ_TRANSITION_NOTIFIER: 2111 mutex_lock(&cpufreq_fast_switch_lock); 2112 2113 if (cpufreq_fast_switch_count > 0) { 2114 mutex_unlock(&cpufreq_fast_switch_lock); 2115 return -EBUSY; 2116 } 2117 ret = srcu_notifier_chain_register( 2118 &cpufreq_transition_notifier_list, nb); 2119 if (!ret) 2120 cpufreq_fast_switch_count--; 2121 2122 mutex_unlock(&cpufreq_fast_switch_lock); 2123 break; 2124 case CPUFREQ_POLICY_NOTIFIER: 2125 ret = blocking_notifier_chain_register( 2126 &cpufreq_policy_notifier_list, nb); 2127 break; 2128 default: 2129 ret = -EINVAL; 2130 } 2131 2132 return ret; 2133 } 2134 EXPORT_SYMBOL(cpufreq_register_notifier); 2135 2136 /** 2137 * cpufreq_unregister_notifier - Unregister a notifier from cpufreq. 2138 * @nb: notifier block to be unregistered. 2139 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER. 2140 * 2141 * Remove a notifier from one of the cpufreq notifier lists. 2142 * 2143 * This function may sleep and it has the same return values as 2144 * blocking_notifier_chain_unregister(). 2145 */ 2146 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) 2147 { 2148 int ret; 2149 2150 if (cpufreq_disabled()) 2151 return -EINVAL; 2152 2153 switch (list) { 2154 case CPUFREQ_TRANSITION_NOTIFIER: 2155 mutex_lock(&cpufreq_fast_switch_lock); 2156 2157 ret = srcu_notifier_chain_unregister( 2158 &cpufreq_transition_notifier_list, nb); 2159 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) 2160 cpufreq_fast_switch_count++; 2161 2162 mutex_unlock(&cpufreq_fast_switch_lock); 2163 break; 2164 case CPUFREQ_POLICY_NOTIFIER: 2165 ret = blocking_notifier_chain_unregister( 2166 &cpufreq_policy_notifier_list, nb); 2167 break; 2168 default: 2169 ret = -EINVAL; 2170 } 2171 2172 return ret; 2173 } 2174 EXPORT_SYMBOL(cpufreq_unregister_notifier); 2175 2176 2177 /********************************************************************* 2178 * GOVERNORS * 2179 *********************************************************************/ 2180 2181 /** 2182 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. 2183 * @policy: cpufreq policy to switch the frequency for. 2184 * @target_freq: New frequency to set (may be approximate). 2185 * 2186 * Carry out a fast frequency switch without sleeping. 2187 * 2188 * The driver's ->fast_switch() callback invoked by this function must be 2189 * suitable for being called from within RCU-sched read-side critical sections 2190 * and it is expected to select the minimum available frequency greater than or 2191 * equal to @target_freq (CPUFREQ_RELATION_L). 2192 * 2193 * This function must not be called if policy->fast_switch_enabled is unset. 2194 * 2195 * Governors calling this function must guarantee that it will never be invoked 2196 * twice in parallel for the same policy and that it will never be called in 2197 * parallel with either ->target() or ->target_index() for the same policy. 2198 * 2199 * Returns the actual frequency set for the CPU. 2200 * 2201 * If 0 is returned by the driver's ->fast_switch() callback to indicate an 2202 * error condition, the hardware configuration must be preserved. 2203 */ 2204 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, 2205 unsigned int target_freq) 2206 { 2207 unsigned int freq; 2208 int cpu; 2209 2210 target_freq = clamp_val(target_freq, policy->min, policy->max); 2211 freq = cpufreq_driver->fast_switch(policy, target_freq); 2212 2213 if (!freq) 2214 return 0; 2215 2216 policy->cur = freq; 2217 arch_set_freq_scale(policy->related_cpus, freq, 2218 arch_scale_freq_ref(policy->cpu)); 2219 cpufreq_stats_record_transition(policy, freq); 2220 2221 if (trace_cpu_frequency_enabled()) { 2222 for_each_cpu(cpu, policy->cpus) 2223 trace_cpu_frequency(freq, cpu); 2224 } 2225 2226 return freq; 2227 } 2228 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); 2229 2230 /** 2231 * cpufreq_driver_adjust_perf - Adjust CPU performance level in one go. 2232 * @cpu: Target CPU. 2233 * @min_perf: Minimum (required) performance level (units of @capacity). 2234 * @target_perf: Target (desired) performance level (units of @capacity). 2235 * @capacity: Capacity of the target CPU. 2236 * 2237 * Carry out a fast performance level switch of @cpu without sleeping. 2238 * 2239 * The driver's ->adjust_perf() callback invoked by this function must be 2240 * suitable for being called from within RCU-sched read-side critical sections 2241 * and it is expected to select a suitable performance level equal to or above 2242 * @min_perf and preferably equal to or below @target_perf. 2243 * 2244 * This function must not be called if policy->fast_switch_enabled is unset. 2245 * 2246 * Governors calling this function must guarantee that it will never be invoked 2247 * twice in parallel for the same CPU and that it will never be called in 2248 * parallel with either ->target() or ->target_index() or ->fast_switch() for 2249 * the same CPU. 2250 */ 2251 void cpufreq_driver_adjust_perf(unsigned int cpu, 2252 unsigned long min_perf, 2253 unsigned long target_perf, 2254 unsigned long capacity) 2255 { 2256 cpufreq_driver->adjust_perf(cpu, min_perf, target_perf, capacity); 2257 } 2258 2259 /** 2260 * cpufreq_driver_has_adjust_perf - Check "direct fast switch" callback. 2261 * 2262 * Return 'true' if the ->adjust_perf callback is present for the 2263 * current driver or 'false' otherwise. 2264 */ 2265 bool cpufreq_driver_has_adjust_perf(void) 2266 { 2267 return !!cpufreq_driver->adjust_perf; 2268 } 2269 2270 /* Must set freqs->new to intermediate frequency */ 2271 static int __target_intermediate(struct cpufreq_policy *policy, 2272 struct cpufreq_freqs *freqs, int index) 2273 { 2274 int ret; 2275 2276 freqs->new = cpufreq_driver->get_intermediate(policy, index); 2277 2278 /* We don't need to switch to intermediate freq */ 2279 if (!freqs->new) 2280 return 0; 2281 2282 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", 2283 __func__, policy->cpu, freqs->old, freqs->new); 2284 2285 cpufreq_freq_transition_begin(policy, freqs); 2286 ret = cpufreq_driver->target_intermediate(policy, index); 2287 cpufreq_freq_transition_end(policy, freqs, ret); 2288 2289 if (ret) 2290 pr_err("%s: Failed to change to intermediate frequency: %d\n", 2291 __func__, ret); 2292 2293 return ret; 2294 } 2295 2296 static int __target_index(struct cpufreq_policy *policy, int index) 2297 { 2298 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; 2299 unsigned int restore_freq, intermediate_freq = 0; 2300 unsigned int newfreq = policy->freq_table[index].frequency; 2301 int retval = -EINVAL; 2302 bool notify; 2303 2304 if (newfreq == policy->cur) 2305 return 0; 2306 2307 /* Save last value to restore later on errors */ 2308 restore_freq = policy->cur; 2309 2310 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); 2311 if (notify) { 2312 /* Handle switching to intermediate frequency */ 2313 if (cpufreq_driver->get_intermediate) { 2314 retval = __target_intermediate(policy, &freqs, index); 2315 if (retval) 2316 return retval; 2317 2318 intermediate_freq = freqs.new; 2319 /* Set old freq to intermediate */ 2320 if (intermediate_freq) 2321 freqs.old = freqs.new; 2322 } 2323 2324 freqs.new = newfreq; 2325 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", 2326 __func__, policy->cpu, freqs.old, freqs.new); 2327 2328 cpufreq_freq_transition_begin(policy, &freqs); 2329 } 2330 2331 retval = cpufreq_driver->target_index(policy, index); 2332 if (retval) 2333 pr_err("%s: Failed to change cpu frequency: %d\n", __func__, 2334 retval); 2335 2336 if (notify) { 2337 cpufreq_freq_transition_end(policy, &freqs, retval); 2338 2339 /* 2340 * Failed after setting to intermediate freq? Driver should have 2341 * reverted back to initial frequency and so should we. Check 2342 * here for intermediate_freq instead of get_intermediate, in 2343 * case we haven't switched to intermediate freq at all. 2344 */ 2345 if (unlikely(retval && intermediate_freq)) { 2346 freqs.old = intermediate_freq; 2347 freqs.new = restore_freq; 2348 cpufreq_freq_transition_begin(policy, &freqs); 2349 cpufreq_freq_transition_end(policy, &freqs, 0); 2350 } 2351 } 2352 2353 return retval; 2354 } 2355 2356 int __cpufreq_driver_target(struct cpufreq_policy *policy, 2357 unsigned int target_freq, 2358 unsigned int relation) 2359 { 2360 unsigned int old_target_freq = target_freq; 2361 2362 if (cpufreq_disabled()) 2363 return -ENODEV; 2364 2365 target_freq = __resolve_freq(policy, target_freq, policy->min, 2366 policy->max, relation); 2367 2368 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", 2369 policy->cpu, target_freq, relation, old_target_freq); 2370 2371 /* 2372 * This might look like a redundant call as we are checking it again 2373 * after finding index. But it is left intentionally for cases where 2374 * exactly same freq is called again and so we can save on few function 2375 * calls. 2376 */ 2377 if (target_freq == policy->cur && 2378 !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS)) 2379 return 0; 2380 2381 if (cpufreq_driver->target) { 2382 /* 2383 * If the driver hasn't setup a single inefficient frequency, 2384 * it's unlikely it knows how to decode CPUFREQ_RELATION_E. 2385 */ 2386 if (!policy->efficiencies_available) 2387 relation &= ~CPUFREQ_RELATION_E; 2388 2389 return cpufreq_driver->target(policy, target_freq, relation); 2390 } 2391 2392 if (!cpufreq_driver->target_index) 2393 return -EINVAL; 2394 2395 return __target_index(policy, policy->cached_resolved_idx); 2396 } 2397 EXPORT_SYMBOL_GPL(__cpufreq_driver_target); 2398 2399 int cpufreq_driver_target(struct cpufreq_policy *policy, 2400 unsigned int target_freq, 2401 unsigned int relation) 2402 { 2403 guard(cpufreq_policy_write)(policy); 2404 2405 return __cpufreq_driver_target(policy, target_freq, relation); 2406 } 2407 EXPORT_SYMBOL_GPL(cpufreq_driver_target); 2408 2409 __weak struct cpufreq_governor *cpufreq_fallback_governor(void) 2410 { 2411 return NULL; 2412 } 2413 2414 static int cpufreq_init_governor(struct cpufreq_policy *policy) 2415 { 2416 int ret; 2417 2418 /* Don't start any governor operations if we are entering suspend */ 2419 if (cpufreq_suspended) 2420 return 0; 2421 /* 2422 * Governor might not be initiated here if ACPI _PPC changed 2423 * notification happened, so check it. 2424 */ 2425 if (!policy->governor) 2426 return -EINVAL; 2427 2428 /* Platform doesn't want dynamic frequency switching ? */ 2429 if (policy->governor->flags & CPUFREQ_GOV_DYNAMIC_SWITCHING && 2430 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) { 2431 struct cpufreq_governor *gov = cpufreq_fallback_governor(); 2432 2433 if (gov) { 2434 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n", 2435 policy->governor->name, gov->name); 2436 policy->governor = gov; 2437 } else { 2438 return -EINVAL; 2439 } 2440 } 2441 2442 if (!try_module_get(policy->governor->owner)) 2443 return -EINVAL; 2444 2445 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2446 2447 if (policy->governor->init) { 2448 ret = policy->governor->init(policy); 2449 if (ret) { 2450 module_put(policy->governor->owner); 2451 return ret; 2452 } 2453 } 2454 2455 policy->strict_target = !!(policy->governor->flags & CPUFREQ_GOV_STRICT_TARGET); 2456 2457 return 0; 2458 } 2459 2460 static void cpufreq_exit_governor(struct cpufreq_policy *policy) 2461 { 2462 if (cpufreq_suspended || !policy->governor) 2463 return; 2464 2465 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2466 2467 if (policy->governor->exit) 2468 policy->governor->exit(policy); 2469 2470 module_put(policy->governor->owner); 2471 } 2472 2473 int cpufreq_start_governor(struct cpufreq_policy *policy) 2474 { 2475 int ret; 2476 2477 if (cpufreq_suspended) 2478 return 0; 2479 2480 if (!policy->governor) 2481 return -EINVAL; 2482 2483 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2484 2485 if (cpufreq_driver->get) 2486 cpufreq_verify_current_freq(policy, false); 2487 2488 if (policy->governor->start) { 2489 ret = policy->governor->start(policy); 2490 if (ret) 2491 return ret; 2492 } 2493 2494 if (policy->governor->limits) 2495 policy->governor->limits(policy); 2496 2497 return 0; 2498 } 2499 2500 void cpufreq_stop_governor(struct cpufreq_policy *policy) 2501 { 2502 if (cpufreq_suspended || !policy->governor) 2503 return; 2504 2505 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2506 2507 if (policy->governor->stop) 2508 policy->governor->stop(policy); 2509 } 2510 2511 static void cpufreq_governor_limits(struct cpufreq_policy *policy) 2512 { 2513 if (cpufreq_suspended || !policy->governor) 2514 return; 2515 2516 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2517 2518 if (policy->governor->limits) 2519 policy->governor->limits(policy); 2520 } 2521 2522 int cpufreq_register_governor(struct cpufreq_governor *governor) 2523 { 2524 int err; 2525 2526 if (!governor) 2527 return -EINVAL; 2528 2529 if (cpufreq_disabled()) 2530 return -ENODEV; 2531 2532 mutex_lock(&cpufreq_governor_mutex); 2533 2534 err = -EBUSY; 2535 if (!find_governor(governor->name)) { 2536 err = 0; 2537 list_add(&governor->governor_list, &cpufreq_governor_list); 2538 } 2539 2540 mutex_unlock(&cpufreq_governor_mutex); 2541 return err; 2542 } 2543 EXPORT_SYMBOL_GPL(cpufreq_register_governor); 2544 2545 void cpufreq_unregister_governor(struct cpufreq_governor *governor) 2546 { 2547 struct cpufreq_policy *policy; 2548 unsigned long flags; 2549 2550 if (!governor) 2551 return; 2552 2553 if (cpufreq_disabled()) 2554 return; 2555 2556 /* clear last_governor for all inactive policies */ 2557 read_lock_irqsave(&cpufreq_driver_lock, flags); 2558 for_each_inactive_policy(policy) { 2559 if (!strcmp(policy->last_governor, governor->name)) { 2560 policy->governor = NULL; 2561 strcpy(policy->last_governor, "\0"); 2562 } 2563 } 2564 read_unlock_irqrestore(&cpufreq_driver_lock, flags); 2565 2566 mutex_lock(&cpufreq_governor_mutex); 2567 list_del(&governor->governor_list); 2568 mutex_unlock(&cpufreq_governor_mutex); 2569 } 2570 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); 2571 2572 2573 /********************************************************************* 2574 * POLICY INTERFACE * 2575 *********************************************************************/ 2576 2577 DEFINE_PER_CPU(unsigned long, cpufreq_pressure); 2578 2579 /** 2580 * cpufreq_update_pressure() - Update cpufreq pressure for CPUs 2581 * @policy: cpufreq policy of the CPUs. 2582 * 2583 * Update the value of cpufreq pressure for all @cpus in the policy. 2584 */ 2585 static void cpufreq_update_pressure(struct cpufreq_policy *policy) 2586 { 2587 unsigned long max_capacity, capped_freq, pressure; 2588 u32 max_freq; 2589 int cpu; 2590 2591 cpu = cpumask_first(policy->related_cpus); 2592 max_freq = arch_scale_freq_ref(cpu); 2593 capped_freq = policy->max; 2594 2595 /* 2596 * Handle properly the boost frequencies, which should simply clean 2597 * the cpufreq pressure value. 2598 */ 2599 if (max_freq <= capped_freq) { 2600 pressure = 0; 2601 } else { 2602 max_capacity = arch_scale_cpu_capacity(cpu); 2603 pressure = max_capacity - 2604 mult_frac(max_capacity, capped_freq, max_freq); 2605 } 2606 2607 for_each_cpu(cpu, policy->related_cpus) 2608 WRITE_ONCE(per_cpu(cpufreq_pressure, cpu), pressure); 2609 } 2610 2611 /** 2612 * cpufreq_set_policy - Modify cpufreq policy parameters. 2613 * @policy: Policy object to modify. 2614 * @new_gov: Policy governor pointer. 2615 * @new_pol: Policy value (for drivers with built-in governors). 2616 * 2617 * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency 2618 * limits to be set for the policy, update @policy with the verified limits 2619 * values and either invoke the driver's ->setpolicy() callback (if present) or 2620 * carry out a governor update for @policy. That is, run the current governor's 2621 * ->limits() callback (if @new_gov points to the same object as the one in 2622 * @policy) or replace the governor for @policy with @new_gov. 2623 * 2624 * The cpuinfo part of @policy is not updated by this function. 2625 */ 2626 static int cpufreq_set_policy(struct cpufreq_policy *policy, 2627 struct cpufreq_governor *new_gov, 2628 unsigned int new_pol) 2629 { 2630 struct cpufreq_policy_data new_data; 2631 struct cpufreq_governor *old_gov; 2632 int ret; 2633 2634 memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); 2635 new_data.freq_table = policy->freq_table; 2636 new_data.cpu = policy->cpu; 2637 /* 2638 * PM QoS framework collects all the requests from users and provide us 2639 * the final aggregated value here. 2640 */ 2641 new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN); 2642 new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX); 2643 2644 pr_debug("setting new policy for CPU %u: %u - %u kHz\n", 2645 new_data.cpu, new_data.min, new_data.max); 2646 2647 /* 2648 * Verify that the CPU speed can be set within these limits and make sure 2649 * that min <= max. 2650 */ 2651 ret = cpufreq_driver->verify(&new_data); 2652 if (ret) 2653 return ret; 2654 2655 /* 2656 * Resolve policy min/max to available frequencies. It ensures 2657 * no frequency resolution will neither overshoot the requested maximum 2658 * nor undershoot the requested minimum. 2659 * 2660 * Avoid storing intermediate values in policy->max or policy->min and 2661 * compiler optimizations around them because they may be accessed 2662 * concurrently by cpufreq_driver_resolve_freq() during the update. 2663 */ 2664 WRITE_ONCE(policy->max, __resolve_freq(policy, new_data.max, 2665 new_data.min, new_data.max, 2666 CPUFREQ_RELATION_H)); 2667 new_data.min = __resolve_freq(policy, new_data.min, new_data.min, 2668 new_data.max, CPUFREQ_RELATION_L); 2669 WRITE_ONCE(policy->min, new_data.min > policy->max ? policy->max : new_data.min); 2670 2671 trace_cpu_frequency_limits(policy); 2672 2673 cpufreq_update_pressure(policy); 2674 2675 policy->cached_target_freq = UINT_MAX; 2676 2677 pr_debug("new min and max freqs are %u - %u kHz\n", 2678 policy->min, policy->max); 2679 2680 if (cpufreq_driver->setpolicy) { 2681 policy->policy = new_pol; 2682 pr_debug("setting range\n"); 2683 return cpufreq_driver->setpolicy(policy); 2684 } 2685 2686 if (new_gov == policy->governor) { 2687 pr_debug("governor limits update\n"); 2688 cpufreq_governor_limits(policy); 2689 return 0; 2690 } 2691 2692 pr_debug("governor switch\n"); 2693 2694 /* save old, working values */ 2695 old_gov = policy->governor; 2696 /* end old governor */ 2697 if (old_gov) { 2698 cpufreq_stop_governor(policy); 2699 cpufreq_exit_governor(policy); 2700 } 2701 2702 /* start new governor */ 2703 policy->governor = new_gov; 2704 ret = cpufreq_init_governor(policy); 2705 if (!ret) { 2706 ret = cpufreq_start_governor(policy); 2707 if (!ret) { 2708 pr_debug("governor change\n"); 2709 return 0; 2710 } 2711 cpufreq_exit_governor(policy); 2712 } 2713 2714 /* new governor failed, so re-start old one */ 2715 pr_debug("starting governor %s failed\n", policy->governor->name); 2716 if (old_gov) { 2717 policy->governor = old_gov; 2718 if (cpufreq_init_governor(policy)) 2719 policy->governor = NULL; 2720 else 2721 cpufreq_start_governor(policy); 2722 } 2723 2724 return ret; 2725 } 2726 2727 static void cpufreq_policy_refresh(struct cpufreq_policy *policy) 2728 { 2729 guard(cpufreq_policy_write)(policy); 2730 2731 /* 2732 * BIOS might change freq behind our back 2733 * -> ask driver for current freq and notify governors about a change 2734 */ 2735 if (cpufreq_driver->get && has_target() && 2736 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false)))) 2737 return; 2738 2739 refresh_frequency_limits(policy); 2740 } 2741 2742 /** 2743 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy. 2744 * @cpu: CPU to re-evaluate the policy for. 2745 * 2746 * Update the current frequency for the cpufreq policy of @cpu and use 2747 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the 2748 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback 2749 * for the policy in question, among other things. 2750 */ 2751 void cpufreq_update_policy(unsigned int cpu) 2752 { 2753 struct cpufreq_policy *policy __free(put_cpufreq_policy); 2754 2755 policy = cpufreq_cpu_get(cpu); 2756 if (!policy) 2757 return; 2758 2759 cpufreq_policy_refresh(policy); 2760 } 2761 EXPORT_SYMBOL(cpufreq_update_policy); 2762 2763 /** 2764 * cpufreq_update_limits - Update policy limits for a given CPU. 2765 * @cpu: CPU to update the policy limits for. 2766 * 2767 * Invoke the driver's ->update_limits callback if present or call 2768 * cpufreq_policy_refresh() for @cpu. 2769 */ 2770 void cpufreq_update_limits(unsigned int cpu) 2771 { 2772 struct cpufreq_policy *policy __free(put_cpufreq_policy); 2773 2774 policy = cpufreq_cpu_get(cpu); 2775 if (!policy) 2776 return; 2777 2778 if (cpufreq_driver->update_limits) 2779 cpufreq_driver->update_limits(policy); 2780 else 2781 cpufreq_policy_refresh(policy); 2782 } 2783 EXPORT_SYMBOL_GPL(cpufreq_update_limits); 2784 2785 /********************************************************************* 2786 * BOOST * 2787 *********************************************************************/ 2788 int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state) 2789 { 2790 int ret; 2791 2792 if (!policy->freq_table) 2793 return -ENXIO; 2794 2795 ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table); 2796 if (ret) { 2797 pr_err("%s: Policy frequency update failed\n", __func__); 2798 return ret; 2799 } 2800 2801 ret = freq_qos_update_request(policy->max_freq_req, policy->max); 2802 if (ret < 0) 2803 return ret; 2804 2805 return 0; 2806 } 2807 EXPORT_SYMBOL_GPL(cpufreq_boost_set_sw); 2808 2809 static int cpufreq_boost_trigger_state(int state) 2810 { 2811 struct cpufreq_policy *policy; 2812 unsigned long flags; 2813 int ret = 0; 2814 2815 /* 2816 * Don't compare 'cpufreq_driver->boost_enabled' with 'state' here to 2817 * make sure all policies are in sync with global boost flag. 2818 */ 2819 2820 write_lock_irqsave(&cpufreq_driver_lock, flags); 2821 cpufreq_driver->boost_enabled = state; 2822 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2823 2824 cpus_read_lock(); 2825 for_each_active_policy(policy) { 2826 if (!policy->boost_supported) 2827 continue; 2828 2829 ret = policy_set_boost(policy, state); 2830 if (ret) 2831 goto err_reset_state; 2832 } 2833 cpus_read_unlock(); 2834 2835 return 0; 2836 2837 err_reset_state: 2838 cpus_read_unlock(); 2839 2840 write_lock_irqsave(&cpufreq_driver_lock, flags); 2841 cpufreq_driver->boost_enabled = !state; 2842 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2843 2844 pr_err("%s: Cannot %s BOOST\n", 2845 __func__, str_enable_disable(state)); 2846 2847 return ret; 2848 } 2849 2850 static bool cpufreq_boost_supported(void) 2851 { 2852 return cpufreq_driver->set_boost; 2853 } 2854 2855 static int create_boost_sysfs_file(void) 2856 { 2857 int ret; 2858 2859 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); 2860 if (ret) 2861 pr_err("%s: cannot register global BOOST sysfs file\n", 2862 __func__); 2863 2864 return ret; 2865 } 2866 2867 static void remove_boost_sysfs_file(void) 2868 { 2869 if (cpufreq_boost_supported()) 2870 sysfs_remove_file(cpufreq_global_kobject, &boost.attr); 2871 } 2872 2873 bool cpufreq_boost_enabled(void) 2874 { 2875 return cpufreq_driver->boost_enabled; 2876 } 2877 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); 2878 2879 /********************************************************************* 2880 * REGISTER / UNREGISTER CPUFREQ DRIVER * 2881 *********************************************************************/ 2882 static enum cpuhp_state hp_online; 2883 2884 static int cpuhp_cpufreq_online(unsigned int cpu) 2885 { 2886 cpufreq_online(cpu); 2887 2888 return 0; 2889 } 2890 2891 static int cpuhp_cpufreq_offline(unsigned int cpu) 2892 { 2893 cpufreq_offline(cpu); 2894 2895 return 0; 2896 } 2897 2898 /** 2899 * cpufreq_register_driver - register a CPU Frequency driver 2900 * @driver_data: A struct cpufreq_driver containing the values# 2901 * submitted by the CPU Frequency driver. 2902 * 2903 * Registers a CPU Frequency driver to this core code. This code 2904 * returns zero on success, -EEXIST when another driver got here first 2905 * (and isn't unregistered in the meantime). 2906 * 2907 */ 2908 int cpufreq_register_driver(struct cpufreq_driver *driver_data) 2909 { 2910 unsigned long flags; 2911 int ret; 2912 2913 if (cpufreq_disabled()) 2914 return -ENODEV; 2915 2916 /* 2917 * The cpufreq core depends heavily on the availability of device 2918 * structure, make sure they are available before proceeding further. 2919 */ 2920 if (!get_cpu_device(0)) 2921 return -EPROBE_DEFER; 2922 2923 if (!driver_data || !driver_data->verify || !driver_data->init || 2924 !(driver_data->setpolicy || driver_data->target_index || 2925 driver_data->target) || 2926 (driver_data->setpolicy && (driver_data->target_index || 2927 driver_data->target)) || 2928 (!driver_data->get_intermediate != !driver_data->target_intermediate) || 2929 (!driver_data->online != !driver_data->offline) || 2930 (driver_data->adjust_perf && !driver_data->fast_switch)) 2931 return -EINVAL; 2932 2933 pr_debug("trying to register driver %s\n", driver_data->name); 2934 2935 /* Protect against concurrent CPU online/offline. */ 2936 cpus_read_lock(); 2937 2938 write_lock_irqsave(&cpufreq_driver_lock, flags); 2939 if (cpufreq_driver) { 2940 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2941 ret = -EEXIST; 2942 goto out; 2943 } 2944 cpufreq_driver = driver_data; 2945 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2946 2947 /* 2948 * Mark support for the scheduler's frequency invariance engine for 2949 * drivers that implement target(), target_index() or fast_switch(). 2950 */ 2951 if (!cpufreq_driver->setpolicy) { 2952 static_branch_enable_cpuslocked(&cpufreq_freq_invariance); 2953 pr_debug("supports frequency invariance"); 2954 } 2955 2956 if (driver_data->setpolicy) 2957 driver_data->flags |= CPUFREQ_CONST_LOOPS; 2958 2959 if (cpufreq_boost_supported()) { 2960 ret = create_boost_sysfs_file(); 2961 if (ret) 2962 goto err_null_driver; 2963 } 2964 2965 ret = subsys_interface_register(&cpufreq_interface); 2966 if (ret) 2967 goto err_boost_unreg; 2968 2969 if (unlikely(list_empty(&cpufreq_policy_list))) { 2970 /* if all ->init() calls failed, unregister */ 2971 ret = -ENODEV; 2972 pr_debug("%s: No CPU initialized for driver %s\n", __func__, 2973 driver_data->name); 2974 goto err_if_unreg; 2975 } 2976 2977 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, 2978 "cpufreq:online", 2979 cpuhp_cpufreq_online, 2980 cpuhp_cpufreq_offline); 2981 if (ret < 0) 2982 goto err_if_unreg; 2983 hp_online = ret; 2984 ret = 0; 2985 2986 pr_debug("driver %s up and running\n", driver_data->name); 2987 goto out; 2988 2989 err_if_unreg: 2990 subsys_interface_unregister(&cpufreq_interface); 2991 err_boost_unreg: 2992 remove_boost_sysfs_file(); 2993 err_null_driver: 2994 write_lock_irqsave(&cpufreq_driver_lock, flags); 2995 cpufreq_driver = NULL; 2996 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2997 out: 2998 cpus_read_unlock(); 2999 return ret; 3000 } 3001 EXPORT_SYMBOL_GPL(cpufreq_register_driver); 3002 3003 /* 3004 * cpufreq_unregister_driver - unregister the current CPUFreq driver 3005 * 3006 * Unregister the current CPUFreq driver. Only call this if you have 3007 * the right to do so, i.e. if you have succeeded in initialising before! 3008 * Returns zero if successful, and -EINVAL if the cpufreq_driver is 3009 * currently not initialised. 3010 */ 3011 void cpufreq_unregister_driver(struct cpufreq_driver *driver) 3012 { 3013 unsigned long flags; 3014 3015 if (WARN_ON(!cpufreq_driver || (driver != cpufreq_driver))) 3016 return; 3017 3018 pr_debug("unregistering driver %s\n", driver->name); 3019 3020 /* Protect against concurrent cpu hotplug */ 3021 cpus_read_lock(); 3022 subsys_interface_unregister(&cpufreq_interface); 3023 remove_boost_sysfs_file(); 3024 static_branch_disable_cpuslocked(&cpufreq_freq_invariance); 3025 cpuhp_remove_state_nocalls_cpuslocked(hp_online); 3026 3027 write_lock_irqsave(&cpufreq_driver_lock, flags); 3028 3029 cpufreq_driver = NULL; 3030 3031 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 3032 cpus_read_unlock(); 3033 } 3034 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); 3035 3036 static int __init cpufreq_core_init(void) 3037 { 3038 struct cpufreq_governor *gov = cpufreq_default_governor(); 3039 struct device *dev_root; 3040 3041 if (cpufreq_disabled()) 3042 return -ENODEV; 3043 3044 dev_root = bus_get_dev_root(&cpu_subsys); 3045 if (dev_root) { 3046 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &dev_root->kobj); 3047 put_device(dev_root); 3048 } 3049 BUG_ON(!cpufreq_global_kobject); 3050 3051 if (!strlen(default_governor)) 3052 strscpy(default_governor, gov->name, CPUFREQ_NAME_LEN); 3053 3054 return 0; 3055 } 3056 3057 static bool cpufreq_policy_is_good_for_eas(unsigned int cpu) 3058 { 3059 struct cpufreq_policy *policy __free(put_cpufreq_policy); 3060 3061 policy = cpufreq_cpu_get(cpu); 3062 if (!policy) { 3063 pr_debug("cpufreq policy not set for CPU: %d\n", cpu); 3064 return false; 3065 } 3066 3067 return sugov_is_governor(policy); 3068 } 3069 3070 bool cpufreq_ready_for_eas(const struct cpumask *cpu_mask) 3071 { 3072 unsigned int cpu; 3073 3074 /* Do not attempt EAS if schedutil is not being used. */ 3075 for_each_cpu(cpu, cpu_mask) { 3076 if (!cpufreq_policy_is_good_for_eas(cpu)) { 3077 pr_debug("rd %*pbl: schedutil is mandatory for EAS\n", 3078 cpumask_pr_args(cpu_mask)); 3079 return false; 3080 } 3081 } 3082 3083 return true; 3084 } 3085 3086 module_param(off, int, 0444); 3087 module_param_string(default_governor, default_governor, CPUFREQ_NAME_LEN, 0444); 3088 core_initcall(cpufreq_core_init); 3089