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