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 policy->boost_enabled = cpufreq_boost_enabled() && policy_has_boost_freq(policy); 1435 1436 /* 1437 * The initialization has succeeded and the policy is online. 1438 * If there is a problem with its frequency table, take it 1439 * offline and drop it. 1440 */ 1441 ret = cpufreq_table_validate_and_sort(policy); 1442 if (ret) 1443 goto out_offline_policy; 1444 1445 /* related_cpus should at least include policy->cpus. */ 1446 cpumask_copy(policy->related_cpus, policy->cpus); 1447 } 1448 1449 /* 1450 * affected cpus must always be the one, which are online. We aren't 1451 * managing offline cpus here. 1452 */ 1453 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); 1454 1455 if (new_policy) { 1456 for_each_cpu(j, policy->related_cpus) { 1457 per_cpu(cpufreq_cpu_data, j) = policy; 1458 add_cpu_dev_symlink(policy, j, get_cpu_device(j)); 1459 } 1460 1461 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req), 1462 GFP_KERNEL); 1463 if (!policy->min_freq_req) { 1464 ret = -ENOMEM; 1465 goto out_destroy_policy; 1466 } 1467 1468 ret = freq_qos_add_request(&policy->constraints, 1469 policy->min_freq_req, FREQ_QOS_MIN, 1470 FREQ_QOS_MIN_DEFAULT_VALUE); 1471 if (ret < 0) { 1472 /* 1473 * So we don't call freq_qos_remove_request() for an 1474 * uninitialized request. 1475 */ 1476 kfree(policy->min_freq_req); 1477 policy->min_freq_req = NULL; 1478 goto out_destroy_policy; 1479 } 1480 1481 /* 1482 * This must be initialized right here to avoid calling 1483 * freq_qos_remove_request() on uninitialized request in case 1484 * of errors. 1485 */ 1486 policy->max_freq_req = policy->min_freq_req + 1; 1487 1488 ret = freq_qos_add_request(&policy->constraints, 1489 policy->max_freq_req, FREQ_QOS_MAX, 1490 FREQ_QOS_MAX_DEFAULT_VALUE); 1491 if (ret < 0) { 1492 policy->max_freq_req = NULL; 1493 goto out_destroy_policy; 1494 } 1495 1496 blocking_notifier_call_chain(&cpufreq_policy_notifier_list, 1497 CPUFREQ_CREATE_POLICY, policy); 1498 } 1499 1500 if (cpufreq_driver->get && has_target()) { 1501 policy->cur = cpufreq_driver->get(policy->cpu); 1502 if (!policy->cur) { 1503 ret = -EIO; 1504 pr_err("%s: ->get() failed\n", __func__); 1505 goto out_destroy_policy; 1506 } 1507 } 1508 1509 /* 1510 * Sometimes boot loaders set CPU frequency to a value outside of 1511 * frequency table present with cpufreq core. In such cases CPU might be 1512 * unstable if it has to run on that frequency for long duration of time 1513 * and so its better to set it to a frequency which is specified in 1514 * freq-table. This also makes cpufreq stats inconsistent as 1515 * cpufreq-stats would fail to register because current frequency of CPU 1516 * isn't found in freq-table. 1517 * 1518 * Because we don't want this change to effect boot process badly, we go 1519 * for the next freq which is >= policy->cur ('cur' must be set by now, 1520 * otherwise we will end up setting freq to lowest of the table as 'cur' 1521 * is initialized to zero). 1522 * 1523 * We are passing target-freq as "policy->cur - 1" otherwise 1524 * __cpufreq_driver_target() would simply fail, as policy->cur will be 1525 * equal to target-freq. 1526 */ 1527 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) 1528 && has_target()) { 1529 unsigned int old_freq = policy->cur; 1530 1531 /* Are we running at unknown frequency ? */ 1532 ret = cpufreq_frequency_table_get_index(policy, old_freq); 1533 if (ret == -EINVAL) { 1534 ret = __cpufreq_driver_target(policy, old_freq - 1, 1535 CPUFREQ_RELATION_L); 1536 1537 /* 1538 * Reaching here after boot in a few seconds may not 1539 * mean that system will remain stable at "unknown" 1540 * frequency for longer duration. Hence, a BUG_ON(). 1541 */ 1542 BUG_ON(ret); 1543 pr_info("%s: CPU%d: Running at unlisted initial frequency: %u KHz, changing to: %u KHz\n", 1544 __func__, policy->cpu, old_freq, policy->cur); 1545 } 1546 } 1547 1548 if (new_policy) { 1549 ret = cpufreq_add_dev_interface(policy); 1550 if (ret) 1551 goto out_destroy_policy; 1552 1553 cpufreq_stats_create_table(policy); 1554 1555 write_lock_irqsave(&cpufreq_driver_lock, flags); 1556 list_add(&policy->policy_list, &cpufreq_policy_list); 1557 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 1558 1559 /* 1560 * Register with the energy model before 1561 * sugov_eas_rebuild_sd() is called, which will result 1562 * in rebuilding of the sched domains, which should only be done 1563 * once the energy model is properly initialized for the policy 1564 * first. 1565 * 1566 * Also, this should be called before the policy is registered 1567 * with cooling framework. 1568 */ 1569 if (cpufreq_driver->register_em) 1570 cpufreq_driver->register_em(policy); 1571 } 1572 1573 ret = cpufreq_init_policy(policy); 1574 if (ret) { 1575 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", 1576 __func__, cpu, ret); 1577 goto out_destroy_policy; 1578 } 1579 1580 up_write(&policy->rwsem); 1581 1582 kobject_uevent(&policy->kobj, KOBJ_ADD); 1583 1584 /* Callback for handling stuff after policy is ready */ 1585 if (cpufreq_driver->ready) 1586 cpufreq_driver->ready(policy); 1587 1588 /* Register cpufreq cooling only for a new policy */ 1589 if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver)) 1590 policy->cdev = of_cpufreq_cooling_register(policy); 1591 1592 pr_debug("initialization complete\n"); 1593 1594 return 0; 1595 1596 out_destroy_policy: 1597 for_each_cpu(j, policy->real_cpus) 1598 remove_cpu_dev_symlink(policy, j, get_cpu_device(j)); 1599 1600 out_offline_policy: 1601 if (cpufreq_driver->offline) 1602 cpufreq_driver->offline(policy); 1603 1604 out_exit_policy: 1605 if (cpufreq_driver->exit) 1606 cpufreq_driver->exit(policy); 1607 1608 out_free_policy: 1609 cpumask_clear(policy->cpus); 1610 up_write(&policy->rwsem); 1611 1612 cpufreq_policy_free(policy); 1613 return ret; 1614 } 1615 1616 /** 1617 * cpufreq_add_dev - the cpufreq interface for a CPU device. 1618 * @dev: CPU device. 1619 * @sif: Subsystem interface structure pointer (not used) 1620 */ 1621 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 1622 { 1623 struct cpufreq_policy *policy; 1624 unsigned cpu = dev->id; 1625 int ret; 1626 1627 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); 1628 1629 if (cpu_online(cpu)) { 1630 ret = cpufreq_online(cpu); 1631 if (ret) 1632 return ret; 1633 } 1634 1635 /* Create sysfs link on CPU registration */ 1636 policy = per_cpu(cpufreq_cpu_data, cpu); 1637 if (policy) 1638 add_cpu_dev_symlink(policy, cpu, dev); 1639 1640 return 0; 1641 } 1642 1643 static void __cpufreq_offline(unsigned int cpu, struct cpufreq_policy *policy) 1644 { 1645 int ret; 1646 1647 if (has_target()) 1648 cpufreq_stop_governor(policy); 1649 1650 cpumask_clear_cpu(cpu, policy->cpus); 1651 1652 if (!policy_is_inactive(policy)) { 1653 /* Nominate a new CPU if necessary. */ 1654 if (cpu == policy->cpu) 1655 policy->cpu = cpumask_any(policy->cpus); 1656 1657 /* Start the governor again for the active policy. */ 1658 if (has_target()) { 1659 ret = cpufreq_start_governor(policy); 1660 if (ret) 1661 pr_err("%s: Failed to start governor\n", __func__); 1662 } 1663 1664 return; 1665 } 1666 1667 if (has_target()) 1668 strscpy(policy->last_governor, policy->governor->name, 1669 CPUFREQ_NAME_LEN); 1670 else 1671 policy->last_policy = policy->policy; 1672 1673 if (has_target()) 1674 cpufreq_exit_governor(policy); 1675 1676 /* 1677 * Perform the ->offline() during light-weight tear-down, as 1678 * that allows fast recovery when the CPU comes back. 1679 */ 1680 if (cpufreq_driver->offline) { 1681 cpufreq_driver->offline(policy); 1682 return; 1683 } 1684 1685 if (cpufreq_driver->exit) 1686 cpufreq_driver->exit(policy); 1687 1688 policy->freq_table = NULL; 1689 } 1690 1691 static int cpufreq_offline(unsigned int cpu) 1692 { 1693 struct cpufreq_policy *policy; 1694 1695 pr_debug("%s: unregistering CPU %u\n", __func__, cpu); 1696 1697 policy = cpufreq_cpu_get_raw(cpu); 1698 if (!policy) { 1699 pr_debug("%s: No cpu_data found\n", __func__); 1700 return 0; 1701 } 1702 1703 down_write(&policy->rwsem); 1704 1705 __cpufreq_offline(cpu, policy); 1706 1707 up_write(&policy->rwsem); 1708 return 0; 1709 } 1710 1711 /* 1712 * cpufreq_remove_dev - remove a CPU device 1713 * 1714 * Removes the cpufreq interface for a CPU device. 1715 */ 1716 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) 1717 { 1718 unsigned int cpu = dev->id; 1719 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); 1720 1721 if (!policy) 1722 return; 1723 1724 down_write(&policy->rwsem); 1725 1726 if (cpu_online(cpu)) 1727 __cpufreq_offline(cpu, policy); 1728 1729 remove_cpu_dev_symlink(policy, cpu, dev); 1730 1731 if (!cpumask_empty(policy->real_cpus)) { 1732 up_write(&policy->rwsem); 1733 return; 1734 } 1735 1736 /* 1737 * Unregister cpufreq cooling once all the CPUs of the policy are 1738 * removed. 1739 */ 1740 if (cpufreq_thermal_control_enabled(cpufreq_driver)) { 1741 cpufreq_cooling_unregister(policy->cdev); 1742 policy->cdev = NULL; 1743 } 1744 1745 /* We did light-weight exit earlier, do full tear down now */ 1746 if (cpufreq_driver->offline && cpufreq_driver->exit) 1747 cpufreq_driver->exit(policy); 1748 1749 up_write(&policy->rwsem); 1750 1751 cpufreq_policy_free(policy); 1752 } 1753 1754 /** 1755 * cpufreq_out_of_sync - Fix up actual and saved CPU frequency difference. 1756 * @policy: Policy managing CPUs. 1757 * @new_freq: New CPU frequency. 1758 * 1759 * Adjust to the current frequency first and clean up later by either calling 1760 * cpufreq_update_policy(), or scheduling handle_update(). 1761 */ 1762 static void cpufreq_out_of_sync(struct cpufreq_policy *policy, 1763 unsigned int new_freq) 1764 { 1765 struct cpufreq_freqs freqs; 1766 1767 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", 1768 policy->cur, new_freq); 1769 1770 freqs.old = policy->cur; 1771 freqs.new = new_freq; 1772 1773 cpufreq_freq_transition_begin(policy, &freqs); 1774 cpufreq_freq_transition_end(policy, &freqs, 0); 1775 } 1776 1777 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update) 1778 { 1779 unsigned int new_freq; 1780 1781 new_freq = cpufreq_driver->get(policy->cpu); 1782 if (!new_freq) 1783 return 0; 1784 1785 /* 1786 * If fast frequency switching is used with the given policy, the check 1787 * against policy->cur is pointless, so skip it in that case. 1788 */ 1789 if (policy->fast_switch_enabled || !has_target()) 1790 return new_freq; 1791 1792 if (policy->cur != new_freq) { 1793 /* 1794 * For some platforms, the frequency returned by hardware may be 1795 * slightly different from what is provided in the frequency 1796 * table, for example hardware may return 499 MHz instead of 500 1797 * MHz. In such cases it is better to avoid getting into 1798 * unnecessary frequency updates. 1799 */ 1800 if (abs(policy->cur - new_freq) < KHZ_PER_MHZ) 1801 return policy->cur; 1802 1803 cpufreq_out_of_sync(policy, new_freq); 1804 if (update) 1805 schedule_work(&policy->update); 1806 } 1807 1808 return new_freq; 1809 } 1810 1811 /** 1812 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur 1813 * @cpu: CPU number 1814 * 1815 * This is the last known freq, without actually getting it from the driver. 1816 * Return value will be same as what is shown in scaling_cur_freq in sysfs. 1817 */ 1818 unsigned int cpufreq_quick_get(unsigned int cpu) 1819 { 1820 struct cpufreq_policy *policy; 1821 unsigned int ret_freq = 0; 1822 unsigned long flags; 1823 1824 read_lock_irqsave(&cpufreq_driver_lock, flags); 1825 1826 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { 1827 ret_freq = cpufreq_driver->get(cpu); 1828 read_unlock_irqrestore(&cpufreq_driver_lock, flags); 1829 return ret_freq; 1830 } 1831 1832 read_unlock_irqrestore(&cpufreq_driver_lock, flags); 1833 1834 policy = cpufreq_cpu_get(cpu); 1835 if (policy) { 1836 ret_freq = policy->cur; 1837 cpufreq_cpu_put(policy); 1838 } 1839 1840 return ret_freq; 1841 } 1842 EXPORT_SYMBOL(cpufreq_quick_get); 1843 1844 /** 1845 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU 1846 * @cpu: CPU number 1847 * 1848 * Just return the max possible frequency for a given CPU. 1849 */ 1850 unsigned int cpufreq_quick_get_max(unsigned int cpu) 1851 { 1852 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); 1853 unsigned int ret_freq = 0; 1854 1855 if (policy) { 1856 ret_freq = policy->max; 1857 cpufreq_cpu_put(policy); 1858 } 1859 1860 return ret_freq; 1861 } 1862 EXPORT_SYMBOL(cpufreq_quick_get_max); 1863 1864 /** 1865 * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU 1866 * @cpu: CPU number 1867 * 1868 * The default return value is the max_freq field of cpuinfo. 1869 */ 1870 __weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu) 1871 { 1872 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); 1873 unsigned int ret_freq = 0; 1874 1875 if (policy) { 1876 ret_freq = policy->cpuinfo.max_freq; 1877 cpufreq_cpu_put(policy); 1878 } 1879 1880 return ret_freq; 1881 } 1882 EXPORT_SYMBOL(cpufreq_get_hw_max_freq); 1883 1884 static unsigned int __cpufreq_get(struct cpufreq_policy *policy) 1885 { 1886 if (unlikely(policy_is_inactive(policy))) 1887 return 0; 1888 1889 return cpufreq_verify_current_freq(policy, true); 1890 } 1891 1892 /** 1893 * cpufreq_get - get the current CPU frequency (in kHz) 1894 * @cpu: CPU number 1895 * 1896 * Get the CPU current (static) CPU frequency 1897 */ 1898 unsigned int cpufreq_get(unsigned int cpu) 1899 { 1900 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); 1901 unsigned int ret_freq = 0; 1902 1903 if (policy) { 1904 down_read(&policy->rwsem); 1905 if (cpufreq_driver->get) 1906 ret_freq = __cpufreq_get(policy); 1907 up_read(&policy->rwsem); 1908 1909 cpufreq_cpu_put(policy); 1910 } 1911 1912 return ret_freq; 1913 } 1914 EXPORT_SYMBOL(cpufreq_get); 1915 1916 static struct subsys_interface cpufreq_interface = { 1917 .name = "cpufreq", 1918 .subsys = &cpu_subsys, 1919 .add_dev = cpufreq_add_dev, 1920 .remove_dev = cpufreq_remove_dev, 1921 }; 1922 1923 /* 1924 * In case platform wants some specific frequency to be configured 1925 * during suspend.. 1926 */ 1927 int cpufreq_generic_suspend(struct cpufreq_policy *policy) 1928 { 1929 int ret; 1930 1931 if (!policy->suspend_freq) { 1932 pr_debug("%s: suspend_freq not defined\n", __func__); 1933 return 0; 1934 } 1935 1936 pr_debug("%s: Setting suspend-freq: %u\n", __func__, 1937 policy->suspend_freq); 1938 1939 ret = __cpufreq_driver_target(policy, policy->suspend_freq, 1940 CPUFREQ_RELATION_H); 1941 if (ret) 1942 pr_err("%s: unable to set suspend-freq: %u. err: %d\n", 1943 __func__, policy->suspend_freq, ret); 1944 1945 return ret; 1946 } 1947 EXPORT_SYMBOL(cpufreq_generic_suspend); 1948 1949 /** 1950 * cpufreq_suspend() - Suspend CPUFreq governors. 1951 * 1952 * Called during system wide Suspend/Hibernate cycles for suspending governors 1953 * as some platforms can't change frequency after this point in suspend cycle. 1954 * Because some of the devices (like: i2c, regulators, etc) they use for 1955 * changing frequency are suspended quickly after this point. 1956 */ 1957 void cpufreq_suspend(void) 1958 { 1959 struct cpufreq_policy *policy; 1960 1961 if (!cpufreq_driver) 1962 return; 1963 1964 if (!has_target() && !cpufreq_driver->suspend) 1965 goto suspend; 1966 1967 pr_debug("%s: Suspending Governors\n", __func__); 1968 1969 for_each_active_policy(policy) { 1970 if (has_target()) { 1971 down_write(&policy->rwsem); 1972 cpufreq_stop_governor(policy); 1973 up_write(&policy->rwsem); 1974 } 1975 1976 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) 1977 pr_err("%s: Failed to suspend driver: %s\n", __func__, 1978 cpufreq_driver->name); 1979 } 1980 1981 suspend: 1982 cpufreq_suspended = true; 1983 } 1984 1985 /** 1986 * cpufreq_resume() - Resume CPUFreq governors. 1987 * 1988 * Called during system wide Suspend/Hibernate cycle for resuming governors that 1989 * are suspended with cpufreq_suspend(). 1990 */ 1991 void cpufreq_resume(void) 1992 { 1993 struct cpufreq_policy *policy; 1994 int ret; 1995 1996 if (!cpufreq_driver) 1997 return; 1998 1999 if (unlikely(!cpufreq_suspended)) 2000 return; 2001 2002 cpufreq_suspended = false; 2003 2004 if (!has_target() && !cpufreq_driver->resume) 2005 return; 2006 2007 pr_debug("%s: Resuming Governors\n", __func__); 2008 2009 for_each_active_policy(policy) { 2010 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { 2011 pr_err("%s: Failed to resume driver: %s\n", __func__, 2012 cpufreq_driver->name); 2013 } else if (has_target()) { 2014 down_write(&policy->rwsem); 2015 ret = cpufreq_start_governor(policy); 2016 up_write(&policy->rwsem); 2017 2018 if (ret) 2019 pr_err("%s: Failed to start governor for CPU%u's policy\n", 2020 __func__, policy->cpu); 2021 } 2022 } 2023 } 2024 2025 /** 2026 * cpufreq_driver_test_flags - Test cpufreq driver's flags against given ones. 2027 * @flags: Flags to test against the current cpufreq driver's flags. 2028 * 2029 * Assumes that the driver is there, so callers must ensure that this is the 2030 * case. 2031 */ 2032 bool cpufreq_driver_test_flags(u16 flags) 2033 { 2034 return !!(cpufreq_driver->flags & flags); 2035 } 2036 2037 /** 2038 * cpufreq_get_current_driver - Return the current driver's name. 2039 * 2040 * Return the name string of the currently registered cpufreq driver or NULL if 2041 * none. 2042 */ 2043 const char *cpufreq_get_current_driver(void) 2044 { 2045 if (cpufreq_driver) 2046 return cpufreq_driver->name; 2047 2048 return NULL; 2049 } 2050 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); 2051 2052 /** 2053 * cpufreq_get_driver_data - Return current driver data. 2054 * 2055 * Return the private data of the currently registered cpufreq driver, or NULL 2056 * if no cpufreq driver has been registered. 2057 */ 2058 void *cpufreq_get_driver_data(void) 2059 { 2060 if (cpufreq_driver) 2061 return cpufreq_driver->driver_data; 2062 2063 return NULL; 2064 } 2065 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); 2066 2067 /********************************************************************* 2068 * NOTIFIER LISTS INTERFACE * 2069 *********************************************************************/ 2070 2071 /** 2072 * cpufreq_register_notifier - Register a notifier with cpufreq. 2073 * @nb: notifier function to register. 2074 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER. 2075 * 2076 * Add a notifier to one of two lists: either a list of notifiers that run on 2077 * clock rate changes (once before and once after every transition), or a list 2078 * of notifiers that ron on cpufreq policy changes. 2079 * 2080 * This function may sleep and it has the same return values as 2081 * blocking_notifier_chain_register(). 2082 */ 2083 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) 2084 { 2085 int ret; 2086 2087 if (cpufreq_disabled()) 2088 return -EINVAL; 2089 2090 switch (list) { 2091 case CPUFREQ_TRANSITION_NOTIFIER: 2092 mutex_lock(&cpufreq_fast_switch_lock); 2093 2094 if (cpufreq_fast_switch_count > 0) { 2095 mutex_unlock(&cpufreq_fast_switch_lock); 2096 return -EBUSY; 2097 } 2098 ret = srcu_notifier_chain_register( 2099 &cpufreq_transition_notifier_list, nb); 2100 if (!ret) 2101 cpufreq_fast_switch_count--; 2102 2103 mutex_unlock(&cpufreq_fast_switch_lock); 2104 break; 2105 case CPUFREQ_POLICY_NOTIFIER: 2106 ret = blocking_notifier_chain_register( 2107 &cpufreq_policy_notifier_list, nb); 2108 break; 2109 default: 2110 ret = -EINVAL; 2111 } 2112 2113 return ret; 2114 } 2115 EXPORT_SYMBOL(cpufreq_register_notifier); 2116 2117 /** 2118 * cpufreq_unregister_notifier - Unregister a notifier from cpufreq. 2119 * @nb: notifier block to be unregistered. 2120 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER. 2121 * 2122 * Remove a notifier from one of the cpufreq notifier lists. 2123 * 2124 * This function may sleep and it has the same return values as 2125 * blocking_notifier_chain_unregister(). 2126 */ 2127 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) 2128 { 2129 int ret; 2130 2131 if (cpufreq_disabled()) 2132 return -EINVAL; 2133 2134 switch (list) { 2135 case CPUFREQ_TRANSITION_NOTIFIER: 2136 mutex_lock(&cpufreq_fast_switch_lock); 2137 2138 ret = srcu_notifier_chain_unregister( 2139 &cpufreq_transition_notifier_list, nb); 2140 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) 2141 cpufreq_fast_switch_count++; 2142 2143 mutex_unlock(&cpufreq_fast_switch_lock); 2144 break; 2145 case CPUFREQ_POLICY_NOTIFIER: 2146 ret = blocking_notifier_chain_unregister( 2147 &cpufreq_policy_notifier_list, nb); 2148 break; 2149 default: 2150 ret = -EINVAL; 2151 } 2152 2153 return ret; 2154 } 2155 EXPORT_SYMBOL(cpufreq_unregister_notifier); 2156 2157 2158 /********************************************************************* 2159 * GOVERNORS * 2160 *********************************************************************/ 2161 2162 /** 2163 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. 2164 * @policy: cpufreq policy to switch the frequency for. 2165 * @target_freq: New frequency to set (may be approximate). 2166 * 2167 * Carry out a fast frequency switch without sleeping. 2168 * 2169 * The driver's ->fast_switch() callback invoked by this function must be 2170 * suitable for being called from within RCU-sched read-side critical sections 2171 * and it is expected to select the minimum available frequency greater than or 2172 * equal to @target_freq (CPUFREQ_RELATION_L). 2173 * 2174 * This function must not be called if policy->fast_switch_enabled is unset. 2175 * 2176 * Governors calling this function must guarantee that it will never be invoked 2177 * twice in parallel for the same policy and that it will never be called in 2178 * parallel with either ->target() or ->target_index() for the same policy. 2179 * 2180 * Returns the actual frequency set for the CPU. 2181 * 2182 * If 0 is returned by the driver's ->fast_switch() callback to indicate an 2183 * error condition, the hardware configuration must be preserved. 2184 */ 2185 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, 2186 unsigned int target_freq) 2187 { 2188 unsigned int freq; 2189 int cpu; 2190 2191 target_freq = clamp_val(target_freq, policy->min, policy->max); 2192 freq = cpufreq_driver->fast_switch(policy, target_freq); 2193 2194 if (!freq) 2195 return 0; 2196 2197 policy->cur = freq; 2198 arch_set_freq_scale(policy->related_cpus, freq, 2199 arch_scale_freq_ref(policy->cpu)); 2200 cpufreq_stats_record_transition(policy, freq); 2201 2202 if (trace_cpu_frequency_enabled()) { 2203 for_each_cpu(cpu, policy->cpus) 2204 trace_cpu_frequency(freq, cpu); 2205 } 2206 2207 return freq; 2208 } 2209 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); 2210 2211 /** 2212 * cpufreq_driver_adjust_perf - Adjust CPU performance level in one go. 2213 * @cpu: Target CPU. 2214 * @min_perf: Minimum (required) performance level (units of @capacity). 2215 * @target_perf: Target (desired) performance level (units of @capacity). 2216 * @capacity: Capacity of the target CPU. 2217 * 2218 * Carry out a fast performance level switch of @cpu without sleeping. 2219 * 2220 * The driver's ->adjust_perf() callback invoked by this function must be 2221 * suitable for being called from within RCU-sched read-side critical sections 2222 * and it is expected to select a suitable performance level equal to or above 2223 * @min_perf and preferably equal to or below @target_perf. 2224 * 2225 * This function must not be called if policy->fast_switch_enabled is unset. 2226 * 2227 * Governors calling this function must guarantee that it will never be invoked 2228 * twice in parallel for the same CPU and that it will never be called in 2229 * parallel with either ->target() or ->target_index() or ->fast_switch() for 2230 * the same CPU. 2231 */ 2232 void cpufreq_driver_adjust_perf(unsigned int cpu, 2233 unsigned long min_perf, 2234 unsigned long target_perf, 2235 unsigned long capacity) 2236 { 2237 cpufreq_driver->adjust_perf(cpu, min_perf, target_perf, capacity); 2238 } 2239 2240 /** 2241 * cpufreq_driver_has_adjust_perf - Check "direct fast switch" callback. 2242 * 2243 * Return 'true' if the ->adjust_perf callback is present for the 2244 * current driver or 'false' otherwise. 2245 */ 2246 bool cpufreq_driver_has_adjust_perf(void) 2247 { 2248 return !!cpufreq_driver->adjust_perf; 2249 } 2250 2251 /* Must set freqs->new to intermediate frequency */ 2252 static int __target_intermediate(struct cpufreq_policy *policy, 2253 struct cpufreq_freqs *freqs, int index) 2254 { 2255 int ret; 2256 2257 freqs->new = cpufreq_driver->get_intermediate(policy, index); 2258 2259 /* We don't need to switch to intermediate freq */ 2260 if (!freqs->new) 2261 return 0; 2262 2263 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", 2264 __func__, policy->cpu, freqs->old, freqs->new); 2265 2266 cpufreq_freq_transition_begin(policy, freqs); 2267 ret = cpufreq_driver->target_intermediate(policy, index); 2268 cpufreq_freq_transition_end(policy, freqs, ret); 2269 2270 if (ret) 2271 pr_err("%s: Failed to change to intermediate frequency: %d\n", 2272 __func__, ret); 2273 2274 return ret; 2275 } 2276 2277 static int __target_index(struct cpufreq_policy *policy, int index) 2278 { 2279 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; 2280 unsigned int restore_freq, intermediate_freq = 0; 2281 unsigned int newfreq = policy->freq_table[index].frequency; 2282 int retval = -EINVAL; 2283 bool notify; 2284 2285 if (newfreq == policy->cur) 2286 return 0; 2287 2288 /* Save last value to restore later on errors */ 2289 restore_freq = policy->cur; 2290 2291 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); 2292 if (notify) { 2293 /* Handle switching to intermediate frequency */ 2294 if (cpufreq_driver->get_intermediate) { 2295 retval = __target_intermediate(policy, &freqs, index); 2296 if (retval) 2297 return retval; 2298 2299 intermediate_freq = freqs.new; 2300 /* Set old freq to intermediate */ 2301 if (intermediate_freq) 2302 freqs.old = freqs.new; 2303 } 2304 2305 freqs.new = newfreq; 2306 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", 2307 __func__, policy->cpu, freqs.old, freqs.new); 2308 2309 cpufreq_freq_transition_begin(policy, &freqs); 2310 } 2311 2312 retval = cpufreq_driver->target_index(policy, index); 2313 if (retval) 2314 pr_err("%s: Failed to change cpu frequency: %d\n", __func__, 2315 retval); 2316 2317 if (notify) { 2318 cpufreq_freq_transition_end(policy, &freqs, retval); 2319 2320 /* 2321 * Failed after setting to intermediate freq? Driver should have 2322 * reverted back to initial frequency and so should we. Check 2323 * here for intermediate_freq instead of get_intermediate, in 2324 * case we haven't switched to intermediate freq at all. 2325 */ 2326 if (unlikely(retval && intermediate_freq)) { 2327 freqs.old = intermediate_freq; 2328 freqs.new = restore_freq; 2329 cpufreq_freq_transition_begin(policy, &freqs); 2330 cpufreq_freq_transition_end(policy, &freqs, 0); 2331 } 2332 } 2333 2334 return retval; 2335 } 2336 2337 int __cpufreq_driver_target(struct cpufreq_policy *policy, 2338 unsigned int target_freq, 2339 unsigned int relation) 2340 { 2341 unsigned int old_target_freq = target_freq; 2342 2343 if (cpufreq_disabled()) 2344 return -ENODEV; 2345 2346 target_freq = __resolve_freq(policy, target_freq, relation); 2347 2348 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", 2349 policy->cpu, target_freq, relation, old_target_freq); 2350 2351 /* 2352 * This might look like a redundant call as we are checking it again 2353 * after finding index. But it is left intentionally for cases where 2354 * exactly same freq is called again and so we can save on few function 2355 * calls. 2356 */ 2357 if (target_freq == policy->cur && 2358 !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS)) 2359 return 0; 2360 2361 if (cpufreq_driver->target) { 2362 /* 2363 * If the driver hasn't setup a single inefficient frequency, 2364 * it's unlikely it knows how to decode CPUFREQ_RELATION_E. 2365 */ 2366 if (!policy->efficiencies_available) 2367 relation &= ~CPUFREQ_RELATION_E; 2368 2369 return cpufreq_driver->target(policy, target_freq, relation); 2370 } 2371 2372 if (!cpufreq_driver->target_index) 2373 return -EINVAL; 2374 2375 return __target_index(policy, policy->cached_resolved_idx); 2376 } 2377 EXPORT_SYMBOL_GPL(__cpufreq_driver_target); 2378 2379 int cpufreq_driver_target(struct cpufreq_policy *policy, 2380 unsigned int target_freq, 2381 unsigned int relation) 2382 { 2383 int ret; 2384 2385 down_write(&policy->rwsem); 2386 2387 ret = __cpufreq_driver_target(policy, target_freq, relation); 2388 2389 up_write(&policy->rwsem); 2390 2391 return ret; 2392 } 2393 EXPORT_SYMBOL_GPL(cpufreq_driver_target); 2394 2395 __weak struct cpufreq_governor *cpufreq_fallback_governor(void) 2396 { 2397 return NULL; 2398 } 2399 2400 static int cpufreq_init_governor(struct cpufreq_policy *policy) 2401 { 2402 int ret; 2403 2404 /* Don't start any governor operations if we are entering suspend */ 2405 if (cpufreq_suspended) 2406 return 0; 2407 /* 2408 * Governor might not be initiated here if ACPI _PPC changed 2409 * notification happened, so check it. 2410 */ 2411 if (!policy->governor) 2412 return -EINVAL; 2413 2414 /* Platform doesn't want dynamic frequency switching ? */ 2415 if (policy->governor->flags & CPUFREQ_GOV_DYNAMIC_SWITCHING && 2416 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) { 2417 struct cpufreq_governor *gov = cpufreq_fallback_governor(); 2418 2419 if (gov) { 2420 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n", 2421 policy->governor->name, gov->name); 2422 policy->governor = gov; 2423 } else { 2424 return -EINVAL; 2425 } 2426 } 2427 2428 if (!try_module_get(policy->governor->owner)) 2429 return -EINVAL; 2430 2431 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2432 2433 if (policy->governor->init) { 2434 ret = policy->governor->init(policy); 2435 if (ret) { 2436 module_put(policy->governor->owner); 2437 return ret; 2438 } 2439 } 2440 2441 policy->strict_target = !!(policy->governor->flags & CPUFREQ_GOV_STRICT_TARGET); 2442 2443 return 0; 2444 } 2445 2446 static void cpufreq_exit_governor(struct cpufreq_policy *policy) 2447 { 2448 if (cpufreq_suspended || !policy->governor) 2449 return; 2450 2451 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2452 2453 if (policy->governor->exit) 2454 policy->governor->exit(policy); 2455 2456 module_put(policy->governor->owner); 2457 } 2458 2459 int cpufreq_start_governor(struct cpufreq_policy *policy) 2460 { 2461 int ret; 2462 2463 if (cpufreq_suspended) 2464 return 0; 2465 2466 if (!policy->governor) 2467 return -EINVAL; 2468 2469 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2470 2471 if (cpufreq_driver->get) 2472 cpufreq_verify_current_freq(policy, false); 2473 2474 if (policy->governor->start) { 2475 ret = policy->governor->start(policy); 2476 if (ret) 2477 return ret; 2478 } 2479 2480 if (policy->governor->limits) 2481 policy->governor->limits(policy); 2482 2483 return 0; 2484 } 2485 2486 void cpufreq_stop_governor(struct cpufreq_policy *policy) 2487 { 2488 if (cpufreq_suspended || !policy->governor) 2489 return; 2490 2491 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2492 2493 if (policy->governor->stop) 2494 policy->governor->stop(policy); 2495 } 2496 2497 static void cpufreq_governor_limits(struct cpufreq_policy *policy) 2498 { 2499 if (cpufreq_suspended || !policy->governor) 2500 return; 2501 2502 pr_debug("%s: for CPU %u\n", __func__, policy->cpu); 2503 2504 if (policy->governor->limits) 2505 policy->governor->limits(policy); 2506 } 2507 2508 int cpufreq_register_governor(struct cpufreq_governor *governor) 2509 { 2510 int err; 2511 2512 if (!governor) 2513 return -EINVAL; 2514 2515 if (cpufreq_disabled()) 2516 return -ENODEV; 2517 2518 mutex_lock(&cpufreq_governor_mutex); 2519 2520 err = -EBUSY; 2521 if (!find_governor(governor->name)) { 2522 err = 0; 2523 list_add(&governor->governor_list, &cpufreq_governor_list); 2524 } 2525 2526 mutex_unlock(&cpufreq_governor_mutex); 2527 return err; 2528 } 2529 EXPORT_SYMBOL_GPL(cpufreq_register_governor); 2530 2531 void cpufreq_unregister_governor(struct cpufreq_governor *governor) 2532 { 2533 struct cpufreq_policy *policy; 2534 unsigned long flags; 2535 2536 if (!governor) 2537 return; 2538 2539 if (cpufreq_disabled()) 2540 return; 2541 2542 /* clear last_governor for all inactive policies */ 2543 read_lock_irqsave(&cpufreq_driver_lock, flags); 2544 for_each_inactive_policy(policy) { 2545 if (!strcmp(policy->last_governor, governor->name)) { 2546 policy->governor = NULL; 2547 strcpy(policy->last_governor, "\0"); 2548 } 2549 } 2550 read_unlock_irqrestore(&cpufreq_driver_lock, flags); 2551 2552 mutex_lock(&cpufreq_governor_mutex); 2553 list_del(&governor->governor_list); 2554 mutex_unlock(&cpufreq_governor_mutex); 2555 } 2556 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); 2557 2558 2559 /********************************************************************* 2560 * POLICY INTERFACE * 2561 *********************************************************************/ 2562 2563 /** 2564 * cpufreq_get_policy - get the current cpufreq_policy 2565 * @policy: struct cpufreq_policy into which the current cpufreq_policy 2566 * is written 2567 * @cpu: CPU to find the policy for 2568 * 2569 * Reads the current cpufreq policy. 2570 */ 2571 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) 2572 { 2573 struct cpufreq_policy *cpu_policy; 2574 if (!policy) 2575 return -EINVAL; 2576 2577 cpu_policy = cpufreq_cpu_get(cpu); 2578 if (!cpu_policy) 2579 return -EINVAL; 2580 2581 memcpy(policy, cpu_policy, sizeof(*policy)); 2582 2583 cpufreq_cpu_put(cpu_policy); 2584 return 0; 2585 } 2586 EXPORT_SYMBOL(cpufreq_get_policy); 2587 2588 DEFINE_PER_CPU(unsigned long, cpufreq_pressure); 2589 2590 /** 2591 * cpufreq_update_pressure() - Update cpufreq pressure for CPUs 2592 * @policy: cpufreq policy of the CPUs. 2593 * 2594 * Update the value of cpufreq pressure for all @cpus in the policy. 2595 */ 2596 static void cpufreq_update_pressure(struct cpufreq_policy *policy) 2597 { 2598 unsigned long max_capacity, capped_freq, pressure; 2599 u32 max_freq; 2600 int cpu; 2601 2602 cpu = cpumask_first(policy->related_cpus); 2603 max_freq = arch_scale_freq_ref(cpu); 2604 capped_freq = policy->max; 2605 2606 /* 2607 * Handle properly the boost frequencies, which should simply clean 2608 * the cpufreq pressure value. 2609 */ 2610 if (max_freq <= capped_freq) { 2611 pressure = 0; 2612 } else { 2613 max_capacity = arch_scale_cpu_capacity(cpu); 2614 pressure = max_capacity - 2615 mult_frac(max_capacity, capped_freq, max_freq); 2616 } 2617 2618 for_each_cpu(cpu, policy->related_cpus) 2619 WRITE_ONCE(per_cpu(cpufreq_pressure, cpu), pressure); 2620 } 2621 2622 /** 2623 * cpufreq_set_policy - Modify cpufreq policy parameters. 2624 * @policy: Policy object to modify. 2625 * @new_gov: Policy governor pointer. 2626 * @new_pol: Policy value (for drivers with built-in governors). 2627 * 2628 * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency 2629 * limits to be set for the policy, update @policy with the verified limits 2630 * values and either invoke the driver's ->setpolicy() callback (if present) or 2631 * carry out a governor update for @policy. That is, run the current governor's 2632 * ->limits() callback (if @new_gov points to the same object as the one in 2633 * @policy) or replace the governor for @policy with @new_gov. 2634 * 2635 * The cpuinfo part of @policy is not updated by this function. 2636 */ 2637 static int cpufreq_set_policy(struct cpufreq_policy *policy, 2638 struct cpufreq_governor *new_gov, 2639 unsigned int new_pol) 2640 { 2641 struct cpufreq_policy_data new_data; 2642 struct cpufreq_governor *old_gov; 2643 int ret; 2644 2645 memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); 2646 new_data.freq_table = policy->freq_table; 2647 new_data.cpu = policy->cpu; 2648 /* 2649 * PM QoS framework collects all the requests from users and provide us 2650 * the final aggregated value here. 2651 */ 2652 new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN); 2653 new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX); 2654 2655 pr_debug("setting new policy for CPU %u: %u - %u kHz\n", 2656 new_data.cpu, new_data.min, new_data.max); 2657 2658 /* 2659 * Verify that the CPU speed can be set within these limits and make sure 2660 * that min <= max. 2661 */ 2662 ret = cpufreq_driver->verify(&new_data); 2663 if (ret) 2664 return ret; 2665 2666 /* 2667 * Resolve policy min/max to available frequencies. It ensures 2668 * no frequency resolution will neither overshoot the requested maximum 2669 * nor undershoot the requested minimum. 2670 */ 2671 policy->min = new_data.min; 2672 policy->max = new_data.max; 2673 policy->min = __resolve_freq(policy, policy->min, CPUFREQ_RELATION_L); 2674 policy->max = __resolve_freq(policy, policy->max, CPUFREQ_RELATION_H); 2675 trace_cpu_frequency_limits(policy); 2676 2677 cpufreq_update_pressure(policy); 2678 2679 policy->cached_target_freq = UINT_MAX; 2680 2681 pr_debug("new min and max freqs are %u - %u kHz\n", 2682 policy->min, policy->max); 2683 2684 if (cpufreq_driver->setpolicy) { 2685 policy->policy = new_pol; 2686 pr_debug("setting range\n"); 2687 return cpufreq_driver->setpolicy(policy); 2688 } 2689 2690 if (new_gov == policy->governor) { 2691 pr_debug("governor limits update\n"); 2692 cpufreq_governor_limits(policy); 2693 return 0; 2694 } 2695 2696 pr_debug("governor switch\n"); 2697 2698 /* save old, working values */ 2699 old_gov = policy->governor; 2700 /* end old governor */ 2701 if (old_gov) { 2702 cpufreq_stop_governor(policy); 2703 cpufreq_exit_governor(policy); 2704 } 2705 2706 /* start new governor */ 2707 policy->governor = new_gov; 2708 ret = cpufreq_init_governor(policy); 2709 if (!ret) { 2710 ret = cpufreq_start_governor(policy); 2711 if (!ret) { 2712 pr_debug("governor change\n"); 2713 return 0; 2714 } 2715 cpufreq_exit_governor(policy); 2716 } 2717 2718 /* new governor failed, so re-start old one */ 2719 pr_debug("starting governor %s failed\n", policy->governor->name); 2720 if (old_gov) { 2721 policy->governor = old_gov; 2722 if (cpufreq_init_governor(policy)) 2723 policy->governor = NULL; 2724 else 2725 cpufreq_start_governor(policy); 2726 } 2727 2728 return ret; 2729 } 2730 2731 /** 2732 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy. 2733 * @cpu: CPU to re-evaluate the policy for. 2734 * 2735 * Update the current frequency for the cpufreq policy of @cpu and use 2736 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the 2737 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback 2738 * for the policy in question, among other things. 2739 */ 2740 void cpufreq_update_policy(unsigned int cpu) 2741 { 2742 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); 2743 2744 if (!policy) 2745 return; 2746 2747 /* 2748 * BIOS might change freq behind our back 2749 * -> ask driver for current freq and notify governors about a change 2750 */ 2751 if (cpufreq_driver->get && has_target() && 2752 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false)))) 2753 goto unlock; 2754 2755 refresh_frequency_limits(policy); 2756 2757 unlock: 2758 cpufreq_cpu_release(policy); 2759 } 2760 EXPORT_SYMBOL(cpufreq_update_policy); 2761 2762 /** 2763 * cpufreq_update_limits - Update policy limits for a given CPU. 2764 * @cpu: CPU to update the policy limits for. 2765 * 2766 * Invoke the driver's ->update_limits callback if present or call 2767 * cpufreq_update_policy() for @cpu. 2768 */ 2769 void cpufreq_update_limits(unsigned int cpu) 2770 { 2771 if (cpufreq_driver->update_limits) 2772 cpufreq_driver->update_limits(cpu); 2773 else 2774 cpufreq_update_policy(cpu); 2775 } 2776 EXPORT_SYMBOL_GPL(cpufreq_update_limits); 2777 2778 /********************************************************************* 2779 * BOOST * 2780 *********************************************************************/ 2781 static int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state) 2782 { 2783 int ret; 2784 2785 if (!policy->freq_table) 2786 return -ENXIO; 2787 2788 ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table); 2789 if (ret) { 2790 pr_err("%s: Policy frequency update failed\n", __func__); 2791 return ret; 2792 } 2793 2794 ret = freq_qos_update_request(policy->max_freq_req, policy->max); 2795 if (ret < 0) 2796 return ret; 2797 2798 return 0; 2799 } 2800 2801 int cpufreq_boost_trigger_state(int state) 2802 { 2803 struct cpufreq_policy *policy; 2804 unsigned long flags; 2805 int ret = 0; 2806 2807 if (cpufreq_driver->boost_enabled == state) 2808 return 0; 2809 2810 write_lock_irqsave(&cpufreq_driver_lock, flags); 2811 cpufreq_driver->boost_enabled = state; 2812 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2813 2814 cpus_read_lock(); 2815 for_each_active_policy(policy) { 2816 policy->boost_enabled = state; 2817 ret = cpufreq_driver->set_boost(policy, state); 2818 if (ret) { 2819 policy->boost_enabled = !policy->boost_enabled; 2820 goto err_reset_state; 2821 } 2822 } 2823 cpus_read_unlock(); 2824 2825 return 0; 2826 2827 err_reset_state: 2828 cpus_read_unlock(); 2829 2830 write_lock_irqsave(&cpufreq_driver_lock, flags); 2831 cpufreq_driver->boost_enabled = !state; 2832 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2833 2834 pr_err("%s: Cannot %s BOOST\n", 2835 __func__, state ? "enable" : "disable"); 2836 2837 return ret; 2838 } 2839 2840 static bool cpufreq_boost_supported(void) 2841 { 2842 return cpufreq_driver->set_boost; 2843 } 2844 2845 static int create_boost_sysfs_file(void) 2846 { 2847 int ret; 2848 2849 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); 2850 if (ret) 2851 pr_err("%s: cannot register global BOOST sysfs file\n", 2852 __func__); 2853 2854 return ret; 2855 } 2856 2857 static void remove_boost_sysfs_file(void) 2858 { 2859 if (cpufreq_boost_supported()) 2860 sysfs_remove_file(cpufreq_global_kobject, &boost.attr); 2861 } 2862 2863 int cpufreq_enable_boost_support(void) 2864 { 2865 if (!cpufreq_driver) 2866 return -EINVAL; 2867 2868 if (cpufreq_boost_supported()) 2869 return 0; 2870 2871 cpufreq_driver->set_boost = cpufreq_boost_set_sw; 2872 2873 /* This will get removed on driver unregister */ 2874 return create_boost_sysfs_file(); 2875 } 2876 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support); 2877 2878 int cpufreq_boost_enabled(void) 2879 { 2880 return cpufreq_driver->boost_enabled; 2881 } 2882 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); 2883 2884 /********************************************************************* 2885 * REGISTER / UNREGISTER CPUFREQ DRIVER * 2886 *********************************************************************/ 2887 static enum cpuhp_state hp_online; 2888 2889 static int cpuhp_cpufreq_online(unsigned int cpu) 2890 { 2891 cpufreq_online(cpu); 2892 2893 return 0; 2894 } 2895 2896 static int cpuhp_cpufreq_offline(unsigned int cpu) 2897 { 2898 cpufreq_offline(cpu); 2899 2900 return 0; 2901 } 2902 2903 /** 2904 * cpufreq_register_driver - register a CPU Frequency driver 2905 * @driver_data: A struct cpufreq_driver containing the values# 2906 * submitted by the CPU Frequency driver. 2907 * 2908 * Registers a CPU Frequency driver to this core code. This code 2909 * returns zero on success, -EEXIST when another driver got here first 2910 * (and isn't unregistered in the meantime). 2911 * 2912 */ 2913 int cpufreq_register_driver(struct cpufreq_driver *driver_data) 2914 { 2915 unsigned long flags; 2916 int ret; 2917 2918 if (cpufreq_disabled()) 2919 return -ENODEV; 2920 2921 /* 2922 * The cpufreq core depends heavily on the availability of device 2923 * structure, make sure they are available before proceeding further. 2924 */ 2925 if (!get_cpu_device(0)) 2926 return -EPROBE_DEFER; 2927 2928 if (!driver_data || !driver_data->verify || !driver_data->init || 2929 !(driver_data->setpolicy || driver_data->target_index || 2930 driver_data->target) || 2931 (driver_data->setpolicy && (driver_data->target_index || 2932 driver_data->target)) || 2933 (!driver_data->get_intermediate != !driver_data->target_intermediate) || 2934 (!driver_data->online != !driver_data->offline) || 2935 (driver_data->adjust_perf && !driver_data->fast_switch)) 2936 return -EINVAL; 2937 2938 pr_debug("trying to register driver %s\n", driver_data->name); 2939 2940 /* Protect against concurrent CPU online/offline. */ 2941 cpus_read_lock(); 2942 2943 write_lock_irqsave(&cpufreq_driver_lock, flags); 2944 if (cpufreq_driver) { 2945 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2946 ret = -EEXIST; 2947 goto out; 2948 } 2949 cpufreq_driver = driver_data; 2950 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 2951 2952 /* 2953 * Mark support for the scheduler's frequency invariance engine for 2954 * drivers that implement target(), target_index() or fast_switch(). 2955 */ 2956 if (!cpufreq_driver->setpolicy) { 2957 static_branch_enable_cpuslocked(&cpufreq_freq_invariance); 2958 pr_debug("supports frequency invariance"); 2959 } 2960 2961 if (driver_data->setpolicy) 2962 driver_data->flags |= CPUFREQ_CONST_LOOPS; 2963 2964 if (cpufreq_boost_supported()) { 2965 ret = create_boost_sysfs_file(); 2966 if (ret) 2967 goto err_null_driver; 2968 } 2969 2970 ret = subsys_interface_register(&cpufreq_interface); 2971 if (ret) 2972 goto err_boost_unreg; 2973 2974 if (unlikely(list_empty(&cpufreq_policy_list))) { 2975 /* if all ->init() calls failed, unregister */ 2976 ret = -ENODEV; 2977 pr_debug("%s: No CPU initialized for driver %s\n", __func__, 2978 driver_data->name); 2979 goto err_if_unreg; 2980 } 2981 2982 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, 2983 "cpufreq:online", 2984 cpuhp_cpufreq_online, 2985 cpuhp_cpufreq_offline); 2986 if (ret < 0) 2987 goto err_if_unreg; 2988 hp_online = ret; 2989 ret = 0; 2990 2991 pr_debug("driver %s up and running\n", driver_data->name); 2992 goto out; 2993 2994 err_if_unreg: 2995 subsys_interface_unregister(&cpufreq_interface); 2996 err_boost_unreg: 2997 remove_boost_sysfs_file(); 2998 err_null_driver: 2999 write_lock_irqsave(&cpufreq_driver_lock, flags); 3000 cpufreq_driver = NULL; 3001 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 3002 out: 3003 cpus_read_unlock(); 3004 return ret; 3005 } 3006 EXPORT_SYMBOL_GPL(cpufreq_register_driver); 3007 3008 /* 3009 * cpufreq_unregister_driver - unregister the current CPUFreq driver 3010 * 3011 * Unregister the current CPUFreq driver. Only call this if you have 3012 * the right to do so, i.e. if you have succeeded in initialising before! 3013 * Returns zero if successful, and -EINVAL if the cpufreq_driver is 3014 * currently not initialised. 3015 */ 3016 void cpufreq_unregister_driver(struct cpufreq_driver *driver) 3017 { 3018 unsigned long flags; 3019 3020 if (WARN_ON(!cpufreq_driver || (driver != cpufreq_driver))) 3021 return; 3022 3023 pr_debug("unregistering driver %s\n", driver->name); 3024 3025 /* Protect against concurrent cpu hotplug */ 3026 cpus_read_lock(); 3027 subsys_interface_unregister(&cpufreq_interface); 3028 remove_boost_sysfs_file(); 3029 static_branch_disable_cpuslocked(&cpufreq_freq_invariance); 3030 cpuhp_remove_state_nocalls_cpuslocked(hp_online); 3031 3032 write_lock_irqsave(&cpufreq_driver_lock, flags); 3033 3034 cpufreq_driver = NULL; 3035 3036 write_unlock_irqrestore(&cpufreq_driver_lock, flags); 3037 cpus_read_unlock(); 3038 } 3039 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); 3040 3041 static int __init cpufreq_core_init(void) 3042 { 3043 struct cpufreq_governor *gov = cpufreq_default_governor(); 3044 struct device *dev_root; 3045 3046 if (cpufreq_disabled()) 3047 return -ENODEV; 3048 3049 dev_root = bus_get_dev_root(&cpu_subsys); 3050 if (dev_root) { 3051 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &dev_root->kobj); 3052 put_device(dev_root); 3053 } 3054 BUG_ON(!cpufreq_global_kobject); 3055 3056 if (!strlen(default_governor)) 3057 strscpy(default_governor, gov->name, CPUFREQ_NAME_LEN); 3058 3059 return 0; 3060 } 3061 module_param(off, int, 0444); 3062 module_param_string(default_governor, default_governor, CPUFREQ_NAME_LEN, 0444); 3063 core_initcall(cpufreq_core_init); 3064