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CommitLineData
1da177e4
LT
1/*
2 * linux/drivers/cpufreq/cpufreq.c
3 *
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
bb176f7d 6 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
1da177e4 7 *
c32b6b8e 8 * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
32ee8c3e 9 * Added handling for CPU hotplug
8ff69732
DJ
10 * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
11 * Fix handling for CPU hotplug -- affected CPUs
c32b6b8e 12 *
1da177e4
LT
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
1da177e4
LT
16 */
17
db701151
VK
18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
5ff0a268 20#include <linux/cpu.h>
1da177e4
LT
21#include <linux/cpufreq.h>
22#include <linux/delay.h>
1da177e4 23#include <linux/device.h>
5ff0a268
VK
24#include <linux/init.h>
25#include <linux/kernel_stat.h>
26#include <linux/module.h>
3fc54d37 27#include <linux/mutex.h>
5ff0a268 28#include <linux/slab.h>
e00e56df 29#include <linux/syscore_ops.h>
5ff0a268 30#include <linux/tick.h>
6f4f2723
TR
31#include <trace/events/power.h>
32
1da177e4 33/**
cd878479 34 * The "cpufreq driver" - the arch- or hardware-dependent low
1da177e4
LT
35 * level driver of CPUFreq support, and its spinlock. This lock
36 * also protects the cpufreq_cpu_data array.
37 */
1c3d85dd 38static struct cpufreq_driver *cpufreq_driver;
7a6aedfa 39static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
8414809c 40static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback);
bb176f7d
VK
41static DEFINE_RWLOCK(cpufreq_driver_lock);
42static DEFINE_MUTEX(cpufreq_governor_lock);
c88a1f8b 43static LIST_HEAD(cpufreq_policy_list);
bb176f7d 44
084f3493
TR
45#ifdef CONFIG_HOTPLUG_CPU
46/* This one keeps track of the previously set governor of a removed CPU */
e77b89f1 47static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
084f3493 48#endif
1da177e4 49
9c0ebcf7
VK
50static inline bool has_target(void)
51{
52 return cpufreq_driver->target_index || cpufreq_driver->target;
53}
54
6eed9404
VK
55/*
56 * rwsem to guarantee that cpufreq driver module doesn't unload during critical
57 * sections
58 */
59static DECLARE_RWSEM(cpufreq_rwsem);
60
1da177e4 61/* internal prototypes */
29464f28
DJ
62static int __cpufreq_governor(struct cpufreq_policy *policy,
63 unsigned int event);
5a01f2e8 64static unsigned int __cpufreq_get(unsigned int cpu);
65f27f38 65static void handle_update(struct work_struct *work);
1da177e4
LT
66
67/**
32ee8c3e
DJ
68 * Two notifier lists: the "policy" list is involved in the
69 * validation process for a new CPU frequency policy; the
1da177e4
LT
70 * "transition" list for kernel code that needs to handle
71 * changes to devices when the CPU clock speed changes.
72 * The mutex locks both lists.
73 */
e041c683 74static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
b4dfdbb3 75static struct srcu_notifier_head cpufreq_transition_notifier_list;
1da177e4 76
74212ca4 77static bool init_cpufreq_transition_notifier_list_called;
b4dfdbb3
AS
78static int __init init_cpufreq_transition_notifier_list(void)
79{
80 srcu_init_notifier_head(&cpufreq_transition_notifier_list);
74212ca4 81 init_cpufreq_transition_notifier_list_called = true;
b4dfdbb3
AS
82 return 0;
83}
b3438f82 84pure_initcall(init_cpufreq_transition_notifier_list);
1da177e4 85
a7b422cd 86static int off __read_mostly;
da584455 87static int cpufreq_disabled(void)
a7b422cd
KRW
88{
89 return off;
90}
91void disable_cpufreq(void)
92{
93 off = 1;
94}
1da177e4 95static LIST_HEAD(cpufreq_governor_list);
29464f28 96static DEFINE_MUTEX(cpufreq_governor_mutex);
1da177e4 97
4d5dcc42
VK
98bool have_governor_per_policy(void)
99{
0b981e70 100 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
4d5dcc42 101}
3f869d6d 102EXPORT_SYMBOL_GPL(have_governor_per_policy);
4d5dcc42 103
944e9a03
VK
104struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
105{
106 if (have_governor_per_policy())
107 return &policy->kobj;
108 else
109 return cpufreq_global_kobject;
110}
111EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
112
72a4ce34
VK
113static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
114{
115 u64 idle_time;
116 u64 cur_wall_time;
117 u64 busy_time;
118
119 cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
120
121 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
122 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
123 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
124 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
125 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
126 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
127
128 idle_time = cur_wall_time - busy_time;
129 if (wall)
130 *wall = cputime_to_usecs(cur_wall_time);
131
132 return cputime_to_usecs(idle_time);
133}
134
135u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
136{
137 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
138
139 if (idle_time == -1ULL)
140 return get_cpu_idle_time_jiffy(cpu, wall);
141 else if (!io_busy)
142 idle_time += get_cpu_iowait_time_us(cpu, wall);
143
144 return idle_time;
145}
146EXPORT_SYMBOL_GPL(get_cpu_idle_time);
147
70e9e778
VK
148/*
149 * This is a generic cpufreq init() routine which can be used by cpufreq
150 * drivers of SMP systems. It will do following:
151 * - validate & show freq table passed
152 * - set policies transition latency
153 * - policy->cpus with all possible CPUs
154 */
155int cpufreq_generic_init(struct cpufreq_policy *policy,
156 struct cpufreq_frequency_table *table,
157 unsigned int transition_latency)
158{
159 int ret;
160
161 ret = cpufreq_table_validate_and_show(policy, table);
162 if (ret) {
163 pr_err("%s: invalid frequency table: %d\n", __func__, ret);
164 return ret;
165 }
166
167 policy->cpuinfo.transition_latency = transition_latency;
168
169 /*
170 * The driver only supports the SMP configuartion where all processors
171 * share the clock and voltage and clock.
172 */
173 cpumask_setall(policy->cpus);
174
175 return 0;
176}
177EXPORT_SYMBOL_GPL(cpufreq_generic_init);
178
6eed9404 179struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
1da177e4 180{
6eed9404 181 struct cpufreq_policy *policy = NULL;
1da177e4
LT
182 unsigned long flags;
183
6eed9404
VK
184 if (cpufreq_disabled() || (cpu >= nr_cpu_ids))
185 return NULL;
186
187 if (!down_read_trylock(&cpufreq_rwsem))
188 return NULL;
1da177e4
LT
189
190 /* get the cpufreq driver */
1c3d85dd 191 read_lock_irqsave(&cpufreq_driver_lock, flags);
1da177e4 192
6eed9404
VK
193 if (cpufreq_driver) {
194 /* get the CPU */
195 policy = per_cpu(cpufreq_cpu_data, cpu);
196 if (policy)
197 kobject_get(&policy->kobj);
198 }
1da177e4 199
6eed9404 200 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1da177e4 201
3a3e9e06 202 if (!policy)
6eed9404 203 up_read(&cpufreq_rwsem);
1da177e4 204
3a3e9e06 205 return policy;
a9144436 206}
1da177e4
LT
207EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
208
3a3e9e06 209void cpufreq_cpu_put(struct cpufreq_policy *policy)
1da177e4 210{
d5aaffa9
DB
211 if (cpufreq_disabled())
212 return;
213
6eed9404
VK
214 kobject_put(&policy->kobj);
215 up_read(&cpufreq_rwsem);
1da177e4
LT
216}
217EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
218
1da177e4
LT
219/*********************************************************************
220 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
221 *********************************************************************/
222
223/**
224 * adjust_jiffies - adjust the system "loops_per_jiffy"
225 *
226 * This function alters the system "loops_per_jiffy" for the clock
227 * speed change. Note that loops_per_jiffy cannot be updated on SMP
32ee8c3e 228 * systems as each CPU might be scaled differently. So, use the arch
1da177e4
LT
229 * per-CPU loops_per_jiffy value wherever possible.
230 */
231#ifndef CONFIG_SMP
232static unsigned long l_p_j_ref;
bb176f7d 233static unsigned int l_p_j_ref_freq;
1da177e4 234
858119e1 235static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
1da177e4
LT
236{
237 if (ci->flags & CPUFREQ_CONST_LOOPS)
238 return;
239
240 if (!l_p_j_ref_freq) {
241 l_p_j_ref = loops_per_jiffy;
242 l_p_j_ref_freq = ci->old;
2d06d8c4 243 pr_debug("saving %lu as reference value for loops_per_jiffy; "
e08f5f5b 244 "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq);
1da177e4 245 }
bb176f7d 246 if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) ||
42d4dc3f 247 (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) {
e08f5f5b
GS
248 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
249 ci->new);
2d06d8c4 250 pr_debug("scaling loops_per_jiffy to %lu "
e08f5f5b 251 "for frequency %u kHz\n", loops_per_jiffy, ci->new);
1da177e4
LT
252 }
253}
254#else
e08f5f5b
GS
255static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
256{
257 return;
258}
1da177e4
LT
259#endif
260
0956df9c 261static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
b43a7ffb 262 struct cpufreq_freqs *freqs, unsigned int state)
1da177e4
LT
263{
264 BUG_ON(irqs_disabled());
265
d5aaffa9
DB
266 if (cpufreq_disabled())
267 return;
268
1c3d85dd 269 freqs->flags = cpufreq_driver->flags;
2d06d8c4 270 pr_debug("notification %u of frequency transition to %u kHz\n",
e4472cb3 271 state, freqs->new);
1da177e4 272
1da177e4 273 switch (state) {
e4472cb3 274
1da177e4 275 case CPUFREQ_PRECHANGE:
32ee8c3e 276 /* detect if the driver reported a value as "old frequency"
e4472cb3
DJ
277 * which is not equal to what the cpufreq core thinks is
278 * "old frequency".
1da177e4 279 */
1c3d85dd 280 if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
e4472cb3
DJ
281 if ((policy) && (policy->cpu == freqs->cpu) &&
282 (policy->cur) && (policy->cur != freqs->old)) {
2d06d8c4 283 pr_debug("Warning: CPU frequency is"
e4472cb3
DJ
284 " %u, cpufreq assumed %u kHz.\n",
285 freqs->old, policy->cur);
286 freqs->old = policy->cur;
1da177e4
LT
287 }
288 }
b4dfdbb3 289 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
e041c683 290 CPUFREQ_PRECHANGE, freqs);
1da177e4
LT
291 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
292 break;
e4472cb3 293
1da177e4
LT
294 case CPUFREQ_POSTCHANGE:
295 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
2d06d8c4 296 pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new,
6f4f2723 297 (unsigned long)freqs->cpu);
25e41933 298 trace_cpu_frequency(freqs->new, freqs->cpu);
b4dfdbb3 299 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
e041c683 300 CPUFREQ_POSTCHANGE, freqs);
e4472cb3
DJ
301 if (likely(policy) && likely(policy->cpu == freqs->cpu))
302 policy->cur = freqs->new;
1da177e4
LT
303 break;
304 }
1da177e4 305}
bb176f7d 306
b43a7ffb
VK
307/**
308 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
309 * on frequency transition.
310 *
311 * This function calls the transition notifiers and the "adjust_jiffies"
312 * function. It is called twice on all CPU frequency changes that have
313 * external effects.
314 */
315void cpufreq_notify_transition(struct cpufreq_policy *policy,
316 struct cpufreq_freqs *freqs, unsigned int state)
317{
318 for_each_cpu(freqs->cpu, policy->cpus)
319 __cpufreq_notify_transition(policy, freqs, state);
320}
1da177e4
LT
321EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
322
323
1da177e4
LT
324/*********************************************************************
325 * SYSFS INTERFACE *
326 *********************************************************************/
327
3bcb09a3
JF
328static struct cpufreq_governor *__find_governor(const char *str_governor)
329{
330 struct cpufreq_governor *t;
331
332 list_for_each_entry(t, &cpufreq_governor_list, governor_list)
29464f28 333 if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN))
3bcb09a3
JF
334 return t;
335
336 return NULL;
337}
338
1da177e4
LT
339/**
340 * cpufreq_parse_governor - parse a governor string
341 */
905d77cd 342static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
1da177e4
LT
343 struct cpufreq_governor **governor)
344{
3bcb09a3 345 int err = -EINVAL;
1c3d85dd
RW
346
347 if (!cpufreq_driver)
3bcb09a3
JF
348 goto out;
349
1c3d85dd 350 if (cpufreq_driver->setpolicy) {
1da177e4
LT
351 if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
352 *policy = CPUFREQ_POLICY_PERFORMANCE;
3bcb09a3 353 err = 0;
e08f5f5b
GS
354 } else if (!strnicmp(str_governor, "powersave",
355 CPUFREQ_NAME_LEN)) {
1da177e4 356 *policy = CPUFREQ_POLICY_POWERSAVE;
3bcb09a3 357 err = 0;
1da177e4 358 }
9c0ebcf7 359 } else if (has_target()) {
1da177e4 360 struct cpufreq_governor *t;
3bcb09a3 361
3fc54d37 362 mutex_lock(&cpufreq_governor_mutex);
3bcb09a3
JF
363
364 t = __find_governor(str_governor);
365
ea714970 366 if (t == NULL) {
1a8e1463 367 int ret;
ea714970 368
1a8e1463
KC
369 mutex_unlock(&cpufreq_governor_mutex);
370 ret = request_module("cpufreq_%s", str_governor);
371 mutex_lock(&cpufreq_governor_mutex);
ea714970 372
1a8e1463
KC
373 if (ret == 0)
374 t = __find_governor(str_governor);
ea714970
JF
375 }
376
3bcb09a3
JF
377 if (t != NULL) {
378 *governor = t;
379 err = 0;
1da177e4 380 }
3bcb09a3 381
3fc54d37 382 mutex_unlock(&cpufreq_governor_mutex);
1da177e4 383 }
29464f28 384out:
3bcb09a3 385 return err;
1da177e4 386}
1da177e4 387
1da177e4 388/**
e08f5f5b
GS
389 * cpufreq_per_cpu_attr_read() / show_##file_name() -
390 * print out cpufreq information
1da177e4
LT
391 *
392 * Write out information from cpufreq_driver->policy[cpu]; object must be
393 * "unsigned int".
394 */
395
32ee8c3e
DJ
396#define show_one(file_name, object) \
397static ssize_t show_##file_name \
905d77cd 398(struct cpufreq_policy *policy, char *buf) \
32ee8c3e 399{ \
29464f28 400 return sprintf(buf, "%u\n", policy->object); \
1da177e4
LT
401}
402
403show_one(cpuinfo_min_freq, cpuinfo.min_freq);
404show_one(cpuinfo_max_freq, cpuinfo.max_freq);
ed129784 405show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
1da177e4
LT
406show_one(scaling_min_freq, min);
407show_one(scaling_max_freq, max);
408show_one(scaling_cur_freq, cur);
409
037ce839 410static int cpufreq_set_policy(struct cpufreq_policy *policy,
3a3e9e06 411 struct cpufreq_policy *new_policy);
7970e08b 412
1da177e4
LT
413/**
414 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
415 */
416#define store_one(file_name, object) \
417static ssize_t store_##file_name \
905d77cd 418(struct cpufreq_policy *policy, const char *buf, size_t count) \
1da177e4 419{ \
5136fa56 420 int ret; \
1da177e4
LT
421 struct cpufreq_policy new_policy; \
422 \
423 ret = cpufreq_get_policy(&new_policy, policy->cpu); \
424 if (ret) \
425 return -EINVAL; \
426 \
29464f28 427 ret = sscanf(buf, "%u", &new_policy.object); \
1da177e4
LT
428 if (ret != 1) \
429 return -EINVAL; \
430 \
037ce839 431 ret = cpufreq_set_policy(policy, &new_policy); \
7970e08b 432 policy->user_policy.object = policy->object; \
1da177e4
LT
433 \
434 return ret ? ret : count; \
435}
436
29464f28
DJ
437store_one(scaling_min_freq, min);
438store_one(scaling_max_freq, max);
1da177e4
LT
439
440/**
441 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
442 */
905d77cd
DJ
443static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
444 char *buf)
1da177e4 445{
5a01f2e8 446 unsigned int cur_freq = __cpufreq_get(policy->cpu);
1da177e4
LT
447 if (!cur_freq)
448 return sprintf(buf, "<unknown>");
449 return sprintf(buf, "%u\n", cur_freq);
450}
451
1da177e4
LT
452/**
453 * show_scaling_governor - show the current policy for the specified CPU
454 */
905d77cd 455static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
1da177e4 456{
29464f28 457 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
1da177e4
LT
458 return sprintf(buf, "powersave\n");
459 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
460 return sprintf(buf, "performance\n");
461 else if (policy->governor)
4b972f0b 462 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
29464f28 463 policy->governor->name);
1da177e4
LT
464 return -EINVAL;
465}
466
1da177e4
LT
467/**
468 * store_scaling_governor - store policy for the specified CPU
469 */
905d77cd
DJ
470static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
471 const char *buf, size_t count)
1da177e4 472{
5136fa56 473 int ret;
1da177e4
LT
474 char str_governor[16];
475 struct cpufreq_policy new_policy;
476
477 ret = cpufreq_get_policy(&new_policy, policy->cpu);
478 if (ret)
479 return ret;
480
29464f28 481 ret = sscanf(buf, "%15s", str_governor);
1da177e4
LT
482 if (ret != 1)
483 return -EINVAL;
484
e08f5f5b
GS
485 if (cpufreq_parse_governor(str_governor, &new_policy.policy,
486 &new_policy.governor))
1da177e4
LT
487 return -EINVAL;
488
037ce839 489 ret = cpufreq_set_policy(policy, &new_policy);
7970e08b
TR
490
491 policy->user_policy.policy = policy->policy;
492 policy->user_policy.governor = policy->governor;
7970e08b 493
e08f5f5b
GS
494 if (ret)
495 return ret;
496 else
497 return count;
1da177e4
LT
498}
499
500/**
501 * show_scaling_driver - show the cpufreq driver currently loaded
502 */
905d77cd 503static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
1da177e4 504{
1c3d85dd 505 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
1da177e4
LT
506}
507
508/**
509 * show_scaling_available_governors - show the available CPUfreq governors
510 */
905d77cd
DJ
511static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
512 char *buf)
1da177e4
LT
513{
514 ssize_t i = 0;
515 struct cpufreq_governor *t;
516
9c0ebcf7 517 if (!has_target()) {
1da177e4
LT
518 i += sprintf(buf, "performance powersave");
519 goto out;
520 }
521
522 list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
29464f28
DJ
523 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
524 - (CPUFREQ_NAME_LEN + 2)))
1da177e4 525 goto out;
4b972f0b 526 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
1da177e4 527 }
7d5e350f 528out:
1da177e4
LT
529 i += sprintf(&buf[i], "\n");
530 return i;
531}
e8628dd0 532
f4fd3797 533ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
1da177e4
LT
534{
535 ssize_t i = 0;
536 unsigned int cpu;
537
835481d9 538 for_each_cpu(cpu, mask) {
1da177e4
LT
539 if (i)
540 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
541 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
542 if (i >= (PAGE_SIZE - 5))
29464f28 543 break;
1da177e4
LT
544 }
545 i += sprintf(&buf[i], "\n");
546 return i;
547}
f4fd3797 548EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
1da177e4 549
e8628dd0
DW
550/**
551 * show_related_cpus - show the CPUs affected by each transition even if
552 * hw coordination is in use
553 */
554static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
555{
f4fd3797 556 return cpufreq_show_cpus(policy->related_cpus, buf);
e8628dd0
DW
557}
558
559/**
560 * show_affected_cpus - show the CPUs affected by each transition
561 */
562static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
563{
f4fd3797 564 return cpufreq_show_cpus(policy->cpus, buf);
e8628dd0
DW
565}
566
9e76988e 567static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
905d77cd 568 const char *buf, size_t count)
9e76988e
VP
569{
570 unsigned int freq = 0;
571 unsigned int ret;
572
879000f9 573 if (!policy->governor || !policy->governor->store_setspeed)
9e76988e
VP
574 return -EINVAL;
575
576 ret = sscanf(buf, "%u", &freq);
577 if (ret != 1)
578 return -EINVAL;
579
580 policy->governor->store_setspeed(policy, freq);
581
582 return count;
583}
584
585static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
586{
879000f9 587 if (!policy->governor || !policy->governor->show_setspeed)
9e76988e
VP
588 return sprintf(buf, "<unsupported>\n");
589
590 return policy->governor->show_setspeed(policy, buf);
591}
1da177e4 592
e2f74f35 593/**
8bf1ac72 594 * show_bios_limit - show the current cpufreq HW/BIOS limitation
e2f74f35
TR
595 */
596static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
597{
598 unsigned int limit;
599 int ret;
1c3d85dd
RW
600 if (cpufreq_driver->bios_limit) {
601 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
e2f74f35
TR
602 if (!ret)
603 return sprintf(buf, "%u\n", limit);
604 }
605 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
606}
607
6dad2a29
BP
608cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
609cpufreq_freq_attr_ro(cpuinfo_min_freq);
610cpufreq_freq_attr_ro(cpuinfo_max_freq);
611cpufreq_freq_attr_ro(cpuinfo_transition_latency);
612cpufreq_freq_attr_ro(scaling_available_governors);
613cpufreq_freq_attr_ro(scaling_driver);
614cpufreq_freq_attr_ro(scaling_cur_freq);
615cpufreq_freq_attr_ro(bios_limit);
616cpufreq_freq_attr_ro(related_cpus);
617cpufreq_freq_attr_ro(affected_cpus);
618cpufreq_freq_attr_rw(scaling_min_freq);
619cpufreq_freq_attr_rw(scaling_max_freq);
620cpufreq_freq_attr_rw(scaling_governor);
621cpufreq_freq_attr_rw(scaling_setspeed);
1da177e4 622
905d77cd 623static struct attribute *default_attrs[] = {
1da177e4
LT
624 &cpuinfo_min_freq.attr,
625 &cpuinfo_max_freq.attr,
ed129784 626 &cpuinfo_transition_latency.attr,
1da177e4
LT
627 &scaling_min_freq.attr,
628 &scaling_max_freq.attr,
629 &affected_cpus.attr,
e8628dd0 630 &related_cpus.attr,
1da177e4
LT
631 &scaling_governor.attr,
632 &scaling_driver.attr,
633 &scaling_available_governors.attr,
9e76988e 634 &scaling_setspeed.attr,
1da177e4
LT
635 NULL
636};
637
29464f28
DJ
638#define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
639#define to_attr(a) container_of(a, struct freq_attr, attr)
1da177e4 640
29464f28 641static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
1da177e4 642{
905d77cd
DJ
643 struct cpufreq_policy *policy = to_policy(kobj);
644 struct freq_attr *fattr = to_attr(attr);
1b750e3b 645 ssize_t ret;
6eed9404
VK
646
647 if (!down_read_trylock(&cpufreq_rwsem))
1b750e3b 648 return -EINVAL;
5a01f2e8 649
ad7722da 650 down_read(&policy->rwsem);
5a01f2e8 651
e08f5f5b
GS
652 if (fattr->show)
653 ret = fattr->show(policy, buf);
654 else
655 ret = -EIO;
656
ad7722da 657 up_read(&policy->rwsem);
6eed9404 658 up_read(&cpufreq_rwsem);
1b750e3b 659
1da177e4
LT
660 return ret;
661}
662
905d77cd
DJ
663static ssize_t store(struct kobject *kobj, struct attribute *attr,
664 const char *buf, size_t count)
1da177e4 665{
905d77cd
DJ
666 struct cpufreq_policy *policy = to_policy(kobj);
667 struct freq_attr *fattr = to_attr(attr);
a07530b4 668 ssize_t ret = -EINVAL;
6eed9404 669
4f750c93
SB
670 get_online_cpus();
671
672 if (!cpu_online(policy->cpu))
673 goto unlock;
674
6eed9404 675 if (!down_read_trylock(&cpufreq_rwsem))
4f750c93 676 goto unlock;
5a01f2e8 677
ad7722da 678 down_write(&policy->rwsem);
5a01f2e8 679
e08f5f5b
GS
680 if (fattr->store)
681 ret = fattr->store(policy, buf, count);
682 else
683 ret = -EIO;
684
ad7722da 685 up_write(&policy->rwsem);
6eed9404 686
6eed9404 687 up_read(&cpufreq_rwsem);
4f750c93
SB
688unlock:
689 put_online_cpus();
690
1da177e4
LT
691 return ret;
692}
693
905d77cd 694static void cpufreq_sysfs_release(struct kobject *kobj)
1da177e4 695{
905d77cd 696 struct cpufreq_policy *policy = to_policy(kobj);
2d06d8c4 697 pr_debug("last reference is dropped\n");
1da177e4
LT
698 complete(&policy->kobj_unregister);
699}
700
52cf25d0 701static const struct sysfs_ops sysfs_ops = {
1da177e4
LT
702 .show = show,
703 .store = store,
704};
705
706static struct kobj_type ktype_cpufreq = {
707 .sysfs_ops = &sysfs_ops,
708 .default_attrs = default_attrs,
709 .release = cpufreq_sysfs_release,
710};
711
2361be23
VK
712struct kobject *cpufreq_global_kobject;
713EXPORT_SYMBOL(cpufreq_global_kobject);
714
715static int cpufreq_global_kobject_usage;
716
717int cpufreq_get_global_kobject(void)
718{
719 if (!cpufreq_global_kobject_usage++)
720 return kobject_add(cpufreq_global_kobject,
721 &cpu_subsys.dev_root->kobj, "%s", "cpufreq");
722
723 return 0;
724}
725EXPORT_SYMBOL(cpufreq_get_global_kobject);
726
727void cpufreq_put_global_kobject(void)
728{
729 if (!--cpufreq_global_kobject_usage)
730 kobject_del(cpufreq_global_kobject);
731}
732EXPORT_SYMBOL(cpufreq_put_global_kobject);
733
734int cpufreq_sysfs_create_file(const struct attribute *attr)
735{
736 int ret = cpufreq_get_global_kobject();
737
738 if (!ret) {
739 ret = sysfs_create_file(cpufreq_global_kobject, attr);
740 if (ret)
741 cpufreq_put_global_kobject();
742 }
743
744 return ret;
745}
746EXPORT_SYMBOL(cpufreq_sysfs_create_file);
747
748void cpufreq_sysfs_remove_file(const struct attribute *attr)
749{
750 sysfs_remove_file(cpufreq_global_kobject, attr);
751 cpufreq_put_global_kobject();
752}
753EXPORT_SYMBOL(cpufreq_sysfs_remove_file);
754
19d6f7ec 755/* symlink affected CPUs */
308b60e7 756static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy)
19d6f7ec
DJ
757{
758 unsigned int j;
759 int ret = 0;
760
761 for_each_cpu(j, policy->cpus) {
8a25a2fd 762 struct device *cpu_dev;
19d6f7ec 763
308b60e7 764 if (j == policy->cpu)
19d6f7ec 765 continue;
19d6f7ec 766
e8fdde10 767 pr_debug("Adding link for CPU: %u\n", j);
8a25a2fd
KS
768 cpu_dev = get_cpu_device(j);
769 ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
19d6f7ec 770 "cpufreq");
71c3461e
RW
771 if (ret)
772 break;
19d6f7ec
DJ
773 }
774 return ret;
775}
776
308b60e7 777static int cpufreq_add_dev_interface(struct cpufreq_policy *policy,
8a25a2fd 778 struct device *dev)
909a694e
DJ
779{
780 struct freq_attr **drv_attr;
909a694e 781 int ret = 0;
909a694e
DJ
782
783 /* prepare interface data */
784 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
8a25a2fd 785 &dev->kobj, "cpufreq");
909a694e
DJ
786 if (ret)
787 return ret;
788
789 /* set up files for this cpu device */
1c3d85dd 790 drv_attr = cpufreq_driver->attr;
909a694e
DJ
791 while ((drv_attr) && (*drv_attr)) {
792 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
793 if (ret)
1c3d85dd 794 goto err_out_kobj_put;
909a694e
DJ
795 drv_attr++;
796 }
1c3d85dd 797 if (cpufreq_driver->get) {
909a694e
DJ
798 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
799 if (ret)
1c3d85dd 800 goto err_out_kobj_put;
909a694e 801 }
9c0ebcf7 802 if (has_target()) {
909a694e
DJ
803 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
804 if (ret)
1c3d85dd 805 goto err_out_kobj_put;
909a694e 806 }
1c3d85dd 807 if (cpufreq_driver->bios_limit) {
e2f74f35
TR
808 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
809 if (ret)
1c3d85dd 810 goto err_out_kobj_put;
e2f74f35 811 }
909a694e 812
308b60e7 813 ret = cpufreq_add_dev_symlink(policy);
ecf7e461
DJ
814 if (ret)
815 goto err_out_kobj_put;
816
e18f1682
SB
817 return ret;
818
819err_out_kobj_put:
820 kobject_put(&policy->kobj);
821 wait_for_completion(&policy->kobj_unregister);
822 return ret;
823}
824
825static void cpufreq_init_policy(struct cpufreq_policy *policy)
826{
827 struct cpufreq_policy new_policy;
828 int ret = 0;
829
d5b73cd8 830 memcpy(&new_policy, policy, sizeof(*policy));
037ce839 831 /* assure that the starting sequence is run in cpufreq_set_policy */
ecf7e461
DJ
832 policy->governor = NULL;
833
834 /* set default policy */
037ce839 835 ret = cpufreq_set_policy(policy, &new_policy);
ecf7e461
DJ
836 policy->user_policy.policy = policy->policy;
837 policy->user_policy.governor = policy->governor;
838
839 if (ret) {
2d06d8c4 840 pr_debug("setting policy failed\n");
1c3d85dd
RW
841 if (cpufreq_driver->exit)
842 cpufreq_driver->exit(policy);
ecf7e461 843 }
909a694e
DJ
844}
845
fcf80582 846#ifdef CONFIG_HOTPLUG_CPU
d8d3b471
VK
847static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
848 unsigned int cpu, struct device *dev,
849 bool frozen)
fcf80582 850{
9c0ebcf7 851 int ret = 0;
fcf80582
VK
852 unsigned long flags;
853
9c0ebcf7 854 if (has_target()) {
3de9bdeb
VK
855 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
856 if (ret) {
857 pr_err("%s: Failed to stop governor\n", __func__);
858 return ret;
859 }
860 }
fcf80582 861
ad7722da 862 down_write(&policy->rwsem);
2eaa3e2d 863
0d1857a1 864 write_lock_irqsave(&cpufreq_driver_lock, flags);
2eaa3e2d 865
fcf80582
VK
866 cpumask_set_cpu(cpu, policy->cpus);
867 per_cpu(cpufreq_cpu_data, cpu) = policy;
0d1857a1 868 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
fcf80582 869
ad7722da 870 up_write(&policy->rwsem);
2eaa3e2d 871
9c0ebcf7 872 if (has_target()) {
3de9bdeb
VK
873 if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
874 (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
875 pr_err("%s: Failed to start governor\n", __func__);
876 return ret;
877 }
820c6ca2 878 }
fcf80582 879
a82fab29 880 /* Don't touch sysfs links during light-weight init */
71c3461e
RW
881 if (!frozen)
882 ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
a82fab29
SB
883
884 return ret;
fcf80582
VK
885}
886#endif
1da177e4 887
8414809c
SB
888static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
889{
890 struct cpufreq_policy *policy;
891 unsigned long flags;
892
44871c9c 893 read_lock_irqsave(&cpufreq_driver_lock, flags);
8414809c
SB
894
895 policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
896
44871c9c 897 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
8414809c
SB
898
899 return policy;
900}
901
e9698cc5
SB
902static struct cpufreq_policy *cpufreq_policy_alloc(void)
903{
904 struct cpufreq_policy *policy;
905
906 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
907 if (!policy)
908 return NULL;
909
910 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
911 goto err_free_policy;
912
913 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
914 goto err_free_cpumask;
915
c88a1f8b 916 INIT_LIST_HEAD(&policy->policy_list);
ad7722da 917 init_rwsem(&policy->rwsem);
918
e9698cc5
SB
919 return policy;
920
921err_free_cpumask:
922 free_cpumask_var(policy->cpus);
923err_free_policy:
924 kfree(policy);
925
926 return NULL;
927}
928
929static void cpufreq_policy_free(struct cpufreq_policy *policy)
930{
931 free_cpumask_var(policy->related_cpus);
932 free_cpumask_var(policy->cpus);
933 kfree(policy);
934}
935
0d66b91e
SB
936static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
937{
99ec899e 938 if (WARN_ON(cpu == policy->cpu))
cb38ed5c
SB
939 return;
940
ad7722da 941 down_write(&policy->rwsem);
8efd5765 942
0d66b91e
SB
943 policy->last_cpu = policy->cpu;
944 policy->cpu = cpu;
945
ad7722da 946 up_write(&policy->rwsem);
8efd5765 947
0d66b91e 948 cpufreq_frequency_table_update_policy_cpu(policy);
0d66b91e
SB
949 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
950 CPUFREQ_UPDATE_POLICY_CPU, policy);
951}
952
a82fab29
SB
953static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
954 bool frozen)
1da177e4 955{
fcf80582 956 unsigned int j, cpu = dev->id;
65922465 957 int ret = -ENOMEM;
1da177e4 958 struct cpufreq_policy *policy;
1da177e4 959 unsigned long flags;
90e41bac 960#ifdef CONFIG_HOTPLUG_CPU
1b274294 961 struct cpufreq_policy *tpolicy;
fcf80582 962 struct cpufreq_governor *gov;
90e41bac 963#endif
1da177e4 964
c32b6b8e
AR
965 if (cpu_is_offline(cpu))
966 return 0;
967
2d06d8c4 968 pr_debug("adding CPU %u\n", cpu);
1da177e4
LT
969
970#ifdef CONFIG_SMP
971 /* check whether a different CPU already registered this
972 * CPU because it is in the same boat. */
973 policy = cpufreq_cpu_get(cpu);
974 if (unlikely(policy)) {
8ff69732 975 cpufreq_cpu_put(policy);
1da177e4
LT
976 return 0;
977 }
5025d628 978#endif
fcf80582 979
6eed9404
VK
980 if (!down_read_trylock(&cpufreq_rwsem))
981 return 0;
982
fcf80582
VK
983#ifdef CONFIG_HOTPLUG_CPU
984 /* Check if this cpu was hot-unplugged earlier and has siblings */
0d1857a1 985 read_lock_irqsave(&cpufreq_driver_lock, flags);
1b274294
VK
986 list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) {
987 if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) {
0d1857a1 988 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1b274294 989 ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev, frozen);
6eed9404
VK
990 up_read(&cpufreq_rwsem);
991 return ret;
2eaa3e2d 992 }
fcf80582 993 }
0d1857a1 994 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1da177e4
LT
995#endif
996
8414809c
SB
997 if (frozen)
998 /* Restore the saved policy when doing light-weight init */
999 policy = cpufreq_policy_restore(cpu);
1000 else
1001 policy = cpufreq_policy_alloc();
1002
059019a3 1003 if (!policy)
1da177e4 1004 goto nomem_out;
059019a3 1005
0d66b91e
SB
1006
1007 /*
1008 * In the resume path, since we restore a saved policy, the assignment
1009 * to policy->cpu is like an update of the existing policy, rather than
1010 * the creation of a brand new one. So we need to perform this update
1011 * by invoking update_policy_cpu().
1012 */
1013 if (frozen && cpu != policy->cpu)
1014 update_policy_cpu(policy, cpu);
1015 else
1016 policy->cpu = cpu;
1017
65922465 1018 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
835481d9 1019 cpumask_copy(policy->cpus, cpumask_of(cpu));
1da177e4 1020
1da177e4 1021 init_completion(&policy->kobj_unregister);
65f27f38 1022 INIT_WORK(&policy->update, handle_update);
1da177e4
LT
1023
1024 /* call driver. From then on the cpufreq must be able
1025 * to accept all calls to ->verify and ->setpolicy for this CPU
1026 */
1c3d85dd 1027 ret = cpufreq_driver->init(policy);
1da177e4 1028 if (ret) {
2d06d8c4 1029 pr_debug("initialization failed\n");
2eaa3e2d 1030 goto err_set_policy_cpu;
1da177e4 1031 }
643ae6e8 1032
da60ce9f
VK
1033 if (cpufreq_driver->get) {
1034 policy->cur = cpufreq_driver->get(policy->cpu);
1035 if (!policy->cur) {
1036 pr_err("%s: ->get() failed\n", __func__);
1037 goto err_get_freq;
1038 }
1039 }
1040
fcf80582
VK
1041 /* related cpus should atleast have policy->cpus */
1042 cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
1043
643ae6e8
VK
1044 /*
1045 * affected cpus must always be the one, which are online. We aren't
1046 * managing offline cpus here.
1047 */
1048 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1049
187d9f4e
MC
1050 policy->user_policy.min = policy->min;
1051 policy->user_policy.max = policy->max;
1da177e4 1052
a1531acd
TR
1053 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1054 CPUFREQ_START, policy);
1055
fcf80582
VK
1056#ifdef CONFIG_HOTPLUG_CPU
1057 gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
1058 if (gov) {
1059 policy->governor = gov;
1060 pr_debug("Restoring governor %s for cpu %d\n",
1061 policy->governor->name, cpu);
4bfa042c 1062 }
fcf80582 1063#endif
1da177e4 1064
e18f1682 1065 write_lock_irqsave(&cpufreq_driver_lock, flags);
474deff7 1066 for_each_cpu(j, policy->cpus)
e18f1682 1067 per_cpu(cpufreq_cpu_data, j) = policy;
e18f1682
SB
1068 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1069
a82fab29 1070 if (!frozen) {
308b60e7 1071 ret = cpufreq_add_dev_interface(policy, dev);
a82fab29
SB
1072 if (ret)
1073 goto err_out_unregister;
1074 }
8ff69732 1075
9515f4d6
VK
1076 write_lock_irqsave(&cpufreq_driver_lock, flags);
1077 list_add(&policy->policy_list, &cpufreq_policy_list);
1078 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1079
e18f1682
SB
1080 cpufreq_init_policy(policy);
1081
038c5b3e 1082 kobject_uevent(&policy->kobj, KOBJ_ADD);
6eed9404
VK
1083 up_read(&cpufreq_rwsem);
1084
2d06d8c4 1085 pr_debug("initialization complete\n");
87c32271 1086
1da177e4
LT
1087 return 0;
1088
1da177e4 1089err_out_unregister:
0d1857a1 1090 write_lock_irqsave(&cpufreq_driver_lock, flags);
474deff7 1091 for_each_cpu(j, policy->cpus)
7a6aedfa 1092 per_cpu(cpufreq_cpu_data, j) = NULL;
0d1857a1 1093 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1da177e4 1094
da60ce9f
VK
1095err_get_freq:
1096 if (cpufreq_driver->exit)
1097 cpufreq_driver->exit(policy);
2eaa3e2d 1098err_set_policy_cpu:
e9698cc5 1099 cpufreq_policy_free(policy);
1da177e4 1100nomem_out:
6eed9404
VK
1101 up_read(&cpufreq_rwsem);
1102
1da177e4
LT
1103 return ret;
1104}
1105
a82fab29
SB
1106/**
1107 * cpufreq_add_dev - add a CPU device
1108 *
1109 * Adds the cpufreq interface for a CPU device.
1110 *
1111 * The Oracle says: try running cpufreq registration/unregistration concurrently
1112 * with with cpu hotplugging and all hell will break loose. Tried to clean this
1113 * mess up, but more thorough testing is needed. - Mathieu
1114 */
1115static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1116{
1117 return __cpufreq_add_dev(dev, sif, false);
1118}
1119
3a3e9e06 1120static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
a82fab29 1121 unsigned int old_cpu, bool frozen)
f9ba680d
SB
1122{
1123 struct device *cpu_dev;
f9ba680d
SB
1124 int ret;
1125
1126 /* first sibling now owns the new sysfs dir */
9c8f1ee4 1127 cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu));
a82fab29
SB
1128
1129 /* Don't touch sysfs files during light-weight tear-down */
1130 if (frozen)
1131 return cpu_dev->id;
1132
f9ba680d 1133 sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
3a3e9e06 1134 ret = kobject_move(&policy->kobj, &cpu_dev->kobj);
f9ba680d
SB
1135 if (ret) {
1136 pr_err("%s: Failed to move kobj: %d", __func__, ret);
1137
ad7722da 1138 down_write(&policy->rwsem);
3a3e9e06 1139 cpumask_set_cpu(old_cpu, policy->cpus);
ad7722da 1140 up_write(&policy->rwsem);
f9ba680d 1141
3a3e9e06 1142 ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
f9ba680d
SB
1143 "cpufreq");
1144
1145 return -EINVAL;
1146 }
1147
1148 return cpu_dev->id;
1149}
1150
cedb70af
SB
1151static int __cpufreq_remove_dev_prepare(struct device *dev,
1152 struct subsys_interface *sif,
1153 bool frozen)
1da177e4 1154{
f9ba680d 1155 unsigned int cpu = dev->id, cpus;
3de9bdeb 1156 int new_cpu, ret;
1da177e4 1157 unsigned long flags;
3a3e9e06 1158 struct cpufreq_policy *policy;
1da177e4 1159
b8eed8af 1160 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1da177e4 1161
0d1857a1 1162 write_lock_irqsave(&cpufreq_driver_lock, flags);
2eaa3e2d 1163
3a3e9e06 1164 policy = per_cpu(cpufreq_cpu_data, cpu);
2eaa3e2d 1165
8414809c
SB
1166 /* Save the policy somewhere when doing a light-weight tear-down */
1167 if (frozen)
3a3e9e06 1168 per_cpu(cpufreq_cpu_data_fallback, cpu) = policy;
8414809c 1169
0d1857a1 1170 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1da177e4 1171
3a3e9e06 1172 if (!policy) {
b8eed8af 1173 pr_debug("%s: No cpu_data found\n", __func__);
1da177e4
LT
1174 return -EINVAL;
1175 }
1da177e4 1176
9c0ebcf7 1177 if (has_target()) {
3de9bdeb
VK
1178 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
1179 if (ret) {
1180 pr_err("%s: Failed to stop governor\n", __func__);
1181 return ret;
1182 }
1183 }
1da177e4 1184
084f3493 1185#ifdef CONFIG_HOTPLUG_CPU
1c3d85dd 1186 if (!cpufreq_driver->setpolicy)
fa69e33f 1187 strncpy(per_cpu(cpufreq_cpu_governor, cpu),
3a3e9e06 1188 policy->governor->name, CPUFREQ_NAME_LEN);
1da177e4
LT
1189#endif
1190
ad7722da 1191 down_read(&policy->rwsem);
3a3e9e06 1192 cpus = cpumask_weight(policy->cpus);
ad7722da 1193 up_read(&policy->rwsem);
084f3493 1194
61173f25
SB
1195 if (cpu != policy->cpu) {
1196 if (!frozen)
1197 sysfs_remove_link(&dev->kobj, "cpufreq");
73bf0fc2 1198 } else if (cpus > 1) {
3a3e9e06 1199 new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen);
f9ba680d 1200 if (new_cpu >= 0) {
3a3e9e06 1201 update_policy_cpu(policy, new_cpu);
a82fab29
SB
1202
1203 if (!frozen) {
75949c9a
VK
1204 pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
1205 __func__, new_cpu, cpu);
a82fab29 1206 }
1da177e4
LT
1207 }
1208 }
1da177e4 1209
cedb70af
SB
1210 return 0;
1211}
1212
1213static int __cpufreq_remove_dev_finish(struct device *dev,
1214 struct subsys_interface *sif,
1215 bool frozen)
1216{
1217 unsigned int cpu = dev->id, cpus;
1218 int ret;
1219 unsigned long flags;
1220 struct cpufreq_policy *policy;
1221 struct kobject *kobj;
1222 struct completion *cmp;
1223
1224 read_lock_irqsave(&cpufreq_driver_lock, flags);
1225 policy = per_cpu(cpufreq_cpu_data, cpu);
1226 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1227
1228 if (!policy) {
1229 pr_debug("%s: No cpu_data found\n", __func__);
1230 return -EINVAL;
1231 }
1232
ad7722da 1233 down_write(&policy->rwsem);
cedb70af 1234 cpus = cpumask_weight(policy->cpus);
9c8f1ee4
VK
1235
1236 if (cpus > 1)
1237 cpumask_clear_cpu(cpu, policy->cpus);
ad7722da 1238 up_write(&policy->rwsem);
cedb70af 1239
b8eed8af
VK
1240 /* If cpu is last user of policy, free policy */
1241 if (cpus == 1) {
9c0ebcf7 1242 if (has_target()) {
3de9bdeb
VK
1243 ret = __cpufreq_governor(policy,
1244 CPUFREQ_GOV_POLICY_EXIT);
1245 if (ret) {
1246 pr_err("%s: Failed to exit governor\n",
1247 __func__);
1248 return ret;
1249 }
edab2fbc 1250 }
2a998599 1251
8414809c 1252 if (!frozen) {
ad7722da 1253 down_read(&policy->rwsem);
3a3e9e06
VK
1254 kobj = &policy->kobj;
1255 cmp = &policy->kobj_unregister;
ad7722da 1256 up_read(&policy->rwsem);
8414809c
SB
1257 kobject_put(kobj);
1258
1259 /*
1260 * We need to make sure that the underlying kobj is
1261 * actually not referenced anymore by anybody before we
1262 * proceed with unloading.
1263 */
1264 pr_debug("waiting for dropping of refcount\n");
1265 wait_for_completion(cmp);
1266 pr_debug("wait complete\n");
1267 }
7d26e2d5 1268
8414809c
SB
1269 /*
1270 * Perform the ->exit() even during light-weight tear-down,
1271 * since this is a core component, and is essential for the
1272 * subsequent light-weight ->init() to succeed.
b8eed8af 1273 */
1c3d85dd 1274 if (cpufreq_driver->exit)
3a3e9e06 1275 cpufreq_driver->exit(policy);
27ecddc2 1276
9515f4d6
VK
1277 /* Remove policy from list of active policies */
1278 write_lock_irqsave(&cpufreq_driver_lock, flags);
1279 list_del(&policy->policy_list);
1280 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1281
8414809c 1282 if (!frozen)
3a3e9e06 1283 cpufreq_policy_free(policy);
2a998599 1284 } else {
9c0ebcf7 1285 if (has_target()) {
3de9bdeb
VK
1286 if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
1287 (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
1288 pr_err("%s: Failed to start governor\n",
1289 __func__);
1290 return ret;
1291 }
2a998599 1292 }
27ecddc2 1293 }
1da177e4 1294
474deff7 1295 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1da177e4
LT
1296 return 0;
1297}
1298
cedb70af 1299/**
27a862e9 1300 * cpufreq_remove_dev - remove a CPU device
cedb70af
SB
1301 *
1302 * Removes the cpufreq interface for a CPU device.
cedb70af 1303 */
8a25a2fd 1304static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
5a01f2e8 1305{
8a25a2fd 1306 unsigned int cpu = dev->id;
27a862e9 1307 int ret;
ec28297a
VP
1308
1309 if (cpu_is_offline(cpu))
1310 return 0;
1311
27a862e9
VK
1312 ret = __cpufreq_remove_dev_prepare(dev, sif, false);
1313
1314 if (!ret)
1315 ret = __cpufreq_remove_dev_finish(dev, sif, false);
1316
1317 return ret;
5a01f2e8
VP
1318}
1319
65f27f38 1320static void handle_update(struct work_struct *work)
1da177e4 1321{
65f27f38
DH
1322 struct cpufreq_policy *policy =
1323 container_of(work, struct cpufreq_policy, update);
1324 unsigned int cpu = policy->cpu;
2d06d8c4 1325 pr_debug("handle_update for cpu %u called\n", cpu);
1da177e4
LT
1326 cpufreq_update_policy(cpu);
1327}
1328
1329/**
bb176f7d
VK
1330 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1331 * in deep trouble.
1da177e4
LT
1332 * @cpu: cpu number
1333 * @old_freq: CPU frequency the kernel thinks the CPU runs at
1334 * @new_freq: CPU frequency the CPU actually runs at
1335 *
29464f28
DJ
1336 * We adjust to current frequency first, and need to clean up later.
1337 * So either call to cpufreq_update_policy() or schedule handle_update()).
1da177e4 1338 */
e08f5f5b
GS
1339static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq,
1340 unsigned int new_freq)
1da177e4 1341{
b43a7ffb 1342 struct cpufreq_policy *policy;
1da177e4 1343 struct cpufreq_freqs freqs;
b43a7ffb
VK
1344 unsigned long flags;
1345
2d06d8c4 1346 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing "
1da177e4
LT
1347 "core thinks of %u, is %u kHz.\n", old_freq, new_freq);
1348
1da177e4
LT
1349 freqs.old = old_freq;
1350 freqs.new = new_freq;
b43a7ffb
VK
1351
1352 read_lock_irqsave(&cpufreq_driver_lock, flags);
1353 policy = per_cpu(cpufreq_cpu_data, cpu);
1354 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1355
1356 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
1357 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
1da177e4
LT
1358}
1359
32ee8c3e 1360/**
4ab70df4 1361 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
95235ca2
VP
1362 * @cpu: CPU number
1363 *
1364 * This is the last known freq, without actually getting it from the driver.
1365 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1366 */
1367unsigned int cpufreq_quick_get(unsigned int cpu)
1368{
9e21ba8b 1369 struct cpufreq_policy *policy;
e08f5f5b 1370 unsigned int ret_freq = 0;
95235ca2 1371
1c3d85dd
RW
1372 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
1373 return cpufreq_driver->get(cpu);
9e21ba8b
DB
1374
1375 policy = cpufreq_cpu_get(cpu);
95235ca2 1376 if (policy) {
e08f5f5b 1377 ret_freq = policy->cur;
95235ca2
VP
1378 cpufreq_cpu_put(policy);
1379 }
1380
4d34a67d 1381 return ret_freq;
95235ca2
VP
1382}
1383EXPORT_SYMBOL(cpufreq_quick_get);
1384
3d737108
JB
1385/**
1386 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1387 * @cpu: CPU number
1388 *
1389 * Just return the max possible frequency for a given CPU.
1390 */
1391unsigned int cpufreq_quick_get_max(unsigned int cpu)
1392{
1393 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1394 unsigned int ret_freq = 0;
1395
1396 if (policy) {
1397 ret_freq = policy->max;
1398 cpufreq_cpu_put(policy);
1399 }
1400
1401 return ret_freq;
1402}
1403EXPORT_SYMBOL(cpufreq_quick_get_max);
1404
5a01f2e8 1405static unsigned int __cpufreq_get(unsigned int cpu)
1da177e4 1406{
7a6aedfa 1407 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
e08f5f5b 1408 unsigned int ret_freq = 0;
5800043b 1409
1c3d85dd 1410 if (!cpufreq_driver->get)
4d34a67d 1411 return ret_freq;
1da177e4 1412
1c3d85dd 1413 ret_freq = cpufreq_driver->get(cpu);
1da177e4 1414
e08f5f5b 1415 if (ret_freq && policy->cur &&
1c3d85dd 1416 !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
e08f5f5b
GS
1417 /* verify no discrepancy between actual and
1418 saved value exists */
1419 if (unlikely(ret_freq != policy->cur)) {
1420 cpufreq_out_of_sync(cpu, policy->cur, ret_freq);
1da177e4
LT
1421 schedule_work(&policy->update);
1422 }
1423 }
1424
4d34a67d 1425 return ret_freq;
5a01f2e8 1426}
1da177e4 1427
5a01f2e8
VP
1428/**
1429 * cpufreq_get - get the current CPU frequency (in kHz)
1430 * @cpu: CPU number
1431 *
1432 * Get the CPU current (static) CPU frequency
1433 */
1434unsigned int cpufreq_get(unsigned int cpu)
1435{
ad7722da 1436 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
5a01f2e8 1437 unsigned int ret_freq = 0;
5a01f2e8 1438
26ca8694
VK
1439 if (cpufreq_disabled() || !cpufreq_driver)
1440 return -ENOENT;
1441
ad7722da 1442 BUG_ON(!policy);
1443
6eed9404
VK
1444 if (!down_read_trylock(&cpufreq_rwsem))
1445 return 0;
5a01f2e8 1446
ad7722da 1447 down_read(&policy->rwsem);
5a01f2e8
VP
1448
1449 ret_freq = __cpufreq_get(cpu);
1450
ad7722da 1451 up_read(&policy->rwsem);
6eed9404
VK
1452 up_read(&cpufreq_rwsem);
1453
4d34a67d 1454 return ret_freq;
1da177e4
LT
1455}
1456EXPORT_SYMBOL(cpufreq_get);
1457
8a25a2fd
KS
1458static struct subsys_interface cpufreq_interface = {
1459 .name = "cpufreq",
1460 .subsys = &cpu_subsys,
1461 .add_dev = cpufreq_add_dev,
1462 .remove_dev = cpufreq_remove_dev,
e00e56df
RW
1463};
1464
42d4dc3f 1465/**
e00e56df
RW
1466 * cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
1467 *
1468 * This function is only executed for the boot processor. The other CPUs
1469 * have been put offline by means of CPU hotplug.
42d4dc3f 1470 */
e00e56df 1471static int cpufreq_bp_suspend(void)
42d4dc3f 1472{
e08f5f5b 1473 int ret = 0;
4bc5d341 1474
e00e56df 1475 int cpu = smp_processor_id();
3a3e9e06 1476 struct cpufreq_policy *policy;
42d4dc3f 1477
2d06d8c4 1478 pr_debug("suspending cpu %u\n", cpu);
42d4dc3f 1479
e00e56df 1480 /* If there's no policy for the boot CPU, we have nothing to do. */
3a3e9e06
VK
1481 policy = cpufreq_cpu_get(cpu);
1482 if (!policy)
e00e56df 1483 return 0;
42d4dc3f 1484
1c3d85dd 1485 if (cpufreq_driver->suspend) {
3a3e9e06 1486 ret = cpufreq_driver->suspend(policy);
ce6c3997 1487 if (ret)
42d4dc3f 1488 printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
3a3e9e06 1489 "step on CPU %u\n", policy->cpu);
42d4dc3f
BH
1490 }
1491
3a3e9e06 1492 cpufreq_cpu_put(policy);
c9060494 1493 return ret;
42d4dc3f
BH
1494}
1495
1da177e4 1496/**
e00e56df 1497 * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU.
1da177e4
LT
1498 *
1499 * 1.) resume CPUfreq hardware support (cpufreq_driver->resume())
ce6c3997
DB
1500 * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are
1501 * restored. It will verify that the current freq is in sync with
1502 * what we believe it to be. This is a bit later than when it
1503 * should be, but nonethteless it's better than calling
1504 * cpufreq_driver->get() here which might re-enable interrupts...
e00e56df
RW
1505 *
1506 * This function is only executed for the boot CPU. The other CPUs have not
1507 * been turned on yet.
1da177e4 1508 */
e00e56df 1509static void cpufreq_bp_resume(void)
1da177e4 1510{
e08f5f5b 1511 int ret = 0;
4bc5d341 1512
e00e56df 1513 int cpu = smp_processor_id();
3a3e9e06 1514 struct cpufreq_policy *policy;
1da177e4 1515
2d06d8c4 1516 pr_debug("resuming cpu %u\n", cpu);
1da177e4 1517
e00e56df 1518 /* If there's no policy for the boot CPU, we have nothing to do. */
3a3e9e06
VK
1519 policy = cpufreq_cpu_get(cpu);
1520 if (!policy)
e00e56df 1521 return;
1da177e4 1522
1c3d85dd 1523 if (cpufreq_driver->resume) {
3a3e9e06 1524 ret = cpufreq_driver->resume(policy);
1da177e4
LT
1525 if (ret) {
1526 printk(KERN_ERR "cpufreq: resume failed in ->resume "
3a3e9e06 1527 "step on CPU %u\n", policy->cpu);
c9060494 1528 goto fail;
1da177e4
LT
1529 }
1530 }
1531
3a3e9e06 1532 schedule_work(&policy->update);
ce6c3997 1533
c9060494 1534fail:
3a3e9e06 1535 cpufreq_cpu_put(policy);
1da177e4
LT
1536}
1537
e00e56df
RW
1538static struct syscore_ops cpufreq_syscore_ops = {
1539 .suspend = cpufreq_bp_suspend,
1540 .resume = cpufreq_bp_resume,
1da177e4
LT
1541};
1542
9d95046e
BP
1543/**
1544 * cpufreq_get_current_driver - return current driver's name
1545 *
1546 * Return the name string of the currently loaded cpufreq driver
1547 * or NULL, if none.
1548 */
1549const char *cpufreq_get_current_driver(void)
1550{
1c3d85dd
RW
1551 if (cpufreq_driver)
1552 return cpufreq_driver->name;
1553
1554 return NULL;
9d95046e
BP
1555}
1556EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1da177e4
LT
1557
1558/*********************************************************************
1559 * NOTIFIER LISTS INTERFACE *
1560 *********************************************************************/
1561
1562/**
1563 * cpufreq_register_notifier - register a driver with cpufreq
1564 * @nb: notifier function to register
1565 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1566 *
32ee8c3e 1567 * Add a driver to one of two lists: either a list of drivers that
1da177e4
LT
1568 * are notified about clock rate changes (once before and once after
1569 * the transition), or a list of drivers that are notified about
1570 * changes in cpufreq policy.
1571 *
1572 * This function may sleep, and has the same return conditions as
e041c683 1573 * blocking_notifier_chain_register.
1da177e4
LT
1574 */
1575int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1576{
1577 int ret;
1578
d5aaffa9
DB
1579 if (cpufreq_disabled())
1580 return -EINVAL;
1581
74212ca4
CEB
1582 WARN_ON(!init_cpufreq_transition_notifier_list_called);
1583
1da177e4
LT
1584 switch (list) {
1585 case CPUFREQ_TRANSITION_NOTIFIER:
b4dfdbb3 1586 ret = srcu_notifier_chain_register(
e041c683 1587 &cpufreq_transition_notifier_list, nb);
1da177e4
LT
1588 break;
1589 case CPUFREQ_POLICY_NOTIFIER:
e041c683
AS
1590 ret = blocking_notifier_chain_register(
1591 &cpufreq_policy_notifier_list, nb);
1da177e4
LT
1592 break;
1593 default:
1594 ret = -EINVAL;
1595 }
1da177e4
LT
1596
1597 return ret;
1598}
1599EXPORT_SYMBOL(cpufreq_register_notifier);
1600
1da177e4
LT
1601/**
1602 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1603 * @nb: notifier block to be unregistered
bb176f7d 1604 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1da177e4
LT
1605 *
1606 * Remove a driver from the CPU frequency notifier list.
1607 *
1608 * This function may sleep, and has the same return conditions as
e041c683 1609 * blocking_notifier_chain_unregister.
1da177e4
LT
1610 */
1611int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1612{
1613 int ret;
1614
d5aaffa9
DB
1615 if (cpufreq_disabled())
1616 return -EINVAL;
1617
1da177e4
LT
1618 switch (list) {
1619 case CPUFREQ_TRANSITION_NOTIFIER:
b4dfdbb3 1620 ret = srcu_notifier_chain_unregister(
e041c683 1621 &cpufreq_transition_notifier_list, nb);
1da177e4
LT
1622 break;
1623 case CPUFREQ_POLICY_NOTIFIER:
e041c683
AS
1624 ret = blocking_notifier_chain_unregister(
1625 &cpufreq_policy_notifier_list, nb);
1da177e4
LT
1626 break;
1627 default:
1628 ret = -EINVAL;
1629 }
1da177e4
LT
1630
1631 return ret;
1632}
1633EXPORT_SYMBOL(cpufreq_unregister_notifier);
1634
1635
1636/*********************************************************************
1637 * GOVERNORS *
1638 *********************************************************************/
1639
1da177e4
LT
1640int __cpufreq_driver_target(struct cpufreq_policy *policy,
1641 unsigned int target_freq,
1642 unsigned int relation)
1643{
1644 int retval = -EINVAL;
7249924e 1645 unsigned int old_target_freq = target_freq;
c32b6b8e 1646
a7b422cd
KRW
1647 if (cpufreq_disabled())
1648 return -ENODEV;
1649
7249924e
VK
1650 /* Make sure that target_freq is within supported range */
1651 if (target_freq > policy->max)
1652 target_freq = policy->max;
1653 if (target_freq < policy->min)
1654 target_freq = policy->min;
1655
1656 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1657 policy->cpu, target_freq, relation, old_target_freq);
5a1c0228 1658
9c0ebcf7
VK
1659 /*
1660 * This might look like a redundant call as we are checking it again
1661 * after finding index. But it is left intentionally for cases where
1662 * exactly same freq is called again and so we can save on few function
1663 * calls.
1664 */
5a1c0228
VK
1665 if (target_freq == policy->cur)
1666 return 0;
1667
1c3d85dd
RW
1668 if (cpufreq_driver->target)
1669 retval = cpufreq_driver->target(policy, target_freq, relation);
9c0ebcf7
VK
1670 else if (cpufreq_driver->target_index) {
1671 struct cpufreq_frequency_table *freq_table;
d4019f0a
VK
1672 struct cpufreq_freqs freqs;
1673 bool notify;
9c0ebcf7 1674 int index;
90d45d17 1675
9c0ebcf7
VK
1676 freq_table = cpufreq_frequency_get_table(policy->cpu);
1677 if (unlikely(!freq_table)) {
1678 pr_err("%s: Unable to find freq_table\n", __func__);
1679 goto out;
1680 }
1681
1682 retval = cpufreq_frequency_table_target(policy, freq_table,
1683 target_freq, relation, &index);
1684 if (unlikely(retval)) {
1685 pr_err("%s: Unable to find matching freq\n", __func__);
1686 goto out;
1687 }
1688
d4019f0a 1689 if (freq_table[index].frequency == policy->cur) {
9c0ebcf7 1690 retval = 0;
d4019f0a
VK
1691 goto out;
1692 }
1693
1694 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
1695
1696 if (notify) {
1697 freqs.old = policy->cur;
1698 freqs.new = freq_table[index].frequency;
1699 freqs.flags = 0;
1700
1701 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1702 __func__, policy->cpu, freqs.old,
1703 freqs.new);
1704
1705 cpufreq_notify_transition(policy, &freqs,
1706 CPUFREQ_PRECHANGE);
1707 }
1708
1709 retval = cpufreq_driver->target_index(policy, index);
1710 if (retval)
1711 pr_err("%s: Failed to change cpu frequency: %d\n",
1712 __func__, retval);
1713
1714 if (notify) {
1715 /*
1716 * Notify with old freq in case we failed to change
1717 * frequency
1718 */
1719 if (retval)
1720 freqs.new = freqs.old;
1721
1722 cpufreq_notify_transition(policy, &freqs,
1723 CPUFREQ_POSTCHANGE);
1724 }
9c0ebcf7
VK
1725 }
1726
1727out:
1da177e4
LT
1728 return retval;
1729}
1730EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
1731
1da177e4
LT
1732int cpufreq_driver_target(struct cpufreq_policy *policy,
1733 unsigned int target_freq,
1734 unsigned int relation)
1735{
f1829e4a 1736 int ret = -EINVAL;
1da177e4 1737
ad7722da 1738 down_write(&policy->rwsem);
1da177e4
LT
1739
1740 ret = __cpufreq_driver_target(policy, target_freq, relation);
1741
ad7722da 1742 up_write(&policy->rwsem);
1da177e4 1743
1da177e4
LT
1744 return ret;
1745}
1746EXPORT_SYMBOL_GPL(cpufreq_driver_target);
1747
153d7f3f 1748/*
153d7f3f
AV
1749 * when "event" is CPUFREQ_GOV_LIMITS
1750 */
1da177e4 1751
e08f5f5b
GS
1752static int __cpufreq_governor(struct cpufreq_policy *policy,
1753 unsigned int event)
1da177e4 1754{
cc993cab 1755 int ret;
6afde10c
TR
1756
1757 /* Only must be defined when default governor is known to have latency
1758 restrictions, like e.g. conservative or ondemand.
1759 That this is the case is already ensured in Kconfig
1760 */
1761#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
1762 struct cpufreq_governor *gov = &cpufreq_gov_performance;
1763#else
1764 struct cpufreq_governor *gov = NULL;
1765#endif
1c256245
TR
1766
1767 if (policy->governor->max_transition_latency &&
1768 policy->cpuinfo.transition_latency >
1769 policy->governor->max_transition_latency) {
6afde10c
TR
1770 if (!gov)
1771 return -EINVAL;
1772 else {
1773 printk(KERN_WARNING "%s governor failed, too long"
1774 " transition latency of HW, fallback"
1775 " to %s governor\n",
1776 policy->governor->name,
1777 gov->name);
1778 policy->governor = gov;
1779 }
1c256245 1780 }
1da177e4 1781
fe492f3f
VK
1782 if (event == CPUFREQ_GOV_POLICY_INIT)
1783 if (!try_module_get(policy->governor->owner))
1784 return -EINVAL;
1da177e4 1785
2d06d8c4 1786 pr_debug("__cpufreq_governor for CPU %u, event %u\n",
e08f5f5b 1787 policy->cpu, event);
95731ebb
XC
1788
1789 mutex_lock(&cpufreq_governor_lock);
56d07db2 1790 if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
f73d3933
VK
1791 || (!policy->governor_enabled
1792 && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
95731ebb
XC
1793 mutex_unlock(&cpufreq_governor_lock);
1794 return -EBUSY;
1795 }
1796
1797 if (event == CPUFREQ_GOV_STOP)
1798 policy->governor_enabled = false;
1799 else if (event == CPUFREQ_GOV_START)
1800 policy->governor_enabled = true;
1801
1802 mutex_unlock(&cpufreq_governor_lock);
1803
1da177e4
LT
1804 ret = policy->governor->governor(policy, event);
1805
4d5dcc42
VK
1806 if (!ret) {
1807 if (event == CPUFREQ_GOV_POLICY_INIT)
1808 policy->governor->initialized++;
1809 else if (event == CPUFREQ_GOV_POLICY_EXIT)
1810 policy->governor->initialized--;
95731ebb
XC
1811 } else {
1812 /* Restore original values */
1813 mutex_lock(&cpufreq_governor_lock);
1814 if (event == CPUFREQ_GOV_STOP)
1815 policy->governor_enabled = true;
1816 else if (event == CPUFREQ_GOV_START)
1817 policy->governor_enabled = false;
1818 mutex_unlock(&cpufreq_governor_lock);
4d5dcc42 1819 }
b394058f 1820
fe492f3f
VK
1821 if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||
1822 ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret))
1da177e4
LT
1823 module_put(policy->governor->owner);
1824
1825 return ret;
1826}
1827
1da177e4
LT
1828int cpufreq_register_governor(struct cpufreq_governor *governor)
1829{
3bcb09a3 1830 int err;
1da177e4
LT
1831
1832 if (!governor)
1833 return -EINVAL;
1834
a7b422cd
KRW
1835 if (cpufreq_disabled())
1836 return -ENODEV;
1837
3fc54d37 1838 mutex_lock(&cpufreq_governor_mutex);
32ee8c3e 1839
b394058f 1840 governor->initialized = 0;
3bcb09a3
JF
1841 err = -EBUSY;
1842 if (__find_governor(governor->name) == NULL) {
1843 err = 0;
1844 list_add(&governor->governor_list, &cpufreq_governor_list);
1da177e4 1845 }
1da177e4 1846
32ee8c3e 1847 mutex_unlock(&cpufreq_governor_mutex);
3bcb09a3 1848 return err;
1da177e4
LT
1849}
1850EXPORT_SYMBOL_GPL(cpufreq_register_governor);
1851
1da177e4
LT
1852void cpufreq_unregister_governor(struct cpufreq_governor *governor)
1853{
90e41bac
PB
1854#ifdef CONFIG_HOTPLUG_CPU
1855 int cpu;
1856#endif
1857
1da177e4
LT
1858 if (!governor)
1859 return;
1860
a7b422cd
KRW
1861 if (cpufreq_disabled())
1862 return;
1863
90e41bac
PB
1864#ifdef CONFIG_HOTPLUG_CPU
1865 for_each_present_cpu(cpu) {
1866 if (cpu_online(cpu))
1867 continue;
1868 if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name))
1869 strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0");
1870 }
1871#endif
1872
3fc54d37 1873 mutex_lock(&cpufreq_governor_mutex);
1da177e4 1874 list_del(&governor->governor_list);
3fc54d37 1875 mutex_unlock(&cpufreq_governor_mutex);
1da177e4
LT
1876 return;
1877}
1878EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
1879
1880
1da177e4
LT
1881/*********************************************************************
1882 * POLICY INTERFACE *
1883 *********************************************************************/
1884
1885/**
1886 * cpufreq_get_policy - get the current cpufreq_policy
29464f28
DJ
1887 * @policy: struct cpufreq_policy into which the current cpufreq_policy
1888 * is written
1da177e4
LT
1889 *
1890 * Reads the current cpufreq policy.
1891 */
1892int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
1893{
1894 struct cpufreq_policy *cpu_policy;
1895 if (!policy)
1896 return -EINVAL;
1897
1898 cpu_policy = cpufreq_cpu_get(cpu);
1899 if (!cpu_policy)
1900 return -EINVAL;
1901
d5b73cd8 1902 memcpy(policy, cpu_policy, sizeof(*policy));
1da177e4
LT
1903
1904 cpufreq_cpu_put(cpu_policy);
1da177e4
LT
1905 return 0;
1906}
1907EXPORT_SYMBOL(cpufreq_get_policy);
1908
153d7f3f 1909/*
037ce839
VK
1910 * policy : current policy.
1911 * new_policy: policy to be set.
153d7f3f 1912 */
037ce839 1913static int cpufreq_set_policy(struct cpufreq_policy *policy,
3a3e9e06 1914 struct cpufreq_policy *new_policy)
1da177e4 1915{
7bd353a9 1916 int ret = 0, failed = 1;
1da177e4 1917
3a3e9e06
VK
1918 pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu,
1919 new_policy->min, new_policy->max);
1da177e4 1920
d5b73cd8 1921 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
1da177e4 1922
3a3e9e06 1923 if (new_policy->min > policy->max || new_policy->max < policy->min) {
9c9a43ed
MD
1924 ret = -EINVAL;
1925 goto error_out;
1926 }
1927
1da177e4 1928 /* verify the cpu speed can be set within this limit */
3a3e9e06 1929 ret = cpufreq_driver->verify(new_policy);
1da177e4
LT
1930 if (ret)
1931 goto error_out;
1932
1da177e4 1933 /* adjust if necessary - all reasons */
e041c683 1934 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
3a3e9e06 1935 CPUFREQ_ADJUST, new_policy);
1da177e4
LT
1936
1937 /* adjust if necessary - hardware incompatibility*/
e041c683 1938 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
3a3e9e06 1939 CPUFREQ_INCOMPATIBLE, new_policy);
1da177e4 1940
bb176f7d
VK
1941 /*
1942 * verify the cpu speed can be set within this limit, which might be
1943 * different to the first one
1944 */
3a3e9e06 1945 ret = cpufreq_driver->verify(new_policy);
e041c683 1946 if (ret)
1da177e4 1947 goto error_out;
1da177e4
LT
1948
1949 /* notification of the new policy */
e041c683 1950 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
3a3e9e06 1951 CPUFREQ_NOTIFY, new_policy);
1da177e4 1952
3a3e9e06
VK
1953 policy->min = new_policy->min;
1954 policy->max = new_policy->max;
1da177e4 1955
2d06d8c4 1956 pr_debug("new min and max freqs are %u - %u kHz\n",
3a3e9e06 1957 policy->min, policy->max);
1da177e4 1958
1c3d85dd 1959 if (cpufreq_driver->setpolicy) {
3a3e9e06 1960 policy->policy = new_policy->policy;
2d06d8c4 1961 pr_debug("setting range\n");
3a3e9e06 1962 ret = cpufreq_driver->setpolicy(new_policy);
1da177e4 1963 } else {
3a3e9e06 1964 if (new_policy->governor != policy->governor) {
1da177e4 1965 /* save old, working values */
3a3e9e06 1966 struct cpufreq_governor *old_gov = policy->governor;
1da177e4 1967
2d06d8c4 1968 pr_debug("governor switch\n");
1da177e4
LT
1969
1970 /* end old governor */
3a3e9e06
VK
1971 if (policy->governor) {
1972 __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
ad7722da 1973 up_write(&policy->rwsem);
3a3e9e06 1974 __cpufreq_governor(policy,
7bd353a9 1975 CPUFREQ_GOV_POLICY_EXIT);
ad7722da 1976 down_write(&policy->rwsem);
7bd353a9 1977 }
1da177e4
LT
1978
1979 /* start new governor */
3a3e9e06
VK
1980 policy->governor = new_policy->governor;
1981 if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) {
1982 if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) {
7bd353a9 1983 failed = 0;
955ef483 1984 } else {
ad7722da 1985 up_write(&policy->rwsem);
3a3e9e06 1986 __cpufreq_governor(policy,
7bd353a9 1987 CPUFREQ_GOV_POLICY_EXIT);
ad7722da 1988 down_write(&policy->rwsem);
955ef483 1989 }
7bd353a9
VK
1990 }
1991
1992 if (failed) {
1da177e4 1993 /* new governor failed, so re-start old one */
2d06d8c4 1994 pr_debug("starting governor %s failed\n",
3a3e9e06 1995 policy->governor->name);
1da177e4 1996 if (old_gov) {
3a3e9e06
VK
1997 policy->governor = old_gov;
1998 __cpufreq_governor(policy,
7bd353a9 1999 CPUFREQ_GOV_POLICY_INIT);
3a3e9e06 2000 __cpufreq_governor(policy,
e08f5f5b 2001 CPUFREQ_GOV_START);
1da177e4
LT
2002 }
2003 ret = -EINVAL;
2004 goto error_out;
2005 }
2006 /* might be a policy change, too, so fall through */
2007 }
2d06d8c4 2008 pr_debug("governor: change or update limits\n");
3de9bdeb 2009 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
1da177e4
LT
2010 }
2011
7d5e350f 2012error_out:
1da177e4
LT
2013 return ret;
2014}
2015
1da177e4
LT
2016/**
2017 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2018 * @cpu: CPU which shall be re-evaluated
2019 *
25985edc 2020 * Useful for policy notifiers which have different necessities
1da177e4
LT
2021 * at different times.
2022 */
2023int cpufreq_update_policy(unsigned int cpu)
2024{
3a3e9e06
VK
2025 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
2026 struct cpufreq_policy new_policy;
f1829e4a 2027 int ret;
1da177e4 2028
3a3e9e06 2029 if (!policy) {
f1829e4a
JL
2030 ret = -ENODEV;
2031 goto no_policy;
2032 }
1da177e4 2033
ad7722da 2034 down_write(&policy->rwsem);
1da177e4 2035
2d06d8c4 2036 pr_debug("updating policy for CPU %u\n", cpu);
d5b73cd8 2037 memcpy(&new_policy, policy, sizeof(*policy));
3a3e9e06
VK
2038 new_policy.min = policy->user_policy.min;
2039 new_policy.max = policy->user_policy.max;
2040 new_policy.policy = policy->user_policy.policy;
2041 new_policy.governor = policy->user_policy.governor;
1da177e4 2042
bb176f7d
VK
2043 /*
2044 * BIOS might change freq behind our back
2045 * -> ask driver for current freq and notify governors about a change
2046 */
1c3d85dd 2047 if (cpufreq_driver->get) {
3a3e9e06
VK
2048 new_policy.cur = cpufreq_driver->get(cpu);
2049 if (!policy->cur) {
2d06d8c4 2050 pr_debug("Driver did not initialize current freq");
3a3e9e06 2051 policy->cur = new_policy.cur;
a85f7bd3 2052 } else {
9c0ebcf7 2053 if (policy->cur != new_policy.cur && has_target())
3a3e9e06
VK
2054 cpufreq_out_of_sync(cpu, policy->cur,
2055 new_policy.cur);
a85f7bd3 2056 }
0961dd0d
TR
2057 }
2058
037ce839 2059 ret = cpufreq_set_policy(policy, &new_policy);
1da177e4 2060
ad7722da 2061 up_write(&policy->rwsem);
5a01f2e8 2062
3a3e9e06 2063 cpufreq_cpu_put(policy);
f1829e4a 2064no_policy:
1da177e4
LT
2065 return ret;
2066}
2067EXPORT_SYMBOL(cpufreq_update_policy);
2068
2760984f 2069static int cpufreq_cpu_callback(struct notifier_block *nfb,
c32b6b8e
AR
2070 unsigned long action, void *hcpu)
2071{
2072 unsigned int cpu = (unsigned long)hcpu;
8a25a2fd 2073 struct device *dev;
5302c3fb 2074 bool frozen = false;
c32b6b8e 2075
8a25a2fd
KS
2076 dev = get_cpu_device(cpu);
2077 if (dev) {
5302c3fb 2078
5302c3fb 2079 switch (action & ~CPU_TASKS_FROZEN) {
c32b6b8e 2080 case CPU_ONLINE:
5302c3fb 2081 __cpufreq_add_dev(dev, NULL, frozen);
23d32899 2082 cpufreq_update_policy(cpu);
c32b6b8e 2083 break;
5302c3fb 2084
c32b6b8e 2085 case CPU_DOWN_PREPARE:
cedb70af 2086 __cpufreq_remove_dev_prepare(dev, NULL, frozen);
1aee40ac
SB
2087 break;
2088
2089 case CPU_POST_DEAD:
cedb70af 2090 __cpufreq_remove_dev_finish(dev, NULL, frozen);
c32b6b8e 2091 break;
5302c3fb 2092
5a01f2e8 2093 case CPU_DOWN_FAILED:
5302c3fb 2094 __cpufreq_add_dev(dev, NULL, frozen);
c32b6b8e
AR
2095 break;
2096 }
2097 }
2098 return NOTIFY_OK;
2099}
2100
9c36f746 2101static struct notifier_block __refdata cpufreq_cpu_notifier = {
bb176f7d 2102 .notifier_call = cpufreq_cpu_callback,
c32b6b8e 2103};
1da177e4
LT
2104
2105/*********************************************************************
2106 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2107 *********************************************************************/
2108
2109/**
2110 * cpufreq_register_driver - register a CPU Frequency driver
2111 * @driver_data: A struct cpufreq_driver containing the values#
2112 * submitted by the CPU Frequency driver.
2113 *
bb176f7d 2114 * Registers a CPU Frequency driver to this core code. This code
1da177e4 2115 * returns zero on success, -EBUSY when another driver got here first
32ee8c3e 2116 * (and isn't unregistered in the meantime).
1da177e4
LT
2117 *
2118 */
221dee28 2119int cpufreq_register_driver(struct cpufreq_driver *driver_data)
1da177e4
LT
2120{
2121 unsigned long flags;
2122 int ret;
2123
a7b422cd
KRW
2124 if (cpufreq_disabled())
2125 return -ENODEV;
2126
1da177e4 2127 if (!driver_data || !driver_data->verify || !driver_data->init ||
9c0ebcf7
VK
2128 !(driver_data->setpolicy || driver_data->target_index ||
2129 driver_data->target))
1da177e4
LT
2130 return -EINVAL;
2131
2d06d8c4 2132 pr_debug("trying to register driver %s\n", driver_data->name);
1da177e4
LT
2133
2134 if (driver_data->setpolicy)
2135 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2136
0d1857a1 2137 write_lock_irqsave(&cpufreq_driver_lock, flags);
1c3d85dd 2138 if (cpufreq_driver) {
0d1857a1 2139 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
4dea5806 2140 return -EEXIST;
1da177e4 2141 }
1c3d85dd 2142 cpufreq_driver = driver_data;
0d1857a1 2143 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1da177e4 2144
8a25a2fd 2145 ret = subsys_interface_register(&cpufreq_interface);
8f5bc2ab
JS
2146 if (ret)
2147 goto err_null_driver;
1da177e4 2148
1c3d85dd 2149 if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) {
1da177e4
LT
2150 int i;
2151 ret = -ENODEV;
2152
2153 /* check for at least one working CPU */
7a6aedfa
MT
2154 for (i = 0; i < nr_cpu_ids; i++)
2155 if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
1da177e4 2156 ret = 0;
7a6aedfa
MT
2157 break;
2158 }
1da177e4
LT
2159
2160 /* if all ->init() calls failed, unregister */
2161 if (ret) {
2d06d8c4 2162 pr_debug("no CPU initialized for driver %s\n",
e08f5f5b 2163 driver_data->name);
8a25a2fd 2164 goto err_if_unreg;
1da177e4
LT
2165 }
2166 }
2167
8f5bc2ab 2168 register_hotcpu_notifier(&cpufreq_cpu_notifier);
2d06d8c4 2169 pr_debug("driver %s up and running\n", driver_data->name);
1da177e4 2170
8f5bc2ab 2171 return 0;
8a25a2fd
KS
2172err_if_unreg:
2173 subsys_interface_unregister(&cpufreq_interface);
8f5bc2ab 2174err_null_driver:
0d1857a1 2175 write_lock_irqsave(&cpufreq_driver_lock, flags);
1c3d85dd 2176 cpufreq_driver = NULL;
0d1857a1 2177 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
4d34a67d 2178 return ret;
1da177e4
LT
2179}
2180EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2181
1da177e4
LT
2182/**
2183 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2184 *
bb176f7d 2185 * Unregister the current CPUFreq driver. Only call this if you have
1da177e4
LT
2186 * the right to do so, i.e. if you have succeeded in initialising before!
2187 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2188 * currently not initialised.
2189 */
221dee28 2190int cpufreq_unregister_driver(struct cpufreq_driver *driver)
1da177e4
LT
2191{
2192 unsigned long flags;
2193
1c3d85dd 2194 if (!cpufreq_driver || (driver != cpufreq_driver))
1da177e4 2195 return -EINVAL;
1da177e4 2196
2d06d8c4 2197 pr_debug("unregistering driver %s\n", driver->name);
1da177e4 2198
8a25a2fd 2199 subsys_interface_unregister(&cpufreq_interface);
65edc68c 2200 unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
1da177e4 2201
6eed9404 2202 down_write(&cpufreq_rwsem);
0d1857a1 2203 write_lock_irqsave(&cpufreq_driver_lock, flags);
6eed9404 2204
1c3d85dd 2205 cpufreq_driver = NULL;
6eed9404 2206
0d1857a1 2207 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
6eed9404 2208 up_write(&cpufreq_rwsem);
1da177e4
LT
2209
2210 return 0;
2211}
2212EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
5a01f2e8
VP
2213
2214static int __init cpufreq_core_init(void)
2215{
a7b422cd
KRW
2216 if (cpufreq_disabled())
2217 return -ENODEV;
2218
2361be23 2219 cpufreq_global_kobject = kobject_create();
8aa84ad8 2220 BUG_ON(!cpufreq_global_kobject);
e00e56df 2221 register_syscore_ops(&cpufreq_syscore_ops);
8aa84ad8 2222
5a01f2e8
VP
2223 return 0;
2224}
5a01f2e8 2225core_initcall(cpufreq_core_init);