Commit | Line | Data |
---|---|---|
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> | |
6 | * | |
c32b6b8e | 7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 8 | * Added handling for CPU hotplug |
8ff69732 DJ |
9 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
10 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 11 | * |
1da177e4 LT |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
1da177e4 LT |
18 | #include <linux/kernel.h> |
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/notifier.h> | |
22 | #include <linux/cpufreq.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <linux/device.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/cpu.h> | |
29 | #include <linux/completion.h> | |
3fc54d37 | 30 | #include <linux/mutex.h> |
e00e56df | 31 | #include <linux/syscore_ops.h> |
1da177e4 | 32 | |
6f4f2723 TR |
33 | #include <trace/events/power.h> |
34 | ||
1da177e4 | 35 | /** |
cd878479 | 36 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
37 | * level driver of CPUFreq support, and its spinlock. This lock |
38 | * also protects the cpufreq_cpu_data array. | |
39 | */ | |
7d5e350f | 40 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 41 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
084f3493 TR |
42 | #ifdef CONFIG_HOTPLUG_CPU |
43 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 44 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 45 | #endif |
1da177e4 LT |
46 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
47 | ||
5a01f2e8 VP |
48 | /* |
49 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
50 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
51 | * | |
52 | * The rules for this semaphore: | |
53 | * - Any routine that wants to read from the policy structure will | |
54 | * do a down_read on this semaphore. | |
55 | * - Any routine that will write to the policy structure and/or may take away | |
56 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
57 | * mode before doing so. | |
58 | * | |
59 | * Additional rules: | |
60 | * - All holders of the lock should check to make sure that the CPU they | |
61 | * are concerned with are online after they get the lock. | |
62 | * - Governor routines that can be called in cpufreq hotplug path should not | |
63 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
64 | * - Lock should not be held across |
65 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 66 | */ |
f1625066 | 67 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
68 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
69 | ||
70 | #define lock_policy_rwsem(mode, cpu) \ | |
226528c6 | 71 | static int lock_policy_rwsem_##mode \ |
5a01f2e8 VP |
72 | (int cpu) \ |
73 | { \ | |
f1625066 | 74 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
75 | BUG_ON(policy_cpu == -1); \ |
76 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
77 | if (unlikely(!cpu_online(cpu))) { \ | |
78 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
79 | return -1; \ | |
80 | } \ | |
81 | \ | |
82 | return 0; \ | |
83 | } | |
84 | ||
85 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 VP |
86 | |
87 | lock_policy_rwsem(write, cpu); | |
5a01f2e8 | 88 | |
226528c6 | 89 | static void unlock_policy_rwsem_read(int cpu) |
5a01f2e8 | 90 | { |
f1625066 | 91 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
92 | BUG_ON(policy_cpu == -1); |
93 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
94 | } | |
5a01f2e8 | 95 | |
226528c6 | 96 | static void unlock_policy_rwsem_write(int cpu) |
5a01f2e8 | 97 | { |
f1625066 | 98 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
99 | BUG_ON(policy_cpu == -1); |
100 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
101 | } | |
5a01f2e8 VP |
102 | |
103 | ||
1da177e4 | 104 | /* internal prototypes */ |
29464f28 DJ |
105 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
106 | unsigned int event); | |
5a01f2e8 | 107 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 108 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
109 | |
110 | /** | |
32ee8c3e DJ |
111 | * Two notifier lists: the "policy" list is involved in the |
112 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
113 | * "transition" list for kernel code that needs to handle |
114 | * changes to devices when the CPU clock speed changes. | |
115 | * The mutex locks both lists. | |
116 | */ | |
e041c683 | 117 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 118 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 119 | |
74212ca4 | 120 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
121 | static int __init init_cpufreq_transition_notifier_list(void) |
122 | { | |
123 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 124 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
125 | return 0; |
126 | } | |
b3438f82 | 127 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 128 | |
a7b422cd KRW |
129 | static int off __read_mostly; |
130 | int cpufreq_disabled(void) | |
131 | { | |
132 | return off; | |
133 | } | |
134 | void disable_cpufreq(void) | |
135 | { | |
136 | off = 1; | |
137 | } | |
1da177e4 | 138 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 139 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 140 | |
7d5e350f | 141 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
142 | { |
143 | struct cpufreq_policy *data; | |
144 | unsigned long flags; | |
145 | ||
7a6aedfa | 146 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
147 | goto err_out; |
148 | ||
149 | /* get the cpufreq driver */ | |
150 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
151 | ||
152 | if (!cpufreq_driver) | |
153 | goto err_out_unlock; | |
154 | ||
155 | if (!try_module_get(cpufreq_driver->owner)) | |
156 | goto err_out_unlock; | |
157 | ||
158 | ||
159 | /* get the CPU */ | |
7a6aedfa | 160 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
161 | |
162 | if (!data) | |
163 | goto err_out_put_module; | |
164 | ||
165 | if (!kobject_get(&data->kobj)) | |
166 | goto err_out_put_module; | |
167 | ||
1da177e4 | 168 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
169 | return data; |
170 | ||
7d5e350f | 171 | err_out_put_module: |
1da177e4 | 172 | module_put(cpufreq_driver->owner); |
7d5e350f | 173 | err_out_unlock: |
1da177e4 | 174 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 175 | err_out: |
1da177e4 LT |
176 | return NULL; |
177 | } | |
178 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
179 | ||
7d5e350f | 180 | |
1da177e4 LT |
181 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
182 | { | |
183 | kobject_put(&data->kobj); | |
184 | module_put(cpufreq_driver->owner); | |
185 | } | |
186 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
187 | ||
188 | ||
1da177e4 LT |
189 | /********************************************************************* |
190 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
191 | *********************************************************************/ | |
192 | ||
193 | /** | |
194 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
195 | * | |
196 | * This function alters the system "loops_per_jiffy" for the clock | |
197 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 198 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
199 | * per-CPU loops_per_jiffy value wherever possible. |
200 | */ | |
201 | #ifndef CONFIG_SMP | |
202 | static unsigned long l_p_j_ref; | |
203 | static unsigned int l_p_j_ref_freq; | |
204 | ||
858119e1 | 205 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
206 | { |
207 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
208 | return; | |
209 | ||
210 | if (!l_p_j_ref_freq) { | |
211 | l_p_j_ref = loops_per_jiffy; | |
212 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 213 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 214 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 215 | } |
d08de0c1 | 216 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 217 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
218 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
219 | ci->new); | |
2d06d8c4 | 220 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 221 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
222 | } |
223 | } | |
224 | #else | |
e08f5f5b GS |
225 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
226 | { | |
227 | return; | |
228 | } | |
1da177e4 LT |
229 | #endif |
230 | ||
231 | ||
232 | /** | |
e4472cb3 DJ |
233 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
234 | * on frequency transition. | |
1da177e4 | 235 | * |
e4472cb3 DJ |
236 | * This function calls the transition notifiers and the "adjust_jiffies" |
237 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 238 | * external effects. |
1da177e4 LT |
239 | */ |
240 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
241 | { | |
e4472cb3 DJ |
242 | struct cpufreq_policy *policy; |
243 | ||
1da177e4 LT |
244 | BUG_ON(irqs_disabled()); |
245 | ||
246 | freqs->flags = cpufreq_driver->flags; | |
2d06d8c4 | 247 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 248 | state, freqs->new); |
1da177e4 | 249 | |
7a6aedfa | 250 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 251 | switch (state) { |
e4472cb3 | 252 | |
1da177e4 | 253 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 254 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
255 | * which is not equal to what the cpufreq core thinks is |
256 | * "old frequency". | |
1da177e4 LT |
257 | */ |
258 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
259 | if ((policy) && (policy->cpu == freqs->cpu) && |
260 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 261 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
262 | " %u, cpufreq assumed %u kHz.\n", |
263 | freqs->old, policy->cur); | |
264 | freqs->old = policy->cur; | |
1da177e4 LT |
265 | } |
266 | } | |
b4dfdbb3 | 267 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 268 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
269 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
270 | break; | |
e4472cb3 | 271 | |
1da177e4 LT |
272 | case CPUFREQ_POSTCHANGE: |
273 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 274 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 TR |
275 | (unsigned long)freqs->cpu); |
276 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 277 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 278 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 279 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
280 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
281 | policy->cur = freqs->new; | |
1da177e4 LT |
282 | break; |
283 | } | |
1da177e4 LT |
284 | } |
285 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
286 | ||
287 | ||
288 | ||
289 | /********************************************************************* | |
290 | * SYSFS INTERFACE * | |
291 | *********************************************************************/ | |
292 | ||
3bcb09a3 JF |
293 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
294 | { | |
295 | struct cpufreq_governor *t; | |
296 | ||
297 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 298 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
299 | return t; |
300 | ||
301 | return NULL; | |
302 | } | |
303 | ||
1da177e4 LT |
304 | /** |
305 | * cpufreq_parse_governor - parse a governor string | |
306 | */ | |
905d77cd | 307 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
308 | struct cpufreq_governor **governor) |
309 | { | |
3bcb09a3 JF |
310 | int err = -EINVAL; |
311 | ||
1da177e4 | 312 | if (!cpufreq_driver) |
3bcb09a3 JF |
313 | goto out; |
314 | ||
1da177e4 LT |
315 | if (cpufreq_driver->setpolicy) { |
316 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
317 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 318 | err = 0; |
e08f5f5b GS |
319 | } else if (!strnicmp(str_governor, "powersave", |
320 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 321 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 322 | err = 0; |
1da177e4 | 323 | } |
3bcb09a3 | 324 | } else if (cpufreq_driver->target) { |
1da177e4 | 325 | struct cpufreq_governor *t; |
3bcb09a3 | 326 | |
3fc54d37 | 327 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
328 | |
329 | t = __find_governor(str_governor); | |
330 | ||
ea714970 | 331 | if (t == NULL) { |
1a8e1463 | 332 | int ret; |
ea714970 | 333 | |
1a8e1463 KC |
334 | mutex_unlock(&cpufreq_governor_mutex); |
335 | ret = request_module("cpufreq_%s", str_governor); | |
336 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 337 | |
1a8e1463 KC |
338 | if (ret == 0) |
339 | t = __find_governor(str_governor); | |
ea714970 JF |
340 | } |
341 | ||
3bcb09a3 JF |
342 | if (t != NULL) { |
343 | *governor = t; | |
344 | err = 0; | |
1da177e4 | 345 | } |
3bcb09a3 | 346 | |
3fc54d37 | 347 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 348 | } |
29464f28 | 349 | out: |
3bcb09a3 | 350 | return err; |
1da177e4 | 351 | } |
1da177e4 LT |
352 | |
353 | ||
1da177e4 | 354 | /** |
e08f5f5b GS |
355 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
356 | * print out cpufreq information | |
1da177e4 LT |
357 | * |
358 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
359 | * "unsigned int". | |
360 | */ | |
361 | ||
32ee8c3e DJ |
362 | #define show_one(file_name, object) \ |
363 | static ssize_t show_##file_name \ | |
905d77cd | 364 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 365 | { \ |
29464f28 | 366 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
367 | } |
368 | ||
369 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
370 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 371 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
372 | show_one(scaling_min_freq, min); |
373 | show_one(scaling_max_freq, max); | |
374 | show_one(scaling_cur_freq, cur); | |
375 | ||
e08f5f5b GS |
376 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
377 | struct cpufreq_policy *policy); | |
7970e08b | 378 | |
1da177e4 LT |
379 | /** |
380 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
381 | */ | |
382 | #define store_one(file_name, object) \ | |
383 | static ssize_t store_##file_name \ | |
905d77cd | 384 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
385 | { \ |
386 | unsigned int ret = -EINVAL; \ | |
387 | struct cpufreq_policy new_policy; \ | |
388 | \ | |
389 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
390 | if (ret) \ | |
391 | return -EINVAL; \ | |
392 | \ | |
29464f28 | 393 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
394 | if (ret != 1) \ |
395 | return -EINVAL; \ | |
396 | \ | |
7970e08b TR |
397 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
398 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
399 | \ |
400 | return ret ? ret : count; \ | |
401 | } | |
402 | ||
29464f28 DJ |
403 | store_one(scaling_min_freq, min); |
404 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
405 | |
406 | /** | |
407 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
408 | */ | |
905d77cd DJ |
409 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
410 | char *buf) | |
1da177e4 | 411 | { |
5a01f2e8 | 412 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
413 | if (!cur_freq) |
414 | return sprintf(buf, "<unknown>"); | |
415 | return sprintf(buf, "%u\n", cur_freq); | |
416 | } | |
417 | ||
418 | ||
419 | /** | |
420 | * show_scaling_governor - show the current policy for the specified CPU | |
421 | */ | |
905d77cd | 422 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 423 | { |
29464f28 | 424 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
425 | return sprintf(buf, "powersave\n"); |
426 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
427 | return sprintf(buf, "performance\n"); | |
428 | else if (policy->governor) | |
29464f28 DJ |
429 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", |
430 | policy->governor->name); | |
1da177e4 LT |
431 | return -EINVAL; |
432 | } | |
433 | ||
434 | ||
435 | /** | |
436 | * store_scaling_governor - store policy for the specified CPU | |
437 | */ | |
905d77cd DJ |
438 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
439 | const char *buf, size_t count) | |
1da177e4 LT |
440 | { |
441 | unsigned int ret = -EINVAL; | |
442 | char str_governor[16]; | |
443 | struct cpufreq_policy new_policy; | |
444 | ||
445 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
446 | if (ret) | |
447 | return ret; | |
448 | ||
29464f28 | 449 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
450 | if (ret != 1) |
451 | return -EINVAL; | |
452 | ||
e08f5f5b GS |
453 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
454 | &new_policy.governor)) | |
1da177e4 LT |
455 | return -EINVAL; |
456 | ||
7970e08b TR |
457 | /* Do not use cpufreq_set_policy here or the user_policy.max |
458 | will be wrongly overridden */ | |
7970e08b TR |
459 | ret = __cpufreq_set_policy(policy, &new_policy); |
460 | ||
461 | policy->user_policy.policy = policy->policy; | |
462 | policy->user_policy.governor = policy->governor; | |
7970e08b | 463 | |
e08f5f5b GS |
464 | if (ret) |
465 | return ret; | |
466 | else | |
467 | return count; | |
1da177e4 LT |
468 | } |
469 | ||
470 | /** | |
471 | * show_scaling_driver - show the cpufreq driver currently loaded | |
472 | */ | |
905d77cd | 473 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
474 | { |
475 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
476 | } | |
477 | ||
478 | /** | |
479 | * show_scaling_available_governors - show the available CPUfreq governors | |
480 | */ | |
905d77cd DJ |
481 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
482 | char *buf) | |
1da177e4 LT |
483 | { |
484 | ssize_t i = 0; | |
485 | struct cpufreq_governor *t; | |
486 | ||
487 | if (!cpufreq_driver->target) { | |
488 | i += sprintf(buf, "performance powersave"); | |
489 | goto out; | |
490 | } | |
491 | ||
492 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
493 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
494 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 LT |
495 | goto out; |
496 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
497 | } | |
7d5e350f | 498 | out: |
1da177e4 LT |
499 | i += sprintf(&buf[i], "\n"); |
500 | return i; | |
501 | } | |
e8628dd0 | 502 | |
835481d9 | 503 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
504 | { |
505 | ssize_t i = 0; | |
506 | unsigned int cpu; | |
507 | ||
835481d9 | 508 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
509 | if (i) |
510 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
511 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
512 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 513 | break; |
1da177e4 LT |
514 | } |
515 | i += sprintf(&buf[i], "\n"); | |
516 | return i; | |
517 | } | |
518 | ||
e8628dd0 DW |
519 | /** |
520 | * show_related_cpus - show the CPUs affected by each transition even if | |
521 | * hw coordination is in use | |
522 | */ | |
523 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
524 | { | |
835481d9 | 525 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
526 | return show_cpus(policy->cpus, buf); |
527 | return show_cpus(policy->related_cpus, buf); | |
528 | } | |
529 | ||
530 | /** | |
531 | * show_affected_cpus - show the CPUs affected by each transition | |
532 | */ | |
533 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
534 | { | |
535 | return show_cpus(policy->cpus, buf); | |
536 | } | |
537 | ||
9e76988e | 538 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 539 | const char *buf, size_t count) |
9e76988e VP |
540 | { |
541 | unsigned int freq = 0; | |
542 | unsigned int ret; | |
543 | ||
879000f9 | 544 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
545 | return -EINVAL; |
546 | ||
547 | ret = sscanf(buf, "%u", &freq); | |
548 | if (ret != 1) | |
549 | return -EINVAL; | |
550 | ||
551 | policy->governor->store_setspeed(policy, freq); | |
552 | ||
553 | return count; | |
554 | } | |
555 | ||
556 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
557 | { | |
879000f9 | 558 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
559 | return sprintf(buf, "<unsupported>\n"); |
560 | ||
561 | return policy->governor->show_setspeed(policy, buf); | |
562 | } | |
1da177e4 | 563 | |
e2f74f35 TR |
564 | /** |
565 | * show_scaling_driver - show the current cpufreq HW/BIOS limitation | |
566 | */ | |
567 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
568 | { | |
569 | unsigned int limit; | |
570 | int ret; | |
571 | if (cpufreq_driver->bios_limit) { | |
572 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
573 | if (!ret) | |
574 | return sprintf(buf, "%u\n", limit); | |
575 | } | |
576 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
577 | } | |
578 | ||
6dad2a29 BP |
579 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
580 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
581 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
582 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
583 | cpufreq_freq_attr_ro(scaling_available_governors); | |
584 | cpufreq_freq_attr_ro(scaling_driver); | |
585 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
586 | cpufreq_freq_attr_ro(bios_limit); | |
587 | cpufreq_freq_attr_ro(related_cpus); | |
588 | cpufreq_freq_attr_ro(affected_cpus); | |
589 | cpufreq_freq_attr_rw(scaling_min_freq); | |
590 | cpufreq_freq_attr_rw(scaling_max_freq); | |
591 | cpufreq_freq_attr_rw(scaling_governor); | |
592 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 593 | |
905d77cd | 594 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
595 | &cpuinfo_min_freq.attr, |
596 | &cpuinfo_max_freq.attr, | |
ed129784 | 597 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
598 | &scaling_min_freq.attr, |
599 | &scaling_max_freq.attr, | |
600 | &affected_cpus.attr, | |
e8628dd0 | 601 | &related_cpus.attr, |
1da177e4 LT |
602 | &scaling_governor.attr, |
603 | &scaling_driver.attr, | |
604 | &scaling_available_governors.attr, | |
9e76988e | 605 | &scaling_setspeed.attr, |
1da177e4 LT |
606 | NULL |
607 | }; | |
608 | ||
8aa84ad8 TR |
609 | struct kobject *cpufreq_global_kobject; |
610 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
611 | ||
29464f28 DJ |
612 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
613 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 614 | |
29464f28 | 615 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 616 | { |
905d77cd DJ |
617 | struct cpufreq_policy *policy = to_policy(kobj); |
618 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 619 | ssize_t ret = -EINVAL; |
1da177e4 LT |
620 | policy = cpufreq_cpu_get(policy->cpu); |
621 | if (!policy) | |
0db4a8a9 | 622 | goto no_policy; |
5a01f2e8 VP |
623 | |
624 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 625 | goto fail; |
5a01f2e8 | 626 | |
e08f5f5b GS |
627 | if (fattr->show) |
628 | ret = fattr->show(policy, buf); | |
629 | else | |
630 | ret = -EIO; | |
631 | ||
5a01f2e8 | 632 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 633 | fail: |
1da177e4 | 634 | cpufreq_cpu_put(policy); |
0db4a8a9 | 635 | no_policy: |
1da177e4 LT |
636 | return ret; |
637 | } | |
638 | ||
905d77cd DJ |
639 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
640 | const char *buf, size_t count) | |
1da177e4 | 641 | { |
905d77cd DJ |
642 | struct cpufreq_policy *policy = to_policy(kobj); |
643 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 644 | ssize_t ret = -EINVAL; |
1da177e4 LT |
645 | policy = cpufreq_cpu_get(policy->cpu); |
646 | if (!policy) | |
a07530b4 | 647 | goto no_policy; |
5a01f2e8 VP |
648 | |
649 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 650 | goto fail; |
5a01f2e8 | 651 | |
e08f5f5b GS |
652 | if (fattr->store) |
653 | ret = fattr->store(policy, buf, count); | |
654 | else | |
655 | ret = -EIO; | |
656 | ||
5a01f2e8 | 657 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 658 | fail: |
1da177e4 | 659 | cpufreq_cpu_put(policy); |
a07530b4 | 660 | no_policy: |
1da177e4 LT |
661 | return ret; |
662 | } | |
663 | ||
905d77cd | 664 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 665 | { |
905d77cd | 666 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 667 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
668 | complete(&policy->kobj_unregister); |
669 | } | |
670 | ||
52cf25d0 | 671 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
672 | .show = show, |
673 | .store = store, | |
674 | }; | |
675 | ||
676 | static struct kobj_type ktype_cpufreq = { | |
677 | .sysfs_ops = &sysfs_ops, | |
678 | .default_attrs = default_attrs, | |
679 | .release = cpufreq_sysfs_release, | |
680 | }; | |
681 | ||
4bfa042c TR |
682 | /* |
683 | * Returns: | |
684 | * Negative: Failure | |
685 | * 0: Success | |
686 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
687 | */ | |
cf3289d0 AC |
688 | static int cpufreq_add_dev_policy(unsigned int cpu, |
689 | struct cpufreq_policy *policy, | |
8a25a2fd | 690 | struct device *dev) |
ecf7e461 DJ |
691 | { |
692 | int ret = 0; | |
693 | #ifdef CONFIG_SMP | |
694 | unsigned long flags; | |
695 | unsigned int j; | |
ecf7e461 | 696 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
697 | struct cpufreq_governor *gov; |
698 | ||
699 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
700 | if (gov) { | |
701 | policy->governor = gov; | |
2d06d8c4 | 702 | pr_debug("Restoring governor %s for cpu %d\n", |
ecf7e461 DJ |
703 | policy->governor->name, cpu); |
704 | } | |
705 | #endif | |
706 | ||
707 | for_each_cpu(j, policy->cpus) { | |
708 | struct cpufreq_policy *managed_policy; | |
709 | ||
710 | if (cpu == j) | |
711 | continue; | |
712 | ||
713 | /* Check for existing affected CPUs. | |
714 | * They may not be aware of it due to CPU Hotplug. | |
715 | * cpufreq_cpu_put is called when the device is removed | |
716 | * in __cpufreq_remove_dev() | |
717 | */ | |
718 | managed_policy = cpufreq_cpu_get(j); | |
719 | if (unlikely(managed_policy)) { | |
720 | ||
721 | /* Set proper policy_cpu */ | |
722 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 723 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
724 | |
725 | if (lock_policy_rwsem_write(cpu) < 0) { | |
726 | /* Should not go through policy unlock path */ | |
727 | if (cpufreq_driver->exit) | |
728 | cpufreq_driver->exit(policy); | |
729 | cpufreq_cpu_put(managed_policy); | |
730 | return -EBUSY; | |
731 | } | |
732 | ||
733 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
734 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
735 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
736 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
737 | ||
2d06d8c4 | 738 | pr_debug("CPU already managed, adding link\n"); |
8a25a2fd | 739 | ret = sysfs_create_link(&dev->kobj, |
ecf7e461 DJ |
740 | &managed_policy->kobj, |
741 | "cpufreq"); | |
742 | if (ret) | |
743 | cpufreq_cpu_put(managed_policy); | |
744 | /* | |
745 | * Success. We only needed to be added to the mask. | |
746 | * Call driver->exit() because only the cpu parent of | |
747 | * the kobj needed to call init(). | |
748 | */ | |
749 | if (cpufreq_driver->exit) | |
750 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
751 | |
752 | if (!ret) | |
753 | return 1; | |
754 | else | |
755 | return ret; | |
ecf7e461 DJ |
756 | } |
757 | } | |
758 | #endif | |
759 | return ret; | |
760 | } | |
761 | ||
762 | ||
19d6f7ec | 763 | /* symlink affected CPUs */ |
cf3289d0 AC |
764 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
765 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
766 | { |
767 | unsigned int j; | |
768 | int ret = 0; | |
769 | ||
770 | for_each_cpu(j, policy->cpus) { | |
771 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 772 | struct device *cpu_dev; |
19d6f7ec DJ |
773 | |
774 | if (j == cpu) | |
775 | continue; | |
776 | if (!cpu_online(j)) | |
777 | continue; | |
778 | ||
2d06d8c4 | 779 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 780 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
781 | cpu_dev = get_cpu_device(j); |
782 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
783 | "cpufreq"); |
784 | if (ret) { | |
785 | cpufreq_cpu_put(managed_policy); | |
786 | return ret; | |
787 | } | |
788 | } | |
789 | return ret; | |
790 | } | |
791 | ||
cf3289d0 AC |
792 | static int cpufreq_add_dev_interface(unsigned int cpu, |
793 | struct cpufreq_policy *policy, | |
8a25a2fd | 794 | struct device *dev) |
909a694e | 795 | { |
ecf7e461 | 796 | struct cpufreq_policy new_policy; |
909a694e DJ |
797 | struct freq_attr **drv_attr; |
798 | unsigned long flags; | |
799 | int ret = 0; | |
800 | unsigned int j; | |
801 | ||
802 | /* prepare interface data */ | |
803 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 804 | &dev->kobj, "cpufreq"); |
909a694e DJ |
805 | if (ret) |
806 | return ret; | |
807 | ||
808 | /* set up files for this cpu device */ | |
809 | drv_attr = cpufreq_driver->attr; | |
810 | while ((drv_attr) && (*drv_attr)) { | |
811 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
812 | if (ret) | |
813 | goto err_out_kobj_put; | |
814 | drv_attr++; | |
815 | } | |
816 | if (cpufreq_driver->get) { | |
817 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
818 | if (ret) | |
819 | goto err_out_kobj_put; | |
820 | } | |
821 | if (cpufreq_driver->target) { | |
822 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
823 | if (ret) | |
824 | goto err_out_kobj_put; | |
825 | } | |
e2f74f35 TR |
826 | if (cpufreq_driver->bios_limit) { |
827 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
828 | if (ret) | |
829 | goto err_out_kobj_put; | |
830 | } | |
909a694e DJ |
831 | |
832 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
833 | for_each_cpu(j, policy->cpus) { | |
bec037aa JL |
834 | if (!cpu_online(j)) |
835 | continue; | |
909a694e | 836 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 837 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
838 | } |
839 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
840 | ||
841 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
842 | if (ret) |
843 | goto err_out_kobj_put; | |
844 | ||
845 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
846 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
847 | policy->governor = NULL; | |
848 | ||
849 | /* set default policy */ | |
850 | ret = __cpufreq_set_policy(policy, &new_policy); | |
851 | policy->user_policy.policy = policy->policy; | |
852 | policy->user_policy.governor = policy->governor; | |
853 | ||
854 | if (ret) { | |
2d06d8c4 | 855 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
856 | if (cpufreq_driver->exit) |
857 | cpufreq_driver->exit(policy); | |
858 | } | |
909a694e DJ |
859 | return ret; |
860 | ||
861 | err_out_kobj_put: | |
862 | kobject_put(&policy->kobj); | |
863 | wait_for_completion(&policy->kobj_unregister); | |
864 | return ret; | |
865 | } | |
866 | ||
1da177e4 LT |
867 | |
868 | /** | |
869 | * cpufreq_add_dev - add a CPU device | |
870 | * | |
32ee8c3e | 871 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
872 | * |
873 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
874 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
875 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 876 | */ |
8a25a2fd | 877 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 878 | { |
8a25a2fd | 879 | unsigned int cpu = dev->id; |
90e41bac | 880 | int ret = 0, found = 0; |
1da177e4 | 881 | struct cpufreq_policy *policy; |
1da177e4 LT |
882 | unsigned long flags; |
883 | unsigned int j; | |
90e41bac PB |
884 | #ifdef CONFIG_HOTPLUG_CPU |
885 | int sibling; | |
886 | #endif | |
1da177e4 | 887 | |
c32b6b8e AR |
888 | if (cpu_is_offline(cpu)) |
889 | return 0; | |
890 | ||
2d06d8c4 | 891 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
892 | |
893 | #ifdef CONFIG_SMP | |
894 | /* check whether a different CPU already registered this | |
895 | * CPU because it is in the same boat. */ | |
896 | policy = cpufreq_cpu_get(cpu); | |
897 | if (unlikely(policy)) { | |
8ff69732 | 898 | cpufreq_cpu_put(policy); |
1da177e4 LT |
899 | return 0; |
900 | } | |
901 | #endif | |
902 | ||
903 | if (!try_module_get(cpufreq_driver->owner)) { | |
904 | ret = -EINVAL; | |
905 | goto module_out; | |
906 | } | |
907 | ||
059019a3 | 908 | ret = -ENOMEM; |
e98df50c | 909 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 910 | if (!policy) |
1da177e4 | 911 | goto nomem_out; |
059019a3 DJ |
912 | |
913 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 914 | goto err_free_policy; |
059019a3 DJ |
915 | |
916 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 917 | goto err_free_cpumask; |
1da177e4 LT |
918 | |
919 | policy->cpu = cpu; | |
835481d9 | 920 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 921 | |
5a01f2e8 | 922 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 923 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
924 | ret = (lock_policy_rwsem_write(cpu) < 0); |
925 | WARN_ON(ret); | |
5a01f2e8 | 926 | |
1da177e4 | 927 | init_completion(&policy->kobj_unregister); |
65f27f38 | 928 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 929 | |
8122c6ce | 930 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
931 | #ifdef CONFIG_HOTPLUG_CPU |
932 | for_each_online_cpu(sibling) { | |
933 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
934 | if (cp && cp->governor && | |
935 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
936 | policy->governor = cp->governor; | |
937 | found = 1; | |
938 | break; | |
939 | } | |
940 | } | |
941 | #endif | |
942 | if (!found) | |
943 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
944 | /* call driver. From then on the cpufreq must be able |
945 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
946 | */ | |
947 | ret = cpufreq_driver->init(policy); | |
948 | if (ret) { | |
2d06d8c4 | 949 | pr_debug("initialization failed\n"); |
3f4a782b | 950 | goto err_unlock_policy; |
1da177e4 | 951 | } |
187d9f4e MC |
952 | policy->user_policy.min = policy->min; |
953 | policy->user_policy.max = policy->max; | |
1da177e4 | 954 | |
a1531acd TR |
955 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
956 | CPUFREQ_START, policy); | |
957 | ||
8a25a2fd | 958 | ret = cpufreq_add_dev_policy(cpu, policy, dev); |
4bfa042c TR |
959 | if (ret) { |
960 | if (ret > 0) | |
961 | /* This is a managed cpu, symlink created, | |
962 | exit with 0 */ | |
963 | ret = 0; | |
ecf7e461 | 964 | goto err_unlock_policy; |
4bfa042c | 965 | } |
1da177e4 | 966 | |
8a25a2fd | 967 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
968 | if (ret) |
969 | goto err_out_unregister; | |
8ff69732 | 970 | |
dca02613 LW |
971 | unlock_policy_rwsem_write(cpu); |
972 | ||
038c5b3e | 973 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 974 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 975 | pr_debug("initialization complete\n"); |
87c32271 | 976 | |
1da177e4 LT |
977 | return 0; |
978 | ||
979 | ||
980 | err_out_unregister: | |
981 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 982 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 983 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
984 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
985 | ||
c10997f6 | 986 | kobject_put(&policy->kobj); |
1da177e4 LT |
987 | wait_for_completion(&policy->kobj_unregister); |
988 | ||
3f4a782b | 989 | err_unlock_policy: |
45709118 | 990 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 991 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
992 | err_free_cpumask: |
993 | free_cpumask_var(policy->cpus); | |
994 | err_free_policy: | |
1da177e4 | 995 | kfree(policy); |
1da177e4 LT |
996 | nomem_out: |
997 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 998 | module_out: |
1da177e4 LT |
999 | return ret; |
1000 | } | |
1001 | ||
1002 | ||
1003 | /** | |
5a01f2e8 | 1004 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1005 | * |
1006 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1007 | * Caller should already have policy_rwsem in write mode for this CPU. |
1008 | * This routine frees the rwsem before returning. | |
1da177e4 | 1009 | */ |
8a25a2fd | 1010 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1011 | { |
8a25a2fd | 1012 | unsigned int cpu = dev->id; |
1da177e4 LT |
1013 | unsigned long flags; |
1014 | struct cpufreq_policy *data; | |
499bca9b AW |
1015 | struct kobject *kobj; |
1016 | struct completion *cmp; | |
1da177e4 | 1017 | #ifdef CONFIG_SMP |
8a25a2fd | 1018 | struct device *cpu_dev; |
1da177e4 LT |
1019 | unsigned int j; |
1020 | #endif | |
1021 | ||
2d06d8c4 | 1022 | pr_debug("unregistering CPU %u\n", cpu); |
1da177e4 LT |
1023 | |
1024 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1025 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1026 | |
1027 | if (!data) { | |
1028 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 1029 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1030 | return -EINVAL; |
1031 | } | |
7a6aedfa | 1032 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1033 | |
1034 | ||
1035 | #ifdef CONFIG_SMP | |
1036 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1037 | * only need to unlink, put and exit |
1da177e4 LT |
1038 | */ |
1039 | if (unlikely(cpu != data->cpu)) { | |
2d06d8c4 | 1040 | pr_debug("removing link\n"); |
835481d9 | 1041 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 | 1042 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8a25a2fd | 1043 | kobj = &dev->kobj; |
1da177e4 | 1044 | cpufreq_cpu_put(data); |
5a01f2e8 | 1045 | unlock_policy_rwsem_write(cpu); |
499bca9b | 1046 | sysfs_remove_link(kobj, "cpufreq"); |
1da177e4 LT |
1047 | return 0; |
1048 | } | |
1049 | #endif | |
1050 | ||
1da177e4 | 1051 | #ifdef CONFIG_SMP |
084f3493 TR |
1052 | |
1053 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1054 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1055 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1056 | #endif |
1057 | ||
1da177e4 LT |
1058 | /* if we have other CPUs still registered, we need to unlink them, |
1059 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1060 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1061 | * the sysfs links afterwards. | |
1da177e4 | 1062 | */ |
835481d9 RR |
1063 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1064 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1065 | if (j == cpu) |
1066 | continue; | |
7a6aedfa | 1067 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1068 | } |
1069 | } | |
1070 | ||
1071 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1072 | ||
835481d9 RR |
1073 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1074 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1075 | if (j == cpu) |
1076 | continue; | |
2d06d8c4 | 1077 | pr_debug("removing link for cpu %u\n", j); |
084f3493 | 1078 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1079 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1080 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1081 | #endif |
8a25a2fd KS |
1082 | cpu_dev = get_cpu_device(j); |
1083 | kobj = &cpu_dev->kobj; | |
499bca9b AW |
1084 | unlock_policy_rwsem_write(cpu); |
1085 | sysfs_remove_link(kobj, "cpufreq"); | |
1086 | lock_policy_rwsem_write(cpu); | |
1da177e4 LT |
1087 | cpufreq_cpu_put(data); |
1088 | } | |
1089 | } | |
1090 | #else | |
1091 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1092 | #endif | |
1093 | ||
1da177e4 LT |
1094 | if (cpufreq_driver->target) |
1095 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1096 | |
499bca9b AW |
1097 | kobj = &data->kobj; |
1098 | cmp = &data->kobj_unregister; | |
1099 | unlock_policy_rwsem_write(cpu); | |
1100 | kobject_put(kobj); | |
1da177e4 LT |
1101 | |
1102 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1103 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1104 | * unloading. |
1105 | */ | |
2d06d8c4 | 1106 | pr_debug("waiting for dropping of refcount\n"); |
499bca9b | 1107 | wait_for_completion(cmp); |
2d06d8c4 | 1108 | pr_debug("wait complete\n"); |
1da177e4 | 1109 | |
499bca9b | 1110 | lock_policy_rwsem_write(cpu); |
1da177e4 LT |
1111 | if (cpufreq_driver->exit) |
1112 | cpufreq_driver->exit(data); | |
7d26e2d5 | 1113 | unlock_policy_rwsem_write(cpu); |
1114 | ||
27ecddc2 JS |
1115 | #ifdef CONFIG_HOTPLUG_CPU |
1116 | /* when the CPU which is the parent of the kobj is hotplugged | |
1117 | * offline, check for siblings, and create cpufreq sysfs interface | |
1118 | * and symlinks | |
1119 | */ | |
1120 | if (unlikely(cpumask_weight(data->cpus) > 1)) { | |
1121 | /* first sibling now owns the new sysfs dir */ | |
1122 | cpumask_clear_cpu(cpu, data->cpus); | |
8a25a2fd | 1123 | cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL); |
27ecddc2 JS |
1124 | |
1125 | /* finally remove our own symlink */ | |
1126 | lock_policy_rwsem_write(cpu); | |
8a25a2fd | 1127 | __cpufreq_remove_dev(dev, sif); |
27ecddc2 JS |
1128 | } |
1129 | #endif | |
1130 | ||
835481d9 RR |
1131 | free_cpumask_var(data->related_cpus); |
1132 | free_cpumask_var(data->cpus); | |
1da177e4 LT |
1133 | kfree(data); |
1134 | ||
1da177e4 LT |
1135 | return 0; |
1136 | } | |
1137 | ||
1138 | ||
8a25a2fd | 1139 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1140 | { |
8a25a2fd | 1141 | unsigned int cpu = dev->id; |
5a01f2e8 | 1142 | int retval; |
ec28297a VP |
1143 | |
1144 | if (cpu_is_offline(cpu)) | |
1145 | return 0; | |
1146 | ||
5a01f2e8 VP |
1147 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1148 | BUG(); | |
1149 | ||
8a25a2fd | 1150 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1151 | return retval; |
1152 | } | |
1153 | ||
1154 | ||
65f27f38 | 1155 | static void handle_update(struct work_struct *work) |
1da177e4 | 1156 | { |
65f27f38 DH |
1157 | struct cpufreq_policy *policy = |
1158 | container_of(work, struct cpufreq_policy, update); | |
1159 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1160 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1161 | cpufreq_update_policy(cpu); |
1162 | } | |
1163 | ||
1164 | /** | |
1165 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1166 | * @cpu: cpu number | |
1167 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1168 | * @new_freq: CPU frequency the CPU actually runs at | |
1169 | * | |
29464f28 DJ |
1170 | * We adjust to current frequency first, and need to clean up later. |
1171 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1172 | */ |
e08f5f5b GS |
1173 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1174 | unsigned int new_freq) | |
1da177e4 LT |
1175 | { |
1176 | struct cpufreq_freqs freqs; | |
1177 | ||
2d06d8c4 | 1178 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1179 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1180 | ||
1181 | freqs.cpu = cpu; | |
1182 | freqs.old = old_freq; | |
1183 | freqs.new = new_freq; | |
1184 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1185 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1186 | } | |
1187 | ||
1188 | ||
32ee8c3e | 1189 | /** |
4ab70df4 | 1190 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1191 | * @cpu: CPU number |
1192 | * | |
1193 | * This is the last known freq, without actually getting it from the driver. | |
1194 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1195 | */ | |
1196 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1197 | { | |
1198 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1199 | unsigned int ret_freq = 0; |
95235ca2 VP |
1200 | |
1201 | if (policy) { | |
e08f5f5b | 1202 | ret_freq = policy->cur; |
95235ca2 VP |
1203 | cpufreq_cpu_put(policy); |
1204 | } | |
1205 | ||
4d34a67d | 1206 | return ret_freq; |
95235ca2 VP |
1207 | } |
1208 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1209 | ||
3d737108 JB |
1210 | /** |
1211 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1212 | * @cpu: CPU number | |
1213 | * | |
1214 | * Just return the max possible frequency for a given CPU. | |
1215 | */ | |
1216 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1217 | { | |
1218 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1219 | unsigned int ret_freq = 0; | |
1220 | ||
1221 | if (policy) { | |
1222 | ret_freq = policy->max; | |
1223 | cpufreq_cpu_put(policy); | |
1224 | } | |
1225 | ||
1226 | return ret_freq; | |
1227 | } | |
1228 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1229 | ||
95235ca2 | 1230 | |
5a01f2e8 | 1231 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1232 | { |
7a6aedfa | 1233 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1234 | unsigned int ret_freq = 0; |
1da177e4 | 1235 | |
1da177e4 | 1236 | if (!cpufreq_driver->get) |
4d34a67d | 1237 | return ret_freq; |
1da177e4 | 1238 | |
e08f5f5b | 1239 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1240 | |
e08f5f5b GS |
1241 | if (ret_freq && policy->cur && |
1242 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1243 | /* verify no discrepancy between actual and | |
1244 | saved value exists */ | |
1245 | if (unlikely(ret_freq != policy->cur)) { | |
1246 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1247 | schedule_work(&policy->update); |
1248 | } | |
1249 | } | |
1250 | ||
4d34a67d | 1251 | return ret_freq; |
5a01f2e8 | 1252 | } |
1da177e4 | 1253 | |
5a01f2e8 VP |
1254 | /** |
1255 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1256 | * @cpu: CPU number | |
1257 | * | |
1258 | * Get the CPU current (static) CPU frequency | |
1259 | */ | |
1260 | unsigned int cpufreq_get(unsigned int cpu) | |
1261 | { | |
1262 | unsigned int ret_freq = 0; | |
1263 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1264 | ||
1265 | if (!policy) | |
1266 | goto out; | |
1267 | ||
1268 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1269 | goto out_policy; | |
1270 | ||
1271 | ret_freq = __cpufreq_get(cpu); | |
1272 | ||
1273 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1274 | |
5a01f2e8 VP |
1275 | out_policy: |
1276 | cpufreq_cpu_put(policy); | |
1277 | out: | |
4d34a67d | 1278 | return ret_freq; |
1da177e4 LT |
1279 | } |
1280 | EXPORT_SYMBOL(cpufreq_get); | |
1281 | ||
8a25a2fd KS |
1282 | static struct subsys_interface cpufreq_interface = { |
1283 | .name = "cpufreq", | |
1284 | .subsys = &cpu_subsys, | |
1285 | .add_dev = cpufreq_add_dev, | |
1286 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1287 | }; |
1288 | ||
1da177e4 | 1289 | |
42d4dc3f | 1290 | /** |
e00e56df RW |
1291 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1292 | * | |
1293 | * This function is only executed for the boot processor. The other CPUs | |
1294 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1295 | */ |
e00e56df | 1296 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1297 | { |
e08f5f5b | 1298 | int ret = 0; |
4bc5d341 | 1299 | |
e00e56df | 1300 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1301 | struct cpufreq_policy *cpu_policy; |
1302 | ||
2d06d8c4 | 1303 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1304 | |
e00e56df | 1305 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1306 | cpu_policy = cpufreq_cpu_get(cpu); |
1307 | if (!cpu_policy) | |
e00e56df | 1308 | return 0; |
42d4dc3f BH |
1309 | |
1310 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1311 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1312 | if (ret) |
42d4dc3f BH |
1313 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1314 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1315 | } |
1316 | ||
42d4dc3f | 1317 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1318 | return ret; |
42d4dc3f BH |
1319 | } |
1320 | ||
1da177e4 | 1321 | /** |
e00e56df | 1322 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1323 | * |
1324 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1325 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1326 | * restored. It will verify that the current freq is in sync with | |
1327 | * what we believe it to be. This is a bit later than when it | |
1328 | * should be, but nonethteless it's better than calling | |
1329 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1330 | * |
1331 | * This function is only executed for the boot CPU. The other CPUs have not | |
1332 | * been turned on yet. | |
1da177e4 | 1333 | */ |
e00e56df | 1334 | static void cpufreq_bp_resume(void) |
1da177e4 | 1335 | { |
e08f5f5b | 1336 | int ret = 0; |
4bc5d341 | 1337 | |
e00e56df | 1338 | int cpu = smp_processor_id(); |
1da177e4 LT |
1339 | struct cpufreq_policy *cpu_policy; |
1340 | ||
2d06d8c4 | 1341 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1342 | |
e00e56df | 1343 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1344 | cpu_policy = cpufreq_cpu_get(cpu); |
1345 | if (!cpu_policy) | |
e00e56df | 1346 | return; |
1da177e4 LT |
1347 | |
1348 | if (cpufreq_driver->resume) { | |
1349 | ret = cpufreq_driver->resume(cpu_policy); | |
1350 | if (ret) { | |
1351 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1352 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1353 | goto fail; |
1da177e4 LT |
1354 | } |
1355 | } | |
1356 | ||
1da177e4 | 1357 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1358 | |
c9060494 | 1359 | fail: |
1da177e4 | 1360 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1361 | } |
1362 | ||
e00e56df RW |
1363 | static struct syscore_ops cpufreq_syscore_ops = { |
1364 | .suspend = cpufreq_bp_suspend, | |
1365 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1366 | }; |
1367 | ||
1368 | ||
1369 | /********************************************************************* | |
1370 | * NOTIFIER LISTS INTERFACE * | |
1371 | *********************************************************************/ | |
1372 | ||
1373 | /** | |
1374 | * cpufreq_register_notifier - register a driver with cpufreq | |
1375 | * @nb: notifier function to register | |
1376 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1377 | * | |
32ee8c3e | 1378 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1379 | * are notified about clock rate changes (once before and once after |
1380 | * the transition), or a list of drivers that are notified about | |
1381 | * changes in cpufreq policy. | |
1382 | * | |
1383 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1384 | * blocking_notifier_chain_register. |
1da177e4 LT |
1385 | */ |
1386 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1387 | { | |
1388 | int ret; | |
1389 | ||
74212ca4 CEB |
1390 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1391 | ||
1da177e4 LT |
1392 | switch (list) { |
1393 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1394 | ret = srcu_notifier_chain_register( |
e041c683 | 1395 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1396 | break; |
1397 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1398 | ret = blocking_notifier_chain_register( |
1399 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1400 | break; |
1401 | default: | |
1402 | ret = -EINVAL; | |
1403 | } | |
1da177e4 LT |
1404 | |
1405 | return ret; | |
1406 | } | |
1407 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1408 | ||
1409 | ||
1410 | /** | |
1411 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1412 | * @nb: notifier block to be unregistered | |
1413 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1414 | * | |
1415 | * Remove a driver from the CPU frequency notifier list. | |
1416 | * | |
1417 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1418 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1419 | */ |
1420 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1421 | { | |
1422 | int ret; | |
1423 | ||
1da177e4 LT |
1424 | switch (list) { |
1425 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1426 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1427 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1428 | break; |
1429 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1430 | ret = blocking_notifier_chain_unregister( |
1431 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1432 | break; |
1433 | default: | |
1434 | ret = -EINVAL; | |
1435 | } | |
1da177e4 LT |
1436 | |
1437 | return ret; | |
1438 | } | |
1439 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1440 | ||
1441 | ||
1442 | /********************************************************************* | |
1443 | * GOVERNORS * | |
1444 | *********************************************************************/ | |
1445 | ||
1446 | ||
1447 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1448 | unsigned int target_freq, | |
1449 | unsigned int relation) | |
1450 | { | |
1451 | int retval = -EINVAL; | |
c32b6b8e | 1452 | |
a7b422cd KRW |
1453 | if (cpufreq_disabled()) |
1454 | return -ENODEV; | |
1455 | ||
2d06d8c4 | 1456 | pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1da177e4 LT |
1457 | target_freq, relation); |
1458 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1459 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1460 | |
1da177e4 LT |
1461 | return retval; |
1462 | } | |
1463 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1464 | ||
1da177e4 LT |
1465 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1466 | unsigned int target_freq, | |
1467 | unsigned int relation) | |
1468 | { | |
f1829e4a | 1469 | int ret = -EINVAL; |
1da177e4 LT |
1470 | |
1471 | policy = cpufreq_cpu_get(policy->cpu); | |
1472 | if (!policy) | |
f1829e4a | 1473 | goto no_policy; |
1da177e4 | 1474 | |
5a01f2e8 | 1475 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1476 | goto fail; |
1da177e4 LT |
1477 | |
1478 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1479 | ||
5a01f2e8 | 1480 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1481 | |
f1829e4a | 1482 | fail: |
1da177e4 | 1483 | cpufreq_cpu_put(policy); |
f1829e4a | 1484 | no_policy: |
1da177e4 LT |
1485 | return ret; |
1486 | } | |
1487 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1488 | ||
bf0b90e3 | 1489 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1490 | { |
1491 | int ret = 0; | |
1492 | ||
1493 | policy = cpufreq_cpu_get(policy->cpu); | |
1494 | if (!policy) | |
1495 | return -EINVAL; | |
1496 | ||
bf0b90e3 | 1497 | if (cpu_online(cpu) && cpufreq_driver->getavg) |
1498 | ret = cpufreq_driver->getavg(policy, cpu); | |
dfde5d62 | 1499 | |
dfde5d62 VP |
1500 | cpufreq_cpu_put(policy); |
1501 | return ret; | |
1502 | } | |
5a01f2e8 | 1503 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1504 | |
153d7f3f | 1505 | /* |
153d7f3f AV |
1506 | * when "event" is CPUFREQ_GOV_LIMITS |
1507 | */ | |
1da177e4 | 1508 | |
e08f5f5b GS |
1509 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1510 | unsigned int event) | |
1da177e4 | 1511 | { |
cc993cab | 1512 | int ret; |
6afde10c TR |
1513 | |
1514 | /* Only must be defined when default governor is known to have latency | |
1515 | restrictions, like e.g. conservative or ondemand. | |
1516 | That this is the case is already ensured in Kconfig | |
1517 | */ | |
1518 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1519 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1520 | #else | |
1521 | struct cpufreq_governor *gov = NULL; | |
1522 | #endif | |
1c256245 TR |
1523 | |
1524 | if (policy->governor->max_transition_latency && | |
1525 | policy->cpuinfo.transition_latency > | |
1526 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1527 | if (!gov) |
1528 | return -EINVAL; | |
1529 | else { | |
1530 | printk(KERN_WARNING "%s governor failed, too long" | |
1531 | " transition latency of HW, fallback" | |
1532 | " to %s governor\n", | |
1533 | policy->governor->name, | |
1534 | gov->name); | |
1535 | policy->governor = gov; | |
1536 | } | |
1c256245 | 1537 | } |
1da177e4 LT |
1538 | |
1539 | if (!try_module_get(policy->governor->owner)) | |
1540 | return -EINVAL; | |
1541 | ||
2d06d8c4 | 1542 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1543 | policy->cpu, event); |
1da177e4 LT |
1544 | ret = policy->governor->governor(policy, event); |
1545 | ||
e08f5f5b GS |
1546 | /* we keep one module reference alive for |
1547 | each CPU governed by this CPU */ | |
1da177e4 LT |
1548 | if ((event != CPUFREQ_GOV_START) || ret) |
1549 | module_put(policy->governor->owner); | |
1550 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1551 | module_put(policy->governor->owner); | |
1552 | ||
1553 | return ret; | |
1554 | } | |
1555 | ||
1556 | ||
1da177e4 LT |
1557 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1558 | { | |
3bcb09a3 | 1559 | int err; |
1da177e4 LT |
1560 | |
1561 | if (!governor) | |
1562 | return -EINVAL; | |
1563 | ||
a7b422cd KRW |
1564 | if (cpufreq_disabled()) |
1565 | return -ENODEV; | |
1566 | ||
3fc54d37 | 1567 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1568 | |
3bcb09a3 JF |
1569 | err = -EBUSY; |
1570 | if (__find_governor(governor->name) == NULL) { | |
1571 | err = 0; | |
1572 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1573 | } |
1da177e4 | 1574 | |
32ee8c3e | 1575 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1576 | return err; |
1da177e4 LT |
1577 | } |
1578 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1579 | ||
1580 | ||
1581 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1582 | { | |
90e41bac PB |
1583 | #ifdef CONFIG_HOTPLUG_CPU |
1584 | int cpu; | |
1585 | #endif | |
1586 | ||
1da177e4 LT |
1587 | if (!governor) |
1588 | return; | |
1589 | ||
a7b422cd KRW |
1590 | if (cpufreq_disabled()) |
1591 | return; | |
1592 | ||
90e41bac PB |
1593 | #ifdef CONFIG_HOTPLUG_CPU |
1594 | for_each_present_cpu(cpu) { | |
1595 | if (cpu_online(cpu)) | |
1596 | continue; | |
1597 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1598 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1599 | } | |
1600 | #endif | |
1601 | ||
3fc54d37 | 1602 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1603 | list_del(&governor->governor_list); |
3fc54d37 | 1604 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1605 | return; |
1606 | } | |
1607 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1608 | ||
1609 | ||
1610 | ||
1611 | /********************************************************************* | |
1612 | * POLICY INTERFACE * | |
1613 | *********************************************************************/ | |
1614 | ||
1615 | /** | |
1616 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1617 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1618 | * is written | |
1da177e4 LT |
1619 | * |
1620 | * Reads the current cpufreq policy. | |
1621 | */ | |
1622 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1623 | { | |
1624 | struct cpufreq_policy *cpu_policy; | |
1625 | if (!policy) | |
1626 | return -EINVAL; | |
1627 | ||
1628 | cpu_policy = cpufreq_cpu_get(cpu); | |
1629 | if (!cpu_policy) | |
1630 | return -EINVAL; | |
1631 | ||
1da177e4 | 1632 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1633 | |
1634 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1635 | return 0; |
1636 | } | |
1637 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1638 | ||
1639 | ||
153d7f3f | 1640 | /* |
e08f5f5b GS |
1641 | * data : current policy. |
1642 | * policy : policy to be set. | |
153d7f3f | 1643 | */ |
e08f5f5b GS |
1644 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1645 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1646 | { |
1647 | int ret = 0; | |
1648 | ||
2d06d8c4 | 1649 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1650 | policy->min, policy->max); |
1651 | ||
e08f5f5b GS |
1652 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1653 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1654 | |
53391fa2 | 1655 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1656 | ret = -EINVAL; |
1657 | goto error_out; | |
1658 | } | |
1659 | ||
1da177e4 LT |
1660 | /* verify the cpu speed can be set within this limit */ |
1661 | ret = cpufreq_driver->verify(policy); | |
1662 | if (ret) | |
1663 | goto error_out; | |
1664 | ||
1da177e4 | 1665 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1666 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1667 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1668 | |
1669 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1670 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1671 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1672 | |
1673 | /* verify the cpu speed can be set within this limit, | |
1674 | which might be different to the first one */ | |
1675 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1676 | if (ret) |
1da177e4 | 1677 | goto error_out; |
1da177e4 LT |
1678 | |
1679 | /* notification of the new policy */ | |
e041c683 AS |
1680 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1681 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1682 | |
7d5e350f DJ |
1683 | data->min = policy->min; |
1684 | data->max = policy->max; | |
1da177e4 | 1685 | |
2d06d8c4 | 1686 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1687 | data->min, data->max); |
1da177e4 LT |
1688 | |
1689 | if (cpufreq_driver->setpolicy) { | |
1690 | data->policy = policy->policy; | |
2d06d8c4 | 1691 | pr_debug("setting range\n"); |
1da177e4 LT |
1692 | ret = cpufreq_driver->setpolicy(policy); |
1693 | } else { | |
1694 | if (policy->governor != data->governor) { | |
1695 | /* save old, working values */ | |
1696 | struct cpufreq_governor *old_gov = data->governor; | |
1697 | ||
2d06d8c4 | 1698 | pr_debug("governor switch\n"); |
1da177e4 LT |
1699 | |
1700 | /* end old governor */ | |
ffe6275f | 1701 | if (data->governor) |
1da177e4 LT |
1702 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1703 | ||
1704 | /* start new governor */ | |
1705 | data->governor = policy->governor; | |
1706 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1707 | /* new governor failed, so re-start old one */ | |
2d06d8c4 | 1708 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1709 | data->governor->name); |
1da177e4 LT |
1710 | if (old_gov) { |
1711 | data->governor = old_gov; | |
e08f5f5b GS |
1712 | __cpufreq_governor(data, |
1713 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1714 | } |
1715 | ret = -EINVAL; | |
1716 | goto error_out; | |
1717 | } | |
1718 | /* might be a policy change, too, so fall through */ | |
1719 | } | |
2d06d8c4 | 1720 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1721 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1722 | } | |
1723 | ||
7d5e350f | 1724 | error_out: |
1da177e4 LT |
1725 | return ret; |
1726 | } | |
1727 | ||
1da177e4 LT |
1728 | /** |
1729 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1730 | * @cpu: CPU which shall be re-evaluated | |
1731 | * | |
25985edc | 1732 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1733 | * at different times. |
1734 | */ | |
1735 | int cpufreq_update_policy(unsigned int cpu) | |
1736 | { | |
1737 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1738 | struct cpufreq_policy policy; | |
f1829e4a | 1739 | int ret; |
1da177e4 | 1740 | |
f1829e4a JL |
1741 | if (!data) { |
1742 | ret = -ENODEV; | |
1743 | goto no_policy; | |
1744 | } | |
1da177e4 | 1745 | |
f1829e4a JL |
1746 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1747 | ret = -EINVAL; | |
1748 | goto fail; | |
1749 | } | |
1da177e4 | 1750 | |
2d06d8c4 | 1751 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1752 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1753 | policy.min = data->user_policy.min; |
1754 | policy.max = data->user_policy.max; | |
1755 | policy.policy = data->user_policy.policy; | |
1756 | policy.governor = data->user_policy.governor; | |
1757 | ||
0961dd0d TR |
1758 | /* BIOS might change freq behind our back |
1759 | -> ask driver for current freq and notify governors about a change */ | |
1760 | if (cpufreq_driver->get) { | |
1761 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1762 | if (!data->cur) { |
2d06d8c4 | 1763 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1764 | data->cur = policy.cur; |
1765 | } else { | |
1766 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1767 | cpufreq_out_of_sync(cpu, data->cur, |
1768 | policy.cur); | |
a85f7bd3 | 1769 | } |
0961dd0d TR |
1770 | } |
1771 | ||
1da177e4 LT |
1772 | ret = __cpufreq_set_policy(data, &policy); |
1773 | ||
5a01f2e8 VP |
1774 | unlock_policy_rwsem_write(cpu); |
1775 | ||
f1829e4a | 1776 | fail: |
1da177e4 | 1777 | cpufreq_cpu_put(data); |
f1829e4a | 1778 | no_policy: |
1da177e4 LT |
1779 | return ret; |
1780 | } | |
1781 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1782 | ||
dd184a01 | 1783 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1784 | unsigned long action, void *hcpu) |
1785 | { | |
1786 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1787 | struct device *dev; |
c32b6b8e | 1788 | |
8a25a2fd KS |
1789 | dev = get_cpu_device(cpu); |
1790 | if (dev) { | |
c32b6b8e AR |
1791 | switch (action) { |
1792 | case CPU_ONLINE: | |
8bb78442 | 1793 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1794 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1795 | break; |
1796 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1797 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1798 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1799 | BUG(); | |
1800 | ||
8a25a2fd | 1801 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1802 | break; |
5a01f2e8 | 1803 | case CPU_DOWN_FAILED: |
8bb78442 | 1804 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1805 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1806 | break; |
1807 | } | |
1808 | } | |
1809 | return NOTIFY_OK; | |
1810 | } | |
1811 | ||
9c36f746 | 1812 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1813 | .notifier_call = cpufreq_cpu_callback, |
1814 | }; | |
1da177e4 LT |
1815 | |
1816 | /********************************************************************* | |
1817 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1818 | *********************************************************************/ | |
1819 | ||
1820 | /** | |
1821 | * cpufreq_register_driver - register a CPU Frequency driver | |
1822 | * @driver_data: A struct cpufreq_driver containing the values# | |
1823 | * submitted by the CPU Frequency driver. | |
1824 | * | |
32ee8c3e | 1825 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1826 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1827 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1828 | * |
1829 | */ | |
221dee28 | 1830 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1831 | { |
1832 | unsigned long flags; | |
1833 | int ret; | |
1834 | ||
a7b422cd KRW |
1835 | if (cpufreq_disabled()) |
1836 | return -ENODEV; | |
1837 | ||
1da177e4 LT |
1838 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1839 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1840 | return -EINVAL; | |
1841 | ||
2d06d8c4 | 1842 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1843 | |
1844 | if (driver_data->setpolicy) | |
1845 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1846 | ||
1847 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1848 | if (cpufreq_driver) { | |
1849 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1850 | return -EBUSY; | |
1851 | } | |
1852 | cpufreq_driver = driver_data; | |
1853 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1854 | ||
8a25a2fd | 1855 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1856 | if (ret) |
1857 | goto err_null_driver; | |
1da177e4 | 1858 | |
8f5bc2ab | 1859 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1860 | int i; |
1861 | ret = -ENODEV; | |
1862 | ||
1863 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1864 | for (i = 0; i < nr_cpu_ids; i++) |
1865 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1866 | ret = 0; |
7a6aedfa MT |
1867 | break; |
1868 | } | |
1da177e4 LT |
1869 | |
1870 | /* if all ->init() calls failed, unregister */ | |
1871 | if (ret) { | |
2d06d8c4 | 1872 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1873 | driver_data->name); |
8a25a2fd | 1874 | goto err_if_unreg; |
1da177e4 LT |
1875 | } |
1876 | } | |
1877 | ||
8f5bc2ab | 1878 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1879 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1880 | |
8f5bc2ab | 1881 | return 0; |
8a25a2fd KS |
1882 | err_if_unreg: |
1883 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1884 | err_null_driver: |
1885 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1886 | cpufreq_driver = NULL; | |
1887 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1888 | return ret; |
1da177e4 LT |
1889 | } |
1890 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1891 | ||
1892 | ||
1893 | /** | |
1894 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1895 | * | |
32ee8c3e | 1896 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1897 | * the right to do so, i.e. if you have succeeded in initialising before! |
1898 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1899 | * currently not initialised. | |
1900 | */ | |
221dee28 | 1901 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1902 | { |
1903 | unsigned long flags; | |
1904 | ||
2d06d8c4 | 1905 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1906 | return -EINVAL; |
1da177e4 | 1907 | |
2d06d8c4 | 1908 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1909 | |
8a25a2fd | 1910 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1911 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1912 | |
1913 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1914 | cpufreq_driver = NULL; | |
1915 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1916 | ||
1917 | return 0; | |
1918 | } | |
1919 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1920 | |
1921 | static int __init cpufreq_core_init(void) | |
1922 | { | |
1923 | int cpu; | |
1924 | ||
a7b422cd KRW |
1925 | if (cpufreq_disabled()) |
1926 | return -ENODEV; | |
1927 | ||
5a01f2e8 | 1928 | for_each_possible_cpu(cpu) { |
f1625066 | 1929 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1930 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1931 | } | |
8aa84ad8 | 1932 | |
8a25a2fd | 1933 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1934 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1935 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1936 | |
5a01f2e8 VP |
1937 | return 0; |
1938 | } | |
5a01f2e8 | 1939 | core_initcall(cpufreq_core_init); |