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 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
1da177e4 LT |
20 | #include <linux/kernel.h> |
21 | #include <linux/module.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/notifier.h> | |
24 | #include <linux/cpufreq.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/spinlock.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/cpu.h> | |
31 | #include <linux/completion.h> | |
3fc54d37 | 32 | #include <linux/mutex.h> |
e00e56df | 33 | #include <linux/syscore_ops.h> |
1da177e4 | 34 | |
6f4f2723 TR |
35 | #include <trace/events/power.h> |
36 | ||
1da177e4 | 37 | /** |
cd878479 | 38 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
39 | * level driver of CPUFreq support, and its spinlock. This lock |
40 | * also protects the cpufreq_cpu_data array. | |
41 | */ | |
7d5e350f | 42 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 43 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
084f3493 TR |
44 | #ifdef CONFIG_HOTPLUG_CPU |
45 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 46 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 47 | #endif |
1da177e4 LT |
48 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
49 | ||
5a01f2e8 VP |
50 | /* |
51 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
52 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
53 | * | |
54 | * The rules for this semaphore: | |
55 | * - Any routine that wants to read from the policy structure will | |
56 | * do a down_read on this semaphore. | |
57 | * - Any routine that will write to the policy structure and/or may take away | |
58 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
59 | * mode before doing so. | |
60 | * | |
61 | * Additional rules: | |
62 | * - All holders of the lock should check to make sure that the CPU they | |
63 | * are concerned with are online after they get the lock. | |
64 | * - Governor routines that can be called in cpufreq hotplug path should not | |
65 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
66 | * - Lock should not be held across |
67 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 68 | */ |
f1625066 | 69 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
70 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
71 | ||
72 | #define lock_policy_rwsem(mode, cpu) \ | |
fa1d8af4 | 73 | static int lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 74 | { \ |
f1625066 | 75 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
76 | BUG_ON(policy_cpu == -1); \ |
77 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 VP |
78 | \ |
79 | return 0; \ | |
80 | } | |
81 | ||
82 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 83 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 84 | |
fa1d8af4 VK |
85 | #define unlock_policy_rwsem(mode, cpu) \ |
86 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
87 | { \ | |
88 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
89 | BUG_ON(policy_cpu == -1); \ | |
90 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 | 91 | } |
5a01f2e8 | 92 | |
fa1d8af4 VK |
93 | unlock_policy_rwsem(read, cpu); |
94 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 95 | |
1da177e4 | 96 | /* internal prototypes */ |
29464f28 DJ |
97 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
98 | unsigned int event); | |
5a01f2e8 | 99 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 100 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
101 | |
102 | /** | |
32ee8c3e DJ |
103 | * Two notifier lists: the "policy" list is involved in the |
104 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
105 | * "transition" list for kernel code that needs to handle |
106 | * changes to devices when the CPU clock speed changes. | |
107 | * The mutex locks both lists. | |
108 | */ | |
e041c683 | 109 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 110 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 111 | |
74212ca4 | 112 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
113 | static int __init init_cpufreq_transition_notifier_list(void) |
114 | { | |
115 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 116 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
117 | return 0; |
118 | } | |
b3438f82 | 119 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 120 | |
a7b422cd | 121 | static int off __read_mostly; |
da584455 | 122 | static int cpufreq_disabled(void) |
a7b422cd KRW |
123 | { |
124 | return off; | |
125 | } | |
126 | void disable_cpufreq(void) | |
127 | { | |
128 | off = 1; | |
129 | } | |
1da177e4 | 130 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 131 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 132 | |
a9144436 | 133 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
134 | { |
135 | struct cpufreq_policy *data; | |
136 | unsigned long flags; | |
137 | ||
7a6aedfa | 138 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
139 | goto err_out; |
140 | ||
141 | /* get the cpufreq driver */ | |
142 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
143 | ||
144 | if (!cpufreq_driver) | |
145 | goto err_out_unlock; | |
146 | ||
147 | if (!try_module_get(cpufreq_driver->owner)) | |
148 | goto err_out_unlock; | |
149 | ||
150 | ||
151 | /* get the CPU */ | |
7a6aedfa | 152 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
153 | |
154 | if (!data) | |
155 | goto err_out_put_module; | |
156 | ||
a9144436 | 157 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
158 | goto err_out_put_module; |
159 | ||
1da177e4 | 160 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
161 | return data; |
162 | ||
7d5e350f | 163 | err_out_put_module: |
1da177e4 | 164 | module_put(cpufreq_driver->owner); |
7d5e350f | 165 | err_out_unlock: |
1da177e4 | 166 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 167 | err_out: |
1da177e4 LT |
168 | return NULL; |
169 | } | |
a9144436 SB |
170 | |
171 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
172 | { | |
d5aaffa9 DB |
173 | if (cpufreq_disabled()) |
174 | return NULL; | |
175 | ||
a9144436 SB |
176 | return __cpufreq_cpu_get(cpu, false); |
177 | } | |
1da177e4 LT |
178 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
179 | ||
a9144436 SB |
180 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
181 | { | |
182 | return __cpufreq_cpu_get(cpu, true); | |
183 | } | |
184 | ||
185 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
186 | { | |
187 | if (!sysfs) | |
188 | kobject_put(&data->kobj); | |
189 | module_put(cpufreq_driver->owner); | |
190 | } | |
7d5e350f | 191 | |
1da177e4 LT |
192 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
193 | { | |
d5aaffa9 DB |
194 | if (cpufreq_disabled()) |
195 | return; | |
196 | ||
a9144436 | 197 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
198 | } |
199 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
200 | ||
a9144436 SB |
201 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
202 | { | |
203 | __cpufreq_cpu_put(data, true); | |
204 | } | |
1da177e4 | 205 | |
1da177e4 LT |
206 | /********************************************************************* |
207 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
208 | *********************************************************************/ | |
209 | ||
210 | /** | |
211 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
212 | * | |
213 | * This function alters the system "loops_per_jiffy" for the clock | |
214 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 215 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
216 | * per-CPU loops_per_jiffy value wherever possible. |
217 | */ | |
218 | #ifndef CONFIG_SMP | |
219 | static unsigned long l_p_j_ref; | |
220 | static unsigned int l_p_j_ref_freq; | |
221 | ||
858119e1 | 222 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
223 | { |
224 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
225 | return; | |
226 | ||
227 | if (!l_p_j_ref_freq) { | |
228 | l_p_j_ref = loops_per_jiffy; | |
229 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 230 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 231 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 232 | } |
d08de0c1 | 233 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 234 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
235 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
236 | ci->new); | |
2d06d8c4 | 237 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 238 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
239 | } |
240 | } | |
241 | #else | |
e08f5f5b GS |
242 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
243 | { | |
244 | return; | |
245 | } | |
1da177e4 LT |
246 | #endif |
247 | ||
248 | ||
249 | /** | |
e4472cb3 DJ |
250 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
251 | * on frequency transition. | |
1da177e4 | 252 | * |
e4472cb3 DJ |
253 | * This function calls the transition notifiers and the "adjust_jiffies" |
254 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 255 | * external effects. |
1da177e4 LT |
256 | */ |
257 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
258 | { | |
e4472cb3 DJ |
259 | struct cpufreq_policy *policy; |
260 | ||
1da177e4 LT |
261 | BUG_ON(irqs_disabled()); |
262 | ||
d5aaffa9 DB |
263 | if (cpufreq_disabled()) |
264 | return; | |
265 | ||
1da177e4 | 266 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 267 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 268 | state, freqs->new); |
1da177e4 | 269 | |
7a6aedfa | 270 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 271 | switch (state) { |
e4472cb3 | 272 | |
1da177e4 | 273 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 274 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
275 | * which is not equal to what the cpufreq core thinks is |
276 | * "old frequency". | |
1da177e4 LT |
277 | */ |
278 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
279 | if ((policy) && (policy->cpu == freqs->cpu) && |
280 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 281 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
282 | " %u, cpufreq assumed %u kHz.\n", |
283 | freqs->old, policy->cur); | |
284 | freqs->old = policy->cur; | |
1da177e4 LT |
285 | } |
286 | } | |
b4dfdbb3 | 287 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 288 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
289 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
290 | break; | |
e4472cb3 | 291 | |
1da177e4 LT |
292 | case CPUFREQ_POSTCHANGE: |
293 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 294 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 TR |
295 | (unsigned long)freqs->cpu); |
296 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 297 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 298 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 299 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
300 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
301 | policy->cur = freqs->new; | |
1da177e4 LT |
302 | break; |
303 | } | |
1da177e4 LT |
304 | } |
305 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
306 | ||
307 | ||
308 | ||
309 | /********************************************************************* | |
310 | * SYSFS INTERFACE * | |
311 | *********************************************************************/ | |
312 | ||
3bcb09a3 JF |
313 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
314 | { | |
315 | struct cpufreq_governor *t; | |
316 | ||
317 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 318 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
319 | return t; |
320 | ||
321 | return NULL; | |
322 | } | |
323 | ||
1da177e4 LT |
324 | /** |
325 | * cpufreq_parse_governor - parse a governor string | |
326 | */ | |
905d77cd | 327 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
328 | struct cpufreq_governor **governor) |
329 | { | |
3bcb09a3 JF |
330 | int err = -EINVAL; |
331 | ||
1da177e4 | 332 | if (!cpufreq_driver) |
3bcb09a3 JF |
333 | goto out; |
334 | ||
1da177e4 LT |
335 | if (cpufreq_driver->setpolicy) { |
336 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
337 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 338 | err = 0; |
e08f5f5b GS |
339 | } else if (!strnicmp(str_governor, "powersave", |
340 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 341 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 342 | err = 0; |
1da177e4 | 343 | } |
3bcb09a3 | 344 | } else if (cpufreq_driver->target) { |
1da177e4 | 345 | struct cpufreq_governor *t; |
3bcb09a3 | 346 | |
3fc54d37 | 347 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
348 | |
349 | t = __find_governor(str_governor); | |
350 | ||
ea714970 | 351 | if (t == NULL) { |
1a8e1463 | 352 | int ret; |
ea714970 | 353 | |
1a8e1463 KC |
354 | mutex_unlock(&cpufreq_governor_mutex); |
355 | ret = request_module("cpufreq_%s", str_governor); | |
356 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 357 | |
1a8e1463 KC |
358 | if (ret == 0) |
359 | t = __find_governor(str_governor); | |
ea714970 JF |
360 | } |
361 | ||
3bcb09a3 JF |
362 | if (t != NULL) { |
363 | *governor = t; | |
364 | err = 0; | |
1da177e4 | 365 | } |
3bcb09a3 | 366 | |
3fc54d37 | 367 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 368 | } |
29464f28 | 369 | out: |
3bcb09a3 | 370 | return err; |
1da177e4 | 371 | } |
1da177e4 LT |
372 | |
373 | ||
1da177e4 | 374 | /** |
e08f5f5b GS |
375 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
376 | * print out cpufreq information | |
1da177e4 LT |
377 | * |
378 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
379 | * "unsigned int". | |
380 | */ | |
381 | ||
32ee8c3e DJ |
382 | #define show_one(file_name, object) \ |
383 | static ssize_t show_##file_name \ | |
905d77cd | 384 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 385 | { \ |
29464f28 | 386 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
387 | } |
388 | ||
389 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
390 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 391 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
392 | show_one(scaling_min_freq, min); |
393 | show_one(scaling_max_freq, max); | |
394 | show_one(scaling_cur_freq, cur); | |
395 | ||
e08f5f5b GS |
396 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
397 | struct cpufreq_policy *policy); | |
7970e08b | 398 | |
1da177e4 LT |
399 | /** |
400 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
401 | */ | |
402 | #define store_one(file_name, object) \ | |
403 | static ssize_t store_##file_name \ | |
905d77cd | 404 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 405 | { \ |
f55c9c26 | 406 | unsigned int ret; \ |
1da177e4 LT |
407 | struct cpufreq_policy new_policy; \ |
408 | \ | |
409 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
410 | if (ret) \ | |
411 | return -EINVAL; \ | |
412 | \ | |
29464f28 | 413 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
414 | if (ret != 1) \ |
415 | return -EINVAL; \ | |
416 | \ | |
7970e08b TR |
417 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
418 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
419 | \ |
420 | return ret ? ret : count; \ | |
421 | } | |
422 | ||
29464f28 DJ |
423 | store_one(scaling_min_freq, min); |
424 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
425 | |
426 | /** | |
427 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
428 | */ | |
905d77cd DJ |
429 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
430 | char *buf) | |
1da177e4 | 431 | { |
5a01f2e8 | 432 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
433 | if (!cur_freq) |
434 | return sprintf(buf, "<unknown>"); | |
435 | return sprintf(buf, "%u\n", cur_freq); | |
436 | } | |
437 | ||
438 | ||
439 | /** | |
440 | * show_scaling_governor - show the current policy for the specified CPU | |
441 | */ | |
905d77cd | 442 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 443 | { |
29464f28 | 444 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
445 | return sprintf(buf, "powersave\n"); |
446 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
447 | return sprintf(buf, "performance\n"); | |
448 | else if (policy->governor) | |
4b972f0b | 449 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 450 | policy->governor->name); |
1da177e4 LT |
451 | return -EINVAL; |
452 | } | |
453 | ||
454 | ||
455 | /** | |
456 | * store_scaling_governor - store policy for the specified CPU | |
457 | */ | |
905d77cd DJ |
458 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
459 | const char *buf, size_t count) | |
1da177e4 | 460 | { |
f55c9c26 | 461 | unsigned int ret; |
1da177e4 LT |
462 | char str_governor[16]; |
463 | struct cpufreq_policy new_policy; | |
464 | ||
465 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
466 | if (ret) | |
467 | return ret; | |
468 | ||
29464f28 | 469 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
470 | if (ret != 1) |
471 | return -EINVAL; | |
472 | ||
e08f5f5b GS |
473 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
474 | &new_policy.governor)) | |
1da177e4 LT |
475 | return -EINVAL; |
476 | ||
7970e08b TR |
477 | /* Do not use cpufreq_set_policy here or the user_policy.max |
478 | will be wrongly overridden */ | |
7970e08b TR |
479 | ret = __cpufreq_set_policy(policy, &new_policy); |
480 | ||
481 | policy->user_policy.policy = policy->policy; | |
482 | policy->user_policy.governor = policy->governor; | |
7970e08b | 483 | |
e08f5f5b GS |
484 | if (ret) |
485 | return ret; | |
486 | else | |
487 | return count; | |
1da177e4 LT |
488 | } |
489 | ||
490 | /** | |
491 | * show_scaling_driver - show the cpufreq driver currently loaded | |
492 | */ | |
905d77cd | 493 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 494 | { |
4b972f0b | 495 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
496 | } |
497 | ||
498 | /** | |
499 | * show_scaling_available_governors - show the available CPUfreq governors | |
500 | */ | |
905d77cd DJ |
501 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
502 | char *buf) | |
1da177e4 LT |
503 | { |
504 | ssize_t i = 0; | |
505 | struct cpufreq_governor *t; | |
506 | ||
507 | if (!cpufreq_driver->target) { | |
508 | i += sprintf(buf, "performance powersave"); | |
509 | goto out; | |
510 | } | |
511 | ||
512 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
513 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
514 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 515 | goto out; |
4b972f0b | 516 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 517 | } |
7d5e350f | 518 | out: |
1da177e4 LT |
519 | i += sprintf(&buf[i], "\n"); |
520 | return i; | |
521 | } | |
e8628dd0 | 522 | |
835481d9 | 523 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
524 | { |
525 | ssize_t i = 0; | |
526 | unsigned int cpu; | |
527 | ||
835481d9 | 528 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
529 | if (i) |
530 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
531 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
532 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 533 | break; |
1da177e4 LT |
534 | } |
535 | i += sprintf(&buf[i], "\n"); | |
536 | return i; | |
537 | } | |
538 | ||
e8628dd0 DW |
539 | /** |
540 | * show_related_cpus - show the CPUs affected by each transition even if | |
541 | * hw coordination is in use | |
542 | */ | |
543 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
544 | { | |
e8628dd0 DW |
545 | return show_cpus(policy->related_cpus, buf); |
546 | } | |
547 | ||
548 | /** | |
549 | * show_affected_cpus - show the CPUs affected by each transition | |
550 | */ | |
551 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
552 | { | |
553 | return show_cpus(policy->cpus, buf); | |
554 | } | |
555 | ||
9e76988e | 556 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 557 | const char *buf, size_t count) |
9e76988e VP |
558 | { |
559 | unsigned int freq = 0; | |
560 | unsigned int ret; | |
561 | ||
879000f9 | 562 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
563 | return -EINVAL; |
564 | ||
565 | ret = sscanf(buf, "%u", &freq); | |
566 | if (ret != 1) | |
567 | return -EINVAL; | |
568 | ||
569 | policy->governor->store_setspeed(policy, freq); | |
570 | ||
571 | return count; | |
572 | } | |
573 | ||
574 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
575 | { | |
879000f9 | 576 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
577 | return sprintf(buf, "<unsupported>\n"); |
578 | ||
579 | return policy->governor->show_setspeed(policy, buf); | |
580 | } | |
1da177e4 | 581 | |
e2f74f35 | 582 | /** |
8bf1ac72 | 583 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
584 | */ |
585 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
586 | { | |
587 | unsigned int limit; | |
588 | int ret; | |
589 | if (cpufreq_driver->bios_limit) { | |
590 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
591 | if (!ret) | |
592 | return sprintf(buf, "%u\n", limit); | |
593 | } | |
594 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
595 | } | |
596 | ||
6dad2a29 BP |
597 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
598 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
599 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
600 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
601 | cpufreq_freq_attr_ro(scaling_available_governors); | |
602 | cpufreq_freq_attr_ro(scaling_driver); | |
603 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
604 | cpufreq_freq_attr_ro(bios_limit); | |
605 | cpufreq_freq_attr_ro(related_cpus); | |
606 | cpufreq_freq_attr_ro(affected_cpus); | |
607 | cpufreq_freq_attr_rw(scaling_min_freq); | |
608 | cpufreq_freq_attr_rw(scaling_max_freq); | |
609 | cpufreq_freq_attr_rw(scaling_governor); | |
610 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 611 | |
905d77cd | 612 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
613 | &cpuinfo_min_freq.attr, |
614 | &cpuinfo_max_freq.attr, | |
ed129784 | 615 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
616 | &scaling_min_freq.attr, |
617 | &scaling_max_freq.attr, | |
618 | &affected_cpus.attr, | |
e8628dd0 | 619 | &related_cpus.attr, |
1da177e4 LT |
620 | &scaling_governor.attr, |
621 | &scaling_driver.attr, | |
622 | &scaling_available_governors.attr, | |
9e76988e | 623 | &scaling_setspeed.attr, |
1da177e4 LT |
624 | NULL |
625 | }; | |
626 | ||
8aa84ad8 TR |
627 | struct kobject *cpufreq_global_kobject; |
628 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
629 | ||
29464f28 DJ |
630 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
631 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 632 | |
29464f28 | 633 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 634 | { |
905d77cd DJ |
635 | struct cpufreq_policy *policy = to_policy(kobj); |
636 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 637 | ssize_t ret = -EINVAL; |
a9144436 | 638 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 639 | if (!policy) |
0db4a8a9 | 640 | goto no_policy; |
5a01f2e8 VP |
641 | |
642 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 643 | goto fail; |
5a01f2e8 | 644 | |
e08f5f5b GS |
645 | if (fattr->show) |
646 | ret = fattr->show(policy, buf); | |
647 | else | |
648 | ret = -EIO; | |
649 | ||
5a01f2e8 | 650 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 651 | fail: |
a9144436 | 652 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 653 | no_policy: |
1da177e4 LT |
654 | return ret; |
655 | } | |
656 | ||
905d77cd DJ |
657 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
658 | const char *buf, size_t count) | |
1da177e4 | 659 | { |
905d77cd DJ |
660 | struct cpufreq_policy *policy = to_policy(kobj); |
661 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 662 | ssize_t ret = -EINVAL; |
a9144436 | 663 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 664 | if (!policy) |
a07530b4 | 665 | goto no_policy; |
5a01f2e8 VP |
666 | |
667 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 668 | goto fail; |
5a01f2e8 | 669 | |
e08f5f5b GS |
670 | if (fattr->store) |
671 | ret = fattr->store(policy, buf, count); | |
672 | else | |
673 | ret = -EIO; | |
674 | ||
5a01f2e8 | 675 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 676 | fail: |
a9144436 | 677 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 678 | no_policy: |
1da177e4 LT |
679 | return ret; |
680 | } | |
681 | ||
905d77cd | 682 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 683 | { |
905d77cd | 684 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 685 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
686 | complete(&policy->kobj_unregister); |
687 | } | |
688 | ||
52cf25d0 | 689 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
690 | .show = show, |
691 | .store = store, | |
692 | }; | |
693 | ||
694 | static struct kobj_type ktype_cpufreq = { | |
695 | .sysfs_ops = &sysfs_ops, | |
696 | .default_attrs = default_attrs, | |
697 | .release = cpufreq_sysfs_release, | |
698 | }; | |
699 | ||
19d6f7ec | 700 | /* symlink affected CPUs */ |
cf3289d0 AC |
701 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
702 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
703 | { |
704 | unsigned int j; | |
705 | int ret = 0; | |
706 | ||
707 | for_each_cpu(j, policy->cpus) { | |
708 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 709 | struct device *cpu_dev; |
19d6f7ec DJ |
710 | |
711 | if (j == cpu) | |
712 | continue; | |
19d6f7ec | 713 | |
2d06d8c4 | 714 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 715 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
716 | cpu_dev = get_cpu_device(j); |
717 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
718 | "cpufreq"); |
719 | if (ret) { | |
720 | cpufreq_cpu_put(managed_policy); | |
721 | return ret; | |
722 | } | |
723 | } | |
724 | return ret; | |
725 | } | |
726 | ||
cf3289d0 AC |
727 | static int cpufreq_add_dev_interface(unsigned int cpu, |
728 | struct cpufreq_policy *policy, | |
8a25a2fd | 729 | struct device *dev) |
909a694e | 730 | { |
ecf7e461 | 731 | struct cpufreq_policy new_policy; |
909a694e DJ |
732 | struct freq_attr **drv_attr; |
733 | unsigned long flags; | |
734 | int ret = 0; | |
735 | unsigned int j; | |
736 | ||
737 | /* prepare interface data */ | |
738 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 739 | &dev->kobj, "cpufreq"); |
909a694e DJ |
740 | if (ret) |
741 | return ret; | |
742 | ||
743 | /* set up files for this cpu device */ | |
744 | drv_attr = cpufreq_driver->attr; | |
745 | while ((drv_attr) && (*drv_attr)) { | |
746 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
747 | if (ret) | |
748 | goto err_out_kobj_put; | |
749 | drv_attr++; | |
750 | } | |
751 | if (cpufreq_driver->get) { | |
752 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
753 | if (ret) | |
754 | goto err_out_kobj_put; | |
755 | } | |
756 | if (cpufreq_driver->target) { | |
757 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
758 | if (ret) | |
759 | goto err_out_kobj_put; | |
760 | } | |
e2f74f35 TR |
761 | if (cpufreq_driver->bios_limit) { |
762 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
763 | if (ret) | |
764 | goto err_out_kobj_put; | |
765 | } | |
909a694e DJ |
766 | |
767 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
768 | for_each_cpu(j, policy->cpus) { | |
909a694e | 769 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 770 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
771 | } |
772 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
773 | ||
774 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
775 | if (ret) |
776 | goto err_out_kobj_put; | |
777 | ||
778 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
779 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
780 | policy->governor = NULL; | |
781 | ||
782 | /* set default policy */ | |
783 | ret = __cpufreq_set_policy(policy, &new_policy); | |
784 | policy->user_policy.policy = policy->policy; | |
785 | policy->user_policy.governor = policy->governor; | |
786 | ||
787 | if (ret) { | |
2d06d8c4 | 788 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
789 | if (cpufreq_driver->exit) |
790 | cpufreq_driver->exit(policy); | |
791 | } | |
909a694e DJ |
792 | return ret; |
793 | ||
794 | err_out_kobj_put: | |
795 | kobject_put(&policy->kobj); | |
796 | wait_for_completion(&policy->kobj_unregister); | |
797 | return ret; | |
798 | } | |
799 | ||
fcf80582 VK |
800 | #ifdef CONFIG_HOTPLUG_CPU |
801 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
802 | struct device *dev) | |
803 | { | |
804 | struct cpufreq_policy *policy; | |
805 | int ret = 0; | |
806 | unsigned long flags; | |
807 | ||
808 | policy = cpufreq_cpu_get(sibling); | |
809 | WARN_ON(!policy); | |
810 | ||
811 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; | |
812 | ||
813 | lock_policy_rwsem_write(cpu); | |
814 | ||
815 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
816 | ||
817 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
818 | cpumask_set_cpu(cpu, policy->cpus); | |
819 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
820 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
821 | ||
822 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
823 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
824 | ||
825 | unlock_policy_rwsem_write(cpu); | |
826 | ||
827 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); | |
828 | if (ret) { | |
829 | cpufreq_cpu_put(policy); | |
830 | return ret; | |
831 | } | |
832 | ||
833 | return 0; | |
834 | } | |
835 | #endif | |
1da177e4 LT |
836 | |
837 | /** | |
838 | * cpufreq_add_dev - add a CPU device | |
839 | * | |
32ee8c3e | 840 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
841 | * |
842 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
843 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
844 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 845 | */ |
8a25a2fd | 846 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 847 | { |
fcf80582 | 848 | unsigned int j, cpu = dev->id; |
65922465 | 849 | int ret = -ENOMEM; |
1da177e4 | 850 | struct cpufreq_policy *policy; |
1da177e4 | 851 | unsigned long flags; |
90e41bac | 852 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 853 | struct cpufreq_governor *gov; |
90e41bac PB |
854 | int sibling; |
855 | #endif | |
1da177e4 | 856 | |
c32b6b8e AR |
857 | if (cpu_is_offline(cpu)) |
858 | return 0; | |
859 | ||
2d06d8c4 | 860 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
861 | |
862 | #ifdef CONFIG_SMP | |
863 | /* check whether a different CPU already registered this | |
864 | * CPU because it is in the same boat. */ | |
865 | policy = cpufreq_cpu_get(cpu); | |
866 | if (unlikely(policy)) { | |
8ff69732 | 867 | cpufreq_cpu_put(policy); |
1da177e4 LT |
868 | return 0; |
869 | } | |
fcf80582 VK |
870 | |
871 | #ifdef CONFIG_HOTPLUG_CPU | |
872 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
873 | for_each_online_cpu(sibling) { | |
874 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
875 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) | |
876 | return cpufreq_add_policy_cpu(cpu, sibling, dev); | |
877 | } | |
878 | #endif | |
1da177e4 LT |
879 | #endif |
880 | ||
881 | if (!try_module_get(cpufreq_driver->owner)) { | |
882 | ret = -EINVAL; | |
883 | goto module_out; | |
884 | } | |
885 | ||
e98df50c | 886 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 887 | if (!policy) |
1da177e4 | 888 | goto nomem_out; |
059019a3 DJ |
889 | |
890 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 891 | goto err_free_policy; |
059019a3 DJ |
892 | |
893 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 894 | goto err_free_cpumask; |
1da177e4 LT |
895 | |
896 | policy->cpu = cpu; | |
65922465 | 897 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 898 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 899 | |
5a01f2e8 | 900 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 901 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
902 | ret = (lock_policy_rwsem_write(cpu) < 0); |
903 | WARN_ON(ret); | |
5a01f2e8 | 904 | |
1da177e4 | 905 | init_completion(&policy->kobj_unregister); |
65f27f38 | 906 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
907 | |
908 | /* call driver. From then on the cpufreq must be able | |
909 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
910 | */ | |
911 | ret = cpufreq_driver->init(policy); | |
912 | if (ret) { | |
2d06d8c4 | 913 | pr_debug("initialization failed\n"); |
3f4a782b | 914 | goto err_unlock_policy; |
1da177e4 | 915 | } |
643ae6e8 | 916 | |
fcf80582 VK |
917 | /* related cpus should atleast have policy->cpus */ |
918 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
919 | ||
643ae6e8 VK |
920 | /* |
921 | * affected cpus must always be the one, which are online. We aren't | |
922 | * managing offline cpus here. | |
923 | */ | |
924 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
925 | ||
187d9f4e MC |
926 | policy->user_policy.min = policy->min; |
927 | policy->user_policy.max = policy->max; | |
1da177e4 | 928 | |
a1531acd TR |
929 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
930 | CPUFREQ_START, policy); | |
931 | ||
fcf80582 VK |
932 | #ifdef CONFIG_HOTPLUG_CPU |
933 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
934 | if (gov) { | |
935 | policy->governor = gov; | |
936 | pr_debug("Restoring governor %s for cpu %d\n", | |
937 | policy->governor->name, cpu); | |
4bfa042c | 938 | } |
fcf80582 | 939 | #endif |
1da177e4 | 940 | |
8a25a2fd | 941 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
942 | if (ret) |
943 | goto err_out_unregister; | |
8ff69732 | 944 | |
dca02613 LW |
945 | unlock_policy_rwsem_write(cpu); |
946 | ||
038c5b3e | 947 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 948 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 949 | pr_debug("initialization complete\n"); |
87c32271 | 950 | |
1da177e4 LT |
951 | return 0; |
952 | ||
1da177e4 LT |
953 | err_out_unregister: |
954 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 955 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 956 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
957 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
958 | ||
c10997f6 | 959 | kobject_put(&policy->kobj); |
1da177e4 LT |
960 | wait_for_completion(&policy->kobj_unregister); |
961 | ||
3f4a782b | 962 | err_unlock_policy: |
45709118 | 963 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 964 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
965 | err_free_cpumask: |
966 | free_cpumask_var(policy->cpus); | |
967 | err_free_policy: | |
1da177e4 | 968 | kfree(policy); |
1da177e4 LT |
969 | nomem_out: |
970 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 971 | module_out: |
1da177e4 LT |
972 | return ret; |
973 | } | |
974 | ||
b8eed8af VK |
975 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
976 | { | |
977 | int j; | |
978 | ||
979 | policy->last_cpu = policy->cpu; | |
980 | policy->cpu = cpu; | |
981 | ||
3361b7b1 | 982 | for_each_cpu(j, policy->cpus) |
b8eed8af | 983 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
984 | |
985 | #ifdef CONFIG_CPU_FREQ_TABLE | |
986 | cpufreq_frequency_table_update_policy_cpu(policy); | |
987 | #endif | |
988 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
989 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
990 | } | |
1da177e4 LT |
991 | |
992 | /** | |
5a01f2e8 | 993 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
994 | * |
995 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
996 | * Caller should already have policy_rwsem in write mode for this CPU. |
997 | * This routine frees the rwsem before returning. | |
1da177e4 | 998 | */ |
8a25a2fd | 999 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1000 | { |
b8eed8af | 1001 | unsigned int cpu = dev->id, ret, cpus; |
1da177e4 LT |
1002 | unsigned long flags; |
1003 | struct cpufreq_policy *data; | |
499bca9b AW |
1004 | struct kobject *kobj; |
1005 | struct completion *cmp; | |
8a25a2fd | 1006 | struct device *cpu_dev; |
1da177e4 | 1007 | |
b8eed8af | 1008 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 LT |
1009 | |
1010 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1011 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1012 | |
1013 | if (!data) { | |
b8eed8af | 1014 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 | 1015 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5a01f2e8 | 1016 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1017 | return -EINVAL; |
1018 | } | |
1da177e4 | 1019 | |
b8eed8af | 1020 | if (cpufreq_driver->target) |
f6a7409c | 1021 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
084f3493 TR |
1022 | |
1023 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1024 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1025 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1026 | #endif |
1027 | ||
b8eed8af VK |
1028 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1029 | cpus = cpumask_weight(data->cpus); | |
1030 | cpumask_clear_cpu(cpu, data->cpus); | |
1da177e4 | 1031 | |
73bf0fc2 VK |
1032 | if (cpu != data->cpu) { |
1033 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
1034 | } else if (cpus > 1) { | |
b8eed8af VK |
1035 | /* first sibling now owns the new sysfs dir */ |
1036 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1037 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1038 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1039 | if (ret) { | |
1040 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1041 | cpumask_set_cpu(cpu, data->cpus); | |
1042 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, | |
1043 | "cpufreq"); | |
1044 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
499bca9b | 1045 | unlock_policy_rwsem_write(cpu); |
b8eed8af | 1046 | return -EINVAL; |
1da177e4 | 1047 | } |
b8eed8af VK |
1048 | |
1049 | update_policy_cpu(data, cpu_dev->id); | |
1050 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", | |
1051 | __func__, cpu_dev->id, cpu); | |
1da177e4 | 1052 | } |
1da177e4 | 1053 | |
b8eed8af | 1054 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5a01f2e8 | 1055 | |
b8eed8af VK |
1056 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); |
1057 | cpufreq_cpu_put(data); | |
499bca9b | 1058 | unlock_policy_rwsem_write(cpu); |
1da177e4 | 1059 | |
b8eed8af VK |
1060 | /* If cpu is last user of policy, free policy */ |
1061 | if (cpus == 1) { | |
1062 | lock_policy_rwsem_write(cpu); | |
1063 | kobj = &data->kobj; | |
1064 | cmp = &data->kobj_unregister; | |
1065 | unlock_policy_rwsem_write(cpu); | |
1066 | kobject_put(kobj); | |
7d26e2d5 | 1067 | |
b8eed8af VK |
1068 | /* we need to make sure that the underlying kobj is actually |
1069 | * not referenced anymore by anybody before we proceed with | |
1070 | * unloading. | |
1071 | */ | |
1072 | pr_debug("waiting for dropping of refcount\n"); | |
1073 | wait_for_completion(cmp); | |
1074 | pr_debug("wait complete\n"); | |
27ecddc2 | 1075 | |
27ecddc2 | 1076 | lock_policy_rwsem_write(cpu); |
b8eed8af VK |
1077 | if (cpufreq_driver->exit) |
1078 | cpufreq_driver->exit(data); | |
1079 | unlock_policy_rwsem_write(cpu); | |
27ecddc2 | 1080 | |
b8eed8af VK |
1081 | free_cpumask_var(data->related_cpus); |
1082 | free_cpumask_var(data->cpus); | |
1083 | kfree(data); | |
1084 | } else if (cpufreq_driver->target) { | |
1085 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1086 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1087 | } | |
1da177e4 | 1088 | |
1da177e4 LT |
1089 | return 0; |
1090 | } | |
1091 | ||
1092 | ||
8a25a2fd | 1093 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1094 | { |
8a25a2fd | 1095 | unsigned int cpu = dev->id; |
5a01f2e8 | 1096 | int retval; |
ec28297a VP |
1097 | |
1098 | if (cpu_is_offline(cpu)) | |
1099 | return 0; | |
1100 | ||
5a01f2e8 VP |
1101 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1102 | BUG(); | |
1103 | ||
8a25a2fd | 1104 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1105 | return retval; |
1106 | } | |
1107 | ||
1108 | ||
65f27f38 | 1109 | static void handle_update(struct work_struct *work) |
1da177e4 | 1110 | { |
65f27f38 DH |
1111 | struct cpufreq_policy *policy = |
1112 | container_of(work, struct cpufreq_policy, update); | |
1113 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1114 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1115 | cpufreq_update_policy(cpu); |
1116 | } | |
1117 | ||
1118 | /** | |
1119 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1120 | * @cpu: cpu number | |
1121 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1122 | * @new_freq: CPU frequency the CPU actually runs at | |
1123 | * | |
29464f28 DJ |
1124 | * We adjust to current frequency first, and need to clean up later. |
1125 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1126 | */ |
e08f5f5b GS |
1127 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1128 | unsigned int new_freq) | |
1da177e4 LT |
1129 | { |
1130 | struct cpufreq_freqs freqs; | |
1131 | ||
2d06d8c4 | 1132 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1133 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1134 | ||
1135 | freqs.cpu = cpu; | |
1136 | freqs.old = old_freq; | |
1137 | freqs.new = new_freq; | |
1138 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1139 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1140 | } | |
1141 | ||
1142 | ||
32ee8c3e | 1143 | /** |
4ab70df4 | 1144 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1145 | * @cpu: CPU number |
1146 | * | |
1147 | * This is the last known freq, without actually getting it from the driver. | |
1148 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1149 | */ | |
1150 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1151 | { | |
1152 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1153 | unsigned int ret_freq = 0; |
95235ca2 VP |
1154 | |
1155 | if (policy) { | |
e08f5f5b | 1156 | ret_freq = policy->cur; |
95235ca2 VP |
1157 | cpufreq_cpu_put(policy); |
1158 | } | |
1159 | ||
4d34a67d | 1160 | return ret_freq; |
95235ca2 VP |
1161 | } |
1162 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1163 | ||
3d737108 JB |
1164 | /** |
1165 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1166 | * @cpu: CPU number | |
1167 | * | |
1168 | * Just return the max possible frequency for a given CPU. | |
1169 | */ | |
1170 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1171 | { | |
1172 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1173 | unsigned int ret_freq = 0; | |
1174 | ||
1175 | if (policy) { | |
1176 | ret_freq = policy->max; | |
1177 | cpufreq_cpu_put(policy); | |
1178 | } | |
1179 | ||
1180 | return ret_freq; | |
1181 | } | |
1182 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1183 | ||
95235ca2 | 1184 | |
5a01f2e8 | 1185 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1186 | { |
7a6aedfa | 1187 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1188 | unsigned int ret_freq = 0; |
1da177e4 | 1189 | |
1da177e4 | 1190 | if (!cpufreq_driver->get) |
4d34a67d | 1191 | return ret_freq; |
1da177e4 | 1192 | |
e08f5f5b | 1193 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1194 | |
e08f5f5b GS |
1195 | if (ret_freq && policy->cur && |
1196 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1197 | /* verify no discrepancy between actual and | |
1198 | saved value exists */ | |
1199 | if (unlikely(ret_freq != policy->cur)) { | |
1200 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1201 | schedule_work(&policy->update); |
1202 | } | |
1203 | } | |
1204 | ||
4d34a67d | 1205 | return ret_freq; |
5a01f2e8 | 1206 | } |
1da177e4 | 1207 | |
5a01f2e8 VP |
1208 | /** |
1209 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1210 | * @cpu: CPU number | |
1211 | * | |
1212 | * Get the CPU current (static) CPU frequency | |
1213 | */ | |
1214 | unsigned int cpufreq_get(unsigned int cpu) | |
1215 | { | |
1216 | unsigned int ret_freq = 0; | |
1217 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1218 | ||
1219 | if (!policy) | |
1220 | goto out; | |
1221 | ||
1222 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1223 | goto out_policy; | |
1224 | ||
1225 | ret_freq = __cpufreq_get(cpu); | |
1226 | ||
1227 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1228 | |
5a01f2e8 VP |
1229 | out_policy: |
1230 | cpufreq_cpu_put(policy); | |
1231 | out: | |
4d34a67d | 1232 | return ret_freq; |
1da177e4 LT |
1233 | } |
1234 | EXPORT_SYMBOL(cpufreq_get); | |
1235 | ||
8a25a2fd KS |
1236 | static struct subsys_interface cpufreq_interface = { |
1237 | .name = "cpufreq", | |
1238 | .subsys = &cpu_subsys, | |
1239 | .add_dev = cpufreq_add_dev, | |
1240 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1241 | }; |
1242 | ||
1da177e4 | 1243 | |
42d4dc3f | 1244 | /** |
e00e56df RW |
1245 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1246 | * | |
1247 | * This function is only executed for the boot processor. The other CPUs | |
1248 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1249 | */ |
e00e56df | 1250 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1251 | { |
e08f5f5b | 1252 | int ret = 0; |
4bc5d341 | 1253 | |
e00e56df | 1254 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1255 | struct cpufreq_policy *cpu_policy; |
1256 | ||
2d06d8c4 | 1257 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1258 | |
e00e56df | 1259 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1260 | cpu_policy = cpufreq_cpu_get(cpu); |
1261 | if (!cpu_policy) | |
e00e56df | 1262 | return 0; |
42d4dc3f BH |
1263 | |
1264 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1265 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1266 | if (ret) |
42d4dc3f BH |
1267 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1268 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1269 | } |
1270 | ||
42d4dc3f | 1271 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1272 | return ret; |
42d4dc3f BH |
1273 | } |
1274 | ||
1da177e4 | 1275 | /** |
e00e56df | 1276 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1277 | * |
1278 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1279 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1280 | * restored. It will verify that the current freq is in sync with | |
1281 | * what we believe it to be. This is a bit later than when it | |
1282 | * should be, but nonethteless it's better than calling | |
1283 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1284 | * |
1285 | * This function is only executed for the boot CPU. The other CPUs have not | |
1286 | * been turned on yet. | |
1da177e4 | 1287 | */ |
e00e56df | 1288 | static void cpufreq_bp_resume(void) |
1da177e4 | 1289 | { |
e08f5f5b | 1290 | int ret = 0; |
4bc5d341 | 1291 | |
e00e56df | 1292 | int cpu = smp_processor_id(); |
1da177e4 LT |
1293 | struct cpufreq_policy *cpu_policy; |
1294 | ||
2d06d8c4 | 1295 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1296 | |
e00e56df | 1297 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1298 | cpu_policy = cpufreq_cpu_get(cpu); |
1299 | if (!cpu_policy) | |
e00e56df | 1300 | return; |
1da177e4 LT |
1301 | |
1302 | if (cpufreq_driver->resume) { | |
1303 | ret = cpufreq_driver->resume(cpu_policy); | |
1304 | if (ret) { | |
1305 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1306 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1307 | goto fail; |
1da177e4 LT |
1308 | } |
1309 | } | |
1310 | ||
1da177e4 | 1311 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1312 | |
c9060494 | 1313 | fail: |
1da177e4 | 1314 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1315 | } |
1316 | ||
e00e56df RW |
1317 | static struct syscore_ops cpufreq_syscore_ops = { |
1318 | .suspend = cpufreq_bp_suspend, | |
1319 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1320 | }; |
1321 | ||
9d95046e BP |
1322 | /** |
1323 | * cpufreq_get_current_driver - return current driver's name | |
1324 | * | |
1325 | * Return the name string of the currently loaded cpufreq driver | |
1326 | * or NULL, if none. | |
1327 | */ | |
1328 | const char *cpufreq_get_current_driver(void) | |
1329 | { | |
1330 | if (cpufreq_driver) | |
1331 | return cpufreq_driver->name; | |
1332 | ||
1333 | return NULL; | |
1334 | } | |
1335 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1336 | |
1337 | /********************************************************************* | |
1338 | * NOTIFIER LISTS INTERFACE * | |
1339 | *********************************************************************/ | |
1340 | ||
1341 | /** | |
1342 | * cpufreq_register_notifier - register a driver with cpufreq | |
1343 | * @nb: notifier function to register | |
1344 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1345 | * | |
32ee8c3e | 1346 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1347 | * are notified about clock rate changes (once before and once after |
1348 | * the transition), or a list of drivers that are notified about | |
1349 | * changes in cpufreq policy. | |
1350 | * | |
1351 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1352 | * blocking_notifier_chain_register. |
1da177e4 LT |
1353 | */ |
1354 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1355 | { | |
1356 | int ret; | |
1357 | ||
d5aaffa9 DB |
1358 | if (cpufreq_disabled()) |
1359 | return -EINVAL; | |
1360 | ||
74212ca4 CEB |
1361 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1362 | ||
1da177e4 LT |
1363 | switch (list) { |
1364 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1365 | ret = srcu_notifier_chain_register( |
e041c683 | 1366 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1367 | break; |
1368 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1369 | ret = blocking_notifier_chain_register( |
1370 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1371 | break; |
1372 | default: | |
1373 | ret = -EINVAL; | |
1374 | } | |
1da177e4 LT |
1375 | |
1376 | return ret; | |
1377 | } | |
1378 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1379 | ||
1380 | ||
1381 | /** | |
1382 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1383 | * @nb: notifier block to be unregistered | |
1384 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1385 | * | |
1386 | * Remove a driver from the CPU frequency notifier list. | |
1387 | * | |
1388 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1389 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1390 | */ |
1391 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1392 | { | |
1393 | int ret; | |
1394 | ||
d5aaffa9 DB |
1395 | if (cpufreq_disabled()) |
1396 | return -EINVAL; | |
1397 | ||
1da177e4 LT |
1398 | switch (list) { |
1399 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1400 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1401 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1402 | break; |
1403 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1404 | ret = blocking_notifier_chain_unregister( |
1405 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1406 | break; |
1407 | default: | |
1408 | ret = -EINVAL; | |
1409 | } | |
1da177e4 LT |
1410 | |
1411 | return ret; | |
1412 | } | |
1413 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1414 | ||
1415 | ||
1416 | /********************************************************************* | |
1417 | * GOVERNORS * | |
1418 | *********************************************************************/ | |
1419 | ||
1420 | ||
1421 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1422 | unsigned int target_freq, | |
1423 | unsigned int relation) | |
1424 | { | |
1425 | int retval = -EINVAL; | |
7249924e | 1426 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1427 | |
a7b422cd KRW |
1428 | if (cpufreq_disabled()) |
1429 | return -ENODEV; | |
1430 | ||
7249924e VK |
1431 | /* Make sure that target_freq is within supported range */ |
1432 | if (target_freq > policy->max) | |
1433 | target_freq = policy->max; | |
1434 | if (target_freq < policy->min) | |
1435 | target_freq = policy->min; | |
1436 | ||
1437 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1438 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1439 | |
1440 | if (target_freq == policy->cur) | |
1441 | return 0; | |
1442 | ||
3361b7b1 | 1443 | if (cpufreq_driver->target) |
1da177e4 | 1444 | retval = cpufreq_driver->target(policy, target_freq, relation); |
90d45d17 | 1445 | |
1da177e4 LT |
1446 | return retval; |
1447 | } | |
1448 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1449 | ||
1da177e4 LT |
1450 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1451 | unsigned int target_freq, | |
1452 | unsigned int relation) | |
1453 | { | |
f1829e4a | 1454 | int ret = -EINVAL; |
1da177e4 LT |
1455 | |
1456 | policy = cpufreq_cpu_get(policy->cpu); | |
1457 | if (!policy) | |
f1829e4a | 1458 | goto no_policy; |
1da177e4 | 1459 | |
5a01f2e8 | 1460 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1461 | goto fail; |
1da177e4 LT |
1462 | |
1463 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1464 | ||
5a01f2e8 | 1465 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1466 | |
f1829e4a | 1467 | fail: |
1da177e4 | 1468 | cpufreq_cpu_put(policy); |
f1829e4a | 1469 | no_policy: |
1da177e4 LT |
1470 | return ret; |
1471 | } | |
1472 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1473 | ||
bf0b90e3 | 1474 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1475 | { |
1476 | int ret = 0; | |
1477 | ||
d5aaffa9 DB |
1478 | if (cpufreq_disabled()) |
1479 | return ret; | |
1480 | ||
3361b7b1 | 1481 | if (!cpufreq_driver->getavg) |
0676f7f2 VK |
1482 | return 0; |
1483 | ||
dfde5d62 VP |
1484 | policy = cpufreq_cpu_get(policy->cpu); |
1485 | if (!policy) | |
1486 | return -EINVAL; | |
1487 | ||
0676f7f2 | 1488 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1489 | |
dfde5d62 VP |
1490 | cpufreq_cpu_put(policy); |
1491 | return ret; | |
1492 | } | |
5a01f2e8 | 1493 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1494 | |
153d7f3f | 1495 | /* |
153d7f3f AV |
1496 | * when "event" is CPUFREQ_GOV_LIMITS |
1497 | */ | |
1da177e4 | 1498 | |
e08f5f5b GS |
1499 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1500 | unsigned int event) | |
1da177e4 | 1501 | { |
cc993cab | 1502 | int ret; |
6afde10c TR |
1503 | |
1504 | /* Only must be defined when default governor is known to have latency | |
1505 | restrictions, like e.g. conservative or ondemand. | |
1506 | That this is the case is already ensured in Kconfig | |
1507 | */ | |
1508 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1509 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1510 | #else | |
1511 | struct cpufreq_governor *gov = NULL; | |
1512 | #endif | |
1c256245 TR |
1513 | |
1514 | if (policy->governor->max_transition_latency && | |
1515 | policy->cpuinfo.transition_latency > | |
1516 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1517 | if (!gov) |
1518 | return -EINVAL; | |
1519 | else { | |
1520 | printk(KERN_WARNING "%s governor failed, too long" | |
1521 | " transition latency of HW, fallback" | |
1522 | " to %s governor\n", | |
1523 | policy->governor->name, | |
1524 | gov->name); | |
1525 | policy->governor = gov; | |
1526 | } | |
1c256245 | 1527 | } |
1da177e4 LT |
1528 | |
1529 | if (!try_module_get(policy->governor->owner)) | |
1530 | return -EINVAL; | |
1531 | ||
2d06d8c4 | 1532 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1533 | policy->cpu, event); |
1da177e4 LT |
1534 | ret = policy->governor->governor(policy, event); |
1535 | ||
8e53695f VK |
1536 | if (event == CPUFREQ_GOV_START) |
1537 | policy->governor->initialized++; | |
1538 | else if (event == CPUFREQ_GOV_STOP) | |
1539 | policy->governor->initialized--; | |
b394058f | 1540 | |
e08f5f5b GS |
1541 | /* we keep one module reference alive for |
1542 | each CPU governed by this CPU */ | |
1da177e4 LT |
1543 | if ((event != CPUFREQ_GOV_START) || ret) |
1544 | module_put(policy->governor->owner); | |
1545 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1546 | module_put(policy->governor->owner); | |
1547 | ||
1548 | return ret; | |
1549 | } | |
1550 | ||
1551 | ||
1da177e4 LT |
1552 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1553 | { | |
3bcb09a3 | 1554 | int err; |
1da177e4 LT |
1555 | |
1556 | if (!governor) | |
1557 | return -EINVAL; | |
1558 | ||
a7b422cd KRW |
1559 | if (cpufreq_disabled()) |
1560 | return -ENODEV; | |
1561 | ||
3fc54d37 | 1562 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1563 | |
b394058f | 1564 | governor->initialized = 0; |
3bcb09a3 JF |
1565 | err = -EBUSY; |
1566 | if (__find_governor(governor->name) == NULL) { | |
1567 | err = 0; | |
1568 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1569 | } |
1da177e4 | 1570 | |
32ee8c3e | 1571 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1572 | return err; |
1da177e4 LT |
1573 | } |
1574 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1575 | ||
1576 | ||
1577 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1578 | { | |
90e41bac PB |
1579 | #ifdef CONFIG_HOTPLUG_CPU |
1580 | int cpu; | |
1581 | #endif | |
1582 | ||
1da177e4 LT |
1583 | if (!governor) |
1584 | return; | |
1585 | ||
a7b422cd KRW |
1586 | if (cpufreq_disabled()) |
1587 | return; | |
1588 | ||
90e41bac PB |
1589 | #ifdef CONFIG_HOTPLUG_CPU |
1590 | for_each_present_cpu(cpu) { | |
1591 | if (cpu_online(cpu)) | |
1592 | continue; | |
1593 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1594 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1595 | } | |
1596 | #endif | |
1597 | ||
3fc54d37 | 1598 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1599 | list_del(&governor->governor_list); |
3fc54d37 | 1600 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1601 | return; |
1602 | } | |
1603 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1604 | ||
1605 | ||
1606 | ||
1607 | /********************************************************************* | |
1608 | * POLICY INTERFACE * | |
1609 | *********************************************************************/ | |
1610 | ||
1611 | /** | |
1612 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1613 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1614 | * is written | |
1da177e4 LT |
1615 | * |
1616 | * Reads the current cpufreq policy. | |
1617 | */ | |
1618 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1619 | { | |
1620 | struct cpufreq_policy *cpu_policy; | |
1621 | if (!policy) | |
1622 | return -EINVAL; | |
1623 | ||
1624 | cpu_policy = cpufreq_cpu_get(cpu); | |
1625 | if (!cpu_policy) | |
1626 | return -EINVAL; | |
1627 | ||
1da177e4 | 1628 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1629 | |
1630 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1631 | return 0; |
1632 | } | |
1633 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1634 | ||
1635 | ||
153d7f3f | 1636 | /* |
e08f5f5b GS |
1637 | * data : current policy. |
1638 | * policy : policy to be set. | |
153d7f3f | 1639 | */ |
e08f5f5b GS |
1640 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1641 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1642 | { |
1643 | int ret = 0; | |
1644 | ||
2d06d8c4 | 1645 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1646 | policy->min, policy->max); |
1647 | ||
e08f5f5b GS |
1648 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1649 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1650 | |
53391fa2 | 1651 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1652 | ret = -EINVAL; |
1653 | goto error_out; | |
1654 | } | |
1655 | ||
1da177e4 LT |
1656 | /* verify the cpu speed can be set within this limit */ |
1657 | ret = cpufreq_driver->verify(policy); | |
1658 | if (ret) | |
1659 | goto error_out; | |
1660 | ||
1da177e4 | 1661 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1662 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1663 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1664 | |
1665 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1666 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1667 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1668 | |
1669 | /* verify the cpu speed can be set within this limit, | |
1670 | which might be different to the first one */ | |
1671 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1672 | if (ret) |
1da177e4 | 1673 | goto error_out; |
1da177e4 LT |
1674 | |
1675 | /* notification of the new policy */ | |
e041c683 AS |
1676 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1677 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1678 | |
7d5e350f DJ |
1679 | data->min = policy->min; |
1680 | data->max = policy->max; | |
1da177e4 | 1681 | |
2d06d8c4 | 1682 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1683 | data->min, data->max); |
1da177e4 LT |
1684 | |
1685 | if (cpufreq_driver->setpolicy) { | |
1686 | data->policy = policy->policy; | |
2d06d8c4 | 1687 | pr_debug("setting range\n"); |
1da177e4 LT |
1688 | ret = cpufreq_driver->setpolicy(policy); |
1689 | } else { | |
1690 | if (policy->governor != data->governor) { | |
1691 | /* save old, working values */ | |
1692 | struct cpufreq_governor *old_gov = data->governor; | |
1693 | ||
2d06d8c4 | 1694 | pr_debug("governor switch\n"); |
1da177e4 LT |
1695 | |
1696 | /* end old governor */ | |
ffe6275f | 1697 | if (data->governor) |
1da177e4 LT |
1698 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1699 | ||
1700 | /* start new governor */ | |
1701 | data->governor = policy->governor; | |
1702 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1703 | /* new governor failed, so re-start old one */ | |
2d06d8c4 | 1704 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1705 | data->governor->name); |
1da177e4 LT |
1706 | if (old_gov) { |
1707 | data->governor = old_gov; | |
e08f5f5b GS |
1708 | __cpufreq_governor(data, |
1709 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1710 | } |
1711 | ret = -EINVAL; | |
1712 | goto error_out; | |
1713 | } | |
1714 | /* might be a policy change, too, so fall through */ | |
1715 | } | |
2d06d8c4 | 1716 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1717 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1718 | } | |
1719 | ||
7d5e350f | 1720 | error_out: |
1da177e4 LT |
1721 | return ret; |
1722 | } | |
1723 | ||
1da177e4 LT |
1724 | /** |
1725 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1726 | * @cpu: CPU which shall be re-evaluated | |
1727 | * | |
25985edc | 1728 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1729 | * at different times. |
1730 | */ | |
1731 | int cpufreq_update_policy(unsigned int cpu) | |
1732 | { | |
1733 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1734 | struct cpufreq_policy policy; | |
f1829e4a | 1735 | int ret; |
1da177e4 | 1736 | |
f1829e4a JL |
1737 | if (!data) { |
1738 | ret = -ENODEV; | |
1739 | goto no_policy; | |
1740 | } | |
1da177e4 | 1741 | |
f1829e4a JL |
1742 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1743 | ret = -EINVAL; | |
1744 | goto fail; | |
1745 | } | |
1da177e4 | 1746 | |
2d06d8c4 | 1747 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1748 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1749 | policy.min = data->user_policy.min; |
1750 | policy.max = data->user_policy.max; | |
1751 | policy.policy = data->user_policy.policy; | |
1752 | policy.governor = data->user_policy.governor; | |
1753 | ||
0961dd0d TR |
1754 | /* BIOS might change freq behind our back |
1755 | -> ask driver for current freq and notify governors about a change */ | |
1756 | if (cpufreq_driver->get) { | |
1757 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1758 | if (!data->cur) { |
2d06d8c4 | 1759 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1760 | data->cur = policy.cur; |
1761 | } else { | |
1762 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1763 | cpufreq_out_of_sync(cpu, data->cur, |
1764 | policy.cur); | |
a85f7bd3 | 1765 | } |
0961dd0d TR |
1766 | } |
1767 | ||
1da177e4 LT |
1768 | ret = __cpufreq_set_policy(data, &policy); |
1769 | ||
5a01f2e8 VP |
1770 | unlock_policy_rwsem_write(cpu); |
1771 | ||
f1829e4a | 1772 | fail: |
1da177e4 | 1773 | cpufreq_cpu_put(data); |
f1829e4a | 1774 | no_policy: |
1da177e4 LT |
1775 | return ret; |
1776 | } | |
1777 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1778 | ||
dd184a01 | 1779 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1780 | unsigned long action, void *hcpu) |
1781 | { | |
1782 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1783 | struct device *dev; |
c32b6b8e | 1784 | |
8a25a2fd KS |
1785 | dev = get_cpu_device(cpu); |
1786 | if (dev) { | |
c32b6b8e AR |
1787 | switch (action) { |
1788 | case CPU_ONLINE: | |
8bb78442 | 1789 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1790 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1791 | break; |
1792 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1793 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1794 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1795 | BUG(); | |
1796 | ||
8a25a2fd | 1797 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1798 | break; |
5a01f2e8 | 1799 | case CPU_DOWN_FAILED: |
8bb78442 | 1800 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1801 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1802 | break; |
1803 | } | |
1804 | } | |
1805 | return NOTIFY_OK; | |
1806 | } | |
1807 | ||
9c36f746 | 1808 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1809 | .notifier_call = cpufreq_cpu_callback, |
1810 | }; | |
1da177e4 LT |
1811 | |
1812 | /********************************************************************* | |
1813 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1814 | *********************************************************************/ | |
1815 | ||
1816 | /** | |
1817 | * cpufreq_register_driver - register a CPU Frequency driver | |
1818 | * @driver_data: A struct cpufreq_driver containing the values# | |
1819 | * submitted by the CPU Frequency driver. | |
1820 | * | |
32ee8c3e | 1821 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1822 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1823 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1824 | * |
1825 | */ | |
221dee28 | 1826 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1827 | { |
1828 | unsigned long flags; | |
1829 | int ret; | |
1830 | ||
a7b422cd KRW |
1831 | if (cpufreq_disabled()) |
1832 | return -ENODEV; | |
1833 | ||
1da177e4 LT |
1834 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1835 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1836 | return -EINVAL; | |
1837 | ||
2d06d8c4 | 1838 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1839 | |
1840 | if (driver_data->setpolicy) | |
1841 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1842 | ||
1843 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1844 | if (cpufreq_driver) { | |
1845 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1846 | return -EBUSY; | |
1847 | } | |
1848 | cpufreq_driver = driver_data; | |
1849 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1850 | ||
8a25a2fd | 1851 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1852 | if (ret) |
1853 | goto err_null_driver; | |
1da177e4 | 1854 | |
8f5bc2ab | 1855 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1856 | int i; |
1857 | ret = -ENODEV; | |
1858 | ||
1859 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1860 | for (i = 0; i < nr_cpu_ids; i++) |
1861 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1862 | ret = 0; |
7a6aedfa MT |
1863 | break; |
1864 | } | |
1da177e4 LT |
1865 | |
1866 | /* if all ->init() calls failed, unregister */ | |
1867 | if (ret) { | |
2d06d8c4 | 1868 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1869 | driver_data->name); |
8a25a2fd | 1870 | goto err_if_unreg; |
1da177e4 LT |
1871 | } |
1872 | } | |
1873 | ||
8f5bc2ab | 1874 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1875 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1876 | |
8f5bc2ab | 1877 | return 0; |
8a25a2fd KS |
1878 | err_if_unreg: |
1879 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1880 | err_null_driver: |
1881 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1882 | cpufreq_driver = NULL; | |
1883 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1884 | return ret; |
1da177e4 LT |
1885 | } |
1886 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1887 | ||
1888 | ||
1889 | /** | |
1890 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1891 | * | |
32ee8c3e | 1892 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1893 | * the right to do so, i.e. if you have succeeded in initialising before! |
1894 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1895 | * currently not initialised. | |
1896 | */ | |
221dee28 | 1897 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1898 | { |
1899 | unsigned long flags; | |
1900 | ||
2d06d8c4 | 1901 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1902 | return -EINVAL; |
1da177e4 | 1903 | |
2d06d8c4 | 1904 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1905 | |
8a25a2fd | 1906 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1907 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1908 | |
1909 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1910 | cpufreq_driver = NULL; | |
1911 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1912 | ||
1913 | return 0; | |
1914 | } | |
1915 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1916 | |
1917 | static int __init cpufreq_core_init(void) | |
1918 | { | |
1919 | int cpu; | |
1920 | ||
a7b422cd KRW |
1921 | if (cpufreq_disabled()) |
1922 | return -ENODEV; | |
1923 | ||
5a01f2e8 | 1924 | for_each_possible_cpu(cpu) { |
f1625066 | 1925 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1926 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1927 | } | |
8aa84ad8 | 1928 | |
8a25a2fd | 1929 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1930 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1931 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1932 | |
5a01f2e8 VP |
1933 | return 0; |
1934 | } | |
5a01f2e8 | 1935 | core_initcall(cpufreq_core_init); |