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 | |
a9144436 | 141 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
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 | ||
a9144436 | 165 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
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 | } | |
a9144436 SB |
178 | |
179 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
180 | { | |
181 | return __cpufreq_cpu_get(cpu, false); | |
182 | } | |
1da177e4 LT |
183 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
184 | ||
a9144436 SB |
185 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
186 | { | |
187 | return __cpufreq_cpu_get(cpu, true); | |
188 | } | |
189 | ||
190 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
191 | { | |
192 | if (!sysfs) | |
193 | kobject_put(&data->kobj); | |
194 | module_put(cpufreq_driver->owner); | |
195 | } | |
7d5e350f | 196 | |
1da177e4 LT |
197 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
198 | { | |
a9144436 | 199 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
200 | } |
201 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
202 | ||
a9144436 SB |
203 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
204 | { | |
205 | __cpufreq_cpu_put(data, true); | |
206 | } | |
1da177e4 | 207 | |
1da177e4 LT |
208 | /********************************************************************* |
209 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
210 | *********************************************************************/ | |
211 | ||
212 | /** | |
213 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
214 | * | |
215 | * This function alters the system "loops_per_jiffy" for the clock | |
216 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 217 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
218 | * per-CPU loops_per_jiffy value wherever possible. |
219 | */ | |
220 | #ifndef CONFIG_SMP | |
221 | static unsigned long l_p_j_ref; | |
222 | static unsigned int l_p_j_ref_freq; | |
223 | ||
858119e1 | 224 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
225 | { |
226 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
227 | return; | |
228 | ||
229 | if (!l_p_j_ref_freq) { | |
230 | l_p_j_ref = loops_per_jiffy; | |
231 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 232 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 233 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 234 | } |
d08de0c1 | 235 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 236 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
237 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
238 | ci->new); | |
2d06d8c4 | 239 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 240 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
241 | } |
242 | } | |
243 | #else | |
e08f5f5b GS |
244 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
245 | { | |
246 | return; | |
247 | } | |
1da177e4 LT |
248 | #endif |
249 | ||
250 | ||
251 | /** | |
e4472cb3 DJ |
252 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
253 | * on frequency transition. | |
1da177e4 | 254 | * |
e4472cb3 DJ |
255 | * This function calls the transition notifiers and the "adjust_jiffies" |
256 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 257 | * external effects. |
1da177e4 LT |
258 | */ |
259 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
260 | { | |
e4472cb3 DJ |
261 | struct cpufreq_policy *policy; |
262 | ||
1da177e4 LT |
263 | BUG_ON(irqs_disabled()); |
264 | ||
265 | freqs->flags = cpufreq_driver->flags; | |
2d06d8c4 | 266 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 267 | state, freqs->new); |
1da177e4 | 268 | |
7a6aedfa | 269 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 270 | switch (state) { |
e4472cb3 | 271 | |
1da177e4 | 272 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 273 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
274 | * which is not equal to what the cpufreq core thinks is |
275 | * "old frequency". | |
1da177e4 LT |
276 | */ |
277 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
278 | if ((policy) && (policy->cpu == freqs->cpu) && |
279 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 280 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
281 | " %u, cpufreq assumed %u kHz.\n", |
282 | freqs->old, policy->cur); | |
283 | freqs->old = policy->cur; | |
1da177e4 LT |
284 | } |
285 | } | |
b4dfdbb3 | 286 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 287 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
288 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
289 | break; | |
e4472cb3 | 290 | |
1da177e4 LT |
291 | case CPUFREQ_POSTCHANGE: |
292 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 293 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 TR |
294 | (unsigned long)freqs->cpu); |
295 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 296 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 297 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 298 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
299 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
300 | policy->cur = freqs->new; | |
1da177e4 LT |
301 | break; |
302 | } | |
1da177e4 LT |
303 | } |
304 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
305 | ||
306 | ||
307 | ||
308 | /********************************************************************* | |
309 | * SYSFS INTERFACE * | |
310 | *********************************************************************/ | |
311 | ||
3bcb09a3 JF |
312 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
313 | { | |
314 | struct cpufreq_governor *t; | |
315 | ||
316 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 317 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
318 | return t; |
319 | ||
320 | return NULL; | |
321 | } | |
322 | ||
1da177e4 LT |
323 | /** |
324 | * cpufreq_parse_governor - parse a governor string | |
325 | */ | |
905d77cd | 326 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
327 | struct cpufreq_governor **governor) |
328 | { | |
3bcb09a3 JF |
329 | int err = -EINVAL; |
330 | ||
1da177e4 | 331 | if (!cpufreq_driver) |
3bcb09a3 JF |
332 | goto out; |
333 | ||
1da177e4 LT |
334 | if (cpufreq_driver->setpolicy) { |
335 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
336 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 337 | err = 0; |
e08f5f5b GS |
338 | } else if (!strnicmp(str_governor, "powersave", |
339 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 340 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 341 | err = 0; |
1da177e4 | 342 | } |
3bcb09a3 | 343 | } else if (cpufreq_driver->target) { |
1da177e4 | 344 | struct cpufreq_governor *t; |
3bcb09a3 | 345 | |
3fc54d37 | 346 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
347 | |
348 | t = __find_governor(str_governor); | |
349 | ||
ea714970 | 350 | if (t == NULL) { |
1a8e1463 | 351 | int ret; |
ea714970 | 352 | |
1a8e1463 KC |
353 | mutex_unlock(&cpufreq_governor_mutex); |
354 | ret = request_module("cpufreq_%s", str_governor); | |
355 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 356 | |
1a8e1463 KC |
357 | if (ret == 0) |
358 | t = __find_governor(str_governor); | |
ea714970 JF |
359 | } |
360 | ||
3bcb09a3 JF |
361 | if (t != NULL) { |
362 | *governor = t; | |
363 | err = 0; | |
1da177e4 | 364 | } |
3bcb09a3 | 365 | |
3fc54d37 | 366 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 367 | } |
29464f28 | 368 | out: |
3bcb09a3 | 369 | return err; |
1da177e4 | 370 | } |
1da177e4 LT |
371 | |
372 | ||
1da177e4 | 373 | /** |
e08f5f5b GS |
374 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
375 | * print out cpufreq information | |
1da177e4 LT |
376 | * |
377 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
378 | * "unsigned int". | |
379 | */ | |
380 | ||
32ee8c3e DJ |
381 | #define show_one(file_name, object) \ |
382 | static ssize_t show_##file_name \ | |
905d77cd | 383 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 384 | { \ |
29464f28 | 385 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
386 | } |
387 | ||
388 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
389 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 390 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
391 | show_one(scaling_min_freq, min); |
392 | show_one(scaling_max_freq, max); | |
393 | show_one(scaling_cur_freq, cur); | |
394 | ||
e08f5f5b GS |
395 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
396 | struct cpufreq_policy *policy); | |
7970e08b | 397 | |
1da177e4 LT |
398 | /** |
399 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
400 | */ | |
401 | #define store_one(file_name, object) \ | |
402 | static ssize_t store_##file_name \ | |
905d77cd | 403 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
404 | { \ |
405 | unsigned int ret = -EINVAL; \ | |
406 | struct cpufreq_policy new_policy; \ | |
407 | \ | |
408 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
409 | if (ret) \ | |
410 | return -EINVAL; \ | |
411 | \ | |
29464f28 | 412 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
413 | if (ret != 1) \ |
414 | return -EINVAL; \ | |
415 | \ | |
7970e08b TR |
416 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
417 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
418 | \ |
419 | return ret ? ret : count; \ | |
420 | } | |
421 | ||
29464f28 DJ |
422 | store_one(scaling_min_freq, min); |
423 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
424 | |
425 | /** | |
426 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
427 | */ | |
905d77cd DJ |
428 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
429 | char *buf) | |
1da177e4 | 430 | { |
5a01f2e8 | 431 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
432 | if (!cur_freq) |
433 | return sprintf(buf, "<unknown>"); | |
434 | return sprintf(buf, "%u\n", cur_freq); | |
435 | } | |
436 | ||
437 | ||
438 | /** | |
439 | * show_scaling_governor - show the current policy for the specified CPU | |
440 | */ | |
905d77cd | 441 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 442 | { |
29464f28 | 443 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
444 | return sprintf(buf, "powersave\n"); |
445 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
446 | return sprintf(buf, "performance\n"); | |
447 | else if (policy->governor) | |
29464f28 DJ |
448 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", |
449 | policy->governor->name); | |
1da177e4 LT |
450 | return -EINVAL; |
451 | } | |
452 | ||
453 | ||
454 | /** | |
455 | * store_scaling_governor - store policy for the specified CPU | |
456 | */ | |
905d77cd DJ |
457 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
458 | const char *buf, size_t count) | |
1da177e4 LT |
459 | { |
460 | unsigned int ret = -EINVAL; | |
461 | char str_governor[16]; | |
462 | struct cpufreq_policy new_policy; | |
463 | ||
464 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
465 | if (ret) | |
466 | return ret; | |
467 | ||
29464f28 | 468 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
469 | if (ret != 1) |
470 | return -EINVAL; | |
471 | ||
e08f5f5b GS |
472 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
473 | &new_policy.governor)) | |
1da177e4 LT |
474 | return -EINVAL; |
475 | ||
7970e08b TR |
476 | /* Do not use cpufreq_set_policy here or the user_policy.max |
477 | will be wrongly overridden */ | |
7970e08b TR |
478 | ret = __cpufreq_set_policy(policy, &new_policy); |
479 | ||
480 | policy->user_policy.policy = policy->policy; | |
481 | policy->user_policy.governor = policy->governor; | |
7970e08b | 482 | |
e08f5f5b GS |
483 | if (ret) |
484 | return ret; | |
485 | else | |
486 | return count; | |
1da177e4 LT |
487 | } |
488 | ||
489 | /** | |
490 | * show_scaling_driver - show the cpufreq driver currently loaded | |
491 | */ | |
905d77cd | 492 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
493 | { |
494 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
495 | } | |
496 | ||
497 | /** | |
498 | * show_scaling_available_governors - show the available CPUfreq governors | |
499 | */ | |
905d77cd DJ |
500 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
501 | char *buf) | |
1da177e4 LT |
502 | { |
503 | ssize_t i = 0; | |
504 | struct cpufreq_governor *t; | |
505 | ||
506 | if (!cpufreq_driver->target) { | |
507 | i += sprintf(buf, "performance powersave"); | |
508 | goto out; | |
509 | } | |
510 | ||
511 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
512 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
513 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 LT |
514 | goto out; |
515 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
516 | } | |
7d5e350f | 517 | out: |
1da177e4 LT |
518 | i += sprintf(&buf[i], "\n"); |
519 | return i; | |
520 | } | |
e8628dd0 | 521 | |
835481d9 | 522 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
523 | { |
524 | ssize_t i = 0; | |
525 | unsigned int cpu; | |
526 | ||
835481d9 | 527 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
528 | if (i) |
529 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
530 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
531 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 532 | break; |
1da177e4 LT |
533 | } |
534 | i += sprintf(&buf[i], "\n"); | |
535 | return i; | |
536 | } | |
537 | ||
e8628dd0 DW |
538 | /** |
539 | * show_related_cpus - show the CPUs affected by each transition even if | |
540 | * hw coordination is in use | |
541 | */ | |
542 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
543 | { | |
835481d9 | 544 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
545 | return show_cpus(policy->cpus, buf); |
546 | return show_cpus(policy->related_cpus, buf); | |
547 | } | |
548 | ||
549 | /** | |
550 | * show_affected_cpus - show the CPUs affected by each transition | |
551 | */ | |
552 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
553 | { | |
554 | return show_cpus(policy->cpus, buf); | |
555 | } | |
556 | ||
9e76988e | 557 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 558 | const char *buf, size_t count) |
9e76988e VP |
559 | { |
560 | unsigned int freq = 0; | |
561 | unsigned int ret; | |
562 | ||
879000f9 | 563 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
564 | return -EINVAL; |
565 | ||
566 | ret = sscanf(buf, "%u", &freq); | |
567 | if (ret != 1) | |
568 | return -EINVAL; | |
569 | ||
570 | policy->governor->store_setspeed(policy, freq); | |
571 | ||
572 | return count; | |
573 | } | |
574 | ||
575 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
576 | { | |
879000f9 | 577 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
578 | return sprintf(buf, "<unsupported>\n"); |
579 | ||
580 | return policy->governor->show_setspeed(policy, buf); | |
581 | } | |
1da177e4 | 582 | |
e2f74f35 TR |
583 | /** |
584 | * show_scaling_driver - show the current cpufreq HW/BIOS limitation | |
585 | */ | |
586 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
587 | { | |
588 | unsigned int limit; | |
589 | int ret; | |
590 | if (cpufreq_driver->bios_limit) { | |
591 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
592 | if (!ret) | |
593 | return sprintf(buf, "%u\n", limit); | |
594 | } | |
595 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
596 | } | |
597 | ||
6dad2a29 BP |
598 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
599 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
600 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
601 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
602 | cpufreq_freq_attr_ro(scaling_available_governors); | |
603 | cpufreq_freq_attr_ro(scaling_driver); | |
604 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
605 | cpufreq_freq_attr_ro(bios_limit); | |
606 | cpufreq_freq_attr_ro(related_cpus); | |
607 | cpufreq_freq_attr_ro(affected_cpus); | |
608 | cpufreq_freq_attr_rw(scaling_min_freq); | |
609 | cpufreq_freq_attr_rw(scaling_max_freq); | |
610 | cpufreq_freq_attr_rw(scaling_governor); | |
611 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 612 | |
905d77cd | 613 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
614 | &cpuinfo_min_freq.attr, |
615 | &cpuinfo_max_freq.attr, | |
ed129784 | 616 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
617 | &scaling_min_freq.attr, |
618 | &scaling_max_freq.attr, | |
619 | &affected_cpus.attr, | |
e8628dd0 | 620 | &related_cpus.attr, |
1da177e4 LT |
621 | &scaling_governor.attr, |
622 | &scaling_driver.attr, | |
623 | &scaling_available_governors.attr, | |
9e76988e | 624 | &scaling_setspeed.attr, |
1da177e4 LT |
625 | NULL |
626 | }; | |
627 | ||
8aa84ad8 TR |
628 | struct kobject *cpufreq_global_kobject; |
629 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
630 | ||
29464f28 DJ |
631 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
632 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 633 | |
29464f28 | 634 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 635 | { |
905d77cd DJ |
636 | struct cpufreq_policy *policy = to_policy(kobj); |
637 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 638 | ssize_t ret = -EINVAL; |
a9144436 | 639 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 640 | if (!policy) |
0db4a8a9 | 641 | goto no_policy; |
5a01f2e8 VP |
642 | |
643 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 644 | goto fail; |
5a01f2e8 | 645 | |
e08f5f5b GS |
646 | if (fattr->show) |
647 | ret = fattr->show(policy, buf); | |
648 | else | |
649 | ret = -EIO; | |
650 | ||
5a01f2e8 | 651 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 652 | fail: |
a9144436 | 653 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 654 | no_policy: |
1da177e4 LT |
655 | return ret; |
656 | } | |
657 | ||
905d77cd DJ |
658 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
659 | const char *buf, size_t count) | |
1da177e4 | 660 | { |
905d77cd DJ |
661 | struct cpufreq_policy *policy = to_policy(kobj); |
662 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 663 | ssize_t ret = -EINVAL; |
a9144436 | 664 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 665 | if (!policy) |
a07530b4 | 666 | goto no_policy; |
5a01f2e8 VP |
667 | |
668 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 669 | goto fail; |
5a01f2e8 | 670 | |
e08f5f5b GS |
671 | if (fattr->store) |
672 | ret = fattr->store(policy, buf, count); | |
673 | else | |
674 | ret = -EIO; | |
675 | ||
5a01f2e8 | 676 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 677 | fail: |
a9144436 | 678 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 679 | no_policy: |
1da177e4 LT |
680 | return ret; |
681 | } | |
682 | ||
905d77cd | 683 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 684 | { |
905d77cd | 685 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 686 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
687 | complete(&policy->kobj_unregister); |
688 | } | |
689 | ||
52cf25d0 | 690 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
691 | .show = show, |
692 | .store = store, | |
693 | }; | |
694 | ||
695 | static struct kobj_type ktype_cpufreq = { | |
696 | .sysfs_ops = &sysfs_ops, | |
697 | .default_attrs = default_attrs, | |
698 | .release = cpufreq_sysfs_release, | |
699 | }; | |
700 | ||
4bfa042c TR |
701 | /* |
702 | * Returns: | |
703 | * Negative: Failure | |
704 | * 0: Success | |
705 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
706 | */ | |
cf3289d0 AC |
707 | static int cpufreq_add_dev_policy(unsigned int cpu, |
708 | struct cpufreq_policy *policy, | |
8a25a2fd | 709 | struct device *dev) |
ecf7e461 DJ |
710 | { |
711 | int ret = 0; | |
712 | #ifdef CONFIG_SMP | |
713 | unsigned long flags; | |
714 | unsigned int j; | |
ecf7e461 | 715 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
716 | struct cpufreq_governor *gov; |
717 | ||
718 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
719 | if (gov) { | |
720 | policy->governor = gov; | |
2d06d8c4 | 721 | pr_debug("Restoring governor %s for cpu %d\n", |
ecf7e461 DJ |
722 | policy->governor->name, cpu); |
723 | } | |
724 | #endif | |
725 | ||
726 | for_each_cpu(j, policy->cpus) { | |
727 | struct cpufreq_policy *managed_policy; | |
728 | ||
729 | if (cpu == j) | |
730 | continue; | |
731 | ||
732 | /* Check for existing affected CPUs. | |
733 | * They may not be aware of it due to CPU Hotplug. | |
734 | * cpufreq_cpu_put is called when the device is removed | |
735 | * in __cpufreq_remove_dev() | |
736 | */ | |
737 | managed_policy = cpufreq_cpu_get(j); | |
738 | if (unlikely(managed_policy)) { | |
739 | ||
740 | /* Set proper policy_cpu */ | |
741 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 742 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
743 | |
744 | if (lock_policy_rwsem_write(cpu) < 0) { | |
745 | /* Should not go through policy unlock path */ | |
746 | if (cpufreq_driver->exit) | |
747 | cpufreq_driver->exit(policy); | |
748 | cpufreq_cpu_put(managed_policy); | |
749 | return -EBUSY; | |
750 | } | |
751 | ||
752 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
753 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
754 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
755 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
756 | ||
2d06d8c4 | 757 | pr_debug("CPU already managed, adding link\n"); |
8a25a2fd | 758 | ret = sysfs_create_link(&dev->kobj, |
ecf7e461 DJ |
759 | &managed_policy->kobj, |
760 | "cpufreq"); | |
761 | if (ret) | |
762 | cpufreq_cpu_put(managed_policy); | |
763 | /* | |
764 | * Success. We only needed to be added to the mask. | |
765 | * Call driver->exit() because only the cpu parent of | |
766 | * the kobj needed to call init(). | |
767 | */ | |
768 | if (cpufreq_driver->exit) | |
769 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
770 | |
771 | if (!ret) | |
772 | return 1; | |
773 | else | |
774 | return ret; | |
ecf7e461 DJ |
775 | } |
776 | } | |
777 | #endif | |
778 | return ret; | |
779 | } | |
780 | ||
781 | ||
19d6f7ec | 782 | /* symlink affected CPUs */ |
cf3289d0 AC |
783 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
784 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
785 | { |
786 | unsigned int j; | |
787 | int ret = 0; | |
788 | ||
789 | for_each_cpu(j, policy->cpus) { | |
790 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 791 | struct device *cpu_dev; |
19d6f7ec DJ |
792 | |
793 | if (j == cpu) | |
794 | continue; | |
795 | if (!cpu_online(j)) | |
796 | continue; | |
797 | ||
2d06d8c4 | 798 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 799 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
800 | cpu_dev = get_cpu_device(j); |
801 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
802 | "cpufreq"); |
803 | if (ret) { | |
804 | cpufreq_cpu_put(managed_policy); | |
805 | return ret; | |
806 | } | |
807 | } | |
808 | return ret; | |
809 | } | |
810 | ||
cf3289d0 AC |
811 | static int cpufreq_add_dev_interface(unsigned int cpu, |
812 | struct cpufreq_policy *policy, | |
8a25a2fd | 813 | struct device *dev) |
909a694e | 814 | { |
ecf7e461 | 815 | struct cpufreq_policy new_policy; |
909a694e DJ |
816 | struct freq_attr **drv_attr; |
817 | unsigned long flags; | |
818 | int ret = 0; | |
819 | unsigned int j; | |
820 | ||
821 | /* prepare interface data */ | |
822 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 823 | &dev->kobj, "cpufreq"); |
909a694e DJ |
824 | if (ret) |
825 | return ret; | |
826 | ||
827 | /* set up files for this cpu device */ | |
828 | drv_attr = cpufreq_driver->attr; | |
829 | while ((drv_attr) && (*drv_attr)) { | |
830 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
831 | if (ret) | |
832 | goto err_out_kobj_put; | |
833 | drv_attr++; | |
834 | } | |
835 | if (cpufreq_driver->get) { | |
836 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
837 | if (ret) | |
838 | goto err_out_kobj_put; | |
839 | } | |
840 | if (cpufreq_driver->target) { | |
841 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
842 | if (ret) | |
843 | goto err_out_kobj_put; | |
844 | } | |
e2f74f35 TR |
845 | if (cpufreq_driver->bios_limit) { |
846 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
847 | if (ret) | |
848 | goto err_out_kobj_put; | |
849 | } | |
909a694e DJ |
850 | |
851 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
852 | for_each_cpu(j, policy->cpus) { | |
bec037aa JL |
853 | if (!cpu_online(j)) |
854 | continue; | |
909a694e | 855 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 856 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
857 | } |
858 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
859 | ||
860 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
861 | if (ret) |
862 | goto err_out_kobj_put; | |
863 | ||
864 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
865 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
866 | policy->governor = NULL; | |
867 | ||
868 | /* set default policy */ | |
869 | ret = __cpufreq_set_policy(policy, &new_policy); | |
870 | policy->user_policy.policy = policy->policy; | |
871 | policy->user_policy.governor = policy->governor; | |
872 | ||
873 | if (ret) { | |
2d06d8c4 | 874 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
875 | if (cpufreq_driver->exit) |
876 | cpufreq_driver->exit(policy); | |
877 | } | |
909a694e DJ |
878 | return ret; |
879 | ||
880 | err_out_kobj_put: | |
881 | kobject_put(&policy->kobj); | |
882 | wait_for_completion(&policy->kobj_unregister); | |
883 | return ret; | |
884 | } | |
885 | ||
1da177e4 LT |
886 | |
887 | /** | |
888 | * cpufreq_add_dev - add a CPU device | |
889 | * | |
32ee8c3e | 890 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
891 | * |
892 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
893 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
894 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 895 | */ |
8a25a2fd | 896 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 897 | { |
8a25a2fd | 898 | unsigned int cpu = dev->id; |
90e41bac | 899 | int ret = 0, found = 0; |
1da177e4 | 900 | struct cpufreq_policy *policy; |
1da177e4 LT |
901 | unsigned long flags; |
902 | unsigned int j; | |
90e41bac PB |
903 | #ifdef CONFIG_HOTPLUG_CPU |
904 | int sibling; | |
905 | #endif | |
1da177e4 | 906 | |
c32b6b8e AR |
907 | if (cpu_is_offline(cpu)) |
908 | return 0; | |
909 | ||
2d06d8c4 | 910 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
911 | |
912 | #ifdef CONFIG_SMP | |
913 | /* check whether a different CPU already registered this | |
914 | * CPU because it is in the same boat. */ | |
915 | policy = cpufreq_cpu_get(cpu); | |
916 | if (unlikely(policy)) { | |
8ff69732 | 917 | cpufreq_cpu_put(policy); |
1da177e4 LT |
918 | return 0; |
919 | } | |
920 | #endif | |
921 | ||
922 | if (!try_module_get(cpufreq_driver->owner)) { | |
923 | ret = -EINVAL; | |
924 | goto module_out; | |
925 | } | |
926 | ||
059019a3 | 927 | ret = -ENOMEM; |
e98df50c | 928 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 929 | if (!policy) |
1da177e4 | 930 | goto nomem_out; |
059019a3 DJ |
931 | |
932 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 933 | goto err_free_policy; |
059019a3 DJ |
934 | |
935 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 936 | goto err_free_cpumask; |
1da177e4 LT |
937 | |
938 | policy->cpu = cpu; | |
835481d9 | 939 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 940 | |
5a01f2e8 | 941 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 942 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
943 | ret = (lock_policy_rwsem_write(cpu) < 0); |
944 | WARN_ON(ret); | |
5a01f2e8 | 945 | |
1da177e4 | 946 | init_completion(&policy->kobj_unregister); |
65f27f38 | 947 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 948 | |
8122c6ce | 949 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
950 | #ifdef CONFIG_HOTPLUG_CPU |
951 | for_each_online_cpu(sibling) { | |
952 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
953 | if (cp && cp->governor && | |
954 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
955 | policy->governor = cp->governor; | |
956 | found = 1; | |
957 | break; | |
958 | } | |
959 | } | |
960 | #endif | |
961 | if (!found) | |
962 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
963 | /* call driver. From then on the cpufreq must be able |
964 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
965 | */ | |
966 | ret = cpufreq_driver->init(policy); | |
967 | if (ret) { | |
2d06d8c4 | 968 | pr_debug("initialization failed\n"); |
3f4a782b | 969 | goto err_unlock_policy; |
1da177e4 | 970 | } |
187d9f4e MC |
971 | policy->user_policy.min = policy->min; |
972 | policy->user_policy.max = policy->max; | |
1da177e4 | 973 | |
a1531acd TR |
974 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
975 | CPUFREQ_START, policy); | |
976 | ||
8a25a2fd | 977 | ret = cpufreq_add_dev_policy(cpu, policy, dev); |
4bfa042c TR |
978 | if (ret) { |
979 | if (ret > 0) | |
980 | /* This is a managed cpu, symlink created, | |
981 | exit with 0 */ | |
982 | ret = 0; | |
ecf7e461 | 983 | goto err_unlock_policy; |
4bfa042c | 984 | } |
1da177e4 | 985 | |
8a25a2fd | 986 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
987 | if (ret) |
988 | goto err_out_unregister; | |
8ff69732 | 989 | |
dca02613 LW |
990 | unlock_policy_rwsem_write(cpu); |
991 | ||
038c5b3e | 992 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 993 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 994 | pr_debug("initialization complete\n"); |
87c32271 | 995 | |
1da177e4 LT |
996 | return 0; |
997 | ||
998 | ||
999 | err_out_unregister: | |
1000 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1001 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1002 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1003 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1004 | ||
c10997f6 | 1005 | kobject_put(&policy->kobj); |
1da177e4 LT |
1006 | wait_for_completion(&policy->kobj_unregister); |
1007 | ||
3f4a782b | 1008 | err_unlock_policy: |
45709118 | 1009 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 1010 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
1011 | err_free_cpumask: |
1012 | free_cpumask_var(policy->cpus); | |
1013 | err_free_policy: | |
1da177e4 | 1014 | kfree(policy); |
1da177e4 LT |
1015 | nomem_out: |
1016 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1017 | module_out: |
1da177e4 LT |
1018 | return ret; |
1019 | } | |
1020 | ||
1021 | ||
1022 | /** | |
5a01f2e8 | 1023 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1024 | * |
1025 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1026 | * Caller should already have policy_rwsem in write mode for this CPU. |
1027 | * This routine frees the rwsem before returning. | |
1da177e4 | 1028 | */ |
8a25a2fd | 1029 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1030 | { |
8a25a2fd | 1031 | unsigned int cpu = dev->id; |
1da177e4 LT |
1032 | unsigned long flags; |
1033 | struct cpufreq_policy *data; | |
499bca9b AW |
1034 | struct kobject *kobj; |
1035 | struct completion *cmp; | |
1da177e4 | 1036 | #ifdef CONFIG_SMP |
8a25a2fd | 1037 | struct device *cpu_dev; |
1da177e4 LT |
1038 | unsigned int j; |
1039 | #endif | |
1040 | ||
2d06d8c4 | 1041 | pr_debug("unregistering CPU %u\n", cpu); |
1da177e4 LT |
1042 | |
1043 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1044 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1045 | |
1046 | if (!data) { | |
1047 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 1048 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1049 | return -EINVAL; |
1050 | } | |
7a6aedfa | 1051 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1052 | |
1053 | ||
1054 | #ifdef CONFIG_SMP | |
1055 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1056 | * only need to unlink, put and exit |
1da177e4 LT |
1057 | */ |
1058 | if (unlikely(cpu != data->cpu)) { | |
2d06d8c4 | 1059 | pr_debug("removing link\n"); |
835481d9 | 1060 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 | 1061 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8a25a2fd | 1062 | kobj = &dev->kobj; |
1da177e4 | 1063 | cpufreq_cpu_put(data); |
5a01f2e8 | 1064 | unlock_policy_rwsem_write(cpu); |
499bca9b | 1065 | sysfs_remove_link(kobj, "cpufreq"); |
1da177e4 LT |
1066 | return 0; |
1067 | } | |
1068 | #endif | |
1069 | ||
1da177e4 | 1070 | #ifdef CONFIG_SMP |
084f3493 TR |
1071 | |
1072 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1073 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1074 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1075 | #endif |
1076 | ||
1da177e4 LT |
1077 | /* if we have other CPUs still registered, we need to unlink them, |
1078 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1079 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1080 | * the sysfs links afterwards. | |
1da177e4 | 1081 | */ |
835481d9 RR |
1082 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1083 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1084 | if (j == cpu) |
1085 | continue; | |
7a6aedfa | 1086 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1087 | } |
1088 | } | |
1089 | ||
1090 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1091 | ||
835481d9 RR |
1092 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1093 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1094 | if (j == cpu) |
1095 | continue; | |
2d06d8c4 | 1096 | pr_debug("removing link for cpu %u\n", j); |
084f3493 | 1097 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1098 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1099 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1100 | #endif |
8a25a2fd KS |
1101 | cpu_dev = get_cpu_device(j); |
1102 | kobj = &cpu_dev->kobj; | |
499bca9b AW |
1103 | unlock_policy_rwsem_write(cpu); |
1104 | sysfs_remove_link(kobj, "cpufreq"); | |
1105 | lock_policy_rwsem_write(cpu); | |
1da177e4 LT |
1106 | cpufreq_cpu_put(data); |
1107 | } | |
1108 | } | |
1109 | #else | |
1110 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1111 | #endif | |
1112 | ||
1da177e4 LT |
1113 | if (cpufreq_driver->target) |
1114 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1115 | |
499bca9b AW |
1116 | kobj = &data->kobj; |
1117 | cmp = &data->kobj_unregister; | |
1118 | unlock_policy_rwsem_write(cpu); | |
1119 | kobject_put(kobj); | |
1da177e4 LT |
1120 | |
1121 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1122 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1123 | * unloading. |
1124 | */ | |
2d06d8c4 | 1125 | pr_debug("waiting for dropping of refcount\n"); |
499bca9b | 1126 | wait_for_completion(cmp); |
2d06d8c4 | 1127 | pr_debug("wait complete\n"); |
1da177e4 | 1128 | |
499bca9b | 1129 | lock_policy_rwsem_write(cpu); |
1da177e4 LT |
1130 | if (cpufreq_driver->exit) |
1131 | cpufreq_driver->exit(data); | |
7d26e2d5 | 1132 | unlock_policy_rwsem_write(cpu); |
1133 | ||
27ecddc2 JS |
1134 | #ifdef CONFIG_HOTPLUG_CPU |
1135 | /* when the CPU which is the parent of the kobj is hotplugged | |
1136 | * offline, check for siblings, and create cpufreq sysfs interface | |
1137 | * and symlinks | |
1138 | */ | |
1139 | if (unlikely(cpumask_weight(data->cpus) > 1)) { | |
1140 | /* first sibling now owns the new sysfs dir */ | |
1141 | cpumask_clear_cpu(cpu, data->cpus); | |
8a25a2fd | 1142 | cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL); |
27ecddc2 JS |
1143 | |
1144 | /* finally remove our own symlink */ | |
1145 | lock_policy_rwsem_write(cpu); | |
8a25a2fd | 1146 | __cpufreq_remove_dev(dev, sif); |
27ecddc2 JS |
1147 | } |
1148 | #endif | |
1149 | ||
835481d9 RR |
1150 | free_cpumask_var(data->related_cpus); |
1151 | free_cpumask_var(data->cpus); | |
1da177e4 LT |
1152 | kfree(data); |
1153 | ||
1da177e4 LT |
1154 | return 0; |
1155 | } | |
1156 | ||
1157 | ||
8a25a2fd | 1158 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1159 | { |
8a25a2fd | 1160 | unsigned int cpu = dev->id; |
5a01f2e8 | 1161 | int retval; |
ec28297a VP |
1162 | |
1163 | if (cpu_is_offline(cpu)) | |
1164 | return 0; | |
1165 | ||
5a01f2e8 VP |
1166 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1167 | BUG(); | |
1168 | ||
8a25a2fd | 1169 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1170 | return retval; |
1171 | } | |
1172 | ||
1173 | ||
65f27f38 | 1174 | static void handle_update(struct work_struct *work) |
1da177e4 | 1175 | { |
65f27f38 DH |
1176 | struct cpufreq_policy *policy = |
1177 | container_of(work, struct cpufreq_policy, update); | |
1178 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1179 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1180 | cpufreq_update_policy(cpu); |
1181 | } | |
1182 | ||
1183 | /** | |
1184 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1185 | * @cpu: cpu number | |
1186 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1187 | * @new_freq: CPU frequency the CPU actually runs at | |
1188 | * | |
29464f28 DJ |
1189 | * We adjust to current frequency first, and need to clean up later. |
1190 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1191 | */ |
e08f5f5b GS |
1192 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1193 | unsigned int new_freq) | |
1da177e4 LT |
1194 | { |
1195 | struct cpufreq_freqs freqs; | |
1196 | ||
2d06d8c4 | 1197 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1198 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1199 | ||
1200 | freqs.cpu = cpu; | |
1201 | freqs.old = old_freq; | |
1202 | freqs.new = new_freq; | |
1203 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1204 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1205 | } | |
1206 | ||
1207 | ||
32ee8c3e | 1208 | /** |
4ab70df4 | 1209 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1210 | * @cpu: CPU number |
1211 | * | |
1212 | * This is the last known freq, without actually getting it from the driver. | |
1213 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1214 | */ | |
1215 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1216 | { | |
1217 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1218 | unsigned int ret_freq = 0; |
95235ca2 VP |
1219 | |
1220 | if (policy) { | |
e08f5f5b | 1221 | ret_freq = policy->cur; |
95235ca2 VP |
1222 | cpufreq_cpu_put(policy); |
1223 | } | |
1224 | ||
4d34a67d | 1225 | return ret_freq; |
95235ca2 VP |
1226 | } |
1227 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1228 | ||
3d737108 JB |
1229 | /** |
1230 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1231 | * @cpu: CPU number | |
1232 | * | |
1233 | * Just return the max possible frequency for a given CPU. | |
1234 | */ | |
1235 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1236 | { | |
1237 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1238 | unsigned int ret_freq = 0; | |
1239 | ||
1240 | if (policy) { | |
1241 | ret_freq = policy->max; | |
1242 | cpufreq_cpu_put(policy); | |
1243 | } | |
1244 | ||
1245 | return ret_freq; | |
1246 | } | |
1247 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1248 | ||
95235ca2 | 1249 | |
5a01f2e8 | 1250 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1251 | { |
7a6aedfa | 1252 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1253 | unsigned int ret_freq = 0; |
1da177e4 | 1254 | |
1da177e4 | 1255 | if (!cpufreq_driver->get) |
4d34a67d | 1256 | return ret_freq; |
1da177e4 | 1257 | |
e08f5f5b | 1258 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1259 | |
e08f5f5b GS |
1260 | if (ret_freq && policy->cur && |
1261 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1262 | /* verify no discrepancy between actual and | |
1263 | saved value exists */ | |
1264 | if (unlikely(ret_freq != policy->cur)) { | |
1265 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1266 | schedule_work(&policy->update); |
1267 | } | |
1268 | } | |
1269 | ||
4d34a67d | 1270 | return ret_freq; |
5a01f2e8 | 1271 | } |
1da177e4 | 1272 | |
5a01f2e8 VP |
1273 | /** |
1274 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1275 | * @cpu: CPU number | |
1276 | * | |
1277 | * Get the CPU current (static) CPU frequency | |
1278 | */ | |
1279 | unsigned int cpufreq_get(unsigned int cpu) | |
1280 | { | |
1281 | unsigned int ret_freq = 0; | |
1282 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1283 | ||
1284 | if (!policy) | |
1285 | goto out; | |
1286 | ||
1287 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1288 | goto out_policy; | |
1289 | ||
1290 | ret_freq = __cpufreq_get(cpu); | |
1291 | ||
1292 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1293 | |
5a01f2e8 VP |
1294 | out_policy: |
1295 | cpufreq_cpu_put(policy); | |
1296 | out: | |
4d34a67d | 1297 | return ret_freq; |
1da177e4 LT |
1298 | } |
1299 | EXPORT_SYMBOL(cpufreq_get); | |
1300 | ||
8a25a2fd KS |
1301 | static struct subsys_interface cpufreq_interface = { |
1302 | .name = "cpufreq", | |
1303 | .subsys = &cpu_subsys, | |
1304 | .add_dev = cpufreq_add_dev, | |
1305 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1306 | }; |
1307 | ||
1da177e4 | 1308 | |
42d4dc3f | 1309 | /** |
e00e56df RW |
1310 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1311 | * | |
1312 | * This function is only executed for the boot processor. The other CPUs | |
1313 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1314 | */ |
e00e56df | 1315 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1316 | { |
e08f5f5b | 1317 | int ret = 0; |
4bc5d341 | 1318 | |
e00e56df | 1319 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1320 | struct cpufreq_policy *cpu_policy; |
1321 | ||
2d06d8c4 | 1322 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1323 | |
e00e56df | 1324 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1325 | cpu_policy = cpufreq_cpu_get(cpu); |
1326 | if (!cpu_policy) | |
e00e56df | 1327 | return 0; |
42d4dc3f BH |
1328 | |
1329 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1330 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1331 | if (ret) |
42d4dc3f BH |
1332 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1333 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1334 | } |
1335 | ||
42d4dc3f | 1336 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1337 | return ret; |
42d4dc3f BH |
1338 | } |
1339 | ||
1da177e4 | 1340 | /** |
e00e56df | 1341 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1342 | * |
1343 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1344 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1345 | * restored. It will verify that the current freq is in sync with | |
1346 | * what we believe it to be. This is a bit later than when it | |
1347 | * should be, but nonethteless it's better than calling | |
1348 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1349 | * |
1350 | * This function is only executed for the boot CPU. The other CPUs have not | |
1351 | * been turned on yet. | |
1da177e4 | 1352 | */ |
e00e56df | 1353 | static void cpufreq_bp_resume(void) |
1da177e4 | 1354 | { |
e08f5f5b | 1355 | int ret = 0; |
4bc5d341 | 1356 | |
e00e56df | 1357 | int cpu = smp_processor_id(); |
1da177e4 LT |
1358 | struct cpufreq_policy *cpu_policy; |
1359 | ||
2d06d8c4 | 1360 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1361 | |
e00e56df | 1362 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1363 | cpu_policy = cpufreq_cpu_get(cpu); |
1364 | if (!cpu_policy) | |
e00e56df | 1365 | return; |
1da177e4 LT |
1366 | |
1367 | if (cpufreq_driver->resume) { | |
1368 | ret = cpufreq_driver->resume(cpu_policy); | |
1369 | if (ret) { | |
1370 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1371 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1372 | goto fail; |
1da177e4 LT |
1373 | } |
1374 | } | |
1375 | ||
1da177e4 | 1376 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1377 | |
c9060494 | 1378 | fail: |
1da177e4 | 1379 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1380 | } |
1381 | ||
e00e56df RW |
1382 | static struct syscore_ops cpufreq_syscore_ops = { |
1383 | .suspend = cpufreq_bp_suspend, | |
1384 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1385 | }; |
1386 | ||
1387 | ||
1388 | /********************************************************************* | |
1389 | * NOTIFIER LISTS INTERFACE * | |
1390 | *********************************************************************/ | |
1391 | ||
1392 | /** | |
1393 | * cpufreq_register_notifier - register a driver with cpufreq | |
1394 | * @nb: notifier function to register | |
1395 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1396 | * | |
32ee8c3e | 1397 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1398 | * are notified about clock rate changes (once before and once after |
1399 | * the transition), or a list of drivers that are notified about | |
1400 | * changes in cpufreq policy. | |
1401 | * | |
1402 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1403 | * blocking_notifier_chain_register. |
1da177e4 LT |
1404 | */ |
1405 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1406 | { | |
1407 | int ret; | |
1408 | ||
74212ca4 CEB |
1409 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1410 | ||
1da177e4 LT |
1411 | switch (list) { |
1412 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1413 | ret = srcu_notifier_chain_register( |
e041c683 | 1414 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1415 | break; |
1416 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1417 | ret = blocking_notifier_chain_register( |
1418 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1419 | break; |
1420 | default: | |
1421 | ret = -EINVAL; | |
1422 | } | |
1da177e4 LT |
1423 | |
1424 | return ret; | |
1425 | } | |
1426 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1427 | ||
1428 | ||
1429 | /** | |
1430 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1431 | * @nb: notifier block to be unregistered | |
1432 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1433 | * | |
1434 | * Remove a driver from the CPU frequency notifier list. | |
1435 | * | |
1436 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1437 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1438 | */ |
1439 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1440 | { | |
1441 | int ret; | |
1442 | ||
1da177e4 LT |
1443 | switch (list) { |
1444 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1445 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1446 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1447 | break; |
1448 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1449 | ret = blocking_notifier_chain_unregister( |
1450 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1451 | break; |
1452 | default: | |
1453 | ret = -EINVAL; | |
1454 | } | |
1da177e4 LT |
1455 | |
1456 | return ret; | |
1457 | } | |
1458 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1459 | ||
1460 | ||
1461 | /********************************************************************* | |
1462 | * GOVERNORS * | |
1463 | *********************************************************************/ | |
1464 | ||
1465 | ||
1466 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1467 | unsigned int target_freq, | |
1468 | unsigned int relation) | |
1469 | { | |
1470 | int retval = -EINVAL; | |
c32b6b8e | 1471 | |
a7b422cd KRW |
1472 | if (cpufreq_disabled()) |
1473 | return -ENODEV; | |
1474 | ||
2d06d8c4 | 1475 | pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1da177e4 LT |
1476 | target_freq, relation); |
1477 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1478 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1479 | |
1da177e4 LT |
1480 | return retval; |
1481 | } | |
1482 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1483 | ||
1da177e4 LT |
1484 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1485 | unsigned int target_freq, | |
1486 | unsigned int relation) | |
1487 | { | |
f1829e4a | 1488 | int ret = -EINVAL; |
1da177e4 LT |
1489 | |
1490 | policy = cpufreq_cpu_get(policy->cpu); | |
1491 | if (!policy) | |
f1829e4a | 1492 | goto no_policy; |
1da177e4 | 1493 | |
5a01f2e8 | 1494 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1495 | goto fail; |
1da177e4 LT |
1496 | |
1497 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1498 | ||
5a01f2e8 | 1499 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1500 | |
f1829e4a | 1501 | fail: |
1da177e4 | 1502 | cpufreq_cpu_put(policy); |
f1829e4a | 1503 | no_policy: |
1da177e4 LT |
1504 | return ret; |
1505 | } | |
1506 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1507 | ||
bf0b90e3 | 1508 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1509 | { |
1510 | int ret = 0; | |
1511 | ||
1512 | policy = cpufreq_cpu_get(policy->cpu); | |
1513 | if (!policy) | |
1514 | return -EINVAL; | |
1515 | ||
bf0b90e3 | 1516 | if (cpu_online(cpu) && cpufreq_driver->getavg) |
1517 | ret = cpufreq_driver->getavg(policy, cpu); | |
dfde5d62 | 1518 | |
dfde5d62 VP |
1519 | cpufreq_cpu_put(policy); |
1520 | return ret; | |
1521 | } | |
5a01f2e8 | 1522 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1523 | |
153d7f3f | 1524 | /* |
153d7f3f AV |
1525 | * when "event" is CPUFREQ_GOV_LIMITS |
1526 | */ | |
1da177e4 | 1527 | |
e08f5f5b GS |
1528 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1529 | unsigned int event) | |
1da177e4 | 1530 | { |
cc993cab | 1531 | int ret; |
6afde10c TR |
1532 | |
1533 | /* Only must be defined when default governor is known to have latency | |
1534 | restrictions, like e.g. conservative or ondemand. | |
1535 | That this is the case is already ensured in Kconfig | |
1536 | */ | |
1537 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1538 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1539 | #else | |
1540 | struct cpufreq_governor *gov = NULL; | |
1541 | #endif | |
1c256245 TR |
1542 | |
1543 | if (policy->governor->max_transition_latency && | |
1544 | policy->cpuinfo.transition_latency > | |
1545 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1546 | if (!gov) |
1547 | return -EINVAL; | |
1548 | else { | |
1549 | printk(KERN_WARNING "%s governor failed, too long" | |
1550 | " transition latency of HW, fallback" | |
1551 | " to %s governor\n", | |
1552 | policy->governor->name, | |
1553 | gov->name); | |
1554 | policy->governor = gov; | |
1555 | } | |
1c256245 | 1556 | } |
1da177e4 LT |
1557 | |
1558 | if (!try_module_get(policy->governor->owner)) | |
1559 | return -EINVAL; | |
1560 | ||
2d06d8c4 | 1561 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1562 | policy->cpu, event); |
1da177e4 LT |
1563 | ret = policy->governor->governor(policy, event); |
1564 | ||
e08f5f5b GS |
1565 | /* we keep one module reference alive for |
1566 | each CPU governed by this CPU */ | |
1da177e4 LT |
1567 | if ((event != CPUFREQ_GOV_START) || ret) |
1568 | module_put(policy->governor->owner); | |
1569 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1570 | module_put(policy->governor->owner); | |
1571 | ||
1572 | return ret; | |
1573 | } | |
1574 | ||
1575 | ||
1da177e4 LT |
1576 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1577 | { | |
3bcb09a3 | 1578 | int err; |
1da177e4 LT |
1579 | |
1580 | if (!governor) | |
1581 | return -EINVAL; | |
1582 | ||
a7b422cd KRW |
1583 | if (cpufreq_disabled()) |
1584 | return -ENODEV; | |
1585 | ||
3fc54d37 | 1586 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1587 | |
3bcb09a3 JF |
1588 | err = -EBUSY; |
1589 | if (__find_governor(governor->name) == NULL) { | |
1590 | err = 0; | |
1591 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1592 | } |
1da177e4 | 1593 | |
32ee8c3e | 1594 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1595 | return err; |
1da177e4 LT |
1596 | } |
1597 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1598 | ||
1599 | ||
1600 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1601 | { | |
90e41bac PB |
1602 | #ifdef CONFIG_HOTPLUG_CPU |
1603 | int cpu; | |
1604 | #endif | |
1605 | ||
1da177e4 LT |
1606 | if (!governor) |
1607 | return; | |
1608 | ||
a7b422cd KRW |
1609 | if (cpufreq_disabled()) |
1610 | return; | |
1611 | ||
90e41bac PB |
1612 | #ifdef CONFIG_HOTPLUG_CPU |
1613 | for_each_present_cpu(cpu) { | |
1614 | if (cpu_online(cpu)) | |
1615 | continue; | |
1616 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1617 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1618 | } | |
1619 | #endif | |
1620 | ||
3fc54d37 | 1621 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1622 | list_del(&governor->governor_list); |
3fc54d37 | 1623 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1624 | return; |
1625 | } | |
1626 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1627 | ||
1628 | ||
1629 | ||
1630 | /********************************************************************* | |
1631 | * POLICY INTERFACE * | |
1632 | *********************************************************************/ | |
1633 | ||
1634 | /** | |
1635 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1636 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1637 | * is written | |
1da177e4 LT |
1638 | * |
1639 | * Reads the current cpufreq policy. | |
1640 | */ | |
1641 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1642 | { | |
1643 | struct cpufreq_policy *cpu_policy; | |
1644 | if (!policy) | |
1645 | return -EINVAL; | |
1646 | ||
1647 | cpu_policy = cpufreq_cpu_get(cpu); | |
1648 | if (!cpu_policy) | |
1649 | return -EINVAL; | |
1650 | ||
1da177e4 | 1651 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1652 | |
1653 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1654 | return 0; |
1655 | } | |
1656 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1657 | ||
1658 | ||
153d7f3f | 1659 | /* |
e08f5f5b GS |
1660 | * data : current policy. |
1661 | * policy : policy to be set. | |
153d7f3f | 1662 | */ |
e08f5f5b GS |
1663 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1664 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1665 | { |
1666 | int ret = 0; | |
1667 | ||
2d06d8c4 | 1668 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1669 | policy->min, policy->max); |
1670 | ||
e08f5f5b GS |
1671 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1672 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1673 | |
53391fa2 | 1674 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1675 | ret = -EINVAL; |
1676 | goto error_out; | |
1677 | } | |
1678 | ||
1da177e4 LT |
1679 | /* verify the cpu speed can be set within this limit */ |
1680 | ret = cpufreq_driver->verify(policy); | |
1681 | if (ret) | |
1682 | goto error_out; | |
1683 | ||
1da177e4 | 1684 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1685 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1686 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1687 | |
1688 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1689 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1690 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1691 | |
1692 | /* verify the cpu speed can be set within this limit, | |
1693 | which might be different to the first one */ | |
1694 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1695 | if (ret) |
1da177e4 | 1696 | goto error_out; |
1da177e4 LT |
1697 | |
1698 | /* notification of the new policy */ | |
e041c683 AS |
1699 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1700 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1701 | |
7d5e350f DJ |
1702 | data->min = policy->min; |
1703 | data->max = policy->max; | |
1da177e4 | 1704 | |
2d06d8c4 | 1705 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1706 | data->min, data->max); |
1da177e4 LT |
1707 | |
1708 | if (cpufreq_driver->setpolicy) { | |
1709 | data->policy = policy->policy; | |
2d06d8c4 | 1710 | pr_debug("setting range\n"); |
1da177e4 LT |
1711 | ret = cpufreq_driver->setpolicy(policy); |
1712 | } else { | |
1713 | if (policy->governor != data->governor) { | |
1714 | /* save old, working values */ | |
1715 | struct cpufreq_governor *old_gov = data->governor; | |
1716 | ||
2d06d8c4 | 1717 | pr_debug("governor switch\n"); |
1da177e4 LT |
1718 | |
1719 | /* end old governor */ | |
ffe6275f | 1720 | if (data->governor) |
1da177e4 LT |
1721 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1722 | ||
1723 | /* start new governor */ | |
1724 | data->governor = policy->governor; | |
1725 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1726 | /* new governor failed, so re-start old one */ | |
2d06d8c4 | 1727 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1728 | data->governor->name); |
1da177e4 LT |
1729 | if (old_gov) { |
1730 | data->governor = old_gov; | |
e08f5f5b GS |
1731 | __cpufreq_governor(data, |
1732 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1733 | } |
1734 | ret = -EINVAL; | |
1735 | goto error_out; | |
1736 | } | |
1737 | /* might be a policy change, too, so fall through */ | |
1738 | } | |
2d06d8c4 | 1739 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1740 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1741 | } | |
1742 | ||
7d5e350f | 1743 | error_out: |
1da177e4 LT |
1744 | return ret; |
1745 | } | |
1746 | ||
1da177e4 LT |
1747 | /** |
1748 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1749 | * @cpu: CPU which shall be re-evaluated | |
1750 | * | |
25985edc | 1751 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1752 | * at different times. |
1753 | */ | |
1754 | int cpufreq_update_policy(unsigned int cpu) | |
1755 | { | |
1756 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1757 | struct cpufreq_policy policy; | |
f1829e4a | 1758 | int ret; |
1da177e4 | 1759 | |
f1829e4a JL |
1760 | if (!data) { |
1761 | ret = -ENODEV; | |
1762 | goto no_policy; | |
1763 | } | |
1da177e4 | 1764 | |
f1829e4a JL |
1765 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1766 | ret = -EINVAL; | |
1767 | goto fail; | |
1768 | } | |
1da177e4 | 1769 | |
2d06d8c4 | 1770 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1771 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1772 | policy.min = data->user_policy.min; |
1773 | policy.max = data->user_policy.max; | |
1774 | policy.policy = data->user_policy.policy; | |
1775 | policy.governor = data->user_policy.governor; | |
1776 | ||
0961dd0d TR |
1777 | /* BIOS might change freq behind our back |
1778 | -> ask driver for current freq and notify governors about a change */ | |
1779 | if (cpufreq_driver->get) { | |
1780 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1781 | if (!data->cur) { |
2d06d8c4 | 1782 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1783 | data->cur = policy.cur; |
1784 | } else { | |
1785 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1786 | cpufreq_out_of_sync(cpu, data->cur, |
1787 | policy.cur); | |
a85f7bd3 | 1788 | } |
0961dd0d TR |
1789 | } |
1790 | ||
1da177e4 LT |
1791 | ret = __cpufreq_set_policy(data, &policy); |
1792 | ||
5a01f2e8 VP |
1793 | unlock_policy_rwsem_write(cpu); |
1794 | ||
f1829e4a | 1795 | fail: |
1da177e4 | 1796 | cpufreq_cpu_put(data); |
f1829e4a | 1797 | no_policy: |
1da177e4 LT |
1798 | return ret; |
1799 | } | |
1800 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1801 | ||
dd184a01 | 1802 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1803 | unsigned long action, void *hcpu) |
1804 | { | |
1805 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1806 | struct device *dev; |
c32b6b8e | 1807 | |
8a25a2fd KS |
1808 | dev = get_cpu_device(cpu); |
1809 | if (dev) { | |
c32b6b8e AR |
1810 | switch (action) { |
1811 | case CPU_ONLINE: | |
8bb78442 | 1812 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1813 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1814 | break; |
1815 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1816 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1817 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1818 | BUG(); | |
1819 | ||
8a25a2fd | 1820 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1821 | break; |
5a01f2e8 | 1822 | case CPU_DOWN_FAILED: |
8bb78442 | 1823 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1824 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1825 | break; |
1826 | } | |
1827 | } | |
1828 | return NOTIFY_OK; | |
1829 | } | |
1830 | ||
9c36f746 | 1831 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1832 | .notifier_call = cpufreq_cpu_callback, |
1833 | }; | |
1da177e4 LT |
1834 | |
1835 | /********************************************************************* | |
1836 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1837 | *********************************************************************/ | |
1838 | ||
1839 | /** | |
1840 | * cpufreq_register_driver - register a CPU Frequency driver | |
1841 | * @driver_data: A struct cpufreq_driver containing the values# | |
1842 | * submitted by the CPU Frequency driver. | |
1843 | * | |
32ee8c3e | 1844 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1845 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1846 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1847 | * |
1848 | */ | |
221dee28 | 1849 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1850 | { |
1851 | unsigned long flags; | |
1852 | int ret; | |
1853 | ||
a7b422cd KRW |
1854 | if (cpufreq_disabled()) |
1855 | return -ENODEV; | |
1856 | ||
1da177e4 LT |
1857 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1858 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1859 | return -EINVAL; | |
1860 | ||
2d06d8c4 | 1861 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1862 | |
1863 | if (driver_data->setpolicy) | |
1864 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1865 | ||
1866 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1867 | if (cpufreq_driver) { | |
1868 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1869 | return -EBUSY; | |
1870 | } | |
1871 | cpufreq_driver = driver_data; | |
1872 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1873 | ||
8a25a2fd | 1874 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1875 | if (ret) |
1876 | goto err_null_driver; | |
1da177e4 | 1877 | |
8f5bc2ab | 1878 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1879 | int i; |
1880 | ret = -ENODEV; | |
1881 | ||
1882 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1883 | for (i = 0; i < nr_cpu_ids; i++) |
1884 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1885 | ret = 0; |
7a6aedfa MT |
1886 | break; |
1887 | } | |
1da177e4 LT |
1888 | |
1889 | /* if all ->init() calls failed, unregister */ | |
1890 | if (ret) { | |
2d06d8c4 | 1891 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1892 | driver_data->name); |
8a25a2fd | 1893 | goto err_if_unreg; |
1da177e4 LT |
1894 | } |
1895 | } | |
1896 | ||
8f5bc2ab | 1897 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1898 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1899 | |
8f5bc2ab | 1900 | return 0; |
8a25a2fd KS |
1901 | err_if_unreg: |
1902 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1903 | err_null_driver: |
1904 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1905 | cpufreq_driver = NULL; | |
1906 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1907 | return ret; |
1da177e4 LT |
1908 | } |
1909 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1910 | ||
1911 | ||
1912 | /** | |
1913 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1914 | * | |
32ee8c3e | 1915 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1916 | * the right to do so, i.e. if you have succeeded in initialising before! |
1917 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1918 | * currently not initialised. | |
1919 | */ | |
221dee28 | 1920 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1921 | { |
1922 | unsigned long flags; | |
1923 | ||
2d06d8c4 | 1924 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1925 | return -EINVAL; |
1da177e4 | 1926 | |
2d06d8c4 | 1927 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1928 | |
8a25a2fd | 1929 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1930 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1931 | |
1932 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1933 | cpufreq_driver = NULL; | |
1934 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1935 | ||
1936 | return 0; | |
1937 | } | |
1938 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1939 | |
1940 | static int __init cpufreq_core_init(void) | |
1941 | { | |
1942 | int cpu; | |
1943 | ||
a7b422cd KRW |
1944 | if (cpufreq_disabled()) |
1945 | return -ENODEV; | |
1946 | ||
5a01f2e8 | 1947 | for_each_possible_cpu(cpu) { |
f1625066 | 1948 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1949 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1950 | } | |
8aa84ad8 | 1951 | |
8a25a2fd | 1952 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1953 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1954 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1955 | |
5a01f2e8 VP |
1956 | return 0; |
1957 | } | |
5a01f2e8 | 1958 | core_initcall(cpufreq_core_init); |