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) \ | |
226528c6 | 73 | static int lock_policy_rwsem_##mode \ |
5a01f2e8 VP |
74 | (int cpu) \ |
75 | { \ | |
f1625066 | 76 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
77 | BUG_ON(policy_cpu == -1); \ |
78 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
79 | if (unlikely(!cpu_online(cpu))) { \ | |
80 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
81 | return -1; \ | |
82 | } \ | |
83 | \ | |
84 | return 0; \ | |
85 | } | |
86 | ||
87 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 VP |
88 | |
89 | lock_policy_rwsem(write, cpu); | |
5a01f2e8 | 90 | |
226528c6 | 91 | static void unlock_policy_rwsem_read(int cpu) |
5a01f2e8 | 92 | { |
f1625066 | 93 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
94 | BUG_ON(policy_cpu == -1); |
95 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
96 | } | |
5a01f2e8 | 97 | |
226528c6 | 98 | static void unlock_policy_rwsem_write(int cpu) |
5a01f2e8 | 99 | { |
f1625066 | 100 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
101 | BUG_ON(policy_cpu == -1); |
102 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
103 | } | |
5a01f2e8 VP |
104 | |
105 | ||
1da177e4 | 106 | /* internal prototypes */ |
29464f28 DJ |
107 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
108 | unsigned int event); | |
5a01f2e8 | 109 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 110 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
111 | |
112 | /** | |
32ee8c3e DJ |
113 | * Two notifier lists: the "policy" list is involved in the |
114 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
115 | * "transition" list for kernel code that needs to handle |
116 | * changes to devices when the CPU clock speed changes. | |
117 | * The mutex locks both lists. | |
118 | */ | |
e041c683 | 119 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 120 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 121 | |
74212ca4 | 122 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
123 | static int __init init_cpufreq_transition_notifier_list(void) |
124 | { | |
125 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 126 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
127 | return 0; |
128 | } | |
b3438f82 | 129 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 130 | |
a7b422cd KRW |
131 | static int off __read_mostly; |
132 | int cpufreq_disabled(void) | |
133 | { | |
134 | return off; | |
135 | } | |
136 | void disable_cpufreq(void) | |
137 | { | |
138 | off = 1; | |
139 | } | |
1da177e4 | 140 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 141 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 142 | |
a9144436 | 143 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
144 | { |
145 | struct cpufreq_policy *data; | |
146 | unsigned long flags; | |
147 | ||
7a6aedfa | 148 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
149 | goto err_out; |
150 | ||
151 | /* get the cpufreq driver */ | |
152 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
153 | ||
154 | if (!cpufreq_driver) | |
155 | goto err_out_unlock; | |
156 | ||
157 | if (!try_module_get(cpufreq_driver->owner)) | |
158 | goto err_out_unlock; | |
159 | ||
160 | ||
161 | /* get the CPU */ | |
7a6aedfa | 162 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
163 | |
164 | if (!data) | |
165 | goto err_out_put_module; | |
166 | ||
a9144436 | 167 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
168 | goto err_out_put_module; |
169 | ||
1da177e4 | 170 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
171 | return data; |
172 | ||
7d5e350f | 173 | err_out_put_module: |
1da177e4 | 174 | module_put(cpufreq_driver->owner); |
7d5e350f | 175 | err_out_unlock: |
1da177e4 | 176 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 177 | err_out: |
1da177e4 LT |
178 | return NULL; |
179 | } | |
a9144436 SB |
180 | |
181 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
182 | { | |
183 | return __cpufreq_cpu_get(cpu, false); | |
184 | } | |
1da177e4 LT |
185 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
186 | ||
a9144436 SB |
187 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
188 | { | |
189 | return __cpufreq_cpu_get(cpu, true); | |
190 | } | |
191 | ||
192 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
193 | { | |
194 | if (!sysfs) | |
195 | kobject_put(&data->kobj); | |
196 | module_put(cpufreq_driver->owner); | |
197 | } | |
7d5e350f | 198 | |
1da177e4 LT |
199 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
200 | { | |
a9144436 | 201 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
202 | } |
203 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
204 | ||
a9144436 SB |
205 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
206 | { | |
207 | __cpufreq_cpu_put(data, true); | |
208 | } | |
1da177e4 | 209 | |
1da177e4 LT |
210 | /********************************************************************* |
211 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
212 | *********************************************************************/ | |
213 | ||
214 | /** | |
215 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
216 | * | |
217 | * This function alters the system "loops_per_jiffy" for the clock | |
218 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 219 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
220 | * per-CPU loops_per_jiffy value wherever possible. |
221 | */ | |
222 | #ifndef CONFIG_SMP | |
223 | static unsigned long l_p_j_ref; | |
224 | static unsigned int l_p_j_ref_freq; | |
225 | ||
858119e1 | 226 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
227 | { |
228 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
229 | return; | |
230 | ||
231 | if (!l_p_j_ref_freq) { | |
232 | l_p_j_ref = loops_per_jiffy; | |
233 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 234 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 235 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 236 | } |
d08de0c1 | 237 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 238 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
239 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
240 | ci->new); | |
2d06d8c4 | 241 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 242 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
243 | } |
244 | } | |
245 | #else | |
e08f5f5b GS |
246 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
247 | { | |
248 | return; | |
249 | } | |
1da177e4 LT |
250 | #endif |
251 | ||
252 | ||
253 | /** | |
e4472cb3 DJ |
254 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
255 | * on frequency transition. | |
1da177e4 | 256 | * |
e4472cb3 DJ |
257 | * This function calls the transition notifiers and the "adjust_jiffies" |
258 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 259 | * external effects. |
1da177e4 LT |
260 | */ |
261 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
262 | { | |
e4472cb3 DJ |
263 | struct cpufreq_policy *policy; |
264 | ||
1da177e4 LT |
265 | BUG_ON(irqs_disabled()); |
266 | ||
267 | freqs->flags = cpufreq_driver->flags; | |
2d06d8c4 | 268 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 269 | state, freqs->new); |
1da177e4 | 270 | |
7a6aedfa | 271 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 272 | switch (state) { |
e4472cb3 | 273 | |
1da177e4 | 274 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 275 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
276 | * which is not equal to what the cpufreq core thinks is |
277 | * "old frequency". | |
1da177e4 LT |
278 | */ |
279 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
280 | if ((policy) && (policy->cpu == freqs->cpu) && |
281 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 282 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
283 | " %u, cpufreq assumed %u kHz.\n", |
284 | freqs->old, policy->cur); | |
285 | freqs->old = policy->cur; | |
1da177e4 LT |
286 | } |
287 | } | |
b4dfdbb3 | 288 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 289 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
290 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
291 | break; | |
e4472cb3 | 292 | |
1da177e4 LT |
293 | case CPUFREQ_POSTCHANGE: |
294 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 295 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 TR |
296 | (unsigned long)freqs->cpu); |
297 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 298 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 299 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 300 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
301 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
302 | policy->cur = freqs->new; | |
1da177e4 LT |
303 | break; |
304 | } | |
1da177e4 LT |
305 | } |
306 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
307 | ||
308 | ||
309 | ||
310 | /********************************************************************* | |
311 | * SYSFS INTERFACE * | |
312 | *********************************************************************/ | |
313 | ||
3bcb09a3 JF |
314 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
315 | { | |
316 | struct cpufreq_governor *t; | |
317 | ||
318 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 319 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
320 | return t; |
321 | ||
322 | return NULL; | |
323 | } | |
324 | ||
1da177e4 LT |
325 | /** |
326 | * cpufreq_parse_governor - parse a governor string | |
327 | */ | |
905d77cd | 328 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
329 | struct cpufreq_governor **governor) |
330 | { | |
3bcb09a3 JF |
331 | int err = -EINVAL; |
332 | ||
1da177e4 | 333 | if (!cpufreq_driver) |
3bcb09a3 JF |
334 | goto out; |
335 | ||
1da177e4 LT |
336 | if (cpufreq_driver->setpolicy) { |
337 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
338 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 339 | err = 0; |
e08f5f5b GS |
340 | } else if (!strnicmp(str_governor, "powersave", |
341 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 342 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 343 | err = 0; |
1da177e4 | 344 | } |
3bcb09a3 | 345 | } else if (cpufreq_driver->target) { |
1da177e4 | 346 | struct cpufreq_governor *t; |
3bcb09a3 | 347 | |
3fc54d37 | 348 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
349 | |
350 | t = __find_governor(str_governor); | |
351 | ||
ea714970 | 352 | if (t == NULL) { |
1a8e1463 | 353 | int ret; |
ea714970 | 354 | |
1a8e1463 KC |
355 | mutex_unlock(&cpufreq_governor_mutex); |
356 | ret = request_module("cpufreq_%s", str_governor); | |
357 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 358 | |
1a8e1463 KC |
359 | if (ret == 0) |
360 | t = __find_governor(str_governor); | |
ea714970 JF |
361 | } |
362 | ||
3bcb09a3 JF |
363 | if (t != NULL) { |
364 | *governor = t; | |
365 | err = 0; | |
1da177e4 | 366 | } |
3bcb09a3 | 367 | |
3fc54d37 | 368 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 369 | } |
29464f28 | 370 | out: |
3bcb09a3 | 371 | return err; |
1da177e4 | 372 | } |
1da177e4 LT |
373 | |
374 | ||
1da177e4 | 375 | /** |
e08f5f5b GS |
376 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
377 | * print out cpufreq information | |
1da177e4 LT |
378 | * |
379 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
380 | * "unsigned int". | |
381 | */ | |
382 | ||
32ee8c3e DJ |
383 | #define show_one(file_name, object) \ |
384 | static ssize_t show_##file_name \ | |
905d77cd | 385 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 386 | { \ |
29464f28 | 387 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
388 | } |
389 | ||
390 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
391 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 392 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
393 | show_one(scaling_min_freq, min); |
394 | show_one(scaling_max_freq, max); | |
395 | show_one(scaling_cur_freq, cur); | |
396 | ||
e08f5f5b GS |
397 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
398 | struct cpufreq_policy *policy); | |
7970e08b | 399 | |
1da177e4 LT |
400 | /** |
401 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
402 | */ | |
403 | #define store_one(file_name, object) \ | |
404 | static ssize_t store_##file_name \ | |
905d77cd | 405 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
406 | { \ |
407 | unsigned int ret = -EINVAL; \ | |
408 | struct cpufreq_policy new_policy; \ | |
409 | \ | |
410 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
411 | if (ret) \ | |
412 | return -EINVAL; \ | |
413 | \ | |
29464f28 | 414 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
415 | if (ret != 1) \ |
416 | return -EINVAL; \ | |
417 | \ | |
7970e08b TR |
418 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
419 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
420 | \ |
421 | return ret ? ret : count; \ | |
422 | } | |
423 | ||
29464f28 DJ |
424 | store_one(scaling_min_freq, min); |
425 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
426 | |
427 | /** | |
428 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
429 | */ | |
905d77cd DJ |
430 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
431 | char *buf) | |
1da177e4 | 432 | { |
5a01f2e8 | 433 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
434 | if (!cur_freq) |
435 | return sprintf(buf, "<unknown>"); | |
436 | return sprintf(buf, "%u\n", cur_freq); | |
437 | } | |
438 | ||
439 | ||
440 | /** | |
441 | * show_scaling_governor - show the current policy for the specified CPU | |
442 | */ | |
905d77cd | 443 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 444 | { |
29464f28 | 445 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
446 | return sprintf(buf, "powersave\n"); |
447 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
448 | return sprintf(buf, "performance\n"); | |
449 | else if (policy->governor) | |
4b972f0b | 450 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 451 | policy->governor->name); |
1da177e4 LT |
452 | return -EINVAL; |
453 | } | |
454 | ||
455 | ||
456 | /** | |
457 | * store_scaling_governor - store policy for the specified CPU | |
458 | */ | |
905d77cd DJ |
459 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
460 | const char *buf, size_t count) | |
1da177e4 LT |
461 | { |
462 | unsigned int ret = -EINVAL; | |
463 | char str_governor[16]; | |
464 | struct cpufreq_policy new_policy; | |
465 | ||
466 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
467 | if (ret) | |
468 | return ret; | |
469 | ||
29464f28 | 470 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
471 | if (ret != 1) |
472 | return -EINVAL; | |
473 | ||
e08f5f5b GS |
474 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
475 | &new_policy.governor)) | |
1da177e4 LT |
476 | return -EINVAL; |
477 | ||
7970e08b TR |
478 | /* Do not use cpufreq_set_policy here or the user_policy.max |
479 | will be wrongly overridden */ | |
7970e08b TR |
480 | ret = __cpufreq_set_policy(policy, &new_policy); |
481 | ||
482 | policy->user_policy.policy = policy->policy; | |
483 | policy->user_policy.governor = policy->governor; | |
7970e08b | 484 | |
e08f5f5b GS |
485 | if (ret) |
486 | return ret; | |
487 | else | |
488 | return count; | |
1da177e4 LT |
489 | } |
490 | ||
491 | /** | |
492 | * show_scaling_driver - show the cpufreq driver currently loaded | |
493 | */ | |
905d77cd | 494 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 495 | { |
4b972f0b | 496 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
497 | } |
498 | ||
499 | /** | |
500 | * show_scaling_available_governors - show the available CPUfreq governors | |
501 | */ | |
905d77cd DJ |
502 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
503 | char *buf) | |
1da177e4 LT |
504 | { |
505 | ssize_t i = 0; | |
506 | struct cpufreq_governor *t; | |
507 | ||
508 | if (!cpufreq_driver->target) { | |
509 | i += sprintf(buf, "performance powersave"); | |
510 | goto out; | |
511 | } | |
512 | ||
513 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
514 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
515 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 516 | goto out; |
4b972f0b | 517 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 518 | } |
7d5e350f | 519 | out: |
1da177e4 LT |
520 | i += sprintf(&buf[i], "\n"); |
521 | return i; | |
522 | } | |
e8628dd0 | 523 | |
835481d9 | 524 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
525 | { |
526 | ssize_t i = 0; | |
527 | unsigned int cpu; | |
528 | ||
835481d9 | 529 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
530 | if (i) |
531 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
532 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
533 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 534 | break; |
1da177e4 LT |
535 | } |
536 | i += sprintf(&buf[i], "\n"); | |
537 | return i; | |
538 | } | |
539 | ||
e8628dd0 DW |
540 | /** |
541 | * show_related_cpus - show the CPUs affected by each transition even if | |
542 | * hw coordination is in use | |
543 | */ | |
544 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
545 | { | |
835481d9 | 546 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
547 | return show_cpus(policy->cpus, buf); |
548 | return show_cpus(policy->related_cpus, buf); | |
549 | } | |
550 | ||
551 | /** | |
552 | * show_affected_cpus - show the CPUs affected by each transition | |
553 | */ | |
554 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
555 | { | |
556 | return show_cpus(policy->cpus, buf); | |
557 | } | |
558 | ||
9e76988e | 559 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 560 | const char *buf, size_t count) |
9e76988e VP |
561 | { |
562 | unsigned int freq = 0; | |
563 | unsigned int ret; | |
564 | ||
879000f9 | 565 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
566 | return -EINVAL; |
567 | ||
568 | ret = sscanf(buf, "%u", &freq); | |
569 | if (ret != 1) | |
570 | return -EINVAL; | |
571 | ||
572 | policy->governor->store_setspeed(policy, freq); | |
573 | ||
574 | return count; | |
575 | } | |
576 | ||
577 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
578 | { | |
879000f9 | 579 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
580 | return sprintf(buf, "<unsupported>\n"); |
581 | ||
582 | return policy->governor->show_setspeed(policy, buf); | |
583 | } | |
1da177e4 | 584 | |
e2f74f35 | 585 | /** |
8bf1ac72 | 586 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
587 | */ |
588 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
589 | { | |
590 | unsigned int limit; | |
591 | int ret; | |
592 | if (cpufreq_driver->bios_limit) { | |
593 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
594 | if (!ret) | |
595 | return sprintf(buf, "%u\n", limit); | |
596 | } | |
597 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
598 | } | |
599 | ||
6dad2a29 BP |
600 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
601 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
602 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
603 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
604 | cpufreq_freq_attr_ro(scaling_available_governors); | |
605 | cpufreq_freq_attr_ro(scaling_driver); | |
606 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
607 | cpufreq_freq_attr_ro(bios_limit); | |
608 | cpufreq_freq_attr_ro(related_cpus); | |
609 | cpufreq_freq_attr_ro(affected_cpus); | |
610 | cpufreq_freq_attr_rw(scaling_min_freq); | |
611 | cpufreq_freq_attr_rw(scaling_max_freq); | |
612 | cpufreq_freq_attr_rw(scaling_governor); | |
613 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 614 | |
905d77cd | 615 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
616 | &cpuinfo_min_freq.attr, |
617 | &cpuinfo_max_freq.attr, | |
ed129784 | 618 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
619 | &scaling_min_freq.attr, |
620 | &scaling_max_freq.attr, | |
621 | &affected_cpus.attr, | |
e8628dd0 | 622 | &related_cpus.attr, |
1da177e4 LT |
623 | &scaling_governor.attr, |
624 | &scaling_driver.attr, | |
625 | &scaling_available_governors.attr, | |
9e76988e | 626 | &scaling_setspeed.attr, |
1da177e4 LT |
627 | NULL |
628 | }; | |
629 | ||
8aa84ad8 TR |
630 | struct kobject *cpufreq_global_kobject; |
631 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
632 | ||
29464f28 DJ |
633 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
634 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 635 | |
29464f28 | 636 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 637 | { |
905d77cd DJ |
638 | struct cpufreq_policy *policy = to_policy(kobj); |
639 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 640 | ssize_t ret = -EINVAL; |
a9144436 | 641 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 642 | if (!policy) |
0db4a8a9 | 643 | goto no_policy; |
5a01f2e8 VP |
644 | |
645 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 646 | goto fail; |
5a01f2e8 | 647 | |
e08f5f5b GS |
648 | if (fattr->show) |
649 | ret = fattr->show(policy, buf); | |
650 | else | |
651 | ret = -EIO; | |
652 | ||
5a01f2e8 | 653 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 654 | fail: |
a9144436 | 655 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 656 | no_policy: |
1da177e4 LT |
657 | return ret; |
658 | } | |
659 | ||
905d77cd DJ |
660 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
661 | const char *buf, size_t count) | |
1da177e4 | 662 | { |
905d77cd DJ |
663 | struct cpufreq_policy *policy = to_policy(kobj); |
664 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 665 | ssize_t ret = -EINVAL; |
a9144436 | 666 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 667 | if (!policy) |
a07530b4 | 668 | goto no_policy; |
5a01f2e8 VP |
669 | |
670 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 671 | goto fail; |
5a01f2e8 | 672 | |
e08f5f5b GS |
673 | if (fattr->store) |
674 | ret = fattr->store(policy, buf, count); | |
675 | else | |
676 | ret = -EIO; | |
677 | ||
5a01f2e8 | 678 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 679 | fail: |
a9144436 | 680 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 681 | no_policy: |
1da177e4 LT |
682 | return ret; |
683 | } | |
684 | ||
905d77cd | 685 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 686 | { |
905d77cd | 687 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 688 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
689 | complete(&policy->kobj_unregister); |
690 | } | |
691 | ||
52cf25d0 | 692 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
693 | .show = show, |
694 | .store = store, | |
695 | }; | |
696 | ||
697 | static struct kobj_type ktype_cpufreq = { | |
698 | .sysfs_ops = &sysfs_ops, | |
699 | .default_attrs = default_attrs, | |
700 | .release = cpufreq_sysfs_release, | |
701 | }; | |
702 | ||
4bfa042c TR |
703 | /* |
704 | * Returns: | |
705 | * Negative: Failure | |
706 | * 0: Success | |
707 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
708 | */ | |
cf3289d0 AC |
709 | static int cpufreq_add_dev_policy(unsigned int cpu, |
710 | struct cpufreq_policy *policy, | |
8a25a2fd | 711 | struct device *dev) |
ecf7e461 DJ |
712 | { |
713 | int ret = 0; | |
714 | #ifdef CONFIG_SMP | |
715 | unsigned long flags; | |
716 | unsigned int j; | |
ecf7e461 | 717 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
718 | struct cpufreq_governor *gov; |
719 | ||
720 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
721 | if (gov) { | |
722 | policy->governor = gov; | |
2d06d8c4 | 723 | pr_debug("Restoring governor %s for cpu %d\n", |
ecf7e461 DJ |
724 | policy->governor->name, cpu); |
725 | } | |
726 | #endif | |
727 | ||
728 | for_each_cpu(j, policy->cpus) { | |
729 | struct cpufreq_policy *managed_policy; | |
730 | ||
731 | if (cpu == j) | |
732 | continue; | |
733 | ||
734 | /* Check for existing affected CPUs. | |
735 | * They may not be aware of it due to CPU Hotplug. | |
736 | * cpufreq_cpu_put is called when the device is removed | |
737 | * in __cpufreq_remove_dev() | |
738 | */ | |
739 | managed_policy = cpufreq_cpu_get(j); | |
740 | if (unlikely(managed_policy)) { | |
741 | ||
742 | /* Set proper policy_cpu */ | |
743 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 744 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
745 | |
746 | if (lock_policy_rwsem_write(cpu) < 0) { | |
747 | /* Should not go through policy unlock path */ | |
748 | if (cpufreq_driver->exit) | |
749 | cpufreq_driver->exit(policy); | |
750 | cpufreq_cpu_put(managed_policy); | |
751 | return -EBUSY; | |
752 | } | |
753 | ||
754 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
755 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
756 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
757 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
758 | ||
2d06d8c4 | 759 | pr_debug("CPU already managed, adding link\n"); |
8a25a2fd | 760 | ret = sysfs_create_link(&dev->kobj, |
ecf7e461 DJ |
761 | &managed_policy->kobj, |
762 | "cpufreq"); | |
763 | if (ret) | |
764 | cpufreq_cpu_put(managed_policy); | |
765 | /* | |
766 | * Success. We only needed to be added to the mask. | |
767 | * Call driver->exit() because only the cpu parent of | |
768 | * the kobj needed to call init(). | |
769 | */ | |
770 | if (cpufreq_driver->exit) | |
771 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
772 | |
773 | if (!ret) | |
774 | return 1; | |
775 | else | |
776 | return ret; | |
ecf7e461 DJ |
777 | } |
778 | } | |
779 | #endif | |
780 | return ret; | |
781 | } | |
782 | ||
783 | ||
19d6f7ec | 784 | /* symlink affected CPUs */ |
cf3289d0 AC |
785 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
786 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
787 | { |
788 | unsigned int j; | |
789 | int ret = 0; | |
790 | ||
791 | for_each_cpu(j, policy->cpus) { | |
792 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 793 | struct device *cpu_dev; |
19d6f7ec DJ |
794 | |
795 | if (j == cpu) | |
796 | continue; | |
797 | if (!cpu_online(j)) | |
798 | continue; | |
799 | ||
2d06d8c4 | 800 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 801 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
802 | cpu_dev = get_cpu_device(j); |
803 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
804 | "cpufreq"); |
805 | if (ret) { | |
806 | cpufreq_cpu_put(managed_policy); | |
807 | return ret; | |
808 | } | |
809 | } | |
810 | return ret; | |
811 | } | |
812 | ||
cf3289d0 AC |
813 | static int cpufreq_add_dev_interface(unsigned int cpu, |
814 | struct cpufreq_policy *policy, | |
8a25a2fd | 815 | struct device *dev) |
909a694e | 816 | { |
ecf7e461 | 817 | struct cpufreq_policy new_policy; |
909a694e DJ |
818 | struct freq_attr **drv_attr; |
819 | unsigned long flags; | |
820 | int ret = 0; | |
821 | unsigned int j; | |
822 | ||
823 | /* prepare interface data */ | |
824 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 825 | &dev->kobj, "cpufreq"); |
909a694e DJ |
826 | if (ret) |
827 | return ret; | |
828 | ||
829 | /* set up files for this cpu device */ | |
830 | drv_attr = cpufreq_driver->attr; | |
831 | while ((drv_attr) && (*drv_attr)) { | |
832 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
833 | if (ret) | |
834 | goto err_out_kobj_put; | |
835 | drv_attr++; | |
836 | } | |
837 | if (cpufreq_driver->get) { | |
838 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
839 | if (ret) | |
840 | goto err_out_kobj_put; | |
841 | } | |
842 | if (cpufreq_driver->target) { | |
843 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
844 | if (ret) | |
845 | goto err_out_kobj_put; | |
846 | } | |
e2f74f35 TR |
847 | if (cpufreq_driver->bios_limit) { |
848 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
849 | if (ret) | |
850 | goto err_out_kobj_put; | |
851 | } | |
909a694e DJ |
852 | |
853 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
854 | for_each_cpu(j, policy->cpus) { | |
bec037aa JL |
855 | if (!cpu_online(j)) |
856 | continue; | |
909a694e | 857 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 858 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
859 | } |
860 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
861 | ||
862 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
863 | if (ret) |
864 | goto err_out_kobj_put; | |
865 | ||
866 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
867 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
868 | policy->governor = NULL; | |
869 | ||
870 | /* set default policy */ | |
871 | ret = __cpufreq_set_policy(policy, &new_policy); | |
872 | policy->user_policy.policy = policy->policy; | |
873 | policy->user_policy.governor = policy->governor; | |
874 | ||
875 | if (ret) { | |
2d06d8c4 | 876 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
877 | if (cpufreq_driver->exit) |
878 | cpufreq_driver->exit(policy); | |
879 | } | |
909a694e DJ |
880 | return ret; |
881 | ||
882 | err_out_kobj_put: | |
883 | kobject_put(&policy->kobj); | |
884 | wait_for_completion(&policy->kobj_unregister); | |
885 | return ret; | |
886 | } | |
887 | ||
1da177e4 LT |
888 | |
889 | /** | |
890 | * cpufreq_add_dev - add a CPU device | |
891 | * | |
32ee8c3e | 892 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
893 | * |
894 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
895 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
896 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 897 | */ |
8a25a2fd | 898 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 899 | { |
8a25a2fd | 900 | unsigned int cpu = dev->id; |
90e41bac | 901 | int ret = 0, found = 0; |
1da177e4 | 902 | struct cpufreq_policy *policy; |
1da177e4 LT |
903 | unsigned long flags; |
904 | unsigned int j; | |
90e41bac PB |
905 | #ifdef CONFIG_HOTPLUG_CPU |
906 | int sibling; | |
907 | #endif | |
1da177e4 | 908 | |
c32b6b8e AR |
909 | if (cpu_is_offline(cpu)) |
910 | return 0; | |
911 | ||
2d06d8c4 | 912 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
913 | |
914 | #ifdef CONFIG_SMP | |
915 | /* check whether a different CPU already registered this | |
916 | * CPU because it is in the same boat. */ | |
917 | policy = cpufreq_cpu_get(cpu); | |
918 | if (unlikely(policy)) { | |
8ff69732 | 919 | cpufreq_cpu_put(policy); |
1da177e4 LT |
920 | return 0; |
921 | } | |
922 | #endif | |
923 | ||
924 | if (!try_module_get(cpufreq_driver->owner)) { | |
925 | ret = -EINVAL; | |
926 | goto module_out; | |
927 | } | |
928 | ||
059019a3 | 929 | ret = -ENOMEM; |
e98df50c | 930 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 931 | if (!policy) |
1da177e4 | 932 | goto nomem_out; |
059019a3 DJ |
933 | |
934 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 935 | goto err_free_policy; |
059019a3 DJ |
936 | |
937 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 938 | goto err_free_cpumask; |
1da177e4 LT |
939 | |
940 | policy->cpu = cpu; | |
835481d9 | 941 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 942 | |
5a01f2e8 | 943 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 944 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
945 | ret = (lock_policy_rwsem_write(cpu) < 0); |
946 | WARN_ON(ret); | |
5a01f2e8 | 947 | |
1da177e4 | 948 | init_completion(&policy->kobj_unregister); |
65f27f38 | 949 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 950 | |
8122c6ce | 951 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
952 | #ifdef CONFIG_HOTPLUG_CPU |
953 | for_each_online_cpu(sibling) { | |
954 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
955 | if (cp && cp->governor && | |
956 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
957 | policy->governor = cp->governor; | |
958 | found = 1; | |
959 | break; | |
960 | } | |
961 | } | |
962 | #endif | |
963 | if (!found) | |
964 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
965 | /* call driver. From then on the cpufreq must be able |
966 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
967 | */ | |
968 | ret = cpufreq_driver->init(policy); | |
969 | if (ret) { | |
2d06d8c4 | 970 | pr_debug("initialization failed\n"); |
3f4a782b | 971 | goto err_unlock_policy; |
1da177e4 | 972 | } |
187d9f4e MC |
973 | policy->user_policy.min = policy->min; |
974 | policy->user_policy.max = policy->max; | |
1da177e4 | 975 | |
a1531acd TR |
976 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
977 | CPUFREQ_START, policy); | |
978 | ||
8a25a2fd | 979 | ret = cpufreq_add_dev_policy(cpu, policy, dev); |
4bfa042c TR |
980 | if (ret) { |
981 | if (ret > 0) | |
982 | /* This is a managed cpu, symlink created, | |
983 | exit with 0 */ | |
984 | ret = 0; | |
ecf7e461 | 985 | goto err_unlock_policy; |
4bfa042c | 986 | } |
1da177e4 | 987 | |
8a25a2fd | 988 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
989 | if (ret) |
990 | goto err_out_unregister; | |
8ff69732 | 991 | |
dca02613 LW |
992 | unlock_policy_rwsem_write(cpu); |
993 | ||
038c5b3e | 994 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 995 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 996 | pr_debug("initialization complete\n"); |
87c32271 | 997 | |
1da177e4 LT |
998 | return 0; |
999 | ||
1000 | ||
1001 | err_out_unregister: | |
1002 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1003 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1004 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1005 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1006 | ||
c10997f6 | 1007 | kobject_put(&policy->kobj); |
1da177e4 LT |
1008 | wait_for_completion(&policy->kobj_unregister); |
1009 | ||
3f4a782b | 1010 | err_unlock_policy: |
45709118 | 1011 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 1012 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
1013 | err_free_cpumask: |
1014 | free_cpumask_var(policy->cpus); | |
1015 | err_free_policy: | |
1da177e4 | 1016 | kfree(policy); |
1da177e4 LT |
1017 | nomem_out: |
1018 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1019 | module_out: |
1da177e4 LT |
1020 | return ret; |
1021 | } | |
1022 | ||
1023 | ||
1024 | /** | |
5a01f2e8 | 1025 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1026 | * |
1027 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1028 | * Caller should already have policy_rwsem in write mode for this CPU. |
1029 | * This routine frees the rwsem before returning. | |
1da177e4 | 1030 | */ |
8a25a2fd | 1031 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1032 | { |
8a25a2fd | 1033 | unsigned int cpu = dev->id; |
1da177e4 LT |
1034 | unsigned long flags; |
1035 | struct cpufreq_policy *data; | |
499bca9b AW |
1036 | struct kobject *kobj; |
1037 | struct completion *cmp; | |
1da177e4 | 1038 | #ifdef CONFIG_SMP |
8a25a2fd | 1039 | struct device *cpu_dev; |
1da177e4 LT |
1040 | unsigned int j; |
1041 | #endif | |
1042 | ||
2d06d8c4 | 1043 | pr_debug("unregistering CPU %u\n", cpu); |
1da177e4 LT |
1044 | |
1045 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1046 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1047 | |
1048 | if (!data) { | |
1049 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 1050 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1051 | return -EINVAL; |
1052 | } | |
7a6aedfa | 1053 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1054 | |
1055 | ||
1056 | #ifdef CONFIG_SMP | |
1057 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1058 | * only need to unlink, put and exit |
1da177e4 LT |
1059 | */ |
1060 | if (unlikely(cpu != data->cpu)) { | |
2d06d8c4 | 1061 | pr_debug("removing link\n"); |
835481d9 | 1062 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 | 1063 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8a25a2fd | 1064 | kobj = &dev->kobj; |
1da177e4 | 1065 | cpufreq_cpu_put(data); |
5a01f2e8 | 1066 | unlock_policy_rwsem_write(cpu); |
499bca9b | 1067 | sysfs_remove_link(kobj, "cpufreq"); |
1da177e4 LT |
1068 | return 0; |
1069 | } | |
1070 | #endif | |
1071 | ||
1da177e4 | 1072 | #ifdef CONFIG_SMP |
084f3493 TR |
1073 | |
1074 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1075 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1076 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1077 | #endif |
1078 | ||
1da177e4 LT |
1079 | /* if we have other CPUs still registered, we need to unlink them, |
1080 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1081 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1082 | * the sysfs links afterwards. | |
1da177e4 | 1083 | */ |
835481d9 RR |
1084 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1085 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1086 | if (j == cpu) |
1087 | continue; | |
7a6aedfa | 1088 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1089 | } |
1090 | } | |
1091 | ||
1092 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1093 | ||
835481d9 RR |
1094 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1095 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1096 | if (j == cpu) |
1097 | continue; | |
2d06d8c4 | 1098 | pr_debug("removing link for cpu %u\n", j); |
084f3493 | 1099 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1100 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1101 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1102 | #endif |
8a25a2fd KS |
1103 | cpu_dev = get_cpu_device(j); |
1104 | kobj = &cpu_dev->kobj; | |
499bca9b AW |
1105 | unlock_policy_rwsem_write(cpu); |
1106 | sysfs_remove_link(kobj, "cpufreq"); | |
1107 | lock_policy_rwsem_write(cpu); | |
1da177e4 LT |
1108 | cpufreq_cpu_put(data); |
1109 | } | |
1110 | } | |
1111 | #else | |
1112 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1113 | #endif | |
1114 | ||
1da177e4 LT |
1115 | if (cpufreq_driver->target) |
1116 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1117 | |
499bca9b AW |
1118 | kobj = &data->kobj; |
1119 | cmp = &data->kobj_unregister; | |
1120 | unlock_policy_rwsem_write(cpu); | |
1121 | kobject_put(kobj); | |
1da177e4 LT |
1122 | |
1123 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1124 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1125 | * unloading. |
1126 | */ | |
2d06d8c4 | 1127 | pr_debug("waiting for dropping of refcount\n"); |
499bca9b | 1128 | wait_for_completion(cmp); |
2d06d8c4 | 1129 | pr_debug("wait complete\n"); |
1da177e4 | 1130 | |
499bca9b | 1131 | lock_policy_rwsem_write(cpu); |
1da177e4 LT |
1132 | if (cpufreq_driver->exit) |
1133 | cpufreq_driver->exit(data); | |
7d26e2d5 | 1134 | unlock_policy_rwsem_write(cpu); |
1135 | ||
27ecddc2 JS |
1136 | #ifdef CONFIG_HOTPLUG_CPU |
1137 | /* when the CPU which is the parent of the kobj is hotplugged | |
1138 | * offline, check for siblings, and create cpufreq sysfs interface | |
1139 | * and symlinks | |
1140 | */ | |
1141 | if (unlikely(cpumask_weight(data->cpus) > 1)) { | |
1142 | /* first sibling now owns the new sysfs dir */ | |
1143 | cpumask_clear_cpu(cpu, data->cpus); | |
8a25a2fd | 1144 | cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL); |
27ecddc2 JS |
1145 | |
1146 | /* finally remove our own symlink */ | |
1147 | lock_policy_rwsem_write(cpu); | |
8a25a2fd | 1148 | __cpufreq_remove_dev(dev, sif); |
27ecddc2 JS |
1149 | } |
1150 | #endif | |
1151 | ||
835481d9 RR |
1152 | free_cpumask_var(data->related_cpus); |
1153 | free_cpumask_var(data->cpus); | |
1da177e4 LT |
1154 | kfree(data); |
1155 | ||
1da177e4 LT |
1156 | return 0; |
1157 | } | |
1158 | ||
1159 | ||
8a25a2fd | 1160 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1161 | { |
8a25a2fd | 1162 | unsigned int cpu = dev->id; |
5a01f2e8 | 1163 | int retval; |
ec28297a VP |
1164 | |
1165 | if (cpu_is_offline(cpu)) | |
1166 | return 0; | |
1167 | ||
5a01f2e8 VP |
1168 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1169 | BUG(); | |
1170 | ||
8a25a2fd | 1171 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1172 | return retval; |
1173 | } | |
1174 | ||
1175 | ||
65f27f38 | 1176 | static void handle_update(struct work_struct *work) |
1da177e4 | 1177 | { |
65f27f38 DH |
1178 | struct cpufreq_policy *policy = |
1179 | container_of(work, struct cpufreq_policy, update); | |
1180 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1181 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1182 | cpufreq_update_policy(cpu); |
1183 | } | |
1184 | ||
1185 | /** | |
1186 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1187 | * @cpu: cpu number | |
1188 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1189 | * @new_freq: CPU frequency the CPU actually runs at | |
1190 | * | |
29464f28 DJ |
1191 | * We adjust to current frequency first, and need to clean up later. |
1192 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1193 | */ |
e08f5f5b GS |
1194 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1195 | unsigned int new_freq) | |
1da177e4 LT |
1196 | { |
1197 | struct cpufreq_freqs freqs; | |
1198 | ||
2d06d8c4 | 1199 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1200 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1201 | ||
1202 | freqs.cpu = cpu; | |
1203 | freqs.old = old_freq; | |
1204 | freqs.new = new_freq; | |
1205 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1206 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1207 | } | |
1208 | ||
1209 | ||
32ee8c3e | 1210 | /** |
4ab70df4 | 1211 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1212 | * @cpu: CPU number |
1213 | * | |
1214 | * This is the last known freq, without actually getting it from the driver. | |
1215 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1216 | */ | |
1217 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1218 | { | |
1219 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1220 | unsigned int ret_freq = 0; |
95235ca2 VP |
1221 | |
1222 | if (policy) { | |
e08f5f5b | 1223 | ret_freq = policy->cur; |
95235ca2 VP |
1224 | cpufreq_cpu_put(policy); |
1225 | } | |
1226 | ||
4d34a67d | 1227 | return ret_freq; |
95235ca2 VP |
1228 | } |
1229 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1230 | ||
3d737108 JB |
1231 | /** |
1232 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1233 | * @cpu: CPU number | |
1234 | * | |
1235 | * Just return the max possible frequency for a given CPU. | |
1236 | */ | |
1237 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1238 | { | |
1239 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1240 | unsigned int ret_freq = 0; | |
1241 | ||
1242 | if (policy) { | |
1243 | ret_freq = policy->max; | |
1244 | cpufreq_cpu_put(policy); | |
1245 | } | |
1246 | ||
1247 | return ret_freq; | |
1248 | } | |
1249 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1250 | ||
95235ca2 | 1251 | |
5a01f2e8 | 1252 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1253 | { |
7a6aedfa | 1254 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1255 | unsigned int ret_freq = 0; |
1da177e4 | 1256 | |
1da177e4 | 1257 | if (!cpufreq_driver->get) |
4d34a67d | 1258 | return ret_freq; |
1da177e4 | 1259 | |
e08f5f5b | 1260 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1261 | |
e08f5f5b GS |
1262 | if (ret_freq && policy->cur && |
1263 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1264 | /* verify no discrepancy between actual and | |
1265 | saved value exists */ | |
1266 | if (unlikely(ret_freq != policy->cur)) { | |
1267 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1268 | schedule_work(&policy->update); |
1269 | } | |
1270 | } | |
1271 | ||
4d34a67d | 1272 | return ret_freq; |
5a01f2e8 | 1273 | } |
1da177e4 | 1274 | |
5a01f2e8 VP |
1275 | /** |
1276 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1277 | * @cpu: CPU number | |
1278 | * | |
1279 | * Get the CPU current (static) CPU frequency | |
1280 | */ | |
1281 | unsigned int cpufreq_get(unsigned int cpu) | |
1282 | { | |
1283 | unsigned int ret_freq = 0; | |
1284 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1285 | ||
1286 | if (!policy) | |
1287 | goto out; | |
1288 | ||
1289 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1290 | goto out_policy; | |
1291 | ||
1292 | ret_freq = __cpufreq_get(cpu); | |
1293 | ||
1294 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1295 | |
5a01f2e8 VP |
1296 | out_policy: |
1297 | cpufreq_cpu_put(policy); | |
1298 | out: | |
4d34a67d | 1299 | return ret_freq; |
1da177e4 LT |
1300 | } |
1301 | EXPORT_SYMBOL(cpufreq_get); | |
1302 | ||
8a25a2fd KS |
1303 | static struct subsys_interface cpufreq_interface = { |
1304 | .name = "cpufreq", | |
1305 | .subsys = &cpu_subsys, | |
1306 | .add_dev = cpufreq_add_dev, | |
1307 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1308 | }; |
1309 | ||
1da177e4 | 1310 | |
42d4dc3f | 1311 | /** |
e00e56df RW |
1312 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1313 | * | |
1314 | * This function is only executed for the boot processor. The other CPUs | |
1315 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1316 | */ |
e00e56df | 1317 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1318 | { |
e08f5f5b | 1319 | int ret = 0; |
4bc5d341 | 1320 | |
e00e56df | 1321 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1322 | struct cpufreq_policy *cpu_policy; |
1323 | ||
2d06d8c4 | 1324 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1325 | |
e00e56df | 1326 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1327 | cpu_policy = cpufreq_cpu_get(cpu); |
1328 | if (!cpu_policy) | |
e00e56df | 1329 | return 0; |
42d4dc3f BH |
1330 | |
1331 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1332 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1333 | if (ret) |
42d4dc3f BH |
1334 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1335 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1336 | } |
1337 | ||
42d4dc3f | 1338 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1339 | return ret; |
42d4dc3f BH |
1340 | } |
1341 | ||
1da177e4 | 1342 | /** |
e00e56df | 1343 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1344 | * |
1345 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1346 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1347 | * restored. It will verify that the current freq is in sync with | |
1348 | * what we believe it to be. This is a bit later than when it | |
1349 | * should be, but nonethteless it's better than calling | |
1350 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1351 | * |
1352 | * This function is only executed for the boot CPU. The other CPUs have not | |
1353 | * been turned on yet. | |
1da177e4 | 1354 | */ |
e00e56df | 1355 | static void cpufreq_bp_resume(void) |
1da177e4 | 1356 | { |
e08f5f5b | 1357 | int ret = 0; |
4bc5d341 | 1358 | |
e00e56df | 1359 | int cpu = smp_processor_id(); |
1da177e4 LT |
1360 | struct cpufreq_policy *cpu_policy; |
1361 | ||
2d06d8c4 | 1362 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1363 | |
e00e56df | 1364 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1365 | cpu_policy = cpufreq_cpu_get(cpu); |
1366 | if (!cpu_policy) | |
e00e56df | 1367 | return; |
1da177e4 LT |
1368 | |
1369 | if (cpufreq_driver->resume) { | |
1370 | ret = cpufreq_driver->resume(cpu_policy); | |
1371 | if (ret) { | |
1372 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1373 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1374 | goto fail; |
1da177e4 LT |
1375 | } |
1376 | } | |
1377 | ||
1da177e4 | 1378 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1379 | |
c9060494 | 1380 | fail: |
1da177e4 | 1381 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1382 | } |
1383 | ||
e00e56df RW |
1384 | static struct syscore_ops cpufreq_syscore_ops = { |
1385 | .suspend = cpufreq_bp_suspend, | |
1386 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1387 | }; |
1388 | ||
1389 | ||
1390 | /********************************************************************* | |
1391 | * NOTIFIER LISTS INTERFACE * | |
1392 | *********************************************************************/ | |
1393 | ||
1394 | /** | |
1395 | * cpufreq_register_notifier - register a driver with cpufreq | |
1396 | * @nb: notifier function to register | |
1397 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1398 | * | |
32ee8c3e | 1399 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1400 | * are notified about clock rate changes (once before and once after |
1401 | * the transition), or a list of drivers that are notified about | |
1402 | * changes in cpufreq policy. | |
1403 | * | |
1404 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1405 | * blocking_notifier_chain_register. |
1da177e4 LT |
1406 | */ |
1407 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1408 | { | |
1409 | int ret; | |
1410 | ||
74212ca4 CEB |
1411 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1412 | ||
1da177e4 LT |
1413 | switch (list) { |
1414 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1415 | ret = srcu_notifier_chain_register( |
e041c683 | 1416 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1417 | break; |
1418 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1419 | ret = blocking_notifier_chain_register( |
1420 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1421 | break; |
1422 | default: | |
1423 | ret = -EINVAL; | |
1424 | } | |
1da177e4 LT |
1425 | |
1426 | return ret; | |
1427 | } | |
1428 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1429 | ||
1430 | ||
1431 | /** | |
1432 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1433 | * @nb: notifier block to be unregistered | |
1434 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1435 | * | |
1436 | * Remove a driver from the CPU frequency notifier list. | |
1437 | * | |
1438 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1439 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1440 | */ |
1441 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1442 | { | |
1443 | int ret; | |
1444 | ||
1da177e4 LT |
1445 | switch (list) { |
1446 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1447 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1448 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1449 | break; |
1450 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1451 | ret = blocking_notifier_chain_unregister( |
1452 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1453 | break; |
1454 | default: | |
1455 | ret = -EINVAL; | |
1456 | } | |
1da177e4 LT |
1457 | |
1458 | return ret; | |
1459 | } | |
1460 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1461 | ||
1462 | ||
1463 | /********************************************************************* | |
1464 | * GOVERNORS * | |
1465 | *********************************************************************/ | |
1466 | ||
1467 | ||
1468 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1469 | unsigned int target_freq, | |
1470 | unsigned int relation) | |
1471 | { | |
1472 | int retval = -EINVAL; | |
c32b6b8e | 1473 | |
a7b422cd KRW |
1474 | if (cpufreq_disabled()) |
1475 | return -ENODEV; | |
1476 | ||
2d06d8c4 | 1477 | pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1da177e4 LT |
1478 | target_freq, relation); |
1479 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1480 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1481 | |
1da177e4 LT |
1482 | return retval; |
1483 | } | |
1484 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1485 | ||
1da177e4 LT |
1486 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1487 | unsigned int target_freq, | |
1488 | unsigned int relation) | |
1489 | { | |
f1829e4a | 1490 | int ret = -EINVAL; |
1da177e4 LT |
1491 | |
1492 | policy = cpufreq_cpu_get(policy->cpu); | |
1493 | if (!policy) | |
f1829e4a | 1494 | goto no_policy; |
1da177e4 | 1495 | |
5a01f2e8 | 1496 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1497 | goto fail; |
1da177e4 LT |
1498 | |
1499 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1500 | ||
5a01f2e8 | 1501 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1502 | |
f1829e4a | 1503 | fail: |
1da177e4 | 1504 | cpufreq_cpu_put(policy); |
f1829e4a | 1505 | no_policy: |
1da177e4 LT |
1506 | return ret; |
1507 | } | |
1508 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1509 | ||
bf0b90e3 | 1510 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1511 | { |
1512 | int ret = 0; | |
1513 | ||
0676f7f2 VK |
1514 | if (!(cpu_online(cpu) && cpufreq_driver->getavg)) |
1515 | return 0; | |
1516 | ||
dfde5d62 VP |
1517 | policy = cpufreq_cpu_get(policy->cpu); |
1518 | if (!policy) | |
1519 | return -EINVAL; | |
1520 | ||
0676f7f2 | 1521 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1522 | |
dfde5d62 VP |
1523 | cpufreq_cpu_put(policy); |
1524 | return ret; | |
1525 | } | |
5a01f2e8 | 1526 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1527 | |
153d7f3f | 1528 | /* |
153d7f3f AV |
1529 | * when "event" is CPUFREQ_GOV_LIMITS |
1530 | */ | |
1da177e4 | 1531 | |
e08f5f5b GS |
1532 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1533 | unsigned int event) | |
1da177e4 | 1534 | { |
cc993cab | 1535 | int ret; |
6afde10c TR |
1536 | |
1537 | /* Only must be defined when default governor is known to have latency | |
1538 | restrictions, like e.g. conservative or ondemand. | |
1539 | That this is the case is already ensured in Kconfig | |
1540 | */ | |
1541 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1542 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1543 | #else | |
1544 | struct cpufreq_governor *gov = NULL; | |
1545 | #endif | |
1c256245 TR |
1546 | |
1547 | if (policy->governor->max_transition_latency && | |
1548 | policy->cpuinfo.transition_latency > | |
1549 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1550 | if (!gov) |
1551 | return -EINVAL; | |
1552 | else { | |
1553 | printk(KERN_WARNING "%s governor failed, too long" | |
1554 | " transition latency of HW, fallback" | |
1555 | " to %s governor\n", | |
1556 | policy->governor->name, | |
1557 | gov->name); | |
1558 | policy->governor = gov; | |
1559 | } | |
1c256245 | 1560 | } |
1da177e4 LT |
1561 | |
1562 | if (!try_module_get(policy->governor->owner)) | |
1563 | return -EINVAL; | |
1564 | ||
2d06d8c4 | 1565 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1566 | policy->cpu, event); |
1da177e4 LT |
1567 | ret = policy->governor->governor(policy, event); |
1568 | ||
e08f5f5b GS |
1569 | /* we keep one module reference alive for |
1570 | each CPU governed by this CPU */ | |
1da177e4 LT |
1571 | if ((event != CPUFREQ_GOV_START) || ret) |
1572 | module_put(policy->governor->owner); | |
1573 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1574 | module_put(policy->governor->owner); | |
1575 | ||
1576 | return ret; | |
1577 | } | |
1578 | ||
1579 | ||
1da177e4 LT |
1580 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1581 | { | |
3bcb09a3 | 1582 | int err; |
1da177e4 LT |
1583 | |
1584 | if (!governor) | |
1585 | return -EINVAL; | |
1586 | ||
a7b422cd KRW |
1587 | if (cpufreq_disabled()) |
1588 | return -ENODEV; | |
1589 | ||
3fc54d37 | 1590 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1591 | |
3bcb09a3 JF |
1592 | err = -EBUSY; |
1593 | if (__find_governor(governor->name) == NULL) { | |
1594 | err = 0; | |
1595 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1596 | } |
1da177e4 | 1597 | |
32ee8c3e | 1598 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1599 | return err; |
1da177e4 LT |
1600 | } |
1601 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1602 | ||
1603 | ||
1604 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1605 | { | |
90e41bac PB |
1606 | #ifdef CONFIG_HOTPLUG_CPU |
1607 | int cpu; | |
1608 | #endif | |
1609 | ||
1da177e4 LT |
1610 | if (!governor) |
1611 | return; | |
1612 | ||
a7b422cd KRW |
1613 | if (cpufreq_disabled()) |
1614 | return; | |
1615 | ||
90e41bac PB |
1616 | #ifdef CONFIG_HOTPLUG_CPU |
1617 | for_each_present_cpu(cpu) { | |
1618 | if (cpu_online(cpu)) | |
1619 | continue; | |
1620 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1621 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1622 | } | |
1623 | #endif | |
1624 | ||
3fc54d37 | 1625 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1626 | list_del(&governor->governor_list); |
3fc54d37 | 1627 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1628 | return; |
1629 | } | |
1630 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1631 | ||
1632 | ||
1633 | ||
1634 | /********************************************************************* | |
1635 | * POLICY INTERFACE * | |
1636 | *********************************************************************/ | |
1637 | ||
1638 | /** | |
1639 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1640 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1641 | * is written | |
1da177e4 LT |
1642 | * |
1643 | * Reads the current cpufreq policy. | |
1644 | */ | |
1645 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1646 | { | |
1647 | struct cpufreq_policy *cpu_policy; | |
1648 | if (!policy) | |
1649 | return -EINVAL; | |
1650 | ||
1651 | cpu_policy = cpufreq_cpu_get(cpu); | |
1652 | if (!cpu_policy) | |
1653 | return -EINVAL; | |
1654 | ||
1da177e4 | 1655 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1656 | |
1657 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1658 | return 0; |
1659 | } | |
1660 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1661 | ||
1662 | ||
153d7f3f | 1663 | /* |
e08f5f5b GS |
1664 | * data : current policy. |
1665 | * policy : policy to be set. | |
153d7f3f | 1666 | */ |
e08f5f5b GS |
1667 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1668 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1669 | { |
1670 | int ret = 0; | |
1671 | ||
2d06d8c4 | 1672 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1673 | policy->min, policy->max); |
1674 | ||
e08f5f5b GS |
1675 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1676 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1677 | |
53391fa2 | 1678 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1679 | ret = -EINVAL; |
1680 | goto error_out; | |
1681 | } | |
1682 | ||
1da177e4 LT |
1683 | /* verify the cpu speed can be set within this limit */ |
1684 | ret = cpufreq_driver->verify(policy); | |
1685 | if (ret) | |
1686 | goto error_out; | |
1687 | ||
1da177e4 | 1688 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1689 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1690 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1691 | |
1692 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1693 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1694 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1695 | |
1696 | /* verify the cpu speed can be set within this limit, | |
1697 | which might be different to the first one */ | |
1698 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1699 | if (ret) |
1da177e4 | 1700 | goto error_out; |
1da177e4 LT |
1701 | |
1702 | /* notification of the new policy */ | |
e041c683 AS |
1703 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1704 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1705 | |
7d5e350f DJ |
1706 | data->min = policy->min; |
1707 | data->max = policy->max; | |
1da177e4 | 1708 | |
2d06d8c4 | 1709 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1710 | data->min, data->max); |
1da177e4 LT |
1711 | |
1712 | if (cpufreq_driver->setpolicy) { | |
1713 | data->policy = policy->policy; | |
2d06d8c4 | 1714 | pr_debug("setting range\n"); |
1da177e4 LT |
1715 | ret = cpufreq_driver->setpolicy(policy); |
1716 | } else { | |
1717 | if (policy->governor != data->governor) { | |
1718 | /* save old, working values */ | |
1719 | struct cpufreq_governor *old_gov = data->governor; | |
1720 | ||
2d06d8c4 | 1721 | pr_debug("governor switch\n"); |
1da177e4 LT |
1722 | |
1723 | /* end old governor */ | |
ffe6275f | 1724 | if (data->governor) |
1da177e4 LT |
1725 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1726 | ||
1727 | /* start new governor */ | |
1728 | data->governor = policy->governor; | |
1729 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1730 | /* new governor failed, so re-start old one */ | |
2d06d8c4 | 1731 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1732 | data->governor->name); |
1da177e4 LT |
1733 | if (old_gov) { |
1734 | data->governor = old_gov; | |
e08f5f5b GS |
1735 | __cpufreq_governor(data, |
1736 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1737 | } |
1738 | ret = -EINVAL; | |
1739 | goto error_out; | |
1740 | } | |
1741 | /* might be a policy change, too, so fall through */ | |
1742 | } | |
2d06d8c4 | 1743 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1744 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1745 | } | |
1746 | ||
7d5e350f | 1747 | error_out: |
1da177e4 LT |
1748 | return ret; |
1749 | } | |
1750 | ||
1da177e4 LT |
1751 | /** |
1752 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1753 | * @cpu: CPU which shall be re-evaluated | |
1754 | * | |
25985edc | 1755 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1756 | * at different times. |
1757 | */ | |
1758 | int cpufreq_update_policy(unsigned int cpu) | |
1759 | { | |
1760 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1761 | struct cpufreq_policy policy; | |
f1829e4a | 1762 | int ret; |
1da177e4 | 1763 | |
f1829e4a JL |
1764 | if (!data) { |
1765 | ret = -ENODEV; | |
1766 | goto no_policy; | |
1767 | } | |
1da177e4 | 1768 | |
f1829e4a JL |
1769 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1770 | ret = -EINVAL; | |
1771 | goto fail; | |
1772 | } | |
1da177e4 | 1773 | |
2d06d8c4 | 1774 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1775 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1776 | policy.min = data->user_policy.min; |
1777 | policy.max = data->user_policy.max; | |
1778 | policy.policy = data->user_policy.policy; | |
1779 | policy.governor = data->user_policy.governor; | |
1780 | ||
0961dd0d TR |
1781 | /* BIOS might change freq behind our back |
1782 | -> ask driver for current freq and notify governors about a change */ | |
1783 | if (cpufreq_driver->get) { | |
1784 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1785 | if (!data->cur) { |
2d06d8c4 | 1786 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1787 | data->cur = policy.cur; |
1788 | } else { | |
1789 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1790 | cpufreq_out_of_sync(cpu, data->cur, |
1791 | policy.cur); | |
a85f7bd3 | 1792 | } |
0961dd0d TR |
1793 | } |
1794 | ||
1da177e4 LT |
1795 | ret = __cpufreq_set_policy(data, &policy); |
1796 | ||
5a01f2e8 VP |
1797 | unlock_policy_rwsem_write(cpu); |
1798 | ||
f1829e4a | 1799 | fail: |
1da177e4 | 1800 | cpufreq_cpu_put(data); |
f1829e4a | 1801 | no_policy: |
1da177e4 LT |
1802 | return ret; |
1803 | } | |
1804 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1805 | ||
dd184a01 | 1806 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1807 | unsigned long action, void *hcpu) |
1808 | { | |
1809 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1810 | struct device *dev; |
c32b6b8e | 1811 | |
8a25a2fd KS |
1812 | dev = get_cpu_device(cpu); |
1813 | if (dev) { | |
c32b6b8e AR |
1814 | switch (action) { |
1815 | case CPU_ONLINE: | |
8bb78442 | 1816 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1817 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1818 | break; |
1819 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1820 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1821 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1822 | BUG(); | |
1823 | ||
8a25a2fd | 1824 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1825 | break; |
5a01f2e8 | 1826 | case CPU_DOWN_FAILED: |
8bb78442 | 1827 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1828 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1829 | break; |
1830 | } | |
1831 | } | |
1832 | return NOTIFY_OK; | |
1833 | } | |
1834 | ||
9c36f746 | 1835 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1836 | .notifier_call = cpufreq_cpu_callback, |
1837 | }; | |
1da177e4 LT |
1838 | |
1839 | /********************************************************************* | |
1840 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1841 | *********************************************************************/ | |
1842 | ||
1843 | /** | |
1844 | * cpufreq_register_driver - register a CPU Frequency driver | |
1845 | * @driver_data: A struct cpufreq_driver containing the values# | |
1846 | * submitted by the CPU Frequency driver. | |
1847 | * | |
32ee8c3e | 1848 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1849 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1850 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1851 | * |
1852 | */ | |
221dee28 | 1853 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1854 | { |
1855 | unsigned long flags; | |
1856 | int ret; | |
1857 | ||
a7b422cd KRW |
1858 | if (cpufreq_disabled()) |
1859 | return -ENODEV; | |
1860 | ||
1da177e4 LT |
1861 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1862 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1863 | return -EINVAL; | |
1864 | ||
2d06d8c4 | 1865 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1866 | |
1867 | if (driver_data->setpolicy) | |
1868 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1869 | ||
1870 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1871 | if (cpufreq_driver) { | |
1872 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1873 | return -EBUSY; | |
1874 | } | |
1875 | cpufreq_driver = driver_data; | |
1876 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1877 | ||
8a25a2fd | 1878 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1879 | if (ret) |
1880 | goto err_null_driver; | |
1da177e4 | 1881 | |
8f5bc2ab | 1882 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1883 | int i; |
1884 | ret = -ENODEV; | |
1885 | ||
1886 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1887 | for (i = 0; i < nr_cpu_ids; i++) |
1888 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1889 | ret = 0; |
7a6aedfa MT |
1890 | break; |
1891 | } | |
1da177e4 LT |
1892 | |
1893 | /* if all ->init() calls failed, unregister */ | |
1894 | if (ret) { | |
2d06d8c4 | 1895 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1896 | driver_data->name); |
8a25a2fd | 1897 | goto err_if_unreg; |
1da177e4 LT |
1898 | } |
1899 | } | |
1900 | ||
8f5bc2ab | 1901 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1902 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1903 | |
8f5bc2ab | 1904 | return 0; |
8a25a2fd KS |
1905 | err_if_unreg: |
1906 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1907 | err_null_driver: |
1908 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1909 | cpufreq_driver = NULL; | |
1910 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1911 | return ret; |
1da177e4 LT |
1912 | } |
1913 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1914 | ||
1915 | ||
1916 | /** | |
1917 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1918 | * | |
32ee8c3e | 1919 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1920 | * the right to do so, i.e. if you have succeeded in initialising before! |
1921 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1922 | * currently not initialised. | |
1923 | */ | |
221dee28 | 1924 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1925 | { |
1926 | unsigned long flags; | |
1927 | ||
2d06d8c4 | 1928 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1929 | return -EINVAL; |
1da177e4 | 1930 | |
2d06d8c4 | 1931 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1932 | |
8a25a2fd | 1933 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1934 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1935 | |
1936 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1937 | cpufreq_driver = NULL; | |
1938 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1939 | ||
1940 | return 0; | |
1941 | } | |
1942 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1943 | |
1944 | static int __init cpufreq_core_init(void) | |
1945 | { | |
1946 | int cpu; | |
1947 | ||
a7b422cd KRW |
1948 | if (cpufreq_disabled()) |
1949 | return -ENODEV; | |
1950 | ||
5a01f2e8 | 1951 | for_each_possible_cpu(cpu) { |
f1625066 | 1952 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1953 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1954 | } | |
8aa84ad8 | 1955 | |
8a25a2fd | 1956 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1957 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1958 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1959 | |
5a01f2e8 VP |
1960 | return 0; |
1961 | } | |
5a01f2e8 | 1962 | core_initcall(cpufreq_core_init); |