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Commit | Line | Data |
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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> |
1da177e4 | 31 | |
e08f5f5b GS |
32 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \ |
33 | "cpufreq-core", msg) | |
1da177e4 LT |
34 | |
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) \ | |
71 | int lock_policy_rwsem_##mode \ | |
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); | |
86 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_read); | |
87 | ||
88 | lock_policy_rwsem(write, cpu); | |
89 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_write); | |
90 | ||
91 | void unlock_policy_rwsem_read(int cpu) | |
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 | } | |
97 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_read); | |
98 | ||
99 | void unlock_policy_rwsem_write(int cpu) | |
100 | { | |
f1625066 | 101 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
102 | BUG_ON(policy_cpu == -1); |
103 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_write); | |
106 | ||
107 | ||
1da177e4 | 108 | /* internal prototypes */ |
29464f28 DJ |
109 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
110 | unsigned int event); | |
5a01f2e8 | 111 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 112 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
113 | |
114 | /** | |
32ee8c3e DJ |
115 | * Two notifier lists: the "policy" list is involved in the |
116 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
117 | * "transition" list for kernel code that needs to handle |
118 | * changes to devices when the CPU clock speed changes. | |
119 | * The mutex locks both lists. | |
120 | */ | |
e041c683 | 121 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 122 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 123 | |
74212ca4 | 124 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
125 | static int __init init_cpufreq_transition_notifier_list(void) |
126 | { | |
127 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 128 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
129 | return 0; |
130 | } | |
b3438f82 | 131 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
132 | |
133 | static LIST_HEAD(cpufreq_governor_list); | |
29464f28 | 134 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 135 | |
7d5e350f | 136 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
137 | { |
138 | struct cpufreq_policy *data; | |
139 | unsigned long flags; | |
140 | ||
7a6aedfa | 141 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
142 | goto err_out; |
143 | ||
144 | /* get the cpufreq driver */ | |
145 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
146 | ||
147 | if (!cpufreq_driver) | |
148 | goto err_out_unlock; | |
149 | ||
150 | if (!try_module_get(cpufreq_driver->owner)) | |
151 | goto err_out_unlock; | |
152 | ||
153 | ||
154 | /* get the CPU */ | |
7a6aedfa | 155 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
156 | |
157 | if (!data) | |
158 | goto err_out_put_module; | |
159 | ||
160 | if (!kobject_get(&data->kobj)) | |
161 | goto err_out_put_module; | |
162 | ||
1da177e4 | 163 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
164 | return data; |
165 | ||
7d5e350f | 166 | err_out_put_module: |
1da177e4 | 167 | module_put(cpufreq_driver->owner); |
7d5e350f | 168 | err_out_unlock: |
1da177e4 | 169 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 170 | err_out: |
1da177e4 LT |
171 | return NULL; |
172 | } | |
173 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
174 | ||
7d5e350f | 175 | |
1da177e4 LT |
176 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
177 | { | |
178 | kobject_put(&data->kobj); | |
179 | module_put(cpufreq_driver->owner); | |
180 | } | |
181 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
182 | ||
183 | ||
184 | /********************************************************************* | |
185 | * UNIFIED DEBUG HELPERS * | |
186 | *********************************************************************/ | |
187 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
188 | ||
189 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
190 | static unsigned int debug; | |
191 | ||
192 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
193 | * set or modify this value. | |
194 | */ | |
195 | static unsigned int debug_ratelimit = 1; | |
196 | ||
197 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
198 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
199 | * is set, and disabled upon cpufreq driver removal | |
200 | */ | |
201 | static unsigned int disable_ratelimit = 1; | |
202 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
203 | ||
858119e1 | 204 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
205 | { |
206 | unsigned long flags; | |
207 | ||
208 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
209 | if (disable_ratelimit) | |
210 | disable_ratelimit--; | |
211 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
212 | } | |
213 | ||
858119e1 | 214 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
215 | { |
216 | unsigned long flags; | |
217 | ||
218 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
219 | disable_ratelimit++; | |
220 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
221 | } | |
222 | ||
e08f5f5b | 223 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
905d77cd | 224 | const char *fmt, ...) |
1da177e4 LT |
225 | { |
226 | char s[256]; | |
227 | va_list args; | |
228 | unsigned int len; | |
229 | unsigned long flags; | |
32ee8c3e | 230 | |
1da177e4 LT |
231 | WARN_ON(!prefix); |
232 | if (type & debug) { | |
233 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
234 | if (!disable_ratelimit && debug_ratelimit |
235 | && !printk_ratelimit()) { | |
1da177e4 LT |
236 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
237 | return; | |
238 | } | |
239 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
240 | ||
241 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
242 | ||
243 | va_start(args, fmt); | |
244 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
245 | va_end(args); | |
246 | ||
247 | printk(s); | |
248 | ||
249 | WARN_ON(len < 5); | |
250 | } | |
251 | } | |
252 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
253 | ||
254 | ||
255 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
256 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
257 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
258 | |
259 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
260 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
261 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
262 | |
263 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
264 | ||
265 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
266 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
267 | ||
268 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
269 | ||
270 | ||
271 | /********************************************************************* | |
272 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
273 | *********************************************************************/ | |
274 | ||
275 | /** | |
276 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
277 | * | |
278 | * This function alters the system "loops_per_jiffy" for the clock | |
279 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 280 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
281 | * per-CPU loops_per_jiffy value wherever possible. |
282 | */ | |
283 | #ifndef CONFIG_SMP | |
284 | static unsigned long l_p_j_ref; | |
285 | static unsigned int l_p_j_ref_freq; | |
286 | ||
858119e1 | 287 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
288 | { |
289 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
290 | return; | |
291 | ||
292 | if (!l_p_j_ref_freq) { | |
293 | l_p_j_ref = loops_per_jiffy; | |
294 | l_p_j_ref_freq = ci->old; | |
a4a9df58 | 295 | dprintk("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 296 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 LT |
297 | } |
298 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
299 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 300 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
301 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
302 | ci->new); | |
a4a9df58 | 303 | dprintk("scaling loops_per_jiffy to %lu " |
e08f5f5b | 304 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
305 | } |
306 | } | |
307 | #else | |
e08f5f5b GS |
308 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
309 | { | |
310 | return; | |
311 | } | |
1da177e4 LT |
312 | #endif |
313 | ||
314 | ||
315 | /** | |
e4472cb3 DJ |
316 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
317 | * on frequency transition. | |
1da177e4 | 318 | * |
e4472cb3 DJ |
319 | * This function calls the transition notifiers and the "adjust_jiffies" |
320 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 321 | * external effects. |
1da177e4 LT |
322 | */ |
323 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
324 | { | |
e4472cb3 DJ |
325 | struct cpufreq_policy *policy; |
326 | ||
1da177e4 LT |
327 | BUG_ON(irqs_disabled()); |
328 | ||
329 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
330 | dprintk("notification %u of frequency transition to %u kHz\n", |
331 | state, freqs->new); | |
1da177e4 | 332 | |
7a6aedfa | 333 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 334 | switch (state) { |
e4472cb3 | 335 | |
1da177e4 | 336 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 337 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
338 | * which is not equal to what the cpufreq core thinks is |
339 | * "old frequency". | |
1da177e4 LT |
340 | */ |
341 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
342 | if ((policy) && (policy->cpu == freqs->cpu) && |
343 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 344 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
345 | " %u, cpufreq assumed %u kHz.\n", |
346 | freqs->old, policy->cur); | |
347 | freqs->old = policy->cur; | |
1da177e4 LT |
348 | } |
349 | } | |
b4dfdbb3 | 350 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 351 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
352 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
353 | break; | |
e4472cb3 | 354 | |
1da177e4 LT |
355 | case CPUFREQ_POSTCHANGE: |
356 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
b4dfdbb3 | 357 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 358 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
359 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
360 | policy->cur = freqs->new; | |
1da177e4 LT |
361 | break; |
362 | } | |
1da177e4 LT |
363 | } |
364 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
365 | ||
366 | ||
367 | ||
368 | /********************************************************************* | |
369 | * SYSFS INTERFACE * | |
370 | *********************************************************************/ | |
371 | ||
3bcb09a3 JF |
372 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
373 | { | |
374 | struct cpufreq_governor *t; | |
375 | ||
376 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 377 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
378 | return t; |
379 | ||
380 | return NULL; | |
381 | } | |
382 | ||
1da177e4 LT |
383 | /** |
384 | * cpufreq_parse_governor - parse a governor string | |
385 | */ | |
905d77cd | 386 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
387 | struct cpufreq_governor **governor) |
388 | { | |
3bcb09a3 JF |
389 | int err = -EINVAL; |
390 | ||
1da177e4 | 391 | if (!cpufreq_driver) |
3bcb09a3 JF |
392 | goto out; |
393 | ||
1da177e4 LT |
394 | if (cpufreq_driver->setpolicy) { |
395 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
396 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 397 | err = 0; |
e08f5f5b GS |
398 | } else if (!strnicmp(str_governor, "powersave", |
399 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 400 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 401 | err = 0; |
1da177e4 | 402 | } |
3bcb09a3 | 403 | } else if (cpufreq_driver->target) { |
1da177e4 | 404 | struct cpufreq_governor *t; |
3bcb09a3 | 405 | |
3fc54d37 | 406 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
407 | |
408 | t = __find_governor(str_governor); | |
409 | ||
ea714970 | 410 | if (t == NULL) { |
e08f5f5b GS |
411 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
412 | str_governor); | |
ea714970 JF |
413 | |
414 | if (name) { | |
415 | int ret; | |
416 | ||
417 | mutex_unlock(&cpufreq_governor_mutex); | |
326f6a5c | 418 | ret = request_module("%s", name); |
ea714970 JF |
419 | mutex_lock(&cpufreq_governor_mutex); |
420 | ||
421 | if (ret == 0) | |
422 | t = __find_governor(str_governor); | |
423 | } | |
424 | ||
425 | kfree(name); | |
426 | } | |
427 | ||
3bcb09a3 JF |
428 | if (t != NULL) { |
429 | *governor = t; | |
430 | err = 0; | |
1da177e4 | 431 | } |
3bcb09a3 | 432 | |
3fc54d37 | 433 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 434 | } |
29464f28 | 435 | out: |
3bcb09a3 | 436 | return err; |
1da177e4 | 437 | } |
1da177e4 LT |
438 | |
439 | ||
1da177e4 | 440 | /** |
e08f5f5b GS |
441 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
442 | * print out cpufreq information | |
1da177e4 LT |
443 | * |
444 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
445 | * "unsigned int". | |
446 | */ | |
447 | ||
32ee8c3e DJ |
448 | #define show_one(file_name, object) \ |
449 | static ssize_t show_##file_name \ | |
905d77cd | 450 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 451 | { \ |
29464f28 | 452 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
453 | } |
454 | ||
455 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
456 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 457 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
458 | show_one(scaling_min_freq, min); |
459 | show_one(scaling_max_freq, max); | |
460 | show_one(scaling_cur_freq, cur); | |
461 | ||
e08f5f5b GS |
462 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
463 | struct cpufreq_policy *policy); | |
7970e08b | 464 | |
1da177e4 LT |
465 | /** |
466 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
467 | */ | |
468 | #define store_one(file_name, object) \ | |
469 | static ssize_t store_##file_name \ | |
905d77cd | 470 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
471 | { \ |
472 | unsigned int ret = -EINVAL; \ | |
473 | struct cpufreq_policy new_policy; \ | |
474 | \ | |
475 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
476 | if (ret) \ | |
477 | return -EINVAL; \ | |
478 | \ | |
29464f28 | 479 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
480 | if (ret != 1) \ |
481 | return -EINVAL; \ | |
482 | \ | |
7970e08b TR |
483 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
484 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
485 | \ |
486 | return ret ? ret : count; \ | |
487 | } | |
488 | ||
29464f28 DJ |
489 | store_one(scaling_min_freq, min); |
490 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
491 | |
492 | /** | |
493 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
494 | */ | |
905d77cd DJ |
495 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
496 | char *buf) | |
1da177e4 | 497 | { |
5a01f2e8 | 498 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
499 | if (!cur_freq) |
500 | return sprintf(buf, "<unknown>"); | |
501 | return sprintf(buf, "%u\n", cur_freq); | |
502 | } | |
503 | ||
504 | ||
505 | /** | |
506 | * show_scaling_governor - show the current policy for the specified CPU | |
507 | */ | |
905d77cd | 508 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 509 | { |
29464f28 | 510 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
511 | return sprintf(buf, "powersave\n"); |
512 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
513 | return sprintf(buf, "performance\n"); | |
514 | else if (policy->governor) | |
29464f28 DJ |
515 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", |
516 | policy->governor->name); | |
1da177e4 LT |
517 | return -EINVAL; |
518 | } | |
519 | ||
520 | ||
521 | /** | |
522 | * store_scaling_governor - store policy for the specified CPU | |
523 | */ | |
905d77cd DJ |
524 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
525 | const char *buf, size_t count) | |
1da177e4 LT |
526 | { |
527 | unsigned int ret = -EINVAL; | |
528 | char str_governor[16]; | |
529 | struct cpufreq_policy new_policy; | |
530 | ||
531 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
532 | if (ret) | |
533 | return ret; | |
534 | ||
29464f28 | 535 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
536 | if (ret != 1) |
537 | return -EINVAL; | |
538 | ||
e08f5f5b GS |
539 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
540 | &new_policy.governor)) | |
1da177e4 LT |
541 | return -EINVAL; |
542 | ||
7970e08b TR |
543 | /* Do not use cpufreq_set_policy here or the user_policy.max |
544 | will be wrongly overridden */ | |
7970e08b TR |
545 | ret = __cpufreq_set_policy(policy, &new_policy); |
546 | ||
547 | policy->user_policy.policy = policy->policy; | |
548 | policy->user_policy.governor = policy->governor; | |
7970e08b | 549 | |
e08f5f5b GS |
550 | if (ret) |
551 | return ret; | |
552 | else | |
553 | return count; | |
1da177e4 LT |
554 | } |
555 | ||
556 | /** | |
557 | * show_scaling_driver - show the cpufreq driver currently loaded | |
558 | */ | |
905d77cd | 559 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
560 | { |
561 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
562 | } | |
563 | ||
564 | /** | |
565 | * show_scaling_available_governors - show the available CPUfreq governors | |
566 | */ | |
905d77cd DJ |
567 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
568 | char *buf) | |
1da177e4 LT |
569 | { |
570 | ssize_t i = 0; | |
571 | struct cpufreq_governor *t; | |
572 | ||
573 | if (!cpufreq_driver->target) { | |
574 | i += sprintf(buf, "performance powersave"); | |
575 | goto out; | |
576 | } | |
577 | ||
578 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
579 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
580 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 LT |
581 | goto out; |
582 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
583 | } | |
7d5e350f | 584 | out: |
1da177e4 LT |
585 | i += sprintf(&buf[i], "\n"); |
586 | return i; | |
587 | } | |
e8628dd0 | 588 | |
835481d9 | 589 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
590 | { |
591 | ssize_t i = 0; | |
592 | unsigned int cpu; | |
593 | ||
835481d9 | 594 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
595 | if (i) |
596 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
597 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
598 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 599 | break; |
1da177e4 LT |
600 | } |
601 | i += sprintf(&buf[i], "\n"); | |
602 | return i; | |
603 | } | |
604 | ||
e8628dd0 DW |
605 | /** |
606 | * show_related_cpus - show the CPUs affected by each transition even if | |
607 | * hw coordination is in use | |
608 | */ | |
609 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
610 | { | |
835481d9 | 611 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
612 | return show_cpus(policy->cpus, buf); |
613 | return show_cpus(policy->related_cpus, buf); | |
614 | } | |
615 | ||
616 | /** | |
617 | * show_affected_cpus - show the CPUs affected by each transition | |
618 | */ | |
619 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
620 | { | |
621 | return show_cpus(policy->cpus, buf); | |
622 | } | |
623 | ||
9e76988e | 624 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 625 | const char *buf, size_t count) |
9e76988e VP |
626 | { |
627 | unsigned int freq = 0; | |
628 | unsigned int ret; | |
629 | ||
879000f9 | 630 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
631 | return -EINVAL; |
632 | ||
633 | ret = sscanf(buf, "%u", &freq); | |
634 | if (ret != 1) | |
635 | return -EINVAL; | |
636 | ||
637 | policy->governor->store_setspeed(policy, freq); | |
638 | ||
639 | return count; | |
640 | } | |
641 | ||
642 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
643 | { | |
879000f9 | 644 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
645 | return sprintf(buf, "<unsupported>\n"); |
646 | ||
647 | return policy->governor->show_setspeed(policy, buf); | |
648 | } | |
1da177e4 | 649 | |
e2f74f35 TR |
650 | /** |
651 | * show_scaling_driver - show the current cpufreq HW/BIOS limitation | |
652 | */ | |
653 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
654 | { | |
655 | unsigned int limit; | |
656 | int ret; | |
657 | if (cpufreq_driver->bios_limit) { | |
658 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
659 | if (!ret) | |
660 | return sprintf(buf, "%u\n", limit); | |
661 | } | |
662 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
663 | } | |
664 | ||
6dad2a29 BP |
665 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
666 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
667 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
668 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
669 | cpufreq_freq_attr_ro(scaling_available_governors); | |
670 | cpufreq_freq_attr_ro(scaling_driver); | |
671 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
672 | cpufreq_freq_attr_ro(bios_limit); | |
673 | cpufreq_freq_attr_ro(related_cpus); | |
674 | cpufreq_freq_attr_ro(affected_cpus); | |
675 | cpufreq_freq_attr_rw(scaling_min_freq); | |
676 | cpufreq_freq_attr_rw(scaling_max_freq); | |
677 | cpufreq_freq_attr_rw(scaling_governor); | |
678 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 679 | |
905d77cd | 680 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
681 | &cpuinfo_min_freq.attr, |
682 | &cpuinfo_max_freq.attr, | |
ed129784 | 683 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
684 | &scaling_min_freq.attr, |
685 | &scaling_max_freq.attr, | |
686 | &affected_cpus.attr, | |
e8628dd0 | 687 | &related_cpus.attr, |
1da177e4 LT |
688 | &scaling_governor.attr, |
689 | &scaling_driver.attr, | |
690 | &scaling_available_governors.attr, | |
9e76988e | 691 | &scaling_setspeed.attr, |
1da177e4 LT |
692 | NULL |
693 | }; | |
694 | ||
8aa84ad8 TR |
695 | struct kobject *cpufreq_global_kobject; |
696 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
697 | ||
29464f28 DJ |
698 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
699 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 700 | |
29464f28 | 701 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 702 | { |
905d77cd DJ |
703 | struct cpufreq_policy *policy = to_policy(kobj); |
704 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 705 | ssize_t ret = -EINVAL; |
1da177e4 LT |
706 | policy = cpufreq_cpu_get(policy->cpu); |
707 | if (!policy) | |
0db4a8a9 | 708 | goto no_policy; |
5a01f2e8 VP |
709 | |
710 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 711 | goto fail; |
5a01f2e8 | 712 | |
e08f5f5b GS |
713 | if (fattr->show) |
714 | ret = fattr->show(policy, buf); | |
715 | else | |
716 | ret = -EIO; | |
717 | ||
5a01f2e8 | 718 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 719 | fail: |
1da177e4 | 720 | cpufreq_cpu_put(policy); |
0db4a8a9 | 721 | no_policy: |
1da177e4 LT |
722 | return ret; |
723 | } | |
724 | ||
905d77cd DJ |
725 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
726 | const char *buf, size_t count) | |
1da177e4 | 727 | { |
905d77cd DJ |
728 | struct cpufreq_policy *policy = to_policy(kobj); |
729 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 730 | ssize_t ret = -EINVAL; |
1da177e4 LT |
731 | policy = cpufreq_cpu_get(policy->cpu); |
732 | if (!policy) | |
a07530b4 | 733 | goto no_policy; |
5a01f2e8 VP |
734 | |
735 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 736 | goto fail; |
5a01f2e8 | 737 | |
e08f5f5b GS |
738 | if (fattr->store) |
739 | ret = fattr->store(policy, buf, count); | |
740 | else | |
741 | ret = -EIO; | |
742 | ||
5a01f2e8 | 743 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 744 | fail: |
1da177e4 | 745 | cpufreq_cpu_put(policy); |
a07530b4 | 746 | no_policy: |
1da177e4 LT |
747 | return ret; |
748 | } | |
749 | ||
905d77cd | 750 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 751 | { |
905d77cd | 752 | struct cpufreq_policy *policy = to_policy(kobj); |
1da177e4 LT |
753 | dprintk("last reference is dropped\n"); |
754 | complete(&policy->kobj_unregister); | |
755 | } | |
756 | ||
52cf25d0 | 757 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
758 | .show = show, |
759 | .store = store, | |
760 | }; | |
761 | ||
762 | static struct kobj_type ktype_cpufreq = { | |
763 | .sysfs_ops = &sysfs_ops, | |
764 | .default_attrs = default_attrs, | |
765 | .release = cpufreq_sysfs_release, | |
766 | }; | |
767 | ||
4bfa042c TR |
768 | /* |
769 | * Returns: | |
770 | * Negative: Failure | |
771 | * 0: Success | |
772 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
773 | */ | |
cf3289d0 AC |
774 | static int cpufreq_add_dev_policy(unsigned int cpu, |
775 | struct cpufreq_policy *policy, | |
776 | struct sys_device *sys_dev) | |
ecf7e461 DJ |
777 | { |
778 | int ret = 0; | |
779 | #ifdef CONFIG_SMP | |
780 | unsigned long flags; | |
781 | unsigned int j; | |
ecf7e461 | 782 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
783 | struct cpufreq_governor *gov; |
784 | ||
785 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
786 | if (gov) { | |
787 | policy->governor = gov; | |
ecf7e461 DJ |
788 | dprintk("Restoring governor %s for cpu %d\n", |
789 | policy->governor->name, cpu); | |
790 | } | |
791 | #endif | |
792 | ||
793 | for_each_cpu(j, policy->cpus) { | |
794 | struct cpufreq_policy *managed_policy; | |
795 | ||
796 | if (cpu == j) | |
797 | continue; | |
798 | ||
799 | /* Check for existing affected CPUs. | |
800 | * They may not be aware of it due to CPU Hotplug. | |
801 | * cpufreq_cpu_put is called when the device is removed | |
802 | * in __cpufreq_remove_dev() | |
803 | */ | |
804 | managed_policy = cpufreq_cpu_get(j); | |
805 | if (unlikely(managed_policy)) { | |
806 | ||
807 | /* Set proper policy_cpu */ | |
808 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 809 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
810 | |
811 | if (lock_policy_rwsem_write(cpu) < 0) { | |
812 | /* Should not go through policy unlock path */ | |
813 | if (cpufreq_driver->exit) | |
814 | cpufreq_driver->exit(policy); | |
815 | cpufreq_cpu_put(managed_policy); | |
816 | return -EBUSY; | |
817 | } | |
818 | ||
819 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
820 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
821 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
822 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
823 | ||
824 | dprintk("CPU already managed, adding link\n"); | |
825 | ret = sysfs_create_link(&sys_dev->kobj, | |
826 | &managed_policy->kobj, | |
827 | "cpufreq"); | |
828 | if (ret) | |
829 | cpufreq_cpu_put(managed_policy); | |
830 | /* | |
831 | * Success. We only needed to be added to the mask. | |
832 | * Call driver->exit() because only the cpu parent of | |
833 | * the kobj needed to call init(). | |
834 | */ | |
835 | if (cpufreq_driver->exit) | |
836 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
837 | |
838 | if (!ret) | |
839 | return 1; | |
840 | else | |
841 | return ret; | |
ecf7e461 DJ |
842 | } |
843 | } | |
844 | #endif | |
845 | return ret; | |
846 | } | |
847 | ||
848 | ||
19d6f7ec | 849 | /* symlink affected CPUs */ |
cf3289d0 AC |
850 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
851 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
852 | { |
853 | unsigned int j; | |
854 | int ret = 0; | |
855 | ||
856 | for_each_cpu(j, policy->cpus) { | |
857 | struct cpufreq_policy *managed_policy; | |
858 | struct sys_device *cpu_sys_dev; | |
859 | ||
860 | if (j == cpu) | |
861 | continue; | |
862 | if (!cpu_online(j)) | |
863 | continue; | |
864 | ||
865 | dprintk("CPU %u already managed, adding link\n", j); | |
866 | managed_policy = cpufreq_cpu_get(cpu); | |
867 | cpu_sys_dev = get_cpu_sysdev(j); | |
868 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
869 | "cpufreq"); | |
870 | if (ret) { | |
871 | cpufreq_cpu_put(managed_policy); | |
872 | return ret; | |
873 | } | |
874 | } | |
875 | return ret; | |
876 | } | |
877 | ||
cf3289d0 AC |
878 | static int cpufreq_add_dev_interface(unsigned int cpu, |
879 | struct cpufreq_policy *policy, | |
880 | struct sys_device *sys_dev) | |
909a694e | 881 | { |
ecf7e461 | 882 | struct cpufreq_policy new_policy; |
909a694e DJ |
883 | struct freq_attr **drv_attr; |
884 | unsigned long flags; | |
885 | int ret = 0; | |
886 | unsigned int j; | |
887 | ||
888 | /* prepare interface data */ | |
889 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
890 | &sys_dev->kobj, "cpufreq"); | |
891 | if (ret) | |
892 | return ret; | |
893 | ||
894 | /* set up files for this cpu device */ | |
895 | drv_attr = cpufreq_driver->attr; | |
896 | while ((drv_attr) && (*drv_attr)) { | |
897 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
898 | if (ret) | |
899 | goto err_out_kobj_put; | |
900 | drv_attr++; | |
901 | } | |
902 | if (cpufreq_driver->get) { | |
903 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
904 | if (ret) | |
905 | goto err_out_kobj_put; | |
906 | } | |
907 | if (cpufreq_driver->target) { | |
908 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
909 | if (ret) | |
910 | goto err_out_kobj_put; | |
911 | } | |
e2f74f35 TR |
912 | if (cpufreq_driver->bios_limit) { |
913 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
914 | if (ret) | |
915 | goto err_out_kobj_put; | |
916 | } | |
909a694e DJ |
917 | |
918 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
919 | for_each_cpu(j, policy->cpus) { | |
920 | if (!cpu_online(j)) | |
921 | continue; | |
922 | per_cpu(cpufreq_cpu_data, j) = policy; | |
f1625066 | 923 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
924 | } |
925 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
926 | ||
927 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
928 | if (ret) |
929 | goto err_out_kobj_put; | |
930 | ||
931 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
932 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
933 | policy->governor = NULL; | |
934 | ||
935 | /* set default policy */ | |
936 | ret = __cpufreq_set_policy(policy, &new_policy); | |
937 | policy->user_policy.policy = policy->policy; | |
938 | policy->user_policy.governor = policy->governor; | |
939 | ||
940 | if (ret) { | |
941 | dprintk("setting policy failed\n"); | |
942 | if (cpufreq_driver->exit) | |
943 | cpufreq_driver->exit(policy); | |
944 | } | |
909a694e DJ |
945 | return ret; |
946 | ||
947 | err_out_kobj_put: | |
948 | kobject_put(&policy->kobj); | |
949 | wait_for_completion(&policy->kobj_unregister); | |
950 | return ret; | |
951 | } | |
952 | ||
1da177e4 LT |
953 | |
954 | /** | |
955 | * cpufreq_add_dev - add a CPU device | |
956 | * | |
32ee8c3e | 957 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
958 | * |
959 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
960 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
961 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 962 | */ |
905d77cd | 963 | static int cpufreq_add_dev(struct sys_device *sys_dev) |
1da177e4 LT |
964 | { |
965 | unsigned int cpu = sys_dev->id; | |
90e41bac | 966 | int ret = 0, found = 0; |
1da177e4 | 967 | struct cpufreq_policy *policy; |
1da177e4 LT |
968 | unsigned long flags; |
969 | unsigned int j; | |
90e41bac PB |
970 | #ifdef CONFIG_HOTPLUG_CPU |
971 | int sibling; | |
972 | #endif | |
1da177e4 | 973 | |
c32b6b8e AR |
974 | if (cpu_is_offline(cpu)) |
975 | return 0; | |
976 | ||
1da177e4 LT |
977 | cpufreq_debug_disable_ratelimit(); |
978 | dprintk("adding CPU %u\n", cpu); | |
979 | ||
980 | #ifdef CONFIG_SMP | |
981 | /* check whether a different CPU already registered this | |
982 | * CPU because it is in the same boat. */ | |
983 | policy = cpufreq_cpu_get(cpu); | |
984 | if (unlikely(policy)) { | |
8ff69732 | 985 | cpufreq_cpu_put(policy); |
1da177e4 LT |
986 | cpufreq_debug_enable_ratelimit(); |
987 | return 0; | |
988 | } | |
989 | #endif | |
990 | ||
991 | if (!try_module_get(cpufreq_driver->owner)) { | |
992 | ret = -EINVAL; | |
993 | goto module_out; | |
994 | } | |
995 | ||
059019a3 | 996 | ret = -ENOMEM; |
e98df50c | 997 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 998 | if (!policy) |
1da177e4 | 999 | goto nomem_out; |
059019a3 DJ |
1000 | |
1001 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 1002 | goto err_free_policy; |
059019a3 DJ |
1003 | |
1004 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 1005 | goto err_free_cpumask; |
1da177e4 LT |
1006 | |
1007 | policy->cpu = cpu; | |
835481d9 | 1008 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1009 | |
5a01f2e8 | 1010 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 1011 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
1012 | ret = (lock_policy_rwsem_write(cpu) < 0); |
1013 | WARN_ON(ret); | |
5a01f2e8 | 1014 | |
1da177e4 | 1015 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1016 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 1017 | |
8122c6ce | 1018 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
1019 | #ifdef CONFIG_HOTPLUG_CPU |
1020 | for_each_online_cpu(sibling) { | |
1021 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
1022 | if (cp && cp->governor && | |
1023 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
1024 | policy->governor = cp->governor; | |
1025 | found = 1; | |
1026 | break; | |
1027 | } | |
1028 | } | |
1029 | #endif | |
1030 | if (!found) | |
1031 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
1032 | /* call driver. From then on the cpufreq must be able |
1033 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1034 | */ | |
1035 | ret = cpufreq_driver->init(policy); | |
1036 | if (ret) { | |
1037 | dprintk("initialization failed\n"); | |
3f4a782b | 1038 | goto err_unlock_policy; |
1da177e4 | 1039 | } |
187d9f4e MC |
1040 | policy->user_policy.min = policy->min; |
1041 | policy->user_policy.max = policy->max; | |
1da177e4 | 1042 | |
a1531acd TR |
1043 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1044 | CPUFREQ_START, policy); | |
1045 | ||
ecf7e461 | 1046 | ret = cpufreq_add_dev_policy(cpu, policy, sys_dev); |
4bfa042c TR |
1047 | if (ret) { |
1048 | if (ret > 0) | |
1049 | /* This is a managed cpu, symlink created, | |
1050 | exit with 0 */ | |
1051 | ret = 0; | |
ecf7e461 | 1052 | goto err_unlock_policy; |
4bfa042c | 1053 | } |
1da177e4 | 1054 | |
909a694e | 1055 | ret = cpufreq_add_dev_interface(cpu, policy, sys_dev); |
19d6f7ec DJ |
1056 | if (ret) |
1057 | goto err_out_unregister; | |
8ff69732 | 1058 | |
dca02613 LW |
1059 | unlock_policy_rwsem_write(cpu); |
1060 | ||
038c5b3e | 1061 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 1062 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
1063 | dprintk("initialization complete\n"); |
1064 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 1065 | |
1da177e4 LT |
1066 | return 0; |
1067 | ||
1068 | ||
1069 | err_out_unregister: | |
1070 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1071 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1072 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1073 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1074 | ||
c10997f6 | 1075 | kobject_put(&policy->kobj); |
1da177e4 LT |
1076 | wait_for_completion(&policy->kobj_unregister); |
1077 | ||
3f4a782b | 1078 | err_unlock_policy: |
45709118 | 1079 | unlock_policy_rwsem_write(cpu); |
3f4a782b MD |
1080 | err_free_cpumask: |
1081 | free_cpumask_var(policy->cpus); | |
1082 | err_free_policy: | |
1da177e4 | 1083 | kfree(policy); |
1da177e4 LT |
1084 | nomem_out: |
1085 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1086 | module_out: |
1da177e4 LT |
1087 | cpufreq_debug_enable_ratelimit(); |
1088 | return ret; | |
1089 | } | |
1090 | ||
1091 | ||
1092 | /** | |
5a01f2e8 | 1093 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1094 | * |
1095 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1096 | * Caller should already have policy_rwsem in write mode for this CPU. |
1097 | * This routine frees the rwsem before returning. | |
1da177e4 | 1098 | */ |
905d77cd | 1099 | static int __cpufreq_remove_dev(struct sys_device *sys_dev) |
1da177e4 LT |
1100 | { |
1101 | unsigned int cpu = sys_dev->id; | |
1102 | unsigned long flags; | |
1103 | struct cpufreq_policy *data; | |
499bca9b AW |
1104 | struct kobject *kobj; |
1105 | struct completion *cmp; | |
1da177e4 | 1106 | #ifdef CONFIG_SMP |
e738cf6d | 1107 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
1108 | unsigned int j; |
1109 | #endif | |
1110 | ||
1111 | cpufreq_debug_disable_ratelimit(); | |
1112 | dprintk("unregistering CPU %u\n", cpu); | |
1113 | ||
1114 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1115 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1116 | |
1117 | if (!data) { | |
1118 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 1119 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 1120 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1121 | return -EINVAL; |
1122 | } | |
7a6aedfa | 1123 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1124 | |
1125 | ||
1126 | #ifdef CONFIG_SMP | |
1127 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1128 | * only need to unlink, put and exit |
1da177e4 LT |
1129 | */ |
1130 | if (unlikely(cpu != data->cpu)) { | |
1131 | dprintk("removing link\n"); | |
835481d9 | 1132 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 | 1133 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
499bca9b | 1134 | kobj = &sys_dev->kobj; |
1da177e4 LT |
1135 | cpufreq_cpu_put(data); |
1136 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 1137 | unlock_policy_rwsem_write(cpu); |
499bca9b | 1138 | sysfs_remove_link(kobj, "cpufreq"); |
1da177e4 LT |
1139 | return 0; |
1140 | } | |
1141 | #endif | |
1142 | ||
1da177e4 | 1143 | #ifdef CONFIG_SMP |
084f3493 TR |
1144 | |
1145 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1146 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1147 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1148 | #endif |
1149 | ||
1da177e4 LT |
1150 | /* if we have other CPUs still registered, we need to unlink them, |
1151 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1152 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1153 | * the sysfs links afterwards. | |
1da177e4 | 1154 | */ |
835481d9 RR |
1155 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1156 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1157 | if (j == cpu) |
1158 | continue; | |
7a6aedfa | 1159 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1160 | } |
1161 | } | |
1162 | ||
1163 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1164 | ||
835481d9 RR |
1165 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1166 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1167 | if (j == cpu) |
1168 | continue; | |
1169 | dprintk("removing link for cpu %u\n", j); | |
084f3493 | 1170 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1171 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1172 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1173 | #endif |
d434fca7 | 1174 | cpu_sys_dev = get_cpu_sysdev(j); |
499bca9b AW |
1175 | kobj = &cpu_sys_dev->kobj; |
1176 | unlock_policy_rwsem_write(cpu); | |
1177 | sysfs_remove_link(kobj, "cpufreq"); | |
1178 | lock_policy_rwsem_write(cpu); | |
1da177e4 LT |
1179 | cpufreq_cpu_put(data); |
1180 | } | |
1181 | } | |
1182 | #else | |
1183 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1184 | #endif | |
1185 | ||
1da177e4 LT |
1186 | if (cpufreq_driver->target) |
1187 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1188 | |
499bca9b AW |
1189 | kobj = &data->kobj; |
1190 | cmp = &data->kobj_unregister; | |
1191 | unlock_policy_rwsem_write(cpu); | |
1192 | kobject_put(kobj); | |
1da177e4 LT |
1193 | |
1194 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1195 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1196 | * unloading. |
1197 | */ | |
1198 | dprintk("waiting for dropping of refcount\n"); | |
499bca9b | 1199 | wait_for_completion(cmp); |
1da177e4 LT |
1200 | dprintk("wait complete\n"); |
1201 | ||
499bca9b | 1202 | lock_policy_rwsem_write(cpu); |
1da177e4 LT |
1203 | if (cpufreq_driver->exit) |
1204 | cpufreq_driver->exit(data); | |
7d26e2d5 | 1205 | unlock_policy_rwsem_write(cpu); |
1206 | ||
835481d9 RR |
1207 | free_cpumask_var(data->related_cpus); |
1208 | free_cpumask_var(data->cpus); | |
1da177e4 | 1209 | kfree(data); |
835481d9 | 1210 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1211 | |
1212 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1213 | return 0; |
1214 | } | |
1215 | ||
1216 | ||
905d77cd | 1217 | static int cpufreq_remove_dev(struct sys_device *sys_dev) |
5a01f2e8 VP |
1218 | { |
1219 | unsigned int cpu = sys_dev->id; | |
1220 | int retval; | |
ec28297a VP |
1221 | |
1222 | if (cpu_is_offline(cpu)) | |
1223 | return 0; | |
1224 | ||
5a01f2e8 VP |
1225 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1226 | BUG(); | |
1227 | ||
1228 | retval = __cpufreq_remove_dev(sys_dev); | |
1229 | return retval; | |
1230 | } | |
1231 | ||
1232 | ||
65f27f38 | 1233 | static void handle_update(struct work_struct *work) |
1da177e4 | 1234 | { |
65f27f38 DH |
1235 | struct cpufreq_policy *policy = |
1236 | container_of(work, struct cpufreq_policy, update); | |
1237 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1238 | dprintk("handle_update for cpu %u called\n", cpu); |
1239 | cpufreq_update_policy(cpu); | |
1240 | } | |
1241 | ||
1242 | /** | |
1243 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1244 | * @cpu: cpu number | |
1245 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1246 | * @new_freq: CPU frequency the CPU actually runs at | |
1247 | * | |
29464f28 DJ |
1248 | * We adjust to current frequency first, and need to clean up later. |
1249 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1250 | */ |
e08f5f5b GS |
1251 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1252 | unsigned int new_freq) | |
1da177e4 LT |
1253 | { |
1254 | struct cpufreq_freqs freqs; | |
1255 | ||
b10eec22 | 1256 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1257 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1258 | ||
1259 | freqs.cpu = cpu; | |
1260 | freqs.old = old_freq; | |
1261 | freqs.new = new_freq; | |
1262 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1263 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1264 | } | |
1265 | ||
1266 | ||
32ee8c3e | 1267 | /** |
4ab70df4 | 1268 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1269 | * @cpu: CPU number |
1270 | * | |
1271 | * This is the last known freq, without actually getting it from the driver. | |
1272 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1273 | */ | |
1274 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1275 | { | |
1276 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1277 | unsigned int ret_freq = 0; |
95235ca2 VP |
1278 | |
1279 | if (policy) { | |
e08f5f5b | 1280 | ret_freq = policy->cur; |
95235ca2 VP |
1281 | cpufreq_cpu_put(policy); |
1282 | } | |
1283 | ||
4d34a67d | 1284 | return ret_freq; |
95235ca2 VP |
1285 | } |
1286 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1287 | ||
1288 | ||
5a01f2e8 | 1289 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1290 | { |
7a6aedfa | 1291 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1292 | unsigned int ret_freq = 0; |
1da177e4 | 1293 | |
1da177e4 | 1294 | if (!cpufreq_driver->get) |
4d34a67d | 1295 | return ret_freq; |
1da177e4 | 1296 | |
e08f5f5b | 1297 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1298 | |
e08f5f5b GS |
1299 | if (ret_freq && policy->cur && |
1300 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1301 | /* verify no discrepancy between actual and | |
1302 | saved value exists */ | |
1303 | if (unlikely(ret_freq != policy->cur)) { | |
1304 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1305 | schedule_work(&policy->update); |
1306 | } | |
1307 | } | |
1308 | ||
4d34a67d | 1309 | return ret_freq; |
5a01f2e8 | 1310 | } |
1da177e4 | 1311 | |
5a01f2e8 VP |
1312 | /** |
1313 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1314 | * @cpu: CPU number | |
1315 | * | |
1316 | * Get the CPU current (static) CPU frequency | |
1317 | */ | |
1318 | unsigned int cpufreq_get(unsigned int cpu) | |
1319 | { | |
1320 | unsigned int ret_freq = 0; | |
1321 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1322 | ||
1323 | if (!policy) | |
1324 | goto out; | |
1325 | ||
1326 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1327 | goto out_policy; | |
1328 | ||
1329 | ret_freq = __cpufreq_get(cpu); | |
1330 | ||
1331 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1332 | |
5a01f2e8 VP |
1333 | out_policy: |
1334 | cpufreq_cpu_put(policy); | |
1335 | out: | |
4d34a67d | 1336 | return ret_freq; |
1da177e4 LT |
1337 | } |
1338 | EXPORT_SYMBOL(cpufreq_get); | |
1339 | ||
1340 | ||
42d4dc3f BH |
1341 | /** |
1342 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1343 | */ | |
1344 | ||
905d77cd | 1345 | static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg) |
42d4dc3f | 1346 | { |
e08f5f5b | 1347 | int ret = 0; |
4bc5d341 | 1348 | |
4bc5d341 | 1349 | int cpu = sysdev->id; |
42d4dc3f BH |
1350 | struct cpufreq_policy *cpu_policy; |
1351 | ||
0e37b159 | 1352 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1353 | |
1354 | if (!cpu_online(cpu)) | |
1355 | return 0; | |
1356 | ||
1357 | /* we may be lax here as interrupts are off. Nonetheless | |
1358 | * we need to grab the correct cpu policy, as to check | |
1359 | * whether we really run on this CPU. | |
1360 | */ | |
1361 | ||
1362 | cpu_policy = cpufreq_cpu_get(cpu); | |
1363 | if (!cpu_policy) | |
1364 | return -EINVAL; | |
1365 | ||
1366 | /* only handle each CPU group once */ | |
c9060494 DJ |
1367 | if (unlikely(cpu_policy->cpu != cpu)) |
1368 | goto out; | |
42d4dc3f BH |
1369 | |
1370 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1371 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
ce6c3997 | 1372 | if (ret) |
42d4dc3f BH |
1373 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1374 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1375 | } |
1376 | ||
7d5e350f | 1377 | out: |
42d4dc3f | 1378 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1379 | return ret; |
42d4dc3f BH |
1380 | } |
1381 | ||
1da177e4 LT |
1382 | /** |
1383 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1384 | * | |
1385 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1386 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1387 | * restored. It will verify that the current freq is in sync with | |
1388 | * what we believe it to be. This is a bit later than when it | |
1389 | * should be, but nonethteless it's better than calling | |
1390 | * cpufreq_driver->get() here which might re-enable interrupts... | |
1da177e4 | 1391 | */ |
905d77cd | 1392 | static int cpufreq_resume(struct sys_device *sysdev) |
1da177e4 | 1393 | { |
e08f5f5b | 1394 | int ret = 0; |
4bc5d341 | 1395 | |
4bc5d341 | 1396 | int cpu = sysdev->id; |
1da177e4 LT |
1397 | struct cpufreq_policy *cpu_policy; |
1398 | ||
1399 | dprintk("resuming cpu %u\n", cpu); | |
1400 | ||
1401 | if (!cpu_online(cpu)) | |
1402 | return 0; | |
1403 | ||
1404 | /* we may be lax here as interrupts are off. Nonetheless | |
1405 | * we need to grab the correct cpu policy, as to check | |
1406 | * whether we really run on this CPU. | |
1407 | */ | |
1408 | ||
1409 | cpu_policy = cpufreq_cpu_get(cpu); | |
1410 | if (!cpu_policy) | |
1411 | return -EINVAL; | |
1412 | ||
1413 | /* only handle each CPU group once */ | |
c9060494 DJ |
1414 | if (unlikely(cpu_policy->cpu != cpu)) |
1415 | goto fail; | |
1da177e4 LT |
1416 | |
1417 | if (cpufreq_driver->resume) { | |
1418 | ret = cpufreq_driver->resume(cpu_policy); | |
1419 | if (ret) { | |
1420 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1421 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1422 | goto fail; |
1da177e4 LT |
1423 | } |
1424 | } | |
1425 | ||
1da177e4 | 1426 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1427 | |
c9060494 | 1428 | fail: |
1da177e4 LT |
1429 | cpufreq_cpu_put(cpu_policy); |
1430 | return ret; | |
1431 | } | |
1432 | ||
1433 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1434 | .add = cpufreq_add_dev, | |
1435 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1436 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1437 | .resume = cpufreq_resume, |
1438 | }; | |
1439 | ||
1440 | ||
1441 | /********************************************************************* | |
1442 | * NOTIFIER LISTS INTERFACE * | |
1443 | *********************************************************************/ | |
1444 | ||
1445 | /** | |
1446 | * cpufreq_register_notifier - register a driver with cpufreq | |
1447 | * @nb: notifier function to register | |
1448 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1449 | * | |
32ee8c3e | 1450 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1451 | * are notified about clock rate changes (once before and once after |
1452 | * the transition), or a list of drivers that are notified about | |
1453 | * changes in cpufreq policy. | |
1454 | * | |
1455 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1456 | * blocking_notifier_chain_register. |
1da177e4 LT |
1457 | */ |
1458 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1459 | { | |
1460 | int ret; | |
1461 | ||
74212ca4 CEB |
1462 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1463 | ||
1da177e4 LT |
1464 | switch (list) { |
1465 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1466 | ret = srcu_notifier_chain_register( |
e041c683 | 1467 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1468 | break; |
1469 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1470 | ret = blocking_notifier_chain_register( |
1471 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1472 | break; |
1473 | default: | |
1474 | ret = -EINVAL; | |
1475 | } | |
1da177e4 LT |
1476 | |
1477 | return ret; | |
1478 | } | |
1479 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1480 | ||
1481 | ||
1482 | /** | |
1483 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1484 | * @nb: notifier block to be unregistered | |
1485 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1486 | * | |
1487 | * Remove a driver from the CPU frequency notifier list. | |
1488 | * | |
1489 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1490 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1491 | */ |
1492 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1493 | { | |
1494 | int ret; | |
1495 | ||
1da177e4 LT |
1496 | switch (list) { |
1497 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1498 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1499 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1500 | break; |
1501 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1502 | ret = blocking_notifier_chain_unregister( |
1503 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1504 | break; |
1505 | default: | |
1506 | ret = -EINVAL; | |
1507 | } | |
1da177e4 LT |
1508 | |
1509 | return ret; | |
1510 | } | |
1511 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1512 | ||
1513 | ||
1514 | /********************************************************************* | |
1515 | * GOVERNORS * | |
1516 | *********************************************************************/ | |
1517 | ||
1518 | ||
1519 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1520 | unsigned int target_freq, | |
1521 | unsigned int relation) | |
1522 | { | |
1523 | int retval = -EINVAL; | |
c32b6b8e | 1524 | |
1da177e4 LT |
1525 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1526 | target_freq, relation); | |
1527 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1528 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1529 | |
1da177e4 LT |
1530 | return retval; |
1531 | } | |
1532 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1533 | ||
1da177e4 LT |
1534 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1535 | unsigned int target_freq, | |
1536 | unsigned int relation) | |
1537 | { | |
f1829e4a | 1538 | int ret = -EINVAL; |
1da177e4 LT |
1539 | |
1540 | policy = cpufreq_cpu_get(policy->cpu); | |
1541 | if (!policy) | |
f1829e4a | 1542 | goto no_policy; |
1da177e4 | 1543 | |
5a01f2e8 | 1544 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1545 | goto fail; |
1da177e4 LT |
1546 | |
1547 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1548 | ||
5a01f2e8 | 1549 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1550 | |
f1829e4a | 1551 | fail: |
1da177e4 | 1552 | cpufreq_cpu_put(policy); |
f1829e4a | 1553 | no_policy: |
1da177e4 LT |
1554 | return ret; |
1555 | } | |
1556 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1557 | ||
bf0b90e3 | 1558 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1559 | { |
1560 | int ret = 0; | |
1561 | ||
1562 | policy = cpufreq_cpu_get(policy->cpu); | |
1563 | if (!policy) | |
1564 | return -EINVAL; | |
1565 | ||
bf0b90e3 | 1566 | if (cpu_online(cpu) && cpufreq_driver->getavg) |
1567 | ret = cpufreq_driver->getavg(policy, cpu); | |
dfde5d62 | 1568 | |
dfde5d62 VP |
1569 | cpufreq_cpu_put(policy); |
1570 | return ret; | |
1571 | } | |
5a01f2e8 | 1572 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1573 | |
153d7f3f | 1574 | /* |
153d7f3f AV |
1575 | * when "event" is CPUFREQ_GOV_LIMITS |
1576 | */ | |
1da177e4 | 1577 | |
e08f5f5b GS |
1578 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1579 | unsigned int event) | |
1da177e4 | 1580 | { |
cc993cab | 1581 | int ret; |
6afde10c TR |
1582 | |
1583 | /* Only must be defined when default governor is known to have latency | |
1584 | restrictions, like e.g. conservative or ondemand. | |
1585 | That this is the case is already ensured in Kconfig | |
1586 | */ | |
1587 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1588 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1589 | #else | |
1590 | struct cpufreq_governor *gov = NULL; | |
1591 | #endif | |
1c256245 TR |
1592 | |
1593 | if (policy->governor->max_transition_latency && | |
1594 | policy->cpuinfo.transition_latency > | |
1595 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1596 | if (!gov) |
1597 | return -EINVAL; | |
1598 | else { | |
1599 | printk(KERN_WARNING "%s governor failed, too long" | |
1600 | " transition latency of HW, fallback" | |
1601 | " to %s governor\n", | |
1602 | policy->governor->name, | |
1603 | gov->name); | |
1604 | policy->governor = gov; | |
1605 | } | |
1c256245 | 1606 | } |
1da177e4 LT |
1607 | |
1608 | if (!try_module_get(policy->governor->owner)) | |
1609 | return -EINVAL; | |
1610 | ||
e08f5f5b GS |
1611 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1612 | policy->cpu, event); | |
1da177e4 LT |
1613 | ret = policy->governor->governor(policy, event); |
1614 | ||
e08f5f5b GS |
1615 | /* we keep one module reference alive for |
1616 | each CPU governed by this CPU */ | |
1da177e4 LT |
1617 | if ((event != CPUFREQ_GOV_START) || ret) |
1618 | module_put(policy->governor->owner); | |
1619 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1620 | module_put(policy->governor->owner); | |
1621 | ||
1622 | return ret; | |
1623 | } | |
1624 | ||
1625 | ||
1da177e4 LT |
1626 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1627 | { | |
3bcb09a3 | 1628 | int err; |
1da177e4 LT |
1629 | |
1630 | if (!governor) | |
1631 | return -EINVAL; | |
1632 | ||
3fc54d37 | 1633 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1634 | |
3bcb09a3 JF |
1635 | err = -EBUSY; |
1636 | if (__find_governor(governor->name) == NULL) { | |
1637 | err = 0; | |
1638 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1639 | } |
1da177e4 | 1640 | |
32ee8c3e | 1641 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1642 | return err; |
1da177e4 LT |
1643 | } |
1644 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1645 | ||
1646 | ||
1647 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1648 | { | |
90e41bac PB |
1649 | #ifdef CONFIG_HOTPLUG_CPU |
1650 | int cpu; | |
1651 | #endif | |
1652 | ||
1da177e4 LT |
1653 | if (!governor) |
1654 | return; | |
1655 | ||
90e41bac PB |
1656 | #ifdef CONFIG_HOTPLUG_CPU |
1657 | for_each_present_cpu(cpu) { | |
1658 | if (cpu_online(cpu)) | |
1659 | continue; | |
1660 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1661 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1662 | } | |
1663 | #endif | |
1664 | ||
3fc54d37 | 1665 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1666 | list_del(&governor->governor_list); |
3fc54d37 | 1667 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1668 | return; |
1669 | } | |
1670 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1671 | ||
1672 | ||
1673 | ||
1674 | /********************************************************************* | |
1675 | * POLICY INTERFACE * | |
1676 | *********************************************************************/ | |
1677 | ||
1678 | /** | |
1679 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1680 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1681 | * is written | |
1da177e4 LT |
1682 | * |
1683 | * Reads the current cpufreq policy. | |
1684 | */ | |
1685 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1686 | { | |
1687 | struct cpufreq_policy *cpu_policy; | |
1688 | if (!policy) | |
1689 | return -EINVAL; | |
1690 | ||
1691 | cpu_policy = cpufreq_cpu_get(cpu); | |
1692 | if (!cpu_policy) | |
1693 | return -EINVAL; | |
1694 | ||
1da177e4 | 1695 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1696 | |
1697 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1698 | return 0; |
1699 | } | |
1700 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1701 | ||
1702 | ||
153d7f3f | 1703 | /* |
e08f5f5b GS |
1704 | * data : current policy. |
1705 | * policy : policy to be set. | |
153d7f3f | 1706 | */ |
e08f5f5b GS |
1707 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1708 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1709 | { |
1710 | int ret = 0; | |
1711 | ||
1712 | cpufreq_debug_disable_ratelimit(); | |
1713 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1714 | policy->min, policy->max); | |
1715 | ||
e08f5f5b GS |
1716 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1717 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1718 | |
53391fa2 | 1719 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1720 | ret = -EINVAL; |
1721 | goto error_out; | |
1722 | } | |
1723 | ||
1da177e4 LT |
1724 | /* verify the cpu speed can be set within this limit */ |
1725 | ret = cpufreq_driver->verify(policy); | |
1726 | if (ret) | |
1727 | goto error_out; | |
1728 | ||
1da177e4 | 1729 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1730 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1731 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1732 | |
1733 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1734 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1735 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1736 | |
1737 | /* verify the cpu speed can be set within this limit, | |
1738 | which might be different to the first one */ | |
1739 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1740 | if (ret) |
1da177e4 | 1741 | goto error_out; |
1da177e4 LT |
1742 | |
1743 | /* notification of the new policy */ | |
e041c683 AS |
1744 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1745 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1746 | |
7d5e350f DJ |
1747 | data->min = policy->min; |
1748 | data->max = policy->max; | |
1da177e4 | 1749 | |
e08f5f5b GS |
1750 | dprintk("new min and max freqs are %u - %u kHz\n", |
1751 | data->min, data->max); | |
1da177e4 LT |
1752 | |
1753 | if (cpufreq_driver->setpolicy) { | |
1754 | data->policy = policy->policy; | |
1755 | dprintk("setting range\n"); | |
1756 | ret = cpufreq_driver->setpolicy(policy); | |
1757 | } else { | |
1758 | if (policy->governor != data->governor) { | |
1759 | /* save old, working values */ | |
1760 | struct cpufreq_governor *old_gov = data->governor; | |
1761 | ||
1762 | dprintk("governor switch\n"); | |
1763 | ||
1764 | /* end old governor */ | |
395913d0 MD |
1765 | if (data->governor) { |
1766 | /* | |
1767 | * Need to release the rwsem around governor | |
1768 | * stop due to lock dependency between | |
1769 | * cancel_delayed_work_sync and the read lock | |
1770 | * taken in the delayed work handler. | |
1771 | */ | |
1772 | unlock_policy_rwsem_write(data->cpu); | |
1da177e4 | 1773 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
395913d0 MD |
1774 | lock_policy_rwsem_write(data->cpu); |
1775 | } | |
1da177e4 LT |
1776 | |
1777 | /* start new governor */ | |
1778 | data->governor = policy->governor; | |
1779 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1780 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1781 | dprintk("starting governor %s failed\n", |
1782 | data->governor->name); | |
1da177e4 LT |
1783 | if (old_gov) { |
1784 | data->governor = old_gov; | |
e08f5f5b GS |
1785 | __cpufreq_governor(data, |
1786 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1787 | } |
1788 | ret = -EINVAL; | |
1789 | goto error_out; | |
1790 | } | |
1791 | /* might be a policy change, too, so fall through */ | |
1792 | } | |
1793 | dprintk("governor: change or update limits\n"); | |
1794 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1795 | } | |
1796 | ||
7d5e350f | 1797 | error_out: |
1da177e4 LT |
1798 | cpufreq_debug_enable_ratelimit(); |
1799 | return ret; | |
1800 | } | |
1801 | ||
1da177e4 LT |
1802 | /** |
1803 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1804 | * @cpu: CPU which shall be re-evaluated | |
1805 | * | |
1806 | * Usefull for policy notifiers which have different necessities | |
1807 | * at different times. | |
1808 | */ | |
1809 | int cpufreq_update_policy(unsigned int cpu) | |
1810 | { | |
1811 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1812 | struct cpufreq_policy policy; | |
f1829e4a | 1813 | int ret; |
1da177e4 | 1814 | |
f1829e4a JL |
1815 | if (!data) { |
1816 | ret = -ENODEV; | |
1817 | goto no_policy; | |
1818 | } | |
1da177e4 | 1819 | |
f1829e4a JL |
1820 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1821 | ret = -EINVAL; | |
1822 | goto fail; | |
1823 | } | |
1da177e4 LT |
1824 | |
1825 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1826 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1827 | policy.min = data->user_policy.min; |
1828 | policy.max = data->user_policy.max; | |
1829 | policy.policy = data->user_policy.policy; | |
1830 | policy.governor = data->user_policy.governor; | |
1831 | ||
0961dd0d TR |
1832 | /* BIOS might change freq behind our back |
1833 | -> ask driver for current freq and notify governors about a change */ | |
1834 | if (cpufreq_driver->get) { | |
1835 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1836 | if (!data->cur) { |
1837 | dprintk("Driver did not initialize current freq"); | |
1838 | data->cur = policy.cur; | |
1839 | } else { | |
1840 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1841 | cpufreq_out_of_sync(cpu, data->cur, |
1842 | policy.cur); | |
a85f7bd3 | 1843 | } |
0961dd0d TR |
1844 | } |
1845 | ||
1da177e4 LT |
1846 | ret = __cpufreq_set_policy(data, &policy); |
1847 | ||
5a01f2e8 VP |
1848 | unlock_policy_rwsem_write(cpu); |
1849 | ||
f1829e4a | 1850 | fail: |
1da177e4 | 1851 | cpufreq_cpu_put(data); |
f1829e4a | 1852 | no_policy: |
1da177e4 LT |
1853 | return ret; |
1854 | } | |
1855 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1856 | ||
dd184a01 | 1857 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1858 | unsigned long action, void *hcpu) |
1859 | { | |
1860 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1861 | struct sys_device *sys_dev; |
1862 | ||
1863 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1864 | if (sys_dev) { |
1865 | switch (action) { | |
1866 | case CPU_ONLINE: | |
8bb78442 | 1867 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1868 | cpufreq_add_dev(sys_dev); |
1869 | break; | |
1870 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1871 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1872 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1873 | BUG(); | |
1874 | ||
5a01f2e8 | 1875 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1876 | break; |
5a01f2e8 | 1877 | case CPU_DOWN_FAILED: |
8bb78442 | 1878 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1879 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1880 | break; |
1881 | } | |
1882 | } | |
1883 | return NOTIFY_OK; | |
1884 | } | |
1885 | ||
f6ebef30 | 1886 | static struct notifier_block __refdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1887 | { |
1888 | .notifier_call = cpufreq_cpu_callback, | |
1889 | }; | |
1da177e4 LT |
1890 | |
1891 | /********************************************************************* | |
1892 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1893 | *********************************************************************/ | |
1894 | ||
1895 | /** | |
1896 | * cpufreq_register_driver - register a CPU Frequency driver | |
1897 | * @driver_data: A struct cpufreq_driver containing the values# | |
1898 | * submitted by the CPU Frequency driver. | |
1899 | * | |
32ee8c3e | 1900 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1901 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1902 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1903 | * |
1904 | */ | |
221dee28 | 1905 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1906 | { |
1907 | unsigned long flags; | |
1908 | int ret; | |
1909 | ||
1910 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1911 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1912 | return -EINVAL; | |
1913 | ||
1914 | dprintk("trying to register driver %s\n", driver_data->name); | |
1915 | ||
1916 | if (driver_data->setpolicy) | |
1917 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1918 | ||
1919 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1920 | if (cpufreq_driver) { | |
1921 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1922 | return -EBUSY; | |
1923 | } | |
1924 | cpufreq_driver = driver_data; | |
1925 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1926 | ||
7a6aedfa MT |
1927 | ret = sysdev_driver_register(&cpu_sysdev_class, |
1928 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1929 | |
1930 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1931 | int i; | |
1932 | ret = -ENODEV; | |
1933 | ||
1934 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1935 | for (i = 0; i < nr_cpu_ids; i++) |
1936 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1937 | ret = 0; |
7a6aedfa MT |
1938 | break; |
1939 | } | |
1da177e4 LT |
1940 | |
1941 | /* if all ->init() calls failed, unregister */ | |
1942 | if (ret) { | |
e08f5f5b GS |
1943 | dprintk("no CPU initialized for driver %s\n", |
1944 | driver_data->name); | |
1945 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1946 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1947 | |
1948 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1949 | cpufreq_driver = NULL; | |
1950 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1951 | } | |
1952 | } | |
1953 | ||
1954 | if (!ret) { | |
65edc68c | 1955 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1956 | dprintk("driver %s up and running\n", driver_data->name); |
1957 | cpufreq_debug_enable_ratelimit(); | |
1958 | } | |
1959 | ||
4d34a67d | 1960 | return ret; |
1da177e4 LT |
1961 | } |
1962 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1963 | ||
1964 | ||
1965 | /** | |
1966 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1967 | * | |
32ee8c3e | 1968 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1969 | * the right to do so, i.e. if you have succeeded in initialising before! |
1970 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1971 | * currently not initialised. | |
1972 | */ | |
221dee28 | 1973 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1974 | { |
1975 | unsigned long flags; | |
1976 | ||
1977 | cpufreq_debug_disable_ratelimit(); | |
1978 | ||
1979 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1980 | cpufreq_debug_enable_ratelimit(); | |
1981 | return -EINVAL; | |
1982 | } | |
1983 | ||
1984 | dprintk("unregistering driver %s\n", driver->name); | |
1985 | ||
1986 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1987 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1988 | |
1989 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1990 | cpufreq_driver = NULL; | |
1991 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1992 | ||
1993 | return 0; | |
1994 | } | |
1995 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1996 | |
1997 | static int __init cpufreq_core_init(void) | |
1998 | { | |
1999 | int cpu; | |
2000 | ||
2001 | for_each_possible_cpu(cpu) { | |
f1625066 | 2002 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
2003 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
2004 | } | |
8aa84ad8 TR |
2005 | |
2006 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", | |
2007 | &cpu_sysdev_class.kset.kobj); | |
2008 | BUG_ON(!cpufreq_global_kobject); | |
2009 | ||
5a01f2e8 VP |
2010 | return 0; |
2011 | } | |
5a01f2e8 | 2012 | core_initcall(cpufreq_core_init); |