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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 | |
6f4f2723 TR |
32 | #include <trace/events/power.h> |
33 | ||
e08f5f5b GS |
34 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \ |
35 | "cpufreq-core", msg) | |
1da177e4 LT |
36 | |
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 LT |
130 | |
131 | static LIST_HEAD(cpufreq_governor_list); | |
29464f28 | 132 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 133 | |
7d5e350f | 134 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
135 | { |
136 | struct cpufreq_policy *data; | |
137 | unsigned long flags; | |
138 | ||
7a6aedfa | 139 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
140 | goto err_out; |
141 | ||
142 | /* get the cpufreq driver */ | |
143 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
144 | ||
145 | if (!cpufreq_driver) | |
146 | goto err_out_unlock; | |
147 | ||
148 | if (!try_module_get(cpufreq_driver->owner)) | |
149 | goto err_out_unlock; | |
150 | ||
151 | ||
152 | /* get the CPU */ | |
7a6aedfa | 153 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
154 | |
155 | if (!data) | |
156 | goto err_out_put_module; | |
157 | ||
158 | if (!kobject_get(&data->kobj)) | |
159 | goto err_out_put_module; | |
160 | ||
1da177e4 | 161 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
162 | return data; |
163 | ||
7d5e350f | 164 | err_out_put_module: |
1da177e4 | 165 | module_put(cpufreq_driver->owner); |
7d5e350f | 166 | err_out_unlock: |
1da177e4 | 167 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 168 | err_out: |
1da177e4 LT |
169 | return NULL; |
170 | } | |
171 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
172 | ||
7d5e350f | 173 | |
1da177e4 LT |
174 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
175 | { | |
176 | kobject_put(&data->kobj); | |
177 | module_put(cpufreq_driver->owner); | |
178 | } | |
179 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
180 | ||
181 | ||
182 | /********************************************************************* | |
183 | * UNIFIED DEBUG HELPERS * | |
184 | *********************************************************************/ | |
185 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
186 | ||
187 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
188 | static unsigned int debug; | |
189 | ||
190 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
191 | * set or modify this value. | |
192 | */ | |
193 | static unsigned int debug_ratelimit = 1; | |
194 | ||
195 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
196 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
197 | * is set, and disabled upon cpufreq driver removal | |
198 | */ | |
199 | static unsigned int disable_ratelimit = 1; | |
200 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
201 | ||
858119e1 | 202 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
203 | { |
204 | unsigned long flags; | |
205 | ||
206 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
207 | if (disable_ratelimit) | |
208 | disable_ratelimit--; | |
209 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
210 | } | |
211 | ||
858119e1 | 212 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
213 | { |
214 | unsigned long flags; | |
215 | ||
216 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
217 | disable_ratelimit++; | |
218 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
219 | } | |
220 | ||
e08f5f5b | 221 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
905d77cd | 222 | const char *fmt, ...) |
1da177e4 LT |
223 | { |
224 | char s[256]; | |
225 | va_list args; | |
226 | unsigned int len; | |
227 | unsigned long flags; | |
32ee8c3e | 228 | |
1da177e4 LT |
229 | WARN_ON(!prefix); |
230 | if (type & debug) { | |
231 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
232 | if (!disable_ratelimit && debug_ratelimit |
233 | && !printk_ratelimit()) { | |
1da177e4 LT |
234 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
235 | return; | |
236 | } | |
237 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
238 | ||
239 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
240 | ||
241 | va_start(args, fmt); | |
242 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
243 | va_end(args); | |
244 | ||
245 | printk(s); | |
246 | ||
247 | WARN_ON(len < 5); | |
248 | } | |
249 | } | |
250 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
251 | ||
252 | ||
253 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
254 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
255 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
256 | |
257 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
258 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
259 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
260 | |
261 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
262 | ||
263 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
264 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
265 | ||
266 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
267 | ||
268 | ||
269 | /********************************************************************* | |
270 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
271 | *********************************************************************/ | |
272 | ||
273 | /** | |
274 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
275 | * | |
276 | * This function alters the system "loops_per_jiffy" for the clock | |
277 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 278 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
279 | * per-CPU loops_per_jiffy value wherever possible. |
280 | */ | |
281 | #ifndef CONFIG_SMP | |
282 | static unsigned long l_p_j_ref; | |
283 | static unsigned int l_p_j_ref_freq; | |
284 | ||
858119e1 | 285 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
286 | { |
287 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
288 | return; | |
289 | ||
290 | if (!l_p_j_ref_freq) { | |
291 | l_p_j_ref = loops_per_jiffy; | |
292 | l_p_j_ref_freq = ci->old; | |
a4a9df58 | 293 | dprintk("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 294 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 LT |
295 | } |
296 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
297 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 298 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
299 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
300 | ci->new); | |
a4a9df58 | 301 | dprintk("scaling loops_per_jiffy to %lu " |
e08f5f5b | 302 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
303 | } |
304 | } | |
305 | #else | |
e08f5f5b GS |
306 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
307 | { | |
308 | return; | |
309 | } | |
1da177e4 LT |
310 | #endif |
311 | ||
312 | ||
313 | /** | |
e4472cb3 DJ |
314 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
315 | * on frequency transition. | |
1da177e4 | 316 | * |
e4472cb3 DJ |
317 | * This function calls the transition notifiers and the "adjust_jiffies" |
318 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 319 | * external effects. |
1da177e4 LT |
320 | */ |
321 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
322 | { | |
e4472cb3 DJ |
323 | struct cpufreq_policy *policy; |
324 | ||
1da177e4 LT |
325 | BUG_ON(irqs_disabled()); |
326 | ||
327 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
328 | dprintk("notification %u of frequency transition to %u kHz\n", |
329 | state, freqs->new); | |
1da177e4 | 330 | |
7a6aedfa | 331 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 332 | switch (state) { |
e4472cb3 | 333 | |
1da177e4 | 334 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 335 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
336 | * which is not equal to what the cpufreq core thinks is |
337 | * "old frequency". | |
1da177e4 LT |
338 | */ |
339 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
340 | if ((policy) && (policy->cpu == freqs->cpu) && |
341 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 342 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
343 | " %u, cpufreq assumed %u kHz.\n", |
344 | freqs->old, policy->cur); | |
345 | freqs->old = policy->cur; | |
1da177e4 LT |
346 | } |
347 | } | |
b4dfdbb3 | 348 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 349 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
350 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
351 | break; | |
e4472cb3 | 352 | |
1da177e4 LT |
353 | case CPUFREQ_POSTCHANGE: |
354 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
6f4f2723 TR |
355 | dprintk("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
356 | (unsigned long)freqs->cpu); | |
357 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
b4dfdbb3 | 358 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 359 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
360 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
361 | policy->cur = freqs->new; | |
1da177e4 LT |
362 | break; |
363 | } | |
1da177e4 LT |
364 | } |
365 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
366 | ||
367 | ||
368 | ||
369 | /********************************************************************* | |
370 | * SYSFS INTERFACE * | |
371 | *********************************************************************/ | |
372 | ||
3bcb09a3 JF |
373 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
374 | { | |
375 | struct cpufreq_governor *t; | |
376 | ||
377 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 378 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
379 | return t; |
380 | ||
381 | return NULL; | |
382 | } | |
383 | ||
1da177e4 LT |
384 | /** |
385 | * cpufreq_parse_governor - parse a governor string | |
386 | */ | |
905d77cd | 387 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
388 | struct cpufreq_governor **governor) |
389 | { | |
3bcb09a3 JF |
390 | int err = -EINVAL; |
391 | ||
1da177e4 | 392 | if (!cpufreq_driver) |
3bcb09a3 JF |
393 | goto out; |
394 | ||
1da177e4 LT |
395 | if (cpufreq_driver->setpolicy) { |
396 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
397 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 398 | err = 0; |
e08f5f5b GS |
399 | } else if (!strnicmp(str_governor, "powersave", |
400 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 401 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 402 | err = 0; |
1da177e4 | 403 | } |
3bcb09a3 | 404 | } else if (cpufreq_driver->target) { |
1da177e4 | 405 | struct cpufreq_governor *t; |
3bcb09a3 | 406 | |
3fc54d37 | 407 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
408 | |
409 | t = __find_governor(str_governor); | |
410 | ||
ea714970 | 411 | if (t == NULL) { |
e08f5f5b GS |
412 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
413 | str_governor); | |
ea714970 JF |
414 | |
415 | if (name) { | |
416 | int ret; | |
417 | ||
418 | mutex_unlock(&cpufreq_governor_mutex); | |
326f6a5c | 419 | ret = request_module("%s", name); |
ea714970 JF |
420 | mutex_lock(&cpufreq_governor_mutex); |
421 | ||
422 | if (ret == 0) | |
423 | t = __find_governor(str_governor); | |
424 | } | |
425 | ||
426 | kfree(name); | |
427 | } | |
428 | ||
3bcb09a3 JF |
429 | if (t != NULL) { |
430 | *governor = t; | |
431 | err = 0; | |
1da177e4 | 432 | } |
3bcb09a3 | 433 | |
3fc54d37 | 434 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 435 | } |
29464f28 | 436 | out: |
3bcb09a3 | 437 | return err; |
1da177e4 | 438 | } |
1da177e4 LT |
439 | |
440 | ||
1da177e4 | 441 | /** |
e08f5f5b GS |
442 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
443 | * print out cpufreq information | |
1da177e4 LT |
444 | * |
445 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
446 | * "unsigned int". | |
447 | */ | |
448 | ||
32ee8c3e DJ |
449 | #define show_one(file_name, object) \ |
450 | static ssize_t show_##file_name \ | |
905d77cd | 451 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 452 | { \ |
29464f28 | 453 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
454 | } |
455 | ||
456 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
457 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 458 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
459 | show_one(scaling_min_freq, min); |
460 | show_one(scaling_max_freq, max); | |
461 | show_one(scaling_cur_freq, cur); | |
462 | ||
e08f5f5b GS |
463 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
464 | struct cpufreq_policy *policy); | |
7970e08b | 465 | |
1da177e4 LT |
466 | /** |
467 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
468 | */ | |
469 | #define store_one(file_name, object) \ | |
470 | static ssize_t store_##file_name \ | |
905d77cd | 471 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
472 | { \ |
473 | unsigned int ret = -EINVAL; \ | |
474 | struct cpufreq_policy new_policy; \ | |
475 | \ | |
476 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
477 | if (ret) \ | |
478 | return -EINVAL; \ | |
479 | \ | |
29464f28 | 480 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
481 | if (ret != 1) \ |
482 | return -EINVAL; \ | |
483 | \ | |
7970e08b TR |
484 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
485 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
486 | \ |
487 | return ret ? ret : count; \ | |
488 | } | |
489 | ||
29464f28 DJ |
490 | store_one(scaling_min_freq, min); |
491 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
492 | |
493 | /** | |
494 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
495 | */ | |
905d77cd DJ |
496 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
497 | char *buf) | |
1da177e4 | 498 | { |
5a01f2e8 | 499 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
500 | if (!cur_freq) |
501 | return sprintf(buf, "<unknown>"); | |
502 | return sprintf(buf, "%u\n", cur_freq); | |
503 | } | |
504 | ||
505 | ||
506 | /** | |
507 | * show_scaling_governor - show the current policy for the specified CPU | |
508 | */ | |
905d77cd | 509 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 510 | { |
29464f28 | 511 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
512 | return sprintf(buf, "powersave\n"); |
513 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
514 | return sprintf(buf, "performance\n"); | |
515 | else if (policy->governor) | |
29464f28 DJ |
516 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", |
517 | policy->governor->name); | |
1da177e4 LT |
518 | return -EINVAL; |
519 | } | |
520 | ||
521 | ||
522 | /** | |
523 | * store_scaling_governor - store policy for the specified CPU | |
524 | */ | |
905d77cd DJ |
525 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
526 | const char *buf, size_t count) | |
1da177e4 LT |
527 | { |
528 | unsigned int ret = -EINVAL; | |
529 | char str_governor[16]; | |
530 | struct cpufreq_policy new_policy; | |
531 | ||
532 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
533 | if (ret) | |
534 | return ret; | |
535 | ||
29464f28 | 536 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
537 | if (ret != 1) |
538 | return -EINVAL; | |
539 | ||
e08f5f5b GS |
540 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
541 | &new_policy.governor)) | |
1da177e4 LT |
542 | return -EINVAL; |
543 | ||
7970e08b TR |
544 | /* Do not use cpufreq_set_policy here or the user_policy.max |
545 | will be wrongly overridden */ | |
7970e08b TR |
546 | ret = __cpufreq_set_policy(policy, &new_policy); |
547 | ||
548 | policy->user_policy.policy = policy->policy; | |
549 | policy->user_policy.governor = policy->governor; | |
7970e08b | 550 | |
e08f5f5b GS |
551 | if (ret) |
552 | return ret; | |
553 | else | |
554 | return count; | |
1da177e4 LT |
555 | } |
556 | ||
557 | /** | |
558 | * show_scaling_driver - show the cpufreq driver currently loaded | |
559 | */ | |
905d77cd | 560 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
561 | { |
562 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
563 | } | |
564 | ||
565 | /** | |
566 | * show_scaling_available_governors - show the available CPUfreq governors | |
567 | */ | |
905d77cd DJ |
568 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
569 | char *buf) | |
1da177e4 LT |
570 | { |
571 | ssize_t i = 0; | |
572 | struct cpufreq_governor *t; | |
573 | ||
574 | if (!cpufreq_driver->target) { | |
575 | i += sprintf(buf, "performance powersave"); | |
576 | goto out; | |
577 | } | |
578 | ||
579 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
580 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
581 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 LT |
582 | goto out; |
583 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
584 | } | |
7d5e350f | 585 | out: |
1da177e4 LT |
586 | i += sprintf(&buf[i], "\n"); |
587 | return i; | |
588 | } | |
e8628dd0 | 589 | |
835481d9 | 590 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
591 | { |
592 | ssize_t i = 0; | |
593 | unsigned int cpu; | |
594 | ||
835481d9 | 595 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
596 | if (i) |
597 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
598 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
599 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 600 | break; |
1da177e4 LT |
601 | } |
602 | i += sprintf(&buf[i], "\n"); | |
603 | return i; | |
604 | } | |
605 | ||
e8628dd0 DW |
606 | /** |
607 | * show_related_cpus - show the CPUs affected by each transition even if | |
608 | * hw coordination is in use | |
609 | */ | |
610 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
611 | { | |
835481d9 | 612 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
613 | return show_cpus(policy->cpus, buf); |
614 | return show_cpus(policy->related_cpus, buf); | |
615 | } | |
616 | ||
617 | /** | |
618 | * show_affected_cpus - show the CPUs affected by each transition | |
619 | */ | |
620 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
621 | { | |
622 | return show_cpus(policy->cpus, buf); | |
623 | } | |
624 | ||
9e76988e | 625 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 626 | const char *buf, size_t count) |
9e76988e VP |
627 | { |
628 | unsigned int freq = 0; | |
629 | unsigned int ret; | |
630 | ||
879000f9 | 631 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
632 | return -EINVAL; |
633 | ||
634 | ret = sscanf(buf, "%u", &freq); | |
635 | if (ret != 1) | |
636 | return -EINVAL; | |
637 | ||
638 | policy->governor->store_setspeed(policy, freq); | |
639 | ||
640 | return count; | |
641 | } | |
642 | ||
643 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
644 | { | |
879000f9 | 645 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
646 | return sprintf(buf, "<unsupported>\n"); |
647 | ||
648 | return policy->governor->show_setspeed(policy, buf); | |
649 | } | |
1da177e4 | 650 | |
e2f74f35 TR |
651 | /** |
652 | * show_scaling_driver - show the current cpufreq HW/BIOS limitation | |
653 | */ | |
654 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
655 | { | |
656 | unsigned int limit; | |
657 | int ret; | |
658 | if (cpufreq_driver->bios_limit) { | |
659 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
660 | if (!ret) | |
661 | return sprintf(buf, "%u\n", limit); | |
662 | } | |
663 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
664 | } | |
665 | ||
6dad2a29 BP |
666 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
667 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
668 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
669 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
670 | cpufreq_freq_attr_ro(scaling_available_governors); | |
671 | cpufreq_freq_attr_ro(scaling_driver); | |
672 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
673 | cpufreq_freq_attr_ro(bios_limit); | |
674 | cpufreq_freq_attr_ro(related_cpus); | |
675 | cpufreq_freq_attr_ro(affected_cpus); | |
676 | cpufreq_freq_attr_rw(scaling_min_freq); | |
677 | cpufreq_freq_attr_rw(scaling_max_freq); | |
678 | cpufreq_freq_attr_rw(scaling_governor); | |
679 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 680 | |
905d77cd | 681 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
682 | &cpuinfo_min_freq.attr, |
683 | &cpuinfo_max_freq.attr, | |
ed129784 | 684 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
685 | &scaling_min_freq.attr, |
686 | &scaling_max_freq.attr, | |
687 | &affected_cpus.attr, | |
e8628dd0 | 688 | &related_cpus.attr, |
1da177e4 LT |
689 | &scaling_governor.attr, |
690 | &scaling_driver.attr, | |
691 | &scaling_available_governors.attr, | |
9e76988e | 692 | &scaling_setspeed.attr, |
1da177e4 LT |
693 | NULL |
694 | }; | |
695 | ||
8aa84ad8 TR |
696 | struct kobject *cpufreq_global_kobject; |
697 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
698 | ||
29464f28 DJ |
699 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
700 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 701 | |
29464f28 | 702 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 703 | { |
905d77cd DJ |
704 | struct cpufreq_policy *policy = to_policy(kobj); |
705 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 706 | ssize_t ret = -EINVAL; |
1da177e4 LT |
707 | policy = cpufreq_cpu_get(policy->cpu); |
708 | if (!policy) | |
0db4a8a9 | 709 | goto no_policy; |
5a01f2e8 VP |
710 | |
711 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 712 | goto fail; |
5a01f2e8 | 713 | |
e08f5f5b GS |
714 | if (fattr->show) |
715 | ret = fattr->show(policy, buf); | |
716 | else | |
717 | ret = -EIO; | |
718 | ||
5a01f2e8 | 719 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 720 | fail: |
1da177e4 | 721 | cpufreq_cpu_put(policy); |
0db4a8a9 | 722 | no_policy: |
1da177e4 LT |
723 | return ret; |
724 | } | |
725 | ||
905d77cd DJ |
726 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
727 | const char *buf, size_t count) | |
1da177e4 | 728 | { |
905d77cd DJ |
729 | struct cpufreq_policy *policy = to_policy(kobj); |
730 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 731 | ssize_t ret = -EINVAL; |
1da177e4 LT |
732 | policy = cpufreq_cpu_get(policy->cpu); |
733 | if (!policy) | |
a07530b4 | 734 | goto no_policy; |
5a01f2e8 VP |
735 | |
736 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 737 | goto fail; |
5a01f2e8 | 738 | |
e08f5f5b GS |
739 | if (fattr->store) |
740 | ret = fattr->store(policy, buf, count); | |
741 | else | |
742 | ret = -EIO; | |
743 | ||
5a01f2e8 | 744 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 745 | fail: |
1da177e4 | 746 | cpufreq_cpu_put(policy); |
a07530b4 | 747 | no_policy: |
1da177e4 LT |
748 | return ret; |
749 | } | |
750 | ||
905d77cd | 751 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 752 | { |
905d77cd | 753 | struct cpufreq_policy *policy = to_policy(kobj); |
1da177e4 LT |
754 | dprintk("last reference is dropped\n"); |
755 | complete(&policy->kobj_unregister); | |
756 | } | |
757 | ||
52cf25d0 | 758 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
759 | .show = show, |
760 | .store = store, | |
761 | }; | |
762 | ||
763 | static struct kobj_type ktype_cpufreq = { | |
764 | .sysfs_ops = &sysfs_ops, | |
765 | .default_attrs = default_attrs, | |
766 | .release = cpufreq_sysfs_release, | |
767 | }; | |
768 | ||
4bfa042c TR |
769 | /* |
770 | * Returns: | |
771 | * Negative: Failure | |
772 | * 0: Success | |
773 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
774 | */ | |
cf3289d0 AC |
775 | static int cpufreq_add_dev_policy(unsigned int cpu, |
776 | struct cpufreq_policy *policy, | |
777 | struct sys_device *sys_dev) | |
ecf7e461 DJ |
778 | { |
779 | int ret = 0; | |
780 | #ifdef CONFIG_SMP | |
781 | unsigned long flags; | |
782 | unsigned int j; | |
ecf7e461 | 783 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
784 | struct cpufreq_governor *gov; |
785 | ||
786 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
787 | if (gov) { | |
788 | policy->governor = gov; | |
ecf7e461 DJ |
789 | dprintk("Restoring governor %s for cpu %d\n", |
790 | policy->governor->name, cpu); | |
791 | } | |
792 | #endif | |
793 | ||
794 | for_each_cpu(j, policy->cpus) { | |
795 | struct cpufreq_policy *managed_policy; | |
796 | ||
797 | if (cpu == j) | |
798 | continue; | |
799 | ||
800 | /* Check for existing affected CPUs. | |
801 | * They may not be aware of it due to CPU Hotplug. | |
802 | * cpufreq_cpu_put is called when the device is removed | |
803 | * in __cpufreq_remove_dev() | |
804 | */ | |
805 | managed_policy = cpufreq_cpu_get(j); | |
806 | if (unlikely(managed_policy)) { | |
807 | ||
808 | /* Set proper policy_cpu */ | |
809 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 810 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
811 | |
812 | if (lock_policy_rwsem_write(cpu) < 0) { | |
813 | /* Should not go through policy unlock path */ | |
814 | if (cpufreq_driver->exit) | |
815 | cpufreq_driver->exit(policy); | |
816 | cpufreq_cpu_put(managed_policy); | |
817 | return -EBUSY; | |
818 | } | |
819 | ||
820 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
821 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
822 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
823 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
824 | ||
825 | dprintk("CPU already managed, adding link\n"); | |
826 | ret = sysfs_create_link(&sys_dev->kobj, | |
827 | &managed_policy->kobj, | |
828 | "cpufreq"); | |
829 | if (ret) | |
830 | cpufreq_cpu_put(managed_policy); | |
831 | /* | |
832 | * Success. We only needed to be added to the mask. | |
833 | * Call driver->exit() because only the cpu parent of | |
834 | * the kobj needed to call init(). | |
835 | */ | |
836 | if (cpufreq_driver->exit) | |
837 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
838 | |
839 | if (!ret) | |
840 | return 1; | |
841 | else | |
842 | return ret; | |
ecf7e461 DJ |
843 | } |
844 | } | |
845 | #endif | |
846 | return ret; | |
847 | } | |
848 | ||
849 | ||
19d6f7ec | 850 | /* symlink affected CPUs */ |
cf3289d0 AC |
851 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
852 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
853 | { |
854 | unsigned int j; | |
855 | int ret = 0; | |
856 | ||
857 | for_each_cpu(j, policy->cpus) { | |
858 | struct cpufreq_policy *managed_policy; | |
859 | struct sys_device *cpu_sys_dev; | |
860 | ||
861 | if (j == cpu) | |
862 | continue; | |
863 | if (!cpu_online(j)) | |
864 | continue; | |
865 | ||
866 | dprintk("CPU %u already managed, adding link\n", j); | |
867 | managed_policy = cpufreq_cpu_get(cpu); | |
868 | cpu_sys_dev = get_cpu_sysdev(j); | |
869 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
870 | "cpufreq"); | |
871 | if (ret) { | |
872 | cpufreq_cpu_put(managed_policy); | |
873 | return ret; | |
874 | } | |
875 | } | |
876 | return ret; | |
877 | } | |
878 | ||
cf3289d0 AC |
879 | static int cpufreq_add_dev_interface(unsigned int cpu, |
880 | struct cpufreq_policy *policy, | |
881 | struct sys_device *sys_dev) | |
909a694e | 882 | { |
ecf7e461 | 883 | struct cpufreq_policy new_policy; |
909a694e DJ |
884 | struct freq_attr **drv_attr; |
885 | unsigned long flags; | |
886 | int ret = 0; | |
887 | unsigned int j; | |
888 | ||
889 | /* prepare interface data */ | |
890 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
891 | &sys_dev->kobj, "cpufreq"); | |
892 | if (ret) | |
893 | return ret; | |
894 | ||
895 | /* set up files for this cpu device */ | |
896 | drv_attr = cpufreq_driver->attr; | |
897 | while ((drv_attr) && (*drv_attr)) { | |
898 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
899 | if (ret) | |
900 | goto err_out_kobj_put; | |
901 | drv_attr++; | |
902 | } | |
903 | if (cpufreq_driver->get) { | |
904 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
905 | if (ret) | |
906 | goto err_out_kobj_put; | |
907 | } | |
908 | if (cpufreq_driver->target) { | |
909 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
910 | if (ret) | |
911 | goto err_out_kobj_put; | |
912 | } | |
e2f74f35 TR |
913 | if (cpufreq_driver->bios_limit) { |
914 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
915 | if (ret) | |
916 | goto err_out_kobj_put; | |
917 | } | |
909a694e DJ |
918 | |
919 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
920 | for_each_cpu(j, policy->cpus) { | |
921 | if (!cpu_online(j)) | |
922 | continue; | |
923 | per_cpu(cpufreq_cpu_data, j) = policy; | |
f1625066 | 924 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
925 | } |
926 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
927 | ||
928 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
929 | if (ret) |
930 | goto err_out_kobj_put; | |
931 | ||
932 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
933 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
934 | policy->governor = NULL; | |
935 | ||
936 | /* set default policy */ | |
937 | ret = __cpufreq_set_policy(policy, &new_policy); | |
938 | policy->user_policy.policy = policy->policy; | |
939 | policy->user_policy.governor = policy->governor; | |
940 | ||
941 | if (ret) { | |
942 | dprintk("setting policy failed\n"); | |
943 | if (cpufreq_driver->exit) | |
944 | cpufreq_driver->exit(policy); | |
945 | } | |
909a694e DJ |
946 | return ret; |
947 | ||
948 | err_out_kobj_put: | |
949 | kobject_put(&policy->kobj); | |
950 | wait_for_completion(&policy->kobj_unregister); | |
951 | return ret; | |
952 | } | |
953 | ||
1da177e4 LT |
954 | |
955 | /** | |
956 | * cpufreq_add_dev - add a CPU device | |
957 | * | |
32ee8c3e | 958 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
959 | * |
960 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
961 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
962 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 963 | */ |
905d77cd | 964 | static int cpufreq_add_dev(struct sys_device *sys_dev) |
1da177e4 LT |
965 | { |
966 | unsigned int cpu = sys_dev->id; | |
90e41bac | 967 | int ret = 0, found = 0; |
1da177e4 | 968 | struct cpufreq_policy *policy; |
1da177e4 LT |
969 | unsigned long flags; |
970 | unsigned int j; | |
90e41bac PB |
971 | #ifdef CONFIG_HOTPLUG_CPU |
972 | int sibling; | |
973 | #endif | |
1da177e4 | 974 | |
c32b6b8e AR |
975 | if (cpu_is_offline(cpu)) |
976 | return 0; | |
977 | ||
1da177e4 LT |
978 | cpufreq_debug_disable_ratelimit(); |
979 | dprintk("adding CPU %u\n", cpu); | |
980 | ||
981 | #ifdef CONFIG_SMP | |
982 | /* check whether a different CPU already registered this | |
983 | * CPU because it is in the same boat. */ | |
984 | policy = cpufreq_cpu_get(cpu); | |
985 | if (unlikely(policy)) { | |
8ff69732 | 986 | cpufreq_cpu_put(policy); |
1da177e4 LT |
987 | cpufreq_debug_enable_ratelimit(); |
988 | return 0; | |
989 | } | |
990 | #endif | |
991 | ||
992 | if (!try_module_get(cpufreq_driver->owner)) { | |
993 | ret = -EINVAL; | |
994 | goto module_out; | |
995 | } | |
996 | ||
059019a3 | 997 | ret = -ENOMEM; |
e98df50c | 998 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 999 | if (!policy) |
1da177e4 | 1000 | goto nomem_out; |
059019a3 DJ |
1001 | |
1002 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 1003 | goto err_free_policy; |
059019a3 DJ |
1004 | |
1005 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 1006 | goto err_free_cpumask; |
1da177e4 LT |
1007 | |
1008 | policy->cpu = cpu; | |
835481d9 | 1009 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1010 | |
5a01f2e8 | 1011 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 1012 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
1013 | ret = (lock_policy_rwsem_write(cpu) < 0); |
1014 | WARN_ON(ret); | |
5a01f2e8 | 1015 | |
1da177e4 | 1016 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1017 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 1018 | |
8122c6ce | 1019 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
1020 | #ifdef CONFIG_HOTPLUG_CPU |
1021 | for_each_online_cpu(sibling) { | |
1022 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
1023 | if (cp && cp->governor && | |
1024 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
1025 | policy->governor = cp->governor; | |
1026 | found = 1; | |
1027 | break; | |
1028 | } | |
1029 | } | |
1030 | #endif | |
1031 | if (!found) | |
1032 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
1033 | /* call driver. From then on the cpufreq must be able |
1034 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1035 | */ | |
1036 | ret = cpufreq_driver->init(policy); | |
1037 | if (ret) { | |
1038 | dprintk("initialization failed\n"); | |
3f4a782b | 1039 | goto err_unlock_policy; |
1da177e4 | 1040 | } |
187d9f4e MC |
1041 | policy->user_policy.min = policy->min; |
1042 | policy->user_policy.max = policy->max; | |
1da177e4 | 1043 | |
a1531acd TR |
1044 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1045 | CPUFREQ_START, policy); | |
1046 | ||
ecf7e461 | 1047 | ret = cpufreq_add_dev_policy(cpu, policy, sys_dev); |
4bfa042c TR |
1048 | if (ret) { |
1049 | if (ret > 0) | |
1050 | /* This is a managed cpu, symlink created, | |
1051 | exit with 0 */ | |
1052 | ret = 0; | |
ecf7e461 | 1053 | goto err_unlock_policy; |
4bfa042c | 1054 | } |
1da177e4 | 1055 | |
909a694e | 1056 | ret = cpufreq_add_dev_interface(cpu, policy, sys_dev); |
19d6f7ec DJ |
1057 | if (ret) |
1058 | goto err_out_unregister; | |
8ff69732 | 1059 | |
dca02613 LW |
1060 | unlock_policy_rwsem_write(cpu); |
1061 | ||
038c5b3e | 1062 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 1063 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
1064 | dprintk("initialization complete\n"); |
1065 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 1066 | |
1da177e4 LT |
1067 | return 0; |
1068 | ||
1069 | ||
1070 | err_out_unregister: | |
1071 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1072 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1073 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1074 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1075 | ||
c10997f6 | 1076 | kobject_put(&policy->kobj); |
1da177e4 LT |
1077 | wait_for_completion(&policy->kobj_unregister); |
1078 | ||
3f4a782b | 1079 | err_unlock_policy: |
45709118 | 1080 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 1081 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
1082 | err_free_cpumask: |
1083 | free_cpumask_var(policy->cpus); | |
1084 | err_free_policy: | |
1da177e4 | 1085 | kfree(policy); |
1da177e4 LT |
1086 | nomem_out: |
1087 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1088 | module_out: |
1da177e4 LT |
1089 | cpufreq_debug_enable_ratelimit(); |
1090 | return ret; | |
1091 | } | |
1092 | ||
1093 | ||
1094 | /** | |
5a01f2e8 | 1095 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1096 | * |
1097 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1098 | * Caller should already have policy_rwsem in write mode for this CPU. |
1099 | * This routine frees the rwsem before returning. | |
1da177e4 | 1100 | */ |
905d77cd | 1101 | static int __cpufreq_remove_dev(struct sys_device *sys_dev) |
1da177e4 LT |
1102 | { |
1103 | unsigned int cpu = sys_dev->id; | |
1104 | unsigned long flags; | |
1105 | struct cpufreq_policy *data; | |
499bca9b AW |
1106 | struct kobject *kobj; |
1107 | struct completion *cmp; | |
1da177e4 | 1108 | #ifdef CONFIG_SMP |
e738cf6d | 1109 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
1110 | unsigned int j; |
1111 | #endif | |
1112 | ||
1113 | cpufreq_debug_disable_ratelimit(); | |
1114 | dprintk("unregistering CPU %u\n", cpu); | |
1115 | ||
1116 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1117 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1118 | |
1119 | if (!data) { | |
1120 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 1121 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 1122 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1123 | return -EINVAL; |
1124 | } | |
7a6aedfa | 1125 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1126 | |
1127 | ||
1128 | #ifdef CONFIG_SMP | |
1129 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1130 | * only need to unlink, put and exit |
1da177e4 LT |
1131 | */ |
1132 | if (unlikely(cpu != data->cpu)) { | |
1133 | dprintk("removing link\n"); | |
835481d9 | 1134 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 | 1135 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
499bca9b | 1136 | kobj = &sys_dev->kobj; |
1da177e4 LT |
1137 | cpufreq_cpu_put(data); |
1138 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 1139 | unlock_policy_rwsem_write(cpu); |
499bca9b | 1140 | sysfs_remove_link(kobj, "cpufreq"); |
1da177e4 LT |
1141 | return 0; |
1142 | } | |
1143 | #endif | |
1144 | ||
1da177e4 | 1145 | #ifdef CONFIG_SMP |
084f3493 TR |
1146 | |
1147 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1148 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1149 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1150 | #endif |
1151 | ||
1da177e4 LT |
1152 | /* if we have other CPUs still registered, we need to unlink them, |
1153 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1154 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1155 | * the sysfs links afterwards. | |
1da177e4 | 1156 | */ |
835481d9 RR |
1157 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1158 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1159 | if (j == cpu) |
1160 | continue; | |
7a6aedfa | 1161 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1162 | } |
1163 | } | |
1164 | ||
1165 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1166 | ||
835481d9 RR |
1167 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1168 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1169 | if (j == cpu) |
1170 | continue; | |
1171 | dprintk("removing link for cpu %u\n", j); | |
084f3493 | 1172 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1173 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1174 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1175 | #endif |
d434fca7 | 1176 | cpu_sys_dev = get_cpu_sysdev(j); |
499bca9b AW |
1177 | kobj = &cpu_sys_dev->kobj; |
1178 | unlock_policy_rwsem_write(cpu); | |
1179 | sysfs_remove_link(kobj, "cpufreq"); | |
1180 | lock_policy_rwsem_write(cpu); | |
1da177e4 LT |
1181 | cpufreq_cpu_put(data); |
1182 | } | |
1183 | } | |
1184 | #else | |
1185 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1186 | #endif | |
1187 | ||
1da177e4 LT |
1188 | if (cpufreq_driver->target) |
1189 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1190 | |
499bca9b AW |
1191 | kobj = &data->kobj; |
1192 | cmp = &data->kobj_unregister; | |
1193 | unlock_policy_rwsem_write(cpu); | |
1194 | kobject_put(kobj); | |
1da177e4 LT |
1195 | |
1196 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1197 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1198 | * unloading. |
1199 | */ | |
1200 | dprintk("waiting for dropping of refcount\n"); | |
499bca9b | 1201 | wait_for_completion(cmp); |
1da177e4 LT |
1202 | dprintk("wait complete\n"); |
1203 | ||
499bca9b | 1204 | lock_policy_rwsem_write(cpu); |
1da177e4 LT |
1205 | if (cpufreq_driver->exit) |
1206 | cpufreq_driver->exit(data); | |
7d26e2d5 | 1207 | unlock_policy_rwsem_write(cpu); |
1208 | ||
835481d9 RR |
1209 | free_cpumask_var(data->related_cpus); |
1210 | free_cpumask_var(data->cpus); | |
1da177e4 | 1211 | kfree(data); |
835481d9 | 1212 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1213 | |
1214 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1215 | return 0; |
1216 | } | |
1217 | ||
1218 | ||
905d77cd | 1219 | static int cpufreq_remove_dev(struct sys_device *sys_dev) |
5a01f2e8 VP |
1220 | { |
1221 | unsigned int cpu = sys_dev->id; | |
1222 | int retval; | |
ec28297a VP |
1223 | |
1224 | if (cpu_is_offline(cpu)) | |
1225 | return 0; | |
1226 | ||
5a01f2e8 VP |
1227 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1228 | BUG(); | |
1229 | ||
1230 | retval = __cpufreq_remove_dev(sys_dev); | |
1231 | return retval; | |
1232 | } | |
1233 | ||
1234 | ||
65f27f38 | 1235 | static void handle_update(struct work_struct *work) |
1da177e4 | 1236 | { |
65f27f38 DH |
1237 | struct cpufreq_policy *policy = |
1238 | container_of(work, struct cpufreq_policy, update); | |
1239 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1240 | dprintk("handle_update for cpu %u called\n", cpu); |
1241 | cpufreq_update_policy(cpu); | |
1242 | } | |
1243 | ||
1244 | /** | |
1245 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1246 | * @cpu: cpu number | |
1247 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1248 | * @new_freq: CPU frequency the CPU actually runs at | |
1249 | * | |
29464f28 DJ |
1250 | * We adjust to current frequency first, and need to clean up later. |
1251 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1252 | */ |
e08f5f5b GS |
1253 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1254 | unsigned int new_freq) | |
1da177e4 LT |
1255 | { |
1256 | struct cpufreq_freqs freqs; | |
1257 | ||
b10eec22 | 1258 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1259 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1260 | ||
1261 | freqs.cpu = cpu; | |
1262 | freqs.old = old_freq; | |
1263 | freqs.new = new_freq; | |
1264 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1265 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1266 | } | |
1267 | ||
1268 | ||
32ee8c3e | 1269 | /** |
4ab70df4 | 1270 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1271 | * @cpu: CPU number |
1272 | * | |
1273 | * This is the last known freq, without actually getting it from the driver. | |
1274 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1275 | */ | |
1276 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1277 | { | |
1278 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1279 | unsigned int ret_freq = 0; |
95235ca2 VP |
1280 | |
1281 | if (policy) { | |
e08f5f5b | 1282 | ret_freq = policy->cur; |
95235ca2 VP |
1283 | cpufreq_cpu_put(policy); |
1284 | } | |
1285 | ||
4d34a67d | 1286 | return ret_freq; |
95235ca2 VP |
1287 | } |
1288 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1289 | ||
1290 | ||
5a01f2e8 | 1291 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1292 | { |
7a6aedfa | 1293 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1294 | unsigned int ret_freq = 0; |
1da177e4 | 1295 | |
1da177e4 | 1296 | if (!cpufreq_driver->get) |
4d34a67d | 1297 | return ret_freq; |
1da177e4 | 1298 | |
e08f5f5b | 1299 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1300 | |
e08f5f5b GS |
1301 | if (ret_freq && policy->cur && |
1302 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1303 | /* verify no discrepancy between actual and | |
1304 | saved value exists */ | |
1305 | if (unlikely(ret_freq != policy->cur)) { | |
1306 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1307 | schedule_work(&policy->update); |
1308 | } | |
1309 | } | |
1310 | ||
4d34a67d | 1311 | return ret_freq; |
5a01f2e8 | 1312 | } |
1da177e4 | 1313 | |
5a01f2e8 VP |
1314 | /** |
1315 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1316 | * @cpu: CPU number | |
1317 | * | |
1318 | * Get the CPU current (static) CPU frequency | |
1319 | */ | |
1320 | unsigned int cpufreq_get(unsigned int cpu) | |
1321 | { | |
1322 | unsigned int ret_freq = 0; | |
1323 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1324 | ||
1325 | if (!policy) | |
1326 | goto out; | |
1327 | ||
1328 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1329 | goto out_policy; | |
1330 | ||
1331 | ret_freq = __cpufreq_get(cpu); | |
1332 | ||
1333 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1334 | |
5a01f2e8 VP |
1335 | out_policy: |
1336 | cpufreq_cpu_put(policy); | |
1337 | out: | |
4d34a67d | 1338 | return ret_freq; |
1da177e4 LT |
1339 | } |
1340 | EXPORT_SYMBOL(cpufreq_get); | |
1341 | ||
1342 | ||
42d4dc3f BH |
1343 | /** |
1344 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1345 | */ | |
1346 | ||
905d77cd | 1347 | static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg) |
42d4dc3f | 1348 | { |
e08f5f5b | 1349 | int ret = 0; |
4bc5d341 | 1350 | |
4bc5d341 | 1351 | int cpu = sysdev->id; |
42d4dc3f BH |
1352 | struct cpufreq_policy *cpu_policy; |
1353 | ||
0e37b159 | 1354 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1355 | |
1356 | if (!cpu_online(cpu)) | |
1357 | return 0; | |
1358 | ||
1359 | /* we may be lax here as interrupts are off. Nonetheless | |
1360 | * we need to grab the correct cpu policy, as to check | |
1361 | * whether we really run on this CPU. | |
1362 | */ | |
1363 | ||
1364 | cpu_policy = cpufreq_cpu_get(cpu); | |
1365 | if (!cpu_policy) | |
1366 | return -EINVAL; | |
1367 | ||
1368 | /* only handle each CPU group once */ | |
c9060494 DJ |
1369 | if (unlikely(cpu_policy->cpu != cpu)) |
1370 | goto out; | |
42d4dc3f BH |
1371 | |
1372 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1373 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
ce6c3997 | 1374 | if (ret) |
42d4dc3f BH |
1375 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1376 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1377 | } |
1378 | ||
7d5e350f | 1379 | out: |
42d4dc3f | 1380 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1381 | return ret; |
42d4dc3f BH |
1382 | } |
1383 | ||
1da177e4 LT |
1384 | /** |
1385 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1386 | * | |
1387 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1388 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1389 | * restored. It will verify that the current freq is in sync with | |
1390 | * what we believe it to be. This is a bit later than when it | |
1391 | * should be, but nonethteless it's better than calling | |
1392 | * cpufreq_driver->get() here which might re-enable interrupts... | |
1da177e4 | 1393 | */ |
905d77cd | 1394 | static int cpufreq_resume(struct sys_device *sysdev) |
1da177e4 | 1395 | { |
e08f5f5b | 1396 | int ret = 0; |
4bc5d341 | 1397 | |
4bc5d341 | 1398 | int cpu = sysdev->id; |
1da177e4 LT |
1399 | struct cpufreq_policy *cpu_policy; |
1400 | ||
1401 | dprintk("resuming cpu %u\n", cpu); | |
1402 | ||
1403 | if (!cpu_online(cpu)) | |
1404 | return 0; | |
1405 | ||
1406 | /* we may be lax here as interrupts are off. Nonetheless | |
1407 | * we need to grab the correct cpu policy, as to check | |
1408 | * whether we really run on this CPU. | |
1409 | */ | |
1410 | ||
1411 | cpu_policy = cpufreq_cpu_get(cpu); | |
1412 | if (!cpu_policy) | |
1413 | return -EINVAL; | |
1414 | ||
1415 | /* only handle each CPU group once */ | |
c9060494 DJ |
1416 | if (unlikely(cpu_policy->cpu != cpu)) |
1417 | goto fail; | |
1da177e4 LT |
1418 | |
1419 | if (cpufreq_driver->resume) { | |
1420 | ret = cpufreq_driver->resume(cpu_policy); | |
1421 | if (ret) { | |
1422 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1423 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1424 | goto fail; |
1da177e4 LT |
1425 | } |
1426 | } | |
1427 | ||
1da177e4 | 1428 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1429 | |
c9060494 | 1430 | fail: |
1da177e4 LT |
1431 | cpufreq_cpu_put(cpu_policy); |
1432 | return ret; | |
1433 | } | |
1434 | ||
1435 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1436 | .add = cpufreq_add_dev, | |
1437 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1438 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1439 | .resume = cpufreq_resume, |
1440 | }; | |
1441 | ||
1442 | ||
1443 | /********************************************************************* | |
1444 | * NOTIFIER LISTS INTERFACE * | |
1445 | *********************************************************************/ | |
1446 | ||
1447 | /** | |
1448 | * cpufreq_register_notifier - register a driver with cpufreq | |
1449 | * @nb: notifier function to register | |
1450 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1451 | * | |
32ee8c3e | 1452 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1453 | * are notified about clock rate changes (once before and once after |
1454 | * the transition), or a list of drivers that are notified about | |
1455 | * changes in cpufreq policy. | |
1456 | * | |
1457 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1458 | * blocking_notifier_chain_register. |
1da177e4 LT |
1459 | */ |
1460 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1461 | { | |
1462 | int ret; | |
1463 | ||
74212ca4 CEB |
1464 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1465 | ||
1da177e4 LT |
1466 | switch (list) { |
1467 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1468 | ret = srcu_notifier_chain_register( |
e041c683 | 1469 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1470 | break; |
1471 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1472 | ret = blocking_notifier_chain_register( |
1473 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1474 | break; |
1475 | default: | |
1476 | ret = -EINVAL; | |
1477 | } | |
1da177e4 LT |
1478 | |
1479 | return ret; | |
1480 | } | |
1481 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1482 | ||
1483 | ||
1484 | /** | |
1485 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1486 | * @nb: notifier block to be unregistered | |
1487 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1488 | * | |
1489 | * Remove a driver from the CPU frequency notifier list. | |
1490 | * | |
1491 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1492 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1493 | */ |
1494 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1495 | { | |
1496 | int ret; | |
1497 | ||
1da177e4 LT |
1498 | switch (list) { |
1499 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1500 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1501 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1502 | break; |
1503 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1504 | ret = blocking_notifier_chain_unregister( |
1505 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1506 | break; |
1507 | default: | |
1508 | ret = -EINVAL; | |
1509 | } | |
1da177e4 LT |
1510 | |
1511 | return ret; | |
1512 | } | |
1513 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1514 | ||
1515 | ||
1516 | /********************************************************************* | |
1517 | * GOVERNORS * | |
1518 | *********************************************************************/ | |
1519 | ||
1520 | ||
1521 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1522 | unsigned int target_freq, | |
1523 | unsigned int relation) | |
1524 | { | |
1525 | int retval = -EINVAL; | |
c32b6b8e | 1526 | |
1da177e4 LT |
1527 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1528 | target_freq, relation); | |
1529 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1530 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1531 | |
1da177e4 LT |
1532 | return retval; |
1533 | } | |
1534 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1535 | ||
1da177e4 LT |
1536 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1537 | unsigned int target_freq, | |
1538 | unsigned int relation) | |
1539 | { | |
f1829e4a | 1540 | int ret = -EINVAL; |
1da177e4 LT |
1541 | |
1542 | policy = cpufreq_cpu_get(policy->cpu); | |
1543 | if (!policy) | |
f1829e4a | 1544 | goto no_policy; |
1da177e4 | 1545 | |
5a01f2e8 | 1546 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1547 | goto fail; |
1da177e4 LT |
1548 | |
1549 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1550 | ||
5a01f2e8 | 1551 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1552 | |
f1829e4a | 1553 | fail: |
1da177e4 | 1554 | cpufreq_cpu_put(policy); |
f1829e4a | 1555 | no_policy: |
1da177e4 LT |
1556 | return ret; |
1557 | } | |
1558 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1559 | ||
bf0b90e3 | 1560 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1561 | { |
1562 | int ret = 0; | |
1563 | ||
1564 | policy = cpufreq_cpu_get(policy->cpu); | |
1565 | if (!policy) | |
1566 | return -EINVAL; | |
1567 | ||
bf0b90e3 | 1568 | if (cpu_online(cpu) && cpufreq_driver->getavg) |
1569 | ret = cpufreq_driver->getavg(policy, cpu); | |
dfde5d62 | 1570 | |
dfde5d62 VP |
1571 | cpufreq_cpu_put(policy); |
1572 | return ret; | |
1573 | } | |
5a01f2e8 | 1574 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1575 | |
153d7f3f | 1576 | /* |
153d7f3f AV |
1577 | * when "event" is CPUFREQ_GOV_LIMITS |
1578 | */ | |
1da177e4 | 1579 | |
e08f5f5b GS |
1580 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1581 | unsigned int event) | |
1da177e4 | 1582 | { |
cc993cab | 1583 | int ret; |
6afde10c TR |
1584 | |
1585 | /* Only must be defined when default governor is known to have latency | |
1586 | restrictions, like e.g. conservative or ondemand. | |
1587 | That this is the case is already ensured in Kconfig | |
1588 | */ | |
1589 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1590 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1591 | #else | |
1592 | struct cpufreq_governor *gov = NULL; | |
1593 | #endif | |
1c256245 TR |
1594 | |
1595 | if (policy->governor->max_transition_latency && | |
1596 | policy->cpuinfo.transition_latency > | |
1597 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1598 | if (!gov) |
1599 | return -EINVAL; | |
1600 | else { | |
1601 | printk(KERN_WARNING "%s governor failed, too long" | |
1602 | " transition latency of HW, fallback" | |
1603 | " to %s governor\n", | |
1604 | policy->governor->name, | |
1605 | gov->name); | |
1606 | policy->governor = gov; | |
1607 | } | |
1c256245 | 1608 | } |
1da177e4 LT |
1609 | |
1610 | if (!try_module_get(policy->governor->owner)) | |
1611 | return -EINVAL; | |
1612 | ||
e08f5f5b GS |
1613 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1614 | policy->cpu, event); | |
1da177e4 LT |
1615 | ret = policy->governor->governor(policy, event); |
1616 | ||
e08f5f5b GS |
1617 | /* we keep one module reference alive for |
1618 | each CPU governed by this CPU */ | |
1da177e4 LT |
1619 | if ((event != CPUFREQ_GOV_START) || ret) |
1620 | module_put(policy->governor->owner); | |
1621 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1622 | module_put(policy->governor->owner); | |
1623 | ||
1624 | return ret; | |
1625 | } | |
1626 | ||
1627 | ||
1da177e4 LT |
1628 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1629 | { | |
3bcb09a3 | 1630 | int err; |
1da177e4 LT |
1631 | |
1632 | if (!governor) | |
1633 | return -EINVAL; | |
1634 | ||
3fc54d37 | 1635 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1636 | |
3bcb09a3 JF |
1637 | err = -EBUSY; |
1638 | if (__find_governor(governor->name) == NULL) { | |
1639 | err = 0; | |
1640 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1641 | } |
1da177e4 | 1642 | |
32ee8c3e | 1643 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1644 | return err; |
1da177e4 LT |
1645 | } |
1646 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1647 | ||
1648 | ||
1649 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1650 | { | |
90e41bac PB |
1651 | #ifdef CONFIG_HOTPLUG_CPU |
1652 | int cpu; | |
1653 | #endif | |
1654 | ||
1da177e4 LT |
1655 | if (!governor) |
1656 | return; | |
1657 | ||
90e41bac PB |
1658 | #ifdef CONFIG_HOTPLUG_CPU |
1659 | for_each_present_cpu(cpu) { | |
1660 | if (cpu_online(cpu)) | |
1661 | continue; | |
1662 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1663 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1664 | } | |
1665 | #endif | |
1666 | ||
3fc54d37 | 1667 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1668 | list_del(&governor->governor_list); |
3fc54d37 | 1669 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1670 | return; |
1671 | } | |
1672 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1673 | ||
1674 | ||
1675 | ||
1676 | /********************************************************************* | |
1677 | * POLICY INTERFACE * | |
1678 | *********************************************************************/ | |
1679 | ||
1680 | /** | |
1681 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1682 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1683 | * is written | |
1da177e4 LT |
1684 | * |
1685 | * Reads the current cpufreq policy. | |
1686 | */ | |
1687 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1688 | { | |
1689 | struct cpufreq_policy *cpu_policy; | |
1690 | if (!policy) | |
1691 | return -EINVAL; | |
1692 | ||
1693 | cpu_policy = cpufreq_cpu_get(cpu); | |
1694 | if (!cpu_policy) | |
1695 | return -EINVAL; | |
1696 | ||
1da177e4 | 1697 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1698 | |
1699 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1700 | return 0; |
1701 | } | |
1702 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1703 | ||
1704 | ||
153d7f3f | 1705 | /* |
e08f5f5b GS |
1706 | * data : current policy. |
1707 | * policy : policy to be set. | |
153d7f3f | 1708 | */ |
e08f5f5b GS |
1709 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1710 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1711 | { |
1712 | int ret = 0; | |
1713 | ||
1714 | cpufreq_debug_disable_ratelimit(); | |
1715 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1716 | policy->min, policy->max); | |
1717 | ||
e08f5f5b GS |
1718 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1719 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1720 | |
53391fa2 | 1721 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1722 | ret = -EINVAL; |
1723 | goto error_out; | |
1724 | } | |
1725 | ||
1da177e4 LT |
1726 | /* verify the cpu speed can be set within this limit */ |
1727 | ret = cpufreq_driver->verify(policy); | |
1728 | if (ret) | |
1729 | goto error_out; | |
1730 | ||
1da177e4 | 1731 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1732 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1733 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1734 | |
1735 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1736 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1737 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1738 | |
1739 | /* verify the cpu speed can be set within this limit, | |
1740 | which might be different to the first one */ | |
1741 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1742 | if (ret) |
1da177e4 | 1743 | goto error_out; |
1da177e4 LT |
1744 | |
1745 | /* notification of the new policy */ | |
e041c683 AS |
1746 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1747 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1748 | |
7d5e350f DJ |
1749 | data->min = policy->min; |
1750 | data->max = policy->max; | |
1da177e4 | 1751 | |
e08f5f5b GS |
1752 | dprintk("new min and max freqs are %u - %u kHz\n", |
1753 | data->min, data->max); | |
1da177e4 LT |
1754 | |
1755 | if (cpufreq_driver->setpolicy) { | |
1756 | data->policy = policy->policy; | |
1757 | dprintk("setting range\n"); | |
1758 | ret = cpufreq_driver->setpolicy(policy); | |
1759 | } else { | |
1760 | if (policy->governor != data->governor) { | |
1761 | /* save old, working values */ | |
1762 | struct cpufreq_governor *old_gov = data->governor; | |
1763 | ||
1764 | dprintk("governor switch\n"); | |
1765 | ||
1766 | /* end old governor */ | |
ffe6275f | 1767 | if (data->governor) |
1da177e4 LT |
1768 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1769 | ||
1770 | /* start new governor */ | |
1771 | data->governor = policy->governor; | |
1772 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1773 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1774 | dprintk("starting governor %s failed\n", |
1775 | data->governor->name); | |
1da177e4 LT |
1776 | if (old_gov) { |
1777 | data->governor = old_gov; | |
e08f5f5b GS |
1778 | __cpufreq_governor(data, |
1779 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1780 | } |
1781 | ret = -EINVAL; | |
1782 | goto error_out; | |
1783 | } | |
1784 | /* might be a policy change, too, so fall through */ | |
1785 | } | |
1786 | dprintk("governor: change or update limits\n"); | |
1787 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1788 | } | |
1789 | ||
7d5e350f | 1790 | error_out: |
1da177e4 LT |
1791 | cpufreq_debug_enable_ratelimit(); |
1792 | return ret; | |
1793 | } | |
1794 | ||
1da177e4 LT |
1795 | /** |
1796 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1797 | * @cpu: CPU which shall be re-evaluated | |
1798 | * | |
1799 | * Usefull for policy notifiers which have different necessities | |
1800 | * at different times. | |
1801 | */ | |
1802 | int cpufreq_update_policy(unsigned int cpu) | |
1803 | { | |
1804 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1805 | struct cpufreq_policy policy; | |
f1829e4a | 1806 | int ret; |
1da177e4 | 1807 | |
f1829e4a JL |
1808 | if (!data) { |
1809 | ret = -ENODEV; | |
1810 | goto no_policy; | |
1811 | } | |
1da177e4 | 1812 | |
f1829e4a JL |
1813 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1814 | ret = -EINVAL; | |
1815 | goto fail; | |
1816 | } | |
1da177e4 LT |
1817 | |
1818 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1819 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1820 | policy.min = data->user_policy.min; |
1821 | policy.max = data->user_policy.max; | |
1822 | policy.policy = data->user_policy.policy; | |
1823 | policy.governor = data->user_policy.governor; | |
1824 | ||
0961dd0d TR |
1825 | /* BIOS might change freq behind our back |
1826 | -> ask driver for current freq and notify governors about a change */ | |
1827 | if (cpufreq_driver->get) { | |
1828 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1829 | if (!data->cur) { |
1830 | dprintk("Driver did not initialize current freq"); | |
1831 | data->cur = policy.cur; | |
1832 | } else { | |
1833 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1834 | cpufreq_out_of_sync(cpu, data->cur, |
1835 | policy.cur); | |
a85f7bd3 | 1836 | } |
0961dd0d TR |
1837 | } |
1838 | ||
1da177e4 LT |
1839 | ret = __cpufreq_set_policy(data, &policy); |
1840 | ||
5a01f2e8 VP |
1841 | unlock_policy_rwsem_write(cpu); |
1842 | ||
f1829e4a | 1843 | fail: |
1da177e4 | 1844 | cpufreq_cpu_put(data); |
f1829e4a | 1845 | no_policy: |
1da177e4 LT |
1846 | return ret; |
1847 | } | |
1848 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1849 | ||
dd184a01 | 1850 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1851 | unsigned long action, void *hcpu) |
1852 | { | |
1853 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1854 | struct sys_device *sys_dev; |
1855 | ||
1856 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1857 | if (sys_dev) { |
1858 | switch (action) { | |
1859 | case CPU_ONLINE: | |
8bb78442 | 1860 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1861 | cpufreq_add_dev(sys_dev); |
1862 | break; | |
1863 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1864 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1865 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1866 | BUG(); | |
1867 | ||
5a01f2e8 | 1868 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1869 | break; |
5a01f2e8 | 1870 | case CPU_DOWN_FAILED: |
8bb78442 | 1871 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1872 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1873 | break; |
1874 | } | |
1875 | } | |
1876 | return NOTIFY_OK; | |
1877 | } | |
1878 | ||
9c36f746 | 1879 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1880 | .notifier_call = cpufreq_cpu_callback, |
1881 | }; | |
1da177e4 LT |
1882 | |
1883 | /********************************************************************* | |
1884 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1885 | *********************************************************************/ | |
1886 | ||
1887 | /** | |
1888 | * cpufreq_register_driver - register a CPU Frequency driver | |
1889 | * @driver_data: A struct cpufreq_driver containing the values# | |
1890 | * submitted by the CPU Frequency driver. | |
1891 | * | |
32ee8c3e | 1892 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1893 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1894 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1895 | * |
1896 | */ | |
221dee28 | 1897 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1898 | { |
1899 | unsigned long flags; | |
1900 | int ret; | |
1901 | ||
1902 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1903 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1904 | return -EINVAL; | |
1905 | ||
1906 | dprintk("trying to register driver %s\n", driver_data->name); | |
1907 | ||
1908 | if (driver_data->setpolicy) | |
1909 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1910 | ||
1911 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1912 | if (cpufreq_driver) { | |
1913 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1914 | return -EBUSY; | |
1915 | } | |
1916 | cpufreq_driver = driver_data; | |
1917 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1918 | ||
7a6aedfa MT |
1919 | ret = sysdev_driver_register(&cpu_sysdev_class, |
1920 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1921 | |
1922 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1923 | int i; | |
1924 | ret = -ENODEV; | |
1925 | ||
1926 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1927 | for (i = 0; i < nr_cpu_ids; i++) |
1928 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1929 | ret = 0; |
7a6aedfa MT |
1930 | break; |
1931 | } | |
1da177e4 LT |
1932 | |
1933 | /* if all ->init() calls failed, unregister */ | |
1934 | if (ret) { | |
e08f5f5b GS |
1935 | dprintk("no CPU initialized for driver %s\n", |
1936 | driver_data->name); | |
1937 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1938 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1939 | |
1940 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1941 | cpufreq_driver = NULL; | |
1942 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1943 | } | |
1944 | } | |
1945 | ||
1946 | if (!ret) { | |
65edc68c | 1947 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1948 | dprintk("driver %s up and running\n", driver_data->name); |
1949 | cpufreq_debug_enable_ratelimit(); | |
1950 | } | |
1951 | ||
4d34a67d | 1952 | return ret; |
1da177e4 LT |
1953 | } |
1954 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1955 | ||
1956 | ||
1957 | /** | |
1958 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1959 | * | |
32ee8c3e | 1960 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1961 | * the right to do so, i.e. if you have succeeded in initialising before! |
1962 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1963 | * currently not initialised. | |
1964 | */ | |
221dee28 | 1965 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1966 | { |
1967 | unsigned long flags; | |
1968 | ||
1969 | cpufreq_debug_disable_ratelimit(); | |
1970 | ||
1971 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1972 | cpufreq_debug_enable_ratelimit(); | |
1973 | return -EINVAL; | |
1974 | } | |
1975 | ||
1976 | dprintk("unregistering driver %s\n", driver->name); | |
1977 | ||
1978 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1979 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1980 | |
1981 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1982 | cpufreq_driver = NULL; | |
1983 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1984 | ||
1985 | return 0; | |
1986 | } | |
1987 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1988 | |
1989 | static int __init cpufreq_core_init(void) | |
1990 | { | |
1991 | int cpu; | |
1992 | ||
1993 | for_each_possible_cpu(cpu) { | |
f1625066 | 1994 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1995 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1996 | } | |
8aa84ad8 TR |
1997 | |
1998 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", | |
1999 | &cpu_sysdev_class.kset.kobj); | |
2000 | BUG_ON(!cpufreq_global_kobject); | |
2001 | ||
5a01f2e8 VP |
2002 | return 0; |
2003 | } | |
5a01f2e8 | 2004 | core_initcall(cpufreq_core_init); |