Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
6 | * | |
c32b6b8e | 7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 8 | * Added handling for CPU hotplug |
8ff69732 DJ |
9 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
10 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 11 | * |
1da177e4 LT |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
1da177e4 LT |
18 | #include <linux/kernel.h> |
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/notifier.h> | |
22 | #include <linux/cpufreq.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <linux/device.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/cpu.h> | |
29 | #include <linux/completion.h> | |
3fc54d37 | 30 | #include <linux/mutex.h> |
e00e56df | 31 | #include <linux/syscore_ops.h> |
1da177e4 | 32 | |
6f4f2723 TR |
33 | #include <trace/events/power.h> |
34 | ||
e08f5f5b GS |
35 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \ |
36 | "cpufreq-core", msg) | |
1da177e4 LT |
37 | |
38 | /** | |
cd878479 | 39 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
40 | * level driver of CPUFreq support, and its spinlock. This lock |
41 | * also protects the cpufreq_cpu_data array. | |
42 | */ | |
7d5e350f | 43 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 44 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
084f3493 TR |
45 | #ifdef CONFIG_HOTPLUG_CPU |
46 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 47 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 48 | #endif |
1da177e4 LT |
49 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
50 | ||
5a01f2e8 VP |
51 | /* |
52 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
53 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
54 | * | |
55 | * The rules for this semaphore: | |
56 | * - Any routine that wants to read from the policy structure will | |
57 | * do a down_read on this semaphore. | |
58 | * - Any routine that will write to the policy structure and/or may take away | |
59 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
60 | * mode before doing so. | |
61 | * | |
62 | * Additional rules: | |
63 | * - All holders of the lock should check to make sure that the CPU they | |
64 | * are concerned with are online after they get the lock. | |
65 | * - Governor routines that can be called in cpufreq hotplug path should not | |
66 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
67 | * - Lock should not be held across |
68 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 69 | */ |
f1625066 | 70 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
71 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
72 | ||
73 | #define lock_policy_rwsem(mode, cpu) \ | |
226528c6 | 74 | static int lock_policy_rwsem_##mode \ |
5a01f2e8 VP |
75 | (int cpu) \ |
76 | { \ | |
f1625066 | 77 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
78 | BUG_ON(policy_cpu == -1); \ |
79 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
80 | if (unlikely(!cpu_online(cpu))) { \ | |
81 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
82 | return -1; \ | |
83 | } \ | |
84 | \ | |
85 | return 0; \ | |
86 | } | |
87 | ||
88 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 VP |
89 | |
90 | lock_policy_rwsem(write, cpu); | |
5a01f2e8 | 91 | |
226528c6 | 92 | static void unlock_policy_rwsem_read(int cpu) |
5a01f2e8 | 93 | { |
f1625066 | 94 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
95 | BUG_ON(policy_cpu == -1); |
96 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
97 | } | |
5a01f2e8 | 98 | |
226528c6 | 99 | static void unlock_policy_rwsem_write(int cpu) |
5a01f2e8 | 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 | } | |
5a01f2e8 VP |
105 | |
106 | ||
1da177e4 | 107 | /* internal prototypes */ |
29464f28 DJ |
108 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
109 | unsigned int event); | |
5a01f2e8 | 110 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 111 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
112 | |
113 | /** | |
32ee8c3e DJ |
114 | * Two notifier lists: the "policy" list is involved in the |
115 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
116 | * "transition" list for kernel code that needs to handle |
117 | * changes to devices when the CPU clock speed changes. | |
118 | * The mutex locks both lists. | |
119 | */ | |
e041c683 | 120 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 121 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 122 | |
74212ca4 | 123 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
124 | static int __init init_cpufreq_transition_notifier_list(void) |
125 | { | |
126 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 127 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
128 | return 0; |
129 | } | |
b3438f82 | 130 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
131 | |
132 | static LIST_HEAD(cpufreq_governor_list); | |
29464f28 | 133 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 134 | |
7d5e350f | 135 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
136 | { |
137 | struct cpufreq_policy *data; | |
138 | unsigned long flags; | |
139 | ||
7a6aedfa | 140 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
141 | goto err_out; |
142 | ||
143 | /* get the cpufreq driver */ | |
144 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
145 | ||
146 | if (!cpufreq_driver) | |
147 | goto err_out_unlock; | |
148 | ||
149 | if (!try_module_get(cpufreq_driver->owner)) | |
150 | goto err_out_unlock; | |
151 | ||
152 | ||
153 | /* get the CPU */ | |
7a6aedfa | 154 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
155 | |
156 | if (!data) | |
157 | goto err_out_put_module; | |
158 | ||
159 | if (!kobject_get(&data->kobj)) | |
160 | goto err_out_put_module; | |
161 | ||
1da177e4 | 162 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
163 | return data; |
164 | ||
7d5e350f | 165 | err_out_put_module: |
1da177e4 | 166 | module_put(cpufreq_driver->owner); |
7d5e350f | 167 | err_out_unlock: |
1da177e4 | 168 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 169 | err_out: |
1da177e4 LT |
170 | return NULL; |
171 | } | |
172 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
173 | ||
7d5e350f | 174 | |
1da177e4 LT |
175 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
176 | { | |
177 | kobject_put(&data->kobj); | |
178 | module_put(cpufreq_driver->owner); | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
181 | ||
182 | ||
183 | /********************************************************************* | |
184 | * UNIFIED DEBUG HELPERS * | |
185 | *********************************************************************/ | |
186 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
187 | ||
188 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
189 | static unsigned int debug; | |
190 | ||
191 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
192 | * set or modify this value. | |
193 | */ | |
194 | static unsigned int debug_ratelimit = 1; | |
195 | ||
196 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
197 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
198 | * is set, and disabled upon cpufreq driver removal | |
199 | */ | |
200 | static unsigned int disable_ratelimit = 1; | |
201 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
202 | ||
858119e1 | 203 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
204 | { |
205 | unsigned long flags; | |
206 | ||
207 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
208 | if (disable_ratelimit) | |
209 | disable_ratelimit--; | |
210 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
211 | } | |
212 | ||
858119e1 | 213 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
214 | { |
215 | unsigned long flags; | |
216 | ||
217 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
218 | disable_ratelimit++; | |
219 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
220 | } | |
221 | ||
e08f5f5b | 222 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
905d77cd | 223 | const char *fmt, ...) |
1da177e4 LT |
224 | { |
225 | char s[256]; | |
226 | va_list args; | |
227 | unsigned int len; | |
228 | unsigned long flags; | |
32ee8c3e | 229 | |
1da177e4 LT |
230 | WARN_ON(!prefix); |
231 | if (type & debug) { | |
232 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
233 | if (!disable_ratelimit && debug_ratelimit |
234 | && !printk_ratelimit()) { | |
1da177e4 LT |
235 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
236 | return; | |
237 | } | |
238 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
239 | ||
240 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
241 | ||
242 | va_start(args, fmt); | |
243 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
244 | va_end(args); | |
245 | ||
246 | printk(s); | |
247 | ||
248 | WARN_ON(len < 5); | |
249 | } | |
250 | } | |
251 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
252 | ||
253 | ||
254 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
255 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
256 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
257 | |
258 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
259 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
260 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
261 | |
262 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
263 | ||
264 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
265 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
266 | ||
267 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
268 | ||
269 | ||
270 | /********************************************************************* | |
271 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
272 | *********************************************************************/ | |
273 | ||
274 | /** | |
275 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
276 | * | |
277 | * This function alters the system "loops_per_jiffy" for the clock | |
278 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 279 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
280 | * per-CPU loops_per_jiffy value wherever possible. |
281 | */ | |
282 | #ifndef CONFIG_SMP | |
283 | static unsigned long l_p_j_ref; | |
284 | static unsigned int l_p_j_ref_freq; | |
285 | ||
858119e1 | 286 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
287 | { |
288 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
289 | return; | |
290 | ||
291 | if (!l_p_j_ref_freq) { | |
292 | l_p_j_ref = loops_per_jiffy; | |
293 | l_p_j_ref_freq = ci->old; | |
a4a9df58 | 294 | dprintk("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 295 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 LT |
296 | } |
297 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
298 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 299 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
300 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
301 | ci->new); | |
a4a9df58 | 302 | dprintk("scaling loops_per_jiffy to %lu " |
e08f5f5b | 303 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
304 | } |
305 | } | |
306 | #else | |
e08f5f5b GS |
307 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
308 | { | |
309 | return; | |
310 | } | |
1da177e4 LT |
311 | #endif |
312 | ||
313 | ||
314 | /** | |
e4472cb3 DJ |
315 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
316 | * on frequency transition. | |
1da177e4 | 317 | * |
e4472cb3 DJ |
318 | * This function calls the transition notifiers and the "adjust_jiffies" |
319 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 320 | * external effects. |
1da177e4 LT |
321 | */ |
322 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
323 | { | |
e4472cb3 DJ |
324 | struct cpufreq_policy *policy; |
325 | ||
1da177e4 LT |
326 | BUG_ON(irqs_disabled()); |
327 | ||
328 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
329 | dprintk("notification %u of frequency transition to %u kHz\n", |
330 | state, freqs->new); | |
1da177e4 | 331 | |
7a6aedfa | 332 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 333 | switch (state) { |
e4472cb3 | 334 | |
1da177e4 | 335 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 336 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
337 | * which is not equal to what the cpufreq core thinks is |
338 | * "old frequency". | |
1da177e4 LT |
339 | */ |
340 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
341 | if ((policy) && (policy->cpu == freqs->cpu) && |
342 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 343 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
344 | " %u, cpufreq assumed %u kHz.\n", |
345 | freqs->old, policy->cur); | |
346 | freqs->old = policy->cur; | |
1da177e4 LT |
347 | } |
348 | } | |
b4dfdbb3 | 349 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 350 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
351 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
352 | break; | |
e4472cb3 | 353 | |
1da177e4 LT |
354 | case CPUFREQ_POSTCHANGE: |
355 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
6f4f2723 TR |
356 | dprintk("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
357 | (unsigned long)freqs->cpu); | |
358 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 359 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 360 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 361 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
362 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
363 | policy->cur = freqs->new; | |
1da177e4 LT |
364 | break; |
365 | } | |
1da177e4 LT |
366 | } |
367 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
368 | ||
369 | ||
370 | ||
371 | /********************************************************************* | |
372 | * SYSFS INTERFACE * | |
373 | *********************************************************************/ | |
374 | ||
3bcb09a3 JF |
375 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
376 | { | |
377 | struct cpufreq_governor *t; | |
378 | ||
379 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 380 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
381 | return t; |
382 | ||
383 | return NULL; | |
384 | } | |
385 | ||
1da177e4 LT |
386 | /** |
387 | * cpufreq_parse_governor - parse a governor string | |
388 | */ | |
905d77cd | 389 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
390 | struct cpufreq_governor **governor) |
391 | { | |
3bcb09a3 JF |
392 | int err = -EINVAL; |
393 | ||
1da177e4 | 394 | if (!cpufreq_driver) |
3bcb09a3 JF |
395 | goto out; |
396 | ||
1da177e4 LT |
397 | if (cpufreq_driver->setpolicy) { |
398 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
399 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 400 | err = 0; |
e08f5f5b GS |
401 | } else if (!strnicmp(str_governor, "powersave", |
402 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 403 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 404 | err = 0; |
1da177e4 | 405 | } |
3bcb09a3 | 406 | } else if (cpufreq_driver->target) { |
1da177e4 | 407 | struct cpufreq_governor *t; |
3bcb09a3 | 408 | |
3fc54d37 | 409 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
410 | |
411 | t = __find_governor(str_governor); | |
412 | ||
ea714970 | 413 | if (t == NULL) { |
e08f5f5b GS |
414 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
415 | str_governor); | |
ea714970 JF |
416 | |
417 | if (name) { | |
418 | int ret; | |
419 | ||
420 | mutex_unlock(&cpufreq_governor_mutex); | |
326f6a5c | 421 | ret = request_module("%s", name); |
ea714970 JF |
422 | mutex_lock(&cpufreq_governor_mutex); |
423 | ||
424 | if (ret == 0) | |
425 | t = __find_governor(str_governor); | |
426 | } | |
427 | ||
428 | kfree(name); | |
429 | } | |
430 | ||
3bcb09a3 JF |
431 | if (t != NULL) { |
432 | *governor = t; | |
433 | err = 0; | |
1da177e4 | 434 | } |
3bcb09a3 | 435 | |
3fc54d37 | 436 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 437 | } |
29464f28 | 438 | out: |
3bcb09a3 | 439 | return err; |
1da177e4 | 440 | } |
1da177e4 LT |
441 | |
442 | ||
1da177e4 | 443 | /** |
e08f5f5b GS |
444 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
445 | * print out cpufreq information | |
1da177e4 LT |
446 | * |
447 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
448 | * "unsigned int". | |
449 | */ | |
450 | ||
32ee8c3e DJ |
451 | #define show_one(file_name, object) \ |
452 | static ssize_t show_##file_name \ | |
905d77cd | 453 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 454 | { \ |
29464f28 | 455 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
456 | } |
457 | ||
458 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
459 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 460 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
461 | show_one(scaling_min_freq, min); |
462 | show_one(scaling_max_freq, max); | |
463 | show_one(scaling_cur_freq, cur); | |
464 | ||
e08f5f5b GS |
465 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
466 | struct cpufreq_policy *policy); | |
7970e08b | 467 | |
1da177e4 LT |
468 | /** |
469 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
470 | */ | |
471 | #define store_one(file_name, object) \ | |
472 | static ssize_t store_##file_name \ | |
905d77cd | 473 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
474 | { \ |
475 | unsigned int ret = -EINVAL; \ | |
476 | struct cpufreq_policy new_policy; \ | |
477 | \ | |
478 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
479 | if (ret) \ | |
480 | return -EINVAL; \ | |
481 | \ | |
29464f28 | 482 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
483 | if (ret != 1) \ |
484 | return -EINVAL; \ | |
485 | \ | |
7970e08b TR |
486 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
487 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
488 | \ |
489 | return ret ? ret : count; \ | |
490 | } | |
491 | ||
29464f28 DJ |
492 | store_one(scaling_min_freq, min); |
493 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
494 | |
495 | /** | |
496 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
497 | */ | |
905d77cd DJ |
498 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
499 | char *buf) | |
1da177e4 | 500 | { |
5a01f2e8 | 501 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
502 | if (!cur_freq) |
503 | return sprintf(buf, "<unknown>"); | |
504 | return sprintf(buf, "%u\n", cur_freq); | |
505 | } | |
506 | ||
507 | ||
508 | /** | |
509 | * show_scaling_governor - show the current policy for the specified CPU | |
510 | */ | |
905d77cd | 511 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 512 | { |
29464f28 | 513 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
514 | return sprintf(buf, "powersave\n"); |
515 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
516 | return sprintf(buf, "performance\n"); | |
517 | else if (policy->governor) | |
29464f28 DJ |
518 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", |
519 | policy->governor->name); | |
1da177e4 LT |
520 | return -EINVAL; |
521 | } | |
522 | ||
523 | ||
524 | /** | |
525 | * store_scaling_governor - store policy for the specified CPU | |
526 | */ | |
905d77cd DJ |
527 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
528 | const char *buf, size_t count) | |
1da177e4 LT |
529 | { |
530 | unsigned int ret = -EINVAL; | |
531 | char str_governor[16]; | |
532 | struct cpufreq_policy new_policy; | |
533 | ||
534 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
535 | if (ret) | |
536 | return ret; | |
537 | ||
29464f28 | 538 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
539 | if (ret != 1) |
540 | return -EINVAL; | |
541 | ||
e08f5f5b GS |
542 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
543 | &new_policy.governor)) | |
1da177e4 LT |
544 | return -EINVAL; |
545 | ||
7970e08b TR |
546 | /* Do not use cpufreq_set_policy here or the user_policy.max |
547 | will be wrongly overridden */ | |
7970e08b TR |
548 | ret = __cpufreq_set_policy(policy, &new_policy); |
549 | ||
550 | policy->user_policy.policy = policy->policy; | |
551 | policy->user_policy.governor = policy->governor; | |
7970e08b | 552 | |
e08f5f5b GS |
553 | if (ret) |
554 | return ret; | |
555 | else | |
556 | return count; | |
1da177e4 LT |
557 | } |
558 | ||
559 | /** | |
560 | * show_scaling_driver - show the cpufreq driver currently loaded | |
561 | */ | |
905d77cd | 562 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
563 | { |
564 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
565 | } | |
566 | ||
567 | /** | |
568 | * show_scaling_available_governors - show the available CPUfreq governors | |
569 | */ | |
905d77cd DJ |
570 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
571 | char *buf) | |
1da177e4 LT |
572 | { |
573 | ssize_t i = 0; | |
574 | struct cpufreq_governor *t; | |
575 | ||
576 | if (!cpufreq_driver->target) { | |
577 | i += sprintf(buf, "performance powersave"); | |
578 | goto out; | |
579 | } | |
580 | ||
581 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
582 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
583 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 LT |
584 | goto out; |
585 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
586 | } | |
7d5e350f | 587 | out: |
1da177e4 LT |
588 | i += sprintf(&buf[i], "\n"); |
589 | return i; | |
590 | } | |
e8628dd0 | 591 | |
835481d9 | 592 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
593 | { |
594 | ssize_t i = 0; | |
595 | unsigned int cpu; | |
596 | ||
835481d9 | 597 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
598 | if (i) |
599 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
600 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
601 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 602 | break; |
1da177e4 LT |
603 | } |
604 | i += sprintf(&buf[i], "\n"); | |
605 | return i; | |
606 | } | |
607 | ||
e8628dd0 DW |
608 | /** |
609 | * show_related_cpus - show the CPUs affected by each transition even if | |
610 | * hw coordination is in use | |
611 | */ | |
612 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
613 | { | |
835481d9 | 614 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
615 | return show_cpus(policy->cpus, buf); |
616 | return show_cpus(policy->related_cpus, buf); | |
617 | } | |
618 | ||
619 | /** | |
620 | * show_affected_cpus - show the CPUs affected by each transition | |
621 | */ | |
622 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
623 | { | |
624 | return show_cpus(policy->cpus, buf); | |
625 | } | |
626 | ||
9e76988e | 627 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 628 | const char *buf, size_t count) |
9e76988e VP |
629 | { |
630 | unsigned int freq = 0; | |
631 | unsigned int ret; | |
632 | ||
879000f9 | 633 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
634 | return -EINVAL; |
635 | ||
636 | ret = sscanf(buf, "%u", &freq); | |
637 | if (ret != 1) | |
638 | return -EINVAL; | |
639 | ||
640 | policy->governor->store_setspeed(policy, freq); | |
641 | ||
642 | return count; | |
643 | } | |
644 | ||
645 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
646 | { | |
879000f9 | 647 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
648 | return sprintf(buf, "<unsupported>\n"); |
649 | ||
650 | return policy->governor->show_setspeed(policy, buf); | |
651 | } | |
1da177e4 | 652 | |
e2f74f35 TR |
653 | /** |
654 | * show_scaling_driver - show the current cpufreq HW/BIOS limitation | |
655 | */ | |
656 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
657 | { | |
658 | unsigned int limit; | |
659 | int ret; | |
660 | if (cpufreq_driver->bios_limit) { | |
661 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
662 | if (!ret) | |
663 | return sprintf(buf, "%u\n", limit); | |
664 | } | |
665 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
666 | } | |
667 | ||
6dad2a29 BP |
668 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
669 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
670 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
671 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
672 | cpufreq_freq_attr_ro(scaling_available_governors); | |
673 | cpufreq_freq_attr_ro(scaling_driver); | |
674 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
675 | cpufreq_freq_attr_ro(bios_limit); | |
676 | cpufreq_freq_attr_ro(related_cpus); | |
677 | cpufreq_freq_attr_ro(affected_cpus); | |
678 | cpufreq_freq_attr_rw(scaling_min_freq); | |
679 | cpufreq_freq_attr_rw(scaling_max_freq); | |
680 | cpufreq_freq_attr_rw(scaling_governor); | |
681 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 682 | |
905d77cd | 683 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
684 | &cpuinfo_min_freq.attr, |
685 | &cpuinfo_max_freq.attr, | |
ed129784 | 686 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
687 | &scaling_min_freq.attr, |
688 | &scaling_max_freq.attr, | |
689 | &affected_cpus.attr, | |
e8628dd0 | 690 | &related_cpus.attr, |
1da177e4 LT |
691 | &scaling_governor.attr, |
692 | &scaling_driver.attr, | |
693 | &scaling_available_governors.attr, | |
9e76988e | 694 | &scaling_setspeed.attr, |
1da177e4 LT |
695 | NULL |
696 | }; | |
697 | ||
8aa84ad8 TR |
698 | struct kobject *cpufreq_global_kobject; |
699 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
700 | ||
29464f28 DJ |
701 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
702 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 703 | |
29464f28 | 704 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 705 | { |
905d77cd DJ |
706 | struct cpufreq_policy *policy = to_policy(kobj); |
707 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 708 | ssize_t ret = -EINVAL; |
1da177e4 LT |
709 | policy = cpufreq_cpu_get(policy->cpu); |
710 | if (!policy) | |
0db4a8a9 | 711 | goto no_policy; |
5a01f2e8 VP |
712 | |
713 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 714 | goto fail; |
5a01f2e8 | 715 | |
e08f5f5b GS |
716 | if (fattr->show) |
717 | ret = fattr->show(policy, buf); | |
718 | else | |
719 | ret = -EIO; | |
720 | ||
5a01f2e8 | 721 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 722 | fail: |
1da177e4 | 723 | cpufreq_cpu_put(policy); |
0db4a8a9 | 724 | no_policy: |
1da177e4 LT |
725 | return ret; |
726 | } | |
727 | ||
905d77cd DJ |
728 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
729 | const char *buf, size_t count) | |
1da177e4 | 730 | { |
905d77cd DJ |
731 | struct cpufreq_policy *policy = to_policy(kobj); |
732 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 733 | ssize_t ret = -EINVAL; |
1da177e4 LT |
734 | policy = cpufreq_cpu_get(policy->cpu); |
735 | if (!policy) | |
a07530b4 | 736 | goto no_policy; |
5a01f2e8 VP |
737 | |
738 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 739 | goto fail; |
5a01f2e8 | 740 | |
e08f5f5b GS |
741 | if (fattr->store) |
742 | ret = fattr->store(policy, buf, count); | |
743 | else | |
744 | ret = -EIO; | |
745 | ||
5a01f2e8 | 746 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 747 | fail: |
1da177e4 | 748 | cpufreq_cpu_put(policy); |
a07530b4 | 749 | no_policy: |
1da177e4 LT |
750 | return ret; |
751 | } | |
752 | ||
905d77cd | 753 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 754 | { |
905d77cd | 755 | struct cpufreq_policy *policy = to_policy(kobj); |
1da177e4 LT |
756 | dprintk("last reference is dropped\n"); |
757 | complete(&policy->kobj_unregister); | |
758 | } | |
759 | ||
52cf25d0 | 760 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
761 | .show = show, |
762 | .store = store, | |
763 | }; | |
764 | ||
765 | static struct kobj_type ktype_cpufreq = { | |
766 | .sysfs_ops = &sysfs_ops, | |
767 | .default_attrs = default_attrs, | |
768 | .release = cpufreq_sysfs_release, | |
769 | }; | |
770 | ||
4bfa042c TR |
771 | /* |
772 | * Returns: | |
773 | * Negative: Failure | |
774 | * 0: Success | |
775 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
776 | */ | |
cf3289d0 AC |
777 | static int cpufreq_add_dev_policy(unsigned int cpu, |
778 | struct cpufreq_policy *policy, | |
779 | struct sys_device *sys_dev) | |
ecf7e461 DJ |
780 | { |
781 | int ret = 0; | |
782 | #ifdef CONFIG_SMP | |
783 | unsigned long flags; | |
784 | unsigned int j; | |
ecf7e461 | 785 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
786 | struct cpufreq_governor *gov; |
787 | ||
788 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
789 | if (gov) { | |
790 | policy->governor = gov; | |
ecf7e461 DJ |
791 | dprintk("Restoring governor %s for cpu %d\n", |
792 | policy->governor->name, cpu); | |
793 | } | |
794 | #endif | |
795 | ||
796 | for_each_cpu(j, policy->cpus) { | |
797 | struct cpufreq_policy *managed_policy; | |
798 | ||
799 | if (cpu == j) | |
800 | continue; | |
801 | ||
802 | /* Check for existing affected CPUs. | |
803 | * They may not be aware of it due to CPU Hotplug. | |
804 | * cpufreq_cpu_put is called when the device is removed | |
805 | * in __cpufreq_remove_dev() | |
806 | */ | |
807 | managed_policy = cpufreq_cpu_get(j); | |
808 | if (unlikely(managed_policy)) { | |
809 | ||
810 | /* Set proper policy_cpu */ | |
811 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 812 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
813 | |
814 | if (lock_policy_rwsem_write(cpu) < 0) { | |
815 | /* Should not go through policy unlock path */ | |
816 | if (cpufreq_driver->exit) | |
817 | cpufreq_driver->exit(policy); | |
818 | cpufreq_cpu_put(managed_policy); | |
819 | return -EBUSY; | |
820 | } | |
821 | ||
822 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
823 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
824 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
825 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
826 | ||
827 | dprintk("CPU already managed, adding link\n"); | |
828 | ret = sysfs_create_link(&sys_dev->kobj, | |
829 | &managed_policy->kobj, | |
830 | "cpufreq"); | |
831 | if (ret) | |
832 | cpufreq_cpu_put(managed_policy); | |
833 | /* | |
834 | * Success. We only needed to be added to the mask. | |
835 | * Call driver->exit() because only the cpu parent of | |
836 | * the kobj needed to call init(). | |
837 | */ | |
838 | if (cpufreq_driver->exit) | |
839 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
840 | |
841 | if (!ret) | |
842 | return 1; | |
843 | else | |
844 | return ret; | |
ecf7e461 DJ |
845 | } |
846 | } | |
847 | #endif | |
848 | return ret; | |
849 | } | |
850 | ||
851 | ||
19d6f7ec | 852 | /* symlink affected CPUs */ |
cf3289d0 AC |
853 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
854 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
855 | { |
856 | unsigned int j; | |
857 | int ret = 0; | |
858 | ||
859 | for_each_cpu(j, policy->cpus) { | |
860 | struct cpufreq_policy *managed_policy; | |
861 | struct sys_device *cpu_sys_dev; | |
862 | ||
863 | if (j == cpu) | |
864 | continue; | |
865 | if (!cpu_online(j)) | |
866 | continue; | |
867 | ||
868 | dprintk("CPU %u already managed, adding link\n", j); | |
869 | managed_policy = cpufreq_cpu_get(cpu); | |
870 | cpu_sys_dev = get_cpu_sysdev(j); | |
871 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
872 | "cpufreq"); | |
873 | if (ret) { | |
874 | cpufreq_cpu_put(managed_policy); | |
875 | return ret; | |
876 | } | |
877 | } | |
878 | return ret; | |
879 | } | |
880 | ||
cf3289d0 AC |
881 | static int cpufreq_add_dev_interface(unsigned int cpu, |
882 | struct cpufreq_policy *policy, | |
883 | struct sys_device *sys_dev) | |
909a694e | 884 | { |
ecf7e461 | 885 | struct cpufreq_policy new_policy; |
909a694e DJ |
886 | struct freq_attr **drv_attr; |
887 | unsigned long flags; | |
888 | int ret = 0; | |
889 | unsigned int j; | |
890 | ||
891 | /* prepare interface data */ | |
892 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
893 | &sys_dev->kobj, "cpufreq"); | |
894 | if (ret) | |
895 | return ret; | |
896 | ||
897 | /* set up files for this cpu device */ | |
898 | drv_attr = cpufreq_driver->attr; | |
899 | while ((drv_attr) && (*drv_attr)) { | |
900 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
901 | if (ret) | |
902 | goto err_out_kobj_put; | |
903 | drv_attr++; | |
904 | } | |
905 | if (cpufreq_driver->get) { | |
906 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
907 | if (ret) | |
908 | goto err_out_kobj_put; | |
909 | } | |
910 | if (cpufreq_driver->target) { | |
911 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
912 | if (ret) | |
913 | goto err_out_kobj_put; | |
914 | } | |
e2f74f35 TR |
915 | if (cpufreq_driver->bios_limit) { |
916 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
917 | if (ret) | |
918 | goto err_out_kobj_put; | |
919 | } | |
909a694e DJ |
920 | |
921 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
922 | for_each_cpu(j, policy->cpus) { | |
bec037aa JL |
923 | if (!cpu_online(j)) |
924 | continue; | |
909a694e | 925 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 926 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
927 | } |
928 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
929 | ||
930 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
931 | if (ret) |
932 | goto err_out_kobj_put; | |
933 | ||
934 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
935 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
936 | policy->governor = NULL; | |
937 | ||
938 | /* set default policy */ | |
939 | ret = __cpufreq_set_policy(policy, &new_policy); | |
940 | policy->user_policy.policy = policy->policy; | |
941 | policy->user_policy.governor = policy->governor; | |
942 | ||
943 | if (ret) { | |
944 | dprintk("setting policy failed\n"); | |
945 | if (cpufreq_driver->exit) | |
946 | cpufreq_driver->exit(policy); | |
947 | } | |
909a694e DJ |
948 | return ret; |
949 | ||
950 | err_out_kobj_put: | |
951 | kobject_put(&policy->kobj); | |
952 | wait_for_completion(&policy->kobj_unregister); | |
953 | return ret; | |
954 | } | |
955 | ||
1da177e4 LT |
956 | |
957 | /** | |
958 | * cpufreq_add_dev - add a CPU device | |
959 | * | |
32ee8c3e | 960 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
961 | * |
962 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
963 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
964 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 965 | */ |
905d77cd | 966 | static int cpufreq_add_dev(struct sys_device *sys_dev) |
1da177e4 LT |
967 | { |
968 | unsigned int cpu = sys_dev->id; | |
90e41bac | 969 | int ret = 0, found = 0; |
1da177e4 | 970 | struct cpufreq_policy *policy; |
1da177e4 LT |
971 | unsigned long flags; |
972 | unsigned int j; | |
90e41bac PB |
973 | #ifdef CONFIG_HOTPLUG_CPU |
974 | int sibling; | |
975 | #endif | |
1da177e4 | 976 | |
c32b6b8e AR |
977 | if (cpu_is_offline(cpu)) |
978 | return 0; | |
979 | ||
1da177e4 LT |
980 | cpufreq_debug_disable_ratelimit(); |
981 | dprintk("adding CPU %u\n", cpu); | |
982 | ||
983 | #ifdef CONFIG_SMP | |
984 | /* check whether a different CPU already registered this | |
985 | * CPU because it is in the same boat. */ | |
986 | policy = cpufreq_cpu_get(cpu); | |
987 | if (unlikely(policy)) { | |
8ff69732 | 988 | cpufreq_cpu_put(policy); |
1da177e4 LT |
989 | cpufreq_debug_enable_ratelimit(); |
990 | return 0; | |
991 | } | |
992 | #endif | |
993 | ||
994 | if (!try_module_get(cpufreq_driver->owner)) { | |
995 | ret = -EINVAL; | |
996 | goto module_out; | |
997 | } | |
998 | ||
059019a3 | 999 | ret = -ENOMEM; |
e98df50c | 1000 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 1001 | if (!policy) |
1da177e4 | 1002 | goto nomem_out; |
059019a3 DJ |
1003 | |
1004 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 1005 | goto err_free_policy; |
059019a3 DJ |
1006 | |
1007 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 1008 | goto err_free_cpumask; |
1da177e4 LT |
1009 | |
1010 | policy->cpu = cpu; | |
835481d9 | 1011 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1012 | |
5a01f2e8 | 1013 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 1014 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
1015 | ret = (lock_policy_rwsem_write(cpu) < 0); |
1016 | WARN_ON(ret); | |
5a01f2e8 | 1017 | |
1da177e4 | 1018 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1019 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 1020 | |
8122c6ce | 1021 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
1022 | #ifdef CONFIG_HOTPLUG_CPU |
1023 | for_each_online_cpu(sibling) { | |
1024 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
1025 | if (cp && cp->governor && | |
1026 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
1027 | policy->governor = cp->governor; | |
1028 | found = 1; | |
1029 | break; | |
1030 | } | |
1031 | } | |
1032 | #endif | |
1033 | if (!found) | |
1034 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
1035 | /* call driver. From then on the cpufreq must be able |
1036 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1037 | */ | |
1038 | ret = cpufreq_driver->init(policy); | |
1039 | if (ret) { | |
1040 | dprintk("initialization failed\n"); | |
3f4a782b | 1041 | goto err_unlock_policy; |
1da177e4 | 1042 | } |
187d9f4e MC |
1043 | policy->user_policy.min = policy->min; |
1044 | policy->user_policy.max = policy->max; | |
1da177e4 | 1045 | |
a1531acd TR |
1046 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1047 | CPUFREQ_START, policy); | |
1048 | ||
ecf7e461 | 1049 | ret = cpufreq_add_dev_policy(cpu, policy, sys_dev); |
4bfa042c TR |
1050 | if (ret) { |
1051 | if (ret > 0) | |
1052 | /* This is a managed cpu, symlink created, | |
1053 | exit with 0 */ | |
1054 | ret = 0; | |
ecf7e461 | 1055 | goto err_unlock_policy; |
4bfa042c | 1056 | } |
1da177e4 | 1057 | |
909a694e | 1058 | ret = cpufreq_add_dev_interface(cpu, policy, sys_dev); |
19d6f7ec DJ |
1059 | if (ret) |
1060 | goto err_out_unregister; | |
8ff69732 | 1061 | |
dca02613 LW |
1062 | unlock_policy_rwsem_write(cpu); |
1063 | ||
038c5b3e | 1064 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 1065 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
1066 | dprintk("initialization complete\n"); |
1067 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 1068 | |
1da177e4 LT |
1069 | return 0; |
1070 | ||
1071 | ||
1072 | err_out_unregister: | |
1073 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1074 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1075 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1076 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1077 | ||
c10997f6 | 1078 | kobject_put(&policy->kobj); |
1da177e4 LT |
1079 | wait_for_completion(&policy->kobj_unregister); |
1080 | ||
3f4a782b | 1081 | err_unlock_policy: |
45709118 | 1082 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 1083 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
1084 | err_free_cpumask: |
1085 | free_cpumask_var(policy->cpus); | |
1086 | err_free_policy: | |
1da177e4 | 1087 | kfree(policy); |
1da177e4 LT |
1088 | nomem_out: |
1089 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1090 | module_out: |
1da177e4 LT |
1091 | cpufreq_debug_enable_ratelimit(); |
1092 | return ret; | |
1093 | } | |
1094 | ||
1095 | ||
1096 | /** | |
5a01f2e8 | 1097 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1098 | * |
1099 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1100 | * Caller should already have policy_rwsem in write mode for this CPU. |
1101 | * This routine frees the rwsem before returning. | |
1da177e4 | 1102 | */ |
905d77cd | 1103 | static int __cpufreq_remove_dev(struct sys_device *sys_dev) |
1da177e4 LT |
1104 | { |
1105 | unsigned int cpu = sys_dev->id; | |
1106 | unsigned long flags; | |
1107 | struct cpufreq_policy *data; | |
499bca9b AW |
1108 | struct kobject *kobj; |
1109 | struct completion *cmp; | |
1da177e4 | 1110 | #ifdef CONFIG_SMP |
e738cf6d | 1111 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
1112 | unsigned int j; |
1113 | #endif | |
1114 | ||
1115 | cpufreq_debug_disable_ratelimit(); | |
1116 | dprintk("unregistering CPU %u\n", cpu); | |
1117 | ||
1118 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1119 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1120 | |
1121 | if (!data) { | |
1122 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 1123 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 1124 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1125 | return -EINVAL; |
1126 | } | |
7a6aedfa | 1127 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1128 | |
1129 | ||
1130 | #ifdef CONFIG_SMP | |
1131 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1132 | * only need to unlink, put and exit |
1da177e4 LT |
1133 | */ |
1134 | if (unlikely(cpu != data->cpu)) { | |
1135 | dprintk("removing link\n"); | |
835481d9 | 1136 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 | 1137 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
499bca9b | 1138 | kobj = &sys_dev->kobj; |
1da177e4 LT |
1139 | cpufreq_cpu_put(data); |
1140 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 1141 | unlock_policy_rwsem_write(cpu); |
499bca9b | 1142 | sysfs_remove_link(kobj, "cpufreq"); |
1da177e4 LT |
1143 | return 0; |
1144 | } | |
1145 | #endif | |
1146 | ||
1da177e4 | 1147 | #ifdef CONFIG_SMP |
084f3493 TR |
1148 | |
1149 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1150 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1151 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1152 | #endif |
1153 | ||
1da177e4 LT |
1154 | /* if we have other CPUs still registered, we need to unlink them, |
1155 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1156 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1157 | * the sysfs links afterwards. | |
1da177e4 | 1158 | */ |
835481d9 RR |
1159 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1160 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1161 | if (j == cpu) |
1162 | continue; | |
7a6aedfa | 1163 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1164 | } |
1165 | } | |
1166 | ||
1167 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1168 | ||
835481d9 RR |
1169 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1170 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1171 | if (j == cpu) |
1172 | continue; | |
1173 | dprintk("removing link for cpu %u\n", j); | |
084f3493 | 1174 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1175 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1176 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1177 | #endif |
d434fca7 | 1178 | cpu_sys_dev = get_cpu_sysdev(j); |
499bca9b AW |
1179 | kobj = &cpu_sys_dev->kobj; |
1180 | unlock_policy_rwsem_write(cpu); | |
1181 | sysfs_remove_link(kobj, "cpufreq"); | |
1182 | lock_policy_rwsem_write(cpu); | |
1da177e4 LT |
1183 | cpufreq_cpu_put(data); |
1184 | } | |
1185 | } | |
1186 | #else | |
1187 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1188 | #endif | |
1189 | ||
1da177e4 LT |
1190 | if (cpufreq_driver->target) |
1191 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1192 | |
499bca9b AW |
1193 | kobj = &data->kobj; |
1194 | cmp = &data->kobj_unregister; | |
1195 | unlock_policy_rwsem_write(cpu); | |
1196 | kobject_put(kobj); | |
1da177e4 LT |
1197 | |
1198 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1199 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1200 | * unloading. |
1201 | */ | |
1202 | dprintk("waiting for dropping of refcount\n"); | |
499bca9b | 1203 | wait_for_completion(cmp); |
1da177e4 LT |
1204 | dprintk("wait complete\n"); |
1205 | ||
499bca9b | 1206 | lock_policy_rwsem_write(cpu); |
1da177e4 LT |
1207 | if (cpufreq_driver->exit) |
1208 | cpufreq_driver->exit(data); | |
7d26e2d5 | 1209 | unlock_policy_rwsem_write(cpu); |
1210 | ||
835481d9 RR |
1211 | free_cpumask_var(data->related_cpus); |
1212 | free_cpumask_var(data->cpus); | |
1da177e4 | 1213 | kfree(data); |
835481d9 | 1214 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1215 | |
1216 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1217 | return 0; |
1218 | } | |
1219 | ||
1220 | ||
905d77cd | 1221 | static int cpufreq_remove_dev(struct sys_device *sys_dev) |
5a01f2e8 VP |
1222 | { |
1223 | unsigned int cpu = sys_dev->id; | |
1224 | int retval; | |
ec28297a VP |
1225 | |
1226 | if (cpu_is_offline(cpu)) | |
1227 | return 0; | |
1228 | ||
5a01f2e8 VP |
1229 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1230 | BUG(); | |
1231 | ||
1232 | retval = __cpufreq_remove_dev(sys_dev); | |
1233 | return retval; | |
1234 | } | |
1235 | ||
1236 | ||
65f27f38 | 1237 | static void handle_update(struct work_struct *work) |
1da177e4 | 1238 | { |
65f27f38 DH |
1239 | struct cpufreq_policy *policy = |
1240 | container_of(work, struct cpufreq_policy, update); | |
1241 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1242 | dprintk("handle_update for cpu %u called\n", cpu); |
1243 | cpufreq_update_policy(cpu); | |
1244 | } | |
1245 | ||
1246 | /** | |
1247 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1248 | * @cpu: cpu number | |
1249 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1250 | * @new_freq: CPU frequency the CPU actually runs at | |
1251 | * | |
29464f28 DJ |
1252 | * We adjust to current frequency first, and need to clean up later. |
1253 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1254 | */ |
e08f5f5b GS |
1255 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1256 | unsigned int new_freq) | |
1da177e4 LT |
1257 | { |
1258 | struct cpufreq_freqs freqs; | |
1259 | ||
b10eec22 | 1260 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1261 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1262 | ||
1263 | freqs.cpu = cpu; | |
1264 | freqs.old = old_freq; | |
1265 | freqs.new = new_freq; | |
1266 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1267 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1268 | } | |
1269 | ||
1270 | ||
32ee8c3e | 1271 | /** |
4ab70df4 | 1272 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1273 | * @cpu: CPU number |
1274 | * | |
1275 | * This is the last known freq, without actually getting it from the driver. | |
1276 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1277 | */ | |
1278 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1279 | { | |
1280 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1281 | unsigned int ret_freq = 0; |
95235ca2 VP |
1282 | |
1283 | if (policy) { | |
e08f5f5b | 1284 | ret_freq = policy->cur; |
95235ca2 VP |
1285 | cpufreq_cpu_put(policy); |
1286 | } | |
1287 | ||
4d34a67d | 1288 | return ret_freq; |
95235ca2 VP |
1289 | } |
1290 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1291 | ||
1292 | ||
5a01f2e8 | 1293 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1294 | { |
7a6aedfa | 1295 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1296 | unsigned int ret_freq = 0; |
1da177e4 | 1297 | |
1da177e4 | 1298 | if (!cpufreq_driver->get) |
4d34a67d | 1299 | return ret_freq; |
1da177e4 | 1300 | |
e08f5f5b | 1301 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1302 | |
e08f5f5b GS |
1303 | if (ret_freq && policy->cur && |
1304 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1305 | /* verify no discrepancy between actual and | |
1306 | saved value exists */ | |
1307 | if (unlikely(ret_freq != policy->cur)) { | |
1308 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1309 | schedule_work(&policy->update); |
1310 | } | |
1311 | } | |
1312 | ||
4d34a67d | 1313 | return ret_freq; |
5a01f2e8 | 1314 | } |
1da177e4 | 1315 | |
5a01f2e8 VP |
1316 | /** |
1317 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1318 | * @cpu: CPU number | |
1319 | * | |
1320 | * Get the CPU current (static) CPU frequency | |
1321 | */ | |
1322 | unsigned int cpufreq_get(unsigned int cpu) | |
1323 | { | |
1324 | unsigned int ret_freq = 0; | |
1325 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1326 | ||
1327 | if (!policy) | |
1328 | goto out; | |
1329 | ||
1330 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1331 | goto out_policy; | |
1332 | ||
1333 | ret_freq = __cpufreq_get(cpu); | |
1334 | ||
1335 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1336 | |
5a01f2e8 VP |
1337 | out_policy: |
1338 | cpufreq_cpu_put(policy); | |
1339 | out: | |
4d34a67d | 1340 | return ret_freq; |
1da177e4 LT |
1341 | } |
1342 | EXPORT_SYMBOL(cpufreq_get); | |
1343 | ||
e00e56df RW |
1344 | static struct sysdev_driver cpufreq_sysdev_driver = { |
1345 | .add = cpufreq_add_dev, | |
1346 | .remove = cpufreq_remove_dev, | |
1347 | }; | |
1348 | ||
1da177e4 | 1349 | |
42d4dc3f | 1350 | /** |
e00e56df RW |
1351 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1352 | * | |
1353 | * This function is only executed for the boot processor. The other CPUs | |
1354 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1355 | */ |
e00e56df | 1356 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1357 | { |
e08f5f5b | 1358 | int ret = 0; |
4bc5d341 | 1359 | |
e00e56df | 1360 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1361 | struct cpufreq_policy *cpu_policy; |
1362 | ||
0e37b159 | 1363 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f | 1364 | |
e00e56df | 1365 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1366 | cpu_policy = cpufreq_cpu_get(cpu); |
1367 | if (!cpu_policy) | |
e00e56df | 1368 | return 0; |
42d4dc3f BH |
1369 | |
1370 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1371 | ret = cpufreq_driver->suspend(cpu_policy); |
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 | ||
42d4dc3f | 1377 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1378 | return ret; |
42d4dc3f BH |
1379 | } |
1380 | ||
1da177e4 | 1381 | /** |
e00e56df | 1382 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1383 | * |
1384 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1385 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1386 | * restored. It will verify that the current freq is in sync with | |
1387 | * what we believe it to be. This is a bit later than when it | |
1388 | * should be, but nonethteless it's better than calling | |
1389 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1390 | * |
1391 | * This function is only executed for the boot CPU. The other CPUs have not | |
1392 | * been turned on yet. | |
1da177e4 | 1393 | */ |
e00e56df | 1394 | static void cpufreq_bp_resume(void) |
1da177e4 | 1395 | { |
e08f5f5b | 1396 | int ret = 0; |
4bc5d341 | 1397 | |
e00e56df | 1398 | int cpu = smp_processor_id(); |
1da177e4 LT |
1399 | struct cpufreq_policy *cpu_policy; |
1400 | ||
1401 | dprintk("resuming cpu %u\n", cpu); | |
1402 | ||
e00e56df | 1403 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1404 | cpu_policy = cpufreq_cpu_get(cpu); |
1405 | if (!cpu_policy) | |
e00e56df | 1406 | return; |
1da177e4 LT |
1407 | |
1408 | if (cpufreq_driver->resume) { | |
1409 | ret = cpufreq_driver->resume(cpu_policy); | |
1410 | if (ret) { | |
1411 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1412 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1413 | goto fail; |
1da177e4 LT |
1414 | } |
1415 | } | |
1416 | ||
1da177e4 | 1417 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1418 | |
c9060494 | 1419 | fail: |
1da177e4 | 1420 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1421 | } |
1422 | ||
e00e56df RW |
1423 | static struct syscore_ops cpufreq_syscore_ops = { |
1424 | .suspend = cpufreq_bp_suspend, | |
1425 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1426 | }; |
1427 | ||
1428 | ||
1429 | /********************************************************************* | |
1430 | * NOTIFIER LISTS INTERFACE * | |
1431 | *********************************************************************/ | |
1432 | ||
1433 | /** | |
1434 | * cpufreq_register_notifier - register a driver with cpufreq | |
1435 | * @nb: notifier function to register | |
1436 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1437 | * | |
32ee8c3e | 1438 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1439 | * are notified about clock rate changes (once before and once after |
1440 | * the transition), or a list of drivers that are notified about | |
1441 | * changes in cpufreq policy. | |
1442 | * | |
1443 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1444 | * blocking_notifier_chain_register. |
1da177e4 LT |
1445 | */ |
1446 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1447 | { | |
1448 | int ret; | |
1449 | ||
74212ca4 CEB |
1450 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1451 | ||
1da177e4 LT |
1452 | switch (list) { |
1453 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1454 | ret = srcu_notifier_chain_register( |
e041c683 | 1455 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1456 | break; |
1457 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1458 | ret = blocking_notifier_chain_register( |
1459 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1460 | break; |
1461 | default: | |
1462 | ret = -EINVAL; | |
1463 | } | |
1da177e4 LT |
1464 | |
1465 | return ret; | |
1466 | } | |
1467 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1468 | ||
1469 | ||
1470 | /** | |
1471 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1472 | * @nb: notifier block to be unregistered | |
1473 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1474 | * | |
1475 | * Remove a driver from the CPU frequency notifier list. | |
1476 | * | |
1477 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1478 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1479 | */ |
1480 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1481 | { | |
1482 | int ret; | |
1483 | ||
1da177e4 LT |
1484 | switch (list) { |
1485 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1486 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1487 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1488 | break; |
1489 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1490 | ret = blocking_notifier_chain_unregister( |
1491 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1492 | break; |
1493 | default: | |
1494 | ret = -EINVAL; | |
1495 | } | |
1da177e4 LT |
1496 | |
1497 | return ret; | |
1498 | } | |
1499 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1500 | ||
1501 | ||
1502 | /********************************************************************* | |
1503 | * GOVERNORS * | |
1504 | *********************************************************************/ | |
1505 | ||
1506 | ||
1507 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1508 | unsigned int target_freq, | |
1509 | unsigned int relation) | |
1510 | { | |
1511 | int retval = -EINVAL; | |
c32b6b8e | 1512 | |
1da177e4 LT |
1513 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1514 | target_freq, relation); | |
1515 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1516 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1517 | |
1da177e4 LT |
1518 | return retval; |
1519 | } | |
1520 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1521 | ||
1da177e4 LT |
1522 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1523 | unsigned int target_freq, | |
1524 | unsigned int relation) | |
1525 | { | |
f1829e4a | 1526 | int ret = -EINVAL; |
1da177e4 LT |
1527 | |
1528 | policy = cpufreq_cpu_get(policy->cpu); | |
1529 | if (!policy) | |
f1829e4a | 1530 | goto no_policy; |
1da177e4 | 1531 | |
5a01f2e8 | 1532 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1533 | goto fail; |
1da177e4 LT |
1534 | |
1535 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1536 | ||
5a01f2e8 | 1537 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1538 | |
f1829e4a | 1539 | fail: |
1da177e4 | 1540 | cpufreq_cpu_put(policy); |
f1829e4a | 1541 | no_policy: |
1da177e4 LT |
1542 | return ret; |
1543 | } | |
1544 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1545 | ||
bf0b90e3 | 1546 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1547 | { |
1548 | int ret = 0; | |
1549 | ||
1550 | policy = cpufreq_cpu_get(policy->cpu); | |
1551 | if (!policy) | |
1552 | return -EINVAL; | |
1553 | ||
bf0b90e3 | 1554 | if (cpu_online(cpu) && cpufreq_driver->getavg) |
1555 | ret = cpufreq_driver->getavg(policy, cpu); | |
dfde5d62 | 1556 | |
dfde5d62 VP |
1557 | cpufreq_cpu_put(policy); |
1558 | return ret; | |
1559 | } | |
5a01f2e8 | 1560 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1561 | |
153d7f3f | 1562 | /* |
153d7f3f AV |
1563 | * when "event" is CPUFREQ_GOV_LIMITS |
1564 | */ | |
1da177e4 | 1565 | |
e08f5f5b GS |
1566 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1567 | unsigned int event) | |
1da177e4 | 1568 | { |
cc993cab | 1569 | int ret; |
6afde10c TR |
1570 | |
1571 | /* Only must be defined when default governor is known to have latency | |
1572 | restrictions, like e.g. conservative or ondemand. | |
1573 | That this is the case is already ensured in Kconfig | |
1574 | */ | |
1575 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1576 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1577 | #else | |
1578 | struct cpufreq_governor *gov = NULL; | |
1579 | #endif | |
1c256245 TR |
1580 | |
1581 | if (policy->governor->max_transition_latency && | |
1582 | policy->cpuinfo.transition_latency > | |
1583 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1584 | if (!gov) |
1585 | return -EINVAL; | |
1586 | else { | |
1587 | printk(KERN_WARNING "%s governor failed, too long" | |
1588 | " transition latency of HW, fallback" | |
1589 | " to %s governor\n", | |
1590 | policy->governor->name, | |
1591 | gov->name); | |
1592 | policy->governor = gov; | |
1593 | } | |
1c256245 | 1594 | } |
1da177e4 LT |
1595 | |
1596 | if (!try_module_get(policy->governor->owner)) | |
1597 | return -EINVAL; | |
1598 | ||
e08f5f5b GS |
1599 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1600 | policy->cpu, event); | |
1da177e4 LT |
1601 | ret = policy->governor->governor(policy, event); |
1602 | ||
e08f5f5b GS |
1603 | /* we keep one module reference alive for |
1604 | each CPU governed by this CPU */ | |
1da177e4 LT |
1605 | if ((event != CPUFREQ_GOV_START) || ret) |
1606 | module_put(policy->governor->owner); | |
1607 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1608 | module_put(policy->governor->owner); | |
1609 | ||
1610 | return ret; | |
1611 | } | |
1612 | ||
1613 | ||
1da177e4 LT |
1614 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1615 | { | |
3bcb09a3 | 1616 | int err; |
1da177e4 LT |
1617 | |
1618 | if (!governor) | |
1619 | return -EINVAL; | |
1620 | ||
3fc54d37 | 1621 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1622 | |
3bcb09a3 JF |
1623 | err = -EBUSY; |
1624 | if (__find_governor(governor->name) == NULL) { | |
1625 | err = 0; | |
1626 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1627 | } |
1da177e4 | 1628 | |
32ee8c3e | 1629 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1630 | return err; |
1da177e4 LT |
1631 | } |
1632 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1633 | ||
1634 | ||
1635 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1636 | { | |
90e41bac PB |
1637 | #ifdef CONFIG_HOTPLUG_CPU |
1638 | int cpu; | |
1639 | #endif | |
1640 | ||
1da177e4 LT |
1641 | if (!governor) |
1642 | return; | |
1643 | ||
90e41bac PB |
1644 | #ifdef CONFIG_HOTPLUG_CPU |
1645 | for_each_present_cpu(cpu) { | |
1646 | if (cpu_online(cpu)) | |
1647 | continue; | |
1648 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1649 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1650 | } | |
1651 | #endif | |
1652 | ||
3fc54d37 | 1653 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1654 | list_del(&governor->governor_list); |
3fc54d37 | 1655 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1656 | return; |
1657 | } | |
1658 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1659 | ||
1660 | ||
1661 | ||
1662 | /********************************************************************* | |
1663 | * POLICY INTERFACE * | |
1664 | *********************************************************************/ | |
1665 | ||
1666 | /** | |
1667 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1668 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1669 | * is written | |
1da177e4 LT |
1670 | * |
1671 | * Reads the current cpufreq policy. | |
1672 | */ | |
1673 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1674 | { | |
1675 | struct cpufreq_policy *cpu_policy; | |
1676 | if (!policy) | |
1677 | return -EINVAL; | |
1678 | ||
1679 | cpu_policy = cpufreq_cpu_get(cpu); | |
1680 | if (!cpu_policy) | |
1681 | return -EINVAL; | |
1682 | ||
1da177e4 | 1683 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1684 | |
1685 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1686 | return 0; |
1687 | } | |
1688 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1689 | ||
1690 | ||
153d7f3f | 1691 | /* |
e08f5f5b GS |
1692 | * data : current policy. |
1693 | * policy : policy to be set. | |
153d7f3f | 1694 | */ |
e08f5f5b GS |
1695 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1696 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1697 | { |
1698 | int ret = 0; | |
1699 | ||
1700 | cpufreq_debug_disable_ratelimit(); | |
1701 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1702 | policy->min, policy->max); | |
1703 | ||
e08f5f5b GS |
1704 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1705 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1706 | |
53391fa2 | 1707 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1708 | ret = -EINVAL; |
1709 | goto error_out; | |
1710 | } | |
1711 | ||
1da177e4 LT |
1712 | /* verify the cpu speed can be set within this limit */ |
1713 | ret = cpufreq_driver->verify(policy); | |
1714 | if (ret) | |
1715 | goto error_out; | |
1716 | ||
1da177e4 | 1717 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1718 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1719 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1720 | |
1721 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1722 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1723 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1724 | |
1725 | /* verify the cpu speed can be set within this limit, | |
1726 | which might be different to the first one */ | |
1727 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1728 | if (ret) |
1da177e4 | 1729 | goto error_out; |
1da177e4 LT |
1730 | |
1731 | /* notification of the new policy */ | |
e041c683 AS |
1732 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1733 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1734 | |
7d5e350f DJ |
1735 | data->min = policy->min; |
1736 | data->max = policy->max; | |
1da177e4 | 1737 | |
e08f5f5b GS |
1738 | dprintk("new min and max freqs are %u - %u kHz\n", |
1739 | data->min, data->max); | |
1da177e4 LT |
1740 | |
1741 | if (cpufreq_driver->setpolicy) { | |
1742 | data->policy = policy->policy; | |
1743 | dprintk("setting range\n"); | |
1744 | ret = cpufreq_driver->setpolicy(policy); | |
1745 | } else { | |
1746 | if (policy->governor != data->governor) { | |
1747 | /* save old, working values */ | |
1748 | struct cpufreq_governor *old_gov = data->governor; | |
1749 | ||
1750 | dprintk("governor switch\n"); | |
1751 | ||
1752 | /* end old governor */ | |
ffe6275f | 1753 | if (data->governor) |
1da177e4 LT |
1754 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1755 | ||
1756 | /* start new governor */ | |
1757 | data->governor = policy->governor; | |
1758 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1759 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1760 | dprintk("starting governor %s failed\n", |
1761 | data->governor->name); | |
1da177e4 LT |
1762 | if (old_gov) { |
1763 | data->governor = old_gov; | |
e08f5f5b GS |
1764 | __cpufreq_governor(data, |
1765 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1766 | } |
1767 | ret = -EINVAL; | |
1768 | goto error_out; | |
1769 | } | |
1770 | /* might be a policy change, too, so fall through */ | |
1771 | } | |
1772 | dprintk("governor: change or update limits\n"); | |
1773 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1774 | } | |
1775 | ||
7d5e350f | 1776 | error_out: |
1da177e4 LT |
1777 | cpufreq_debug_enable_ratelimit(); |
1778 | return ret; | |
1779 | } | |
1780 | ||
1da177e4 LT |
1781 | /** |
1782 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1783 | * @cpu: CPU which shall be re-evaluated | |
1784 | * | |
1785 | * Usefull for policy notifiers which have different necessities | |
1786 | * at different times. | |
1787 | */ | |
1788 | int cpufreq_update_policy(unsigned int cpu) | |
1789 | { | |
1790 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1791 | struct cpufreq_policy policy; | |
f1829e4a | 1792 | int ret; |
1da177e4 | 1793 | |
f1829e4a JL |
1794 | if (!data) { |
1795 | ret = -ENODEV; | |
1796 | goto no_policy; | |
1797 | } | |
1da177e4 | 1798 | |
f1829e4a JL |
1799 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1800 | ret = -EINVAL; | |
1801 | goto fail; | |
1802 | } | |
1da177e4 LT |
1803 | |
1804 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1805 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1806 | policy.min = data->user_policy.min; |
1807 | policy.max = data->user_policy.max; | |
1808 | policy.policy = data->user_policy.policy; | |
1809 | policy.governor = data->user_policy.governor; | |
1810 | ||
0961dd0d TR |
1811 | /* BIOS might change freq behind our back |
1812 | -> ask driver for current freq and notify governors about a change */ | |
1813 | if (cpufreq_driver->get) { | |
1814 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1815 | if (!data->cur) { |
1816 | dprintk("Driver did not initialize current freq"); | |
1817 | data->cur = policy.cur; | |
1818 | } else { | |
1819 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1820 | cpufreq_out_of_sync(cpu, data->cur, |
1821 | policy.cur); | |
a85f7bd3 | 1822 | } |
0961dd0d TR |
1823 | } |
1824 | ||
1da177e4 LT |
1825 | ret = __cpufreq_set_policy(data, &policy); |
1826 | ||
5a01f2e8 VP |
1827 | unlock_policy_rwsem_write(cpu); |
1828 | ||
f1829e4a | 1829 | fail: |
1da177e4 | 1830 | cpufreq_cpu_put(data); |
f1829e4a | 1831 | no_policy: |
1da177e4 LT |
1832 | return ret; |
1833 | } | |
1834 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1835 | ||
dd184a01 | 1836 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1837 | unsigned long action, void *hcpu) |
1838 | { | |
1839 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1840 | struct sys_device *sys_dev; |
1841 | ||
1842 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1843 | if (sys_dev) { |
1844 | switch (action) { | |
1845 | case CPU_ONLINE: | |
8bb78442 | 1846 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1847 | cpufreq_add_dev(sys_dev); |
1848 | break; | |
1849 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1850 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1851 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1852 | BUG(); | |
1853 | ||
5a01f2e8 | 1854 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1855 | break; |
5a01f2e8 | 1856 | case CPU_DOWN_FAILED: |
8bb78442 | 1857 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1858 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1859 | break; |
1860 | } | |
1861 | } | |
1862 | return NOTIFY_OK; | |
1863 | } | |
1864 | ||
9c36f746 | 1865 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1866 | .notifier_call = cpufreq_cpu_callback, |
1867 | }; | |
1da177e4 LT |
1868 | |
1869 | /********************************************************************* | |
1870 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1871 | *********************************************************************/ | |
1872 | ||
1873 | /** | |
1874 | * cpufreq_register_driver - register a CPU Frequency driver | |
1875 | * @driver_data: A struct cpufreq_driver containing the values# | |
1876 | * submitted by the CPU Frequency driver. | |
1877 | * | |
32ee8c3e | 1878 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1879 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1880 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1881 | * |
1882 | */ | |
221dee28 | 1883 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1884 | { |
1885 | unsigned long flags; | |
1886 | int ret; | |
1887 | ||
1888 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1889 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1890 | return -EINVAL; | |
1891 | ||
1892 | dprintk("trying to register driver %s\n", driver_data->name); | |
1893 | ||
1894 | if (driver_data->setpolicy) | |
1895 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1896 | ||
1897 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1898 | if (cpufreq_driver) { | |
1899 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1900 | return -EBUSY; | |
1901 | } | |
1902 | cpufreq_driver = driver_data; | |
1903 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1904 | ||
7a6aedfa MT |
1905 | ret = sysdev_driver_register(&cpu_sysdev_class, |
1906 | &cpufreq_sysdev_driver); | |
8f5bc2ab JS |
1907 | if (ret) |
1908 | goto err_null_driver; | |
1da177e4 | 1909 | |
8f5bc2ab | 1910 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1911 | int i; |
1912 | ret = -ENODEV; | |
1913 | ||
1914 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1915 | for (i = 0; i < nr_cpu_ids; i++) |
1916 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1917 | ret = 0; |
7a6aedfa MT |
1918 | break; |
1919 | } | |
1da177e4 LT |
1920 | |
1921 | /* if all ->init() calls failed, unregister */ | |
1922 | if (ret) { | |
e08f5f5b GS |
1923 | dprintk("no CPU initialized for driver %s\n", |
1924 | driver_data->name); | |
8f5bc2ab | 1925 | goto err_sysdev_unreg; |
1da177e4 LT |
1926 | } |
1927 | } | |
1928 | ||
8f5bc2ab JS |
1929 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1930 | dprintk("driver %s up and running\n", driver_data->name); | |
1931 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 | 1932 | |
8f5bc2ab JS |
1933 | return 0; |
1934 | err_sysdev_unreg: | |
1935 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1936 | &cpufreq_sysdev_driver); | |
1937 | err_null_driver: | |
1938 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1939 | cpufreq_driver = NULL; | |
1940 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1941 | return ret; |
1da177e4 LT |
1942 | } |
1943 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1944 | ||
1945 | ||
1946 | /** | |
1947 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1948 | * | |
32ee8c3e | 1949 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1950 | * the right to do so, i.e. if you have succeeded in initialising before! |
1951 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1952 | * currently not initialised. | |
1953 | */ | |
221dee28 | 1954 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1955 | { |
1956 | unsigned long flags; | |
1957 | ||
1958 | cpufreq_debug_disable_ratelimit(); | |
1959 | ||
1960 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1961 | cpufreq_debug_enable_ratelimit(); | |
1962 | return -EINVAL; | |
1963 | } | |
1964 | ||
1965 | dprintk("unregistering driver %s\n", driver->name); | |
1966 | ||
1967 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1968 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1969 | |
1970 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1971 | cpufreq_driver = NULL; | |
1972 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1973 | ||
1974 | return 0; | |
1975 | } | |
1976 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1977 | |
1978 | static int __init cpufreq_core_init(void) | |
1979 | { | |
1980 | int cpu; | |
1981 | ||
1982 | for_each_possible_cpu(cpu) { | |
f1625066 | 1983 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1984 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1985 | } | |
8aa84ad8 TR |
1986 | |
1987 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", | |
1988 | &cpu_sysdev_class.kset.kobj); | |
1989 | BUG_ON(!cpufreq_global_kobject); | |
e00e56df | 1990 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1991 | |
5a01f2e8 VP |
1992 | return 0; |
1993 | } | |
5a01f2e8 | 1994 | core_initcall(cpufreq_core_init); |