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> |
1da177e4 | 31 | |
e08f5f5b GS |
32 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \ |
33 | "cpufreq-core", msg) | |
1da177e4 LT |
34 | |
35 | /** | |
cd878479 | 36 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
37 | * level driver of CPUFreq support, and its spinlock. This lock |
38 | * also protects the cpufreq_cpu_data array. | |
39 | */ | |
7d5e350f | 40 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 41 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
084f3493 TR |
42 | #ifdef CONFIG_HOTPLUG_CPU |
43 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 44 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 45 | #endif |
1da177e4 LT |
46 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
47 | ||
5a01f2e8 VP |
48 | /* |
49 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
50 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
51 | * | |
52 | * The rules for this semaphore: | |
53 | * - Any routine that wants to read from the policy structure will | |
54 | * do a down_read on this semaphore. | |
55 | * - Any routine that will write to the policy structure and/or may take away | |
56 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
57 | * mode before doing so. | |
58 | * | |
59 | * Additional rules: | |
60 | * - All holders of the lock should check to make sure that the CPU they | |
61 | * are concerned with are online after they get the lock. | |
62 | * - Governor routines that can be called in cpufreq hotplug path should not | |
63 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
64 | * - Lock should not be held across |
65 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 VP |
66 | */ |
67 | static DEFINE_PER_CPU(int, policy_cpu); | |
68 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); | |
69 | ||
70 | #define lock_policy_rwsem(mode, cpu) \ | |
71 | int lock_policy_rwsem_##mode \ | |
72 | (int cpu) \ | |
73 | { \ | |
74 | int policy_cpu = per_cpu(policy_cpu, cpu); \ | |
75 | BUG_ON(policy_cpu == -1); \ | |
76 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
77 | if (unlikely(!cpu_online(cpu))) { \ | |
78 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
79 | return -1; \ | |
80 | } \ | |
81 | \ | |
82 | return 0; \ | |
83 | } | |
84 | ||
85 | lock_policy_rwsem(read, cpu); | |
86 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_read); | |
87 | ||
88 | lock_policy_rwsem(write, cpu); | |
89 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_write); | |
90 | ||
91 | void unlock_policy_rwsem_read(int cpu) | |
92 | { | |
93 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
94 | BUG_ON(policy_cpu == -1); | |
95 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
96 | } | |
97 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_read); | |
98 | ||
99 | void unlock_policy_rwsem_write(int cpu) | |
100 | { | |
101 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
102 | BUG_ON(policy_cpu == -1); | |
103 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_write); | |
106 | ||
107 | ||
1da177e4 | 108 | /* internal prototypes */ |
29464f28 DJ |
109 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
110 | unsigned int event); | |
5a01f2e8 | 111 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 112 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
113 | |
114 | /** | |
32ee8c3e DJ |
115 | * Two notifier lists: the "policy" list is involved in the |
116 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
117 | * "transition" list for kernel code that needs to handle |
118 | * changes to devices when the CPU clock speed changes. | |
119 | * The mutex locks both lists. | |
120 | */ | |
e041c683 | 121 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 122 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 123 | |
74212ca4 | 124 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
125 | static int __init init_cpufreq_transition_notifier_list(void) |
126 | { | |
127 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 128 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
129 | return 0; |
130 | } | |
b3438f82 | 131 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
132 | |
133 | static LIST_HEAD(cpufreq_governor_list); | |
29464f28 | 134 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 135 | |
7d5e350f | 136 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
137 | { |
138 | struct cpufreq_policy *data; | |
139 | unsigned long flags; | |
140 | ||
7a6aedfa | 141 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
142 | goto err_out; |
143 | ||
144 | /* get the cpufreq driver */ | |
145 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
146 | ||
147 | if (!cpufreq_driver) | |
148 | goto err_out_unlock; | |
149 | ||
150 | if (!try_module_get(cpufreq_driver->owner)) | |
151 | goto err_out_unlock; | |
152 | ||
153 | ||
154 | /* get the CPU */ | |
7a6aedfa | 155 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
156 | |
157 | if (!data) | |
158 | goto err_out_put_module; | |
159 | ||
160 | if (!kobject_get(&data->kobj)) | |
161 | goto err_out_put_module; | |
162 | ||
1da177e4 | 163 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
164 | return data; |
165 | ||
7d5e350f | 166 | err_out_put_module: |
1da177e4 | 167 | module_put(cpufreq_driver->owner); |
7d5e350f | 168 | err_out_unlock: |
1da177e4 | 169 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 170 | err_out: |
1da177e4 LT |
171 | return NULL; |
172 | } | |
173 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
174 | ||
7d5e350f | 175 | |
1da177e4 LT |
176 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
177 | { | |
178 | kobject_put(&data->kobj); | |
179 | module_put(cpufreq_driver->owner); | |
180 | } | |
181 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
182 | ||
183 | ||
184 | /********************************************************************* | |
185 | * UNIFIED DEBUG HELPERS * | |
186 | *********************************************************************/ | |
187 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
188 | ||
189 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
190 | static unsigned int debug; | |
191 | ||
192 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
193 | * set or modify this value. | |
194 | */ | |
195 | static unsigned int debug_ratelimit = 1; | |
196 | ||
197 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
198 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
199 | * is set, and disabled upon cpufreq driver removal | |
200 | */ | |
201 | static unsigned int disable_ratelimit = 1; | |
202 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
203 | ||
858119e1 | 204 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
205 | { |
206 | unsigned long flags; | |
207 | ||
208 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
209 | if (disable_ratelimit) | |
210 | disable_ratelimit--; | |
211 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
212 | } | |
213 | ||
858119e1 | 214 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
215 | { |
216 | unsigned long flags; | |
217 | ||
218 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
219 | disable_ratelimit++; | |
220 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
221 | } | |
222 | ||
e08f5f5b | 223 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
905d77cd | 224 | const char *fmt, ...) |
1da177e4 LT |
225 | { |
226 | char s[256]; | |
227 | va_list args; | |
228 | unsigned int len; | |
229 | unsigned long flags; | |
32ee8c3e | 230 | |
1da177e4 LT |
231 | WARN_ON(!prefix); |
232 | if (type & debug) { | |
233 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
234 | if (!disable_ratelimit && debug_ratelimit |
235 | && !printk_ratelimit()) { | |
1da177e4 LT |
236 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
237 | return; | |
238 | } | |
239 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
240 | ||
241 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
242 | ||
243 | va_start(args, fmt); | |
244 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
245 | va_end(args); | |
246 | ||
247 | printk(s); | |
248 | ||
249 | WARN_ON(len < 5); | |
250 | } | |
251 | } | |
252 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
253 | ||
254 | ||
255 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
256 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
257 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
258 | |
259 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
260 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
261 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
262 | |
263 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
264 | ||
265 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
266 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
267 | ||
268 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
269 | ||
270 | ||
271 | /********************************************************************* | |
272 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
273 | *********************************************************************/ | |
274 | ||
275 | /** | |
276 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
277 | * | |
278 | * This function alters the system "loops_per_jiffy" for the clock | |
279 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 280 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
281 | * per-CPU loops_per_jiffy value wherever possible. |
282 | */ | |
283 | #ifndef CONFIG_SMP | |
284 | static unsigned long l_p_j_ref; | |
285 | static unsigned int l_p_j_ref_freq; | |
286 | ||
858119e1 | 287 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
288 | { |
289 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
290 | return; | |
291 | ||
292 | if (!l_p_j_ref_freq) { | |
293 | l_p_j_ref = loops_per_jiffy; | |
294 | l_p_j_ref_freq = ci->old; | |
a4a9df58 | 295 | dprintk("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 296 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 LT |
297 | } |
298 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
299 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 300 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
301 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
302 | ci->new); | |
a4a9df58 | 303 | dprintk("scaling loops_per_jiffy to %lu " |
e08f5f5b | 304 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
305 | } |
306 | } | |
307 | #else | |
e08f5f5b GS |
308 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
309 | { | |
310 | return; | |
311 | } | |
1da177e4 LT |
312 | #endif |
313 | ||
314 | ||
315 | /** | |
e4472cb3 DJ |
316 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
317 | * on frequency transition. | |
1da177e4 | 318 | * |
e4472cb3 DJ |
319 | * This function calls the transition notifiers and the "adjust_jiffies" |
320 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 321 | * external effects. |
1da177e4 LT |
322 | */ |
323 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
324 | { | |
e4472cb3 DJ |
325 | struct cpufreq_policy *policy; |
326 | ||
1da177e4 LT |
327 | BUG_ON(irqs_disabled()); |
328 | ||
329 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
330 | dprintk("notification %u of frequency transition to %u kHz\n", |
331 | state, freqs->new); | |
1da177e4 | 332 | |
7a6aedfa | 333 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 334 | switch (state) { |
e4472cb3 | 335 | |
1da177e4 | 336 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 337 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
338 | * which is not equal to what the cpufreq core thinks is |
339 | * "old frequency". | |
1da177e4 LT |
340 | */ |
341 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
342 | if ((policy) && (policy->cpu == freqs->cpu) && |
343 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 344 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
345 | " %u, cpufreq assumed %u kHz.\n", |
346 | freqs->old, policy->cur); | |
347 | freqs->old = policy->cur; | |
1da177e4 LT |
348 | } |
349 | } | |
b4dfdbb3 | 350 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 351 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
352 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
353 | break; | |
e4472cb3 | 354 | |
1da177e4 LT |
355 | case CPUFREQ_POSTCHANGE: |
356 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
b4dfdbb3 | 357 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 358 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
359 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
360 | policy->cur = freqs->new; | |
1da177e4 LT |
361 | break; |
362 | } | |
1da177e4 LT |
363 | } |
364 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
365 | ||
366 | ||
367 | ||
368 | /********************************************************************* | |
369 | * SYSFS INTERFACE * | |
370 | *********************************************************************/ | |
371 | ||
3bcb09a3 JF |
372 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
373 | { | |
374 | struct cpufreq_governor *t; | |
375 | ||
376 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 377 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
378 | return t; |
379 | ||
380 | return NULL; | |
381 | } | |
382 | ||
1da177e4 LT |
383 | /** |
384 | * cpufreq_parse_governor - parse a governor string | |
385 | */ | |
905d77cd | 386 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
387 | struct cpufreq_governor **governor) |
388 | { | |
3bcb09a3 JF |
389 | int err = -EINVAL; |
390 | ||
1da177e4 | 391 | if (!cpufreq_driver) |
3bcb09a3 JF |
392 | goto out; |
393 | ||
1da177e4 LT |
394 | if (cpufreq_driver->setpolicy) { |
395 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
396 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 397 | err = 0; |
e08f5f5b GS |
398 | } else if (!strnicmp(str_governor, "powersave", |
399 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 400 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 401 | err = 0; |
1da177e4 | 402 | } |
3bcb09a3 | 403 | } else if (cpufreq_driver->target) { |
1da177e4 | 404 | struct cpufreq_governor *t; |
3bcb09a3 | 405 | |
3fc54d37 | 406 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
407 | |
408 | t = __find_governor(str_governor); | |
409 | ||
ea714970 | 410 | if (t == NULL) { |
e08f5f5b GS |
411 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
412 | str_governor); | |
ea714970 JF |
413 | |
414 | if (name) { | |
415 | int ret; | |
416 | ||
417 | mutex_unlock(&cpufreq_governor_mutex); | |
326f6a5c | 418 | ret = request_module("%s", name); |
ea714970 JF |
419 | mutex_lock(&cpufreq_governor_mutex); |
420 | ||
421 | if (ret == 0) | |
422 | t = __find_governor(str_governor); | |
423 | } | |
424 | ||
425 | kfree(name); | |
426 | } | |
427 | ||
3bcb09a3 JF |
428 | if (t != NULL) { |
429 | *governor = t; | |
430 | err = 0; | |
1da177e4 | 431 | } |
3bcb09a3 | 432 | |
3fc54d37 | 433 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 434 | } |
29464f28 | 435 | out: |
3bcb09a3 | 436 | return err; |
1da177e4 | 437 | } |
1da177e4 LT |
438 | |
439 | ||
1da177e4 | 440 | /** |
e08f5f5b GS |
441 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
442 | * print out cpufreq information | |
1da177e4 LT |
443 | * |
444 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
445 | * "unsigned int". | |
446 | */ | |
447 | ||
32ee8c3e DJ |
448 | #define show_one(file_name, object) \ |
449 | static ssize_t show_##file_name \ | |
905d77cd | 450 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 451 | { \ |
29464f28 | 452 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
453 | } |
454 | ||
455 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
456 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 457 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
458 | show_one(scaling_min_freq, min); |
459 | show_one(scaling_max_freq, max); | |
460 | show_one(scaling_cur_freq, cur); | |
461 | ||
e08f5f5b GS |
462 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
463 | struct cpufreq_policy *policy); | |
7970e08b | 464 | |
1da177e4 LT |
465 | /** |
466 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
467 | */ | |
468 | #define store_one(file_name, object) \ | |
469 | static ssize_t store_##file_name \ | |
905d77cd | 470 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
471 | { \ |
472 | unsigned int ret = -EINVAL; \ | |
473 | struct cpufreq_policy new_policy; \ | |
474 | \ | |
475 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
476 | if (ret) \ | |
477 | return -EINVAL; \ | |
478 | \ | |
29464f28 | 479 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
480 | if (ret != 1) \ |
481 | return -EINVAL; \ | |
482 | \ | |
7970e08b TR |
483 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
484 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
485 | \ |
486 | return ret ? ret : count; \ | |
487 | } | |
488 | ||
29464f28 DJ |
489 | store_one(scaling_min_freq, min); |
490 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
491 | |
492 | /** | |
493 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
494 | */ | |
905d77cd DJ |
495 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
496 | char *buf) | |
1da177e4 | 497 | { |
5a01f2e8 | 498 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
499 | if (!cur_freq) |
500 | return sprintf(buf, "<unknown>"); | |
501 | return sprintf(buf, "%u\n", cur_freq); | |
502 | } | |
503 | ||
504 | ||
505 | /** | |
506 | * show_scaling_governor - show the current policy for the specified CPU | |
507 | */ | |
905d77cd | 508 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 509 | { |
29464f28 | 510 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
511 | return sprintf(buf, "powersave\n"); |
512 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
513 | return sprintf(buf, "performance\n"); | |
514 | else if (policy->governor) | |
29464f28 DJ |
515 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", |
516 | policy->governor->name); | |
1da177e4 LT |
517 | return -EINVAL; |
518 | } | |
519 | ||
520 | ||
521 | /** | |
522 | * store_scaling_governor - store policy for the specified CPU | |
523 | */ | |
905d77cd DJ |
524 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
525 | const char *buf, size_t count) | |
1da177e4 LT |
526 | { |
527 | unsigned int ret = -EINVAL; | |
528 | char str_governor[16]; | |
529 | struct cpufreq_policy new_policy; | |
530 | ||
531 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
532 | if (ret) | |
533 | return ret; | |
534 | ||
29464f28 | 535 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
536 | if (ret != 1) |
537 | return -EINVAL; | |
538 | ||
e08f5f5b GS |
539 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
540 | &new_policy.governor)) | |
1da177e4 LT |
541 | return -EINVAL; |
542 | ||
7970e08b TR |
543 | /* Do not use cpufreq_set_policy here or the user_policy.max |
544 | will be wrongly overridden */ | |
7970e08b TR |
545 | ret = __cpufreq_set_policy(policy, &new_policy); |
546 | ||
547 | policy->user_policy.policy = policy->policy; | |
548 | policy->user_policy.governor = policy->governor; | |
7970e08b | 549 | |
e08f5f5b GS |
550 | if (ret) |
551 | return ret; | |
552 | else | |
553 | return count; | |
1da177e4 LT |
554 | } |
555 | ||
556 | /** | |
557 | * show_scaling_driver - show the cpufreq driver currently loaded | |
558 | */ | |
905d77cd | 559 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
560 | { |
561 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
562 | } | |
563 | ||
564 | /** | |
565 | * show_scaling_available_governors - show the available CPUfreq governors | |
566 | */ | |
905d77cd DJ |
567 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
568 | char *buf) | |
1da177e4 LT |
569 | { |
570 | ssize_t i = 0; | |
571 | struct cpufreq_governor *t; | |
572 | ||
573 | if (!cpufreq_driver->target) { | |
574 | i += sprintf(buf, "performance powersave"); | |
575 | goto out; | |
576 | } | |
577 | ||
578 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
579 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
580 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 LT |
581 | goto out; |
582 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
583 | } | |
7d5e350f | 584 | out: |
1da177e4 LT |
585 | i += sprintf(&buf[i], "\n"); |
586 | return i; | |
587 | } | |
e8628dd0 | 588 | |
835481d9 | 589 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
590 | { |
591 | ssize_t i = 0; | |
592 | unsigned int cpu; | |
593 | ||
835481d9 | 594 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
595 | if (i) |
596 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
597 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
598 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 599 | break; |
1da177e4 LT |
600 | } |
601 | i += sprintf(&buf[i], "\n"); | |
602 | return i; | |
603 | } | |
604 | ||
e8628dd0 DW |
605 | /** |
606 | * show_related_cpus - show the CPUs affected by each transition even if | |
607 | * hw coordination is in use | |
608 | */ | |
609 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
610 | { | |
835481d9 | 611 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
612 | return show_cpus(policy->cpus, buf); |
613 | return show_cpus(policy->related_cpus, buf); | |
614 | } | |
615 | ||
616 | /** | |
617 | * show_affected_cpus - show the CPUs affected by each transition | |
618 | */ | |
619 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
620 | { | |
621 | return show_cpus(policy->cpus, buf); | |
622 | } | |
623 | ||
9e76988e | 624 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 625 | const char *buf, size_t count) |
9e76988e VP |
626 | { |
627 | unsigned int freq = 0; | |
628 | unsigned int ret; | |
629 | ||
879000f9 | 630 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
631 | return -EINVAL; |
632 | ||
633 | ret = sscanf(buf, "%u", &freq); | |
634 | if (ret != 1) | |
635 | return -EINVAL; | |
636 | ||
637 | policy->governor->store_setspeed(policy, freq); | |
638 | ||
639 | return count; | |
640 | } | |
641 | ||
642 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
643 | { | |
879000f9 | 644 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
645 | return sprintf(buf, "<unsupported>\n"); |
646 | ||
647 | return policy->governor->show_setspeed(policy, buf); | |
648 | } | |
1da177e4 LT |
649 | |
650 | #define define_one_ro(_name) \ | |
651 | static struct freq_attr _name = \ | |
652 | __ATTR(_name, 0444, show_##_name, NULL) | |
653 | ||
654 | #define define_one_ro0400(_name) \ | |
655 | static struct freq_attr _name = \ | |
656 | __ATTR(_name, 0400, show_##_name, NULL) | |
657 | ||
658 | #define define_one_rw(_name) \ | |
659 | static struct freq_attr _name = \ | |
660 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
661 | ||
662 | define_one_ro0400(cpuinfo_cur_freq); | |
663 | define_one_ro(cpuinfo_min_freq); | |
664 | define_one_ro(cpuinfo_max_freq); | |
ed129784 | 665 | define_one_ro(cpuinfo_transition_latency); |
1da177e4 LT |
666 | define_one_ro(scaling_available_governors); |
667 | define_one_ro(scaling_driver); | |
668 | define_one_ro(scaling_cur_freq); | |
e8628dd0 | 669 | define_one_ro(related_cpus); |
1da177e4 LT |
670 | define_one_ro(affected_cpus); |
671 | define_one_rw(scaling_min_freq); | |
672 | define_one_rw(scaling_max_freq); | |
673 | define_one_rw(scaling_governor); | |
9e76988e | 674 | define_one_rw(scaling_setspeed); |
1da177e4 | 675 | |
905d77cd | 676 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
677 | &cpuinfo_min_freq.attr, |
678 | &cpuinfo_max_freq.attr, | |
ed129784 | 679 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
680 | &scaling_min_freq.attr, |
681 | &scaling_max_freq.attr, | |
682 | &affected_cpus.attr, | |
e8628dd0 | 683 | &related_cpus.attr, |
1da177e4 LT |
684 | &scaling_governor.attr, |
685 | &scaling_driver.attr, | |
686 | &scaling_available_governors.attr, | |
9e76988e | 687 | &scaling_setspeed.attr, |
1da177e4 LT |
688 | NULL |
689 | }; | |
690 | ||
8aa84ad8 TR |
691 | struct kobject *cpufreq_global_kobject; |
692 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
693 | ||
29464f28 DJ |
694 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
695 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 696 | |
29464f28 | 697 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 698 | { |
905d77cd DJ |
699 | struct cpufreq_policy *policy = to_policy(kobj); |
700 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 701 | ssize_t ret = -EINVAL; |
1da177e4 LT |
702 | policy = cpufreq_cpu_get(policy->cpu); |
703 | if (!policy) | |
0db4a8a9 | 704 | goto no_policy; |
5a01f2e8 VP |
705 | |
706 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 707 | goto fail; |
5a01f2e8 | 708 | |
e08f5f5b GS |
709 | if (fattr->show) |
710 | ret = fattr->show(policy, buf); | |
711 | else | |
712 | ret = -EIO; | |
713 | ||
5a01f2e8 | 714 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 715 | fail: |
1da177e4 | 716 | cpufreq_cpu_put(policy); |
0db4a8a9 | 717 | no_policy: |
1da177e4 LT |
718 | return ret; |
719 | } | |
720 | ||
905d77cd DJ |
721 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
722 | const char *buf, size_t count) | |
1da177e4 | 723 | { |
905d77cd DJ |
724 | struct cpufreq_policy *policy = to_policy(kobj); |
725 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 726 | ssize_t ret = -EINVAL; |
1da177e4 LT |
727 | policy = cpufreq_cpu_get(policy->cpu); |
728 | if (!policy) | |
a07530b4 | 729 | goto no_policy; |
5a01f2e8 VP |
730 | |
731 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 732 | goto fail; |
5a01f2e8 | 733 | |
e08f5f5b GS |
734 | if (fattr->store) |
735 | ret = fattr->store(policy, buf, count); | |
736 | else | |
737 | ret = -EIO; | |
738 | ||
5a01f2e8 | 739 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 740 | fail: |
1da177e4 | 741 | cpufreq_cpu_put(policy); |
a07530b4 | 742 | no_policy: |
1da177e4 LT |
743 | return ret; |
744 | } | |
745 | ||
905d77cd | 746 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 747 | { |
905d77cd | 748 | struct cpufreq_policy *policy = to_policy(kobj); |
1da177e4 LT |
749 | dprintk("last reference is dropped\n"); |
750 | complete(&policy->kobj_unregister); | |
751 | } | |
752 | ||
753 | static struct sysfs_ops sysfs_ops = { | |
754 | .show = show, | |
755 | .store = store, | |
756 | }; | |
757 | ||
758 | static struct kobj_type ktype_cpufreq = { | |
759 | .sysfs_ops = &sysfs_ops, | |
760 | .default_attrs = default_attrs, | |
761 | .release = cpufreq_sysfs_release, | |
762 | }; | |
763 | ||
4bfa042c TR |
764 | /* |
765 | * Returns: | |
766 | * Negative: Failure | |
767 | * 0: Success | |
768 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
769 | */ | |
ecf7e461 DJ |
770 | int cpufreq_add_dev_policy(unsigned int cpu, struct cpufreq_policy *policy, |
771 | struct sys_device *sys_dev) | |
772 | { | |
773 | int ret = 0; | |
774 | #ifdef CONFIG_SMP | |
775 | unsigned long flags; | |
776 | unsigned int j; | |
ecf7e461 | 777 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
778 | struct cpufreq_governor *gov; |
779 | ||
780 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
781 | if (gov) { | |
782 | policy->governor = gov; | |
ecf7e461 DJ |
783 | dprintk("Restoring governor %s for cpu %d\n", |
784 | policy->governor->name, cpu); | |
785 | } | |
786 | #endif | |
787 | ||
788 | for_each_cpu(j, policy->cpus) { | |
789 | struct cpufreq_policy *managed_policy; | |
790 | ||
791 | if (cpu == j) | |
792 | continue; | |
793 | ||
794 | /* Check for existing affected CPUs. | |
795 | * They may not be aware of it due to CPU Hotplug. | |
796 | * cpufreq_cpu_put is called when the device is removed | |
797 | * in __cpufreq_remove_dev() | |
798 | */ | |
799 | managed_policy = cpufreq_cpu_get(j); | |
800 | if (unlikely(managed_policy)) { | |
801 | ||
802 | /* Set proper policy_cpu */ | |
803 | unlock_policy_rwsem_write(cpu); | |
804 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
805 | ||
806 | if (lock_policy_rwsem_write(cpu) < 0) { | |
807 | /* Should not go through policy unlock path */ | |
808 | if (cpufreq_driver->exit) | |
809 | cpufreq_driver->exit(policy); | |
810 | cpufreq_cpu_put(managed_policy); | |
811 | return -EBUSY; | |
812 | } | |
813 | ||
814 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
815 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
816 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
817 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
818 | ||
819 | dprintk("CPU already managed, adding link\n"); | |
820 | ret = sysfs_create_link(&sys_dev->kobj, | |
821 | &managed_policy->kobj, | |
822 | "cpufreq"); | |
823 | if (ret) | |
824 | cpufreq_cpu_put(managed_policy); | |
825 | /* | |
826 | * Success. We only needed to be added to the mask. | |
827 | * Call driver->exit() because only the cpu parent of | |
828 | * the kobj needed to call init(). | |
829 | */ | |
830 | if (cpufreq_driver->exit) | |
831 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
832 | |
833 | if (!ret) | |
834 | return 1; | |
835 | else | |
836 | return ret; | |
ecf7e461 DJ |
837 | } |
838 | } | |
839 | #endif | |
840 | return ret; | |
841 | } | |
842 | ||
843 | ||
19d6f7ec DJ |
844 | /* symlink affected CPUs */ |
845 | int cpufreq_add_dev_symlink(unsigned int cpu, struct cpufreq_policy *policy) | |
846 | { | |
847 | unsigned int j; | |
848 | int ret = 0; | |
849 | ||
850 | for_each_cpu(j, policy->cpus) { | |
851 | struct cpufreq_policy *managed_policy; | |
852 | struct sys_device *cpu_sys_dev; | |
853 | ||
854 | if (j == cpu) | |
855 | continue; | |
856 | if (!cpu_online(j)) | |
857 | continue; | |
858 | ||
859 | dprintk("CPU %u already managed, adding link\n", j); | |
860 | managed_policy = cpufreq_cpu_get(cpu); | |
861 | cpu_sys_dev = get_cpu_sysdev(j); | |
862 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
863 | "cpufreq"); | |
864 | if (ret) { | |
865 | cpufreq_cpu_put(managed_policy); | |
866 | return ret; | |
867 | } | |
868 | } | |
869 | return ret; | |
870 | } | |
871 | ||
909a694e DJ |
872 | int cpufreq_add_dev_interface(unsigned int cpu, struct cpufreq_policy *policy, |
873 | struct sys_device *sys_dev) | |
874 | { | |
ecf7e461 | 875 | struct cpufreq_policy new_policy; |
909a694e DJ |
876 | struct freq_attr **drv_attr; |
877 | unsigned long flags; | |
878 | int ret = 0; | |
879 | unsigned int j; | |
880 | ||
881 | /* prepare interface data */ | |
882 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
883 | &sys_dev->kobj, "cpufreq"); | |
884 | if (ret) | |
885 | return ret; | |
886 | ||
887 | /* set up files for this cpu device */ | |
888 | drv_attr = cpufreq_driver->attr; | |
889 | while ((drv_attr) && (*drv_attr)) { | |
890 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
891 | if (ret) | |
892 | goto err_out_kobj_put; | |
893 | drv_attr++; | |
894 | } | |
895 | if (cpufreq_driver->get) { | |
896 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
897 | if (ret) | |
898 | goto err_out_kobj_put; | |
899 | } | |
900 | if (cpufreq_driver->target) { | |
901 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
902 | if (ret) | |
903 | goto err_out_kobj_put; | |
904 | } | |
905 | ||
906 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
907 | for_each_cpu(j, policy->cpus) { | |
908 | if (!cpu_online(j)) | |
909 | continue; | |
910 | per_cpu(cpufreq_cpu_data, j) = policy; | |
911 | per_cpu(policy_cpu, j) = policy->cpu; | |
912 | } | |
913 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
914 | ||
915 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
916 | if (ret) |
917 | goto err_out_kobj_put; | |
918 | ||
919 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
920 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
921 | policy->governor = NULL; | |
922 | ||
923 | /* set default policy */ | |
924 | ret = __cpufreq_set_policy(policy, &new_policy); | |
925 | policy->user_policy.policy = policy->policy; | |
926 | policy->user_policy.governor = policy->governor; | |
927 | ||
928 | if (ret) { | |
929 | dprintk("setting policy failed\n"); | |
930 | if (cpufreq_driver->exit) | |
931 | cpufreq_driver->exit(policy); | |
932 | } | |
909a694e DJ |
933 | return ret; |
934 | ||
935 | err_out_kobj_put: | |
936 | kobject_put(&policy->kobj); | |
937 | wait_for_completion(&policy->kobj_unregister); | |
938 | return ret; | |
939 | } | |
940 | ||
1da177e4 LT |
941 | |
942 | /** | |
943 | * cpufreq_add_dev - add a CPU device | |
944 | * | |
32ee8c3e | 945 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
946 | * |
947 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
948 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
949 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 950 | */ |
905d77cd | 951 | static int cpufreq_add_dev(struct sys_device *sys_dev) |
1da177e4 LT |
952 | { |
953 | unsigned int cpu = sys_dev->id; | |
954 | int ret = 0; | |
1da177e4 | 955 | struct cpufreq_policy *policy; |
1da177e4 LT |
956 | unsigned long flags; |
957 | unsigned int j; | |
958 | ||
c32b6b8e AR |
959 | if (cpu_is_offline(cpu)) |
960 | return 0; | |
961 | ||
1da177e4 LT |
962 | cpufreq_debug_disable_ratelimit(); |
963 | dprintk("adding CPU %u\n", cpu); | |
964 | ||
965 | #ifdef CONFIG_SMP | |
966 | /* check whether a different CPU already registered this | |
967 | * CPU because it is in the same boat. */ | |
968 | policy = cpufreq_cpu_get(cpu); | |
969 | if (unlikely(policy)) { | |
8ff69732 | 970 | cpufreq_cpu_put(policy); |
1da177e4 LT |
971 | cpufreq_debug_enable_ratelimit(); |
972 | return 0; | |
973 | } | |
974 | #endif | |
975 | ||
976 | if (!try_module_get(cpufreq_driver->owner)) { | |
977 | ret = -EINVAL; | |
978 | goto module_out; | |
979 | } | |
980 | ||
059019a3 | 981 | ret = -ENOMEM; |
e98df50c | 982 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 983 | if (!policy) |
1da177e4 | 984 | goto nomem_out; |
059019a3 DJ |
985 | |
986 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 987 | goto err_free_policy; |
059019a3 DJ |
988 | |
989 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 990 | goto err_free_cpumask; |
1da177e4 LT |
991 | |
992 | policy->cpu = cpu; | |
835481d9 | 993 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 994 | |
5a01f2e8 VP |
995 | /* Initially set CPU itself as the policy_cpu */ |
996 | per_cpu(policy_cpu, cpu) = cpu; | |
3f4a782b MD |
997 | ret = (lock_policy_rwsem_write(cpu) < 0); |
998 | WARN_ON(ret); | |
5a01f2e8 | 999 | |
1da177e4 | 1000 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1001 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 1002 | |
8122c6ce TR |
1003 | /* Set governor before ->init, so that driver could check it */ |
1004 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
1005 | /* call driver. From then on the cpufreq must be able |
1006 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1007 | */ | |
1008 | ret = cpufreq_driver->init(policy); | |
1009 | if (ret) { | |
1010 | dprintk("initialization failed\n"); | |
3f4a782b | 1011 | goto err_unlock_policy; |
1da177e4 | 1012 | } |
187d9f4e MC |
1013 | policy->user_policy.min = policy->min; |
1014 | policy->user_policy.max = policy->max; | |
1da177e4 | 1015 | |
a1531acd TR |
1016 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1017 | CPUFREQ_START, policy); | |
1018 | ||
ecf7e461 | 1019 | ret = cpufreq_add_dev_policy(cpu, policy, sys_dev); |
4bfa042c TR |
1020 | if (ret) { |
1021 | if (ret > 0) | |
1022 | /* This is a managed cpu, symlink created, | |
1023 | exit with 0 */ | |
1024 | ret = 0; | |
ecf7e461 | 1025 | goto err_unlock_policy; |
4bfa042c | 1026 | } |
1da177e4 | 1027 | |
909a694e | 1028 | ret = cpufreq_add_dev_interface(cpu, policy, sys_dev); |
19d6f7ec DJ |
1029 | if (ret) |
1030 | goto err_out_unregister; | |
8ff69732 | 1031 | |
dca02613 LW |
1032 | unlock_policy_rwsem_write(cpu); |
1033 | ||
038c5b3e | 1034 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 1035 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
1036 | dprintk("initialization complete\n"); |
1037 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 1038 | |
1da177e4 LT |
1039 | return 0; |
1040 | ||
1041 | ||
1042 | err_out_unregister: | |
1043 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1044 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1045 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1046 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1047 | ||
c10997f6 | 1048 | kobject_put(&policy->kobj); |
1da177e4 LT |
1049 | wait_for_completion(&policy->kobj_unregister); |
1050 | ||
3f4a782b | 1051 | err_unlock_policy: |
45709118 | 1052 | unlock_policy_rwsem_write(cpu); |
3f4a782b MD |
1053 | err_free_cpumask: |
1054 | free_cpumask_var(policy->cpus); | |
1055 | err_free_policy: | |
1da177e4 | 1056 | kfree(policy); |
1da177e4 LT |
1057 | nomem_out: |
1058 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1059 | module_out: |
1da177e4 LT |
1060 | cpufreq_debug_enable_ratelimit(); |
1061 | return ret; | |
1062 | } | |
1063 | ||
1064 | ||
1065 | /** | |
5a01f2e8 | 1066 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1067 | * |
1068 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1069 | * Caller should already have policy_rwsem in write mode for this CPU. |
1070 | * This routine frees the rwsem before returning. | |
1da177e4 | 1071 | */ |
905d77cd | 1072 | static int __cpufreq_remove_dev(struct sys_device *sys_dev) |
1da177e4 LT |
1073 | { |
1074 | unsigned int cpu = sys_dev->id; | |
1075 | unsigned long flags; | |
1076 | struct cpufreq_policy *data; | |
1077 | #ifdef CONFIG_SMP | |
e738cf6d | 1078 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
1079 | unsigned int j; |
1080 | #endif | |
1081 | ||
1082 | cpufreq_debug_disable_ratelimit(); | |
1083 | dprintk("unregistering CPU %u\n", cpu); | |
1084 | ||
1085 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1086 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1087 | |
1088 | if (!data) { | |
1089 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 1090 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 1091 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1092 | return -EINVAL; |
1093 | } | |
7a6aedfa | 1094 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1095 | |
1096 | ||
1097 | #ifdef CONFIG_SMP | |
1098 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1099 | * only need to unlink, put and exit |
1da177e4 LT |
1100 | */ |
1101 | if (unlikely(cpu != data->cpu)) { | |
1102 | dprintk("removing link\n"); | |
835481d9 | 1103 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 LT |
1104 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1105 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1106 | cpufreq_cpu_put(data); |
1107 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 1108 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1109 | return 0; |
1110 | } | |
1111 | #endif | |
1112 | ||
1da177e4 | 1113 | #ifdef CONFIG_SMP |
084f3493 TR |
1114 | |
1115 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1116 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1117 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1118 | #endif |
1119 | ||
1da177e4 LT |
1120 | /* if we have other CPUs still registered, we need to unlink them, |
1121 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1122 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1123 | * the sysfs links afterwards. | |
1da177e4 | 1124 | */ |
835481d9 RR |
1125 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1126 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1127 | if (j == cpu) |
1128 | continue; | |
7a6aedfa | 1129 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1130 | } |
1131 | } | |
1132 | ||
1133 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1134 | ||
835481d9 RR |
1135 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1136 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1137 | if (j == cpu) |
1138 | continue; | |
1139 | dprintk("removing link for cpu %u\n", j); | |
084f3493 | 1140 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1141 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1142 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1143 | #endif |
d434fca7 AR |
1144 | cpu_sys_dev = get_cpu_sysdev(j); |
1145 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1146 | cpufreq_cpu_put(data); |
1147 | } | |
1148 | } | |
1149 | #else | |
1150 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1151 | #endif | |
1152 | ||
1da177e4 LT |
1153 | if (cpufreq_driver->target) |
1154 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1155 | |
1da177e4 LT |
1156 | kobject_put(&data->kobj); |
1157 | ||
1158 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1159 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1160 | * unloading. |
1161 | */ | |
1162 | dprintk("waiting for dropping of refcount\n"); | |
1163 | wait_for_completion(&data->kobj_unregister); | |
1164 | dprintk("wait complete\n"); | |
1165 | ||
1166 | if (cpufreq_driver->exit) | |
1167 | cpufreq_driver->exit(data); | |
1168 | ||
7d26e2d5 | 1169 | unlock_policy_rwsem_write(cpu); |
1170 | ||
835481d9 RR |
1171 | free_cpumask_var(data->related_cpus); |
1172 | free_cpumask_var(data->cpus); | |
1da177e4 | 1173 | kfree(data); |
835481d9 | 1174 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1175 | |
1176 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1177 | return 0; |
1178 | } | |
1179 | ||
1180 | ||
905d77cd | 1181 | static int cpufreq_remove_dev(struct sys_device *sys_dev) |
5a01f2e8 VP |
1182 | { |
1183 | unsigned int cpu = sys_dev->id; | |
1184 | int retval; | |
ec28297a VP |
1185 | |
1186 | if (cpu_is_offline(cpu)) | |
1187 | return 0; | |
1188 | ||
5a01f2e8 VP |
1189 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1190 | BUG(); | |
1191 | ||
1192 | retval = __cpufreq_remove_dev(sys_dev); | |
1193 | return retval; | |
1194 | } | |
1195 | ||
1196 | ||
65f27f38 | 1197 | static void handle_update(struct work_struct *work) |
1da177e4 | 1198 | { |
65f27f38 DH |
1199 | struct cpufreq_policy *policy = |
1200 | container_of(work, struct cpufreq_policy, update); | |
1201 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1202 | dprintk("handle_update for cpu %u called\n", cpu); |
1203 | cpufreq_update_policy(cpu); | |
1204 | } | |
1205 | ||
1206 | /** | |
1207 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1208 | * @cpu: cpu number | |
1209 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1210 | * @new_freq: CPU frequency the CPU actually runs at | |
1211 | * | |
29464f28 DJ |
1212 | * We adjust to current frequency first, and need to clean up later. |
1213 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1214 | */ |
e08f5f5b GS |
1215 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1216 | unsigned int new_freq) | |
1da177e4 LT |
1217 | { |
1218 | struct cpufreq_freqs freqs; | |
1219 | ||
b10eec22 | 1220 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1221 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1222 | ||
1223 | freqs.cpu = cpu; | |
1224 | freqs.old = old_freq; | |
1225 | freqs.new = new_freq; | |
1226 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1227 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1228 | } | |
1229 | ||
1230 | ||
32ee8c3e | 1231 | /** |
4ab70df4 | 1232 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1233 | * @cpu: CPU number |
1234 | * | |
1235 | * This is the last known freq, without actually getting it from the driver. | |
1236 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1237 | */ | |
1238 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1239 | { | |
1240 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1241 | unsigned int ret_freq = 0; |
95235ca2 VP |
1242 | |
1243 | if (policy) { | |
e08f5f5b | 1244 | ret_freq = policy->cur; |
95235ca2 VP |
1245 | cpufreq_cpu_put(policy); |
1246 | } | |
1247 | ||
4d34a67d | 1248 | return ret_freq; |
95235ca2 VP |
1249 | } |
1250 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1251 | ||
1252 | ||
5a01f2e8 | 1253 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1254 | { |
7a6aedfa | 1255 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1256 | unsigned int ret_freq = 0; |
1da177e4 | 1257 | |
1da177e4 | 1258 | if (!cpufreq_driver->get) |
4d34a67d | 1259 | return ret_freq; |
1da177e4 | 1260 | |
e08f5f5b | 1261 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1262 | |
e08f5f5b GS |
1263 | if (ret_freq && policy->cur && |
1264 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1265 | /* verify no discrepancy between actual and | |
1266 | saved value exists */ | |
1267 | if (unlikely(ret_freq != policy->cur)) { | |
1268 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1269 | schedule_work(&policy->update); |
1270 | } | |
1271 | } | |
1272 | ||
4d34a67d | 1273 | return ret_freq; |
5a01f2e8 | 1274 | } |
1da177e4 | 1275 | |
5a01f2e8 VP |
1276 | /** |
1277 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1278 | * @cpu: CPU number | |
1279 | * | |
1280 | * Get the CPU current (static) CPU frequency | |
1281 | */ | |
1282 | unsigned int cpufreq_get(unsigned int cpu) | |
1283 | { | |
1284 | unsigned int ret_freq = 0; | |
1285 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1286 | ||
1287 | if (!policy) | |
1288 | goto out; | |
1289 | ||
1290 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1291 | goto out_policy; | |
1292 | ||
1293 | ret_freq = __cpufreq_get(cpu); | |
1294 | ||
1295 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1296 | |
5a01f2e8 VP |
1297 | out_policy: |
1298 | cpufreq_cpu_put(policy); | |
1299 | out: | |
4d34a67d | 1300 | return ret_freq; |
1da177e4 LT |
1301 | } |
1302 | EXPORT_SYMBOL(cpufreq_get); | |
1303 | ||
1304 | ||
42d4dc3f BH |
1305 | /** |
1306 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1307 | */ | |
1308 | ||
905d77cd | 1309 | static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg) |
42d4dc3f | 1310 | { |
e08f5f5b | 1311 | int ret = 0; |
4bc5d341 | 1312 | |
4bc5d341 | 1313 | int cpu = sysdev->id; |
42d4dc3f BH |
1314 | struct cpufreq_policy *cpu_policy; |
1315 | ||
0e37b159 | 1316 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1317 | |
1318 | if (!cpu_online(cpu)) | |
1319 | return 0; | |
1320 | ||
1321 | /* we may be lax here as interrupts are off. Nonetheless | |
1322 | * we need to grab the correct cpu policy, as to check | |
1323 | * whether we really run on this CPU. | |
1324 | */ | |
1325 | ||
1326 | cpu_policy = cpufreq_cpu_get(cpu); | |
1327 | if (!cpu_policy) | |
1328 | return -EINVAL; | |
1329 | ||
1330 | /* only handle each CPU group once */ | |
c9060494 DJ |
1331 | if (unlikely(cpu_policy->cpu != cpu)) |
1332 | goto out; | |
42d4dc3f BH |
1333 | |
1334 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1335 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
ce6c3997 | 1336 | if (ret) |
42d4dc3f BH |
1337 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1338 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1339 | } |
1340 | ||
7d5e350f | 1341 | out: |
42d4dc3f | 1342 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1343 | return ret; |
42d4dc3f BH |
1344 | } |
1345 | ||
1da177e4 LT |
1346 | /** |
1347 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1348 | * | |
1349 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1350 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1351 | * restored. It will verify that the current freq is in sync with | |
1352 | * what we believe it to be. This is a bit later than when it | |
1353 | * should be, but nonethteless it's better than calling | |
1354 | * cpufreq_driver->get() here which might re-enable interrupts... | |
1da177e4 | 1355 | */ |
905d77cd | 1356 | static int cpufreq_resume(struct sys_device *sysdev) |
1da177e4 | 1357 | { |
e08f5f5b | 1358 | int ret = 0; |
4bc5d341 | 1359 | |
4bc5d341 | 1360 | int cpu = sysdev->id; |
1da177e4 LT |
1361 | struct cpufreq_policy *cpu_policy; |
1362 | ||
1363 | dprintk("resuming cpu %u\n", cpu); | |
1364 | ||
1365 | if (!cpu_online(cpu)) | |
1366 | return 0; | |
1367 | ||
1368 | /* we may be lax here as interrupts are off. Nonetheless | |
1369 | * we need to grab the correct cpu policy, as to check | |
1370 | * whether we really run on this CPU. | |
1371 | */ | |
1372 | ||
1373 | cpu_policy = cpufreq_cpu_get(cpu); | |
1374 | if (!cpu_policy) | |
1375 | return -EINVAL; | |
1376 | ||
1377 | /* only handle each CPU group once */ | |
c9060494 DJ |
1378 | if (unlikely(cpu_policy->cpu != cpu)) |
1379 | goto fail; | |
1da177e4 LT |
1380 | |
1381 | if (cpufreq_driver->resume) { | |
1382 | ret = cpufreq_driver->resume(cpu_policy); | |
1383 | if (ret) { | |
1384 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1385 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1386 | goto fail; |
1da177e4 LT |
1387 | } |
1388 | } | |
1389 | ||
1da177e4 | 1390 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1391 | |
c9060494 | 1392 | fail: |
1da177e4 LT |
1393 | cpufreq_cpu_put(cpu_policy); |
1394 | return ret; | |
1395 | } | |
1396 | ||
1397 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1398 | .add = cpufreq_add_dev, | |
1399 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1400 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1401 | .resume = cpufreq_resume, |
1402 | }; | |
1403 | ||
1404 | ||
1405 | /********************************************************************* | |
1406 | * NOTIFIER LISTS INTERFACE * | |
1407 | *********************************************************************/ | |
1408 | ||
1409 | /** | |
1410 | * cpufreq_register_notifier - register a driver with cpufreq | |
1411 | * @nb: notifier function to register | |
1412 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1413 | * | |
32ee8c3e | 1414 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1415 | * are notified about clock rate changes (once before and once after |
1416 | * the transition), or a list of drivers that are notified about | |
1417 | * changes in cpufreq policy. | |
1418 | * | |
1419 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1420 | * blocking_notifier_chain_register. |
1da177e4 LT |
1421 | */ |
1422 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1423 | { | |
1424 | int ret; | |
1425 | ||
74212ca4 CEB |
1426 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1427 | ||
1da177e4 LT |
1428 | switch (list) { |
1429 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1430 | ret = srcu_notifier_chain_register( |
e041c683 | 1431 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1432 | break; |
1433 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1434 | ret = blocking_notifier_chain_register( |
1435 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1436 | break; |
1437 | default: | |
1438 | ret = -EINVAL; | |
1439 | } | |
1da177e4 LT |
1440 | |
1441 | return ret; | |
1442 | } | |
1443 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1444 | ||
1445 | ||
1446 | /** | |
1447 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1448 | * @nb: notifier block to be unregistered | |
1449 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1450 | * | |
1451 | * Remove a driver from the CPU frequency notifier list. | |
1452 | * | |
1453 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1454 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1455 | */ |
1456 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1457 | { | |
1458 | int ret; | |
1459 | ||
1da177e4 LT |
1460 | switch (list) { |
1461 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1462 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1463 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1464 | break; |
1465 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1466 | ret = blocking_notifier_chain_unregister( |
1467 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1468 | break; |
1469 | default: | |
1470 | ret = -EINVAL; | |
1471 | } | |
1da177e4 LT |
1472 | |
1473 | return ret; | |
1474 | } | |
1475 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1476 | ||
1477 | ||
1478 | /********************************************************************* | |
1479 | * GOVERNORS * | |
1480 | *********************************************************************/ | |
1481 | ||
1482 | ||
1483 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1484 | unsigned int target_freq, | |
1485 | unsigned int relation) | |
1486 | { | |
1487 | int retval = -EINVAL; | |
c32b6b8e | 1488 | |
1da177e4 LT |
1489 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1490 | target_freq, relation); | |
1491 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1492 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1493 | |
1da177e4 LT |
1494 | return retval; |
1495 | } | |
1496 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1497 | ||
1da177e4 LT |
1498 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1499 | unsigned int target_freq, | |
1500 | unsigned int relation) | |
1501 | { | |
f1829e4a | 1502 | int ret = -EINVAL; |
1da177e4 LT |
1503 | |
1504 | policy = cpufreq_cpu_get(policy->cpu); | |
1505 | if (!policy) | |
f1829e4a | 1506 | goto no_policy; |
1da177e4 | 1507 | |
5a01f2e8 | 1508 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1509 | goto fail; |
1da177e4 LT |
1510 | |
1511 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1512 | ||
5a01f2e8 | 1513 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1514 | |
f1829e4a | 1515 | fail: |
1da177e4 | 1516 | cpufreq_cpu_put(policy); |
f1829e4a | 1517 | no_policy: |
1da177e4 LT |
1518 | return ret; |
1519 | } | |
1520 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1521 | ||
bf0b90e3 | 1522 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1523 | { |
1524 | int ret = 0; | |
1525 | ||
1526 | policy = cpufreq_cpu_get(policy->cpu); | |
1527 | if (!policy) | |
1528 | return -EINVAL; | |
1529 | ||
bf0b90e3 | 1530 | if (cpu_online(cpu) && cpufreq_driver->getavg) |
1531 | ret = cpufreq_driver->getavg(policy, cpu); | |
dfde5d62 | 1532 | |
dfde5d62 VP |
1533 | cpufreq_cpu_put(policy); |
1534 | return ret; | |
1535 | } | |
5a01f2e8 | 1536 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1537 | |
153d7f3f | 1538 | /* |
153d7f3f AV |
1539 | * when "event" is CPUFREQ_GOV_LIMITS |
1540 | */ | |
1da177e4 | 1541 | |
e08f5f5b GS |
1542 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1543 | unsigned int event) | |
1da177e4 | 1544 | { |
cc993cab | 1545 | int ret; |
6afde10c TR |
1546 | |
1547 | /* Only must be defined when default governor is known to have latency | |
1548 | restrictions, like e.g. conservative or ondemand. | |
1549 | That this is the case is already ensured in Kconfig | |
1550 | */ | |
1551 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1552 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1553 | #else | |
1554 | struct cpufreq_governor *gov = NULL; | |
1555 | #endif | |
1c256245 TR |
1556 | |
1557 | if (policy->governor->max_transition_latency && | |
1558 | policy->cpuinfo.transition_latency > | |
1559 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1560 | if (!gov) |
1561 | return -EINVAL; | |
1562 | else { | |
1563 | printk(KERN_WARNING "%s governor failed, too long" | |
1564 | " transition latency of HW, fallback" | |
1565 | " to %s governor\n", | |
1566 | policy->governor->name, | |
1567 | gov->name); | |
1568 | policy->governor = gov; | |
1569 | } | |
1c256245 | 1570 | } |
1da177e4 LT |
1571 | |
1572 | if (!try_module_get(policy->governor->owner)) | |
1573 | return -EINVAL; | |
1574 | ||
e08f5f5b GS |
1575 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1576 | policy->cpu, event); | |
1da177e4 LT |
1577 | ret = policy->governor->governor(policy, event); |
1578 | ||
e08f5f5b GS |
1579 | /* we keep one module reference alive for |
1580 | each CPU governed by this CPU */ | |
1da177e4 LT |
1581 | if ((event != CPUFREQ_GOV_START) || ret) |
1582 | module_put(policy->governor->owner); | |
1583 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1584 | module_put(policy->governor->owner); | |
1585 | ||
1586 | return ret; | |
1587 | } | |
1588 | ||
1589 | ||
1da177e4 LT |
1590 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1591 | { | |
3bcb09a3 | 1592 | int err; |
1da177e4 LT |
1593 | |
1594 | if (!governor) | |
1595 | return -EINVAL; | |
1596 | ||
3fc54d37 | 1597 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1598 | |
3bcb09a3 JF |
1599 | err = -EBUSY; |
1600 | if (__find_governor(governor->name) == NULL) { | |
1601 | err = 0; | |
1602 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1603 | } |
1da177e4 | 1604 | |
32ee8c3e | 1605 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1606 | return err; |
1da177e4 LT |
1607 | } |
1608 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1609 | ||
1610 | ||
1611 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1612 | { | |
1613 | if (!governor) | |
1614 | return; | |
1615 | ||
3fc54d37 | 1616 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1617 | list_del(&governor->governor_list); |
3fc54d37 | 1618 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1619 | return; |
1620 | } | |
1621 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1622 | ||
1623 | ||
1624 | ||
1625 | /********************************************************************* | |
1626 | * POLICY INTERFACE * | |
1627 | *********************************************************************/ | |
1628 | ||
1629 | /** | |
1630 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1631 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1632 | * is written | |
1da177e4 LT |
1633 | * |
1634 | * Reads the current cpufreq policy. | |
1635 | */ | |
1636 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1637 | { | |
1638 | struct cpufreq_policy *cpu_policy; | |
1639 | if (!policy) | |
1640 | return -EINVAL; | |
1641 | ||
1642 | cpu_policy = cpufreq_cpu_get(cpu); | |
1643 | if (!cpu_policy) | |
1644 | return -EINVAL; | |
1645 | ||
1da177e4 | 1646 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1647 | |
1648 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1649 | return 0; |
1650 | } | |
1651 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1652 | ||
1653 | ||
153d7f3f | 1654 | /* |
e08f5f5b GS |
1655 | * data : current policy. |
1656 | * policy : policy to be set. | |
153d7f3f | 1657 | */ |
e08f5f5b GS |
1658 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1659 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1660 | { |
1661 | int ret = 0; | |
1662 | ||
1663 | cpufreq_debug_disable_ratelimit(); | |
1664 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1665 | policy->min, policy->max); | |
1666 | ||
e08f5f5b GS |
1667 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1668 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1669 | |
53391fa2 | 1670 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1671 | ret = -EINVAL; |
1672 | goto error_out; | |
1673 | } | |
1674 | ||
1da177e4 LT |
1675 | /* verify the cpu speed can be set within this limit */ |
1676 | ret = cpufreq_driver->verify(policy); | |
1677 | if (ret) | |
1678 | goto error_out; | |
1679 | ||
1da177e4 | 1680 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1681 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1682 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1683 | |
1684 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1685 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1686 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1687 | |
1688 | /* verify the cpu speed can be set within this limit, | |
1689 | which might be different to the first one */ | |
1690 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1691 | if (ret) |
1da177e4 | 1692 | goto error_out; |
1da177e4 LT |
1693 | |
1694 | /* notification of the new policy */ | |
e041c683 AS |
1695 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1696 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1697 | |
7d5e350f DJ |
1698 | data->min = policy->min; |
1699 | data->max = policy->max; | |
1da177e4 | 1700 | |
e08f5f5b GS |
1701 | dprintk("new min and max freqs are %u - %u kHz\n", |
1702 | data->min, data->max); | |
1da177e4 LT |
1703 | |
1704 | if (cpufreq_driver->setpolicy) { | |
1705 | data->policy = policy->policy; | |
1706 | dprintk("setting range\n"); | |
1707 | ret = cpufreq_driver->setpolicy(policy); | |
1708 | } else { | |
1709 | if (policy->governor != data->governor) { | |
1710 | /* save old, working values */ | |
1711 | struct cpufreq_governor *old_gov = data->governor; | |
1712 | ||
1713 | dprintk("governor switch\n"); | |
1714 | ||
1715 | /* end old governor */ | |
395913d0 MD |
1716 | if (data->governor) { |
1717 | /* | |
1718 | * Need to release the rwsem around governor | |
1719 | * stop due to lock dependency between | |
1720 | * cancel_delayed_work_sync and the read lock | |
1721 | * taken in the delayed work handler. | |
1722 | */ | |
1723 | unlock_policy_rwsem_write(data->cpu); | |
1da177e4 | 1724 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
395913d0 MD |
1725 | lock_policy_rwsem_write(data->cpu); |
1726 | } | |
1da177e4 LT |
1727 | |
1728 | /* start new governor */ | |
1729 | data->governor = policy->governor; | |
1730 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1731 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1732 | dprintk("starting governor %s failed\n", |
1733 | data->governor->name); | |
1da177e4 LT |
1734 | if (old_gov) { |
1735 | data->governor = old_gov; | |
e08f5f5b GS |
1736 | __cpufreq_governor(data, |
1737 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1738 | } |
1739 | ret = -EINVAL; | |
1740 | goto error_out; | |
1741 | } | |
1742 | /* might be a policy change, too, so fall through */ | |
1743 | } | |
1744 | dprintk("governor: change or update limits\n"); | |
1745 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1746 | } | |
1747 | ||
7d5e350f | 1748 | error_out: |
1da177e4 LT |
1749 | cpufreq_debug_enable_ratelimit(); |
1750 | return ret; | |
1751 | } | |
1752 | ||
1da177e4 LT |
1753 | /** |
1754 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1755 | * @cpu: CPU which shall be re-evaluated | |
1756 | * | |
1757 | * Usefull for policy notifiers which have different necessities | |
1758 | * at different times. | |
1759 | */ | |
1760 | int cpufreq_update_policy(unsigned int cpu) | |
1761 | { | |
1762 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1763 | struct cpufreq_policy policy; | |
f1829e4a | 1764 | int ret; |
1da177e4 | 1765 | |
f1829e4a JL |
1766 | if (!data) { |
1767 | ret = -ENODEV; | |
1768 | goto no_policy; | |
1769 | } | |
1da177e4 | 1770 | |
f1829e4a JL |
1771 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1772 | ret = -EINVAL; | |
1773 | goto fail; | |
1774 | } | |
1da177e4 LT |
1775 | |
1776 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1777 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1778 | policy.min = data->user_policy.min; |
1779 | policy.max = data->user_policy.max; | |
1780 | policy.policy = data->user_policy.policy; | |
1781 | policy.governor = data->user_policy.governor; | |
1782 | ||
0961dd0d TR |
1783 | /* BIOS might change freq behind our back |
1784 | -> ask driver for current freq and notify governors about a change */ | |
1785 | if (cpufreq_driver->get) { | |
1786 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1787 | if (!data->cur) { |
1788 | dprintk("Driver did not initialize current freq"); | |
1789 | data->cur = policy.cur; | |
1790 | } else { | |
1791 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1792 | cpufreq_out_of_sync(cpu, data->cur, |
1793 | policy.cur); | |
a85f7bd3 | 1794 | } |
0961dd0d TR |
1795 | } |
1796 | ||
1da177e4 LT |
1797 | ret = __cpufreq_set_policy(data, &policy); |
1798 | ||
5a01f2e8 VP |
1799 | unlock_policy_rwsem_write(cpu); |
1800 | ||
f1829e4a | 1801 | fail: |
1da177e4 | 1802 | cpufreq_cpu_put(data); |
f1829e4a | 1803 | no_policy: |
1da177e4 LT |
1804 | return ret; |
1805 | } | |
1806 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1807 | ||
dd184a01 | 1808 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1809 | unsigned long action, void *hcpu) |
1810 | { | |
1811 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1812 | struct sys_device *sys_dev; |
1813 | ||
1814 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1815 | if (sys_dev) { |
1816 | switch (action) { | |
1817 | case CPU_ONLINE: | |
8bb78442 | 1818 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1819 | cpufreq_add_dev(sys_dev); |
1820 | break; | |
1821 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1822 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1823 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1824 | BUG(); | |
1825 | ||
5a01f2e8 | 1826 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1827 | break; |
5a01f2e8 | 1828 | case CPU_DOWN_FAILED: |
8bb78442 | 1829 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1830 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1831 | break; |
1832 | } | |
1833 | } | |
1834 | return NOTIFY_OK; | |
1835 | } | |
1836 | ||
f6ebef30 | 1837 | static struct notifier_block __refdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1838 | { |
1839 | .notifier_call = cpufreq_cpu_callback, | |
1840 | }; | |
1da177e4 LT |
1841 | |
1842 | /********************************************************************* | |
1843 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1844 | *********************************************************************/ | |
1845 | ||
1846 | /** | |
1847 | * cpufreq_register_driver - register a CPU Frequency driver | |
1848 | * @driver_data: A struct cpufreq_driver containing the values# | |
1849 | * submitted by the CPU Frequency driver. | |
1850 | * | |
32ee8c3e | 1851 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1852 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1853 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1854 | * |
1855 | */ | |
221dee28 | 1856 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1857 | { |
1858 | unsigned long flags; | |
1859 | int ret; | |
1860 | ||
1861 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1862 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1863 | return -EINVAL; | |
1864 | ||
1865 | dprintk("trying to register driver %s\n", driver_data->name); | |
1866 | ||
1867 | if (driver_data->setpolicy) | |
1868 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1869 | ||
1870 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1871 | if (cpufreq_driver) { | |
1872 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1873 | return -EBUSY; | |
1874 | } | |
1875 | cpufreq_driver = driver_data; | |
1876 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1877 | ||
7a6aedfa MT |
1878 | ret = sysdev_driver_register(&cpu_sysdev_class, |
1879 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1880 | |
1881 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1882 | int i; | |
1883 | ret = -ENODEV; | |
1884 | ||
1885 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1886 | for (i = 0; i < nr_cpu_ids; i++) |
1887 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1888 | ret = 0; |
7a6aedfa MT |
1889 | break; |
1890 | } | |
1da177e4 LT |
1891 | |
1892 | /* if all ->init() calls failed, unregister */ | |
1893 | if (ret) { | |
e08f5f5b GS |
1894 | dprintk("no CPU initialized for driver %s\n", |
1895 | driver_data->name); | |
1896 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1897 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1898 | |
1899 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1900 | cpufreq_driver = NULL; | |
1901 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1902 | } | |
1903 | } | |
1904 | ||
1905 | if (!ret) { | |
65edc68c | 1906 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1907 | dprintk("driver %s up and running\n", driver_data->name); |
1908 | cpufreq_debug_enable_ratelimit(); | |
1909 | } | |
1910 | ||
4d34a67d | 1911 | return ret; |
1da177e4 LT |
1912 | } |
1913 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1914 | ||
1915 | ||
1916 | /** | |
1917 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1918 | * | |
32ee8c3e | 1919 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1920 | * the right to do so, i.e. if you have succeeded in initialising before! |
1921 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1922 | * currently not initialised. | |
1923 | */ | |
221dee28 | 1924 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1925 | { |
1926 | unsigned long flags; | |
1927 | ||
1928 | cpufreq_debug_disable_ratelimit(); | |
1929 | ||
1930 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1931 | cpufreq_debug_enable_ratelimit(); | |
1932 | return -EINVAL; | |
1933 | } | |
1934 | ||
1935 | dprintk("unregistering driver %s\n", driver->name); | |
1936 | ||
1937 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1938 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
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 | return 0; | |
1945 | } | |
1946 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1947 | |
1948 | static int __init cpufreq_core_init(void) | |
1949 | { | |
1950 | int cpu; | |
1951 | ||
1952 | for_each_possible_cpu(cpu) { | |
1953 | per_cpu(policy_cpu, cpu) = -1; | |
1954 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1955 | } | |
8aa84ad8 TR |
1956 | |
1957 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", | |
1958 | &cpu_sysdev_class.kset.kobj); | |
1959 | BUG_ON(!cpufreq_global_kobject); | |
1960 | ||
5a01f2e8 VP |
1961 | return 0; |
1962 | } | |
5a01f2e8 | 1963 | core_initcall(cpufreq_core_init); |