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 DJ |
40 | static struct cpufreq_driver *cpufreq_driver; |
41 | static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; | |
084f3493 TR |
42 | #ifdef CONFIG_HOTPLUG_CPU |
43 | /* This one keeps track of the previously set governor of a removed CPU */ | |
44 | static struct cpufreq_governor *cpufreq_cpu_governor[NR_CPUS]; | |
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. | |
64 | */ | |
65 | static DEFINE_PER_CPU(int, policy_cpu); | |
66 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); | |
67 | ||
68 | #define lock_policy_rwsem(mode, cpu) \ | |
69 | int lock_policy_rwsem_##mode \ | |
70 | (int cpu) \ | |
71 | { \ | |
72 | int policy_cpu = per_cpu(policy_cpu, cpu); \ | |
73 | BUG_ON(policy_cpu == -1); \ | |
74 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
75 | if (unlikely(!cpu_online(cpu))) { \ | |
76 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
77 | return -1; \ | |
78 | } \ | |
79 | \ | |
80 | return 0; \ | |
81 | } | |
82 | ||
83 | lock_policy_rwsem(read, cpu); | |
84 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_read); | |
85 | ||
86 | lock_policy_rwsem(write, cpu); | |
87 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_write); | |
88 | ||
89 | void unlock_policy_rwsem_read(int cpu) | |
90 | { | |
91 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
92 | BUG_ON(policy_cpu == -1); | |
93 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_read); | |
96 | ||
97 | void unlock_policy_rwsem_write(int cpu) | |
98 | { | |
99 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
100 | BUG_ON(policy_cpu == -1); | |
101 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
102 | } | |
103 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_write); | |
104 | ||
105 | ||
1da177e4 LT |
106 | /* internal prototypes */ |
107 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); | |
5a01f2e8 | 108 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 109 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
110 | |
111 | /** | |
32ee8c3e DJ |
112 | * Two notifier lists: the "policy" list is involved in the |
113 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
114 | * "transition" list for kernel code that needs to handle |
115 | * changes to devices when the CPU clock speed changes. | |
116 | * The mutex locks both lists. | |
117 | */ | |
e041c683 | 118 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 119 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 120 | |
b4dfdbb3 AS |
121 | static int __init init_cpufreq_transition_notifier_list(void) |
122 | { | |
123 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
124 | return 0; | |
125 | } | |
b3438f82 | 126 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
127 | |
128 | static LIST_HEAD(cpufreq_governor_list); | |
7d5e350f | 129 | static DEFINE_MUTEX (cpufreq_governor_mutex); |
1da177e4 | 130 | |
7d5e350f | 131 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
132 | { |
133 | struct cpufreq_policy *data; | |
134 | unsigned long flags; | |
135 | ||
136 | if (cpu >= NR_CPUS) | |
137 | goto err_out; | |
138 | ||
139 | /* get the cpufreq driver */ | |
140 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
141 | ||
142 | if (!cpufreq_driver) | |
143 | goto err_out_unlock; | |
144 | ||
145 | if (!try_module_get(cpufreq_driver->owner)) | |
146 | goto err_out_unlock; | |
147 | ||
148 | ||
149 | /* get the CPU */ | |
150 | data = cpufreq_cpu_data[cpu]; | |
151 | ||
152 | if (!data) | |
153 | goto err_out_put_module; | |
154 | ||
155 | if (!kobject_get(&data->kobj)) | |
156 | goto err_out_put_module; | |
157 | ||
1da177e4 | 158 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
159 | return data; |
160 | ||
7d5e350f | 161 | err_out_put_module: |
1da177e4 | 162 | module_put(cpufreq_driver->owner); |
7d5e350f | 163 | err_out_unlock: |
1da177e4 | 164 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 165 | err_out: |
1da177e4 LT |
166 | return NULL; |
167 | } | |
168 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
169 | ||
7d5e350f | 170 | |
1da177e4 LT |
171 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
172 | { | |
173 | kobject_put(&data->kobj); | |
174 | module_put(cpufreq_driver->owner); | |
175 | } | |
176 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
177 | ||
178 | ||
179 | /********************************************************************* | |
180 | * UNIFIED DEBUG HELPERS * | |
181 | *********************************************************************/ | |
182 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
183 | ||
184 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
185 | static unsigned int debug; | |
186 | ||
187 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
188 | * set or modify this value. | |
189 | */ | |
190 | static unsigned int debug_ratelimit = 1; | |
191 | ||
192 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
193 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
194 | * is set, and disabled upon cpufreq driver removal | |
195 | */ | |
196 | static unsigned int disable_ratelimit = 1; | |
197 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
198 | ||
858119e1 | 199 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
200 | { |
201 | unsigned long flags; | |
202 | ||
203 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
204 | if (disable_ratelimit) | |
205 | disable_ratelimit--; | |
206 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
207 | } | |
208 | ||
858119e1 | 209 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
210 | { |
211 | unsigned long flags; | |
212 | ||
213 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
214 | disable_ratelimit++; | |
215 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
216 | } | |
217 | ||
e08f5f5b GS |
218 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
219 | const char *fmt, ...) | |
1da177e4 LT |
220 | { |
221 | char s[256]; | |
222 | va_list args; | |
223 | unsigned int len; | |
224 | unsigned long flags; | |
32ee8c3e | 225 | |
1da177e4 LT |
226 | WARN_ON(!prefix); |
227 | if (type & debug) { | |
228 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
229 | if (!disable_ratelimit && debug_ratelimit |
230 | && !printk_ratelimit()) { | |
1da177e4 LT |
231 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
232 | return; | |
233 | } | |
234 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
235 | ||
236 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
237 | ||
238 | va_start(args, fmt); | |
239 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
240 | va_end(args); | |
241 | ||
242 | printk(s); | |
243 | ||
244 | WARN_ON(len < 5); | |
245 | } | |
246 | } | |
247 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
248 | ||
249 | ||
250 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
251 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
252 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
253 | |
254 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
255 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
256 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
257 | |
258 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
259 | ||
260 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
261 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
262 | ||
263 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
264 | ||
265 | ||
266 | /********************************************************************* | |
267 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
268 | *********************************************************************/ | |
269 | ||
270 | /** | |
271 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
272 | * | |
273 | * This function alters the system "loops_per_jiffy" for the clock | |
274 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 275 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
276 | * per-CPU loops_per_jiffy value wherever possible. |
277 | */ | |
278 | #ifndef CONFIG_SMP | |
279 | static unsigned long l_p_j_ref; | |
280 | static unsigned int l_p_j_ref_freq; | |
281 | ||
858119e1 | 282 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
283 | { |
284 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
285 | return; | |
286 | ||
287 | if (!l_p_j_ref_freq) { | |
288 | l_p_j_ref = loops_per_jiffy; | |
289 | l_p_j_ref_freq = ci->old; | |
e08f5f5b GS |
290 | dprintk("saving %lu as reference value for loops_per_jiffy;" |
291 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 LT |
292 | } |
293 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
294 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 295 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
296 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
297 | ci->new); | |
298 | dprintk("scaling loops_per_jiffy to %lu" | |
299 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
1da177e4 LT |
300 | } |
301 | } | |
302 | #else | |
e08f5f5b GS |
303 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
304 | { | |
305 | return; | |
306 | } | |
1da177e4 LT |
307 | #endif |
308 | ||
309 | ||
310 | /** | |
e4472cb3 DJ |
311 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
312 | * on frequency transition. | |
1da177e4 | 313 | * |
e4472cb3 DJ |
314 | * This function calls the transition notifiers and the "adjust_jiffies" |
315 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 316 | * external effects. |
1da177e4 LT |
317 | */ |
318 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
319 | { | |
e4472cb3 DJ |
320 | struct cpufreq_policy *policy; |
321 | ||
1da177e4 LT |
322 | BUG_ON(irqs_disabled()); |
323 | ||
324 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
325 | dprintk("notification %u of frequency transition to %u kHz\n", |
326 | state, freqs->new); | |
1da177e4 | 327 | |
e4472cb3 | 328 | policy = cpufreq_cpu_data[freqs->cpu]; |
1da177e4 | 329 | switch (state) { |
e4472cb3 | 330 | |
1da177e4 | 331 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 332 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
333 | * which is not equal to what the cpufreq core thinks is |
334 | * "old frequency". | |
1da177e4 LT |
335 | */ |
336 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
337 | if ((policy) && (policy->cpu == freqs->cpu) && |
338 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 339 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
340 | " %u, cpufreq assumed %u kHz.\n", |
341 | freqs->old, policy->cur); | |
342 | freqs->old = policy->cur; | |
1da177e4 LT |
343 | } |
344 | } | |
b4dfdbb3 | 345 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 346 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
347 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
348 | break; | |
e4472cb3 | 349 | |
1da177e4 LT |
350 | case CPUFREQ_POSTCHANGE: |
351 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
b4dfdbb3 | 352 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 353 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
354 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
355 | policy->cur = freqs->new; | |
1da177e4 LT |
356 | break; |
357 | } | |
1da177e4 LT |
358 | } |
359 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
360 | ||
361 | ||
362 | ||
363 | /********************************************************************* | |
364 | * SYSFS INTERFACE * | |
365 | *********************************************************************/ | |
366 | ||
3bcb09a3 JF |
367 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
368 | { | |
369 | struct cpufreq_governor *t; | |
370 | ||
371 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
372 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) | |
373 | return t; | |
374 | ||
375 | return NULL; | |
376 | } | |
377 | ||
1da177e4 LT |
378 | /** |
379 | * cpufreq_parse_governor - parse a governor string | |
380 | */ | |
381 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
382 | struct cpufreq_governor **governor) | |
383 | { | |
3bcb09a3 JF |
384 | int err = -EINVAL; |
385 | ||
1da177e4 | 386 | if (!cpufreq_driver) |
3bcb09a3 JF |
387 | goto out; |
388 | ||
1da177e4 LT |
389 | if (cpufreq_driver->setpolicy) { |
390 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
391 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 392 | err = 0; |
e08f5f5b GS |
393 | } else if (!strnicmp(str_governor, "powersave", |
394 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 395 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 396 | err = 0; |
1da177e4 | 397 | } |
3bcb09a3 | 398 | } else if (cpufreq_driver->target) { |
1da177e4 | 399 | struct cpufreq_governor *t; |
3bcb09a3 | 400 | |
3fc54d37 | 401 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
402 | |
403 | t = __find_governor(str_governor); | |
404 | ||
ea714970 | 405 | if (t == NULL) { |
e08f5f5b GS |
406 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
407 | str_governor); | |
ea714970 JF |
408 | |
409 | if (name) { | |
410 | int ret; | |
411 | ||
412 | mutex_unlock(&cpufreq_governor_mutex); | |
413 | ret = request_module(name); | |
414 | mutex_lock(&cpufreq_governor_mutex); | |
415 | ||
416 | if (ret == 0) | |
417 | t = __find_governor(str_governor); | |
418 | } | |
419 | ||
420 | kfree(name); | |
421 | } | |
422 | ||
3bcb09a3 JF |
423 | if (t != NULL) { |
424 | *governor = t; | |
425 | err = 0; | |
1da177e4 | 426 | } |
3bcb09a3 | 427 | |
3fc54d37 | 428 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 429 | } |
3bcb09a3 JF |
430 | out: |
431 | return err; | |
1da177e4 | 432 | } |
1da177e4 LT |
433 | |
434 | ||
435 | /* drivers/base/cpu.c */ | |
436 | extern struct sysdev_class cpu_sysdev_class; | |
437 | ||
438 | ||
439 | /** | |
e08f5f5b GS |
440 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
441 | * print out cpufreq information | |
1da177e4 LT |
442 | * |
443 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
444 | * "unsigned int". | |
445 | */ | |
446 | ||
32ee8c3e DJ |
447 | #define show_one(file_name, object) \ |
448 | static ssize_t show_##file_name \ | |
449 | (struct cpufreq_policy * policy, char *buf) \ | |
450 | { \ | |
451 | return sprintf (buf, "%u\n", policy->object); \ | |
1da177e4 LT |
452 | } |
453 | ||
454 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
455 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
456 | show_one(scaling_min_freq, min); | |
457 | show_one(scaling_max_freq, max); | |
458 | show_one(scaling_cur_freq, cur); | |
459 | ||
e08f5f5b GS |
460 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
461 | struct cpufreq_policy *policy); | |
7970e08b | 462 | |
1da177e4 LT |
463 | /** |
464 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
465 | */ | |
466 | #define store_one(file_name, object) \ | |
467 | static ssize_t store_##file_name \ | |
468 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
469 | { \ | |
470 | unsigned int ret = -EINVAL; \ | |
471 | struct cpufreq_policy new_policy; \ | |
472 | \ | |
473 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
474 | if (ret) \ | |
475 | return -EINVAL; \ | |
476 | \ | |
477 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
478 | if (ret != 1) \ | |
479 | return -EINVAL; \ | |
480 | \ | |
7970e08b TR |
481 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
482 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
483 | \ |
484 | return ret ? ret : count; \ | |
485 | } | |
486 | ||
487 | store_one(scaling_min_freq,min); | |
488 | store_one(scaling_max_freq,max); | |
489 | ||
490 | /** | |
491 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
492 | */ | |
e08f5f5b GS |
493 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, |
494 | char *buf) | |
1da177e4 | 495 | { |
5a01f2e8 | 496 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
497 | if (!cur_freq) |
498 | return sprintf(buf, "<unknown>"); | |
499 | return sprintf(buf, "%u\n", cur_freq); | |
500 | } | |
501 | ||
502 | ||
503 | /** | |
504 | * show_scaling_governor - show the current policy for the specified CPU | |
505 | */ | |
e08f5f5b GS |
506 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, |
507 | char *buf) | |
1da177e4 LT |
508 | { |
509 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
510 | return sprintf(buf, "powersave\n"); | |
511 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
512 | return sprintf(buf, "performance\n"); | |
513 | else if (policy->governor) | |
514 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
515 | return -EINVAL; | |
516 | } | |
517 | ||
518 | ||
519 | /** | |
520 | * store_scaling_governor - store policy for the specified CPU | |
521 | */ | |
32ee8c3e DJ |
522 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, |
523 | const char *buf, size_t count) | |
1da177e4 LT |
524 | { |
525 | unsigned int ret = -EINVAL; | |
526 | char str_governor[16]; | |
527 | struct cpufreq_policy new_policy; | |
528 | ||
529 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
530 | if (ret) | |
531 | return ret; | |
532 | ||
533 | ret = sscanf (buf, "%15s", str_governor); | |
534 | if (ret != 1) | |
535 | return -EINVAL; | |
536 | ||
e08f5f5b GS |
537 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
538 | &new_policy.governor)) | |
1da177e4 LT |
539 | return -EINVAL; |
540 | ||
7970e08b TR |
541 | /* Do not use cpufreq_set_policy here or the user_policy.max |
542 | will be wrongly overridden */ | |
7970e08b TR |
543 | ret = __cpufreq_set_policy(policy, &new_policy); |
544 | ||
545 | policy->user_policy.policy = policy->policy; | |
546 | policy->user_policy.governor = policy->governor; | |
7970e08b | 547 | |
e08f5f5b GS |
548 | if (ret) |
549 | return ret; | |
550 | else | |
551 | return count; | |
1da177e4 LT |
552 | } |
553 | ||
554 | /** | |
555 | * show_scaling_driver - show the cpufreq driver currently loaded | |
556 | */ | |
557 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
558 | { | |
559 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
560 | } | |
561 | ||
562 | /** | |
563 | * show_scaling_available_governors - show the available CPUfreq governors | |
564 | */ | |
e08f5f5b | 565 | static ssize_t show_scaling_available_governors (struct cpufreq_policy *policy, |
1da177e4 LT |
566 | char *buf) |
567 | { | |
568 | ssize_t i = 0; | |
569 | struct cpufreq_governor *t; | |
570 | ||
571 | if (!cpufreq_driver->target) { | |
572 | i += sprintf(buf, "performance powersave"); | |
573 | goto out; | |
574 | } | |
575 | ||
576 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
577 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
578 | goto out; | |
579 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
580 | } | |
7d5e350f | 581 | out: |
1da177e4 LT |
582 | i += sprintf(&buf[i], "\n"); |
583 | return i; | |
584 | } | |
585 | /** | |
586 | * show_affected_cpus - show the CPUs affected by each transition | |
587 | */ | |
588 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
589 | { | |
590 | ssize_t i = 0; | |
591 | unsigned int cpu; | |
592 | ||
593 | for_each_cpu_mask(cpu, policy->cpus) { | |
594 | if (i) | |
595 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
596 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
597 | if (i >= (PAGE_SIZE - 5)) | |
598 | break; | |
599 | } | |
600 | i += sprintf(&buf[i], "\n"); | |
601 | return i; | |
602 | } | |
603 | ||
604 | ||
605 | #define define_one_ro(_name) \ | |
606 | static struct freq_attr _name = \ | |
607 | __ATTR(_name, 0444, show_##_name, NULL) | |
608 | ||
609 | #define define_one_ro0400(_name) \ | |
610 | static struct freq_attr _name = \ | |
611 | __ATTR(_name, 0400, show_##_name, NULL) | |
612 | ||
613 | #define define_one_rw(_name) \ | |
614 | static struct freq_attr _name = \ | |
615 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
616 | ||
617 | define_one_ro0400(cpuinfo_cur_freq); | |
618 | define_one_ro(cpuinfo_min_freq); | |
619 | define_one_ro(cpuinfo_max_freq); | |
620 | define_one_ro(scaling_available_governors); | |
621 | define_one_ro(scaling_driver); | |
622 | define_one_ro(scaling_cur_freq); | |
623 | define_one_ro(affected_cpus); | |
624 | define_one_rw(scaling_min_freq); | |
625 | define_one_rw(scaling_max_freq); | |
626 | define_one_rw(scaling_governor); | |
627 | ||
628 | static struct attribute * default_attrs[] = { | |
629 | &cpuinfo_min_freq.attr, | |
630 | &cpuinfo_max_freq.attr, | |
631 | &scaling_min_freq.attr, | |
632 | &scaling_max_freq.attr, | |
633 | &affected_cpus.attr, | |
634 | &scaling_governor.attr, | |
635 | &scaling_driver.attr, | |
636 | &scaling_available_governors.attr, | |
637 | NULL | |
638 | }; | |
639 | ||
640 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
641 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
642 | ||
643 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
644 | { | |
645 | struct cpufreq_policy * policy = to_policy(kobj); | |
646 | struct freq_attr * fattr = to_attr(attr); | |
647 | ssize_t ret; | |
648 | policy = cpufreq_cpu_get(policy->cpu); | |
649 | if (!policy) | |
650 | return -EINVAL; | |
5a01f2e8 VP |
651 | |
652 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
653 | return -EINVAL; | |
654 | ||
e08f5f5b GS |
655 | if (fattr->show) |
656 | ret = fattr->show(policy, buf); | |
657 | else | |
658 | ret = -EIO; | |
659 | ||
5a01f2e8 VP |
660 | unlock_policy_rwsem_read(policy->cpu); |
661 | ||
1da177e4 LT |
662 | cpufreq_cpu_put(policy); |
663 | return ret; | |
664 | } | |
665 | ||
32ee8c3e | 666 | static ssize_t store(struct kobject * kobj, struct attribute * attr, |
1da177e4 LT |
667 | const char * buf, size_t count) |
668 | { | |
669 | struct cpufreq_policy * policy = to_policy(kobj); | |
670 | struct freq_attr * fattr = to_attr(attr); | |
671 | ssize_t ret; | |
672 | policy = cpufreq_cpu_get(policy->cpu); | |
673 | if (!policy) | |
674 | return -EINVAL; | |
5a01f2e8 VP |
675 | |
676 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
677 | return -EINVAL; | |
678 | ||
e08f5f5b GS |
679 | if (fattr->store) |
680 | ret = fattr->store(policy, buf, count); | |
681 | else | |
682 | ret = -EIO; | |
683 | ||
5a01f2e8 VP |
684 | unlock_policy_rwsem_write(policy->cpu); |
685 | ||
1da177e4 LT |
686 | cpufreq_cpu_put(policy); |
687 | return ret; | |
688 | } | |
689 | ||
690 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
691 | { | |
692 | struct cpufreq_policy * policy = to_policy(kobj); | |
693 | dprintk("last reference is dropped\n"); | |
694 | complete(&policy->kobj_unregister); | |
695 | } | |
696 | ||
697 | static struct sysfs_ops sysfs_ops = { | |
698 | .show = show, | |
699 | .store = store, | |
700 | }; | |
701 | ||
702 | static struct kobj_type ktype_cpufreq = { | |
703 | .sysfs_ops = &sysfs_ops, | |
704 | .default_attrs = default_attrs, | |
705 | .release = cpufreq_sysfs_release, | |
706 | }; | |
707 | ||
708 | ||
709 | /** | |
710 | * cpufreq_add_dev - add a CPU device | |
711 | * | |
32ee8c3e | 712 | * Adds the cpufreq interface for a CPU device. |
1da177e4 LT |
713 | */ |
714 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
715 | { | |
716 | unsigned int cpu = sys_dev->id; | |
717 | int ret = 0; | |
718 | struct cpufreq_policy new_policy; | |
719 | struct cpufreq_policy *policy; | |
720 | struct freq_attr **drv_attr; | |
8ff69732 | 721 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
722 | unsigned long flags; |
723 | unsigned int j; | |
8ff69732 DJ |
724 | #ifdef CONFIG_SMP |
725 | struct cpufreq_policy *managed_policy; | |
726 | #endif | |
1da177e4 | 727 | |
c32b6b8e AR |
728 | if (cpu_is_offline(cpu)) |
729 | return 0; | |
730 | ||
1da177e4 LT |
731 | cpufreq_debug_disable_ratelimit(); |
732 | dprintk("adding CPU %u\n", cpu); | |
733 | ||
734 | #ifdef CONFIG_SMP | |
735 | /* check whether a different CPU already registered this | |
736 | * CPU because it is in the same boat. */ | |
737 | policy = cpufreq_cpu_get(cpu); | |
738 | if (unlikely(policy)) { | |
8ff69732 | 739 | cpufreq_cpu_put(policy); |
1da177e4 LT |
740 | cpufreq_debug_enable_ratelimit(); |
741 | return 0; | |
742 | } | |
743 | #endif | |
744 | ||
745 | if (!try_module_get(cpufreq_driver->owner)) { | |
746 | ret = -EINVAL; | |
747 | goto module_out; | |
748 | } | |
749 | ||
e98df50c | 750 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
751 | if (!policy) { |
752 | ret = -ENOMEM; | |
753 | goto nomem_out; | |
754 | } | |
1da177e4 LT |
755 | |
756 | policy->cpu = cpu; | |
757 | policy->cpus = cpumask_of_cpu(cpu); | |
758 | ||
5a01f2e8 VP |
759 | /* Initially set CPU itself as the policy_cpu */ |
760 | per_cpu(policy_cpu, cpu) = cpu; | |
761 | lock_policy_rwsem_write(cpu); | |
762 | ||
1da177e4 | 763 | init_completion(&policy->kobj_unregister); |
65f27f38 | 764 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 765 | |
8122c6ce TR |
766 | /* Set governor before ->init, so that driver could check it */ |
767 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
768 | /* call driver. From then on the cpufreq must be able |
769 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
770 | */ | |
771 | ret = cpufreq_driver->init(policy); | |
772 | if (ret) { | |
773 | dprintk("initialization failed\n"); | |
5a01f2e8 | 774 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
775 | goto err_out; |
776 | } | |
22c970f3 TR |
777 | policy->user_policy.min = policy->cpuinfo.min_freq; |
778 | policy->user_policy.max = policy->cpuinfo.max_freq; | |
1da177e4 | 779 | |
8ff69732 | 780 | #ifdef CONFIG_SMP |
084f3493 TR |
781 | |
782 | #ifdef CONFIG_HOTPLUG_CPU | |
783 | if (cpufreq_cpu_governor[cpu]){ | |
784 | policy->governor = cpufreq_cpu_governor[cpu]; | |
785 | dprintk("Restoring governor %s for cpu %d\n", | |
786 | policy->governor->name, cpu); | |
787 | } | |
788 | #endif | |
789 | ||
8ff69732 DJ |
790 | for_each_cpu_mask(j, policy->cpus) { |
791 | if (cpu == j) | |
792 | continue; | |
793 | ||
794 | /* check for existing affected CPUs. They may not be aware | |
795 | * of it due to CPU Hotplug. | |
796 | */ | |
797 | managed_policy = cpufreq_cpu_get(j); | |
798 | if (unlikely(managed_policy)) { | |
5a01f2e8 VP |
799 | |
800 | /* Set proper policy_cpu */ | |
801 | unlock_policy_rwsem_write(cpu); | |
802 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
803 | ||
804 | if (lock_policy_rwsem_write(cpu) < 0) | |
805 | goto err_out_driver_exit; | |
806 | ||
8ff69732 DJ |
807 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
808 | managed_policy->cpus = policy->cpus; | |
809 | cpufreq_cpu_data[cpu] = managed_policy; | |
810 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
811 | ||
812 | dprintk("CPU already managed, adding link\n"); | |
0142f9dc AD |
813 | ret = sysfs_create_link(&sys_dev->kobj, |
814 | &managed_policy->kobj, | |
815 | "cpufreq"); | |
816 | if (ret) { | |
5a01f2e8 | 817 | unlock_policy_rwsem_write(cpu); |
0142f9dc AD |
818 | goto err_out_driver_exit; |
819 | } | |
8ff69732 DJ |
820 | |
821 | cpufreq_debug_enable_ratelimit(); | |
8ff69732 | 822 | ret = 0; |
5a01f2e8 | 823 | unlock_policy_rwsem_write(cpu); |
8ff69732 DJ |
824 | goto err_out_driver_exit; /* call driver->exit() */ |
825 | } | |
826 | } | |
827 | #endif | |
1da177e4 LT |
828 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
829 | ||
830 | /* prepare interface data */ | |
038c5b3e GKH |
831 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj, |
832 | "cpufreq"); | |
f3876c1b | 833 | if (ret) { |
5a01f2e8 | 834 | unlock_policy_rwsem_write(cpu); |
8085e1f1 | 835 | goto err_out_driver_exit; |
f3876c1b | 836 | } |
1da177e4 LT |
837 | /* set up files for this cpu device */ |
838 | drv_attr = cpufreq_driver->attr; | |
839 | while ((drv_attr) && (*drv_attr)) { | |
58a7295b | 840 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
bd6cba53 DJ |
841 | if (ret) { |
842 | unlock_policy_rwsem_write(cpu); | |
0a4b2ccc | 843 | goto err_out_driver_exit; |
bd6cba53 | 844 | } |
1da177e4 LT |
845 | drv_attr++; |
846 | } | |
0a4b2ccc | 847 | if (cpufreq_driver->get){ |
58a7295b | 848 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
bd6cba53 DJ |
849 | if (ret) { |
850 | unlock_policy_rwsem_write(cpu); | |
0a4b2ccc | 851 | goto err_out_driver_exit; |
bd6cba53 | 852 | } |
0a4b2ccc TR |
853 | } |
854 | if (cpufreq_driver->target){ | |
58a7295b | 855 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
bd6cba53 DJ |
856 | if (ret) { |
857 | unlock_policy_rwsem_write(cpu); | |
0a4b2ccc | 858 | goto err_out_driver_exit; |
bd6cba53 | 859 | } |
0a4b2ccc | 860 | } |
1da177e4 LT |
861 | |
862 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 863 | for_each_cpu_mask(j, policy->cpus) { |
1da177e4 | 864 | cpufreq_cpu_data[j] = policy; |
5a01f2e8 VP |
865 | per_cpu(policy_cpu, j) = policy->cpu; |
866 | } | |
1da177e4 | 867 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8ff69732 DJ |
868 | |
869 | /* symlink affected CPUs */ | |
870 | for_each_cpu_mask(j, policy->cpus) { | |
871 | if (j == cpu) | |
872 | continue; | |
873 | if (!cpu_online(j)) | |
874 | continue; | |
875 | ||
1f8b2c9d | 876 | dprintk("CPU %u already managed, adding link\n", j); |
8ff69732 DJ |
877 | cpufreq_cpu_get(cpu); |
878 | cpu_sys_dev = get_cpu_sysdev(j); | |
0142f9dc AD |
879 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, |
880 | "cpufreq"); | |
881 | if (ret) { | |
5a01f2e8 | 882 | unlock_policy_rwsem_write(cpu); |
0142f9dc AD |
883 | goto err_out_unregister; |
884 | } | |
8ff69732 DJ |
885 | } |
886 | ||
1da177e4 LT |
887 | policy->governor = NULL; /* to assure that the starting sequence is |
888 | * run in cpufreq_set_policy */ | |
87c32271 | 889 | |
1da177e4 | 890 | /* set default policy */ |
22c970f3 TR |
891 | ret = __cpufreq_set_policy(policy, &new_policy); |
892 | policy->user_policy.policy = policy->policy; | |
084f3493 | 893 | policy->user_policy.governor = policy->governor; |
22c970f3 TR |
894 | |
895 | unlock_policy_rwsem_write(cpu); | |
896 | ||
1da177e4 LT |
897 | if (ret) { |
898 | dprintk("setting policy failed\n"); | |
899 | goto err_out_unregister; | |
900 | } | |
901 | ||
038c5b3e | 902 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 903 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
904 | dprintk("initialization complete\n"); |
905 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 906 | |
1da177e4 LT |
907 | return 0; |
908 | ||
909 | ||
910 | err_out_unregister: | |
911 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
912 | for_each_cpu_mask(j, policy->cpus) | |
913 | cpufreq_cpu_data[j] = NULL; | |
914 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
915 | ||
c10997f6 | 916 | kobject_put(&policy->kobj); |
1da177e4 LT |
917 | wait_for_completion(&policy->kobj_unregister); |
918 | ||
8085e1f1 VP |
919 | err_out_driver_exit: |
920 | if (cpufreq_driver->exit) | |
921 | cpufreq_driver->exit(policy); | |
922 | ||
1da177e4 LT |
923 | err_out: |
924 | kfree(policy); | |
925 | ||
926 | nomem_out: | |
927 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 928 | module_out: |
1da177e4 LT |
929 | cpufreq_debug_enable_ratelimit(); |
930 | return ret; | |
931 | } | |
932 | ||
933 | ||
934 | /** | |
5a01f2e8 | 935 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
936 | * |
937 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
938 | * Caller should already have policy_rwsem in write mode for this CPU. |
939 | * This routine frees the rwsem before returning. | |
1da177e4 | 940 | */ |
5a01f2e8 | 941 | static int __cpufreq_remove_dev (struct sys_device * sys_dev) |
1da177e4 LT |
942 | { |
943 | unsigned int cpu = sys_dev->id; | |
944 | unsigned long flags; | |
945 | struct cpufreq_policy *data; | |
946 | #ifdef CONFIG_SMP | |
e738cf6d | 947 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
948 | unsigned int j; |
949 | #endif | |
950 | ||
951 | cpufreq_debug_disable_ratelimit(); | |
952 | dprintk("unregistering CPU %u\n", cpu); | |
953 | ||
954 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
955 | data = cpufreq_cpu_data[cpu]; | |
956 | ||
957 | if (!data) { | |
958 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 959 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 960 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
961 | return -EINVAL; |
962 | } | |
963 | cpufreq_cpu_data[cpu] = NULL; | |
964 | ||
965 | ||
966 | #ifdef CONFIG_SMP | |
967 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 968 | * only need to unlink, put and exit |
1da177e4 LT |
969 | */ |
970 | if (unlikely(cpu != data->cpu)) { | |
971 | dprintk("removing link\n"); | |
8ff69732 | 972 | cpu_clear(cpu, data->cpus); |
1da177e4 LT |
973 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
974 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
975 | cpufreq_cpu_put(data); |
976 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 977 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
978 | return 0; |
979 | } | |
980 | #endif | |
981 | ||
1da177e4 LT |
982 | |
983 | if (!kobject_get(&data->kobj)) { | |
984 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
985 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 986 | unlock_policy_rwsem_write(cpu); |
32ee8c3e | 987 | return -EFAULT; |
1da177e4 LT |
988 | } |
989 | ||
990 | #ifdef CONFIG_SMP | |
084f3493 TR |
991 | |
992 | #ifdef CONFIG_HOTPLUG_CPU | |
993 | cpufreq_cpu_governor[cpu] = data->governor; | |
994 | #endif | |
995 | ||
1da177e4 LT |
996 | /* if we have other CPUs still registered, we need to unlink them, |
997 | * or else wait_for_completion below will lock up. Clean the | |
998 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
999 | * links afterwards. | |
1000 | */ | |
1001 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1002 | for_each_cpu_mask(j, data->cpus) { | |
1003 | if (j == cpu) | |
1004 | continue; | |
1005 | cpufreq_cpu_data[j] = NULL; | |
1006 | } | |
1007 | } | |
1008 | ||
1009 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1010 | ||
1011 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1012 | for_each_cpu_mask(j, data->cpus) { | |
1013 | if (j == cpu) | |
1014 | continue; | |
1015 | dprintk("removing link for cpu %u\n", j); | |
084f3493 TR |
1016 | #ifdef CONFIG_HOTPLUG_CPU |
1017 | cpufreq_cpu_governor[j] = data->governor; | |
1018 | #endif | |
d434fca7 AR |
1019 | cpu_sys_dev = get_cpu_sysdev(j); |
1020 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1021 | cpufreq_cpu_put(data); |
1022 | } | |
1023 | } | |
1024 | #else | |
1025 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1026 | #endif | |
1027 | ||
1da177e4 LT |
1028 | if (cpufreq_driver->target) |
1029 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 VP |
1030 | |
1031 | unlock_policy_rwsem_write(cpu); | |
1da177e4 | 1032 | |
1da177e4 LT |
1033 | kobject_put(&data->kobj); |
1034 | ||
1035 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1036 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1037 | * unloading. |
1038 | */ | |
1039 | dprintk("waiting for dropping of refcount\n"); | |
1040 | wait_for_completion(&data->kobj_unregister); | |
1041 | dprintk("wait complete\n"); | |
1042 | ||
1043 | if (cpufreq_driver->exit) | |
1044 | cpufreq_driver->exit(data); | |
1045 | ||
1046 | kfree(data); | |
1047 | ||
1048 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1049 | return 0; |
1050 | } | |
1051 | ||
1052 | ||
5a01f2e8 VP |
1053 | static int cpufreq_remove_dev (struct sys_device * sys_dev) |
1054 | { | |
1055 | unsigned int cpu = sys_dev->id; | |
1056 | int retval; | |
ec28297a VP |
1057 | |
1058 | if (cpu_is_offline(cpu)) | |
1059 | return 0; | |
1060 | ||
5a01f2e8 VP |
1061 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1062 | BUG(); | |
1063 | ||
1064 | retval = __cpufreq_remove_dev(sys_dev); | |
1065 | return retval; | |
1066 | } | |
1067 | ||
1068 | ||
65f27f38 | 1069 | static void handle_update(struct work_struct *work) |
1da177e4 | 1070 | { |
65f27f38 DH |
1071 | struct cpufreq_policy *policy = |
1072 | container_of(work, struct cpufreq_policy, update); | |
1073 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1074 | dprintk("handle_update for cpu %u called\n", cpu); |
1075 | cpufreq_update_policy(cpu); | |
1076 | } | |
1077 | ||
1078 | /** | |
1079 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1080 | * @cpu: cpu number | |
1081 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1082 | * @new_freq: CPU frequency the CPU actually runs at | |
1083 | * | |
1084 | * We adjust to current frequency first, and need to clean up later. So either call | |
1085 | * to cpufreq_update_policy() or schedule handle_update()). | |
1086 | */ | |
e08f5f5b GS |
1087 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1088 | unsigned int new_freq) | |
1da177e4 LT |
1089 | { |
1090 | struct cpufreq_freqs freqs; | |
1091 | ||
b10eec22 | 1092 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1093 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1094 | ||
1095 | freqs.cpu = cpu; | |
1096 | freqs.old = old_freq; | |
1097 | freqs.new = new_freq; | |
1098 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1099 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1100 | } | |
1101 | ||
1102 | ||
32ee8c3e | 1103 | /** |
4ab70df4 | 1104 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1105 | * @cpu: CPU number |
1106 | * | |
1107 | * This is the last known freq, without actually getting it from the driver. | |
1108 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1109 | */ | |
1110 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1111 | { | |
1112 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1113 | unsigned int ret_freq = 0; |
95235ca2 VP |
1114 | |
1115 | if (policy) { | |
e08f5f5b | 1116 | ret_freq = policy->cur; |
95235ca2 VP |
1117 | cpufreq_cpu_put(policy); |
1118 | } | |
1119 | ||
e08f5f5b | 1120 | return (ret_freq); |
95235ca2 VP |
1121 | } |
1122 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1123 | ||
1124 | ||
5a01f2e8 | 1125 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1126 | { |
5a01f2e8 | 1127 | struct cpufreq_policy *policy = cpufreq_cpu_data[cpu]; |
e08f5f5b | 1128 | unsigned int ret_freq = 0; |
1da177e4 | 1129 | |
1da177e4 | 1130 | if (!cpufreq_driver->get) |
5a01f2e8 | 1131 | return (ret_freq); |
1da177e4 | 1132 | |
e08f5f5b | 1133 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1134 | |
e08f5f5b GS |
1135 | if (ret_freq && policy->cur && |
1136 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1137 | /* verify no discrepancy between actual and | |
1138 | saved value exists */ | |
1139 | if (unlikely(ret_freq != policy->cur)) { | |
1140 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1141 | schedule_work(&policy->update); |
1142 | } | |
1143 | } | |
1144 | ||
5a01f2e8 VP |
1145 | return (ret_freq); |
1146 | } | |
1da177e4 | 1147 | |
5a01f2e8 VP |
1148 | /** |
1149 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1150 | * @cpu: CPU number | |
1151 | * | |
1152 | * Get the CPU current (static) CPU frequency | |
1153 | */ | |
1154 | unsigned int cpufreq_get(unsigned int cpu) | |
1155 | { | |
1156 | unsigned int ret_freq = 0; | |
1157 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1158 | ||
1159 | if (!policy) | |
1160 | goto out; | |
1161 | ||
1162 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1163 | goto out_policy; | |
1164 | ||
1165 | ret_freq = __cpufreq_get(cpu); | |
1166 | ||
1167 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1168 | |
5a01f2e8 VP |
1169 | out_policy: |
1170 | cpufreq_cpu_put(policy); | |
1171 | out: | |
e08f5f5b | 1172 | return (ret_freq); |
1da177e4 LT |
1173 | } |
1174 | EXPORT_SYMBOL(cpufreq_get); | |
1175 | ||
1176 | ||
42d4dc3f BH |
1177 | /** |
1178 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1179 | */ | |
1180 | ||
e00d9967 | 1181 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
42d4dc3f BH |
1182 | { |
1183 | int cpu = sysdev->id; | |
e08f5f5b | 1184 | int ret = 0; |
42d4dc3f BH |
1185 | unsigned int cur_freq = 0; |
1186 | struct cpufreq_policy *cpu_policy; | |
1187 | ||
0e37b159 | 1188 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1189 | |
1190 | if (!cpu_online(cpu)) | |
1191 | return 0; | |
1192 | ||
1193 | /* we may be lax here as interrupts are off. Nonetheless | |
1194 | * we need to grab the correct cpu policy, as to check | |
1195 | * whether we really run on this CPU. | |
1196 | */ | |
1197 | ||
1198 | cpu_policy = cpufreq_cpu_get(cpu); | |
1199 | if (!cpu_policy) | |
1200 | return -EINVAL; | |
1201 | ||
1202 | /* only handle each CPU group once */ | |
1203 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1204 | cpufreq_cpu_put(cpu_policy); | |
1205 | return 0; | |
1206 | } | |
1207 | ||
1208 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1209 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
1210 | if (ret) { |
1211 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1212 | "step on CPU %u\n", cpu_policy->cpu); | |
1213 | cpufreq_cpu_put(cpu_policy); | |
1214 | return ret; | |
1215 | } | |
1216 | } | |
1217 | ||
1218 | ||
1219 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
1220 | goto out; | |
1221 | ||
1222 | if (cpufreq_driver->get) | |
1223 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1224 | ||
1225 | if (!cur_freq || !cpu_policy->cur) { | |
1226 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1227 | "frequency is what timing core thinks it is.\n"); | |
1228 | goto out; | |
1229 | } | |
1230 | ||
1231 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1232 | struct cpufreq_freqs freqs; | |
1233 | ||
1234 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
b10eec22 | 1235 | dprintk("Warning: CPU frequency is %u, " |
42d4dc3f BH |
1236 | "cpufreq assumed %u kHz.\n", |
1237 | cur_freq, cpu_policy->cur); | |
1238 | ||
1239 | freqs.cpu = cpu; | |
1240 | freqs.old = cpu_policy->cur; | |
1241 | freqs.new = cur_freq; | |
1242 | ||
b4dfdbb3 | 1243 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
42d4dc3f BH |
1244 | CPUFREQ_SUSPENDCHANGE, &freqs); |
1245 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1246 | ||
1247 | cpu_policy->cur = cur_freq; | |
1248 | } | |
1249 | ||
7d5e350f | 1250 | out: |
42d4dc3f BH |
1251 | cpufreq_cpu_put(cpu_policy); |
1252 | return 0; | |
1253 | } | |
1254 | ||
1da177e4 LT |
1255 | /** |
1256 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1257 | * | |
1258 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1259 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1260 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1261 | * restored. | |
1da177e4 LT |
1262 | */ |
1263 | static int cpufreq_resume(struct sys_device * sysdev) | |
1264 | { | |
1265 | int cpu = sysdev->id; | |
e08f5f5b | 1266 | int ret = 0; |
1da177e4 LT |
1267 | struct cpufreq_policy *cpu_policy; |
1268 | ||
1269 | dprintk("resuming cpu %u\n", cpu); | |
1270 | ||
1271 | if (!cpu_online(cpu)) | |
1272 | return 0; | |
1273 | ||
1274 | /* we may be lax here as interrupts are off. Nonetheless | |
1275 | * we need to grab the correct cpu policy, as to check | |
1276 | * whether we really run on this CPU. | |
1277 | */ | |
1278 | ||
1279 | cpu_policy = cpufreq_cpu_get(cpu); | |
1280 | if (!cpu_policy) | |
1281 | return -EINVAL; | |
1282 | ||
1283 | /* only handle each CPU group once */ | |
1284 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1285 | cpufreq_cpu_put(cpu_policy); | |
1286 | return 0; | |
1287 | } | |
1288 | ||
1289 | if (cpufreq_driver->resume) { | |
1290 | ret = cpufreq_driver->resume(cpu_policy); | |
1291 | if (ret) { | |
1292 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1293 | "step on CPU %u\n", cpu_policy->cpu); | |
1294 | cpufreq_cpu_put(cpu_policy); | |
1295 | return ret; | |
1296 | } | |
1297 | } | |
1298 | ||
1299 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1300 | unsigned int cur_freq = 0; | |
1301 | ||
1302 | if (cpufreq_driver->get) | |
1303 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1304 | ||
1305 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1306 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1307 | "current frequency is what timing core " | |
1308 | "thinks it is.\n"); | |
1da177e4 LT |
1309 | goto out; |
1310 | } | |
1311 | ||
1312 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1313 | struct cpufreq_freqs freqs; | |
1314 | ||
ac09f698 | 1315 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
b10eec22 | 1316 | dprintk("Warning: CPU frequency" |
ac09f698 BH |
1317 | "is %u, cpufreq assumed %u kHz.\n", |
1318 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1319 | |
1320 | freqs.cpu = cpu; | |
1321 | freqs.old = cpu_policy->cur; | |
1322 | freqs.new = cur_freq; | |
1323 | ||
b4dfdbb3 | 1324 | srcu_notifier_call_chain( |
e041c683 | 1325 | &cpufreq_transition_notifier_list, |
42d4dc3f | 1326 | CPUFREQ_RESUMECHANGE, &freqs); |
1da177e4 LT |
1327 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1328 | ||
1329 | cpu_policy->cur = cur_freq; | |
1330 | } | |
1331 | } | |
1332 | ||
1333 | out: | |
1334 | schedule_work(&cpu_policy->update); | |
1335 | cpufreq_cpu_put(cpu_policy); | |
1336 | return ret; | |
1337 | } | |
1338 | ||
1339 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1340 | .add = cpufreq_add_dev, | |
1341 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1342 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1343 | .resume = cpufreq_resume, |
1344 | }; | |
1345 | ||
1346 | ||
1347 | /********************************************************************* | |
1348 | * NOTIFIER LISTS INTERFACE * | |
1349 | *********************************************************************/ | |
1350 | ||
1351 | /** | |
1352 | * cpufreq_register_notifier - register a driver with cpufreq | |
1353 | * @nb: notifier function to register | |
1354 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1355 | * | |
32ee8c3e | 1356 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1357 | * are notified about clock rate changes (once before and once after |
1358 | * the transition), or a list of drivers that are notified about | |
1359 | * changes in cpufreq policy. | |
1360 | * | |
1361 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1362 | * blocking_notifier_chain_register. |
1da177e4 LT |
1363 | */ |
1364 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1365 | { | |
1366 | int ret; | |
1367 | ||
1da177e4 LT |
1368 | switch (list) { |
1369 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1370 | ret = srcu_notifier_chain_register( |
e041c683 | 1371 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1372 | break; |
1373 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1374 | ret = blocking_notifier_chain_register( |
1375 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1376 | break; |
1377 | default: | |
1378 | ret = -EINVAL; | |
1379 | } | |
1da177e4 LT |
1380 | |
1381 | return ret; | |
1382 | } | |
1383 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1384 | ||
1385 | ||
1386 | /** | |
1387 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1388 | * @nb: notifier block to be unregistered | |
1389 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1390 | * | |
1391 | * Remove a driver from the CPU frequency notifier list. | |
1392 | * | |
1393 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1394 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1395 | */ |
1396 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1397 | { | |
1398 | int ret; | |
1399 | ||
1da177e4 LT |
1400 | switch (list) { |
1401 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1402 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1403 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1404 | break; |
1405 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1406 | ret = blocking_notifier_chain_unregister( |
1407 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1408 | break; |
1409 | default: | |
1410 | ret = -EINVAL; | |
1411 | } | |
1da177e4 LT |
1412 | |
1413 | return ret; | |
1414 | } | |
1415 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1416 | ||
1417 | ||
1418 | /********************************************************************* | |
1419 | * GOVERNORS * | |
1420 | *********************************************************************/ | |
1421 | ||
1422 | ||
1423 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1424 | unsigned int target_freq, | |
1425 | unsigned int relation) | |
1426 | { | |
1427 | int retval = -EINVAL; | |
c32b6b8e | 1428 | |
1da177e4 LT |
1429 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1430 | target_freq, relation); | |
1431 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1432 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1433 | |
1da177e4 LT |
1434 | return retval; |
1435 | } | |
1436 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1437 | ||
1da177e4 LT |
1438 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1439 | unsigned int target_freq, | |
1440 | unsigned int relation) | |
1441 | { | |
cc993cab | 1442 | int ret; |
1da177e4 LT |
1443 | |
1444 | policy = cpufreq_cpu_get(policy->cpu); | |
1445 | if (!policy) | |
1446 | return -EINVAL; | |
1447 | ||
5a01f2e8 VP |
1448 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
1449 | return -EINVAL; | |
1da177e4 LT |
1450 | |
1451 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1452 | ||
5a01f2e8 | 1453 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 LT |
1454 | |
1455 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1456 | return ret; |
1457 | } | |
1458 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1459 | ||
5a01f2e8 | 1460 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy) |
dfde5d62 VP |
1461 | { |
1462 | int ret = 0; | |
1463 | ||
1464 | policy = cpufreq_cpu_get(policy->cpu); | |
1465 | if (!policy) | |
1466 | return -EINVAL; | |
1467 | ||
dfde5d62 VP |
1468 | if (cpu_online(policy->cpu) && cpufreq_driver->getavg) |
1469 | ret = cpufreq_driver->getavg(policy->cpu); | |
1470 | ||
dfde5d62 VP |
1471 | cpufreq_cpu_put(policy); |
1472 | return ret; | |
1473 | } | |
5a01f2e8 | 1474 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1475 | |
153d7f3f | 1476 | /* |
153d7f3f AV |
1477 | * when "event" is CPUFREQ_GOV_LIMITS |
1478 | */ | |
1da177e4 | 1479 | |
e08f5f5b GS |
1480 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1481 | unsigned int event) | |
1da177e4 | 1482 | { |
cc993cab | 1483 | int ret; |
6afde10c TR |
1484 | |
1485 | /* Only must be defined when default governor is known to have latency | |
1486 | restrictions, like e.g. conservative or ondemand. | |
1487 | That this is the case is already ensured in Kconfig | |
1488 | */ | |
1489 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1490 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1491 | #else | |
1492 | struct cpufreq_governor *gov = NULL; | |
1493 | #endif | |
1c256245 TR |
1494 | |
1495 | if (policy->governor->max_transition_latency && | |
1496 | policy->cpuinfo.transition_latency > | |
1497 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1498 | if (!gov) |
1499 | return -EINVAL; | |
1500 | else { | |
1501 | printk(KERN_WARNING "%s governor failed, too long" | |
1502 | " transition latency of HW, fallback" | |
1503 | " to %s governor\n", | |
1504 | policy->governor->name, | |
1505 | gov->name); | |
1506 | policy->governor = gov; | |
1507 | } | |
1c256245 | 1508 | } |
1da177e4 LT |
1509 | |
1510 | if (!try_module_get(policy->governor->owner)) | |
1511 | return -EINVAL; | |
1512 | ||
e08f5f5b GS |
1513 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1514 | policy->cpu, event); | |
1da177e4 LT |
1515 | ret = policy->governor->governor(policy, event); |
1516 | ||
e08f5f5b GS |
1517 | /* we keep one module reference alive for |
1518 | each CPU governed by this CPU */ | |
1da177e4 LT |
1519 | if ((event != CPUFREQ_GOV_START) || ret) |
1520 | module_put(policy->governor->owner); | |
1521 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1522 | module_put(policy->governor->owner); | |
1523 | ||
1524 | return ret; | |
1525 | } | |
1526 | ||
1527 | ||
1da177e4 LT |
1528 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1529 | { | |
3bcb09a3 | 1530 | int err; |
1da177e4 LT |
1531 | |
1532 | if (!governor) | |
1533 | return -EINVAL; | |
1534 | ||
3fc54d37 | 1535 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1536 | |
3bcb09a3 JF |
1537 | err = -EBUSY; |
1538 | if (__find_governor(governor->name) == NULL) { | |
1539 | err = 0; | |
1540 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1541 | } |
1da177e4 | 1542 | |
32ee8c3e | 1543 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1544 | return err; |
1da177e4 LT |
1545 | } |
1546 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1547 | ||
1548 | ||
1549 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1550 | { | |
1551 | if (!governor) | |
1552 | return; | |
1553 | ||
3fc54d37 | 1554 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1555 | list_del(&governor->governor_list); |
3fc54d37 | 1556 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1557 | return; |
1558 | } | |
1559 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1560 | ||
1561 | ||
1562 | ||
1563 | /********************************************************************* | |
1564 | * POLICY INTERFACE * | |
1565 | *********************************************************************/ | |
1566 | ||
1567 | /** | |
1568 | * cpufreq_get_policy - get the current cpufreq_policy | |
1569 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1570 | * | |
1571 | * Reads the current cpufreq policy. | |
1572 | */ | |
1573 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1574 | { | |
1575 | struct cpufreq_policy *cpu_policy; | |
1576 | if (!policy) | |
1577 | return -EINVAL; | |
1578 | ||
1579 | cpu_policy = cpufreq_cpu_get(cpu); | |
1580 | if (!cpu_policy) | |
1581 | return -EINVAL; | |
1582 | ||
1da177e4 | 1583 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1584 | |
1585 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1586 | return 0; |
1587 | } | |
1588 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1589 | ||
1590 | ||
153d7f3f | 1591 | /* |
e08f5f5b GS |
1592 | * data : current policy. |
1593 | * policy : policy to be set. | |
153d7f3f | 1594 | */ |
e08f5f5b GS |
1595 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1596 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1597 | { |
1598 | int ret = 0; | |
1599 | ||
1600 | cpufreq_debug_disable_ratelimit(); | |
1601 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1602 | policy->min, policy->max); | |
1603 | ||
e08f5f5b GS |
1604 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1605 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1606 | |
53391fa2 | 1607 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1608 | ret = -EINVAL; |
1609 | goto error_out; | |
1610 | } | |
1611 | ||
1da177e4 LT |
1612 | /* verify the cpu speed can be set within this limit */ |
1613 | ret = cpufreq_driver->verify(policy); | |
1614 | if (ret) | |
1615 | goto error_out; | |
1616 | ||
1da177e4 | 1617 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1618 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1619 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1620 | |
1621 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1622 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1623 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1624 | |
1625 | /* verify the cpu speed can be set within this limit, | |
1626 | which might be different to the first one */ | |
1627 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1628 | if (ret) |
1da177e4 | 1629 | goto error_out; |
1da177e4 LT |
1630 | |
1631 | /* notification of the new policy */ | |
e041c683 AS |
1632 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1633 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1634 | |
7d5e350f DJ |
1635 | data->min = policy->min; |
1636 | data->max = policy->max; | |
1da177e4 | 1637 | |
e08f5f5b GS |
1638 | dprintk("new min and max freqs are %u - %u kHz\n", |
1639 | data->min, data->max); | |
1da177e4 LT |
1640 | |
1641 | if (cpufreq_driver->setpolicy) { | |
1642 | data->policy = policy->policy; | |
1643 | dprintk("setting range\n"); | |
1644 | ret = cpufreq_driver->setpolicy(policy); | |
1645 | } else { | |
1646 | if (policy->governor != data->governor) { | |
1647 | /* save old, working values */ | |
1648 | struct cpufreq_governor *old_gov = data->governor; | |
1649 | ||
1650 | dprintk("governor switch\n"); | |
1651 | ||
1652 | /* end old governor */ | |
1653 | if (data->governor) | |
1654 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1655 | ||
1656 | /* start new governor */ | |
1657 | data->governor = policy->governor; | |
1658 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1659 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1660 | dprintk("starting governor %s failed\n", |
1661 | data->governor->name); | |
1da177e4 LT |
1662 | if (old_gov) { |
1663 | data->governor = old_gov; | |
e08f5f5b GS |
1664 | __cpufreq_governor(data, |
1665 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1666 | } |
1667 | ret = -EINVAL; | |
1668 | goto error_out; | |
1669 | } | |
1670 | /* might be a policy change, too, so fall through */ | |
1671 | } | |
1672 | dprintk("governor: change or update limits\n"); | |
1673 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1674 | } | |
1675 | ||
7d5e350f | 1676 | error_out: |
1da177e4 LT |
1677 | cpufreq_debug_enable_ratelimit(); |
1678 | return ret; | |
1679 | } | |
1680 | ||
1da177e4 LT |
1681 | /** |
1682 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1683 | * @cpu: CPU which shall be re-evaluated | |
1684 | * | |
1685 | * Usefull for policy notifiers which have different necessities | |
1686 | * at different times. | |
1687 | */ | |
1688 | int cpufreq_update_policy(unsigned int cpu) | |
1689 | { | |
1690 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1691 | struct cpufreq_policy policy; | |
1692 | int ret = 0; | |
1693 | ||
1694 | if (!data) | |
1695 | return -ENODEV; | |
1696 | ||
5a01f2e8 VP |
1697 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1698 | return -EINVAL; | |
1da177e4 LT |
1699 | |
1700 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1701 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1702 | policy.min = data->user_policy.min; |
1703 | policy.max = data->user_policy.max; | |
1704 | policy.policy = data->user_policy.policy; | |
1705 | policy.governor = data->user_policy.governor; | |
1706 | ||
0961dd0d TR |
1707 | /* BIOS might change freq behind our back |
1708 | -> ask driver for current freq and notify governors about a change */ | |
1709 | if (cpufreq_driver->get) { | |
1710 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1711 | if (!data->cur) { |
1712 | dprintk("Driver did not initialize current freq"); | |
1713 | data->cur = policy.cur; | |
1714 | } else { | |
1715 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1716 | cpufreq_out_of_sync(cpu, data->cur, |
1717 | policy.cur); | |
a85f7bd3 | 1718 | } |
0961dd0d TR |
1719 | } |
1720 | ||
1da177e4 LT |
1721 | ret = __cpufreq_set_policy(data, &policy); |
1722 | ||
5a01f2e8 VP |
1723 | unlock_policy_rwsem_write(cpu); |
1724 | ||
1da177e4 LT |
1725 | cpufreq_cpu_put(data); |
1726 | return ret; | |
1727 | } | |
1728 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1729 | ||
dd184a01 | 1730 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1731 | unsigned long action, void *hcpu) |
1732 | { | |
1733 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1734 | struct sys_device *sys_dev; |
1735 | ||
1736 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1737 | if (sys_dev) { |
1738 | switch (action) { | |
1739 | case CPU_ONLINE: | |
8bb78442 | 1740 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1741 | cpufreq_add_dev(sys_dev); |
1742 | break; | |
1743 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1744 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1745 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1746 | BUG(); | |
1747 | ||
5a01f2e8 | 1748 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1749 | break; |
5a01f2e8 | 1750 | case CPU_DOWN_FAILED: |
8bb78442 | 1751 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1752 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1753 | break; |
1754 | } | |
1755 | } | |
1756 | return NOTIFY_OK; | |
1757 | } | |
1758 | ||
74b85f37 | 1759 | static struct notifier_block __cpuinitdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1760 | { |
1761 | .notifier_call = cpufreq_cpu_callback, | |
1762 | }; | |
1da177e4 LT |
1763 | |
1764 | /********************************************************************* | |
1765 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1766 | *********************************************************************/ | |
1767 | ||
1768 | /** | |
1769 | * cpufreq_register_driver - register a CPU Frequency driver | |
1770 | * @driver_data: A struct cpufreq_driver containing the values# | |
1771 | * submitted by the CPU Frequency driver. | |
1772 | * | |
32ee8c3e | 1773 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1774 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1775 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1776 | * |
1777 | */ | |
221dee28 | 1778 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1779 | { |
1780 | unsigned long flags; | |
1781 | int ret; | |
1782 | ||
1783 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1784 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1785 | return -EINVAL; | |
1786 | ||
1787 | dprintk("trying to register driver %s\n", driver_data->name); | |
1788 | ||
1789 | if (driver_data->setpolicy) | |
1790 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1791 | ||
1792 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1793 | if (cpufreq_driver) { | |
1794 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1795 | return -EBUSY; | |
1796 | } | |
1797 | cpufreq_driver = driver_data; | |
1798 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1799 | ||
1800 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1801 | ||
1802 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1803 | int i; | |
1804 | ret = -ENODEV; | |
1805 | ||
1806 | /* check for at least one working CPU */ | |
1807 | for (i=0; i<NR_CPUS; i++) | |
1808 | if (cpufreq_cpu_data[i]) | |
1809 | ret = 0; | |
1810 | ||
1811 | /* if all ->init() calls failed, unregister */ | |
1812 | if (ret) { | |
e08f5f5b GS |
1813 | dprintk("no CPU initialized for driver %s\n", |
1814 | driver_data->name); | |
1815 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1816 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1817 | |
1818 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1819 | cpufreq_driver = NULL; | |
1820 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1821 | } | |
1822 | } | |
1823 | ||
1824 | if (!ret) { | |
65edc68c | 1825 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1826 | dprintk("driver %s up and running\n", driver_data->name); |
1827 | cpufreq_debug_enable_ratelimit(); | |
1828 | } | |
1829 | ||
1830 | return (ret); | |
1831 | } | |
1832 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1833 | ||
1834 | ||
1835 | /** | |
1836 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1837 | * | |
32ee8c3e | 1838 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1839 | * the right to do so, i.e. if you have succeeded in initialising before! |
1840 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1841 | * currently not initialised. | |
1842 | */ | |
221dee28 | 1843 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1844 | { |
1845 | unsigned long flags; | |
1846 | ||
1847 | cpufreq_debug_disable_ratelimit(); | |
1848 | ||
1849 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1850 | cpufreq_debug_enable_ratelimit(); | |
1851 | return -EINVAL; | |
1852 | } | |
1853 | ||
1854 | dprintk("unregistering driver %s\n", driver->name); | |
1855 | ||
1856 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1857 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1858 | |
1859 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1860 | cpufreq_driver = NULL; | |
1861 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1862 | ||
1863 | return 0; | |
1864 | } | |
1865 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1866 | |
1867 | static int __init cpufreq_core_init(void) | |
1868 | { | |
1869 | int cpu; | |
1870 | ||
1871 | for_each_possible_cpu(cpu) { | |
1872 | per_cpu(policy_cpu, cpu) = -1; | |
1873 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1874 | } | |
1875 | return 0; | |
1876 | } | |
1877 | ||
1878 | core_initcall(cpufreq_core_init); |