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; | |
a4a9df58 | 290 | dprintk("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 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); | |
a4a9df58 | 298 | dprintk("scaling loops_per_jiffy to %lu " |
e08f5f5b | 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 | ||
9e76988e VP |
604 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
605 | const char *buf, size_t count) | |
606 | { | |
607 | unsigned int freq = 0; | |
608 | unsigned int ret; | |
609 | ||
610 | if (!policy->governor->store_setspeed) | |
611 | return -EINVAL; | |
612 | ||
613 | ret = sscanf(buf, "%u", &freq); | |
614 | if (ret != 1) | |
615 | return -EINVAL; | |
616 | ||
617 | policy->governor->store_setspeed(policy, freq); | |
618 | ||
619 | return count; | |
620 | } | |
621 | ||
622 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
623 | { | |
624 | if (!policy->governor->show_setspeed) | |
625 | return sprintf(buf, "<unsupported>\n"); | |
626 | ||
627 | return policy->governor->show_setspeed(policy, buf); | |
628 | } | |
1da177e4 LT |
629 | |
630 | #define define_one_ro(_name) \ | |
631 | static struct freq_attr _name = \ | |
632 | __ATTR(_name, 0444, show_##_name, NULL) | |
633 | ||
634 | #define define_one_ro0400(_name) \ | |
635 | static struct freq_attr _name = \ | |
636 | __ATTR(_name, 0400, show_##_name, NULL) | |
637 | ||
638 | #define define_one_rw(_name) \ | |
639 | static struct freq_attr _name = \ | |
640 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
641 | ||
642 | define_one_ro0400(cpuinfo_cur_freq); | |
643 | define_one_ro(cpuinfo_min_freq); | |
644 | define_one_ro(cpuinfo_max_freq); | |
645 | define_one_ro(scaling_available_governors); | |
646 | define_one_ro(scaling_driver); | |
647 | define_one_ro(scaling_cur_freq); | |
648 | define_one_ro(affected_cpus); | |
649 | define_one_rw(scaling_min_freq); | |
650 | define_one_rw(scaling_max_freq); | |
651 | define_one_rw(scaling_governor); | |
9e76988e | 652 | define_one_rw(scaling_setspeed); |
1da177e4 LT |
653 | |
654 | static struct attribute * default_attrs[] = { | |
655 | &cpuinfo_min_freq.attr, | |
656 | &cpuinfo_max_freq.attr, | |
657 | &scaling_min_freq.attr, | |
658 | &scaling_max_freq.attr, | |
659 | &affected_cpus.attr, | |
660 | &scaling_governor.attr, | |
661 | &scaling_driver.attr, | |
662 | &scaling_available_governors.attr, | |
9e76988e | 663 | &scaling_setspeed.attr, |
1da177e4 LT |
664 | NULL |
665 | }; | |
666 | ||
667 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
668 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
669 | ||
670 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
671 | { | |
672 | struct cpufreq_policy * policy = to_policy(kobj); | |
673 | struct freq_attr * fattr = to_attr(attr); | |
0db4a8a9 | 674 | ssize_t ret = -EINVAL; |
1da177e4 LT |
675 | policy = cpufreq_cpu_get(policy->cpu); |
676 | if (!policy) | |
0db4a8a9 | 677 | goto no_policy; |
5a01f2e8 VP |
678 | |
679 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 680 | goto fail; |
5a01f2e8 | 681 | |
e08f5f5b GS |
682 | if (fattr->show) |
683 | ret = fattr->show(policy, buf); | |
684 | else | |
685 | ret = -EIO; | |
686 | ||
5a01f2e8 | 687 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 688 | fail: |
1da177e4 | 689 | cpufreq_cpu_put(policy); |
0db4a8a9 | 690 | no_policy: |
1da177e4 LT |
691 | return ret; |
692 | } | |
693 | ||
32ee8c3e | 694 | static ssize_t store(struct kobject * kobj, struct attribute * attr, |
1da177e4 LT |
695 | const char * buf, size_t count) |
696 | { | |
697 | struct cpufreq_policy * policy = to_policy(kobj); | |
698 | struct freq_attr * fattr = to_attr(attr); | |
699 | ssize_t ret; | |
700 | policy = cpufreq_cpu_get(policy->cpu); | |
701 | if (!policy) | |
702 | return -EINVAL; | |
5a01f2e8 VP |
703 | |
704 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
705 | return -EINVAL; | |
706 | ||
e08f5f5b GS |
707 | if (fattr->store) |
708 | ret = fattr->store(policy, buf, count); | |
709 | else | |
710 | ret = -EIO; | |
711 | ||
5a01f2e8 VP |
712 | unlock_policy_rwsem_write(policy->cpu); |
713 | ||
1da177e4 LT |
714 | cpufreq_cpu_put(policy); |
715 | return ret; | |
716 | } | |
717 | ||
718 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
719 | { | |
720 | struct cpufreq_policy * policy = to_policy(kobj); | |
721 | dprintk("last reference is dropped\n"); | |
722 | complete(&policy->kobj_unregister); | |
723 | } | |
724 | ||
725 | static struct sysfs_ops sysfs_ops = { | |
726 | .show = show, | |
727 | .store = store, | |
728 | }; | |
729 | ||
730 | static struct kobj_type ktype_cpufreq = { | |
731 | .sysfs_ops = &sysfs_ops, | |
732 | .default_attrs = default_attrs, | |
733 | .release = cpufreq_sysfs_release, | |
734 | }; | |
735 | ||
736 | ||
737 | /** | |
738 | * cpufreq_add_dev - add a CPU device | |
739 | * | |
32ee8c3e | 740 | * Adds the cpufreq interface for a CPU device. |
1da177e4 LT |
741 | */ |
742 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
743 | { | |
744 | unsigned int cpu = sys_dev->id; | |
745 | int ret = 0; | |
746 | struct cpufreq_policy new_policy; | |
747 | struct cpufreq_policy *policy; | |
748 | struct freq_attr **drv_attr; | |
8ff69732 | 749 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
750 | unsigned long flags; |
751 | unsigned int j; | |
8ff69732 DJ |
752 | #ifdef CONFIG_SMP |
753 | struct cpufreq_policy *managed_policy; | |
754 | #endif | |
1da177e4 | 755 | |
c32b6b8e AR |
756 | if (cpu_is_offline(cpu)) |
757 | return 0; | |
758 | ||
1da177e4 LT |
759 | cpufreq_debug_disable_ratelimit(); |
760 | dprintk("adding CPU %u\n", cpu); | |
761 | ||
762 | #ifdef CONFIG_SMP | |
763 | /* check whether a different CPU already registered this | |
764 | * CPU because it is in the same boat. */ | |
765 | policy = cpufreq_cpu_get(cpu); | |
766 | if (unlikely(policy)) { | |
8ff69732 | 767 | cpufreq_cpu_put(policy); |
1da177e4 LT |
768 | cpufreq_debug_enable_ratelimit(); |
769 | return 0; | |
770 | } | |
771 | #endif | |
772 | ||
773 | if (!try_module_get(cpufreq_driver->owner)) { | |
774 | ret = -EINVAL; | |
775 | goto module_out; | |
776 | } | |
777 | ||
e98df50c | 778 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
779 | if (!policy) { |
780 | ret = -ENOMEM; | |
781 | goto nomem_out; | |
782 | } | |
1da177e4 LT |
783 | |
784 | policy->cpu = cpu; | |
785 | policy->cpus = cpumask_of_cpu(cpu); | |
786 | ||
5a01f2e8 VP |
787 | /* Initially set CPU itself as the policy_cpu */ |
788 | per_cpu(policy_cpu, cpu) = cpu; | |
789 | lock_policy_rwsem_write(cpu); | |
790 | ||
1da177e4 | 791 | init_completion(&policy->kobj_unregister); |
65f27f38 | 792 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 793 | |
8122c6ce TR |
794 | /* Set governor before ->init, so that driver could check it */ |
795 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
796 | /* call driver. From then on the cpufreq must be able |
797 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
798 | */ | |
799 | ret = cpufreq_driver->init(policy); | |
800 | if (ret) { | |
801 | dprintk("initialization failed\n"); | |
5a01f2e8 | 802 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
803 | goto err_out; |
804 | } | |
22c970f3 TR |
805 | policy->user_policy.min = policy->cpuinfo.min_freq; |
806 | policy->user_policy.max = policy->cpuinfo.max_freq; | |
1da177e4 | 807 | |
8ff69732 | 808 | #ifdef CONFIG_SMP |
084f3493 TR |
809 | |
810 | #ifdef CONFIG_HOTPLUG_CPU | |
811 | if (cpufreq_cpu_governor[cpu]){ | |
812 | policy->governor = cpufreq_cpu_governor[cpu]; | |
813 | dprintk("Restoring governor %s for cpu %d\n", | |
814 | policy->governor->name, cpu); | |
815 | } | |
816 | #endif | |
817 | ||
8ff69732 DJ |
818 | for_each_cpu_mask(j, policy->cpus) { |
819 | if (cpu == j) | |
820 | continue; | |
821 | ||
822 | /* check for existing affected CPUs. They may not be aware | |
823 | * of it due to CPU Hotplug. | |
824 | */ | |
825 | managed_policy = cpufreq_cpu_get(j); | |
826 | if (unlikely(managed_policy)) { | |
5a01f2e8 VP |
827 | |
828 | /* Set proper policy_cpu */ | |
829 | unlock_policy_rwsem_write(cpu); | |
830 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
831 | ||
832 | if (lock_policy_rwsem_write(cpu) < 0) | |
833 | goto err_out_driver_exit; | |
834 | ||
8ff69732 DJ |
835 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
836 | managed_policy->cpus = policy->cpus; | |
837 | cpufreq_cpu_data[cpu] = managed_policy; | |
838 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
839 | ||
840 | dprintk("CPU already managed, adding link\n"); | |
0142f9dc AD |
841 | ret = sysfs_create_link(&sys_dev->kobj, |
842 | &managed_policy->kobj, | |
843 | "cpufreq"); | |
844 | if (ret) { | |
5a01f2e8 | 845 | unlock_policy_rwsem_write(cpu); |
0142f9dc AD |
846 | goto err_out_driver_exit; |
847 | } | |
8ff69732 DJ |
848 | |
849 | cpufreq_debug_enable_ratelimit(); | |
8ff69732 | 850 | ret = 0; |
5a01f2e8 | 851 | unlock_policy_rwsem_write(cpu); |
8ff69732 DJ |
852 | goto err_out_driver_exit; /* call driver->exit() */ |
853 | } | |
854 | } | |
855 | #endif | |
1da177e4 LT |
856 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
857 | ||
858 | /* prepare interface data */ | |
038c5b3e GKH |
859 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj, |
860 | "cpufreq"); | |
f3876c1b | 861 | if (ret) { |
5a01f2e8 | 862 | unlock_policy_rwsem_write(cpu); |
8085e1f1 | 863 | goto err_out_driver_exit; |
f3876c1b | 864 | } |
1da177e4 LT |
865 | /* set up files for this cpu device */ |
866 | drv_attr = cpufreq_driver->attr; | |
867 | while ((drv_attr) && (*drv_attr)) { | |
58a7295b | 868 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
bd6cba53 DJ |
869 | if (ret) { |
870 | unlock_policy_rwsem_write(cpu); | |
0a4b2ccc | 871 | goto err_out_driver_exit; |
bd6cba53 | 872 | } |
1da177e4 LT |
873 | drv_attr++; |
874 | } | |
0a4b2ccc | 875 | if (cpufreq_driver->get){ |
58a7295b | 876 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
bd6cba53 DJ |
877 | if (ret) { |
878 | unlock_policy_rwsem_write(cpu); | |
0a4b2ccc | 879 | goto err_out_driver_exit; |
bd6cba53 | 880 | } |
0a4b2ccc TR |
881 | } |
882 | if (cpufreq_driver->target){ | |
58a7295b | 883 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
bd6cba53 DJ |
884 | if (ret) { |
885 | unlock_policy_rwsem_write(cpu); | |
0a4b2ccc | 886 | goto err_out_driver_exit; |
bd6cba53 | 887 | } |
0a4b2ccc | 888 | } |
1da177e4 LT |
889 | |
890 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 891 | for_each_cpu_mask(j, policy->cpus) { |
1da177e4 | 892 | cpufreq_cpu_data[j] = policy; |
5a01f2e8 VP |
893 | per_cpu(policy_cpu, j) = policy->cpu; |
894 | } | |
1da177e4 | 895 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8ff69732 DJ |
896 | |
897 | /* symlink affected CPUs */ | |
898 | for_each_cpu_mask(j, policy->cpus) { | |
899 | if (j == cpu) | |
900 | continue; | |
901 | if (!cpu_online(j)) | |
902 | continue; | |
903 | ||
1f8b2c9d | 904 | dprintk("CPU %u already managed, adding link\n", j); |
8ff69732 DJ |
905 | cpufreq_cpu_get(cpu); |
906 | cpu_sys_dev = get_cpu_sysdev(j); | |
0142f9dc AD |
907 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, |
908 | "cpufreq"); | |
909 | if (ret) { | |
5a01f2e8 | 910 | unlock_policy_rwsem_write(cpu); |
0142f9dc AD |
911 | goto err_out_unregister; |
912 | } | |
8ff69732 DJ |
913 | } |
914 | ||
1da177e4 LT |
915 | policy->governor = NULL; /* to assure that the starting sequence is |
916 | * run in cpufreq_set_policy */ | |
87c32271 | 917 | |
1da177e4 | 918 | /* set default policy */ |
22c970f3 TR |
919 | ret = __cpufreq_set_policy(policy, &new_policy); |
920 | policy->user_policy.policy = policy->policy; | |
084f3493 | 921 | policy->user_policy.governor = policy->governor; |
22c970f3 TR |
922 | |
923 | unlock_policy_rwsem_write(cpu); | |
924 | ||
1da177e4 LT |
925 | if (ret) { |
926 | dprintk("setting policy failed\n"); | |
927 | goto err_out_unregister; | |
928 | } | |
929 | ||
038c5b3e | 930 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 931 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
932 | dprintk("initialization complete\n"); |
933 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 934 | |
1da177e4 LT |
935 | return 0; |
936 | ||
937 | ||
938 | err_out_unregister: | |
939 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
940 | for_each_cpu_mask(j, policy->cpus) | |
941 | cpufreq_cpu_data[j] = NULL; | |
942 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
943 | ||
c10997f6 | 944 | kobject_put(&policy->kobj); |
1da177e4 LT |
945 | wait_for_completion(&policy->kobj_unregister); |
946 | ||
8085e1f1 VP |
947 | err_out_driver_exit: |
948 | if (cpufreq_driver->exit) | |
949 | cpufreq_driver->exit(policy); | |
950 | ||
1da177e4 LT |
951 | err_out: |
952 | kfree(policy); | |
953 | ||
954 | nomem_out: | |
955 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 956 | module_out: |
1da177e4 LT |
957 | cpufreq_debug_enable_ratelimit(); |
958 | return ret; | |
959 | } | |
960 | ||
961 | ||
962 | /** | |
5a01f2e8 | 963 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
964 | * |
965 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
966 | * Caller should already have policy_rwsem in write mode for this CPU. |
967 | * This routine frees the rwsem before returning. | |
1da177e4 | 968 | */ |
5a01f2e8 | 969 | static int __cpufreq_remove_dev (struct sys_device * sys_dev) |
1da177e4 LT |
970 | { |
971 | unsigned int cpu = sys_dev->id; | |
972 | unsigned long flags; | |
973 | struct cpufreq_policy *data; | |
974 | #ifdef CONFIG_SMP | |
e738cf6d | 975 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
976 | unsigned int j; |
977 | #endif | |
978 | ||
979 | cpufreq_debug_disable_ratelimit(); | |
980 | dprintk("unregistering CPU %u\n", cpu); | |
981 | ||
982 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
983 | data = cpufreq_cpu_data[cpu]; | |
984 | ||
985 | if (!data) { | |
986 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 987 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 988 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
989 | return -EINVAL; |
990 | } | |
991 | cpufreq_cpu_data[cpu] = NULL; | |
992 | ||
993 | ||
994 | #ifdef CONFIG_SMP | |
995 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 996 | * only need to unlink, put and exit |
1da177e4 LT |
997 | */ |
998 | if (unlikely(cpu != data->cpu)) { | |
999 | dprintk("removing link\n"); | |
8ff69732 | 1000 | cpu_clear(cpu, data->cpus); |
1da177e4 LT |
1001 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1002 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1003 | cpufreq_cpu_put(data); |
1004 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 1005 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1006 | return 0; |
1007 | } | |
1008 | #endif | |
1009 | ||
1da177e4 | 1010 | #ifdef CONFIG_SMP |
084f3493 TR |
1011 | |
1012 | #ifdef CONFIG_HOTPLUG_CPU | |
1013 | cpufreq_cpu_governor[cpu] = data->governor; | |
1014 | #endif | |
1015 | ||
1da177e4 LT |
1016 | /* if we have other CPUs still registered, we need to unlink them, |
1017 | * or else wait_for_completion below will lock up. Clean the | |
1018 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
1019 | * links afterwards. | |
1020 | */ | |
1021 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1022 | for_each_cpu_mask(j, data->cpus) { | |
1023 | if (j == cpu) | |
1024 | continue; | |
1025 | cpufreq_cpu_data[j] = NULL; | |
1026 | } | |
1027 | } | |
1028 | ||
1029 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1030 | ||
1031 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1032 | for_each_cpu_mask(j, data->cpus) { | |
1033 | if (j == cpu) | |
1034 | continue; | |
1035 | dprintk("removing link for cpu %u\n", j); | |
084f3493 TR |
1036 | #ifdef CONFIG_HOTPLUG_CPU |
1037 | cpufreq_cpu_governor[j] = data->governor; | |
1038 | #endif | |
d434fca7 AR |
1039 | cpu_sys_dev = get_cpu_sysdev(j); |
1040 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1041 | cpufreq_cpu_put(data); |
1042 | } | |
1043 | } | |
1044 | #else | |
1045 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1046 | #endif | |
1047 | ||
1da177e4 LT |
1048 | if (cpufreq_driver->target) |
1049 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 VP |
1050 | |
1051 | unlock_policy_rwsem_write(cpu); | |
1da177e4 | 1052 | |
1da177e4 LT |
1053 | kobject_put(&data->kobj); |
1054 | ||
1055 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1056 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1057 | * unloading. |
1058 | */ | |
1059 | dprintk("waiting for dropping of refcount\n"); | |
1060 | wait_for_completion(&data->kobj_unregister); | |
1061 | dprintk("wait complete\n"); | |
1062 | ||
1063 | if (cpufreq_driver->exit) | |
1064 | cpufreq_driver->exit(data); | |
1065 | ||
1066 | kfree(data); | |
1067 | ||
1068 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1069 | return 0; |
1070 | } | |
1071 | ||
1072 | ||
5a01f2e8 VP |
1073 | static int cpufreq_remove_dev (struct sys_device * sys_dev) |
1074 | { | |
1075 | unsigned int cpu = sys_dev->id; | |
1076 | int retval; | |
ec28297a VP |
1077 | |
1078 | if (cpu_is_offline(cpu)) | |
1079 | return 0; | |
1080 | ||
5a01f2e8 VP |
1081 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1082 | BUG(); | |
1083 | ||
1084 | retval = __cpufreq_remove_dev(sys_dev); | |
1085 | return retval; | |
1086 | } | |
1087 | ||
1088 | ||
65f27f38 | 1089 | static void handle_update(struct work_struct *work) |
1da177e4 | 1090 | { |
65f27f38 DH |
1091 | struct cpufreq_policy *policy = |
1092 | container_of(work, struct cpufreq_policy, update); | |
1093 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1094 | dprintk("handle_update for cpu %u called\n", cpu); |
1095 | cpufreq_update_policy(cpu); | |
1096 | } | |
1097 | ||
1098 | /** | |
1099 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1100 | * @cpu: cpu number | |
1101 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1102 | * @new_freq: CPU frequency the CPU actually runs at | |
1103 | * | |
1104 | * We adjust to current frequency first, and need to clean up later. So either call | |
1105 | * to cpufreq_update_policy() or schedule handle_update()). | |
1106 | */ | |
e08f5f5b GS |
1107 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1108 | unsigned int new_freq) | |
1da177e4 LT |
1109 | { |
1110 | struct cpufreq_freqs freqs; | |
1111 | ||
b10eec22 | 1112 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1113 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1114 | ||
1115 | freqs.cpu = cpu; | |
1116 | freqs.old = old_freq; | |
1117 | freqs.new = new_freq; | |
1118 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1119 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1120 | } | |
1121 | ||
1122 | ||
32ee8c3e | 1123 | /** |
4ab70df4 | 1124 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1125 | * @cpu: CPU number |
1126 | * | |
1127 | * This is the last known freq, without actually getting it from the driver. | |
1128 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1129 | */ | |
1130 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1131 | { | |
1132 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1133 | unsigned int ret_freq = 0; |
95235ca2 VP |
1134 | |
1135 | if (policy) { | |
e08f5f5b | 1136 | ret_freq = policy->cur; |
95235ca2 VP |
1137 | cpufreq_cpu_put(policy); |
1138 | } | |
1139 | ||
e08f5f5b | 1140 | return (ret_freq); |
95235ca2 VP |
1141 | } |
1142 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1143 | ||
1144 | ||
5a01f2e8 | 1145 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1146 | { |
5a01f2e8 | 1147 | struct cpufreq_policy *policy = cpufreq_cpu_data[cpu]; |
e08f5f5b | 1148 | unsigned int ret_freq = 0; |
1da177e4 | 1149 | |
1da177e4 | 1150 | if (!cpufreq_driver->get) |
5a01f2e8 | 1151 | return (ret_freq); |
1da177e4 | 1152 | |
e08f5f5b | 1153 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1154 | |
e08f5f5b GS |
1155 | if (ret_freq && policy->cur && |
1156 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1157 | /* verify no discrepancy between actual and | |
1158 | saved value exists */ | |
1159 | if (unlikely(ret_freq != policy->cur)) { | |
1160 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1161 | schedule_work(&policy->update); |
1162 | } | |
1163 | } | |
1164 | ||
5a01f2e8 VP |
1165 | return (ret_freq); |
1166 | } | |
1da177e4 | 1167 | |
5a01f2e8 VP |
1168 | /** |
1169 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1170 | * @cpu: CPU number | |
1171 | * | |
1172 | * Get the CPU current (static) CPU frequency | |
1173 | */ | |
1174 | unsigned int cpufreq_get(unsigned int cpu) | |
1175 | { | |
1176 | unsigned int ret_freq = 0; | |
1177 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1178 | ||
1179 | if (!policy) | |
1180 | goto out; | |
1181 | ||
1182 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1183 | goto out_policy; | |
1184 | ||
1185 | ret_freq = __cpufreq_get(cpu); | |
1186 | ||
1187 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1188 | |
5a01f2e8 VP |
1189 | out_policy: |
1190 | cpufreq_cpu_put(policy); | |
1191 | out: | |
e08f5f5b | 1192 | return (ret_freq); |
1da177e4 LT |
1193 | } |
1194 | EXPORT_SYMBOL(cpufreq_get); | |
1195 | ||
1196 | ||
42d4dc3f BH |
1197 | /** |
1198 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1199 | */ | |
1200 | ||
e00d9967 | 1201 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
42d4dc3f BH |
1202 | { |
1203 | int cpu = sysdev->id; | |
e08f5f5b | 1204 | int ret = 0; |
42d4dc3f BH |
1205 | unsigned int cur_freq = 0; |
1206 | struct cpufreq_policy *cpu_policy; | |
1207 | ||
0e37b159 | 1208 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1209 | |
1210 | if (!cpu_online(cpu)) | |
1211 | return 0; | |
1212 | ||
1213 | /* we may be lax here as interrupts are off. Nonetheless | |
1214 | * we need to grab the correct cpu policy, as to check | |
1215 | * whether we really run on this CPU. | |
1216 | */ | |
1217 | ||
1218 | cpu_policy = cpufreq_cpu_get(cpu); | |
1219 | if (!cpu_policy) | |
1220 | return -EINVAL; | |
1221 | ||
1222 | /* only handle each CPU group once */ | |
1223 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1224 | cpufreq_cpu_put(cpu_policy); | |
1225 | return 0; | |
1226 | } | |
1227 | ||
1228 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1229 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
1230 | if (ret) { |
1231 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1232 | "step on CPU %u\n", cpu_policy->cpu); | |
1233 | cpufreq_cpu_put(cpu_policy); | |
1234 | return ret; | |
1235 | } | |
1236 | } | |
1237 | ||
1238 | ||
1239 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
1240 | goto out; | |
1241 | ||
1242 | if (cpufreq_driver->get) | |
1243 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1244 | ||
1245 | if (!cur_freq || !cpu_policy->cur) { | |
1246 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1247 | "frequency is what timing core thinks it is.\n"); | |
1248 | goto out; | |
1249 | } | |
1250 | ||
1251 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1252 | struct cpufreq_freqs freqs; | |
1253 | ||
1254 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
b10eec22 | 1255 | dprintk("Warning: CPU frequency is %u, " |
42d4dc3f BH |
1256 | "cpufreq assumed %u kHz.\n", |
1257 | cur_freq, cpu_policy->cur); | |
1258 | ||
1259 | freqs.cpu = cpu; | |
1260 | freqs.old = cpu_policy->cur; | |
1261 | freqs.new = cur_freq; | |
1262 | ||
b4dfdbb3 | 1263 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
42d4dc3f BH |
1264 | CPUFREQ_SUSPENDCHANGE, &freqs); |
1265 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1266 | ||
1267 | cpu_policy->cur = cur_freq; | |
1268 | } | |
1269 | ||
7d5e350f | 1270 | out: |
42d4dc3f BH |
1271 | cpufreq_cpu_put(cpu_policy); |
1272 | return 0; | |
1273 | } | |
1274 | ||
1da177e4 LT |
1275 | /** |
1276 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1277 | * | |
1278 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1279 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1280 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1281 | * restored. | |
1da177e4 LT |
1282 | */ |
1283 | static int cpufreq_resume(struct sys_device * sysdev) | |
1284 | { | |
1285 | int cpu = sysdev->id; | |
e08f5f5b | 1286 | int ret = 0; |
1da177e4 LT |
1287 | struct cpufreq_policy *cpu_policy; |
1288 | ||
1289 | dprintk("resuming cpu %u\n", cpu); | |
1290 | ||
1291 | if (!cpu_online(cpu)) | |
1292 | return 0; | |
1293 | ||
1294 | /* we may be lax here as interrupts are off. Nonetheless | |
1295 | * we need to grab the correct cpu policy, as to check | |
1296 | * whether we really run on this CPU. | |
1297 | */ | |
1298 | ||
1299 | cpu_policy = cpufreq_cpu_get(cpu); | |
1300 | if (!cpu_policy) | |
1301 | return -EINVAL; | |
1302 | ||
1303 | /* only handle each CPU group once */ | |
1304 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1305 | cpufreq_cpu_put(cpu_policy); | |
1306 | return 0; | |
1307 | } | |
1308 | ||
1309 | if (cpufreq_driver->resume) { | |
1310 | ret = cpufreq_driver->resume(cpu_policy); | |
1311 | if (ret) { | |
1312 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1313 | "step on CPU %u\n", cpu_policy->cpu); | |
1314 | cpufreq_cpu_put(cpu_policy); | |
1315 | return ret; | |
1316 | } | |
1317 | } | |
1318 | ||
1319 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1320 | unsigned int cur_freq = 0; | |
1321 | ||
1322 | if (cpufreq_driver->get) | |
1323 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1324 | ||
1325 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1326 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1327 | "current frequency is what timing core " | |
1328 | "thinks it is.\n"); | |
1da177e4 LT |
1329 | goto out; |
1330 | } | |
1331 | ||
1332 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1333 | struct cpufreq_freqs freqs; | |
1334 | ||
ac09f698 | 1335 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
a4a9df58 | 1336 | dprintk("Warning: CPU frequency " |
ac09f698 BH |
1337 | "is %u, cpufreq assumed %u kHz.\n", |
1338 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1339 | |
1340 | freqs.cpu = cpu; | |
1341 | freqs.old = cpu_policy->cur; | |
1342 | freqs.new = cur_freq; | |
1343 | ||
b4dfdbb3 | 1344 | srcu_notifier_call_chain( |
e041c683 | 1345 | &cpufreq_transition_notifier_list, |
42d4dc3f | 1346 | CPUFREQ_RESUMECHANGE, &freqs); |
1da177e4 LT |
1347 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1348 | ||
1349 | cpu_policy->cur = cur_freq; | |
1350 | } | |
1351 | } | |
1352 | ||
1353 | out: | |
1354 | schedule_work(&cpu_policy->update); | |
1355 | cpufreq_cpu_put(cpu_policy); | |
1356 | return ret; | |
1357 | } | |
1358 | ||
1359 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1360 | .add = cpufreq_add_dev, | |
1361 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1362 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1363 | .resume = cpufreq_resume, |
1364 | }; | |
1365 | ||
1366 | ||
1367 | /********************************************************************* | |
1368 | * NOTIFIER LISTS INTERFACE * | |
1369 | *********************************************************************/ | |
1370 | ||
1371 | /** | |
1372 | * cpufreq_register_notifier - register a driver with cpufreq | |
1373 | * @nb: notifier function to register | |
1374 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1375 | * | |
32ee8c3e | 1376 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1377 | * are notified about clock rate changes (once before and once after |
1378 | * the transition), or a list of drivers that are notified about | |
1379 | * changes in cpufreq policy. | |
1380 | * | |
1381 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1382 | * blocking_notifier_chain_register. |
1da177e4 LT |
1383 | */ |
1384 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1385 | { | |
1386 | int ret; | |
1387 | ||
1da177e4 LT |
1388 | switch (list) { |
1389 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1390 | ret = srcu_notifier_chain_register( |
e041c683 | 1391 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1392 | break; |
1393 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1394 | ret = blocking_notifier_chain_register( |
1395 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1396 | break; |
1397 | default: | |
1398 | ret = -EINVAL; | |
1399 | } | |
1da177e4 LT |
1400 | |
1401 | return ret; | |
1402 | } | |
1403 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1404 | ||
1405 | ||
1406 | /** | |
1407 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1408 | * @nb: notifier block to be unregistered | |
1409 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1410 | * | |
1411 | * Remove a driver from the CPU frequency notifier list. | |
1412 | * | |
1413 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1414 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1415 | */ |
1416 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1417 | { | |
1418 | int ret; | |
1419 | ||
1da177e4 LT |
1420 | switch (list) { |
1421 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1422 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1423 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1424 | break; |
1425 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1426 | ret = blocking_notifier_chain_unregister( |
1427 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1428 | break; |
1429 | default: | |
1430 | ret = -EINVAL; | |
1431 | } | |
1da177e4 LT |
1432 | |
1433 | return ret; | |
1434 | } | |
1435 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1436 | ||
1437 | ||
1438 | /********************************************************************* | |
1439 | * GOVERNORS * | |
1440 | *********************************************************************/ | |
1441 | ||
1442 | ||
1443 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1444 | unsigned int target_freq, | |
1445 | unsigned int relation) | |
1446 | { | |
1447 | int retval = -EINVAL; | |
c32b6b8e | 1448 | |
1da177e4 LT |
1449 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1450 | target_freq, relation); | |
1451 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1452 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1453 | |
1da177e4 LT |
1454 | return retval; |
1455 | } | |
1456 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1457 | ||
1da177e4 LT |
1458 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1459 | unsigned int target_freq, | |
1460 | unsigned int relation) | |
1461 | { | |
cc993cab | 1462 | int ret; |
1da177e4 LT |
1463 | |
1464 | policy = cpufreq_cpu_get(policy->cpu); | |
1465 | if (!policy) | |
1466 | return -EINVAL; | |
1467 | ||
5a01f2e8 VP |
1468 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
1469 | return -EINVAL; | |
1da177e4 LT |
1470 | |
1471 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1472 | ||
5a01f2e8 | 1473 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 LT |
1474 | |
1475 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1476 | return ret; |
1477 | } | |
1478 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1479 | ||
5a01f2e8 | 1480 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy) |
dfde5d62 VP |
1481 | { |
1482 | int ret = 0; | |
1483 | ||
1484 | policy = cpufreq_cpu_get(policy->cpu); | |
1485 | if (!policy) | |
1486 | return -EINVAL; | |
1487 | ||
dfde5d62 VP |
1488 | if (cpu_online(policy->cpu) && cpufreq_driver->getavg) |
1489 | ret = cpufreq_driver->getavg(policy->cpu); | |
1490 | ||
dfde5d62 VP |
1491 | cpufreq_cpu_put(policy); |
1492 | return ret; | |
1493 | } | |
5a01f2e8 | 1494 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1495 | |
153d7f3f | 1496 | /* |
153d7f3f AV |
1497 | * when "event" is CPUFREQ_GOV_LIMITS |
1498 | */ | |
1da177e4 | 1499 | |
e08f5f5b GS |
1500 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1501 | unsigned int event) | |
1da177e4 | 1502 | { |
cc993cab | 1503 | int ret; |
6afde10c TR |
1504 | |
1505 | /* Only must be defined when default governor is known to have latency | |
1506 | restrictions, like e.g. conservative or ondemand. | |
1507 | That this is the case is already ensured in Kconfig | |
1508 | */ | |
1509 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1510 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1511 | #else | |
1512 | struct cpufreq_governor *gov = NULL; | |
1513 | #endif | |
1c256245 TR |
1514 | |
1515 | if (policy->governor->max_transition_latency && | |
1516 | policy->cpuinfo.transition_latency > | |
1517 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1518 | if (!gov) |
1519 | return -EINVAL; | |
1520 | else { | |
1521 | printk(KERN_WARNING "%s governor failed, too long" | |
1522 | " transition latency of HW, fallback" | |
1523 | " to %s governor\n", | |
1524 | policy->governor->name, | |
1525 | gov->name); | |
1526 | policy->governor = gov; | |
1527 | } | |
1c256245 | 1528 | } |
1da177e4 LT |
1529 | |
1530 | if (!try_module_get(policy->governor->owner)) | |
1531 | return -EINVAL; | |
1532 | ||
e08f5f5b GS |
1533 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1534 | policy->cpu, event); | |
1da177e4 LT |
1535 | ret = policy->governor->governor(policy, event); |
1536 | ||
e08f5f5b GS |
1537 | /* we keep one module reference alive for |
1538 | each CPU governed by this CPU */ | |
1da177e4 LT |
1539 | if ((event != CPUFREQ_GOV_START) || ret) |
1540 | module_put(policy->governor->owner); | |
1541 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1542 | module_put(policy->governor->owner); | |
1543 | ||
1544 | return ret; | |
1545 | } | |
1546 | ||
1547 | ||
1da177e4 LT |
1548 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1549 | { | |
3bcb09a3 | 1550 | int err; |
1da177e4 LT |
1551 | |
1552 | if (!governor) | |
1553 | return -EINVAL; | |
1554 | ||
3fc54d37 | 1555 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1556 | |
3bcb09a3 JF |
1557 | err = -EBUSY; |
1558 | if (__find_governor(governor->name) == NULL) { | |
1559 | err = 0; | |
1560 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1561 | } |
1da177e4 | 1562 | |
32ee8c3e | 1563 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1564 | return err; |
1da177e4 LT |
1565 | } |
1566 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1567 | ||
1568 | ||
1569 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1570 | { | |
1571 | if (!governor) | |
1572 | return; | |
1573 | ||
3fc54d37 | 1574 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1575 | list_del(&governor->governor_list); |
3fc54d37 | 1576 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1577 | return; |
1578 | } | |
1579 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1580 | ||
1581 | ||
1582 | ||
1583 | /********************************************************************* | |
1584 | * POLICY INTERFACE * | |
1585 | *********************************************************************/ | |
1586 | ||
1587 | /** | |
1588 | * cpufreq_get_policy - get the current cpufreq_policy | |
1589 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1590 | * | |
1591 | * Reads the current cpufreq policy. | |
1592 | */ | |
1593 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1594 | { | |
1595 | struct cpufreq_policy *cpu_policy; | |
1596 | if (!policy) | |
1597 | return -EINVAL; | |
1598 | ||
1599 | cpu_policy = cpufreq_cpu_get(cpu); | |
1600 | if (!cpu_policy) | |
1601 | return -EINVAL; | |
1602 | ||
1da177e4 | 1603 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1604 | |
1605 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1606 | return 0; |
1607 | } | |
1608 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1609 | ||
1610 | ||
153d7f3f | 1611 | /* |
e08f5f5b GS |
1612 | * data : current policy. |
1613 | * policy : policy to be set. | |
153d7f3f | 1614 | */ |
e08f5f5b GS |
1615 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1616 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1617 | { |
1618 | int ret = 0; | |
1619 | ||
1620 | cpufreq_debug_disable_ratelimit(); | |
1621 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1622 | policy->min, policy->max); | |
1623 | ||
e08f5f5b GS |
1624 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1625 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1626 | |
53391fa2 | 1627 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1628 | ret = -EINVAL; |
1629 | goto error_out; | |
1630 | } | |
1631 | ||
1da177e4 LT |
1632 | /* verify the cpu speed can be set within this limit */ |
1633 | ret = cpufreq_driver->verify(policy); | |
1634 | if (ret) | |
1635 | goto error_out; | |
1636 | ||
1da177e4 | 1637 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1638 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1639 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1640 | |
1641 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1642 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1643 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1644 | |
1645 | /* verify the cpu speed can be set within this limit, | |
1646 | which might be different to the first one */ | |
1647 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1648 | if (ret) |
1da177e4 | 1649 | goto error_out; |
1da177e4 LT |
1650 | |
1651 | /* notification of the new policy */ | |
e041c683 AS |
1652 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1653 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1654 | |
7d5e350f DJ |
1655 | data->min = policy->min; |
1656 | data->max = policy->max; | |
1da177e4 | 1657 | |
e08f5f5b GS |
1658 | dprintk("new min and max freqs are %u - %u kHz\n", |
1659 | data->min, data->max); | |
1da177e4 LT |
1660 | |
1661 | if (cpufreq_driver->setpolicy) { | |
1662 | data->policy = policy->policy; | |
1663 | dprintk("setting range\n"); | |
1664 | ret = cpufreq_driver->setpolicy(policy); | |
1665 | } else { | |
1666 | if (policy->governor != data->governor) { | |
1667 | /* save old, working values */ | |
1668 | struct cpufreq_governor *old_gov = data->governor; | |
1669 | ||
1670 | dprintk("governor switch\n"); | |
1671 | ||
1672 | /* end old governor */ | |
1673 | if (data->governor) | |
1674 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1675 | ||
1676 | /* start new governor */ | |
1677 | data->governor = policy->governor; | |
1678 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1679 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1680 | dprintk("starting governor %s failed\n", |
1681 | data->governor->name); | |
1da177e4 LT |
1682 | if (old_gov) { |
1683 | data->governor = old_gov; | |
e08f5f5b GS |
1684 | __cpufreq_governor(data, |
1685 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1686 | } |
1687 | ret = -EINVAL; | |
1688 | goto error_out; | |
1689 | } | |
1690 | /* might be a policy change, too, so fall through */ | |
1691 | } | |
1692 | dprintk("governor: change or update limits\n"); | |
1693 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1694 | } | |
1695 | ||
7d5e350f | 1696 | error_out: |
1da177e4 LT |
1697 | cpufreq_debug_enable_ratelimit(); |
1698 | return ret; | |
1699 | } | |
1700 | ||
1da177e4 LT |
1701 | /** |
1702 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1703 | * @cpu: CPU which shall be re-evaluated | |
1704 | * | |
1705 | * Usefull for policy notifiers which have different necessities | |
1706 | * at different times. | |
1707 | */ | |
1708 | int cpufreq_update_policy(unsigned int cpu) | |
1709 | { | |
1710 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1711 | struct cpufreq_policy policy; | |
1712 | int ret = 0; | |
1713 | ||
1714 | if (!data) | |
1715 | return -ENODEV; | |
1716 | ||
5a01f2e8 VP |
1717 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1718 | return -EINVAL; | |
1da177e4 LT |
1719 | |
1720 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1721 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1722 | policy.min = data->user_policy.min; |
1723 | policy.max = data->user_policy.max; | |
1724 | policy.policy = data->user_policy.policy; | |
1725 | policy.governor = data->user_policy.governor; | |
1726 | ||
0961dd0d TR |
1727 | /* BIOS might change freq behind our back |
1728 | -> ask driver for current freq and notify governors about a change */ | |
1729 | if (cpufreq_driver->get) { | |
1730 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1731 | if (!data->cur) { |
1732 | dprintk("Driver did not initialize current freq"); | |
1733 | data->cur = policy.cur; | |
1734 | } else { | |
1735 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1736 | cpufreq_out_of_sync(cpu, data->cur, |
1737 | policy.cur); | |
a85f7bd3 | 1738 | } |
0961dd0d TR |
1739 | } |
1740 | ||
1da177e4 LT |
1741 | ret = __cpufreq_set_policy(data, &policy); |
1742 | ||
5a01f2e8 VP |
1743 | unlock_policy_rwsem_write(cpu); |
1744 | ||
1da177e4 LT |
1745 | cpufreq_cpu_put(data); |
1746 | return ret; | |
1747 | } | |
1748 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1749 | ||
dd184a01 | 1750 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1751 | unsigned long action, void *hcpu) |
1752 | { | |
1753 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1754 | struct sys_device *sys_dev; |
1755 | ||
1756 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1757 | if (sys_dev) { |
1758 | switch (action) { | |
1759 | case CPU_ONLINE: | |
8bb78442 | 1760 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1761 | cpufreq_add_dev(sys_dev); |
1762 | break; | |
1763 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1764 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1765 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1766 | BUG(); | |
1767 | ||
5a01f2e8 | 1768 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1769 | break; |
5a01f2e8 | 1770 | case CPU_DOWN_FAILED: |
8bb78442 | 1771 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1772 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1773 | break; |
1774 | } | |
1775 | } | |
1776 | return NOTIFY_OK; | |
1777 | } | |
1778 | ||
74b85f37 | 1779 | static struct notifier_block __cpuinitdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1780 | { |
1781 | .notifier_call = cpufreq_cpu_callback, | |
1782 | }; | |
1da177e4 LT |
1783 | |
1784 | /********************************************************************* | |
1785 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1786 | *********************************************************************/ | |
1787 | ||
1788 | /** | |
1789 | * cpufreq_register_driver - register a CPU Frequency driver | |
1790 | * @driver_data: A struct cpufreq_driver containing the values# | |
1791 | * submitted by the CPU Frequency driver. | |
1792 | * | |
32ee8c3e | 1793 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1794 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1795 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1796 | * |
1797 | */ | |
221dee28 | 1798 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1799 | { |
1800 | unsigned long flags; | |
1801 | int ret; | |
1802 | ||
1803 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1804 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1805 | return -EINVAL; | |
1806 | ||
1807 | dprintk("trying to register driver %s\n", driver_data->name); | |
1808 | ||
1809 | if (driver_data->setpolicy) | |
1810 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1811 | ||
1812 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1813 | if (cpufreq_driver) { | |
1814 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1815 | return -EBUSY; | |
1816 | } | |
1817 | cpufreq_driver = driver_data; | |
1818 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1819 | ||
1820 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1821 | ||
1822 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1823 | int i; | |
1824 | ret = -ENODEV; | |
1825 | ||
1826 | /* check for at least one working CPU */ | |
1827 | for (i=0; i<NR_CPUS; i++) | |
1828 | if (cpufreq_cpu_data[i]) | |
1829 | ret = 0; | |
1830 | ||
1831 | /* if all ->init() calls failed, unregister */ | |
1832 | if (ret) { | |
e08f5f5b GS |
1833 | dprintk("no CPU initialized for driver %s\n", |
1834 | driver_data->name); | |
1835 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1836 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1837 | |
1838 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1839 | cpufreq_driver = NULL; | |
1840 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1841 | } | |
1842 | } | |
1843 | ||
1844 | if (!ret) { | |
65edc68c | 1845 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1846 | dprintk("driver %s up and running\n", driver_data->name); |
1847 | cpufreq_debug_enable_ratelimit(); | |
1848 | } | |
1849 | ||
1850 | return (ret); | |
1851 | } | |
1852 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1853 | ||
1854 | ||
1855 | /** | |
1856 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1857 | * | |
32ee8c3e | 1858 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1859 | * the right to do so, i.e. if you have succeeded in initialising before! |
1860 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1861 | * currently not initialised. | |
1862 | */ | |
221dee28 | 1863 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1864 | { |
1865 | unsigned long flags; | |
1866 | ||
1867 | cpufreq_debug_disable_ratelimit(); | |
1868 | ||
1869 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1870 | cpufreq_debug_enable_ratelimit(); | |
1871 | return -EINVAL; | |
1872 | } | |
1873 | ||
1874 | dprintk("unregistering driver %s\n", driver->name); | |
1875 | ||
1876 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1877 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1878 | |
1879 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1880 | cpufreq_driver = NULL; | |
1881 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1882 | ||
1883 | return 0; | |
1884 | } | |
1885 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1886 | |
1887 | static int __init cpufreq_core_init(void) | |
1888 | { | |
1889 | int cpu; | |
1890 | ||
1891 | for_each_possible_cpu(cpu) { | |
1892 | per_cpu(policy_cpu, cpu) = -1; | |
1893 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1894 | } | |
1895 | return 0; | |
1896 | } | |
1897 | ||
1898 | core_initcall(cpufreq_core_init); |