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]; | |
1da177e4 LT |
42 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
43 | ||
5a01f2e8 VP |
44 | /* |
45 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
46 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
47 | * | |
48 | * The rules for this semaphore: | |
49 | * - Any routine that wants to read from the policy structure will | |
50 | * do a down_read on this semaphore. | |
51 | * - Any routine that will write to the policy structure and/or may take away | |
52 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
53 | * mode before doing so. | |
54 | * | |
55 | * Additional rules: | |
56 | * - All holders of the lock should check to make sure that the CPU they | |
57 | * are concerned with are online after they get the lock. | |
58 | * - Governor routines that can be called in cpufreq hotplug path should not | |
59 | * take this sem as top level hotplug notifier handler takes this. | |
60 | */ | |
61 | static DEFINE_PER_CPU(int, policy_cpu); | |
62 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); | |
63 | ||
64 | #define lock_policy_rwsem(mode, cpu) \ | |
65 | int lock_policy_rwsem_##mode \ | |
66 | (int cpu) \ | |
67 | { \ | |
68 | int policy_cpu = per_cpu(policy_cpu, cpu); \ | |
69 | BUG_ON(policy_cpu == -1); \ | |
70 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
71 | if (unlikely(!cpu_online(cpu))) { \ | |
72 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
73 | return -1; \ | |
74 | } \ | |
75 | \ | |
76 | return 0; \ | |
77 | } | |
78 | ||
79 | lock_policy_rwsem(read, cpu); | |
80 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_read); | |
81 | ||
82 | lock_policy_rwsem(write, cpu); | |
83 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_write); | |
84 | ||
85 | void unlock_policy_rwsem_read(int cpu) | |
86 | { | |
87 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
88 | BUG_ON(policy_cpu == -1); | |
89 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
90 | } | |
91 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_read); | |
92 | ||
93 | void unlock_policy_rwsem_write(int cpu) | |
94 | { | |
95 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
96 | BUG_ON(policy_cpu == -1); | |
97 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_write); | |
100 | ||
101 | ||
1da177e4 LT |
102 | /* internal prototypes */ |
103 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); | |
5a01f2e8 | 104 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 105 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
106 | |
107 | /** | |
32ee8c3e DJ |
108 | * Two notifier lists: the "policy" list is involved in the |
109 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
110 | * "transition" list for kernel code that needs to handle |
111 | * changes to devices when the CPU clock speed changes. | |
112 | * The mutex locks both lists. | |
113 | */ | |
e041c683 | 114 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 115 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 116 | |
b4dfdbb3 AS |
117 | static int __init init_cpufreq_transition_notifier_list(void) |
118 | { | |
119 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
120 | return 0; | |
121 | } | |
b3438f82 | 122 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
123 | |
124 | static LIST_HEAD(cpufreq_governor_list); | |
7d5e350f | 125 | static DEFINE_MUTEX (cpufreq_governor_mutex); |
1da177e4 | 126 | |
7d5e350f | 127 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
128 | { |
129 | struct cpufreq_policy *data; | |
130 | unsigned long flags; | |
131 | ||
132 | if (cpu >= NR_CPUS) | |
133 | goto err_out; | |
134 | ||
135 | /* get the cpufreq driver */ | |
136 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
137 | ||
138 | if (!cpufreq_driver) | |
139 | goto err_out_unlock; | |
140 | ||
141 | if (!try_module_get(cpufreq_driver->owner)) | |
142 | goto err_out_unlock; | |
143 | ||
144 | ||
145 | /* get the CPU */ | |
146 | data = cpufreq_cpu_data[cpu]; | |
147 | ||
148 | if (!data) | |
149 | goto err_out_put_module; | |
150 | ||
151 | if (!kobject_get(&data->kobj)) | |
152 | goto err_out_put_module; | |
153 | ||
1da177e4 | 154 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
155 | return data; |
156 | ||
7d5e350f | 157 | err_out_put_module: |
1da177e4 | 158 | module_put(cpufreq_driver->owner); |
7d5e350f | 159 | err_out_unlock: |
1da177e4 | 160 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 161 | err_out: |
1da177e4 LT |
162 | return NULL; |
163 | } | |
164 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
165 | ||
7d5e350f | 166 | |
1da177e4 LT |
167 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
168 | { | |
169 | kobject_put(&data->kobj); | |
170 | module_put(cpufreq_driver->owner); | |
171 | } | |
172 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
173 | ||
174 | ||
175 | /********************************************************************* | |
176 | * UNIFIED DEBUG HELPERS * | |
177 | *********************************************************************/ | |
178 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
179 | ||
180 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
181 | static unsigned int debug; | |
182 | ||
183 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
184 | * set or modify this value. | |
185 | */ | |
186 | static unsigned int debug_ratelimit = 1; | |
187 | ||
188 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
189 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
190 | * is set, and disabled upon cpufreq driver removal | |
191 | */ | |
192 | static unsigned int disable_ratelimit = 1; | |
193 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
194 | ||
858119e1 | 195 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
196 | { |
197 | unsigned long flags; | |
198 | ||
199 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
200 | if (disable_ratelimit) | |
201 | disable_ratelimit--; | |
202 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
203 | } | |
204 | ||
858119e1 | 205 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
206 | { |
207 | unsigned long flags; | |
208 | ||
209 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
210 | disable_ratelimit++; | |
211 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
212 | } | |
213 | ||
e08f5f5b GS |
214 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
215 | const char *fmt, ...) | |
1da177e4 LT |
216 | { |
217 | char s[256]; | |
218 | va_list args; | |
219 | unsigned int len; | |
220 | unsigned long flags; | |
32ee8c3e | 221 | |
1da177e4 LT |
222 | WARN_ON(!prefix); |
223 | if (type & debug) { | |
224 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
225 | if (!disable_ratelimit && debug_ratelimit |
226 | && !printk_ratelimit()) { | |
1da177e4 LT |
227 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
228 | return; | |
229 | } | |
230 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
231 | ||
232 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
233 | ||
234 | va_start(args, fmt); | |
235 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
236 | va_end(args); | |
237 | ||
238 | printk(s); | |
239 | ||
240 | WARN_ON(len < 5); | |
241 | } | |
242 | } | |
243 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
244 | ||
245 | ||
246 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
247 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
248 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
249 | |
250 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
251 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
252 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
253 | |
254 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
255 | ||
256 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
257 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
258 | ||
259 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
260 | ||
261 | ||
262 | /********************************************************************* | |
263 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
264 | *********************************************************************/ | |
265 | ||
266 | /** | |
267 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
268 | * | |
269 | * This function alters the system "loops_per_jiffy" for the clock | |
270 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 271 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
272 | * per-CPU loops_per_jiffy value wherever possible. |
273 | */ | |
274 | #ifndef CONFIG_SMP | |
275 | static unsigned long l_p_j_ref; | |
276 | static unsigned int l_p_j_ref_freq; | |
277 | ||
858119e1 | 278 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
279 | { |
280 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
281 | return; | |
282 | ||
283 | if (!l_p_j_ref_freq) { | |
284 | l_p_j_ref = loops_per_jiffy; | |
285 | l_p_j_ref_freq = ci->old; | |
e08f5f5b GS |
286 | dprintk("saving %lu as reference value for loops_per_jiffy;" |
287 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 LT |
288 | } |
289 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
290 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 291 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
292 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
293 | ci->new); | |
294 | dprintk("scaling loops_per_jiffy to %lu" | |
295 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
1da177e4 LT |
296 | } |
297 | } | |
298 | #else | |
e08f5f5b GS |
299 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
300 | { | |
301 | return; | |
302 | } | |
1da177e4 LT |
303 | #endif |
304 | ||
305 | ||
306 | /** | |
e4472cb3 DJ |
307 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
308 | * on frequency transition. | |
1da177e4 | 309 | * |
e4472cb3 DJ |
310 | * This function calls the transition notifiers and the "adjust_jiffies" |
311 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 312 | * external effects. |
1da177e4 LT |
313 | */ |
314 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
315 | { | |
e4472cb3 DJ |
316 | struct cpufreq_policy *policy; |
317 | ||
1da177e4 LT |
318 | BUG_ON(irqs_disabled()); |
319 | ||
320 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
321 | dprintk("notification %u of frequency transition to %u kHz\n", |
322 | state, freqs->new); | |
1da177e4 | 323 | |
e4472cb3 | 324 | policy = cpufreq_cpu_data[freqs->cpu]; |
1da177e4 | 325 | switch (state) { |
e4472cb3 | 326 | |
1da177e4 | 327 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 328 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
329 | * which is not equal to what the cpufreq core thinks is |
330 | * "old frequency". | |
1da177e4 LT |
331 | */ |
332 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
333 | if ((policy) && (policy->cpu == freqs->cpu) && |
334 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 335 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
336 | " %u, cpufreq assumed %u kHz.\n", |
337 | freqs->old, policy->cur); | |
338 | freqs->old = policy->cur; | |
1da177e4 LT |
339 | } |
340 | } | |
b4dfdbb3 | 341 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 342 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
343 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
344 | break; | |
e4472cb3 | 345 | |
1da177e4 LT |
346 | case CPUFREQ_POSTCHANGE: |
347 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
b4dfdbb3 | 348 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 349 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
350 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
351 | policy->cur = freqs->new; | |
1da177e4 LT |
352 | break; |
353 | } | |
1da177e4 LT |
354 | } |
355 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
356 | ||
357 | ||
358 | ||
359 | /********************************************************************* | |
360 | * SYSFS INTERFACE * | |
361 | *********************************************************************/ | |
362 | ||
3bcb09a3 JF |
363 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
364 | { | |
365 | struct cpufreq_governor *t; | |
366 | ||
367 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
368 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) | |
369 | return t; | |
370 | ||
371 | return NULL; | |
372 | } | |
373 | ||
1da177e4 LT |
374 | /** |
375 | * cpufreq_parse_governor - parse a governor string | |
376 | */ | |
377 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
378 | struct cpufreq_governor **governor) | |
379 | { | |
3bcb09a3 JF |
380 | int err = -EINVAL; |
381 | ||
1da177e4 | 382 | if (!cpufreq_driver) |
3bcb09a3 JF |
383 | goto out; |
384 | ||
1da177e4 LT |
385 | if (cpufreq_driver->setpolicy) { |
386 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
387 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 388 | err = 0; |
e08f5f5b GS |
389 | } else if (!strnicmp(str_governor, "powersave", |
390 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 391 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 392 | err = 0; |
1da177e4 | 393 | } |
3bcb09a3 | 394 | } else if (cpufreq_driver->target) { |
1da177e4 | 395 | struct cpufreq_governor *t; |
3bcb09a3 | 396 | |
3fc54d37 | 397 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
398 | |
399 | t = __find_governor(str_governor); | |
400 | ||
ea714970 | 401 | if (t == NULL) { |
e08f5f5b GS |
402 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
403 | str_governor); | |
ea714970 JF |
404 | |
405 | if (name) { | |
406 | int ret; | |
407 | ||
408 | mutex_unlock(&cpufreq_governor_mutex); | |
409 | ret = request_module(name); | |
410 | mutex_lock(&cpufreq_governor_mutex); | |
411 | ||
412 | if (ret == 0) | |
413 | t = __find_governor(str_governor); | |
414 | } | |
415 | ||
416 | kfree(name); | |
417 | } | |
418 | ||
3bcb09a3 JF |
419 | if (t != NULL) { |
420 | *governor = t; | |
421 | err = 0; | |
1da177e4 | 422 | } |
3bcb09a3 | 423 | |
3fc54d37 | 424 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 425 | } |
3bcb09a3 JF |
426 | out: |
427 | return err; | |
1da177e4 | 428 | } |
1da177e4 LT |
429 | |
430 | ||
431 | /* drivers/base/cpu.c */ | |
432 | extern struct sysdev_class cpu_sysdev_class; | |
433 | ||
434 | ||
435 | /** | |
e08f5f5b GS |
436 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
437 | * print out cpufreq information | |
1da177e4 LT |
438 | * |
439 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
440 | * "unsigned int". | |
441 | */ | |
442 | ||
32ee8c3e DJ |
443 | #define show_one(file_name, object) \ |
444 | static ssize_t show_##file_name \ | |
445 | (struct cpufreq_policy * policy, char *buf) \ | |
446 | { \ | |
447 | return sprintf (buf, "%u\n", policy->object); \ | |
1da177e4 LT |
448 | } |
449 | ||
450 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
451 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
452 | show_one(scaling_min_freq, min); | |
453 | show_one(scaling_max_freq, max); | |
454 | show_one(scaling_cur_freq, cur); | |
455 | ||
e08f5f5b GS |
456 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
457 | struct cpufreq_policy *policy); | |
7970e08b | 458 | |
1da177e4 LT |
459 | /** |
460 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
461 | */ | |
462 | #define store_one(file_name, object) \ | |
463 | static ssize_t store_##file_name \ | |
464 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
465 | { \ | |
466 | unsigned int ret = -EINVAL; \ | |
467 | struct cpufreq_policy new_policy; \ | |
468 | \ | |
469 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
470 | if (ret) \ | |
471 | return -EINVAL; \ | |
472 | \ | |
473 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
474 | if (ret != 1) \ | |
475 | return -EINVAL; \ | |
476 | \ | |
7970e08b TR |
477 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
478 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
479 | \ |
480 | return ret ? ret : count; \ | |
481 | } | |
482 | ||
483 | store_one(scaling_min_freq,min); | |
484 | store_one(scaling_max_freq,max); | |
485 | ||
486 | /** | |
487 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
488 | */ | |
e08f5f5b GS |
489 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, |
490 | char *buf) | |
1da177e4 | 491 | { |
5a01f2e8 | 492 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
493 | if (!cur_freq) |
494 | return sprintf(buf, "<unknown>"); | |
495 | return sprintf(buf, "%u\n", cur_freq); | |
496 | } | |
497 | ||
498 | ||
499 | /** | |
500 | * show_scaling_governor - show the current policy for the specified CPU | |
501 | */ | |
e08f5f5b GS |
502 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, |
503 | char *buf) | |
1da177e4 LT |
504 | { |
505 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
506 | return sprintf(buf, "powersave\n"); | |
507 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
508 | return sprintf(buf, "performance\n"); | |
509 | else if (policy->governor) | |
510 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
511 | return -EINVAL; | |
512 | } | |
513 | ||
514 | ||
515 | /** | |
516 | * store_scaling_governor - store policy for the specified CPU | |
517 | */ | |
32ee8c3e DJ |
518 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, |
519 | const char *buf, size_t count) | |
1da177e4 LT |
520 | { |
521 | unsigned int ret = -EINVAL; | |
522 | char str_governor[16]; | |
523 | struct cpufreq_policy new_policy; | |
524 | ||
525 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
526 | if (ret) | |
527 | return ret; | |
528 | ||
529 | ret = sscanf (buf, "%15s", str_governor); | |
530 | if (ret != 1) | |
531 | return -EINVAL; | |
532 | ||
e08f5f5b GS |
533 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
534 | &new_policy.governor)) | |
1da177e4 LT |
535 | return -EINVAL; |
536 | ||
7970e08b TR |
537 | /* Do not use cpufreq_set_policy here or the user_policy.max |
538 | will be wrongly overridden */ | |
7970e08b TR |
539 | ret = __cpufreq_set_policy(policy, &new_policy); |
540 | ||
541 | policy->user_policy.policy = policy->policy; | |
542 | policy->user_policy.governor = policy->governor; | |
7970e08b | 543 | |
e08f5f5b GS |
544 | if (ret) |
545 | return ret; | |
546 | else | |
547 | return count; | |
1da177e4 LT |
548 | } |
549 | ||
550 | /** | |
551 | * show_scaling_driver - show the cpufreq driver currently loaded | |
552 | */ | |
553 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
554 | { | |
555 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
556 | } | |
557 | ||
558 | /** | |
559 | * show_scaling_available_governors - show the available CPUfreq governors | |
560 | */ | |
e08f5f5b | 561 | static ssize_t show_scaling_available_governors (struct cpufreq_policy *policy, |
1da177e4 LT |
562 | char *buf) |
563 | { | |
564 | ssize_t i = 0; | |
565 | struct cpufreq_governor *t; | |
566 | ||
567 | if (!cpufreq_driver->target) { | |
568 | i += sprintf(buf, "performance powersave"); | |
569 | goto out; | |
570 | } | |
571 | ||
572 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
573 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
574 | goto out; | |
575 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
576 | } | |
7d5e350f | 577 | out: |
1da177e4 LT |
578 | i += sprintf(&buf[i], "\n"); |
579 | return i; | |
580 | } | |
581 | /** | |
582 | * show_affected_cpus - show the CPUs affected by each transition | |
583 | */ | |
584 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
585 | { | |
586 | ssize_t i = 0; | |
587 | unsigned int cpu; | |
588 | ||
589 | for_each_cpu_mask(cpu, policy->cpus) { | |
590 | if (i) | |
591 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
592 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
593 | if (i >= (PAGE_SIZE - 5)) | |
594 | break; | |
595 | } | |
596 | i += sprintf(&buf[i], "\n"); | |
597 | return i; | |
598 | } | |
599 | ||
600 | ||
601 | #define define_one_ro(_name) \ | |
602 | static struct freq_attr _name = \ | |
603 | __ATTR(_name, 0444, show_##_name, NULL) | |
604 | ||
605 | #define define_one_ro0400(_name) \ | |
606 | static struct freq_attr _name = \ | |
607 | __ATTR(_name, 0400, show_##_name, NULL) | |
608 | ||
609 | #define define_one_rw(_name) \ | |
610 | static struct freq_attr _name = \ | |
611 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
612 | ||
613 | define_one_ro0400(cpuinfo_cur_freq); | |
614 | define_one_ro(cpuinfo_min_freq); | |
615 | define_one_ro(cpuinfo_max_freq); | |
616 | define_one_ro(scaling_available_governors); | |
617 | define_one_ro(scaling_driver); | |
618 | define_one_ro(scaling_cur_freq); | |
619 | define_one_ro(affected_cpus); | |
620 | define_one_rw(scaling_min_freq); | |
621 | define_one_rw(scaling_max_freq); | |
622 | define_one_rw(scaling_governor); | |
623 | ||
624 | static struct attribute * default_attrs[] = { | |
625 | &cpuinfo_min_freq.attr, | |
626 | &cpuinfo_max_freq.attr, | |
627 | &scaling_min_freq.attr, | |
628 | &scaling_max_freq.attr, | |
629 | &affected_cpus.attr, | |
630 | &scaling_governor.attr, | |
631 | &scaling_driver.attr, | |
632 | &scaling_available_governors.attr, | |
633 | NULL | |
634 | }; | |
635 | ||
636 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
637 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
638 | ||
639 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
640 | { | |
641 | struct cpufreq_policy * policy = to_policy(kobj); | |
642 | struct freq_attr * fattr = to_attr(attr); | |
643 | ssize_t ret; | |
644 | policy = cpufreq_cpu_get(policy->cpu); | |
645 | if (!policy) | |
646 | return -EINVAL; | |
5a01f2e8 VP |
647 | |
648 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
649 | return -EINVAL; | |
650 | ||
e08f5f5b GS |
651 | if (fattr->show) |
652 | ret = fattr->show(policy, buf); | |
653 | else | |
654 | ret = -EIO; | |
655 | ||
5a01f2e8 VP |
656 | unlock_policy_rwsem_read(policy->cpu); |
657 | ||
1da177e4 LT |
658 | cpufreq_cpu_put(policy); |
659 | return ret; | |
660 | } | |
661 | ||
32ee8c3e | 662 | static ssize_t store(struct kobject * kobj, struct attribute * attr, |
1da177e4 LT |
663 | const char * buf, size_t count) |
664 | { | |
665 | struct cpufreq_policy * policy = to_policy(kobj); | |
666 | struct freq_attr * fattr = to_attr(attr); | |
667 | ssize_t ret; | |
668 | policy = cpufreq_cpu_get(policy->cpu); | |
669 | if (!policy) | |
670 | return -EINVAL; | |
5a01f2e8 VP |
671 | |
672 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
673 | return -EINVAL; | |
674 | ||
e08f5f5b GS |
675 | if (fattr->store) |
676 | ret = fattr->store(policy, buf, count); | |
677 | else | |
678 | ret = -EIO; | |
679 | ||
5a01f2e8 VP |
680 | unlock_policy_rwsem_write(policy->cpu); |
681 | ||
1da177e4 LT |
682 | cpufreq_cpu_put(policy); |
683 | return ret; | |
684 | } | |
685 | ||
686 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
687 | { | |
688 | struct cpufreq_policy * policy = to_policy(kobj); | |
689 | dprintk("last reference is dropped\n"); | |
690 | complete(&policy->kobj_unregister); | |
691 | } | |
692 | ||
693 | static struct sysfs_ops sysfs_ops = { | |
694 | .show = show, | |
695 | .store = store, | |
696 | }; | |
697 | ||
698 | static struct kobj_type ktype_cpufreq = { | |
699 | .sysfs_ops = &sysfs_ops, | |
700 | .default_attrs = default_attrs, | |
701 | .release = cpufreq_sysfs_release, | |
702 | }; | |
703 | ||
704 | ||
705 | /** | |
706 | * cpufreq_add_dev - add a CPU device | |
707 | * | |
32ee8c3e | 708 | * Adds the cpufreq interface for a CPU device. |
1da177e4 LT |
709 | */ |
710 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
711 | { | |
712 | unsigned int cpu = sys_dev->id; | |
713 | int ret = 0; | |
714 | struct cpufreq_policy new_policy; | |
715 | struct cpufreq_policy *policy; | |
716 | struct freq_attr **drv_attr; | |
8ff69732 | 717 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
718 | unsigned long flags; |
719 | unsigned int j; | |
8ff69732 DJ |
720 | #ifdef CONFIG_SMP |
721 | struct cpufreq_policy *managed_policy; | |
722 | #endif | |
1da177e4 | 723 | |
c32b6b8e AR |
724 | if (cpu_is_offline(cpu)) |
725 | return 0; | |
726 | ||
1da177e4 LT |
727 | cpufreq_debug_disable_ratelimit(); |
728 | dprintk("adding CPU %u\n", cpu); | |
729 | ||
730 | #ifdef CONFIG_SMP | |
731 | /* check whether a different CPU already registered this | |
732 | * CPU because it is in the same boat. */ | |
733 | policy = cpufreq_cpu_get(cpu); | |
734 | if (unlikely(policy)) { | |
8ff69732 | 735 | cpufreq_cpu_put(policy); |
1da177e4 LT |
736 | cpufreq_debug_enable_ratelimit(); |
737 | return 0; | |
738 | } | |
739 | #endif | |
740 | ||
741 | if (!try_module_get(cpufreq_driver->owner)) { | |
742 | ret = -EINVAL; | |
743 | goto module_out; | |
744 | } | |
745 | ||
e98df50c | 746 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
747 | if (!policy) { |
748 | ret = -ENOMEM; | |
749 | goto nomem_out; | |
750 | } | |
1da177e4 LT |
751 | |
752 | policy->cpu = cpu; | |
753 | policy->cpus = cpumask_of_cpu(cpu); | |
754 | ||
5a01f2e8 VP |
755 | /* Initially set CPU itself as the policy_cpu */ |
756 | per_cpu(policy_cpu, cpu) = cpu; | |
757 | lock_policy_rwsem_write(cpu); | |
758 | ||
1da177e4 | 759 | init_completion(&policy->kobj_unregister); |
65f27f38 | 760 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
761 | |
762 | /* call driver. From then on the cpufreq must be able | |
763 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
764 | */ | |
765 | ret = cpufreq_driver->init(policy); | |
766 | if (ret) { | |
767 | dprintk("initialization failed\n"); | |
5a01f2e8 | 768 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
769 | goto err_out; |
770 | } | |
771 | ||
8ff69732 DJ |
772 | #ifdef CONFIG_SMP |
773 | for_each_cpu_mask(j, policy->cpus) { | |
774 | if (cpu == j) | |
775 | continue; | |
776 | ||
777 | /* check for existing affected CPUs. They may not be aware | |
778 | * of it due to CPU Hotplug. | |
779 | */ | |
780 | managed_policy = cpufreq_cpu_get(j); | |
781 | if (unlikely(managed_policy)) { | |
5a01f2e8 VP |
782 | |
783 | /* Set proper policy_cpu */ | |
784 | unlock_policy_rwsem_write(cpu); | |
785 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
786 | ||
787 | if (lock_policy_rwsem_write(cpu) < 0) | |
788 | goto err_out_driver_exit; | |
789 | ||
8ff69732 DJ |
790 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
791 | managed_policy->cpus = policy->cpus; | |
792 | cpufreq_cpu_data[cpu] = managed_policy; | |
793 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
794 | ||
795 | dprintk("CPU already managed, adding link\n"); | |
0142f9dc AD |
796 | ret = sysfs_create_link(&sys_dev->kobj, |
797 | &managed_policy->kobj, | |
798 | "cpufreq"); | |
799 | if (ret) { | |
5a01f2e8 | 800 | unlock_policy_rwsem_write(cpu); |
0142f9dc AD |
801 | goto err_out_driver_exit; |
802 | } | |
8ff69732 DJ |
803 | |
804 | cpufreq_debug_enable_ratelimit(); | |
8ff69732 | 805 | ret = 0; |
5a01f2e8 | 806 | unlock_policy_rwsem_write(cpu); |
8ff69732 DJ |
807 | goto err_out_driver_exit; /* call driver->exit() */ |
808 | } | |
809 | } | |
810 | #endif | |
1da177e4 LT |
811 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
812 | ||
813 | /* prepare interface data */ | |
814 | policy->kobj.parent = &sys_dev->kobj; | |
815 | policy->kobj.ktype = &ktype_cpufreq; | |
816 | strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); | |
817 | ||
818 | ret = kobject_register(&policy->kobj); | |
f3876c1b | 819 | if (ret) { |
5a01f2e8 | 820 | unlock_policy_rwsem_write(cpu); |
8085e1f1 | 821 | goto err_out_driver_exit; |
f3876c1b | 822 | } |
1da177e4 LT |
823 | /* set up files for this cpu device */ |
824 | drv_attr = cpufreq_driver->attr; | |
825 | while ((drv_attr) && (*drv_attr)) { | |
826 | sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
827 | drv_attr++; | |
828 | } | |
829 | if (cpufreq_driver->get) | |
830 | sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
831 | if (cpufreq_driver->target) | |
832 | sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
833 | ||
834 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 835 | for_each_cpu_mask(j, policy->cpus) { |
1da177e4 | 836 | cpufreq_cpu_data[j] = policy; |
5a01f2e8 VP |
837 | per_cpu(policy_cpu, j) = policy->cpu; |
838 | } | |
1da177e4 | 839 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8ff69732 DJ |
840 | |
841 | /* symlink affected CPUs */ | |
842 | for_each_cpu_mask(j, policy->cpus) { | |
843 | if (j == cpu) | |
844 | continue; | |
845 | if (!cpu_online(j)) | |
846 | continue; | |
847 | ||
1f8b2c9d | 848 | dprintk("CPU %u already managed, adding link\n", j); |
8ff69732 DJ |
849 | cpufreq_cpu_get(cpu); |
850 | cpu_sys_dev = get_cpu_sysdev(j); | |
0142f9dc AD |
851 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, |
852 | "cpufreq"); | |
853 | if (ret) { | |
5a01f2e8 | 854 | unlock_policy_rwsem_write(cpu); |
0142f9dc AD |
855 | goto err_out_unregister; |
856 | } | |
8ff69732 DJ |
857 | } |
858 | ||
1da177e4 LT |
859 | policy->governor = NULL; /* to assure that the starting sequence is |
860 | * run in cpufreq_set_policy */ | |
5a01f2e8 | 861 | unlock_policy_rwsem_write(cpu); |
87c32271 | 862 | |
1da177e4 | 863 | /* set default policy */ |
1da177e4 LT |
864 | ret = cpufreq_set_policy(&new_policy); |
865 | if (ret) { | |
866 | dprintk("setting policy failed\n"); | |
867 | goto err_out_unregister; | |
868 | } | |
869 | ||
870 | module_put(cpufreq_driver->owner); | |
1da177e4 LT |
871 | dprintk("initialization complete\n"); |
872 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 873 | |
1da177e4 LT |
874 | return 0; |
875 | ||
876 | ||
877 | err_out_unregister: | |
878 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
879 | for_each_cpu_mask(j, policy->cpus) | |
880 | cpufreq_cpu_data[j] = NULL; | |
881 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
882 | ||
883 | kobject_unregister(&policy->kobj); | |
884 | wait_for_completion(&policy->kobj_unregister); | |
885 | ||
8085e1f1 VP |
886 | err_out_driver_exit: |
887 | if (cpufreq_driver->exit) | |
888 | cpufreq_driver->exit(policy); | |
889 | ||
1da177e4 LT |
890 | err_out: |
891 | kfree(policy); | |
892 | ||
893 | nomem_out: | |
894 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 895 | module_out: |
1da177e4 LT |
896 | cpufreq_debug_enable_ratelimit(); |
897 | return ret; | |
898 | } | |
899 | ||
900 | ||
901 | /** | |
5a01f2e8 | 902 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
903 | * |
904 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
905 | * Caller should already have policy_rwsem in write mode for this CPU. |
906 | * This routine frees the rwsem before returning. | |
1da177e4 | 907 | */ |
5a01f2e8 | 908 | static int __cpufreq_remove_dev (struct sys_device * sys_dev) |
1da177e4 LT |
909 | { |
910 | unsigned int cpu = sys_dev->id; | |
911 | unsigned long flags; | |
912 | struct cpufreq_policy *data; | |
913 | #ifdef CONFIG_SMP | |
e738cf6d | 914 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
915 | unsigned int j; |
916 | #endif | |
917 | ||
918 | cpufreq_debug_disable_ratelimit(); | |
919 | dprintk("unregistering CPU %u\n", cpu); | |
920 | ||
921 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
922 | data = cpufreq_cpu_data[cpu]; | |
923 | ||
924 | if (!data) { | |
925 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 926 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 927 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
928 | return -EINVAL; |
929 | } | |
930 | cpufreq_cpu_data[cpu] = NULL; | |
931 | ||
932 | ||
933 | #ifdef CONFIG_SMP | |
934 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 935 | * only need to unlink, put and exit |
1da177e4 LT |
936 | */ |
937 | if (unlikely(cpu != data->cpu)) { | |
938 | dprintk("removing link\n"); | |
8ff69732 | 939 | cpu_clear(cpu, data->cpus); |
1da177e4 LT |
940 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
941 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
942 | cpufreq_cpu_put(data); |
943 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 944 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
945 | return 0; |
946 | } | |
947 | #endif | |
948 | ||
1da177e4 LT |
949 | |
950 | if (!kobject_get(&data->kobj)) { | |
951 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
952 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 953 | unlock_policy_rwsem_write(cpu); |
32ee8c3e | 954 | return -EFAULT; |
1da177e4 LT |
955 | } |
956 | ||
957 | #ifdef CONFIG_SMP | |
958 | /* if we have other CPUs still registered, we need to unlink them, | |
959 | * or else wait_for_completion below will lock up. Clean the | |
960 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
961 | * links afterwards. | |
962 | */ | |
963 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
964 | for_each_cpu_mask(j, data->cpus) { | |
965 | if (j == cpu) | |
966 | continue; | |
967 | cpufreq_cpu_data[j] = NULL; | |
968 | } | |
969 | } | |
970 | ||
971 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
972 | ||
973 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
974 | for_each_cpu_mask(j, data->cpus) { | |
975 | if (j == cpu) | |
976 | continue; | |
977 | dprintk("removing link for cpu %u\n", j); | |
d434fca7 AR |
978 | cpu_sys_dev = get_cpu_sysdev(j); |
979 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
980 | cpufreq_cpu_put(data); |
981 | } | |
982 | } | |
983 | #else | |
984 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
985 | #endif | |
986 | ||
1da177e4 LT |
987 | if (cpufreq_driver->target) |
988 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 VP |
989 | |
990 | unlock_policy_rwsem_write(cpu); | |
1da177e4 LT |
991 | |
992 | kobject_unregister(&data->kobj); | |
993 | ||
994 | kobject_put(&data->kobj); | |
995 | ||
996 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 997 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
998 | * unloading. |
999 | */ | |
1000 | dprintk("waiting for dropping of refcount\n"); | |
1001 | wait_for_completion(&data->kobj_unregister); | |
1002 | dprintk("wait complete\n"); | |
1003 | ||
1004 | if (cpufreq_driver->exit) | |
1005 | cpufreq_driver->exit(data); | |
1006 | ||
1007 | kfree(data); | |
1008 | ||
1009 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1010 | return 0; |
1011 | } | |
1012 | ||
1013 | ||
5a01f2e8 VP |
1014 | static int cpufreq_remove_dev (struct sys_device * sys_dev) |
1015 | { | |
1016 | unsigned int cpu = sys_dev->id; | |
1017 | int retval; | |
ec28297a VP |
1018 | |
1019 | if (cpu_is_offline(cpu)) | |
1020 | return 0; | |
1021 | ||
5a01f2e8 VP |
1022 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1023 | BUG(); | |
1024 | ||
1025 | retval = __cpufreq_remove_dev(sys_dev); | |
1026 | return retval; | |
1027 | } | |
1028 | ||
1029 | ||
65f27f38 | 1030 | static void handle_update(struct work_struct *work) |
1da177e4 | 1031 | { |
65f27f38 DH |
1032 | struct cpufreq_policy *policy = |
1033 | container_of(work, struct cpufreq_policy, update); | |
1034 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1035 | dprintk("handle_update for cpu %u called\n", cpu); |
1036 | cpufreq_update_policy(cpu); | |
1037 | } | |
1038 | ||
1039 | /** | |
1040 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1041 | * @cpu: cpu number | |
1042 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1043 | * @new_freq: CPU frequency the CPU actually runs at | |
1044 | * | |
1045 | * We adjust to current frequency first, and need to clean up later. So either call | |
1046 | * to cpufreq_update_policy() or schedule handle_update()). | |
1047 | */ | |
e08f5f5b GS |
1048 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1049 | unsigned int new_freq) | |
1da177e4 LT |
1050 | { |
1051 | struct cpufreq_freqs freqs; | |
1052 | ||
b10eec22 | 1053 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1054 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1055 | ||
1056 | freqs.cpu = cpu; | |
1057 | freqs.old = old_freq; | |
1058 | freqs.new = new_freq; | |
1059 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1060 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1061 | } | |
1062 | ||
1063 | ||
32ee8c3e | 1064 | /** |
4ab70df4 | 1065 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1066 | * @cpu: CPU number |
1067 | * | |
1068 | * This is the last known freq, without actually getting it from the driver. | |
1069 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1070 | */ | |
1071 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1072 | { | |
1073 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1074 | unsigned int ret_freq = 0; |
95235ca2 VP |
1075 | |
1076 | if (policy) { | |
5a01f2e8 VP |
1077 | if (unlikely(lock_policy_rwsem_read(cpu))) |
1078 | return ret_freq; | |
1079 | ||
e08f5f5b | 1080 | ret_freq = policy->cur; |
5a01f2e8 VP |
1081 | |
1082 | unlock_policy_rwsem_read(cpu); | |
95235ca2 VP |
1083 | cpufreq_cpu_put(policy); |
1084 | } | |
1085 | ||
e08f5f5b | 1086 | return (ret_freq); |
95235ca2 VP |
1087 | } |
1088 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1089 | ||
1090 | ||
5a01f2e8 | 1091 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1092 | { |
5a01f2e8 | 1093 | struct cpufreq_policy *policy = cpufreq_cpu_data[cpu]; |
e08f5f5b | 1094 | unsigned int ret_freq = 0; |
1da177e4 | 1095 | |
1da177e4 | 1096 | if (!cpufreq_driver->get) |
5a01f2e8 | 1097 | return (ret_freq); |
1da177e4 | 1098 | |
e08f5f5b | 1099 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1100 | |
e08f5f5b GS |
1101 | if (ret_freq && policy->cur && |
1102 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1103 | /* verify no discrepancy between actual and | |
1104 | saved value exists */ | |
1105 | if (unlikely(ret_freq != policy->cur)) { | |
1106 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1107 | schedule_work(&policy->update); |
1108 | } | |
1109 | } | |
1110 | ||
5a01f2e8 VP |
1111 | return (ret_freq); |
1112 | } | |
1da177e4 | 1113 | |
5a01f2e8 VP |
1114 | /** |
1115 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1116 | * @cpu: CPU number | |
1117 | * | |
1118 | * Get the CPU current (static) CPU frequency | |
1119 | */ | |
1120 | unsigned int cpufreq_get(unsigned int cpu) | |
1121 | { | |
1122 | unsigned int ret_freq = 0; | |
1123 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1124 | ||
1125 | if (!policy) | |
1126 | goto out; | |
1127 | ||
1128 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1129 | goto out_policy; | |
1130 | ||
1131 | ret_freq = __cpufreq_get(cpu); | |
1132 | ||
1133 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1134 | |
5a01f2e8 VP |
1135 | out_policy: |
1136 | cpufreq_cpu_put(policy); | |
1137 | out: | |
e08f5f5b | 1138 | return (ret_freq); |
1da177e4 LT |
1139 | } |
1140 | EXPORT_SYMBOL(cpufreq_get); | |
1141 | ||
1142 | ||
42d4dc3f BH |
1143 | /** |
1144 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1145 | */ | |
1146 | ||
e00d9967 | 1147 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
42d4dc3f BH |
1148 | { |
1149 | int cpu = sysdev->id; | |
e08f5f5b | 1150 | int ret = 0; |
42d4dc3f BH |
1151 | unsigned int cur_freq = 0; |
1152 | struct cpufreq_policy *cpu_policy; | |
1153 | ||
0e37b159 | 1154 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1155 | |
1156 | if (!cpu_online(cpu)) | |
1157 | return 0; | |
1158 | ||
1159 | /* we may be lax here as interrupts are off. Nonetheless | |
1160 | * we need to grab the correct cpu policy, as to check | |
1161 | * whether we really run on this CPU. | |
1162 | */ | |
1163 | ||
1164 | cpu_policy = cpufreq_cpu_get(cpu); | |
1165 | if (!cpu_policy) | |
1166 | return -EINVAL; | |
1167 | ||
1168 | /* only handle each CPU group once */ | |
1169 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1170 | cpufreq_cpu_put(cpu_policy); | |
1171 | return 0; | |
1172 | } | |
1173 | ||
1174 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1175 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
1176 | if (ret) { |
1177 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1178 | "step on CPU %u\n", cpu_policy->cpu); | |
1179 | cpufreq_cpu_put(cpu_policy); | |
1180 | return ret; | |
1181 | } | |
1182 | } | |
1183 | ||
1184 | ||
1185 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
1186 | goto out; | |
1187 | ||
1188 | if (cpufreq_driver->get) | |
1189 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1190 | ||
1191 | if (!cur_freq || !cpu_policy->cur) { | |
1192 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1193 | "frequency is what timing core thinks it is.\n"); | |
1194 | goto out; | |
1195 | } | |
1196 | ||
1197 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1198 | struct cpufreq_freqs freqs; | |
1199 | ||
1200 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
b10eec22 | 1201 | dprintk("Warning: CPU frequency is %u, " |
42d4dc3f BH |
1202 | "cpufreq assumed %u kHz.\n", |
1203 | cur_freq, cpu_policy->cur); | |
1204 | ||
1205 | freqs.cpu = cpu; | |
1206 | freqs.old = cpu_policy->cur; | |
1207 | freqs.new = cur_freq; | |
1208 | ||
b4dfdbb3 | 1209 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
42d4dc3f BH |
1210 | CPUFREQ_SUSPENDCHANGE, &freqs); |
1211 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1212 | ||
1213 | cpu_policy->cur = cur_freq; | |
1214 | } | |
1215 | ||
7d5e350f | 1216 | out: |
42d4dc3f BH |
1217 | cpufreq_cpu_put(cpu_policy); |
1218 | return 0; | |
1219 | } | |
1220 | ||
1da177e4 LT |
1221 | /** |
1222 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1223 | * | |
1224 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1225 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1226 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1227 | * restored. | |
1da177e4 LT |
1228 | */ |
1229 | static int cpufreq_resume(struct sys_device * sysdev) | |
1230 | { | |
1231 | int cpu = sysdev->id; | |
e08f5f5b | 1232 | int ret = 0; |
1da177e4 LT |
1233 | struct cpufreq_policy *cpu_policy; |
1234 | ||
1235 | dprintk("resuming cpu %u\n", cpu); | |
1236 | ||
1237 | if (!cpu_online(cpu)) | |
1238 | return 0; | |
1239 | ||
1240 | /* we may be lax here as interrupts are off. Nonetheless | |
1241 | * we need to grab the correct cpu policy, as to check | |
1242 | * whether we really run on this CPU. | |
1243 | */ | |
1244 | ||
1245 | cpu_policy = cpufreq_cpu_get(cpu); | |
1246 | if (!cpu_policy) | |
1247 | return -EINVAL; | |
1248 | ||
1249 | /* only handle each CPU group once */ | |
1250 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1251 | cpufreq_cpu_put(cpu_policy); | |
1252 | return 0; | |
1253 | } | |
1254 | ||
1255 | if (cpufreq_driver->resume) { | |
1256 | ret = cpufreq_driver->resume(cpu_policy); | |
1257 | if (ret) { | |
1258 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1259 | "step on CPU %u\n", cpu_policy->cpu); | |
1260 | cpufreq_cpu_put(cpu_policy); | |
1261 | return ret; | |
1262 | } | |
1263 | } | |
1264 | ||
1265 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1266 | unsigned int cur_freq = 0; | |
1267 | ||
1268 | if (cpufreq_driver->get) | |
1269 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1270 | ||
1271 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1272 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1273 | "current frequency is what timing core " | |
1274 | "thinks it is.\n"); | |
1da177e4 LT |
1275 | goto out; |
1276 | } | |
1277 | ||
1278 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1279 | struct cpufreq_freqs freqs; | |
1280 | ||
ac09f698 | 1281 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
b10eec22 | 1282 | dprintk("Warning: CPU frequency" |
ac09f698 BH |
1283 | "is %u, cpufreq assumed %u kHz.\n", |
1284 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1285 | |
1286 | freqs.cpu = cpu; | |
1287 | freqs.old = cpu_policy->cur; | |
1288 | freqs.new = cur_freq; | |
1289 | ||
b4dfdbb3 | 1290 | srcu_notifier_call_chain( |
e041c683 | 1291 | &cpufreq_transition_notifier_list, |
42d4dc3f | 1292 | CPUFREQ_RESUMECHANGE, &freqs); |
1da177e4 LT |
1293 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1294 | ||
1295 | cpu_policy->cur = cur_freq; | |
1296 | } | |
1297 | } | |
1298 | ||
1299 | out: | |
1300 | schedule_work(&cpu_policy->update); | |
1301 | cpufreq_cpu_put(cpu_policy); | |
1302 | return ret; | |
1303 | } | |
1304 | ||
1305 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1306 | .add = cpufreq_add_dev, | |
1307 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1308 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1309 | .resume = cpufreq_resume, |
1310 | }; | |
1311 | ||
1312 | ||
1313 | /********************************************************************* | |
1314 | * NOTIFIER LISTS INTERFACE * | |
1315 | *********************************************************************/ | |
1316 | ||
1317 | /** | |
1318 | * cpufreq_register_notifier - register a driver with cpufreq | |
1319 | * @nb: notifier function to register | |
1320 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1321 | * | |
32ee8c3e | 1322 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1323 | * are notified about clock rate changes (once before and once after |
1324 | * the transition), or a list of drivers that are notified about | |
1325 | * changes in cpufreq policy. | |
1326 | * | |
1327 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1328 | * blocking_notifier_chain_register. |
1da177e4 LT |
1329 | */ |
1330 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1331 | { | |
1332 | int ret; | |
1333 | ||
1da177e4 LT |
1334 | switch (list) { |
1335 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1336 | ret = srcu_notifier_chain_register( |
e041c683 | 1337 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1338 | break; |
1339 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1340 | ret = blocking_notifier_chain_register( |
1341 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1342 | break; |
1343 | default: | |
1344 | ret = -EINVAL; | |
1345 | } | |
1da177e4 LT |
1346 | |
1347 | return ret; | |
1348 | } | |
1349 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1350 | ||
1351 | ||
1352 | /** | |
1353 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1354 | * @nb: notifier block to be unregistered | |
1355 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1356 | * | |
1357 | * Remove a driver from the CPU frequency notifier list. | |
1358 | * | |
1359 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1360 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1361 | */ |
1362 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1363 | { | |
1364 | int ret; | |
1365 | ||
1da177e4 LT |
1366 | switch (list) { |
1367 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1368 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1369 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1370 | break; |
1371 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1372 | ret = blocking_notifier_chain_unregister( |
1373 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1374 | break; |
1375 | default: | |
1376 | ret = -EINVAL; | |
1377 | } | |
1da177e4 LT |
1378 | |
1379 | return ret; | |
1380 | } | |
1381 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1382 | ||
1383 | ||
1384 | /********************************************************************* | |
1385 | * GOVERNORS * | |
1386 | *********************************************************************/ | |
1387 | ||
1388 | ||
1389 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1390 | unsigned int target_freq, | |
1391 | unsigned int relation) | |
1392 | { | |
1393 | int retval = -EINVAL; | |
c32b6b8e | 1394 | |
1da177e4 LT |
1395 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1396 | target_freq, relation); | |
1397 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1398 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1399 | |
1da177e4 LT |
1400 | return retval; |
1401 | } | |
1402 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1403 | ||
1da177e4 LT |
1404 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1405 | unsigned int target_freq, | |
1406 | unsigned int relation) | |
1407 | { | |
cc993cab | 1408 | int ret; |
1da177e4 LT |
1409 | |
1410 | policy = cpufreq_cpu_get(policy->cpu); | |
1411 | if (!policy) | |
1412 | return -EINVAL; | |
1413 | ||
5a01f2e8 VP |
1414 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
1415 | return -EINVAL; | |
1da177e4 LT |
1416 | |
1417 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1418 | ||
5a01f2e8 | 1419 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 LT |
1420 | |
1421 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1422 | return ret; |
1423 | } | |
1424 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1425 | ||
5a01f2e8 | 1426 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy) |
dfde5d62 VP |
1427 | { |
1428 | int ret = 0; | |
1429 | ||
1430 | policy = cpufreq_cpu_get(policy->cpu); | |
1431 | if (!policy) | |
1432 | return -EINVAL; | |
1433 | ||
dfde5d62 VP |
1434 | if (cpu_online(policy->cpu) && cpufreq_driver->getavg) |
1435 | ret = cpufreq_driver->getavg(policy->cpu); | |
1436 | ||
dfde5d62 VP |
1437 | cpufreq_cpu_put(policy); |
1438 | return ret; | |
1439 | } | |
5a01f2e8 | 1440 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1441 | |
153d7f3f | 1442 | /* |
153d7f3f AV |
1443 | * when "event" is CPUFREQ_GOV_LIMITS |
1444 | */ | |
1da177e4 | 1445 | |
e08f5f5b GS |
1446 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1447 | unsigned int event) | |
1da177e4 | 1448 | { |
cc993cab | 1449 | int ret; |
1da177e4 LT |
1450 | |
1451 | if (!try_module_get(policy->governor->owner)) | |
1452 | return -EINVAL; | |
1453 | ||
e08f5f5b GS |
1454 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1455 | policy->cpu, event); | |
1da177e4 LT |
1456 | ret = policy->governor->governor(policy, event); |
1457 | ||
e08f5f5b GS |
1458 | /* we keep one module reference alive for |
1459 | each CPU governed by this CPU */ | |
1da177e4 LT |
1460 | if ((event != CPUFREQ_GOV_START) || ret) |
1461 | module_put(policy->governor->owner); | |
1462 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1463 | module_put(policy->governor->owner); | |
1464 | ||
1465 | return ret; | |
1466 | } | |
1467 | ||
1468 | ||
1da177e4 LT |
1469 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1470 | { | |
3bcb09a3 | 1471 | int err; |
1da177e4 LT |
1472 | |
1473 | if (!governor) | |
1474 | return -EINVAL; | |
1475 | ||
3fc54d37 | 1476 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1477 | |
3bcb09a3 JF |
1478 | err = -EBUSY; |
1479 | if (__find_governor(governor->name) == NULL) { | |
1480 | err = 0; | |
1481 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1482 | } |
1da177e4 | 1483 | |
32ee8c3e | 1484 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1485 | return err; |
1da177e4 LT |
1486 | } |
1487 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1488 | ||
1489 | ||
1490 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1491 | { | |
1492 | if (!governor) | |
1493 | return; | |
1494 | ||
3fc54d37 | 1495 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1496 | list_del(&governor->governor_list); |
3fc54d37 | 1497 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1498 | return; |
1499 | } | |
1500 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1501 | ||
1502 | ||
1503 | ||
1504 | /********************************************************************* | |
1505 | * POLICY INTERFACE * | |
1506 | *********************************************************************/ | |
1507 | ||
1508 | /** | |
1509 | * cpufreq_get_policy - get the current cpufreq_policy | |
1510 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1511 | * | |
1512 | * Reads the current cpufreq policy. | |
1513 | */ | |
1514 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1515 | { | |
1516 | struct cpufreq_policy *cpu_policy; | |
1517 | if (!policy) | |
1518 | return -EINVAL; | |
1519 | ||
1520 | cpu_policy = cpufreq_cpu_get(cpu); | |
1521 | if (!cpu_policy) | |
1522 | return -EINVAL; | |
1523 | ||
1da177e4 | 1524 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1525 | |
1526 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1527 | return 0; |
1528 | } | |
1529 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1530 | ||
1531 | ||
153d7f3f | 1532 | /* |
e08f5f5b GS |
1533 | * data : current policy. |
1534 | * policy : policy to be set. | |
153d7f3f | 1535 | */ |
e08f5f5b GS |
1536 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1537 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1538 | { |
1539 | int ret = 0; | |
1540 | ||
1541 | cpufreq_debug_disable_ratelimit(); | |
1542 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1543 | policy->min, policy->max); | |
1544 | ||
e08f5f5b GS |
1545 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1546 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1547 | |
9c9a43ed MD |
1548 | if (policy->min > data->min && policy->min > policy->max) { |
1549 | ret = -EINVAL; | |
1550 | goto error_out; | |
1551 | } | |
1552 | ||
1da177e4 LT |
1553 | /* verify the cpu speed can be set within this limit */ |
1554 | ret = cpufreq_driver->verify(policy); | |
1555 | if (ret) | |
1556 | goto error_out; | |
1557 | ||
1da177e4 | 1558 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1559 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1560 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1561 | |
1562 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1563 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1564 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1565 | |
1566 | /* verify the cpu speed can be set within this limit, | |
1567 | which might be different to the first one */ | |
1568 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1569 | if (ret) |
1da177e4 | 1570 | goto error_out; |
1da177e4 LT |
1571 | |
1572 | /* notification of the new policy */ | |
e041c683 AS |
1573 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1574 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1575 | |
7d5e350f DJ |
1576 | data->min = policy->min; |
1577 | data->max = policy->max; | |
1da177e4 | 1578 | |
e08f5f5b GS |
1579 | dprintk("new min and max freqs are %u - %u kHz\n", |
1580 | data->min, data->max); | |
1da177e4 LT |
1581 | |
1582 | if (cpufreq_driver->setpolicy) { | |
1583 | data->policy = policy->policy; | |
1584 | dprintk("setting range\n"); | |
1585 | ret = cpufreq_driver->setpolicy(policy); | |
1586 | } else { | |
1587 | if (policy->governor != data->governor) { | |
1588 | /* save old, working values */ | |
1589 | struct cpufreq_governor *old_gov = data->governor; | |
1590 | ||
1591 | dprintk("governor switch\n"); | |
1592 | ||
1593 | /* end old governor */ | |
1594 | if (data->governor) | |
1595 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1596 | ||
1597 | /* start new governor */ | |
1598 | data->governor = policy->governor; | |
1599 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1600 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1601 | dprintk("starting governor %s failed\n", |
1602 | data->governor->name); | |
1da177e4 LT |
1603 | if (old_gov) { |
1604 | data->governor = old_gov; | |
e08f5f5b GS |
1605 | __cpufreq_governor(data, |
1606 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1607 | } |
1608 | ret = -EINVAL; | |
1609 | goto error_out; | |
1610 | } | |
1611 | /* might be a policy change, too, so fall through */ | |
1612 | } | |
1613 | dprintk("governor: change or update limits\n"); | |
1614 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1615 | } | |
1616 | ||
7d5e350f | 1617 | error_out: |
1da177e4 LT |
1618 | cpufreq_debug_enable_ratelimit(); |
1619 | return ret; | |
1620 | } | |
1621 | ||
1622 | /** | |
1623 | * cpufreq_set_policy - set a new CPUFreq policy | |
1624 | * @policy: policy to be set. | |
1625 | * | |
1626 | * Sets a new CPU frequency and voltage scaling policy. | |
1627 | */ | |
1628 | int cpufreq_set_policy(struct cpufreq_policy *policy) | |
1629 | { | |
1630 | int ret = 0; | |
1631 | struct cpufreq_policy *data; | |
1632 | ||
1633 | if (!policy) | |
1634 | return -EINVAL; | |
1635 | ||
1636 | data = cpufreq_cpu_get(policy->cpu); | |
1637 | if (!data) | |
1638 | return -EINVAL; | |
1639 | ||
5a01f2e8 VP |
1640 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
1641 | return -EINVAL; | |
1642 | ||
1da177e4 LT |
1643 | |
1644 | ret = __cpufreq_set_policy(data, policy); | |
1645 | data->user_policy.min = data->min; | |
1646 | data->user_policy.max = data->max; | |
1647 | data->user_policy.policy = data->policy; | |
1648 | data->user_policy.governor = data->governor; | |
1649 | ||
5a01f2e8 | 1650 | unlock_policy_rwsem_write(policy->cpu); |
153d7f3f | 1651 | |
1da177e4 LT |
1652 | cpufreq_cpu_put(data); |
1653 | ||
1654 | return ret; | |
1655 | } | |
1656 | EXPORT_SYMBOL(cpufreq_set_policy); | |
1657 | ||
1658 | ||
1659 | /** | |
1660 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1661 | * @cpu: CPU which shall be re-evaluated | |
1662 | * | |
1663 | * Usefull for policy notifiers which have different necessities | |
1664 | * at different times. | |
1665 | */ | |
1666 | int cpufreq_update_policy(unsigned int cpu) | |
1667 | { | |
1668 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1669 | struct cpufreq_policy policy; | |
1670 | int ret = 0; | |
1671 | ||
1672 | if (!data) | |
1673 | return -ENODEV; | |
1674 | ||
5a01f2e8 VP |
1675 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1676 | return -EINVAL; | |
1da177e4 LT |
1677 | |
1678 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1679 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1680 | policy.min = data->user_policy.min; |
1681 | policy.max = data->user_policy.max; | |
1682 | policy.policy = data->user_policy.policy; | |
1683 | policy.governor = data->user_policy.governor; | |
1684 | ||
0961dd0d TR |
1685 | /* BIOS might change freq behind our back |
1686 | -> ask driver for current freq and notify governors about a change */ | |
1687 | if (cpufreq_driver->get) { | |
1688 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1689 | if (!data->cur) { |
1690 | dprintk("Driver did not initialize current freq"); | |
1691 | data->cur = policy.cur; | |
1692 | } else { | |
1693 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1694 | cpufreq_out_of_sync(cpu, data->cur, |
1695 | policy.cur); | |
a85f7bd3 | 1696 | } |
0961dd0d TR |
1697 | } |
1698 | ||
1da177e4 LT |
1699 | ret = __cpufreq_set_policy(data, &policy); |
1700 | ||
5a01f2e8 VP |
1701 | unlock_policy_rwsem_write(cpu); |
1702 | ||
1da177e4 LT |
1703 | cpufreq_cpu_put(data); |
1704 | return ret; | |
1705 | } | |
1706 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1707 | ||
65edc68c | 1708 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1709 | unsigned long action, void *hcpu) |
1710 | { | |
1711 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e | 1712 | struct sys_device *sys_dev; |
5a01f2e8 | 1713 | struct cpufreq_policy *policy; |
c32b6b8e AR |
1714 | |
1715 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1716 | if (sys_dev) { |
1717 | switch (action) { | |
1718 | case CPU_ONLINE: | |
1719 | cpufreq_add_dev(sys_dev); | |
1720 | break; | |
1721 | case CPU_DOWN_PREPARE: | |
5a01f2e8 VP |
1722 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1723 | BUG(); | |
1724 | ||
c32b6b8e AR |
1725 | policy = cpufreq_cpu_data[cpu]; |
1726 | if (policy) { | |
5a01f2e8 | 1727 | __cpufreq_driver_target(policy, policy->min, |
c32b6b8e AR |
1728 | CPUFREQ_RELATION_H); |
1729 | } | |
5a01f2e8 | 1730 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1731 | break; |
5a01f2e8 VP |
1732 | case CPU_DOWN_FAILED: |
1733 | cpufreq_add_dev(sys_dev); | |
c32b6b8e AR |
1734 | break; |
1735 | } | |
1736 | } | |
1737 | return NOTIFY_OK; | |
1738 | } | |
1739 | ||
74b85f37 | 1740 | static struct notifier_block __cpuinitdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1741 | { |
1742 | .notifier_call = cpufreq_cpu_callback, | |
1743 | }; | |
1da177e4 LT |
1744 | |
1745 | /********************************************************************* | |
1746 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1747 | *********************************************************************/ | |
1748 | ||
1749 | /** | |
1750 | * cpufreq_register_driver - register a CPU Frequency driver | |
1751 | * @driver_data: A struct cpufreq_driver containing the values# | |
1752 | * submitted by the CPU Frequency driver. | |
1753 | * | |
32ee8c3e | 1754 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1755 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1756 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1757 | * |
1758 | */ | |
221dee28 | 1759 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1760 | { |
1761 | unsigned long flags; | |
1762 | int ret; | |
1763 | ||
1764 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1765 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1766 | return -EINVAL; | |
1767 | ||
1768 | dprintk("trying to register driver %s\n", driver_data->name); | |
1769 | ||
1770 | if (driver_data->setpolicy) | |
1771 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1772 | ||
1773 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1774 | if (cpufreq_driver) { | |
1775 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1776 | return -EBUSY; | |
1777 | } | |
1778 | cpufreq_driver = driver_data; | |
1779 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1780 | ||
1781 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1782 | ||
1783 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1784 | int i; | |
1785 | ret = -ENODEV; | |
1786 | ||
1787 | /* check for at least one working CPU */ | |
1788 | for (i=0; i<NR_CPUS; i++) | |
1789 | if (cpufreq_cpu_data[i]) | |
1790 | ret = 0; | |
1791 | ||
1792 | /* if all ->init() calls failed, unregister */ | |
1793 | if (ret) { | |
e08f5f5b GS |
1794 | dprintk("no CPU initialized for driver %s\n", |
1795 | driver_data->name); | |
1796 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1797 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1798 | |
1799 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1800 | cpufreq_driver = NULL; | |
1801 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1802 | } | |
1803 | } | |
1804 | ||
1805 | if (!ret) { | |
65edc68c | 1806 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1807 | dprintk("driver %s up and running\n", driver_data->name); |
1808 | cpufreq_debug_enable_ratelimit(); | |
1809 | } | |
1810 | ||
1811 | return (ret); | |
1812 | } | |
1813 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1814 | ||
1815 | ||
1816 | /** | |
1817 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1818 | * | |
32ee8c3e | 1819 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1820 | * the right to do so, i.e. if you have succeeded in initialising before! |
1821 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1822 | * currently not initialised. | |
1823 | */ | |
221dee28 | 1824 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1825 | { |
1826 | unsigned long flags; | |
1827 | ||
1828 | cpufreq_debug_disable_ratelimit(); | |
1829 | ||
1830 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1831 | cpufreq_debug_enable_ratelimit(); | |
1832 | return -EINVAL; | |
1833 | } | |
1834 | ||
1835 | dprintk("unregistering driver %s\n", driver->name); | |
1836 | ||
1837 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1838 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1839 | |
1840 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1841 | cpufreq_driver = NULL; | |
1842 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1843 | ||
1844 | return 0; | |
1845 | } | |
1846 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1847 | |
1848 | static int __init cpufreq_core_init(void) | |
1849 | { | |
1850 | int cpu; | |
1851 | ||
1852 | for_each_possible_cpu(cpu) { | |
1853 | per_cpu(policy_cpu, cpu) = -1; | |
1854 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1855 | } | |
1856 | return 0; | |
1857 | } | |
1858 | ||
1859 | core_initcall(cpufreq_core_init); |