Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
6 | * | |
c32b6b8e | 7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 8 | * Added handling for CPU hotplug |
8ff69732 DJ |
9 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
10 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 11 | * |
1da177e4 LT |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
1da177e4 LT |
18 | #include <linux/kernel.h> |
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/notifier.h> | |
22 | #include <linux/cpufreq.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <linux/device.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/cpu.h> | |
29 | #include <linux/completion.h> | |
3fc54d37 | 30 | #include <linux/mutex.h> |
1da177e4 | 31 | |
e08f5f5b GS |
32 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \ |
33 | "cpufreq-core", msg) | |
1da177e4 LT |
34 | |
35 | /** | |
cd878479 | 36 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
37 | * level driver of CPUFreq support, and its spinlock. This lock |
38 | * also protects the cpufreq_cpu_data array. | |
39 | */ | |
7d5e350f | 40 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 41 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
084f3493 TR |
42 | #ifdef CONFIG_HOTPLUG_CPU |
43 | /* This one keeps track of the previously set governor of a removed CPU */ | |
7a6aedfa | 44 | static DEFINE_PER_CPU(struct cpufreq_governor *, cpufreq_cpu_governor); |
084f3493 | 45 | #endif |
1da177e4 LT |
46 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
47 | ||
5a01f2e8 VP |
48 | /* |
49 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
50 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
51 | * | |
52 | * The rules for this semaphore: | |
53 | * - Any routine that wants to read from the policy structure will | |
54 | * do a down_read on this semaphore. | |
55 | * - Any routine that will write to the policy structure and/or may take away | |
56 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
57 | * mode before doing so. | |
58 | * | |
59 | * Additional rules: | |
60 | * - All holders of the lock should check to make sure that the CPU they | |
61 | * are concerned with are online after they get the lock. | |
62 | * - Governor routines that can be called in cpufreq hotplug path should not | |
63 | * take this sem as top level hotplug notifier handler takes this. | |
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 | |
74212ca4 | 121 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
122 | static int __init init_cpufreq_transition_notifier_list(void) |
123 | { | |
124 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 125 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
126 | return 0; |
127 | } | |
b3438f82 | 128 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
129 | |
130 | static LIST_HEAD(cpufreq_governor_list); | |
7d5e350f | 131 | static DEFINE_MUTEX (cpufreq_governor_mutex); |
1da177e4 | 132 | |
7d5e350f | 133 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
134 | { |
135 | struct cpufreq_policy *data; | |
136 | unsigned long flags; | |
137 | ||
7a6aedfa | 138 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
139 | goto err_out; |
140 | ||
141 | /* get the cpufreq driver */ | |
142 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
143 | ||
144 | if (!cpufreq_driver) | |
145 | goto err_out_unlock; | |
146 | ||
147 | if (!try_module_get(cpufreq_driver->owner)) | |
148 | goto err_out_unlock; | |
149 | ||
150 | ||
151 | /* get the CPU */ | |
7a6aedfa | 152 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
153 | |
154 | if (!data) | |
155 | goto err_out_put_module; | |
156 | ||
157 | if (!kobject_get(&data->kobj)) | |
158 | goto err_out_put_module; | |
159 | ||
1da177e4 | 160 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
161 | return data; |
162 | ||
7d5e350f | 163 | err_out_put_module: |
1da177e4 | 164 | module_put(cpufreq_driver->owner); |
7d5e350f | 165 | err_out_unlock: |
1da177e4 | 166 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 167 | err_out: |
1da177e4 LT |
168 | return NULL; |
169 | } | |
170 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
171 | ||
7d5e350f | 172 | |
1da177e4 LT |
173 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
174 | { | |
175 | kobject_put(&data->kobj); | |
176 | module_put(cpufreq_driver->owner); | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
179 | ||
180 | ||
181 | /********************************************************************* | |
182 | * UNIFIED DEBUG HELPERS * | |
183 | *********************************************************************/ | |
184 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
185 | ||
186 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
187 | static unsigned int debug; | |
188 | ||
189 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
190 | * set or modify this value. | |
191 | */ | |
192 | static unsigned int debug_ratelimit = 1; | |
193 | ||
194 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
195 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
196 | * is set, and disabled upon cpufreq driver removal | |
197 | */ | |
198 | static unsigned int disable_ratelimit = 1; | |
199 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
200 | ||
858119e1 | 201 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
202 | { |
203 | unsigned long flags; | |
204 | ||
205 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
206 | if (disable_ratelimit) | |
207 | disable_ratelimit--; | |
208 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
209 | } | |
210 | ||
858119e1 | 211 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
212 | { |
213 | unsigned long flags; | |
214 | ||
215 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
216 | disable_ratelimit++; | |
217 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
218 | } | |
219 | ||
e08f5f5b | 220 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
905d77cd | 221 | const char *fmt, ...) |
1da177e4 LT |
222 | { |
223 | char s[256]; | |
224 | va_list args; | |
225 | unsigned int len; | |
226 | unsigned long flags; | |
32ee8c3e | 227 | |
1da177e4 LT |
228 | WARN_ON(!prefix); |
229 | if (type & debug) { | |
230 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
231 | if (!disable_ratelimit && debug_ratelimit |
232 | && !printk_ratelimit()) { | |
1da177e4 LT |
233 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
234 | return; | |
235 | } | |
236 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
237 | ||
238 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
239 | ||
240 | va_start(args, fmt); | |
241 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
242 | va_end(args); | |
243 | ||
244 | printk(s); | |
245 | ||
246 | WARN_ON(len < 5); | |
247 | } | |
248 | } | |
249 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
250 | ||
251 | ||
252 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
253 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
254 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
255 | |
256 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
257 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
258 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
259 | |
260 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
261 | ||
262 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
263 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
264 | ||
265 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
266 | ||
267 | ||
268 | /********************************************************************* | |
269 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
270 | *********************************************************************/ | |
271 | ||
272 | /** | |
273 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
274 | * | |
275 | * This function alters the system "loops_per_jiffy" for the clock | |
276 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 277 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
278 | * per-CPU loops_per_jiffy value wherever possible. |
279 | */ | |
280 | #ifndef CONFIG_SMP | |
281 | static unsigned long l_p_j_ref; | |
282 | static unsigned int l_p_j_ref_freq; | |
283 | ||
858119e1 | 284 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
285 | { |
286 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
287 | return; | |
288 | ||
289 | if (!l_p_j_ref_freq) { | |
290 | l_p_j_ref = loops_per_jiffy; | |
291 | l_p_j_ref_freq = ci->old; | |
a4a9df58 | 292 | dprintk("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 293 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 LT |
294 | } |
295 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
296 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 297 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
298 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
299 | ci->new); | |
a4a9df58 | 300 | dprintk("scaling loops_per_jiffy to %lu " |
e08f5f5b | 301 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
302 | } |
303 | } | |
304 | #else | |
e08f5f5b GS |
305 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
306 | { | |
307 | return; | |
308 | } | |
1da177e4 LT |
309 | #endif |
310 | ||
311 | ||
312 | /** | |
e4472cb3 DJ |
313 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
314 | * on frequency transition. | |
1da177e4 | 315 | * |
e4472cb3 DJ |
316 | * This function calls the transition notifiers and the "adjust_jiffies" |
317 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 318 | * external effects. |
1da177e4 LT |
319 | */ |
320 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
321 | { | |
e4472cb3 DJ |
322 | struct cpufreq_policy *policy; |
323 | ||
1da177e4 LT |
324 | BUG_ON(irqs_disabled()); |
325 | ||
326 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
327 | dprintk("notification %u of frequency transition to %u kHz\n", |
328 | state, freqs->new); | |
1da177e4 | 329 | |
7a6aedfa | 330 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 331 | switch (state) { |
e4472cb3 | 332 | |
1da177e4 | 333 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 334 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
335 | * which is not equal to what the cpufreq core thinks is |
336 | * "old frequency". | |
1da177e4 LT |
337 | */ |
338 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
339 | if ((policy) && (policy->cpu == freqs->cpu) && |
340 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 341 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
342 | " %u, cpufreq assumed %u kHz.\n", |
343 | freqs->old, policy->cur); | |
344 | freqs->old = policy->cur; | |
1da177e4 LT |
345 | } |
346 | } | |
b4dfdbb3 | 347 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 348 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
349 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
350 | break; | |
e4472cb3 | 351 | |
1da177e4 LT |
352 | case CPUFREQ_POSTCHANGE: |
353 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
b4dfdbb3 | 354 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 355 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
356 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
357 | policy->cur = freqs->new; | |
1da177e4 LT |
358 | break; |
359 | } | |
1da177e4 LT |
360 | } |
361 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
362 | ||
363 | ||
364 | ||
365 | /********************************************************************* | |
366 | * SYSFS INTERFACE * | |
367 | *********************************************************************/ | |
368 | ||
3bcb09a3 JF |
369 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
370 | { | |
371 | struct cpufreq_governor *t; | |
372 | ||
373 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
374 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) | |
375 | return t; | |
376 | ||
377 | return NULL; | |
378 | } | |
379 | ||
1da177e4 LT |
380 | /** |
381 | * cpufreq_parse_governor - parse a governor string | |
382 | */ | |
905d77cd | 383 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
384 | struct cpufreq_governor **governor) |
385 | { | |
3bcb09a3 JF |
386 | int err = -EINVAL; |
387 | ||
1da177e4 | 388 | if (!cpufreq_driver) |
3bcb09a3 JF |
389 | goto out; |
390 | ||
1da177e4 LT |
391 | if (cpufreq_driver->setpolicy) { |
392 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
393 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 394 | err = 0; |
e08f5f5b GS |
395 | } else if (!strnicmp(str_governor, "powersave", |
396 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 397 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 398 | err = 0; |
1da177e4 | 399 | } |
3bcb09a3 | 400 | } else if (cpufreq_driver->target) { |
1da177e4 | 401 | struct cpufreq_governor *t; |
3bcb09a3 | 402 | |
3fc54d37 | 403 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
404 | |
405 | t = __find_governor(str_governor); | |
406 | ||
ea714970 | 407 | if (t == NULL) { |
e08f5f5b GS |
408 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
409 | str_governor); | |
ea714970 JF |
410 | |
411 | if (name) { | |
412 | int ret; | |
413 | ||
414 | mutex_unlock(&cpufreq_governor_mutex); | |
415 | ret = request_module(name); | |
416 | mutex_lock(&cpufreq_governor_mutex); | |
417 | ||
418 | if (ret == 0) | |
419 | t = __find_governor(str_governor); | |
420 | } | |
421 | ||
422 | kfree(name); | |
423 | } | |
424 | ||
3bcb09a3 JF |
425 | if (t != NULL) { |
426 | *governor = t; | |
427 | err = 0; | |
1da177e4 | 428 | } |
3bcb09a3 | 429 | |
3fc54d37 | 430 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 431 | } |
3bcb09a3 JF |
432 | out: |
433 | return err; | |
1da177e4 | 434 | } |
1da177e4 LT |
435 | |
436 | ||
437 | /* drivers/base/cpu.c */ | |
438 | extern struct sysdev_class cpu_sysdev_class; | |
439 | ||
440 | ||
441 | /** | |
e08f5f5b GS |
442 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
443 | * print out cpufreq information | |
1da177e4 LT |
444 | * |
445 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
446 | * "unsigned int". | |
447 | */ | |
448 | ||
32ee8c3e DJ |
449 | #define show_one(file_name, object) \ |
450 | static ssize_t show_##file_name \ | |
905d77cd | 451 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e DJ |
452 | { \ |
453 | return sprintf (buf, "%u\n", policy->object); \ | |
1da177e4 LT |
454 | } |
455 | ||
456 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
457 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
458 | show_one(scaling_min_freq, min); | |
459 | show_one(scaling_max_freq, max); | |
460 | show_one(scaling_cur_freq, cur); | |
461 | ||
e08f5f5b GS |
462 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
463 | struct cpufreq_policy *policy); | |
7970e08b | 464 | |
1da177e4 LT |
465 | /** |
466 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
467 | */ | |
468 | #define store_one(file_name, object) \ | |
469 | static ssize_t store_##file_name \ | |
905d77cd | 470 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
471 | { \ |
472 | unsigned int ret = -EINVAL; \ | |
473 | struct cpufreq_policy new_policy; \ | |
474 | \ | |
475 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
476 | if (ret) \ | |
477 | return -EINVAL; \ | |
478 | \ | |
479 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
480 | if (ret != 1) \ | |
481 | return -EINVAL; \ | |
482 | \ | |
7970e08b TR |
483 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
484 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
485 | \ |
486 | return ret ? ret : count; \ | |
487 | } | |
488 | ||
489 | store_one(scaling_min_freq,min); | |
490 | store_one(scaling_max_freq,max); | |
491 | ||
492 | /** | |
493 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
494 | */ | |
905d77cd DJ |
495 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
496 | char *buf) | |
1da177e4 | 497 | { |
5a01f2e8 | 498 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
499 | if (!cur_freq) |
500 | return sprintf(buf, "<unknown>"); | |
501 | return sprintf(buf, "%u\n", cur_freq); | |
502 | } | |
503 | ||
504 | ||
505 | /** | |
506 | * show_scaling_governor - show the current policy for the specified CPU | |
507 | */ | |
905d77cd | 508 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
509 | { |
510 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
511 | return sprintf(buf, "powersave\n"); | |
512 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
513 | return sprintf(buf, "performance\n"); | |
514 | else if (policy->governor) | |
515 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
516 | return -EINVAL; | |
517 | } | |
518 | ||
519 | ||
520 | /** | |
521 | * store_scaling_governor - store policy for the specified CPU | |
522 | */ | |
905d77cd DJ |
523 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
524 | const char *buf, size_t count) | |
1da177e4 LT |
525 | { |
526 | unsigned int ret = -EINVAL; | |
527 | char str_governor[16]; | |
528 | struct cpufreq_policy new_policy; | |
529 | ||
530 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
531 | if (ret) | |
532 | return ret; | |
533 | ||
534 | ret = sscanf (buf, "%15s", str_governor); | |
535 | if (ret != 1) | |
536 | return -EINVAL; | |
537 | ||
e08f5f5b GS |
538 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
539 | &new_policy.governor)) | |
1da177e4 LT |
540 | return -EINVAL; |
541 | ||
7970e08b TR |
542 | /* Do not use cpufreq_set_policy here or the user_policy.max |
543 | will be wrongly overridden */ | |
7970e08b TR |
544 | ret = __cpufreq_set_policy(policy, &new_policy); |
545 | ||
546 | policy->user_policy.policy = policy->policy; | |
547 | policy->user_policy.governor = policy->governor; | |
7970e08b | 548 | |
e08f5f5b GS |
549 | if (ret) |
550 | return ret; | |
551 | else | |
552 | return count; | |
1da177e4 LT |
553 | } |
554 | ||
555 | /** | |
556 | * show_scaling_driver - show the cpufreq driver currently loaded | |
557 | */ | |
905d77cd | 558 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
559 | { |
560 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
561 | } | |
562 | ||
563 | /** | |
564 | * show_scaling_available_governors - show the available CPUfreq governors | |
565 | */ | |
905d77cd DJ |
566 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
567 | char *buf) | |
1da177e4 LT |
568 | { |
569 | ssize_t i = 0; | |
570 | struct cpufreq_governor *t; | |
571 | ||
572 | if (!cpufreq_driver->target) { | |
573 | i += sprintf(buf, "performance powersave"); | |
574 | goto out; | |
575 | } | |
576 | ||
577 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
578 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
579 | goto out; | |
580 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
581 | } | |
7d5e350f | 582 | out: |
1da177e4 LT |
583 | i += sprintf(&buf[i], "\n"); |
584 | return i; | |
585 | } | |
e8628dd0 DW |
586 | |
587 | static ssize_t show_cpus(cpumask_t mask, char *buf) | |
1da177e4 LT |
588 | { |
589 | ssize_t i = 0; | |
590 | unsigned int cpu; | |
591 | ||
e8628dd0 | 592 | for_each_cpu_mask(cpu, mask) { |
1da177e4 LT |
593 | if (i) |
594 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
595 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
596 | if (i >= (PAGE_SIZE - 5)) | |
597 | break; | |
598 | } | |
599 | i += sprintf(&buf[i], "\n"); | |
600 | return i; | |
601 | } | |
602 | ||
e8628dd0 DW |
603 | /** |
604 | * show_related_cpus - show the CPUs affected by each transition even if | |
605 | * hw coordination is in use | |
606 | */ | |
607 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
608 | { | |
609 | if (cpus_empty(policy->related_cpus)) | |
610 | return show_cpus(policy->cpus, buf); | |
611 | return show_cpus(policy->related_cpus, buf); | |
612 | } | |
613 | ||
614 | /** | |
615 | * show_affected_cpus - show the CPUs affected by each transition | |
616 | */ | |
617 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
618 | { | |
619 | return show_cpus(policy->cpus, buf); | |
620 | } | |
621 | ||
9e76988e | 622 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 623 | const char *buf, size_t count) |
9e76988e VP |
624 | { |
625 | unsigned int freq = 0; | |
626 | unsigned int ret; | |
627 | ||
628 | if (!policy->governor->store_setspeed) | |
629 | return -EINVAL; | |
630 | ||
631 | ret = sscanf(buf, "%u", &freq); | |
632 | if (ret != 1) | |
633 | return -EINVAL; | |
634 | ||
635 | policy->governor->store_setspeed(policy, freq); | |
636 | ||
637 | return count; | |
638 | } | |
639 | ||
640 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
641 | { | |
642 | if (!policy->governor->show_setspeed) | |
643 | return sprintf(buf, "<unsupported>\n"); | |
644 | ||
645 | return policy->governor->show_setspeed(policy, buf); | |
646 | } | |
1da177e4 LT |
647 | |
648 | #define define_one_ro(_name) \ | |
649 | static struct freq_attr _name = \ | |
650 | __ATTR(_name, 0444, show_##_name, NULL) | |
651 | ||
652 | #define define_one_ro0400(_name) \ | |
653 | static struct freq_attr _name = \ | |
654 | __ATTR(_name, 0400, show_##_name, NULL) | |
655 | ||
656 | #define define_one_rw(_name) \ | |
657 | static struct freq_attr _name = \ | |
658 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
659 | ||
660 | define_one_ro0400(cpuinfo_cur_freq); | |
661 | define_one_ro(cpuinfo_min_freq); | |
662 | define_one_ro(cpuinfo_max_freq); | |
663 | define_one_ro(scaling_available_governors); | |
664 | define_one_ro(scaling_driver); | |
665 | define_one_ro(scaling_cur_freq); | |
e8628dd0 | 666 | define_one_ro(related_cpus); |
1da177e4 LT |
667 | define_one_ro(affected_cpus); |
668 | define_one_rw(scaling_min_freq); | |
669 | define_one_rw(scaling_max_freq); | |
670 | define_one_rw(scaling_governor); | |
9e76988e | 671 | define_one_rw(scaling_setspeed); |
1da177e4 | 672 | |
905d77cd | 673 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
674 | &cpuinfo_min_freq.attr, |
675 | &cpuinfo_max_freq.attr, | |
676 | &scaling_min_freq.attr, | |
677 | &scaling_max_freq.attr, | |
678 | &affected_cpus.attr, | |
e8628dd0 | 679 | &related_cpus.attr, |
1da177e4 LT |
680 | &scaling_governor.attr, |
681 | &scaling_driver.attr, | |
682 | &scaling_available_governors.attr, | |
9e76988e | 683 | &scaling_setspeed.attr, |
1da177e4 LT |
684 | NULL |
685 | }; | |
686 | ||
687 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
688 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
689 | ||
905d77cd | 690 | static ssize_t show(struct kobject *kobj, struct attribute *attr ,char *buf) |
1da177e4 | 691 | { |
905d77cd DJ |
692 | struct cpufreq_policy *policy = to_policy(kobj); |
693 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 694 | ssize_t ret = -EINVAL; |
1da177e4 LT |
695 | policy = cpufreq_cpu_get(policy->cpu); |
696 | if (!policy) | |
0db4a8a9 | 697 | goto no_policy; |
5a01f2e8 VP |
698 | |
699 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 700 | goto fail; |
5a01f2e8 | 701 | |
e08f5f5b GS |
702 | if (fattr->show) |
703 | ret = fattr->show(policy, buf); | |
704 | else | |
705 | ret = -EIO; | |
706 | ||
5a01f2e8 | 707 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 708 | fail: |
1da177e4 | 709 | cpufreq_cpu_put(policy); |
0db4a8a9 | 710 | no_policy: |
1da177e4 LT |
711 | return ret; |
712 | } | |
713 | ||
905d77cd DJ |
714 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
715 | const char *buf, size_t count) | |
1da177e4 | 716 | { |
905d77cd DJ |
717 | struct cpufreq_policy *policy = to_policy(kobj); |
718 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 719 | ssize_t ret = -EINVAL; |
1da177e4 LT |
720 | policy = cpufreq_cpu_get(policy->cpu); |
721 | if (!policy) | |
a07530b4 | 722 | goto no_policy; |
5a01f2e8 VP |
723 | |
724 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 725 | goto fail; |
5a01f2e8 | 726 | |
e08f5f5b GS |
727 | if (fattr->store) |
728 | ret = fattr->store(policy, buf, count); | |
729 | else | |
730 | ret = -EIO; | |
731 | ||
5a01f2e8 | 732 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 733 | fail: |
1da177e4 | 734 | cpufreq_cpu_put(policy); |
a07530b4 | 735 | no_policy: |
1da177e4 LT |
736 | return ret; |
737 | } | |
738 | ||
905d77cd | 739 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 740 | { |
905d77cd | 741 | struct cpufreq_policy *policy = to_policy(kobj); |
1da177e4 LT |
742 | dprintk("last reference is dropped\n"); |
743 | complete(&policy->kobj_unregister); | |
744 | } | |
745 | ||
746 | static struct sysfs_ops sysfs_ops = { | |
747 | .show = show, | |
748 | .store = store, | |
749 | }; | |
750 | ||
751 | static struct kobj_type ktype_cpufreq = { | |
752 | .sysfs_ops = &sysfs_ops, | |
753 | .default_attrs = default_attrs, | |
754 | .release = cpufreq_sysfs_release, | |
755 | }; | |
756 | ||
757 | ||
758 | /** | |
759 | * cpufreq_add_dev - add a CPU device | |
760 | * | |
32ee8c3e | 761 | * Adds the cpufreq interface for a CPU device. |
1da177e4 | 762 | */ |
905d77cd | 763 | static int cpufreq_add_dev(struct sys_device *sys_dev) |
1da177e4 LT |
764 | { |
765 | unsigned int cpu = sys_dev->id; | |
766 | int ret = 0; | |
767 | struct cpufreq_policy new_policy; | |
768 | struct cpufreq_policy *policy; | |
769 | struct freq_attr **drv_attr; | |
8ff69732 | 770 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
771 | unsigned long flags; |
772 | unsigned int j; | |
8ff69732 DJ |
773 | #ifdef CONFIG_SMP |
774 | struct cpufreq_policy *managed_policy; | |
775 | #endif | |
1da177e4 | 776 | |
c32b6b8e AR |
777 | if (cpu_is_offline(cpu)) |
778 | return 0; | |
779 | ||
1da177e4 LT |
780 | cpufreq_debug_disable_ratelimit(); |
781 | dprintk("adding CPU %u\n", cpu); | |
782 | ||
783 | #ifdef CONFIG_SMP | |
784 | /* check whether a different CPU already registered this | |
785 | * CPU because it is in the same boat. */ | |
786 | policy = cpufreq_cpu_get(cpu); | |
787 | if (unlikely(policy)) { | |
8ff69732 | 788 | cpufreq_cpu_put(policy); |
1da177e4 LT |
789 | cpufreq_debug_enable_ratelimit(); |
790 | return 0; | |
791 | } | |
792 | #endif | |
793 | ||
794 | if (!try_module_get(cpufreq_driver->owner)) { | |
795 | ret = -EINVAL; | |
796 | goto module_out; | |
797 | } | |
798 | ||
e98df50c | 799 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
800 | if (!policy) { |
801 | ret = -ENOMEM; | |
802 | goto nomem_out; | |
803 | } | |
1da177e4 LT |
804 | |
805 | policy->cpu = cpu; | |
806 | policy->cpus = cpumask_of_cpu(cpu); | |
807 | ||
5a01f2e8 VP |
808 | /* Initially set CPU itself as the policy_cpu */ |
809 | per_cpu(policy_cpu, cpu) = cpu; | |
810 | lock_policy_rwsem_write(cpu); | |
811 | ||
1da177e4 | 812 | init_completion(&policy->kobj_unregister); |
65f27f38 | 813 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 814 | |
8122c6ce TR |
815 | /* Set governor before ->init, so that driver could check it */ |
816 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
817 | /* call driver. From then on the cpufreq must be able |
818 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
819 | */ | |
820 | ret = cpufreq_driver->init(policy); | |
821 | if (ret) { | |
822 | dprintk("initialization failed\n"); | |
823 | goto err_out; | |
824 | } | |
22c970f3 TR |
825 | policy->user_policy.min = policy->cpuinfo.min_freq; |
826 | policy->user_policy.max = policy->cpuinfo.max_freq; | |
1da177e4 | 827 | |
8ff69732 | 828 | #ifdef CONFIG_SMP |
084f3493 TR |
829 | |
830 | #ifdef CONFIG_HOTPLUG_CPU | |
7a6aedfa MT |
831 | if (per_cpu(cpufreq_cpu_governor, cpu)) { |
832 | policy->governor = per_cpu(cpufreq_cpu_governor, cpu); | |
084f3493 TR |
833 | dprintk("Restoring governor %s for cpu %d\n", |
834 | policy->governor->name, cpu); | |
835 | } | |
836 | #endif | |
837 | ||
8ff69732 DJ |
838 | for_each_cpu_mask(j, policy->cpus) { |
839 | if (cpu == j) | |
840 | continue; | |
841 | ||
842 | /* check for existing affected CPUs. They may not be aware | |
843 | * of it due to CPU Hotplug. | |
844 | */ | |
45709118 | 845 | managed_policy = cpufreq_cpu_get(j); // FIXME: Where is this released? What about error paths? |
8ff69732 | 846 | if (unlikely(managed_policy)) { |
5a01f2e8 VP |
847 | |
848 | /* Set proper policy_cpu */ | |
849 | unlock_policy_rwsem_write(cpu); | |
850 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
851 | ||
852 | if (lock_policy_rwsem_write(cpu) < 0) | |
853 | goto err_out_driver_exit; | |
854 | ||
8ff69732 DJ |
855 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
856 | managed_policy->cpus = policy->cpus; | |
7a6aedfa | 857 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; |
8ff69732 DJ |
858 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
859 | ||
860 | dprintk("CPU already managed, adding link\n"); | |
0142f9dc AD |
861 | ret = sysfs_create_link(&sys_dev->kobj, |
862 | &managed_policy->kobj, | |
863 | "cpufreq"); | |
45709118 | 864 | if (ret) |
0142f9dc | 865 | goto err_out_driver_exit; |
8ff69732 DJ |
866 | |
867 | cpufreq_debug_enable_ratelimit(); | |
8ff69732 DJ |
868 | ret = 0; |
869 | goto err_out_driver_exit; /* call driver->exit() */ | |
870 | } | |
871 | } | |
872 | #endif | |
1da177e4 LT |
873 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
874 | ||
875 | /* prepare interface data */ | |
038c5b3e GKH |
876 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj, |
877 | "cpufreq"); | |
45709118 | 878 | if (ret) |
8085e1f1 | 879 | goto err_out_driver_exit; |
45709118 | 880 | |
1da177e4 LT |
881 | /* set up files for this cpu device */ |
882 | drv_attr = cpufreq_driver->attr; | |
883 | while ((drv_attr) && (*drv_attr)) { | |
58a7295b | 884 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
45709118 | 885 | if (ret) |
0a4b2ccc | 886 | goto err_out_driver_exit; |
1da177e4 LT |
887 | drv_attr++; |
888 | } | |
45709118 | 889 | if (cpufreq_driver->get) { |
58a7295b | 890 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
45709118 | 891 | if (ret) |
0a4b2ccc TR |
892 | goto err_out_driver_exit; |
893 | } | |
45709118 | 894 | if (cpufreq_driver->target) { |
58a7295b | 895 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
45709118 | 896 | if (ret) |
0a4b2ccc TR |
897 | goto err_out_driver_exit; |
898 | } | |
1da177e4 LT |
899 | |
900 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 901 | for_each_cpu_mask(j, policy->cpus) { |
7a6aedfa | 902 | per_cpu(cpufreq_cpu_data, j) = policy; |
5a01f2e8 VP |
903 | per_cpu(policy_cpu, j) = policy->cpu; |
904 | } | |
1da177e4 | 905 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8ff69732 DJ |
906 | |
907 | /* symlink affected CPUs */ | |
908 | for_each_cpu_mask(j, policy->cpus) { | |
909 | if (j == cpu) | |
910 | continue; | |
911 | if (!cpu_online(j)) | |
912 | continue; | |
913 | ||
1f8b2c9d | 914 | dprintk("CPU %u already managed, adding link\n", j); |
8ff69732 DJ |
915 | cpufreq_cpu_get(cpu); |
916 | cpu_sys_dev = get_cpu_sysdev(j); | |
0142f9dc AD |
917 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, |
918 | "cpufreq"); | |
45709118 | 919 | if (ret) |
0142f9dc | 920 | goto err_out_unregister; |
8ff69732 DJ |
921 | } |
922 | ||
1da177e4 LT |
923 | policy->governor = NULL; /* to assure that the starting sequence is |
924 | * run in cpufreq_set_policy */ | |
87c32271 | 925 | |
1da177e4 | 926 | /* set default policy */ |
22c970f3 TR |
927 | ret = __cpufreq_set_policy(policy, &new_policy); |
928 | policy->user_policy.policy = policy->policy; | |
084f3493 | 929 | policy->user_policy.governor = policy->governor; |
22c970f3 TR |
930 | |
931 | unlock_policy_rwsem_write(cpu); | |
932 | ||
1da177e4 LT |
933 | if (ret) { |
934 | dprintk("setting policy failed\n"); | |
935 | goto err_out_unregister; | |
936 | } | |
937 | ||
038c5b3e | 938 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 939 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
940 | dprintk("initialization complete\n"); |
941 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 942 | |
1da177e4 LT |
943 | return 0; |
944 | ||
945 | ||
946 | err_out_unregister: | |
947 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
948 | for_each_cpu_mask(j, policy->cpus) | |
7a6aedfa | 949 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
950 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
951 | ||
c10997f6 | 952 | kobject_put(&policy->kobj); |
1da177e4 LT |
953 | wait_for_completion(&policy->kobj_unregister); |
954 | ||
8085e1f1 VP |
955 | err_out_driver_exit: |
956 | if (cpufreq_driver->exit) | |
957 | cpufreq_driver->exit(policy); | |
958 | ||
1da177e4 | 959 | err_out: |
45709118 | 960 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
961 | kfree(policy); |
962 | ||
963 | nomem_out: | |
964 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 965 | module_out: |
1da177e4 LT |
966 | cpufreq_debug_enable_ratelimit(); |
967 | return ret; | |
968 | } | |
969 | ||
970 | ||
971 | /** | |
5a01f2e8 | 972 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
973 | * |
974 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
975 | * Caller should already have policy_rwsem in write mode for this CPU. |
976 | * This routine frees the rwsem before returning. | |
1da177e4 | 977 | */ |
905d77cd | 978 | static int __cpufreq_remove_dev(struct sys_device *sys_dev) |
1da177e4 LT |
979 | { |
980 | unsigned int cpu = sys_dev->id; | |
981 | unsigned long flags; | |
982 | struct cpufreq_policy *data; | |
983 | #ifdef CONFIG_SMP | |
e738cf6d | 984 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
985 | unsigned int j; |
986 | #endif | |
987 | ||
988 | cpufreq_debug_disable_ratelimit(); | |
989 | dprintk("unregistering CPU %u\n", cpu); | |
990 | ||
991 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 992 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
993 | |
994 | if (!data) { | |
995 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 996 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 997 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
998 | return -EINVAL; |
999 | } | |
7a6aedfa | 1000 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1001 | |
1002 | ||
1003 | #ifdef CONFIG_SMP | |
1004 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1005 | * only need to unlink, put and exit |
1da177e4 LT |
1006 | */ |
1007 | if (unlikely(cpu != data->cpu)) { | |
1008 | dprintk("removing link\n"); | |
8ff69732 | 1009 | cpu_clear(cpu, data->cpus); |
1da177e4 LT |
1010 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1011 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1012 | cpufreq_cpu_put(data); |
1013 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 1014 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1015 | return 0; |
1016 | } | |
1017 | #endif | |
1018 | ||
1da177e4 | 1019 | #ifdef CONFIG_SMP |
084f3493 TR |
1020 | |
1021 | #ifdef CONFIG_HOTPLUG_CPU | |
7a6aedfa | 1022 | per_cpu(cpufreq_cpu_governor, cpu) = data->governor; |
084f3493 TR |
1023 | #endif |
1024 | ||
1da177e4 LT |
1025 | /* if we have other CPUs still registered, we need to unlink them, |
1026 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1027 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1028 | * the sysfs links afterwards. | |
1da177e4 LT |
1029 | */ |
1030 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1031 | for_each_cpu_mask(j, data->cpus) { | |
1032 | if (j == cpu) | |
1033 | continue; | |
7a6aedfa | 1034 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1035 | } |
1036 | } | |
1037 | ||
1038 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1039 | ||
1040 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1041 | for_each_cpu_mask(j, data->cpus) { | |
1042 | if (j == cpu) | |
1043 | continue; | |
1044 | dprintk("removing link for cpu %u\n", j); | |
084f3493 | 1045 | #ifdef CONFIG_HOTPLUG_CPU |
7a6aedfa | 1046 | per_cpu(cpufreq_cpu_governor, j) = data->governor; |
084f3493 | 1047 | #endif |
d434fca7 AR |
1048 | cpu_sys_dev = get_cpu_sysdev(j); |
1049 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1050 | cpufreq_cpu_put(data); |
1051 | } | |
1052 | } | |
1053 | #else | |
1054 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1055 | #endif | |
1056 | ||
1da177e4 LT |
1057 | if (cpufreq_driver->target) |
1058 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 VP |
1059 | |
1060 | unlock_policy_rwsem_write(cpu); | |
1da177e4 | 1061 | |
1da177e4 LT |
1062 | kobject_put(&data->kobj); |
1063 | ||
1064 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1065 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1066 | * unloading. |
1067 | */ | |
1068 | dprintk("waiting for dropping of refcount\n"); | |
1069 | wait_for_completion(&data->kobj_unregister); | |
1070 | dprintk("wait complete\n"); | |
1071 | ||
1072 | if (cpufreq_driver->exit) | |
1073 | cpufreq_driver->exit(data); | |
1074 | ||
1075 | kfree(data); | |
1076 | ||
1077 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1078 | return 0; |
1079 | } | |
1080 | ||
1081 | ||
905d77cd | 1082 | static int cpufreq_remove_dev(struct sys_device *sys_dev) |
5a01f2e8 VP |
1083 | { |
1084 | unsigned int cpu = sys_dev->id; | |
1085 | int retval; | |
ec28297a VP |
1086 | |
1087 | if (cpu_is_offline(cpu)) | |
1088 | return 0; | |
1089 | ||
5a01f2e8 VP |
1090 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1091 | BUG(); | |
1092 | ||
1093 | retval = __cpufreq_remove_dev(sys_dev); | |
1094 | return retval; | |
1095 | } | |
1096 | ||
1097 | ||
65f27f38 | 1098 | static void handle_update(struct work_struct *work) |
1da177e4 | 1099 | { |
65f27f38 DH |
1100 | struct cpufreq_policy *policy = |
1101 | container_of(work, struct cpufreq_policy, update); | |
1102 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1103 | dprintk("handle_update for cpu %u called\n", cpu); |
1104 | cpufreq_update_policy(cpu); | |
1105 | } | |
1106 | ||
1107 | /** | |
1108 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1109 | * @cpu: cpu number | |
1110 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1111 | * @new_freq: CPU frequency the CPU actually runs at | |
1112 | * | |
1113 | * We adjust to current frequency first, and need to clean up later. So either call | |
1114 | * to cpufreq_update_policy() or schedule handle_update()). | |
1115 | */ | |
e08f5f5b GS |
1116 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1117 | unsigned int new_freq) | |
1da177e4 LT |
1118 | { |
1119 | struct cpufreq_freqs freqs; | |
1120 | ||
b10eec22 | 1121 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1122 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1123 | ||
1124 | freqs.cpu = cpu; | |
1125 | freqs.old = old_freq; | |
1126 | freqs.new = new_freq; | |
1127 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1128 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1129 | } | |
1130 | ||
1131 | ||
32ee8c3e | 1132 | /** |
4ab70df4 | 1133 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1134 | * @cpu: CPU number |
1135 | * | |
1136 | * This is the last known freq, without actually getting it from the driver. | |
1137 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1138 | */ | |
1139 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1140 | { | |
1141 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1142 | unsigned int ret_freq = 0; |
95235ca2 VP |
1143 | |
1144 | if (policy) { | |
e08f5f5b | 1145 | ret_freq = policy->cur; |
95235ca2 VP |
1146 | cpufreq_cpu_put(policy); |
1147 | } | |
1148 | ||
4d34a67d | 1149 | return ret_freq; |
95235ca2 VP |
1150 | } |
1151 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1152 | ||
1153 | ||
5a01f2e8 | 1154 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1155 | { |
7a6aedfa | 1156 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1157 | unsigned int ret_freq = 0; |
1da177e4 | 1158 | |
1da177e4 | 1159 | if (!cpufreq_driver->get) |
4d34a67d | 1160 | return ret_freq; |
1da177e4 | 1161 | |
e08f5f5b | 1162 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1163 | |
e08f5f5b GS |
1164 | if (ret_freq && policy->cur && |
1165 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1166 | /* verify no discrepancy between actual and | |
1167 | saved value exists */ | |
1168 | if (unlikely(ret_freq != policy->cur)) { | |
1169 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1170 | schedule_work(&policy->update); |
1171 | } | |
1172 | } | |
1173 | ||
4d34a67d | 1174 | return ret_freq; |
5a01f2e8 | 1175 | } |
1da177e4 | 1176 | |
5a01f2e8 VP |
1177 | /** |
1178 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1179 | * @cpu: CPU number | |
1180 | * | |
1181 | * Get the CPU current (static) CPU frequency | |
1182 | */ | |
1183 | unsigned int cpufreq_get(unsigned int cpu) | |
1184 | { | |
1185 | unsigned int ret_freq = 0; | |
1186 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1187 | ||
1188 | if (!policy) | |
1189 | goto out; | |
1190 | ||
1191 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1192 | goto out_policy; | |
1193 | ||
1194 | ret_freq = __cpufreq_get(cpu); | |
1195 | ||
1196 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1197 | |
5a01f2e8 VP |
1198 | out_policy: |
1199 | cpufreq_cpu_put(policy); | |
1200 | out: | |
4d34a67d | 1201 | return ret_freq; |
1da177e4 LT |
1202 | } |
1203 | EXPORT_SYMBOL(cpufreq_get); | |
1204 | ||
1205 | ||
42d4dc3f BH |
1206 | /** |
1207 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1208 | */ | |
1209 | ||
905d77cd | 1210 | static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg) |
42d4dc3f BH |
1211 | { |
1212 | int cpu = sysdev->id; | |
e08f5f5b | 1213 | int ret = 0; |
42d4dc3f BH |
1214 | unsigned int cur_freq = 0; |
1215 | struct cpufreq_policy *cpu_policy; | |
1216 | ||
0e37b159 | 1217 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1218 | |
1219 | if (!cpu_online(cpu)) | |
1220 | return 0; | |
1221 | ||
1222 | /* we may be lax here as interrupts are off. Nonetheless | |
1223 | * we need to grab the correct cpu policy, as to check | |
1224 | * whether we really run on this CPU. | |
1225 | */ | |
1226 | ||
1227 | cpu_policy = cpufreq_cpu_get(cpu); | |
1228 | if (!cpu_policy) | |
1229 | return -EINVAL; | |
1230 | ||
1231 | /* only handle each CPU group once */ | |
c9060494 DJ |
1232 | if (unlikely(cpu_policy->cpu != cpu)) |
1233 | goto out; | |
42d4dc3f BH |
1234 | |
1235 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1236 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
1237 | if (ret) { |
1238 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1239 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1240 | goto out; |
42d4dc3f BH |
1241 | } |
1242 | } | |
1243 | ||
42d4dc3f BH |
1244 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) |
1245 | goto out; | |
1246 | ||
1247 | if (cpufreq_driver->get) | |
1248 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1249 | ||
1250 | if (!cur_freq || !cpu_policy->cur) { | |
1251 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1252 | "frequency is what timing core thinks it is.\n"); | |
1253 | goto out; | |
1254 | } | |
1255 | ||
1256 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1257 | struct cpufreq_freqs freqs; | |
1258 | ||
1259 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
b10eec22 | 1260 | dprintk("Warning: CPU frequency is %u, " |
42d4dc3f BH |
1261 | "cpufreq assumed %u kHz.\n", |
1262 | cur_freq, cpu_policy->cur); | |
1263 | ||
1264 | freqs.cpu = cpu; | |
1265 | freqs.old = cpu_policy->cur; | |
1266 | freqs.new = cur_freq; | |
1267 | ||
b4dfdbb3 | 1268 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
42d4dc3f BH |
1269 | CPUFREQ_SUSPENDCHANGE, &freqs); |
1270 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1271 | ||
1272 | cpu_policy->cur = cur_freq; | |
1273 | } | |
1274 | ||
7d5e350f | 1275 | out: |
42d4dc3f | 1276 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1277 | return ret; |
42d4dc3f BH |
1278 | } |
1279 | ||
1da177e4 LT |
1280 | /** |
1281 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1282 | * | |
1283 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1284 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1285 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1286 | * restored. | |
1da177e4 | 1287 | */ |
905d77cd | 1288 | static int cpufreq_resume(struct sys_device *sysdev) |
1da177e4 LT |
1289 | { |
1290 | int cpu = sysdev->id; | |
e08f5f5b | 1291 | int ret = 0; |
1da177e4 LT |
1292 | struct cpufreq_policy *cpu_policy; |
1293 | ||
1294 | dprintk("resuming cpu %u\n", cpu); | |
1295 | ||
1296 | if (!cpu_online(cpu)) | |
1297 | return 0; | |
1298 | ||
1299 | /* we may be lax here as interrupts are off. Nonetheless | |
1300 | * we need to grab the correct cpu policy, as to check | |
1301 | * whether we really run on this CPU. | |
1302 | */ | |
1303 | ||
1304 | cpu_policy = cpufreq_cpu_get(cpu); | |
1305 | if (!cpu_policy) | |
1306 | return -EINVAL; | |
1307 | ||
1308 | /* only handle each CPU group once */ | |
c9060494 DJ |
1309 | if (unlikely(cpu_policy->cpu != cpu)) |
1310 | goto fail; | |
1da177e4 LT |
1311 | |
1312 | if (cpufreq_driver->resume) { | |
1313 | ret = cpufreq_driver->resume(cpu_policy); | |
1314 | if (ret) { | |
1315 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1316 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1317 | goto fail; |
1da177e4 LT |
1318 | } |
1319 | } | |
1320 | ||
1321 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1322 | unsigned int cur_freq = 0; | |
1323 | ||
1324 | if (cpufreq_driver->get) | |
1325 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1326 | ||
1327 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1328 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1329 | "current frequency is what timing core " | |
1330 | "thinks it is.\n"); | |
1da177e4 LT |
1331 | goto out; |
1332 | } | |
1333 | ||
1334 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1335 | struct cpufreq_freqs freqs; | |
1336 | ||
ac09f698 | 1337 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
a4a9df58 | 1338 | dprintk("Warning: CPU frequency " |
ac09f698 BH |
1339 | "is %u, cpufreq assumed %u kHz.\n", |
1340 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1341 | |
1342 | freqs.cpu = cpu; | |
1343 | freqs.old = cpu_policy->cur; | |
1344 | freqs.new = cur_freq; | |
1345 | ||
b4dfdbb3 | 1346 | srcu_notifier_call_chain( |
e041c683 | 1347 | &cpufreq_transition_notifier_list, |
42d4dc3f | 1348 | CPUFREQ_RESUMECHANGE, &freqs); |
1da177e4 LT |
1349 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1350 | ||
1351 | cpu_policy->cur = cur_freq; | |
1352 | } | |
1353 | } | |
1354 | ||
1355 | out: | |
1356 | schedule_work(&cpu_policy->update); | |
c9060494 | 1357 | fail: |
1da177e4 LT |
1358 | cpufreq_cpu_put(cpu_policy); |
1359 | return ret; | |
1360 | } | |
1361 | ||
1362 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1363 | .add = cpufreq_add_dev, | |
1364 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1365 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1366 | .resume = cpufreq_resume, |
1367 | }; | |
1368 | ||
1369 | ||
1370 | /********************************************************************* | |
1371 | * NOTIFIER LISTS INTERFACE * | |
1372 | *********************************************************************/ | |
1373 | ||
1374 | /** | |
1375 | * cpufreq_register_notifier - register a driver with cpufreq | |
1376 | * @nb: notifier function to register | |
1377 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1378 | * | |
32ee8c3e | 1379 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1380 | * are notified about clock rate changes (once before and once after |
1381 | * the transition), or a list of drivers that are notified about | |
1382 | * changes in cpufreq policy. | |
1383 | * | |
1384 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1385 | * blocking_notifier_chain_register. |
1da177e4 LT |
1386 | */ |
1387 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1388 | { | |
1389 | int ret; | |
1390 | ||
74212ca4 CEB |
1391 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1392 | ||
1da177e4 LT |
1393 | switch (list) { |
1394 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1395 | ret = srcu_notifier_chain_register( |
e041c683 | 1396 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1397 | break; |
1398 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1399 | ret = blocking_notifier_chain_register( |
1400 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1401 | break; |
1402 | default: | |
1403 | ret = -EINVAL; | |
1404 | } | |
1da177e4 LT |
1405 | |
1406 | return ret; | |
1407 | } | |
1408 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1409 | ||
1410 | ||
1411 | /** | |
1412 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1413 | * @nb: notifier block to be unregistered | |
1414 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1415 | * | |
1416 | * Remove a driver from the CPU frequency notifier list. | |
1417 | * | |
1418 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1419 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1420 | */ |
1421 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1422 | { | |
1423 | int ret; | |
1424 | ||
1da177e4 LT |
1425 | switch (list) { |
1426 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1427 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1428 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1429 | break; |
1430 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1431 | ret = blocking_notifier_chain_unregister( |
1432 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1433 | break; |
1434 | default: | |
1435 | ret = -EINVAL; | |
1436 | } | |
1da177e4 LT |
1437 | |
1438 | return ret; | |
1439 | } | |
1440 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1441 | ||
1442 | ||
1443 | /********************************************************************* | |
1444 | * GOVERNORS * | |
1445 | *********************************************************************/ | |
1446 | ||
1447 | ||
1448 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1449 | unsigned int target_freq, | |
1450 | unsigned int relation) | |
1451 | { | |
1452 | int retval = -EINVAL; | |
c32b6b8e | 1453 | |
1da177e4 LT |
1454 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1455 | target_freq, relation); | |
1456 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1457 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1458 | |
1da177e4 LT |
1459 | return retval; |
1460 | } | |
1461 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1462 | ||
1da177e4 LT |
1463 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1464 | unsigned int target_freq, | |
1465 | unsigned int relation) | |
1466 | { | |
cc993cab | 1467 | int ret; |
1da177e4 LT |
1468 | |
1469 | policy = cpufreq_cpu_get(policy->cpu); | |
1470 | if (!policy) | |
1471 | return -EINVAL; | |
1472 | ||
5a01f2e8 VP |
1473 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
1474 | return -EINVAL; | |
1da177e4 LT |
1475 | |
1476 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1477 | ||
5a01f2e8 | 1478 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 LT |
1479 | |
1480 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1481 | return ret; |
1482 | } | |
1483 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1484 | ||
5a01f2e8 | 1485 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy) |
dfde5d62 VP |
1486 | { |
1487 | int ret = 0; | |
1488 | ||
1489 | policy = cpufreq_cpu_get(policy->cpu); | |
1490 | if (!policy) | |
1491 | return -EINVAL; | |
1492 | ||
dfde5d62 VP |
1493 | if (cpu_online(policy->cpu) && cpufreq_driver->getavg) |
1494 | ret = cpufreq_driver->getavg(policy->cpu); | |
1495 | ||
dfde5d62 VP |
1496 | cpufreq_cpu_put(policy); |
1497 | return ret; | |
1498 | } | |
5a01f2e8 | 1499 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1500 | |
153d7f3f | 1501 | /* |
153d7f3f AV |
1502 | * when "event" is CPUFREQ_GOV_LIMITS |
1503 | */ | |
1da177e4 | 1504 | |
e08f5f5b GS |
1505 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1506 | unsigned int event) | |
1da177e4 | 1507 | { |
cc993cab | 1508 | int ret; |
6afde10c TR |
1509 | |
1510 | /* Only must be defined when default governor is known to have latency | |
1511 | restrictions, like e.g. conservative or ondemand. | |
1512 | That this is the case is already ensured in Kconfig | |
1513 | */ | |
1514 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1515 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1516 | #else | |
1517 | struct cpufreq_governor *gov = NULL; | |
1518 | #endif | |
1c256245 TR |
1519 | |
1520 | if (policy->governor->max_transition_latency && | |
1521 | policy->cpuinfo.transition_latency > | |
1522 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1523 | if (!gov) |
1524 | return -EINVAL; | |
1525 | else { | |
1526 | printk(KERN_WARNING "%s governor failed, too long" | |
1527 | " transition latency of HW, fallback" | |
1528 | " to %s governor\n", | |
1529 | policy->governor->name, | |
1530 | gov->name); | |
1531 | policy->governor = gov; | |
1532 | } | |
1c256245 | 1533 | } |
1da177e4 LT |
1534 | |
1535 | if (!try_module_get(policy->governor->owner)) | |
1536 | return -EINVAL; | |
1537 | ||
e08f5f5b GS |
1538 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1539 | policy->cpu, event); | |
1da177e4 LT |
1540 | ret = policy->governor->governor(policy, event); |
1541 | ||
e08f5f5b GS |
1542 | /* we keep one module reference alive for |
1543 | each CPU governed by this CPU */ | |
1da177e4 LT |
1544 | if ((event != CPUFREQ_GOV_START) || ret) |
1545 | module_put(policy->governor->owner); | |
1546 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1547 | module_put(policy->governor->owner); | |
1548 | ||
1549 | return ret; | |
1550 | } | |
1551 | ||
1552 | ||
1da177e4 LT |
1553 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1554 | { | |
3bcb09a3 | 1555 | int err; |
1da177e4 LT |
1556 | |
1557 | if (!governor) | |
1558 | return -EINVAL; | |
1559 | ||
3fc54d37 | 1560 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1561 | |
3bcb09a3 JF |
1562 | err = -EBUSY; |
1563 | if (__find_governor(governor->name) == NULL) { | |
1564 | err = 0; | |
1565 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1566 | } |
1da177e4 | 1567 | |
32ee8c3e | 1568 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1569 | return err; |
1da177e4 LT |
1570 | } |
1571 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1572 | ||
1573 | ||
1574 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1575 | { | |
1576 | if (!governor) | |
1577 | return; | |
1578 | ||
3fc54d37 | 1579 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1580 | list_del(&governor->governor_list); |
3fc54d37 | 1581 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1582 | return; |
1583 | } | |
1584 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1585 | ||
1586 | ||
1587 | ||
1588 | /********************************************************************* | |
1589 | * POLICY INTERFACE * | |
1590 | *********************************************************************/ | |
1591 | ||
1592 | /** | |
1593 | * cpufreq_get_policy - get the current cpufreq_policy | |
1594 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1595 | * | |
1596 | * Reads the current cpufreq policy. | |
1597 | */ | |
1598 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1599 | { | |
1600 | struct cpufreq_policy *cpu_policy; | |
1601 | if (!policy) | |
1602 | return -EINVAL; | |
1603 | ||
1604 | cpu_policy = cpufreq_cpu_get(cpu); | |
1605 | if (!cpu_policy) | |
1606 | return -EINVAL; | |
1607 | ||
1da177e4 | 1608 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1609 | |
1610 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1611 | return 0; |
1612 | } | |
1613 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1614 | ||
1615 | ||
153d7f3f | 1616 | /* |
e08f5f5b GS |
1617 | * data : current policy. |
1618 | * policy : policy to be set. | |
153d7f3f | 1619 | */ |
e08f5f5b GS |
1620 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1621 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1622 | { |
1623 | int ret = 0; | |
1624 | ||
1625 | cpufreq_debug_disable_ratelimit(); | |
1626 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1627 | policy->min, policy->max); | |
1628 | ||
e08f5f5b GS |
1629 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1630 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1631 | |
53391fa2 | 1632 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1633 | ret = -EINVAL; |
1634 | goto error_out; | |
1635 | } | |
1636 | ||
1da177e4 LT |
1637 | /* verify the cpu speed can be set within this limit */ |
1638 | ret = cpufreq_driver->verify(policy); | |
1639 | if (ret) | |
1640 | goto error_out; | |
1641 | ||
1da177e4 | 1642 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1643 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1644 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1645 | |
1646 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1647 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1648 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1649 | |
1650 | /* verify the cpu speed can be set within this limit, | |
1651 | which might be different to the first one */ | |
1652 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1653 | if (ret) |
1da177e4 | 1654 | goto error_out; |
1da177e4 LT |
1655 | |
1656 | /* notification of the new policy */ | |
e041c683 AS |
1657 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1658 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1659 | |
7d5e350f DJ |
1660 | data->min = policy->min; |
1661 | data->max = policy->max; | |
1da177e4 | 1662 | |
e08f5f5b GS |
1663 | dprintk("new min and max freqs are %u - %u kHz\n", |
1664 | data->min, data->max); | |
1da177e4 LT |
1665 | |
1666 | if (cpufreq_driver->setpolicy) { | |
1667 | data->policy = policy->policy; | |
1668 | dprintk("setting range\n"); | |
1669 | ret = cpufreq_driver->setpolicy(policy); | |
1670 | } else { | |
1671 | if (policy->governor != data->governor) { | |
1672 | /* save old, working values */ | |
1673 | struct cpufreq_governor *old_gov = data->governor; | |
1674 | ||
1675 | dprintk("governor switch\n"); | |
1676 | ||
1677 | /* end old governor */ | |
1678 | if (data->governor) | |
1679 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1680 | ||
1681 | /* start new governor */ | |
1682 | data->governor = policy->governor; | |
1683 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1684 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1685 | dprintk("starting governor %s failed\n", |
1686 | data->governor->name); | |
1da177e4 LT |
1687 | if (old_gov) { |
1688 | data->governor = old_gov; | |
e08f5f5b GS |
1689 | __cpufreq_governor(data, |
1690 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1691 | } |
1692 | ret = -EINVAL; | |
1693 | goto error_out; | |
1694 | } | |
1695 | /* might be a policy change, too, so fall through */ | |
1696 | } | |
1697 | dprintk("governor: change or update limits\n"); | |
1698 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1699 | } | |
1700 | ||
7d5e350f | 1701 | error_out: |
1da177e4 LT |
1702 | cpufreq_debug_enable_ratelimit(); |
1703 | return ret; | |
1704 | } | |
1705 | ||
1da177e4 LT |
1706 | /** |
1707 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1708 | * @cpu: CPU which shall be re-evaluated | |
1709 | * | |
1710 | * Usefull for policy notifiers which have different necessities | |
1711 | * at different times. | |
1712 | */ | |
1713 | int cpufreq_update_policy(unsigned int cpu) | |
1714 | { | |
1715 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1716 | struct cpufreq_policy policy; | |
1717 | int ret = 0; | |
1718 | ||
1719 | if (!data) | |
1720 | return -ENODEV; | |
1721 | ||
5a01f2e8 VP |
1722 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1723 | return -EINVAL; | |
1da177e4 LT |
1724 | |
1725 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1726 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1727 | policy.min = data->user_policy.min; |
1728 | policy.max = data->user_policy.max; | |
1729 | policy.policy = data->user_policy.policy; | |
1730 | policy.governor = data->user_policy.governor; | |
1731 | ||
0961dd0d TR |
1732 | /* BIOS might change freq behind our back |
1733 | -> ask driver for current freq and notify governors about a change */ | |
1734 | if (cpufreq_driver->get) { | |
1735 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1736 | if (!data->cur) { |
1737 | dprintk("Driver did not initialize current freq"); | |
1738 | data->cur = policy.cur; | |
1739 | } else { | |
1740 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1741 | cpufreq_out_of_sync(cpu, data->cur, |
1742 | policy.cur); | |
a85f7bd3 | 1743 | } |
0961dd0d TR |
1744 | } |
1745 | ||
1da177e4 LT |
1746 | ret = __cpufreq_set_policy(data, &policy); |
1747 | ||
5a01f2e8 VP |
1748 | unlock_policy_rwsem_write(cpu); |
1749 | ||
1da177e4 LT |
1750 | cpufreq_cpu_put(data); |
1751 | return ret; | |
1752 | } | |
1753 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1754 | ||
dd184a01 | 1755 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1756 | unsigned long action, void *hcpu) |
1757 | { | |
1758 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1759 | struct sys_device *sys_dev; |
1760 | ||
1761 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1762 | if (sys_dev) { |
1763 | switch (action) { | |
1764 | case CPU_ONLINE: | |
8bb78442 | 1765 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1766 | cpufreq_add_dev(sys_dev); |
1767 | break; | |
1768 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1769 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1770 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1771 | BUG(); | |
1772 | ||
5a01f2e8 | 1773 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1774 | break; |
5a01f2e8 | 1775 | case CPU_DOWN_FAILED: |
8bb78442 | 1776 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1777 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1778 | break; |
1779 | } | |
1780 | } | |
1781 | return NOTIFY_OK; | |
1782 | } | |
1783 | ||
f6ebef30 | 1784 | static struct notifier_block __refdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1785 | { |
1786 | .notifier_call = cpufreq_cpu_callback, | |
1787 | }; | |
1da177e4 LT |
1788 | |
1789 | /********************************************************************* | |
1790 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1791 | *********************************************************************/ | |
1792 | ||
1793 | /** | |
1794 | * cpufreq_register_driver - register a CPU Frequency driver | |
1795 | * @driver_data: A struct cpufreq_driver containing the values# | |
1796 | * submitted by the CPU Frequency driver. | |
1797 | * | |
32ee8c3e | 1798 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1799 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1800 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1801 | * |
1802 | */ | |
221dee28 | 1803 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1804 | { |
1805 | unsigned long flags; | |
1806 | int ret; | |
1807 | ||
1808 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1809 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1810 | return -EINVAL; | |
1811 | ||
1812 | dprintk("trying to register driver %s\n", driver_data->name); | |
1813 | ||
1814 | if (driver_data->setpolicy) | |
1815 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1816 | ||
1817 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1818 | if (cpufreq_driver) { | |
1819 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1820 | return -EBUSY; | |
1821 | } | |
1822 | cpufreq_driver = driver_data; | |
1823 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1824 | ||
7a6aedfa MT |
1825 | ret = sysdev_driver_register(&cpu_sysdev_class, |
1826 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1827 | |
1828 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1829 | int i; | |
1830 | ret = -ENODEV; | |
1831 | ||
1832 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1833 | for (i = 0; i < nr_cpu_ids; i++) |
1834 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1835 | ret = 0; |
7a6aedfa MT |
1836 | break; |
1837 | } | |
1da177e4 LT |
1838 | |
1839 | /* if all ->init() calls failed, unregister */ | |
1840 | if (ret) { | |
e08f5f5b GS |
1841 | dprintk("no CPU initialized for driver %s\n", |
1842 | driver_data->name); | |
1843 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1844 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1845 | |
1846 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1847 | cpufreq_driver = NULL; | |
1848 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1849 | } | |
1850 | } | |
1851 | ||
1852 | if (!ret) { | |
65edc68c | 1853 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1854 | dprintk("driver %s up and running\n", driver_data->name); |
1855 | cpufreq_debug_enable_ratelimit(); | |
1856 | } | |
1857 | ||
4d34a67d | 1858 | return ret; |
1da177e4 LT |
1859 | } |
1860 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1861 | ||
1862 | ||
1863 | /** | |
1864 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1865 | * | |
32ee8c3e | 1866 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1867 | * the right to do so, i.e. if you have succeeded in initialising before! |
1868 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1869 | * currently not initialised. | |
1870 | */ | |
221dee28 | 1871 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1872 | { |
1873 | unsigned long flags; | |
1874 | ||
1875 | cpufreq_debug_disable_ratelimit(); | |
1876 | ||
1877 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1878 | cpufreq_debug_enable_ratelimit(); | |
1879 | return -EINVAL; | |
1880 | } | |
1881 | ||
1882 | dprintk("unregistering driver %s\n", driver->name); | |
1883 | ||
1884 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1885 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1886 | |
1887 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1888 | cpufreq_driver = NULL; | |
1889 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1890 | ||
1891 | return 0; | |
1892 | } | |
1893 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1894 | |
1895 | static int __init cpufreq_core_init(void) | |
1896 | { | |
1897 | int cpu; | |
1898 | ||
1899 | for_each_possible_cpu(cpu) { | |
1900 | per_cpu(policy_cpu, cpu) = -1; | |
1901 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1902 | } | |
1903 | return 0; | |
1904 | } | |
1905 | ||
1906 | core_initcall(cpufreq_core_init); |