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 | 106 | /* internal prototypes */ |
29464f28 DJ |
107 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
108 | unsigned int event); | |
5a01f2e8 | 109 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 110 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
111 | |
112 | /** | |
32ee8c3e DJ |
113 | * Two notifier lists: the "policy" list is involved in the |
114 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
115 | * "transition" list for kernel code that needs to handle |
116 | * changes to devices when the CPU clock speed changes. | |
117 | * The mutex locks both lists. | |
118 | */ | |
e041c683 | 119 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 120 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 121 | |
74212ca4 | 122 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
123 | static int __init init_cpufreq_transition_notifier_list(void) |
124 | { | |
125 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 126 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
127 | return 0; |
128 | } | |
b3438f82 | 129 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
130 | |
131 | static LIST_HEAD(cpufreq_governor_list); | |
29464f28 | 132 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 133 | |
7d5e350f | 134 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
135 | { |
136 | struct cpufreq_policy *data; | |
137 | unsigned long flags; | |
138 | ||
7a6aedfa | 139 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
140 | goto err_out; |
141 | ||
142 | /* get the cpufreq driver */ | |
143 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
144 | ||
145 | if (!cpufreq_driver) | |
146 | goto err_out_unlock; | |
147 | ||
148 | if (!try_module_get(cpufreq_driver->owner)) | |
149 | goto err_out_unlock; | |
150 | ||
151 | ||
152 | /* get the CPU */ | |
7a6aedfa | 153 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
154 | |
155 | if (!data) | |
156 | goto err_out_put_module; | |
157 | ||
158 | if (!kobject_get(&data->kobj)) | |
159 | goto err_out_put_module; | |
160 | ||
1da177e4 | 161 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
162 | return data; |
163 | ||
7d5e350f | 164 | err_out_put_module: |
1da177e4 | 165 | module_put(cpufreq_driver->owner); |
7d5e350f | 166 | err_out_unlock: |
1da177e4 | 167 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 168 | err_out: |
1da177e4 LT |
169 | return NULL; |
170 | } | |
171 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
172 | ||
7d5e350f | 173 | |
1da177e4 LT |
174 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
175 | { | |
176 | kobject_put(&data->kobj); | |
177 | module_put(cpufreq_driver->owner); | |
178 | } | |
179 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
180 | ||
181 | ||
182 | /********************************************************************* | |
183 | * UNIFIED DEBUG HELPERS * | |
184 | *********************************************************************/ | |
185 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
186 | ||
187 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
188 | static unsigned int debug; | |
189 | ||
190 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
191 | * set or modify this value. | |
192 | */ | |
193 | static unsigned int debug_ratelimit = 1; | |
194 | ||
195 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
196 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
197 | * is set, and disabled upon cpufreq driver removal | |
198 | */ | |
199 | static unsigned int disable_ratelimit = 1; | |
200 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
201 | ||
858119e1 | 202 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
203 | { |
204 | unsigned long flags; | |
205 | ||
206 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
207 | if (disable_ratelimit) | |
208 | disable_ratelimit--; | |
209 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
210 | } | |
211 | ||
858119e1 | 212 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
213 | { |
214 | unsigned long flags; | |
215 | ||
216 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
217 | disable_ratelimit++; | |
218 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
219 | } | |
220 | ||
e08f5f5b | 221 | void cpufreq_debug_printk(unsigned int type, const char *prefix, |
905d77cd | 222 | const char *fmt, ...) |
1da177e4 LT |
223 | { |
224 | char s[256]; | |
225 | va_list args; | |
226 | unsigned int len; | |
227 | unsigned long flags; | |
32ee8c3e | 228 | |
1da177e4 LT |
229 | WARN_ON(!prefix); |
230 | if (type & debug) { | |
231 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
e08f5f5b GS |
232 | if (!disable_ratelimit && debug_ratelimit |
233 | && !printk_ratelimit()) { | |
1da177e4 LT |
234 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); |
235 | return; | |
236 | } | |
237 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
238 | ||
239 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
240 | ||
241 | va_start(args, fmt); | |
242 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
243 | va_end(args); | |
244 | ||
245 | printk(s); | |
246 | ||
247 | WARN_ON(len < 5); | |
248 | } | |
249 | } | |
250 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
251 | ||
252 | ||
253 | module_param(debug, uint, 0644); | |
e08f5f5b GS |
254 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," |
255 | " 2 to debug drivers, and 4 to debug governors."); | |
1da177e4 LT |
256 | |
257 | module_param(debug_ratelimit, uint, 0644); | |
e08f5f5b GS |
258 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" |
259 | " set to 0 to disable ratelimiting."); | |
1da177e4 LT |
260 | |
261 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
262 | ||
263 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
264 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
265 | ||
266 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
267 | ||
268 | ||
269 | /********************************************************************* | |
270 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
271 | *********************************************************************/ | |
272 | ||
273 | /** | |
274 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
275 | * | |
276 | * This function alters the system "loops_per_jiffy" for the clock | |
277 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 278 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
279 | * per-CPU loops_per_jiffy value wherever possible. |
280 | */ | |
281 | #ifndef CONFIG_SMP | |
282 | static unsigned long l_p_j_ref; | |
283 | static unsigned int l_p_j_ref_freq; | |
284 | ||
858119e1 | 285 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
286 | { |
287 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
288 | return; | |
289 | ||
290 | if (!l_p_j_ref_freq) { | |
291 | l_p_j_ref = loops_per_jiffy; | |
292 | l_p_j_ref_freq = ci->old; | |
a4a9df58 | 293 | dprintk("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 294 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 LT |
295 | } |
296 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
297 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 298 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
299 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
300 | ci->new); | |
a4a9df58 | 301 | dprintk("scaling loops_per_jiffy to %lu " |
e08f5f5b | 302 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
303 | } |
304 | } | |
305 | #else | |
e08f5f5b GS |
306 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
307 | { | |
308 | return; | |
309 | } | |
1da177e4 LT |
310 | #endif |
311 | ||
312 | ||
313 | /** | |
e4472cb3 DJ |
314 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
315 | * on frequency transition. | |
1da177e4 | 316 | * |
e4472cb3 DJ |
317 | * This function calls the transition notifiers and the "adjust_jiffies" |
318 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 319 | * external effects. |
1da177e4 LT |
320 | */ |
321 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
322 | { | |
e4472cb3 DJ |
323 | struct cpufreq_policy *policy; |
324 | ||
1da177e4 LT |
325 | BUG_ON(irqs_disabled()); |
326 | ||
327 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
328 | dprintk("notification %u of frequency transition to %u kHz\n", |
329 | state, freqs->new); | |
1da177e4 | 330 | |
7a6aedfa | 331 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 332 | switch (state) { |
e4472cb3 | 333 | |
1da177e4 | 334 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 335 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
336 | * which is not equal to what the cpufreq core thinks is |
337 | * "old frequency". | |
1da177e4 LT |
338 | */ |
339 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
340 | if ((policy) && (policy->cpu == freqs->cpu) && |
341 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 342 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
343 | " %u, cpufreq assumed %u kHz.\n", |
344 | freqs->old, policy->cur); | |
345 | freqs->old = policy->cur; | |
1da177e4 LT |
346 | } |
347 | } | |
b4dfdbb3 | 348 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 349 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
350 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
351 | break; | |
e4472cb3 | 352 | |
1da177e4 LT |
353 | case CPUFREQ_POSTCHANGE: |
354 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
b4dfdbb3 | 355 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 356 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
357 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
358 | policy->cur = freqs->new; | |
1da177e4 LT |
359 | break; |
360 | } | |
1da177e4 LT |
361 | } |
362 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
363 | ||
364 | ||
365 | ||
366 | /********************************************************************* | |
367 | * SYSFS INTERFACE * | |
368 | *********************************************************************/ | |
369 | ||
3bcb09a3 JF |
370 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
371 | { | |
372 | struct cpufreq_governor *t; | |
373 | ||
374 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 375 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
376 | return t; |
377 | ||
378 | return NULL; | |
379 | } | |
380 | ||
1da177e4 LT |
381 | /** |
382 | * cpufreq_parse_governor - parse a governor string | |
383 | */ | |
905d77cd | 384 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
385 | struct cpufreq_governor **governor) |
386 | { | |
3bcb09a3 JF |
387 | int err = -EINVAL; |
388 | ||
1da177e4 | 389 | if (!cpufreq_driver) |
3bcb09a3 JF |
390 | goto out; |
391 | ||
1da177e4 LT |
392 | if (cpufreq_driver->setpolicy) { |
393 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
394 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 395 | err = 0; |
e08f5f5b GS |
396 | } else if (!strnicmp(str_governor, "powersave", |
397 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 398 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 399 | err = 0; |
1da177e4 | 400 | } |
3bcb09a3 | 401 | } else if (cpufreq_driver->target) { |
1da177e4 | 402 | struct cpufreq_governor *t; |
3bcb09a3 | 403 | |
3fc54d37 | 404 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
405 | |
406 | t = __find_governor(str_governor); | |
407 | ||
ea714970 | 408 | if (t == NULL) { |
e08f5f5b GS |
409 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", |
410 | str_governor); | |
ea714970 JF |
411 | |
412 | if (name) { | |
413 | int ret; | |
414 | ||
415 | mutex_unlock(&cpufreq_governor_mutex); | |
326f6a5c | 416 | ret = request_module("%s", name); |
ea714970 JF |
417 | mutex_lock(&cpufreq_governor_mutex); |
418 | ||
419 | if (ret == 0) | |
420 | t = __find_governor(str_governor); | |
421 | } | |
422 | ||
423 | kfree(name); | |
424 | } | |
425 | ||
3bcb09a3 JF |
426 | if (t != NULL) { |
427 | *governor = t; | |
428 | err = 0; | |
1da177e4 | 429 | } |
3bcb09a3 | 430 | |
3fc54d37 | 431 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 432 | } |
29464f28 | 433 | out: |
3bcb09a3 | 434 | return err; |
1da177e4 | 435 | } |
1da177e4 LT |
436 | |
437 | ||
1da177e4 | 438 | /** |
e08f5f5b GS |
439 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
440 | * print out cpufreq information | |
1da177e4 LT |
441 | * |
442 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
443 | * "unsigned int". | |
444 | */ | |
445 | ||
32ee8c3e DJ |
446 | #define show_one(file_name, object) \ |
447 | static ssize_t show_##file_name \ | |
905d77cd | 448 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 449 | { \ |
29464f28 | 450 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
451 | } |
452 | ||
453 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
454 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 455 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
456 | show_one(scaling_min_freq, min); |
457 | show_one(scaling_max_freq, max); | |
458 | show_one(scaling_cur_freq, cur); | |
459 | ||
e08f5f5b GS |
460 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
461 | struct cpufreq_policy *policy); | |
7970e08b | 462 | |
1da177e4 LT |
463 | /** |
464 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
465 | */ | |
466 | #define store_one(file_name, object) \ | |
467 | static ssize_t store_##file_name \ | |
905d77cd | 468 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 LT |
469 | { \ |
470 | unsigned int ret = -EINVAL; \ | |
471 | struct cpufreq_policy new_policy; \ | |
472 | \ | |
473 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
474 | if (ret) \ | |
475 | return -EINVAL; \ | |
476 | \ | |
29464f28 | 477 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
478 | if (ret != 1) \ |
479 | return -EINVAL; \ | |
480 | \ | |
7970e08b TR |
481 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
482 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
483 | \ |
484 | return ret ? ret : count; \ | |
485 | } | |
486 | ||
29464f28 DJ |
487 | store_one(scaling_min_freq, min); |
488 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
489 | |
490 | /** | |
491 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
492 | */ | |
905d77cd DJ |
493 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
494 | char *buf) | |
1da177e4 | 495 | { |
5a01f2e8 | 496 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
497 | if (!cur_freq) |
498 | return sprintf(buf, "<unknown>"); | |
499 | return sprintf(buf, "%u\n", cur_freq); | |
500 | } | |
501 | ||
502 | ||
503 | /** | |
504 | * show_scaling_governor - show the current policy for the specified CPU | |
505 | */ | |
905d77cd | 506 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 507 | { |
29464f28 | 508 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
509 | return sprintf(buf, "powersave\n"); |
510 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
511 | return sprintf(buf, "performance\n"); | |
512 | else if (policy->governor) | |
29464f28 DJ |
513 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", |
514 | policy->governor->name); | |
1da177e4 LT |
515 | return -EINVAL; |
516 | } | |
517 | ||
518 | ||
519 | /** | |
520 | * store_scaling_governor - store policy for the specified CPU | |
521 | */ | |
905d77cd DJ |
522 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
523 | const char *buf, size_t count) | |
1da177e4 LT |
524 | { |
525 | unsigned int ret = -EINVAL; | |
526 | char str_governor[16]; | |
527 | struct cpufreq_policy new_policy; | |
528 | ||
529 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
530 | if (ret) | |
531 | return ret; | |
532 | ||
29464f28 | 533 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
534 | if (ret != 1) |
535 | return -EINVAL; | |
536 | ||
e08f5f5b GS |
537 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
538 | &new_policy.governor)) | |
1da177e4 LT |
539 | return -EINVAL; |
540 | ||
7970e08b TR |
541 | /* Do not use cpufreq_set_policy here or the user_policy.max |
542 | will be wrongly overridden */ | |
7970e08b TR |
543 | ret = __cpufreq_set_policy(policy, &new_policy); |
544 | ||
545 | policy->user_policy.policy = policy->policy; | |
546 | policy->user_policy.governor = policy->governor; | |
7970e08b | 547 | |
e08f5f5b GS |
548 | if (ret) |
549 | return ret; | |
550 | else | |
551 | return count; | |
1da177e4 LT |
552 | } |
553 | ||
554 | /** | |
555 | * show_scaling_driver - show the cpufreq driver currently loaded | |
556 | */ | |
905d77cd | 557 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 LT |
558 | { |
559 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
560 | } | |
561 | ||
562 | /** | |
563 | * show_scaling_available_governors - show the available CPUfreq governors | |
564 | */ | |
905d77cd DJ |
565 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
566 | char *buf) | |
1da177e4 LT |
567 | { |
568 | ssize_t i = 0; | |
569 | struct cpufreq_governor *t; | |
570 | ||
571 | if (!cpufreq_driver->target) { | |
572 | i += sprintf(buf, "performance powersave"); | |
573 | goto out; | |
574 | } | |
575 | ||
576 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
577 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
578 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 LT |
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 | 586 | |
835481d9 | 587 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
588 | { |
589 | ssize_t i = 0; | |
590 | unsigned int cpu; | |
591 | ||
835481d9 | 592 | for_each_cpu(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)) | |
29464f28 | 597 | break; |
1da177e4 LT |
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 | { | |
835481d9 | 609 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
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 | ||
879000f9 | 628 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
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 | { | |
879000f9 | 642 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
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); | |
ed129784 | 663 | define_one_ro(cpuinfo_transition_latency); |
1da177e4 LT |
664 | define_one_ro(scaling_available_governors); |
665 | define_one_ro(scaling_driver); | |
666 | define_one_ro(scaling_cur_freq); | |
e8628dd0 | 667 | define_one_ro(related_cpus); |
1da177e4 LT |
668 | define_one_ro(affected_cpus); |
669 | define_one_rw(scaling_min_freq); | |
670 | define_one_rw(scaling_max_freq); | |
671 | define_one_rw(scaling_governor); | |
9e76988e | 672 | define_one_rw(scaling_setspeed); |
1da177e4 | 673 | |
905d77cd | 674 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
675 | &cpuinfo_min_freq.attr, |
676 | &cpuinfo_max_freq.attr, | |
ed129784 | 677 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
678 | &scaling_min_freq.attr, |
679 | &scaling_max_freq.attr, | |
680 | &affected_cpus.attr, | |
e8628dd0 | 681 | &related_cpus.attr, |
1da177e4 LT |
682 | &scaling_governor.attr, |
683 | &scaling_driver.attr, | |
684 | &scaling_available_governors.attr, | |
9e76988e | 685 | &scaling_setspeed.attr, |
1da177e4 LT |
686 | NULL |
687 | }; | |
688 | ||
29464f28 DJ |
689 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
690 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 691 | |
29464f28 | 692 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 693 | { |
905d77cd DJ |
694 | struct cpufreq_policy *policy = to_policy(kobj); |
695 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 696 | ssize_t ret = -EINVAL; |
1da177e4 LT |
697 | policy = cpufreq_cpu_get(policy->cpu); |
698 | if (!policy) | |
0db4a8a9 | 699 | goto no_policy; |
5a01f2e8 VP |
700 | |
701 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 702 | goto fail; |
5a01f2e8 | 703 | |
e08f5f5b GS |
704 | if (fattr->show) |
705 | ret = fattr->show(policy, buf); | |
706 | else | |
707 | ret = -EIO; | |
708 | ||
5a01f2e8 | 709 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 710 | fail: |
1da177e4 | 711 | cpufreq_cpu_put(policy); |
0db4a8a9 | 712 | no_policy: |
1da177e4 LT |
713 | return ret; |
714 | } | |
715 | ||
905d77cd DJ |
716 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
717 | const char *buf, size_t count) | |
1da177e4 | 718 | { |
905d77cd DJ |
719 | struct cpufreq_policy *policy = to_policy(kobj); |
720 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 721 | ssize_t ret = -EINVAL; |
1da177e4 LT |
722 | policy = cpufreq_cpu_get(policy->cpu); |
723 | if (!policy) | |
a07530b4 | 724 | goto no_policy; |
5a01f2e8 VP |
725 | |
726 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 727 | goto fail; |
5a01f2e8 | 728 | |
e08f5f5b GS |
729 | if (fattr->store) |
730 | ret = fattr->store(policy, buf, count); | |
731 | else | |
732 | ret = -EIO; | |
733 | ||
5a01f2e8 | 734 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 735 | fail: |
1da177e4 | 736 | cpufreq_cpu_put(policy); |
a07530b4 | 737 | no_policy: |
1da177e4 LT |
738 | return ret; |
739 | } | |
740 | ||
905d77cd | 741 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 742 | { |
905d77cd | 743 | struct cpufreq_policy *policy = to_policy(kobj); |
1da177e4 LT |
744 | dprintk("last reference is dropped\n"); |
745 | complete(&policy->kobj_unregister); | |
746 | } | |
747 | ||
748 | static struct sysfs_ops sysfs_ops = { | |
749 | .show = show, | |
750 | .store = store, | |
751 | }; | |
752 | ||
753 | static struct kobj_type ktype_cpufreq = { | |
754 | .sysfs_ops = &sysfs_ops, | |
755 | .default_attrs = default_attrs, | |
756 | .release = cpufreq_sysfs_release, | |
757 | }; | |
758 | ||
759 | ||
760 | /** | |
761 | * cpufreq_add_dev - add a CPU device | |
762 | * | |
32ee8c3e | 763 | * Adds the cpufreq interface for a CPU device. |
1da177e4 | 764 | */ |
905d77cd | 765 | static int cpufreq_add_dev(struct sys_device *sys_dev) |
1da177e4 LT |
766 | { |
767 | unsigned int cpu = sys_dev->id; | |
768 | int ret = 0; | |
769 | struct cpufreq_policy new_policy; | |
770 | struct cpufreq_policy *policy; | |
771 | struct freq_attr **drv_attr; | |
8ff69732 | 772 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
773 | unsigned long flags; |
774 | unsigned int j; | |
8ff69732 DJ |
775 | #ifdef CONFIG_SMP |
776 | struct cpufreq_policy *managed_policy; | |
777 | #endif | |
1da177e4 | 778 | |
c32b6b8e AR |
779 | if (cpu_is_offline(cpu)) |
780 | return 0; | |
781 | ||
1da177e4 LT |
782 | cpufreq_debug_disable_ratelimit(); |
783 | dprintk("adding CPU %u\n", cpu); | |
784 | ||
785 | #ifdef CONFIG_SMP | |
786 | /* check whether a different CPU already registered this | |
787 | * CPU because it is in the same boat. */ | |
788 | policy = cpufreq_cpu_get(cpu); | |
789 | if (unlikely(policy)) { | |
8ff69732 | 790 | cpufreq_cpu_put(policy); |
1da177e4 LT |
791 | cpufreq_debug_enable_ratelimit(); |
792 | return 0; | |
793 | } | |
794 | #endif | |
795 | ||
796 | if (!try_module_get(cpufreq_driver->owner)) { | |
797 | ret = -EINVAL; | |
798 | goto module_out; | |
799 | } | |
800 | ||
e98df50c | 801 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
802 | if (!policy) { |
803 | ret = -ENOMEM; | |
804 | goto nomem_out; | |
805 | } | |
835481d9 RR |
806 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) { |
807 | kfree(policy); | |
808 | ret = -ENOMEM; | |
809 | goto nomem_out; | |
810 | } | |
811 | if (!alloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) { | |
812 | free_cpumask_var(policy->cpus); | |
813 | kfree(policy); | |
814 | ret = -ENOMEM; | |
815 | goto nomem_out; | |
816 | } | |
1da177e4 LT |
817 | |
818 | policy->cpu = cpu; | |
835481d9 | 819 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 820 | |
5a01f2e8 VP |
821 | /* Initially set CPU itself as the policy_cpu */ |
822 | per_cpu(policy_cpu, cpu) = cpu; | |
823 | lock_policy_rwsem_write(cpu); | |
824 | ||
1da177e4 | 825 | init_completion(&policy->kobj_unregister); |
65f27f38 | 826 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 827 | |
8122c6ce TR |
828 | /* Set governor before ->init, so that driver could check it */ |
829 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
830 | /* call driver. From then on the cpufreq must be able |
831 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
832 | */ | |
833 | ret = cpufreq_driver->init(policy); | |
834 | if (ret) { | |
835 | dprintk("initialization failed\n"); | |
836 | goto err_out; | |
837 | } | |
187d9f4e MC |
838 | policy->user_policy.min = policy->min; |
839 | policy->user_policy.max = policy->max; | |
1da177e4 | 840 | |
a1531acd TR |
841 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
842 | CPUFREQ_START, policy); | |
843 | ||
8ff69732 | 844 | #ifdef CONFIG_SMP |
084f3493 TR |
845 | |
846 | #ifdef CONFIG_HOTPLUG_CPU | |
7a6aedfa MT |
847 | if (per_cpu(cpufreq_cpu_governor, cpu)) { |
848 | policy->governor = per_cpu(cpufreq_cpu_governor, cpu); | |
084f3493 TR |
849 | dprintk("Restoring governor %s for cpu %d\n", |
850 | policy->governor->name, cpu); | |
851 | } | |
852 | #endif | |
853 | ||
835481d9 | 854 | for_each_cpu(j, policy->cpus) { |
8ff69732 DJ |
855 | if (cpu == j) |
856 | continue; | |
857 | ||
29464f28 DJ |
858 | /* Check for existing affected CPUs. |
859 | * They may not be aware of it due to CPU Hotplug. | |
8ff69732 | 860 | */ |
29464f28 | 861 | managed_policy = cpufreq_cpu_get(j); /* FIXME: Where is this released? What about error paths? */ |
8ff69732 | 862 | if (unlikely(managed_policy)) { |
5a01f2e8 VP |
863 | |
864 | /* Set proper policy_cpu */ | |
865 | unlock_policy_rwsem_write(cpu); | |
866 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
867 | ||
868 | if (lock_policy_rwsem_write(cpu) < 0) | |
869 | goto err_out_driver_exit; | |
870 | ||
8ff69732 | 871 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
835481d9 | 872 | cpumask_copy(managed_policy->cpus, policy->cpus); |
7a6aedfa | 873 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; |
8ff69732 DJ |
874 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
875 | ||
876 | dprintk("CPU already managed, adding link\n"); | |
0142f9dc AD |
877 | ret = sysfs_create_link(&sys_dev->kobj, |
878 | &managed_policy->kobj, | |
879 | "cpufreq"); | |
45709118 | 880 | if (ret) |
0142f9dc | 881 | goto err_out_driver_exit; |
8ff69732 DJ |
882 | |
883 | cpufreq_debug_enable_ratelimit(); | |
8ff69732 DJ |
884 | ret = 0; |
885 | goto err_out_driver_exit; /* call driver->exit() */ | |
886 | } | |
887 | } | |
888 | #endif | |
1da177e4 LT |
889 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
890 | ||
891 | /* prepare interface data */ | |
129f8ae9 DJ |
892 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj, |
893 | "cpufreq"); | |
894 | if (ret) | |
895 | goto err_out_driver_exit; | |
896 | ||
897 | /* set up files for this cpu device */ | |
898 | drv_attr = cpufreq_driver->attr; | |
899 | while ((drv_attr) && (*drv_attr)) { | |
900 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
45709118 | 901 | if (ret) |
0a4b2ccc | 902 | goto err_out_driver_exit; |
129f8ae9 DJ |
903 | drv_attr++; |
904 | } | |
905 | if (cpufreq_driver->get) { | |
906 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
907 | if (ret) | |
908 | goto err_out_driver_exit; | |
909 | } | |
910 | if (cpufreq_driver->target) { | |
911 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
45709118 | 912 | if (ret) |
0a4b2ccc TR |
913 | goto err_out_driver_exit; |
914 | } | |
1da177e4 LT |
915 | |
916 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 917 | for_each_cpu(j, policy->cpus) { |
7a6aedfa | 918 | per_cpu(cpufreq_cpu_data, j) = policy; |
5a01f2e8 VP |
919 | per_cpu(policy_cpu, j) = policy->cpu; |
920 | } | |
1da177e4 | 921 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8ff69732 DJ |
922 | |
923 | /* symlink affected CPUs */ | |
835481d9 | 924 | for_each_cpu(j, policy->cpus) { |
8ff69732 DJ |
925 | if (j == cpu) |
926 | continue; | |
927 | if (!cpu_online(j)) | |
928 | continue; | |
929 | ||
1f8b2c9d | 930 | dprintk("CPU %u already managed, adding link\n", j); |
8ff69732 DJ |
931 | cpufreq_cpu_get(cpu); |
932 | cpu_sys_dev = get_cpu_sysdev(j); | |
0142f9dc AD |
933 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, |
934 | "cpufreq"); | |
45709118 | 935 | if (ret) |
0142f9dc | 936 | goto err_out_unregister; |
8ff69732 DJ |
937 | } |
938 | ||
1da177e4 LT |
939 | policy->governor = NULL; /* to assure that the starting sequence is |
940 | * run in cpufreq_set_policy */ | |
87c32271 | 941 | |
1da177e4 | 942 | /* set default policy */ |
22c970f3 TR |
943 | ret = __cpufreq_set_policy(policy, &new_policy); |
944 | policy->user_policy.policy = policy->policy; | |
084f3493 | 945 | policy->user_policy.governor = policy->governor; |
22c970f3 | 946 | |
1da177e4 LT |
947 | if (ret) { |
948 | dprintk("setting policy failed\n"); | |
949 | goto err_out_unregister; | |
950 | } | |
951 | ||
dca02613 LW |
952 | unlock_policy_rwsem_write(cpu); |
953 | ||
038c5b3e | 954 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 955 | module_put(cpufreq_driver->owner); |
1da177e4 LT |
956 | dprintk("initialization complete\n"); |
957 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 958 | |
1da177e4 LT |
959 | return 0; |
960 | ||
961 | ||
962 | err_out_unregister: | |
963 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 964 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 965 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
966 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
967 | ||
c10997f6 | 968 | kobject_put(&policy->kobj); |
1da177e4 LT |
969 | wait_for_completion(&policy->kobj_unregister); |
970 | ||
8085e1f1 VP |
971 | err_out_driver_exit: |
972 | if (cpufreq_driver->exit) | |
973 | cpufreq_driver->exit(policy); | |
974 | ||
1da177e4 | 975 | err_out: |
45709118 | 976 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
977 | kfree(policy); |
978 | ||
979 | nomem_out: | |
980 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 981 | module_out: |
1da177e4 LT |
982 | cpufreq_debug_enable_ratelimit(); |
983 | return ret; | |
984 | } | |
985 | ||
986 | ||
987 | /** | |
5a01f2e8 | 988 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
989 | * |
990 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
991 | * Caller should already have policy_rwsem in write mode for this CPU. |
992 | * This routine frees the rwsem before returning. | |
1da177e4 | 993 | */ |
905d77cd | 994 | static int __cpufreq_remove_dev(struct sys_device *sys_dev) |
1da177e4 LT |
995 | { |
996 | unsigned int cpu = sys_dev->id; | |
997 | unsigned long flags; | |
998 | struct cpufreq_policy *data; | |
999 | #ifdef CONFIG_SMP | |
e738cf6d | 1000 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
1001 | unsigned int j; |
1002 | #endif | |
1003 | ||
1004 | cpufreq_debug_disable_ratelimit(); | |
1005 | dprintk("unregistering CPU %u\n", cpu); | |
1006 | ||
1007 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1008 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1009 | |
1010 | if (!data) { | |
1011 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 | 1012 | cpufreq_debug_enable_ratelimit(); |
5a01f2e8 | 1013 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1014 | return -EINVAL; |
1015 | } | |
7a6aedfa | 1016 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1017 | |
1018 | ||
1019 | #ifdef CONFIG_SMP | |
1020 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1021 | * only need to unlink, put and exit |
1da177e4 LT |
1022 | */ |
1023 | if (unlikely(cpu != data->cpu)) { | |
1024 | dprintk("removing link\n"); | |
835481d9 | 1025 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 LT |
1026 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1027 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1028 | cpufreq_cpu_put(data); |
1029 | cpufreq_debug_enable_ratelimit(); | |
5a01f2e8 | 1030 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1031 | return 0; |
1032 | } | |
1033 | #endif | |
1034 | ||
1da177e4 | 1035 | #ifdef CONFIG_SMP |
084f3493 TR |
1036 | |
1037 | #ifdef CONFIG_HOTPLUG_CPU | |
7a6aedfa | 1038 | per_cpu(cpufreq_cpu_governor, cpu) = data->governor; |
084f3493 TR |
1039 | #endif |
1040 | ||
1da177e4 LT |
1041 | /* if we have other CPUs still registered, we need to unlink them, |
1042 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1043 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1044 | * the sysfs links afterwards. | |
1da177e4 | 1045 | */ |
835481d9 RR |
1046 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1047 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1048 | if (j == cpu) |
1049 | continue; | |
7a6aedfa | 1050 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1051 | } |
1052 | } | |
1053 | ||
1054 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1055 | ||
835481d9 RR |
1056 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1057 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1058 | if (j == cpu) |
1059 | continue; | |
1060 | dprintk("removing link for cpu %u\n", j); | |
084f3493 | 1061 | #ifdef CONFIG_HOTPLUG_CPU |
7a6aedfa | 1062 | per_cpu(cpufreq_cpu_governor, j) = data->governor; |
084f3493 | 1063 | #endif |
d434fca7 AR |
1064 | cpu_sys_dev = get_cpu_sysdev(j); |
1065 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
1066 | cpufreq_cpu_put(data); |
1067 | } | |
1068 | } | |
1069 | #else | |
1070 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1071 | #endif | |
1072 | ||
1da177e4 LT |
1073 | if (cpufreq_driver->target) |
1074 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 VP |
1075 | |
1076 | unlock_policy_rwsem_write(cpu); | |
1da177e4 | 1077 | |
1da177e4 LT |
1078 | kobject_put(&data->kobj); |
1079 | ||
1080 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1081 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1082 | * unloading. |
1083 | */ | |
1084 | dprintk("waiting for dropping of refcount\n"); | |
1085 | wait_for_completion(&data->kobj_unregister); | |
1086 | dprintk("wait complete\n"); | |
1087 | ||
1088 | if (cpufreq_driver->exit) | |
1089 | cpufreq_driver->exit(data); | |
1090 | ||
835481d9 RR |
1091 | free_cpumask_var(data->related_cpus); |
1092 | free_cpumask_var(data->cpus); | |
1da177e4 | 1093 | kfree(data); |
835481d9 | 1094 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1095 | |
1096 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
1097 | return 0; |
1098 | } | |
1099 | ||
1100 | ||
905d77cd | 1101 | static int cpufreq_remove_dev(struct sys_device *sys_dev) |
5a01f2e8 VP |
1102 | { |
1103 | unsigned int cpu = sys_dev->id; | |
1104 | int retval; | |
ec28297a VP |
1105 | |
1106 | if (cpu_is_offline(cpu)) | |
1107 | return 0; | |
1108 | ||
5a01f2e8 VP |
1109 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1110 | BUG(); | |
1111 | ||
1112 | retval = __cpufreq_remove_dev(sys_dev); | |
1113 | return retval; | |
1114 | } | |
1115 | ||
1116 | ||
65f27f38 | 1117 | static void handle_update(struct work_struct *work) |
1da177e4 | 1118 | { |
65f27f38 DH |
1119 | struct cpufreq_policy *policy = |
1120 | container_of(work, struct cpufreq_policy, update); | |
1121 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
1122 | dprintk("handle_update for cpu %u called\n", cpu); |
1123 | cpufreq_update_policy(cpu); | |
1124 | } | |
1125 | ||
1126 | /** | |
1127 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1128 | * @cpu: cpu number | |
1129 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1130 | * @new_freq: CPU frequency the CPU actually runs at | |
1131 | * | |
29464f28 DJ |
1132 | * We adjust to current frequency first, and need to clean up later. |
1133 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1134 | */ |
e08f5f5b GS |
1135 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1136 | unsigned int new_freq) | |
1da177e4 LT |
1137 | { |
1138 | struct cpufreq_freqs freqs; | |
1139 | ||
b10eec22 | 1140 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1141 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1142 | ||
1143 | freqs.cpu = cpu; | |
1144 | freqs.old = old_freq; | |
1145 | freqs.new = new_freq; | |
1146 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1147 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1148 | } | |
1149 | ||
1150 | ||
32ee8c3e | 1151 | /** |
4ab70df4 | 1152 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1153 | * @cpu: CPU number |
1154 | * | |
1155 | * This is the last known freq, without actually getting it from the driver. | |
1156 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1157 | */ | |
1158 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1159 | { | |
1160 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1161 | unsigned int ret_freq = 0; |
95235ca2 VP |
1162 | |
1163 | if (policy) { | |
e08f5f5b | 1164 | ret_freq = policy->cur; |
95235ca2 VP |
1165 | cpufreq_cpu_put(policy); |
1166 | } | |
1167 | ||
4d34a67d | 1168 | return ret_freq; |
95235ca2 VP |
1169 | } |
1170 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1171 | ||
1172 | ||
5a01f2e8 | 1173 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1174 | { |
7a6aedfa | 1175 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1176 | unsigned int ret_freq = 0; |
1da177e4 | 1177 | |
1da177e4 | 1178 | if (!cpufreq_driver->get) |
4d34a67d | 1179 | return ret_freq; |
1da177e4 | 1180 | |
e08f5f5b | 1181 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1182 | |
e08f5f5b GS |
1183 | if (ret_freq && policy->cur && |
1184 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1185 | /* verify no discrepancy between actual and | |
1186 | saved value exists */ | |
1187 | if (unlikely(ret_freq != policy->cur)) { | |
1188 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1189 | schedule_work(&policy->update); |
1190 | } | |
1191 | } | |
1192 | ||
4d34a67d | 1193 | return ret_freq; |
5a01f2e8 | 1194 | } |
1da177e4 | 1195 | |
5a01f2e8 VP |
1196 | /** |
1197 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1198 | * @cpu: CPU number | |
1199 | * | |
1200 | * Get the CPU current (static) CPU frequency | |
1201 | */ | |
1202 | unsigned int cpufreq_get(unsigned int cpu) | |
1203 | { | |
1204 | unsigned int ret_freq = 0; | |
1205 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1206 | ||
1207 | if (!policy) | |
1208 | goto out; | |
1209 | ||
1210 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1211 | goto out_policy; | |
1212 | ||
1213 | ret_freq = __cpufreq_get(cpu); | |
1214 | ||
1215 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1216 | |
5a01f2e8 VP |
1217 | out_policy: |
1218 | cpufreq_cpu_put(policy); | |
1219 | out: | |
4d34a67d | 1220 | return ret_freq; |
1da177e4 LT |
1221 | } |
1222 | EXPORT_SYMBOL(cpufreq_get); | |
1223 | ||
1224 | ||
42d4dc3f BH |
1225 | /** |
1226 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1227 | */ | |
1228 | ||
905d77cd | 1229 | static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg) |
42d4dc3f BH |
1230 | { |
1231 | int cpu = sysdev->id; | |
e08f5f5b | 1232 | int ret = 0; |
42d4dc3f BH |
1233 | unsigned int cur_freq = 0; |
1234 | struct cpufreq_policy *cpu_policy; | |
1235 | ||
0e37b159 | 1236 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1237 | |
1238 | if (!cpu_online(cpu)) | |
1239 | return 0; | |
1240 | ||
1241 | /* we may be lax here as interrupts are off. Nonetheless | |
1242 | * we need to grab the correct cpu policy, as to check | |
1243 | * whether we really run on this CPU. | |
1244 | */ | |
1245 | ||
1246 | cpu_policy = cpufreq_cpu_get(cpu); | |
1247 | if (!cpu_policy) | |
1248 | return -EINVAL; | |
1249 | ||
1250 | /* only handle each CPU group once */ | |
c9060494 DJ |
1251 | if (unlikely(cpu_policy->cpu != cpu)) |
1252 | goto out; | |
42d4dc3f BH |
1253 | |
1254 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1255 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
1256 | if (ret) { |
1257 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1258 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1259 | goto out; |
42d4dc3f BH |
1260 | } |
1261 | } | |
1262 | ||
42d4dc3f BH |
1263 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) |
1264 | goto out; | |
1265 | ||
1266 | if (cpufreq_driver->get) | |
1267 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1268 | ||
1269 | if (!cur_freq || !cpu_policy->cur) { | |
1270 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1271 | "frequency is what timing core thinks it is.\n"); | |
1272 | goto out; | |
1273 | } | |
1274 | ||
1275 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1276 | struct cpufreq_freqs freqs; | |
1277 | ||
1278 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
b10eec22 | 1279 | dprintk("Warning: CPU frequency is %u, " |
42d4dc3f BH |
1280 | "cpufreq assumed %u kHz.\n", |
1281 | cur_freq, cpu_policy->cur); | |
1282 | ||
1283 | freqs.cpu = cpu; | |
1284 | freqs.old = cpu_policy->cur; | |
1285 | freqs.new = cur_freq; | |
1286 | ||
b4dfdbb3 | 1287 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
42d4dc3f BH |
1288 | CPUFREQ_SUSPENDCHANGE, &freqs); |
1289 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1290 | ||
1291 | cpu_policy->cur = cur_freq; | |
1292 | } | |
1293 | ||
7d5e350f | 1294 | out: |
42d4dc3f | 1295 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1296 | return ret; |
42d4dc3f BH |
1297 | } |
1298 | ||
1da177e4 LT |
1299 | /** |
1300 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1301 | * | |
1302 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1303 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1304 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1305 | * restored. | |
1da177e4 | 1306 | */ |
905d77cd | 1307 | static int cpufreq_resume(struct sys_device *sysdev) |
1da177e4 LT |
1308 | { |
1309 | int cpu = sysdev->id; | |
e08f5f5b | 1310 | int ret = 0; |
1da177e4 LT |
1311 | struct cpufreq_policy *cpu_policy; |
1312 | ||
1313 | dprintk("resuming cpu %u\n", cpu); | |
1314 | ||
1315 | if (!cpu_online(cpu)) | |
1316 | return 0; | |
1317 | ||
1318 | /* we may be lax here as interrupts are off. Nonetheless | |
1319 | * we need to grab the correct cpu policy, as to check | |
1320 | * whether we really run on this CPU. | |
1321 | */ | |
1322 | ||
1323 | cpu_policy = cpufreq_cpu_get(cpu); | |
1324 | if (!cpu_policy) | |
1325 | return -EINVAL; | |
1326 | ||
1327 | /* only handle each CPU group once */ | |
c9060494 DJ |
1328 | if (unlikely(cpu_policy->cpu != cpu)) |
1329 | goto fail; | |
1da177e4 LT |
1330 | |
1331 | if (cpufreq_driver->resume) { | |
1332 | ret = cpufreq_driver->resume(cpu_policy); | |
1333 | if (ret) { | |
1334 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1335 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1336 | goto fail; |
1da177e4 LT |
1337 | } |
1338 | } | |
1339 | ||
1340 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1341 | unsigned int cur_freq = 0; | |
1342 | ||
1343 | if (cpufreq_driver->get) | |
1344 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1345 | ||
1346 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1347 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1348 | "current frequency is what timing core " | |
1349 | "thinks it is.\n"); | |
1da177e4 LT |
1350 | goto out; |
1351 | } | |
1352 | ||
1353 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1354 | struct cpufreq_freqs freqs; | |
1355 | ||
ac09f698 | 1356 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
a4a9df58 | 1357 | dprintk("Warning: CPU frequency " |
ac09f698 BH |
1358 | "is %u, cpufreq assumed %u kHz.\n", |
1359 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1360 | |
1361 | freqs.cpu = cpu; | |
1362 | freqs.old = cpu_policy->cur; | |
1363 | freqs.new = cur_freq; | |
1364 | ||
b4dfdbb3 | 1365 | srcu_notifier_call_chain( |
e041c683 | 1366 | &cpufreq_transition_notifier_list, |
42d4dc3f | 1367 | CPUFREQ_RESUMECHANGE, &freqs); |
1da177e4 LT |
1368 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1369 | ||
1370 | cpu_policy->cur = cur_freq; | |
1371 | } | |
1372 | } | |
1373 | ||
1374 | out: | |
1375 | schedule_work(&cpu_policy->update); | |
c9060494 | 1376 | fail: |
1da177e4 LT |
1377 | cpufreq_cpu_put(cpu_policy); |
1378 | return ret; | |
1379 | } | |
1380 | ||
1381 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1382 | .add = cpufreq_add_dev, | |
1383 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1384 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1385 | .resume = cpufreq_resume, |
1386 | }; | |
1387 | ||
1388 | ||
1389 | /********************************************************************* | |
1390 | * NOTIFIER LISTS INTERFACE * | |
1391 | *********************************************************************/ | |
1392 | ||
1393 | /** | |
1394 | * cpufreq_register_notifier - register a driver with cpufreq | |
1395 | * @nb: notifier function to register | |
1396 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1397 | * | |
32ee8c3e | 1398 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1399 | * are notified about clock rate changes (once before and once after |
1400 | * the transition), or a list of drivers that are notified about | |
1401 | * changes in cpufreq policy. | |
1402 | * | |
1403 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1404 | * blocking_notifier_chain_register. |
1da177e4 LT |
1405 | */ |
1406 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1407 | { | |
1408 | int ret; | |
1409 | ||
74212ca4 CEB |
1410 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1411 | ||
1da177e4 LT |
1412 | switch (list) { |
1413 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1414 | ret = srcu_notifier_chain_register( |
e041c683 | 1415 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1416 | break; |
1417 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1418 | ret = blocking_notifier_chain_register( |
1419 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1420 | break; |
1421 | default: | |
1422 | ret = -EINVAL; | |
1423 | } | |
1da177e4 LT |
1424 | |
1425 | return ret; | |
1426 | } | |
1427 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1428 | ||
1429 | ||
1430 | /** | |
1431 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1432 | * @nb: notifier block to be unregistered | |
1433 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1434 | * | |
1435 | * Remove a driver from the CPU frequency notifier list. | |
1436 | * | |
1437 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1438 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1439 | */ |
1440 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1441 | { | |
1442 | int ret; | |
1443 | ||
1da177e4 LT |
1444 | switch (list) { |
1445 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1446 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1447 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1448 | break; |
1449 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1450 | ret = blocking_notifier_chain_unregister( |
1451 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1452 | break; |
1453 | default: | |
1454 | ret = -EINVAL; | |
1455 | } | |
1da177e4 LT |
1456 | |
1457 | return ret; | |
1458 | } | |
1459 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1460 | ||
1461 | ||
1462 | /********************************************************************* | |
1463 | * GOVERNORS * | |
1464 | *********************************************************************/ | |
1465 | ||
1466 | ||
1467 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1468 | unsigned int target_freq, | |
1469 | unsigned int relation) | |
1470 | { | |
1471 | int retval = -EINVAL; | |
c32b6b8e | 1472 | |
1da177e4 LT |
1473 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1474 | target_freq, relation); | |
1475 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1476 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1477 | |
1da177e4 LT |
1478 | return retval; |
1479 | } | |
1480 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1481 | ||
1da177e4 LT |
1482 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1483 | unsigned int target_freq, | |
1484 | unsigned int relation) | |
1485 | { | |
f1829e4a | 1486 | int ret = -EINVAL; |
1da177e4 LT |
1487 | |
1488 | policy = cpufreq_cpu_get(policy->cpu); | |
1489 | if (!policy) | |
f1829e4a | 1490 | goto no_policy; |
1da177e4 | 1491 | |
5a01f2e8 | 1492 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1493 | goto fail; |
1da177e4 LT |
1494 | |
1495 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1496 | ||
5a01f2e8 | 1497 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1498 | |
f1829e4a | 1499 | fail: |
1da177e4 | 1500 | cpufreq_cpu_put(policy); |
f1829e4a | 1501 | no_policy: |
1da177e4 LT |
1502 | return ret; |
1503 | } | |
1504 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1505 | ||
bf0b90e3 | 1506 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1507 | { |
1508 | int ret = 0; | |
1509 | ||
1510 | policy = cpufreq_cpu_get(policy->cpu); | |
1511 | if (!policy) | |
1512 | return -EINVAL; | |
1513 | ||
bf0b90e3 | 1514 | if (cpu_online(cpu) && cpufreq_driver->getavg) |
1515 | ret = cpufreq_driver->getavg(policy, cpu); | |
dfde5d62 | 1516 | |
dfde5d62 VP |
1517 | cpufreq_cpu_put(policy); |
1518 | return ret; | |
1519 | } | |
5a01f2e8 | 1520 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1521 | |
153d7f3f | 1522 | /* |
153d7f3f AV |
1523 | * when "event" is CPUFREQ_GOV_LIMITS |
1524 | */ | |
1da177e4 | 1525 | |
e08f5f5b GS |
1526 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1527 | unsigned int event) | |
1da177e4 | 1528 | { |
cc993cab | 1529 | int ret; |
6afde10c TR |
1530 | |
1531 | /* Only must be defined when default governor is known to have latency | |
1532 | restrictions, like e.g. conservative or ondemand. | |
1533 | That this is the case is already ensured in Kconfig | |
1534 | */ | |
1535 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1536 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1537 | #else | |
1538 | struct cpufreq_governor *gov = NULL; | |
1539 | #endif | |
1c256245 TR |
1540 | |
1541 | if (policy->governor->max_transition_latency && | |
1542 | policy->cpuinfo.transition_latency > | |
1543 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1544 | if (!gov) |
1545 | return -EINVAL; | |
1546 | else { | |
1547 | printk(KERN_WARNING "%s governor failed, too long" | |
1548 | " transition latency of HW, fallback" | |
1549 | " to %s governor\n", | |
1550 | policy->governor->name, | |
1551 | gov->name); | |
1552 | policy->governor = gov; | |
1553 | } | |
1c256245 | 1554 | } |
1da177e4 LT |
1555 | |
1556 | if (!try_module_get(policy->governor->owner)) | |
1557 | return -EINVAL; | |
1558 | ||
e08f5f5b GS |
1559 | dprintk("__cpufreq_governor for CPU %u, event %u\n", |
1560 | policy->cpu, event); | |
1da177e4 LT |
1561 | ret = policy->governor->governor(policy, event); |
1562 | ||
e08f5f5b GS |
1563 | /* we keep one module reference alive for |
1564 | each CPU governed by this CPU */ | |
1da177e4 LT |
1565 | if ((event != CPUFREQ_GOV_START) || ret) |
1566 | module_put(policy->governor->owner); | |
1567 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1568 | module_put(policy->governor->owner); | |
1569 | ||
1570 | return ret; | |
1571 | } | |
1572 | ||
1573 | ||
1da177e4 LT |
1574 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1575 | { | |
3bcb09a3 | 1576 | int err; |
1da177e4 LT |
1577 | |
1578 | if (!governor) | |
1579 | return -EINVAL; | |
1580 | ||
3fc54d37 | 1581 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1582 | |
3bcb09a3 JF |
1583 | err = -EBUSY; |
1584 | if (__find_governor(governor->name) == NULL) { | |
1585 | err = 0; | |
1586 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1587 | } |
1da177e4 | 1588 | |
32ee8c3e | 1589 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1590 | return err; |
1da177e4 LT |
1591 | } |
1592 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1593 | ||
1594 | ||
1595 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1596 | { | |
1597 | if (!governor) | |
1598 | return; | |
1599 | ||
3fc54d37 | 1600 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1601 | list_del(&governor->governor_list); |
3fc54d37 | 1602 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1603 | return; |
1604 | } | |
1605 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1606 | ||
1607 | ||
1608 | ||
1609 | /********************************************************************* | |
1610 | * POLICY INTERFACE * | |
1611 | *********************************************************************/ | |
1612 | ||
1613 | /** | |
1614 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1615 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1616 | * is written | |
1da177e4 LT |
1617 | * |
1618 | * Reads the current cpufreq policy. | |
1619 | */ | |
1620 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1621 | { | |
1622 | struct cpufreq_policy *cpu_policy; | |
1623 | if (!policy) | |
1624 | return -EINVAL; | |
1625 | ||
1626 | cpu_policy = cpufreq_cpu_get(cpu); | |
1627 | if (!cpu_policy) | |
1628 | return -EINVAL; | |
1629 | ||
1da177e4 | 1630 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1631 | |
1632 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1633 | return 0; |
1634 | } | |
1635 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1636 | ||
1637 | ||
153d7f3f | 1638 | /* |
e08f5f5b GS |
1639 | * data : current policy. |
1640 | * policy : policy to be set. | |
153d7f3f | 1641 | */ |
e08f5f5b GS |
1642 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1643 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1644 | { |
1645 | int ret = 0; | |
1646 | ||
1647 | cpufreq_debug_disable_ratelimit(); | |
1648 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1649 | policy->min, policy->max); | |
1650 | ||
e08f5f5b GS |
1651 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1652 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1653 | |
53391fa2 | 1654 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1655 | ret = -EINVAL; |
1656 | goto error_out; | |
1657 | } | |
1658 | ||
1da177e4 LT |
1659 | /* verify the cpu speed can be set within this limit */ |
1660 | ret = cpufreq_driver->verify(policy); | |
1661 | if (ret) | |
1662 | goto error_out; | |
1663 | ||
1da177e4 | 1664 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1665 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1666 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1667 | |
1668 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1669 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1670 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1671 | |
1672 | /* verify the cpu speed can be set within this limit, | |
1673 | which might be different to the first one */ | |
1674 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1675 | if (ret) |
1da177e4 | 1676 | goto error_out; |
1da177e4 LT |
1677 | |
1678 | /* notification of the new policy */ | |
e041c683 AS |
1679 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1680 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1681 | |
7d5e350f DJ |
1682 | data->min = policy->min; |
1683 | data->max = policy->max; | |
1da177e4 | 1684 | |
e08f5f5b GS |
1685 | dprintk("new min and max freqs are %u - %u kHz\n", |
1686 | data->min, data->max); | |
1da177e4 LT |
1687 | |
1688 | if (cpufreq_driver->setpolicy) { | |
1689 | data->policy = policy->policy; | |
1690 | dprintk("setting range\n"); | |
1691 | ret = cpufreq_driver->setpolicy(policy); | |
1692 | } else { | |
1693 | if (policy->governor != data->governor) { | |
1694 | /* save old, working values */ | |
1695 | struct cpufreq_governor *old_gov = data->governor; | |
1696 | ||
1697 | dprintk("governor switch\n"); | |
1698 | ||
1699 | /* end old governor */ | |
1700 | if (data->governor) | |
1701 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1702 | ||
1703 | /* start new governor */ | |
1704 | data->governor = policy->governor; | |
1705 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1706 | /* new governor failed, so re-start old one */ | |
e08f5f5b GS |
1707 | dprintk("starting governor %s failed\n", |
1708 | data->governor->name); | |
1da177e4 LT |
1709 | if (old_gov) { |
1710 | data->governor = old_gov; | |
e08f5f5b GS |
1711 | __cpufreq_governor(data, |
1712 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1713 | } |
1714 | ret = -EINVAL; | |
1715 | goto error_out; | |
1716 | } | |
1717 | /* might be a policy change, too, so fall through */ | |
1718 | } | |
1719 | dprintk("governor: change or update limits\n"); | |
1720 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1721 | } | |
1722 | ||
7d5e350f | 1723 | error_out: |
1da177e4 LT |
1724 | cpufreq_debug_enable_ratelimit(); |
1725 | return ret; | |
1726 | } | |
1727 | ||
1da177e4 LT |
1728 | /** |
1729 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1730 | * @cpu: CPU which shall be re-evaluated | |
1731 | * | |
1732 | * Usefull for policy notifiers which have different necessities | |
1733 | * at different times. | |
1734 | */ | |
1735 | int cpufreq_update_policy(unsigned int cpu) | |
1736 | { | |
1737 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1738 | struct cpufreq_policy policy; | |
f1829e4a | 1739 | int ret; |
1da177e4 | 1740 | |
f1829e4a JL |
1741 | if (!data) { |
1742 | ret = -ENODEV; | |
1743 | goto no_policy; | |
1744 | } | |
1da177e4 | 1745 | |
f1829e4a JL |
1746 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1747 | ret = -EINVAL; | |
1748 | goto fail; | |
1749 | } | |
1da177e4 LT |
1750 | |
1751 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1752 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1753 | policy.min = data->user_policy.min; |
1754 | policy.max = data->user_policy.max; | |
1755 | policy.policy = data->user_policy.policy; | |
1756 | policy.governor = data->user_policy.governor; | |
1757 | ||
0961dd0d TR |
1758 | /* BIOS might change freq behind our back |
1759 | -> ask driver for current freq and notify governors about a change */ | |
1760 | if (cpufreq_driver->get) { | |
1761 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1762 | if (!data->cur) { |
1763 | dprintk("Driver did not initialize current freq"); | |
1764 | data->cur = policy.cur; | |
1765 | } else { | |
1766 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1767 | cpufreq_out_of_sync(cpu, data->cur, |
1768 | policy.cur); | |
a85f7bd3 | 1769 | } |
0961dd0d TR |
1770 | } |
1771 | ||
1da177e4 LT |
1772 | ret = __cpufreq_set_policy(data, &policy); |
1773 | ||
5a01f2e8 VP |
1774 | unlock_policy_rwsem_write(cpu); |
1775 | ||
f1829e4a | 1776 | fail: |
1da177e4 | 1777 | cpufreq_cpu_put(data); |
f1829e4a | 1778 | no_policy: |
1da177e4 LT |
1779 | return ret; |
1780 | } | |
1781 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1782 | ||
dd184a01 | 1783 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1784 | unsigned long action, void *hcpu) |
1785 | { | |
1786 | unsigned int cpu = (unsigned long)hcpu; | |
c32b6b8e AR |
1787 | struct sys_device *sys_dev; |
1788 | ||
1789 | sys_dev = get_cpu_sysdev(cpu); | |
c32b6b8e AR |
1790 | if (sys_dev) { |
1791 | switch (action) { | |
1792 | case CPU_ONLINE: | |
8bb78442 | 1793 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
1794 | cpufreq_add_dev(sys_dev); |
1795 | break; | |
1796 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1797 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1798 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1799 | BUG(); | |
1800 | ||
5a01f2e8 | 1801 | __cpufreq_remove_dev(sys_dev); |
c32b6b8e | 1802 | break; |
5a01f2e8 | 1803 | case CPU_DOWN_FAILED: |
8bb78442 | 1804 | case CPU_DOWN_FAILED_FROZEN: |
5a01f2e8 | 1805 | cpufreq_add_dev(sys_dev); |
c32b6b8e AR |
1806 | break; |
1807 | } | |
1808 | } | |
1809 | return NOTIFY_OK; | |
1810 | } | |
1811 | ||
f6ebef30 | 1812 | static struct notifier_block __refdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1813 | { |
1814 | .notifier_call = cpufreq_cpu_callback, | |
1815 | }; | |
1da177e4 LT |
1816 | |
1817 | /********************************************************************* | |
1818 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1819 | *********************************************************************/ | |
1820 | ||
1821 | /** | |
1822 | * cpufreq_register_driver - register a CPU Frequency driver | |
1823 | * @driver_data: A struct cpufreq_driver containing the values# | |
1824 | * submitted by the CPU Frequency driver. | |
1825 | * | |
32ee8c3e | 1826 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1827 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1828 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1829 | * |
1830 | */ | |
221dee28 | 1831 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1832 | { |
1833 | unsigned long flags; | |
1834 | int ret; | |
1835 | ||
1836 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1837 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1838 | return -EINVAL; | |
1839 | ||
1840 | dprintk("trying to register driver %s\n", driver_data->name); | |
1841 | ||
1842 | if (driver_data->setpolicy) | |
1843 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1844 | ||
1845 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1846 | if (cpufreq_driver) { | |
1847 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1848 | return -EBUSY; | |
1849 | } | |
1850 | cpufreq_driver = driver_data; | |
1851 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1852 | ||
7a6aedfa MT |
1853 | ret = sysdev_driver_register(&cpu_sysdev_class, |
1854 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1855 | |
1856 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1857 | int i; | |
1858 | ret = -ENODEV; | |
1859 | ||
1860 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1861 | for (i = 0; i < nr_cpu_ids; i++) |
1862 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1863 | ret = 0; |
7a6aedfa MT |
1864 | break; |
1865 | } | |
1da177e4 LT |
1866 | |
1867 | /* if all ->init() calls failed, unregister */ | |
1868 | if (ret) { | |
e08f5f5b GS |
1869 | dprintk("no CPU initialized for driver %s\n", |
1870 | driver_data->name); | |
1871 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1872 | &cpufreq_sysdev_driver); | |
1da177e4 LT |
1873 | |
1874 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1875 | cpufreq_driver = NULL; | |
1876 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1877 | } | |
1878 | } | |
1879 | ||
1880 | if (!ret) { | |
65edc68c | 1881 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1882 | dprintk("driver %s up and running\n", driver_data->name); |
1883 | cpufreq_debug_enable_ratelimit(); | |
1884 | } | |
1885 | ||
4d34a67d | 1886 | return ret; |
1da177e4 LT |
1887 | } |
1888 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1889 | ||
1890 | ||
1891 | /** | |
1892 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1893 | * | |
32ee8c3e | 1894 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1895 | * the right to do so, i.e. if you have succeeded in initialising before! |
1896 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1897 | * currently not initialised. | |
1898 | */ | |
221dee28 | 1899 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1900 | { |
1901 | unsigned long flags; | |
1902 | ||
1903 | cpufreq_debug_disable_ratelimit(); | |
1904 | ||
1905 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1906 | cpufreq_debug_enable_ratelimit(); | |
1907 | return -EINVAL; | |
1908 | } | |
1909 | ||
1910 | dprintk("unregistering driver %s\n", driver->name); | |
1911 | ||
1912 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1913 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1914 | |
1915 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1916 | cpufreq_driver = NULL; | |
1917 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1918 | ||
1919 | return 0; | |
1920 | } | |
1921 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1922 | |
1923 | static int __init cpufreq_core_init(void) | |
1924 | { | |
1925 | int cpu; | |
1926 | ||
1927 | for_each_possible_cpu(cpu) { | |
1928 | per_cpu(policy_cpu, cpu) = -1; | |
1929 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1930 | } | |
1931 | return 0; | |
1932 | } | |
1933 | ||
1934 | core_initcall(cpufreq_core_init); |