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 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
1da177e4 LT |
20 | #include <linux/kernel.h> |
21 | #include <linux/module.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/notifier.h> | |
24 | #include <linux/cpufreq.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/spinlock.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/cpu.h> | |
31 | #include <linux/completion.h> | |
3fc54d37 | 32 | #include <linux/mutex.h> |
e00e56df | 33 | #include <linux/syscore_ops.h> |
1da177e4 | 34 | |
6f4f2723 TR |
35 | #include <trace/events/power.h> |
36 | ||
1da177e4 | 37 | /** |
cd878479 | 38 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
39 | * level driver of CPUFreq support, and its spinlock. This lock |
40 | * also protects the cpufreq_cpu_data array. | |
41 | */ | |
5800043b | 42 | static struct cpufreq_driver __rcu *cpufreq_driver; |
7a6aedfa | 43 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
084f3493 TR |
44 | #ifdef CONFIG_HOTPLUG_CPU |
45 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 46 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 47 | #endif |
0d1857a1 | 48 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
1da177e4 | 49 | |
5a01f2e8 VP |
50 | /* |
51 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
52 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
53 | * | |
54 | * The rules for this semaphore: | |
55 | * - Any routine that wants to read from the policy structure will | |
56 | * do a down_read on this semaphore. | |
57 | * - Any routine that will write to the policy structure and/or may take away | |
58 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
59 | * mode before doing so. | |
60 | * | |
61 | * Additional rules: | |
5a01f2e8 VP |
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. | |
395913d0 MD |
64 | * - Lock should not be held across |
65 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 66 | */ |
f1625066 | 67 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
68 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
69 | ||
70 | #define lock_policy_rwsem(mode, cpu) \ | |
fa1d8af4 | 71 | static int lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 72 | { \ |
f1625066 | 73 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
74 | BUG_ON(policy_cpu == -1); \ |
75 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 VP |
76 | \ |
77 | return 0; \ | |
78 | } | |
79 | ||
80 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 81 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 82 | |
fa1d8af4 VK |
83 | #define unlock_policy_rwsem(mode, cpu) \ |
84 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
85 | { \ | |
86 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
87 | BUG_ON(policy_cpu == -1); \ | |
88 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 | 89 | } |
5a01f2e8 | 90 | |
fa1d8af4 VK |
91 | unlock_policy_rwsem(read, cpu); |
92 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 93 | |
1da177e4 | 94 | /* internal prototypes */ |
29464f28 DJ |
95 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
96 | unsigned int event); | |
5a01f2e8 | 97 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 98 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
99 | |
100 | /** | |
32ee8c3e DJ |
101 | * Two notifier lists: the "policy" list is involved in the |
102 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
103 | * "transition" list for kernel code that needs to handle |
104 | * changes to devices when the CPU clock speed changes. | |
105 | * The mutex locks both lists. | |
106 | */ | |
e041c683 | 107 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 108 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 109 | |
74212ca4 | 110 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
111 | static int __init init_cpufreq_transition_notifier_list(void) |
112 | { | |
113 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 114 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
115 | return 0; |
116 | } | |
b3438f82 | 117 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 118 | |
a7b422cd | 119 | static int off __read_mostly; |
da584455 | 120 | static int cpufreq_disabled(void) |
a7b422cd KRW |
121 | { |
122 | return off; | |
123 | } | |
124 | void disable_cpufreq(void) | |
125 | { | |
126 | off = 1; | |
127 | } | |
1da177e4 | 128 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 129 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 130 | |
4d5dcc42 VK |
131 | bool have_governor_per_policy(void) |
132 | { | |
5800043b NZ |
133 | bool have_governor_per_policy; |
134 | rcu_read_lock(); | |
135 | have_governor_per_policy = | |
136 | rcu_dereference(cpufreq_driver)->have_governor_per_policy; | |
137 | rcu_read_unlock(); | |
138 | return have_governor_per_policy; | |
4d5dcc42 VK |
139 | } |
140 | ||
a9144436 | 141 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
142 | { |
143 | struct cpufreq_policy *data; | |
5800043b | 144 | struct cpufreq_driver *driver; |
1da177e4 LT |
145 | unsigned long flags; |
146 | ||
7a6aedfa | 147 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
148 | goto err_out; |
149 | ||
150 | /* get the cpufreq driver */ | |
5800043b NZ |
151 | rcu_read_lock(); |
152 | driver = rcu_dereference(cpufreq_driver); | |
1da177e4 | 153 | |
5800043b | 154 | if (!driver) |
1da177e4 LT |
155 | goto err_out_unlock; |
156 | ||
5800043b | 157 | if (!try_module_get(driver->owner)) |
1da177e4 LT |
158 | goto err_out_unlock; |
159 | ||
5800043b | 160 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 LT |
161 | |
162 | /* get the CPU */ | |
7a6aedfa | 163 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
164 | |
165 | if (!data) | |
166 | goto err_out_put_module; | |
167 | ||
a9144436 | 168 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
169 | goto err_out_put_module; |
170 | ||
0d1857a1 | 171 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5800043b | 172 | rcu_read_unlock(); |
1da177e4 LT |
173 | return data; |
174 | ||
7d5e350f | 175 | err_out_put_module: |
5800043b | 176 | module_put(driver->owner); |
0d1857a1 | 177 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5800043b NZ |
178 | err_out_unlock: |
179 | rcu_read_unlock(); | |
7d5e350f | 180 | err_out: |
1da177e4 LT |
181 | return NULL; |
182 | } | |
a9144436 SB |
183 | |
184 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
185 | { | |
d5aaffa9 DB |
186 | if (cpufreq_disabled()) |
187 | return NULL; | |
188 | ||
a9144436 SB |
189 | return __cpufreq_cpu_get(cpu, false); |
190 | } | |
1da177e4 LT |
191 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
192 | ||
a9144436 SB |
193 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
194 | { | |
195 | return __cpufreq_cpu_get(cpu, true); | |
196 | } | |
197 | ||
198 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
199 | { | |
200 | if (!sysfs) | |
201 | kobject_put(&data->kobj); | |
5800043b NZ |
202 | rcu_read_lock(); |
203 | module_put(rcu_dereference(cpufreq_driver)->owner); | |
204 | rcu_read_unlock(); | |
a9144436 | 205 | } |
7d5e350f | 206 | |
1da177e4 LT |
207 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
208 | { | |
d5aaffa9 DB |
209 | if (cpufreq_disabled()) |
210 | return; | |
211 | ||
a9144436 | 212 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
213 | } |
214 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
215 | ||
a9144436 SB |
216 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
217 | { | |
218 | __cpufreq_cpu_put(data, true); | |
219 | } | |
1da177e4 | 220 | |
1da177e4 LT |
221 | /********************************************************************* |
222 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
223 | *********************************************************************/ | |
224 | ||
225 | /** | |
226 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
227 | * | |
228 | * This function alters the system "loops_per_jiffy" for the clock | |
229 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 230 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
231 | * per-CPU loops_per_jiffy value wherever possible. |
232 | */ | |
233 | #ifndef CONFIG_SMP | |
234 | static unsigned long l_p_j_ref; | |
235 | static unsigned int l_p_j_ref_freq; | |
236 | ||
858119e1 | 237 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
238 | { |
239 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
240 | return; | |
241 | ||
242 | if (!l_p_j_ref_freq) { | |
243 | l_p_j_ref = loops_per_jiffy; | |
244 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 245 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 246 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 247 | } |
d08de0c1 | 248 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 249 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
250 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
251 | ci->new); | |
2d06d8c4 | 252 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 253 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
254 | } |
255 | } | |
256 | #else | |
e08f5f5b GS |
257 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
258 | { | |
259 | return; | |
260 | } | |
1da177e4 LT |
261 | #endif |
262 | ||
263 | ||
b43a7ffb VK |
264 | void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
265 | struct cpufreq_freqs *freqs, unsigned int state) | |
1da177e4 LT |
266 | { |
267 | BUG_ON(irqs_disabled()); | |
268 | ||
d5aaffa9 DB |
269 | if (cpufreq_disabled()) |
270 | return; | |
271 | ||
5800043b NZ |
272 | rcu_read_lock(); |
273 | freqs->flags = rcu_dereference(cpufreq_driver)->flags; | |
274 | rcu_read_unlock(); | |
2d06d8c4 | 275 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 276 | state, freqs->new); |
1da177e4 | 277 | |
1da177e4 | 278 | switch (state) { |
e4472cb3 | 279 | |
1da177e4 | 280 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 281 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
282 | * which is not equal to what the cpufreq core thinks is |
283 | * "old frequency". | |
1da177e4 | 284 | */ |
5800043b | 285 | if (!(freqs->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
286 | if ((policy) && (policy->cpu == freqs->cpu) && |
287 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 288 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
289 | " %u, cpufreq assumed %u kHz.\n", |
290 | freqs->old, policy->cur); | |
291 | freqs->old = policy->cur; | |
1da177e4 LT |
292 | } |
293 | } | |
b4dfdbb3 | 294 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 295 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
296 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
297 | break; | |
e4472cb3 | 298 | |
1da177e4 LT |
299 | case CPUFREQ_POSTCHANGE: |
300 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 301 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 302 | (unsigned long)freqs->cpu); |
25e41933 | 303 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 304 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 305 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
306 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
307 | policy->cur = freqs->new; | |
1da177e4 LT |
308 | break; |
309 | } | |
1da177e4 | 310 | } |
b43a7ffb VK |
311 | /** |
312 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
313 | * on frequency transition. | |
314 | * | |
315 | * This function calls the transition notifiers and the "adjust_jiffies" | |
316 | * function. It is called twice on all CPU frequency changes that have | |
317 | * external effects. | |
318 | */ | |
319 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
320 | struct cpufreq_freqs *freqs, unsigned int state) | |
321 | { | |
322 | for_each_cpu(freqs->cpu, policy->cpus) | |
323 | __cpufreq_notify_transition(policy, freqs, state); | |
324 | } | |
1da177e4 LT |
325 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
326 | ||
327 | ||
328 | ||
329 | /********************************************************************* | |
330 | * SYSFS INTERFACE * | |
331 | *********************************************************************/ | |
332 | ||
3bcb09a3 JF |
333 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
334 | { | |
335 | struct cpufreq_governor *t; | |
336 | ||
337 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 338 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
339 | return t; |
340 | ||
341 | return NULL; | |
342 | } | |
343 | ||
1da177e4 LT |
344 | /** |
345 | * cpufreq_parse_governor - parse a governor string | |
346 | */ | |
905d77cd | 347 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
348 | struct cpufreq_governor **governor) |
349 | { | |
3bcb09a3 | 350 | int err = -EINVAL; |
5800043b NZ |
351 | struct cpufreq_driver *driver; |
352 | bool has_setpolicy; | |
353 | bool has_target; | |
354 | ||
355 | rcu_read_lock(); | |
356 | driver = rcu_dereference(cpufreq_driver); | |
357 | if (!driver) { | |
358 | rcu_read_unlock(); | |
3bcb09a3 | 359 | goto out; |
5800043b NZ |
360 | } |
361 | has_setpolicy = driver->setpolicy ? true : false; | |
362 | has_target = driver->target ? true : false; | |
363 | rcu_read_unlock(); | |
3bcb09a3 | 364 | |
5800043b | 365 | if (has_setpolicy) { |
1da177e4 LT |
366 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
367 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 368 | err = 0; |
e08f5f5b GS |
369 | } else if (!strnicmp(str_governor, "powersave", |
370 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 371 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 372 | err = 0; |
1da177e4 | 373 | } |
5800043b | 374 | } else if (has_target) { |
1da177e4 | 375 | struct cpufreq_governor *t; |
3bcb09a3 | 376 | |
3fc54d37 | 377 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
378 | |
379 | t = __find_governor(str_governor); | |
380 | ||
ea714970 | 381 | if (t == NULL) { |
1a8e1463 | 382 | int ret; |
ea714970 | 383 | |
1a8e1463 KC |
384 | mutex_unlock(&cpufreq_governor_mutex); |
385 | ret = request_module("cpufreq_%s", str_governor); | |
386 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 387 | |
1a8e1463 KC |
388 | if (ret == 0) |
389 | t = __find_governor(str_governor); | |
ea714970 JF |
390 | } |
391 | ||
3bcb09a3 JF |
392 | if (t != NULL) { |
393 | *governor = t; | |
394 | err = 0; | |
1da177e4 | 395 | } |
3bcb09a3 | 396 | |
3fc54d37 | 397 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 398 | } |
29464f28 | 399 | out: |
3bcb09a3 | 400 | return err; |
1da177e4 | 401 | } |
1da177e4 LT |
402 | |
403 | ||
1da177e4 | 404 | /** |
e08f5f5b GS |
405 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
406 | * print out cpufreq information | |
1da177e4 LT |
407 | * |
408 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
409 | * "unsigned int". | |
410 | */ | |
411 | ||
32ee8c3e DJ |
412 | #define show_one(file_name, object) \ |
413 | static ssize_t show_##file_name \ | |
905d77cd | 414 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 415 | { \ |
29464f28 | 416 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
417 | } |
418 | ||
419 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
420 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 421 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
422 | show_one(scaling_min_freq, min); |
423 | show_one(scaling_max_freq, max); | |
424 | show_one(scaling_cur_freq, cur); | |
425 | ||
e08f5f5b GS |
426 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
427 | struct cpufreq_policy *policy); | |
7970e08b | 428 | |
1da177e4 LT |
429 | /** |
430 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
431 | */ | |
432 | #define store_one(file_name, object) \ | |
433 | static ssize_t store_##file_name \ | |
905d77cd | 434 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 435 | { \ |
f55c9c26 | 436 | unsigned int ret; \ |
1da177e4 LT |
437 | struct cpufreq_policy new_policy; \ |
438 | \ | |
439 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
440 | if (ret) \ | |
441 | return -EINVAL; \ | |
442 | \ | |
29464f28 | 443 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
444 | if (ret != 1) \ |
445 | return -EINVAL; \ | |
446 | \ | |
7970e08b TR |
447 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
448 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
449 | \ |
450 | return ret ? ret : count; \ | |
451 | } | |
452 | ||
29464f28 DJ |
453 | store_one(scaling_min_freq, min); |
454 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
455 | |
456 | /** | |
457 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
458 | */ | |
905d77cd DJ |
459 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
460 | char *buf) | |
1da177e4 | 461 | { |
5a01f2e8 | 462 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
463 | if (!cur_freq) |
464 | return sprintf(buf, "<unknown>"); | |
465 | return sprintf(buf, "%u\n", cur_freq); | |
466 | } | |
467 | ||
468 | ||
469 | /** | |
470 | * show_scaling_governor - show the current policy for the specified CPU | |
471 | */ | |
905d77cd | 472 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 473 | { |
29464f28 | 474 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
475 | return sprintf(buf, "powersave\n"); |
476 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
477 | return sprintf(buf, "performance\n"); | |
478 | else if (policy->governor) | |
4b972f0b | 479 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 480 | policy->governor->name); |
1da177e4 LT |
481 | return -EINVAL; |
482 | } | |
483 | ||
484 | ||
485 | /** | |
486 | * store_scaling_governor - store policy for the specified CPU | |
487 | */ | |
905d77cd DJ |
488 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
489 | const char *buf, size_t count) | |
1da177e4 | 490 | { |
f55c9c26 | 491 | unsigned int ret; |
1da177e4 LT |
492 | char str_governor[16]; |
493 | struct cpufreq_policy new_policy; | |
494 | ||
495 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
496 | if (ret) | |
497 | return ret; | |
498 | ||
29464f28 | 499 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
500 | if (ret != 1) |
501 | return -EINVAL; | |
502 | ||
e08f5f5b GS |
503 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
504 | &new_policy.governor)) | |
1da177e4 LT |
505 | return -EINVAL; |
506 | ||
7970e08b TR |
507 | /* Do not use cpufreq_set_policy here or the user_policy.max |
508 | will be wrongly overridden */ | |
7970e08b TR |
509 | ret = __cpufreq_set_policy(policy, &new_policy); |
510 | ||
511 | policy->user_policy.policy = policy->policy; | |
512 | policy->user_policy.governor = policy->governor; | |
7970e08b | 513 | |
e08f5f5b GS |
514 | if (ret) |
515 | return ret; | |
516 | else | |
517 | return count; | |
1da177e4 LT |
518 | } |
519 | ||
520 | /** | |
521 | * show_scaling_driver - show the cpufreq driver currently loaded | |
522 | */ | |
905d77cd | 523 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 524 | { |
5800043b NZ |
525 | ssize_t size; |
526 | rcu_read_lock(); | |
527 | size = scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", | |
528 | rcu_dereference(cpufreq_driver)->name); | |
529 | rcu_read_unlock(); | |
530 | return size; | |
1da177e4 LT |
531 | } |
532 | ||
533 | /** | |
534 | * show_scaling_available_governors - show the available CPUfreq governors | |
535 | */ | |
905d77cd DJ |
536 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
537 | char *buf) | |
1da177e4 LT |
538 | { |
539 | ssize_t i = 0; | |
540 | struct cpufreq_governor *t; | |
541 | ||
5800043b NZ |
542 | rcu_read_lock(); |
543 | if (!rcu_dereference(cpufreq_driver)->target) { | |
544 | rcu_read_unlock(); | |
1da177e4 LT |
545 | i += sprintf(buf, "performance powersave"); |
546 | goto out; | |
547 | } | |
5800043b | 548 | rcu_read_unlock(); |
1da177e4 LT |
549 | |
550 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
551 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
552 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 553 | goto out; |
4b972f0b | 554 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 555 | } |
7d5e350f | 556 | out: |
1da177e4 LT |
557 | i += sprintf(&buf[i], "\n"); |
558 | return i; | |
559 | } | |
e8628dd0 | 560 | |
835481d9 | 561 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
562 | { |
563 | ssize_t i = 0; | |
564 | unsigned int cpu; | |
565 | ||
835481d9 | 566 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
567 | if (i) |
568 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
569 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
570 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 571 | break; |
1da177e4 LT |
572 | } |
573 | i += sprintf(&buf[i], "\n"); | |
574 | return i; | |
575 | } | |
576 | ||
e8628dd0 DW |
577 | /** |
578 | * show_related_cpus - show the CPUs affected by each transition even if | |
579 | * hw coordination is in use | |
580 | */ | |
581 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
582 | { | |
e8628dd0 DW |
583 | return show_cpus(policy->related_cpus, buf); |
584 | } | |
585 | ||
586 | /** | |
587 | * show_affected_cpus - show the CPUs affected by each transition | |
588 | */ | |
589 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
590 | { | |
591 | return show_cpus(policy->cpus, buf); | |
592 | } | |
593 | ||
9e76988e | 594 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 595 | const char *buf, size_t count) |
9e76988e VP |
596 | { |
597 | unsigned int freq = 0; | |
598 | unsigned int ret; | |
599 | ||
879000f9 | 600 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
601 | return -EINVAL; |
602 | ||
603 | ret = sscanf(buf, "%u", &freq); | |
604 | if (ret != 1) | |
605 | return -EINVAL; | |
606 | ||
607 | policy->governor->store_setspeed(policy, freq); | |
608 | ||
609 | return count; | |
610 | } | |
611 | ||
612 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
613 | { | |
879000f9 | 614 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
615 | return sprintf(buf, "<unsupported>\n"); |
616 | ||
617 | return policy->governor->show_setspeed(policy, buf); | |
618 | } | |
1da177e4 | 619 | |
e2f74f35 | 620 | /** |
8bf1ac72 | 621 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
622 | */ |
623 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
624 | { | |
625 | unsigned int limit; | |
5800043b | 626 | int (*bios_limit)(int cpu, unsigned int *limit); |
e2f74f35 | 627 | int ret; |
5800043b NZ |
628 | |
629 | rcu_read_lock(); | |
630 | bios_limit = rcu_dereference(cpufreq_driver)->bios_limit; | |
631 | rcu_read_unlock(); | |
632 | ||
633 | if (bios_limit) { | |
634 | ret = bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
635 | if (!ret) |
636 | return sprintf(buf, "%u\n", limit); | |
637 | } | |
638 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
639 | } | |
640 | ||
6dad2a29 BP |
641 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
642 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
643 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
644 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
645 | cpufreq_freq_attr_ro(scaling_available_governors); | |
646 | cpufreq_freq_attr_ro(scaling_driver); | |
647 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
648 | cpufreq_freq_attr_ro(bios_limit); | |
649 | cpufreq_freq_attr_ro(related_cpus); | |
650 | cpufreq_freq_attr_ro(affected_cpus); | |
651 | cpufreq_freq_attr_rw(scaling_min_freq); | |
652 | cpufreq_freq_attr_rw(scaling_max_freq); | |
653 | cpufreq_freq_attr_rw(scaling_governor); | |
654 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 655 | |
905d77cd | 656 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
657 | &cpuinfo_min_freq.attr, |
658 | &cpuinfo_max_freq.attr, | |
ed129784 | 659 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
660 | &scaling_min_freq.attr, |
661 | &scaling_max_freq.attr, | |
662 | &affected_cpus.attr, | |
e8628dd0 | 663 | &related_cpus.attr, |
1da177e4 LT |
664 | &scaling_governor.attr, |
665 | &scaling_driver.attr, | |
666 | &scaling_available_governors.attr, | |
9e76988e | 667 | &scaling_setspeed.attr, |
1da177e4 LT |
668 | NULL |
669 | }; | |
670 | ||
8aa84ad8 TR |
671 | struct kobject *cpufreq_global_kobject; |
672 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
673 | ||
29464f28 DJ |
674 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
675 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 676 | |
29464f28 | 677 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 678 | { |
905d77cd DJ |
679 | struct cpufreq_policy *policy = to_policy(kobj); |
680 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 681 | ssize_t ret = -EINVAL; |
a9144436 | 682 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 683 | if (!policy) |
0db4a8a9 | 684 | goto no_policy; |
5a01f2e8 VP |
685 | |
686 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 687 | goto fail; |
5a01f2e8 | 688 | |
e08f5f5b GS |
689 | if (fattr->show) |
690 | ret = fattr->show(policy, buf); | |
691 | else | |
692 | ret = -EIO; | |
693 | ||
5a01f2e8 | 694 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 695 | fail: |
a9144436 | 696 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 697 | no_policy: |
1da177e4 LT |
698 | return ret; |
699 | } | |
700 | ||
905d77cd DJ |
701 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
702 | const char *buf, size_t count) | |
1da177e4 | 703 | { |
905d77cd DJ |
704 | struct cpufreq_policy *policy = to_policy(kobj); |
705 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 706 | ssize_t ret = -EINVAL; |
a9144436 | 707 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 708 | if (!policy) |
a07530b4 | 709 | goto no_policy; |
5a01f2e8 VP |
710 | |
711 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 712 | goto fail; |
5a01f2e8 | 713 | |
e08f5f5b GS |
714 | if (fattr->store) |
715 | ret = fattr->store(policy, buf, count); | |
716 | else | |
717 | ret = -EIO; | |
718 | ||
5a01f2e8 | 719 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 720 | fail: |
a9144436 | 721 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 722 | no_policy: |
1da177e4 LT |
723 | return ret; |
724 | } | |
725 | ||
905d77cd | 726 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 727 | { |
905d77cd | 728 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 729 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
730 | complete(&policy->kobj_unregister); |
731 | } | |
732 | ||
52cf25d0 | 733 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
734 | .show = show, |
735 | .store = store, | |
736 | }; | |
737 | ||
738 | static struct kobj_type ktype_cpufreq = { | |
739 | .sysfs_ops = &sysfs_ops, | |
740 | .default_attrs = default_attrs, | |
741 | .release = cpufreq_sysfs_release, | |
742 | }; | |
743 | ||
19d6f7ec | 744 | /* symlink affected CPUs */ |
cf3289d0 AC |
745 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
746 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
747 | { |
748 | unsigned int j; | |
749 | int ret = 0; | |
750 | ||
751 | for_each_cpu(j, policy->cpus) { | |
752 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 753 | struct device *cpu_dev; |
19d6f7ec DJ |
754 | |
755 | if (j == cpu) | |
756 | continue; | |
19d6f7ec | 757 | |
2d06d8c4 | 758 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 759 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
760 | cpu_dev = get_cpu_device(j); |
761 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
762 | "cpufreq"); |
763 | if (ret) { | |
764 | cpufreq_cpu_put(managed_policy); | |
765 | return ret; | |
766 | } | |
767 | } | |
768 | return ret; | |
769 | } | |
770 | ||
cf3289d0 AC |
771 | static int cpufreq_add_dev_interface(unsigned int cpu, |
772 | struct cpufreq_policy *policy, | |
8a25a2fd | 773 | struct device *dev) |
909a694e | 774 | { |
ecf7e461 | 775 | struct cpufreq_policy new_policy; |
909a694e | 776 | struct freq_attr **drv_attr; |
5800043b | 777 | struct cpufreq_driver *driver; |
909a694e DJ |
778 | unsigned long flags; |
779 | int ret = 0; | |
780 | unsigned int j; | |
781 | ||
782 | /* prepare interface data */ | |
783 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 784 | &dev->kobj, "cpufreq"); |
909a694e DJ |
785 | if (ret) |
786 | return ret; | |
787 | ||
788 | /* set up files for this cpu device */ | |
5800043b NZ |
789 | rcu_read_lock(); |
790 | driver = rcu_dereference(cpufreq_driver); | |
791 | drv_attr = driver->attr; | |
909a694e DJ |
792 | while ((drv_attr) && (*drv_attr)) { |
793 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
794 | if (ret) | |
5800043b | 795 | goto err_out_unlock; |
909a694e DJ |
796 | drv_attr++; |
797 | } | |
5800043b | 798 | if (driver->get) { |
909a694e DJ |
799 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
800 | if (ret) | |
5800043b | 801 | goto err_out_unlock; |
909a694e | 802 | } |
5800043b | 803 | if (driver->target) { |
909a694e DJ |
804 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
805 | if (ret) | |
5800043b | 806 | goto err_out_unlock; |
909a694e | 807 | } |
5800043b | 808 | if (driver->bios_limit) { |
e2f74f35 TR |
809 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
810 | if (ret) | |
5800043b | 811 | goto err_out_unlock; |
e2f74f35 | 812 | } |
5800043b | 813 | rcu_read_unlock(); |
909a694e | 814 | |
0d1857a1 | 815 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
909a694e | 816 | for_each_cpu(j, policy->cpus) { |
909a694e | 817 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 818 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e | 819 | } |
0d1857a1 | 820 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
909a694e DJ |
821 | |
822 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
823 | if (ret) |
824 | goto err_out_kobj_put; | |
825 | ||
826 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
827 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
828 | policy->governor = NULL; | |
829 | ||
830 | /* set default policy */ | |
831 | ret = __cpufreq_set_policy(policy, &new_policy); | |
832 | policy->user_policy.policy = policy->policy; | |
833 | policy->user_policy.governor = policy->governor; | |
834 | ||
835 | if (ret) { | |
5800043b NZ |
836 | int (*exit)(struct cpufreq_policy *policy); |
837 | ||
2d06d8c4 | 838 | pr_debug("setting policy failed\n"); |
5800043b NZ |
839 | rcu_read_lock(); |
840 | exit = rcu_dereference(cpufreq_driver)->exit; | |
841 | rcu_read_unlock(); | |
842 | if (exit) | |
843 | exit(policy); | |
844 | ||
ecf7e461 | 845 | } |
909a694e DJ |
846 | return ret; |
847 | ||
5800043b NZ |
848 | err_out_unlock: |
849 | rcu_read_unlock(); | |
909a694e DJ |
850 | err_out_kobj_put: |
851 | kobject_put(&policy->kobj); | |
852 | wait_for_completion(&policy->kobj_unregister); | |
853 | return ret; | |
854 | } | |
855 | ||
fcf80582 VK |
856 | #ifdef CONFIG_HOTPLUG_CPU |
857 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
858 | struct device *dev) | |
859 | { | |
860 | struct cpufreq_policy *policy; | |
820c6ca2 | 861 | int ret = 0, has_target = 0; |
fcf80582 VK |
862 | unsigned long flags; |
863 | ||
864 | policy = cpufreq_cpu_get(sibling); | |
865 | WARN_ON(!policy); | |
866 | ||
820c6ca2 VK |
867 | rcu_read_lock(); |
868 | has_target = !!rcu_dereference(cpufreq_driver)->target; | |
869 | rcu_read_unlock(); | |
870 | ||
871 | if (has_target) | |
872 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
fcf80582 | 873 | |
2eaa3e2d VK |
874 | lock_policy_rwsem_write(sibling); |
875 | ||
0d1857a1 | 876 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 877 | |
fcf80582 | 878 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 879 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
fcf80582 | 880 | per_cpu(cpufreq_cpu_data, cpu) = policy; |
0d1857a1 | 881 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 882 | |
2eaa3e2d VK |
883 | unlock_policy_rwsem_write(sibling); |
884 | ||
820c6ca2 VK |
885 | if (has_target) { |
886 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
887 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
888 | } | |
fcf80582 | 889 | |
fcf80582 VK |
890 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
891 | if (ret) { | |
892 | cpufreq_cpu_put(policy); | |
893 | return ret; | |
894 | } | |
895 | ||
896 | return 0; | |
897 | } | |
898 | #endif | |
1da177e4 LT |
899 | |
900 | /** | |
901 | * cpufreq_add_dev - add a CPU device | |
902 | * | |
32ee8c3e | 903 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
904 | * |
905 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
906 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
907 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 908 | */ |
8a25a2fd | 909 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 910 | { |
fcf80582 | 911 | unsigned int j, cpu = dev->id; |
65922465 | 912 | int ret = -ENOMEM; |
1da177e4 | 913 | struct cpufreq_policy *policy; |
5800043b NZ |
914 | struct cpufreq_driver *driver; |
915 | int (*init)(struct cpufreq_policy *policy); | |
1da177e4 | 916 | unsigned long flags; |
90e41bac | 917 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 918 | struct cpufreq_governor *gov; |
90e41bac PB |
919 | int sibling; |
920 | #endif | |
1da177e4 | 921 | |
c32b6b8e AR |
922 | if (cpu_is_offline(cpu)) |
923 | return 0; | |
924 | ||
2d06d8c4 | 925 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
926 | |
927 | #ifdef CONFIG_SMP | |
928 | /* check whether a different CPU already registered this | |
929 | * CPU because it is in the same boat. */ | |
930 | policy = cpufreq_cpu_get(cpu); | |
931 | if (unlikely(policy)) { | |
8ff69732 | 932 | cpufreq_cpu_put(policy); |
1da177e4 LT |
933 | return 0; |
934 | } | |
fcf80582 VK |
935 | |
936 | #ifdef CONFIG_HOTPLUG_CPU | |
937 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 938 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
939 | for_each_online_cpu(sibling) { |
940 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d | 941 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
0d1857a1 | 942 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 943 | return cpufreq_add_policy_cpu(cpu, sibling, dev); |
2eaa3e2d | 944 | } |
fcf80582 | 945 | } |
0d1857a1 | 946 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 947 | #endif |
1da177e4 LT |
948 | #endif |
949 | ||
5800043b NZ |
950 | rcu_read_lock(); |
951 | driver = rcu_dereference(cpufreq_driver); | |
952 | if (!try_module_get(driver->owner)) { | |
953 | rcu_read_unlock(); | |
1da177e4 LT |
954 | ret = -EINVAL; |
955 | goto module_out; | |
956 | } | |
5800043b NZ |
957 | init = driver->init; |
958 | rcu_read_unlock(); | |
1da177e4 | 959 | |
e98df50c | 960 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 961 | if (!policy) |
1da177e4 | 962 | goto nomem_out; |
059019a3 DJ |
963 | |
964 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 965 | goto err_free_policy; |
059019a3 DJ |
966 | |
967 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 968 | goto err_free_cpumask; |
1da177e4 LT |
969 | |
970 | policy->cpu = cpu; | |
65922465 | 971 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 972 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 973 | |
5a01f2e8 | 974 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 975 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 976 | |
1da177e4 | 977 | init_completion(&policy->kobj_unregister); |
65f27f38 | 978 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
979 | |
980 | /* call driver. From then on the cpufreq must be able | |
981 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
982 | */ | |
5800043b | 983 | ret = init(policy); |
1da177e4 | 984 | if (ret) { |
2d06d8c4 | 985 | pr_debug("initialization failed\n"); |
2eaa3e2d | 986 | goto err_set_policy_cpu; |
1da177e4 | 987 | } |
643ae6e8 | 988 | |
fcf80582 VK |
989 | /* related cpus should atleast have policy->cpus */ |
990 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
991 | ||
643ae6e8 VK |
992 | /* |
993 | * affected cpus must always be the one, which are online. We aren't | |
994 | * managing offline cpus here. | |
995 | */ | |
996 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
997 | ||
187d9f4e MC |
998 | policy->user_policy.min = policy->min; |
999 | policy->user_policy.max = policy->max; | |
1da177e4 | 1000 | |
a1531acd TR |
1001 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1002 | CPUFREQ_START, policy); | |
1003 | ||
fcf80582 VK |
1004 | #ifdef CONFIG_HOTPLUG_CPU |
1005 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1006 | if (gov) { | |
1007 | policy->governor = gov; | |
1008 | pr_debug("Restoring governor %s for cpu %d\n", | |
1009 | policy->governor->name, cpu); | |
4bfa042c | 1010 | } |
fcf80582 | 1011 | #endif |
1da177e4 | 1012 | |
8a25a2fd | 1013 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
1014 | if (ret) |
1015 | goto err_out_unregister; | |
8ff69732 | 1016 | |
038c5b3e | 1017 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
5800043b NZ |
1018 | rcu_read_lock(); |
1019 | module_put(rcu_dereference(cpufreq_driver)->owner); | |
1020 | rcu_read_unlock(); | |
2d06d8c4 | 1021 | pr_debug("initialization complete\n"); |
87c32271 | 1022 | |
1da177e4 LT |
1023 | return 0; |
1024 | ||
1da177e4 | 1025 | err_out_unregister: |
0d1857a1 | 1026 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
835481d9 | 1027 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1028 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1029 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1030 | |
c10997f6 | 1031 | kobject_put(&policy->kobj); |
1da177e4 LT |
1032 | wait_for_completion(&policy->kobj_unregister); |
1033 | ||
2eaa3e2d VK |
1034 | err_set_policy_cpu: |
1035 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
cad70a6a | 1036 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
1037 | err_free_cpumask: |
1038 | free_cpumask_var(policy->cpus); | |
1039 | err_free_policy: | |
1da177e4 | 1040 | kfree(policy); |
1da177e4 | 1041 | nomem_out: |
5800043b NZ |
1042 | rcu_read_lock(); |
1043 | module_put(rcu_dereference(cpufreq_driver)->owner); | |
1044 | rcu_read_unlock(); | |
c32b6b8e | 1045 | module_out: |
1da177e4 LT |
1046 | return ret; |
1047 | } | |
1048 | ||
b8eed8af VK |
1049 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1050 | { | |
1051 | int j; | |
1052 | ||
1053 | policy->last_cpu = policy->cpu; | |
1054 | policy->cpu = cpu; | |
1055 | ||
3361b7b1 | 1056 | for_each_cpu(j, policy->cpus) |
b8eed8af | 1057 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
1058 | |
1059 | #ifdef CONFIG_CPU_FREQ_TABLE | |
1060 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1061 | #endif | |
1062 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1063 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1064 | } | |
1da177e4 LT |
1065 | |
1066 | /** | |
5a01f2e8 | 1067 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1068 | * |
1069 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1070 | * Caller should already have policy_rwsem in write mode for this CPU. |
1071 | * This routine frees the rwsem before returning. | |
1da177e4 | 1072 | */ |
8a25a2fd | 1073 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1074 | { |
b8eed8af | 1075 | unsigned int cpu = dev->id, ret, cpus; |
1da177e4 LT |
1076 | unsigned long flags; |
1077 | struct cpufreq_policy *data; | |
5800043b | 1078 | struct cpufreq_driver *driver; |
499bca9b AW |
1079 | struct kobject *kobj; |
1080 | struct completion *cmp; | |
8a25a2fd | 1081 | struct device *cpu_dev; |
5800043b NZ |
1082 | bool has_target; |
1083 | int (*exit)(struct cpufreq_policy *policy); | |
1da177e4 | 1084 | |
b8eed8af | 1085 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1086 | |
0d1857a1 | 1087 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1088 | |
7a6aedfa | 1089 | data = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1090 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1091 | ||
0d1857a1 | 1092 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1093 | |
1094 | if (!data) { | |
b8eed8af | 1095 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1096 | return -EINVAL; |
1097 | } | |
1da177e4 | 1098 | |
5800043b NZ |
1099 | rcu_read_lock(); |
1100 | driver = rcu_dereference(cpufreq_driver); | |
1101 | has_target = driver->target ? true : false; | |
1102 | exit = driver->exit; | |
1103 | if (has_target) | |
f6a7409c | 1104 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1da177e4 | 1105 | |
084f3493 | 1106 | #ifdef CONFIG_HOTPLUG_CPU |
5800043b | 1107 | if (!driver->setpolicy) |
fa69e33f DB |
1108 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
1109 | data->governor->name, CPUFREQ_NAME_LEN); | |
1da177e4 | 1110 | #endif |
5800043b | 1111 | rcu_read_unlock(); |
1da177e4 | 1112 | |
2eaa3e2d | 1113 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1114 | cpus = cpumask_weight(data->cpus); |
e4969eba VK |
1115 | |
1116 | if (cpus > 1) | |
1117 | cpumask_clear_cpu(cpu, data->cpus); | |
2eaa3e2d | 1118 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1119 | |
73bf0fc2 VK |
1120 | if (cpu != data->cpu) { |
1121 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
1122 | } else if (cpus > 1) { | |
b8eed8af VK |
1123 | /* first sibling now owns the new sysfs dir */ |
1124 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1125 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1126 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1127 | if (ret) { | |
1128 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
084f3493 | 1129 | |
2eaa3e2d | 1130 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1131 | cpumask_set_cpu(cpu, data->cpus); |
1da177e4 | 1132 | |
0d1857a1 | 1133 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1134 | per_cpu(cpufreq_cpu_data, cpu) = data; |
0d1857a1 | 1135 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1136 | |
499bca9b | 1137 | unlock_policy_rwsem_write(cpu); |
1da177e4 | 1138 | |
2eaa3e2d VK |
1139 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, |
1140 | "cpufreq"); | |
b8eed8af | 1141 | return -EINVAL; |
1da177e4 | 1142 | } |
5a01f2e8 | 1143 | |
2eaa3e2d | 1144 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1145 | update_policy_cpu(data, cpu_dev->id); |
2eaa3e2d | 1146 | unlock_policy_rwsem_write(cpu); |
b8eed8af VK |
1147 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1148 | __func__, cpu_dev->id, cpu); | |
1da177e4 | 1149 | } |
1da177e4 | 1150 | |
b8eed8af VK |
1151 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); |
1152 | cpufreq_cpu_put(data); | |
1da177e4 | 1153 | |
b8eed8af VK |
1154 | /* If cpu is last user of policy, free policy */ |
1155 | if (cpus == 1) { | |
820c6ca2 VK |
1156 | if (has_target) |
1157 | __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); | |
7bd353a9 | 1158 | |
2eaa3e2d | 1159 | lock_policy_rwsem_read(cpu); |
b8eed8af VK |
1160 | kobj = &data->kobj; |
1161 | cmp = &data->kobj_unregister; | |
2eaa3e2d | 1162 | unlock_policy_rwsem_read(cpu); |
b8eed8af | 1163 | kobject_put(kobj); |
7d26e2d5 | 1164 | |
b8eed8af VK |
1165 | /* we need to make sure that the underlying kobj is actually |
1166 | * not referenced anymore by anybody before we proceed with | |
1167 | * unloading. | |
1168 | */ | |
1169 | pr_debug("waiting for dropping of refcount\n"); | |
1170 | wait_for_completion(cmp); | |
1171 | pr_debug("wait complete\n"); | |
7d26e2d5 | 1172 | |
5800043b NZ |
1173 | if (exit) |
1174 | exit(data); | |
27ecddc2 | 1175 | |
b8eed8af VK |
1176 | free_cpumask_var(data->related_cpus); |
1177 | free_cpumask_var(data->cpus); | |
1178 | kfree(data); | |
5800043b | 1179 | } else if (has_target) { |
b8eed8af VK |
1180 | __cpufreq_governor(data, CPUFREQ_GOV_START); |
1181 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
27ecddc2 | 1182 | } |
1da177e4 | 1183 | |
2eaa3e2d | 1184 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
1da177e4 LT |
1185 | return 0; |
1186 | } | |
1187 | ||
1188 | ||
8a25a2fd | 1189 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1190 | { |
8a25a2fd | 1191 | unsigned int cpu = dev->id; |
5a01f2e8 | 1192 | int retval; |
ec28297a VP |
1193 | |
1194 | if (cpu_is_offline(cpu)) | |
1195 | return 0; | |
1196 | ||
8a25a2fd | 1197 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1198 | return retval; |
1199 | } | |
1200 | ||
1201 | ||
65f27f38 | 1202 | static void handle_update(struct work_struct *work) |
1da177e4 | 1203 | { |
65f27f38 DH |
1204 | struct cpufreq_policy *policy = |
1205 | container_of(work, struct cpufreq_policy, update); | |
1206 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1207 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1208 | cpufreq_update_policy(cpu); |
1209 | } | |
1210 | ||
1211 | /** | |
1212 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1213 | * @cpu: cpu number | |
1214 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1215 | * @new_freq: CPU frequency the CPU actually runs at | |
1216 | * | |
29464f28 DJ |
1217 | * We adjust to current frequency first, and need to clean up later. |
1218 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1219 | */ |
e08f5f5b GS |
1220 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1221 | unsigned int new_freq) | |
1da177e4 | 1222 | { |
b43a7ffb | 1223 | struct cpufreq_policy *policy; |
1da177e4 | 1224 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1225 | unsigned long flags; |
1226 | ||
1da177e4 | 1227 | |
2d06d8c4 | 1228 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1229 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1230 | ||
1da177e4 LT |
1231 | freqs.old = old_freq; |
1232 | freqs.new = new_freq; | |
b43a7ffb VK |
1233 | |
1234 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1235 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1236 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1237 | ||
1238 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1239 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1240 | } |
1241 | ||
1242 | ||
32ee8c3e | 1243 | /** |
4ab70df4 | 1244 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1245 | * @cpu: CPU number |
1246 | * | |
1247 | * This is the last known freq, without actually getting it from the driver. | |
1248 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1249 | */ | |
1250 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1251 | { | |
9e21ba8b | 1252 | struct cpufreq_policy *policy; |
5800043b NZ |
1253 | struct cpufreq_driver *driver; |
1254 | unsigned int (*get)(unsigned int cpu); | |
e08f5f5b | 1255 | unsigned int ret_freq = 0; |
95235ca2 | 1256 | |
5800043b NZ |
1257 | rcu_read_lock(); |
1258 | driver = rcu_dereference(cpufreq_driver); | |
1259 | if (driver && driver->setpolicy && driver->get) { | |
1260 | get = driver->get; | |
1261 | rcu_read_unlock(); | |
1262 | return get(cpu); | |
1263 | } | |
1264 | rcu_read_unlock(); | |
9e21ba8b DB |
1265 | |
1266 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1267 | if (policy) { |
e08f5f5b | 1268 | ret_freq = policy->cur; |
95235ca2 VP |
1269 | cpufreq_cpu_put(policy); |
1270 | } | |
1271 | ||
4d34a67d | 1272 | return ret_freq; |
95235ca2 VP |
1273 | } |
1274 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1275 | ||
3d737108 JB |
1276 | /** |
1277 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1278 | * @cpu: CPU number | |
1279 | * | |
1280 | * Just return the max possible frequency for a given CPU. | |
1281 | */ | |
1282 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1283 | { | |
1284 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1285 | unsigned int ret_freq = 0; | |
1286 | ||
1287 | if (policy) { | |
1288 | ret_freq = policy->max; | |
1289 | cpufreq_cpu_put(policy); | |
1290 | } | |
1291 | ||
1292 | return ret_freq; | |
1293 | } | |
1294 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1295 | ||
95235ca2 | 1296 | |
5a01f2e8 | 1297 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1298 | { |
7a6aedfa | 1299 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
5800043b NZ |
1300 | struct cpufreq_driver *driver; |
1301 | unsigned int (*get)(unsigned int cpu); | |
e08f5f5b | 1302 | unsigned int ret_freq = 0; |
5800043b NZ |
1303 | u8 flags; |
1304 | ||
1da177e4 | 1305 | |
5800043b NZ |
1306 | rcu_read_lock(); |
1307 | driver = rcu_dereference(cpufreq_driver); | |
1308 | if (!driver->get) { | |
1309 | rcu_read_unlock(); | |
4d34a67d | 1310 | return ret_freq; |
5800043b NZ |
1311 | } |
1312 | flags = driver->flags; | |
1313 | get = driver->get; | |
1314 | rcu_read_unlock(); | |
1da177e4 | 1315 | |
5800043b | 1316 | ret_freq = get(cpu); |
1da177e4 | 1317 | |
e08f5f5b | 1318 | if (ret_freq && policy->cur && |
5800043b | 1319 | !(flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1320 | /* verify no discrepancy between actual and |
1321 | saved value exists */ | |
1322 | if (unlikely(ret_freq != policy->cur)) { | |
1323 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1324 | schedule_work(&policy->update); |
1325 | } | |
1326 | } | |
1327 | ||
4d34a67d | 1328 | return ret_freq; |
5a01f2e8 | 1329 | } |
1da177e4 | 1330 | |
5a01f2e8 VP |
1331 | /** |
1332 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1333 | * @cpu: CPU number | |
1334 | * | |
1335 | * Get the CPU current (static) CPU frequency | |
1336 | */ | |
1337 | unsigned int cpufreq_get(unsigned int cpu) | |
1338 | { | |
1339 | unsigned int ret_freq = 0; | |
1340 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1341 | ||
1342 | if (!policy) | |
1343 | goto out; | |
1344 | ||
1345 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1346 | goto out_policy; | |
1347 | ||
1348 | ret_freq = __cpufreq_get(cpu); | |
1349 | ||
1350 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1351 | |
5a01f2e8 VP |
1352 | out_policy: |
1353 | cpufreq_cpu_put(policy); | |
1354 | out: | |
4d34a67d | 1355 | return ret_freq; |
1da177e4 LT |
1356 | } |
1357 | EXPORT_SYMBOL(cpufreq_get); | |
1358 | ||
8a25a2fd KS |
1359 | static struct subsys_interface cpufreq_interface = { |
1360 | .name = "cpufreq", | |
1361 | .subsys = &cpu_subsys, | |
1362 | .add_dev = cpufreq_add_dev, | |
1363 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1364 | }; |
1365 | ||
1da177e4 | 1366 | |
42d4dc3f | 1367 | /** |
e00e56df RW |
1368 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1369 | * | |
1370 | * This function is only executed for the boot processor. The other CPUs | |
1371 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1372 | */ |
e00e56df | 1373 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1374 | { |
5800043b | 1375 | int (*suspend)(struct cpufreq_policy *policy); |
e08f5f5b | 1376 | int ret = 0; |
4bc5d341 | 1377 | |
e00e56df | 1378 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1379 | struct cpufreq_policy *cpu_policy; |
1380 | ||
2d06d8c4 | 1381 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1382 | |
e00e56df | 1383 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1384 | cpu_policy = cpufreq_cpu_get(cpu); |
1385 | if (!cpu_policy) | |
e00e56df | 1386 | return 0; |
42d4dc3f | 1387 | |
5800043b NZ |
1388 | rcu_read_lock(); |
1389 | suspend = rcu_dereference(cpufreq_driver)->suspend; | |
1390 | rcu_read_unlock(); | |
1391 | if (suspend) { | |
1392 | ret = suspend(cpu_policy); | |
ce6c3997 | 1393 | if (ret) |
42d4dc3f BH |
1394 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1395 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1396 | } |
1397 | ||
42d4dc3f | 1398 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1399 | return ret; |
42d4dc3f BH |
1400 | } |
1401 | ||
1da177e4 | 1402 | /** |
e00e56df | 1403 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1404 | * |
1405 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1406 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1407 | * restored. It will verify that the current freq is in sync with | |
1408 | * what we believe it to be. This is a bit later than when it | |
1409 | * should be, but nonethteless it's better than calling | |
1410 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1411 | * |
1412 | * This function is only executed for the boot CPU. The other CPUs have not | |
1413 | * been turned on yet. | |
1da177e4 | 1414 | */ |
e00e56df | 1415 | static void cpufreq_bp_resume(void) |
1da177e4 | 1416 | { |
e08f5f5b | 1417 | int ret = 0; |
5800043b | 1418 | int (*resume)(struct cpufreq_policy *policy); |
4bc5d341 | 1419 | |
e00e56df | 1420 | int cpu = smp_processor_id(); |
1da177e4 LT |
1421 | struct cpufreq_policy *cpu_policy; |
1422 | ||
2d06d8c4 | 1423 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1424 | |
e00e56df | 1425 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1426 | cpu_policy = cpufreq_cpu_get(cpu); |
1427 | if (!cpu_policy) | |
e00e56df | 1428 | return; |
1da177e4 | 1429 | |
5800043b NZ |
1430 | rcu_read_lock(); |
1431 | resume = rcu_dereference(cpufreq_driver)->resume; | |
1432 | rcu_read_unlock(); | |
1433 | ||
1434 | if (resume) { | |
1435 | ret = resume(cpu_policy); | |
1da177e4 LT |
1436 | if (ret) { |
1437 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1438 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1439 | goto fail; |
1da177e4 LT |
1440 | } |
1441 | } | |
1442 | ||
1da177e4 | 1443 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1444 | |
c9060494 | 1445 | fail: |
1da177e4 | 1446 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1447 | } |
1448 | ||
e00e56df RW |
1449 | static struct syscore_ops cpufreq_syscore_ops = { |
1450 | .suspend = cpufreq_bp_suspend, | |
1451 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1452 | }; |
1453 | ||
9d95046e BP |
1454 | /** |
1455 | * cpufreq_get_current_driver - return current driver's name | |
1456 | * | |
1457 | * Return the name string of the currently loaded cpufreq driver | |
1458 | * or NULL, if none. | |
1459 | */ | |
1460 | const char *cpufreq_get_current_driver(void) | |
1461 | { | |
5800043b NZ |
1462 | struct cpufreq_driver *driver; |
1463 | const char *name = NULL; | |
1464 | rcu_read_lock(); | |
1465 | driver = rcu_dereference(cpufreq_driver); | |
1466 | if (driver) | |
1467 | name = driver->name; | |
1468 | rcu_read_unlock(); | |
1469 | return name; | |
9d95046e BP |
1470 | } |
1471 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1472 | |
1473 | /********************************************************************* | |
1474 | * NOTIFIER LISTS INTERFACE * | |
1475 | *********************************************************************/ | |
1476 | ||
1477 | /** | |
1478 | * cpufreq_register_notifier - register a driver with cpufreq | |
1479 | * @nb: notifier function to register | |
1480 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1481 | * | |
32ee8c3e | 1482 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1483 | * are notified about clock rate changes (once before and once after |
1484 | * the transition), or a list of drivers that are notified about | |
1485 | * changes in cpufreq policy. | |
1486 | * | |
1487 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1488 | * blocking_notifier_chain_register. |
1da177e4 LT |
1489 | */ |
1490 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1491 | { | |
1492 | int ret; | |
1493 | ||
d5aaffa9 DB |
1494 | if (cpufreq_disabled()) |
1495 | return -EINVAL; | |
1496 | ||
74212ca4 CEB |
1497 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1498 | ||
1da177e4 LT |
1499 | switch (list) { |
1500 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1501 | ret = srcu_notifier_chain_register( |
e041c683 | 1502 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1503 | break; |
1504 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1505 | ret = blocking_notifier_chain_register( |
1506 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1507 | break; |
1508 | default: | |
1509 | ret = -EINVAL; | |
1510 | } | |
1da177e4 LT |
1511 | |
1512 | return ret; | |
1513 | } | |
1514 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1515 | ||
1516 | ||
1517 | /** | |
1518 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1519 | * @nb: notifier block to be unregistered | |
1520 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1521 | * | |
1522 | * Remove a driver from the CPU frequency notifier list. | |
1523 | * | |
1524 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1525 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1526 | */ |
1527 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1528 | { | |
1529 | int ret; | |
1530 | ||
d5aaffa9 DB |
1531 | if (cpufreq_disabled()) |
1532 | return -EINVAL; | |
1533 | ||
1da177e4 LT |
1534 | switch (list) { |
1535 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1536 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1537 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1538 | break; |
1539 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1540 | ret = blocking_notifier_chain_unregister( |
1541 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1542 | break; |
1543 | default: | |
1544 | ret = -EINVAL; | |
1545 | } | |
1da177e4 LT |
1546 | |
1547 | return ret; | |
1548 | } | |
1549 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1550 | ||
1551 | ||
1552 | /********************************************************************* | |
1553 | * GOVERNORS * | |
1554 | *********************************************************************/ | |
1555 | ||
1556 | ||
1557 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1558 | unsigned int target_freq, | |
1559 | unsigned int relation) | |
1560 | { | |
1561 | int retval = -EINVAL; | |
7249924e | 1562 | unsigned int old_target_freq = target_freq; |
5800043b NZ |
1563 | int (*target)(struct cpufreq_policy *policy, |
1564 | unsigned int target_freq, | |
1565 | unsigned int relation); | |
c32b6b8e | 1566 | |
a7b422cd KRW |
1567 | if (cpufreq_disabled()) |
1568 | return -ENODEV; | |
1569 | ||
7249924e VK |
1570 | /* Make sure that target_freq is within supported range */ |
1571 | if (target_freq > policy->max) | |
1572 | target_freq = policy->max; | |
1573 | if (target_freq < policy->min) | |
1574 | target_freq = policy->min; | |
1575 | ||
1576 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1577 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1578 | |
1579 | if (target_freq == policy->cur) | |
1580 | return 0; | |
1581 | ||
5800043b NZ |
1582 | rcu_read_lock(); |
1583 | target = rcu_dereference(cpufreq_driver)->target; | |
1584 | rcu_read_unlock(); | |
1585 | if (target) | |
1586 | retval = target(policy, target_freq, relation); | |
90d45d17 | 1587 | |
1da177e4 LT |
1588 | return retval; |
1589 | } | |
1590 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1591 | ||
1da177e4 LT |
1592 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1593 | unsigned int target_freq, | |
1594 | unsigned int relation) | |
1595 | { | |
f1829e4a | 1596 | int ret = -EINVAL; |
1da177e4 LT |
1597 | |
1598 | policy = cpufreq_cpu_get(policy->cpu); | |
1599 | if (!policy) | |
f1829e4a | 1600 | goto no_policy; |
1da177e4 | 1601 | |
5a01f2e8 | 1602 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1603 | goto fail; |
1da177e4 LT |
1604 | |
1605 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1606 | ||
5a01f2e8 | 1607 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1608 | |
f1829e4a | 1609 | fail: |
1da177e4 | 1610 | cpufreq_cpu_put(policy); |
f1829e4a | 1611 | no_policy: |
1da177e4 LT |
1612 | return ret; |
1613 | } | |
1614 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1615 | ||
bf0b90e3 | 1616 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1617 | { |
1618 | int ret = 0; | |
5800043b NZ |
1619 | unsigned int (*getavg)(struct cpufreq_policy *policy, |
1620 | unsigned int cpu); | |
dfde5d62 | 1621 | |
d5aaffa9 DB |
1622 | if (cpufreq_disabled()) |
1623 | return ret; | |
1624 | ||
5800043b NZ |
1625 | rcu_read_lock(); |
1626 | getavg = rcu_dereference(cpufreq_driver)->getavg; | |
1627 | rcu_read_unlock(); | |
1628 | ||
1629 | if (!getavg) | |
0676f7f2 VK |
1630 | return 0; |
1631 | ||
dfde5d62 VP |
1632 | policy = cpufreq_cpu_get(policy->cpu); |
1633 | if (!policy) | |
1634 | return -EINVAL; | |
1635 | ||
5800043b | 1636 | ret = getavg(policy, cpu); |
dfde5d62 | 1637 | |
dfde5d62 VP |
1638 | cpufreq_cpu_put(policy); |
1639 | return ret; | |
1640 | } | |
5a01f2e8 | 1641 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1642 | |
153d7f3f | 1643 | /* |
153d7f3f AV |
1644 | * when "event" is CPUFREQ_GOV_LIMITS |
1645 | */ | |
1da177e4 | 1646 | |
e08f5f5b GS |
1647 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1648 | unsigned int event) | |
1da177e4 | 1649 | { |
cc993cab | 1650 | int ret; |
6afde10c TR |
1651 | |
1652 | /* Only must be defined when default governor is known to have latency | |
1653 | restrictions, like e.g. conservative or ondemand. | |
1654 | That this is the case is already ensured in Kconfig | |
1655 | */ | |
1656 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1657 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1658 | #else | |
1659 | struct cpufreq_governor *gov = NULL; | |
1660 | #endif | |
1c256245 TR |
1661 | |
1662 | if (policy->governor->max_transition_latency && | |
1663 | policy->cpuinfo.transition_latency > | |
1664 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1665 | if (!gov) |
1666 | return -EINVAL; | |
1667 | else { | |
1668 | printk(KERN_WARNING "%s governor failed, too long" | |
1669 | " transition latency of HW, fallback" | |
1670 | " to %s governor\n", | |
1671 | policy->governor->name, | |
1672 | gov->name); | |
1673 | policy->governor = gov; | |
1674 | } | |
1c256245 | 1675 | } |
1da177e4 LT |
1676 | |
1677 | if (!try_module_get(policy->governor->owner)) | |
1678 | return -EINVAL; | |
1679 | ||
2d06d8c4 | 1680 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1681 | policy->cpu, event); |
1da177e4 LT |
1682 | ret = policy->governor->governor(policy, event); |
1683 | ||
4d5dcc42 VK |
1684 | if (!ret) { |
1685 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1686 | policy->governor->initialized++; | |
1687 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1688 | policy->governor->initialized--; | |
1689 | } | |
b394058f | 1690 | |
e08f5f5b GS |
1691 | /* we keep one module reference alive for |
1692 | each CPU governed by this CPU */ | |
1da177e4 LT |
1693 | if ((event != CPUFREQ_GOV_START) || ret) |
1694 | module_put(policy->governor->owner); | |
1695 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1696 | module_put(policy->governor->owner); | |
1697 | ||
1698 | return ret; | |
1699 | } | |
1700 | ||
1701 | ||
1da177e4 LT |
1702 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1703 | { | |
3bcb09a3 | 1704 | int err; |
1da177e4 LT |
1705 | |
1706 | if (!governor) | |
1707 | return -EINVAL; | |
1708 | ||
a7b422cd KRW |
1709 | if (cpufreq_disabled()) |
1710 | return -ENODEV; | |
1711 | ||
3fc54d37 | 1712 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1713 | |
b394058f | 1714 | governor->initialized = 0; |
3bcb09a3 JF |
1715 | err = -EBUSY; |
1716 | if (__find_governor(governor->name) == NULL) { | |
1717 | err = 0; | |
1718 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1719 | } |
1da177e4 | 1720 | |
32ee8c3e | 1721 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1722 | return err; |
1da177e4 LT |
1723 | } |
1724 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1725 | ||
1726 | ||
1727 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1728 | { | |
90e41bac PB |
1729 | #ifdef CONFIG_HOTPLUG_CPU |
1730 | int cpu; | |
1731 | #endif | |
1732 | ||
1da177e4 LT |
1733 | if (!governor) |
1734 | return; | |
1735 | ||
a7b422cd KRW |
1736 | if (cpufreq_disabled()) |
1737 | return; | |
1738 | ||
90e41bac PB |
1739 | #ifdef CONFIG_HOTPLUG_CPU |
1740 | for_each_present_cpu(cpu) { | |
1741 | if (cpu_online(cpu)) | |
1742 | continue; | |
1743 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1744 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1745 | } | |
1746 | #endif | |
1747 | ||
3fc54d37 | 1748 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1749 | list_del(&governor->governor_list); |
3fc54d37 | 1750 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1751 | return; |
1752 | } | |
1753 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1754 | ||
1755 | ||
1756 | ||
1757 | /********************************************************************* | |
1758 | * POLICY INTERFACE * | |
1759 | *********************************************************************/ | |
1760 | ||
1761 | /** | |
1762 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1763 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1764 | * is written | |
1da177e4 LT |
1765 | * |
1766 | * Reads the current cpufreq policy. | |
1767 | */ | |
1768 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1769 | { | |
1770 | struct cpufreq_policy *cpu_policy; | |
1771 | if (!policy) | |
1772 | return -EINVAL; | |
1773 | ||
1774 | cpu_policy = cpufreq_cpu_get(cpu); | |
1775 | if (!cpu_policy) | |
1776 | return -EINVAL; | |
1777 | ||
1da177e4 | 1778 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1779 | |
1780 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1781 | return 0; |
1782 | } | |
1783 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1784 | ||
1785 | ||
153d7f3f | 1786 | /* |
e08f5f5b GS |
1787 | * data : current policy. |
1788 | * policy : policy to be set. | |
153d7f3f | 1789 | */ |
e08f5f5b GS |
1790 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1791 | struct cpufreq_policy *policy) | |
1da177e4 | 1792 | { |
7bd353a9 | 1793 | int ret = 0, failed = 1; |
5800043b NZ |
1794 | struct cpufreq_driver *driver; |
1795 | int (*verify)(struct cpufreq_policy *policy); | |
1796 | int (*setpolicy)(struct cpufreq_policy *policy); | |
1da177e4 | 1797 | |
2d06d8c4 | 1798 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1799 | policy->min, policy->max); |
1800 | ||
e08f5f5b GS |
1801 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1802 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1803 | |
53391fa2 | 1804 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1805 | ret = -EINVAL; |
1806 | goto error_out; | |
1807 | } | |
1808 | ||
1da177e4 | 1809 | /* verify the cpu speed can be set within this limit */ |
5800043b NZ |
1810 | rcu_read_lock(); |
1811 | driver = rcu_dereference(cpufreq_driver); | |
1812 | verify = driver->verify; | |
1813 | setpolicy = driver->setpolicy; | |
1814 | rcu_read_unlock(); | |
1815 | ||
1816 | ret = verify(policy); | |
1da177e4 LT |
1817 | if (ret) |
1818 | goto error_out; | |
1819 | ||
1da177e4 | 1820 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1821 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1822 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1823 | |
1824 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1825 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1826 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1827 | |
1828 | /* verify the cpu speed can be set within this limit, | |
1829 | which might be different to the first one */ | |
5800043b | 1830 | ret = verify(policy); |
e041c683 | 1831 | if (ret) |
1da177e4 | 1832 | goto error_out; |
1da177e4 LT |
1833 | |
1834 | /* notification of the new policy */ | |
e041c683 AS |
1835 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1836 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1837 | |
7d5e350f DJ |
1838 | data->min = policy->min; |
1839 | data->max = policy->max; | |
1da177e4 | 1840 | |
2d06d8c4 | 1841 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1842 | data->min, data->max); |
1da177e4 | 1843 | |
5800043b | 1844 | if (setpolicy) { |
1da177e4 | 1845 | data->policy = policy->policy; |
2d06d8c4 | 1846 | pr_debug("setting range\n"); |
5800043b | 1847 | ret = setpolicy(policy); |
1da177e4 LT |
1848 | } else { |
1849 | if (policy->governor != data->governor) { | |
1850 | /* save old, working values */ | |
1851 | struct cpufreq_governor *old_gov = data->governor; | |
1852 | ||
2d06d8c4 | 1853 | pr_debug("governor switch\n"); |
1da177e4 LT |
1854 | |
1855 | /* end old governor */ | |
7bd353a9 | 1856 | if (data->governor) { |
1da177e4 | 1857 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
7bd353a9 VK |
1858 | __cpufreq_governor(data, |
1859 | CPUFREQ_GOV_POLICY_EXIT); | |
1860 | } | |
1da177e4 LT |
1861 | |
1862 | /* start new governor */ | |
1863 | data->governor = policy->governor; | |
7bd353a9 VK |
1864 | if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { |
1865 | if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) | |
1866 | failed = 0; | |
1867 | else | |
1868 | __cpufreq_governor(data, | |
1869 | CPUFREQ_GOV_POLICY_EXIT); | |
1870 | } | |
1871 | ||
1872 | if (failed) { | |
1da177e4 | 1873 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1874 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1875 | data->governor->name); |
1da177e4 LT |
1876 | if (old_gov) { |
1877 | data->governor = old_gov; | |
7bd353a9 VK |
1878 | __cpufreq_governor(data, |
1879 | CPUFREQ_GOV_POLICY_INIT); | |
e08f5f5b GS |
1880 | __cpufreq_governor(data, |
1881 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1882 | } |
1883 | ret = -EINVAL; | |
1884 | goto error_out; | |
1885 | } | |
1886 | /* might be a policy change, too, so fall through */ | |
1887 | } | |
2d06d8c4 | 1888 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1889 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1890 | } | |
1891 | ||
7d5e350f | 1892 | error_out: |
1da177e4 LT |
1893 | return ret; |
1894 | } | |
1895 | ||
1da177e4 LT |
1896 | /** |
1897 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1898 | * @cpu: CPU which shall be re-evaluated | |
1899 | * | |
25985edc | 1900 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1901 | * at different times. |
1902 | */ | |
1903 | int cpufreq_update_policy(unsigned int cpu) | |
1904 | { | |
1905 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1906 | struct cpufreq_policy policy; | |
5800043b NZ |
1907 | struct cpufreq_driver *driver; |
1908 | unsigned int (*get)(unsigned int cpu); | |
1909 | int (*target)(struct cpufreq_policy *policy, | |
1910 | unsigned int target_freq, | |
1911 | unsigned int relation); | |
f1829e4a | 1912 | int ret; |
1da177e4 | 1913 | |
f1829e4a JL |
1914 | if (!data) { |
1915 | ret = -ENODEV; | |
1916 | goto no_policy; | |
1917 | } | |
1da177e4 | 1918 | |
f1829e4a JL |
1919 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1920 | ret = -EINVAL; | |
1921 | goto fail; | |
1922 | } | |
1da177e4 | 1923 | |
2d06d8c4 | 1924 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1925 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1926 | policy.min = data->user_policy.min; |
1927 | policy.max = data->user_policy.max; | |
1928 | policy.policy = data->user_policy.policy; | |
1929 | policy.governor = data->user_policy.governor; | |
1930 | ||
0961dd0d TR |
1931 | /* BIOS might change freq behind our back |
1932 | -> ask driver for current freq and notify governors about a change */ | |
5800043b NZ |
1933 | rcu_read_lock(); |
1934 | driver = rcu_access_pointer(cpufreq_driver); | |
1935 | get = driver->get; | |
1936 | target = driver->target; | |
1937 | rcu_read_unlock(); | |
1938 | if (get) { | |
1939 | policy.cur = get(cpu); | |
a85f7bd3 | 1940 | if (!data->cur) { |
2d06d8c4 | 1941 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1942 | data->cur = policy.cur; |
1943 | } else { | |
5800043b | 1944 | if (data->cur != policy.cur && target) |
e08f5f5b GS |
1945 | cpufreq_out_of_sync(cpu, data->cur, |
1946 | policy.cur); | |
a85f7bd3 | 1947 | } |
0961dd0d TR |
1948 | } |
1949 | ||
1da177e4 LT |
1950 | ret = __cpufreq_set_policy(data, &policy); |
1951 | ||
5a01f2e8 VP |
1952 | unlock_policy_rwsem_write(cpu); |
1953 | ||
f1829e4a | 1954 | fail: |
1da177e4 | 1955 | cpufreq_cpu_put(data); |
f1829e4a | 1956 | no_policy: |
1da177e4 LT |
1957 | return ret; |
1958 | } | |
1959 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1960 | ||
dd184a01 | 1961 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1962 | unsigned long action, void *hcpu) |
1963 | { | |
1964 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1965 | struct device *dev; |
c32b6b8e | 1966 | |
8a25a2fd KS |
1967 | dev = get_cpu_device(cpu); |
1968 | if (dev) { | |
c32b6b8e AR |
1969 | switch (action) { |
1970 | case CPU_ONLINE: | |
8bb78442 | 1971 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1972 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1973 | break; |
1974 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1975 | case CPU_DOWN_PREPARE_FROZEN: |
8a25a2fd | 1976 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1977 | break; |
5a01f2e8 | 1978 | case CPU_DOWN_FAILED: |
8bb78442 | 1979 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1980 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1981 | break; |
1982 | } | |
1983 | } | |
1984 | return NOTIFY_OK; | |
1985 | } | |
1986 | ||
9c36f746 | 1987 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1988 | .notifier_call = cpufreq_cpu_callback, |
1989 | }; | |
1da177e4 LT |
1990 | |
1991 | /********************************************************************* | |
1992 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1993 | *********************************************************************/ | |
1994 | ||
1995 | /** | |
1996 | * cpufreq_register_driver - register a CPU Frequency driver | |
1997 | * @driver_data: A struct cpufreq_driver containing the values# | |
1998 | * submitted by the CPU Frequency driver. | |
1999 | * | |
32ee8c3e | 2000 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2001 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2002 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2003 | * |
2004 | */ | |
221dee28 | 2005 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2006 | { |
2007 | unsigned long flags; | |
2008 | int ret; | |
2009 | ||
a7b422cd KRW |
2010 | if (cpufreq_disabled()) |
2011 | return -ENODEV; | |
2012 | ||
1da177e4 LT |
2013 | if (!driver_data || !driver_data->verify || !driver_data->init || |
2014 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2015 | return -EINVAL; | |
2016 | ||
2d06d8c4 | 2017 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2018 | |
2019 | if (driver_data->setpolicy) | |
2020 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2021 | ||
0d1857a1 | 2022 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
5800043b | 2023 | if (rcu_access_pointer(cpufreq_driver)) { |
0d1857a1 | 2024 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2025 | return -EBUSY; |
2026 | } | |
5800043b | 2027 | rcu_assign_pointer(cpufreq_driver, driver_data); |
0d1857a1 | 2028 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5800043b | 2029 | synchronize_rcu(); |
1da177e4 | 2030 | |
8a25a2fd | 2031 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2032 | if (ret) |
2033 | goto err_null_driver; | |
1da177e4 | 2034 | |
5800043b | 2035 | if (!(driver_data->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2036 | int i; |
2037 | ret = -ENODEV; | |
2038 | ||
2039 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2040 | for (i = 0; i < nr_cpu_ids; i++) |
2041 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2042 | ret = 0; |
7a6aedfa MT |
2043 | break; |
2044 | } | |
1da177e4 LT |
2045 | |
2046 | /* if all ->init() calls failed, unregister */ | |
2047 | if (ret) { | |
2d06d8c4 | 2048 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2049 | driver_data->name); |
8a25a2fd | 2050 | goto err_if_unreg; |
1da177e4 LT |
2051 | } |
2052 | } | |
2053 | ||
8f5bc2ab | 2054 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2055 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2056 | |
8f5bc2ab | 2057 | return 0; |
8a25a2fd KS |
2058 | err_if_unreg: |
2059 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2060 | err_null_driver: |
0d1857a1 | 2061 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
5800043b | 2062 | rcu_assign_pointer(cpufreq_driver, NULL); |
0d1857a1 | 2063 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5800043b | 2064 | synchronize_rcu(); |
4d34a67d | 2065 | return ret; |
1da177e4 LT |
2066 | } |
2067 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2068 | ||
2069 | ||
2070 | /** | |
2071 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2072 | * | |
32ee8c3e | 2073 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2074 | * the right to do so, i.e. if you have succeeded in initialising before! |
2075 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2076 | * currently not initialised. | |
2077 | */ | |
221dee28 | 2078 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2079 | { |
2080 | unsigned long flags; | |
5800043b | 2081 | struct cpufreq_driver *old_driver; |
1da177e4 | 2082 | |
5800043b NZ |
2083 | rcu_read_lock(); |
2084 | old_driver = rcu_access_pointer(cpufreq_driver); | |
2085 | if (!old_driver || (driver != old_driver)) { | |
2086 | rcu_read_unlock(); | |
1da177e4 | 2087 | return -EINVAL; |
5800043b NZ |
2088 | } |
2089 | rcu_read_unlock(); | |
1da177e4 | 2090 | |
2d06d8c4 | 2091 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2092 | |
8a25a2fd | 2093 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2094 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2095 | |
0d1857a1 | 2096 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
5800043b | 2097 | rcu_assign_pointer(cpufreq_driver, NULL); |
0d1857a1 | 2098 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5800043b | 2099 | synchronize_rcu(); |
1da177e4 LT |
2100 | |
2101 | return 0; | |
2102 | } | |
2103 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2104 | |
2105 | static int __init cpufreq_core_init(void) | |
2106 | { | |
2107 | int cpu; | |
2108 | ||
a7b422cd KRW |
2109 | if (cpufreq_disabled()) |
2110 | return -ENODEV; | |
2111 | ||
5a01f2e8 | 2112 | for_each_possible_cpu(cpu) { |
f1625066 | 2113 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
2114 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
2115 | } | |
8aa84ad8 | 2116 | |
8a25a2fd | 2117 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 2118 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2119 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2120 | |
5a01f2e8 VP |
2121 | return 0; |
2122 | } | |
5a01f2e8 | 2123 | core_initcall(cpufreq_core_init); |