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Commit | Line | Data |
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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 | */ | |
7d5e350f | 42 | static struct cpufreq_driver *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 |
1da177e4 LT |
48 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
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 | |
a9144436 | 131 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
132 | { |
133 | struct cpufreq_policy *data; | |
134 | unsigned long flags; | |
135 | ||
7a6aedfa | 136 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
137 | goto err_out; |
138 | ||
139 | /* get the cpufreq driver */ | |
140 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
141 | ||
142 | if (!cpufreq_driver) | |
143 | goto err_out_unlock; | |
144 | ||
145 | if (!try_module_get(cpufreq_driver->owner)) | |
146 | goto err_out_unlock; | |
147 | ||
148 | ||
149 | /* get the CPU */ | |
7a6aedfa | 150 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
151 | |
152 | if (!data) | |
153 | goto err_out_put_module; | |
154 | ||
a9144436 | 155 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
156 | goto err_out_put_module; |
157 | ||
1da177e4 | 158 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
159 | return data; |
160 | ||
7d5e350f | 161 | err_out_put_module: |
1da177e4 | 162 | module_put(cpufreq_driver->owner); |
7d5e350f | 163 | err_out_unlock: |
1da177e4 | 164 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 165 | err_out: |
1da177e4 LT |
166 | return NULL; |
167 | } | |
a9144436 SB |
168 | |
169 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
170 | { | |
d5aaffa9 DB |
171 | if (cpufreq_disabled()) |
172 | return NULL; | |
173 | ||
a9144436 SB |
174 | return __cpufreq_cpu_get(cpu, false); |
175 | } | |
1da177e4 LT |
176 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
177 | ||
a9144436 SB |
178 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
179 | { | |
180 | return __cpufreq_cpu_get(cpu, true); | |
181 | } | |
182 | ||
183 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
184 | { | |
185 | if (!sysfs) | |
186 | kobject_put(&data->kobj); | |
187 | module_put(cpufreq_driver->owner); | |
188 | } | |
7d5e350f | 189 | |
1da177e4 LT |
190 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
191 | { | |
d5aaffa9 DB |
192 | if (cpufreq_disabled()) |
193 | return; | |
194 | ||
a9144436 | 195 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
196 | } |
197 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
198 | ||
a9144436 SB |
199 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
200 | { | |
201 | __cpufreq_cpu_put(data, true); | |
202 | } | |
1da177e4 | 203 | |
1da177e4 LT |
204 | /********************************************************************* |
205 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
206 | *********************************************************************/ | |
207 | ||
208 | /** | |
209 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
210 | * | |
211 | * This function alters the system "loops_per_jiffy" for the clock | |
212 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 213 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
214 | * per-CPU loops_per_jiffy value wherever possible. |
215 | */ | |
216 | #ifndef CONFIG_SMP | |
217 | static unsigned long l_p_j_ref; | |
218 | static unsigned int l_p_j_ref_freq; | |
219 | ||
858119e1 | 220 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
221 | { |
222 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
223 | return; | |
224 | ||
225 | if (!l_p_j_ref_freq) { | |
226 | l_p_j_ref = loops_per_jiffy; | |
227 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 228 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 229 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 230 | } |
d08de0c1 | 231 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 232 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
233 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
234 | ci->new); | |
2d06d8c4 | 235 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 236 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
237 | } |
238 | } | |
239 | #else | |
e08f5f5b GS |
240 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
241 | { | |
242 | return; | |
243 | } | |
1da177e4 LT |
244 | #endif |
245 | ||
246 | ||
247 | /** | |
e4472cb3 DJ |
248 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
249 | * on frequency transition. | |
1da177e4 | 250 | * |
e4472cb3 DJ |
251 | * This function calls the transition notifiers and the "adjust_jiffies" |
252 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 253 | * external effects. |
1da177e4 LT |
254 | */ |
255 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
256 | { | |
e4472cb3 | 257 | struct cpufreq_policy *policy; |
2eaa3e2d | 258 | unsigned long flags; |
e4472cb3 | 259 | |
1da177e4 LT |
260 | BUG_ON(irqs_disabled()); |
261 | ||
d5aaffa9 DB |
262 | if (cpufreq_disabled()) |
263 | return; | |
264 | ||
1da177e4 | 265 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 266 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 267 | state, freqs->new); |
1da177e4 | 268 | |
2eaa3e2d | 269 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
7a6aedfa | 270 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
2eaa3e2d VK |
271 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
272 | ||
1da177e4 | 273 | switch (state) { |
e4472cb3 | 274 | |
1da177e4 | 275 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 276 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
277 | * which is not equal to what the cpufreq core thinks is |
278 | * "old frequency". | |
1da177e4 LT |
279 | */ |
280 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
281 | if ((policy) && (policy->cpu == freqs->cpu) && |
282 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 283 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
284 | " %u, cpufreq assumed %u kHz.\n", |
285 | freqs->old, policy->cur); | |
286 | freqs->old = policy->cur; | |
1da177e4 LT |
287 | } |
288 | } | |
b4dfdbb3 | 289 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 290 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
291 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
292 | break; | |
e4472cb3 | 293 | |
1da177e4 LT |
294 | case CPUFREQ_POSTCHANGE: |
295 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 296 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 297 | (unsigned long)freqs->cpu); |
25e41933 | 298 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 299 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 300 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
301 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
302 | policy->cur = freqs->new; | |
1da177e4 LT |
303 | break; |
304 | } | |
1da177e4 LT |
305 | } |
306 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
307 | ||
308 | ||
309 | ||
310 | /********************************************************************* | |
311 | * SYSFS INTERFACE * | |
312 | *********************************************************************/ | |
313 | ||
3bcb09a3 JF |
314 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
315 | { | |
316 | struct cpufreq_governor *t; | |
317 | ||
318 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 319 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
320 | return t; |
321 | ||
322 | return NULL; | |
323 | } | |
324 | ||
1da177e4 LT |
325 | /** |
326 | * cpufreq_parse_governor - parse a governor string | |
327 | */ | |
905d77cd | 328 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
329 | struct cpufreq_governor **governor) |
330 | { | |
3bcb09a3 JF |
331 | int err = -EINVAL; |
332 | ||
1da177e4 | 333 | if (!cpufreq_driver) |
3bcb09a3 JF |
334 | goto out; |
335 | ||
1da177e4 LT |
336 | if (cpufreq_driver->setpolicy) { |
337 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
338 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 339 | err = 0; |
e08f5f5b GS |
340 | } else if (!strnicmp(str_governor, "powersave", |
341 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 342 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 343 | err = 0; |
1da177e4 | 344 | } |
3bcb09a3 | 345 | } else if (cpufreq_driver->target) { |
1da177e4 | 346 | struct cpufreq_governor *t; |
3bcb09a3 | 347 | |
3fc54d37 | 348 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
349 | |
350 | t = __find_governor(str_governor); | |
351 | ||
ea714970 | 352 | if (t == NULL) { |
1a8e1463 | 353 | int ret; |
ea714970 | 354 | |
1a8e1463 KC |
355 | mutex_unlock(&cpufreq_governor_mutex); |
356 | ret = request_module("cpufreq_%s", str_governor); | |
357 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 358 | |
1a8e1463 KC |
359 | if (ret == 0) |
360 | t = __find_governor(str_governor); | |
ea714970 JF |
361 | } |
362 | ||
3bcb09a3 JF |
363 | if (t != NULL) { |
364 | *governor = t; | |
365 | err = 0; | |
1da177e4 | 366 | } |
3bcb09a3 | 367 | |
3fc54d37 | 368 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 369 | } |
29464f28 | 370 | out: |
3bcb09a3 | 371 | return err; |
1da177e4 | 372 | } |
1da177e4 LT |
373 | |
374 | ||
1da177e4 | 375 | /** |
e08f5f5b GS |
376 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
377 | * print out cpufreq information | |
1da177e4 LT |
378 | * |
379 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
380 | * "unsigned int". | |
381 | */ | |
382 | ||
32ee8c3e DJ |
383 | #define show_one(file_name, object) \ |
384 | static ssize_t show_##file_name \ | |
905d77cd | 385 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 386 | { \ |
29464f28 | 387 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
388 | } |
389 | ||
390 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
391 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 392 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
393 | show_one(scaling_min_freq, min); |
394 | show_one(scaling_max_freq, max); | |
395 | show_one(scaling_cur_freq, cur); | |
396 | ||
e08f5f5b GS |
397 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
398 | struct cpufreq_policy *policy); | |
7970e08b | 399 | |
1da177e4 LT |
400 | /** |
401 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
402 | */ | |
403 | #define store_one(file_name, object) \ | |
404 | static ssize_t store_##file_name \ | |
905d77cd | 405 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 406 | { \ |
f55c9c26 | 407 | unsigned int ret; \ |
1da177e4 LT |
408 | struct cpufreq_policy new_policy; \ |
409 | \ | |
410 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
411 | if (ret) \ | |
412 | return -EINVAL; \ | |
413 | \ | |
29464f28 | 414 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
415 | if (ret != 1) \ |
416 | return -EINVAL; \ | |
417 | \ | |
7970e08b TR |
418 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
419 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
420 | \ |
421 | return ret ? ret : count; \ | |
422 | } | |
423 | ||
29464f28 DJ |
424 | store_one(scaling_min_freq, min); |
425 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
426 | |
427 | /** | |
428 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
429 | */ | |
905d77cd DJ |
430 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
431 | char *buf) | |
1da177e4 | 432 | { |
5a01f2e8 | 433 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
434 | if (!cur_freq) |
435 | return sprintf(buf, "<unknown>"); | |
436 | return sprintf(buf, "%u\n", cur_freq); | |
437 | } | |
438 | ||
439 | ||
440 | /** | |
441 | * show_scaling_governor - show the current policy for the specified CPU | |
442 | */ | |
905d77cd | 443 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 444 | { |
29464f28 | 445 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
446 | return sprintf(buf, "powersave\n"); |
447 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
448 | return sprintf(buf, "performance\n"); | |
449 | else if (policy->governor) | |
4b972f0b | 450 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 451 | policy->governor->name); |
1da177e4 LT |
452 | return -EINVAL; |
453 | } | |
454 | ||
455 | ||
456 | /** | |
457 | * store_scaling_governor - store policy for the specified CPU | |
458 | */ | |
905d77cd DJ |
459 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
460 | const char *buf, size_t count) | |
1da177e4 | 461 | { |
f55c9c26 | 462 | unsigned int ret; |
1da177e4 LT |
463 | char str_governor[16]; |
464 | struct cpufreq_policy new_policy; | |
465 | ||
466 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
467 | if (ret) | |
468 | return ret; | |
469 | ||
29464f28 | 470 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
471 | if (ret != 1) |
472 | return -EINVAL; | |
473 | ||
e08f5f5b GS |
474 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
475 | &new_policy.governor)) | |
1da177e4 LT |
476 | return -EINVAL; |
477 | ||
7970e08b TR |
478 | /* Do not use cpufreq_set_policy here or the user_policy.max |
479 | will be wrongly overridden */ | |
7970e08b TR |
480 | ret = __cpufreq_set_policy(policy, &new_policy); |
481 | ||
482 | policy->user_policy.policy = policy->policy; | |
483 | policy->user_policy.governor = policy->governor; | |
7970e08b | 484 | |
e08f5f5b GS |
485 | if (ret) |
486 | return ret; | |
487 | else | |
488 | return count; | |
1da177e4 LT |
489 | } |
490 | ||
491 | /** | |
492 | * show_scaling_driver - show the cpufreq driver currently loaded | |
493 | */ | |
905d77cd | 494 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 495 | { |
4b972f0b | 496 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
497 | } |
498 | ||
499 | /** | |
500 | * show_scaling_available_governors - show the available CPUfreq governors | |
501 | */ | |
905d77cd DJ |
502 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
503 | char *buf) | |
1da177e4 LT |
504 | { |
505 | ssize_t i = 0; | |
506 | struct cpufreq_governor *t; | |
507 | ||
508 | if (!cpufreq_driver->target) { | |
509 | i += sprintf(buf, "performance powersave"); | |
510 | goto out; | |
511 | } | |
512 | ||
513 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
514 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
515 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 516 | goto out; |
4b972f0b | 517 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 518 | } |
7d5e350f | 519 | out: |
1da177e4 LT |
520 | i += sprintf(&buf[i], "\n"); |
521 | return i; | |
522 | } | |
e8628dd0 | 523 | |
835481d9 | 524 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
525 | { |
526 | ssize_t i = 0; | |
527 | unsigned int cpu; | |
528 | ||
835481d9 | 529 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
530 | if (i) |
531 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
532 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
533 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 534 | break; |
1da177e4 LT |
535 | } |
536 | i += sprintf(&buf[i], "\n"); | |
537 | return i; | |
538 | } | |
539 | ||
e8628dd0 DW |
540 | /** |
541 | * show_related_cpus - show the CPUs affected by each transition even if | |
542 | * hw coordination is in use | |
543 | */ | |
544 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
545 | { | |
e8628dd0 DW |
546 | return show_cpus(policy->related_cpus, buf); |
547 | } | |
548 | ||
549 | /** | |
550 | * show_affected_cpus - show the CPUs affected by each transition | |
551 | */ | |
552 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
553 | { | |
554 | return show_cpus(policy->cpus, buf); | |
555 | } | |
556 | ||
9e76988e | 557 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 558 | const char *buf, size_t count) |
9e76988e VP |
559 | { |
560 | unsigned int freq = 0; | |
561 | unsigned int ret; | |
562 | ||
879000f9 | 563 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
564 | return -EINVAL; |
565 | ||
566 | ret = sscanf(buf, "%u", &freq); | |
567 | if (ret != 1) | |
568 | return -EINVAL; | |
569 | ||
570 | policy->governor->store_setspeed(policy, freq); | |
571 | ||
572 | return count; | |
573 | } | |
574 | ||
575 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
576 | { | |
879000f9 | 577 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
578 | return sprintf(buf, "<unsupported>\n"); |
579 | ||
580 | return policy->governor->show_setspeed(policy, buf); | |
581 | } | |
1da177e4 | 582 | |
e2f74f35 | 583 | /** |
8bf1ac72 | 584 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
585 | */ |
586 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
587 | { | |
588 | unsigned int limit; | |
589 | int ret; | |
590 | if (cpufreq_driver->bios_limit) { | |
591 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
592 | if (!ret) | |
593 | return sprintf(buf, "%u\n", limit); | |
594 | } | |
595 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
596 | } | |
597 | ||
6dad2a29 BP |
598 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
599 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
600 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
601 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
602 | cpufreq_freq_attr_ro(scaling_available_governors); | |
603 | cpufreq_freq_attr_ro(scaling_driver); | |
604 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
605 | cpufreq_freq_attr_ro(bios_limit); | |
606 | cpufreq_freq_attr_ro(related_cpus); | |
607 | cpufreq_freq_attr_ro(affected_cpus); | |
608 | cpufreq_freq_attr_rw(scaling_min_freq); | |
609 | cpufreq_freq_attr_rw(scaling_max_freq); | |
610 | cpufreq_freq_attr_rw(scaling_governor); | |
611 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 612 | |
905d77cd | 613 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
614 | &cpuinfo_min_freq.attr, |
615 | &cpuinfo_max_freq.attr, | |
ed129784 | 616 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
617 | &scaling_min_freq.attr, |
618 | &scaling_max_freq.attr, | |
619 | &affected_cpus.attr, | |
e8628dd0 | 620 | &related_cpus.attr, |
1da177e4 LT |
621 | &scaling_governor.attr, |
622 | &scaling_driver.attr, | |
623 | &scaling_available_governors.attr, | |
9e76988e | 624 | &scaling_setspeed.attr, |
1da177e4 LT |
625 | NULL |
626 | }; | |
627 | ||
8aa84ad8 TR |
628 | struct kobject *cpufreq_global_kobject; |
629 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
630 | ||
29464f28 DJ |
631 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
632 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 633 | |
29464f28 | 634 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 635 | { |
905d77cd DJ |
636 | struct cpufreq_policy *policy = to_policy(kobj); |
637 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 638 | ssize_t ret = -EINVAL; |
a9144436 | 639 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 640 | if (!policy) |
0db4a8a9 | 641 | goto no_policy; |
5a01f2e8 VP |
642 | |
643 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 644 | goto fail; |
5a01f2e8 | 645 | |
e08f5f5b GS |
646 | if (fattr->show) |
647 | ret = fattr->show(policy, buf); | |
648 | else | |
649 | ret = -EIO; | |
650 | ||
5a01f2e8 | 651 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 652 | fail: |
a9144436 | 653 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 654 | no_policy: |
1da177e4 LT |
655 | return ret; |
656 | } | |
657 | ||
905d77cd DJ |
658 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
659 | const char *buf, size_t count) | |
1da177e4 | 660 | { |
905d77cd DJ |
661 | struct cpufreq_policy *policy = to_policy(kobj); |
662 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 663 | ssize_t ret = -EINVAL; |
a9144436 | 664 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 665 | if (!policy) |
a07530b4 | 666 | goto no_policy; |
5a01f2e8 VP |
667 | |
668 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 669 | goto fail; |
5a01f2e8 | 670 | |
e08f5f5b GS |
671 | if (fattr->store) |
672 | ret = fattr->store(policy, buf, count); | |
673 | else | |
674 | ret = -EIO; | |
675 | ||
5a01f2e8 | 676 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 677 | fail: |
a9144436 | 678 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 679 | no_policy: |
1da177e4 LT |
680 | return ret; |
681 | } | |
682 | ||
905d77cd | 683 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 684 | { |
905d77cd | 685 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 686 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
687 | complete(&policy->kobj_unregister); |
688 | } | |
689 | ||
52cf25d0 | 690 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
691 | .show = show, |
692 | .store = store, | |
693 | }; | |
694 | ||
695 | static struct kobj_type ktype_cpufreq = { | |
696 | .sysfs_ops = &sysfs_ops, | |
697 | .default_attrs = default_attrs, | |
698 | .release = cpufreq_sysfs_release, | |
699 | }; | |
700 | ||
19d6f7ec | 701 | /* symlink affected CPUs */ |
cf3289d0 AC |
702 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
703 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
704 | { |
705 | unsigned int j; | |
706 | int ret = 0; | |
707 | ||
708 | for_each_cpu(j, policy->cpus) { | |
709 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 710 | struct device *cpu_dev; |
19d6f7ec DJ |
711 | |
712 | if (j == cpu) | |
713 | continue; | |
19d6f7ec | 714 | |
2d06d8c4 | 715 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 716 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
717 | cpu_dev = get_cpu_device(j); |
718 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
719 | "cpufreq"); |
720 | if (ret) { | |
721 | cpufreq_cpu_put(managed_policy); | |
722 | return ret; | |
723 | } | |
724 | } | |
725 | return ret; | |
726 | } | |
727 | ||
cf3289d0 AC |
728 | static int cpufreq_add_dev_interface(unsigned int cpu, |
729 | struct cpufreq_policy *policy, | |
8a25a2fd | 730 | struct device *dev) |
909a694e | 731 | { |
ecf7e461 | 732 | struct cpufreq_policy new_policy; |
909a694e DJ |
733 | struct freq_attr **drv_attr; |
734 | unsigned long flags; | |
735 | int ret = 0; | |
736 | unsigned int j; | |
737 | ||
738 | /* prepare interface data */ | |
739 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 740 | &dev->kobj, "cpufreq"); |
909a694e DJ |
741 | if (ret) |
742 | return ret; | |
743 | ||
744 | /* set up files for this cpu device */ | |
745 | drv_attr = cpufreq_driver->attr; | |
746 | while ((drv_attr) && (*drv_attr)) { | |
747 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
748 | if (ret) | |
749 | goto err_out_kobj_put; | |
750 | drv_attr++; | |
751 | } | |
752 | if (cpufreq_driver->get) { | |
753 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
754 | if (ret) | |
755 | goto err_out_kobj_put; | |
756 | } | |
757 | if (cpufreq_driver->target) { | |
758 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
759 | if (ret) | |
760 | goto err_out_kobj_put; | |
761 | } | |
e2f74f35 TR |
762 | if (cpufreq_driver->bios_limit) { |
763 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
764 | if (ret) | |
765 | goto err_out_kobj_put; | |
766 | } | |
909a694e DJ |
767 | |
768 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
769 | for_each_cpu(j, policy->cpus) { | |
909a694e | 770 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 771 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
772 | } |
773 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
774 | ||
775 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
776 | if (ret) |
777 | goto err_out_kobj_put; | |
778 | ||
779 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
780 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
781 | policy->governor = NULL; | |
782 | ||
783 | /* set default policy */ | |
784 | ret = __cpufreq_set_policy(policy, &new_policy); | |
785 | policy->user_policy.policy = policy->policy; | |
786 | policy->user_policy.governor = policy->governor; | |
787 | ||
788 | if (ret) { | |
2d06d8c4 | 789 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
790 | if (cpufreq_driver->exit) |
791 | cpufreq_driver->exit(policy); | |
792 | } | |
909a694e DJ |
793 | return ret; |
794 | ||
795 | err_out_kobj_put: | |
796 | kobject_put(&policy->kobj); | |
797 | wait_for_completion(&policy->kobj_unregister); | |
798 | return ret; | |
799 | } | |
800 | ||
fcf80582 VK |
801 | #ifdef CONFIG_HOTPLUG_CPU |
802 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
803 | struct device *dev) | |
804 | { | |
805 | struct cpufreq_policy *policy; | |
806 | int ret = 0; | |
807 | unsigned long flags; | |
808 | ||
809 | policy = cpufreq_cpu_get(sibling); | |
810 | WARN_ON(!policy); | |
811 | ||
fcf80582 VK |
812 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
813 | ||
2eaa3e2d VK |
814 | lock_policy_rwsem_write(sibling); |
815 | ||
fcf80582 | 816 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 817 | |
fcf80582 | 818 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 819 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
fcf80582 VK |
820 | per_cpu(cpufreq_cpu_data, cpu) = policy; |
821 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
822 | ||
2eaa3e2d VK |
823 | unlock_policy_rwsem_write(sibling); |
824 | ||
fcf80582 VK |
825 | __cpufreq_governor(policy, CPUFREQ_GOV_START); |
826 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
827 | ||
fcf80582 VK |
828 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
829 | if (ret) { | |
830 | cpufreq_cpu_put(policy); | |
831 | return ret; | |
832 | } | |
833 | ||
834 | return 0; | |
835 | } | |
836 | #endif | |
1da177e4 LT |
837 | |
838 | /** | |
839 | * cpufreq_add_dev - add a CPU device | |
840 | * | |
32ee8c3e | 841 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
842 | * |
843 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
844 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
845 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 846 | */ |
8a25a2fd | 847 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 848 | { |
fcf80582 | 849 | unsigned int j, cpu = dev->id; |
65922465 | 850 | int ret = -ENOMEM; |
1da177e4 | 851 | struct cpufreq_policy *policy; |
1da177e4 | 852 | unsigned long flags; |
90e41bac | 853 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 854 | struct cpufreq_governor *gov; |
90e41bac PB |
855 | int sibling; |
856 | #endif | |
1da177e4 | 857 | |
c32b6b8e AR |
858 | if (cpu_is_offline(cpu)) |
859 | return 0; | |
860 | ||
2d06d8c4 | 861 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
862 | |
863 | #ifdef CONFIG_SMP | |
864 | /* check whether a different CPU already registered this | |
865 | * CPU because it is in the same boat. */ | |
866 | policy = cpufreq_cpu_get(cpu); | |
867 | if (unlikely(policy)) { | |
8ff69732 | 868 | cpufreq_cpu_put(policy); |
1da177e4 LT |
869 | return 0; |
870 | } | |
fcf80582 VK |
871 | |
872 | #ifdef CONFIG_HOTPLUG_CPU | |
873 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
2eaa3e2d | 874 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
875 | for_each_online_cpu(sibling) { |
876 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d VK |
877 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
878 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
fcf80582 | 879 | return cpufreq_add_policy_cpu(cpu, sibling, dev); |
2eaa3e2d | 880 | } |
fcf80582 | 881 | } |
2eaa3e2d | 882 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 883 | #endif |
1da177e4 LT |
884 | #endif |
885 | ||
886 | if (!try_module_get(cpufreq_driver->owner)) { | |
887 | ret = -EINVAL; | |
888 | goto module_out; | |
889 | } | |
890 | ||
e98df50c | 891 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 892 | if (!policy) |
1da177e4 | 893 | goto nomem_out; |
059019a3 DJ |
894 | |
895 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 896 | goto err_free_policy; |
059019a3 DJ |
897 | |
898 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 899 | goto err_free_cpumask; |
1da177e4 LT |
900 | |
901 | policy->cpu = cpu; | |
65922465 | 902 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 903 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 904 | |
5a01f2e8 | 905 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 906 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 907 | |
1da177e4 | 908 | init_completion(&policy->kobj_unregister); |
65f27f38 | 909 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
910 | |
911 | /* call driver. From then on the cpufreq must be able | |
912 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
913 | */ | |
914 | ret = cpufreq_driver->init(policy); | |
915 | if (ret) { | |
2d06d8c4 | 916 | pr_debug("initialization failed\n"); |
2eaa3e2d | 917 | goto err_set_policy_cpu; |
1da177e4 | 918 | } |
643ae6e8 | 919 | |
fcf80582 VK |
920 | /* related cpus should atleast have policy->cpus */ |
921 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
922 | ||
643ae6e8 VK |
923 | /* |
924 | * affected cpus must always be the one, which are online. We aren't | |
925 | * managing offline cpus here. | |
926 | */ | |
927 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
928 | ||
187d9f4e MC |
929 | policy->user_policy.min = policy->min; |
930 | policy->user_policy.max = policy->max; | |
1da177e4 | 931 | |
a1531acd TR |
932 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
933 | CPUFREQ_START, policy); | |
934 | ||
fcf80582 VK |
935 | #ifdef CONFIG_HOTPLUG_CPU |
936 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
937 | if (gov) { | |
938 | policy->governor = gov; | |
939 | pr_debug("Restoring governor %s for cpu %d\n", | |
940 | policy->governor->name, cpu); | |
4bfa042c | 941 | } |
fcf80582 | 942 | #endif |
1da177e4 | 943 | |
8a25a2fd | 944 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
945 | if (ret) |
946 | goto err_out_unregister; | |
8ff69732 | 947 | |
038c5b3e | 948 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 949 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 950 | pr_debug("initialization complete\n"); |
87c32271 | 951 | |
1da177e4 LT |
952 | return 0; |
953 | ||
1da177e4 LT |
954 | err_out_unregister: |
955 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 956 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 957 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
958 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
959 | ||
c10997f6 | 960 | kobject_put(&policy->kobj); |
1da177e4 LT |
961 | wait_for_completion(&policy->kobj_unregister); |
962 | ||
2eaa3e2d VK |
963 | err_set_policy_cpu: |
964 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
cad70a6a | 965 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
966 | err_free_cpumask: |
967 | free_cpumask_var(policy->cpus); | |
968 | err_free_policy: | |
1da177e4 | 969 | kfree(policy); |
1da177e4 LT |
970 | nomem_out: |
971 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 972 | module_out: |
1da177e4 LT |
973 | return ret; |
974 | } | |
975 | ||
b8eed8af VK |
976 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
977 | { | |
978 | int j; | |
979 | ||
980 | policy->last_cpu = policy->cpu; | |
981 | policy->cpu = cpu; | |
982 | ||
3361b7b1 | 983 | for_each_cpu(j, policy->cpus) |
b8eed8af | 984 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
985 | |
986 | #ifdef CONFIG_CPU_FREQ_TABLE | |
987 | cpufreq_frequency_table_update_policy_cpu(policy); | |
988 | #endif | |
989 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
990 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
991 | } | |
1da177e4 LT |
992 | |
993 | /** | |
5a01f2e8 | 994 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
995 | * |
996 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
997 | * Caller should already have policy_rwsem in write mode for this CPU. |
998 | * This routine frees the rwsem before returning. | |
1da177e4 | 999 | */ |
8a25a2fd | 1000 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1001 | { |
b8eed8af | 1002 | unsigned int cpu = dev->id, ret, cpus; |
1da177e4 LT |
1003 | unsigned long flags; |
1004 | struct cpufreq_policy *data; | |
499bca9b AW |
1005 | struct kobject *kobj; |
1006 | struct completion *cmp; | |
8a25a2fd | 1007 | struct device *cpu_dev; |
1da177e4 | 1008 | |
b8eed8af | 1009 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 LT |
1010 | |
1011 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
2eaa3e2d | 1012 | |
7a6aedfa | 1013 | data = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1014 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1015 | ||
1016 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 LT |
1017 | |
1018 | if (!data) { | |
b8eed8af | 1019 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1020 | return -EINVAL; |
1021 | } | |
1da177e4 | 1022 | |
b8eed8af | 1023 | if (cpufreq_driver->target) |
f6a7409c | 1024 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1da177e4 | 1025 | |
084f3493 | 1026 | #ifdef CONFIG_HOTPLUG_CPU |
fa69e33f DB |
1027 | if (!cpufreq_driver->setpolicy) |
1028 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), | |
1029 | data->governor->name, CPUFREQ_NAME_LEN); | |
1da177e4 LT |
1030 | #endif |
1031 | ||
2eaa3e2d | 1032 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af VK |
1033 | cpus = cpumask_weight(data->cpus); |
1034 | cpumask_clear_cpu(cpu, data->cpus); | |
2eaa3e2d | 1035 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1036 | |
73bf0fc2 VK |
1037 | if (cpu != data->cpu) { |
1038 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
1039 | } else if (cpus > 1) { | |
b8eed8af VK |
1040 | /* first sibling now owns the new sysfs dir */ |
1041 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1042 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1043 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1044 | if (ret) { | |
1045 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
084f3493 | 1046 | |
2eaa3e2d | 1047 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1048 | cpumask_set_cpu(cpu, data->cpus); |
1da177e4 | 1049 | |
2eaa3e2d VK |
1050 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
1051 | per_cpu(cpufreq_cpu_data, cpu) = data; | |
b8eed8af | 1052 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1053 | |
499bca9b | 1054 | unlock_policy_rwsem_write(cpu); |
1da177e4 | 1055 | |
2eaa3e2d VK |
1056 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, |
1057 | "cpufreq"); | |
b8eed8af | 1058 | return -EINVAL; |
1da177e4 | 1059 | } |
5a01f2e8 | 1060 | |
2eaa3e2d | 1061 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1062 | update_policy_cpu(data, cpu_dev->id); |
2eaa3e2d | 1063 | unlock_policy_rwsem_write(cpu); |
b8eed8af VK |
1064 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1065 | __func__, cpu_dev->id, cpu); | |
1da177e4 | 1066 | } |
1da177e4 | 1067 | |
b8eed8af VK |
1068 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); |
1069 | cpufreq_cpu_put(data); | |
1da177e4 | 1070 | |
b8eed8af VK |
1071 | /* If cpu is last user of policy, free policy */ |
1072 | if (cpus == 1) { | |
2eaa3e2d | 1073 | lock_policy_rwsem_read(cpu); |
b8eed8af VK |
1074 | kobj = &data->kobj; |
1075 | cmp = &data->kobj_unregister; | |
2eaa3e2d | 1076 | unlock_policy_rwsem_read(cpu); |
b8eed8af | 1077 | kobject_put(kobj); |
7d26e2d5 | 1078 | |
b8eed8af VK |
1079 | /* we need to make sure that the underlying kobj is actually |
1080 | * not referenced anymore by anybody before we proceed with | |
1081 | * unloading. | |
1082 | */ | |
1083 | pr_debug("waiting for dropping of refcount\n"); | |
1084 | wait_for_completion(cmp); | |
1085 | pr_debug("wait complete\n"); | |
7d26e2d5 | 1086 | |
b8eed8af VK |
1087 | if (cpufreq_driver->exit) |
1088 | cpufreq_driver->exit(data); | |
27ecddc2 | 1089 | |
b8eed8af VK |
1090 | free_cpumask_var(data->related_cpus); |
1091 | free_cpumask_var(data->cpus); | |
1092 | kfree(data); | |
1093 | } else if (cpufreq_driver->target) { | |
1094 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1095 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
27ecddc2 | 1096 | } |
1da177e4 | 1097 | |
2eaa3e2d | 1098 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
1da177e4 LT |
1099 | return 0; |
1100 | } | |
1101 | ||
1102 | ||
8a25a2fd | 1103 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1104 | { |
8a25a2fd | 1105 | unsigned int cpu = dev->id; |
5a01f2e8 | 1106 | int retval; |
ec28297a VP |
1107 | |
1108 | if (cpu_is_offline(cpu)) | |
1109 | return 0; | |
1110 | ||
8a25a2fd | 1111 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1112 | return retval; |
1113 | } | |
1114 | ||
1115 | ||
65f27f38 | 1116 | static void handle_update(struct work_struct *work) |
1da177e4 | 1117 | { |
65f27f38 DH |
1118 | struct cpufreq_policy *policy = |
1119 | container_of(work, struct cpufreq_policy, update); | |
1120 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1121 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1122 | cpufreq_update_policy(cpu); |
1123 | } | |
1124 | ||
1125 | /** | |
1126 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1127 | * @cpu: cpu number | |
1128 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1129 | * @new_freq: CPU frequency the CPU actually runs at | |
1130 | * | |
29464f28 DJ |
1131 | * We adjust to current frequency first, and need to clean up later. |
1132 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1133 | */ |
e08f5f5b GS |
1134 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1135 | unsigned int new_freq) | |
1da177e4 LT |
1136 | { |
1137 | struct cpufreq_freqs freqs; | |
1138 | ||
2d06d8c4 | 1139 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1140 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1141 | ||
1142 | freqs.cpu = cpu; | |
1143 | freqs.old = old_freq; | |
1144 | freqs.new = new_freq; | |
1145 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1146 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1147 | } | |
1148 | ||
1149 | ||
32ee8c3e | 1150 | /** |
4ab70df4 | 1151 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1152 | * @cpu: CPU number |
1153 | * | |
1154 | * This is the last known freq, without actually getting it from the driver. | |
1155 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1156 | */ | |
1157 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1158 | { | |
9e21ba8b | 1159 | struct cpufreq_policy *policy; |
e08f5f5b | 1160 | unsigned int ret_freq = 0; |
95235ca2 | 1161 | |
9e21ba8b DB |
1162 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1163 | return cpufreq_driver->get(cpu); | |
1164 | ||
1165 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1166 | if (policy) { |
e08f5f5b | 1167 | ret_freq = policy->cur; |
95235ca2 VP |
1168 | cpufreq_cpu_put(policy); |
1169 | } | |
1170 | ||
4d34a67d | 1171 | return ret_freq; |
95235ca2 VP |
1172 | } |
1173 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1174 | ||
3d737108 JB |
1175 | /** |
1176 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1177 | * @cpu: CPU number | |
1178 | * | |
1179 | * Just return the max possible frequency for a given CPU. | |
1180 | */ | |
1181 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1182 | { | |
1183 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1184 | unsigned int ret_freq = 0; | |
1185 | ||
1186 | if (policy) { | |
1187 | ret_freq = policy->max; | |
1188 | cpufreq_cpu_put(policy); | |
1189 | } | |
1190 | ||
1191 | return ret_freq; | |
1192 | } | |
1193 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1194 | ||
95235ca2 | 1195 | |
5a01f2e8 | 1196 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1197 | { |
7a6aedfa | 1198 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1199 | unsigned int ret_freq = 0; |
1da177e4 | 1200 | |
1da177e4 | 1201 | if (!cpufreq_driver->get) |
4d34a67d | 1202 | return ret_freq; |
1da177e4 | 1203 | |
e08f5f5b | 1204 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1205 | |
e08f5f5b GS |
1206 | if (ret_freq && policy->cur && |
1207 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1208 | /* verify no discrepancy between actual and | |
1209 | saved value exists */ | |
1210 | if (unlikely(ret_freq != policy->cur)) { | |
1211 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1212 | schedule_work(&policy->update); |
1213 | } | |
1214 | } | |
1215 | ||
4d34a67d | 1216 | return ret_freq; |
5a01f2e8 | 1217 | } |
1da177e4 | 1218 | |
5a01f2e8 VP |
1219 | /** |
1220 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1221 | * @cpu: CPU number | |
1222 | * | |
1223 | * Get the CPU current (static) CPU frequency | |
1224 | */ | |
1225 | unsigned int cpufreq_get(unsigned int cpu) | |
1226 | { | |
1227 | unsigned int ret_freq = 0; | |
1228 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1229 | ||
1230 | if (!policy) | |
1231 | goto out; | |
1232 | ||
1233 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1234 | goto out_policy; | |
1235 | ||
1236 | ret_freq = __cpufreq_get(cpu); | |
1237 | ||
1238 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1239 | |
5a01f2e8 VP |
1240 | out_policy: |
1241 | cpufreq_cpu_put(policy); | |
1242 | out: | |
4d34a67d | 1243 | return ret_freq; |
1da177e4 LT |
1244 | } |
1245 | EXPORT_SYMBOL(cpufreq_get); | |
1246 | ||
8a25a2fd KS |
1247 | static struct subsys_interface cpufreq_interface = { |
1248 | .name = "cpufreq", | |
1249 | .subsys = &cpu_subsys, | |
1250 | .add_dev = cpufreq_add_dev, | |
1251 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1252 | }; |
1253 | ||
1da177e4 | 1254 | |
42d4dc3f | 1255 | /** |
e00e56df RW |
1256 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1257 | * | |
1258 | * This function is only executed for the boot processor. The other CPUs | |
1259 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1260 | */ |
e00e56df | 1261 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1262 | { |
e08f5f5b | 1263 | int ret = 0; |
4bc5d341 | 1264 | |
e00e56df | 1265 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1266 | struct cpufreq_policy *cpu_policy; |
1267 | ||
2d06d8c4 | 1268 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1269 | |
e00e56df | 1270 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1271 | cpu_policy = cpufreq_cpu_get(cpu); |
1272 | if (!cpu_policy) | |
e00e56df | 1273 | return 0; |
42d4dc3f BH |
1274 | |
1275 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1276 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1277 | if (ret) |
42d4dc3f BH |
1278 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1279 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1280 | } |
1281 | ||
42d4dc3f | 1282 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1283 | return ret; |
42d4dc3f BH |
1284 | } |
1285 | ||
1da177e4 | 1286 | /** |
e00e56df | 1287 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1288 | * |
1289 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1290 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1291 | * restored. It will verify that the current freq is in sync with | |
1292 | * what we believe it to be. This is a bit later than when it | |
1293 | * should be, but nonethteless it's better than calling | |
1294 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1295 | * |
1296 | * This function is only executed for the boot CPU. The other CPUs have not | |
1297 | * been turned on yet. | |
1da177e4 | 1298 | */ |
e00e56df | 1299 | static void cpufreq_bp_resume(void) |
1da177e4 | 1300 | { |
e08f5f5b | 1301 | int ret = 0; |
4bc5d341 | 1302 | |
e00e56df | 1303 | int cpu = smp_processor_id(); |
1da177e4 LT |
1304 | struct cpufreq_policy *cpu_policy; |
1305 | ||
2d06d8c4 | 1306 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1307 | |
e00e56df | 1308 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1309 | cpu_policy = cpufreq_cpu_get(cpu); |
1310 | if (!cpu_policy) | |
e00e56df | 1311 | return; |
1da177e4 LT |
1312 | |
1313 | if (cpufreq_driver->resume) { | |
1314 | ret = cpufreq_driver->resume(cpu_policy); | |
1315 | if (ret) { | |
1316 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1317 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1318 | goto fail; |
1da177e4 LT |
1319 | } |
1320 | } | |
1321 | ||
1da177e4 | 1322 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1323 | |
c9060494 | 1324 | fail: |
1da177e4 | 1325 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1326 | } |
1327 | ||
e00e56df RW |
1328 | static struct syscore_ops cpufreq_syscore_ops = { |
1329 | .suspend = cpufreq_bp_suspend, | |
1330 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1331 | }; |
1332 | ||
9d95046e BP |
1333 | /** |
1334 | * cpufreq_get_current_driver - return current driver's name | |
1335 | * | |
1336 | * Return the name string of the currently loaded cpufreq driver | |
1337 | * or NULL, if none. | |
1338 | */ | |
1339 | const char *cpufreq_get_current_driver(void) | |
1340 | { | |
1341 | if (cpufreq_driver) | |
1342 | return cpufreq_driver->name; | |
1343 | ||
1344 | return NULL; | |
1345 | } | |
1346 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1347 | |
1348 | /********************************************************************* | |
1349 | * NOTIFIER LISTS INTERFACE * | |
1350 | *********************************************************************/ | |
1351 | ||
1352 | /** | |
1353 | * cpufreq_register_notifier - register a driver with cpufreq | |
1354 | * @nb: notifier function to register | |
1355 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1356 | * | |
32ee8c3e | 1357 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1358 | * are notified about clock rate changes (once before and once after |
1359 | * the transition), or a list of drivers that are notified about | |
1360 | * changes in cpufreq policy. | |
1361 | * | |
1362 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1363 | * blocking_notifier_chain_register. |
1da177e4 LT |
1364 | */ |
1365 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1366 | { | |
1367 | int ret; | |
1368 | ||
d5aaffa9 DB |
1369 | if (cpufreq_disabled()) |
1370 | return -EINVAL; | |
1371 | ||
74212ca4 CEB |
1372 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1373 | ||
1da177e4 LT |
1374 | switch (list) { |
1375 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1376 | ret = srcu_notifier_chain_register( |
e041c683 | 1377 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1378 | break; |
1379 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1380 | ret = blocking_notifier_chain_register( |
1381 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1382 | break; |
1383 | default: | |
1384 | ret = -EINVAL; | |
1385 | } | |
1da177e4 LT |
1386 | |
1387 | return ret; | |
1388 | } | |
1389 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1390 | ||
1391 | ||
1392 | /** | |
1393 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1394 | * @nb: notifier block to be unregistered | |
1395 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1396 | * | |
1397 | * Remove a driver from the CPU frequency notifier list. | |
1398 | * | |
1399 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1400 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1401 | */ |
1402 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1403 | { | |
1404 | int ret; | |
1405 | ||
d5aaffa9 DB |
1406 | if (cpufreq_disabled()) |
1407 | return -EINVAL; | |
1408 | ||
1da177e4 LT |
1409 | switch (list) { |
1410 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1411 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1412 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1413 | break; |
1414 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1415 | ret = blocking_notifier_chain_unregister( |
1416 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1417 | break; |
1418 | default: | |
1419 | ret = -EINVAL; | |
1420 | } | |
1da177e4 LT |
1421 | |
1422 | return ret; | |
1423 | } | |
1424 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1425 | ||
1426 | ||
1427 | /********************************************************************* | |
1428 | * GOVERNORS * | |
1429 | *********************************************************************/ | |
1430 | ||
1431 | ||
1432 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1433 | unsigned int target_freq, | |
1434 | unsigned int relation) | |
1435 | { | |
1436 | int retval = -EINVAL; | |
7249924e | 1437 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1438 | |
a7b422cd KRW |
1439 | if (cpufreq_disabled()) |
1440 | return -ENODEV; | |
1441 | ||
7249924e VK |
1442 | /* Make sure that target_freq is within supported range */ |
1443 | if (target_freq > policy->max) | |
1444 | target_freq = policy->max; | |
1445 | if (target_freq < policy->min) | |
1446 | target_freq = policy->min; | |
1447 | ||
1448 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1449 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1450 | |
1451 | if (target_freq == policy->cur) | |
1452 | return 0; | |
1453 | ||
3361b7b1 | 1454 | if (cpufreq_driver->target) |
1da177e4 | 1455 | retval = cpufreq_driver->target(policy, target_freq, relation); |
90d45d17 | 1456 | |
1da177e4 LT |
1457 | return retval; |
1458 | } | |
1459 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1460 | ||
1da177e4 LT |
1461 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1462 | unsigned int target_freq, | |
1463 | unsigned int relation) | |
1464 | { | |
f1829e4a | 1465 | int ret = -EINVAL; |
1da177e4 LT |
1466 | |
1467 | policy = cpufreq_cpu_get(policy->cpu); | |
1468 | if (!policy) | |
f1829e4a | 1469 | goto no_policy; |
1da177e4 | 1470 | |
5a01f2e8 | 1471 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1472 | goto fail; |
1da177e4 LT |
1473 | |
1474 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1475 | ||
5a01f2e8 | 1476 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1477 | |
f1829e4a | 1478 | fail: |
1da177e4 | 1479 | cpufreq_cpu_put(policy); |
f1829e4a | 1480 | no_policy: |
1da177e4 LT |
1481 | return ret; |
1482 | } | |
1483 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1484 | ||
bf0b90e3 | 1485 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1486 | { |
1487 | int ret = 0; | |
1488 | ||
d5aaffa9 DB |
1489 | if (cpufreq_disabled()) |
1490 | return ret; | |
1491 | ||
3361b7b1 | 1492 | if (!cpufreq_driver->getavg) |
0676f7f2 VK |
1493 | return 0; |
1494 | ||
dfde5d62 VP |
1495 | policy = cpufreq_cpu_get(policy->cpu); |
1496 | if (!policy) | |
1497 | return -EINVAL; | |
1498 | ||
0676f7f2 | 1499 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1500 | |
dfde5d62 VP |
1501 | cpufreq_cpu_put(policy); |
1502 | return ret; | |
1503 | } | |
5a01f2e8 | 1504 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1505 | |
153d7f3f | 1506 | /* |
153d7f3f AV |
1507 | * when "event" is CPUFREQ_GOV_LIMITS |
1508 | */ | |
1da177e4 | 1509 | |
e08f5f5b GS |
1510 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1511 | unsigned int event) | |
1da177e4 | 1512 | { |
cc993cab | 1513 | int ret; |
6afde10c TR |
1514 | |
1515 | /* Only must be defined when default governor is known to have latency | |
1516 | restrictions, like e.g. conservative or ondemand. | |
1517 | That this is the case is already ensured in Kconfig | |
1518 | */ | |
1519 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1520 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1521 | #else | |
1522 | struct cpufreq_governor *gov = NULL; | |
1523 | #endif | |
1c256245 TR |
1524 | |
1525 | if (policy->governor->max_transition_latency && | |
1526 | policy->cpuinfo.transition_latency > | |
1527 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1528 | if (!gov) |
1529 | return -EINVAL; | |
1530 | else { | |
1531 | printk(KERN_WARNING "%s governor failed, too long" | |
1532 | " transition latency of HW, fallback" | |
1533 | " to %s governor\n", | |
1534 | policy->governor->name, | |
1535 | gov->name); | |
1536 | policy->governor = gov; | |
1537 | } | |
1c256245 | 1538 | } |
1da177e4 LT |
1539 | |
1540 | if (!try_module_get(policy->governor->owner)) | |
1541 | return -EINVAL; | |
1542 | ||
2d06d8c4 | 1543 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1544 | policy->cpu, event); |
1da177e4 LT |
1545 | ret = policy->governor->governor(policy, event); |
1546 | ||
8e53695f VK |
1547 | if (event == CPUFREQ_GOV_START) |
1548 | policy->governor->initialized++; | |
1549 | else if (event == CPUFREQ_GOV_STOP) | |
1550 | policy->governor->initialized--; | |
b394058f | 1551 | |
e08f5f5b GS |
1552 | /* we keep one module reference alive for |
1553 | each CPU governed by this CPU */ | |
1da177e4 LT |
1554 | if ((event != CPUFREQ_GOV_START) || ret) |
1555 | module_put(policy->governor->owner); | |
1556 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1557 | module_put(policy->governor->owner); | |
1558 | ||
1559 | return ret; | |
1560 | } | |
1561 | ||
1562 | ||
1da177e4 LT |
1563 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1564 | { | |
3bcb09a3 | 1565 | int err; |
1da177e4 LT |
1566 | |
1567 | if (!governor) | |
1568 | return -EINVAL; | |
1569 | ||
a7b422cd KRW |
1570 | if (cpufreq_disabled()) |
1571 | return -ENODEV; | |
1572 | ||
3fc54d37 | 1573 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1574 | |
b394058f | 1575 | governor->initialized = 0; |
3bcb09a3 JF |
1576 | err = -EBUSY; |
1577 | if (__find_governor(governor->name) == NULL) { | |
1578 | err = 0; | |
1579 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1580 | } |
1da177e4 | 1581 | |
32ee8c3e | 1582 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1583 | return err; |
1da177e4 LT |
1584 | } |
1585 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1586 | ||
1587 | ||
1588 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1589 | { | |
90e41bac PB |
1590 | #ifdef CONFIG_HOTPLUG_CPU |
1591 | int cpu; | |
1592 | #endif | |
1593 | ||
1da177e4 LT |
1594 | if (!governor) |
1595 | return; | |
1596 | ||
a7b422cd KRW |
1597 | if (cpufreq_disabled()) |
1598 | return; | |
1599 | ||
90e41bac PB |
1600 | #ifdef CONFIG_HOTPLUG_CPU |
1601 | for_each_present_cpu(cpu) { | |
1602 | if (cpu_online(cpu)) | |
1603 | continue; | |
1604 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1605 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1606 | } | |
1607 | #endif | |
1608 | ||
3fc54d37 | 1609 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1610 | list_del(&governor->governor_list); |
3fc54d37 | 1611 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1612 | return; |
1613 | } | |
1614 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1615 | ||
1616 | ||
1617 | ||
1618 | /********************************************************************* | |
1619 | * POLICY INTERFACE * | |
1620 | *********************************************************************/ | |
1621 | ||
1622 | /** | |
1623 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1624 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1625 | * is written | |
1da177e4 LT |
1626 | * |
1627 | * Reads the current cpufreq policy. | |
1628 | */ | |
1629 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1630 | { | |
1631 | struct cpufreq_policy *cpu_policy; | |
1632 | if (!policy) | |
1633 | return -EINVAL; | |
1634 | ||
1635 | cpu_policy = cpufreq_cpu_get(cpu); | |
1636 | if (!cpu_policy) | |
1637 | return -EINVAL; | |
1638 | ||
1da177e4 | 1639 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1640 | |
1641 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1642 | return 0; |
1643 | } | |
1644 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1645 | ||
1646 | ||
153d7f3f | 1647 | /* |
e08f5f5b GS |
1648 | * data : current policy. |
1649 | * policy : policy to be set. | |
153d7f3f | 1650 | */ |
e08f5f5b GS |
1651 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1652 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1653 | { |
1654 | int ret = 0; | |
1655 | ||
2d06d8c4 | 1656 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1657 | policy->min, policy->max); |
1658 | ||
e08f5f5b GS |
1659 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1660 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1661 | |
53391fa2 | 1662 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1663 | ret = -EINVAL; |
1664 | goto error_out; | |
1665 | } | |
1666 | ||
1da177e4 LT |
1667 | /* verify the cpu speed can be set within this limit */ |
1668 | ret = cpufreq_driver->verify(policy); | |
1669 | if (ret) | |
1670 | goto error_out; | |
1671 | ||
1da177e4 | 1672 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1673 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1674 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1675 | |
1676 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1677 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1678 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1679 | |
1680 | /* verify the cpu speed can be set within this limit, | |
1681 | which might be different to the first one */ | |
1682 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1683 | if (ret) |
1da177e4 | 1684 | goto error_out; |
1da177e4 LT |
1685 | |
1686 | /* notification of the new policy */ | |
e041c683 AS |
1687 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1688 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1689 | |
7d5e350f DJ |
1690 | data->min = policy->min; |
1691 | data->max = policy->max; | |
1da177e4 | 1692 | |
2d06d8c4 | 1693 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1694 | data->min, data->max); |
1da177e4 LT |
1695 | |
1696 | if (cpufreq_driver->setpolicy) { | |
1697 | data->policy = policy->policy; | |
2d06d8c4 | 1698 | pr_debug("setting range\n"); |
1da177e4 LT |
1699 | ret = cpufreq_driver->setpolicy(policy); |
1700 | } else { | |
1701 | if (policy->governor != data->governor) { | |
1702 | /* save old, working values */ | |
1703 | struct cpufreq_governor *old_gov = data->governor; | |
1704 | ||
2d06d8c4 | 1705 | pr_debug("governor switch\n"); |
1da177e4 LT |
1706 | |
1707 | /* end old governor */ | |
ffe6275f | 1708 | if (data->governor) |
1da177e4 LT |
1709 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1710 | ||
1711 | /* start new governor */ | |
1712 | data->governor = policy->governor; | |
1713 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1714 | /* new governor failed, so re-start old one */ | |
2d06d8c4 | 1715 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1716 | data->governor->name); |
1da177e4 LT |
1717 | if (old_gov) { |
1718 | data->governor = old_gov; | |
e08f5f5b GS |
1719 | __cpufreq_governor(data, |
1720 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1721 | } |
1722 | ret = -EINVAL; | |
1723 | goto error_out; | |
1724 | } | |
1725 | /* might be a policy change, too, so fall through */ | |
1726 | } | |
2d06d8c4 | 1727 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1728 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1729 | } | |
1730 | ||
7d5e350f | 1731 | error_out: |
1da177e4 LT |
1732 | return ret; |
1733 | } | |
1734 | ||
1da177e4 LT |
1735 | /** |
1736 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1737 | * @cpu: CPU which shall be re-evaluated | |
1738 | * | |
25985edc | 1739 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1740 | * at different times. |
1741 | */ | |
1742 | int cpufreq_update_policy(unsigned int cpu) | |
1743 | { | |
1744 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1745 | struct cpufreq_policy policy; | |
f1829e4a | 1746 | int ret; |
1da177e4 | 1747 | |
f1829e4a JL |
1748 | if (!data) { |
1749 | ret = -ENODEV; | |
1750 | goto no_policy; | |
1751 | } | |
1da177e4 | 1752 | |
f1829e4a JL |
1753 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1754 | ret = -EINVAL; | |
1755 | goto fail; | |
1756 | } | |
1da177e4 | 1757 | |
2d06d8c4 | 1758 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1759 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1760 | policy.min = data->user_policy.min; |
1761 | policy.max = data->user_policy.max; | |
1762 | policy.policy = data->user_policy.policy; | |
1763 | policy.governor = data->user_policy.governor; | |
1764 | ||
0961dd0d TR |
1765 | /* BIOS might change freq behind our back |
1766 | -> ask driver for current freq and notify governors about a change */ | |
1767 | if (cpufreq_driver->get) { | |
1768 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1769 | if (!data->cur) { |
2d06d8c4 | 1770 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1771 | data->cur = policy.cur; |
1772 | } else { | |
f6b0515b | 1773 | if (data->cur != policy.cur && cpufreq_driver->target) |
e08f5f5b GS |
1774 | cpufreq_out_of_sync(cpu, data->cur, |
1775 | policy.cur); | |
a85f7bd3 | 1776 | } |
0961dd0d TR |
1777 | } |
1778 | ||
1da177e4 LT |
1779 | ret = __cpufreq_set_policy(data, &policy); |
1780 | ||
5a01f2e8 VP |
1781 | unlock_policy_rwsem_write(cpu); |
1782 | ||
f1829e4a | 1783 | fail: |
1da177e4 | 1784 | cpufreq_cpu_put(data); |
f1829e4a | 1785 | no_policy: |
1da177e4 LT |
1786 | return ret; |
1787 | } | |
1788 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1789 | ||
dd184a01 | 1790 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1791 | unsigned long action, void *hcpu) |
1792 | { | |
1793 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1794 | struct device *dev; |
c32b6b8e | 1795 | |
8a25a2fd KS |
1796 | dev = get_cpu_device(cpu); |
1797 | if (dev) { | |
c32b6b8e AR |
1798 | switch (action) { |
1799 | case CPU_ONLINE: | |
8bb78442 | 1800 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1801 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1802 | break; |
1803 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1804 | case CPU_DOWN_PREPARE_FROZEN: |
8a25a2fd | 1805 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1806 | break; |
5a01f2e8 | 1807 | case CPU_DOWN_FAILED: |
8bb78442 | 1808 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1809 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1810 | break; |
1811 | } | |
1812 | } | |
1813 | return NOTIFY_OK; | |
1814 | } | |
1815 | ||
9c36f746 | 1816 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1817 | .notifier_call = cpufreq_cpu_callback, |
1818 | }; | |
1da177e4 LT |
1819 | |
1820 | /********************************************************************* | |
1821 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1822 | *********************************************************************/ | |
1823 | ||
1824 | /** | |
1825 | * cpufreq_register_driver - register a CPU Frequency driver | |
1826 | * @driver_data: A struct cpufreq_driver containing the values# | |
1827 | * submitted by the CPU Frequency driver. | |
1828 | * | |
32ee8c3e | 1829 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1830 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1831 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1832 | * |
1833 | */ | |
221dee28 | 1834 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1835 | { |
1836 | unsigned long flags; | |
1837 | int ret; | |
1838 | ||
a7b422cd KRW |
1839 | if (cpufreq_disabled()) |
1840 | return -ENODEV; | |
1841 | ||
1da177e4 LT |
1842 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1843 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1844 | return -EINVAL; | |
1845 | ||
2d06d8c4 | 1846 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1847 | |
1848 | if (driver_data->setpolicy) | |
1849 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1850 | ||
1851 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1852 | if (cpufreq_driver) { | |
1853 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1854 | return -EBUSY; | |
1855 | } | |
1856 | cpufreq_driver = driver_data; | |
1857 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1858 | ||
8a25a2fd | 1859 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1860 | if (ret) |
1861 | goto err_null_driver; | |
1da177e4 | 1862 | |
8f5bc2ab | 1863 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1864 | int i; |
1865 | ret = -ENODEV; | |
1866 | ||
1867 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1868 | for (i = 0; i < nr_cpu_ids; i++) |
1869 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1870 | ret = 0; |
7a6aedfa MT |
1871 | break; |
1872 | } | |
1da177e4 LT |
1873 | |
1874 | /* if all ->init() calls failed, unregister */ | |
1875 | if (ret) { | |
2d06d8c4 | 1876 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1877 | driver_data->name); |
8a25a2fd | 1878 | goto err_if_unreg; |
1da177e4 LT |
1879 | } |
1880 | } | |
1881 | ||
8f5bc2ab | 1882 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1883 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1884 | |
8f5bc2ab | 1885 | return 0; |
8a25a2fd KS |
1886 | err_if_unreg: |
1887 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1888 | err_null_driver: |
1889 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1890 | cpufreq_driver = NULL; | |
1891 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1892 | return ret; |
1da177e4 LT |
1893 | } |
1894 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1895 | ||
1896 | ||
1897 | /** | |
1898 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1899 | * | |
32ee8c3e | 1900 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1901 | * the right to do so, i.e. if you have succeeded in initialising before! |
1902 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1903 | * currently not initialised. | |
1904 | */ | |
221dee28 | 1905 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1906 | { |
1907 | unsigned long flags; | |
1908 | ||
2d06d8c4 | 1909 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1910 | return -EINVAL; |
1da177e4 | 1911 | |
2d06d8c4 | 1912 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1913 | |
8a25a2fd | 1914 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1915 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1916 | |
1917 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1918 | cpufreq_driver = NULL; | |
1919 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1920 | ||
1921 | return 0; | |
1922 | } | |
1923 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1924 | |
1925 | static int __init cpufreq_core_init(void) | |
1926 | { | |
1927 | int cpu; | |
1928 | ||
a7b422cd KRW |
1929 | if (cpufreq_disabled()) |
1930 | return -ENODEV; | |
1931 | ||
5a01f2e8 | 1932 | for_each_possible_cpu(cpu) { |
f1625066 | 1933 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1934 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1935 | } | |
8aa84ad8 | 1936 | |
8a25a2fd | 1937 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1938 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1939 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1940 | |
5a01f2e8 VP |
1941 | return 0; |
1942 | } | |
5a01f2e8 | 1943 | core_initcall(cpufreq_core_init); |