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 | */ | |
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 TR |
297 | (unsigned long)freqs->cpu); |
298 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 299 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 300 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 301 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
302 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
303 | policy->cur = freqs->new; | |
1da177e4 LT |
304 | break; |
305 | } | |
1da177e4 LT |
306 | } |
307 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
308 | ||
309 | ||
310 | ||
311 | /********************************************************************* | |
312 | * SYSFS INTERFACE * | |
313 | *********************************************************************/ | |
314 | ||
3bcb09a3 JF |
315 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
316 | { | |
317 | struct cpufreq_governor *t; | |
318 | ||
319 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 320 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
321 | return t; |
322 | ||
323 | return NULL; | |
324 | } | |
325 | ||
1da177e4 LT |
326 | /** |
327 | * cpufreq_parse_governor - parse a governor string | |
328 | */ | |
905d77cd | 329 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
330 | struct cpufreq_governor **governor) |
331 | { | |
3bcb09a3 JF |
332 | int err = -EINVAL; |
333 | ||
1da177e4 | 334 | if (!cpufreq_driver) |
3bcb09a3 JF |
335 | goto out; |
336 | ||
1da177e4 LT |
337 | if (cpufreq_driver->setpolicy) { |
338 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
339 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 340 | err = 0; |
e08f5f5b GS |
341 | } else if (!strnicmp(str_governor, "powersave", |
342 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 343 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 344 | err = 0; |
1da177e4 | 345 | } |
3bcb09a3 | 346 | } else if (cpufreq_driver->target) { |
1da177e4 | 347 | struct cpufreq_governor *t; |
3bcb09a3 | 348 | |
3fc54d37 | 349 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
350 | |
351 | t = __find_governor(str_governor); | |
352 | ||
ea714970 | 353 | if (t == NULL) { |
1a8e1463 | 354 | int ret; |
ea714970 | 355 | |
1a8e1463 KC |
356 | mutex_unlock(&cpufreq_governor_mutex); |
357 | ret = request_module("cpufreq_%s", str_governor); | |
358 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 359 | |
1a8e1463 KC |
360 | if (ret == 0) |
361 | t = __find_governor(str_governor); | |
ea714970 JF |
362 | } |
363 | ||
3bcb09a3 JF |
364 | if (t != NULL) { |
365 | *governor = t; | |
366 | err = 0; | |
1da177e4 | 367 | } |
3bcb09a3 | 368 | |
3fc54d37 | 369 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 370 | } |
29464f28 | 371 | out: |
3bcb09a3 | 372 | return err; |
1da177e4 | 373 | } |
1da177e4 LT |
374 | |
375 | ||
1da177e4 | 376 | /** |
e08f5f5b GS |
377 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
378 | * print out cpufreq information | |
1da177e4 LT |
379 | * |
380 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
381 | * "unsigned int". | |
382 | */ | |
383 | ||
32ee8c3e DJ |
384 | #define show_one(file_name, object) \ |
385 | static ssize_t show_##file_name \ | |
905d77cd | 386 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 387 | { \ |
29464f28 | 388 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
389 | } |
390 | ||
391 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
392 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 393 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
394 | show_one(scaling_min_freq, min); |
395 | show_one(scaling_max_freq, max); | |
396 | show_one(scaling_cur_freq, cur); | |
397 | ||
e08f5f5b GS |
398 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
399 | struct cpufreq_policy *policy); | |
7970e08b | 400 | |
1da177e4 LT |
401 | /** |
402 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
403 | */ | |
404 | #define store_one(file_name, object) \ | |
405 | static ssize_t store_##file_name \ | |
905d77cd | 406 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 407 | { \ |
f55c9c26 | 408 | unsigned int ret; \ |
1da177e4 LT |
409 | struct cpufreq_policy new_policy; \ |
410 | \ | |
411 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
412 | if (ret) \ | |
413 | return -EINVAL; \ | |
414 | \ | |
29464f28 | 415 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
416 | if (ret != 1) \ |
417 | return -EINVAL; \ | |
418 | \ | |
7970e08b TR |
419 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
420 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
421 | \ |
422 | return ret ? ret : count; \ | |
423 | } | |
424 | ||
29464f28 DJ |
425 | store_one(scaling_min_freq, min); |
426 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
427 | |
428 | /** | |
429 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
430 | */ | |
905d77cd DJ |
431 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
432 | char *buf) | |
1da177e4 | 433 | { |
5a01f2e8 | 434 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
435 | if (!cur_freq) |
436 | return sprintf(buf, "<unknown>"); | |
437 | return sprintf(buf, "%u\n", cur_freq); | |
438 | } | |
439 | ||
440 | ||
441 | /** | |
442 | * show_scaling_governor - show the current policy for the specified CPU | |
443 | */ | |
905d77cd | 444 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 445 | { |
29464f28 | 446 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
447 | return sprintf(buf, "powersave\n"); |
448 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
449 | return sprintf(buf, "performance\n"); | |
450 | else if (policy->governor) | |
4b972f0b | 451 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 452 | policy->governor->name); |
1da177e4 LT |
453 | return -EINVAL; |
454 | } | |
455 | ||
456 | ||
457 | /** | |
458 | * store_scaling_governor - store policy for the specified CPU | |
459 | */ | |
905d77cd DJ |
460 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
461 | const char *buf, size_t count) | |
1da177e4 | 462 | { |
f55c9c26 | 463 | unsigned int ret; |
1da177e4 LT |
464 | char str_governor[16]; |
465 | struct cpufreq_policy new_policy; | |
466 | ||
467 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
468 | if (ret) | |
469 | return ret; | |
470 | ||
29464f28 | 471 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
472 | if (ret != 1) |
473 | return -EINVAL; | |
474 | ||
e08f5f5b GS |
475 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
476 | &new_policy.governor)) | |
1da177e4 LT |
477 | return -EINVAL; |
478 | ||
7970e08b TR |
479 | /* Do not use cpufreq_set_policy here or the user_policy.max |
480 | will be wrongly overridden */ | |
7970e08b TR |
481 | ret = __cpufreq_set_policy(policy, &new_policy); |
482 | ||
483 | policy->user_policy.policy = policy->policy; | |
484 | policy->user_policy.governor = policy->governor; | |
7970e08b | 485 | |
e08f5f5b GS |
486 | if (ret) |
487 | return ret; | |
488 | else | |
489 | return count; | |
1da177e4 LT |
490 | } |
491 | ||
492 | /** | |
493 | * show_scaling_driver - show the cpufreq driver currently loaded | |
494 | */ | |
905d77cd | 495 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 496 | { |
4b972f0b | 497 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
498 | } |
499 | ||
500 | /** | |
501 | * show_scaling_available_governors - show the available CPUfreq governors | |
502 | */ | |
905d77cd DJ |
503 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
504 | char *buf) | |
1da177e4 LT |
505 | { |
506 | ssize_t i = 0; | |
507 | struct cpufreq_governor *t; | |
508 | ||
509 | if (!cpufreq_driver->target) { | |
510 | i += sprintf(buf, "performance powersave"); | |
511 | goto out; | |
512 | } | |
513 | ||
514 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
515 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
516 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 517 | goto out; |
4b972f0b | 518 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 519 | } |
7d5e350f | 520 | out: |
1da177e4 LT |
521 | i += sprintf(&buf[i], "\n"); |
522 | return i; | |
523 | } | |
e8628dd0 | 524 | |
835481d9 | 525 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
526 | { |
527 | ssize_t i = 0; | |
528 | unsigned int cpu; | |
529 | ||
835481d9 | 530 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
531 | if (i) |
532 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
533 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
534 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 535 | break; |
1da177e4 LT |
536 | } |
537 | i += sprintf(&buf[i], "\n"); | |
538 | return i; | |
539 | } | |
540 | ||
e8628dd0 DW |
541 | /** |
542 | * show_related_cpus - show the CPUs affected by each transition even if | |
543 | * hw coordination is in use | |
544 | */ | |
545 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
546 | { | |
e8628dd0 DW |
547 | return show_cpus(policy->related_cpus, buf); |
548 | } | |
549 | ||
550 | /** | |
551 | * show_affected_cpus - show the CPUs affected by each transition | |
552 | */ | |
553 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
554 | { | |
555 | return show_cpus(policy->cpus, buf); | |
556 | } | |
557 | ||
9e76988e | 558 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 559 | const char *buf, size_t count) |
9e76988e VP |
560 | { |
561 | unsigned int freq = 0; | |
562 | unsigned int ret; | |
563 | ||
879000f9 | 564 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
565 | return -EINVAL; |
566 | ||
567 | ret = sscanf(buf, "%u", &freq); | |
568 | if (ret != 1) | |
569 | return -EINVAL; | |
570 | ||
571 | policy->governor->store_setspeed(policy, freq); | |
572 | ||
573 | return count; | |
574 | } | |
575 | ||
576 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
577 | { | |
879000f9 | 578 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
579 | return sprintf(buf, "<unsupported>\n"); |
580 | ||
581 | return policy->governor->show_setspeed(policy, buf); | |
582 | } | |
1da177e4 | 583 | |
e2f74f35 | 584 | /** |
8bf1ac72 | 585 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
586 | */ |
587 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
588 | { | |
589 | unsigned int limit; | |
590 | int ret; | |
591 | if (cpufreq_driver->bios_limit) { | |
592 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
593 | if (!ret) | |
594 | return sprintf(buf, "%u\n", limit); | |
595 | } | |
596 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
597 | } | |
598 | ||
6dad2a29 BP |
599 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
600 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
601 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
602 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
603 | cpufreq_freq_attr_ro(scaling_available_governors); | |
604 | cpufreq_freq_attr_ro(scaling_driver); | |
605 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
606 | cpufreq_freq_attr_ro(bios_limit); | |
607 | cpufreq_freq_attr_ro(related_cpus); | |
608 | cpufreq_freq_attr_ro(affected_cpus); | |
609 | cpufreq_freq_attr_rw(scaling_min_freq); | |
610 | cpufreq_freq_attr_rw(scaling_max_freq); | |
611 | cpufreq_freq_attr_rw(scaling_governor); | |
612 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 613 | |
905d77cd | 614 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
615 | &cpuinfo_min_freq.attr, |
616 | &cpuinfo_max_freq.attr, | |
ed129784 | 617 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
618 | &scaling_min_freq.attr, |
619 | &scaling_max_freq.attr, | |
620 | &affected_cpus.attr, | |
e8628dd0 | 621 | &related_cpus.attr, |
1da177e4 LT |
622 | &scaling_governor.attr, |
623 | &scaling_driver.attr, | |
624 | &scaling_available_governors.attr, | |
9e76988e | 625 | &scaling_setspeed.attr, |
1da177e4 LT |
626 | NULL |
627 | }; | |
628 | ||
8aa84ad8 TR |
629 | struct kobject *cpufreq_global_kobject; |
630 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
631 | ||
29464f28 DJ |
632 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
633 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 634 | |
29464f28 | 635 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 636 | { |
905d77cd DJ |
637 | struct cpufreq_policy *policy = to_policy(kobj); |
638 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 639 | ssize_t ret = -EINVAL; |
a9144436 | 640 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 641 | if (!policy) |
0db4a8a9 | 642 | goto no_policy; |
5a01f2e8 VP |
643 | |
644 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 645 | goto fail; |
5a01f2e8 | 646 | |
e08f5f5b GS |
647 | if (fattr->show) |
648 | ret = fattr->show(policy, buf); | |
649 | else | |
650 | ret = -EIO; | |
651 | ||
5a01f2e8 | 652 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 653 | fail: |
a9144436 | 654 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 655 | no_policy: |
1da177e4 LT |
656 | return ret; |
657 | } | |
658 | ||
905d77cd DJ |
659 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
660 | const char *buf, size_t count) | |
1da177e4 | 661 | { |
905d77cd DJ |
662 | struct cpufreq_policy *policy = to_policy(kobj); |
663 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 664 | ssize_t ret = -EINVAL; |
a9144436 | 665 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 666 | if (!policy) |
a07530b4 | 667 | goto no_policy; |
5a01f2e8 VP |
668 | |
669 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 670 | goto fail; |
5a01f2e8 | 671 | |
e08f5f5b GS |
672 | if (fattr->store) |
673 | ret = fattr->store(policy, buf, count); | |
674 | else | |
675 | ret = -EIO; | |
676 | ||
5a01f2e8 | 677 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 678 | fail: |
a9144436 | 679 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 680 | no_policy: |
1da177e4 LT |
681 | return ret; |
682 | } | |
683 | ||
905d77cd | 684 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 685 | { |
905d77cd | 686 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 687 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
688 | complete(&policy->kobj_unregister); |
689 | } | |
690 | ||
52cf25d0 | 691 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
692 | .show = show, |
693 | .store = store, | |
694 | }; | |
695 | ||
696 | static struct kobj_type ktype_cpufreq = { | |
697 | .sysfs_ops = &sysfs_ops, | |
698 | .default_attrs = default_attrs, | |
699 | .release = cpufreq_sysfs_release, | |
700 | }; | |
701 | ||
19d6f7ec | 702 | /* symlink affected CPUs */ |
cf3289d0 AC |
703 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
704 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
705 | { |
706 | unsigned int j; | |
707 | int ret = 0; | |
708 | ||
709 | for_each_cpu(j, policy->cpus) { | |
710 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 711 | struct device *cpu_dev; |
19d6f7ec DJ |
712 | |
713 | if (j == cpu) | |
714 | continue; | |
19d6f7ec | 715 | |
2d06d8c4 | 716 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 717 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
718 | cpu_dev = get_cpu_device(j); |
719 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
720 | "cpufreq"); |
721 | if (ret) { | |
722 | cpufreq_cpu_put(managed_policy); | |
723 | return ret; | |
724 | } | |
725 | } | |
726 | return ret; | |
727 | } | |
728 | ||
cf3289d0 AC |
729 | static int cpufreq_add_dev_interface(unsigned int cpu, |
730 | struct cpufreq_policy *policy, | |
8a25a2fd | 731 | struct device *dev) |
909a694e | 732 | { |
ecf7e461 | 733 | struct cpufreq_policy new_policy; |
909a694e DJ |
734 | struct freq_attr **drv_attr; |
735 | unsigned long flags; | |
736 | int ret = 0; | |
737 | unsigned int j; | |
738 | ||
739 | /* prepare interface data */ | |
740 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 741 | &dev->kobj, "cpufreq"); |
909a694e DJ |
742 | if (ret) |
743 | return ret; | |
744 | ||
745 | /* set up files for this cpu device */ | |
746 | drv_attr = cpufreq_driver->attr; | |
747 | while ((drv_attr) && (*drv_attr)) { | |
748 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
749 | if (ret) | |
750 | goto err_out_kobj_put; | |
751 | drv_attr++; | |
752 | } | |
753 | if (cpufreq_driver->get) { | |
754 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
755 | if (ret) | |
756 | goto err_out_kobj_put; | |
757 | } | |
758 | if (cpufreq_driver->target) { | |
759 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
760 | if (ret) | |
761 | goto err_out_kobj_put; | |
762 | } | |
e2f74f35 TR |
763 | if (cpufreq_driver->bios_limit) { |
764 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
765 | if (ret) | |
766 | goto err_out_kobj_put; | |
767 | } | |
909a694e DJ |
768 | |
769 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
770 | for_each_cpu(j, policy->cpus) { | |
909a694e | 771 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 772 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
773 | } |
774 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
775 | ||
776 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
777 | if (ret) |
778 | goto err_out_kobj_put; | |
779 | ||
780 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
781 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
782 | policy->governor = NULL; | |
783 | ||
784 | /* set default policy */ | |
785 | ret = __cpufreq_set_policy(policy, &new_policy); | |
786 | policy->user_policy.policy = policy->policy; | |
787 | policy->user_policy.governor = policy->governor; | |
788 | ||
789 | if (ret) { | |
2d06d8c4 | 790 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
791 | if (cpufreq_driver->exit) |
792 | cpufreq_driver->exit(policy); | |
793 | } | |
909a694e DJ |
794 | return ret; |
795 | ||
796 | err_out_kobj_put: | |
797 | kobject_put(&policy->kobj); | |
798 | wait_for_completion(&policy->kobj_unregister); | |
799 | return ret; | |
800 | } | |
801 | ||
fcf80582 VK |
802 | #ifdef CONFIG_HOTPLUG_CPU |
803 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
804 | struct device *dev) | |
805 | { | |
806 | struct cpufreq_policy *policy; | |
807 | int ret = 0; | |
808 | unsigned long flags; | |
809 | ||
810 | policy = cpufreq_cpu_get(sibling); | |
811 | WARN_ON(!policy); | |
812 | ||
fcf80582 VK |
813 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
814 | ||
2eaa3e2d VK |
815 | lock_policy_rwsem_write(sibling); |
816 | ||
fcf80582 | 817 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 818 | |
fcf80582 | 819 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 820 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
fcf80582 VK |
821 | per_cpu(cpufreq_cpu_data, cpu) = policy; |
822 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
823 | ||
2eaa3e2d VK |
824 | unlock_policy_rwsem_write(sibling); |
825 | ||
fcf80582 VK |
826 | __cpufreq_governor(policy, CPUFREQ_GOV_START); |
827 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
828 | ||
fcf80582 VK |
829 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
830 | if (ret) { | |
831 | cpufreq_cpu_put(policy); | |
832 | return ret; | |
833 | } | |
834 | ||
835 | return 0; | |
836 | } | |
837 | #endif | |
1da177e4 LT |
838 | |
839 | /** | |
840 | * cpufreq_add_dev - add a CPU device | |
841 | * | |
32ee8c3e | 842 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
843 | * |
844 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
845 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
846 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 847 | */ |
8a25a2fd | 848 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 849 | { |
fcf80582 | 850 | unsigned int j, cpu = dev->id; |
65922465 | 851 | int ret = -ENOMEM; |
1da177e4 | 852 | struct cpufreq_policy *policy; |
1da177e4 | 853 | unsigned long flags; |
90e41bac | 854 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 855 | struct cpufreq_governor *gov; |
90e41bac PB |
856 | int sibling; |
857 | #endif | |
1da177e4 | 858 | |
c32b6b8e AR |
859 | if (cpu_is_offline(cpu)) |
860 | return 0; | |
861 | ||
2d06d8c4 | 862 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
863 | |
864 | #ifdef CONFIG_SMP | |
865 | /* check whether a different CPU already registered this | |
866 | * CPU because it is in the same boat. */ | |
867 | policy = cpufreq_cpu_get(cpu); | |
868 | if (unlikely(policy)) { | |
8ff69732 | 869 | cpufreq_cpu_put(policy); |
1da177e4 LT |
870 | return 0; |
871 | } | |
fcf80582 VK |
872 | |
873 | #ifdef CONFIG_HOTPLUG_CPU | |
874 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
2eaa3e2d | 875 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
876 | for_each_online_cpu(sibling) { |
877 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d VK |
878 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
879 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
fcf80582 | 880 | return cpufreq_add_policy_cpu(cpu, sibling, dev); |
2eaa3e2d | 881 | } |
fcf80582 | 882 | } |
2eaa3e2d | 883 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 884 | #endif |
1da177e4 LT |
885 | #endif |
886 | ||
887 | if (!try_module_get(cpufreq_driver->owner)) { | |
888 | ret = -EINVAL; | |
889 | goto module_out; | |
890 | } | |
891 | ||
e98df50c | 892 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 893 | if (!policy) |
1da177e4 | 894 | goto nomem_out; |
059019a3 DJ |
895 | |
896 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 897 | goto err_free_policy; |
059019a3 DJ |
898 | |
899 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 900 | goto err_free_cpumask; |
1da177e4 LT |
901 | |
902 | policy->cpu = cpu; | |
65922465 | 903 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 904 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 905 | |
5a01f2e8 | 906 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 907 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 908 | |
1da177e4 | 909 | init_completion(&policy->kobj_unregister); |
65f27f38 | 910 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
911 | |
912 | /* call driver. From then on the cpufreq must be able | |
913 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
914 | */ | |
915 | ret = cpufreq_driver->init(policy); | |
916 | if (ret) { | |
2d06d8c4 | 917 | pr_debug("initialization failed\n"); |
2eaa3e2d | 918 | goto err_set_policy_cpu; |
1da177e4 | 919 | } |
643ae6e8 | 920 | |
fcf80582 VK |
921 | /* related cpus should atleast have policy->cpus */ |
922 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
923 | ||
643ae6e8 VK |
924 | /* |
925 | * affected cpus must always be the one, which are online. We aren't | |
926 | * managing offline cpus here. | |
927 | */ | |
928 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
929 | ||
187d9f4e MC |
930 | policy->user_policy.min = policy->min; |
931 | policy->user_policy.max = policy->max; | |
1da177e4 | 932 | |
a1531acd TR |
933 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
934 | CPUFREQ_START, policy); | |
935 | ||
fcf80582 VK |
936 | #ifdef CONFIG_HOTPLUG_CPU |
937 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
938 | if (gov) { | |
939 | policy->governor = gov; | |
940 | pr_debug("Restoring governor %s for cpu %d\n", | |
941 | policy->governor->name, cpu); | |
4bfa042c | 942 | } |
fcf80582 | 943 | #endif |
1da177e4 | 944 | |
8a25a2fd | 945 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
946 | if (ret) |
947 | goto err_out_unregister; | |
8ff69732 | 948 | |
038c5b3e | 949 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 950 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 951 | pr_debug("initialization complete\n"); |
87c32271 | 952 | |
1da177e4 LT |
953 | return 0; |
954 | ||
1da177e4 LT |
955 | err_out_unregister: |
956 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 957 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 958 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
959 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
960 | ||
c10997f6 | 961 | kobject_put(&policy->kobj); |
1da177e4 LT |
962 | wait_for_completion(&policy->kobj_unregister); |
963 | ||
2eaa3e2d VK |
964 | err_set_policy_cpu: |
965 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
cad70a6a | 966 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
967 | err_free_cpumask: |
968 | free_cpumask_var(policy->cpus); | |
969 | err_free_policy: | |
1da177e4 | 970 | kfree(policy); |
1da177e4 LT |
971 | nomem_out: |
972 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 973 | module_out: |
1da177e4 LT |
974 | return ret; |
975 | } | |
976 | ||
b8eed8af VK |
977 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
978 | { | |
979 | int j; | |
980 | ||
981 | policy->last_cpu = policy->cpu; | |
982 | policy->cpu = cpu; | |
983 | ||
3361b7b1 | 984 | for_each_cpu(j, policy->cpus) |
b8eed8af | 985 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
986 | |
987 | #ifdef CONFIG_CPU_FREQ_TABLE | |
988 | cpufreq_frequency_table_update_policy_cpu(policy); | |
989 | #endif | |
990 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
991 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
992 | } | |
1da177e4 LT |
993 | |
994 | /** | |
5a01f2e8 | 995 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
996 | * |
997 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
998 | * Caller should already have policy_rwsem in write mode for this CPU. |
999 | * This routine frees the rwsem before returning. | |
1da177e4 | 1000 | */ |
8a25a2fd | 1001 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1002 | { |
b8eed8af | 1003 | unsigned int cpu = dev->id, ret, cpus; |
1da177e4 LT |
1004 | unsigned long flags; |
1005 | struct cpufreq_policy *data; | |
499bca9b AW |
1006 | struct kobject *kobj; |
1007 | struct completion *cmp; | |
8a25a2fd | 1008 | struct device *cpu_dev; |
1da177e4 | 1009 | |
b8eed8af | 1010 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 LT |
1011 | |
1012 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
2eaa3e2d | 1013 | |
7a6aedfa | 1014 | data = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1015 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1016 | ||
1017 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 LT |
1018 | |
1019 | if (!data) { | |
b8eed8af | 1020 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1021 | return -EINVAL; |
1022 | } | |
1da177e4 | 1023 | |
b8eed8af | 1024 | if (cpufreq_driver->target) |
f6a7409c | 1025 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
084f3493 TR |
1026 | |
1027 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1028 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1029 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
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); |
1da177e4 | 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); | |
2eaa3e2d VK |
1046 | |
1047 | WARN_ON(lock_policy_rwsem_write(cpu)); | |
b8eed8af | 1048 | cpumask_set_cpu(cpu, data->cpus); |
2eaa3e2d VK |
1049 | |
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); |
2eaa3e2d | 1053 | |
499bca9b | 1054 | unlock_policy_rwsem_write(cpu); |
2eaa3e2d VK |
1055 | |
1056 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, | |
1057 | "cpufreq"); | |
b8eed8af | 1058 | return -EINVAL; |
1da177e4 | 1059 | } |
b8eed8af | 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"); | |
27ecddc2 | 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); | |
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 | { | |
1159 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1160 | unsigned int ret_freq = 0; |
95235ca2 VP |
1161 | |
1162 | if (policy) { | |
e08f5f5b | 1163 | ret_freq = policy->cur; |
95235ca2 VP |
1164 | cpufreq_cpu_put(policy); |
1165 | } | |
1166 | ||
4d34a67d | 1167 | return ret_freq; |
95235ca2 VP |
1168 | } |
1169 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1170 | ||
3d737108 JB |
1171 | /** |
1172 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1173 | * @cpu: CPU number | |
1174 | * | |
1175 | * Just return the max possible frequency for a given CPU. | |
1176 | */ | |
1177 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1178 | { | |
1179 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1180 | unsigned int ret_freq = 0; | |
1181 | ||
1182 | if (policy) { | |
1183 | ret_freq = policy->max; | |
1184 | cpufreq_cpu_put(policy); | |
1185 | } | |
1186 | ||
1187 | return ret_freq; | |
1188 | } | |
1189 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1190 | ||
95235ca2 | 1191 | |
5a01f2e8 | 1192 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1193 | { |
7a6aedfa | 1194 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1195 | unsigned int ret_freq = 0; |
1da177e4 | 1196 | |
1da177e4 | 1197 | if (!cpufreq_driver->get) |
4d34a67d | 1198 | return ret_freq; |
1da177e4 | 1199 | |
e08f5f5b | 1200 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1201 | |
e08f5f5b GS |
1202 | if (ret_freq && policy->cur && |
1203 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1204 | /* verify no discrepancy between actual and | |
1205 | saved value exists */ | |
1206 | if (unlikely(ret_freq != policy->cur)) { | |
1207 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1208 | schedule_work(&policy->update); |
1209 | } | |
1210 | } | |
1211 | ||
4d34a67d | 1212 | return ret_freq; |
5a01f2e8 | 1213 | } |
1da177e4 | 1214 | |
5a01f2e8 VP |
1215 | /** |
1216 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1217 | * @cpu: CPU number | |
1218 | * | |
1219 | * Get the CPU current (static) CPU frequency | |
1220 | */ | |
1221 | unsigned int cpufreq_get(unsigned int cpu) | |
1222 | { | |
1223 | unsigned int ret_freq = 0; | |
1224 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1225 | ||
1226 | if (!policy) | |
1227 | goto out; | |
1228 | ||
1229 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1230 | goto out_policy; | |
1231 | ||
1232 | ret_freq = __cpufreq_get(cpu); | |
1233 | ||
1234 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1235 | |
5a01f2e8 VP |
1236 | out_policy: |
1237 | cpufreq_cpu_put(policy); | |
1238 | out: | |
4d34a67d | 1239 | return ret_freq; |
1da177e4 LT |
1240 | } |
1241 | EXPORT_SYMBOL(cpufreq_get); | |
1242 | ||
8a25a2fd KS |
1243 | static struct subsys_interface cpufreq_interface = { |
1244 | .name = "cpufreq", | |
1245 | .subsys = &cpu_subsys, | |
1246 | .add_dev = cpufreq_add_dev, | |
1247 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1248 | }; |
1249 | ||
1da177e4 | 1250 | |
42d4dc3f | 1251 | /** |
e00e56df RW |
1252 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1253 | * | |
1254 | * This function is only executed for the boot processor. The other CPUs | |
1255 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1256 | */ |
e00e56df | 1257 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1258 | { |
e08f5f5b | 1259 | int ret = 0; |
4bc5d341 | 1260 | |
e00e56df | 1261 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1262 | struct cpufreq_policy *cpu_policy; |
1263 | ||
2d06d8c4 | 1264 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1265 | |
e00e56df | 1266 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1267 | cpu_policy = cpufreq_cpu_get(cpu); |
1268 | if (!cpu_policy) | |
e00e56df | 1269 | return 0; |
42d4dc3f BH |
1270 | |
1271 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1272 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1273 | if (ret) |
42d4dc3f BH |
1274 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1275 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1276 | } |
1277 | ||
42d4dc3f | 1278 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1279 | return ret; |
42d4dc3f BH |
1280 | } |
1281 | ||
1da177e4 | 1282 | /** |
e00e56df | 1283 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1284 | * |
1285 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1286 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1287 | * restored. It will verify that the current freq is in sync with | |
1288 | * what we believe it to be. This is a bit later than when it | |
1289 | * should be, but nonethteless it's better than calling | |
1290 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1291 | * |
1292 | * This function is only executed for the boot CPU. The other CPUs have not | |
1293 | * been turned on yet. | |
1da177e4 | 1294 | */ |
e00e56df | 1295 | static void cpufreq_bp_resume(void) |
1da177e4 | 1296 | { |
e08f5f5b | 1297 | int ret = 0; |
4bc5d341 | 1298 | |
e00e56df | 1299 | int cpu = smp_processor_id(); |
1da177e4 LT |
1300 | struct cpufreq_policy *cpu_policy; |
1301 | ||
2d06d8c4 | 1302 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1303 | |
e00e56df | 1304 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1305 | cpu_policy = cpufreq_cpu_get(cpu); |
1306 | if (!cpu_policy) | |
e00e56df | 1307 | return; |
1da177e4 LT |
1308 | |
1309 | if (cpufreq_driver->resume) { | |
1310 | ret = cpufreq_driver->resume(cpu_policy); | |
1311 | if (ret) { | |
1312 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1313 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1314 | goto fail; |
1da177e4 LT |
1315 | } |
1316 | } | |
1317 | ||
1da177e4 | 1318 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1319 | |
c9060494 | 1320 | fail: |
1da177e4 | 1321 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1322 | } |
1323 | ||
e00e56df RW |
1324 | static struct syscore_ops cpufreq_syscore_ops = { |
1325 | .suspend = cpufreq_bp_suspend, | |
1326 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1327 | }; |
1328 | ||
9d95046e BP |
1329 | /** |
1330 | * cpufreq_get_current_driver - return current driver's name | |
1331 | * | |
1332 | * Return the name string of the currently loaded cpufreq driver | |
1333 | * or NULL, if none. | |
1334 | */ | |
1335 | const char *cpufreq_get_current_driver(void) | |
1336 | { | |
1337 | if (cpufreq_driver) | |
1338 | return cpufreq_driver->name; | |
1339 | ||
1340 | return NULL; | |
1341 | } | |
1342 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1343 | |
1344 | /********************************************************************* | |
1345 | * NOTIFIER LISTS INTERFACE * | |
1346 | *********************************************************************/ | |
1347 | ||
1348 | /** | |
1349 | * cpufreq_register_notifier - register a driver with cpufreq | |
1350 | * @nb: notifier function to register | |
1351 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1352 | * | |
32ee8c3e | 1353 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1354 | * are notified about clock rate changes (once before and once after |
1355 | * the transition), or a list of drivers that are notified about | |
1356 | * changes in cpufreq policy. | |
1357 | * | |
1358 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1359 | * blocking_notifier_chain_register. |
1da177e4 LT |
1360 | */ |
1361 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1362 | { | |
1363 | int ret; | |
1364 | ||
d5aaffa9 DB |
1365 | if (cpufreq_disabled()) |
1366 | return -EINVAL; | |
1367 | ||
74212ca4 CEB |
1368 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1369 | ||
1da177e4 LT |
1370 | switch (list) { |
1371 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1372 | ret = srcu_notifier_chain_register( |
e041c683 | 1373 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1374 | break; |
1375 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1376 | ret = blocking_notifier_chain_register( |
1377 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1378 | break; |
1379 | default: | |
1380 | ret = -EINVAL; | |
1381 | } | |
1da177e4 LT |
1382 | |
1383 | return ret; | |
1384 | } | |
1385 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1386 | ||
1387 | ||
1388 | /** | |
1389 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1390 | * @nb: notifier block to be unregistered | |
1391 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1392 | * | |
1393 | * Remove a driver from the CPU frequency notifier list. | |
1394 | * | |
1395 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1396 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1397 | */ |
1398 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1399 | { | |
1400 | int ret; | |
1401 | ||
d5aaffa9 DB |
1402 | if (cpufreq_disabled()) |
1403 | return -EINVAL; | |
1404 | ||
1da177e4 LT |
1405 | switch (list) { |
1406 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1407 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1408 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1409 | break; |
1410 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1411 | ret = blocking_notifier_chain_unregister( |
1412 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1413 | break; |
1414 | default: | |
1415 | ret = -EINVAL; | |
1416 | } | |
1da177e4 LT |
1417 | |
1418 | return ret; | |
1419 | } | |
1420 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1421 | ||
1422 | ||
1423 | /********************************************************************* | |
1424 | * GOVERNORS * | |
1425 | *********************************************************************/ | |
1426 | ||
1427 | ||
1428 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1429 | unsigned int target_freq, | |
1430 | unsigned int relation) | |
1431 | { | |
1432 | int retval = -EINVAL; | |
7249924e | 1433 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1434 | |
a7b422cd KRW |
1435 | if (cpufreq_disabled()) |
1436 | return -ENODEV; | |
1437 | ||
7249924e VK |
1438 | /* Make sure that target_freq is within supported range */ |
1439 | if (target_freq > policy->max) | |
1440 | target_freq = policy->max; | |
1441 | if (target_freq < policy->min) | |
1442 | target_freq = policy->min; | |
1443 | ||
1444 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1445 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1446 | |
1447 | if (target_freq == policy->cur) | |
1448 | return 0; | |
1449 | ||
3361b7b1 | 1450 | if (cpufreq_driver->target) |
1da177e4 | 1451 | retval = cpufreq_driver->target(policy, target_freq, relation); |
90d45d17 | 1452 | |
1da177e4 LT |
1453 | return retval; |
1454 | } | |
1455 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1456 | ||
1da177e4 LT |
1457 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1458 | unsigned int target_freq, | |
1459 | unsigned int relation) | |
1460 | { | |
f1829e4a | 1461 | int ret = -EINVAL; |
1da177e4 LT |
1462 | |
1463 | policy = cpufreq_cpu_get(policy->cpu); | |
1464 | if (!policy) | |
f1829e4a | 1465 | goto no_policy; |
1da177e4 | 1466 | |
5a01f2e8 | 1467 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1468 | goto fail; |
1da177e4 LT |
1469 | |
1470 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1471 | ||
5a01f2e8 | 1472 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1473 | |
f1829e4a | 1474 | fail: |
1da177e4 | 1475 | cpufreq_cpu_put(policy); |
f1829e4a | 1476 | no_policy: |
1da177e4 LT |
1477 | return ret; |
1478 | } | |
1479 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1480 | ||
bf0b90e3 | 1481 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1482 | { |
1483 | int ret = 0; | |
1484 | ||
d5aaffa9 DB |
1485 | if (cpufreq_disabled()) |
1486 | return ret; | |
1487 | ||
3361b7b1 | 1488 | if (!cpufreq_driver->getavg) |
0676f7f2 VK |
1489 | return 0; |
1490 | ||
dfde5d62 VP |
1491 | policy = cpufreq_cpu_get(policy->cpu); |
1492 | if (!policy) | |
1493 | return -EINVAL; | |
1494 | ||
0676f7f2 | 1495 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1496 | |
dfde5d62 VP |
1497 | cpufreq_cpu_put(policy); |
1498 | return ret; | |
1499 | } | |
5a01f2e8 | 1500 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1501 | |
153d7f3f | 1502 | /* |
153d7f3f AV |
1503 | * when "event" is CPUFREQ_GOV_LIMITS |
1504 | */ | |
1da177e4 | 1505 | |
e08f5f5b GS |
1506 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1507 | unsigned int event) | |
1da177e4 | 1508 | { |
cc993cab | 1509 | int ret; |
6afde10c TR |
1510 | |
1511 | /* Only must be defined when default governor is known to have latency | |
1512 | restrictions, like e.g. conservative or ondemand. | |
1513 | That this is the case is already ensured in Kconfig | |
1514 | */ | |
1515 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1516 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1517 | #else | |
1518 | struct cpufreq_governor *gov = NULL; | |
1519 | #endif | |
1c256245 TR |
1520 | |
1521 | if (policy->governor->max_transition_latency && | |
1522 | policy->cpuinfo.transition_latency > | |
1523 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1524 | if (!gov) |
1525 | return -EINVAL; | |
1526 | else { | |
1527 | printk(KERN_WARNING "%s governor failed, too long" | |
1528 | " transition latency of HW, fallback" | |
1529 | " to %s governor\n", | |
1530 | policy->governor->name, | |
1531 | gov->name); | |
1532 | policy->governor = gov; | |
1533 | } | |
1c256245 | 1534 | } |
1da177e4 LT |
1535 | |
1536 | if (!try_module_get(policy->governor->owner)) | |
1537 | return -EINVAL; | |
1538 | ||
2d06d8c4 | 1539 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1540 | policy->cpu, event); |
1da177e4 LT |
1541 | ret = policy->governor->governor(policy, event); |
1542 | ||
8e53695f VK |
1543 | if (event == CPUFREQ_GOV_START) |
1544 | policy->governor->initialized++; | |
1545 | else if (event == CPUFREQ_GOV_STOP) | |
1546 | policy->governor->initialized--; | |
b394058f | 1547 | |
e08f5f5b GS |
1548 | /* we keep one module reference alive for |
1549 | each CPU governed by this CPU */ | |
1da177e4 LT |
1550 | if ((event != CPUFREQ_GOV_START) || ret) |
1551 | module_put(policy->governor->owner); | |
1552 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1553 | module_put(policy->governor->owner); | |
1554 | ||
1555 | return ret; | |
1556 | } | |
1557 | ||
1558 | ||
1da177e4 LT |
1559 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1560 | { | |
3bcb09a3 | 1561 | int err; |
1da177e4 LT |
1562 | |
1563 | if (!governor) | |
1564 | return -EINVAL; | |
1565 | ||
a7b422cd KRW |
1566 | if (cpufreq_disabled()) |
1567 | return -ENODEV; | |
1568 | ||
3fc54d37 | 1569 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1570 | |
b394058f | 1571 | governor->initialized = 0; |
3bcb09a3 JF |
1572 | err = -EBUSY; |
1573 | if (__find_governor(governor->name) == NULL) { | |
1574 | err = 0; | |
1575 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1576 | } |
1da177e4 | 1577 | |
32ee8c3e | 1578 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1579 | return err; |
1da177e4 LT |
1580 | } |
1581 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1582 | ||
1583 | ||
1584 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1585 | { | |
90e41bac PB |
1586 | #ifdef CONFIG_HOTPLUG_CPU |
1587 | int cpu; | |
1588 | #endif | |
1589 | ||
1da177e4 LT |
1590 | if (!governor) |
1591 | return; | |
1592 | ||
a7b422cd KRW |
1593 | if (cpufreq_disabled()) |
1594 | return; | |
1595 | ||
90e41bac PB |
1596 | #ifdef CONFIG_HOTPLUG_CPU |
1597 | for_each_present_cpu(cpu) { | |
1598 | if (cpu_online(cpu)) | |
1599 | continue; | |
1600 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1601 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1602 | } | |
1603 | #endif | |
1604 | ||
3fc54d37 | 1605 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1606 | list_del(&governor->governor_list); |
3fc54d37 | 1607 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1608 | return; |
1609 | } | |
1610 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1611 | ||
1612 | ||
1613 | ||
1614 | /********************************************************************* | |
1615 | * POLICY INTERFACE * | |
1616 | *********************************************************************/ | |
1617 | ||
1618 | /** | |
1619 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1620 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1621 | * is written | |
1da177e4 LT |
1622 | * |
1623 | * Reads the current cpufreq policy. | |
1624 | */ | |
1625 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1626 | { | |
1627 | struct cpufreq_policy *cpu_policy; | |
1628 | if (!policy) | |
1629 | return -EINVAL; | |
1630 | ||
1631 | cpu_policy = cpufreq_cpu_get(cpu); | |
1632 | if (!cpu_policy) | |
1633 | return -EINVAL; | |
1634 | ||
1da177e4 | 1635 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1636 | |
1637 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1638 | return 0; |
1639 | } | |
1640 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1641 | ||
1642 | ||
153d7f3f | 1643 | /* |
e08f5f5b GS |
1644 | * data : current policy. |
1645 | * policy : policy to be set. | |
153d7f3f | 1646 | */ |
e08f5f5b GS |
1647 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1648 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1649 | { |
1650 | int ret = 0; | |
1651 | ||
2d06d8c4 | 1652 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1653 | policy->min, policy->max); |
1654 | ||
e08f5f5b GS |
1655 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1656 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1657 | |
53391fa2 | 1658 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1659 | ret = -EINVAL; |
1660 | goto error_out; | |
1661 | } | |
1662 | ||
1da177e4 LT |
1663 | /* verify the cpu speed can be set within this limit */ |
1664 | ret = cpufreq_driver->verify(policy); | |
1665 | if (ret) | |
1666 | goto error_out; | |
1667 | ||
1da177e4 | 1668 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1669 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1670 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1671 | |
1672 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1673 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1674 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1675 | |
1676 | /* verify the cpu speed can be set within this limit, | |
1677 | which might be different to the first one */ | |
1678 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1679 | if (ret) |
1da177e4 | 1680 | goto error_out; |
1da177e4 LT |
1681 | |
1682 | /* notification of the new policy */ | |
e041c683 AS |
1683 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1684 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1685 | |
7d5e350f DJ |
1686 | data->min = policy->min; |
1687 | data->max = policy->max; | |
1da177e4 | 1688 | |
2d06d8c4 | 1689 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1690 | data->min, data->max); |
1da177e4 LT |
1691 | |
1692 | if (cpufreq_driver->setpolicy) { | |
1693 | data->policy = policy->policy; | |
2d06d8c4 | 1694 | pr_debug("setting range\n"); |
1da177e4 LT |
1695 | ret = cpufreq_driver->setpolicy(policy); |
1696 | } else { | |
1697 | if (policy->governor != data->governor) { | |
1698 | /* save old, working values */ | |
1699 | struct cpufreq_governor *old_gov = data->governor; | |
1700 | ||
2d06d8c4 | 1701 | pr_debug("governor switch\n"); |
1da177e4 LT |
1702 | |
1703 | /* end old governor */ | |
ffe6275f | 1704 | if (data->governor) |
1da177e4 LT |
1705 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1706 | ||
1707 | /* start new governor */ | |
1708 | data->governor = policy->governor; | |
1709 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1710 | /* new governor failed, so re-start old one */ | |
2d06d8c4 | 1711 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1712 | data->governor->name); |
1da177e4 LT |
1713 | if (old_gov) { |
1714 | data->governor = old_gov; | |
e08f5f5b GS |
1715 | __cpufreq_governor(data, |
1716 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1717 | } |
1718 | ret = -EINVAL; | |
1719 | goto error_out; | |
1720 | } | |
1721 | /* might be a policy change, too, so fall through */ | |
1722 | } | |
2d06d8c4 | 1723 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1724 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1725 | } | |
1726 | ||
7d5e350f | 1727 | error_out: |
1da177e4 LT |
1728 | return ret; |
1729 | } | |
1730 | ||
1da177e4 LT |
1731 | /** |
1732 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1733 | * @cpu: CPU which shall be re-evaluated | |
1734 | * | |
25985edc | 1735 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1736 | * at different times. |
1737 | */ | |
1738 | int cpufreq_update_policy(unsigned int cpu) | |
1739 | { | |
1740 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1741 | struct cpufreq_policy policy; | |
f1829e4a | 1742 | int ret; |
1da177e4 | 1743 | |
f1829e4a JL |
1744 | if (!data) { |
1745 | ret = -ENODEV; | |
1746 | goto no_policy; | |
1747 | } | |
1da177e4 | 1748 | |
f1829e4a JL |
1749 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1750 | ret = -EINVAL; | |
1751 | goto fail; | |
1752 | } | |
1da177e4 | 1753 | |
2d06d8c4 | 1754 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1755 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1756 | policy.min = data->user_policy.min; |
1757 | policy.max = data->user_policy.max; | |
1758 | policy.policy = data->user_policy.policy; | |
1759 | policy.governor = data->user_policy.governor; | |
1760 | ||
0961dd0d TR |
1761 | /* BIOS might change freq behind our back |
1762 | -> ask driver for current freq and notify governors about a change */ | |
1763 | if (cpufreq_driver->get) { | |
1764 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1765 | if (!data->cur) { |
2d06d8c4 | 1766 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1767 | data->cur = policy.cur; |
1768 | } else { | |
1769 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1770 | cpufreq_out_of_sync(cpu, data->cur, |
1771 | policy.cur); | |
a85f7bd3 | 1772 | } |
0961dd0d TR |
1773 | } |
1774 | ||
1da177e4 LT |
1775 | ret = __cpufreq_set_policy(data, &policy); |
1776 | ||
5a01f2e8 VP |
1777 | unlock_policy_rwsem_write(cpu); |
1778 | ||
f1829e4a | 1779 | fail: |
1da177e4 | 1780 | cpufreq_cpu_put(data); |
f1829e4a | 1781 | no_policy: |
1da177e4 LT |
1782 | return ret; |
1783 | } | |
1784 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1785 | ||
dd184a01 | 1786 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1787 | unsigned long action, void *hcpu) |
1788 | { | |
1789 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1790 | struct device *dev; |
c32b6b8e | 1791 | |
8a25a2fd KS |
1792 | dev = get_cpu_device(cpu); |
1793 | if (dev) { | |
c32b6b8e AR |
1794 | switch (action) { |
1795 | case CPU_ONLINE: | |
8bb78442 | 1796 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1797 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1798 | break; |
1799 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1800 | case CPU_DOWN_PREPARE_FROZEN: |
8a25a2fd | 1801 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1802 | break; |
5a01f2e8 | 1803 | case CPU_DOWN_FAILED: |
8bb78442 | 1804 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1805 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1806 | break; |
1807 | } | |
1808 | } | |
1809 | return NOTIFY_OK; | |
1810 | } | |
1811 | ||
9c36f746 | 1812 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1813 | .notifier_call = cpufreq_cpu_callback, |
1814 | }; | |
1da177e4 LT |
1815 | |
1816 | /********************************************************************* | |
1817 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1818 | *********************************************************************/ | |
1819 | ||
1820 | /** | |
1821 | * cpufreq_register_driver - register a CPU Frequency driver | |
1822 | * @driver_data: A struct cpufreq_driver containing the values# | |
1823 | * submitted by the CPU Frequency driver. | |
1824 | * | |
32ee8c3e | 1825 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1826 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1827 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1828 | * |
1829 | */ | |
221dee28 | 1830 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1831 | { |
1832 | unsigned long flags; | |
1833 | int ret; | |
1834 | ||
a7b422cd KRW |
1835 | if (cpufreq_disabled()) |
1836 | return -ENODEV; | |
1837 | ||
1da177e4 LT |
1838 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1839 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1840 | return -EINVAL; | |
1841 | ||
2d06d8c4 | 1842 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1843 | |
1844 | if (driver_data->setpolicy) | |
1845 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1846 | ||
1847 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1848 | if (cpufreq_driver) { | |
1849 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1850 | return -EBUSY; | |
1851 | } | |
1852 | cpufreq_driver = driver_data; | |
1853 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1854 | ||
8a25a2fd | 1855 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1856 | if (ret) |
1857 | goto err_null_driver; | |
1da177e4 | 1858 | |
8f5bc2ab | 1859 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1860 | int i; |
1861 | ret = -ENODEV; | |
1862 | ||
1863 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1864 | for (i = 0; i < nr_cpu_ids; i++) |
1865 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1866 | ret = 0; |
7a6aedfa MT |
1867 | break; |
1868 | } | |
1da177e4 LT |
1869 | |
1870 | /* if all ->init() calls failed, unregister */ | |
1871 | if (ret) { | |
2d06d8c4 | 1872 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1873 | driver_data->name); |
8a25a2fd | 1874 | goto err_if_unreg; |
1da177e4 LT |
1875 | } |
1876 | } | |
1877 | ||
8f5bc2ab | 1878 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1879 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1880 | |
8f5bc2ab | 1881 | return 0; |
8a25a2fd KS |
1882 | err_if_unreg: |
1883 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1884 | err_null_driver: |
1885 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1886 | cpufreq_driver = NULL; | |
1887 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1888 | return ret; |
1da177e4 LT |
1889 | } |
1890 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1891 | ||
1892 | ||
1893 | /** | |
1894 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1895 | * | |
32ee8c3e | 1896 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1897 | * the right to do so, i.e. if you have succeeded in initialising before! |
1898 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1899 | * currently not initialised. | |
1900 | */ | |
221dee28 | 1901 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1902 | { |
1903 | unsigned long flags; | |
1904 | ||
2d06d8c4 | 1905 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1906 | return -EINVAL; |
1da177e4 | 1907 | |
2d06d8c4 | 1908 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1909 | |
8a25a2fd | 1910 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1911 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1912 | |
1913 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1914 | cpufreq_driver = NULL; | |
1915 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1916 | ||
1917 | return 0; | |
1918 | } | |
1919 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1920 | |
1921 | static int __init cpufreq_core_init(void) | |
1922 | { | |
1923 | int cpu; | |
1924 | ||
a7b422cd KRW |
1925 | if (cpufreq_disabled()) |
1926 | return -ENODEV; | |
1927 | ||
5a01f2e8 | 1928 | for_each_possible_cpu(cpu) { |
f1625066 | 1929 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1930 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1931 | } | |
8aa84ad8 | 1932 | |
8a25a2fd | 1933 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1934 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1935 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1936 | |
5a01f2e8 VP |
1937 | return 0; |
1938 | } | |
5a01f2e8 | 1939 | core_initcall(cpufreq_core_init); |