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 | */ | |
1c3d85dd | 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 |
0d1857a1 | 48 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
1da177e4 | 49 | |
5a01f2e8 VP |
50 | /* |
51 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
52 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
53 | * | |
54 | * The rules for this semaphore: | |
55 | * - Any routine that wants to read from the policy structure will | |
56 | * do a down_read on this semaphore. | |
57 | * - Any routine that will write to the policy structure and/or may take away | |
58 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
59 | * mode before doing so. | |
60 | * | |
61 | * Additional rules: | |
5a01f2e8 VP |
62 | * - Governor routines that can be called in cpufreq hotplug path should not |
63 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
64 | * - Lock should not be held across |
65 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 66 | */ |
f1625066 | 67 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
68 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
69 | ||
70 | #define lock_policy_rwsem(mode, cpu) \ | |
fa1d8af4 | 71 | static int lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 72 | { \ |
f1625066 | 73 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
74 | BUG_ON(policy_cpu == -1); \ |
75 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 VP |
76 | \ |
77 | return 0; \ | |
78 | } | |
79 | ||
80 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 81 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 82 | |
fa1d8af4 VK |
83 | #define unlock_policy_rwsem(mode, cpu) \ |
84 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
85 | { \ | |
86 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
87 | BUG_ON(policy_cpu == -1); \ | |
88 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 | 89 | } |
5a01f2e8 | 90 | |
fa1d8af4 VK |
91 | unlock_policy_rwsem(read, cpu); |
92 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 93 | |
1da177e4 | 94 | /* internal prototypes */ |
29464f28 DJ |
95 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
96 | unsigned int event); | |
5a01f2e8 | 97 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 98 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
99 | |
100 | /** | |
32ee8c3e DJ |
101 | * Two notifier lists: the "policy" list is involved in the |
102 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
103 | * "transition" list for kernel code that needs to handle |
104 | * changes to devices when the CPU clock speed changes. | |
105 | * The mutex locks both lists. | |
106 | */ | |
e041c683 | 107 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 108 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 109 | |
74212ca4 | 110 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
111 | static int __init init_cpufreq_transition_notifier_list(void) |
112 | { | |
113 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 114 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
115 | return 0; |
116 | } | |
b3438f82 | 117 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 118 | |
a7b422cd | 119 | static int off __read_mostly; |
da584455 | 120 | static int cpufreq_disabled(void) |
a7b422cd KRW |
121 | { |
122 | return off; | |
123 | } | |
124 | void disable_cpufreq(void) | |
125 | { | |
126 | off = 1; | |
127 | } | |
1da177e4 | 128 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 129 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 130 | |
4d5dcc42 VK |
131 | bool have_governor_per_policy(void) |
132 | { | |
1c3d85dd | 133 | return cpufreq_driver->have_governor_per_policy; |
4d5dcc42 | 134 | } |
3f869d6d | 135 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 136 | |
944e9a03 VK |
137 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
138 | { | |
139 | if (have_governor_per_policy()) | |
140 | return &policy->kobj; | |
141 | else | |
142 | return cpufreq_global_kobject; | |
143 | } | |
144 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
145 | ||
a9144436 | 146 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
147 | { |
148 | struct cpufreq_policy *data; | |
149 | unsigned long flags; | |
150 | ||
7a6aedfa | 151 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
152 | goto err_out; |
153 | ||
154 | /* get the cpufreq driver */ | |
1c3d85dd | 155 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 156 | |
1c3d85dd | 157 | if (!cpufreq_driver) |
1da177e4 LT |
158 | goto err_out_unlock; |
159 | ||
1c3d85dd | 160 | if (!try_module_get(cpufreq_driver->owner)) |
1da177e4 LT |
161 | goto err_out_unlock; |
162 | ||
163 | ||
164 | /* get the CPU */ | |
7a6aedfa | 165 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
166 | |
167 | if (!data) | |
168 | goto err_out_put_module; | |
169 | ||
a9144436 | 170 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
171 | goto err_out_put_module; |
172 | ||
0d1857a1 | 173 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
174 | return data; |
175 | ||
7d5e350f | 176 | err_out_put_module: |
1c3d85dd | 177 | module_put(cpufreq_driver->owner); |
5800043b | 178 | err_out_unlock: |
1c3d85dd | 179 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 180 | err_out: |
1da177e4 LT |
181 | return NULL; |
182 | } | |
a9144436 SB |
183 | |
184 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
185 | { | |
d5aaffa9 DB |
186 | if (cpufreq_disabled()) |
187 | return NULL; | |
188 | ||
a9144436 SB |
189 | return __cpufreq_cpu_get(cpu, false); |
190 | } | |
1da177e4 LT |
191 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
192 | ||
a9144436 SB |
193 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
194 | { | |
195 | return __cpufreq_cpu_get(cpu, true); | |
196 | } | |
197 | ||
198 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
199 | { | |
200 | if (!sysfs) | |
201 | kobject_put(&data->kobj); | |
1c3d85dd | 202 | module_put(cpufreq_driver->owner); |
a9144436 | 203 | } |
7d5e350f | 204 | |
1da177e4 LT |
205 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
206 | { | |
d5aaffa9 DB |
207 | if (cpufreq_disabled()) |
208 | return; | |
209 | ||
a9144436 | 210 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
211 | } |
212 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
213 | ||
a9144436 SB |
214 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
215 | { | |
216 | __cpufreq_cpu_put(data, true); | |
217 | } | |
1da177e4 | 218 | |
1da177e4 LT |
219 | /********************************************************************* |
220 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
221 | *********************************************************************/ | |
222 | ||
223 | /** | |
224 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
225 | * | |
226 | * This function alters the system "loops_per_jiffy" for the clock | |
227 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 228 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
229 | * per-CPU loops_per_jiffy value wherever possible. |
230 | */ | |
231 | #ifndef CONFIG_SMP | |
232 | static unsigned long l_p_j_ref; | |
233 | static unsigned int l_p_j_ref_freq; | |
234 | ||
858119e1 | 235 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
236 | { |
237 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
238 | return; | |
239 | ||
240 | if (!l_p_j_ref_freq) { | |
241 | l_p_j_ref = loops_per_jiffy; | |
242 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 243 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 244 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 245 | } |
d08de0c1 | 246 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 247 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
248 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
249 | ci->new); | |
2d06d8c4 | 250 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 251 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
252 | } |
253 | } | |
254 | #else | |
e08f5f5b GS |
255 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
256 | { | |
257 | return; | |
258 | } | |
1da177e4 LT |
259 | #endif |
260 | ||
261 | ||
b43a7ffb VK |
262 | void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
263 | struct cpufreq_freqs *freqs, unsigned int state) | |
1da177e4 LT |
264 | { |
265 | BUG_ON(irqs_disabled()); | |
266 | ||
d5aaffa9 DB |
267 | if (cpufreq_disabled()) |
268 | return; | |
269 | ||
1c3d85dd | 270 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 271 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 272 | state, freqs->new); |
1da177e4 | 273 | |
1da177e4 | 274 | switch (state) { |
e4472cb3 | 275 | |
1da177e4 | 276 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 277 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
278 | * which is not equal to what the cpufreq core thinks is |
279 | * "old frequency". | |
1da177e4 | 280 | */ |
1c3d85dd | 281 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
282 | if ((policy) && (policy->cpu == freqs->cpu) && |
283 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 284 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
285 | " %u, cpufreq assumed %u kHz.\n", |
286 | freqs->old, policy->cur); | |
287 | freqs->old = policy->cur; | |
1da177e4 LT |
288 | } |
289 | } | |
b4dfdbb3 | 290 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 291 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
292 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
293 | break; | |
e4472cb3 | 294 | |
1da177e4 LT |
295 | case CPUFREQ_POSTCHANGE: |
296 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 297 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 298 | (unsigned long)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 | 306 | } |
b43a7ffb VK |
307 | /** |
308 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
309 | * on frequency transition. | |
310 | * | |
311 | * This function calls the transition notifiers and the "adjust_jiffies" | |
312 | * function. It is called twice on all CPU frequency changes that have | |
313 | * external effects. | |
314 | */ | |
315 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
316 | struct cpufreq_freqs *freqs, unsigned int state) | |
317 | { | |
318 | for_each_cpu(freqs->cpu, policy->cpus) | |
319 | __cpufreq_notify_transition(policy, freqs, state); | |
320 | } | |
1da177e4 LT |
321 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
322 | ||
323 | ||
324 | ||
325 | /********************************************************************* | |
326 | * SYSFS INTERFACE * | |
327 | *********************************************************************/ | |
328 | ||
3bcb09a3 JF |
329 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
330 | { | |
331 | struct cpufreq_governor *t; | |
332 | ||
333 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 334 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
335 | return t; |
336 | ||
337 | return NULL; | |
338 | } | |
339 | ||
1da177e4 LT |
340 | /** |
341 | * cpufreq_parse_governor - parse a governor string | |
342 | */ | |
905d77cd | 343 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
344 | struct cpufreq_governor **governor) |
345 | { | |
3bcb09a3 | 346 | int err = -EINVAL; |
1c3d85dd RW |
347 | |
348 | if (!cpufreq_driver) | |
3bcb09a3 JF |
349 | goto out; |
350 | ||
1c3d85dd | 351 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
352 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
353 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 354 | err = 0; |
e08f5f5b GS |
355 | } else if (!strnicmp(str_governor, "powersave", |
356 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 357 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 358 | err = 0; |
1da177e4 | 359 | } |
1c3d85dd | 360 | } else if (cpufreq_driver->target) { |
1da177e4 | 361 | struct cpufreq_governor *t; |
3bcb09a3 | 362 | |
3fc54d37 | 363 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
364 | |
365 | t = __find_governor(str_governor); | |
366 | ||
ea714970 | 367 | if (t == NULL) { |
1a8e1463 | 368 | int ret; |
ea714970 | 369 | |
1a8e1463 KC |
370 | mutex_unlock(&cpufreq_governor_mutex); |
371 | ret = request_module("cpufreq_%s", str_governor); | |
372 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 373 | |
1a8e1463 KC |
374 | if (ret == 0) |
375 | t = __find_governor(str_governor); | |
ea714970 JF |
376 | } |
377 | ||
3bcb09a3 JF |
378 | if (t != NULL) { |
379 | *governor = t; | |
380 | err = 0; | |
1da177e4 | 381 | } |
3bcb09a3 | 382 | |
3fc54d37 | 383 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 384 | } |
29464f28 | 385 | out: |
3bcb09a3 | 386 | return err; |
1da177e4 | 387 | } |
1da177e4 LT |
388 | |
389 | ||
1da177e4 | 390 | /** |
e08f5f5b GS |
391 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
392 | * print out cpufreq information | |
1da177e4 LT |
393 | * |
394 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
395 | * "unsigned int". | |
396 | */ | |
397 | ||
32ee8c3e DJ |
398 | #define show_one(file_name, object) \ |
399 | static ssize_t show_##file_name \ | |
905d77cd | 400 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 401 | { \ |
29464f28 | 402 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
403 | } |
404 | ||
405 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
406 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 407 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
408 | show_one(scaling_min_freq, min); |
409 | show_one(scaling_max_freq, max); | |
410 | show_one(scaling_cur_freq, cur); | |
411 | ||
e08f5f5b GS |
412 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
413 | struct cpufreq_policy *policy); | |
7970e08b | 414 | |
1da177e4 LT |
415 | /** |
416 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
417 | */ | |
418 | #define store_one(file_name, object) \ | |
419 | static ssize_t store_##file_name \ | |
905d77cd | 420 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 421 | { \ |
f55c9c26 | 422 | unsigned int ret; \ |
1da177e4 LT |
423 | struct cpufreq_policy new_policy; \ |
424 | \ | |
425 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
426 | if (ret) \ | |
427 | return -EINVAL; \ | |
428 | \ | |
29464f28 | 429 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
430 | if (ret != 1) \ |
431 | return -EINVAL; \ | |
432 | \ | |
7970e08b TR |
433 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
434 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
435 | \ |
436 | return ret ? ret : count; \ | |
437 | } | |
438 | ||
29464f28 DJ |
439 | store_one(scaling_min_freq, min); |
440 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
441 | |
442 | /** | |
443 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
444 | */ | |
905d77cd DJ |
445 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
446 | char *buf) | |
1da177e4 | 447 | { |
5a01f2e8 | 448 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
449 | if (!cur_freq) |
450 | return sprintf(buf, "<unknown>"); | |
451 | return sprintf(buf, "%u\n", cur_freq); | |
452 | } | |
453 | ||
454 | ||
455 | /** | |
456 | * show_scaling_governor - show the current policy for the specified CPU | |
457 | */ | |
905d77cd | 458 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 459 | { |
29464f28 | 460 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
461 | return sprintf(buf, "powersave\n"); |
462 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
463 | return sprintf(buf, "performance\n"); | |
464 | else if (policy->governor) | |
4b972f0b | 465 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 466 | policy->governor->name); |
1da177e4 LT |
467 | return -EINVAL; |
468 | } | |
469 | ||
470 | ||
471 | /** | |
472 | * store_scaling_governor - store policy for the specified CPU | |
473 | */ | |
905d77cd DJ |
474 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
475 | const char *buf, size_t count) | |
1da177e4 | 476 | { |
f55c9c26 | 477 | unsigned int ret; |
1da177e4 LT |
478 | char str_governor[16]; |
479 | struct cpufreq_policy new_policy; | |
480 | ||
481 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
482 | if (ret) | |
483 | return ret; | |
484 | ||
29464f28 | 485 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
486 | if (ret != 1) |
487 | return -EINVAL; | |
488 | ||
e08f5f5b GS |
489 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
490 | &new_policy.governor)) | |
1da177e4 LT |
491 | return -EINVAL; |
492 | ||
7970e08b TR |
493 | /* Do not use cpufreq_set_policy here or the user_policy.max |
494 | will be wrongly overridden */ | |
7970e08b TR |
495 | ret = __cpufreq_set_policy(policy, &new_policy); |
496 | ||
497 | policy->user_policy.policy = policy->policy; | |
498 | policy->user_policy.governor = policy->governor; | |
7970e08b | 499 | |
e08f5f5b GS |
500 | if (ret) |
501 | return ret; | |
502 | else | |
503 | return count; | |
1da177e4 LT |
504 | } |
505 | ||
506 | /** | |
507 | * show_scaling_driver - show the cpufreq driver currently loaded | |
508 | */ | |
905d77cd | 509 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 510 | { |
1c3d85dd | 511 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
512 | } |
513 | ||
514 | /** | |
515 | * show_scaling_available_governors - show the available CPUfreq governors | |
516 | */ | |
905d77cd DJ |
517 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
518 | char *buf) | |
1da177e4 LT |
519 | { |
520 | ssize_t i = 0; | |
521 | struct cpufreq_governor *t; | |
522 | ||
1c3d85dd | 523 | if (!cpufreq_driver->target) { |
1da177e4 LT |
524 | i += sprintf(buf, "performance powersave"); |
525 | goto out; | |
526 | } | |
527 | ||
528 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
529 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
530 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 531 | goto out; |
4b972f0b | 532 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 533 | } |
7d5e350f | 534 | out: |
1da177e4 LT |
535 | i += sprintf(&buf[i], "\n"); |
536 | return i; | |
537 | } | |
e8628dd0 | 538 | |
835481d9 | 539 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
540 | { |
541 | ssize_t i = 0; | |
542 | unsigned int cpu; | |
543 | ||
835481d9 | 544 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
545 | if (i) |
546 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
547 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
548 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 549 | break; |
1da177e4 LT |
550 | } |
551 | i += sprintf(&buf[i], "\n"); | |
552 | return i; | |
553 | } | |
554 | ||
e8628dd0 DW |
555 | /** |
556 | * show_related_cpus - show the CPUs affected by each transition even if | |
557 | * hw coordination is in use | |
558 | */ | |
559 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
560 | { | |
e8628dd0 DW |
561 | return show_cpus(policy->related_cpus, buf); |
562 | } | |
563 | ||
564 | /** | |
565 | * show_affected_cpus - show the CPUs affected by each transition | |
566 | */ | |
567 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
568 | { | |
569 | return show_cpus(policy->cpus, buf); | |
570 | } | |
571 | ||
9e76988e | 572 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 573 | const char *buf, size_t count) |
9e76988e VP |
574 | { |
575 | unsigned int freq = 0; | |
576 | unsigned int ret; | |
577 | ||
879000f9 | 578 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
579 | return -EINVAL; |
580 | ||
581 | ret = sscanf(buf, "%u", &freq); | |
582 | if (ret != 1) | |
583 | return -EINVAL; | |
584 | ||
585 | policy->governor->store_setspeed(policy, freq); | |
586 | ||
587 | return count; | |
588 | } | |
589 | ||
590 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
591 | { | |
879000f9 | 592 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
593 | return sprintf(buf, "<unsupported>\n"); |
594 | ||
595 | return policy->governor->show_setspeed(policy, buf); | |
596 | } | |
1da177e4 | 597 | |
e2f74f35 | 598 | /** |
8bf1ac72 | 599 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
600 | */ |
601 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
602 | { | |
603 | unsigned int limit; | |
604 | int ret; | |
1c3d85dd RW |
605 | if (cpufreq_driver->bios_limit) { |
606 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
607 | if (!ret) |
608 | return sprintf(buf, "%u\n", limit); | |
609 | } | |
610 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
611 | } | |
612 | ||
6dad2a29 BP |
613 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
614 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
615 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
616 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
617 | cpufreq_freq_attr_ro(scaling_available_governors); | |
618 | cpufreq_freq_attr_ro(scaling_driver); | |
619 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
620 | cpufreq_freq_attr_ro(bios_limit); | |
621 | cpufreq_freq_attr_ro(related_cpus); | |
622 | cpufreq_freq_attr_ro(affected_cpus); | |
623 | cpufreq_freq_attr_rw(scaling_min_freq); | |
624 | cpufreq_freq_attr_rw(scaling_max_freq); | |
625 | cpufreq_freq_attr_rw(scaling_governor); | |
626 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 627 | |
905d77cd | 628 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
629 | &cpuinfo_min_freq.attr, |
630 | &cpuinfo_max_freq.attr, | |
ed129784 | 631 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
632 | &scaling_min_freq.attr, |
633 | &scaling_max_freq.attr, | |
634 | &affected_cpus.attr, | |
e8628dd0 | 635 | &related_cpus.attr, |
1da177e4 LT |
636 | &scaling_governor.attr, |
637 | &scaling_driver.attr, | |
638 | &scaling_available_governors.attr, | |
9e76988e | 639 | &scaling_setspeed.attr, |
1da177e4 LT |
640 | NULL |
641 | }; | |
642 | ||
8aa84ad8 TR |
643 | struct kobject *cpufreq_global_kobject; |
644 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
645 | ||
29464f28 DJ |
646 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
647 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 648 | |
29464f28 | 649 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 650 | { |
905d77cd DJ |
651 | struct cpufreq_policy *policy = to_policy(kobj); |
652 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 653 | ssize_t ret = -EINVAL; |
a9144436 | 654 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 655 | if (!policy) |
0db4a8a9 | 656 | goto no_policy; |
5a01f2e8 VP |
657 | |
658 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 659 | goto fail; |
5a01f2e8 | 660 | |
e08f5f5b GS |
661 | if (fattr->show) |
662 | ret = fattr->show(policy, buf); | |
663 | else | |
664 | ret = -EIO; | |
665 | ||
5a01f2e8 | 666 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 667 | fail: |
a9144436 | 668 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 669 | no_policy: |
1da177e4 LT |
670 | return ret; |
671 | } | |
672 | ||
905d77cd DJ |
673 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
674 | const char *buf, size_t count) | |
1da177e4 | 675 | { |
905d77cd DJ |
676 | struct cpufreq_policy *policy = to_policy(kobj); |
677 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 678 | ssize_t ret = -EINVAL; |
a9144436 | 679 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 680 | if (!policy) |
a07530b4 | 681 | goto no_policy; |
5a01f2e8 VP |
682 | |
683 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 684 | goto fail; |
5a01f2e8 | 685 | |
e08f5f5b GS |
686 | if (fattr->store) |
687 | ret = fattr->store(policy, buf, count); | |
688 | else | |
689 | ret = -EIO; | |
690 | ||
5a01f2e8 | 691 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 692 | fail: |
a9144436 | 693 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 694 | no_policy: |
1da177e4 LT |
695 | return ret; |
696 | } | |
697 | ||
905d77cd | 698 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 699 | { |
905d77cd | 700 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 701 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
702 | complete(&policy->kobj_unregister); |
703 | } | |
704 | ||
52cf25d0 | 705 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
706 | .show = show, |
707 | .store = store, | |
708 | }; | |
709 | ||
710 | static struct kobj_type ktype_cpufreq = { | |
711 | .sysfs_ops = &sysfs_ops, | |
712 | .default_attrs = default_attrs, | |
713 | .release = cpufreq_sysfs_release, | |
714 | }; | |
715 | ||
19d6f7ec | 716 | /* symlink affected CPUs */ |
cf3289d0 AC |
717 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
718 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
719 | { |
720 | unsigned int j; | |
721 | int ret = 0; | |
722 | ||
723 | for_each_cpu(j, policy->cpus) { | |
724 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 725 | struct device *cpu_dev; |
19d6f7ec DJ |
726 | |
727 | if (j == cpu) | |
728 | continue; | |
19d6f7ec | 729 | |
2d06d8c4 | 730 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 731 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
732 | cpu_dev = get_cpu_device(j); |
733 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
734 | "cpufreq"); |
735 | if (ret) { | |
736 | cpufreq_cpu_put(managed_policy); | |
737 | return ret; | |
738 | } | |
739 | } | |
740 | return ret; | |
741 | } | |
742 | ||
cf3289d0 AC |
743 | static int cpufreq_add_dev_interface(unsigned int cpu, |
744 | struct cpufreq_policy *policy, | |
8a25a2fd | 745 | struct device *dev) |
909a694e | 746 | { |
ecf7e461 | 747 | struct cpufreq_policy new_policy; |
909a694e DJ |
748 | struct freq_attr **drv_attr; |
749 | unsigned long flags; | |
750 | int ret = 0; | |
751 | unsigned int j; | |
752 | ||
753 | /* prepare interface data */ | |
754 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 755 | &dev->kobj, "cpufreq"); |
909a694e DJ |
756 | if (ret) |
757 | return ret; | |
758 | ||
759 | /* set up files for this cpu device */ | |
1c3d85dd | 760 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
761 | while ((drv_attr) && (*drv_attr)) { |
762 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
763 | if (ret) | |
1c3d85dd | 764 | goto err_out_kobj_put; |
909a694e DJ |
765 | drv_attr++; |
766 | } | |
1c3d85dd | 767 | if (cpufreq_driver->get) { |
909a694e DJ |
768 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
769 | if (ret) | |
1c3d85dd | 770 | goto err_out_kobj_put; |
909a694e | 771 | } |
1c3d85dd | 772 | if (cpufreq_driver->target) { |
909a694e DJ |
773 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
774 | if (ret) | |
1c3d85dd | 775 | goto err_out_kobj_put; |
909a694e | 776 | } |
1c3d85dd | 777 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
778 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
779 | if (ret) | |
1c3d85dd | 780 | goto err_out_kobj_put; |
e2f74f35 | 781 | } |
909a694e | 782 | |
0d1857a1 | 783 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
909a694e | 784 | for_each_cpu(j, policy->cpus) { |
909a694e | 785 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 786 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e | 787 | } |
0d1857a1 | 788 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
909a694e DJ |
789 | |
790 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
791 | if (ret) |
792 | goto err_out_kobj_put; | |
793 | ||
794 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
795 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
796 | policy->governor = NULL; | |
797 | ||
798 | /* set default policy */ | |
799 | ret = __cpufreq_set_policy(policy, &new_policy); | |
800 | policy->user_policy.policy = policy->policy; | |
801 | policy->user_policy.governor = policy->governor; | |
802 | ||
803 | if (ret) { | |
2d06d8c4 | 804 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
805 | if (cpufreq_driver->exit) |
806 | cpufreq_driver->exit(policy); | |
ecf7e461 | 807 | } |
909a694e DJ |
808 | return ret; |
809 | ||
810 | err_out_kobj_put: | |
811 | kobject_put(&policy->kobj); | |
812 | wait_for_completion(&policy->kobj_unregister); | |
813 | return ret; | |
814 | } | |
815 | ||
fcf80582 VK |
816 | #ifdef CONFIG_HOTPLUG_CPU |
817 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
818 | struct device *dev) | |
819 | { | |
820 | struct cpufreq_policy *policy; | |
1c3d85dd | 821 | int ret = 0, has_target = !!cpufreq_driver->target; |
fcf80582 VK |
822 | unsigned long flags; |
823 | ||
824 | policy = cpufreq_cpu_get(sibling); | |
825 | WARN_ON(!policy); | |
826 | ||
820c6ca2 VK |
827 | if (has_target) |
828 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
fcf80582 | 829 | |
2eaa3e2d VK |
830 | lock_policy_rwsem_write(sibling); |
831 | ||
0d1857a1 | 832 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 833 | |
fcf80582 | 834 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 835 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
fcf80582 | 836 | per_cpu(cpufreq_cpu_data, cpu) = policy; |
0d1857a1 | 837 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 838 | |
2eaa3e2d VK |
839 | unlock_policy_rwsem_write(sibling); |
840 | ||
820c6ca2 VK |
841 | if (has_target) { |
842 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
843 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
844 | } | |
fcf80582 | 845 | |
fcf80582 VK |
846 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
847 | if (ret) { | |
848 | cpufreq_cpu_put(policy); | |
849 | return ret; | |
850 | } | |
851 | ||
852 | return 0; | |
853 | } | |
854 | #endif | |
1da177e4 LT |
855 | |
856 | /** | |
857 | * cpufreq_add_dev - add a CPU device | |
858 | * | |
32ee8c3e | 859 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
860 | * |
861 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
862 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
863 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 864 | */ |
8a25a2fd | 865 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 866 | { |
fcf80582 | 867 | unsigned int j, cpu = dev->id; |
65922465 | 868 | int ret = -ENOMEM; |
1da177e4 | 869 | struct cpufreq_policy *policy; |
1da177e4 | 870 | unsigned long flags; |
90e41bac | 871 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 872 | struct cpufreq_governor *gov; |
90e41bac PB |
873 | int sibling; |
874 | #endif | |
1da177e4 | 875 | |
c32b6b8e AR |
876 | if (cpu_is_offline(cpu)) |
877 | return 0; | |
878 | ||
2d06d8c4 | 879 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
880 | |
881 | #ifdef CONFIG_SMP | |
882 | /* check whether a different CPU already registered this | |
883 | * CPU because it is in the same boat. */ | |
884 | policy = cpufreq_cpu_get(cpu); | |
885 | if (unlikely(policy)) { | |
8ff69732 | 886 | cpufreq_cpu_put(policy); |
1da177e4 LT |
887 | return 0; |
888 | } | |
fcf80582 VK |
889 | |
890 | #ifdef CONFIG_HOTPLUG_CPU | |
891 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 892 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
893 | for_each_online_cpu(sibling) { |
894 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d | 895 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
0d1857a1 | 896 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 897 | return cpufreq_add_policy_cpu(cpu, sibling, dev); |
2eaa3e2d | 898 | } |
fcf80582 | 899 | } |
0d1857a1 | 900 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 901 | #endif |
1da177e4 LT |
902 | #endif |
903 | ||
1c3d85dd | 904 | if (!try_module_get(cpufreq_driver->owner)) { |
1da177e4 LT |
905 | ret = -EINVAL; |
906 | goto module_out; | |
907 | } | |
908 | ||
e98df50c | 909 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 910 | if (!policy) |
1da177e4 | 911 | goto nomem_out; |
059019a3 DJ |
912 | |
913 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 914 | goto err_free_policy; |
059019a3 DJ |
915 | |
916 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 917 | goto err_free_cpumask; |
1da177e4 LT |
918 | |
919 | policy->cpu = cpu; | |
65922465 | 920 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 921 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 922 | |
5a01f2e8 | 923 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 924 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 925 | |
1da177e4 | 926 | init_completion(&policy->kobj_unregister); |
65f27f38 | 927 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
928 | |
929 | /* call driver. From then on the cpufreq must be able | |
930 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
931 | */ | |
1c3d85dd | 932 | ret = cpufreq_driver->init(policy); |
1da177e4 | 933 | if (ret) { |
2d06d8c4 | 934 | pr_debug("initialization failed\n"); |
2eaa3e2d | 935 | goto err_set_policy_cpu; |
1da177e4 | 936 | } |
643ae6e8 | 937 | |
fcf80582 VK |
938 | /* related cpus should atleast have policy->cpus */ |
939 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
940 | ||
643ae6e8 VK |
941 | /* |
942 | * affected cpus must always be the one, which are online. We aren't | |
943 | * managing offline cpus here. | |
944 | */ | |
945 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
946 | ||
187d9f4e MC |
947 | policy->user_policy.min = policy->min; |
948 | policy->user_policy.max = policy->max; | |
1da177e4 | 949 | |
a1531acd TR |
950 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
951 | CPUFREQ_START, policy); | |
952 | ||
fcf80582 VK |
953 | #ifdef CONFIG_HOTPLUG_CPU |
954 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
955 | if (gov) { | |
956 | policy->governor = gov; | |
957 | pr_debug("Restoring governor %s for cpu %d\n", | |
958 | policy->governor->name, cpu); | |
4bfa042c | 959 | } |
fcf80582 | 960 | #endif |
1da177e4 | 961 | |
8a25a2fd | 962 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
963 | if (ret) |
964 | goto err_out_unregister; | |
8ff69732 | 965 | |
038c5b3e | 966 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1c3d85dd | 967 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 968 | pr_debug("initialization complete\n"); |
87c32271 | 969 | |
1da177e4 LT |
970 | return 0; |
971 | ||
1da177e4 | 972 | err_out_unregister: |
0d1857a1 | 973 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
835481d9 | 974 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 975 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 976 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 977 | |
c10997f6 | 978 | kobject_put(&policy->kobj); |
1da177e4 LT |
979 | wait_for_completion(&policy->kobj_unregister); |
980 | ||
2eaa3e2d VK |
981 | err_set_policy_cpu: |
982 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
cad70a6a | 983 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
984 | err_free_cpumask: |
985 | free_cpumask_var(policy->cpus); | |
986 | err_free_policy: | |
1da177e4 | 987 | kfree(policy); |
1da177e4 | 988 | nomem_out: |
1c3d85dd | 989 | module_put(cpufreq_driver->owner); |
c32b6b8e | 990 | module_out: |
1da177e4 LT |
991 | return ret; |
992 | } | |
993 | ||
b8eed8af VK |
994 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
995 | { | |
996 | int j; | |
997 | ||
998 | policy->last_cpu = policy->cpu; | |
999 | policy->cpu = cpu; | |
1000 | ||
3361b7b1 | 1001 | for_each_cpu(j, policy->cpus) |
b8eed8af | 1002 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
1003 | |
1004 | #ifdef CONFIG_CPU_FREQ_TABLE | |
1005 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1006 | #endif | |
1007 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1008 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1009 | } | |
1da177e4 LT |
1010 | |
1011 | /** | |
5a01f2e8 | 1012 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1013 | * |
1014 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1015 | * Caller should already have policy_rwsem in write mode for this CPU. |
1016 | * This routine frees the rwsem before returning. | |
1da177e4 | 1017 | */ |
8a25a2fd | 1018 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1019 | { |
b8eed8af | 1020 | unsigned int cpu = dev->id, ret, cpus; |
1da177e4 LT |
1021 | unsigned long flags; |
1022 | struct cpufreq_policy *data; | |
499bca9b AW |
1023 | struct kobject *kobj; |
1024 | struct completion *cmp; | |
8a25a2fd | 1025 | struct device *cpu_dev; |
1da177e4 | 1026 | |
b8eed8af | 1027 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1028 | |
0d1857a1 | 1029 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1030 | |
7a6aedfa | 1031 | data = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1032 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1033 | ||
0d1857a1 | 1034 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1035 | |
1036 | if (!data) { | |
b8eed8af | 1037 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1038 | return -EINVAL; |
1039 | } | |
1da177e4 | 1040 | |
1c3d85dd | 1041 | if (cpufreq_driver->target) |
f6a7409c | 1042 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1da177e4 | 1043 | |
084f3493 | 1044 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1045 | if (!cpufreq_driver->setpolicy) |
fa69e33f DB |
1046 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
1047 | data->governor->name, CPUFREQ_NAME_LEN); | |
1da177e4 LT |
1048 | #endif |
1049 | ||
2eaa3e2d | 1050 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1051 | cpus = cpumask_weight(data->cpus); |
e4969eba VK |
1052 | |
1053 | if (cpus > 1) | |
1054 | cpumask_clear_cpu(cpu, data->cpus); | |
2eaa3e2d | 1055 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1056 | |
73bf0fc2 VK |
1057 | if (cpu != data->cpu) { |
1058 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
1059 | } else if (cpus > 1) { | |
b8eed8af VK |
1060 | /* first sibling now owns the new sysfs dir */ |
1061 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1062 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1063 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1064 | if (ret) { | |
1065 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
084f3493 | 1066 | |
2eaa3e2d | 1067 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1068 | cpumask_set_cpu(cpu, data->cpus); |
1da177e4 | 1069 | |
0d1857a1 | 1070 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1071 | per_cpu(cpufreq_cpu_data, cpu) = data; |
0d1857a1 | 1072 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1073 | |
499bca9b | 1074 | unlock_policy_rwsem_write(cpu); |
1da177e4 | 1075 | |
2eaa3e2d VK |
1076 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, |
1077 | "cpufreq"); | |
b8eed8af | 1078 | return -EINVAL; |
1da177e4 | 1079 | } |
5a01f2e8 | 1080 | |
2eaa3e2d | 1081 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1082 | update_policy_cpu(data, cpu_dev->id); |
2eaa3e2d | 1083 | unlock_policy_rwsem_write(cpu); |
b8eed8af VK |
1084 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1085 | __func__, cpu_dev->id, cpu); | |
1da177e4 | 1086 | } |
1da177e4 | 1087 | |
d96038e0 VK |
1088 | if ((cpus == 1) && (cpufreq_driver->target)) |
1089 | __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); | |
1090 | ||
b8eed8af VK |
1091 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); |
1092 | cpufreq_cpu_put(data); | |
1da177e4 | 1093 | |
b8eed8af VK |
1094 | /* If cpu is last user of policy, free policy */ |
1095 | if (cpus == 1) { | |
2eaa3e2d | 1096 | lock_policy_rwsem_read(cpu); |
b8eed8af VK |
1097 | kobj = &data->kobj; |
1098 | cmp = &data->kobj_unregister; | |
2eaa3e2d | 1099 | unlock_policy_rwsem_read(cpu); |
b8eed8af | 1100 | kobject_put(kobj); |
7d26e2d5 | 1101 | |
b8eed8af VK |
1102 | /* we need to make sure that the underlying kobj is actually |
1103 | * not referenced anymore by anybody before we proceed with | |
1104 | * unloading. | |
1105 | */ | |
1106 | pr_debug("waiting for dropping of refcount\n"); | |
1107 | wait_for_completion(cmp); | |
1108 | pr_debug("wait complete\n"); | |
7d26e2d5 | 1109 | |
1c3d85dd RW |
1110 | if (cpufreq_driver->exit) |
1111 | cpufreq_driver->exit(data); | |
27ecddc2 | 1112 | |
b8eed8af VK |
1113 | free_cpumask_var(data->related_cpus); |
1114 | free_cpumask_var(data->cpus); | |
1115 | kfree(data); | |
1c3d85dd | 1116 | } else if (cpufreq_driver->target) { |
b8eed8af VK |
1117 | __cpufreq_governor(data, CPUFREQ_GOV_START); |
1118 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
27ecddc2 | 1119 | } |
1da177e4 | 1120 | |
2eaa3e2d | 1121 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
1da177e4 LT |
1122 | return 0; |
1123 | } | |
1124 | ||
1125 | ||
8a25a2fd | 1126 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1127 | { |
8a25a2fd | 1128 | unsigned int cpu = dev->id; |
5a01f2e8 | 1129 | int retval; |
ec28297a VP |
1130 | |
1131 | if (cpu_is_offline(cpu)) | |
1132 | return 0; | |
1133 | ||
8a25a2fd | 1134 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1135 | return retval; |
1136 | } | |
1137 | ||
1138 | ||
65f27f38 | 1139 | static void handle_update(struct work_struct *work) |
1da177e4 | 1140 | { |
65f27f38 DH |
1141 | struct cpufreq_policy *policy = |
1142 | container_of(work, struct cpufreq_policy, update); | |
1143 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1144 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1145 | cpufreq_update_policy(cpu); |
1146 | } | |
1147 | ||
1148 | /** | |
1149 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1150 | * @cpu: cpu number | |
1151 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1152 | * @new_freq: CPU frequency the CPU actually runs at | |
1153 | * | |
29464f28 DJ |
1154 | * We adjust to current frequency first, and need to clean up later. |
1155 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1156 | */ |
e08f5f5b GS |
1157 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1158 | unsigned int new_freq) | |
1da177e4 | 1159 | { |
b43a7ffb | 1160 | struct cpufreq_policy *policy; |
1da177e4 | 1161 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1162 | unsigned long flags; |
1163 | ||
1da177e4 | 1164 | |
2d06d8c4 | 1165 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1166 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1167 | ||
1da177e4 LT |
1168 | freqs.old = old_freq; |
1169 | freqs.new = new_freq; | |
b43a7ffb VK |
1170 | |
1171 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1172 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1173 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1174 | ||
1175 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1176 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1177 | } |
1178 | ||
1179 | ||
32ee8c3e | 1180 | /** |
4ab70df4 | 1181 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1182 | * @cpu: CPU number |
1183 | * | |
1184 | * This is the last known freq, without actually getting it from the driver. | |
1185 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1186 | */ | |
1187 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1188 | { | |
9e21ba8b | 1189 | struct cpufreq_policy *policy; |
e08f5f5b | 1190 | unsigned int ret_freq = 0; |
95235ca2 | 1191 | |
1c3d85dd RW |
1192 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1193 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1194 | |
1195 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1196 | if (policy) { |
e08f5f5b | 1197 | ret_freq = policy->cur; |
95235ca2 VP |
1198 | cpufreq_cpu_put(policy); |
1199 | } | |
1200 | ||
4d34a67d | 1201 | return ret_freq; |
95235ca2 VP |
1202 | } |
1203 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1204 | ||
3d737108 JB |
1205 | /** |
1206 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1207 | * @cpu: CPU number | |
1208 | * | |
1209 | * Just return the max possible frequency for a given CPU. | |
1210 | */ | |
1211 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1212 | { | |
1213 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1214 | unsigned int ret_freq = 0; | |
1215 | ||
1216 | if (policy) { | |
1217 | ret_freq = policy->max; | |
1218 | cpufreq_cpu_put(policy); | |
1219 | } | |
1220 | ||
1221 | return ret_freq; | |
1222 | } | |
1223 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1224 | ||
95235ca2 | 1225 | |
5a01f2e8 | 1226 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1227 | { |
7a6aedfa | 1228 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1229 | unsigned int ret_freq = 0; |
5800043b | 1230 | |
1c3d85dd | 1231 | if (!cpufreq_driver->get) |
4d34a67d | 1232 | return ret_freq; |
1da177e4 | 1233 | |
1c3d85dd | 1234 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1235 | |
e08f5f5b | 1236 | if (ret_freq && policy->cur && |
1c3d85dd | 1237 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1238 | /* verify no discrepancy between actual and |
1239 | saved value exists */ | |
1240 | if (unlikely(ret_freq != policy->cur)) { | |
1241 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1242 | schedule_work(&policy->update); |
1243 | } | |
1244 | } | |
1245 | ||
4d34a67d | 1246 | return ret_freq; |
5a01f2e8 | 1247 | } |
1da177e4 | 1248 | |
5a01f2e8 VP |
1249 | /** |
1250 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1251 | * @cpu: CPU number | |
1252 | * | |
1253 | * Get the CPU current (static) CPU frequency | |
1254 | */ | |
1255 | unsigned int cpufreq_get(unsigned int cpu) | |
1256 | { | |
1257 | unsigned int ret_freq = 0; | |
1258 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1259 | ||
1260 | if (!policy) | |
1261 | goto out; | |
1262 | ||
1263 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1264 | goto out_policy; | |
1265 | ||
1266 | ret_freq = __cpufreq_get(cpu); | |
1267 | ||
1268 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1269 | |
5a01f2e8 VP |
1270 | out_policy: |
1271 | cpufreq_cpu_put(policy); | |
1272 | out: | |
4d34a67d | 1273 | return ret_freq; |
1da177e4 LT |
1274 | } |
1275 | EXPORT_SYMBOL(cpufreq_get); | |
1276 | ||
8a25a2fd KS |
1277 | static struct subsys_interface cpufreq_interface = { |
1278 | .name = "cpufreq", | |
1279 | .subsys = &cpu_subsys, | |
1280 | .add_dev = cpufreq_add_dev, | |
1281 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1282 | }; |
1283 | ||
1da177e4 | 1284 | |
42d4dc3f | 1285 | /** |
e00e56df RW |
1286 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1287 | * | |
1288 | * This function is only executed for the boot processor. The other CPUs | |
1289 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1290 | */ |
e00e56df | 1291 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1292 | { |
e08f5f5b | 1293 | int ret = 0; |
4bc5d341 | 1294 | |
e00e56df | 1295 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1296 | struct cpufreq_policy *cpu_policy; |
1297 | ||
2d06d8c4 | 1298 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1299 | |
e00e56df | 1300 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1301 | cpu_policy = cpufreq_cpu_get(cpu); |
1302 | if (!cpu_policy) | |
e00e56df | 1303 | return 0; |
42d4dc3f | 1304 | |
1c3d85dd RW |
1305 | if (cpufreq_driver->suspend) { |
1306 | ret = cpufreq_driver->suspend(cpu_policy); | |
ce6c3997 | 1307 | if (ret) |
42d4dc3f BH |
1308 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1309 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1310 | } |
1311 | ||
42d4dc3f | 1312 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1313 | return ret; |
42d4dc3f BH |
1314 | } |
1315 | ||
1da177e4 | 1316 | /** |
e00e56df | 1317 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1318 | * |
1319 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1320 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1321 | * restored. It will verify that the current freq is in sync with | |
1322 | * what we believe it to be. This is a bit later than when it | |
1323 | * should be, but nonethteless it's better than calling | |
1324 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1325 | * |
1326 | * This function is only executed for the boot CPU. The other CPUs have not | |
1327 | * been turned on yet. | |
1da177e4 | 1328 | */ |
e00e56df | 1329 | static void cpufreq_bp_resume(void) |
1da177e4 | 1330 | { |
e08f5f5b | 1331 | int ret = 0; |
4bc5d341 | 1332 | |
e00e56df | 1333 | int cpu = smp_processor_id(); |
1da177e4 LT |
1334 | struct cpufreq_policy *cpu_policy; |
1335 | ||
2d06d8c4 | 1336 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1337 | |
e00e56df | 1338 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1339 | cpu_policy = cpufreq_cpu_get(cpu); |
1340 | if (!cpu_policy) | |
e00e56df | 1341 | return; |
1da177e4 | 1342 | |
1c3d85dd RW |
1343 | if (cpufreq_driver->resume) { |
1344 | ret = cpufreq_driver->resume(cpu_policy); | |
1da177e4 LT |
1345 | if (ret) { |
1346 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1347 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1348 | goto fail; |
1da177e4 LT |
1349 | } |
1350 | } | |
1351 | ||
1da177e4 | 1352 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1353 | |
c9060494 | 1354 | fail: |
1da177e4 | 1355 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1356 | } |
1357 | ||
e00e56df RW |
1358 | static struct syscore_ops cpufreq_syscore_ops = { |
1359 | .suspend = cpufreq_bp_suspend, | |
1360 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1361 | }; |
1362 | ||
9d95046e BP |
1363 | /** |
1364 | * cpufreq_get_current_driver - return current driver's name | |
1365 | * | |
1366 | * Return the name string of the currently loaded cpufreq driver | |
1367 | * or NULL, if none. | |
1368 | */ | |
1369 | const char *cpufreq_get_current_driver(void) | |
1370 | { | |
1c3d85dd RW |
1371 | if (cpufreq_driver) |
1372 | return cpufreq_driver->name; | |
1373 | ||
1374 | return NULL; | |
9d95046e BP |
1375 | } |
1376 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1377 | |
1378 | /********************************************************************* | |
1379 | * NOTIFIER LISTS INTERFACE * | |
1380 | *********************************************************************/ | |
1381 | ||
1382 | /** | |
1383 | * cpufreq_register_notifier - register a driver with cpufreq | |
1384 | * @nb: notifier function to register | |
1385 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1386 | * | |
32ee8c3e | 1387 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1388 | * are notified about clock rate changes (once before and once after |
1389 | * the transition), or a list of drivers that are notified about | |
1390 | * changes in cpufreq policy. | |
1391 | * | |
1392 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1393 | * blocking_notifier_chain_register. |
1da177e4 LT |
1394 | */ |
1395 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1396 | { | |
1397 | int ret; | |
1398 | ||
d5aaffa9 DB |
1399 | if (cpufreq_disabled()) |
1400 | return -EINVAL; | |
1401 | ||
74212ca4 CEB |
1402 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1403 | ||
1da177e4 LT |
1404 | switch (list) { |
1405 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1406 | ret = srcu_notifier_chain_register( |
e041c683 | 1407 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1408 | break; |
1409 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1410 | ret = blocking_notifier_chain_register( |
1411 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1412 | break; |
1413 | default: | |
1414 | ret = -EINVAL; | |
1415 | } | |
1da177e4 LT |
1416 | |
1417 | return ret; | |
1418 | } | |
1419 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1420 | ||
1421 | ||
1422 | /** | |
1423 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1424 | * @nb: notifier block to be unregistered | |
1425 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1426 | * | |
1427 | * Remove a driver from the CPU frequency notifier list. | |
1428 | * | |
1429 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1430 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1431 | */ |
1432 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1433 | { | |
1434 | int ret; | |
1435 | ||
d5aaffa9 DB |
1436 | if (cpufreq_disabled()) |
1437 | return -EINVAL; | |
1438 | ||
1da177e4 LT |
1439 | switch (list) { |
1440 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1441 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1442 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1443 | break; |
1444 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1445 | ret = blocking_notifier_chain_unregister( |
1446 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1447 | break; |
1448 | default: | |
1449 | ret = -EINVAL; | |
1450 | } | |
1da177e4 LT |
1451 | |
1452 | return ret; | |
1453 | } | |
1454 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1455 | ||
1456 | ||
1457 | /********************************************************************* | |
1458 | * GOVERNORS * | |
1459 | *********************************************************************/ | |
1460 | ||
1461 | ||
1462 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1463 | unsigned int target_freq, | |
1464 | unsigned int relation) | |
1465 | { | |
1466 | int retval = -EINVAL; | |
7249924e | 1467 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1468 | |
a7b422cd KRW |
1469 | if (cpufreq_disabled()) |
1470 | return -ENODEV; | |
1471 | ||
7249924e VK |
1472 | /* Make sure that target_freq is within supported range */ |
1473 | if (target_freq > policy->max) | |
1474 | target_freq = policy->max; | |
1475 | if (target_freq < policy->min) | |
1476 | target_freq = policy->min; | |
1477 | ||
1478 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1479 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1480 | |
1481 | if (target_freq == policy->cur) | |
1482 | return 0; | |
1483 | ||
1c3d85dd RW |
1484 | if (cpufreq_driver->target) |
1485 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1486 | |
1da177e4 LT |
1487 | return retval; |
1488 | } | |
1489 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1490 | ||
1da177e4 LT |
1491 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1492 | unsigned int target_freq, | |
1493 | unsigned int relation) | |
1494 | { | |
f1829e4a | 1495 | int ret = -EINVAL; |
1da177e4 LT |
1496 | |
1497 | policy = cpufreq_cpu_get(policy->cpu); | |
1498 | if (!policy) | |
f1829e4a | 1499 | goto no_policy; |
1da177e4 | 1500 | |
5a01f2e8 | 1501 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1502 | goto fail; |
1da177e4 LT |
1503 | |
1504 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1505 | ||
5a01f2e8 | 1506 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1507 | |
f1829e4a | 1508 | fail: |
1da177e4 | 1509 | cpufreq_cpu_put(policy); |
f1829e4a | 1510 | no_policy: |
1da177e4 LT |
1511 | return ret; |
1512 | } | |
1513 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1514 | ||
bf0b90e3 | 1515 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1516 | { |
1517 | int ret = 0; | |
1518 | ||
d5aaffa9 DB |
1519 | if (cpufreq_disabled()) |
1520 | return ret; | |
1521 | ||
1c3d85dd | 1522 | if (!cpufreq_driver->getavg) |
0676f7f2 VK |
1523 | return 0; |
1524 | ||
dfde5d62 VP |
1525 | policy = cpufreq_cpu_get(policy->cpu); |
1526 | if (!policy) | |
1527 | return -EINVAL; | |
1528 | ||
1c3d85dd | 1529 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1530 | |
dfde5d62 VP |
1531 | cpufreq_cpu_put(policy); |
1532 | return ret; | |
1533 | } | |
5a01f2e8 | 1534 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1535 | |
153d7f3f | 1536 | /* |
153d7f3f AV |
1537 | * when "event" is CPUFREQ_GOV_LIMITS |
1538 | */ | |
1da177e4 | 1539 | |
e08f5f5b GS |
1540 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1541 | unsigned int event) | |
1da177e4 | 1542 | { |
cc993cab | 1543 | int ret; |
6afde10c TR |
1544 | |
1545 | /* Only must be defined when default governor is known to have latency | |
1546 | restrictions, like e.g. conservative or ondemand. | |
1547 | That this is the case is already ensured in Kconfig | |
1548 | */ | |
1549 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1550 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1551 | #else | |
1552 | struct cpufreq_governor *gov = NULL; | |
1553 | #endif | |
1c256245 TR |
1554 | |
1555 | if (policy->governor->max_transition_latency && | |
1556 | policy->cpuinfo.transition_latency > | |
1557 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1558 | if (!gov) |
1559 | return -EINVAL; | |
1560 | else { | |
1561 | printk(KERN_WARNING "%s governor failed, too long" | |
1562 | " transition latency of HW, fallback" | |
1563 | " to %s governor\n", | |
1564 | policy->governor->name, | |
1565 | gov->name); | |
1566 | policy->governor = gov; | |
1567 | } | |
1c256245 | 1568 | } |
1da177e4 LT |
1569 | |
1570 | if (!try_module_get(policy->governor->owner)) | |
1571 | return -EINVAL; | |
1572 | ||
2d06d8c4 | 1573 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1574 | policy->cpu, event); |
1da177e4 LT |
1575 | ret = policy->governor->governor(policy, event); |
1576 | ||
4d5dcc42 VK |
1577 | if (!ret) { |
1578 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1579 | policy->governor->initialized++; | |
1580 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1581 | policy->governor->initialized--; | |
1582 | } | |
b394058f | 1583 | |
e08f5f5b GS |
1584 | /* we keep one module reference alive for |
1585 | each CPU governed by this CPU */ | |
1da177e4 LT |
1586 | if ((event != CPUFREQ_GOV_START) || ret) |
1587 | module_put(policy->governor->owner); | |
1588 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1589 | module_put(policy->governor->owner); | |
1590 | ||
1591 | return ret; | |
1592 | } | |
1593 | ||
1594 | ||
1da177e4 LT |
1595 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1596 | { | |
3bcb09a3 | 1597 | int err; |
1da177e4 LT |
1598 | |
1599 | if (!governor) | |
1600 | return -EINVAL; | |
1601 | ||
a7b422cd KRW |
1602 | if (cpufreq_disabled()) |
1603 | return -ENODEV; | |
1604 | ||
3fc54d37 | 1605 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1606 | |
b394058f | 1607 | governor->initialized = 0; |
3bcb09a3 JF |
1608 | err = -EBUSY; |
1609 | if (__find_governor(governor->name) == NULL) { | |
1610 | err = 0; | |
1611 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1612 | } |
1da177e4 | 1613 | |
32ee8c3e | 1614 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1615 | return err; |
1da177e4 LT |
1616 | } |
1617 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1618 | ||
1619 | ||
1620 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1621 | { | |
90e41bac PB |
1622 | #ifdef CONFIG_HOTPLUG_CPU |
1623 | int cpu; | |
1624 | #endif | |
1625 | ||
1da177e4 LT |
1626 | if (!governor) |
1627 | return; | |
1628 | ||
a7b422cd KRW |
1629 | if (cpufreq_disabled()) |
1630 | return; | |
1631 | ||
90e41bac PB |
1632 | #ifdef CONFIG_HOTPLUG_CPU |
1633 | for_each_present_cpu(cpu) { | |
1634 | if (cpu_online(cpu)) | |
1635 | continue; | |
1636 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1637 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1638 | } | |
1639 | #endif | |
1640 | ||
3fc54d37 | 1641 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1642 | list_del(&governor->governor_list); |
3fc54d37 | 1643 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1644 | return; |
1645 | } | |
1646 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1647 | ||
1648 | ||
1649 | ||
1650 | /********************************************************************* | |
1651 | * POLICY INTERFACE * | |
1652 | *********************************************************************/ | |
1653 | ||
1654 | /** | |
1655 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1656 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1657 | * is written | |
1da177e4 LT |
1658 | * |
1659 | * Reads the current cpufreq policy. | |
1660 | */ | |
1661 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1662 | { | |
1663 | struct cpufreq_policy *cpu_policy; | |
1664 | if (!policy) | |
1665 | return -EINVAL; | |
1666 | ||
1667 | cpu_policy = cpufreq_cpu_get(cpu); | |
1668 | if (!cpu_policy) | |
1669 | return -EINVAL; | |
1670 | ||
1da177e4 | 1671 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1672 | |
1673 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1674 | return 0; |
1675 | } | |
1676 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1677 | ||
1678 | ||
153d7f3f | 1679 | /* |
e08f5f5b GS |
1680 | * data : current policy. |
1681 | * policy : policy to be set. | |
153d7f3f | 1682 | */ |
e08f5f5b GS |
1683 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1684 | struct cpufreq_policy *policy) | |
1da177e4 | 1685 | { |
7bd353a9 | 1686 | int ret = 0, failed = 1; |
1da177e4 | 1687 | |
2d06d8c4 | 1688 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1689 | policy->min, policy->max); |
1690 | ||
e08f5f5b GS |
1691 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1692 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1693 | |
53391fa2 | 1694 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1695 | ret = -EINVAL; |
1696 | goto error_out; | |
1697 | } | |
1698 | ||
1da177e4 | 1699 | /* verify the cpu speed can be set within this limit */ |
1c3d85dd | 1700 | ret = cpufreq_driver->verify(policy); |
1da177e4 LT |
1701 | if (ret) |
1702 | goto error_out; | |
1703 | ||
1da177e4 | 1704 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1705 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1706 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1707 | |
1708 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1709 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1710 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1711 | |
1712 | /* verify the cpu speed can be set within this limit, | |
1713 | which might be different to the first one */ | |
1c3d85dd | 1714 | ret = cpufreq_driver->verify(policy); |
e041c683 | 1715 | if (ret) |
1da177e4 | 1716 | goto error_out; |
1da177e4 LT |
1717 | |
1718 | /* notification of the new policy */ | |
e041c683 AS |
1719 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1720 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1721 | |
7d5e350f DJ |
1722 | data->min = policy->min; |
1723 | data->max = policy->max; | |
1da177e4 | 1724 | |
2d06d8c4 | 1725 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1726 | data->min, data->max); |
1da177e4 | 1727 | |
1c3d85dd | 1728 | if (cpufreq_driver->setpolicy) { |
1da177e4 | 1729 | data->policy = policy->policy; |
2d06d8c4 | 1730 | pr_debug("setting range\n"); |
1c3d85dd | 1731 | ret = cpufreq_driver->setpolicy(policy); |
1da177e4 LT |
1732 | } else { |
1733 | if (policy->governor != data->governor) { | |
1734 | /* save old, working values */ | |
1735 | struct cpufreq_governor *old_gov = data->governor; | |
1736 | ||
2d06d8c4 | 1737 | pr_debug("governor switch\n"); |
1da177e4 LT |
1738 | |
1739 | /* end old governor */ | |
7bd353a9 | 1740 | if (data->governor) { |
1da177e4 | 1741 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
955ef483 | 1742 | unlock_policy_rwsem_write(policy->cpu); |
7bd353a9 VK |
1743 | __cpufreq_governor(data, |
1744 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 | 1745 | lock_policy_rwsem_write(policy->cpu); |
7bd353a9 | 1746 | } |
1da177e4 LT |
1747 | |
1748 | /* start new governor */ | |
1749 | data->governor = policy->governor; | |
7bd353a9 | 1750 | if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { |
955ef483 | 1751 | if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) { |
7bd353a9 | 1752 | failed = 0; |
955ef483 VK |
1753 | } else { |
1754 | unlock_policy_rwsem_write(policy->cpu); | |
7bd353a9 VK |
1755 | __cpufreq_governor(data, |
1756 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 VK |
1757 | lock_policy_rwsem_write(policy->cpu); |
1758 | } | |
7bd353a9 VK |
1759 | } |
1760 | ||
1761 | if (failed) { | |
1da177e4 | 1762 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1763 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1764 | data->governor->name); |
1da177e4 LT |
1765 | if (old_gov) { |
1766 | data->governor = old_gov; | |
7bd353a9 VK |
1767 | __cpufreq_governor(data, |
1768 | CPUFREQ_GOV_POLICY_INIT); | |
e08f5f5b GS |
1769 | __cpufreq_governor(data, |
1770 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1771 | } |
1772 | ret = -EINVAL; | |
1773 | goto error_out; | |
1774 | } | |
1775 | /* might be a policy change, too, so fall through */ | |
1776 | } | |
2d06d8c4 | 1777 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1778 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1779 | } | |
1780 | ||
7d5e350f | 1781 | error_out: |
1da177e4 LT |
1782 | return ret; |
1783 | } | |
1784 | ||
1da177e4 LT |
1785 | /** |
1786 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1787 | * @cpu: CPU which shall be re-evaluated | |
1788 | * | |
25985edc | 1789 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1790 | * at different times. |
1791 | */ | |
1792 | int cpufreq_update_policy(unsigned int cpu) | |
1793 | { | |
1794 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1795 | struct cpufreq_policy policy; | |
f1829e4a | 1796 | int ret; |
1da177e4 | 1797 | |
f1829e4a JL |
1798 | if (!data) { |
1799 | ret = -ENODEV; | |
1800 | goto no_policy; | |
1801 | } | |
1da177e4 | 1802 | |
f1829e4a JL |
1803 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1804 | ret = -EINVAL; | |
1805 | goto fail; | |
1806 | } | |
1da177e4 | 1807 | |
2d06d8c4 | 1808 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1809 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1810 | policy.min = data->user_policy.min; |
1811 | policy.max = data->user_policy.max; | |
1812 | policy.policy = data->user_policy.policy; | |
1813 | policy.governor = data->user_policy.governor; | |
1814 | ||
0961dd0d TR |
1815 | /* BIOS might change freq behind our back |
1816 | -> ask driver for current freq and notify governors about a change */ | |
1c3d85dd RW |
1817 | if (cpufreq_driver->get) { |
1818 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1819 | if (!data->cur) { |
2d06d8c4 | 1820 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1821 | data->cur = policy.cur; |
1822 | } else { | |
1c3d85dd | 1823 | if (data->cur != policy.cur && cpufreq_driver->target) |
e08f5f5b GS |
1824 | cpufreq_out_of_sync(cpu, data->cur, |
1825 | policy.cur); | |
a85f7bd3 | 1826 | } |
0961dd0d TR |
1827 | } |
1828 | ||
1da177e4 LT |
1829 | ret = __cpufreq_set_policy(data, &policy); |
1830 | ||
5a01f2e8 VP |
1831 | unlock_policy_rwsem_write(cpu); |
1832 | ||
f1829e4a | 1833 | fail: |
1da177e4 | 1834 | cpufreq_cpu_put(data); |
f1829e4a | 1835 | no_policy: |
1da177e4 LT |
1836 | return ret; |
1837 | } | |
1838 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1839 | ||
dd184a01 | 1840 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1841 | unsigned long action, void *hcpu) |
1842 | { | |
1843 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1844 | struct device *dev; |
c32b6b8e | 1845 | |
8a25a2fd KS |
1846 | dev = get_cpu_device(cpu); |
1847 | if (dev) { | |
c32b6b8e AR |
1848 | switch (action) { |
1849 | case CPU_ONLINE: | |
8a25a2fd | 1850 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1851 | break; |
1852 | case CPU_DOWN_PREPARE: | |
a66b2e50 | 1853 | case CPU_UP_CANCELED_FROZEN: |
8a25a2fd | 1854 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1855 | break; |
5a01f2e8 | 1856 | case CPU_DOWN_FAILED: |
8a25a2fd | 1857 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1858 | break; |
1859 | } | |
1860 | } | |
1861 | return NOTIFY_OK; | |
1862 | } | |
1863 | ||
9c36f746 | 1864 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1865 | .notifier_call = cpufreq_cpu_callback, |
1866 | }; | |
1da177e4 LT |
1867 | |
1868 | /********************************************************************* | |
1869 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1870 | *********************************************************************/ | |
1871 | ||
1872 | /** | |
1873 | * cpufreq_register_driver - register a CPU Frequency driver | |
1874 | * @driver_data: A struct cpufreq_driver containing the values# | |
1875 | * submitted by the CPU Frequency driver. | |
1876 | * | |
32ee8c3e | 1877 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1878 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1879 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1880 | * |
1881 | */ | |
221dee28 | 1882 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1883 | { |
1884 | unsigned long flags; | |
1885 | int ret; | |
1886 | ||
a7b422cd KRW |
1887 | if (cpufreq_disabled()) |
1888 | return -ENODEV; | |
1889 | ||
1da177e4 LT |
1890 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1891 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1892 | return -EINVAL; | |
1893 | ||
2d06d8c4 | 1894 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1895 | |
1896 | if (driver_data->setpolicy) | |
1897 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1898 | ||
0d1857a1 | 1899 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 1900 | if (cpufreq_driver) { |
0d1857a1 | 1901 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1902 | return -EBUSY; |
1903 | } | |
1c3d85dd | 1904 | cpufreq_driver = driver_data; |
0d1857a1 | 1905 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1906 | |
8a25a2fd | 1907 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1908 | if (ret) |
1909 | goto err_null_driver; | |
1da177e4 | 1910 | |
1c3d85dd | 1911 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1912 | int i; |
1913 | ret = -ENODEV; | |
1914 | ||
1915 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1916 | for (i = 0; i < nr_cpu_ids; i++) |
1917 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1918 | ret = 0; |
7a6aedfa MT |
1919 | break; |
1920 | } | |
1da177e4 LT |
1921 | |
1922 | /* if all ->init() calls failed, unregister */ | |
1923 | if (ret) { | |
2d06d8c4 | 1924 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1925 | driver_data->name); |
8a25a2fd | 1926 | goto err_if_unreg; |
1da177e4 LT |
1927 | } |
1928 | } | |
1929 | ||
8f5bc2ab | 1930 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1931 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1932 | |
8f5bc2ab | 1933 | return 0; |
8a25a2fd KS |
1934 | err_if_unreg: |
1935 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 1936 | err_null_driver: |
0d1857a1 | 1937 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 1938 | cpufreq_driver = NULL; |
0d1857a1 | 1939 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 1940 | return ret; |
1da177e4 LT |
1941 | } |
1942 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1943 | ||
1944 | ||
1945 | /** | |
1946 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1947 | * | |
32ee8c3e | 1948 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1949 | * the right to do so, i.e. if you have succeeded in initialising before! |
1950 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1951 | * currently not initialised. | |
1952 | */ | |
221dee28 | 1953 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1954 | { |
1955 | unsigned long flags; | |
1956 | ||
1c3d85dd | 1957 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1958 | return -EINVAL; |
1da177e4 | 1959 | |
2d06d8c4 | 1960 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1961 | |
8a25a2fd | 1962 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1963 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 1964 | |
0d1857a1 | 1965 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 1966 | cpufreq_driver = NULL; |
0d1857a1 | 1967 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1968 | |
1969 | return 0; | |
1970 | } | |
1971 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1972 | |
1973 | static int __init cpufreq_core_init(void) | |
1974 | { | |
1975 | int cpu; | |
1976 | ||
a7b422cd KRW |
1977 | if (cpufreq_disabled()) |
1978 | return -ENODEV; | |
1979 | ||
5a01f2e8 | 1980 | for_each_possible_cpu(cpu) { |
f1625066 | 1981 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1982 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1983 | } | |
8aa84ad8 | 1984 | |
8a25a2fd | 1985 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1986 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1987 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1988 | |
5a01f2e8 VP |
1989 | return 0; |
1990 | } | |
5a01f2e8 | 1991 | core_initcall(cpufreq_core_init); |