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 | ||
6954ca9c VK |
50 | /* Used when we unregister cpufreq driver */ |
51 | static struct cpumask cpufreq_online_mask; | |
52 | ||
5a01f2e8 VP |
53 | /* |
54 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
55 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
56 | * | |
57 | * The rules for this semaphore: | |
58 | * - Any routine that wants to read from the policy structure will | |
59 | * do a down_read on this semaphore. | |
60 | * - Any routine that will write to the policy structure and/or may take away | |
61 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
62 | * mode before doing so. | |
63 | * | |
64 | * Additional rules: | |
65 | * - All holders of the lock should check to make sure that the CPU they | |
66 | * are concerned with are online after they get the lock. | |
67 | * - Governor routines that can be called in cpufreq hotplug path should not | |
68 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
69 | * - Lock should not be held across |
70 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 71 | */ |
f1625066 | 72 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
73 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
74 | ||
75 | #define lock_policy_rwsem(mode, cpu) \ | |
226528c6 | 76 | static int lock_policy_rwsem_##mode \ |
5a01f2e8 VP |
77 | (int cpu) \ |
78 | { \ | |
f1625066 | 79 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
80 | BUG_ON(policy_cpu == -1); \ |
81 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
82 | if (unlikely(!cpu_online(cpu))) { \ | |
83 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
84 | return -1; \ | |
85 | } \ | |
86 | \ | |
87 | return 0; \ | |
88 | } | |
89 | ||
90 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 VP |
91 | |
92 | lock_policy_rwsem(write, cpu); | |
5a01f2e8 | 93 | |
226528c6 | 94 | static void unlock_policy_rwsem_read(int cpu) |
5a01f2e8 | 95 | { |
f1625066 | 96 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
97 | BUG_ON(policy_cpu == -1); |
98 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
99 | } | |
5a01f2e8 | 100 | |
226528c6 | 101 | static void unlock_policy_rwsem_write(int cpu) |
5a01f2e8 | 102 | { |
f1625066 | 103 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
104 | BUG_ON(policy_cpu == -1); |
105 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
106 | } | |
5a01f2e8 VP |
107 | |
108 | ||
1da177e4 | 109 | /* internal prototypes */ |
29464f28 DJ |
110 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
111 | unsigned int event); | |
5a01f2e8 | 112 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 113 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
114 | |
115 | /** | |
32ee8c3e DJ |
116 | * Two notifier lists: the "policy" list is involved in the |
117 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
118 | * "transition" list for kernel code that needs to handle |
119 | * changes to devices when the CPU clock speed changes. | |
120 | * The mutex locks both lists. | |
121 | */ | |
e041c683 | 122 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 123 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 124 | |
74212ca4 | 125 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
126 | static int __init init_cpufreq_transition_notifier_list(void) |
127 | { | |
128 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 129 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
130 | return 0; |
131 | } | |
b3438f82 | 132 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 133 | |
a7b422cd | 134 | static int off __read_mostly; |
da584455 | 135 | static int cpufreq_disabled(void) |
a7b422cd KRW |
136 | { |
137 | return off; | |
138 | } | |
139 | void disable_cpufreq(void) | |
140 | { | |
141 | off = 1; | |
142 | } | |
1da177e4 | 143 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 144 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 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 */ | |
155 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
156 | ||
157 | if (!cpufreq_driver) | |
158 | goto err_out_unlock; | |
159 | ||
160 | if (!try_module_get(cpufreq_driver->owner)) | |
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 | ||
1da177e4 | 173 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
174 | return data; |
175 | ||
7d5e350f | 176 | err_out_put_module: |
1da177e4 | 177 | module_put(cpufreq_driver->owner); |
7d5e350f | 178 | err_out_unlock: |
1da177e4 | 179 | spin_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 | { | |
186 | return __cpufreq_cpu_get(cpu, false); | |
187 | } | |
1da177e4 LT |
188 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
189 | ||
a9144436 SB |
190 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
191 | { | |
192 | return __cpufreq_cpu_get(cpu, true); | |
193 | } | |
194 | ||
195 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
196 | { | |
197 | if (!sysfs) | |
198 | kobject_put(&data->kobj); | |
199 | module_put(cpufreq_driver->owner); | |
200 | } | |
7d5e350f | 201 | |
1da177e4 LT |
202 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
203 | { | |
a9144436 | 204 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
205 | } |
206 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
207 | ||
a9144436 SB |
208 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
209 | { | |
210 | __cpufreq_cpu_put(data, true); | |
211 | } | |
1da177e4 | 212 | |
1da177e4 LT |
213 | /********************************************************************* |
214 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
215 | *********************************************************************/ | |
216 | ||
217 | /** | |
218 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
219 | * | |
220 | * This function alters the system "loops_per_jiffy" for the clock | |
221 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 222 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
223 | * per-CPU loops_per_jiffy value wherever possible. |
224 | */ | |
225 | #ifndef CONFIG_SMP | |
226 | static unsigned long l_p_j_ref; | |
227 | static unsigned int l_p_j_ref_freq; | |
228 | ||
858119e1 | 229 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
230 | { |
231 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
232 | return; | |
233 | ||
234 | if (!l_p_j_ref_freq) { | |
235 | l_p_j_ref = loops_per_jiffy; | |
236 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 237 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 238 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 239 | } |
d08de0c1 | 240 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 241 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
242 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
243 | ci->new); | |
2d06d8c4 | 244 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 245 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
246 | } |
247 | } | |
248 | #else | |
e08f5f5b GS |
249 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
250 | { | |
251 | return; | |
252 | } | |
1da177e4 LT |
253 | #endif |
254 | ||
255 | ||
256 | /** | |
e4472cb3 DJ |
257 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
258 | * on frequency transition. | |
1da177e4 | 259 | * |
e4472cb3 DJ |
260 | * This function calls the transition notifiers and the "adjust_jiffies" |
261 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 262 | * external effects. |
1da177e4 LT |
263 | */ |
264 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
265 | { | |
e4472cb3 DJ |
266 | struct cpufreq_policy *policy; |
267 | ||
1da177e4 LT |
268 | BUG_ON(irqs_disabled()); |
269 | ||
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 | |
7a6aedfa | 274 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 275 | switch (state) { |
e4472cb3 | 276 | |
1da177e4 | 277 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 278 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
279 | * which is not equal to what the cpufreq core thinks is |
280 | * "old frequency". | |
1da177e4 LT |
281 | */ |
282 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
283 | if ((policy) && (policy->cpu == freqs->cpu) && |
284 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 285 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
286 | " %u, cpufreq assumed %u kHz.\n", |
287 | freqs->old, policy->cur); | |
288 | freqs->old = policy->cur; | |
1da177e4 LT |
289 | } |
290 | } | |
b4dfdbb3 | 291 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 292 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
293 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
294 | break; | |
e4472cb3 | 295 | |
1da177e4 LT |
296 | case CPUFREQ_POSTCHANGE: |
297 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 298 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 TR |
299 | (unsigned long)freqs->cpu); |
300 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 301 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 302 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 303 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
304 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
305 | policy->cur = freqs->new; | |
1da177e4 LT |
306 | break; |
307 | } | |
1da177e4 LT |
308 | } |
309 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
310 | ||
311 | ||
312 | ||
313 | /********************************************************************* | |
314 | * SYSFS INTERFACE * | |
315 | *********************************************************************/ | |
316 | ||
3bcb09a3 JF |
317 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
318 | { | |
319 | struct cpufreq_governor *t; | |
320 | ||
321 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 322 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
323 | return t; |
324 | ||
325 | return NULL; | |
326 | } | |
327 | ||
1da177e4 LT |
328 | /** |
329 | * cpufreq_parse_governor - parse a governor string | |
330 | */ | |
905d77cd | 331 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
332 | struct cpufreq_governor **governor) |
333 | { | |
3bcb09a3 JF |
334 | int err = -EINVAL; |
335 | ||
1da177e4 | 336 | if (!cpufreq_driver) |
3bcb09a3 JF |
337 | goto out; |
338 | ||
1da177e4 LT |
339 | if (cpufreq_driver->setpolicy) { |
340 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
341 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 342 | err = 0; |
e08f5f5b GS |
343 | } else if (!strnicmp(str_governor, "powersave", |
344 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 345 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 346 | err = 0; |
1da177e4 | 347 | } |
3bcb09a3 | 348 | } else if (cpufreq_driver->target) { |
1da177e4 | 349 | struct cpufreq_governor *t; |
3bcb09a3 | 350 | |
3fc54d37 | 351 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
352 | |
353 | t = __find_governor(str_governor); | |
354 | ||
ea714970 | 355 | if (t == NULL) { |
1a8e1463 | 356 | int ret; |
ea714970 | 357 | |
1a8e1463 KC |
358 | mutex_unlock(&cpufreq_governor_mutex); |
359 | ret = request_module("cpufreq_%s", str_governor); | |
360 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 361 | |
1a8e1463 KC |
362 | if (ret == 0) |
363 | t = __find_governor(str_governor); | |
ea714970 JF |
364 | } |
365 | ||
3bcb09a3 JF |
366 | if (t != NULL) { |
367 | *governor = t; | |
368 | err = 0; | |
1da177e4 | 369 | } |
3bcb09a3 | 370 | |
3fc54d37 | 371 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 372 | } |
29464f28 | 373 | out: |
3bcb09a3 | 374 | return err; |
1da177e4 | 375 | } |
1da177e4 LT |
376 | |
377 | ||
1da177e4 | 378 | /** |
e08f5f5b GS |
379 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
380 | * print out cpufreq information | |
1da177e4 LT |
381 | * |
382 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
383 | * "unsigned int". | |
384 | */ | |
385 | ||
32ee8c3e DJ |
386 | #define show_one(file_name, object) \ |
387 | static ssize_t show_##file_name \ | |
905d77cd | 388 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 389 | { \ |
29464f28 | 390 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
391 | } |
392 | ||
393 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
394 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 395 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
396 | show_one(scaling_min_freq, min); |
397 | show_one(scaling_max_freq, max); | |
398 | show_one(scaling_cur_freq, cur); | |
399 | ||
e08f5f5b GS |
400 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
401 | struct cpufreq_policy *policy); | |
7970e08b | 402 | |
1da177e4 LT |
403 | /** |
404 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
405 | */ | |
406 | #define store_one(file_name, object) \ | |
407 | static ssize_t store_##file_name \ | |
905d77cd | 408 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 409 | { \ |
f55c9c26 | 410 | unsigned int ret; \ |
1da177e4 LT |
411 | struct cpufreq_policy new_policy; \ |
412 | \ | |
413 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
414 | if (ret) \ | |
415 | return -EINVAL; \ | |
416 | \ | |
29464f28 | 417 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
418 | if (ret != 1) \ |
419 | return -EINVAL; \ | |
420 | \ | |
7970e08b TR |
421 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
422 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
423 | \ |
424 | return ret ? ret : count; \ | |
425 | } | |
426 | ||
29464f28 DJ |
427 | store_one(scaling_min_freq, min); |
428 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
429 | |
430 | /** | |
431 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
432 | */ | |
905d77cd DJ |
433 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
434 | char *buf) | |
1da177e4 | 435 | { |
5a01f2e8 | 436 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
437 | if (!cur_freq) |
438 | return sprintf(buf, "<unknown>"); | |
439 | return sprintf(buf, "%u\n", cur_freq); | |
440 | } | |
441 | ||
442 | ||
443 | /** | |
444 | * show_scaling_governor - show the current policy for the specified CPU | |
445 | */ | |
905d77cd | 446 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 447 | { |
29464f28 | 448 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
449 | return sprintf(buf, "powersave\n"); |
450 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
451 | return sprintf(buf, "performance\n"); | |
452 | else if (policy->governor) | |
4b972f0b | 453 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 454 | policy->governor->name); |
1da177e4 LT |
455 | return -EINVAL; |
456 | } | |
457 | ||
458 | ||
459 | /** | |
460 | * store_scaling_governor - store policy for the specified CPU | |
461 | */ | |
905d77cd DJ |
462 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
463 | const char *buf, size_t count) | |
1da177e4 | 464 | { |
f55c9c26 | 465 | unsigned int ret; |
1da177e4 LT |
466 | char str_governor[16]; |
467 | struct cpufreq_policy new_policy; | |
468 | ||
469 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
470 | if (ret) | |
471 | return ret; | |
472 | ||
29464f28 | 473 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
474 | if (ret != 1) |
475 | return -EINVAL; | |
476 | ||
e08f5f5b GS |
477 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
478 | &new_policy.governor)) | |
1da177e4 LT |
479 | return -EINVAL; |
480 | ||
7970e08b TR |
481 | /* Do not use cpufreq_set_policy here or the user_policy.max |
482 | will be wrongly overridden */ | |
7970e08b TR |
483 | ret = __cpufreq_set_policy(policy, &new_policy); |
484 | ||
485 | policy->user_policy.policy = policy->policy; | |
486 | policy->user_policy.governor = policy->governor; | |
7970e08b | 487 | |
e08f5f5b GS |
488 | if (ret) |
489 | return ret; | |
490 | else | |
491 | return count; | |
1da177e4 LT |
492 | } |
493 | ||
494 | /** | |
495 | * show_scaling_driver - show the cpufreq driver currently loaded | |
496 | */ | |
905d77cd | 497 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 498 | { |
4b972f0b | 499 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
500 | } |
501 | ||
502 | /** | |
503 | * show_scaling_available_governors - show the available CPUfreq governors | |
504 | */ | |
905d77cd DJ |
505 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
506 | char *buf) | |
1da177e4 LT |
507 | { |
508 | ssize_t i = 0; | |
509 | struct cpufreq_governor *t; | |
510 | ||
511 | if (!cpufreq_driver->target) { | |
512 | i += sprintf(buf, "performance powersave"); | |
513 | goto out; | |
514 | } | |
515 | ||
516 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
517 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
518 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 519 | goto out; |
4b972f0b | 520 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 521 | } |
7d5e350f | 522 | out: |
1da177e4 LT |
523 | i += sprintf(&buf[i], "\n"); |
524 | return i; | |
525 | } | |
e8628dd0 | 526 | |
835481d9 | 527 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
528 | { |
529 | ssize_t i = 0; | |
530 | unsigned int cpu; | |
531 | ||
835481d9 | 532 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
533 | if (i) |
534 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
535 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
536 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 537 | break; |
1da177e4 LT |
538 | } |
539 | i += sprintf(&buf[i], "\n"); | |
540 | return i; | |
541 | } | |
542 | ||
e8628dd0 DW |
543 | /** |
544 | * show_related_cpus - show the CPUs affected by each transition even if | |
545 | * hw coordination is in use | |
546 | */ | |
547 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
548 | { | |
835481d9 | 549 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
550 | return show_cpus(policy->cpus, buf); |
551 | return show_cpus(policy->related_cpus, buf); | |
552 | } | |
553 | ||
554 | /** | |
555 | * show_affected_cpus - show the CPUs affected by each transition | |
556 | */ | |
557 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
558 | { | |
559 | return show_cpus(policy->cpus, buf); | |
560 | } | |
561 | ||
9e76988e | 562 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 563 | const char *buf, size_t count) |
9e76988e VP |
564 | { |
565 | unsigned int freq = 0; | |
566 | unsigned int ret; | |
567 | ||
879000f9 | 568 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
569 | return -EINVAL; |
570 | ||
571 | ret = sscanf(buf, "%u", &freq); | |
572 | if (ret != 1) | |
573 | return -EINVAL; | |
574 | ||
575 | policy->governor->store_setspeed(policy, freq); | |
576 | ||
577 | return count; | |
578 | } | |
579 | ||
580 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
581 | { | |
879000f9 | 582 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
583 | return sprintf(buf, "<unsupported>\n"); |
584 | ||
585 | return policy->governor->show_setspeed(policy, buf); | |
586 | } | |
1da177e4 | 587 | |
e2f74f35 | 588 | /** |
8bf1ac72 | 589 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
590 | */ |
591 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
592 | { | |
593 | unsigned int limit; | |
594 | int ret; | |
595 | if (cpufreq_driver->bios_limit) { | |
596 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
597 | if (!ret) | |
598 | return sprintf(buf, "%u\n", limit); | |
599 | } | |
600 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
601 | } | |
602 | ||
6dad2a29 BP |
603 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
604 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
605 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
606 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
607 | cpufreq_freq_attr_ro(scaling_available_governors); | |
608 | cpufreq_freq_attr_ro(scaling_driver); | |
609 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
610 | cpufreq_freq_attr_ro(bios_limit); | |
611 | cpufreq_freq_attr_ro(related_cpus); | |
612 | cpufreq_freq_attr_ro(affected_cpus); | |
613 | cpufreq_freq_attr_rw(scaling_min_freq); | |
614 | cpufreq_freq_attr_rw(scaling_max_freq); | |
615 | cpufreq_freq_attr_rw(scaling_governor); | |
616 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 617 | |
905d77cd | 618 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
619 | &cpuinfo_min_freq.attr, |
620 | &cpuinfo_max_freq.attr, | |
ed129784 | 621 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
622 | &scaling_min_freq.attr, |
623 | &scaling_max_freq.attr, | |
624 | &affected_cpus.attr, | |
e8628dd0 | 625 | &related_cpus.attr, |
1da177e4 LT |
626 | &scaling_governor.attr, |
627 | &scaling_driver.attr, | |
628 | &scaling_available_governors.attr, | |
9e76988e | 629 | &scaling_setspeed.attr, |
1da177e4 LT |
630 | NULL |
631 | }; | |
632 | ||
8aa84ad8 TR |
633 | struct kobject *cpufreq_global_kobject; |
634 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
635 | ||
29464f28 DJ |
636 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
637 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 638 | |
29464f28 | 639 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 640 | { |
905d77cd DJ |
641 | struct cpufreq_policy *policy = to_policy(kobj); |
642 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 643 | ssize_t ret = -EINVAL; |
a9144436 | 644 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 645 | if (!policy) |
0db4a8a9 | 646 | goto no_policy; |
5a01f2e8 VP |
647 | |
648 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 649 | goto fail; |
5a01f2e8 | 650 | |
e08f5f5b GS |
651 | if (fattr->show) |
652 | ret = fattr->show(policy, buf); | |
653 | else | |
654 | ret = -EIO; | |
655 | ||
5a01f2e8 | 656 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 657 | fail: |
a9144436 | 658 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 659 | no_policy: |
1da177e4 LT |
660 | return ret; |
661 | } | |
662 | ||
905d77cd DJ |
663 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
664 | const char *buf, size_t count) | |
1da177e4 | 665 | { |
905d77cd DJ |
666 | struct cpufreq_policy *policy = to_policy(kobj); |
667 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 668 | ssize_t ret = -EINVAL; |
a9144436 | 669 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 670 | if (!policy) |
a07530b4 | 671 | goto no_policy; |
5a01f2e8 VP |
672 | |
673 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 674 | goto fail; |
5a01f2e8 | 675 | |
e08f5f5b GS |
676 | if (fattr->store) |
677 | ret = fattr->store(policy, buf, count); | |
678 | else | |
679 | ret = -EIO; | |
680 | ||
5a01f2e8 | 681 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 682 | fail: |
a9144436 | 683 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 684 | no_policy: |
1da177e4 LT |
685 | return ret; |
686 | } | |
687 | ||
905d77cd | 688 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 689 | { |
905d77cd | 690 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 691 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
692 | complete(&policy->kobj_unregister); |
693 | } | |
694 | ||
52cf25d0 | 695 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
696 | .show = show, |
697 | .store = store, | |
698 | }; | |
699 | ||
700 | static struct kobj_type ktype_cpufreq = { | |
701 | .sysfs_ops = &sysfs_ops, | |
702 | .default_attrs = default_attrs, | |
703 | .release = cpufreq_sysfs_release, | |
704 | }; | |
705 | ||
4bfa042c TR |
706 | /* |
707 | * Returns: | |
708 | * Negative: Failure | |
709 | * 0: Success | |
710 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
711 | */ | |
cf3289d0 AC |
712 | static int cpufreq_add_dev_policy(unsigned int cpu, |
713 | struct cpufreq_policy *policy, | |
8a25a2fd | 714 | struct device *dev) |
ecf7e461 DJ |
715 | { |
716 | int ret = 0; | |
717 | #ifdef CONFIG_SMP | |
718 | unsigned long flags; | |
719 | unsigned int j; | |
ecf7e461 | 720 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
721 | struct cpufreq_governor *gov; |
722 | ||
723 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
724 | if (gov) { | |
725 | policy->governor = gov; | |
2d06d8c4 | 726 | pr_debug("Restoring governor %s for cpu %d\n", |
ecf7e461 DJ |
727 | policy->governor->name, cpu); |
728 | } | |
729 | #endif | |
730 | ||
731 | for_each_cpu(j, policy->cpus) { | |
732 | struct cpufreq_policy *managed_policy; | |
733 | ||
734 | if (cpu == j) | |
735 | continue; | |
736 | ||
737 | /* Check for existing affected CPUs. | |
738 | * They may not be aware of it due to CPU Hotplug. | |
739 | * cpufreq_cpu_put is called when the device is removed | |
740 | * in __cpufreq_remove_dev() | |
741 | */ | |
742 | managed_policy = cpufreq_cpu_get(j); | |
743 | if (unlikely(managed_policy)) { | |
744 | ||
745 | /* Set proper policy_cpu */ | |
746 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 747 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
748 | |
749 | if (lock_policy_rwsem_write(cpu) < 0) { | |
750 | /* Should not go through policy unlock path */ | |
751 | if (cpufreq_driver->exit) | |
752 | cpufreq_driver->exit(policy); | |
753 | cpufreq_cpu_put(managed_policy); | |
754 | return -EBUSY; | |
755 | } | |
756 | ||
f6a7409c VK |
757 | __cpufreq_governor(managed_policy, CPUFREQ_GOV_STOP); |
758 | ||
ecf7e461 DJ |
759 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
760 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
761 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
762 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
763 | ||
f6a7409c VK |
764 | __cpufreq_governor(managed_policy, CPUFREQ_GOV_START); |
765 | __cpufreq_governor(managed_policy, CPUFREQ_GOV_LIMITS); | |
766 | ||
2d06d8c4 | 767 | pr_debug("CPU already managed, adding link\n"); |
8a25a2fd | 768 | ret = sysfs_create_link(&dev->kobj, |
ecf7e461 DJ |
769 | &managed_policy->kobj, |
770 | "cpufreq"); | |
771 | if (ret) | |
772 | cpufreq_cpu_put(managed_policy); | |
773 | /* | |
774 | * Success. We only needed to be added to the mask. | |
775 | * Call driver->exit() because only the cpu parent of | |
776 | * the kobj needed to call init(). | |
777 | */ | |
778 | if (cpufreq_driver->exit) | |
779 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
780 | |
781 | if (!ret) | |
782 | return 1; | |
783 | else | |
784 | return ret; | |
ecf7e461 DJ |
785 | } |
786 | } | |
787 | #endif | |
788 | return ret; | |
789 | } | |
790 | ||
791 | ||
19d6f7ec | 792 | /* symlink affected CPUs */ |
cf3289d0 AC |
793 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
794 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
795 | { |
796 | unsigned int j; | |
797 | int ret = 0; | |
798 | ||
799 | for_each_cpu(j, policy->cpus) { | |
800 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 801 | struct device *cpu_dev; |
19d6f7ec DJ |
802 | |
803 | if (j == cpu) | |
804 | continue; | |
805 | if (!cpu_online(j)) | |
806 | continue; | |
807 | ||
2d06d8c4 | 808 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 809 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
810 | cpu_dev = get_cpu_device(j); |
811 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
812 | "cpufreq"); |
813 | if (ret) { | |
814 | cpufreq_cpu_put(managed_policy); | |
815 | return ret; | |
816 | } | |
817 | } | |
818 | return ret; | |
819 | } | |
820 | ||
cf3289d0 AC |
821 | static int cpufreq_add_dev_interface(unsigned int cpu, |
822 | struct cpufreq_policy *policy, | |
8a25a2fd | 823 | struct device *dev) |
909a694e | 824 | { |
ecf7e461 | 825 | struct cpufreq_policy new_policy; |
909a694e DJ |
826 | struct freq_attr **drv_attr; |
827 | unsigned long flags; | |
828 | int ret = 0; | |
829 | unsigned int j; | |
830 | ||
831 | /* prepare interface data */ | |
832 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 833 | &dev->kobj, "cpufreq"); |
909a694e DJ |
834 | if (ret) |
835 | return ret; | |
836 | ||
837 | /* set up files for this cpu device */ | |
838 | drv_attr = cpufreq_driver->attr; | |
839 | while ((drv_attr) && (*drv_attr)) { | |
840 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
841 | if (ret) | |
842 | goto err_out_kobj_put; | |
843 | drv_attr++; | |
844 | } | |
845 | if (cpufreq_driver->get) { | |
846 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
847 | if (ret) | |
848 | goto err_out_kobj_put; | |
849 | } | |
850 | if (cpufreq_driver->target) { | |
851 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
852 | if (ret) | |
853 | goto err_out_kobj_put; | |
854 | } | |
e2f74f35 TR |
855 | if (cpufreq_driver->bios_limit) { |
856 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
857 | if (ret) | |
858 | goto err_out_kobj_put; | |
859 | } | |
909a694e DJ |
860 | |
861 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
862 | for_each_cpu(j, policy->cpus) { | |
bec037aa JL |
863 | if (!cpu_online(j)) |
864 | continue; | |
909a694e | 865 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 866 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
867 | } |
868 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
869 | ||
870 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
871 | if (ret) |
872 | goto err_out_kobj_put; | |
873 | ||
874 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
875 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
876 | policy->governor = NULL; | |
877 | ||
878 | /* set default policy */ | |
879 | ret = __cpufreq_set_policy(policy, &new_policy); | |
880 | policy->user_policy.policy = policy->policy; | |
881 | policy->user_policy.governor = policy->governor; | |
882 | ||
883 | if (ret) { | |
2d06d8c4 | 884 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
885 | if (cpufreq_driver->exit) |
886 | cpufreq_driver->exit(policy); | |
887 | } | |
909a694e DJ |
888 | return ret; |
889 | ||
890 | err_out_kobj_put: | |
891 | kobject_put(&policy->kobj); | |
892 | wait_for_completion(&policy->kobj_unregister); | |
893 | return ret; | |
894 | } | |
895 | ||
1da177e4 LT |
896 | |
897 | /** | |
898 | * cpufreq_add_dev - add a CPU device | |
899 | * | |
32ee8c3e | 900 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
901 | * |
902 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
903 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
904 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 905 | */ |
8a25a2fd | 906 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 907 | { |
8a25a2fd | 908 | unsigned int cpu = dev->id; |
90e41bac | 909 | int ret = 0, found = 0; |
1da177e4 | 910 | struct cpufreq_policy *policy; |
1da177e4 LT |
911 | unsigned long flags; |
912 | unsigned int j; | |
90e41bac PB |
913 | #ifdef CONFIG_HOTPLUG_CPU |
914 | int sibling; | |
915 | #endif | |
1da177e4 | 916 | |
c32b6b8e AR |
917 | if (cpu_is_offline(cpu)) |
918 | return 0; | |
919 | ||
2d06d8c4 | 920 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
921 | |
922 | #ifdef CONFIG_SMP | |
923 | /* check whether a different CPU already registered this | |
924 | * CPU because it is in the same boat. */ | |
925 | policy = cpufreq_cpu_get(cpu); | |
926 | if (unlikely(policy)) { | |
8ff69732 | 927 | cpufreq_cpu_put(policy); |
1da177e4 LT |
928 | return 0; |
929 | } | |
930 | #endif | |
931 | ||
932 | if (!try_module_get(cpufreq_driver->owner)) { | |
933 | ret = -EINVAL; | |
934 | goto module_out; | |
935 | } | |
936 | ||
059019a3 | 937 | ret = -ENOMEM; |
e98df50c | 938 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 939 | if (!policy) |
1da177e4 | 940 | goto nomem_out; |
059019a3 DJ |
941 | |
942 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 943 | goto err_free_policy; |
059019a3 DJ |
944 | |
945 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 946 | goto err_free_cpumask; |
1da177e4 LT |
947 | |
948 | policy->cpu = cpu; | |
835481d9 | 949 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 950 | |
5a01f2e8 | 951 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 952 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
953 | ret = (lock_policy_rwsem_write(cpu) < 0); |
954 | WARN_ON(ret); | |
5a01f2e8 | 955 | |
1da177e4 | 956 | init_completion(&policy->kobj_unregister); |
65f27f38 | 957 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 958 | |
8122c6ce | 959 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
960 | #ifdef CONFIG_HOTPLUG_CPU |
961 | for_each_online_cpu(sibling) { | |
962 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
963 | if (cp && cp->governor && | |
964 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
965 | policy->governor = cp->governor; | |
966 | found = 1; | |
967 | break; | |
968 | } | |
969 | } | |
970 | #endif | |
971 | if (!found) | |
972 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
973 | /* call driver. From then on the cpufreq must be able |
974 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
975 | */ | |
976 | ret = cpufreq_driver->init(policy); | |
977 | if (ret) { | |
2d06d8c4 | 978 | pr_debug("initialization failed\n"); |
3f4a782b | 979 | goto err_unlock_policy; |
1da177e4 | 980 | } |
643ae6e8 VK |
981 | |
982 | /* | |
983 | * affected cpus must always be the one, which are online. We aren't | |
984 | * managing offline cpus here. | |
985 | */ | |
986 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
6954ca9c | 987 | cpumask_and(policy->cpus, policy->cpus, &cpufreq_online_mask); |
643ae6e8 | 988 | |
187d9f4e MC |
989 | policy->user_policy.min = policy->min; |
990 | policy->user_policy.max = policy->max; | |
1da177e4 | 991 | |
a1531acd TR |
992 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
993 | CPUFREQ_START, policy); | |
994 | ||
8a25a2fd | 995 | ret = cpufreq_add_dev_policy(cpu, policy, dev); |
4bfa042c TR |
996 | if (ret) { |
997 | if (ret > 0) | |
998 | /* This is a managed cpu, symlink created, | |
999 | exit with 0 */ | |
1000 | ret = 0; | |
ecf7e461 | 1001 | goto err_unlock_policy; |
4bfa042c | 1002 | } |
1da177e4 | 1003 | |
8a25a2fd | 1004 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
1005 | if (ret) |
1006 | goto err_out_unregister; | |
8ff69732 | 1007 | |
dca02613 LW |
1008 | unlock_policy_rwsem_write(cpu); |
1009 | ||
038c5b3e | 1010 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 1011 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 1012 | pr_debug("initialization complete\n"); |
87c32271 | 1013 | |
1da177e4 LT |
1014 | return 0; |
1015 | ||
1016 | ||
1017 | err_out_unregister: | |
1018 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1019 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1020 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1021 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1022 | ||
c10997f6 | 1023 | kobject_put(&policy->kobj); |
1da177e4 LT |
1024 | wait_for_completion(&policy->kobj_unregister); |
1025 | ||
3f4a782b | 1026 | err_unlock_policy: |
45709118 | 1027 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 1028 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
1029 | err_free_cpumask: |
1030 | free_cpumask_var(policy->cpus); | |
1031 | err_free_policy: | |
1da177e4 | 1032 | kfree(policy); |
1da177e4 LT |
1033 | nomem_out: |
1034 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1035 | module_out: |
1da177e4 LT |
1036 | return ret; |
1037 | } | |
1038 | ||
1039 | ||
1040 | /** | |
5a01f2e8 | 1041 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1042 | * |
1043 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1044 | * Caller should already have policy_rwsem in write mode for this CPU. |
1045 | * This routine frees the rwsem before returning. | |
1da177e4 | 1046 | */ |
8a25a2fd | 1047 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1048 | { |
8a25a2fd | 1049 | unsigned int cpu = dev->id; |
1da177e4 LT |
1050 | unsigned long flags; |
1051 | struct cpufreq_policy *data; | |
499bca9b AW |
1052 | struct kobject *kobj; |
1053 | struct completion *cmp; | |
1da177e4 | 1054 | #ifdef CONFIG_SMP |
8a25a2fd | 1055 | struct device *cpu_dev; |
1da177e4 LT |
1056 | unsigned int j; |
1057 | #endif | |
1058 | ||
2d06d8c4 | 1059 | pr_debug("unregistering CPU %u\n", cpu); |
1da177e4 LT |
1060 | |
1061 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1062 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1063 | |
1064 | if (!data) { | |
1065 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
5a01f2e8 | 1066 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1067 | return -EINVAL; |
1068 | } | |
7a6aedfa | 1069 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 | 1070 | |
1da177e4 LT |
1071 | #ifdef CONFIG_SMP |
1072 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 1073 | * only need to unlink, put and exit |
1da177e4 LT |
1074 | */ |
1075 | if (unlikely(cpu != data->cpu)) { | |
2d06d8c4 | 1076 | pr_debug("removing link\n"); |
f6a7409c | 1077 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
835481d9 | 1078 | cpumask_clear_cpu(cpu, data->cpus); |
1da177e4 | 1079 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
f6a7409c VK |
1080 | |
1081 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1082 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1083 | ||
8a25a2fd | 1084 | kobj = &dev->kobj; |
1da177e4 | 1085 | cpufreq_cpu_put(data); |
5a01f2e8 | 1086 | unlock_policy_rwsem_write(cpu); |
499bca9b | 1087 | sysfs_remove_link(kobj, "cpufreq"); |
1da177e4 LT |
1088 | return 0; |
1089 | } | |
1090 | #endif | |
1091 | ||
1da177e4 | 1092 | #ifdef CONFIG_SMP |
084f3493 TR |
1093 | |
1094 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1095 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1096 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1097 | #endif |
1098 | ||
1da177e4 LT |
1099 | /* if we have other CPUs still registered, we need to unlink them, |
1100 | * or else wait_for_completion below will lock up. Clean the | |
7a6aedfa MT |
1101 | * per_cpu(cpufreq_cpu_data) while holding the lock, and remove |
1102 | * the sysfs links afterwards. | |
1da177e4 | 1103 | */ |
835481d9 RR |
1104 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1105 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1106 | if (j == cpu) |
1107 | continue; | |
7a6aedfa | 1108 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1109 | } |
1110 | } | |
1111 | ||
1112 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1113 | ||
835481d9 RR |
1114 | if (unlikely(cpumask_weight(data->cpus) > 1)) { |
1115 | for_each_cpu(j, data->cpus) { | |
1da177e4 LT |
1116 | if (j == cpu) |
1117 | continue; | |
2d06d8c4 | 1118 | pr_debug("removing link for cpu %u\n", j); |
084f3493 | 1119 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
1120 | strncpy(per_cpu(cpufreq_cpu_governor, j), |
1121 | data->governor->name, CPUFREQ_NAME_LEN); | |
084f3493 | 1122 | #endif |
8a25a2fd KS |
1123 | cpu_dev = get_cpu_device(j); |
1124 | kobj = &cpu_dev->kobj; | |
499bca9b AW |
1125 | unlock_policy_rwsem_write(cpu); |
1126 | sysfs_remove_link(kobj, "cpufreq"); | |
1127 | lock_policy_rwsem_write(cpu); | |
1da177e4 LT |
1128 | cpufreq_cpu_put(data); |
1129 | } | |
1130 | } | |
1131 | #else | |
1132 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1133 | #endif | |
1134 | ||
1da177e4 LT |
1135 | if (cpufreq_driver->target) |
1136 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 1137 | |
499bca9b AW |
1138 | kobj = &data->kobj; |
1139 | cmp = &data->kobj_unregister; | |
1140 | unlock_policy_rwsem_write(cpu); | |
1141 | kobject_put(kobj); | |
1da177e4 LT |
1142 | |
1143 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 1144 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
1145 | * unloading. |
1146 | */ | |
2d06d8c4 | 1147 | pr_debug("waiting for dropping of refcount\n"); |
499bca9b | 1148 | wait_for_completion(cmp); |
2d06d8c4 | 1149 | pr_debug("wait complete\n"); |
1da177e4 | 1150 | |
499bca9b | 1151 | lock_policy_rwsem_write(cpu); |
1da177e4 LT |
1152 | if (cpufreq_driver->exit) |
1153 | cpufreq_driver->exit(data); | |
7d26e2d5 | 1154 | unlock_policy_rwsem_write(cpu); |
1155 | ||
27ecddc2 JS |
1156 | #ifdef CONFIG_HOTPLUG_CPU |
1157 | /* when the CPU which is the parent of the kobj is hotplugged | |
1158 | * offline, check for siblings, and create cpufreq sysfs interface | |
1159 | * and symlinks | |
1160 | */ | |
1161 | if (unlikely(cpumask_weight(data->cpus) > 1)) { | |
1162 | /* first sibling now owns the new sysfs dir */ | |
1163 | cpumask_clear_cpu(cpu, data->cpus); | |
8a25a2fd | 1164 | cpufreq_add_dev(get_cpu_device(cpumask_first(data->cpus)), NULL); |
27ecddc2 JS |
1165 | |
1166 | /* finally remove our own symlink */ | |
1167 | lock_policy_rwsem_write(cpu); | |
8a25a2fd | 1168 | __cpufreq_remove_dev(dev, sif); |
27ecddc2 JS |
1169 | } |
1170 | #endif | |
1171 | ||
835481d9 RR |
1172 | free_cpumask_var(data->related_cpus); |
1173 | free_cpumask_var(data->cpus); | |
1da177e4 LT |
1174 | kfree(data); |
1175 | ||
1da177e4 LT |
1176 | return 0; |
1177 | } | |
1178 | ||
1179 | ||
8a25a2fd | 1180 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1181 | { |
8a25a2fd | 1182 | unsigned int cpu = dev->id; |
5a01f2e8 | 1183 | int retval; |
ec28297a VP |
1184 | |
1185 | if (cpu_is_offline(cpu)) | |
1186 | return 0; | |
1187 | ||
5a01f2e8 VP |
1188 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1189 | BUG(); | |
1190 | ||
6954ca9c | 1191 | cpumask_clear_cpu(cpu, &cpufreq_online_mask); |
8a25a2fd | 1192 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1193 | return retval; |
1194 | } | |
1195 | ||
1196 | ||
65f27f38 | 1197 | static void handle_update(struct work_struct *work) |
1da177e4 | 1198 | { |
65f27f38 DH |
1199 | struct cpufreq_policy *policy = |
1200 | container_of(work, struct cpufreq_policy, update); | |
1201 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1202 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1203 | cpufreq_update_policy(cpu); |
1204 | } | |
1205 | ||
1206 | /** | |
1207 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1208 | * @cpu: cpu number | |
1209 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1210 | * @new_freq: CPU frequency the CPU actually runs at | |
1211 | * | |
29464f28 DJ |
1212 | * We adjust to current frequency first, and need to clean up later. |
1213 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1214 | */ |
e08f5f5b GS |
1215 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1216 | unsigned int new_freq) | |
1da177e4 LT |
1217 | { |
1218 | struct cpufreq_freqs freqs; | |
1219 | ||
2d06d8c4 | 1220 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1221 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1222 | ||
1223 | freqs.cpu = cpu; | |
1224 | freqs.old = old_freq; | |
1225 | freqs.new = new_freq; | |
1226 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1227 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1228 | } | |
1229 | ||
1230 | ||
32ee8c3e | 1231 | /** |
4ab70df4 | 1232 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1233 | * @cpu: CPU number |
1234 | * | |
1235 | * This is the last known freq, without actually getting it from the driver. | |
1236 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1237 | */ | |
1238 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1239 | { | |
1240 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1241 | unsigned int ret_freq = 0; |
95235ca2 VP |
1242 | |
1243 | if (policy) { | |
e08f5f5b | 1244 | ret_freq = policy->cur; |
95235ca2 VP |
1245 | cpufreq_cpu_put(policy); |
1246 | } | |
1247 | ||
4d34a67d | 1248 | return ret_freq; |
95235ca2 VP |
1249 | } |
1250 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1251 | ||
3d737108 JB |
1252 | /** |
1253 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1254 | * @cpu: CPU number | |
1255 | * | |
1256 | * Just return the max possible frequency for a given CPU. | |
1257 | */ | |
1258 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1259 | { | |
1260 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1261 | unsigned int ret_freq = 0; | |
1262 | ||
1263 | if (policy) { | |
1264 | ret_freq = policy->max; | |
1265 | cpufreq_cpu_put(policy); | |
1266 | } | |
1267 | ||
1268 | return ret_freq; | |
1269 | } | |
1270 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1271 | ||
95235ca2 | 1272 | |
5a01f2e8 | 1273 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1274 | { |
7a6aedfa | 1275 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1276 | unsigned int ret_freq = 0; |
1da177e4 | 1277 | |
1da177e4 | 1278 | if (!cpufreq_driver->get) |
4d34a67d | 1279 | return ret_freq; |
1da177e4 | 1280 | |
e08f5f5b | 1281 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1282 | |
e08f5f5b GS |
1283 | if (ret_freq && policy->cur && |
1284 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1285 | /* verify no discrepancy between actual and | |
1286 | saved value exists */ | |
1287 | if (unlikely(ret_freq != policy->cur)) { | |
1288 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1289 | schedule_work(&policy->update); |
1290 | } | |
1291 | } | |
1292 | ||
4d34a67d | 1293 | return ret_freq; |
5a01f2e8 | 1294 | } |
1da177e4 | 1295 | |
5a01f2e8 VP |
1296 | /** |
1297 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1298 | * @cpu: CPU number | |
1299 | * | |
1300 | * Get the CPU current (static) CPU frequency | |
1301 | */ | |
1302 | unsigned int cpufreq_get(unsigned int cpu) | |
1303 | { | |
1304 | unsigned int ret_freq = 0; | |
1305 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1306 | ||
1307 | if (!policy) | |
1308 | goto out; | |
1309 | ||
1310 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1311 | goto out_policy; | |
1312 | ||
1313 | ret_freq = __cpufreq_get(cpu); | |
1314 | ||
1315 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1316 | |
5a01f2e8 VP |
1317 | out_policy: |
1318 | cpufreq_cpu_put(policy); | |
1319 | out: | |
4d34a67d | 1320 | return ret_freq; |
1da177e4 LT |
1321 | } |
1322 | EXPORT_SYMBOL(cpufreq_get); | |
1323 | ||
8a25a2fd KS |
1324 | static struct subsys_interface cpufreq_interface = { |
1325 | .name = "cpufreq", | |
1326 | .subsys = &cpu_subsys, | |
1327 | .add_dev = cpufreq_add_dev, | |
1328 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1329 | }; |
1330 | ||
1da177e4 | 1331 | |
42d4dc3f | 1332 | /** |
e00e56df RW |
1333 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1334 | * | |
1335 | * This function is only executed for the boot processor. The other CPUs | |
1336 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1337 | */ |
e00e56df | 1338 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1339 | { |
e08f5f5b | 1340 | int ret = 0; |
4bc5d341 | 1341 | |
e00e56df | 1342 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1343 | struct cpufreq_policy *cpu_policy; |
1344 | ||
2d06d8c4 | 1345 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1346 | |
e00e56df | 1347 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1348 | cpu_policy = cpufreq_cpu_get(cpu); |
1349 | if (!cpu_policy) | |
e00e56df | 1350 | return 0; |
42d4dc3f BH |
1351 | |
1352 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1353 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1354 | if (ret) |
42d4dc3f BH |
1355 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1356 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1357 | } |
1358 | ||
42d4dc3f | 1359 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1360 | return ret; |
42d4dc3f BH |
1361 | } |
1362 | ||
1da177e4 | 1363 | /** |
e00e56df | 1364 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1365 | * |
1366 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1367 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1368 | * restored. It will verify that the current freq is in sync with | |
1369 | * what we believe it to be. This is a bit later than when it | |
1370 | * should be, but nonethteless it's better than calling | |
1371 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1372 | * |
1373 | * This function is only executed for the boot CPU. The other CPUs have not | |
1374 | * been turned on yet. | |
1da177e4 | 1375 | */ |
e00e56df | 1376 | static void cpufreq_bp_resume(void) |
1da177e4 | 1377 | { |
e08f5f5b | 1378 | int ret = 0; |
4bc5d341 | 1379 | |
e00e56df | 1380 | int cpu = smp_processor_id(); |
1da177e4 LT |
1381 | struct cpufreq_policy *cpu_policy; |
1382 | ||
2d06d8c4 | 1383 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1384 | |
e00e56df | 1385 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1386 | cpu_policy = cpufreq_cpu_get(cpu); |
1387 | if (!cpu_policy) | |
e00e56df | 1388 | return; |
1da177e4 LT |
1389 | |
1390 | if (cpufreq_driver->resume) { | |
1391 | ret = cpufreq_driver->resume(cpu_policy); | |
1392 | if (ret) { | |
1393 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1394 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1395 | goto fail; |
1da177e4 LT |
1396 | } |
1397 | } | |
1398 | ||
1da177e4 | 1399 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1400 | |
c9060494 | 1401 | fail: |
1da177e4 | 1402 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1403 | } |
1404 | ||
e00e56df RW |
1405 | static struct syscore_ops cpufreq_syscore_ops = { |
1406 | .suspend = cpufreq_bp_suspend, | |
1407 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1408 | }; |
1409 | ||
1410 | ||
1411 | /********************************************************************* | |
1412 | * NOTIFIER LISTS INTERFACE * | |
1413 | *********************************************************************/ | |
1414 | ||
1415 | /** | |
1416 | * cpufreq_register_notifier - register a driver with cpufreq | |
1417 | * @nb: notifier function to register | |
1418 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1419 | * | |
32ee8c3e | 1420 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1421 | * are notified about clock rate changes (once before and once after |
1422 | * the transition), or a list of drivers that are notified about | |
1423 | * changes in cpufreq policy. | |
1424 | * | |
1425 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1426 | * blocking_notifier_chain_register. |
1da177e4 LT |
1427 | */ |
1428 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1429 | { | |
1430 | int ret; | |
1431 | ||
74212ca4 CEB |
1432 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1433 | ||
1da177e4 LT |
1434 | switch (list) { |
1435 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1436 | ret = srcu_notifier_chain_register( |
e041c683 | 1437 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1438 | break; |
1439 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1440 | ret = blocking_notifier_chain_register( |
1441 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1442 | break; |
1443 | default: | |
1444 | ret = -EINVAL; | |
1445 | } | |
1da177e4 LT |
1446 | |
1447 | return ret; | |
1448 | } | |
1449 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1450 | ||
1451 | ||
1452 | /** | |
1453 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1454 | * @nb: notifier block to be unregistered | |
1455 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1456 | * | |
1457 | * Remove a driver from the CPU frequency notifier list. | |
1458 | * | |
1459 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1460 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1461 | */ |
1462 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1463 | { | |
1464 | int ret; | |
1465 | ||
1da177e4 LT |
1466 | switch (list) { |
1467 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1468 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1469 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1470 | break; |
1471 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1472 | ret = blocking_notifier_chain_unregister( |
1473 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1474 | break; |
1475 | default: | |
1476 | ret = -EINVAL; | |
1477 | } | |
1da177e4 LT |
1478 | |
1479 | return ret; | |
1480 | } | |
1481 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1482 | ||
1483 | ||
1484 | /********************************************************************* | |
1485 | * GOVERNORS * | |
1486 | *********************************************************************/ | |
1487 | ||
1488 | ||
1489 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1490 | unsigned int target_freq, | |
1491 | unsigned int relation) | |
1492 | { | |
1493 | int retval = -EINVAL; | |
7249924e | 1494 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1495 | |
a7b422cd KRW |
1496 | if (cpufreq_disabled()) |
1497 | return -ENODEV; | |
1498 | ||
7249924e VK |
1499 | /* Make sure that target_freq is within supported range */ |
1500 | if (target_freq > policy->max) | |
1501 | target_freq = policy->max; | |
1502 | if (target_freq < policy->min) | |
1503 | target_freq = policy->min; | |
1504 | ||
1505 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1506 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1507 | |
1508 | if (target_freq == policy->cur) | |
1509 | return 0; | |
1510 | ||
1da177e4 LT |
1511 | if (cpu_online(policy->cpu) && cpufreq_driver->target) |
1512 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1513 | |
1da177e4 LT |
1514 | return retval; |
1515 | } | |
1516 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1517 | ||
1da177e4 LT |
1518 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1519 | unsigned int target_freq, | |
1520 | unsigned int relation) | |
1521 | { | |
f1829e4a | 1522 | int ret = -EINVAL; |
1da177e4 LT |
1523 | |
1524 | policy = cpufreq_cpu_get(policy->cpu); | |
1525 | if (!policy) | |
f1829e4a | 1526 | goto no_policy; |
1da177e4 | 1527 | |
5a01f2e8 | 1528 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1529 | goto fail; |
1da177e4 LT |
1530 | |
1531 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1532 | ||
5a01f2e8 | 1533 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1534 | |
f1829e4a | 1535 | fail: |
1da177e4 | 1536 | cpufreq_cpu_put(policy); |
f1829e4a | 1537 | no_policy: |
1da177e4 LT |
1538 | return ret; |
1539 | } | |
1540 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1541 | ||
bf0b90e3 | 1542 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1543 | { |
1544 | int ret = 0; | |
1545 | ||
0676f7f2 VK |
1546 | if (!(cpu_online(cpu) && cpufreq_driver->getavg)) |
1547 | return 0; | |
1548 | ||
dfde5d62 VP |
1549 | policy = cpufreq_cpu_get(policy->cpu); |
1550 | if (!policy) | |
1551 | return -EINVAL; | |
1552 | ||
0676f7f2 | 1553 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1554 | |
dfde5d62 VP |
1555 | cpufreq_cpu_put(policy); |
1556 | return ret; | |
1557 | } | |
5a01f2e8 | 1558 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1559 | |
153d7f3f | 1560 | /* |
153d7f3f AV |
1561 | * when "event" is CPUFREQ_GOV_LIMITS |
1562 | */ | |
1da177e4 | 1563 | |
e08f5f5b GS |
1564 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1565 | unsigned int event) | |
1da177e4 | 1566 | { |
cc993cab | 1567 | int ret; |
6afde10c TR |
1568 | |
1569 | /* Only must be defined when default governor is known to have latency | |
1570 | restrictions, like e.g. conservative or ondemand. | |
1571 | That this is the case is already ensured in Kconfig | |
1572 | */ | |
1573 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1574 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1575 | #else | |
1576 | struct cpufreq_governor *gov = NULL; | |
1577 | #endif | |
1c256245 TR |
1578 | |
1579 | if (policy->governor->max_transition_latency && | |
1580 | policy->cpuinfo.transition_latency > | |
1581 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1582 | if (!gov) |
1583 | return -EINVAL; | |
1584 | else { | |
1585 | printk(KERN_WARNING "%s governor failed, too long" | |
1586 | " transition latency of HW, fallback" | |
1587 | " to %s governor\n", | |
1588 | policy->governor->name, | |
1589 | gov->name); | |
1590 | policy->governor = gov; | |
1591 | } | |
1c256245 | 1592 | } |
1da177e4 LT |
1593 | |
1594 | if (!try_module_get(policy->governor->owner)) | |
1595 | return -EINVAL; | |
1596 | ||
2d06d8c4 | 1597 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1598 | policy->cpu, event); |
1da177e4 LT |
1599 | ret = policy->governor->governor(policy, event); |
1600 | ||
e08f5f5b GS |
1601 | /* we keep one module reference alive for |
1602 | each CPU governed by this CPU */ | |
1da177e4 LT |
1603 | if ((event != CPUFREQ_GOV_START) || ret) |
1604 | module_put(policy->governor->owner); | |
1605 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1606 | module_put(policy->governor->owner); | |
1607 | ||
1608 | return ret; | |
1609 | } | |
1610 | ||
1611 | ||
1da177e4 LT |
1612 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1613 | { | |
3bcb09a3 | 1614 | int err; |
1da177e4 LT |
1615 | |
1616 | if (!governor) | |
1617 | return -EINVAL; | |
1618 | ||
a7b422cd KRW |
1619 | if (cpufreq_disabled()) |
1620 | return -ENODEV; | |
1621 | ||
3fc54d37 | 1622 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1623 | |
3bcb09a3 JF |
1624 | err = -EBUSY; |
1625 | if (__find_governor(governor->name) == NULL) { | |
1626 | err = 0; | |
1627 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1628 | } |
1da177e4 | 1629 | |
32ee8c3e | 1630 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1631 | return err; |
1da177e4 LT |
1632 | } |
1633 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1634 | ||
1635 | ||
1636 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1637 | { | |
90e41bac PB |
1638 | #ifdef CONFIG_HOTPLUG_CPU |
1639 | int cpu; | |
1640 | #endif | |
1641 | ||
1da177e4 LT |
1642 | if (!governor) |
1643 | return; | |
1644 | ||
a7b422cd KRW |
1645 | if (cpufreq_disabled()) |
1646 | return; | |
1647 | ||
90e41bac PB |
1648 | #ifdef CONFIG_HOTPLUG_CPU |
1649 | for_each_present_cpu(cpu) { | |
1650 | if (cpu_online(cpu)) | |
1651 | continue; | |
1652 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1653 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1654 | } | |
1655 | #endif | |
1656 | ||
3fc54d37 | 1657 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1658 | list_del(&governor->governor_list); |
3fc54d37 | 1659 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1660 | return; |
1661 | } | |
1662 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1663 | ||
1664 | ||
1665 | ||
1666 | /********************************************************************* | |
1667 | * POLICY INTERFACE * | |
1668 | *********************************************************************/ | |
1669 | ||
1670 | /** | |
1671 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1672 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1673 | * is written | |
1da177e4 LT |
1674 | * |
1675 | * Reads the current cpufreq policy. | |
1676 | */ | |
1677 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1678 | { | |
1679 | struct cpufreq_policy *cpu_policy; | |
1680 | if (!policy) | |
1681 | return -EINVAL; | |
1682 | ||
1683 | cpu_policy = cpufreq_cpu_get(cpu); | |
1684 | if (!cpu_policy) | |
1685 | return -EINVAL; | |
1686 | ||
1da177e4 | 1687 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1688 | |
1689 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1690 | return 0; |
1691 | } | |
1692 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1693 | ||
1694 | ||
153d7f3f | 1695 | /* |
e08f5f5b GS |
1696 | * data : current policy. |
1697 | * policy : policy to be set. | |
153d7f3f | 1698 | */ |
e08f5f5b GS |
1699 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1700 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1701 | { |
1702 | int ret = 0; | |
1703 | ||
2d06d8c4 | 1704 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1705 | policy->min, policy->max); |
1706 | ||
e08f5f5b GS |
1707 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1708 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1709 | |
53391fa2 | 1710 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1711 | ret = -EINVAL; |
1712 | goto error_out; | |
1713 | } | |
1714 | ||
1da177e4 LT |
1715 | /* verify the cpu speed can be set within this limit */ |
1716 | ret = cpufreq_driver->verify(policy); | |
1717 | if (ret) | |
1718 | goto error_out; | |
1719 | ||
1da177e4 | 1720 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1721 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1722 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1723 | |
1724 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1725 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1726 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1727 | |
1728 | /* verify the cpu speed can be set within this limit, | |
1729 | which might be different to the first one */ | |
1730 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1731 | if (ret) |
1da177e4 | 1732 | goto error_out; |
1da177e4 LT |
1733 | |
1734 | /* notification of the new policy */ | |
e041c683 AS |
1735 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1736 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1737 | |
7d5e350f DJ |
1738 | data->min = policy->min; |
1739 | data->max = policy->max; | |
1da177e4 | 1740 | |
2d06d8c4 | 1741 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1742 | data->min, data->max); |
1da177e4 LT |
1743 | |
1744 | if (cpufreq_driver->setpolicy) { | |
1745 | data->policy = policy->policy; | |
2d06d8c4 | 1746 | pr_debug("setting range\n"); |
1da177e4 LT |
1747 | ret = cpufreq_driver->setpolicy(policy); |
1748 | } else { | |
1749 | if (policy->governor != data->governor) { | |
1750 | /* save old, working values */ | |
1751 | struct cpufreq_governor *old_gov = data->governor; | |
1752 | ||
2d06d8c4 | 1753 | pr_debug("governor switch\n"); |
1da177e4 LT |
1754 | |
1755 | /* end old governor */ | |
ffe6275f | 1756 | if (data->governor) |
1da177e4 LT |
1757 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1758 | ||
1759 | /* start new governor */ | |
1760 | data->governor = policy->governor; | |
1761 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
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; | |
e08f5f5b GS |
1767 | __cpufreq_governor(data, |
1768 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1769 | } |
1770 | ret = -EINVAL; | |
1771 | goto error_out; | |
1772 | } | |
1773 | /* might be a policy change, too, so fall through */ | |
1774 | } | |
2d06d8c4 | 1775 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1776 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1777 | } | |
1778 | ||
7d5e350f | 1779 | error_out: |
1da177e4 LT |
1780 | return ret; |
1781 | } | |
1782 | ||
1da177e4 LT |
1783 | /** |
1784 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1785 | * @cpu: CPU which shall be re-evaluated | |
1786 | * | |
25985edc | 1787 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1788 | * at different times. |
1789 | */ | |
1790 | int cpufreq_update_policy(unsigned int cpu) | |
1791 | { | |
1792 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1793 | struct cpufreq_policy policy; | |
f1829e4a | 1794 | int ret; |
1da177e4 | 1795 | |
f1829e4a JL |
1796 | if (!data) { |
1797 | ret = -ENODEV; | |
1798 | goto no_policy; | |
1799 | } | |
1da177e4 | 1800 | |
f1829e4a JL |
1801 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1802 | ret = -EINVAL; | |
1803 | goto fail; | |
1804 | } | |
1da177e4 | 1805 | |
2d06d8c4 | 1806 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1807 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1808 | policy.min = data->user_policy.min; |
1809 | policy.max = data->user_policy.max; | |
1810 | policy.policy = data->user_policy.policy; | |
1811 | policy.governor = data->user_policy.governor; | |
1812 | ||
0961dd0d TR |
1813 | /* BIOS might change freq behind our back |
1814 | -> ask driver for current freq and notify governors about a change */ | |
1815 | if (cpufreq_driver->get) { | |
1816 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1817 | if (!data->cur) { |
2d06d8c4 | 1818 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1819 | data->cur = policy.cur; |
1820 | } else { | |
1821 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1822 | cpufreq_out_of_sync(cpu, data->cur, |
1823 | policy.cur); | |
a85f7bd3 | 1824 | } |
0961dd0d TR |
1825 | } |
1826 | ||
1da177e4 LT |
1827 | ret = __cpufreq_set_policy(data, &policy); |
1828 | ||
5a01f2e8 VP |
1829 | unlock_policy_rwsem_write(cpu); |
1830 | ||
f1829e4a | 1831 | fail: |
1da177e4 | 1832 | cpufreq_cpu_put(data); |
f1829e4a | 1833 | no_policy: |
1da177e4 LT |
1834 | return ret; |
1835 | } | |
1836 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1837 | ||
dd184a01 | 1838 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1839 | unsigned long action, void *hcpu) |
1840 | { | |
1841 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1842 | struct device *dev; |
c32b6b8e | 1843 | |
8a25a2fd KS |
1844 | dev = get_cpu_device(cpu); |
1845 | if (dev) { | |
c32b6b8e AR |
1846 | switch (action) { |
1847 | case CPU_ONLINE: | |
8bb78442 | 1848 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1849 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1850 | break; |
1851 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1852 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1853 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1854 | BUG(); | |
1855 | ||
8a25a2fd | 1856 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1857 | break; |
5a01f2e8 | 1858 | case CPU_DOWN_FAILED: |
8bb78442 | 1859 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1860 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1861 | break; |
1862 | } | |
1863 | } | |
1864 | return NOTIFY_OK; | |
1865 | } | |
1866 | ||
9c36f746 | 1867 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1868 | .notifier_call = cpufreq_cpu_callback, |
1869 | }; | |
1da177e4 LT |
1870 | |
1871 | /********************************************************************* | |
1872 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1873 | *********************************************************************/ | |
1874 | ||
1875 | /** | |
1876 | * cpufreq_register_driver - register a CPU Frequency driver | |
1877 | * @driver_data: A struct cpufreq_driver containing the values# | |
1878 | * submitted by the CPU Frequency driver. | |
1879 | * | |
32ee8c3e | 1880 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1881 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1882 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1883 | * |
1884 | */ | |
221dee28 | 1885 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1886 | { |
1887 | unsigned long flags; | |
1888 | int ret; | |
1889 | ||
a7b422cd KRW |
1890 | if (cpufreq_disabled()) |
1891 | return -ENODEV; | |
1892 | ||
1da177e4 LT |
1893 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1894 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1895 | return -EINVAL; | |
1896 | ||
2d06d8c4 | 1897 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1898 | |
1899 | if (driver_data->setpolicy) | |
1900 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1901 | ||
1902 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1903 | if (cpufreq_driver) { | |
1904 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1905 | return -EBUSY; | |
1906 | } | |
1907 | cpufreq_driver = driver_data; | |
1908 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1909 | ||
6954ca9c VK |
1910 | cpumask_setall(&cpufreq_online_mask); |
1911 | ||
8a25a2fd | 1912 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1913 | if (ret) |
1914 | goto err_null_driver; | |
1da177e4 | 1915 | |
8f5bc2ab | 1916 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1917 | int i; |
1918 | ret = -ENODEV; | |
1919 | ||
1920 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1921 | for (i = 0; i < nr_cpu_ids; i++) |
1922 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1923 | ret = 0; |
7a6aedfa MT |
1924 | break; |
1925 | } | |
1da177e4 LT |
1926 | |
1927 | /* if all ->init() calls failed, unregister */ | |
1928 | if (ret) { | |
2d06d8c4 | 1929 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1930 | driver_data->name); |
8a25a2fd | 1931 | goto err_if_unreg; |
1da177e4 LT |
1932 | } |
1933 | } | |
1934 | ||
8f5bc2ab | 1935 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1936 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1937 | |
8f5bc2ab | 1938 | return 0; |
8a25a2fd KS |
1939 | err_if_unreg: |
1940 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1941 | err_null_driver: |
1942 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1943 | cpufreq_driver = NULL; | |
1944 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1945 | return ret; |
1da177e4 LT |
1946 | } |
1947 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1948 | ||
1949 | ||
1950 | /** | |
1951 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1952 | * | |
32ee8c3e | 1953 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1954 | * the right to do so, i.e. if you have succeeded in initialising before! |
1955 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1956 | * currently not initialised. | |
1957 | */ | |
221dee28 | 1958 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1959 | { |
1960 | unsigned long flags; | |
1961 | ||
2d06d8c4 | 1962 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1963 | return -EINVAL; |
1da177e4 | 1964 | |
2d06d8c4 | 1965 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1966 | |
8a25a2fd | 1967 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1968 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1969 | |
1970 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1971 | cpufreq_driver = NULL; | |
1972 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1973 | ||
1974 | return 0; | |
1975 | } | |
1976 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1977 | |
1978 | static int __init cpufreq_core_init(void) | |
1979 | { | |
1980 | int cpu; | |
1981 | ||
a7b422cd KRW |
1982 | if (cpufreq_disabled()) |
1983 | return -ENODEV; | |
1984 | ||
5a01f2e8 | 1985 | for_each_possible_cpu(cpu) { |
f1625066 | 1986 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1987 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1988 | } | |
8aa84ad8 | 1989 | |
8a25a2fd | 1990 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1991 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1992 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1993 | |
5a01f2e8 VP |
1994 | return 0; |
1995 | } | |
5a01f2e8 | 1996 | core_initcall(cpufreq_core_init); |