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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
6 | * | |
c32b6b8e | 7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 8 | * Added handling for CPU hotplug |
8ff69732 DJ |
9 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
10 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 11 | * |
1da177e4 LT |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
1da177e4 LT |
20 | #include <linux/kernel.h> |
21 | #include <linux/module.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/notifier.h> | |
24 | #include <linux/cpufreq.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/spinlock.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/cpu.h> | |
31 | #include <linux/completion.h> | |
3fc54d37 | 32 | #include <linux/mutex.h> |
e00e56df | 33 | #include <linux/syscore_ops.h> |
1da177e4 | 34 | |
6f4f2723 TR |
35 | #include <trace/events/power.h> |
36 | ||
1da177e4 | 37 | /** |
cd878479 | 38 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
39 | * level driver of CPUFreq support, and its spinlock. This lock |
40 | * also protects the cpufreq_cpu_data array. | |
41 | */ | |
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 | |
a9144436 | 137 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
138 | { |
139 | struct cpufreq_policy *data; | |
140 | unsigned long flags; | |
141 | ||
7a6aedfa | 142 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
143 | goto err_out; |
144 | ||
145 | /* get the cpufreq driver */ | |
1c3d85dd | 146 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 147 | |
1c3d85dd | 148 | if (!cpufreq_driver) |
1da177e4 LT |
149 | goto err_out_unlock; |
150 | ||
1c3d85dd | 151 | if (!try_module_get(cpufreq_driver->owner)) |
1da177e4 LT |
152 | goto err_out_unlock; |
153 | ||
154 | ||
155 | /* get the CPU */ | |
7a6aedfa | 156 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
157 | |
158 | if (!data) | |
159 | goto err_out_put_module; | |
160 | ||
a9144436 | 161 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
162 | goto err_out_put_module; |
163 | ||
0d1857a1 | 164 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
165 | return data; |
166 | ||
7d5e350f | 167 | err_out_put_module: |
1c3d85dd | 168 | module_put(cpufreq_driver->owner); |
5800043b | 169 | err_out_unlock: |
1c3d85dd | 170 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 171 | err_out: |
1da177e4 LT |
172 | return NULL; |
173 | } | |
a9144436 SB |
174 | |
175 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
176 | { | |
d5aaffa9 DB |
177 | if (cpufreq_disabled()) |
178 | return NULL; | |
179 | ||
a9144436 SB |
180 | return __cpufreq_cpu_get(cpu, false); |
181 | } | |
1da177e4 LT |
182 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
183 | ||
a9144436 SB |
184 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
185 | { | |
186 | return __cpufreq_cpu_get(cpu, true); | |
187 | } | |
188 | ||
189 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
190 | { | |
191 | if (!sysfs) | |
192 | kobject_put(&data->kobj); | |
1c3d85dd | 193 | module_put(cpufreq_driver->owner); |
a9144436 | 194 | } |
7d5e350f | 195 | |
1da177e4 LT |
196 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
197 | { | |
d5aaffa9 DB |
198 | if (cpufreq_disabled()) |
199 | return; | |
200 | ||
a9144436 | 201 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
202 | } |
203 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
204 | ||
a9144436 SB |
205 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
206 | { | |
207 | __cpufreq_cpu_put(data, true); | |
208 | } | |
1da177e4 | 209 | |
1da177e4 LT |
210 | /********************************************************************* |
211 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
212 | *********************************************************************/ | |
213 | ||
214 | /** | |
215 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
216 | * | |
217 | * This function alters the system "loops_per_jiffy" for the clock | |
218 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 219 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
220 | * per-CPU loops_per_jiffy value wherever possible. |
221 | */ | |
222 | #ifndef CONFIG_SMP | |
223 | static unsigned long l_p_j_ref; | |
224 | static unsigned int l_p_j_ref_freq; | |
225 | ||
858119e1 | 226 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
227 | { |
228 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
229 | return; | |
230 | ||
231 | if (!l_p_j_ref_freq) { | |
232 | l_p_j_ref = loops_per_jiffy; | |
233 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 234 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 235 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 236 | } |
d08de0c1 | 237 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 238 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
239 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
240 | ci->new); | |
2d06d8c4 | 241 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 242 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
243 | } |
244 | } | |
245 | #else | |
e08f5f5b GS |
246 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
247 | { | |
248 | return; | |
249 | } | |
1da177e4 LT |
250 | #endif |
251 | ||
252 | ||
b43a7ffb VK |
253 | void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
254 | struct cpufreq_freqs *freqs, unsigned int state) | |
1da177e4 LT |
255 | { |
256 | BUG_ON(irqs_disabled()); | |
257 | ||
d5aaffa9 DB |
258 | if (cpufreq_disabled()) |
259 | return; | |
260 | ||
1c3d85dd | 261 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 262 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 263 | state, freqs->new); |
1da177e4 | 264 | |
1da177e4 | 265 | switch (state) { |
e4472cb3 | 266 | |
1da177e4 | 267 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 268 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
269 | * which is not equal to what the cpufreq core thinks is |
270 | * "old frequency". | |
1da177e4 | 271 | */ |
1c3d85dd | 272 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
273 | if ((policy) && (policy->cpu == freqs->cpu) && |
274 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 275 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
276 | " %u, cpufreq assumed %u kHz.\n", |
277 | freqs->old, policy->cur); | |
278 | freqs->old = policy->cur; | |
1da177e4 LT |
279 | } |
280 | } | |
b4dfdbb3 | 281 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 282 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
283 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
284 | break; | |
e4472cb3 | 285 | |
1da177e4 LT |
286 | case CPUFREQ_POSTCHANGE: |
287 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 288 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 289 | (unsigned long)freqs->cpu); |
25e41933 | 290 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 291 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 292 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
293 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
294 | policy->cur = freqs->new; | |
1da177e4 LT |
295 | break; |
296 | } | |
1da177e4 | 297 | } |
b43a7ffb VK |
298 | /** |
299 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
300 | * on frequency transition. | |
301 | * | |
302 | * This function calls the transition notifiers and the "adjust_jiffies" | |
303 | * function. It is called twice on all CPU frequency changes that have | |
304 | * external effects. | |
305 | */ | |
306 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
307 | struct cpufreq_freqs *freqs, unsigned int state) | |
308 | { | |
309 | for_each_cpu(freqs->cpu, policy->cpus) | |
310 | __cpufreq_notify_transition(policy, freqs, state); | |
311 | } | |
1da177e4 LT |
312 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
313 | ||
314 | ||
315 | ||
316 | /********************************************************************* | |
317 | * SYSFS INTERFACE * | |
318 | *********************************************************************/ | |
319 | ||
3bcb09a3 JF |
320 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
321 | { | |
322 | struct cpufreq_governor *t; | |
323 | ||
324 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 325 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
326 | return t; |
327 | ||
328 | return NULL; | |
329 | } | |
330 | ||
1da177e4 LT |
331 | /** |
332 | * cpufreq_parse_governor - parse a governor string | |
333 | */ | |
905d77cd | 334 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
335 | struct cpufreq_governor **governor) |
336 | { | |
3bcb09a3 | 337 | int err = -EINVAL; |
1c3d85dd RW |
338 | |
339 | if (!cpufreq_driver) | |
3bcb09a3 JF |
340 | goto out; |
341 | ||
1c3d85dd | 342 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
343 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
344 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 345 | err = 0; |
e08f5f5b GS |
346 | } else if (!strnicmp(str_governor, "powersave", |
347 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 348 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 349 | err = 0; |
1da177e4 | 350 | } |
1c3d85dd | 351 | } else if (cpufreq_driver->target) { |
1da177e4 | 352 | struct cpufreq_governor *t; |
3bcb09a3 | 353 | |
3fc54d37 | 354 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
355 | |
356 | t = __find_governor(str_governor); | |
357 | ||
ea714970 | 358 | if (t == NULL) { |
1a8e1463 | 359 | int ret; |
ea714970 | 360 | |
1a8e1463 KC |
361 | mutex_unlock(&cpufreq_governor_mutex); |
362 | ret = request_module("cpufreq_%s", str_governor); | |
363 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 364 | |
1a8e1463 KC |
365 | if (ret == 0) |
366 | t = __find_governor(str_governor); | |
ea714970 JF |
367 | } |
368 | ||
3bcb09a3 JF |
369 | if (t != NULL) { |
370 | *governor = t; | |
371 | err = 0; | |
1da177e4 | 372 | } |
3bcb09a3 | 373 | |
3fc54d37 | 374 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 375 | } |
29464f28 | 376 | out: |
3bcb09a3 | 377 | return err; |
1da177e4 | 378 | } |
1da177e4 LT |
379 | |
380 | ||
1da177e4 | 381 | /** |
e08f5f5b GS |
382 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
383 | * print out cpufreq information | |
1da177e4 LT |
384 | * |
385 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
386 | * "unsigned int". | |
387 | */ | |
388 | ||
32ee8c3e DJ |
389 | #define show_one(file_name, object) \ |
390 | static ssize_t show_##file_name \ | |
905d77cd | 391 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 392 | { \ |
29464f28 | 393 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
394 | } |
395 | ||
396 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
397 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 398 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
399 | show_one(scaling_min_freq, min); |
400 | show_one(scaling_max_freq, max); | |
401 | show_one(scaling_cur_freq, cur); | |
402 | ||
e08f5f5b GS |
403 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
404 | struct cpufreq_policy *policy); | |
7970e08b | 405 | |
1da177e4 LT |
406 | /** |
407 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
408 | */ | |
409 | #define store_one(file_name, object) \ | |
410 | static ssize_t store_##file_name \ | |
905d77cd | 411 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 412 | { \ |
f55c9c26 | 413 | unsigned int ret; \ |
1da177e4 LT |
414 | struct cpufreq_policy new_policy; \ |
415 | \ | |
416 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
417 | if (ret) \ | |
418 | return -EINVAL; \ | |
419 | \ | |
29464f28 | 420 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
421 | if (ret != 1) \ |
422 | return -EINVAL; \ | |
423 | \ | |
7970e08b TR |
424 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
425 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
426 | \ |
427 | return ret ? ret : count; \ | |
428 | } | |
429 | ||
29464f28 DJ |
430 | store_one(scaling_min_freq, min); |
431 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
432 | |
433 | /** | |
434 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
435 | */ | |
905d77cd DJ |
436 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
437 | char *buf) | |
1da177e4 | 438 | { |
5a01f2e8 | 439 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
440 | if (!cur_freq) |
441 | return sprintf(buf, "<unknown>"); | |
442 | return sprintf(buf, "%u\n", cur_freq); | |
443 | } | |
444 | ||
445 | ||
446 | /** | |
447 | * show_scaling_governor - show the current policy for the specified CPU | |
448 | */ | |
905d77cd | 449 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 450 | { |
29464f28 | 451 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
452 | return sprintf(buf, "powersave\n"); |
453 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
454 | return sprintf(buf, "performance\n"); | |
455 | else if (policy->governor) | |
4b972f0b | 456 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 457 | policy->governor->name); |
1da177e4 LT |
458 | return -EINVAL; |
459 | } | |
460 | ||
461 | ||
462 | /** | |
463 | * store_scaling_governor - store policy for the specified CPU | |
464 | */ | |
905d77cd DJ |
465 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
466 | const char *buf, size_t count) | |
1da177e4 | 467 | { |
f55c9c26 | 468 | unsigned int ret; |
1da177e4 LT |
469 | char str_governor[16]; |
470 | struct cpufreq_policy new_policy; | |
471 | ||
472 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
473 | if (ret) | |
474 | return ret; | |
475 | ||
29464f28 | 476 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
477 | if (ret != 1) |
478 | return -EINVAL; | |
479 | ||
e08f5f5b GS |
480 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
481 | &new_policy.governor)) | |
1da177e4 LT |
482 | return -EINVAL; |
483 | ||
7970e08b TR |
484 | /* Do not use cpufreq_set_policy here or the user_policy.max |
485 | will be wrongly overridden */ | |
7970e08b TR |
486 | ret = __cpufreq_set_policy(policy, &new_policy); |
487 | ||
488 | policy->user_policy.policy = policy->policy; | |
489 | policy->user_policy.governor = policy->governor; | |
7970e08b | 490 | |
e08f5f5b GS |
491 | if (ret) |
492 | return ret; | |
493 | else | |
494 | return count; | |
1da177e4 LT |
495 | } |
496 | ||
497 | /** | |
498 | * show_scaling_driver - show the cpufreq driver currently loaded | |
499 | */ | |
905d77cd | 500 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 501 | { |
1c3d85dd | 502 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
503 | } |
504 | ||
505 | /** | |
506 | * show_scaling_available_governors - show the available CPUfreq governors | |
507 | */ | |
905d77cd DJ |
508 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
509 | char *buf) | |
1da177e4 LT |
510 | { |
511 | ssize_t i = 0; | |
512 | struct cpufreq_governor *t; | |
513 | ||
1c3d85dd | 514 | if (!cpufreq_driver->target) { |
1da177e4 LT |
515 | i += sprintf(buf, "performance powersave"); |
516 | goto out; | |
517 | } | |
518 | ||
519 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
520 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
521 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 522 | goto out; |
4b972f0b | 523 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 524 | } |
7d5e350f | 525 | out: |
1da177e4 LT |
526 | i += sprintf(&buf[i], "\n"); |
527 | return i; | |
528 | } | |
e8628dd0 | 529 | |
835481d9 | 530 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
531 | { |
532 | ssize_t i = 0; | |
533 | unsigned int cpu; | |
534 | ||
835481d9 | 535 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
536 | if (i) |
537 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
538 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
539 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 540 | break; |
1da177e4 LT |
541 | } |
542 | i += sprintf(&buf[i], "\n"); | |
543 | return i; | |
544 | } | |
545 | ||
e8628dd0 DW |
546 | /** |
547 | * show_related_cpus - show the CPUs affected by each transition even if | |
548 | * hw coordination is in use | |
549 | */ | |
550 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
551 | { | |
e8628dd0 DW |
552 | return show_cpus(policy->related_cpus, buf); |
553 | } | |
554 | ||
555 | /** | |
556 | * show_affected_cpus - show the CPUs affected by each transition | |
557 | */ | |
558 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
559 | { | |
560 | return show_cpus(policy->cpus, buf); | |
561 | } | |
562 | ||
9e76988e | 563 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 564 | const char *buf, size_t count) |
9e76988e VP |
565 | { |
566 | unsigned int freq = 0; | |
567 | unsigned int ret; | |
568 | ||
879000f9 | 569 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
570 | return -EINVAL; |
571 | ||
572 | ret = sscanf(buf, "%u", &freq); | |
573 | if (ret != 1) | |
574 | return -EINVAL; | |
575 | ||
576 | policy->governor->store_setspeed(policy, freq); | |
577 | ||
578 | return count; | |
579 | } | |
580 | ||
581 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
582 | { | |
879000f9 | 583 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
584 | return sprintf(buf, "<unsupported>\n"); |
585 | ||
586 | return policy->governor->show_setspeed(policy, buf); | |
587 | } | |
1da177e4 | 588 | |
e2f74f35 | 589 | /** |
8bf1ac72 | 590 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
591 | */ |
592 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
593 | { | |
594 | unsigned int limit; | |
595 | int ret; | |
1c3d85dd RW |
596 | if (cpufreq_driver->bios_limit) { |
597 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
598 | if (!ret) |
599 | return sprintf(buf, "%u\n", limit); | |
600 | } | |
601 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
602 | } | |
603 | ||
6dad2a29 BP |
604 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
605 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
606 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
607 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
608 | cpufreq_freq_attr_ro(scaling_available_governors); | |
609 | cpufreq_freq_attr_ro(scaling_driver); | |
610 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
611 | cpufreq_freq_attr_ro(bios_limit); | |
612 | cpufreq_freq_attr_ro(related_cpus); | |
613 | cpufreq_freq_attr_ro(affected_cpus); | |
614 | cpufreq_freq_attr_rw(scaling_min_freq); | |
615 | cpufreq_freq_attr_rw(scaling_max_freq); | |
616 | cpufreq_freq_attr_rw(scaling_governor); | |
617 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 618 | |
905d77cd | 619 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
620 | &cpuinfo_min_freq.attr, |
621 | &cpuinfo_max_freq.attr, | |
ed129784 | 622 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
623 | &scaling_min_freq.attr, |
624 | &scaling_max_freq.attr, | |
625 | &affected_cpus.attr, | |
e8628dd0 | 626 | &related_cpus.attr, |
1da177e4 LT |
627 | &scaling_governor.attr, |
628 | &scaling_driver.attr, | |
629 | &scaling_available_governors.attr, | |
9e76988e | 630 | &scaling_setspeed.attr, |
1da177e4 LT |
631 | NULL |
632 | }; | |
633 | ||
8aa84ad8 TR |
634 | struct kobject *cpufreq_global_kobject; |
635 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
636 | ||
29464f28 DJ |
637 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
638 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 639 | |
29464f28 | 640 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 641 | { |
905d77cd DJ |
642 | struct cpufreq_policy *policy = to_policy(kobj); |
643 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 644 | ssize_t ret = -EINVAL; |
a9144436 | 645 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 646 | if (!policy) |
0db4a8a9 | 647 | goto no_policy; |
5a01f2e8 VP |
648 | |
649 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 650 | goto fail; |
5a01f2e8 | 651 | |
e08f5f5b GS |
652 | if (fattr->show) |
653 | ret = fattr->show(policy, buf); | |
654 | else | |
655 | ret = -EIO; | |
656 | ||
5a01f2e8 | 657 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 658 | fail: |
a9144436 | 659 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 660 | no_policy: |
1da177e4 LT |
661 | return ret; |
662 | } | |
663 | ||
905d77cd DJ |
664 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
665 | const char *buf, size_t count) | |
1da177e4 | 666 | { |
905d77cd DJ |
667 | struct cpufreq_policy *policy = to_policy(kobj); |
668 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 669 | ssize_t ret = -EINVAL; |
a9144436 | 670 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 671 | if (!policy) |
a07530b4 | 672 | goto no_policy; |
5a01f2e8 VP |
673 | |
674 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 675 | goto fail; |
5a01f2e8 | 676 | |
e08f5f5b GS |
677 | if (fattr->store) |
678 | ret = fattr->store(policy, buf, count); | |
679 | else | |
680 | ret = -EIO; | |
681 | ||
5a01f2e8 | 682 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 683 | fail: |
a9144436 | 684 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 685 | no_policy: |
1da177e4 LT |
686 | return ret; |
687 | } | |
688 | ||
905d77cd | 689 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 690 | { |
905d77cd | 691 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 692 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
693 | complete(&policy->kobj_unregister); |
694 | } | |
695 | ||
52cf25d0 | 696 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
697 | .show = show, |
698 | .store = store, | |
699 | }; | |
700 | ||
701 | static struct kobj_type ktype_cpufreq = { | |
702 | .sysfs_ops = &sysfs_ops, | |
703 | .default_attrs = default_attrs, | |
704 | .release = cpufreq_sysfs_release, | |
705 | }; | |
706 | ||
19d6f7ec | 707 | /* symlink affected CPUs */ |
cf3289d0 AC |
708 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
709 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
710 | { |
711 | unsigned int j; | |
712 | int ret = 0; | |
713 | ||
714 | for_each_cpu(j, policy->cpus) { | |
715 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 716 | struct device *cpu_dev; |
19d6f7ec DJ |
717 | |
718 | if (j == cpu) | |
719 | continue; | |
19d6f7ec | 720 | |
2d06d8c4 | 721 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 722 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
723 | cpu_dev = get_cpu_device(j); |
724 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
725 | "cpufreq"); |
726 | if (ret) { | |
727 | cpufreq_cpu_put(managed_policy); | |
728 | return ret; | |
729 | } | |
730 | } | |
731 | return ret; | |
732 | } | |
733 | ||
cf3289d0 AC |
734 | static int cpufreq_add_dev_interface(unsigned int cpu, |
735 | struct cpufreq_policy *policy, | |
8a25a2fd | 736 | struct device *dev) |
909a694e | 737 | { |
ecf7e461 | 738 | struct cpufreq_policy new_policy; |
909a694e DJ |
739 | struct freq_attr **drv_attr; |
740 | unsigned long flags; | |
741 | int ret = 0; | |
742 | unsigned int j; | |
743 | ||
744 | /* prepare interface data */ | |
745 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 746 | &dev->kobj, "cpufreq"); |
909a694e DJ |
747 | if (ret) |
748 | return ret; | |
749 | ||
750 | /* set up files for this cpu device */ | |
1c3d85dd | 751 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
752 | while ((drv_attr) && (*drv_attr)) { |
753 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
754 | if (ret) | |
1c3d85dd | 755 | goto err_out_kobj_put; |
909a694e DJ |
756 | drv_attr++; |
757 | } | |
1c3d85dd | 758 | if (cpufreq_driver->get) { |
909a694e DJ |
759 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
760 | if (ret) | |
1c3d85dd | 761 | goto err_out_kobj_put; |
909a694e | 762 | } |
1c3d85dd | 763 | if (cpufreq_driver->target) { |
909a694e DJ |
764 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
765 | if (ret) | |
1c3d85dd | 766 | goto err_out_kobj_put; |
909a694e | 767 | } |
1c3d85dd | 768 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
769 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
770 | if (ret) | |
1c3d85dd | 771 | goto err_out_kobj_put; |
e2f74f35 | 772 | } |
909a694e | 773 | |
0d1857a1 | 774 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
909a694e | 775 | for_each_cpu(j, policy->cpus) { |
909a694e | 776 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 777 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e | 778 | } |
0d1857a1 | 779 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
909a694e DJ |
780 | |
781 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
782 | if (ret) |
783 | goto err_out_kobj_put; | |
784 | ||
785 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
786 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
787 | policy->governor = NULL; | |
788 | ||
789 | /* set default policy */ | |
790 | ret = __cpufreq_set_policy(policy, &new_policy); | |
791 | policy->user_policy.policy = policy->policy; | |
792 | policy->user_policy.governor = policy->governor; | |
793 | ||
794 | if (ret) { | |
2d06d8c4 | 795 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
796 | if (cpufreq_driver->exit) |
797 | cpufreq_driver->exit(policy); | |
ecf7e461 | 798 | } |
909a694e DJ |
799 | return ret; |
800 | ||
801 | err_out_kobj_put: | |
802 | kobject_put(&policy->kobj); | |
803 | wait_for_completion(&policy->kobj_unregister); | |
804 | return ret; | |
805 | } | |
806 | ||
fcf80582 VK |
807 | #ifdef CONFIG_HOTPLUG_CPU |
808 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
809 | struct device *dev) | |
810 | { | |
811 | struct cpufreq_policy *policy; | |
1c3d85dd | 812 | int ret = 0, has_target = !!cpufreq_driver->target; |
fcf80582 VK |
813 | unsigned long flags; |
814 | ||
815 | policy = cpufreq_cpu_get(sibling); | |
816 | WARN_ON(!policy); | |
817 | ||
820c6ca2 VK |
818 | if (has_target) |
819 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
fcf80582 | 820 | |
2eaa3e2d VK |
821 | lock_policy_rwsem_write(sibling); |
822 | ||
0d1857a1 | 823 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 824 | |
fcf80582 | 825 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 826 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
fcf80582 | 827 | per_cpu(cpufreq_cpu_data, cpu) = policy; |
0d1857a1 | 828 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 829 | |
2eaa3e2d VK |
830 | unlock_policy_rwsem_write(sibling); |
831 | ||
820c6ca2 VK |
832 | if (has_target) { |
833 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
834 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
835 | } | |
fcf80582 | 836 | |
fcf80582 VK |
837 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
838 | if (ret) { | |
839 | cpufreq_cpu_put(policy); | |
840 | return ret; | |
841 | } | |
842 | ||
843 | return 0; | |
844 | } | |
845 | #endif | |
1da177e4 LT |
846 | |
847 | /** | |
848 | * cpufreq_add_dev - add a CPU device | |
849 | * | |
32ee8c3e | 850 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
851 | * |
852 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
853 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
854 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 855 | */ |
8a25a2fd | 856 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 857 | { |
fcf80582 | 858 | unsigned int j, cpu = dev->id; |
65922465 | 859 | int ret = -ENOMEM; |
1da177e4 | 860 | struct cpufreq_policy *policy; |
1da177e4 | 861 | unsigned long flags; |
90e41bac | 862 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 863 | struct cpufreq_governor *gov; |
90e41bac PB |
864 | int sibling; |
865 | #endif | |
1da177e4 | 866 | |
c32b6b8e AR |
867 | if (cpu_is_offline(cpu)) |
868 | return 0; | |
869 | ||
2d06d8c4 | 870 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
871 | |
872 | #ifdef CONFIG_SMP | |
873 | /* check whether a different CPU already registered this | |
874 | * CPU because it is in the same boat. */ | |
875 | policy = cpufreq_cpu_get(cpu); | |
876 | if (unlikely(policy)) { | |
8ff69732 | 877 | cpufreq_cpu_put(policy); |
1da177e4 LT |
878 | return 0; |
879 | } | |
fcf80582 VK |
880 | |
881 | #ifdef CONFIG_HOTPLUG_CPU | |
882 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 883 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
884 | for_each_online_cpu(sibling) { |
885 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d | 886 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
0d1857a1 | 887 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 888 | return cpufreq_add_policy_cpu(cpu, sibling, dev); |
2eaa3e2d | 889 | } |
fcf80582 | 890 | } |
0d1857a1 | 891 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 892 | #endif |
1da177e4 LT |
893 | #endif |
894 | ||
1c3d85dd | 895 | if (!try_module_get(cpufreq_driver->owner)) { |
1da177e4 LT |
896 | ret = -EINVAL; |
897 | goto module_out; | |
898 | } | |
899 | ||
e98df50c | 900 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 901 | if (!policy) |
1da177e4 | 902 | goto nomem_out; |
059019a3 DJ |
903 | |
904 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 905 | goto err_free_policy; |
059019a3 DJ |
906 | |
907 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 908 | goto err_free_cpumask; |
1da177e4 LT |
909 | |
910 | policy->cpu = cpu; | |
65922465 | 911 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 912 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 913 | |
5a01f2e8 | 914 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 915 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 916 | |
1da177e4 | 917 | init_completion(&policy->kobj_unregister); |
65f27f38 | 918 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
919 | |
920 | /* call driver. From then on the cpufreq must be able | |
921 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
922 | */ | |
1c3d85dd | 923 | ret = cpufreq_driver->init(policy); |
1da177e4 | 924 | if (ret) { |
2d06d8c4 | 925 | pr_debug("initialization failed\n"); |
2eaa3e2d | 926 | goto err_set_policy_cpu; |
1da177e4 | 927 | } |
643ae6e8 | 928 | |
fcf80582 VK |
929 | /* related cpus should atleast have policy->cpus */ |
930 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
931 | ||
643ae6e8 VK |
932 | /* |
933 | * affected cpus must always be the one, which are online. We aren't | |
934 | * managing offline cpus here. | |
935 | */ | |
936 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
937 | ||
187d9f4e MC |
938 | policy->user_policy.min = policy->min; |
939 | policy->user_policy.max = policy->max; | |
1da177e4 | 940 | |
a1531acd TR |
941 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
942 | CPUFREQ_START, policy); | |
943 | ||
fcf80582 VK |
944 | #ifdef CONFIG_HOTPLUG_CPU |
945 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
946 | if (gov) { | |
947 | policy->governor = gov; | |
948 | pr_debug("Restoring governor %s for cpu %d\n", | |
949 | policy->governor->name, cpu); | |
4bfa042c | 950 | } |
fcf80582 | 951 | #endif |
1da177e4 | 952 | |
8a25a2fd | 953 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
954 | if (ret) |
955 | goto err_out_unregister; | |
8ff69732 | 956 | |
038c5b3e | 957 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1c3d85dd | 958 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 959 | pr_debug("initialization complete\n"); |
87c32271 | 960 | |
1da177e4 LT |
961 | return 0; |
962 | ||
1da177e4 | 963 | err_out_unregister: |
0d1857a1 | 964 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
835481d9 | 965 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 966 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 967 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 968 | |
c10997f6 | 969 | kobject_put(&policy->kobj); |
1da177e4 LT |
970 | wait_for_completion(&policy->kobj_unregister); |
971 | ||
2eaa3e2d VK |
972 | err_set_policy_cpu: |
973 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
cad70a6a | 974 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
975 | err_free_cpumask: |
976 | free_cpumask_var(policy->cpus); | |
977 | err_free_policy: | |
1da177e4 | 978 | kfree(policy); |
1da177e4 | 979 | nomem_out: |
1c3d85dd | 980 | module_put(cpufreq_driver->owner); |
c32b6b8e | 981 | module_out: |
1da177e4 LT |
982 | return ret; |
983 | } | |
984 | ||
b8eed8af VK |
985 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
986 | { | |
987 | int j; | |
988 | ||
989 | policy->last_cpu = policy->cpu; | |
990 | policy->cpu = cpu; | |
991 | ||
3361b7b1 | 992 | for_each_cpu(j, policy->cpus) |
b8eed8af | 993 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
994 | |
995 | #ifdef CONFIG_CPU_FREQ_TABLE | |
996 | cpufreq_frequency_table_update_policy_cpu(policy); | |
997 | #endif | |
998 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
999 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1000 | } | |
1da177e4 LT |
1001 | |
1002 | /** | |
5a01f2e8 | 1003 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1004 | * |
1005 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1006 | * Caller should already have policy_rwsem in write mode for this CPU. |
1007 | * This routine frees the rwsem before returning. | |
1da177e4 | 1008 | */ |
8a25a2fd | 1009 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1010 | { |
b8eed8af | 1011 | unsigned int cpu = dev->id, ret, cpus; |
1da177e4 LT |
1012 | unsigned long flags; |
1013 | struct cpufreq_policy *data; | |
499bca9b AW |
1014 | struct kobject *kobj; |
1015 | struct completion *cmp; | |
8a25a2fd | 1016 | struct device *cpu_dev; |
1da177e4 | 1017 | |
b8eed8af | 1018 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1019 | |
0d1857a1 | 1020 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1021 | |
7a6aedfa | 1022 | data = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1023 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1024 | ||
0d1857a1 | 1025 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1026 | |
1027 | if (!data) { | |
b8eed8af | 1028 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1029 | return -EINVAL; |
1030 | } | |
1da177e4 | 1031 | |
1c3d85dd | 1032 | if (cpufreq_driver->target) |
f6a7409c | 1033 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1da177e4 | 1034 | |
084f3493 | 1035 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1036 | if (!cpufreq_driver->setpolicy) |
fa69e33f DB |
1037 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
1038 | data->governor->name, CPUFREQ_NAME_LEN); | |
1da177e4 LT |
1039 | #endif |
1040 | ||
2eaa3e2d | 1041 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1042 | cpus = cpumask_weight(data->cpus); |
e4969eba VK |
1043 | |
1044 | if (cpus > 1) | |
1045 | cpumask_clear_cpu(cpu, data->cpus); | |
2eaa3e2d | 1046 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1047 | |
73bf0fc2 VK |
1048 | if (cpu != data->cpu) { |
1049 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
1050 | } else if (cpus > 1) { | |
b8eed8af VK |
1051 | /* first sibling now owns the new sysfs dir */ |
1052 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1053 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1054 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1055 | if (ret) { | |
1056 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
084f3493 | 1057 | |
2eaa3e2d | 1058 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1059 | cpumask_set_cpu(cpu, data->cpus); |
1da177e4 | 1060 | |
0d1857a1 | 1061 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1062 | per_cpu(cpufreq_cpu_data, cpu) = data; |
0d1857a1 | 1063 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1064 | |
499bca9b | 1065 | unlock_policy_rwsem_write(cpu); |
1da177e4 | 1066 | |
2eaa3e2d VK |
1067 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, |
1068 | "cpufreq"); | |
b8eed8af | 1069 | return -EINVAL; |
1da177e4 | 1070 | } |
5a01f2e8 | 1071 | |
2eaa3e2d | 1072 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1073 | update_policy_cpu(data, cpu_dev->id); |
2eaa3e2d | 1074 | unlock_policy_rwsem_write(cpu); |
b8eed8af VK |
1075 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1076 | __func__, cpu_dev->id, cpu); | |
1da177e4 | 1077 | } |
1da177e4 | 1078 | |
d96038e0 VK |
1079 | if ((cpus == 1) && (cpufreq_driver->target)) |
1080 | __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); | |
1081 | ||
b8eed8af VK |
1082 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); |
1083 | cpufreq_cpu_put(data); | |
1da177e4 | 1084 | |
b8eed8af VK |
1085 | /* If cpu is last user of policy, free policy */ |
1086 | if (cpus == 1) { | |
2eaa3e2d | 1087 | lock_policy_rwsem_read(cpu); |
b8eed8af VK |
1088 | kobj = &data->kobj; |
1089 | cmp = &data->kobj_unregister; | |
2eaa3e2d | 1090 | unlock_policy_rwsem_read(cpu); |
b8eed8af | 1091 | kobject_put(kobj); |
7d26e2d5 | 1092 | |
b8eed8af VK |
1093 | /* we need to make sure that the underlying kobj is actually |
1094 | * not referenced anymore by anybody before we proceed with | |
1095 | * unloading. | |
1096 | */ | |
1097 | pr_debug("waiting for dropping of refcount\n"); | |
1098 | wait_for_completion(cmp); | |
1099 | pr_debug("wait complete\n"); | |
7d26e2d5 | 1100 | |
1c3d85dd RW |
1101 | if (cpufreq_driver->exit) |
1102 | cpufreq_driver->exit(data); | |
27ecddc2 | 1103 | |
b8eed8af VK |
1104 | free_cpumask_var(data->related_cpus); |
1105 | free_cpumask_var(data->cpus); | |
1106 | kfree(data); | |
1c3d85dd | 1107 | } else if (cpufreq_driver->target) { |
b8eed8af VK |
1108 | __cpufreq_governor(data, CPUFREQ_GOV_START); |
1109 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
27ecddc2 | 1110 | } |
1da177e4 | 1111 | |
2eaa3e2d | 1112 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
1da177e4 LT |
1113 | return 0; |
1114 | } | |
1115 | ||
1116 | ||
8a25a2fd | 1117 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1118 | { |
8a25a2fd | 1119 | unsigned int cpu = dev->id; |
5a01f2e8 | 1120 | int retval; |
ec28297a VP |
1121 | |
1122 | if (cpu_is_offline(cpu)) | |
1123 | return 0; | |
1124 | ||
8a25a2fd | 1125 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1126 | return retval; |
1127 | } | |
1128 | ||
1129 | ||
65f27f38 | 1130 | static void handle_update(struct work_struct *work) |
1da177e4 | 1131 | { |
65f27f38 DH |
1132 | struct cpufreq_policy *policy = |
1133 | container_of(work, struct cpufreq_policy, update); | |
1134 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1135 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1136 | cpufreq_update_policy(cpu); |
1137 | } | |
1138 | ||
1139 | /** | |
1140 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1141 | * @cpu: cpu number | |
1142 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1143 | * @new_freq: CPU frequency the CPU actually runs at | |
1144 | * | |
29464f28 DJ |
1145 | * We adjust to current frequency first, and need to clean up later. |
1146 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1147 | */ |
e08f5f5b GS |
1148 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1149 | unsigned int new_freq) | |
1da177e4 | 1150 | { |
b43a7ffb | 1151 | struct cpufreq_policy *policy; |
1da177e4 | 1152 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1153 | unsigned long flags; |
1154 | ||
1da177e4 | 1155 | |
2d06d8c4 | 1156 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1157 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1158 | ||
1da177e4 LT |
1159 | freqs.old = old_freq; |
1160 | freqs.new = new_freq; | |
b43a7ffb VK |
1161 | |
1162 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1163 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1164 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1165 | ||
1166 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1167 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1168 | } |
1169 | ||
1170 | ||
32ee8c3e | 1171 | /** |
4ab70df4 | 1172 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1173 | * @cpu: CPU number |
1174 | * | |
1175 | * This is the last known freq, without actually getting it from the driver. | |
1176 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1177 | */ | |
1178 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1179 | { | |
9e21ba8b | 1180 | struct cpufreq_policy *policy; |
e08f5f5b | 1181 | unsigned int ret_freq = 0; |
95235ca2 | 1182 | |
1c3d85dd RW |
1183 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1184 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1185 | |
1186 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1187 | if (policy) { |
e08f5f5b | 1188 | ret_freq = policy->cur; |
95235ca2 VP |
1189 | cpufreq_cpu_put(policy); |
1190 | } | |
1191 | ||
4d34a67d | 1192 | return ret_freq; |
95235ca2 VP |
1193 | } |
1194 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1195 | ||
3d737108 JB |
1196 | /** |
1197 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1198 | * @cpu: CPU number | |
1199 | * | |
1200 | * Just return the max possible frequency for a given CPU. | |
1201 | */ | |
1202 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1203 | { | |
1204 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1205 | unsigned int ret_freq = 0; | |
1206 | ||
1207 | if (policy) { | |
1208 | ret_freq = policy->max; | |
1209 | cpufreq_cpu_put(policy); | |
1210 | } | |
1211 | ||
1212 | return ret_freq; | |
1213 | } | |
1214 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1215 | ||
95235ca2 | 1216 | |
5a01f2e8 | 1217 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1218 | { |
7a6aedfa | 1219 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1220 | unsigned int ret_freq = 0; |
5800043b | 1221 | |
1c3d85dd | 1222 | if (!cpufreq_driver->get) |
4d34a67d | 1223 | return ret_freq; |
1da177e4 | 1224 | |
1c3d85dd | 1225 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1226 | |
e08f5f5b | 1227 | if (ret_freq && policy->cur && |
1c3d85dd | 1228 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1229 | /* verify no discrepancy between actual and |
1230 | saved value exists */ | |
1231 | if (unlikely(ret_freq != policy->cur)) { | |
1232 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1233 | schedule_work(&policy->update); |
1234 | } | |
1235 | } | |
1236 | ||
4d34a67d | 1237 | return ret_freq; |
5a01f2e8 | 1238 | } |
1da177e4 | 1239 | |
5a01f2e8 VP |
1240 | /** |
1241 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1242 | * @cpu: CPU number | |
1243 | * | |
1244 | * Get the CPU current (static) CPU frequency | |
1245 | */ | |
1246 | unsigned int cpufreq_get(unsigned int cpu) | |
1247 | { | |
1248 | unsigned int ret_freq = 0; | |
1249 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1250 | ||
1251 | if (!policy) | |
1252 | goto out; | |
1253 | ||
1254 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1255 | goto out_policy; | |
1256 | ||
1257 | ret_freq = __cpufreq_get(cpu); | |
1258 | ||
1259 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1260 | |
5a01f2e8 VP |
1261 | out_policy: |
1262 | cpufreq_cpu_put(policy); | |
1263 | out: | |
4d34a67d | 1264 | return ret_freq; |
1da177e4 LT |
1265 | } |
1266 | EXPORT_SYMBOL(cpufreq_get); | |
1267 | ||
8a25a2fd KS |
1268 | static struct subsys_interface cpufreq_interface = { |
1269 | .name = "cpufreq", | |
1270 | .subsys = &cpu_subsys, | |
1271 | .add_dev = cpufreq_add_dev, | |
1272 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1273 | }; |
1274 | ||
1da177e4 | 1275 | |
42d4dc3f | 1276 | /** |
e00e56df RW |
1277 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1278 | * | |
1279 | * This function is only executed for the boot processor. The other CPUs | |
1280 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1281 | */ |
e00e56df | 1282 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1283 | { |
e08f5f5b | 1284 | int ret = 0; |
4bc5d341 | 1285 | |
e00e56df | 1286 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1287 | struct cpufreq_policy *cpu_policy; |
1288 | ||
2d06d8c4 | 1289 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1290 | |
e00e56df | 1291 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1292 | cpu_policy = cpufreq_cpu_get(cpu); |
1293 | if (!cpu_policy) | |
e00e56df | 1294 | return 0; |
42d4dc3f | 1295 | |
1c3d85dd RW |
1296 | if (cpufreq_driver->suspend) { |
1297 | ret = cpufreq_driver->suspend(cpu_policy); | |
ce6c3997 | 1298 | if (ret) |
42d4dc3f BH |
1299 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1300 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1301 | } |
1302 | ||
42d4dc3f | 1303 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1304 | return ret; |
42d4dc3f BH |
1305 | } |
1306 | ||
1da177e4 | 1307 | /** |
e00e56df | 1308 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1309 | * |
1310 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1311 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1312 | * restored. It will verify that the current freq is in sync with | |
1313 | * what we believe it to be. This is a bit later than when it | |
1314 | * should be, but nonethteless it's better than calling | |
1315 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1316 | * |
1317 | * This function is only executed for the boot CPU. The other CPUs have not | |
1318 | * been turned on yet. | |
1da177e4 | 1319 | */ |
e00e56df | 1320 | static void cpufreq_bp_resume(void) |
1da177e4 | 1321 | { |
e08f5f5b | 1322 | int ret = 0; |
4bc5d341 | 1323 | |
e00e56df | 1324 | int cpu = smp_processor_id(); |
1da177e4 LT |
1325 | struct cpufreq_policy *cpu_policy; |
1326 | ||
2d06d8c4 | 1327 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1328 | |
e00e56df | 1329 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1330 | cpu_policy = cpufreq_cpu_get(cpu); |
1331 | if (!cpu_policy) | |
e00e56df | 1332 | return; |
1da177e4 | 1333 | |
1c3d85dd RW |
1334 | if (cpufreq_driver->resume) { |
1335 | ret = cpufreq_driver->resume(cpu_policy); | |
1da177e4 LT |
1336 | if (ret) { |
1337 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1338 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1339 | goto fail; |
1da177e4 LT |
1340 | } |
1341 | } | |
1342 | ||
1da177e4 | 1343 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1344 | |
c9060494 | 1345 | fail: |
1da177e4 | 1346 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1347 | } |
1348 | ||
e00e56df RW |
1349 | static struct syscore_ops cpufreq_syscore_ops = { |
1350 | .suspend = cpufreq_bp_suspend, | |
1351 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1352 | }; |
1353 | ||
9d95046e BP |
1354 | /** |
1355 | * cpufreq_get_current_driver - return current driver's name | |
1356 | * | |
1357 | * Return the name string of the currently loaded cpufreq driver | |
1358 | * or NULL, if none. | |
1359 | */ | |
1360 | const char *cpufreq_get_current_driver(void) | |
1361 | { | |
1c3d85dd RW |
1362 | if (cpufreq_driver) |
1363 | return cpufreq_driver->name; | |
1364 | ||
1365 | return NULL; | |
9d95046e BP |
1366 | } |
1367 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1368 | |
1369 | /********************************************************************* | |
1370 | * NOTIFIER LISTS INTERFACE * | |
1371 | *********************************************************************/ | |
1372 | ||
1373 | /** | |
1374 | * cpufreq_register_notifier - register a driver with cpufreq | |
1375 | * @nb: notifier function to register | |
1376 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1377 | * | |
32ee8c3e | 1378 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1379 | * are notified about clock rate changes (once before and once after |
1380 | * the transition), or a list of drivers that are notified about | |
1381 | * changes in cpufreq policy. | |
1382 | * | |
1383 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1384 | * blocking_notifier_chain_register. |
1da177e4 LT |
1385 | */ |
1386 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1387 | { | |
1388 | int ret; | |
1389 | ||
d5aaffa9 DB |
1390 | if (cpufreq_disabled()) |
1391 | return -EINVAL; | |
1392 | ||
74212ca4 CEB |
1393 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1394 | ||
1da177e4 LT |
1395 | switch (list) { |
1396 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1397 | ret = srcu_notifier_chain_register( |
e041c683 | 1398 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1399 | break; |
1400 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1401 | ret = blocking_notifier_chain_register( |
1402 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1403 | break; |
1404 | default: | |
1405 | ret = -EINVAL; | |
1406 | } | |
1da177e4 LT |
1407 | |
1408 | return ret; | |
1409 | } | |
1410 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1411 | ||
1412 | ||
1413 | /** | |
1414 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1415 | * @nb: notifier block to be unregistered | |
1416 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1417 | * | |
1418 | * Remove a driver from the CPU frequency notifier list. | |
1419 | * | |
1420 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1421 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1422 | */ |
1423 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1424 | { | |
1425 | int ret; | |
1426 | ||
d5aaffa9 DB |
1427 | if (cpufreq_disabled()) |
1428 | return -EINVAL; | |
1429 | ||
1da177e4 LT |
1430 | switch (list) { |
1431 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1432 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1433 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1434 | break; |
1435 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1436 | ret = blocking_notifier_chain_unregister( |
1437 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1438 | break; |
1439 | default: | |
1440 | ret = -EINVAL; | |
1441 | } | |
1da177e4 LT |
1442 | |
1443 | return ret; | |
1444 | } | |
1445 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1446 | ||
1447 | ||
1448 | /********************************************************************* | |
1449 | * GOVERNORS * | |
1450 | *********************************************************************/ | |
1451 | ||
1452 | ||
1453 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1454 | unsigned int target_freq, | |
1455 | unsigned int relation) | |
1456 | { | |
1457 | int retval = -EINVAL; | |
7249924e | 1458 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1459 | |
a7b422cd KRW |
1460 | if (cpufreq_disabled()) |
1461 | return -ENODEV; | |
1462 | ||
7249924e VK |
1463 | /* Make sure that target_freq is within supported range */ |
1464 | if (target_freq > policy->max) | |
1465 | target_freq = policy->max; | |
1466 | if (target_freq < policy->min) | |
1467 | target_freq = policy->min; | |
1468 | ||
1469 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1470 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1471 | |
1472 | if (target_freq == policy->cur) | |
1473 | return 0; | |
1474 | ||
1c3d85dd RW |
1475 | if (cpufreq_driver->target) |
1476 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1477 | |
1da177e4 LT |
1478 | return retval; |
1479 | } | |
1480 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1481 | ||
1da177e4 LT |
1482 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1483 | unsigned int target_freq, | |
1484 | unsigned int relation) | |
1485 | { | |
f1829e4a | 1486 | int ret = -EINVAL; |
1da177e4 LT |
1487 | |
1488 | policy = cpufreq_cpu_get(policy->cpu); | |
1489 | if (!policy) | |
f1829e4a | 1490 | goto no_policy; |
1da177e4 | 1491 | |
5a01f2e8 | 1492 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1493 | goto fail; |
1da177e4 LT |
1494 | |
1495 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1496 | ||
5a01f2e8 | 1497 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1498 | |
f1829e4a | 1499 | fail: |
1da177e4 | 1500 | cpufreq_cpu_put(policy); |
f1829e4a | 1501 | no_policy: |
1da177e4 LT |
1502 | return ret; |
1503 | } | |
1504 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1505 | ||
bf0b90e3 | 1506 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1507 | { |
1508 | int ret = 0; | |
1509 | ||
d5aaffa9 DB |
1510 | if (cpufreq_disabled()) |
1511 | return ret; | |
1512 | ||
1c3d85dd | 1513 | if (!cpufreq_driver->getavg) |
0676f7f2 VK |
1514 | return 0; |
1515 | ||
dfde5d62 VP |
1516 | policy = cpufreq_cpu_get(policy->cpu); |
1517 | if (!policy) | |
1518 | return -EINVAL; | |
1519 | ||
1c3d85dd | 1520 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1521 | |
dfde5d62 VP |
1522 | cpufreq_cpu_put(policy); |
1523 | return ret; | |
1524 | } | |
5a01f2e8 | 1525 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1526 | |
153d7f3f | 1527 | /* |
153d7f3f AV |
1528 | * when "event" is CPUFREQ_GOV_LIMITS |
1529 | */ | |
1da177e4 | 1530 | |
e08f5f5b GS |
1531 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1532 | unsigned int event) | |
1da177e4 | 1533 | { |
cc993cab | 1534 | int ret; |
6afde10c TR |
1535 | |
1536 | /* Only must be defined when default governor is known to have latency | |
1537 | restrictions, like e.g. conservative or ondemand. | |
1538 | That this is the case is already ensured in Kconfig | |
1539 | */ | |
1540 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1541 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1542 | #else | |
1543 | struct cpufreq_governor *gov = NULL; | |
1544 | #endif | |
1c256245 TR |
1545 | |
1546 | if (policy->governor->max_transition_latency && | |
1547 | policy->cpuinfo.transition_latency > | |
1548 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1549 | if (!gov) |
1550 | return -EINVAL; | |
1551 | else { | |
1552 | printk(KERN_WARNING "%s governor failed, too long" | |
1553 | " transition latency of HW, fallback" | |
1554 | " to %s governor\n", | |
1555 | policy->governor->name, | |
1556 | gov->name); | |
1557 | policy->governor = gov; | |
1558 | } | |
1c256245 | 1559 | } |
1da177e4 LT |
1560 | |
1561 | if (!try_module_get(policy->governor->owner)) | |
1562 | return -EINVAL; | |
1563 | ||
2d06d8c4 | 1564 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1565 | policy->cpu, event); |
1da177e4 LT |
1566 | ret = policy->governor->governor(policy, event); |
1567 | ||
4d5dcc42 VK |
1568 | if (!ret) { |
1569 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1570 | policy->governor->initialized++; | |
1571 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1572 | policy->governor->initialized--; | |
1573 | } | |
b394058f | 1574 | |
e08f5f5b GS |
1575 | /* we keep one module reference alive for |
1576 | each CPU governed by this CPU */ | |
1da177e4 LT |
1577 | if ((event != CPUFREQ_GOV_START) || ret) |
1578 | module_put(policy->governor->owner); | |
1579 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1580 | module_put(policy->governor->owner); | |
1581 | ||
1582 | return ret; | |
1583 | } | |
1584 | ||
1585 | ||
1da177e4 LT |
1586 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1587 | { | |
3bcb09a3 | 1588 | int err; |
1da177e4 LT |
1589 | |
1590 | if (!governor) | |
1591 | return -EINVAL; | |
1592 | ||
a7b422cd KRW |
1593 | if (cpufreq_disabled()) |
1594 | return -ENODEV; | |
1595 | ||
3fc54d37 | 1596 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1597 | |
b394058f | 1598 | governor->initialized = 0; |
3bcb09a3 JF |
1599 | err = -EBUSY; |
1600 | if (__find_governor(governor->name) == NULL) { | |
1601 | err = 0; | |
1602 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1603 | } |
1da177e4 | 1604 | |
32ee8c3e | 1605 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1606 | return err; |
1da177e4 LT |
1607 | } |
1608 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1609 | ||
1610 | ||
1611 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1612 | { | |
90e41bac PB |
1613 | #ifdef CONFIG_HOTPLUG_CPU |
1614 | int cpu; | |
1615 | #endif | |
1616 | ||
1da177e4 LT |
1617 | if (!governor) |
1618 | return; | |
1619 | ||
a7b422cd KRW |
1620 | if (cpufreq_disabled()) |
1621 | return; | |
1622 | ||
90e41bac PB |
1623 | #ifdef CONFIG_HOTPLUG_CPU |
1624 | for_each_present_cpu(cpu) { | |
1625 | if (cpu_online(cpu)) | |
1626 | continue; | |
1627 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1628 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1629 | } | |
1630 | #endif | |
1631 | ||
3fc54d37 | 1632 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1633 | list_del(&governor->governor_list); |
3fc54d37 | 1634 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1635 | return; |
1636 | } | |
1637 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1638 | ||
1639 | ||
1640 | ||
1641 | /********************************************************************* | |
1642 | * POLICY INTERFACE * | |
1643 | *********************************************************************/ | |
1644 | ||
1645 | /** | |
1646 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1647 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1648 | * is written | |
1da177e4 LT |
1649 | * |
1650 | * Reads the current cpufreq policy. | |
1651 | */ | |
1652 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1653 | { | |
1654 | struct cpufreq_policy *cpu_policy; | |
1655 | if (!policy) | |
1656 | return -EINVAL; | |
1657 | ||
1658 | cpu_policy = cpufreq_cpu_get(cpu); | |
1659 | if (!cpu_policy) | |
1660 | return -EINVAL; | |
1661 | ||
1da177e4 | 1662 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1663 | |
1664 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1665 | return 0; |
1666 | } | |
1667 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1668 | ||
1669 | ||
153d7f3f | 1670 | /* |
e08f5f5b GS |
1671 | * data : current policy. |
1672 | * policy : policy to be set. | |
153d7f3f | 1673 | */ |
e08f5f5b GS |
1674 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1675 | struct cpufreq_policy *policy) | |
1da177e4 | 1676 | { |
7bd353a9 | 1677 | int ret = 0, failed = 1; |
1da177e4 | 1678 | |
2d06d8c4 | 1679 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1680 | policy->min, policy->max); |
1681 | ||
e08f5f5b GS |
1682 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1683 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1684 | |
53391fa2 | 1685 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1686 | ret = -EINVAL; |
1687 | goto error_out; | |
1688 | } | |
1689 | ||
1da177e4 | 1690 | /* verify the cpu speed can be set within this limit */ |
1c3d85dd | 1691 | ret = cpufreq_driver->verify(policy); |
1da177e4 LT |
1692 | if (ret) |
1693 | goto error_out; | |
1694 | ||
1da177e4 | 1695 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1696 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1697 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1698 | |
1699 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1700 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1701 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1702 | |
1703 | /* verify the cpu speed can be set within this limit, | |
1704 | which might be different to the first one */ | |
1c3d85dd | 1705 | ret = cpufreq_driver->verify(policy); |
e041c683 | 1706 | if (ret) |
1da177e4 | 1707 | goto error_out; |
1da177e4 LT |
1708 | |
1709 | /* notification of the new policy */ | |
e041c683 AS |
1710 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1711 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1712 | |
7d5e350f DJ |
1713 | data->min = policy->min; |
1714 | data->max = policy->max; | |
1da177e4 | 1715 | |
2d06d8c4 | 1716 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1717 | data->min, data->max); |
1da177e4 | 1718 | |
1c3d85dd | 1719 | if (cpufreq_driver->setpolicy) { |
1da177e4 | 1720 | data->policy = policy->policy; |
2d06d8c4 | 1721 | pr_debug("setting range\n"); |
1c3d85dd | 1722 | ret = cpufreq_driver->setpolicy(policy); |
1da177e4 LT |
1723 | } else { |
1724 | if (policy->governor != data->governor) { | |
1725 | /* save old, working values */ | |
1726 | struct cpufreq_governor *old_gov = data->governor; | |
1727 | ||
2d06d8c4 | 1728 | pr_debug("governor switch\n"); |
1da177e4 LT |
1729 | |
1730 | /* end old governor */ | |
7bd353a9 | 1731 | if (data->governor) { |
1da177e4 | 1732 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
955ef483 | 1733 | unlock_policy_rwsem_write(policy->cpu); |
7bd353a9 VK |
1734 | __cpufreq_governor(data, |
1735 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 | 1736 | lock_policy_rwsem_write(policy->cpu); |
7bd353a9 | 1737 | } |
1da177e4 LT |
1738 | |
1739 | /* start new governor */ | |
1740 | data->governor = policy->governor; | |
7bd353a9 | 1741 | if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { |
955ef483 | 1742 | if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) { |
7bd353a9 | 1743 | failed = 0; |
955ef483 VK |
1744 | } else { |
1745 | unlock_policy_rwsem_write(policy->cpu); | |
7bd353a9 VK |
1746 | __cpufreq_governor(data, |
1747 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 VK |
1748 | lock_policy_rwsem_write(policy->cpu); |
1749 | } | |
7bd353a9 VK |
1750 | } |
1751 | ||
1752 | if (failed) { | |
1da177e4 | 1753 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1754 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1755 | data->governor->name); |
1da177e4 LT |
1756 | if (old_gov) { |
1757 | data->governor = old_gov; | |
7bd353a9 VK |
1758 | __cpufreq_governor(data, |
1759 | CPUFREQ_GOV_POLICY_INIT); | |
e08f5f5b GS |
1760 | __cpufreq_governor(data, |
1761 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1762 | } |
1763 | ret = -EINVAL; | |
1764 | goto error_out; | |
1765 | } | |
1766 | /* might be a policy change, too, so fall through */ | |
1767 | } | |
2d06d8c4 | 1768 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1769 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1770 | } | |
1771 | ||
7d5e350f | 1772 | error_out: |
1da177e4 LT |
1773 | return ret; |
1774 | } | |
1775 | ||
1da177e4 LT |
1776 | /** |
1777 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1778 | * @cpu: CPU which shall be re-evaluated | |
1779 | * | |
25985edc | 1780 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1781 | * at different times. |
1782 | */ | |
1783 | int cpufreq_update_policy(unsigned int cpu) | |
1784 | { | |
1785 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1786 | struct cpufreq_policy policy; | |
f1829e4a | 1787 | int ret; |
1da177e4 | 1788 | |
f1829e4a JL |
1789 | if (!data) { |
1790 | ret = -ENODEV; | |
1791 | goto no_policy; | |
1792 | } | |
1da177e4 | 1793 | |
f1829e4a JL |
1794 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1795 | ret = -EINVAL; | |
1796 | goto fail; | |
1797 | } | |
1da177e4 | 1798 | |
2d06d8c4 | 1799 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1800 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1801 | policy.min = data->user_policy.min; |
1802 | policy.max = data->user_policy.max; | |
1803 | policy.policy = data->user_policy.policy; | |
1804 | policy.governor = data->user_policy.governor; | |
1805 | ||
0961dd0d TR |
1806 | /* BIOS might change freq behind our back |
1807 | -> ask driver for current freq and notify governors about a change */ | |
1c3d85dd RW |
1808 | if (cpufreq_driver->get) { |
1809 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1810 | if (!data->cur) { |
2d06d8c4 | 1811 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1812 | data->cur = policy.cur; |
1813 | } else { | |
1c3d85dd | 1814 | if (data->cur != policy.cur && cpufreq_driver->target) |
e08f5f5b GS |
1815 | cpufreq_out_of_sync(cpu, data->cur, |
1816 | policy.cur); | |
a85f7bd3 | 1817 | } |
0961dd0d TR |
1818 | } |
1819 | ||
1da177e4 LT |
1820 | ret = __cpufreq_set_policy(data, &policy); |
1821 | ||
5a01f2e8 VP |
1822 | unlock_policy_rwsem_write(cpu); |
1823 | ||
f1829e4a | 1824 | fail: |
1da177e4 | 1825 | cpufreq_cpu_put(data); |
f1829e4a | 1826 | no_policy: |
1da177e4 LT |
1827 | return ret; |
1828 | } | |
1829 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1830 | ||
dd184a01 | 1831 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1832 | unsigned long action, void *hcpu) |
1833 | { | |
1834 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1835 | struct device *dev; |
c32b6b8e | 1836 | |
8a25a2fd KS |
1837 | dev = get_cpu_device(cpu); |
1838 | if (dev) { | |
c32b6b8e AR |
1839 | switch (action) { |
1840 | case CPU_ONLINE: | |
8a25a2fd | 1841 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1842 | break; |
1843 | case CPU_DOWN_PREPARE: | |
a66b2e50 | 1844 | case CPU_UP_CANCELED_FROZEN: |
8a25a2fd | 1845 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1846 | break; |
5a01f2e8 | 1847 | case CPU_DOWN_FAILED: |
8a25a2fd | 1848 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1849 | break; |
1850 | } | |
1851 | } | |
1852 | return NOTIFY_OK; | |
1853 | } | |
1854 | ||
9c36f746 | 1855 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1856 | .notifier_call = cpufreq_cpu_callback, |
1857 | }; | |
1da177e4 LT |
1858 | |
1859 | /********************************************************************* | |
1860 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1861 | *********************************************************************/ | |
1862 | ||
1863 | /** | |
1864 | * cpufreq_register_driver - register a CPU Frequency driver | |
1865 | * @driver_data: A struct cpufreq_driver containing the values# | |
1866 | * submitted by the CPU Frequency driver. | |
1867 | * | |
32ee8c3e | 1868 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1869 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1870 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1871 | * |
1872 | */ | |
221dee28 | 1873 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1874 | { |
1875 | unsigned long flags; | |
1876 | int ret; | |
1877 | ||
a7b422cd KRW |
1878 | if (cpufreq_disabled()) |
1879 | return -ENODEV; | |
1880 | ||
1da177e4 LT |
1881 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1882 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1883 | return -EINVAL; | |
1884 | ||
2d06d8c4 | 1885 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1886 | |
1887 | if (driver_data->setpolicy) | |
1888 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1889 | ||
0d1857a1 | 1890 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 1891 | if (cpufreq_driver) { |
0d1857a1 | 1892 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1893 | return -EBUSY; |
1894 | } | |
1c3d85dd | 1895 | cpufreq_driver = driver_data; |
0d1857a1 | 1896 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1897 | |
8a25a2fd | 1898 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1899 | if (ret) |
1900 | goto err_null_driver; | |
1da177e4 | 1901 | |
1c3d85dd | 1902 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1903 | int i; |
1904 | ret = -ENODEV; | |
1905 | ||
1906 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1907 | for (i = 0; i < nr_cpu_ids; i++) |
1908 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1909 | ret = 0; |
7a6aedfa MT |
1910 | break; |
1911 | } | |
1da177e4 LT |
1912 | |
1913 | /* if all ->init() calls failed, unregister */ | |
1914 | if (ret) { | |
2d06d8c4 | 1915 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1916 | driver_data->name); |
8a25a2fd | 1917 | goto err_if_unreg; |
1da177e4 LT |
1918 | } |
1919 | } | |
1920 | ||
8f5bc2ab | 1921 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1922 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1923 | |
8f5bc2ab | 1924 | return 0; |
8a25a2fd KS |
1925 | err_if_unreg: |
1926 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 1927 | err_null_driver: |
0d1857a1 | 1928 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 1929 | cpufreq_driver = NULL; |
0d1857a1 | 1930 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 1931 | return ret; |
1da177e4 LT |
1932 | } |
1933 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1934 | ||
1935 | ||
1936 | /** | |
1937 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1938 | * | |
32ee8c3e | 1939 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1940 | * the right to do so, i.e. if you have succeeded in initialising before! |
1941 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1942 | * currently not initialised. | |
1943 | */ | |
221dee28 | 1944 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1945 | { |
1946 | unsigned long flags; | |
1947 | ||
1c3d85dd | 1948 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1949 | return -EINVAL; |
1da177e4 | 1950 | |
2d06d8c4 | 1951 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1952 | |
8a25a2fd | 1953 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1954 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 1955 | |
0d1857a1 | 1956 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 1957 | cpufreq_driver = NULL; |
0d1857a1 | 1958 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1959 | |
1960 | return 0; | |
1961 | } | |
1962 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1963 | |
1964 | static int __init cpufreq_core_init(void) | |
1965 | { | |
1966 | int cpu; | |
1967 | ||
a7b422cd KRW |
1968 | if (cpufreq_disabled()) |
1969 | return -ENODEV; | |
1970 | ||
5a01f2e8 | 1971 | for_each_possible_cpu(cpu) { |
f1625066 | 1972 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1973 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1974 | } | |
8aa84ad8 | 1975 | |
8a25a2fd | 1976 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1977 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1978 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1979 | |
5a01f2e8 VP |
1980 | return 0; |
1981 | } | |
5a01f2e8 | 1982 | core_initcall(cpufreq_core_init); |