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> | |
bb176f7d | 6 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> |
1da177e4 | 7 | * |
c32b6b8e | 8 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 9 | * Added handling for CPU hotplug |
8ff69732 DJ |
10 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
11 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 12 | * |
1da177e4 LT |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
1da177e4 LT |
16 | */ |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
5ff0a268 | 20 | #include <linux/cpu.h> |
1da177e4 LT |
21 | #include <linux/cpufreq.h> |
22 | #include <linux/delay.h> | |
1da177e4 | 23 | #include <linux/device.h> |
5ff0a268 VK |
24 | #include <linux/init.h> |
25 | #include <linux/kernel_stat.h> | |
26 | #include <linux/module.h> | |
3fc54d37 | 27 | #include <linux/mutex.h> |
5ff0a268 | 28 | #include <linux/slab.h> |
2f0aea93 | 29 | #include <linux/suspend.h> |
5ff0a268 | 30 | #include <linux/tick.h> |
6f4f2723 TR |
31 | #include <trace/events/power.h> |
32 | ||
1da177e4 | 33 | /** |
cd878479 | 34 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
35 | * level driver of CPUFreq support, and its spinlock. This lock |
36 | * also protects the cpufreq_cpu_data array. | |
37 | */ | |
1c3d85dd | 38 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 39 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
8414809c | 40 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); |
bb176f7d | 41 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
6f1e4efd | 42 | DEFINE_MUTEX(cpufreq_governor_lock); |
c88a1f8b | 43 | static LIST_HEAD(cpufreq_policy_list); |
bb176f7d | 44 | |
084f3493 | 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); |
1da177e4 | 47 | |
2f0aea93 VK |
48 | /* Flag to suspend/resume CPUFreq governors */ |
49 | static bool cpufreq_suspended; | |
50 | ||
9c0ebcf7 VK |
51 | static inline bool has_target(void) |
52 | { | |
53 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
54 | } | |
55 | ||
6eed9404 VK |
56 | /* |
57 | * rwsem to guarantee that cpufreq driver module doesn't unload during critical | |
58 | * sections | |
59 | */ | |
60 | static DECLARE_RWSEM(cpufreq_rwsem); | |
61 | ||
1da177e4 | 62 | /* internal prototypes */ |
29464f28 DJ |
63 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
64 | unsigned int event); | |
5a01f2e8 | 65 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 66 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
67 | |
68 | /** | |
32ee8c3e DJ |
69 | * Two notifier lists: the "policy" list is involved in the |
70 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
71 | * "transition" list for kernel code that needs to handle |
72 | * changes to devices when the CPU clock speed changes. | |
73 | * The mutex locks both lists. | |
74 | */ | |
e041c683 | 75 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 76 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 77 | |
74212ca4 | 78 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
79 | static int __init init_cpufreq_transition_notifier_list(void) |
80 | { | |
81 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 82 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
83 | return 0; |
84 | } | |
b3438f82 | 85 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 86 | |
a7b422cd | 87 | static int off __read_mostly; |
da584455 | 88 | static int cpufreq_disabled(void) |
a7b422cd KRW |
89 | { |
90 | return off; | |
91 | } | |
92 | void disable_cpufreq(void) | |
93 | { | |
94 | off = 1; | |
95 | } | |
1da177e4 | 96 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 97 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 98 | |
4d5dcc42 VK |
99 | bool have_governor_per_policy(void) |
100 | { | |
0b981e70 | 101 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 102 | } |
3f869d6d | 103 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 104 | |
944e9a03 VK |
105 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
106 | { | |
107 | if (have_governor_per_policy()) | |
108 | return &policy->kobj; | |
109 | else | |
110 | return cpufreq_global_kobject; | |
111 | } | |
112 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
113 | ||
72a4ce34 VK |
114 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
115 | { | |
116 | u64 idle_time; | |
117 | u64 cur_wall_time; | |
118 | u64 busy_time; | |
119 | ||
120 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
121 | ||
122 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
123 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
124 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
125 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
126 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
127 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
128 | ||
129 | idle_time = cur_wall_time - busy_time; | |
130 | if (wall) | |
131 | *wall = cputime_to_usecs(cur_wall_time); | |
132 | ||
133 | return cputime_to_usecs(idle_time); | |
134 | } | |
135 | ||
136 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
137 | { | |
138 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
139 | ||
140 | if (idle_time == -1ULL) | |
141 | return get_cpu_idle_time_jiffy(cpu, wall); | |
142 | else if (!io_busy) | |
143 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
144 | ||
145 | return idle_time; | |
146 | } | |
147 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
148 | ||
70e9e778 VK |
149 | /* |
150 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
151 | * drivers of SMP systems. It will do following: | |
152 | * - validate & show freq table passed | |
153 | * - set policies transition latency | |
154 | * - policy->cpus with all possible CPUs | |
155 | */ | |
156 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
157 | struct cpufreq_frequency_table *table, | |
158 | unsigned int transition_latency) | |
159 | { | |
160 | int ret; | |
161 | ||
162 | ret = cpufreq_table_validate_and_show(policy, table); | |
163 | if (ret) { | |
164 | pr_err("%s: invalid frequency table: %d\n", __func__, ret); | |
165 | return ret; | |
166 | } | |
167 | ||
168 | policy->cpuinfo.transition_latency = transition_latency; | |
169 | ||
170 | /* | |
171 | * The driver only supports the SMP configuartion where all processors | |
172 | * share the clock and voltage and clock. | |
173 | */ | |
174 | cpumask_setall(policy->cpus); | |
175 | ||
176 | return 0; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
179 | ||
652ed95d VK |
180 | unsigned int cpufreq_generic_get(unsigned int cpu) |
181 | { | |
182 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
183 | ||
184 | if (!policy || IS_ERR(policy->clk)) { | |
185 | pr_err("%s: No %s associated to cpu: %d\n", __func__, | |
186 | policy ? "clk" : "policy", cpu); | |
187 | return 0; | |
188 | } | |
189 | ||
190 | return clk_get_rate(policy->clk) / 1000; | |
191 | } | |
192 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
193 | ||
6eed9404 | 194 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 195 | { |
6eed9404 | 196 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
197 | unsigned long flags; |
198 | ||
6eed9404 VK |
199 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
200 | return NULL; | |
201 | ||
202 | if (!down_read_trylock(&cpufreq_rwsem)) | |
203 | return NULL; | |
1da177e4 LT |
204 | |
205 | /* get the cpufreq driver */ | |
1c3d85dd | 206 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 207 | |
6eed9404 VK |
208 | if (cpufreq_driver) { |
209 | /* get the CPU */ | |
210 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
211 | if (policy) | |
212 | kobject_get(&policy->kobj); | |
213 | } | |
1da177e4 | 214 | |
6eed9404 | 215 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 216 | |
3a3e9e06 | 217 | if (!policy) |
6eed9404 | 218 | up_read(&cpufreq_rwsem); |
1da177e4 | 219 | |
3a3e9e06 | 220 | return policy; |
a9144436 | 221 | } |
1da177e4 LT |
222 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
223 | ||
3a3e9e06 | 224 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 225 | { |
d5aaffa9 DB |
226 | if (cpufreq_disabled()) |
227 | return; | |
228 | ||
6eed9404 VK |
229 | kobject_put(&policy->kobj); |
230 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
231 | } |
232 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
233 | ||
1da177e4 LT |
234 | /********************************************************************* |
235 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
236 | *********************************************************************/ | |
237 | ||
238 | /** | |
239 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
240 | * | |
241 | * This function alters the system "loops_per_jiffy" for the clock | |
242 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 243 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
244 | * per-CPU loops_per_jiffy value wherever possible. |
245 | */ | |
246 | #ifndef CONFIG_SMP | |
247 | static unsigned long l_p_j_ref; | |
bb176f7d | 248 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 249 | |
858119e1 | 250 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
251 | { |
252 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
253 | return; | |
254 | ||
255 | if (!l_p_j_ref_freq) { | |
256 | l_p_j_ref = loops_per_jiffy; | |
257 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 258 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 259 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 260 | } |
bb176f7d | 261 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 262 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
263 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
264 | ci->new); | |
2d06d8c4 | 265 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 266 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
267 | } |
268 | } | |
269 | #else | |
e08f5f5b GS |
270 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
271 | { | |
272 | return; | |
273 | } | |
1da177e4 LT |
274 | #endif |
275 | ||
0956df9c | 276 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 277 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
278 | { |
279 | BUG_ON(irqs_disabled()); | |
280 | ||
d5aaffa9 DB |
281 | if (cpufreq_disabled()) |
282 | return; | |
283 | ||
1c3d85dd | 284 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 285 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 286 | state, freqs->new); |
1da177e4 | 287 | |
1da177e4 | 288 | switch (state) { |
e4472cb3 | 289 | |
1da177e4 | 290 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 291 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
292 | * which is not equal to what the cpufreq core thinks is |
293 | * "old frequency". | |
1da177e4 | 294 | */ |
1c3d85dd | 295 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
296 | if ((policy) && (policy->cpu == freqs->cpu) && |
297 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 298 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
299 | " %u, cpufreq assumed %u kHz.\n", |
300 | freqs->old, policy->cur); | |
301 | freqs->old = policy->cur; | |
1da177e4 LT |
302 | } |
303 | } | |
b4dfdbb3 | 304 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 305 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
306 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
307 | break; | |
e4472cb3 | 308 | |
1da177e4 LT |
309 | case CPUFREQ_POSTCHANGE: |
310 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 311 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 312 | (unsigned long)freqs->cpu); |
25e41933 | 313 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 314 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 315 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
316 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
317 | policy->cur = freqs->new; | |
1da177e4 LT |
318 | break; |
319 | } | |
1da177e4 | 320 | } |
bb176f7d | 321 | |
b43a7ffb VK |
322 | /** |
323 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
324 | * on frequency transition. | |
325 | * | |
326 | * This function calls the transition notifiers and the "adjust_jiffies" | |
327 | * function. It is called twice on all CPU frequency changes that have | |
328 | * external effects. | |
329 | */ | |
330 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
331 | struct cpufreq_freqs *freqs, unsigned int state) | |
332 | { | |
333 | for_each_cpu(freqs->cpu, policy->cpus) | |
334 | __cpufreq_notify_transition(policy, freqs, state); | |
335 | } | |
1da177e4 LT |
336 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
337 | ||
f7ba3b41 VK |
338 | /* Do post notifications when there are chances that transition has failed */ |
339 | void cpufreq_notify_post_transition(struct cpufreq_policy *policy, | |
340 | struct cpufreq_freqs *freqs, int transition_failed) | |
341 | { | |
342 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
343 | if (!transition_failed) | |
344 | return; | |
345 | ||
346 | swap(freqs->old, freqs->new); | |
347 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
348 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
349 | } | |
350 | EXPORT_SYMBOL_GPL(cpufreq_notify_post_transition); | |
351 | ||
1da177e4 | 352 | |
1da177e4 LT |
353 | /********************************************************************* |
354 | * SYSFS INTERFACE * | |
355 | *********************************************************************/ | |
8a5c74a1 | 356 | static ssize_t show_boost(struct kobject *kobj, |
6f19efc0 LM |
357 | struct attribute *attr, char *buf) |
358 | { | |
359 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
360 | } | |
361 | ||
362 | static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, | |
363 | const char *buf, size_t count) | |
364 | { | |
365 | int ret, enable; | |
366 | ||
367 | ret = sscanf(buf, "%d", &enable); | |
368 | if (ret != 1 || enable < 0 || enable > 1) | |
369 | return -EINVAL; | |
370 | ||
371 | if (cpufreq_boost_trigger_state(enable)) { | |
372 | pr_err("%s: Cannot %s BOOST!\n", __func__, | |
373 | enable ? "enable" : "disable"); | |
374 | return -EINVAL; | |
375 | } | |
376 | ||
377 | pr_debug("%s: cpufreq BOOST %s\n", __func__, | |
378 | enable ? "enabled" : "disabled"); | |
379 | ||
380 | return count; | |
381 | } | |
382 | define_one_global_rw(boost); | |
1da177e4 | 383 | |
3bcb09a3 JF |
384 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
385 | { | |
386 | struct cpufreq_governor *t; | |
387 | ||
388 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 389 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
390 | return t; |
391 | ||
392 | return NULL; | |
393 | } | |
394 | ||
1da177e4 LT |
395 | /** |
396 | * cpufreq_parse_governor - parse a governor string | |
397 | */ | |
905d77cd | 398 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
399 | struct cpufreq_governor **governor) |
400 | { | |
3bcb09a3 | 401 | int err = -EINVAL; |
1c3d85dd RW |
402 | |
403 | if (!cpufreq_driver) | |
3bcb09a3 JF |
404 | goto out; |
405 | ||
1c3d85dd | 406 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
407 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
408 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 409 | err = 0; |
e08f5f5b GS |
410 | } else if (!strnicmp(str_governor, "powersave", |
411 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 412 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 413 | err = 0; |
1da177e4 | 414 | } |
9c0ebcf7 | 415 | } else if (has_target()) { |
1da177e4 | 416 | struct cpufreq_governor *t; |
3bcb09a3 | 417 | |
3fc54d37 | 418 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
419 | |
420 | t = __find_governor(str_governor); | |
421 | ||
ea714970 | 422 | if (t == NULL) { |
1a8e1463 | 423 | int ret; |
ea714970 | 424 | |
1a8e1463 KC |
425 | mutex_unlock(&cpufreq_governor_mutex); |
426 | ret = request_module("cpufreq_%s", str_governor); | |
427 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 428 | |
1a8e1463 KC |
429 | if (ret == 0) |
430 | t = __find_governor(str_governor); | |
ea714970 JF |
431 | } |
432 | ||
3bcb09a3 JF |
433 | if (t != NULL) { |
434 | *governor = t; | |
435 | err = 0; | |
1da177e4 | 436 | } |
3bcb09a3 | 437 | |
3fc54d37 | 438 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 439 | } |
29464f28 | 440 | out: |
3bcb09a3 | 441 | return err; |
1da177e4 | 442 | } |
1da177e4 | 443 | |
1da177e4 | 444 | /** |
e08f5f5b GS |
445 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
446 | * print out cpufreq information | |
1da177e4 LT |
447 | * |
448 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
449 | * "unsigned int". | |
450 | */ | |
451 | ||
32ee8c3e DJ |
452 | #define show_one(file_name, object) \ |
453 | static ssize_t show_##file_name \ | |
905d77cd | 454 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 455 | { \ |
29464f28 | 456 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
457 | } |
458 | ||
459 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
460 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 461 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
462 | show_one(scaling_min_freq, min); |
463 | show_one(scaling_max_freq, max); | |
464 | show_one(scaling_cur_freq, cur); | |
465 | ||
037ce839 | 466 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 467 | struct cpufreq_policy *new_policy); |
7970e08b | 468 | |
1da177e4 LT |
469 | /** |
470 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
471 | */ | |
472 | #define store_one(file_name, object) \ | |
473 | static ssize_t store_##file_name \ | |
905d77cd | 474 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 475 | { \ |
5136fa56 | 476 | int ret; \ |
1da177e4 LT |
477 | struct cpufreq_policy new_policy; \ |
478 | \ | |
479 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
480 | if (ret) \ | |
481 | return -EINVAL; \ | |
482 | \ | |
29464f28 | 483 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
484 | if (ret != 1) \ |
485 | return -EINVAL; \ | |
486 | \ | |
037ce839 | 487 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 488 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
489 | \ |
490 | return ret ? ret : count; \ | |
491 | } | |
492 | ||
29464f28 DJ |
493 | store_one(scaling_min_freq, min); |
494 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
495 | |
496 | /** | |
497 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
498 | */ | |
905d77cd DJ |
499 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
500 | char *buf) | |
1da177e4 | 501 | { |
5a01f2e8 | 502 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
503 | if (!cur_freq) |
504 | return sprintf(buf, "<unknown>"); | |
505 | return sprintf(buf, "%u\n", cur_freq); | |
506 | } | |
507 | ||
1da177e4 LT |
508 | /** |
509 | * show_scaling_governor - show the current policy for the specified CPU | |
510 | */ | |
905d77cd | 511 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 512 | { |
29464f28 | 513 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
514 | return sprintf(buf, "powersave\n"); |
515 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
516 | return sprintf(buf, "performance\n"); | |
517 | else if (policy->governor) | |
4b972f0b | 518 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 519 | policy->governor->name); |
1da177e4 LT |
520 | return -EINVAL; |
521 | } | |
522 | ||
1da177e4 LT |
523 | /** |
524 | * store_scaling_governor - store policy for the specified CPU | |
525 | */ | |
905d77cd DJ |
526 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
527 | const char *buf, size_t count) | |
1da177e4 | 528 | { |
5136fa56 | 529 | int ret; |
1da177e4 LT |
530 | char str_governor[16]; |
531 | struct cpufreq_policy new_policy; | |
532 | ||
533 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
534 | if (ret) | |
535 | return ret; | |
536 | ||
29464f28 | 537 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
538 | if (ret != 1) |
539 | return -EINVAL; | |
540 | ||
e08f5f5b GS |
541 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
542 | &new_policy.governor)) | |
1da177e4 LT |
543 | return -EINVAL; |
544 | ||
037ce839 | 545 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
546 | |
547 | policy->user_policy.policy = policy->policy; | |
548 | policy->user_policy.governor = policy->governor; | |
7970e08b | 549 | |
e08f5f5b GS |
550 | if (ret) |
551 | return ret; | |
552 | else | |
553 | return count; | |
1da177e4 LT |
554 | } |
555 | ||
556 | /** | |
557 | * show_scaling_driver - show the cpufreq driver currently loaded | |
558 | */ | |
905d77cd | 559 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 560 | { |
1c3d85dd | 561 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
562 | } |
563 | ||
564 | /** | |
565 | * show_scaling_available_governors - show the available CPUfreq governors | |
566 | */ | |
905d77cd DJ |
567 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
568 | char *buf) | |
1da177e4 LT |
569 | { |
570 | ssize_t i = 0; | |
571 | struct cpufreq_governor *t; | |
572 | ||
9c0ebcf7 | 573 | if (!has_target()) { |
1da177e4 LT |
574 | i += sprintf(buf, "performance powersave"); |
575 | goto out; | |
576 | } | |
577 | ||
578 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
579 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
580 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 581 | goto out; |
4b972f0b | 582 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 583 | } |
7d5e350f | 584 | out: |
1da177e4 LT |
585 | i += sprintf(&buf[i], "\n"); |
586 | return i; | |
587 | } | |
e8628dd0 | 588 | |
f4fd3797 | 589 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
590 | { |
591 | ssize_t i = 0; | |
592 | unsigned int cpu; | |
593 | ||
835481d9 | 594 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
595 | if (i) |
596 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
597 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
598 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 599 | break; |
1da177e4 LT |
600 | } |
601 | i += sprintf(&buf[i], "\n"); | |
602 | return i; | |
603 | } | |
f4fd3797 | 604 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 605 | |
e8628dd0 DW |
606 | /** |
607 | * show_related_cpus - show the CPUs affected by each transition even if | |
608 | * hw coordination is in use | |
609 | */ | |
610 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
611 | { | |
f4fd3797 | 612 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
613 | } |
614 | ||
615 | /** | |
616 | * show_affected_cpus - show the CPUs affected by each transition | |
617 | */ | |
618 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
619 | { | |
f4fd3797 | 620 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
621 | } |
622 | ||
9e76988e | 623 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 624 | const char *buf, size_t count) |
9e76988e VP |
625 | { |
626 | unsigned int freq = 0; | |
627 | unsigned int ret; | |
628 | ||
879000f9 | 629 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
630 | return -EINVAL; |
631 | ||
632 | ret = sscanf(buf, "%u", &freq); | |
633 | if (ret != 1) | |
634 | return -EINVAL; | |
635 | ||
636 | policy->governor->store_setspeed(policy, freq); | |
637 | ||
638 | return count; | |
639 | } | |
640 | ||
641 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
642 | { | |
879000f9 | 643 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
644 | return sprintf(buf, "<unsupported>\n"); |
645 | ||
646 | return policy->governor->show_setspeed(policy, buf); | |
647 | } | |
1da177e4 | 648 | |
e2f74f35 | 649 | /** |
8bf1ac72 | 650 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
651 | */ |
652 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
653 | { | |
654 | unsigned int limit; | |
655 | int ret; | |
1c3d85dd RW |
656 | if (cpufreq_driver->bios_limit) { |
657 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
658 | if (!ret) |
659 | return sprintf(buf, "%u\n", limit); | |
660 | } | |
661 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
662 | } | |
663 | ||
6dad2a29 BP |
664 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
665 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
666 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
667 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
668 | cpufreq_freq_attr_ro(scaling_available_governors); | |
669 | cpufreq_freq_attr_ro(scaling_driver); | |
670 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
671 | cpufreq_freq_attr_ro(bios_limit); | |
672 | cpufreq_freq_attr_ro(related_cpus); | |
673 | cpufreq_freq_attr_ro(affected_cpus); | |
674 | cpufreq_freq_attr_rw(scaling_min_freq); | |
675 | cpufreq_freq_attr_rw(scaling_max_freq); | |
676 | cpufreq_freq_attr_rw(scaling_governor); | |
677 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 678 | |
905d77cd | 679 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
680 | &cpuinfo_min_freq.attr, |
681 | &cpuinfo_max_freq.attr, | |
ed129784 | 682 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
683 | &scaling_min_freq.attr, |
684 | &scaling_max_freq.attr, | |
685 | &affected_cpus.attr, | |
e8628dd0 | 686 | &related_cpus.attr, |
1da177e4 LT |
687 | &scaling_governor.attr, |
688 | &scaling_driver.attr, | |
689 | &scaling_available_governors.attr, | |
9e76988e | 690 | &scaling_setspeed.attr, |
1da177e4 LT |
691 | NULL |
692 | }; | |
693 | ||
29464f28 DJ |
694 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
695 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 696 | |
29464f28 | 697 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 698 | { |
905d77cd DJ |
699 | struct cpufreq_policy *policy = to_policy(kobj); |
700 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 701 | ssize_t ret; |
6eed9404 VK |
702 | |
703 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 704 | return -EINVAL; |
5a01f2e8 | 705 | |
ad7722da | 706 | down_read(&policy->rwsem); |
5a01f2e8 | 707 | |
e08f5f5b GS |
708 | if (fattr->show) |
709 | ret = fattr->show(policy, buf); | |
710 | else | |
711 | ret = -EIO; | |
712 | ||
ad7722da | 713 | up_read(&policy->rwsem); |
6eed9404 | 714 | up_read(&cpufreq_rwsem); |
1b750e3b | 715 | |
1da177e4 LT |
716 | return ret; |
717 | } | |
718 | ||
905d77cd DJ |
719 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
720 | const char *buf, size_t count) | |
1da177e4 | 721 | { |
905d77cd DJ |
722 | struct cpufreq_policy *policy = to_policy(kobj); |
723 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 724 | ssize_t ret = -EINVAL; |
6eed9404 | 725 | |
4f750c93 SB |
726 | get_online_cpus(); |
727 | ||
728 | if (!cpu_online(policy->cpu)) | |
729 | goto unlock; | |
730 | ||
6eed9404 | 731 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 732 | goto unlock; |
5a01f2e8 | 733 | |
ad7722da | 734 | down_write(&policy->rwsem); |
5a01f2e8 | 735 | |
e08f5f5b GS |
736 | if (fattr->store) |
737 | ret = fattr->store(policy, buf, count); | |
738 | else | |
739 | ret = -EIO; | |
740 | ||
ad7722da | 741 | up_write(&policy->rwsem); |
6eed9404 | 742 | |
6eed9404 | 743 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
744 | unlock: |
745 | put_online_cpus(); | |
746 | ||
1da177e4 LT |
747 | return ret; |
748 | } | |
749 | ||
905d77cd | 750 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 751 | { |
905d77cd | 752 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 753 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
754 | complete(&policy->kobj_unregister); |
755 | } | |
756 | ||
52cf25d0 | 757 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
758 | .show = show, |
759 | .store = store, | |
760 | }; | |
761 | ||
762 | static struct kobj_type ktype_cpufreq = { | |
763 | .sysfs_ops = &sysfs_ops, | |
764 | .default_attrs = default_attrs, | |
765 | .release = cpufreq_sysfs_release, | |
766 | }; | |
767 | ||
2361be23 VK |
768 | struct kobject *cpufreq_global_kobject; |
769 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
770 | ||
771 | static int cpufreq_global_kobject_usage; | |
772 | ||
773 | int cpufreq_get_global_kobject(void) | |
774 | { | |
775 | if (!cpufreq_global_kobject_usage++) | |
776 | return kobject_add(cpufreq_global_kobject, | |
777 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
778 | ||
779 | return 0; | |
780 | } | |
781 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
782 | ||
783 | void cpufreq_put_global_kobject(void) | |
784 | { | |
785 | if (!--cpufreq_global_kobject_usage) | |
786 | kobject_del(cpufreq_global_kobject); | |
787 | } | |
788 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
789 | ||
790 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
791 | { | |
792 | int ret = cpufreq_get_global_kobject(); | |
793 | ||
794 | if (!ret) { | |
795 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
796 | if (ret) | |
797 | cpufreq_put_global_kobject(); | |
798 | } | |
799 | ||
800 | return ret; | |
801 | } | |
802 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
803 | ||
804 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
805 | { | |
806 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
807 | cpufreq_put_global_kobject(); | |
808 | } | |
809 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
810 | ||
19d6f7ec | 811 | /* symlink affected CPUs */ |
308b60e7 | 812 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
813 | { |
814 | unsigned int j; | |
815 | int ret = 0; | |
816 | ||
817 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 818 | struct device *cpu_dev; |
19d6f7ec | 819 | |
308b60e7 | 820 | if (j == policy->cpu) |
19d6f7ec | 821 | continue; |
19d6f7ec | 822 | |
e8fdde10 | 823 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
824 | cpu_dev = get_cpu_device(j); |
825 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 826 | "cpufreq"); |
71c3461e RW |
827 | if (ret) |
828 | break; | |
19d6f7ec DJ |
829 | } |
830 | return ret; | |
831 | } | |
832 | ||
308b60e7 | 833 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 834 | struct device *dev) |
909a694e DJ |
835 | { |
836 | struct freq_attr **drv_attr; | |
909a694e | 837 | int ret = 0; |
909a694e DJ |
838 | |
839 | /* prepare interface data */ | |
840 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 841 | &dev->kobj, "cpufreq"); |
909a694e DJ |
842 | if (ret) |
843 | return ret; | |
844 | ||
845 | /* set up files for this cpu device */ | |
1c3d85dd | 846 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
847 | while ((drv_attr) && (*drv_attr)) { |
848 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
849 | if (ret) | |
1c3d85dd | 850 | goto err_out_kobj_put; |
909a694e DJ |
851 | drv_attr++; |
852 | } | |
1c3d85dd | 853 | if (cpufreq_driver->get) { |
909a694e DJ |
854 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
855 | if (ret) | |
1c3d85dd | 856 | goto err_out_kobj_put; |
909a694e | 857 | } |
9c0ebcf7 | 858 | if (has_target()) { |
909a694e DJ |
859 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
860 | if (ret) | |
1c3d85dd | 861 | goto err_out_kobj_put; |
909a694e | 862 | } |
1c3d85dd | 863 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
864 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
865 | if (ret) | |
1c3d85dd | 866 | goto err_out_kobj_put; |
e2f74f35 | 867 | } |
909a694e | 868 | |
308b60e7 | 869 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
870 | if (ret) |
871 | goto err_out_kobj_put; | |
872 | ||
e18f1682 SB |
873 | return ret; |
874 | ||
875 | err_out_kobj_put: | |
876 | kobject_put(&policy->kobj); | |
877 | wait_for_completion(&policy->kobj_unregister); | |
878 | return ret; | |
879 | } | |
880 | ||
881 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
882 | { | |
6e2c89d1 | 883 | struct cpufreq_governor *gov = NULL; |
e18f1682 SB |
884 | struct cpufreq_policy new_policy; |
885 | int ret = 0; | |
886 | ||
d5b73cd8 | 887 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 888 | |
6e2c89d1 | 889 | /* Update governor of new_policy to the governor used before hotplug */ |
890 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); | |
891 | if (gov) | |
892 | pr_debug("Restoring governor %s for cpu %d\n", | |
893 | policy->governor->name, policy->cpu); | |
894 | else | |
895 | gov = CPUFREQ_DEFAULT_GOVERNOR; | |
896 | ||
897 | new_policy.governor = gov; | |
898 | ||
a27a9ab7 JB |
899 | /* Use the default policy if its valid. */ |
900 | if (cpufreq_driver->setpolicy) | |
6e2c89d1 | 901 | cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); |
ecf7e461 DJ |
902 | |
903 | /* set default policy */ | |
037ce839 | 904 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 | 905 | if (ret) { |
2d06d8c4 | 906 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
907 | if (cpufreq_driver->exit) |
908 | cpufreq_driver->exit(policy); | |
ecf7e461 | 909 | } |
909a694e DJ |
910 | } |
911 | ||
fcf80582 | 912 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 | 913 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 914 | unsigned int cpu, struct device *dev) |
fcf80582 | 915 | { |
9c0ebcf7 | 916 | int ret = 0; |
fcf80582 VK |
917 | unsigned long flags; |
918 | ||
9c0ebcf7 | 919 | if (has_target()) { |
3de9bdeb VK |
920 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
921 | if (ret) { | |
922 | pr_err("%s: Failed to stop governor\n", __func__); | |
923 | return ret; | |
924 | } | |
925 | } | |
fcf80582 | 926 | |
ad7722da | 927 | down_write(&policy->rwsem); |
2eaa3e2d | 928 | |
0d1857a1 | 929 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 930 | |
fcf80582 VK |
931 | cpumask_set_cpu(cpu, policy->cpus); |
932 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 933 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 934 | |
ad7722da | 935 | up_write(&policy->rwsem); |
2eaa3e2d | 936 | |
9c0ebcf7 | 937 | if (has_target()) { |
3de9bdeb VK |
938 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
939 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
940 | pr_err("%s: Failed to start governor\n", __func__); | |
941 | return ret; | |
942 | } | |
820c6ca2 | 943 | } |
fcf80582 | 944 | |
42f921a6 | 945 | return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
fcf80582 VK |
946 | } |
947 | #endif | |
1da177e4 | 948 | |
8414809c SB |
949 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
950 | { | |
951 | struct cpufreq_policy *policy; | |
952 | unsigned long flags; | |
953 | ||
44871c9c | 954 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
955 | |
956 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
957 | ||
44871c9c | 958 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c | 959 | |
6e2c89d1 | 960 | policy->governor = NULL; |
961 | ||
8414809c SB |
962 | return policy; |
963 | } | |
964 | ||
e9698cc5 SB |
965 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
966 | { | |
967 | struct cpufreq_policy *policy; | |
968 | ||
969 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
970 | if (!policy) | |
971 | return NULL; | |
972 | ||
973 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
974 | goto err_free_policy; | |
975 | ||
976 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
977 | goto err_free_cpumask; | |
978 | ||
c88a1f8b | 979 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 980 | init_rwsem(&policy->rwsem); |
981 | ||
e9698cc5 SB |
982 | return policy; |
983 | ||
984 | err_free_cpumask: | |
985 | free_cpumask_var(policy->cpus); | |
986 | err_free_policy: | |
987 | kfree(policy); | |
988 | ||
989 | return NULL; | |
990 | } | |
991 | ||
42f921a6 VK |
992 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
993 | { | |
994 | struct kobject *kobj; | |
995 | struct completion *cmp; | |
996 | ||
fcd7af91 VK |
997 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
998 | CPUFREQ_REMOVE_POLICY, policy); | |
999 | ||
42f921a6 VK |
1000 | down_read(&policy->rwsem); |
1001 | kobj = &policy->kobj; | |
1002 | cmp = &policy->kobj_unregister; | |
1003 | up_read(&policy->rwsem); | |
1004 | kobject_put(kobj); | |
1005 | ||
1006 | /* | |
1007 | * We need to make sure that the underlying kobj is | |
1008 | * actually not referenced anymore by anybody before we | |
1009 | * proceed with unloading. | |
1010 | */ | |
1011 | pr_debug("waiting for dropping of refcount\n"); | |
1012 | wait_for_completion(cmp); | |
1013 | pr_debug("wait complete\n"); | |
1014 | } | |
1015 | ||
e9698cc5 SB |
1016 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
1017 | { | |
1018 | free_cpumask_var(policy->related_cpus); | |
1019 | free_cpumask_var(policy->cpus); | |
1020 | kfree(policy); | |
1021 | } | |
1022 | ||
0d66b91e SB |
1023 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1024 | { | |
99ec899e | 1025 | if (WARN_ON(cpu == policy->cpu)) |
cb38ed5c SB |
1026 | return; |
1027 | ||
ad7722da | 1028 | down_write(&policy->rwsem); |
8efd5765 | 1029 | |
0d66b91e SB |
1030 | policy->last_cpu = policy->cpu; |
1031 | policy->cpu = cpu; | |
1032 | ||
ad7722da | 1033 | up_write(&policy->rwsem); |
8efd5765 | 1034 | |
0d66b91e | 1035 | cpufreq_frequency_table_update_policy_cpu(policy); |
0d66b91e SB |
1036 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1037 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1038 | } | |
1039 | ||
a82fab29 SB |
1040 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, |
1041 | bool frozen) | |
1da177e4 | 1042 | { |
fcf80582 | 1043 | unsigned int j, cpu = dev->id; |
65922465 | 1044 | int ret = -ENOMEM; |
1da177e4 | 1045 | struct cpufreq_policy *policy; |
1da177e4 | 1046 | unsigned long flags; |
90e41bac | 1047 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 1048 | struct cpufreq_policy *tpolicy; |
90e41bac | 1049 | #endif |
1da177e4 | 1050 | |
c32b6b8e AR |
1051 | if (cpu_is_offline(cpu)) |
1052 | return 0; | |
1053 | ||
2d06d8c4 | 1054 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
1055 | |
1056 | #ifdef CONFIG_SMP | |
1057 | /* check whether a different CPU already registered this | |
1058 | * CPU because it is in the same boat. */ | |
1059 | policy = cpufreq_cpu_get(cpu); | |
1060 | if (unlikely(policy)) { | |
8ff69732 | 1061 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1062 | return 0; |
1063 | } | |
5025d628 | 1064 | #endif |
fcf80582 | 1065 | |
6eed9404 VK |
1066 | if (!down_read_trylock(&cpufreq_rwsem)) |
1067 | return 0; | |
1068 | ||
fcf80582 VK |
1069 | #ifdef CONFIG_HOTPLUG_CPU |
1070 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1071 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1072 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1073 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1074 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
42f921a6 | 1075 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev); |
6eed9404 VK |
1076 | up_read(&cpufreq_rwsem); |
1077 | return ret; | |
2eaa3e2d | 1078 | } |
fcf80582 | 1079 | } |
0d1857a1 | 1080 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1081 | #endif |
1082 | ||
72368d12 RW |
1083 | /* |
1084 | * Restore the saved policy when doing light-weight init and fall back | |
1085 | * to the full init if that fails. | |
1086 | */ | |
1087 | policy = frozen ? cpufreq_policy_restore(cpu) : NULL; | |
1088 | if (!policy) { | |
1089 | frozen = false; | |
8414809c | 1090 | policy = cpufreq_policy_alloc(); |
72368d12 RW |
1091 | if (!policy) |
1092 | goto nomem_out; | |
1093 | } | |
0d66b91e SB |
1094 | |
1095 | /* | |
1096 | * In the resume path, since we restore a saved policy, the assignment | |
1097 | * to policy->cpu is like an update of the existing policy, rather than | |
1098 | * the creation of a brand new one. So we need to perform this update | |
1099 | * by invoking update_policy_cpu(). | |
1100 | */ | |
1101 | if (frozen && cpu != policy->cpu) | |
1102 | update_policy_cpu(policy, cpu); | |
1103 | else | |
1104 | policy->cpu = cpu; | |
1105 | ||
835481d9 | 1106 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1107 | |
1da177e4 | 1108 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1109 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1110 | |
1111 | /* call driver. From then on the cpufreq must be able | |
1112 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1113 | */ | |
1c3d85dd | 1114 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1115 | if (ret) { |
2d06d8c4 | 1116 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1117 | goto err_set_policy_cpu; |
1da177e4 | 1118 | } |
643ae6e8 | 1119 | |
5a7e56a5 VK |
1120 | /* related cpus should atleast have policy->cpus */ |
1121 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1122 | ||
1123 | /* | |
1124 | * affected cpus must always be the one, which are online. We aren't | |
1125 | * managing offline cpus here. | |
1126 | */ | |
1127 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1128 | ||
1129 | if (!frozen) { | |
1130 | policy->user_policy.min = policy->min; | |
1131 | policy->user_policy.max = policy->max; | |
1132 | } | |
1133 | ||
4e97b631 | 1134 | down_write(&policy->rwsem); |
652ed95d VK |
1135 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1136 | for_each_cpu(j, policy->cpus) | |
1137 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1138 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1139 | ||
da60ce9f VK |
1140 | if (cpufreq_driver->get) { |
1141 | policy->cur = cpufreq_driver->get(policy->cpu); | |
1142 | if (!policy->cur) { | |
1143 | pr_err("%s: ->get() failed\n", __func__); | |
1144 | goto err_get_freq; | |
1145 | } | |
1146 | } | |
1147 | ||
d3916691 VK |
1148 | /* |
1149 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1150 | * frequency table present with cpufreq core. In such cases CPU might be | |
1151 | * unstable if it has to run on that frequency for long duration of time | |
1152 | * and so its better to set it to a frequency which is specified in | |
1153 | * freq-table. This also makes cpufreq stats inconsistent as | |
1154 | * cpufreq-stats would fail to register because current frequency of CPU | |
1155 | * isn't found in freq-table. | |
1156 | * | |
1157 | * Because we don't want this change to effect boot process badly, we go | |
1158 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1159 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1160 | * is initialized to zero). | |
1161 | * | |
1162 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1163 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1164 | * equal to target-freq. | |
1165 | */ | |
1166 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1167 | && has_target()) { | |
1168 | /* Are we running at unknown frequency ? */ | |
1169 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1170 | if (ret == -EINVAL) { | |
1171 | /* Warn user and fix it */ | |
1172 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1173 | __func__, policy->cpu, policy->cur); | |
1174 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1175 | CPUFREQ_RELATION_L); | |
1176 | ||
1177 | /* | |
1178 | * Reaching here after boot in a few seconds may not | |
1179 | * mean that system will remain stable at "unknown" | |
1180 | * frequency for longer duration. Hence, a BUG_ON(). | |
1181 | */ | |
1182 | BUG_ON(ret); | |
1183 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1184 | __func__, policy->cpu, policy->cur); | |
1185 | } | |
1186 | } | |
1187 | ||
a1531acd TR |
1188 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1189 | CPUFREQ_START, policy); | |
1190 | ||
a82fab29 | 1191 | if (!frozen) { |
308b60e7 | 1192 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1193 | if (ret) |
1194 | goto err_out_unregister; | |
fcd7af91 VK |
1195 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1196 | CPUFREQ_CREATE_POLICY, policy); | |
a82fab29 | 1197 | } |
8ff69732 | 1198 | |
9515f4d6 VK |
1199 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1200 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1201 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1202 | ||
e18f1682 SB |
1203 | cpufreq_init_policy(policy); |
1204 | ||
08fd8c1c VK |
1205 | if (!frozen) { |
1206 | policy->user_policy.policy = policy->policy; | |
1207 | policy->user_policy.governor = policy->governor; | |
1208 | } | |
4e97b631 | 1209 | up_write(&policy->rwsem); |
08fd8c1c | 1210 | |
038c5b3e | 1211 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1212 | up_read(&cpufreq_rwsem); |
1213 | ||
2d06d8c4 | 1214 | pr_debug("initialization complete\n"); |
87c32271 | 1215 | |
1da177e4 LT |
1216 | return 0; |
1217 | ||
1da177e4 | 1218 | err_out_unregister: |
652ed95d | 1219 | err_get_freq: |
0d1857a1 | 1220 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1221 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1222 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1223 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1224 | |
da60ce9f VK |
1225 | if (cpufreq_driver->exit) |
1226 | cpufreq_driver->exit(policy); | |
2eaa3e2d | 1227 | err_set_policy_cpu: |
72368d12 RW |
1228 | if (frozen) { |
1229 | /* Do not leave stale fallback data behind. */ | |
1230 | per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; | |
42f921a6 | 1231 | cpufreq_policy_put_kobj(policy); |
72368d12 | 1232 | } |
e9698cc5 | 1233 | cpufreq_policy_free(policy); |
42f921a6 | 1234 | |
1da177e4 | 1235 | nomem_out: |
6eed9404 VK |
1236 | up_read(&cpufreq_rwsem); |
1237 | ||
1da177e4 LT |
1238 | return ret; |
1239 | } | |
1240 | ||
a82fab29 SB |
1241 | /** |
1242 | * cpufreq_add_dev - add a CPU device | |
1243 | * | |
1244 | * Adds the cpufreq interface for a CPU device. | |
1245 | * | |
1246 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1247 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1248 | * mess up, but more thorough testing is needed. - Mathieu | |
1249 | */ | |
1250 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1251 | { | |
1252 | return __cpufreq_add_dev(dev, sif, false); | |
1253 | } | |
1254 | ||
3a3e9e06 | 1255 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 1256 | unsigned int old_cpu) |
f9ba680d SB |
1257 | { |
1258 | struct device *cpu_dev; | |
f9ba680d SB |
1259 | int ret; |
1260 | ||
1261 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1262 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 | 1263 | |
f9ba680d | 1264 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1265 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d SB |
1266 | if (ret) { |
1267 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1268 | ||
ad7722da | 1269 | down_write(&policy->rwsem); |
3a3e9e06 | 1270 | cpumask_set_cpu(old_cpu, policy->cpus); |
ad7722da | 1271 | up_write(&policy->rwsem); |
f9ba680d | 1272 | |
3a3e9e06 | 1273 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1274 | "cpufreq"); |
1275 | ||
1276 | return -EINVAL; | |
1277 | } | |
1278 | ||
1279 | return cpu_dev->id; | |
1280 | } | |
1281 | ||
cedb70af SB |
1282 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
1283 | struct subsys_interface *sif, | |
1284 | bool frozen) | |
1da177e4 | 1285 | { |
f9ba680d | 1286 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1287 | int new_cpu, ret; |
1da177e4 | 1288 | unsigned long flags; |
3a3e9e06 | 1289 | struct cpufreq_policy *policy; |
1da177e4 | 1290 | |
b8eed8af | 1291 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1292 | |
0d1857a1 | 1293 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1294 | |
3a3e9e06 | 1295 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1296 | |
8414809c SB |
1297 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1298 | if (frozen) | |
3a3e9e06 | 1299 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1300 | |
0d1857a1 | 1301 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1302 | |
3a3e9e06 | 1303 | if (!policy) { |
b8eed8af | 1304 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1305 | return -EINVAL; |
1306 | } | |
1da177e4 | 1307 | |
9c0ebcf7 | 1308 | if (has_target()) { |
3de9bdeb VK |
1309 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1310 | if (ret) { | |
1311 | pr_err("%s: Failed to stop governor\n", __func__); | |
1312 | return ret; | |
1313 | } | |
1314 | } | |
1da177e4 | 1315 | |
1c3d85dd | 1316 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1317 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1318 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 | 1319 | |
ad7722da | 1320 | down_read(&policy->rwsem); |
3a3e9e06 | 1321 | cpus = cpumask_weight(policy->cpus); |
ad7722da | 1322 | up_read(&policy->rwsem); |
084f3493 | 1323 | |
61173f25 | 1324 | if (cpu != policy->cpu) { |
6964d91d | 1325 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
73bf0fc2 | 1326 | } else if (cpus > 1) { |
42f921a6 | 1327 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu); |
f9ba680d | 1328 | if (new_cpu >= 0) { |
3a3e9e06 | 1329 | update_policy_cpu(policy, new_cpu); |
a82fab29 SB |
1330 | |
1331 | if (!frozen) { | |
75949c9a VK |
1332 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1333 | __func__, new_cpu, cpu); | |
a82fab29 | 1334 | } |
1da177e4 LT |
1335 | } |
1336 | } | |
1da177e4 | 1337 | |
cedb70af SB |
1338 | return 0; |
1339 | } | |
1340 | ||
1341 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
1342 | struct subsys_interface *sif, | |
1343 | bool frozen) | |
1344 | { | |
1345 | unsigned int cpu = dev->id, cpus; | |
1346 | int ret; | |
1347 | unsigned long flags; | |
1348 | struct cpufreq_policy *policy; | |
cedb70af SB |
1349 | |
1350 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1351 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1352 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1353 | ||
1354 | if (!policy) { | |
1355 | pr_debug("%s: No cpu_data found\n", __func__); | |
1356 | return -EINVAL; | |
1357 | } | |
1358 | ||
ad7722da | 1359 | down_write(&policy->rwsem); |
cedb70af | 1360 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1361 | |
1362 | if (cpus > 1) | |
1363 | cpumask_clear_cpu(cpu, policy->cpus); | |
ad7722da | 1364 | up_write(&policy->rwsem); |
cedb70af | 1365 | |
b8eed8af VK |
1366 | /* If cpu is last user of policy, free policy */ |
1367 | if (cpus == 1) { | |
9c0ebcf7 | 1368 | if (has_target()) { |
3de9bdeb VK |
1369 | ret = __cpufreq_governor(policy, |
1370 | CPUFREQ_GOV_POLICY_EXIT); | |
1371 | if (ret) { | |
1372 | pr_err("%s: Failed to exit governor\n", | |
1373 | __func__); | |
1374 | return ret; | |
1375 | } | |
edab2fbc | 1376 | } |
2a998599 | 1377 | |
42f921a6 VK |
1378 | if (!frozen) |
1379 | cpufreq_policy_put_kobj(policy); | |
7d26e2d5 | 1380 | |
8414809c SB |
1381 | /* |
1382 | * Perform the ->exit() even during light-weight tear-down, | |
1383 | * since this is a core component, and is essential for the | |
1384 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1385 | */ |
1c3d85dd | 1386 | if (cpufreq_driver->exit) |
3a3e9e06 | 1387 | cpufreq_driver->exit(policy); |
27ecddc2 | 1388 | |
9515f4d6 VK |
1389 | /* Remove policy from list of active policies */ |
1390 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1391 | list_del(&policy->policy_list); | |
1392 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1393 | ||
8414809c | 1394 | if (!frozen) |
3a3e9e06 | 1395 | cpufreq_policy_free(policy); |
2a998599 | 1396 | } else { |
9c0ebcf7 | 1397 | if (has_target()) { |
3de9bdeb VK |
1398 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
1399 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
1400 | pr_err("%s: Failed to start governor\n", | |
1401 | __func__); | |
1402 | return ret; | |
1403 | } | |
2a998599 | 1404 | } |
27ecddc2 | 1405 | } |
1da177e4 | 1406 | |
474deff7 | 1407 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1408 | return 0; |
1409 | } | |
1410 | ||
cedb70af | 1411 | /** |
27a862e9 | 1412 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1413 | * |
1414 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1415 | */ |
8a25a2fd | 1416 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1417 | { |
8a25a2fd | 1418 | unsigned int cpu = dev->id; |
27a862e9 | 1419 | int ret; |
ec28297a VP |
1420 | |
1421 | if (cpu_is_offline(cpu)) | |
1422 | return 0; | |
1423 | ||
27a862e9 VK |
1424 | ret = __cpufreq_remove_dev_prepare(dev, sif, false); |
1425 | ||
1426 | if (!ret) | |
1427 | ret = __cpufreq_remove_dev_finish(dev, sif, false); | |
1428 | ||
1429 | return ret; | |
5a01f2e8 VP |
1430 | } |
1431 | ||
65f27f38 | 1432 | static void handle_update(struct work_struct *work) |
1da177e4 | 1433 | { |
65f27f38 DH |
1434 | struct cpufreq_policy *policy = |
1435 | container_of(work, struct cpufreq_policy, update); | |
1436 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1437 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1438 | cpufreq_update_policy(cpu); |
1439 | } | |
1440 | ||
1441 | /** | |
bb176f7d VK |
1442 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1443 | * in deep trouble. | |
1da177e4 LT |
1444 | * @cpu: cpu number |
1445 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1446 | * @new_freq: CPU frequency the CPU actually runs at | |
1447 | * | |
29464f28 DJ |
1448 | * We adjust to current frequency first, and need to clean up later. |
1449 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1450 | */ |
e08f5f5b GS |
1451 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1452 | unsigned int new_freq) | |
1da177e4 | 1453 | { |
b43a7ffb | 1454 | struct cpufreq_policy *policy; |
1da177e4 | 1455 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1456 | unsigned long flags; |
1457 | ||
2d06d8c4 | 1458 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1459 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1460 | ||
1da177e4 LT |
1461 | freqs.old = old_freq; |
1462 | freqs.new = new_freq; | |
b43a7ffb VK |
1463 | |
1464 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1465 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1466 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1467 | ||
1468 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1469 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1470 | } |
1471 | ||
32ee8c3e | 1472 | /** |
4ab70df4 | 1473 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1474 | * @cpu: CPU number |
1475 | * | |
1476 | * This is the last known freq, without actually getting it from the driver. | |
1477 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1478 | */ | |
1479 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1480 | { | |
9e21ba8b | 1481 | struct cpufreq_policy *policy; |
e08f5f5b | 1482 | unsigned int ret_freq = 0; |
95235ca2 | 1483 | |
1c3d85dd RW |
1484 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1485 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1486 | |
1487 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1488 | if (policy) { |
e08f5f5b | 1489 | ret_freq = policy->cur; |
95235ca2 VP |
1490 | cpufreq_cpu_put(policy); |
1491 | } | |
1492 | ||
4d34a67d | 1493 | return ret_freq; |
95235ca2 VP |
1494 | } |
1495 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1496 | ||
3d737108 JB |
1497 | /** |
1498 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1499 | * @cpu: CPU number | |
1500 | * | |
1501 | * Just return the max possible frequency for a given CPU. | |
1502 | */ | |
1503 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1504 | { | |
1505 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1506 | unsigned int ret_freq = 0; | |
1507 | ||
1508 | if (policy) { | |
1509 | ret_freq = policy->max; | |
1510 | cpufreq_cpu_put(policy); | |
1511 | } | |
1512 | ||
1513 | return ret_freq; | |
1514 | } | |
1515 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1516 | ||
5a01f2e8 | 1517 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1518 | { |
7a6aedfa | 1519 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1520 | unsigned int ret_freq = 0; |
5800043b | 1521 | |
1c3d85dd | 1522 | if (!cpufreq_driver->get) |
4d34a67d | 1523 | return ret_freq; |
1da177e4 | 1524 | |
1c3d85dd | 1525 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1526 | |
e08f5f5b | 1527 | if (ret_freq && policy->cur && |
1c3d85dd | 1528 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1529 | /* verify no discrepancy between actual and |
1530 | saved value exists */ | |
1531 | if (unlikely(ret_freq != policy->cur)) { | |
1532 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1533 | schedule_work(&policy->update); |
1534 | } | |
1535 | } | |
1536 | ||
4d34a67d | 1537 | return ret_freq; |
5a01f2e8 | 1538 | } |
1da177e4 | 1539 | |
5a01f2e8 VP |
1540 | /** |
1541 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1542 | * @cpu: CPU number | |
1543 | * | |
1544 | * Get the CPU current (static) CPU frequency | |
1545 | */ | |
1546 | unsigned int cpufreq_get(unsigned int cpu) | |
1547 | { | |
999976e0 | 1548 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1549 | unsigned int ret_freq = 0; |
5a01f2e8 | 1550 | |
999976e0 AP |
1551 | if (policy) { |
1552 | down_read(&policy->rwsem); | |
1553 | ret_freq = __cpufreq_get(cpu); | |
1554 | up_read(&policy->rwsem); | |
5a01f2e8 | 1555 | |
999976e0 AP |
1556 | cpufreq_cpu_put(policy); |
1557 | } | |
6eed9404 | 1558 | |
4d34a67d | 1559 | return ret_freq; |
1da177e4 LT |
1560 | } |
1561 | EXPORT_SYMBOL(cpufreq_get); | |
1562 | ||
8a25a2fd KS |
1563 | static struct subsys_interface cpufreq_interface = { |
1564 | .name = "cpufreq", | |
1565 | .subsys = &cpu_subsys, | |
1566 | .add_dev = cpufreq_add_dev, | |
1567 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1568 | }; |
1569 | ||
42d4dc3f | 1570 | /** |
2f0aea93 | 1571 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1572 | * |
2f0aea93 VK |
1573 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1574 | * as some platforms can't change frequency after this point in suspend cycle. | |
1575 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1576 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1577 | */ |
2f0aea93 | 1578 | void cpufreq_suspend(void) |
42d4dc3f | 1579 | { |
3a3e9e06 | 1580 | struct cpufreq_policy *policy; |
42d4dc3f | 1581 | |
2f0aea93 VK |
1582 | if (!cpufreq_driver) |
1583 | return; | |
42d4dc3f | 1584 | |
2f0aea93 VK |
1585 | if (!has_target()) |
1586 | return; | |
42d4dc3f | 1587 | |
2f0aea93 VK |
1588 | pr_debug("%s: Suspending Governors\n", __func__); |
1589 | ||
1590 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
1591 | if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) | |
1592 | pr_err("%s: Failed to stop governor for policy: %p\n", | |
1593 | __func__, policy); | |
1594 | else if (cpufreq_driver->suspend | |
1595 | && cpufreq_driver->suspend(policy)) | |
1596 | pr_err("%s: Failed to suspend driver: %p\n", __func__, | |
1597 | policy); | |
42d4dc3f BH |
1598 | } |
1599 | ||
2f0aea93 | 1600 | cpufreq_suspended = true; |
42d4dc3f BH |
1601 | } |
1602 | ||
1da177e4 | 1603 | /** |
2f0aea93 | 1604 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1605 | * |
2f0aea93 VK |
1606 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1607 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1608 | */ |
2f0aea93 | 1609 | void cpufreq_resume(void) |
1da177e4 | 1610 | { |
3a3e9e06 | 1611 | struct cpufreq_policy *policy; |
1da177e4 | 1612 | |
2f0aea93 VK |
1613 | if (!cpufreq_driver) |
1614 | return; | |
1da177e4 | 1615 | |
2f0aea93 | 1616 | if (!has_target()) |
e00e56df | 1617 | return; |
1da177e4 | 1618 | |
2f0aea93 | 1619 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1620 | |
2f0aea93 | 1621 | cpufreq_suspended = false; |
ce6c3997 | 1622 | |
2f0aea93 VK |
1623 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
1624 | if (__cpufreq_governor(policy, CPUFREQ_GOV_START) | |
1625 | || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) | |
1626 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1627 | __func__, policy); | |
1628 | else if (cpufreq_driver->resume | |
1629 | && cpufreq_driver->resume(policy)) | |
1630 | pr_err("%s: Failed to resume driver: %p\n", __func__, | |
1631 | policy); | |
1da177e4 | 1632 | |
2f0aea93 VK |
1633 | /* |
1634 | * schedule call cpufreq_update_policy() for boot CPU, i.e. last | |
1635 | * policy in list. It will verify that the current freq is in | |
1636 | * sync with what we believe it to be. | |
1637 | */ | |
1638 | if (list_is_last(&policy->policy_list, &cpufreq_policy_list)) | |
1639 | schedule_work(&policy->update); | |
1640 | } | |
1641 | } | |
1da177e4 | 1642 | |
9d95046e BP |
1643 | /** |
1644 | * cpufreq_get_current_driver - return current driver's name | |
1645 | * | |
1646 | * Return the name string of the currently loaded cpufreq driver | |
1647 | * or NULL, if none. | |
1648 | */ | |
1649 | const char *cpufreq_get_current_driver(void) | |
1650 | { | |
1c3d85dd RW |
1651 | if (cpufreq_driver) |
1652 | return cpufreq_driver->name; | |
1653 | ||
1654 | return NULL; | |
9d95046e BP |
1655 | } |
1656 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1657 | |
1658 | /********************************************************************* | |
1659 | * NOTIFIER LISTS INTERFACE * | |
1660 | *********************************************************************/ | |
1661 | ||
1662 | /** | |
1663 | * cpufreq_register_notifier - register a driver with cpufreq | |
1664 | * @nb: notifier function to register | |
1665 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1666 | * | |
32ee8c3e | 1667 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1668 | * are notified about clock rate changes (once before and once after |
1669 | * the transition), or a list of drivers that are notified about | |
1670 | * changes in cpufreq policy. | |
1671 | * | |
1672 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1673 | * blocking_notifier_chain_register. |
1da177e4 LT |
1674 | */ |
1675 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1676 | { | |
1677 | int ret; | |
1678 | ||
d5aaffa9 DB |
1679 | if (cpufreq_disabled()) |
1680 | return -EINVAL; | |
1681 | ||
74212ca4 CEB |
1682 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1683 | ||
1da177e4 LT |
1684 | switch (list) { |
1685 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1686 | ret = srcu_notifier_chain_register( |
e041c683 | 1687 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1688 | break; |
1689 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1690 | ret = blocking_notifier_chain_register( |
1691 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1692 | break; |
1693 | default: | |
1694 | ret = -EINVAL; | |
1695 | } | |
1da177e4 LT |
1696 | |
1697 | return ret; | |
1698 | } | |
1699 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1700 | ||
1da177e4 LT |
1701 | /** |
1702 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1703 | * @nb: notifier block to be unregistered | |
bb176f7d | 1704 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1705 | * |
1706 | * Remove a driver from the CPU frequency notifier list. | |
1707 | * | |
1708 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1709 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1710 | */ |
1711 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1712 | { | |
1713 | int ret; | |
1714 | ||
d5aaffa9 DB |
1715 | if (cpufreq_disabled()) |
1716 | return -EINVAL; | |
1717 | ||
1da177e4 LT |
1718 | switch (list) { |
1719 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1720 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1721 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1722 | break; |
1723 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1724 | ret = blocking_notifier_chain_unregister( |
1725 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1726 | break; |
1727 | default: | |
1728 | ret = -EINVAL; | |
1729 | } | |
1da177e4 LT |
1730 | |
1731 | return ret; | |
1732 | } | |
1733 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1734 | ||
1735 | ||
1736 | /********************************************************************* | |
1737 | * GOVERNORS * | |
1738 | *********************************************************************/ | |
1739 | ||
1da177e4 LT |
1740 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1741 | unsigned int target_freq, | |
1742 | unsigned int relation) | |
1743 | { | |
1744 | int retval = -EINVAL; | |
7249924e | 1745 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1746 | |
a7b422cd KRW |
1747 | if (cpufreq_disabled()) |
1748 | return -ENODEV; | |
1749 | ||
7249924e VK |
1750 | /* Make sure that target_freq is within supported range */ |
1751 | if (target_freq > policy->max) | |
1752 | target_freq = policy->max; | |
1753 | if (target_freq < policy->min) | |
1754 | target_freq = policy->min; | |
1755 | ||
1756 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1757 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 | 1758 | |
9c0ebcf7 VK |
1759 | /* |
1760 | * This might look like a redundant call as we are checking it again | |
1761 | * after finding index. But it is left intentionally for cases where | |
1762 | * exactly same freq is called again and so we can save on few function | |
1763 | * calls. | |
1764 | */ | |
5a1c0228 VK |
1765 | if (target_freq == policy->cur) |
1766 | return 0; | |
1767 | ||
1c3d85dd RW |
1768 | if (cpufreq_driver->target) |
1769 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
9c0ebcf7 VK |
1770 | else if (cpufreq_driver->target_index) { |
1771 | struct cpufreq_frequency_table *freq_table; | |
d4019f0a VK |
1772 | struct cpufreq_freqs freqs; |
1773 | bool notify; | |
9c0ebcf7 | 1774 | int index; |
90d45d17 | 1775 | |
9c0ebcf7 VK |
1776 | freq_table = cpufreq_frequency_get_table(policy->cpu); |
1777 | if (unlikely(!freq_table)) { | |
1778 | pr_err("%s: Unable to find freq_table\n", __func__); | |
1779 | goto out; | |
1780 | } | |
1781 | ||
1782 | retval = cpufreq_frequency_table_target(policy, freq_table, | |
1783 | target_freq, relation, &index); | |
1784 | if (unlikely(retval)) { | |
1785 | pr_err("%s: Unable to find matching freq\n", __func__); | |
1786 | goto out; | |
1787 | } | |
1788 | ||
d4019f0a | 1789 | if (freq_table[index].frequency == policy->cur) { |
9c0ebcf7 | 1790 | retval = 0; |
d4019f0a VK |
1791 | goto out; |
1792 | } | |
1793 | ||
1794 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); | |
1795 | ||
1796 | if (notify) { | |
1797 | freqs.old = policy->cur; | |
1798 | freqs.new = freq_table[index].frequency; | |
1799 | freqs.flags = 0; | |
1800 | ||
1801 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", | |
1802 | __func__, policy->cpu, freqs.old, | |
1803 | freqs.new); | |
1804 | ||
1805 | cpufreq_notify_transition(policy, &freqs, | |
1806 | CPUFREQ_PRECHANGE); | |
1807 | } | |
1808 | ||
1809 | retval = cpufreq_driver->target_index(policy, index); | |
1810 | if (retval) | |
1811 | pr_err("%s: Failed to change cpu frequency: %d\n", | |
1812 | __func__, retval); | |
1813 | ||
ab1b1c4e VK |
1814 | if (notify) |
1815 | cpufreq_notify_post_transition(policy, &freqs, retval); | |
9c0ebcf7 VK |
1816 | } |
1817 | ||
1818 | out: | |
1da177e4 LT |
1819 | return retval; |
1820 | } | |
1821 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1822 | ||
1da177e4 LT |
1823 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1824 | unsigned int target_freq, | |
1825 | unsigned int relation) | |
1826 | { | |
f1829e4a | 1827 | int ret = -EINVAL; |
1da177e4 | 1828 | |
ad7722da | 1829 | down_write(&policy->rwsem); |
1da177e4 LT |
1830 | |
1831 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1832 | ||
ad7722da | 1833 | up_write(&policy->rwsem); |
1da177e4 | 1834 | |
1da177e4 LT |
1835 | return ret; |
1836 | } | |
1837 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1838 | ||
153d7f3f | 1839 | /* |
153d7f3f AV |
1840 | * when "event" is CPUFREQ_GOV_LIMITS |
1841 | */ | |
1da177e4 | 1842 | |
e08f5f5b GS |
1843 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1844 | unsigned int event) | |
1da177e4 | 1845 | { |
cc993cab | 1846 | int ret; |
6afde10c TR |
1847 | |
1848 | /* Only must be defined when default governor is known to have latency | |
1849 | restrictions, like e.g. conservative or ondemand. | |
1850 | That this is the case is already ensured in Kconfig | |
1851 | */ | |
1852 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1853 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1854 | #else | |
1855 | struct cpufreq_governor *gov = NULL; | |
1856 | #endif | |
1c256245 | 1857 | |
2f0aea93 VK |
1858 | /* Don't start any governor operations if we are entering suspend */ |
1859 | if (cpufreq_suspended) | |
1860 | return 0; | |
1861 | ||
1c256245 TR |
1862 | if (policy->governor->max_transition_latency && |
1863 | policy->cpuinfo.transition_latency > | |
1864 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1865 | if (!gov) |
1866 | return -EINVAL; | |
1867 | else { | |
1868 | printk(KERN_WARNING "%s governor failed, too long" | |
1869 | " transition latency of HW, fallback" | |
1870 | " to %s governor\n", | |
1871 | policy->governor->name, | |
1872 | gov->name); | |
1873 | policy->governor = gov; | |
1874 | } | |
1c256245 | 1875 | } |
1da177e4 | 1876 | |
fe492f3f VK |
1877 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1878 | if (!try_module_get(policy->governor->owner)) | |
1879 | return -EINVAL; | |
1da177e4 | 1880 | |
2d06d8c4 | 1881 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1882 | policy->cpu, event); |
95731ebb XC |
1883 | |
1884 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1885 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1886 | || (!policy->governor_enabled |
1887 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1888 | mutex_unlock(&cpufreq_governor_lock); |
1889 | return -EBUSY; | |
1890 | } | |
1891 | ||
1892 | if (event == CPUFREQ_GOV_STOP) | |
1893 | policy->governor_enabled = false; | |
1894 | else if (event == CPUFREQ_GOV_START) | |
1895 | policy->governor_enabled = true; | |
1896 | ||
1897 | mutex_unlock(&cpufreq_governor_lock); | |
1898 | ||
1da177e4 LT |
1899 | ret = policy->governor->governor(policy, event); |
1900 | ||
4d5dcc42 VK |
1901 | if (!ret) { |
1902 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1903 | policy->governor->initialized++; | |
1904 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1905 | policy->governor->initialized--; | |
95731ebb XC |
1906 | } else { |
1907 | /* Restore original values */ | |
1908 | mutex_lock(&cpufreq_governor_lock); | |
1909 | if (event == CPUFREQ_GOV_STOP) | |
1910 | policy->governor_enabled = true; | |
1911 | else if (event == CPUFREQ_GOV_START) | |
1912 | policy->governor_enabled = false; | |
1913 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1914 | } |
b394058f | 1915 | |
fe492f3f VK |
1916 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1917 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1918 | module_put(policy->governor->owner); |
1919 | ||
1920 | return ret; | |
1921 | } | |
1922 | ||
1da177e4 LT |
1923 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1924 | { | |
3bcb09a3 | 1925 | int err; |
1da177e4 LT |
1926 | |
1927 | if (!governor) | |
1928 | return -EINVAL; | |
1929 | ||
a7b422cd KRW |
1930 | if (cpufreq_disabled()) |
1931 | return -ENODEV; | |
1932 | ||
3fc54d37 | 1933 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1934 | |
b394058f | 1935 | governor->initialized = 0; |
3bcb09a3 JF |
1936 | err = -EBUSY; |
1937 | if (__find_governor(governor->name) == NULL) { | |
1938 | err = 0; | |
1939 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1940 | } |
1da177e4 | 1941 | |
32ee8c3e | 1942 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1943 | return err; |
1da177e4 LT |
1944 | } |
1945 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1946 | ||
1da177e4 LT |
1947 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1948 | { | |
90e41bac | 1949 | int cpu; |
90e41bac | 1950 | |
1da177e4 LT |
1951 | if (!governor) |
1952 | return; | |
1953 | ||
a7b422cd KRW |
1954 | if (cpufreq_disabled()) |
1955 | return; | |
1956 | ||
90e41bac PB |
1957 | for_each_present_cpu(cpu) { |
1958 | if (cpu_online(cpu)) | |
1959 | continue; | |
1960 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1961 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1962 | } | |
90e41bac | 1963 | |
3fc54d37 | 1964 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1965 | list_del(&governor->governor_list); |
3fc54d37 | 1966 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1967 | return; |
1968 | } | |
1969 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1970 | ||
1971 | ||
1da177e4 LT |
1972 | /********************************************************************* |
1973 | * POLICY INTERFACE * | |
1974 | *********************************************************************/ | |
1975 | ||
1976 | /** | |
1977 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1978 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1979 | * is written | |
1da177e4 LT |
1980 | * |
1981 | * Reads the current cpufreq policy. | |
1982 | */ | |
1983 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1984 | { | |
1985 | struct cpufreq_policy *cpu_policy; | |
1986 | if (!policy) | |
1987 | return -EINVAL; | |
1988 | ||
1989 | cpu_policy = cpufreq_cpu_get(cpu); | |
1990 | if (!cpu_policy) | |
1991 | return -EINVAL; | |
1992 | ||
d5b73cd8 | 1993 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
1994 | |
1995 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1996 | return 0; |
1997 | } | |
1998 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1999 | ||
153d7f3f | 2000 | /* |
037ce839 VK |
2001 | * policy : current policy. |
2002 | * new_policy: policy to be set. | |
153d7f3f | 2003 | */ |
037ce839 | 2004 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 2005 | struct cpufreq_policy *new_policy) |
1da177e4 | 2006 | { |
d9a789c7 RW |
2007 | struct cpufreq_governor *old_gov; |
2008 | int ret; | |
1da177e4 | 2009 | |
3a3e9e06 VK |
2010 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, |
2011 | new_policy->min, new_policy->max); | |
1da177e4 | 2012 | |
d5b73cd8 | 2013 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2014 | |
d9a789c7 RW |
2015 | if (new_policy->min > policy->max || new_policy->max < policy->min) |
2016 | return -EINVAL; | |
9c9a43ed | 2017 | |
1da177e4 | 2018 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2019 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2020 | if (ret) |
d9a789c7 | 2021 | return ret; |
1da177e4 | 2022 | |
1da177e4 | 2023 | /* adjust if necessary - all reasons */ |
e041c683 | 2024 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2025 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
2026 | |
2027 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 2028 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2029 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 2030 | |
bb176f7d VK |
2031 | /* |
2032 | * verify the cpu speed can be set within this limit, which might be | |
2033 | * different to the first one | |
2034 | */ | |
3a3e9e06 | 2035 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2036 | if (ret) |
d9a789c7 | 2037 | return ret; |
1da177e4 LT |
2038 | |
2039 | /* notification of the new policy */ | |
e041c683 | 2040 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2041 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2042 | |
3a3e9e06 VK |
2043 | policy->min = new_policy->min; |
2044 | policy->max = new_policy->max; | |
1da177e4 | 2045 | |
2d06d8c4 | 2046 | pr_debug("new min and max freqs are %u - %u kHz\n", |
3a3e9e06 | 2047 | policy->min, policy->max); |
1da177e4 | 2048 | |
1c3d85dd | 2049 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2050 | policy->policy = new_policy->policy; |
2d06d8c4 | 2051 | pr_debug("setting range\n"); |
d9a789c7 RW |
2052 | return cpufreq_driver->setpolicy(new_policy); |
2053 | } | |
1da177e4 | 2054 | |
d9a789c7 RW |
2055 | if (new_policy->governor == policy->governor) |
2056 | goto out; | |
7bd353a9 | 2057 | |
d9a789c7 RW |
2058 | pr_debug("governor switch\n"); |
2059 | ||
2060 | /* save old, working values */ | |
2061 | old_gov = policy->governor; | |
2062 | /* end old governor */ | |
2063 | if (old_gov) { | |
2064 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
2065 | up_write(&policy->rwsem); | |
2066 | __cpufreq_governor(policy,CPUFREQ_GOV_POLICY_EXIT); | |
2067 | down_write(&policy->rwsem); | |
1da177e4 LT |
2068 | } |
2069 | ||
d9a789c7 RW |
2070 | /* start new governor */ |
2071 | policy->governor = new_policy->governor; | |
2072 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
2073 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) | |
2074 | goto out; | |
2075 | ||
2076 | up_write(&policy->rwsem); | |
2077 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); | |
2078 | down_write(&policy->rwsem); | |
2079 | } | |
2080 | ||
2081 | /* new governor failed, so re-start old one */ | |
2082 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2083 | if (old_gov) { | |
2084 | policy->governor = old_gov; | |
2085 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); | |
2086 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
2087 | } | |
2088 | ||
2089 | return -EINVAL; | |
2090 | ||
2091 | out: | |
2092 | pr_debug("governor: change or update limits\n"); | |
2093 | return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1da177e4 LT |
2094 | } |
2095 | ||
1da177e4 LT |
2096 | /** |
2097 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2098 | * @cpu: CPU which shall be re-evaluated | |
2099 | * | |
25985edc | 2100 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2101 | * at different times. |
2102 | */ | |
2103 | int cpufreq_update_policy(unsigned int cpu) | |
2104 | { | |
3a3e9e06 VK |
2105 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2106 | struct cpufreq_policy new_policy; | |
f1829e4a | 2107 | int ret; |
1da177e4 | 2108 | |
3a3e9e06 | 2109 | if (!policy) { |
f1829e4a JL |
2110 | ret = -ENODEV; |
2111 | goto no_policy; | |
2112 | } | |
1da177e4 | 2113 | |
ad7722da | 2114 | down_write(&policy->rwsem); |
1da177e4 | 2115 | |
2d06d8c4 | 2116 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2117 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2118 | new_policy.min = policy->user_policy.min; |
2119 | new_policy.max = policy->user_policy.max; | |
2120 | new_policy.policy = policy->user_policy.policy; | |
2121 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 2122 | |
bb176f7d VK |
2123 | /* |
2124 | * BIOS might change freq behind our back | |
2125 | * -> ask driver for current freq and notify governors about a change | |
2126 | */ | |
1c3d85dd | 2127 | if (cpufreq_driver->get) { |
3a3e9e06 | 2128 | new_policy.cur = cpufreq_driver->get(cpu); |
bd0fa9bb VK |
2129 | if (WARN_ON(!new_policy.cur)) { |
2130 | ret = -EIO; | |
2131 | goto no_policy; | |
2132 | } | |
2133 | ||
3a3e9e06 | 2134 | if (!policy->cur) { |
2d06d8c4 | 2135 | pr_debug("Driver did not initialize current freq"); |
3a3e9e06 | 2136 | policy->cur = new_policy.cur; |
a85f7bd3 | 2137 | } else { |
9c0ebcf7 | 2138 | if (policy->cur != new_policy.cur && has_target()) |
3a3e9e06 VK |
2139 | cpufreq_out_of_sync(cpu, policy->cur, |
2140 | new_policy.cur); | |
a85f7bd3 | 2141 | } |
0961dd0d TR |
2142 | } |
2143 | ||
037ce839 | 2144 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2145 | |
ad7722da | 2146 | up_write(&policy->rwsem); |
5a01f2e8 | 2147 | |
3a3e9e06 | 2148 | cpufreq_cpu_put(policy); |
f1829e4a | 2149 | no_policy: |
1da177e4 LT |
2150 | return ret; |
2151 | } | |
2152 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2153 | ||
2760984f | 2154 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2155 | unsigned long action, void *hcpu) |
2156 | { | |
2157 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2158 | struct device *dev; |
5302c3fb | 2159 | bool frozen = false; |
c32b6b8e | 2160 | |
8a25a2fd KS |
2161 | dev = get_cpu_device(cpu); |
2162 | if (dev) { | |
5302c3fb | 2163 | |
d4faadd5 RW |
2164 | if (action & CPU_TASKS_FROZEN) |
2165 | frozen = true; | |
2166 | ||
5302c3fb | 2167 | switch (action & ~CPU_TASKS_FROZEN) { |
c32b6b8e | 2168 | case CPU_ONLINE: |
5302c3fb | 2169 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e | 2170 | break; |
5302c3fb | 2171 | |
c32b6b8e | 2172 | case CPU_DOWN_PREPARE: |
cedb70af | 2173 | __cpufreq_remove_dev_prepare(dev, NULL, frozen); |
1aee40ac SB |
2174 | break; |
2175 | ||
2176 | case CPU_POST_DEAD: | |
cedb70af | 2177 | __cpufreq_remove_dev_finish(dev, NULL, frozen); |
c32b6b8e | 2178 | break; |
5302c3fb | 2179 | |
5a01f2e8 | 2180 | case CPU_DOWN_FAILED: |
5302c3fb | 2181 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2182 | break; |
2183 | } | |
2184 | } | |
2185 | return NOTIFY_OK; | |
2186 | } | |
2187 | ||
9c36f746 | 2188 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2189 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2190 | }; |
1da177e4 | 2191 | |
6f19efc0 LM |
2192 | /********************************************************************* |
2193 | * BOOST * | |
2194 | *********************************************************************/ | |
2195 | static int cpufreq_boost_set_sw(int state) | |
2196 | { | |
2197 | struct cpufreq_frequency_table *freq_table; | |
2198 | struct cpufreq_policy *policy; | |
2199 | int ret = -EINVAL; | |
2200 | ||
2201 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
2202 | freq_table = cpufreq_frequency_get_table(policy->cpu); | |
2203 | if (freq_table) { | |
2204 | ret = cpufreq_frequency_table_cpuinfo(policy, | |
2205 | freq_table); | |
2206 | if (ret) { | |
2207 | pr_err("%s: Policy frequency update failed\n", | |
2208 | __func__); | |
2209 | break; | |
2210 | } | |
2211 | policy->user_policy.max = policy->max; | |
2212 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
2213 | } | |
2214 | } | |
2215 | ||
2216 | return ret; | |
2217 | } | |
2218 | ||
2219 | int cpufreq_boost_trigger_state(int state) | |
2220 | { | |
2221 | unsigned long flags; | |
2222 | int ret = 0; | |
2223 | ||
2224 | if (cpufreq_driver->boost_enabled == state) | |
2225 | return 0; | |
2226 | ||
2227 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2228 | cpufreq_driver->boost_enabled = state; | |
2229 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2230 | ||
2231 | ret = cpufreq_driver->set_boost(state); | |
2232 | if (ret) { | |
2233 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2234 | cpufreq_driver->boost_enabled = !state; | |
2235 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2236 | ||
2237 | pr_err("%s: Cannot %s BOOST\n", __func__, | |
2238 | state ? "enable" : "disable"); | |
2239 | } | |
2240 | ||
2241 | return ret; | |
2242 | } | |
2243 | ||
2244 | int cpufreq_boost_supported(void) | |
2245 | { | |
2246 | if (likely(cpufreq_driver)) | |
2247 | return cpufreq_driver->boost_supported; | |
2248 | ||
2249 | return 0; | |
2250 | } | |
2251 | EXPORT_SYMBOL_GPL(cpufreq_boost_supported); | |
2252 | ||
2253 | int cpufreq_boost_enabled(void) | |
2254 | { | |
2255 | return cpufreq_driver->boost_enabled; | |
2256 | } | |
2257 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2258 | ||
1da177e4 LT |
2259 | /********************************************************************* |
2260 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2261 | *********************************************************************/ | |
2262 | ||
2263 | /** | |
2264 | * cpufreq_register_driver - register a CPU Frequency driver | |
2265 | * @driver_data: A struct cpufreq_driver containing the values# | |
2266 | * submitted by the CPU Frequency driver. | |
2267 | * | |
bb176f7d | 2268 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2269 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2270 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2271 | * |
2272 | */ | |
221dee28 | 2273 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2274 | { |
2275 | unsigned long flags; | |
2276 | int ret; | |
2277 | ||
a7b422cd KRW |
2278 | if (cpufreq_disabled()) |
2279 | return -ENODEV; | |
2280 | ||
1da177e4 | 2281 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 VK |
2282 | !(driver_data->setpolicy || driver_data->target_index || |
2283 | driver_data->target)) | |
1da177e4 LT |
2284 | return -EINVAL; |
2285 | ||
2d06d8c4 | 2286 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2287 | |
2288 | if (driver_data->setpolicy) | |
2289 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2290 | ||
0d1857a1 | 2291 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2292 | if (cpufreq_driver) { |
0d1857a1 | 2293 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2294 | return -EEXIST; |
1da177e4 | 2295 | } |
1c3d85dd | 2296 | cpufreq_driver = driver_data; |
0d1857a1 | 2297 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2298 | |
6f19efc0 LM |
2299 | if (cpufreq_boost_supported()) { |
2300 | /* | |
2301 | * Check if driver provides function to enable boost - | |
2302 | * if not, use cpufreq_boost_set_sw as default | |
2303 | */ | |
2304 | if (!cpufreq_driver->set_boost) | |
2305 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; | |
2306 | ||
2307 | ret = cpufreq_sysfs_create_file(&boost.attr); | |
2308 | if (ret) { | |
2309 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
2310 | __func__); | |
2311 | goto err_null_driver; | |
2312 | } | |
2313 | } | |
2314 | ||
8a25a2fd | 2315 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2316 | if (ret) |
6f19efc0 | 2317 | goto err_boost_unreg; |
1da177e4 | 2318 | |
1c3d85dd | 2319 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2320 | int i; |
2321 | ret = -ENODEV; | |
2322 | ||
2323 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2324 | for (i = 0; i < nr_cpu_ids; i++) |
2325 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2326 | ret = 0; |
7a6aedfa MT |
2327 | break; |
2328 | } | |
1da177e4 LT |
2329 | |
2330 | /* if all ->init() calls failed, unregister */ | |
2331 | if (ret) { | |
2d06d8c4 | 2332 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2333 | driver_data->name); |
8a25a2fd | 2334 | goto err_if_unreg; |
1da177e4 LT |
2335 | } |
2336 | } | |
2337 | ||
8f5bc2ab | 2338 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2339 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2340 | |
8f5bc2ab | 2341 | return 0; |
8a25a2fd KS |
2342 | err_if_unreg: |
2343 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 LM |
2344 | err_boost_unreg: |
2345 | if (cpufreq_boost_supported()) | |
2346 | cpufreq_sysfs_remove_file(&boost.attr); | |
8f5bc2ab | 2347 | err_null_driver: |
0d1857a1 | 2348 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2349 | cpufreq_driver = NULL; |
0d1857a1 | 2350 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2351 | return ret; |
1da177e4 LT |
2352 | } |
2353 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2354 | ||
1da177e4 LT |
2355 | /** |
2356 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2357 | * | |
bb176f7d | 2358 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2359 | * the right to do so, i.e. if you have succeeded in initialising before! |
2360 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2361 | * currently not initialised. | |
2362 | */ | |
221dee28 | 2363 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2364 | { |
2365 | unsigned long flags; | |
2366 | ||
1c3d85dd | 2367 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2368 | return -EINVAL; |
1da177e4 | 2369 | |
2d06d8c4 | 2370 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2371 | |
8a25a2fd | 2372 | subsys_interface_unregister(&cpufreq_interface); |
6f19efc0 LM |
2373 | if (cpufreq_boost_supported()) |
2374 | cpufreq_sysfs_remove_file(&boost.attr); | |
2375 | ||
65edc68c | 2376 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2377 | |
6eed9404 | 2378 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2379 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2380 | |
1c3d85dd | 2381 | cpufreq_driver = NULL; |
6eed9404 | 2382 | |
0d1857a1 | 2383 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2384 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2385 | |
2386 | return 0; | |
2387 | } | |
2388 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2389 | |
2390 | static int __init cpufreq_core_init(void) | |
2391 | { | |
a7b422cd KRW |
2392 | if (cpufreq_disabled()) |
2393 | return -ENODEV; | |
2394 | ||
2361be23 | 2395 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 TR |
2396 | BUG_ON(!cpufreq_global_kobject); |
2397 | ||
5a01f2e8 VP |
2398 | return 0; |
2399 | } | |
5a01f2e8 | 2400 | core_initcall(cpufreq_core_init); |