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; | |
1da177e4 | 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)) { | |
e837f9b5 JP |
185 | pr_err("%s: No %s associated to cpu: %d\n", |
186 | __func__, policy ? "clk" : "policy", cpu); | |
652ed95d VK |
187 | return 0; |
188 | } | |
189 | ||
190 | return clk_get_rate(policy->clk) / 1000; | |
191 | } | |
192 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
193 | ||
e0b3165b VK |
194 | /* Only for cpufreq core internal use */ |
195 | struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) | |
196 | { | |
197 | return per_cpu(cpufreq_cpu_data, cpu); | |
198 | } | |
199 | ||
6eed9404 | 200 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 201 | { |
6eed9404 | 202 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
203 | unsigned long flags; |
204 | ||
6eed9404 VK |
205 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
206 | return NULL; | |
207 | ||
208 | if (!down_read_trylock(&cpufreq_rwsem)) | |
209 | return NULL; | |
1da177e4 LT |
210 | |
211 | /* get the cpufreq driver */ | |
1c3d85dd | 212 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 213 | |
6eed9404 VK |
214 | if (cpufreq_driver) { |
215 | /* get the CPU */ | |
216 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
217 | if (policy) | |
218 | kobject_get(&policy->kobj); | |
219 | } | |
1da177e4 | 220 | |
6eed9404 | 221 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 222 | |
3a3e9e06 | 223 | if (!policy) |
6eed9404 | 224 | up_read(&cpufreq_rwsem); |
1da177e4 | 225 | |
3a3e9e06 | 226 | return policy; |
a9144436 | 227 | } |
1da177e4 LT |
228 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
229 | ||
3a3e9e06 | 230 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 231 | { |
d5aaffa9 DB |
232 | if (cpufreq_disabled()) |
233 | return; | |
234 | ||
6eed9404 VK |
235 | kobject_put(&policy->kobj); |
236 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
237 | } |
238 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
239 | ||
1da177e4 LT |
240 | /********************************************************************* |
241 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
242 | *********************************************************************/ | |
243 | ||
244 | /** | |
245 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
246 | * | |
247 | * This function alters the system "loops_per_jiffy" for the clock | |
248 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 249 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
250 | * per-CPU loops_per_jiffy value wherever possible. |
251 | */ | |
252 | #ifndef CONFIG_SMP | |
253 | static unsigned long l_p_j_ref; | |
bb176f7d | 254 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 255 | |
858119e1 | 256 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
257 | { |
258 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
259 | return; | |
260 | ||
261 | if (!l_p_j_ref_freq) { | |
262 | l_p_j_ref = loops_per_jiffy; | |
263 | l_p_j_ref_freq = ci->old; | |
e837f9b5 JP |
264 | pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", |
265 | l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 | 266 | } |
0b443ead | 267 | if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { |
e08f5f5b GS |
268 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
269 | ci->new); | |
e837f9b5 JP |
270 | pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", |
271 | loops_per_jiffy, ci->new); | |
1da177e4 LT |
272 | } |
273 | } | |
274 | #else | |
e08f5f5b GS |
275 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
276 | { | |
277 | return; | |
278 | } | |
1da177e4 LT |
279 | #endif |
280 | ||
0956df9c | 281 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 282 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
283 | { |
284 | BUG_ON(irqs_disabled()); | |
285 | ||
d5aaffa9 DB |
286 | if (cpufreq_disabled()) |
287 | return; | |
288 | ||
1c3d85dd | 289 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 290 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e837f9b5 | 291 | state, freqs->new); |
1da177e4 | 292 | |
1da177e4 | 293 | switch (state) { |
e4472cb3 | 294 | |
1da177e4 | 295 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 296 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
297 | * which is not equal to what the cpufreq core thinks is |
298 | * "old frequency". | |
1da177e4 | 299 | */ |
1c3d85dd | 300 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
301 | if ((policy) && (policy->cpu == freqs->cpu) && |
302 | (policy->cur) && (policy->cur != freqs->old)) { | |
e837f9b5 JP |
303 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", |
304 | freqs->old, policy->cur); | |
e4472cb3 | 305 | freqs->old = policy->cur; |
1da177e4 LT |
306 | } |
307 | } | |
b4dfdbb3 | 308 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 309 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
310 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
311 | break; | |
e4472cb3 | 312 | |
1da177e4 LT |
313 | case CPUFREQ_POSTCHANGE: |
314 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
e837f9b5 JP |
315 | pr_debug("FREQ: %lu - CPU: %lu\n", |
316 | (unsigned long)freqs->new, (unsigned long)freqs->cpu); | |
25e41933 | 317 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 318 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 319 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
320 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
321 | policy->cur = freqs->new; | |
1da177e4 LT |
322 | break; |
323 | } | |
1da177e4 | 324 | } |
bb176f7d | 325 | |
b43a7ffb VK |
326 | /** |
327 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
328 | * on frequency transition. | |
329 | * | |
330 | * This function calls the transition notifiers and the "adjust_jiffies" | |
331 | * function. It is called twice on all CPU frequency changes that have | |
332 | * external effects. | |
333 | */ | |
334 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
335 | struct cpufreq_freqs *freqs, unsigned int state) | |
336 | { | |
337 | for_each_cpu(freqs->cpu, policy->cpus) | |
338 | __cpufreq_notify_transition(policy, freqs, state); | |
339 | } | |
1da177e4 LT |
340 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
341 | ||
f7ba3b41 VK |
342 | /* Do post notifications when there are chances that transition has failed */ |
343 | void cpufreq_notify_post_transition(struct cpufreq_policy *policy, | |
344 | struct cpufreq_freqs *freqs, int transition_failed) | |
345 | { | |
346 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
347 | if (!transition_failed) | |
348 | return; | |
349 | ||
350 | swap(freqs->old, freqs->new); | |
351 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
352 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
353 | } | |
354 | EXPORT_SYMBOL_GPL(cpufreq_notify_post_transition); | |
355 | ||
1da177e4 | 356 | |
1da177e4 LT |
357 | /********************************************************************* |
358 | * SYSFS INTERFACE * | |
359 | *********************************************************************/ | |
8a5c74a1 | 360 | static ssize_t show_boost(struct kobject *kobj, |
6f19efc0 LM |
361 | struct attribute *attr, char *buf) |
362 | { | |
363 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
364 | } | |
365 | ||
366 | static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, | |
367 | const char *buf, size_t count) | |
368 | { | |
369 | int ret, enable; | |
370 | ||
371 | ret = sscanf(buf, "%d", &enable); | |
372 | if (ret != 1 || enable < 0 || enable > 1) | |
373 | return -EINVAL; | |
374 | ||
375 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
376 | pr_err("%s: Cannot %s BOOST!\n", |
377 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
378 | return -EINVAL; |
379 | } | |
380 | ||
e837f9b5 JP |
381 | pr_debug("%s: cpufreq BOOST %s\n", |
382 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
383 | |
384 | return count; | |
385 | } | |
386 | define_one_global_rw(boost); | |
1da177e4 | 387 | |
3bcb09a3 JF |
388 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
389 | { | |
390 | struct cpufreq_governor *t; | |
391 | ||
392 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 393 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
394 | return t; |
395 | ||
396 | return NULL; | |
397 | } | |
398 | ||
1da177e4 LT |
399 | /** |
400 | * cpufreq_parse_governor - parse a governor string | |
401 | */ | |
905d77cd | 402 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
403 | struct cpufreq_governor **governor) |
404 | { | |
3bcb09a3 | 405 | int err = -EINVAL; |
1c3d85dd RW |
406 | |
407 | if (!cpufreq_driver) | |
3bcb09a3 JF |
408 | goto out; |
409 | ||
1c3d85dd | 410 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
411 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
412 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 413 | err = 0; |
e08f5f5b GS |
414 | } else if (!strnicmp(str_governor, "powersave", |
415 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 416 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 417 | err = 0; |
1da177e4 | 418 | } |
9c0ebcf7 | 419 | } else if (has_target()) { |
1da177e4 | 420 | struct cpufreq_governor *t; |
3bcb09a3 | 421 | |
3fc54d37 | 422 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
423 | |
424 | t = __find_governor(str_governor); | |
425 | ||
ea714970 | 426 | if (t == NULL) { |
1a8e1463 | 427 | int ret; |
ea714970 | 428 | |
1a8e1463 KC |
429 | mutex_unlock(&cpufreq_governor_mutex); |
430 | ret = request_module("cpufreq_%s", str_governor); | |
431 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 432 | |
1a8e1463 KC |
433 | if (ret == 0) |
434 | t = __find_governor(str_governor); | |
ea714970 JF |
435 | } |
436 | ||
3bcb09a3 JF |
437 | if (t != NULL) { |
438 | *governor = t; | |
439 | err = 0; | |
1da177e4 | 440 | } |
3bcb09a3 | 441 | |
3fc54d37 | 442 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 443 | } |
29464f28 | 444 | out: |
3bcb09a3 | 445 | return err; |
1da177e4 | 446 | } |
1da177e4 | 447 | |
1da177e4 | 448 | /** |
e08f5f5b GS |
449 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
450 | * print out cpufreq information | |
1da177e4 LT |
451 | * |
452 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
453 | * "unsigned int". | |
454 | */ | |
455 | ||
32ee8c3e DJ |
456 | #define show_one(file_name, object) \ |
457 | static ssize_t show_##file_name \ | |
905d77cd | 458 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 459 | { \ |
29464f28 | 460 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
461 | } |
462 | ||
463 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
464 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 465 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
466 | show_one(scaling_min_freq, min); |
467 | show_one(scaling_max_freq, max); | |
468 | show_one(scaling_cur_freq, cur); | |
469 | ||
037ce839 | 470 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 471 | struct cpufreq_policy *new_policy); |
7970e08b | 472 | |
1da177e4 LT |
473 | /** |
474 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
475 | */ | |
476 | #define store_one(file_name, object) \ | |
477 | static ssize_t store_##file_name \ | |
905d77cd | 478 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 479 | { \ |
5136fa56 | 480 | int ret; \ |
1da177e4 LT |
481 | struct cpufreq_policy new_policy; \ |
482 | \ | |
483 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
484 | if (ret) \ | |
485 | return -EINVAL; \ | |
486 | \ | |
29464f28 | 487 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
488 | if (ret != 1) \ |
489 | return -EINVAL; \ | |
490 | \ | |
037ce839 | 491 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 492 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
493 | \ |
494 | return ret ? ret : count; \ | |
495 | } | |
496 | ||
29464f28 DJ |
497 | store_one(scaling_min_freq, min); |
498 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
499 | |
500 | /** | |
501 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
502 | */ | |
905d77cd DJ |
503 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
504 | char *buf) | |
1da177e4 | 505 | { |
5a01f2e8 | 506 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
507 | if (!cur_freq) |
508 | return sprintf(buf, "<unknown>"); | |
509 | return sprintf(buf, "%u\n", cur_freq); | |
510 | } | |
511 | ||
1da177e4 LT |
512 | /** |
513 | * show_scaling_governor - show the current policy for the specified CPU | |
514 | */ | |
905d77cd | 515 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 516 | { |
29464f28 | 517 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
518 | return sprintf(buf, "powersave\n"); |
519 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
520 | return sprintf(buf, "performance\n"); | |
521 | else if (policy->governor) | |
4b972f0b | 522 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 523 | policy->governor->name); |
1da177e4 LT |
524 | return -EINVAL; |
525 | } | |
526 | ||
1da177e4 LT |
527 | /** |
528 | * store_scaling_governor - store policy for the specified CPU | |
529 | */ | |
905d77cd DJ |
530 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
531 | const char *buf, size_t count) | |
1da177e4 | 532 | { |
5136fa56 | 533 | int ret; |
1da177e4 LT |
534 | char str_governor[16]; |
535 | struct cpufreq_policy new_policy; | |
536 | ||
537 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
538 | if (ret) | |
539 | return ret; | |
540 | ||
29464f28 | 541 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
542 | if (ret != 1) |
543 | return -EINVAL; | |
544 | ||
e08f5f5b GS |
545 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
546 | &new_policy.governor)) | |
1da177e4 LT |
547 | return -EINVAL; |
548 | ||
037ce839 | 549 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
550 | |
551 | policy->user_policy.policy = policy->policy; | |
552 | policy->user_policy.governor = policy->governor; | |
7970e08b | 553 | |
e08f5f5b GS |
554 | if (ret) |
555 | return ret; | |
556 | else | |
557 | return count; | |
1da177e4 LT |
558 | } |
559 | ||
560 | /** | |
561 | * show_scaling_driver - show the cpufreq driver currently loaded | |
562 | */ | |
905d77cd | 563 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 564 | { |
1c3d85dd | 565 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
566 | } |
567 | ||
568 | /** | |
569 | * show_scaling_available_governors - show the available CPUfreq governors | |
570 | */ | |
905d77cd DJ |
571 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
572 | char *buf) | |
1da177e4 LT |
573 | { |
574 | ssize_t i = 0; | |
575 | struct cpufreq_governor *t; | |
576 | ||
9c0ebcf7 | 577 | if (!has_target()) { |
1da177e4 LT |
578 | i += sprintf(buf, "performance powersave"); |
579 | goto out; | |
580 | } | |
581 | ||
582 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
583 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
584 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 585 | goto out; |
4b972f0b | 586 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 587 | } |
7d5e350f | 588 | out: |
1da177e4 LT |
589 | i += sprintf(&buf[i], "\n"); |
590 | return i; | |
591 | } | |
e8628dd0 | 592 | |
f4fd3797 | 593 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
594 | { |
595 | ssize_t i = 0; | |
596 | unsigned int cpu; | |
597 | ||
835481d9 | 598 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
599 | if (i) |
600 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
601 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
602 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 603 | break; |
1da177e4 LT |
604 | } |
605 | i += sprintf(&buf[i], "\n"); | |
606 | return i; | |
607 | } | |
f4fd3797 | 608 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 609 | |
e8628dd0 DW |
610 | /** |
611 | * show_related_cpus - show the CPUs affected by each transition even if | |
612 | * hw coordination is in use | |
613 | */ | |
614 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
615 | { | |
f4fd3797 | 616 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
617 | } |
618 | ||
619 | /** | |
620 | * show_affected_cpus - show the CPUs affected by each transition | |
621 | */ | |
622 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
623 | { | |
f4fd3797 | 624 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
625 | } |
626 | ||
9e76988e | 627 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 628 | const char *buf, size_t count) |
9e76988e VP |
629 | { |
630 | unsigned int freq = 0; | |
631 | unsigned int ret; | |
632 | ||
879000f9 | 633 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
634 | return -EINVAL; |
635 | ||
636 | ret = sscanf(buf, "%u", &freq); | |
637 | if (ret != 1) | |
638 | return -EINVAL; | |
639 | ||
640 | policy->governor->store_setspeed(policy, freq); | |
641 | ||
642 | return count; | |
643 | } | |
644 | ||
645 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
646 | { | |
879000f9 | 647 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
648 | return sprintf(buf, "<unsupported>\n"); |
649 | ||
650 | return policy->governor->show_setspeed(policy, buf); | |
651 | } | |
1da177e4 | 652 | |
e2f74f35 | 653 | /** |
8bf1ac72 | 654 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
655 | */ |
656 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
657 | { | |
658 | unsigned int limit; | |
659 | int ret; | |
1c3d85dd RW |
660 | if (cpufreq_driver->bios_limit) { |
661 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
662 | if (!ret) |
663 | return sprintf(buf, "%u\n", limit); | |
664 | } | |
665 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
666 | } | |
667 | ||
6dad2a29 BP |
668 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
669 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
670 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
671 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
672 | cpufreq_freq_attr_ro(scaling_available_governors); | |
673 | cpufreq_freq_attr_ro(scaling_driver); | |
674 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
675 | cpufreq_freq_attr_ro(bios_limit); | |
676 | cpufreq_freq_attr_ro(related_cpus); | |
677 | cpufreq_freq_attr_ro(affected_cpus); | |
678 | cpufreq_freq_attr_rw(scaling_min_freq); | |
679 | cpufreq_freq_attr_rw(scaling_max_freq); | |
680 | cpufreq_freq_attr_rw(scaling_governor); | |
681 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 682 | |
905d77cd | 683 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
684 | &cpuinfo_min_freq.attr, |
685 | &cpuinfo_max_freq.attr, | |
ed129784 | 686 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
687 | &scaling_min_freq.attr, |
688 | &scaling_max_freq.attr, | |
689 | &affected_cpus.attr, | |
e8628dd0 | 690 | &related_cpus.attr, |
1da177e4 LT |
691 | &scaling_governor.attr, |
692 | &scaling_driver.attr, | |
693 | &scaling_available_governors.attr, | |
9e76988e | 694 | &scaling_setspeed.attr, |
1da177e4 LT |
695 | NULL |
696 | }; | |
697 | ||
29464f28 DJ |
698 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
699 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 700 | |
29464f28 | 701 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 702 | { |
905d77cd DJ |
703 | struct cpufreq_policy *policy = to_policy(kobj); |
704 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 705 | ssize_t ret; |
6eed9404 VK |
706 | |
707 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 708 | return -EINVAL; |
5a01f2e8 | 709 | |
ad7722da | 710 | down_read(&policy->rwsem); |
5a01f2e8 | 711 | |
e08f5f5b GS |
712 | if (fattr->show) |
713 | ret = fattr->show(policy, buf); | |
714 | else | |
715 | ret = -EIO; | |
716 | ||
ad7722da | 717 | up_read(&policy->rwsem); |
6eed9404 | 718 | up_read(&cpufreq_rwsem); |
1b750e3b | 719 | |
1da177e4 LT |
720 | return ret; |
721 | } | |
722 | ||
905d77cd DJ |
723 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
724 | const char *buf, size_t count) | |
1da177e4 | 725 | { |
905d77cd DJ |
726 | struct cpufreq_policy *policy = to_policy(kobj); |
727 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 728 | ssize_t ret = -EINVAL; |
6eed9404 | 729 | |
4f750c93 SB |
730 | get_online_cpus(); |
731 | ||
732 | if (!cpu_online(policy->cpu)) | |
733 | goto unlock; | |
734 | ||
6eed9404 | 735 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 736 | goto unlock; |
5a01f2e8 | 737 | |
ad7722da | 738 | down_write(&policy->rwsem); |
5a01f2e8 | 739 | |
e08f5f5b GS |
740 | if (fattr->store) |
741 | ret = fattr->store(policy, buf, count); | |
742 | else | |
743 | ret = -EIO; | |
744 | ||
ad7722da | 745 | up_write(&policy->rwsem); |
6eed9404 | 746 | |
6eed9404 | 747 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
748 | unlock: |
749 | put_online_cpus(); | |
750 | ||
1da177e4 LT |
751 | return ret; |
752 | } | |
753 | ||
905d77cd | 754 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 755 | { |
905d77cd | 756 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 757 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
758 | complete(&policy->kobj_unregister); |
759 | } | |
760 | ||
52cf25d0 | 761 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
762 | .show = show, |
763 | .store = store, | |
764 | }; | |
765 | ||
766 | static struct kobj_type ktype_cpufreq = { | |
767 | .sysfs_ops = &sysfs_ops, | |
768 | .default_attrs = default_attrs, | |
769 | .release = cpufreq_sysfs_release, | |
770 | }; | |
771 | ||
2361be23 VK |
772 | struct kobject *cpufreq_global_kobject; |
773 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
774 | ||
775 | static int cpufreq_global_kobject_usage; | |
776 | ||
777 | int cpufreq_get_global_kobject(void) | |
778 | { | |
779 | if (!cpufreq_global_kobject_usage++) | |
780 | return kobject_add(cpufreq_global_kobject, | |
781 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
782 | ||
783 | return 0; | |
784 | } | |
785 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
786 | ||
787 | void cpufreq_put_global_kobject(void) | |
788 | { | |
789 | if (!--cpufreq_global_kobject_usage) | |
790 | kobject_del(cpufreq_global_kobject); | |
791 | } | |
792 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
793 | ||
794 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
795 | { | |
796 | int ret = cpufreq_get_global_kobject(); | |
797 | ||
798 | if (!ret) { | |
799 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
800 | if (ret) | |
801 | cpufreq_put_global_kobject(); | |
802 | } | |
803 | ||
804 | return ret; | |
805 | } | |
806 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
807 | ||
808 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
809 | { | |
810 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
811 | cpufreq_put_global_kobject(); | |
812 | } | |
813 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
814 | ||
19d6f7ec | 815 | /* symlink affected CPUs */ |
308b60e7 | 816 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
817 | { |
818 | unsigned int j; | |
819 | int ret = 0; | |
820 | ||
821 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 822 | struct device *cpu_dev; |
19d6f7ec | 823 | |
308b60e7 | 824 | if (j == policy->cpu) |
19d6f7ec | 825 | continue; |
19d6f7ec | 826 | |
e8fdde10 | 827 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
828 | cpu_dev = get_cpu_device(j); |
829 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 830 | "cpufreq"); |
71c3461e RW |
831 | if (ret) |
832 | break; | |
19d6f7ec DJ |
833 | } |
834 | return ret; | |
835 | } | |
836 | ||
308b60e7 | 837 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 838 | struct device *dev) |
909a694e DJ |
839 | { |
840 | struct freq_attr **drv_attr; | |
909a694e | 841 | int ret = 0; |
909a694e DJ |
842 | |
843 | /* prepare interface data */ | |
844 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 845 | &dev->kobj, "cpufreq"); |
909a694e DJ |
846 | if (ret) |
847 | return ret; | |
848 | ||
849 | /* set up files for this cpu device */ | |
1c3d85dd | 850 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
851 | while ((drv_attr) && (*drv_attr)) { |
852 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
853 | if (ret) | |
1c3d85dd | 854 | goto err_out_kobj_put; |
909a694e DJ |
855 | drv_attr++; |
856 | } | |
1c3d85dd | 857 | if (cpufreq_driver->get) { |
909a694e DJ |
858 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
859 | if (ret) | |
1c3d85dd | 860 | goto err_out_kobj_put; |
909a694e | 861 | } |
9c0ebcf7 | 862 | if (has_target()) { |
909a694e DJ |
863 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
864 | if (ret) | |
1c3d85dd | 865 | goto err_out_kobj_put; |
909a694e | 866 | } |
1c3d85dd | 867 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
868 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
869 | if (ret) | |
1c3d85dd | 870 | goto err_out_kobj_put; |
e2f74f35 | 871 | } |
909a694e | 872 | |
308b60e7 | 873 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
874 | if (ret) |
875 | goto err_out_kobj_put; | |
876 | ||
e18f1682 SB |
877 | return ret; |
878 | ||
879 | err_out_kobj_put: | |
880 | kobject_put(&policy->kobj); | |
881 | wait_for_completion(&policy->kobj_unregister); | |
882 | return ret; | |
883 | } | |
884 | ||
885 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
886 | { | |
6e2c89d1 | 887 | struct cpufreq_governor *gov = NULL; |
e18f1682 SB |
888 | struct cpufreq_policy new_policy; |
889 | int ret = 0; | |
890 | ||
d5b73cd8 | 891 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 892 | |
6e2c89d1 | 893 | /* Update governor of new_policy to the governor used before hotplug */ |
894 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); | |
895 | if (gov) | |
896 | pr_debug("Restoring governor %s for cpu %d\n", | |
897 | policy->governor->name, policy->cpu); | |
898 | else | |
899 | gov = CPUFREQ_DEFAULT_GOVERNOR; | |
900 | ||
901 | new_policy.governor = gov; | |
902 | ||
a27a9ab7 JB |
903 | /* Use the default policy if its valid. */ |
904 | if (cpufreq_driver->setpolicy) | |
6e2c89d1 | 905 | cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); |
ecf7e461 DJ |
906 | |
907 | /* set default policy */ | |
037ce839 | 908 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 | 909 | if (ret) { |
2d06d8c4 | 910 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
911 | if (cpufreq_driver->exit) |
912 | cpufreq_driver->exit(policy); | |
ecf7e461 | 913 | } |
909a694e DJ |
914 | } |
915 | ||
fcf80582 | 916 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 | 917 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 918 | unsigned int cpu, struct device *dev) |
fcf80582 | 919 | { |
9c0ebcf7 | 920 | int ret = 0; |
fcf80582 VK |
921 | unsigned long flags; |
922 | ||
9c0ebcf7 | 923 | if (has_target()) { |
3de9bdeb VK |
924 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
925 | if (ret) { | |
926 | pr_err("%s: Failed to stop governor\n", __func__); | |
927 | return ret; | |
928 | } | |
929 | } | |
fcf80582 | 930 | |
ad7722da | 931 | down_write(&policy->rwsem); |
2eaa3e2d | 932 | |
0d1857a1 | 933 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 934 | |
fcf80582 VK |
935 | cpumask_set_cpu(cpu, policy->cpus); |
936 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 937 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 938 | |
ad7722da | 939 | up_write(&policy->rwsem); |
2eaa3e2d | 940 | |
9c0ebcf7 | 941 | if (has_target()) { |
3de9bdeb VK |
942 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
943 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
944 | pr_err("%s: Failed to start governor\n", __func__); | |
945 | return ret; | |
946 | } | |
820c6ca2 | 947 | } |
fcf80582 | 948 | |
42f921a6 | 949 | return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
fcf80582 VK |
950 | } |
951 | #endif | |
1da177e4 | 952 | |
8414809c SB |
953 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
954 | { | |
955 | struct cpufreq_policy *policy; | |
956 | unsigned long flags; | |
957 | ||
44871c9c | 958 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
959 | |
960 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
961 | ||
44871c9c | 962 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c | 963 | |
6e2c89d1 | 964 | policy->governor = NULL; |
965 | ||
8414809c SB |
966 | return policy; |
967 | } | |
968 | ||
e9698cc5 SB |
969 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
970 | { | |
971 | struct cpufreq_policy *policy; | |
972 | ||
973 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
974 | if (!policy) | |
975 | return NULL; | |
976 | ||
977 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
978 | goto err_free_policy; | |
979 | ||
980 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
981 | goto err_free_cpumask; | |
982 | ||
c88a1f8b | 983 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 984 | init_rwsem(&policy->rwsem); |
985 | ||
e9698cc5 SB |
986 | return policy; |
987 | ||
988 | err_free_cpumask: | |
989 | free_cpumask_var(policy->cpus); | |
990 | err_free_policy: | |
991 | kfree(policy); | |
992 | ||
993 | return NULL; | |
994 | } | |
995 | ||
42f921a6 VK |
996 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
997 | { | |
998 | struct kobject *kobj; | |
999 | struct completion *cmp; | |
1000 | ||
fcd7af91 VK |
1001 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1002 | CPUFREQ_REMOVE_POLICY, policy); | |
1003 | ||
42f921a6 VK |
1004 | down_read(&policy->rwsem); |
1005 | kobj = &policy->kobj; | |
1006 | cmp = &policy->kobj_unregister; | |
1007 | up_read(&policy->rwsem); | |
1008 | kobject_put(kobj); | |
1009 | ||
1010 | /* | |
1011 | * We need to make sure that the underlying kobj is | |
1012 | * actually not referenced anymore by anybody before we | |
1013 | * proceed with unloading. | |
1014 | */ | |
1015 | pr_debug("waiting for dropping of refcount\n"); | |
1016 | wait_for_completion(cmp); | |
1017 | pr_debug("wait complete\n"); | |
1018 | } | |
1019 | ||
e9698cc5 SB |
1020 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
1021 | { | |
1022 | free_cpumask_var(policy->related_cpus); | |
1023 | free_cpumask_var(policy->cpus); | |
1024 | kfree(policy); | |
1025 | } | |
1026 | ||
0d66b91e SB |
1027 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1028 | { | |
99ec899e | 1029 | if (WARN_ON(cpu == policy->cpu)) |
cb38ed5c SB |
1030 | return; |
1031 | ||
ad7722da | 1032 | down_write(&policy->rwsem); |
8efd5765 | 1033 | |
0d66b91e SB |
1034 | policy->last_cpu = policy->cpu; |
1035 | policy->cpu = cpu; | |
1036 | ||
ad7722da | 1037 | up_write(&policy->rwsem); |
8efd5765 | 1038 | |
0d66b91e SB |
1039 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1040 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1041 | } | |
1042 | ||
96bbbe4a | 1043 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1044 | { |
fcf80582 | 1045 | unsigned int j, cpu = dev->id; |
65922465 | 1046 | int ret = -ENOMEM; |
1da177e4 | 1047 | struct cpufreq_policy *policy; |
1da177e4 | 1048 | unsigned long flags; |
96bbbe4a | 1049 | bool recover_policy = cpufreq_suspended; |
90e41bac | 1050 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 1051 | struct cpufreq_policy *tpolicy; |
90e41bac | 1052 | #endif |
1da177e4 | 1053 | |
c32b6b8e AR |
1054 | if (cpu_is_offline(cpu)) |
1055 | return 0; | |
1056 | ||
2d06d8c4 | 1057 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
1058 | |
1059 | #ifdef CONFIG_SMP | |
1060 | /* check whether a different CPU already registered this | |
1061 | * CPU because it is in the same boat. */ | |
1062 | policy = cpufreq_cpu_get(cpu); | |
1063 | if (unlikely(policy)) { | |
8ff69732 | 1064 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1065 | return 0; |
1066 | } | |
5025d628 | 1067 | #endif |
fcf80582 | 1068 | |
6eed9404 VK |
1069 | if (!down_read_trylock(&cpufreq_rwsem)) |
1070 | return 0; | |
1071 | ||
fcf80582 VK |
1072 | #ifdef CONFIG_HOTPLUG_CPU |
1073 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1074 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1075 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1076 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1077 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
42f921a6 | 1078 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev); |
6eed9404 VK |
1079 | up_read(&cpufreq_rwsem); |
1080 | return ret; | |
2eaa3e2d | 1081 | } |
fcf80582 | 1082 | } |
0d1857a1 | 1083 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1084 | #endif |
1085 | ||
72368d12 RW |
1086 | /* |
1087 | * Restore the saved policy when doing light-weight init and fall back | |
1088 | * to the full init if that fails. | |
1089 | */ | |
96bbbe4a | 1090 | policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL; |
72368d12 | 1091 | if (!policy) { |
96bbbe4a | 1092 | recover_policy = false; |
8414809c | 1093 | policy = cpufreq_policy_alloc(); |
72368d12 RW |
1094 | if (!policy) |
1095 | goto nomem_out; | |
1096 | } | |
0d66b91e SB |
1097 | |
1098 | /* | |
1099 | * In the resume path, since we restore a saved policy, the assignment | |
1100 | * to policy->cpu is like an update of the existing policy, rather than | |
1101 | * the creation of a brand new one. So we need to perform this update | |
1102 | * by invoking update_policy_cpu(). | |
1103 | */ | |
96bbbe4a | 1104 | if (recover_policy && cpu != policy->cpu) |
0d66b91e SB |
1105 | update_policy_cpu(policy, cpu); |
1106 | else | |
1107 | policy->cpu = cpu; | |
1108 | ||
835481d9 | 1109 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1110 | |
1da177e4 | 1111 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1112 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1113 | |
1114 | /* call driver. From then on the cpufreq must be able | |
1115 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1116 | */ | |
1c3d85dd | 1117 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1118 | if (ret) { |
2d06d8c4 | 1119 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1120 | goto err_set_policy_cpu; |
1da177e4 | 1121 | } |
643ae6e8 | 1122 | |
5a7e56a5 VK |
1123 | /* related cpus should atleast have policy->cpus */ |
1124 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1125 | ||
1126 | /* | |
1127 | * affected cpus must always be the one, which are online. We aren't | |
1128 | * managing offline cpus here. | |
1129 | */ | |
1130 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1131 | ||
96bbbe4a | 1132 | if (!recover_policy) { |
5a7e56a5 VK |
1133 | policy->user_policy.min = policy->min; |
1134 | policy->user_policy.max = policy->max; | |
1135 | } | |
1136 | ||
4e97b631 | 1137 | down_write(&policy->rwsem); |
652ed95d VK |
1138 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1139 | for_each_cpu(j, policy->cpus) | |
1140 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1141 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1142 | ||
2ed99e39 | 1143 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
da60ce9f VK |
1144 | policy->cur = cpufreq_driver->get(policy->cpu); |
1145 | if (!policy->cur) { | |
1146 | pr_err("%s: ->get() failed\n", __func__); | |
1147 | goto err_get_freq; | |
1148 | } | |
1149 | } | |
1150 | ||
d3916691 VK |
1151 | /* |
1152 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1153 | * frequency table present with cpufreq core. In such cases CPU might be | |
1154 | * unstable if it has to run on that frequency for long duration of time | |
1155 | * and so its better to set it to a frequency which is specified in | |
1156 | * freq-table. This also makes cpufreq stats inconsistent as | |
1157 | * cpufreq-stats would fail to register because current frequency of CPU | |
1158 | * isn't found in freq-table. | |
1159 | * | |
1160 | * Because we don't want this change to effect boot process badly, we go | |
1161 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1162 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1163 | * is initialized to zero). | |
1164 | * | |
1165 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1166 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1167 | * equal to target-freq. | |
1168 | */ | |
1169 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1170 | && has_target()) { | |
1171 | /* Are we running at unknown frequency ? */ | |
1172 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1173 | if (ret == -EINVAL) { | |
1174 | /* Warn user and fix it */ | |
1175 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1176 | __func__, policy->cpu, policy->cur); | |
1177 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1178 | CPUFREQ_RELATION_L); | |
1179 | ||
1180 | /* | |
1181 | * Reaching here after boot in a few seconds may not | |
1182 | * mean that system will remain stable at "unknown" | |
1183 | * frequency for longer duration. Hence, a BUG_ON(). | |
1184 | */ | |
1185 | BUG_ON(ret); | |
1186 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1187 | __func__, policy->cpu, policy->cur); | |
1188 | } | |
1189 | } | |
1190 | ||
a1531acd TR |
1191 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1192 | CPUFREQ_START, policy); | |
1193 | ||
96bbbe4a | 1194 | if (!recover_policy) { |
308b60e7 | 1195 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1196 | if (ret) |
1197 | goto err_out_unregister; | |
fcd7af91 VK |
1198 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1199 | CPUFREQ_CREATE_POLICY, policy); | |
a82fab29 | 1200 | } |
8ff69732 | 1201 | |
9515f4d6 VK |
1202 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1203 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1204 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1205 | ||
e18f1682 SB |
1206 | cpufreq_init_policy(policy); |
1207 | ||
96bbbe4a | 1208 | if (!recover_policy) { |
08fd8c1c VK |
1209 | policy->user_policy.policy = policy->policy; |
1210 | policy->user_policy.governor = policy->governor; | |
1211 | } | |
4e97b631 | 1212 | up_write(&policy->rwsem); |
08fd8c1c | 1213 | |
038c5b3e | 1214 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1215 | up_read(&cpufreq_rwsem); |
1216 | ||
2d06d8c4 | 1217 | pr_debug("initialization complete\n"); |
87c32271 | 1218 | |
1da177e4 LT |
1219 | return 0; |
1220 | ||
1da177e4 | 1221 | err_out_unregister: |
652ed95d | 1222 | err_get_freq: |
0d1857a1 | 1223 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1224 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1225 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1226 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1227 | |
da60ce9f VK |
1228 | if (cpufreq_driver->exit) |
1229 | cpufreq_driver->exit(policy); | |
2eaa3e2d | 1230 | err_set_policy_cpu: |
96bbbe4a | 1231 | if (recover_policy) { |
72368d12 RW |
1232 | /* Do not leave stale fallback data behind. */ |
1233 | per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; | |
42f921a6 | 1234 | cpufreq_policy_put_kobj(policy); |
72368d12 | 1235 | } |
e9698cc5 | 1236 | cpufreq_policy_free(policy); |
42f921a6 | 1237 | |
1da177e4 | 1238 | nomem_out: |
6eed9404 VK |
1239 | up_read(&cpufreq_rwsem); |
1240 | ||
1da177e4 LT |
1241 | return ret; |
1242 | } | |
1243 | ||
a82fab29 SB |
1244 | /** |
1245 | * cpufreq_add_dev - add a CPU device | |
1246 | * | |
1247 | * Adds the cpufreq interface for a CPU device. | |
1248 | * | |
1249 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1250 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1251 | * mess up, but more thorough testing is needed. - Mathieu | |
1252 | */ | |
1253 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1254 | { | |
96bbbe4a | 1255 | return __cpufreq_add_dev(dev, sif); |
a82fab29 SB |
1256 | } |
1257 | ||
3a3e9e06 | 1258 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 1259 | unsigned int old_cpu) |
f9ba680d SB |
1260 | { |
1261 | struct device *cpu_dev; | |
f9ba680d SB |
1262 | int ret; |
1263 | ||
1264 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1265 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 | 1266 | |
f9ba680d | 1267 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1268 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d | 1269 | if (ret) { |
e837f9b5 | 1270 | pr_err("%s: Failed to move kobj: %d\n", __func__, ret); |
f9ba680d | 1271 | |
ad7722da | 1272 | down_write(&policy->rwsem); |
3a3e9e06 | 1273 | cpumask_set_cpu(old_cpu, policy->cpus); |
ad7722da | 1274 | up_write(&policy->rwsem); |
f9ba680d | 1275 | |
3a3e9e06 | 1276 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1277 | "cpufreq"); |
1278 | ||
1279 | return -EINVAL; | |
1280 | } | |
1281 | ||
1282 | return cpu_dev->id; | |
1283 | } | |
1284 | ||
cedb70af | 1285 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
96bbbe4a | 1286 | struct subsys_interface *sif) |
1da177e4 | 1287 | { |
f9ba680d | 1288 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1289 | int new_cpu, ret; |
1da177e4 | 1290 | unsigned long flags; |
3a3e9e06 | 1291 | struct cpufreq_policy *policy; |
1da177e4 | 1292 | |
b8eed8af | 1293 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1294 | |
0d1857a1 | 1295 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1296 | |
3a3e9e06 | 1297 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1298 | |
8414809c | 1299 | /* Save the policy somewhere when doing a light-weight tear-down */ |
96bbbe4a | 1300 | if (cpufreq_suspended) |
3a3e9e06 | 1301 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1302 | |
0d1857a1 | 1303 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1304 | |
3a3e9e06 | 1305 | if (!policy) { |
b8eed8af | 1306 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1307 | return -EINVAL; |
1308 | } | |
1da177e4 | 1309 | |
9c0ebcf7 | 1310 | if (has_target()) { |
3de9bdeb VK |
1311 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1312 | if (ret) { | |
1313 | pr_err("%s: Failed to stop governor\n", __func__); | |
1314 | return ret; | |
1315 | } | |
1316 | } | |
1da177e4 | 1317 | |
1c3d85dd | 1318 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1319 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1320 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 | 1321 | |
ad7722da | 1322 | down_read(&policy->rwsem); |
3a3e9e06 | 1323 | cpus = cpumask_weight(policy->cpus); |
ad7722da | 1324 | up_read(&policy->rwsem); |
084f3493 | 1325 | |
61173f25 | 1326 | if (cpu != policy->cpu) { |
6964d91d | 1327 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
73bf0fc2 | 1328 | } else if (cpus > 1) { |
42f921a6 | 1329 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu); |
f9ba680d | 1330 | if (new_cpu >= 0) { |
3a3e9e06 | 1331 | update_policy_cpu(policy, new_cpu); |
a82fab29 | 1332 | |
96bbbe4a | 1333 | if (!cpufreq_suspended) { |
75949c9a | 1334 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
e837f9b5 | 1335 | __func__, new_cpu, cpu); |
a82fab29 | 1336 | } |
1da177e4 LT |
1337 | } |
1338 | } | |
1da177e4 | 1339 | |
cedb70af SB |
1340 | return 0; |
1341 | } | |
1342 | ||
1343 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
96bbbe4a | 1344 | struct subsys_interface *sif) |
cedb70af SB |
1345 | { |
1346 | unsigned int cpu = dev->id, cpus; | |
1347 | int ret; | |
1348 | unsigned long flags; | |
1349 | struct cpufreq_policy *policy; | |
cedb70af SB |
1350 | |
1351 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1352 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1353 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1354 | ||
1355 | if (!policy) { | |
1356 | pr_debug("%s: No cpu_data found\n", __func__); | |
1357 | return -EINVAL; | |
1358 | } | |
1359 | ||
ad7722da | 1360 | down_write(&policy->rwsem); |
cedb70af | 1361 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1362 | |
1363 | if (cpus > 1) | |
1364 | cpumask_clear_cpu(cpu, policy->cpus); | |
ad7722da | 1365 | up_write(&policy->rwsem); |
cedb70af | 1366 | |
b8eed8af VK |
1367 | /* If cpu is last user of policy, free policy */ |
1368 | if (cpus == 1) { | |
9c0ebcf7 | 1369 | if (has_target()) { |
3de9bdeb VK |
1370 | ret = __cpufreq_governor(policy, |
1371 | CPUFREQ_GOV_POLICY_EXIT); | |
1372 | if (ret) { | |
1373 | pr_err("%s: Failed to exit governor\n", | |
e837f9b5 | 1374 | __func__); |
3de9bdeb VK |
1375 | return ret; |
1376 | } | |
edab2fbc | 1377 | } |
2a998599 | 1378 | |
96bbbe4a | 1379 | if (!cpufreq_suspended) |
42f921a6 | 1380 | cpufreq_policy_put_kobj(policy); |
7d26e2d5 | 1381 | |
8414809c SB |
1382 | /* |
1383 | * Perform the ->exit() even during light-weight tear-down, | |
1384 | * since this is a core component, and is essential for the | |
1385 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1386 | */ |
1c3d85dd | 1387 | if (cpufreq_driver->exit) |
3a3e9e06 | 1388 | cpufreq_driver->exit(policy); |
27ecddc2 | 1389 | |
9515f4d6 VK |
1390 | /* Remove policy from list of active policies */ |
1391 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1392 | list_del(&policy->policy_list); | |
1393 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1394 | ||
96bbbe4a | 1395 | if (!cpufreq_suspended) |
3a3e9e06 | 1396 | cpufreq_policy_free(policy); |
2a998599 | 1397 | } else { |
9c0ebcf7 | 1398 | if (has_target()) { |
3de9bdeb VK |
1399 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
1400 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
1401 | pr_err("%s: Failed to start governor\n", | |
e837f9b5 | 1402 | __func__); |
3de9bdeb VK |
1403 | return ret; |
1404 | } | |
2a998599 | 1405 | } |
27ecddc2 | 1406 | } |
1da177e4 | 1407 | |
474deff7 | 1408 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1409 | return 0; |
1410 | } | |
1411 | ||
cedb70af | 1412 | /** |
27a862e9 | 1413 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1414 | * |
1415 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1416 | */ |
8a25a2fd | 1417 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1418 | { |
8a25a2fd | 1419 | unsigned int cpu = dev->id; |
27a862e9 | 1420 | int ret; |
ec28297a VP |
1421 | |
1422 | if (cpu_is_offline(cpu)) | |
1423 | return 0; | |
1424 | ||
96bbbe4a | 1425 | ret = __cpufreq_remove_dev_prepare(dev, sif); |
27a862e9 VK |
1426 | |
1427 | if (!ret) | |
96bbbe4a | 1428 | ret = __cpufreq_remove_dev_finish(dev, sif); |
27a862e9 VK |
1429 | |
1430 | return ret; | |
5a01f2e8 VP |
1431 | } |
1432 | ||
65f27f38 | 1433 | static void handle_update(struct work_struct *work) |
1da177e4 | 1434 | { |
65f27f38 DH |
1435 | struct cpufreq_policy *policy = |
1436 | container_of(work, struct cpufreq_policy, update); | |
1437 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1438 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1439 | cpufreq_update_policy(cpu); |
1440 | } | |
1441 | ||
1442 | /** | |
bb176f7d VK |
1443 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1444 | * in deep trouble. | |
1da177e4 LT |
1445 | * @cpu: cpu number |
1446 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1447 | * @new_freq: CPU frequency the CPU actually runs at | |
1448 | * | |
29464f28 DJ |
1449 | * We adjust to current frequency first, and need to clean up later. |
1450 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1451 | */ |
e08f5f5b GS |
1452 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1453 | unsigned int new_freq) | |
1da177e4 | 1454 | { |
b43a7ffb | 1455 | struct cpufreq_policy *policy; |
1da177e4 | 1456 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1457 | unsigned long flags; |
1458 | ||
e837f9b5 JP |
1459 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
1460 | old_freq, new_freq); | |
1da177e4 | 1461 | |
1da177e4 LT |
1462 | freqs.old = old_freq; |
1463 | freqs.new = new_freq; | |
b43a7ffb VK |
1464 | |
1465 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1466 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1467 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1468 | ||
1469 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1470 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1471 | } |
1472 | ||
32ee8c3e | 1473 | /** |
4ab70df4 | 1474 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1475 | * @cpu: CPU number |
1476 | * | |
1477 | * This is the last known freq, without actually getting it from the driver. | |
1478 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1479 | */ | |
1480 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1481 | { | |
9e21ba8b | 1482 | struct cpufreq_policy *policy; |
e08f5f5b | 1483 | unsigned int ret_freq = 0; |
95235ca2 | 1484 | |
1c3d85dd RW |
1485 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1486 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1487 | |
1488 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1489 | if (policy) { |
e08f5f5b | 1490 | ret_freq = policy->cur; |
95235ca2 VP |
1491 | cpufreq_cpu_put(policy); |
1492 | } | |
1493 | ||
4d34a67d | 1494 | return ret_freq; |
95235ca2 VP |
1495 | } |
1496 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1497 | ||
3d737108 JB |
1498 | /** |
1499 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1500 | * @cpu: CPU number | |
1501 | * | |
1502 | * Just return the max possible frequency for a given CPU. | |
1503 | */ | |
1504 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1505 | { | |
1506 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1507 | unsigned int ret_freq = 0; | |
1508 | ||
1509 | if (policy) { | |
1510 | ret_freq = policy->max; | |
1511 | cpufreq_cpu_put(policy); | |
1512 | } | |
1513 | ||
1514 | return ret_freq; | |
1515 | } | |
1516 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1517 | ||
5a01f2e8 | 1518 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1519 | { |
7a6aedfa | 1520 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1521 | unsigned int ret_freq = 0; |
5800043b | 1522 | |
1c3d85dd | 1523 | if (!cpufreq_driver->get) |
4d34a67d | 1524 | return ret_freq; |
1da177e4 | 1525 | |
1c3d85dd | 1526 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1527 | |
e08f5f5b | 1528 | if (ret_freq && policy->cur && |
1c3d85dd | 1529 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1530 | /* verify no discrepancy between actual and |
1531 | saved value exists */ | |
1532 | if (unlikely(ret_freq != policy->cur)) { | |
1533 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1534 | schedule_work(&policy->update); |
1535 | } | |
1536 | } | |
1537 | ||
4d34a67d | 1538 | return ret_freq; |
5a01f2e8 | 1539 | } |
1da177e4 | 1540 | |
5a01f2e8 VP |
1541 | /** |
1542 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1543 | * @cpu: CPU number | |
1544 | * | |
1545 | * Get the CPU current (static) CPU frequency | |
1546 | */ | |
1547 | unsigned int cpufreq_get(unsigned int cpu) | |
1548 | { | |
999976e0 | 1549 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1550 | unsigned int ret_freq = 0; |
5a01f2e8 | 1551 | |
999976e0 AP |
1552 | if (policy) { |
1553 | down_read(&policy->rwsem); | |
1554 | ret_freq = __cpufreq_get(cpu); | |
1555 | up_read(&policy->rwsem); | |
5a01f2e8 | 1556 | |
999976e0 AP |
1557 | cpufreq_cpu_put(policy); |
1558 | } | |
6eed9404 | 1559 | |
4d34a67d | 1560 | return ret_freq; |
1da177e4 LT |
1561 | } |
1562 | EXPORT_SYMBOL(cpufreq_get); | |
1563 | ||
8a25a2fd KS |
1564 | static struct subsys_interface cpufreq_interface = { |
1565 | .name = "cpufreq", | |
1566 | .subsys = &cpu_subsys, | |
1567 | .add_dev = cpufreq_add_dev, | |
1568 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1569 | }; |
1570 | ||
e28867ea VK |
1571 | /* |
1572 | * In case platform wants some specific frequency to be configured | |
1573 | * during suspend.. | |
1574 | */ | |
1575 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1576 | { | |
1577 | int ret; | |
1578 | ||
1579 | if (!policy->suspend_freq) { | |
1580 | pr_err("%s: suspend_freq can't be zero\n", __func__); | |
1581 | return -EINVAL; | |
1582 | } | |
1583 | ||
1584 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1585 | policy->suspend_freq); | |
1586 | ||
1587 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1588 | CPUFREQ_RELATION_H); | |
1589 | if (ret) | |
1590 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1591 | __func__, policy->suspend_freq, ret); | |
1592 | ||
1593 | return ret; | |
1594 | } | |
1595 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1596 | ||
42d4dc3f | 1597 | /** |
2f0aea93 | 1598 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1599 | * |
2f0aea93 VK |
1600 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1601 | * as some platforms can't change frequency after this point in suspend cycle. | |
1602 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1603 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1604 | */ |
2f0aea93 | 1605 | void cpufreq_suspend(void) |
42d4dc3f | 1606 | { |
3a3e9e06 | 1607 | struct cpufreq_policy *policy; |
42d4dc3f | 1608 | |
2f0aea93 VK |
1609 | if (!cpufreq_driver) |
1610 | return; | |
42d4dc3f | 1611 | |
2f0aea93 VK |
1612 | if (!has_target()) |
1613 | return; | |
42d4dc3f | 1614 | |
2f0aea93 VK |
1615 | pr_debug("%s: Suspending Governors\n", __func__); |
1616 | ||
1617 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
1618 | if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) | |
1619 | pr_err("%s: Failed to stop governor for policy: %p\n", | |
1620 | __func__, policy); | |
1621 | else if (cpufreq_driver->suspend | |
1622 | && cpufreq_driver->suspend(policy)) | |
1623 | pr_err("%s: Failed to suspend driver: %p\n", __func__, | |
1624 | policy); | |
42d4dc3f BH |
1625 | } |
1626 | ||
2f0aea93 | 1627 | cpufreq_suspended = true; |
42d4dc3f BH |
1628 | } |
1629 | ||
1da177e4 | 1630 | /** |
2f0aea93 | 1631 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1632 | * |
2f0aea93 VK |
1633 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1634 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1635 | */ |
2f0aea93 | 1636 | void cpufreq_resume(void) |
1da177e4 | 1637 | { |
3a3e9e06 | 1638 | struct cpufreq_policy *policy; |
1da177e4 | 1639 | |
2f0aea93 VK |
1640 | if (!cpufreq_driver) |
1641 | return; | |
1da177e4 | 1642 | |
2f0aea93 | 1643 | if (!has_target()) |
e00e56df | 1644 | return; |
1da177e4 | 1645 | |
2f0aea93 | 1646 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1647 | |
2f0aea93 | 1648 | cpufreq_suspended = false; |
ce6c3997 | 1649 | |
2f0aea93 VK |
1650 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
1651 | if (__cpufreq_governor(policy, CPUFREQ_GOV_START) | |
1652 | || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) | |
1653 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1654 | __func__, policy); | |
1655 | else if (cpufreq_driver->resume | |
1656 | && cpufreq_driver->resume(policy)) | |
1657 | pr_err("%s: Failed to resume driver: %p\n", __func__, | |
1658 | policy); | |
1da177e4 | 1659 | |
2f0aea93 VK |
1660 | /* |
1661 | * schedule call cpufreq_update_policy() for boot CPU, i.e. last | |
1662 | * policy in list. It will verify that the current freq is in | |
1663 | * sync with what we believe it to be. | |
1664 | */ | |
1665 | if (list_is_last(&policy->policy_list, &cpufreq_policy_list)) | |
1666 | schedule_work(&policy->update); | |
1667 | } | |
1668 | } | |
1da177e4 | 1669 | |
9d95046e BP |
1670 | /** |
1671 | * cpufreq_get_current_driver - return current driver's name | |
1672 | * | |
1673 | * Return the name string of the currently loaded cpufreq driver | |
1674 | * or NULL, if none. | |
1675 | */ | |
1676 | const char *cpufreq_get_current_driver(void) | |
1677 | { | |
1c3d85dd RW |
1678 | if (cpufreq_driver) |
1679 | return cpufreq_driver->name; | |
1680 | ||
1681 | return NULL; | |
9d95046e BP |
1682 | } |
1683 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1684 | |
1685 | /********************************************************************* | |
1686 | * NOTIFIER LISTS INTERFACE * | |
1687 | *********************************************************************/ | |
1688 | ||
1689 | /** | |
1690 | * cpufreq_register_notifier - register a driver with cpufreq | |
1691 | * @nb: notifier function to register | |
1692 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1693 | * | |
32ee8c3e | 1694 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1695 | * are notified about clock rate changes (once before and once after |
1696 | * the transition), or a list of drivers that are notified about | |
1697 | * changes in cpufreq policy. | |
1698 | * | |
1699 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1700 | * blocking_notifier_chain_register. |
1da177e4 LT |
1701 | */ |
1702 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1703 | { | |
1704 | int ret; | |
1705 | ||
d5aaffa9 DB |
1706 | if (cpufreq_disabled()) |
1707 | return -EINVAL; | |
1708 | ||
74212ca4 CEB |
1709 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1710 | ||
1da177e4 LT |
1711 | switch (list) { |
1712 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1713 | ret = srcu_notifier_chain_register( |
e041c683 | 1714 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1715 | break; |
1716 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1717 | ret = blocking_notifier_chain_register( |
1718 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1719 | break; |
1720 | default: | |
1721 | ret = -EINVAL; | |
1722 | } | |
1da177e4 LT |
1723 | |
1724 | return ret; | |
1725 | } | |
1726 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1727 | ||
1da177e4 LT |
1728 | /** |
1729 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1730 | * @nb: notifier block to be unregistered | |
bb176f7d | 1731 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1732 | * |
1733 | * Remove a driver from the CPU frequency notifier list. | |
1734 | * | |
1735 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1736 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1737 | */ |
1738 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1739 | { | |
1740 | int ret; | |
1741 | ||
d5aaffa9 DB |
1742 | if (cpufreq_disabled()) |
1743 | return -EINVAL; | |
1744 | ||
1da177e4 LT |
1745 | switch (list) { |
1746 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1747 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1748 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1749 | break; |
1750 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1751 | ret = blocking_notifier_chain_unregister( |
1752 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1753 | break; |
1754 | default: | |
1755 | ret = -EINVAL; | |
1756 | } | |
1da177e4 LT |
1757 | |
1758 | return ret; | |
1759 | } | |
1760 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1761 | ||
1762 | ||
1763 | /********************************************************************* | |
1764 | * GOVERNORS * | |
1765 | *********************************************************************/ | |
1766 | ||
1da177e4 LT |
1767 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1768 | unsigned int target_freq, | |
1769 | unsigned int relation) | |
1770 | { | |
1771 | int retval = -EINVAL; | |
7249924e | 1772 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1773 | |
a7b422cd KRW |
1774 | if (cpufreq_disabled()) |
1775 | return -ENODEV; | |
1776 | ||
7249924e VK |
1777 | /* Make sure that target_freq is within supported range */ |
1778 | if (target_freq > policy->max) | |
1779 | target_freq = policy->max; | |
1780 | if (target_freq < policy->min) | |
1781 | target_freq = policy->min; | |
1782 | ||
1783 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 1784 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 1785 | |
9c0ebcf7 VK |
1786 | /* |
1787 | * This might look like a redundant call as we are checking it again | |
1788 | * after finding index. But it is left intentionally for cases where | |
1789 | * exactly same freq is called again and so we can save on few function | |
1790 | * calls. | |
1791 | */ | |
5a1c0228 VK |
1792 | if (target_freq == policy->cur) |
1793 | return 0; | |
1794 | ||
1c3d85dd RW |
1795 | if (cpufreq_driver->target) |
1796 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
9c0ebcf7 VK |
1797 | else if (cpufreq_driver->target_index) { |
1798 | struct cpufreq_frequency_table *freq_table; | |
d4019f0a VK |
1799 | struct cpufreq_freqs freqs; |
1800 | bool notify; | |
9c0ebcf7 | 1801 | int index; |
90d45d17 | 1802 | |
9c0ebcf7 VK |
1803 | freq_table = cpufreq_frequency_get_table(policy->cpu); |
1804 | if (unlikely(!freq_table)) { | |
1805 | pr_err("%s: Unable to find freq_table\n", __func__); | |
1806 | goto out; | |
1807 | } | |
1808 | ||
1809 | retval = cpufreq_frequency_table_target(policy, freq_table, | |
1810 | target_freq, relation, &index); | |
1811 | if (unlikely(retval)) { | |
1812 | pr_err("%s: Unable to find matching freq\n", __func__); | |
1813 | goto out; | |
1814 | } | |
1815 | ||
d4019f0a | 1816 | if (freq_table[index].frequency == policy->cur) { |
9c0ebcf7 | 1817 | retval = 0; |
d4019f0a VK |
1818 | goto out; |
1819 | } | |
1820 | ||
1821 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); | |
1822 | ||
1823 | if (notify) { | |
1824 | freqs.old = policy->cur; | |
1825 | freqs.new = freq_table[index].frequency; | |
1826 | freqs.flags = 0; | |
1827 | ||
1828 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", | |
e837f9b5 | 1829 | __func__, policy->cpu, freqs.old, freqs.new); |
d4019f0a VK |
1830 | |
1831 | cpufreq_notify_transition(policy, &freqs, | |
1832 | CPUFREQ_PRECHANGE); | |
1833 | } | |
1834 | ||
1835 | retval = cpufreq_driver->target_index(policy, index); | |
1836 | if (retval) | |
1837 | pr_err("%s: Failed to change cpu frequency: %d\n", | |
e837f9b5 | 1838 | __func__, retval); |
d4019f0a | 1839 | |
ab1b1c4e VK |
1840 | if (notify) |
1841 | cpufreq_notify_post_transition(policy, &freqs, retval); | |
9c0ebcf7 VK |
1842 | } |
1843 | ||
1844 | out: | |
1da177e4 LT |
1845 | return retval; |
1846 | } | |
1847 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1848 | ||
1da177e4 LT |
1849 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1850 | unsigned int target_freq, | |
1851 | unsigned int relation) | |
1852 | { | |
f1829e4a | 1853 | int ret = -EINVAL; |
1da177e4 | 1854 | |
ad7722da | 1855 | down_write(&policy->rwsem); |
1da177e4 LT |
1856 | |
1857 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1858 | ||
ad7722da | 1859 | up_write(&policy->rwsem); |
1da177e4 | 1860 | |
1da177e4 LT |
1861 | return ret; |
1862 | } | |
1863 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1864 | ||
153d7f3f | 1865 | /* |
153d7f3f AV |
1866 | * when "event" is CPUFREQ_GOV_LIMITS |
1867 | */ | |
1da177e4 | 1868 | |
e08f5f5b GS |
1869 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1870 | unsigned int event) | |
1da177e4 | 1871 | { |
cc993cab | 1872 | int ret; |
6afde10c TR |
1873 | |
1874 | /* Only must be defined when default governor is known to have latency | |
1875 | restrictions, like e.g. conservative or ondemand. | |
1876 | That this is the case is already ensured in Kconfig | |
1877 | */ | |
1878 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1879 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1880 | #else | |
1881 | struct cpufreq_governor *gov = NULL; | |
1882 | #endif | |
1c256245 | 1883 | |
2f0aea93 VK |
1884 | /* Don't start any governor operations if we are entering suspend */ |
1885 | if (cpufreq_suspended) | |
1886 | return 0; | |
1887 | ||
1c256245 TR |
1888 | if (policy->governor->max_transition_latency && |
1889 | policy->cpuinfo.transition_latency > | |
1890 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1891 | if (!gov) |
1892 | return -EINVAL; | |
1893 | else { | |
e837f9b5 JP |
1894 | pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", |
1895 | policy->governor->name, gov->name); | |
6afde10c TR |
1896 | policy->governor = gov; |
1897 | } | |
1c256245 | 1898 | } |
1da177e4 | 1899 | |
fe492f3f VK |
1900 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1901 | if (!try_module_get(policy->governor->owner)) | |
1902 | return -EINVAL; | |
1da177e4 | 1903 | |
2d06d8c4 | 1904 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e837f9b5 | 1905 | policy->cpu, event); |
95731ebb XC |
1906 | |
1907 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1908 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1909 | || (!policy->governor_enabled |
1910 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1911 | mutex_unlock(&cpufreq_governor_lock); |
1912 | return -EBUSY; | |
1913 | } | |
1914 | ||
1915 | if (event == CPUFREQ_GOV_STOP) | |
1916 | policy->governor_enabled = false; | |
1917 | else if (event == CPUFREQ_GOV_START) | |
1918 | policy->governor_enabled = true; | |
1919 | ||
1920 | mutex_unlock(&cpufreq_governor_lock); | |
1921 | ||
1da177e4 LT |
1922 | ret = policy->governor->governor(policy, event); |
1923 | ||
4d5dcc42 VK |
1924 | if (!ret) { |
1925 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1926 | policy->governor->initialized++; | |
1927 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1928 | policy->governor->initialized--; | |
95731ebb XC |
1929 | } else { |
1930 | /* Restore original values */ | |
1931 | mutex_lock(&cpufreq_governor_lock); | |
1932 | if (event == CPUFREQ_GOV_STOP) | |
1933 | policy->governor_enabled = true; | |
1934 | else if (event == CPUFREQ_GOV_START) | |
1935 | policy->governor_enabled = false; | |
1936 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1937 | } |
b394058f | 1938 | |
fe492f3f VK |
1939 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1940 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1941 | module_put(policy->governor->owner); |
1942 | ||
1943 | return ret; | |
1944 | } | |
1945 | ||
1da177e4 LT |
1946 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1947 | { | |
3bcb09a3 | 1948 | int err; |
1da177e4 LT |
1949 | |
1950 | if (!governor) | |
1951 | return -EINVAL; | |
1952 | ||
a7b422cd KRW |
1953 | if (cpufreq_disabled()) |
1954 | return -ENODEV; | |
1955 | ||
3fc54d37 | 1956 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1957 | |
b394058f | 1958 | governor->initialized = 0; |
3bcb09a3 JF |
1959 | err = -EBUSY; |
1960 | if (__find_governor(governor->name) == NULL) { | |
1961 | err = 0; | |
1962 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1963 | } |
1da177e4 | 1964 | |
32ee8c3e | 1965 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1966 | return err; |
1da177e4 LT |
1967 | } |
1968 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1969 | ||
1da177e4 LT |
1970 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1971 | { | |
90e41bac | 1972 | int cpu; |
90e41bac | 1973 | |
1da177e4 LT |
1974 | if (!governor) |
1975 | return; | |
1976 | ||
a7b422cd KRW |
1977 | if (cpufreq_disabled()) |
1978 | return; | |
1979 | ||
90e41bac PB |
1980 | for_each_present_cpu(cpu) { |
1981 | if (cpu_online(cpu)) | |
1982 | continue; | |
1983 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1984 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1985 | } | |
90e41bac | 1986 | |
3fc54d37 | 1987 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1988 | list_del(&governor->governor_list); |
3fc54d37 | 1989 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1990 | return; |
1991 | } | |
1992 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1993 | ||
1994 | ||
1da177e4 LT |
1995 | /********************************************************************* |
1996 | * POLICY INTERFACE * | |
1997 | *********************************************************************/ | |
1998 | ||
1999 | /** | |
2000 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2001 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2002 | * is written | |
1da177e4 LT |
2003 | * |
2004 | * Reads the current cpufreq policy. | |
2005 | */ | |
2006 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2007 | { | |
2008 | struct cpufreq_policy *cpu_policy; | |
2009 | if (!policy) | |
2010 | return -EINVAL; | |
2011 | ||
2012 | cpu_policy = cpufreq_cpu_get(cpu); | |
2013 | if (!cpu_policy) | |
2014 | return -EINVAL; | |
2015 | ||
d5b73cd8 | 2016 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2017 | |
2018 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2019 | return 0; |
2020 | } | |
2021 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2022 | ||
153d7f3f | 2023 | /* |
037ce839 VK |
2024 | * policy : current policy. |
2025 | * new_policy: policy to be set. | |
153d7f3f | 2026 | */ |
037ce839 | 2027 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 2028 | struct cpufreq_policy *new_policy) |
1da177e4 | 2029 | { |
d9a789c7 RW |
2030 | struct cpufreq_governor *old_gov; |
2031 | int ret; | |
1da177e4 | 2032 | |
e837f9b5 JP |
2033 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2034 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2035 | |
d5b73cd8 | 2036 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2037 | |
d9a789c7 RW |
2038 | if (new_policy->min > policy->max || new_policy->max < policy->min) |
2039 | return -EINVAL; | |
9c9a43ed | 2040 | |
1da177e4 | 2041 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2042 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2043 | if (ret) |
d9a789c7 | 2044 | return ret; |
1da177e4 | 2045 | |
1da177e4 | 2046 | /* adjust if necessary - all reasons */ |
e041c683 | 2047 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2048 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
2049 | |
2050 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 2051 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2052 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 2053 | |
bb176f7d VK |
2054 | /* |
2055 | * verify the cpu speed can be set within this limit, which might be | |
2056 | * different to the first one | |
2057 | */ | |
3a3e9e06 | 2058 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2059 | if (ret) |
d9a789c7 | 2060 | return ret; |
1da177e4 LT |
2061 | |
2062 | /* notification of the new policy */ | |
e041c683 | 2063 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2064 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2065 | |
3a3e9e06 VK |
2066 | policy->min = new_policy->min; |
2067 | policy->max = new_policy->max; | |
1da177e4 | 2068 | |
2d06d8c4 | 2069 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2070 | policy->min, policy->max); |
1da177e4 | 2071 | |
1c3d85dd | 2072 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2073 | policy->policy = new_policy->policy; |
2d06d8c4 | 2074 | pr_debug("setting range\n"); |
d9a789c7 RW |
2075 | return cpufreq_driver->setpolicy(new_policy); |
2076 | } | |
1da177e4 | 2077 | |
d9a789c7 RW |
2078 | if (new_policy->governor == policy->governor) |
2079 | goto out; | |
7bd353a9 | 2080 | |
d9a789c7 RW |
2081 | pr_debug("governor switch\n"); |
2082 | ||
2083 | /* save old, working values */ | |
2084 | old_gov = policy->governor; | |
2085 | /* end old governor */ | |
2086 | if (old_gov) { | |
2087 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
2088 | up_write(&policy->rwsem); | |
2089 | __cpufreq_governor(policy,CPUFREQ_GOV_POLICY_EXIT); | |
2090 | down_write(&policy->rwsem); | |
1da177e4 LT |
2091 | } |
2092 | ||
d9a789c7 RW |
2093 | /* start new governor */ |
2094 | policy->governor = new_policy->governor; | |
2095 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
2096 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) | |
2097 | goto out; | |
2098 | ||
2099 | up_write(&policy->rwsem); | |
2100 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); | |
2101 | down_write(&policy->rwsem); | |
2102 | } | |
2103 | ||
2104 | /* new governor failed, so re-start old one */ | |
2105 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2106 | if (old_gov) { | |
2107 | policy->governor = old_gov; | |
2108 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); | |
2109 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
2110 | } | |
2111 | ||
2112 | return -EINVAL; | |
2113 | ||
2114 | out: | |
2115 | pr_debug("governor: change or update limits\n"); | |
2116 | return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1da177e4 LT |
2117 | } |
2118 | ||
1da177e4 LT |
2119 | /** |
2120 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2121 | * @cpu: CPU which shall be re-evaluated | |
2122 | * | |
25985edc | 2123 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2124 | * at different times. |
2125 | */ | |
2126 | int cpufreq_update_policy(unsigned int cpu) | |
2127 | { | |
3a3e9e06 VK |
2128 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2129 | struct cpufreq_policy new_policy; | |
f1829e4a | 2130 | int ret; |
1da177e4 | 2131 | |
3a3e9e06 | 2132 | if (!policy) { |
f1829e4a JL |
2133 | ret = -ENODEV; |
2134 | goto no_policy; | |
2135 | } | |
1da177e4 | 2136 | |
ad7722da | 2137 | down_write(&policy->rwsem); |
1da177e4 | 2138 | |
2d06d8c4 | 2139 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2140 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2141 | new_policy.min = policy->user_policy.min; |
2142 | new_policy.max = policy->user_policy.max; | |
2143 | new_policy.policy = policy->user_policy.policy; | |
2144 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 2145 | |
bb176f7d VK |
2146 | /* |
2147 | * BIOS might change freq behind our back | |
2148 | * -> ask driver for current freq and notify governors about a change | |
2149 | */ | |
2ed99e39 | 2150 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
3a3e9e06 | 2151 | new_policy.cur = cpufreq_driver->get(cpu); |
bd0fa9bb VK |
2152 | if (WARN_ON(!new_policy.cur)) { |
2153 | ret = -EIO; | |
2154 | goto no_policy; | |
2155 | } | |
2156 | ||
3a3e9e06 | 2157 | if (!policy->cur) { |
e837f9b5 | 2158 | pr_debug("Driver did not initialize current freq\n"); |
3a3e9e06 | 2159 | policy->cur = new_policy.cur; |
a85f7bd3 | 2160 | } else { |
9c0ebcf7 | 2161 | if (policy->cur != new_policy.cur && has_target()) |
3a3e9e06 VK |
2162 | cpufreq_out_of_sync(cpu, policy->cur, |
2163 | new_policy.cur); | |
a85f7bd3 | 2164 | } |
0961dd0d TR |
2165 | } |
2166 | ||
037ce839 | 2167 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2168 | |
ad7722da | 2169 | up_write(&policy->rwsem); |
5a01f2e8 | 2170 | |
3a3e9e06 | 2171 | cpufreq_cpu_put(policy); |
f1829e4a | 2172 | no_policy: |
1da177e4 LT |
2173 | return ret; |
2174 | } | |
2175 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2176 | ||
2760984f | 2177 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2178 | unsigned long action, void *hcpu) |
2179 | { | |
2180 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2181 | struct device *dev; |
c32b6b8e | 2182 | |
8a25a2fd KS |
2183 | dev = get_cpu_device(cpu); |
2184 | if (dev) { | |
5302c3fb | 2185 | switch (action & ~CPU_TASKS_FROZEN) { |
c32b6b8e | 2186 | case CPU_ONLINE: |
96bbbe4a | 2187 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e | 2188 | break; |
5302c3fb | 2189 | |
c32b6b8e | 2190 | case CPU_DOWN_PREPARE: |
96bbbe4a | 2191 | __cpufreq_remove_dev_prepare(dev, NULL); |
1aee40ac SB |
2192 | break; |
2193 | ||
2194 | case CPU_POST_DEAD: | |
96bbbe4a | 2195 | __cpufreq_remove_dev_finish(dev, NULL); |
c32b6b8e | 2196 | break; |
5302c3fb | 2197 | |
5a01f2e8 | 2198 | case CPU_DOWN_FAILED: |
96bbbe4a | 2199 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
2200 | break; |
2201 | } | |
2202 | } | |
2203 | return NOTIFY_OK; | |
2204 | } | |
2205 | ||
9c36f746 | 2206 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2207 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2208 | }; |
1da177e4 | 2209 | |
6f19efc0 LM |
2210 | /********************************************************************* |
2211 | * BOOST * | |
2212 | *********************************************************************/ | |
2213 | static int cpufreq_boost_set_sw(int state) | |
2214 | { | |
2215 | struct cpufreq_frequency_table *freq_table; | |
2216 | struct cpufreq_policy *policy; | |
2217 | int ret = -EINVAL; | |
2218 | ||
2219 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
2220 | freq_table = cpufreq_frequency_get_table(policy->cpu); | |
2221 | if (freq_table) { | |
2222 | ret = cpufreq_frequency_table_cpuinfo(policy, | |
2223 | freq_table); | |
2224 | if (ret) { | |
2225 | pr_err("%s: Policy frequency update failed\n", | |
2226 | __func__); | |
2227 | break; | |
2228 | } | |
2229 | policy->user_policy.max = policy->max; | |
2230 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
2231 | } | |
2232 | } | |
2233 | ||
2234 | return ret; | |
2235 | } | |
2236 | ||
2237 | int cpufreq_boost_trigger_state(int state) | |
2238 | { | |
2239 | unsigned long flags; | |
2240 | int ret = 0; | |
2241 | ||
2242 | if (cpufreq_driver->boost_enabled == state) | |
2243 | return 0; | |
2244 | ||
2245 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2246 | cpufreq_driver->boost_enabled = state; | |
2247 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2248 | ||
2249 | ret = cpufreq_driver->set_boost(state); | |
2250 | if (ret) { | |
2251 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2252 | cpufreq_driver->boost_enabled = !state; | |
2253 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2254 | ||
e837f9b5 JP |
2255 | pr_err("%s: Cannot %s BOOST\n", |
2256 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2257 | } |
2258 | ||
2259 | return ret; | |
2260 | } | |
2261 | ||
2262 | int cpufreq_boost_supported(void) | |
2263 | { | |
2264 | if (likely(cpufreq_driver)) | |
2265 | return cpufreq_driver->boost_supported; | |
2266 | ||
2267 | return 0; | |
2268 | } | |
2269 | EXPORT_SYMBOL_GPL(cpufreq_boost_supported); | |
2270 | ||
2271 | int cpufreq_boost_enabled(void) | |
2272 | { | |
2273 | return cpufreq_driver->boost_enabled; | |
2274 | } | |
2275 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2276 | ||
1da177e4 LT |
2277 | /********************************************************************* |
2278 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2279 | *********************************************************************/ | |
2280 | ||
2281 | /** | |
2282 | * cpufreq_register_driver - register a CPU Frequency driver | |
2283 | * @driver_data: A struct cpufreq_driver containing the values# | |
2284 | * submitted by the CPU Frequency driver. | |
2285 | * | |
bb176f7d | 2286 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2287 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2288 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2289 | * |
2290 | */ | |
221dee28 | 2291 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2292 | { |
2293 | unsigned long flags; | |
2294 | int ret; | |
2295 | ||
a7b422cd KRW |
2296 | if (cpufreq_disabled()) |
2297 | return -ENODEV; | |
2298 | ||
1da177e4 | 2299 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2300 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2301 | driver_data->target) || |
2302 | (driver_data->setpolicy && (driver_data->target_index || | |
2303 | driver_data->target))) | |
1da177e4 LT |
2304 | return -EINVAL; |
2305 | ||
2d06d8c4 | 2306 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2307 | |
2308 | if (driver_data->setpolicy) | |
2309 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2310 | ||
0d1857a1 | 2311 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2312 | if (cpufreq_driver) { |
0d1857a1 | 2313 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2314 | return -EEXIST; |
1da177e4 | 2315 | } |
1c3d85dd | 2316 | cpufreq_driver = driver_data; |
0d1857a1 | 2317 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2318 | |
6f19efc0 LM |
2319 | if (cpufreq_boost_supported()) { |
2320 | /* | |
2321 | * Check if driver provides function to enable boost - | |
2322 | * if not, use cpufreq_boost_set_sw as default | |
2323 | */ | |
2324 | if (!cpufreq_driver->set_boost) | |
2325 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; | |
2326 | ||
2327 | ret = cpufreq_sysfs_create_file(&boost.attr); | |
2328 | if (ret) { | |
2329 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
e837f9b5 | 2330 | __func__); |
6f19efc0 LM |
2331 | goto err_null_driver; |
2332 | } | |
2333 | } | |
2334 | ||
8a25a2fd | 2335 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2336 | if (ret) |
6f19efc0 | 2337 | goto err_boost_unreg; |
1da177e4 | 2338 | |
1c3d85dd | 2339 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2340 | int i; |
2341 | ret = -ENODEV; | |
2342 | ||
2343 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2344 | for (i = 0; i < nr_cpu_ids; i++) |
2345 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2346 | ret = 0; |
7a6aedfa MT |
2347 | break; |
2348 | } | |
1da177e4 LT |
2349 | |
2350 | /* if all ->init() calls failed, unregister */ | |
2351 | if (ret) { | |
2d06d8c4 | 2352 | pr_debug("no CPU initialized for driver %s\n", |
e837f9b5 | 2353 | driver_data->name); |
8a25a2fd | 2354 | goto err_if_unreg; |
1da177e4 LT |
2355 | } |
2356 | } | |
2357 | ||
8f5bc2ab | 2358 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2359 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2360 | |
8f5bc2ab | 2361 | return 0; |
8a25a2fd KS |
2362 | err_if_unreg: |
2363 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 LM |
2364 | err_boost_unreg: |
2365 | if (cpufreq_boost_supported()) | |
2366 | cpufreq_sysfs_remove_file(&boost.attr); | |
8f5bc2ab | 2367 | err_null_driver: |
0d1857a1 | 2368 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2369 | cpufreq_driver = NULL; |
0d1857a1 | 2370 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2371 | return ret; |
1da177e4 LT |
2372 | } |
2373 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2374 | ||
1da177e4 LT |
2375 | /** |
2376 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2377 | * | |
bb176f7d | 2378 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2379 | * the right to do so, i.e. if you have succeeded in initialising before! |
2380 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2381 | * currently not initialised. | |
2382 | */ | |
221dee28 | 2383 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2384 | { |
2385 | unsigned long flags; | |
2386 | ||
1c3d85dd | 2387 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2388 | return -EINVAL; |
1da177e4 | 2389 | |
2d06d8c4 | 2390 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2391 | |
8a25a2fd | 2392 | subsys_interface_unregister(&cpufreq_interface); |
6f19efc0 LM |
2393 | if (cpufreq_boost_supported()) |
2394 | cpufreq_sysfs_remove_file(&boost.attr); | |
2395 | ||
65edc68c | 2396 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2397 | |
6eed9404 | 2398 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2399 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2400 | |
1c3d85dd | 2401 | cpufreq_driver = NULL; |
6eed9404 | 2402 | |
0d1857a1 | 2403 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2404 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2405 | |
2406 | return 0; | |
2407 | } | |
2408 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2409 | |
2410 | static int __init cpufreq_core_init(void) | |
2411 | { | |
a7b422cd KRW |
2412 | if (cpufreq_disabled()) |
2413 | return -ENODEV; | |
2414 | ||
2361be23 | 2415 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 TR |
2416 | BUG_ON(!cpufreq_global_kobject); |
2417 | ||
5a01f2e8 VP |
2418 | return 0; |
2419 | } | |
5a01f2e8 | 2420 | core_initcall(cpufreq_core_init); |