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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
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 | ||
12478cf0 SB |
356 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
357 | struct cpufreq_freqs *freqs) | |
358 | { | |
359 | wait: | |
360 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
361 | ||
362 | spin_lock(&policy->transition_lock); | |
363 | ||
364 | if (unlikely(policy->transition_ongoing)) { | |
365 | spin_unlock(&policy->transition_lock); | |
366 | goto wait; | |
367 | } | |
368 | ||
369 | policy->transition_ongoing = true; | |
370 | ||
371 | spin_unlock(&policy->transition_lock); | |
372 | ||
373 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
374 | } | |
375 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
376 | ||
377 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
378 | struct cpufreq_freqs *freqs, int transition_failed) | |
379 | { | |
380 | if (unlikely(WARN_ON(!policy->transition_ongoing))) | |
381 | return; | |
382 | ||
383 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
384 | ||
385 | policy->transition_ongoing = false; | |
386 | ||
387 | wake_up(&policy->transition_wait); | |
388 | } | |
389 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
390 | ||
1da177e4 | 391 | |
1da177e4 LT |
392 | /********************************************************************* |
393 | * SYSFS INTERFACE * | |
394 | *********************************************************************/ | |
8a5c74a1 | 395 | static ssize_t show_boost(struct kobject *kobj, |
6f19efc0 LM |
396 | struct attribute *attr, char *buf) |
397 | { | |
398 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
399 | } | |
400 | ||
401 | static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, | |
402 | const char *buf, size_t count) | |
403 | { | |
404 | int ret, enable; | |
405 | ||
406 | ret = sscanf(buf, "%d", &enable); | |
407 | if (ret != 1 || enable < 0 || enable > 1) | |
408 | return -EINVAL; | |
409 | ||
410 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
411 | pr_err("%s: Cannot %s BOOST!\n", |
412 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
413 | return -EINVAL; |
414 | } | |
415 | ||
e837f9b5 JP |
416 | pr_debug("%s: cpufreq BOOST %s\n", |
417 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
418 | |
419 | return count; | |
420 | } | |
421 | define_one_global_rw(boost); | |
1da177e4 | 422 | |
3bcb09a3 JF |
423 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
424 | { | |
425 | struct cpufreq_governor *t; | |
426 | ||
427 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 428 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
429 | return t; |
430 | ||
431 | return NULL; | |
432 | } | |
433 | ||
1da177e4 LT |
434 | /** |
435 | * cpufreq_parse_governor - parse a governor string | |
436 | */ | |
905d77cd | 437 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
438 | struct cpufreq_governor **governor) |
439 | { | |
3bcb09a3 | 440 | int err = -EINVAL; |
1c3d85dd RW |
441 | |
442 | if (!cpufreq_driver) | |
3bcb09a3 JF |
443 | goto out; |
444 | ||
1c3d85dd | 445 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
446 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
447 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 448 | err = 0; |
e08f5f5b GS |
449 | } else if (!strnicmp(str_governor, "powersave", |
450 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 451 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 452 | err = 0; |
1da177e4 | 453 | } |
9c0ebcf7 | 454 | } else if (has_target()) { |
1da177e4 | 455 | struct cpufreq_governor *t; |
3bcb09a3 | 456 | |
3fc54d37 | 457 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
458 | |
459 | t = __find_governor(str_governor); | |
460 | ||
ea714970 | 461 | if (t == NULL) { |
1a8e1463 | 462 | int ret; |
ea714970 | 463 | |
1a8e1463 KC |
464 | mutex_unlock(&cpufreq_governor_mutex); |
465 | ret = request_module("cpufreq_%s", str_governor); | |
466 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 467 | |
1a8e1463 KC |
468 | if (ret == 0) |
469 | t = __find_governor(str_governor); | |
ea714970 JF |
470 | } |
471 | ||
3bcb09a3 JF |
472 | if (t != NULL) { |
473 | *governor = t; | |
474 | err = 0; | |
1da177e4 | 475 | } |
3bcb09a3 | 476 | |
3fc54d37 | 477 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 478 | } |
29464f28 | 479 | out: |
3bcb09a3 | 480 | return err; |
1da177e4 | 481 | } |
1da177e4 | 482 | |
1da177e4 | 483 | /** |
e08f5f5b GS |
484 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
485 | * print out cpufreq information | |
1da177e4 LT |
486 | * |
487 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
488 | * "unsigned int". | |
489 | */ | |
490 | ||
32ee8c3e DJ |
491 | #define show_one(file_name, object) \ |
492 | static ssize_t show_##file_name \ | |
905d77cd | 493 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 494 | { \ |
29464f28 | 495 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
496 | } |
497 | ||
498 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
499 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 500 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
501 | show_one(scaling_min_freq, min); |
502 | show_one(scaling_max_freq, max); | |
503 | show_one(scaling_cur_freq, cur); | |
504 | ||
037ce839 | 505 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 506 | struct cpufreq_policy *new_policy); |
7970e08b | 507 | |
1da177e4 LT |
508 | /** |
509 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
510 | */ | |
511 | #define store_one(file_name, object) \ | |
512 | static ssize_t store_##file_name \ | |
905d77cd | 513 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 514 | { \ |
5136fa56 | 515 | int ret; \ |
1da177e4 LT |
516 | struct cpufreq_policy new_policy; \ |
517 | \ | |
518 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
519 | if (ret) \ | |
520 | return -EINVAL; \ | |
521 | \ | |
29464f28 | 522 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
523 | if (ret != 1) \ |
524 | return -EINVAL; \ | |
525 | \ | |
037ce839 | 526 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 527 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
528 | \ |
529 | return ret ? ret : count; \ | |
530 | } | |
531 | ||
29464f28 DJ |
532 | store_one(scaling_min_freq, min); |
533 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
534 | |
535 | /** | |
536 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
537 | */ | |
905d77cd DJ |
538 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
539 | char *buf) | |
1da177e4 | 540 | { |
5a01f2e8 | 541 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
542 | if (!cur_freq) |
543 | return sprintf(buf, "<unknown>"); | |
544 | return sprintf(buf, "%u\n", cur_freq); | |
545 | } | |
546 | ||
1da177e4 LT |
547 | /** |
548 | * show_scaling_governor - show the current policy for the specified CPU | |
549 | */ | |
905d77cd | 550 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 551 | { |
29464f28 | 552 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
553 | return sprintf(buf, "powersave\n"); |
554 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
555 | return sprintf(buf, "performance\n"); | |
556 | else if (policy->governor) | |
4b972f0b | 557 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 558 | policy->governor->name); |
1da177e4 LT |
559 | return -EINVAL; |
560 | } | |
561 | ||
1da177e4 LT |
562 | /** |
563 | * store_scaling_governor - store policy for the specified CPU | |
564 | */ | |
905d77cd DJ |
565 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
566 | const char *buf, size_t count) | |
1da177e4 | 567 | { |
5136fa56 | 568 | int ret; |
1da177e4 LT |
569 | char str_governor[16]; |
570 | struct cpufreq_policy new_policy; | |
571 | ||
572 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
573 | if (ret) | |
574 | return ret; | |
575 | ||
29464f28 | 576 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
577 | if (ret != 1) |
578 | return -EINVAL; | |
579 | ||
e08f5f5b GS |
580 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
581 | &new_policy.governor)) | |
1da177e4 LT |
582 | return -EINVAL; |
583 | ||
037ce839 | 584 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
585 | |
586 | policy->user_policy.policy = policy->policy; | |
587 | policy->user_policy.governor = policy->governor; | |
7970e08b | 588 | |
e08f5f5b GS |
589 | if (ret) |
590 | return ret; | |
591 | else | |
592 | return count; | |
1da177e4 LT |
593 | } |
594 | ||
595 | /** | |
596 | * show_scaling_driver - show the cpufreq driver currently loaded | |
597 | */ | |
905d77cd | 598 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 599 | { |
1c3d85dd | 600 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
601 | } |
602 | ||
603 | /** | |
604 | * show_scaling_available_governors - show the available CPUfreq governors | |
605 | */ | |
905d77cd DJ |
606 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
607 | char *buf) | |
1da177e4 LT |
608 | { |
609 | ssize_t i = 0; | |
610 | struct cpufreq_governor *t; | |
611 | ||
9c0ebcf7 | 612 | if (!has_target()) { |
1da177e4 LT |
613 | i += sprintf(buf, "performance powersave"); |
614 | goto out; | |
615 | } | |
616 | ||
617 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
618 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
619 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 620 | goto out; |
4b972f0b | 621 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 622 | } |
7d5e350f | 623 | out: |
1da177e4 LT |
624 | i += sprintf(&buf[i], "\n"); |
625 | return i; | |
626 | } | |
e8628dd0 | 627 | |
f4fd3797 | 628 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
629 | { |
630 | ssize_t i = 0; | |
631 | unsigned int cpu; | |
632 | ||
835481d9 | 633 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
634 | if (i) |
635 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
636 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
637 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 638 | break; |
1da177e4 LT |
639 | } |
640 | i += sprintf(&buf[i], "\n"); | |
641 | return i; | |
642 | } | |
f4fd3797 | 643 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 644 | |
e8628dd0 DW |
645 | /** |
646 | * show_related_cpus - show the CPUs affected by each transition even if | |
647 | * hw coordination is in use | |
648 | */ | |
649 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
650 | { | |
f4fd3797 | 651 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
652 | } |
653 | ||
654 | /** | |
655 | * show_affected_cpus - show the CPUs affected by each transition | |
656 | */ | |
657 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
658 | { | |
f4fd3797 | 659 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
660 | } |
661 | ||
9e76988e | 662 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 663 | const char *buf, size_t count) |
9e76988e VP |
664 | { |
665 | unsigned int freq = 0; | |
666 | unsigned int ret; | |
667 | ||
879000f9 | 668 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
669 | return -EINVAL; |
670 | ||
671 | ret = sscanf(buf, "%u", &freq); | |
672 | if (ret != 1) | |
673 | return -EINVAL; | |
674 | ||
675 | policy->governor->store_setspeed(policy, freq); | |
676 | ||
677 | return count; | |
678 | } | |
679 | ||
680 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
681 | { | |
879000f9 | 682 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
683 | return sprintf(buf, "<unsupported>\n"); |
684 | ||
685 | return policy->governor->show_setspeed(policy, buf); | |
686 | } | |
1da177e4 | 687 | |
e2f74f35 | 688 | /** |
8bf1ac72 | 689 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
690 | */ |
691 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
692 | { | |
693 | unsigned int limit; | |
694 | int ret; | |
1c3d85dd RW |
695 | if (cpufreq_driver->bios_limit) { |
696 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
697 | if (!ret) |
698 | return sprintf(buf, "%u\n", limit); | |
699 | } | |
700 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
701 | } | |
702 | ||
6dad2a29 BP |
703 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
704 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
705 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
706 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
707 | cpufreq_freq_attr_ro(scaling_available_governors); | |
708 | cpufreq_freq_attr_ro(scaling_driver); | |
709 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
710 | cpufreq_freq_attr_ro(bios_limit); | |
711 | cpufreq_freq_attr_ro(related_cpus); | |
712 | cpufreq_freq_attr_ro(affected_cpus); | |
713 | cpufreq_freq_attr_rw(scaling_min_freq); | |
714 | cpufreq_freq_attr_rw(scaling_max_freq); | |
715 | cpufreq_freq_attr_rw(scaling_governor); | |
716 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 717 | |
905d77cd | 718 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
719 | &cpuinfo_min_freq.attr, |
720 | &cpuinfo_max_freq.attr, | |
ed129784 | 721 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
722 | &scaling_min_freq.attr, |
723 | &scaling_max_freq.attr, | |
724 | &affected_cpus.attr, | |
e8628dd0 | 725 | &related_cpus.attr, |
1da177e4 LT |
726 | &scaling_governor.attr, |
727 | &scaling_driver.attr, | |
728 | &scaling_available_governors.attr, | |
9e76988e | 729 | &scaling_setspeed.attr, |
1da177e4 LT |
730 | NULL |
731 | }; | |
732 | ||
29464f28 DJ |
733 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
734 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 735 | |
29464f28 | 736 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 737 | { |
905d77cd DJ |
738 | struct cpufreq_policy *policy = to_policy(kobj); |
739 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 740 | ssize_t ret; |
6eed9404 VK |
741 | |
742 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 743 | return -EINVAL; |
5a01f2e8 | 744 | |
ad7722da | 745 | down_read(&policy->rwsem); |
5a01f2e8 | 746 | |
e08f5f5b GS |
747 | if (fattr->show) |
748 | ret = fattr->show(policy, buf); | |
749 | else | |
750 | ret = -EIO; | |
751 | ||
ad7722da | 752 | up_read(&policy->rwsem); |
6eed9404 | 753 | up_read(&cpufreq_rwsem); |
1b750e3b | 754 | |
1da177e4 LT |
755 | return ret; |
756 | } | |
757 | ||
905d77cd DJ |
758 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
759 | const char *buf, size_t count) | |
1da177e4 | 760 | { |
905d77cd DJ |
761 | struct cpufreq_policy *policy = to_policy(kobj); |
762 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 763 | ssize_t ret = -EINVAL; |
6eed9404 | 764 | |
4f750c93 SB |
765 | get_online_cpus(); |
766 | ||
767 | if (!cpu_online(policy->cpu)) | |
768 | goto unlock; | |
769 | ||
6eed9404 | 770 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 771 | goto unlock; |
5a01f2e8 | 772 | |
ad7722da | 773 | down_write(&policy->rwsem); |
5a01f2e8 | 774 | |
e08f5f5b GS |
775 | if (fattr->store) |
776 | ret = fattr->store(policy, buf, count); | |
777 | else | |
778 | ret = -EIO; | |
779 | ||
ad7722da | 780 | up_write(&policy->rwsem); |
6eed9404 | 781 | |
6eed9404 | 782 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
783 | unlock: |
784 | put_online_cpus(); | |
785 | ||
1da177e4 LT |
786 | return ret; |
787 | } | |
788 | ||
905d77cd | 789 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 790 | { |
905d77cd | 791 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 792 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
793 | complete(&policy->kobj_unregister); |
794 | } | |
795 | ||
52cf25d0 | 796 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
797 | .show = show, |
798 | .store = store, | |
799 | }; | |
800 | ||
801 | static struct kobj_type ktype_cpufreq = { | |
802 | .sysfs_ops = &sysfs_ops, | |
803 | .default_attrs = default_attrs, | |
804 | .release = cpufreq_sysfs_release, | |
805 | }; | |
806 | ||
2361be23 VK |
807 | struct kobject *cpufreq_global_kobject; |
808 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
809 | ||
810 | static int cpufreq_global_kobject_usage; | |
811 | ||
812 | int cpufreq_get_global_kobject(void) | |
813 | { | |
814 | if (!cpufreq_global_kobject_usage++) | |
815 | return kobject_add(cpufreq_global_kobject, | |
816 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
817 | ||
818 | return 0; | |
819 | } | |
820 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
821 | ||
822 | void cpufreq_put_global_kobject(void) | |
823 | { | |
824 | if (!--cpufreq_global_kobject_usage) | |
825 | kobject_del(cpufreq_global_kobject); | |
826 | } | |
827 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
828 | ||
829 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
830 | { | |
831 | int ret = cpufreq_get_global_kobject(); | |
832 | ||
833 | if (!ret) { | |
834 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
835 | if (ret) | |
836 | cpufreq_put_global_kobject(); | |
837 | } | |
838 | ||
839 | return ret; | |
840 | } | |
841 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
842 | ||
843 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
844 | { | |
845 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
846 | cpufreq_put_global_kobject(); | |
847 | } | |
848 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
849 | ||
19d6f7ec | 850 | /* symlink affected CPUs */ |
308b60e7 | 851 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
852 | { |
853 | unsigned int j; | |
854 | int ret = 0; | |
855 | ||
856 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 857 | struct device *cpu_dev; |
19d6f7ec | 858 | |
308b60e7 | 859 | if (j == policy->cpu) |
19d6f7ec | 860 | continue; |
19d6f7ec | 861 | |
e8fdde10 | 862 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
863 | cpu_dev = get_cpu_device(j); |
864 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 865 | "cpufreq"); |
71c3461e RW |
866 | if (ret) |
867 | break; | |
19d6f7ec DJ |
868 | } |
869 | return ret; | |
870 | } | |
871 | ||
308b60e7 | 872 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 873 | struct device *dev) |
909a694e DJ |
874 | { |
875 | struct freq_attr **drv_attr; | |
909a694e | 876 | int ret = 0; |
909a694e DJ |
877 | |
878 | /* prepare interface data */ | |
879 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 880 | &dev->kobj, "cpufreq"); |
909a694e DJ |
881 | if (ret) |
882 | return ret; | |
883 | ||
884 | /* set up files for this cpu device */ | |
1c3d85dd | 885 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
886 | while ((drv_attr) && (*drv_attr)) { |
887 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
888 | if (ret) | |
1c3d85dd | 889 | goto err_out_kobj_put; |
909a694e DJ |
890 | drv_attr++; |
891 | } | |
1c3d85dd | 892 | if (cpufreq_driver->get) { |
909a694e DJ |
893 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
894 | if (ret) | |
1c3d85dd | 895 | goto err_out_kobj_put; |
909a694e | 896 | } |
9c0ebcf7 | 897 | if (has_target()) { |
909a694e DJ |
898 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
899 | if (ret) | |
1c3d85dd | 900 | goto err_out_kobj_put; |
909a694e | 901 | } |
1c3d85dd | 902 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
903 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
904 | if (ret) | |
1c3d85dd | 905 | goto err_out_kobj_put; |
e2f74f35 | 906 | } |
909a694e | 907 | |
308b60e7 | 908 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
909 | if (ret) |
910 | goto err_out_kobj_put; | |
911 | ||
e18f1682 SB |
912 | return ret; |
913 | ||
914 | err_out_kobj_put: | |
915 | kobject_put(&policy->kobj); | |
916 | wait_for_completion(&policy->kobj_unregister); | |
917 | return ret; | |
918 | } | |
919 | ||
920 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
921 | { | |
6e2c89d1 | 922 | struct cpufreq_governor *gov = NULL; |
e18f1682 SB |
923 | struct cpufreq_policy new_policy; |
924 | int ret = 0; | |
925 | ||
d5b73cd8 | 926 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 927 | |
6e2c89d1 | 928 | /* Update governor of new_policy to the governor used before hotplug */ |
929 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); | |
930 | if (gov) | |
931 | pr_debug("Restoring governor %s for cpu %d\n", | |
932 | policy->governor->name, policy->cpu); | |
933 | else | |
934 | gov = CPUFREQ_DEFAULT_GOVERNOR; | |
935 | ||
936 | new_policy.governor = gov; | |
937 | ||
a27a9ab7 JB |
938 | /* Use the default policy if its valid. */ |
939 | if (cpufreq_driver->setpolicy) | |
6e2c89d1 | 940 | cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); |
ecf7e461 DJ |
941 | |
942 | /* set default policy */ | |
037ce839 | 943 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 | 944 | if (ret) { |
2d06d8c4 | 945 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
946 | if (cpufreq_driver->exit) |
947 | cpufreq_driver->exit(policy); | |
ecf7e461 | 948 | } |
909a694e DJ |
949 | } |
950 | ||
fcf80582 | 951 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 | 952 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 953 | unsigned int cpu, struct device *dev) |
fcf80582 | 954 | { |
9c0ebcf7 | 955 | int ret = 0; |
fcf80582 VK |
956 | unsigned long flags; |
957 | ||
9c0ebcf7 | 958 | if (has_target()) { |
3de9bdeb VK |
959 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
960 | if (ret) { | |
961 | pr_err("%s: Failed to stop governor\n", __func__); | |
962 | return ret; | |
963 | } | |
964 | } | |
fcf80582 | 965 | |
ad7722da | 966 | down_write(&policy->rwsem); |
2eaa3e2d | 967 | |
0d1857a1 | 968 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 969 | |
fcf80582 VK |
970 | cpumask_set_cpu(cpu, policy->cpus); |
971 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 972 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 973 | |
ad7722da | 974 | up_write(&policy->rwsem); |
2eaa3e2d | 975 | |
9c0ebcf7 | 976 | if (has_target()) { |
e5c87b76 SK |
977 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); |
978 | if (!ret) | |
979 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
980 | ||
981 | if (ret) { | |
3de9bdeb VK |
982 | pr_err("%s: Failed to start governor\n", __func__); |
983 | return ret; | |
984 | } | |
820c6ca2 | 985 | } |
fcf80582 | 986 | |
42f921a6 | 987 | return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
fcf80582 VK |
988 | } |
989 | #endif | |
1da177e4 | 990 | |
8414809c SB |
991 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
992 | { | |
993 | struct cpufreq_policy *policy; | |
994 | unsigned long flags; | |
995 | ||
44871c9c | 996 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
997 | |
998 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
999 | ||
44871c9c | 1000 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c | 1001 | |
6e2c89d1 | 1002 | policy->governor = NULL; |
1003 | ||
8414809c SB |
1004 | return policy; |
1005 | } | |
1006 | ||
e9698cc5 SB |
1007 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
1008 | { | |
1009 | struct cpufreq_policy *policy; | |
1010 | ||
1011 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
1012 | if (!policy) | |
1013 | return NULL; | |
1014 | ||
1015 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1016 | goto err_free_policy; | |
1017 | ||
1018 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1019 | goto err_free_cpumask; | |
1020 | ||
c88a1f8b | 1021 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1022 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1023 | spin_lock_init(&policy->transition_lock); |
1024 | init_waitqueue_head(&policy->transition_wait); | |
ad7722da | 1025 | |
e9698cc5 SB |
1026 | return policy; |
1027 | ||
1028 | err_free_cpumask: | |
1029 | free_cpumask_var(policy->cpus); | |
1030 | err_free_policy: | |
1031 | kfree(policy); | |
1032 | ||
1033 | return NULL; | |
1034 | } | |
1035 | ||
42f921a6 VK |
1036 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
1037 | { | |
1038 | struct kobject *kobj; | |
1039 | struct completion *cmp; | |
1040 | ||
fcd7af91 VK |
1041 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1042 | CPUFREQ_REMOVE_POLICY, policy); | |
1043 | ||
42f921a6 VK |
1044 | down_read(&policy->rwsem); |
1045 | kobj = &policy->kobj; | |
1046 | cmp = &policy->kobj_unregister; | |
1047 | up_read(&policy->rwsem); | |
1048 | kobject_put(kobj); | |
1049 | ||
1050 | /* | |
1051 | * We need to make sure that the underlying kobj is | |
1052 | * actually not referenced anymore by anybody before we | |
1053 | * proceed with unloading. | |
1054 | */ | |
1055 | pr_debug("waiting for dropping of refcount\n"); | |
1056 | wait_for_completion(cmp); | |
1057 | pr_debug("wait complete\n"); | |
1058 | } | |
1059 | ||
e9698cc5 SB |
1060 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
1061 | { | |
1062 | free_cpumask_var(policy->related_cpus); | |
1063 | free_cpumask_var(policy->cpus); | |
1064 | kfree(policy); | |
1065 | } | |
1066 | ||
0d66b91e SB |
1067 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1068 | { | |
99ec899e | 1069 | if (WARN_ON(cpu == policy->cpu)) |
cb38ed5c SB |
1070 | return; |
1071 | ||
ad7722da | 1072 | down_write(&policy->rwsem); |
8efd5765 | 1073 | |
0d66b91e SB |
1074 | policy->last_cpu = policy->cpu; |
1075 | policy->cpu = cpu; | |
1076 | ||
ad7722da | 1077 | up_write(&policy->rwsem); |
8efd5765 | 1078 | |
0d66b91e SB |
1079 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1080 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1081 | } | |
1082 | ||
96bbbe4a | 1083 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1084 | { |
fcf80582 | 1085 | unsigned int j, cpu = dev->id; |
65922465 | 1086 | int ret = -ENOMEM; |
1da177e4 | 1087 | struct cpufreq_policy *policy; |
1da177e4 | 1088 | unsigned long flags; |
96bbbe4a | 1089 | bool recover_policy = cpufreq_suspended; |
90e41bac | 1090 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 1091 | struct cpufreq_policy *tpolicy; |
90e41bac | 1092 | #endif |
1da177e4 | 1093 | |
c32b6b8e AR |
1094 | if (cpu_is_offline(cpu)) |
1095 | return 0; | |
1096 | ||
2d06d8c4 | 1097 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
1098 | |
1099 | #ifdef CONFIG_SMP | |
1100 | /* check whether a different CPU already registered this | |
1101 | * CPU because it is in the same boat. */ | |
1102 | policy = cpufreq_cpu_get(cpu); | |
1103 | if (unlikely(policy)) { | |
8ff69732 | 1104 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1105 | return 0; |
1106 | } | |
5025d628 | 1107 | #endif |
fcf80582 | 1108 | |
6eed9404 VK |
1109 | if (!down_read_trylock(&cpufreq_rwsem)) |
1110 | return 0; | |
1111 | ||
fcf80582 VK |
1112 | #ifdef CONFIG_HOTPLUG_CPU |
1113 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1114 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1115 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1116 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1117 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
42f921a6 | 1118 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev); |
6eed9404 VK |
1119 | up_read(&cpufreq_rwsem); |
1120 | return ret; | |
2eaa3e2d | 1121 | } |
fcf80582 | 1122 | } |
0d1857a1 | 1123 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1124 | #endif |
1125 | ||
72368d12 RW |
1126 | /* |
1127 | * Restore the saved policy when doing light-weight init and fall back | |
1128 | * to the full init if that fails. | |
1129 | */ | |
96bbbe4a | 1130 | policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL; |
72368d12 | 1131 | if (!policy) { |
96bbbe4a | 1132 | recover_policy = false; |
8414809c | 1133 | policy = cpufreq_policy_alloc(); |
72368d12 RW |
1134 | if (!policy) |
1135 | goto nomem_out; | |
1136 | } | |
0d66b91e SB |
1137 | |
1138 | /* | |
1139 | * In the resume path, since we restore a saved policy, the assignment | |
1140 | * to policy->cpu is like an update of the existing policy, rather than | |
1141 | * the creation of a brand new one. So we need to perform this update | |
1142 | * by invoking update_policy_cpu(). | |
1143 | */ | |
96bbbe4a | 1144 | if (recover_policy && cpu != policy->cpu) |
0d66b91e SB |
1145 | update_policy_cpu(policy, cpu); |
1146 | else | |
1147 | policy->cpu = cpu; | |
1148 | ||
835481d9 | 1149 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1150 | |
1da177e4 | 1151 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1152 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1153 | |
1154 | /* call driver. From then on the cpufreq must be able | |
1155 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1156 | */ | |
1c3d85dd | 1157 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1158 | if (ret) { |
2d06d8c4 | 1159 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1160 | goto err_set_policy_cpu; |
1da177e4 | 1161 | } |
643ae6e8 | 1162 | |
5a7e56a5 VK |
1163 | /* related cpus should atleast have policy->cpus */ |
1164 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1165 | ||
1166 | /* | |
1167 | * affected cpus must always be the one, which are online. We aren't | |
1168 | * managing offline cpus here. | |
1169 | */ | |
1170 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1171 | ||
96bbbe4a | 1172 | if (!recover_policy) { |
5a7e56a5 VK |
1173 | policy->user_policy.min = policy->min; |
1174 | policy->user_policy.max = policy->max; | |
1175 | } | |
1176 | ||
4e97b631 | 1177 | down_write(&policy->rwsem); |
652ed95d VK |
1178 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1179 | for_each_cpu(j, policy->cpus) | |
1180 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1181 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1182 | ||
2ed99e39 | 1183 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
da60ce9f VK |
1184 | policy->cur = cpufreq_driver->get(policy->cpu); |
1185 | if (!policy->cur) { | |
1186 | pr_err("%s: ->get() failed\n", __func__); | |
1187 | goto err_get_freq; | |
1188 | } | |
1189 | } | |
1190 | ||
d3916691 VK |
1191 | /* |
1192 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1193 | * frequency table present with cpufreq core. In such cases CPU might be | |
1194 | * unstable if it has to run on that frequency for long duration of time | |
1195 | * and so its better to set it to a frequency which is specified in | |
1196 | * freq-table. This also makes cpufreq stats inconsistent as | |
1197 | * cpufreq-stats would fail to register because current frequency of CPU | |
1198 | * isn't found in freq-table. | |
1199 | * | |
1200 | * Because we don't want this change to effect boot process badly, we go | |
1201 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1202 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1203 | * is initialized to zero). | |
1204 | * | |
1205 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1206 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1207 | * equal to target-freq. | |
1208 | */ | |
1209 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1210 | && has_target()) { | |
1211 | /* Are we running at unknown frequency ? */ | |
1212 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1213 | if (ret == -EINVAL) { | |
1214 | /* Warn user and fix it */ | |
1215 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1216 | __func__, policy->cpu, policy->cur); | |
1217 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1218 | CPUFREQ_RELATION_L); | |
1219 | ||
1220 | /* | |
1221 | * Reaching here after boot in a few seconds may not | |
1222 | * mean that system will remain stable at "unknown" | |
1223 | * frequency for longer duration. Hence, a BUG_ON(). | |
1224 | */ | |
1225 | BUG_ON(ret); | |
1226 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1227 | __func__, policy->cpu, policy->cur); | |
1228 | } | |
1229 | } | |
1230 | ||
a1531acd TR |
1231 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1232 | CPUFREQ_START, policy); | |
1233 | ||
96bbbe4a | 1234 | if (!recover_policy) { |
308b60e7 | 1235 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1236 | if (ret) |
1237 | goto err_out_unregister; | |
fcd7af91 VK |
1238 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1239 | CPUFREQ_CREATE_POLICY, policy); | |
a82fab29 | 1240 | } |
8ff69732 | 1241 | |
9515f4d6 VK |
1242 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1243 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1244 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1245 | ||
e18f1682 SB |
1246 | cpufreq_init_policy(policy); |
1247 | ||
96bbbe4a | 1248 | if (!recover_policy) { |
08fd8c1c VK |
1249 | policy->user_policy.policy = policy->policy; |
1250 | policy->user_policy.governor = policy->governor; | |
1251 | } | |
4e97b631 | 1252 | up_write(&policy->rwsem); |
08fd8c1c | 1253 | |
038c5b3e | 1254 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1255 | up_read(&cpufreq_rwsem); |
1256 | ||
2d06d8c4 | 1257 | pr_debug("initialization complete\n"); |
87c32271 | 1258 | |
1da177e4 LT |
1259 | return 0; |
1260 | ||
1da177e4 | 1261 | err_out_unregister: |
652ed95d | 1262 | err_get_freq: |
0d1857a1 | 1263 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1264 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1265 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1266 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1267 | |
da60ce9f VK |
1268 | if (cpufreq_driver->exit) |
1269 | cpufreq_driver->exit(policy); | |
2eaa3e2d | 1270 | err_set_policy_cpu: |
96bbbe4a | 1271 | if (recover_policy) { |
72368d12 RW |
1272 | /* Do not leave stale fallback data behind. */ |
1273 | per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; | |
42f921a6 | 1274 | cpufreq_policy_put_kobj(policy); |
72368d12 | 1275 | } |
e9698cc5 | 1276 | cpufreq_policy_free(policy); |
42f921a6 | 1277 | |
1da177e4 | 1278 | nomem_out: |
6eed9404 VK |
1279 | up_read(&cpufreq_rwsem); |
1280 | ||
1da177e4 LT |
1281 | return ret; |
1282 | } | |
1283 | ||
a82fab29 SB |
1284 | /** |
1285 | * cpufreq_add_dev - add a CPU device | |
1286 | * | |
1287 | * Adds the cpufreq interface for a CPU device. | |
1288 | * | |
1289 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1290 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1291 | * mess up, but more thorough testing is needed. - Mathieu | |
1292 | */ | |
1293 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1294 | { | |
96bbbe4a | 1295 | return __cpufreq_add_dev(dev, sif); |
a82fab29 SB |
1296 | } |
1297 | ||
3a3e9e06 | 1298 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 1299 | unsigned int old_cpu) |
f9ba680d SB |
1300 | { |
1301 | struct device *cpu_dev; | |
f9ba680d SB |
1302 | int ret; |
1303 | ||
1304 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1305 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 | 1306 | |
f9ba680d | 1307 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1308 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d | 1309 | if (ret) { |
e837f9b5 | 1310 | pr_err("%s: Failed to move kobj: %d\n", __func__, ret); |
f9ba680d | 1311 | |
ad7722da | 1312 | down_write(&policy->rwsem); |
3a3e9e06 | 1313 | cpumask_set_cpu(old_cpu, policy->cpus); |
ad7722da | 1314 | up_write(&policy->rwsem); |
f9ba680d | 1315 | |
3a3e9e06 | 1316 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1317 | "cpufreq"); |
1318 | ||
1319 | return -EINVAL; | |
1320 | } | |
1321 | ||
1322 | return cpu_dev->id; | |
1323 | } | |
1324 | ||
cedb70af | 1325 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
96bbbe4a | 1326 | struct subsys_interface *sif) |
1da177e4 | 1327 | { |
f9ba680d | 1328 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1329 | int new_cpu, ret; |
1da177e4 | 1330 | unsigned long flags; |
3a3e9e06 | 1331 | struct cpufreq_policy *policy; |
1da177e4 | 1332 | |
b8eed8af | 1333 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1334 | |
0d1857a1 | 1335 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1336 | |
3a3e9e06 | 1337 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1338 | |
8414809c | 1339 | /* Save the policy somewhere when doing a light-weight tear-down */ |
96bbbe4a | 1340 | if (cpufreq_suspended) |
3a3e9e06 | 1341 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1342 | |
0d1857a1 | 1343 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1344 | |
3a3e9e06 | 1345 | if (!policy) { |
b8eed8af | 1346 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1347 | return -EINVAL; |
1348 | } | |
1da177e4 | 1349 | |
9c0ebcf7 | 1350 | if (has_target()) { |
3de9bdeb VK |
1351 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1352 | if (ret) { | |
1353 | pr_err("%s: Failed to stop governor\n", __func__); | |
1354 | return ret; | |
1355 | } | |
1356 | } | |
1da177e4 | 1357 | |
1c3d85dd | 1358 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1359 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1360 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 | 1361 | |
ad7722da | 1362 | down_read(&policy->rwsem); |
3a3e9e06 | 1363 | cpus = cpumask_weight(policy->cpus); |
ad7722da | 1364 | up_read(&policy->rwsem); |
084f3493 | 1365 | |
61173f25 | 1366 | if (cpu != policy->cpu) { |
6964d91d | 1367 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
73bf0fc2 | 1368 | } else if (cpus > 1) { |
42f921a6 | 1369 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu); |
f9ba680d | 1370 | if (new_cpu >= 0) { |
3a3e9e06 | 1371 | update_policy_cpu(policy, new_cpu); |
a82fab29 | 1372 | |
bda9f552 | 1373 | if (!cpufreq_suspended) |
75949c9a | 1374 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
e837f9b5 | 1375 | __func__, new_cpu, cpu); |
1da177e4 | 1376 | } |
367dc4aa DB |
1377 | } else if (cpufreq_driver->stop_cpu && cpufreq_driver->setpolicy) { |
1378 | cpufreq_driver->stop_cpu(policy); | |
1da177e4 | 1379 | } |
1da177e4 | 1380 | |
cedb70af SB |
1381 | return 0; |
1382 | } | |
1383 | ||
1384 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
96bbbe4a | 1385 | struct subsys_interface *sif) |
cedb70af SB |
1386 | { |
1387 | unsigned int cpu = dev->id, cpus; | |
1388 | int ret; | |
1389 | unsigned long flags; | |
1390 | struct cpufreq_policy *policy; | |
cedb70af SB |
1391 | |
1392 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1393 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1394 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1395 | ||
1396 | if (!policy) { | |
1397 | pr_debug("%s: No cpu_data found\n", __func__); | |
1398 | return -EINVAL; | |
1399 | } | |
1400 | ||
ad7722da | 1401 | down_write(&policy->rwsem); |
cedb70af | 1402 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1403 | |
1404 | if (cpus > 1) | |
1405 | cpumask_clear_cpu(cpu, policy->cpus); | |
ad7722da | 1406 | up_write(&policy->rwsem); |
cedb70af | 1407 | |
b8eed8af VK |
1408 | /* If cpu is last user of policy, free policy */ |
1409 | if (cpus == 1) { | |
9c0ebcf7 | 1410 | if (has_target()) { |
3de9bdeb VK |
1411 | ret = __cpufreq_governor(policy, |
1412 | CPUFREQ_GOV_POLICY_EXIT); | |
1413 | if (ret) { | |
1414 | pr_err("%s: Failed to exit governor\n", | |
e837f9b5 | 1415 | __func__); |
3de9bdeb VK |
1416 | return ret; |
1417 | } | |
edab2fbc | 1418 | } |
2a998599 | 1419 | |
96bbbe4a | 1420 | if (!cpufreq_suspended) |
42f921a6 | 1421 | cpufreq_policy_put_kobj(policy); |
7d26e2d5 | 1422 | |
8414809c SB |
1423 | /* |
1424 | * Perform the ->exit() even during light-weight tear-down, | |
1425 | * since this is a core component, and is essential for the | |
1426 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1427 | */ |
1c3d85dd | 1428 | if (cpufreq_driver->exit) |
3a3e9e06 | 1429 | cpufreq_driver->exit(policy); |
27ecddc2 | 1430 | |
9515f4d6 VK |
1431 | /* Remove policy from list of active policies */ |
1432 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1433 | list_del(&policy->policy_list); | |
1434 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1435 | ||
96bbbe4a | 1436 | if (!cpufreq_suspended) |
3a3e9e06 | 1437 | cpufreq_policy_free(policy); |
e5c87b76 SK |
1438 | } else if (has_target()) { |
1439 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
1440 | if (!ret) | |
1441 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1442 | ||
1443 | if (ret) { | |
1444 | pr_err("%s: Failed to start governor\n", __func__); | |
1445 | return ret; | |
2a998599 | 1446 | } |
27ecddc2 | 1447 | } |
1da177e4 | 1448 | |
474deff7 | 1449 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1450 | return 0; |
1451 | } | |
1452 | ||
cedb70af | 1453 | /** |
27a862e9 | 1454 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1455 | * |
1456 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1457 | */ |
8a25a2fd | 1458 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1459 | { |
8a25a2fd | 1460 | unsigned int cpu = dev->id; |
27a862e9 | 1461 | int ret; |
ec28297a VP |
1462 | |
1463 | if (cpu_is_offline(cpu)) | |
1464 | return 0; | |
1465 | ||
96bbbe4a | 1466 | ret = __cpufreq_remove_dev_prepare(dev, sif); |
27a862e9 VK |
1467 | |
1468 | if (!ret) | |
96bbbe4a | 1469 | ret = __cpufreq_remove_dev_finish(dev, sif); |
27a862e9 VK |
1470 | |
1471 | return ret; | |
5a01f2e8 VP |
1472 | } |
1473 | ||
65f27f38 | 1474 | static void handle_update(struct work_struct *work) |
1da177e4 | 1475 | { |
65f27f38 DH |
1476 | struct cpufreq_policy *policy = |
1477 | container_of(work, struct cpufreq_policy, update); | |
1478 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1479 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1480 | cpufreq_update_policy(cpu); |
1481 | } | |
1482 | ||
1483 | /** | |
bb176f7d VK |
1484 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1485 | * in deep trouble. | |
1da177e4 LT |
1486 | * @cpu: cpu number |
1487 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1488 | * @new_freq: CPU frequency the CPU actually runs at | |
1489 | * | |
29464f28 DJ |
1490 | * We adjust to current frequency first, and need to clean up later. |
1491 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1492 | */ |
e08f5f5b GS |
1493 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1494 | unsigned int new_freq) | |
1da177e4 | 1495 | { |
b43a7ffb | 1496 | struct cpufreq_policy *policy; |
1da177e4 | 1497 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1498 | unsigned long flags; |
1499 | ||
e837f9b5 JP |
1500 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
1501 | old_freq, new_freq); | |
1da177e4 | 1502 | |
1da177e4 LT |
1503 | freqs.old = old_freq; |
1504 | freqs.new = new_freq; | |
b43a7ffb VK |
1505 | |
1506 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1507 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1508 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1509 | ||
1510 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1511 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1512 | } |
1513 | ||
32ee8c3e | 1514 | /** |
4ab70df4 | 1515 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1516 | * @cpu: CPU number |
1517 | * | |
1518 | * This is the last known freq, without actually getting it from the driver. | |
1519 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1520 | */ | |
1521 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1522 | { | |
9e21ba8b | 1523 | struct cpufreq_policy *policy; |
e08f5f5b | 1524 | unsigned int ret_freq = 0; |
95235ca2 | 1525 | |
1c3d85dd RW |
1526 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1527 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1528 | |
1529 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1530 | if (policy) { |
e08f5f5b | 1531 | ret_freq = policy->cur; |
95235ca2 VP |
1532 | cpufreq_cpu_put(policy); |
1533 | } | |
1534 | ||
4d34a67d | 1535 | return ret_freq; |
95235ca2 VP |
1536 | } |
1537 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1538 | ||
3d737108 JB |
1539 | /** |
1540 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1541 | * @cpu: CPU number | |
1542 | * | |
1543 | * Just return the max possible frequency for a given CPU. | |
1544 | */ | |
1545 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1546 | { | |
1547 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1548 | unsigned int ret_freq = 0; | |
1549 | ||
1550 | if (policy) { | |
1551 | ret_freq = policy->max; | |
1552 | cpufreq_cpu_put(policy); | |
1553 | } | |
1554 | ||
1555 | return ret_freq; | |
1556 | } | |
1557 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1558 | ||
5a01f2e8 | 1559 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1560 | { |
7a6aedfa | 1561 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1562 | unsigned int ret_freq = 0; |
5800043b | 1563 | |
1c3d85dd | 1564 | if (!cpufreq_driver->get) |
4d34a67d | 1565 | return ret_freq; |
1da177e4 | 1566 | |
1c3d85dd | 1567 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1568 | |
e08f5f5b | 1569 | if (ret_freq && policy->cur && |
1c3d85dd | 1570 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1571 | /* verify no discrepancy between actual and |
1572 | saved value exists */ | |
1573 | if (unlikely(ret_freq != policy->cur)) { | |
1574 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1575 | schedule_work(&policy->update); |
1576 | } | |
1577 | } | |
1578 | ||
4d34a67d | 1579 | return ret_freq; |
5a01f2e8 | 1580 | } |
1da177e4 | 1581 | |
5a01f2e8 VP |
1582 | /** |
1583 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1584 | * @cpu: CPU number | |
1585 | * | |
1586 | * Get the CPU current (static) CPU frequency | |
1587 | */ | |
1588 | unsigned int cpufreq_get(unsigned int cpu) | |
1589 | { | |
999976e0 | 1590 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1591 | unsigned int ret_freq = 0; |
5a01f2e8 | 1592 | |
999976e0 AP |
1593 | if (policy) { |
1594 | down_read(&policy->rwsem); | |
1595 | ret_freq = __cpufreq_get(cpu); | |
1596 | up_read(&policy->rwsem); | |
5a01f2e8 | 1597 | |
999976e0 AP |
1598 | cpufreq_cpu_put(policy); |
1599 | } | |
6eed9404 | 1600 | |
4d34a67d | 1601 | return ret_freq; |
1da177e4 LT |
1602 | } |
1603 | EXPORT_SYMBOL(cpufreq_get); | |
1604 | ||
8a25a2fd KS |
1605 | static struct subsys_interface cpufreq_interface = { |
1606 | .name = "cpufreq", | |
1607 | .subsys = &cpu_subsys, | |
1608 | .add_dev = cpufreq_add_dev, | |
1609 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1610 | }; |
1611 | ||
e28867ea VK |
1612 | /* |
1613 | * In case platform wants some specific frequency to be configured | |
1614 | * during suspend.. | |
1615 | */ | |
1616 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1617 | { | |
1618 | int ret; | |
1619 | ||
1620 | if (!policy->suspend_freq) { | |
1621 | pr_err("%s: suspend_freq can't be zero\n", __func__); | |
1622 | return -EINVAL; | |
1623 | } | |
1624 | ||
1625 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1626 | policy->suspend_freq); | |
1627 | ||
1628 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1629 | CPUFREQ_RELATION_H); | |
1630 | if (ret) | |
1631 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1632 | __func__, policy->suspend_freq, ret); | |
1633 | ||
1634 | return ret; | |
1635 | } | |
1636 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1637 | ||
42d4dc3f | 1638 | /** |
2f0aea93 | 1639 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1640 | * |
2f0aea93 VK |
1641 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1642 | * as some platforms can't change frequency after this point in suspend cycle. | |
1643 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1644 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1645 | */ |
2f0aea93 | 1646 | void cpufreq_suspend(void) |
42d4dc3f | 1647 | { |
3a3e9e06 | 1648 | struct cpufreq_policy *policy; |
42d4dc3f | 1649 | |
2f0aea93 VK |
1650 | if (!cpufreq_driver) |
1651 | return; | |
42d4dc3f | 1652 | |
2f0aea93 VK |
1653 | if (!has_target()) |
1654 | return; | |
42d4dc3f | 1655 | |
2f0aea93 VK |
1656 | pr_debug("%s: Suspending Governors\n", __func__); |
1657 | ||
1658 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
1659 | if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) | |
1660 | pr_err("%s: Failed to stop governor for policy: %p\n", | |
1661 | __func__, policy); | |
1662 | else if (cpufreq_driver->suspend | |
1663 | && cpufreq_driver->suspend(policy)) | |
1664 | pr_err("%s: Failed to suspend driver: %p\n", __func__, | |
1665 | policy); | |
42d4dc3f BH |
1666 | } |
1667 | ||
2f0aea93 | 1668 | cpufreq_suspended = true; |
42d4dc3f BH |
1669 | } |
1670 | ||
1da177e4 | 1671 | /** |
2f0aea93 | 1672 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1673 | * |
2f0aea93 VK |
1674 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1675 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1676 | */ |
2f0aea93 | 1677 | void cpufreq_resume(void) |
1da177e4 | 1678 | { |
3a3e9e06 | 1679 | struct cpufreq_policy *policy; |
1da177e4 | 1680 | |
2f0aea93 VK |
1681 | if (!cpufreq_driver) |
1682 | return; | |
1da177e4 | 1683 | |
2f0aea93 | 1684 | if (!has_target()) |
e00e56df | 1685 | return; |
1da177e4 | 1686 | |
2f0aea93 | 1687 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1688 | |
2f0aea93 | 1689 | cpufreq_suspended = false; |
ce6c3997 | 1690 | |
2f0aea93 | 1691 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
0c5aa405 VK |
1692 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) |
1693 | pr_err("%s: Failed to resume driver: %p\n", __func__, | |
1694 | policy); | |
1695 | else if (__cpufreq_governor(policy, CPUFREQ_GOV_START) | |
2f0aea93 VK |
1696 | || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) |
1697 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1698 | __func__, policy); | |
1da177e4 | 1699 | |
2f0aea93 VK |
1700 | /* |
1701 | * schedule call cpufreq_update_policy() for boot CPU, i.e. last | |
1702 | * policy in list. It will verify that the current freq is in | |
1703 | * sync with what we believe it to be. | |
1704 | */ | |
1705 | if (list_is_last(&policy->policy_list, &cpufreq_policy_list)) | |
1706 | schedule_work(&policy->update); | |
1707 | } | |
1708 | } | |
1da177e4 | 1709 | |
9d95046e BP |
1710 | /** |
1711 | * cpufreq_get_current_driver - return current driver's name | |
1712 | * | |
1713 | * Return the name string of the currently loaded cpufreq driver | |
1714 | * or NULL, if none. | |
1715 | */ | |
1716 | const char *cpufreq_get_current_driver(void) | |
1717 | { | |
1c3d85dd RW |
1718 | if (cpufreq_driver) |
1719 | return cpufreq_driver->name; | |
1720 | ||
1721 | return NULL; | |
9d95046e BP |
1722 | } |
1723 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1724 | |
1725 | /********************************************************************* | |
1726 | * NOTIFIER LISTS INTERFACE * | |
1727 | *********************************************************************/ | |
1728 | ||
1729 | /** | |
1730 | * cpufreq_register_notifier - register a driver with cpufreq | |
1731 | * @nb: notifier function to register | |
1732 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1733 | * | |
32ee8c3e | 1734 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1735 | * are notified about clock rate changes (once before and once after |
1736 | * the transition), or a list of drivers that are notified about | |
1737 | * changes in cpufreq policy. | |
1738 | * | |
1739 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1740 | * blocking_notifier_chain_register. |
1da177e4 LT |
1741 | */ |
1742 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1743 | { | |
1744 | int ret; | |
1745 | ||
d5aaffa9 DB |
1746 | if (cpufreq_disabled()) |
1747 | return -EINVAL; | |
1748 | ||
74212ca4 CEB |
1749 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1750 | ||
1da177e4 LT |
1751 | switch (list) { |
1752 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1753 | ret = srcu_notifier_chain_register( |
e041c683 | 1754 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1755 | break; |
1756 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1757 | ret = blocking_notifier_chain_register( |
1758 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1759 | break; |
1760 | default: | |
1761 | ret = -EINVAL; | |
1762 | } | |
1da177e4 LT |
1763 | |
1764 | return ret; | |
1765 | } | |
1766 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1767 | ||
1da177e4 LT |
1768 | /** |
1769 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1770 | * @nb: notifier block to be unregistered | |
bb176f7d | 1771 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1772 | * |
1773 | * Remove a driver from the CPU frequency notifier list. | |
1774 | * | |
1775 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1776 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1777 | */ |
1778 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1779 | { | |
1780 | int ret; | |
1781 | ||
d5aaffa9 DB |
1782 | if (cpufreq_disabled()) |
1783 | return -EINVAL; | |
1784 | ||
1da177e4 LT |
1785 | switch (list) { |
1786 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1787 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1788 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1789 | break; |
1790 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1791 | ret = blocking_notifier_chain_unregister( |
1792 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1793 | break; |
1794 | default: | |
1795 | ret = -EINVAL; | |
1796 | } | |
1da177e4 LT |
1797 | |
1798 | return ret; | |
1799 | } | |
1800 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1801 | ||
1802 | ||
1803 | /********************************************************************* | |
1804 | * GOVERNORS * | |
1805 | *********************************************************************/ | |
1806 | ||
1da177e4 LT |
1807 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1808 | unsigned int target_freq, | |
1809 | unsigned int relation) | |
1810 | { | |
1811 | int retval = -EINVAL; | |
7249924e | 1812 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1813 | |
a7b422cd KRW |
1814 | if (cpufreq_disabled()) |
1815 | return -ENODEV; | |
1816 | ||
7249924e VK |
1817 | /* Make sure that target_freq is within supported range */ |
1818 | if (target_freq > policy->max) | |
1819 | target_freq = policy->max; | |
1820 | if (target_freq < policy->min) | |
1821 | target_freq = policy->min; | |
1822 | ||
1823 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 1824 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 1825 | |
9c0ebcf7 VK |
1826 | /* |
1827 | * This might look like a redundant call as we are checking it again | |
1828 | * after finding index. But it is left intentionally for cases where | |
1829 | * exactly same freq is called again and so we can save on few function | |
1830 | * calls. | |
1831 | */ | |
5a1c0228 VK |
1832 | if (target_freq == policy->cur) |
1833 | return 0; | |
1834 | ||
1c3d85dd RW |
1835 | if (cpufreq_driver->target) |
1836 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
9c0ebcf7 VK |
1837 | else if (cpufreq_driver->target_index) { |
1838 | struct cpufreq_frequency_table *freq_table; | |
d4019f0a VK |
1839 | struct cpufreq_freqs freqs; |
1840 | bool notify; | |
9c0ebcf7 | 1841 | int index; |
90d45d17 | 1842 | |
9c0ebcf7 VK |
1843 | freq_table = cpufreq_frequency_get_table(policy->cpu); |
1844 | if (unlikely(!freq_table)) { | |
1845 | pr_err("%s: Unable to find freq_table\n", __func__); | |
1846 | goto out; | |
1847 | } | |
1848 | ||
1849 | retval = cpufreq_frequency_table_target(policy, freq_table, | |
1850 | target_freq, relation, &index); | |
1851 | if (unlikely(retval)) { | |
1852 | pr_err("%s: Unable to find matching freq\n", __func__); | |
1853 | goto out; | |
1854 | } | |
1855 | ||
d4019f0a | 1856 | if (freq_table[index].frequency == policy->cur) { |
9c0ebcf7 | 1857 | retval = 0; |
d4019f0a VK |
1858 | goto out; |
1859 | } | |
1860 | ||
1861 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); | |
1862 | ||
1863 | if (notify) { | |
1864 | freqs.old = policy->cur; | |
1865 | freqs.new = freq_table[index].frequency; | |
1866 | freqs.flags = 0; | |
1867 | ||
1868 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", | |
e837f9b5 | 1869 | __func__, policy->cpu, freqs.old, freqs.new); |
d4019f0a VK |
1870 | |
1871 | cpufreq_notify_transition(policy, &freqs, | |
1872 | CPUFREQ_PRECHANGE); | |
1873 | } | |
1874 | ||
1875 | retval = cpufreq_driver->target_index(policy, index); | |
1876 | if (retval) | |
1877 | pr_err("%s: Failed to change cpu frequency: %d\n", | |
e837f9b5 | 1878 | __func__, retval); |
d4019f0a | 1879 | |
ab1b1c4e VK |
1880 | if (notify) |
1881 | cpufreq_notify_post_transition(policy, &freqs, retval); | |
9c0ebcf7 VK |
1882 | } |
1883 | ||
1884 | out: | |
1da177e4 LT |
1885 | return retval; |
1886 | } | |
1887 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1888 | ||
1da177e4 LT |
1889 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1890 | unsigned int target_freq, | |
1891 | unsigned int relation) | |
1892 | { | |
f1829e4a | 1893 | int ret = -EINVAL; |
1da177e4 | 1894 | |
ad7722da | 1895 | down_write(&policy->rwsem); |
1da177e4 LT |
1896 | |
1897 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1898 | ||
ad7722da | 1899 | up_write(&policy->rwsem); |
1da177e4 | 1900 | |
1da177e4 LT |
1901 | return ret; |
1902 | } | |
1903 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1904 | ||
153d7f3f | 1905 | /* |
153d7f3f AV |
1906 | * when "event" is CPUFREQ_GOV_LIMITS |
1907 | */ | |
1da177e4 | 1908 | |
e08f5f5b GS |
1909 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1910 | unsigned int event) | |
1da177e4 | 1911 | { |
cc993cab | 1912 | int ret; |
6afde10c TR |
1913 | |
1914 | /* Only must be defined when default governor is known to have latency | |
1915 | restrictions, like e.g. conservative or ondemand. | |
1916 | That this is the case is already ensured in Kconfig | |
1917 | */ | |
1918 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1919 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1920 | #else | |
1921 | struct cpufreq_governor *gov = NULL; | |
1922 | #endif | |
1c256245 | 1923 | |
2f0aea93 VK |
1924 | /* Don't start any governor operations if we are entering suspend */ |
1925 | if (cpufreq_suspended) | |
1926 | return 0; | |
1927 | ||
1c256245 TR |
1928 | if (policy->governor->max_transition_latency && |
1929 | policy->cpuinfo.transition_latency > | |
1930 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1931 | if (!gov) |
1932 | return -EINVAL; | |
1933 | else { | |
e837f9b5 JP |
1934 | pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", |
1935 | policy->governor->name, gov->name); | |
6afde10c TR |
1936 | policy->governor = gov; |
1937 | } | |
1c256245 | 1938 | } |
1da177e4 | 1939 | |
fe492f3f VK |
1940 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1941 | if (!try_module_get(policy->governor->owner)) | |
1942 | return -EINVAL; | |
1da177e4 | 1943 | |
2d06d8c4 | 1944 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e837f9b5 | 1945 | policy->cpu, event); |
95731ebb XC |
1946 | |
1947 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1948 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1949 | || (!policy->governor_enabled |
1950 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1951 | mutex_unlock(&cpufreq_governor_lock); |
1952 | return -EBUSY; | |
1953 | } | |
1954 | ||
1955 | if (event == CPUFREQ_GOV_STOP) | |
1956 | policy->governor_enabled = false; | |
1957 | else if (event == CPUFREQ_GOV_START) | |
1958 | policy->governor_enabled = true; | |
1959 | ||
1960 | mutex_unlock(&cpufreq_governor_lock); | |
1961 | ||
1da177e4 LT |
1962 | ret = policy->governor->governor(policy, event); |
1963 | ||
4d5dcc42 VK |
1964 | if (!ret) { |
1965 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1966 | policy->governor->initialized++; | |
1967 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1968 | policy->governor->initialized--; | |
95731ebb XC |
1969 | } else { |
1970 | /* Restore original values */ | |
1971 | mutex_lock(&cpufreq_governor_lock); | |
1972 | if (event == CPUFREQ_GOV_STOP) | |
1973 | policy->governor_enabled = true; | |
1974 | else if (event == CPUFREQ_GOV_START) | |
1975 | policy->governor_enabled = false; | |
1976 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1977 | } |
b394058f | 1978 | |
fe492f3f VK |
1979 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1980 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1981 | module_put(policy->governor->owner); |
1982 | ||
1983 | return ret; | |
1984 | } | |
1985 | ||
1da177e4 LT |
1986 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1987 | { | |
3bcb09a3 | 1988 | int err; |
1da177e4 LT |
1989 | |
1990 | if (!governor) | |
1991 | return -EINVAL; | |
1992 | ||
a7b422cd KRW |
1993 | if (cpufreq_disabled()) |
1994 | return -ENODEV; | |
1995 | ||
3fc54d37 | 1996 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1997 | |
b394058f | 1998 | governor->initialized = 0; |
3bcb09a3 JF |
1999 | err = -EBUSY; |
2000 | if (__find_governor(governor->name) == NULL) { | |
2001 | err = 0; | |
2002 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2003 | } |
1da177e4 | 2004 | |
32ee8c3e | 2005 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2006 | return err; |
1da177e4 LT |
2007 | } |
2008 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2009 | ||
1da177e4 LT |
2010 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2011 | { | |
90e41bac | 2012 | int cpu; |
90e41bac | 2013 | |
1da177e4 LT |
2014 | if (!governor) |
2015 | return; | |
2016 | ||
a7b422cd KRW |
2017 | if (cpufreq_disabled()) |
2018 | return; | |
2019 | ||
90e41bac PB |
2020 | for_each_present_cpu(cpu) { |
2021 | if (cpu_online(cpu)) | |
2022 | continue; | |
2023 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
2024 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
2025 | } | |
90e41bac | 2026 | |
3fc54d37 | 2027 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2028 | list_del(&governor->governor_list); |
3fc54d37 | 2029 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2030 | return; |
2031 | } | |
2032 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2033 | ||
2034 | ||
1da177e4 LT |
2035 | /********************************************************************* |
2036 | * POLICY INTERFACE * | |
2037 | *********************************************************************/ | |
2038 | ||
2039 | /** | |
2040 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2041 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2042 | * is written | |
1da177e4 LT |
2043 | * |
2044 | * Reads the current cpufreq policy. | |
2045 | */ | |
2046 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2047 | { | |
2048 | struct cpufreq_policy *cpu_policy; | |
2049 | if (!policy) | |
2050 | return -EINVAL; | |
2051 | ||
2052 | cpu_policy = cpufreq_cpu_get(cpu); | |
2053 | if (!cpu_policy) | |
2054 | return -EINVAL; | |
2055 | ||
d5b73cd8 | 2056 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2057 | |
2058 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2059 | return 0; |
2060 | } | |
2061 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2062 | ||
153d7f3f | 2063 | /* |
037ce839 VK |
2064 | * policy : current policy. |
2065 | * new_policy: policy to be set. | |
153d7f3f | 2066 | */ |
037ce839 | 2067 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 2068 | struct cpufreq_policy *new_policy) |
1da177e4 | 2069 | { |
d9a789c7 RW |
2070 | struct cpufreq_governor *old_gov; |
2071 | int ret; | |
1da177e4 | 2072 | |
e837f9b5 JP |
2073 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2074 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2075 | |
d5b73cd8 | 2076 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2077 | |
d9a789c7 RW |
2078 | if (new_policy->min > policy->max || new_policy->max < policy->min) |
2079 | return -EINVAL; | |
9c9a43ed | 2080 | |
1da177e4 | 2081 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2082 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2083 | if (ret) |
d9a789c7 | 2084 | return ret; |
1da177e4 | 2085 | |
1da177e4 | 2086 | /* adjust if necessary - all reasons */ |
e041c683 | 2087 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2088 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
2089 | |
2090 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 2091 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2092 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 2093 | |
bb176f7d VK |
2094 | /* |
2095 | * verify the cpu speed can be set within this limit, which might be | |
2096 | * different to the first one | |
2097 | */ | |
3a3e9e06 | 2098 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2099 | if (ret) |
d9a789c7 | 2100 | return ret; |
1da177e4 LT |
2101 | |
2102 | /* notification of the new policy */ | |
e041c683 | 2103 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2104 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2105 | |
3a3e9e06 VK |
2106 | policy->min = new_policy->min; |
2107 | policy->max = new_policy->max; | |
1da177e4 | 2108 | |
2d06d8c4 | 2109 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2110 | policy->min, policy->max); |
1da177e4 | 2111 | |
1c3d85dd | 2112 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2113 | policy->policy = new_policy->policy; |
2d06d8c4 | 2114 | pr_debug("setting range\n"); |
d9a789c7 RW |
2115 | return cpufreq_driver->setpolicy(new_policy); |
2116 | } | |
1da177e4 | 2117 | |
d9a789c7 RW |
2118 | if (new_policy->governor == policy->governor) |
2119 | goto out; | |
7bd353a9 | 2120 | |
d9a789c7 RW |
2121 | pr_debug("governor switch\n"); |
2122 | ||
2123 | /* save old, working values */ | |
2124 | old_gov = policy->governor; | |
2125 | /* end old governor */ | |
2126 | if (old_gov) { | |
2127 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
2128 | up_write(&policy->rwsem); | |
e5c87b76 | 2129 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); |
d9a789c7 | 2130 | down_write(&policy->rwsem); |
1da177e4 LT |
2131 | } |
2132 | ||
d9a789c7 RW |
2133 | /* start new governor */ |
2134 | policy->governor = new_policy->governor; | |
2135 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
2136 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) | |
2137 | goto out; | |
2138 | ||
2139 | up_write(&policy->rwsem); | |
2140 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); | |
2141 | down_write(&policy->rwsem); | |
2142 | } | |
2143 | ||
2144 | /* new governor failed, so re-start old one */ | |
2145 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2146 | if (old_gov) { | |
2147 | policy->governor = old_gov; | |
2148 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); | |
2149 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
2150 | } | |
2151 | ||
2152 | return -EINVAL; | |
2153 | ||
2154 | out: | |
2155 | pr_debug("governor: change or update limits\n"); | |
2156 | return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1da177e4 LT |
2157 | } |
2158 | ||
1da177e4 LT |
2159 | /** |
2160 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2161 | * @cpu: CPU which shall be re-evaluated | |
2162 | * | |
25985edc | 2163 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2164 | * at different times. |
2165 | */ | |
2166 | int cpufreq_update_policy(unsigned int cpu) | |
2167 | { | |
3a3e9e06 VK |
2168 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2169 | struct cpufreq_policy new_policy; | |
f1829e4a | 2170 | int ret; |
1da177e4 | 2171 | |
3a3e9e06 | 2172 | if (!policy) { |
f1829e4a JL |
2173 | ret = -ENODEV; |
2174 | goto no_policy; | |
2175 | } | |
1da177e4 | 2176 | |
ad7722da | 2177 | down_write(&policy->rwsem); |
1da177e4 | 2178 | |
2d06d8c4 | 2179 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2180 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2181 | new_policy.min = policy->user_policy.min; |
2182 | new_policy.max = policy->user_policy.max; | |
2183 | new_policy.policy = policy->user_policy.policy; | |
2184 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 2185 | |
bb176f7d VK |
2186 | /* |
2187 | * BIOS might change freq behind our back | |
2188 | * -> ask driver for current freq and notify governors about a change | |
2189 | */ | |
2ed99e39 | 2190 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
3a3e9e06 | 2191 | new_policy.cur = cpufreq_driver->get(cpu); |
bd0fa9bb VK |
2192 | if (WARN_ON(!new_policy.cur)) { |
2193 | ret = -EIO; | |
2194 | goto no_policy; | |
2195 | } | |
2196 | ||
3a3e9e06 | 2197 | if (!policy->cur) { |
e837f9b5 | 2198 | pr_debug("Driver did not initialize current freq\n"); |
3a3e9e06 | 2199 | policy->cur = new_policy.cur; |
a85f7bd3 | 2200 | } else { |
9c0ebcf7 | 2201 | if (policy->cur != new_policy.cur && has_target()) |
3a3e9e06 VK |
2202 | cpufreq_out_of_sync(cpu, policy->cur, |
2203 | new_policy.cur); | |
a85f7bd3 | 2204 | } |
0961dd0d TR |
2205 | } |
2206 | ||
037ce839 | 2207 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2208 | |
ad7722da | 2209 | up_write(&policy->rwsem); |
5a01f2e8 | 2210 | |
3a3e9e06 | 2211 | cpufreq_cpu_put(policy); |
f1829e4a | 2212 | no_policy: |
1da177e4 LT |
2213 | return ret; |
2214 | } | |
2215 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2216 | ||
2760984f | 2217 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2218 | unsigned long action, void *hcpu) |
2219 | { | |
2220 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2221 | struct device *dev; |
c32b6b8e | 2222 | |
8a25a2fd KS |
2223 | dev = get_cpu_device(cpu); |
2224 | if (dev) { | |
5302c3fb | 2225 | switch (action & ~CPU_TASKS_FROZEN) { |
c32b6b8e | 2226 | case CPU_ONLINE: |
96bbbe4a | 2227 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e | 2228 | break; |
5302c3fb | 2229 | |
c32b6b8e | 2230 | case CPU_DOWN_PREPARE: |
96bbbe4a | 2231 | __cpufreq_remove_dev_prepare(dev, NULL); |
1aee40ac SB |
2232 | break; |
2233 | ||
2234 | case CPU_POST_DEAD: | |
96bbbe4a | 2235 | __cpufreq_remove_dev_finish(dev, NULL); |
c32b6b8e | 2236 | break; |
5302c3fb | 2237 | |
5a01f2e8 | 2238 | case CPU_DOWN_FAILED: |
96bbbe4a | 2239 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
2240 | break; |
2241 | } | |
2242 | } | |
2243 | return NOTIFY_OK; | |
2244 | } | |
2245 | ||
9c36f746 | 2246 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2247 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2248 | }; |
1da177e4 | 2249 | |
6f19efc0 LM |
2250 | /********************************************************************* |
2251 | * BOOST * | |
2252 | *********************************************************************/ | |
2253 | static int cpufreq_boost_set_sw(int state) | |
2254 | { | |
2255 | struct cpufreq_frequency_table *freq_table; | |
2256 | struct cpufreq_policy *policy; | |
2257 | int ret = -EINVAL; | |
2258 | ||
2259 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
2260 | freq_table = cpufreq_frequency_get_table(policy->cpu); | |
2261 | if (freq_table) { | |
2262 | ret = cpufreq_frequency_table_cpuinfo(policy, | |
2263 | freq_table); | |
2264 | if (ret) { | |
2265 | pr_err("%s: Policy frequency update failed\n", | |
2266 | __func__); | |
2267 | break; | |
2268 | } | |
2269 | policy->user_policy.max = policy->max; | |
2270 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
2271 | } | |
2272 | } | |
2273 | ||
2274 | return ret; | |
2275 | } | |
2276 | ||
2277 | int cpufreq_boost_trigger_state(int state) | |
2278 | { | |
2279 | unsigned long flags; | |
2280 | int ret = 0; | |
2281 | ||
2282 | if (cpufreq_driver->boost_enabled == state) | |
2283 | return 0; | |
2284 | ||
2285 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2286 | cpufreq_driver->boost_enabled = state; | |
2287 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2288 | ||
2289 | ret = cpufreq_driver->set_boost(state); | |
2290 | if (ret) { | |
2291 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2292 | cpufreq_driver->boost_enabled = !state; | |
2293 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2294 | ||
e837f9b5 JP |
2295 | pr_err("%s: Cannot %s BOOST\n", |
2296 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2297 | } |
2298 | ||
2299 | return ret; | |
2300 | } | |
2301 | ||
2302 | int cpufreq_boost_supported(void) | |
2303 | { | |
2304 | if (likely(cpufreq_driver)) | |
2305 | return cpufreq_driver->boost_supported; | |
2306 | ||
2307 | return 0; | |
2308 | } | |
2309 | EXPORT_SYMBOL_GPL(cpufreq_boost_supported); | |
2310 | ||
2311 | int cpufreq_boost_enabled(void) | |
2312 | { | |
2313 | return cpufreq_driver->boost_enabled; | |
2314 | } | |
2315 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2316 | ||
1da177e4 LT |
2317 | /********************************************************************* |
2318 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2319 | *********************************************************************/ | |
2320 | ||
2321 | /** | |
2322 | * cpufreq_register_driver - register a CPU Frequency driver | |
2323 | * @driver_data: A struct cpufreq_driver containing the values# | |
2324 | * submitted by the CPU Frequency driver. | |
2325 | * | |
bb176f7d | 2326 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2327 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2328 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2329 | * |
2330 | */ | |
221dee28 | 2331 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2332 | { |
2333 | unsigned long flags; | |
2334 | int ret; | |
2335 | ||
a7b422cd KRW |
2336 | if (cpufreq_disabled()) |
2337 | return -ENODEV; | |
2338 | ||
1da177e4 | 2339 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2340 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2341 | driver_data->target) || |
2342 | (driver_data->setpolicy && (driver_data->target_index || | |
2343 | driver_data->target))) | |
1da177e4 LT |
2344 | return -EINVAL; |
2345 | ||
2d06d8c4 | 2346 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2347 | |
2348 | if (driver_data->setpolicy) | |
2349 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2350 | ||
0d1857a1 | 2351 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2352 | if (cpufreq_driver) { |
0d1857a1 | 2353 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2354 | return -EEXIST; |
1da177e4 | 2355 | } |
1c3d85dd | 2356 | cpufreq_driver = driver_data; |
0d1857a1 | 2357 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2358 | |
6f19efc0 LM |
2359 | if (cpufreq_boost_supported()) { |
2360 | /* | |
2361 | * Check if driver provides function to enable boost - | |
2362 | * if not, use cpufreq_boost_set_sw as default | |
2363 | */ | |
2364 | if (!cpufreq_driver->set_boost) | |
2365 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; | |
2366 | ||
2367 | ret = cpufreq_sysfs_create_file(&boost.attr); | |
2368 | if (ret) { | |
2369 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
e837f9b5 | 2370 | __func__); |
6f19efc0 LM |
2371 | goto err_null_driver; |
2372 | } | |
2373 | } | |
2374 | ||
8a25a2fd | 2375 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2376 | if (ret) |
6f19efc0 | 2377 | goto err_boost_unreg; |
1da177e4 | 2378 | |
1c3d85dd | 2379 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2380 | int i; |
2381 | ret = -ENODEV; | |
2382 | ||
2383 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2384 | for (i = 0; i < nr_cpu_ids; i++) |
2385 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2386 | ret = 0; |
7a6aedfa MT |
2387 | break; |
2388 | } | |
1da177e4 LT |
2389 | |
2390 | /* if all ->init() calls failed, unregister */ | |
2391 | if (ret) { | |
2d06d8c4 | 2392 | pr_debug("no CPU initialized for driver %s\n", |
e837f9b5 | 2393 | driver_data->name); |
8a25a2fd | 2394 | goto err_if_unreg; |
1da177e4 LT |
2395 | } |
2396 | } | |
2397 | ||
8f5bc2ab | 2398 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2399 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2400 | |
8f5bc2ab | 2401 | return 0; |
8a25a2fd KS |
2402 | err_if_unreg: |
2403 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 LM |
2404 | err_boost_unreg: |
2405 | if (cpufreq_boost_supported()) | |
2406 | cpufreq_sysfs_remove_file(&boost.attr); | |
8f5bc2ab | 2407 | err_null_driver: |
0d1857a1 | 2408 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2409 | cpufreq_driver = NULL; |
0d1857a1 | 2410 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2411 | return ret; |
1da177e4 LT |
2412 | } |
2413 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2414 | ||
1da177e4 LT |
2415 | /** |
2416 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2417 | * | |
bb176f7d | 2418 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2419 | * the right to do so, i.e. if you have succeeded in initialising before! |
2420 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2421 | * currently not initialised. | |
2422 | */ | |
221dee28 | 2423 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2424 | { |
2425 | unsigned long flags; | |
2426 | ||
1c3d85dd | 2427 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2428 | return -EINVAL; |
1da177e4 | 2429 | |
2d06d8c4 | 2430 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2431 | |
8a25a2fd | 2432 | subsys_interface_unregister(&cpufreq_interface); |
6f19efc0 LM |
2433 | if (cpufreq_boost_supported()) |
2434 | cpufreq_sysfs_remove_file(&boost.attr); | |
2435 | ||
65edc68c | 2436 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2437 | |
6eed9404 | 2438 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2439 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2440 | |
1c3d85dd | 2441 | cpufreq_driver = NULL; |
6eed9404 | 2442 | |
0d1857a1 | 2443 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2444 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2445 | |
2446 | return 0; | |
2447 | } | |
2448 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2449 | |
2450 | static int __init cpufreq_core_init(void) | |
2451 | { | |
a7b422cd KRW |
2452 | if (cpufreq_disabled()) |
2453 | return -ENODEV; | |
2454 | ||
2361be23 | 2455 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 TR |
2456 | BUG_ON(!cpufreq_global_kobject); |
2457 | ||
5a01f2e8 VP |
2458 | return 0; |
2459 | } | |
5a01f2e8 | 2460 | core_initcall(cpufreq_core_init); |