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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 | */ | |
236a9800 | 334 | static void cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb VK |
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 | 340 | |
f7ba3b41 | 341 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 342 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
343 | struct cpufreq_freqs *freqs, int transition_failed) |
344 | { | |
345 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
346 | if (!transition_failed) | |
347 | return; | |
348 | ||
349 | swap(freqs->old, freqs->new); | |
350 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
351 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
352 | } | |
f7ba3b41 | 353 | |
12478cf0 SB |
354 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
355 | struct cpufreq_freqs *freqs) | |
356 | { | |
ca654dc3 SB |
357 | |
358 | /* | |
359 | * Catch double invocations of _begin() which lead to self-deadlock. | |
360 | * ASYNC_NOTIFICATION drivers are left out because the cpufreq core | |
361 | * doesn't invoke _begin() on their behalf, and hence the chances of | |
362 | * double invocations are very low. Moreover, there are scenarios | |
363 | * where these checks can emit false-positive warnings in these | |
364 | * drivers; so we avoid that by skipping them altogether. | |
365 | */ | |
366 | WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) | |
367 | && current == policy->transition_task); | |
368 | ||
12478cf0 SB |
369 | wait: |
370 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
371 | ||
372 | spin_lock(&policy->transition_lock); | |
373 | ||
374 | if (unlikely(policy->transition_ongoing)) { | |
375 | spin_unlock(&policy->transition_lock); | |
376 | goto wait; | |
377 | } | |
378 | ||
379 | policy->transition_ongoing = true; | |
ca654dc3 | 380 | policy->transition_task = current; |
12478cf0 SB |
381 | |
382 | spin_unlock(&policy->transition_lock); | |
383 | ||
384 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
385 | } | |
386 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
387 | ||
388 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
389 | struct cpufreq_freqs *freqs, int transition_failed) | |
390 | { | |
391 | if (unlikely(WARN_ON(!policy->transition_ongoing))) | |
392 | return; | |
393 | ||
394 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
395 | ||
396 | policy->transition_ongoing = false; | |
ca654dc3 | 397 | policy->transition_task = NULL; |
12478cf0 SB |
398 | |
399 | wake_up(&policy->transition_wait); | |
400 | } | |
401 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
402 | ||
1da177e4 | 403 | |
1da177e4 LT |
404 | /********************************************************************* |
405 | * SYSFS INTERFACE * | |
406 | *********************************************************************/ | |
8a5c74a1 | 407 | static ssize_t show_boost(struct kobject *kobj, |
6f19efc0 LM |
408 | struct attribute *attr, char *buf) |
409 | { | |
410 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
411 | } | |
412 | ||
413 | static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, | |
414 | const char *buf, size_t count) | |
415 | { | |
416 | int ret, enable; | |
417 | ||
418 | ret = sscanf(buf, "%d", &enable); | |
419 | if (ret != 1 || enable < 0 || enable > 1) | |
420 | return -EINVAL; | |
421 | ||
422 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
423 | pr_err("%s: Cannot %s BOOST!\n", |
424 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
425 | return -EINVAL; |
426 | } | |
427 | ||
e837f9b5 JP |
428 | pr_debug("%s: cpufreq BOOST %s\n", |
429 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
430 | |
431 | return count; | |
432 | } | |
433 | define_one_global_rw(boost); | |
1da177e4 | 434 | |
3bcb09a3 JF |
435 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
436 | { | |
437 | struct cpufreq_governor *t; | |
438 | ||
439 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 440 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
441 | return t; |
442 | ||
443 | return NULL; | |
444 | } | |
445 | ||
1da177e4 LT |
446 | /** |
447 | * cpufreq_parse_governor - parse a governor string | |
448 | */ | |
905d77cd | 449 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
450 | struct cpufreq_governor **governor) |
451 | { | |
3bcb09a3 | 452 | int err = -EINVAL; |
1c3d85dd RW |
453 | |
454 | if (!cpufreq_driver) | |
3bcb09a3 JF |
455 | goto out; |
456 | ||
1c3d85dd | 457 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
458 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
459 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 460 | err = 0; |
e08f5f5b GS |
461 | } else if (!strnicmp(str_governor, "powersave", |
462 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 463 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 464 | err = 0; |
1da177e4 | 465 | } |
9c0ebcf7 | 466 | } else if (has_target()) { |
1da177e4 | 467 | struct cpufreq_governor *t; |
3bcb09a3 | 468 | |
3fc54d37 | 469 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
470 | |
471 | t = __find_governor(str_governor); | |
472 | ||
ea714970 | 473 | if (t == NULL) { |
1a8e1463 | 474 | int ret; |
ea714970 | 475 | |
1a8e1463 KC |
476 | mutex_unlock(&cpufreq_governor_mutex); |
477 | ret = request_module("cpufreq_%s", str_governor); | |
478 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 479 | |
1a8e1463 KC |
480 | if (ret == 0) |
481 | t = __find_governor(str_governor); | |
ea714970 JF |
482 | } |
483 | ||
3bcb09a3 JF |
484 | if (t != NULL) { |
485 | *governor = t; | |
486 | err = 0; | |
1da177e4 | 487 | } |
3bcb09a3 | 488 | |
3fc54d37 | 489 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 490 | } |
29464f28 | 491 | out: |
3bcb09a3 | 492 | return err; |
1da177e4 | 493 | } |
1da177e4 | 494 | |
1da177e4 | 495 | /** |
e08f5f5b GS |
496 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
497 | * print out cpufreq information | |
1da177e4 LT |
498 | * |
499 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
500 | * "unsigned int". | |
501 | */ | |
502 | ||
32ee8c3e DJ |
503 | #define show_one(file_name, object) \ |
504 | static ssize_t show_##file_name \ | |
905d77cd | 505 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 506 | { \ |
29464f28 | 507 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
508 | } |
509 | ||
510 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
511 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 512 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
513 | show_one(scaling_min_freq, min); |
514 | show_one(scaling_max_freq, max); | |
515 | show_one(scaling_cur_freq, cur); | |
516 | ||
037ce839 | 517 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 518 | struct cpufreq_policy *new_policy); |
7970e08b | 519 | |
1da177e4 LT |
520 | /** |
521 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
522 | */ | |
523 | #define store_one(file_name, object) \ | |
524 | static ssize_t store_##file_name \ | |
905d77cd | 525 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 526 | { \ |
5136fa56 | 527 | int ret; \ |
1da177e4 LT |
528 | struct cpufreq_policy new_policy; \ |
529 | \ | |
530 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
531 | if (ret) \ | |
532 | return -EINVAL; \ | |
533 | \ | |
29464f28 | 534 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
535 | if (ret != 1) \ |
536 | return -EINVAL; \ | |
537 | \ | |
037ce839 | 538 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 539 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
540 | \ |
541 | return ret ? ret : count; \ | |
542 | } | |
543 | ||
29464f28 DJ |
544 | store_one(scaling_min_freq, min); |
545 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
546 | |
547 | /** | |
548 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
549 | */ | |
905d77cd DJ |
550 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
551 | char *buf) | |
1da177e4 | 552 | { |
5a01f2e8 | 553 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
554 | if (!cur_freq) |
555 | return sprintf(buf, "<unknown>"); | |
556 | return sprintf(buf, "%u\n", cur_freq); | |
557 | } | |
558 | ||
1da177e4 LT |
559 | /** |
560 | * show_scaling_governor - show the current policy for the specified CPU | |
561 | */ | |
905d77cd | 562 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 563 | { |
29464f28 | 564 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
565 | return sprintf(buf, "powersave\n"); |
566 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
567 | return sprintf(buf, "performance\n"); | |
568 | else if (policy->governor) | |
4b972f0b | 569 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 570 | policy->governor->name); |
1da177e4 LT |
571 | return -EINVAL; |
572 | } | |
573 | ||
1da177e4 LT |
574 | /** |
575 | * store_scaling_governor - store policy for the specified CPU | |
576 | */ | |
905d77cd DJ |
577 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
578 | const char *buf, size_t count) | |
1da177e4 | 579 | { |
5136fa56 | 580 | int ret; |
1da177e4 LT |
581 | char str_governor[16]; |
582 | struct cpufreq_policy new_policy; | |
583 | ||
584 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
585 | if (ret) | |
586 | return ret; | |
587 | ||
29464f28 | 588 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
589 | if (ret != 1) |
590 | return -EINVAL; | |
591 | ||
e08f5f5b GS |
592 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
593 | &new_policy.governor)) | |
1da177e4 LT |
594 | return -EINVAL; |
595 | ||
037ce839 | 596 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
597 | |
598 | policy->user_policy.policy = policy->policy; | |
599 | policy->user_policy.governor = policy->governor; | |
7970e08b | 600 | |
e08f5f5b GS |
601 | if (ret) |
602 | return ret; | |
603 | else | |
604 | return count; | |
1da177e4 LT |
605 | } |
606 | ||
607 | /** | |
608 | * show_scaling_driver - show the cpufreq driver currently loaded | |
609 | */ | |
905d77cd | 610 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 611 | { |
1c3d85dd | 612 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
613 | } |
614 | ||
615 | /** | |
616 | * show_scaling_available_governors - show the available CPUfreq governors | |
617 | */ | |
905d77cd DJ |
618 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
619 | char *buf) | |
1da177e4 LT |
620 | { |
621 | ssize_t i = 0; | |
622 | struct cpufreq_governor *t; | |
623 | ||
9c0ebcf7 | 624 | if (!has_target()) { |
1da177e4 LT |
625 | i += sprintf(buf, "performance powersave"); |
626 | goto out; | |
627 | } | |
628 | ||
629 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
630 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
631 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 632 | goto out; |
4b972f0b | 633 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 634 | } |
7d5e350f | 635 | out: |
1da177e4 LT |
636 | i += sprintf(&buf[i], "\n"); |
637 | return i; | |
638 | } | |
e8628dd0 | 639 | |
f4fd3797 | 640 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
641 | { |
642 | ssize_t i = 0; | |
643 | unsigned int cpu; | |
644 | ||
835481d9 | 645 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
646 | if (i) |
647 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
648 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
649 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 650 | break; |
1da177e4 LT |
651 | } |
652 | i += sprintf(&buf[i], "\n"); | |
653 | return i; | |
654 | } | |
f4fd3797 | 655 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 656 | |
e8628dd0 DW |
657 | /** |
658 | * show_related_cpus - show the CPUs affected by each transition even if | |
659 | * hw coordination is in use | |
660 | */ | |
661 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
662 | { | |
f4fd3797 | 663 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
664 | } |
665 | ||
666 | /** | |
667 | * show_affected_cpus - show the CPUs affected by each transition | |
668 | */ | |
669 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
670 | { | |
f4fd3797 | 671 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
672 | } |
673 | ||
9e76988e | 674 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 675 | const char *buf, size_t count) |
9e76988e VP |
676 | { |
677 | unsigned int freq = 0; | |
678 | unsigned int ret; | |
679 | ||
879000f9 | 680 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
681 | return -EINVAL; |
682 | ||
683 | ret = sscanf(buf, "%u", &freq); | |
684 | if (ret != 1) | |
685 | return -EINVAL; | |
686 | ||
687 | policy->governor->store_setspeed(policy, freq); | |
688 | ||
689 | return count; | |
690 | } | |
691 | ||
692 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
693 | { | |
879000f9 | 694 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
695 | return sprintf(buf, "<unsupported>\n"); |
696 | ||
697 | return policy->governor->show_setspeed(policy, buf); | |
698 | } | |
1da177e4 | 699 | |
e2f74f35 | 700 | /** |
8bf1ac72 | 701 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
702 | */ |
703 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
704 | { | |
705 | unsigned int limit; | |
706 | int ret; | |
1c3d85dd RW |
707 | if (cpufreq_driver->bios_limit) { |
708 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
709 | if (!ret) |
710 | return sprintf(buf, "%u\n", limit); | |
711 | } | |
712 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
713 | } | |
714 | ||
6dad2a29 BP |
715 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
716 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
717 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
718 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
719 | cpufreq_freq_attr_ro(scaling_available_governors); | |
720 | cpufreq_freq_attr_ro(scaling_driver); | |
721 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
722 | cpufreq_freq_attr_ro(bios_limit); | |
723 | cpufreq_freq_attr_ro(related_cpus); | |
724 | cpufreq_freq_attr_ro(affected_cpus); | |
725 | cpufreq_freq_attr_rw(scaling_min_freq); | |
726 | cpufreq_freq_attr_rw(scaling_max_freq); | |
727 | cpufreq_freq_attr_rw(scaling_governor); | |
728 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 729 | |
905d77cd | 730 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
731 | &cpuinfo_min_freq.attr, |
732 | &cpuinfo_max_freq.attr, | |
ed129784 | 733 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
734 | &scaling_min_freq.attr, |
735 | &scaling_max_freq.attr, | |
736 | &affected_cpus.attr, | |
e8628dd0 | 737 | &related_cpus.attr, |
1da177e4 LT |
738 | &scaling_governor.attr, |
739 | &scaling_driver.attr, | |
740 | &scaling_available_governors.attr, | |
9e76988e | 741 | &scaling_setspeed.attr, |
1da177e4 LT |
742 | NULL |
743 | }; | |
744 | ||
29464f28 DJ |
745 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
746 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 747 | |
29464f28 | 748 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 749 | { |
905d77cd DJ |
750 | struct cpufreq_policy *policy = to_policy(kobj); |
751 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 752 | ssize_t ret; |
6eed9404 VK |
753 | |
754 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 755 | return -EINVAL; |
5a01f2e8 | 756 | |
ad7722da | 757 | down_read(&policy->rwsem); |
5a01f2e8 | 758 | |
e08f5f5b GS |
759 | if (fattr->show) |
760 | ret = fattr->show(policy, buf); | |
761 | else | |
762 | ret = -EIO; | |
763 | ||
ad7722da | 764 | up_read(&policy->rwsem); |
6eed9404 | 765 | up_read(&cpufreq_rwsem); |
1b750e3b | 766 | |
1da177e4 LT |
767 | return ret; |
768 | } | |
769 | ||
905d77cd DJ |
770 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
771 | const char *buf, size_t count) | |
1da177e4 | 772 | { |
905d77cd DJ |
773 | struct cpufreq_policy *policy = to_policy(kobj); |
774 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 775 | ssize_t ret = -EINVAL; |
6eed9404 | 776 | |
4f750c93 SB |
777 | get_online_cpus(); |
778 | ||
779 | if (!cpu_online(policy->cpu)) | |
780 | goto unlock; | |
781 | ||
6eed9404 | 782 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 783 | goto unlock; |
5a01f2e8 | 784 | |
ad7722da | 785 | down_write(&policy->rwsem); |
5a01f2e8 | 786 | |
e08f5f5b GS |
787 | if (fattr->store) |
788 | ret = fattr->store(policy, buf, count); | |
789 | else | |
790 | ret = -EIO; | |
791 | ||
ad7722da | 792 | up_write(&policy->rwsem); |
6eed9404 | 793 | |
6eed9404 | 794 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
795 | unlock: |
796 | put_online_cpus(); | |
797 | ||
1da177e4 LT |
798 | return ret; |
799 | } | |
800 | ||
905d77cd | 801 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 802 | { |
905d77cd | 803 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 804 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
805 | complete(&policy->kobj_unregister); |
806 | } | |
807 | ||
52cf25d0 | 808 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
809 | .show = show, |
810 | .store = store, | |
811 | }; | |
812 | ||
813 | static struct kobj_type ktype_cpufreq = { | |
814 | .sysfs_ops = &sysfs_ops, | |
815 | .default_attrs = default_attrs, | |
816 | .release = cpufreq_sysfs_release, | |
817 | }; | |
818 | ||
2361be23 VK |
819 | struct kobject *cpufreq_global_kobject; |
820 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
821 | ||
822 | static int cpufreq_global_kobject_usage; | |
823 | ||
824 | int cpufreq_get_global_kobject(void) | |
825 | { | |
826 | if (!cpufreq_global_kobject_usage++) | |
827 | return kobject_add(cpufreq_global_kobject, | |
828 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
829 | ||
830 | return 0; | |
831 | } | |
832 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
833 | ||
834 | void cpufreq_put_global_kobject(void) | |
835 | { | |
836 | if (!--cpufreq_global_kobject_usage) | |
837 | kobject_del(cpufreq_global_kobject); | |
838 | } | |
839 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
840 | ||
841 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
842 | { | |
843 | int ret = cpufreq_get_global_kobject(); | |
844 | ||
845 | if (!ret) { | |
846 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
847 | if (ret) | |
848 | cpufreq_put_global_kobject(); | |
849 | } | |
850 | ||
851 | return ret; | |
852 | } | |
853 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
854 | ||
855 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
856 | { | |
857 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
858 | cpufreq_put_global_kobject(); | |
859 | } | |
860 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
861 | ||
19d6f7ec | 862 | /* symlink affected CPUs */ |
308b60e7 | 863 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
864 | { |
865 | unsigned int j; | |
866 | int ret = 0; | |
867 | ||
868 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 869 | struct device *cpu_dev; |
19d6f7ec | 870 | |
308b60e7 | 871 | if (j == policy->cpu) |
19d6f7ec | 872 | continue; |
19d6f7ec | 873 | |
e8fdde10 | 874 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
875 | cpu_dev = get_cpu_device(j); |
876 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 877 | "cpufreq"); |
71c3461e RW |
878 | if (ret) |
879 | break; | |
19d6f7ec DJ |
880 | } |
881 | return ret; | |
882 | } | |
883 | ||
308b60e7 | 884 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 885 | struct device *dev) |
909a694e DJ |
886 | { |
887 | struct freq_attr **drv_attr; | |
909a694e | 888 | int ret = 0; |
909a694e DJ |
889 | |
890 | /* prepare interface data */ | |
891 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 892 | &dev->kobj, "cpufreq"); |
909a694e DJ |
893 | if (ret) |
894 | return ret; | |
895 | ||
896 | /* set up files for this cpu device */ | |
1c3d85dd | 897 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
898 | while ((drv_attr) && (*drv_attr)) { |
899 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
900 | if (ret) | |
1c3d85dd | 901 | goto err_out_kobj_put; |
909a694e DJ |
902 | drv_attr++; |
903 | } | |
1c3d85dd | 904 | if (cpufreq_driver->get) { |
909a694e DJ |
905 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
906 | if (ret) | |
1c3d85dd | 907 | goto err_out_kobj_put; |
909a694e | 908 | } |
9c0ebcf7 | 909 | if (has_target()) { |
909a694e DJ |
910 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
911 | if (ret) | |
1c3d85dd | 912 | goto err_out_kobj_put; |
909a694e | 913 | } |
1c3d85dd | 914 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
915 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
916 | if (ret) | |
1c3d85dd | 917 | goto err_out_kobj_put; |
e2f74f35 | 918 | } |
909a694e | 919 | |
308b60e7 | 920 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
921 | if (ret) |
922 | goto err_out_kobj_put; | |
923 | ||
e18f1682 SB |
924 | return ret; |
925 | ||
926 | err_out_kobj_put: | |
927 | kobject_put(&policy->kobj); | |
928 | wait_for_completion(&policy->kobj_unregister); | |
929 | return ret; | |
930 | } | |
931 | ||
932 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
933 | { | |
6e2c89d1 | 934 | struct cpufreq_governor *gov = NULL; |
e18f1682 SB |
935 | struct cpufreq_policy new_policy; |
936 | int ret = 0; | |
937 | ||
d5b73cd8 | 938 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 939 | |
6e2c89d1 | 940 | /* Update governor of new_policy to the governor used before hotplug */ |
941 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); | |
942 | if (gov) | |
943 | pr_debug("Restoring governor %s for cpu %d\n", | |
944 | policy->governor->name, policy->cpu); | |
945 | else | |
946 | gov = CPUFREQ_DEFAULT_GOVERNOR; | |
947 | ||
948 | new_policy.governor = gov; | |
949 | ||
a27a9ab7 JB |
950 | /* Use the default policy if its valid. */ |
951 | if (cpufreq_driver->setpolicy) | |
6e2c89d1 | 952 | cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); |
ecf7e461 DJ |
953 | |
954 | /* set default policy */ | |
037ce839 | 955 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 | 956 | if (ret) { |
2d06d8c4 | 957 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
958 | if (cpufreq_driver->exit) |
959 | cpufreq_driver->exit(policy); | |
ecf7e461 | 960 | } |
909a694e DJ |
961 | } |
962 | ||
fcf80582 | 963 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 | 964 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 965 | unsigned int cpu, struct device *dev) |
fcf80582 | 966 | { |
9c0ebcf7 | 967 | int ret = 0; |
fcf80582 VK |
968 | unsigned long flags; |
969 | ||
9c0ebcf7 | 970 | if (has_target()) { |
3de9bdeb VK |
971 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
972 | if (ret) { | |
973 | pr_err("%s: Failed to stop governor\n", __func__); | |
974 | return ret; | |
975 | } | |
976 | } | |
fcf80582 | 977 | |
ad7722da | 978 | down_write(&policy->rwsem); |
2eaa3e2d | 979 | |
0d1857a1 | 980 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 981 | |
fcf80582 VK |
982 | cpumask_set_cpu(cpu, policy->cpus); |
983 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 984 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 985 | |
ad7722da | 986 | up_write(&policy->rwsem); |
2eaa3e2d | 987 | |
9c0ebcf7 | 988 | if (has_target()) { |
e5c87b76 SK |
989 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); |
990 | if (!ret) | |
991 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
992 | ||
993 | if (ret) { | |
3de9bdeb VK |
994 | pr_err("%s: Failed to start governor\n", __func__); |
995 | return ret; | |
996 | } | |
820c6ca2 | 997 | } |
fcf80582 | 998 | |
42f921a6 | 999 | return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
fcf80582 VK |
1000 | } |
1001 | #endif | |
1da177e4 | 1002 | |
8414809c SB |
1003 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
1004 | { | |
1005 | struct cpufreq_policy *policy; | |
1006 | unsigned long flags; | |
1007 | ||
44871c9c | 1008 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
1009 | |
1010 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
1011 | ||
44871c9c | 1012 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c | 1013 | |
6e2c89d1 | 1014 | policy->governor = NULL; |
1015 | ||
8414809c SB |
1016 | return policy; |
1017 | } | |
1018 | ||
e9698cc5 SB |
1019 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
1020 | { | |
1021 | struct cpufreq_policy *policy; | |
1022 | ||
1023 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
1024 | if (!policy) | |
1025 | return NULL; | |
1026 | ||
1027 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1028 | goto err_free_policy; | |
1029 | ||
1030 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1031 | goto err_free_cpumask; | |
1032 | ||
c88a1f8b | 1033 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1034 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1035 | spin_lock_init(&policy->transition_lock); |
1036 | init_waitqueue_head(&policy->transition_wait); | |
ad7722da | 1037 | |
e9698cc5 SB |
1038 | return policy; |
1039 | ||
1040 | err_free_cpumask: | |
1041 | free_cpumask_var(policy->cpus); | |
1042 | err_free_policy: | |
1043 | kfree(policy); | |
1044 | ||
1045 | return NULL; | |
1046 | } | |
1047 | ||
42f921a6 VK |
1048 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
1049 | { | |
1050 | struct kobject *kobj; | |
1051 | struct completion *cmp; | |
1052 | ||
fcd7af91 VK |
1053 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1054 | CPUFREQ_REMOVE_POLICY, policy); | |
1055 | ||
42f921a6 VK |
1056 | down_read(&policy->rwsem); |
1057 | kobj = &policy->kobj; | |
1058 | cmp = &policy->kobj_unregister; | |
1059 | up_read(&policy->rwsem); | |
1060 | kobject_put(kobj); | |
1061 | ||
1062 | /* | |
1063 | * We need to make sure that the underlying kobj is | |
1064 | * actually not referenced anymore by anybody before we | |
1065 | * proceed with unloading. | |
1066 | */ | |
1067 | pr_debug("waiting for dropping of refcount\n"); | |
1068 | wait_for_completion(cmp); | |
1069 | pr_debug("wait complete\n"); | |
1070 | } | |
1071 | ||
e9698cc5 SB |
1072 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
1073 | { | |
1074 | free_cpumask_var(policy->related_cpus); | |
1075 | free_cpumask_var(policy->cpus); | |
1076 | kfree(policy); | |
1077 | } | |
1078 | ||
1bfb425b VK |
1079 | static int update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu, |
1080 | struct device *cpu_dev) | |
0d66b91e | 1081 | { |
1bfb425b VK |
1082 | int ret; |
1083 | ||
99ec899e | 1084 | if (WARN_ON(cpu == policy->cpu)) |
1bfb425b VK |
1085 | return 0; |
1086 | ||
1087 | /* Move kobject to the new policy->cpu */ | |
1088 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); | |
1089 | if (ret) { | |
1090 | pr_err("%s: Failed to move kobj: %d\n", __func__, ret); | |
1091 | return ret; | |
1092 | } | |
cb38ed5c | 1093 | |
ad7722da | 1094 | down_write(&policy->rwsem); |
8efd5765 | 1095 | |
0d66b91e SB |
1096 | policy->last_cpu = policy->cpu; |
1097 | policy->cpu = cpu; | |
1098 | ||
ad7722da | 1099 | up_write(&policy->rwsem); |
8efd5765 | 1100 | |
0d66b91e SB |
1101 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1102 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1bfb425b VK |
1103 | |
1104 | return 0; | |
0d66b91e SB |
1105 | } |
1106 | ||
96bbbe4a | 1107 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1108 | { |
fcf80582 | 1109 | unsigned int j, cpu = dev->id; |
65922465 | 1110 | int ret = -ENOMEM; |
1da177e4 | 1111 | struct cpufreq_policy *policy; |
1da177e4 | 1112 | unsigned long flags; |
96bbbe4a | 1113 | bool recover_policy = cpufreq_suspended; |
90e41bac | 1114 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 1115 | struct cpufreq_policy *tpolicy; |
90e41bac | 1116 | #endif |
1da177e4 | 1117 | |
c32b6b8e AR |
1118 | if (cpu_is_offline(cpu)) |
1119 | return 0; | |
1120 | ||
2d06d8c4 | 1121 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
1122 | |
1123 | #ifdef CONFIG_SMP | |
1124 | /* check whether a different CPU already registered this | |
1125 | * CPU because it is in the same boat. */ | |
1126 | policy = cpufreq_cpu_get(cpu); | |
1127 | if (unlikely(policy)) { | |
8ff69732 | 1128 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1129 | return 0; |
1130 | } | |
5025d628 | 1131 | #endif |
fcf80582 | 1132 | |
6eed9404 VK |
1133 | if (!down_read_trylock(&cpufreq_rwsem)) |
1134 | return 0; | |
1135 | ||
fcf80582 VK |
1136 | #ifdef CONFIG_HOTPLUG_CPU |
1137 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1138 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1139 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1140 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1141 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
42f921a6 | 1142 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev); |
6eed9404 VK |
1143 | up_read(&cpufreq_rwsem); |
1144 | return ret; | |
2eaa3e2d | 1145 | } |
fcf80582 | 1146 | } |
0d1857a1 | 1147 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1148 | #endif |
1149 | ||
72368d12 RW |
1150 | /* |
1151 | * Restore the saved policy when doing light-weight init and fall back | |
1152 | * to the full init if that fails. | |
1153 | */ | |
96bbbe4a | 1154 | policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL; |
72368d12 | 1155 | if (!policy) { |
96bbbe4a | 1156 | recover_policy = false; |
8414809c | 1157 | policy = cpufreq_policy_alloc(); |
72368d12 RW |
1158 | if (!policy) |
1159 | goto nomem_out; | |
1160 | } | |
0d66b91e SB |
1161 | |
1162 | /* | |
1163 | * In the resume path, since we restore a saved policy, the assignment | |
1164 | * to policy->cpu is like an update of the existing policy, rather than | |
1165 | * the creation of a brand new one. So we need to perform this update | |
1166 | * by invoking update_policy_cpu(). | |
1167 | */ | |
1bfb425b VK |
1168 | if (recover_policy && cpu != policy->cpu) |
1169 | WARN_ON(update_policy_cpu(policy, cpu, dev)); | |
1170 | else | |
0d66b91e SB |
1171 | policy->cpu = cpu; |
1172 | ||
835481d9 | 1173 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1174 | |
1da177e4 | 1175 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1176 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1177 | |
1178 | /* call driver. From then on the cpufreq must be able | |
1179 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1180 | */ | |
1c3d85dd | 1181 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1182 | if (ret) { |
2d06d8c4 | 1183 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1184 | goto err_set_policy_cpu; |
1da177e4 | 1185 | } |
643ae6e8 | 1186 | |
5a7e56a5 VK |
1187 | /* related cpus should atleast have policy->cpus */ |
1188 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1189 | ||
1190 | /* | |
1191 | * affected cpus must always be the one, which are online. We aren't | |
1192 | * managing offline cpus here. | |
1193 | */ | |
1194 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1195 | ||
96bbbe4a | 1196 | if (!recover_policy) { |
5a7e56a5 VK |
1197 | policy->user_policy.min = policy->min; |
1198 | policy->user_policy.max = policy->max; | |
1199 | } | |
1200 | ||
4e97b631 | 1201 | down_write(&policy->rwsem); |
652ed95d VK |
1202 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1203 | for_each_cpu(j, policy->cpus) | |
1204 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1205 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1206 | ||
2ed99e39 | 1207 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
da60ce9f VK |
1208 | policy->cur = cpufreq_driver->get(policy->cpu); |
1209 | if (!policy->cur) { | |
1210 | pr_err("%s: ->get() failed\n", __func__); | |
1211 | goto err_get_freq; | |
1212 | } | |
1213 | } | |
1214 | ||
d3916691 VK |
1215 | /* |
1216 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1217 | * frequency table present with cpufreq core. In such cases CPU might be | |
1218 | * unstable if it has to run on that frequency for long duration of time | |
1219 | * and so its better to set it to a frequency which is specified in | |
1220 | * freq-table. This also makes cpufreq stats inconsistent as | |
1221 | * cpufreq-stats would fail to register because current frequency of CPU | |
1222 | * isn't found in freq-table. | |
1223 | * | |
1224 | * Because we don't want this change to effect boot process badly, we go | |
1225 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1226 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1227 | * is initialized to zero). | |
1228 | * | |
1229 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1230 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1231 | * equal to target-freq. | |
1232 | */ | |
1233 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1234 | && has_target()) { | |
1235 | /* Are we running at unknown frequency ? */ | |
1236 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1237 | if (ret == -EINVAL) { | |
1238 | /* Warn user and fix it */ | |
1239 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1240 | __func__, policy->cpu, policy->cur); | |
1241 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1242 | CPUFREQ_RELATION_L); | |
1243 | ||
1244 | /* | |
1245 | * Reaching here after boot in a few seconds may not | |
1246 | * mean that system will remain stable at "unknown" | |
1247 | * frequency for longer duration. Hence, a BUG_ON(). | |
1248 | */ | |
1249 | BUG_ON(ret); | |
1250 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1251 | __func__, policy->cpu, policy->cur); | |
1252 | } | |
1253 | } | |
1254 | ||
a1531acd TR |
1255 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1256 | CPUFREQ_START, policy); | |
1257 | ||
96bbbe4a | 1258 | if (!recover_policy) { |
308b60e7 | 1259 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1260 | if (ret) |
1261 | goto err_out_unregister; | |
fcd7af91 VK |
1262 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1263 | CPUFREQ_CREATE_POLICY, policy); | |
a82fab29 | 1264 | } |
8ff69732 | 1265 | |
9515f4d6 VK |
1266 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1267 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1268 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1269 | ||
e18f1682 SB |
1270 | cpufreq_init_policy(policy); |
1271 | ||
96bbbe4a | 1272 | if (!recover_policy) { |
08fd8c1c VK |
1273 | policy->user_policy.policy = policy->policy; |
1274 | policy->user_policy.governor = policy->governor; | |
1275 | } | |
4e97b631 | 1276 | up_write(&policy->rwsem); |
08fd8c1c | 1277 | |
038c5b3e | 1278 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1279 | up_read(&cpufreq_rwsem); |
1280 | ||
2d06d8c4 | 1281 | pr_debug("initialization complete\n"); |
87c32271 | 1282 | |
1da177e4 LT |
1283 | return 0; |
1284 | ||
1da177e4 | 1285 | err_out_unregister: |
652ed95d | 1286 | err_get_freq: |
0d1857a1 | 1287 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1288 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1289 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1290 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1291 | |
7106e02b PB |
1292 | up_write(&policy->rwsem); |
1293 | ||
da60ce9f VK |
1294 | if (cpufreq_driver->exit) |
1295 | cpufreq_driver->exit(policy); | |
2eaa3e2d | 1296 | err_set_policy_cpu: |
96bbbe4a | 1297 | if (recover_policy) { |
72368d12 RW |
1298 | /* Do not leave stale fallback data behind. */ |
1299 | per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; | |
42f921a6 | 1300 | cpufreq_policy_put_kobj(policy); |
72368d12 | 1301 | } |
e9698cc5 | 1302 | cpufreq_policy_free(policy); |
42f921a6 | 1303 | |
1da177e4 | 1304 | nomem_out: |
6eed9404 VK |
1305 | up_read(&cpufreq_rwsem); |
1306 | ||
1da177e4 LT |
1307 | return ret; |
1308 | } | |
1309 | ||
a82fab29 SB |
1310 | /** |
1311 | * cpufreq_add_dev - add a CPU device | |
1312 | * | |
1313 | * Adds the cpufreq interface for a CPU device. | |
1314 | * | |
1315 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1316 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1317 | * mess up, but more thorough testing is needed. - Mathieu | |
1318 | */ | |
1319 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1320 | { | |
96bbbe4a | 1321 | return __cpufreq_add_dev(dev, sif); |
a82fab29 SB |
1322 | } |
1323 | ||
cedb70af | 1324 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
96bbbe4a | 1325 | struct subsys_interface *sif) |
1da177e4 | 1326 | { |
f9ba680d | 1327 | unsigned int cpu = dev->id, cpus; |
1bfb425b | 1328 | int ret; |
1da177e4 | 1329 | unsigned long flags; |
3a3e9e06 | 1330 | struct cpufreq_policy *policy; |
1da177e4 | 1331 | |
b8eed8af | 1332 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1333 | |
0d1857a1 | 1334 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1335 | |
3a3e9e06 | 1336 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1337 | |
8414809c | 1338 | /* Save the policy somewhere when doing a light-weight tear-down */ |
96bbbe4a | 1339 | if (cpufreq_suspended) |
3a3e9e06 | 1340 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1341 | |
0d1857a1 | 1342 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1343 | |
3a3e9e06 | 1344 | if (!policy) { |
b8eed8af | 1345 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1346 | return -EINVAL; |
1347 | } | |
1da177e4 | 1348 | |
9c0ebcf7 | 1349 | if (has_target()) { |
3de9bdeb VK |
1350 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1351 | if (ret) { | |
1352 | pr_err("%s: Failed to stop governor\n", __func__); | |
1353 | return ret; | |
1354 | } | |
1355 | } | |
1da177e4 | 1356 | |
1c3d85dd | 1357 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1358 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1359 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 | 1360 | |
ad7722da | 1361 | down_read(&policy->rwsem); |
3a3e9e06 | 1362 | cpus = cpumask_weight(policy->cpus); |
ad7722da | 1363 | up_read(&policy->rwsem); |
084f3493 | 1364 | |
61173f25 | 1365 | if (cpu != policy->cpu) { |
6964d91d | 1366 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
73bf0fc2 | 1367 | } else if (cpus > 1) { |
1bfb425b VK |
1368 | /* Nominate new CPU */ |
1369 | int new_cpu = cpumask_any_but(policy->cpus, cpu); | |
1370 | struct device *cpu_dev = get_cpu_device(new_cpu); | |
a82fab29 | 1371 | |
1bfb425b VK |
1372 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
1373 | ret = update_policy_cpu(policy, new_cpu, cpu_dev); | |
1374 | if (ret) { | |
1375 | if (sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
1376 | "cpufreq")) | |
1377 | pr_err("%s: Failed to restore kobj link to cpu:%d\n", | |
1378 | __func__, cpu_dev->id); | |
1379 | return ret; | |
1da177e4 | 1380 | } |
1bfb425b VK |
1381 | |
1382 | if (!cpufreq_suspended) | |
1383 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", | |
1384 | __func__, new_cpu, cpu); | |
367dc4aa DB |
1385 | } else if (cpufreq_driver->stop_cpu && cpufreq_driver->setpolicy) { |
1386 | cpufreq_driver->stop_cpu(policy); | |
1da177e4 | 1387 | } |
1da177e4 | 1388 | |
cedb70af SB |
1389 | return 0; |
1390 | } | |
1391 | ||
1392 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
96bbbe4a | 1393 | struct subsys_interface *sif) |
cedb70af SB |
1394 | { |
1395 | unsigned int cpu = dev->id, cpus; | |
1396 | int ret; | |
1397 | unsigned long flags; | |
1398 | struct cpufreq_policy *policy; | |
cedb70af SB |
1399 | |
1400 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1401 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1402 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1403 | ||
1404 | if (!policy) { | |
1405 | pr_debug("%s: No cpu_data found\n", __func__); | |
1406 | return -EINVAL; | |
1407 | } | |
1408 | ||
ad7722da | 1409 | down_write(&policy->rwsem); |
cedb70af | 1410 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1411 | |
1412 | if (cpus > 1) | |
1413 | cpumask_clear_cpu(cpu, policy->cpus); | |
ad7722da | 1414 | up_write(&policy->rwsem); |
cedb70af | 1415 | |
b8eed8af VK |
1416 | /* If cpu is last user of policy, free policy */ |
1417 | if (cpus == 1) { | |
9c0ebcf7 | 1418 | if (has_target()) { |
3de9bdeb VK |
1419 | ret = __cpufreq_governor(policy, |
1420 | CPUFREQ_GOV_POLICY_EXIT); | |
1421 | if (ret) { | |
1422 | pr_err("%s: Failed to exit governor\n", | |
e837f9b5 | 1423 | __func__); |
3de9bdeb VK |
1424 | return ret; |
1425 | } | |
edab2fbc | 1426 | } |
2a998599 | 1427 | |
96bbbe4a | 1428 | if (!cpufreq_suspended) |
42f921a6 | 1429 | cpufreq_policy_put_kobj(policy); |
7d26e2d5 | 1430 | |
8414809c SB |
1431 | /* |
1432 | * Perform the ->exit() even during light-weight tear-down, | |
1433 | * since this is a core component, and is essential for the | |
1434 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1435 | */ |
1c3d85dd | 1436 | if (cpufreq_driver->exit) |
3a3e9e06 | 1437 | cpufreq_driver->exit(policy); |
27ecddc2 | 1438 | |
9515f4d6 VK |
1439 | /* Remove policy from list of active policies */ |
1440 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1441 | list_del(&policy->policy_list); | |
1442 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1443 | ||
96bbbe4a | 1444 | if (!cpufreq_suspended) |
3a3e9e06 | 1445 | cpufreq_policy_free(policy); |
e5c87b76 SK |
1446 | } else if (has_target()) { |
1447 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
1448 | if (!ret) | |
1449 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1450 | ||
1451 | if (ret) { | |
1452 | pr_err("%s: Failed to start governor\n", __func__); | |
1453 | return ret; | |
2a998599 | 1454 | } |
27ecddc2 | 1455 | } |
1da177e4 | 1456 | |
474deff7 | 1457 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1458 | return 0; |
1459 | } | |
1460 | ||
cedb70af | 1461 | /** |
27a862e9 | 1462 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1463 | * |
1464 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1465 | */ |
8a25a2fd | 1466 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1467 | { |
8a25a2fd | 1468 | unsigned int cpu = dev->id; |
27a862e9 | 1469 | int ret; |
ec28297a VP |
1470 | |
1471 | if (cpu_is_offline(cpu)) | |
1472 | return 0; | |
1473 | ||
96bbbe4a | 1474 | ret = __cpufreq_remove_dev_prepare(dev, sif); |
27a862e9 VK |
1475 | |
1476 | if (!ret) | |
96bbbe4a | 1477 | ret = __cpufreq_remove_dev_finish(dev, sif); |
27a862e9 VK |
1478 | |
1479 | return ret; | |
5a01f2e8 VP |
1480 | } |
1481 | ||
65f27f38 | 1482 | static void handle_update(struct work_struct *work) |
1da177e4 | 1483 | { |
65f27f38 DH |
1484 | struct cpufreq_policy *policy = |
1485 | container_of(work, struct cpufreq_policy, update); | |
1486 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1487 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1488 | cpufreq_update_policy(cpu); |
1489 | } | |
1490 | ||
1491 | /** | |
bb176f7d VK |
1492 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1493 | * in deep trouble. | |
1da177e4 LT |
1494 | * @cpu: cpu number |
1495 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1496 | * @new_freq: CPU frequency the CPU actually runs at | |
1497 | * | |
29464f28 DJ |
1498 | * We adjust to current frequency first, and need to clean up later. |
1499 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1500 | */ |
e08f5f5b GS |
1501 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1502 | unsigned int new_freq) | |
1da177e4 | 1503 | { |
b43a7ffb | 1504 | struct cpufreq_policy *policy; |
1da177e4 | 1505 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1506 | unsigned long flags; |
1507 | ||
e837f9b5 JP |
1508 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
1509 | old_freq, new_freq); | |
1da177e4 | 1510 | |
1da177e4 LT |
1511 | freqs.old = old_freq; |
1512 | freqs.new = new_freq; | |
b43a7ffb VK |
1513 | |
1514 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1515 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1516 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1517 | ||
8fec051e VK |
1518 | cpufreq_freq_transition_begin(policy, &freqs); |
1519 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1520 | } |
1521 | ||
32ee8c3e | 1522 | /** |
4ab70df4 | 1523 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1524 | * @cpu: CPU number |
1525 | * | |
1526 | * This is the last known freq, without actually getting it from the driver. | |
1527 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1528 | */ | |
1529 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1530 | { | |
9e21ba8b | 1531 | struct cpufreq_policy *policy; |
e08f5f5b | 1532 | unsigned int ret_freq = 0; |
95235ca2 | 1533 | |
1c3d85dd RW |
1534 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1535 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1536 | |
1537 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1538 | if (policy) { |
e08f5f5b | 1539 | ret_freq = policy->cur; |
95235ca2 VP |
1540 | cpufreq_cpu_put(policy); |
1541 | } | |
1542 | ||
4d34a67d | 1543 | return ret_freq; |
95235ca2 VP |
1544 | } |
1545 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1546 | ||
3d737108 JB |
1547 | /** |
1548 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1549 | * @cpu: CPU number | |
1550 | * | |
1551 | * Just return the max possible frequency for a given CPU. | |
1552 | */ | |
1553 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1554 | { | |
1555 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1556 | unsigned int ret_freq = 0; | |
1557 | ||
1558 | if (policy) { | |
1559 | ret_freq = policy->max; | |
1560 | cpufreq_cpu_put(policy); | |
1561 | } | |
1562 | ||
1563 | return ret_freq; | |
1564 | } | |
1565 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1566 | ||
5a01f2e8 | 1567 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1568 | { |
7a6aedfa | 1569 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1570 | unsigned int ret_freq = 0; |
5800043b | 1571 | |
1c3d85dd | 1572 | if (!cpufreq_driver->get) |
4d34a67d | 1573 | return ret_freq; |
1da177e4 | 1574 | |
1c3d85dd | 1575 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1576 | |
e08f5f5b | 1577 | if (ret_freq && policy->cur && |
1c3d85dd | 1578 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1579 | /* verify no discrepancy between actual and |
1580 | saved value exists */ | |
1581 | if (unlikely(ret_freq != policy->cur)) { | |
1582 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1583 | schedule_work(&policy->update); |
1584 | } | |
1585 | } | |
1586 | ||
4d34a67d | 1587 | return ret_freq; |
5a01f2e8 | 1588 | } |
1da177e4 | 1589 | |
5a01f2e8 VP |
1590 | /** |
1591 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1592 | * @cpu: CPU number | |
1593 | * | |
1594 | * Get the CPU current (static) CPU frequency | |
1595 | */ | |
1596 | unsigned int cpufreq_get(unsigned int cpu) | |
1597 | { | |
999976e0 | 1598 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1599 | unsigned int ret_freq = 0; |
5a01f2e8 | 1600 | |
999976e0 AP |
1601 | if (policy) { |
1602 | down_read(&policy->rwsem); | |
1603 | ret_freq = __cpufreq_get(cpu); | |
1604 | up_read(&policy->rwsem); | |
5a01f2e8 | 1605 | |
999976e0 AP |
1606 | cpufreq_cpu_put(policy); |
1607 | } | |
6eed9404 | 1608 | |
4d34a67d | 1609 | return ret_freq; |
1da177e4 LT |
1610 | } |
1611 | EXPORT_SYMBOL(cpufreq_get); | |
1612 | ||
8a25a2fd KS |
1613 | static struct subsys_interface cpufreq_interface = { |
1614 | .name = "cpufreq", | |
1615 | .subsys = &cpu_subsys, | |
1616 | .add_dev = cpufreq_add_dev, | |
1617 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1618 | }; |
1619 | ||
e28867ea VK |
1620 | /* |
1621 | * In case platform wants some specific frequency to be configured | |
1622 | * during suspend.. | |
1623 | */ | |
1624 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1625 | { | |
1626 | int ret; | |
1627 | ||
1628 | if (!policy->suspend_freq) { | |
1629 | pr_err("%s: suspend_freq can't be zero\n", __func__); | |
1630 | return -EINVAL; | |
1631 | } | |
1632 | ||
1633 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1634 | policy->suspend_freq); | |
1635 | ||
1636 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1637 | CPUFREQ_RELATION_H); | |
1638 | if (ret) | |
1639 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1640 | __func__, policy->suspend_freq, ret); | |
1641 | ||
1642 | return ret; | |
1643 | } | |
1644 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1645 | ||
42d4dc3f | 1646 | /** |
2f0aea93 | 1647 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1648 | * |
2f0aea93 VK |
1649 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1650 | * as some platforms can't change frequency after this point in suspend cycle. | |
1651 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1652 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1653 | */ |
2f0aea93 | 1654 | void cpufreq_suspend(void) |
42d4dc3f | 1655 | { |
3a3e9e06 | 1656 | struct cpufreq_policy *policy; |
42d4dc3f | 1657 | |
2f0aea93 VK |
1658 | if (!cpufreq_driver) |
1659 | return; | |
42d4dc3f | 1660 | |
8e30444e LT |
1661 | cpufreq_suspended = true; |
1662 | ||
2f0aea93 VK |
1663 | if (!has_target()) |
1664 | return; | |
42d4dc3f | 1665 | |
2f0aea93 VK |
1666 | pr_debug("%s: Suspending Governors\n", __func__); |
1667 | ||
1668 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
1669 | if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) | |
1670 | pr_err("%s: Failed to stop governor for policy: %p\n", | |
1671 | __func__, policy); | |
1672 | else if (cpufreq_driver->suspend | |
1673 | && cpufreq_driver->suspend(policy)) | |
1674 | pr_err("%s: Failed to suspend driver: %p\n", __func__, | |
1675 | policy); | |
42d4dc3f | 1676 | } |
42d4dc3f BH |
1677 | } |
1678 | ||
1da177e4 | 1679 | /** |
2f0aea93 | 1680 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1681 | * |
2f0aea93 VK |
1682 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1683 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1684 | */ |
2f0aea93 | 1685 | void cpufreq_resume(void) |
1da177e4 | 1686 | { |
3a3e9e06 | 1687 | struct cpufreq_policy *policy; |
1da177e4 | 1688 | |
2f0aea93 VK |
1689 | if (!cpufreq_driver) |
1690 | return; | |
1da177e4 | 1691 | |
8e30444e LT |
1692 | cpufreq_suspended = false; |
1693 | ||
2f0aea93 | 1694 | if (!has_target()) |
e00e56df | 1695 | return; |
1da177e4 | 1696 | |
2f0aea93 | 1697 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1698 | |
2f0aea93 | 1699 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
0c5aa405 VK |
1700 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) |
1701 | pr_err("%s: Failed to resume driver: %p\n", __func__, | |
1702 | policy); | |
1703 | else if (__cpufreq_governor(policy, CPUFREQ_GOV_START) | |
2f0aea93 VK |
1704 | || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) |
1705 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1706 | __func__, policy); | |
1da177e4 | 1707 | |
2f0aea93 VK |
1708 | /* |
1709 | * schedule call cpufreq_update_policy() for boot CPU, i.e. last | |
1710 | * policy in list. It will verify that the current freq is in | |
1711 | * sync with what we believe it to be. | |
1712 | */ | |
1713 | if (list_is_last(&policy->policy_list, &cpufreq_policy_list)) | |
1714 | schedule_work(&policy->update); | |
1715 | } | |
1716 | } | |
1da177e4 | 1717 | |
9d95046e BP |
1718 | /** |
1719 | * cpufreq_get_current_driver - return current driver's name | |
1720 | * | |
1721 | * Return the name string of the currently loaded cpufreq driver | |
1722 | * or NULL, if none. | |
1723 | */ | |
1724 | const char *cpufreq_get_current_driver(void) | |
1725 | { | |
1c3d85dd RW |
1726 | if (cpufreq_driver) |
1727 | return cpufreq_driver->name; | |
1728 | ||
1729 | return NULL; | |
9d95046e BP |
1730 | } |
1731 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1732 | |
1733 | /********************************************************************* | |
1734 | * NOTIFIER LISTS INTERFACE * | |
1735 | *********************************************************************/ | |
1736 | ||
1737 | /** | |
1738 | * cpufreq_register_notifier - register a driver with cpufreq | |
1739 | * @nb: notifier function to register | |
1740 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1741 | * | |
32ee8c3e | 1742 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1743 | * are notified about clock rate changes (once before and once after |
1744 | * the transition), or a list of drivers that are notified about | |
1745 | * changes in cpufreq policy. | |
1746 | * | |
1747 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1748 | * blocking_notifier_chain_register. |
1da177e4 LT |
1749 | */ |
1750 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1751 | { | |
1752 | int ret; | |
1753 | ||
d5aaffa9 DB |
1754 | if (cpufreq_disabled()) |
1755 | return -EINVAL; | |
1756 | ||
74212ca4 CEB |
1757 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1758 | ||
1da177e4 LT |
1759 | switch (list) { |
1760 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1761 | ret = srcu_notifier_chain_register( |
e041c683 | 1762 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1763 | break; |
1764 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1765 | ret = blocking_notifier_chain_register( |
1766 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1767 | break; |
1768 | default: | |
1769 | ret = -EINVAL; | |
1770 | } | |
1da177e4 LT |
1771 | |
1772 | return ret; | |
1773 | } | |
1774 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1775 | ||
1da177e4 LT |
1776 | /** |
1777 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1778 | * @nb: notifier block to be unregistered | |
bb176f7d | 1779 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1780 | * |
1781 | * Remove a driver from the CPU frequency notifier list. | |
1782 | * | |
1783 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1784 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1785 | */ |
1786 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1787 | { | |
1788 | int ret; | |
1789 | ||
d5aaffa9 DB |
1790 | if (cpufreq_disabled()) |
1791 | return -EINVAL; | |
1792 | ||
1da177e4 LT |
1793 | switch (list) { |
1794 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1795 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1796 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1797 | break; |
1798 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1799 | ret = blocking_notifier_chain_unregister( |
1800 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1801 | break; |
1802 | default: | |
1803 | ret = -EINVAL; | |
1804 | } | |
1da177e4 LT |
1805 | |
1806 | return ret; | |
1807 | } | |
1808 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1809 | ||
1810 | ||
1811 | /********************************************************************* | |
1812 | * GOVERNORS * | |
1813 | *********************************************************************/ | |
1814 | ||
1c03a2d0 VK |
1815 | /* Must set freqs->new to intermediate frequency */ |
1816 | static int __target_intermediate(struct cpufreq_policy *policy, | |
1817 | struct cpufreq_freqs *freqs, int index) | |
1818 | { | |
1819 | int ret; | |
1820 | ||
1821 | freqs->new = cpufreq_driver->get_intermediate(policy, index); | |
1822 | ||
1823 | /* We don't need to switch to intermediate freq */ | |
1824 | if (!freqs->new) | |
1825 | return 0; | |
1826 | ||
1827 | pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", | |
1828 | __func__, policy->cpu, freqs->old, freqs->new); | |
1829 | ||
1830 | cpufreq_freq_transition_begin(policy, freqs); | |
1831 | ret = cpufreq_driver->target_intermediate(policy, index); | |
1832 | cpufreq_freq_transition_end(policy, freqs, ret); | |
1833 | ||
1834 | if (ret) | |
1835 | pr_err("%s: Failed to change to intermediate frequency: %d\n", | |
1836 | __func__, ret); | |
1837 | ||
1838 | return ret; | |
1839 | } | |
1840 | ||
8d65775d VK |
1841 | static int __target_index(struct cpufreq_policy *policy, |
1842 | struct cpufreq_frequency_table *freq_table, int index) | |
1843 | { | |
1c03a2d0 VK |
1844 | struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
1845 | unsigned int intermediate_freq = 0; | |
8d65775d VK |
1846 | int retval = -EINVAL; |
1847 | bool notify; | |
1848 | ||
1849 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); | |
8d65775d | 1850 | if (notify) { |
1c03a2d0 VK |
1851 | /* Handle switching to intermediate frequency */ |
1852 | if (cpufreq_driver->get_intermediate) { | |
1853 | retval = __target_intermediate(policy, &freqs, index); | |
1854 | if (retval) | |
1855 | return retval; | |
1856 | ||
1857 | intermediate_freq = freqs.new; | |
1858 | /* Set old freq to intermediate */ | |
1859 | if (intermediate_freq) | |
1860 | freqs.old = freqs.new; | |
1861 | } | |
8d65775d | 1862 | |
1c03a2d0 | 1863 | freqs.new = freq_table[index].frequency; |
8d65775d VK |
1864 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", |
1865 | __func__, policy->cpu, freqs.old, freqs.new); | |
1866 | ||
1867 | cpufreq_freq_transition_begin(policy, &freqs); | |
1868 | } | |
1869 | ||
1870 | retval = cpufreq_driver->target_index(policy, index); | |
1871 | if (retval) | |
1872 | pr_err("%s: Failed to change cpu frequency: %d\n", __func__, | |
1873 | retval); | |
1874 | ||
1c03a2d0 | 1875 | if (notify) { |
8d65775d VK |
1876 | cpufreq_freq_transition_end(policy, &freqs, retval); |
1877 | ||
1c03a2d0 VK |
1878 | /* |
1879 | * Failed after setting to intermediate freq? Driver should have | |
1880 | * reverted back to initial frequency and so should we. Check | |
1881 | * here for intermediate_freq instead of get_intermediate, in | |
1882 | * case we have't switched to intermediate freq at all. | |
1883 | */ | |
1884 | if (unlikely(retval && intermediate_freq)) { | |
1885 | freqs.old = intermediate_freq; | |
1886 | freqs.new = policy->restore_freq; | |
1887 | cpufreq_freq_transition_begin(policy, &freqs); | |
1888 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1889 | } | |
1890 | } | |
1891 | ||
8d65775d VK |
1892 | return retval; |
1893 | } | |
1894 | ||
1da177e4 LT |
1895 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1896 | unsigned int target_freq, | |
1897 | unsigned int relation) | |
1898 | { | |
7249924e | 1899 | unsigned int old_target_freq = target_freq; |
8d65775d | 1900 | int retval = -EINVAL; |
c32b6b8e | 1901 | |
a7b422cd KRW |
1902 | if (cpufreq_disabled()) |
1903 | return -ENODEV; | |
1904 | ||
7249924e VK |
1905 | /* Make sure that target_freq is within supported range */ |
1906 | if (target_freq > policy->max) | |
1907 | target_freq = policy->max; | |
1908 | if (target_freq < policy->min) | |
1909 | target_freq = policy->min; | |
1910 | ||
1911 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 1912 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 1913 | |
9c0ebcf7 VK |
1914 | /* |
1915 | * This might look like a redundant call as we are checking it again | |
1916 | * after finding index. But it is left intentionally for cases where | |
1917 | * exactly same freq is called again and so we can save on few function | |
1918 | * calls. | |
1919 | */ | |
5a1c0228 VK |
1920 | if (target_freq == policy->cur) |
1921 | return 0; | |
1922 | ||
1c03a2d0 VK |
1923 | /* Save last value to restore later on errors */ |
1924 | policy->restore_freq = policy->cur; | |
1925 | ||
1c3d85dd RW |
1926 | if (cpufreq_driver->target) |
1927 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
9c0ebcf7 VK |
1928 | else if (cpufreq_driver->target_index) { |
1929 | struct cpufreq_frequency_table *freq_table; | |
1930 | int index; | |
90d45d17 | 1931 | |
9c0ebcf7 VK |
1932 | freq_table = cpufreq_frequency_get_table(policy->cpu); |
1933 | if (unlikely(!freq_table)) { | |
1934 | pr_err("%s: Unable to find freq_table\n", __func__); | |
1935 | goto out; | |
1936 | } | |
1937 | ||
1938 | retval = cpufreq_frequency_table_target(policy, freq_table, | |
1939 | target_freq, relation, &index); | |
1940 | if (unlikely(retval)) { | |
1941 | pr_err("%s: Unable to find matching freq\n", __func__); | |
1942 | goto out; | |
1943 | } | |
1944 | ||
d4019f0a | 1945 | if (freq_table[index].frequency == policy->cur) { |
9c0ebcf7 | 1946 | retval = 0; |
d4019f0a VK |
1947 | goto out; |
1948 | } | |
1949 | ||
8d65775d | 1950 | retval = __target_index(policy, freq_table, index); |
9c0ebcf7 VK |
1951 | } |
1952 | ||
1953 | out: | |
1da177e4 LT |
1954 | return retval; |
1955 | } | |
1956 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1957 | ||
1da177e4 LT |
1958 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1959 | unsigned int target_freq, | |
1960 | unsigned int relation) | |
1961 | { | |
f1829e4a | 1962 | int ret = -EINVAL; |
1da177e4 | 1963 | |
ad7722da | 1964 | down_write(&policy->rwsem); |
1da177e4 LT |
1965 | |
1966 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1967 | ||
ad7722da | 1968 | up_write(&policy->rwsem); |
1da177e4 | 1969 | |
1da177e4 LT |
1970 | return ret; |
1971 | } | |
1972 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1973 | ||
153d7f3f | 1974 | /* |
153d7f3f AV |
1975 | * when "event" is CPUFREQ_GOV_LIMITS |
1976 | */ | |
1da177e4 | 1977 | |
e08f5f5b GS |
1978 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1979 | unsigned int event) | |
1da177e4 | 1980 | { |
cc993cab | 1981 | int ret; |
6afde10c TR |
1982 | |
1983 | /* Only must be defined when default governor is known to have latency | |
1984 | restrictions, like e.g. conservative or ondemand. | |
1985 | That this is the case is already ensured in Kconfig | |
1986 | */ | |
1987 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1988 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1989 | #else | |
1990 | struct cpufreq_governor *gov = NULL; | |
1991 | #endif | |
1c256245 | 1992 | |
2f0aea93 VK |
1993 | /* Don't start any governor operations if we are entering suspend */ |
1994 | if (cpufreq_suspended) | |
1995 | return 0; | |
1996 | ||
1c256245 TR |
1997 | if (policy->governor->max_transition_latency && |
1998 | policy->cpuinfo.transition_latency > | |
1999 | policy->governor->max_transition_latency) { | |
6afde10c TR |
2000 | if (!gov) |
2001 | return -EINVAL; | |
2002 | else { | |
e837f9b5 JP |
2003 | pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", |
2004 | policy->governor->name, gov->name); | |
6afde10c TR |
2005 | policy->governor = gov; |
2006 | } | |
1c256245 | 2007 | } |
1da177e4 | 2008 | |
fe492f3f VK |
2009 | if (event == CPUFREQ_GOV_POLICY_INIT) |
2010 | if (!try_module_get(policy->governor->owner)) | |
2011 | return -EINVAL; | |
1da177e4 | 2012 | |
2d06d8c4 | 2013 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e837f9b5 | 2014 | policy->cpu, event); |
95731ebb XC |
2015 | |
2016 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 2017 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
2018 | || (!policy->governor_enabled |
2019 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
2020 | mutex_unlock(&cpufreq_governor_lock); |
2021 | return -EBUSY; | |
2022 | } | |
2023 | ||
2024 | if (event == CPUFREQ_GOV_STOP) | |
2025 | policy->governor_enabled = false; | |
2026 | else if (event == CPUFREQ_GOV_START) | |
2027 | policy->governor_enabled = true; | |
2028 | ||
2029 | mutex_unlock(&cpufreq_governor_lock); | |
2030 | ||
1da177e4 LT |
2031 | ret = policy->governor->governor(policy, event); |
2032 | ||
4d5dcc42 VK |
2033 | if (!ret) { |
2034 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
2035 | policy->governor->initialized++; | |
2036 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
2037 | policy->governor->initialized--; | |
95731ebb XC |
2038 | } else { |
2039 | /* Restore original values */ | |
2040 | mutex_lock(&cpufreq_governor_lock); | |
2041 | if (event == CPUFREQ_GOV_STOP) | |
2042 | policy->governor_enabled = true; | |
2043 | else if (event == CPUFREQ_GOV_START) | |
2044 | policy->governor_enabled = false; | |
2045 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 2046 | } |
b394058f | 2047 | |
fe492f3f VK |
2048 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
2049 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
2050 | module_put(policy->governor->owner); |
2051 | ||
2052 | return ret; | |
2053 | } | |
2054 | ||
1da177e4 LT |
2055 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
2056 | { | |
3bcb09a3 | 2057 | int err; |
1da177e4 LT |
2058 | |
2059 | if (!governor) | |
2060 | return -EINVAL; | |
2061 | ||
a7b422cd KRW |
2062 | if (cpufreq_disabled()) |
2063 | return -ENODEV; | |
2064 | ||
3fc54d37 | 2065 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 2066 | |
b394058f | 2067 | governor->initialized = 0; |
3bcb09a3 JF |
2068 | err = -EBUSY; |
2069 | if (__find_governor(governor->name) == NULL) { | |
2070 | err = 0; | |
2071 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2072 | } |
1da177e4 | 2073 | |
32ee8c3e | 2074 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2075 | return err; |
1da177e4 LT |
2076 | } |
2077 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2078 | ||
1da177e4 LT |
2079 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2080 | { | |
90e41bac | 2081 | int cpu; |
90e41bac | 2082 | |
1da177e4 LT |
2083 | if (!governor) |
2084 | return; | |
2085 | ||
a7b422cd KRW |
2086 | if (cpufreq_disabled()) |
2087 | return; | |
2088 | ||
90e41bac PB |
2089 | for_each_present_cpu(cpu) { |
2090 | if (cpu_online(cpu)) | |
2091 | continue; | |
2092 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
2093 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
2094 | } | |
90e41bac | 2095 | |
3fc54d37 | 2096 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2097 | list_del(&governor->governor_list); |
3fc54d37 | 2098 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2099 | return; |
2100 | } | |
2101 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2102 | ||
2103 | ||
1da177e4 LT |
2104 | /********************************************************************* |
2105 | * POLICY INTERFACE * | |
2106 | *********************************************************************/ | |
2107 | ||
2108 | /** | |
2109 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2110 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2111 | * is written | |
1da177e4 LT |
2112 | * |
2113 | * Reads the current cpufreq policy. | |
2114 | */ | |
2115 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2116 | { | |
2117 | struct cpufreq_policy *cpu_policy; | |
2118 | if (!policy) | |
2119 | return -EINVAL; | |
2120 | ||
2121 | cpu_policy = cpufreq_cpu_get(cpu); | |
2122 | if (!cpu_policy) | |
2123 | return -EINVAL; | |
2124 | ||
d5b73cd8 | 2125 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2126 | |
2127 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2128 | return 0; |
2129 | } | |
2130 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2131 | ||
153d7f3f | 2132 | /* |
037ce839 VK |
2133 | * policy : current policy. |
2134 | * new_policy: policy to be set. | |
153d7f3f | 2135 | */ |
037ce839 | 2136 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 2137 | struct cpufreq_policy *new_policy) |
1da177e4 | 2138 | { |
d9a789c7 RW |
2139 | struct cpufreq_governor *old_gov; |
2140 | int ret; | |
1da177e4 | 2141 | |
e837f9b5 JP |
2142 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2143 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2144 | |
d5b73cd8 | 2145 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2146 | |
d9a789c7 RW |
2147 | if (new_policy->min > policy->max || new_policy->max < policy->min) |
2148 | return -EINVAL; | |
9c9a43ed | 2149 | |
1da177e4 | 2150 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2151 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2152 | if (ret) |
d9a789c7 | 2153 | return ret; |
1da177e4 | 2154 | |
1da177e4 | 2155 | /* adjust if necessary - all reasons */ |
e041c683 | 2156 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2157 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
2158 | |
2159 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 2160 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2161 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 2162 | |
bb176f7d VK |
2163 | /* |
2164 | * verify the cpu speed can be set within this limit, which might be | |
2165 | * different to the first one | |
2166 | */ | |
3a3e9e06 | 2167 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2168 | if (ret) |
d9a789c7 | 2169 | return ret; |
1da177e4 LT |
2170 | |
2171 | /* notification of the new policy */ | |
e041c683 | 2172 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2173 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2174 | |
3a3e9e06 VK |
2175 | policy->min = new_policy->min; |
2176 | policy->max = new_policy->max; | |
1da177e4 | 2177 | |
2d06d8c4 | 2178 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2179 | policy->min, policy->max); |
1da177e4 | 2180 | |
1c3d85dd | 2181 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2182 | policy->policy = new_policy->policy; |
2d06d8c4 | 2183 | pr_debug("setting range\n"); |
d9a789c7 RW |
2184 | return cpufreq_driver->setpolicy(new_policy); |
2185 | } | |
1da177e4 | 2186 | |
d9a789c7 RW |
2187 | if (new_policy->governor == policy->governor) |
2188 | goto out; | |
7bd353a9 | 2189 | |
d9a789c7 RW |
2190 | pr_debug("governor switch\n"); |
2191 | ||
2192 | /* save old, working values */ | |
2193 | old_gov = policy->governor; | |
2194 | /* end old governor */ | |
2195 | if (old_gov) { | |
2196 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
2197 | up_write(&policy->rwsem); | |
e5c87b76 | 2198 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); |
d9a789c7 | 2199 | down_write(&policy->rwsem); |
1da177e4 LT |
2200 | } |
2201 | ||
d9a789c7 RW |
2202 | /* start new governor */ |
2203 | policy->governor = new_policy->governor; | |
2204 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
2205 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) | |
2206 | goto out; | |
2207 | ||
2208 | up_write(&policy->rwsem); | |
2209 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); | |
2210 | down_write(&policy->rwsem); | |
2211 | } | |
2212 | ||
2213 | /* new governor failed, so re-start old one */ | |
2214 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2215 | if (old_gov) { | |
2216 | policy->governor = old_gov; | |
2217 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); | |
2218 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
2219 | } | |
2220 | ||
2221 | return -EINVAL; | |
2222 | ||
2223 | out: | |
2224 | pr_debug("governor: change or update limits\n"); | |
2225 | return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1da177e4 LT |
2226 | } |
2227 | ||
1da177e4 LT |
2228 | /** |
2229 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2230 | * @cpu: CPU which shall be re-evaluated | |
2231 | * | |
25985edc | 2232 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2233 | * at different times. |
2234 | */ | |
2235 | int cpufreq_update_policy(unsigned int cpu) | |
2236 | { | |
3a3e9e06 VK |
2237 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2238 | struct cpufreq_policy new_policy; | |
f1829e4a | 2239 | int ret; |
1da177e4 | 2240 | |
fefa8ff8 AP |
2241 | if (!policy) |
2242 | return -ENODEV; | |
1da177e4 | 2243 | |
ad7722da | 2244 | down_write(&policy->rwsem); |
1da177e4 | 2245 | |
2d06d8c4 | 2246 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2247 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2248 | new_policy.min = policy->user_policy.min; |
2249 | new_policy.max = policy->user_policy.max; | |
2250 | new_policy.policy = policy->user_policy.policy; | |
2251 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 2252 | |
bb176f7d VK |
2253 | /* |
2254 | * BIOS might change freq behind our back | |
2255 | * -> ask driver for current freq and notify governors about a change | |
2256 | */ | |
2ed99e39 | 2257 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
3a3e9e06 | 2258 | new_policy.cur = cpufreq_driver->get(cpu); |
bd0fa9bb VK |
2259 | if (WARN_ON(!new_policy.cur)) { |
2260 | ret = -EIO; | |
fefa8ff8 | 2261 | goto unlock; |
bd0fa9bb VK |
2262 | } |
2263 | ||
3a3e9e06 | 2264 | if (!policy->cur) { |
e837f9b5 | 2265 | pr_debug("Driver did not initialize current freq\n"); |
3a3e9e06 | 2266 | policy->cur = new_policy.cur; |
a85f7bd3 | 2267 | } else { |
9c0ebcf7 | 2268 | if (policy->cur != new_policy.cur && has_target()) |
3a3e9e06 VK |
2269 | cpufreq_out_of_sync(cpu, policy->cur, |
2270 | new_policy.cur); | |
a85f7bd3 | 2271 | } |
0961dd0d TR |
2272 | } |
2273 | ||
037ce839 | 2274 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2275 | |
fefa8ff8 | 2276 | unlock: |
ad7722da | 2277 | up_write(&policy->rwsem); |
5a01f2e8 | 2278 | |
3a3e9e06 | 2279 | cpufreq_cpu_put(policy); |
1da177e4 LT |
2280 | return ret; |
2281 | } | |
2282 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2283 | ||
2760984f | 2284 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2285 | unsigned long action, void *hcpu) |
2286 | { | |
2287 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2288 | struct device *dev; |
c32b6b8e | 2289 | |
8a25a2fd KS |
2290 | dev = get_cpu_device(cpu); |
2291 | if (dev) { | |
5302c3fb | 2292 | switch (action & ~CPU_TASKS_FROZEN) { |
c32b6b8e | 2293 | case CPU_ONLINE: |
96bbbe4a | 2294 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e | 2295 | break; |
5302c3fb | 2296 | |
c32b6b8e | 2297 | case CPU_DOWN_PREPARE: |
96bbbe4a | 2298 | __cpufreq_remove_dev_prepare(dev, NULL); |
1aee40ac SB |
2299 | break; |
2300 | ||
2301 | case CPU_POST_DEAD: | |
96bbbe4a | 2302 | __cpufreq_remove_dev_finish(dev, NULL); |
c32b6b8e | 2303 | break; |
5302c3fb | 2304 | |
5a01f2e8 | 2305 | case CPU_DOWN_FAILED: |
96bbbe4a | 2306 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
2307 | break; |
2308 | } | |
2309 | } | |
2310 | return NOTIFY_OK; | |
2311 | } | |
2312 | ||
9c36f746 | 2313 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2314 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2315 | }; |
1da177e4 | 2316 | |
6f19efc0 LM |
2317 | /********************************************************************* |
2318 | * BOOST * | |
2319 | *********************************************************************/ | |
2320 | static int cpufreq_boost_set_sw(int state) | |
2321 | { | |
2322 | struct cpufreq_frequency_table *freq_table; | |
2323 | struct cpufreq_policy *policy; | |
2324 | int ret = -EINVAL; | |
2325 | ||
2326 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
2327 | freq_table = cpufreq_frequency_get_table(policy->cpu); | |
2328 | if (freq_table) { | |
2329 | ret = cpufreq_frequency_table_cpuinfo(policy, | |
2330 | freq_table); | |
2331 | if (ret) { | |
2332 | pr_err("%s: Policy frequency update failed\n", | |
2333 | __func__); | |
2334 | break; | |
2335 | } | |
2336 | policy->user_policy.max = policy->max; | |
2337 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
2338 | } | |
2339 | } | |
2340 | ||
2341 | return ret; | |
2342 | } | |
2343 | ||
2344 | int cpufreq_boost_trigger_state(int state) | |
2345 | { | |
2346 | unsigned long flags; | |
2347 | int ret = 0; | |
2348 | ||
2349 | if (cpufreq_driver->boost_enabled == state) | |
2350 | return 0; | |
2351 | ||
2352 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2353 | cpufreq_driver->boost_enabled = state; | |
2354 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2355 | ||
2356 | ret = cpufreq_driver->set_boost(state); | |
2357 | if (ret) { | |
2358 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2359 | cpufreq_driver->boost_enabled = !state; | |
2360 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2361 | ||
e837f9b5 JP |
2362 | pr_err("%s: Cannot %s BOOST\n", |
2363 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2364 | } |
2365 | ||
2366 | return ret; | |
2367 | } | |
2368 | ||
2369 | int cpufreq_boost_supported(void) | |
2370 | { | |
2371 | if (likely(cpufreq_driver)) | |
2372 | return cpufreq_driver->boost_supported; | |
2373 | ||
2374 | return 0; | |
2375 | } | |
2376 | EXPORT_SYMBOL_GPL(cpufreq_boost_supported); | |
2377 | ||
2378 | int cpufreq_boost_enabled(void) | |
2379 | { | |
2380 | return cpufreq_driver->boost_enabled; | |
2381 | } | |
2382 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2383 | ||
1da177e4 LT |
2384 | /********************************************************************* |
2385 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2386 | *********************************************************************/ | |
2387 | ||
2388 | /** | |
2389 | * cpufreq_register_driver - register a CPU Frequency driver | |
2390 | * @driver_data: A struct cpufreq_driver containing the values# | |
2391 | * submitted by the CPU Frequency driver. | |
2392 | * | |
bb176f7d | 2393 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2394 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2395 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2396 | * |
2397 | */ | |
221dee28 | 2398 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2399 | { |
2400 | unsigned long flags; | |
2401 | int ret; | |
2402 | ||
a7b422cd KRW |
2403 | if (cpufreq_disabled()) |
2404 | return -ENODEV; | |
2405 | ||
1da177e4 | 2406 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2407 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2408 | driver_data->target) || |
2409 | (driver_data->setpolicy && (driver_data->target_index || | |
1c03a2d0 VK |
2410 | driver_data->target)) || |
2411 | (!!driver_data->get_intermediate != !!driver_data->target_intermediate)) | |
1da177e4 LT |
2412 | return -EINVAL; |
2413 | ||
2d06d8c4 | 2414 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2415 | |
2416 | if (driver_data->setpolicy) | |
2417 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2418 | ||
0d1857a1 | 2419 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2420 | if (cpufreq_driver) { |
0d1857a1 | 2421 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2422 | return -EEXIST; |
1da177e4 | 2423 | } |
1c3d85dd | 2424 | cpufreq_driver = driver_data; |
0d1857a1 | 2425 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2426 | |
6f19efc0 LM |
2427 | if (cpufreq_boost_supported()) { |
2428 | /* | |
2429 | * Check if driver provides function to enable boost - | |
2430 | * if not, use cpufreq_boost_set_sw as default | |
2431 | */ | |
2432 | if (!cpufreq_driver->set_boost) | |
2433 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; | |
2434 | ||
2435 | ret = cpufreq_sysfs_create_file(&boost.attr); | |
2436 | if (ret) { | |
2437 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
e837f9b5 | 2438 | __func__); |
6f19efc0 LM |
2439 | goto err_null_driver; |
2440 | } | |
2441 | } | |
2442 | ||
8a25a2fd | 2443 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2444 | if (ret) |
6f19efc0 | 2445 | goto err_boost_unreg; |
1da177e4 | 2446 | |
1c3d85dd | 2447 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2448 | int i; |
2449 | ret = -ENODEV; | |
2450 | ||
2451 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2452 | for (i = 0; i < nr_cpu_ids; i++) |
2453 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2454 | ret = 0; |
7a6aedfa MT |
2455 | break; |
2456 | } | |
1da177e4 LT |
2457 | |
2458 | /* if all ->init() calls failed, unregister */ | |
2459 | if (ret) { | |
2d06d8c4 | 2460 | pr_debug("no CPU initialized for driver %s\n", |
e837f9b5 | 2461 | driver_data->name); |
8a25a2fd | 2462 | goto err_if_unreg; |
1da177e4 LT |
2463 | } |
2464 | } | |
2465 | ||
8f5bc2ab | 2466 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2467 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2468 | |
8f5bc2ab | 2469 | return 0; |
8a25a2fd KS |
2470 | err_if_unreg: |
2471 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 LM |
2472 | err_boost_unreg: |
2473 | if (cpufreq_boost_supported()) | |
2474 | cpufreq_sysfs_remove_file(&boost.attr); | |
8f5bc2ab | 2475 | err_null_driver: |
0d1857a1 | 2476 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2477 | cpufreq_driver = NULL; |
0d1857a1 | 2478 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2479 | return ret; |
1da177e4 LT |
2480 | } |
2481 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2482 | ||
1da177e4 LT |
2483 | /** |
2484 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2485 | * | |
bb176f7d | 2486 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2487 | * the right to do so, i.e. if you have succeeded in initialising before! |
2488 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2489 | * currently not initialised. | |
2490 | */ | |
221dee28 | 2491 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2492 | { |
2493 | unsigned long flags; | |
2494 | ||
1c3d85dd | 2495 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2496 | return -EINVAL; |
1da177e4 | 2497 | |
2d06d8c4 | 2498 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2499 | |
8a25a2fd | 2500 | subsys_interface_unregister(&cpufreq_interface); |
6f19efc0 LM |
2501 | if (cpufreq_boost_supported()) |
2502 | cpufreq_sysfs_remove_file(&boost.attr); | |
2503 | ||
65edc68c | 2504 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2505 | |
6eed9404 | 2506 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2507 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2508 | |
1c3d85dd | 2509 | cpufreq_driver = NULL; |
6eed9404 | 2510 | |
0d1857a1 | 2511 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2512 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2513 | |
2514 | return 0; | |
2515 | } | |
2516 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2517 | |
2518 | static int __init cpufreq_core_init(void) | |
2519 | { | |
a7b422cd KRW |
2520 | if (cpufreq_disabled()) |
2521 | return -ENODEV; | |
2522 | ||
2361be23 | 2523 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 TR |
2524 | BUG_ON(!cpufreq_global_kobject); |
2525 | ||
5a01f2e8 VP |
2526 | return 0; |
2527 | } | |
5a01f2e8 | 2528 | core_initcall(cpufreq_core_init); |