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 | 21 | #include <linux/cpufreq.h> |
5c238a8b | 22 | #include <linux/cpu_cooling.h> |
1da177e4 | 23 | #include <linux/delay.h> |
1da177e4 | 24 | #include <linux/device.h> |
5ff0a268 VK |
25 | #include <linux/init.h> |
26 | #include <linux/kernel_stat.h> | |
27 | #include <linux/module.h> | |
3fc54d37 | 28 | #include <linux/mutex.h> |
5ff0a268 | 29 | #include <linux/slab.h> |
2f0aea93 | 30 | #include <linux/suspend.h> |
90de2a4a | 31 | #include <linux/syscore_ops.h> |
5ff0a268 | 32 | #include <linux/tick.h> |
6f4f2723 TR |
33 | #include <trace/events/power.h> |
34 | ||
b4f0676f | 35 | static LIST_HEAD(cpufreq_policy_list); |
f963735a | 36 | |
f963735a | 37 | /* Macros to iterate over CPU policies */ |
fd7dc7e6 EB |
38 | #define for_each_suitable_policy(__policy, __active) \ |
39 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \ | |
40 | if ((__active) == !policy_is_inactive(__policy)) | |
f963735a VK |
41 | |
42 | #define for_each_active_policy(__policy) \ | |
43 | for_each_suitable_policy(__policy, true) | |
44 | #define for_each_inactive_policy(__policy) \ | |
45 | for_each_suitable_policy(__policy, false) | |
46 | ||
47 | #define for_each_policy(__policy) \ | |
b4f0676f VK |
48 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) |
49 | ||
f7b27061 VK |
50 | /* Iterate over governors */ |
51 | static LIST_HEAD(cpufreq_governor_list); | |
52 | #define for_each_governor(__governor) \ | |
53 | list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) | |
54 | ||
1da177e4 | 55 | /** |
cd878479 | 56 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
57 | * level driver of CPUFreq support, and its spinlock. This lock |
58 | * also protects the cpufreq_cpu_data array. | |
59 | */ | |
1c3d85dd | 60 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 61 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
bb176f7d | 62 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
bb176f7d | 63 | |
2f0aea93 VK |
64 | /* Flag to suspend/resume CPUFreq governors */ |
65 | static bool cpufreq_suspended; | |
1da177e4 | 66 | |
9c0ebcf7 VK |
67 | static inline bool has_target(void) |
68 | { | |
69 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
70 | } | |
71 | ||
1da177e4 | 72 | /* internal prototypes */ |
d92d50a4 | 73 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy); |
a92604b4 RW |
74 | static int cpufreq_init_governor(struct cpufreq_policy *policy); |
75 | static void cpufreq_exit_governor(struct cpufreq_policy *policy); | |
0a300767 | 76 | static int cpufreq_start_governor(struct cpufreq_policy *policy); |
a92604b4 RW |
77 | static void cpufreq_stop_governor(struct cpufreq_policy *policy); |
78 | static void cpufreq_governor_limits(struct cpufreq_policy *policy); | |
45482c70 | 79 | |
1da177e4 | 80 | /** |
32ee8c3e DJ |
81 | * Two notifier lists: the "policy" list is involved in the |
82 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
83 | * "transition" list for kernel code that needs to handle |
84 | * changes to devices when the CPU clock speed changes. | |
85 | * The mutex locks both lists. | |
86 | */ | |
e041c683 | 87 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
cc85de36 | 88 | SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list); |
1da177e4 | 89 | |
a7b422cd | 90 | static int off __read_mostly; |
da584455 | 91 | static int cpufreq_disabled(void) |
a7b422cd KRW |
92 | { |
93 | return off; | |
94 | } | |
95 | void disable_cpufreq(void) | |
96 | { | |
97 | off = 1; | |
98 | } | |
29464f28 | 99 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 100 | |
4d5dcc42 VK |
101 | bool have_governor_per_policy(void) |
102 | { | |
0b981e70 | 103 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 104 | } |
3f869d6d | 105 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 106 | |
944e9a03 VK |
107 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
108 | { | |
109 | if (have_governor_per_policy()) | |
110 | return &policy->kobj; | |
111 | else | |
112 | return cpufreq_global_kobject; | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
115 | ||
72a4ce34 VK |
116 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
117 | { | |
118 | u64 idle_time; | |
119 | u64 cur_wall_time; | |
120 | u64 busy_time; | |
121 | ||
7fb1327e | 122 | cur_wall_time = jiffies64_to_nsecs(get_jiffies_64()); |
72a4ce34 VK |
123 | |
124 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
125 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
126 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
127 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
128 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
129 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
130 | ||
131 | idle_time = cur_wall_time - busy_time; | |
132 | if (wall) | |
7fb1327e | 133 | *wall = div_u64(cur_wall_time, NSEC_PER_USEC); |
72a4ce34 | 134 | |
7fb1327e | 135 | return div_u64(idle_time, NSEC_PER_USEC); |
72a4ce34 VK |
136 | } |
137 | ||
138 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
139 | { | |
140 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
141 | ||
142 | if (idle_time == -1ULL) | |
143 | return get_cpu_idle_time_jiffy(cpu, wall); | |
144 | else if (!io_busy) | |
145 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
146 | ||
147 | return idle_time; | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
150 | ||
e7d5459d DE |
151 | __weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, |
152 | unsigned long max_freq) | |
153 | { | |
154 | } | |
155 | EXPORT_SYMBOL_GPL(arch_set_freq_scale); | |
156 | ||
70e9e778 VK |
157 | /* |
158 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
159 | * drivers of SMP systems. It will do following: | |
160 | * - validate & show freq table passed | |
161 | * - set policies transition latency | |
162 | * - policy->cpus with all possible CPUs | |
163 | */ | |
164 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
165 | struct cpufreq_frequency_table *table, | |
166 | unsigned int transition_latency) | |
167 | { | |
92c99d15 | 168 | policy->freq_table = table; |
70e9e778 VK |
169 | policy->cpuinfo.transition_latency = transition_latency; |
170 | ||
171 | /* | |
58405af6 | 172 | * The driver only supports the SMP configuration where all processors |
70e9e778 VK |
173 | * share the clock and voltage and clock. |
174 | */ | |
175 | cpumask_setall(policy->cpus); | |
176 | ||
177 | return 0; | |
178 | } | |
179 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
180 | ||
1f0bd44e | 181 | struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) |
652ed95d VK |
182 | { |
183 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
184 | ||
988bed09 VK |
185 | return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL; |
186 | } | |
1f0bd44e | 187 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw); |
988bed09 VK |
188 | |
189 | unsigned int cpufreq_generic_get(unsigned int cpu) | |
190 | { | |
191 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); | |
192 | ||
652ed95d | 193 | if (!policy || IS_ERR(policy->clk)) { |
e837f9b5 JP |
194 | pr_err("%s: No %s associated to cpu: %d\n", |
195 | __func__, policy ? "clk" : "policy", cpu); | |
652ed95d VK |
196 | return 0; |
197 | } | |
198 | ||
199 | return clk_get_rate(policy->clk) / 1000; | |
200 | } | |
201 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
202 | ||
50e9c852 | 203 | /** |
5d094fea RW |
204 | * cpufreq_cpu_get - Return policy for a CPU and mark it as busy. |
205 | * @cpu: CPU to find the policy for. | |
50e9c852 | 206 | * |
5d094fea RW |
207 | * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment |
208 | * the kobject reference counter of that policy. Return a valid policy on | |
209 | * success or NULL on failure. | |
50e9c852 | 210 | * |
5d094fea RW |
211 | * The policy returned by this function has to be released with the help of |
212 | * cpufreq_cpu_put() to balance its kobject reference counter properly. | |
50e9c852 | 213 | */ |
6eed9404 | 214 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 215 | { |
6eed9404 | 216 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
217 | unsigned long flags; |
218 | ||
1b947c90 | 219 | if (WARN_ON(cpu >= nr_cpu_ids)) |
6eed9404 VK |
220 | return NULL; |
221 | ||
1da177e4 | 222 | /* get the cpufreq driver */ |
1c3d85dd | 223 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 224 | |
6eed9404 VK |
225 | if (cpufreq_driver) { |
226 | /* get the CPU */ | |
988bed09 | 227 | policy = cpufreq_cpu_get_raw(cpu); |
6eed9404 VK |
228 | if (policy) |
229 | kobject_get(&policy->kobj); | |
230 | } | |
1da177e4 | 231 | |
6eed9404 | 232 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 233 | |
3a3e9e06 | 234 | return policy; |
a9144436 | 235 | } |
1da177e4 LT |
236 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
237 | ||
50e9c852 | 238 | /** |
5d094fea RW |
239 | * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy. |
240 | * @policy: cpufreq policy returned by cpufreq_cpu_get(). | |
50e9c852 | 241 | */ |
3a3e9e06 | 242 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 243 | { |
6eed9404 | 244 | kobject_put(&policy->kobj); |
1da177e4 LT |
245 | } |
246 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
247 | ||
540a3758 RW |
248 | /** |
249 | * cpufreq_cpu_release - Unlock a policy and decrement its usage counter. | |
250 | * @policy: cpufreq policy returned by cpufreq_cpu_acquire(). | |
251 | */ | |
9083e498 | 252 | void cpufreq_cpu_release(struct cpufreq_policy *policy) |
540a3758 RW |
253 | { |
254 | if (WARN_ON(!policy)) | |
255 | return; | |
256 | ||
257 | lockdep_assert_held(&policy->rwsem); | |
258 | ||
259 | up_write(&policy->rwsem); | |
260 | ||
261 | cpufreq_cpu_put(policy); | |
262 | } | |
263 | ||
264 | /** | |
265 | * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it. | |
266 | * @cpu: CPU to find the policy for. | |
267 | * | |
268 | * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and | |
269 | * if the policy returned by it is not NULL, acquire its rwsem for writing. | |
270 | * Return the policy if it is active or release it and return NULL otherwise. | |
271 | * | |
272 | * The policy returned by this function has to be released with the help of | |
273 | * cpufreq_cpu_release() in order to release its rwsem and balance its usage | |
274 | * counter properly. | |
275 | */ | |
9083e498 | 276 | struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu) |
540a3758 RW |
277 | { |
278 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
279 | ||
280 | if (!policy) | |
281 | return NULL; | |
282 | ||
283 | down_write(&policy->rwsem); | |
284 | ||
285 | if (policy_is_inactive(policy)) { | |
286 | cpufreq_cpu_release(policy); | |
287 | return NULL; | |
288 | } | |
289 | ||
290 | return policy; | |
291 | } | |
292 | ||
1da177e4 LT |
293 | /********************************************************************* |
294 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
295 | *********************************************************************/ | |
296 | ||
297 | /** | |
298 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
299 | * | |
300 | * This function alters the system "loops_per_jiffy" for the clock | |
301 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 302 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
303 | * per-CPU loops_per_jiffy value wherever possible. |
304 | */ | |
858119e1 | 305 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 | 306 | { |
39c132ee VK |
307 | #ifndef CONFIG_SMP |
308 | static unsigned long l_p_j_ref; | |
309 | static unsigned int l_p_j_ref_freq; | |
310 | ||
1da177e4 LT |
311 | if (ci->flags & CPUFREQ_CONST_LOOPS) |
312 | return; | |
313 | ||
314 | if (!l_p_j_ref_freq) { | |
315 | l_p_j_ref = loops_per_jiffy; | |
316 | l_p_j_ref_freq = ci->old; | |
e837f9b5 JP |
317 | pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", |
318 | l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 | 319 | } |
0b443ead | 320 | if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { |
e08f5f5b GS |
321 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
322 | ci->new); | |
e837f9b5 JP |
323 | pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", |
324 | loops_per_jiffy, ci->new); | |
1da177e4 | 325 | } |
1da177e4 | 326 | #endif |
39c132ee | 327 | } |
1da177e4 | 328 | |
20b5324d VK |
329 | /** |
330 | * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies. | |
331 | * @policy: cpufreq policy to enable fast frequency switching for. | |
332 | * @freqs: contain details of the frequency update. | |
333 | * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. | |
334 | * | |
335 | * This function calls the transition notifiers and the "adjust_jiffies" | |
336 | * function. It is called twice on all CPU frequency changes that have | |
337 | * external effects. | |
338 | */ | |
339 | static void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
340 | struct cpufreq_freqs *freqs, | |
341 | unsigned int state) | |
1da177e4 | 342 | { |
df24014a VK |
343 | int cpu; |
344 | ||
1da177e4 LT |
345 | BUG_ON(irqs_disabled()); |
346 | ||
d5aaffa9 DB |
347 | if (cpufreq_disabled()) |
348 | return; | |
349 | ||
df24014a | 350 | freqs->policy = policy; |
1c3d85dd | 351 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 352 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e837f9b5 | 353 | state, freqs->new); |
1da177e4 | 354 | |
1da177e4 LT |
355 | switch (state) { |
356 | case CPUFREQ_PRECHANGE: | |
20b5324d VK |
357 | /* |
358 | * Detect if the driver reported a value as "old frequency" | |
e4472cb3 DJ |
359 | * which is not equal to what the cpufreq core thinks is |
360 | * "old frequency". | |
1da177e4 | 361 | */ |
98015228 VK |
362 | if (policy->cur && policy->cur != freqs->old) { |
363 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", | |
364 | freqs->old, policy->cur); | |
365 | freqs->old = policy->cur; | |
1da177e4 | 366 | } |
20b5324d | 367 | |
df24014a VK |
368 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
369 | CPUFREQ_PRECHANGE, freqs); | |
20b5324d | 370 | |
1da177e4 LT |
371 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
372 | break; | |
e4472cb3 | 373 | |
1da177e4 LT |
374 | case CPUFREQ_POSTCHANGE: |
375 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
20b5324d VK |
376 | pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new, |
377 | cpumask_pr_args(policy->cpus)); | |
378 | ||
df24014a VK |
379 | for_each_cpu(cpu, policy->cpus) |
380 | trace_cpu_frequency(freqs->new, cpu); | |
381 | ||
382 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
383 | CPUFREQ_POSTCHANGE, freqs); | |
20b5324d | 384 | |
1aefc75b | 385 | cpufreq_stats_record_transition(policy, freqs->new); |
20b5324d | 386 | policy->cur = freqs->new; |
1da177e4 | 387 | } |
1da177e4 | 388 | } |
bb176f7d | 389 | |
f7ba3b41 | 390 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 391 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
392 | struct cpufreq_freqs *freqs, int transition_failed) |
393 | { | |
394 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
395 | if (!transition_failed) | |
396 | return; | |
397 | ||
398 | swap(freqs->old, freqs->new); | |
399 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
400 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
401 | } | |
f7ba3b41 | 402 | |
12478cf0 SB |
403 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
404 | struct cpufreq_freqs *freqs) | |
405 | { | |
ca654dc3 SB |
406 | |
407 | /* | |
408 | * Catch double invocations of _begin() which lead to self-deadlock. | |
409 | * ASYNC_NOTIFICATION drivers are left out because the cpufreq core | |
410 | * doesn't invoke _begin() on their behalf, and hence the chances of | |
411 | * double invocations are very low. Moreover, there are scenarios | |
412 | * where these checks can emit false-positive warnings in these | |
413 | * drivers; so we avoid that by skipping them altogether. | |
414 | */ | |
415 | WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) | |
416 | && current == policy->transition_task); | |
417 | ||
12478cf0 SB |
418 | wait: |
419 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
420 | ||
421 | spin_lock(&policy->transition_lock); | |
422 | ||
423 | if (unlikely(policy->transition_ongoing)) { | |
424 | spin_unlock(&policy->transition_lock); | |
425 | goto wait; | |
426 | } | |
427 | ||
428 | policy->transition_ongoing = true; | |
ca654dc3 | 429 | policy->transition_task = current; |
12478cf0 SB |
430 | |
431 | spin_unlock(&policy->transition_lock); | |
432 | ||
433 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
434 | } | |
435 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
436 | ||
437 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
438 | struct cpufreq_freqs *freqs, int transition_failed) | |
439 | { | |
0e7ea2f3 | 440 | if (WARN_ON(!policy->transition_ongoing)) |
12478cf0 SB |
441 | return; |
442 | ||
443 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
444 | ||
445 | policy->transition_ongoing = false; | |
ca654dc3 | 446 | policy->transition_task = NULL; |
12478cf0 SB |
447 | |
448 | wake_up(&policy->transition_wait); | |
449 | } | |
450 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
451 | ||
b7898fda RW |
452 | /* |
453 | * Fast frequency switching status count. Positive means "enabled", negative | |
454 | * means "disabled" and 0 means "not decided yet". | |
455 | */ | |
456 | static int cpufreq_fast_switch_count; | |
457 | static DEFINE_MUTEX(cpufreq_fast_switch_lock); | |
458 | ||
459 | static void cpufreq_list_transition_notifiers(void) | |
460 | { | |
461 | struct notifier_block *nb; | |
462 | ||
463 | pr_info("Registered transition notifiers:\n"); | |
464 | ||
465 | mutex_lock(&cpufreq_transition_notifier_list.mutex); | |
466 | ||
467 | for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next) | |
d75f773c | 468 | pr_info("%pS\n", nb->notifier_call); |
b7898fda RW |
469 | |
470 | mutex_unlock(&cpufreq_transition_notifier_list.mutex); | |
471 | } | |
472 | ||
473 | /** | |
474 | * cpufreq_enable_fast_switch - Enable fast frequency switching for policy. | |
475 | * @policy: cpufreq policy to enable fast frequency switching for. | |
476 | * | |
477 | * Try to enable fast frequency switching for @policy. | |
478 | * | |
479 | * The attempt will fail if there is at least one transition notifier registered | |
480 | * at this point, as fast frequency switching is quite fundamentally at odds | |
481 | * with transition notifiers. Thus if successful, it will make registration of | |
482 | * transition notifiers fail going forward. | |
483 | */ | |
484 | void cpufreq_enable_fast_switch(struct cpufreq_policy *policy) | |
485 | { | |
486 | lockdep_assert_held(&policy->rwsem); | |
487 | ||
488 | if (!policy->fast_switch_possible) | |
489 | return; | |
490 | ||
491 | mutex_lock(&cpufreq_fast_switch_lock); | |
492 | if (cpufreq_fast_switch_count >= 0) { | |
493 | cpufreq_fast_switch_count++; | |
494 | policy->fast_switch_enabled = true; | |
495 | } else { | |
496 | pr_warn("CPU%u: Fast frequency switching not enabled\n", | |
497 | policy->cpu); | |
498 | cpufreq_list_transition_notifiers(); | |
499 | } | |
500 | mutex_unlock(&cpufreq_fast_switch_lock); | |
501 | } | |
502 | EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); | |
503 | ||
6c9d9c81 RW |
504 | /** |
505 | * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. | |
506 | * @policy: cpufreq policy to disable fast frequency switching for. | |
507 | */ | |
508 | void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) | |
b7898fda RW |
509 | { |
510 | mutex_lock(&cpufreq_fast_switch_lock); | |
511 | if (policy->fast_switch_enabled) { | |
512 | policy->fast_switch_enabled = false; | |
513 | if (!WARN_ON(cpufreq_fast_switch_count <= 0)) | |
514 | cpufreq_fast_switch_count--; | |
515 | } | |
516 | mutex_unlock(&cpufreq_fast_switch_lock); | |
517 | } | |
6c9d9c81 | 518 | EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); |
1da177e4 | 519 | |
e3c06236 SM |
520 | /** |
521 | * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported | |
522 | * one. | |
523 | * @target_freq: target frequency to resolve. | |
524 | * | |
525 | * The target to driver frequency mapping is cached in the policy. | |
526 | * | |
527 | * Return: Lowest driver-supported frequency greater than or equal to the | |
528 | * given target_freq, subject to policy (min/max) and driver limitations. | |
529 | */ | |
530 | unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, | |
531 | unsigned int target_freq) | |
532 | { | |
533 | target_freq = clamp_val(target_freq, policy->min, policy->max); | |
534 | policy->cached_target_freq = target_freq; | |
abe8bd02 VK |
535 | |
536 | if (cpufreq_driver->target_index) { | |
537 | int idx; | |
538 | ||
539 | idx = cpufreq_frequency_table_target(policy, target_freq, | |
540 | CPUFREQ_RELATION_L); | |
541 | policy->cached_resolved_idx = idx; | |
542 | return policy->freq_table[idx].frequency; | |
543 | } | |
544 | ||
e3c06236 SM |
545 | if (cpufreq_driver->resolve_freq) |
546 | return cpufreq_driver->resolve_freq(policy, target_freq); | |
abe8bd02 VK |
547 | |
548 | return target_freq; | |
e3c06236 | 549 | } |
ae2c1ca6 | 550 | EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); |
e3c06236 | 551 | |
aa7519af VK |
552 | unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy) |
553 | { | |
554 | unsigned int latency; | |
555 | ||
556 | if (policy->transition_delay_us) | |
557 | return policy->transition_delay_us; | |
558 | ||
559 | latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC; | |
e948bc8f VK |
560 | if (latency) { |
561 | /* | |
562 | * For platforms that can change the frequency very fast (< 10 | |
563 | * us), the above formula gives a decent transition delay. But | |
564 | * for platforms where transition_latency is in milliseconds, it | |
565 | * ends up giving unrealistic values. | |
566 | * | |
567 | * Cap the default transition delay to 10 ms, which seems to be | |
568 | * a reasonable amount of time after which we should reevaluate | |
569 | * the frequency. | |
570 | */ | |
571 | return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000); | |
572 | } | |
aa7519af VK |
573 | |
574 | return LATENCY_MULTIPLIER; | |
575 | } | |
576 | EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us); | |
577 | ||
1da177e4 LT |
578 | /********************************************************************* |
579 | * SYSFS INTERFACE * | |
580 | *********************************************************************/ | |
8a5c74a1 | 581 | static ssize_t show_boost(struct kobject *kobj, |
625c85a6 | 582 | struct kobj_attribute *attr, char *buf) |
6f19efc0 LM |
583 | { |
584 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
585 | } | |
586 | ||
625c85a6 VK |
587 | static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr, |
588 | const char *buf, size_t count) | |
6f19efc0 LM |
589 | { |
590 | int ret, enable; | |
591 | ||
592 | ret = sscanf(buf, "%d", &enable); | |
593 | if (ret != 1 || enable < 0 || enable > 1) | |
594 | return -EINVAL; | |
595 | ||
596 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
597 | pr_err("%s: Cannot %s BOOST!\n", |
598 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
599 | return -EINVAL; |
600 | } | |
601 | ||
e837f9b5 JP |
602 | pr_debug("%s: cpufreq BOOST %s\n", |
603 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
604 | |
605 | return count; | |
606 | } | |
607 | define_one_global_rw(boost); | |
1da177e4 | 608 | |
42f91fa1 | 609 | static struct cpufreq_governor *find_governor(const char *str_governor) |
3bcb09a3 JF |
610 | { |
611 | struct cpufreq_governor *t; | |
612 | ||
f7b27061 | 613 | for_each_governor(t) |
7c4f4539 | 614 | if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
615 | return t; |
616 | ||
617 | return NULL; | |
618 | } | |
619 | ||
ab05d97a YH |
620 | static int cpufreq_parse_policy(char *str_governor, |
621 | struct cpufreq_policy *policy) | |
622 | { | |
623 | if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
624 | policy->policy = CPUFREQ_POLICY_PERFORMANCE; | |
625 | return 0; | |
626 | } | |
627 | if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { | |
628 | policy->policy = CPUFREQ_POLICY_POWERSAVE; | |
629 | return 0; | |
630 | } | |
631 | return -EINVAL; | |
632 | } | |
633 | ||
1da177e4 | 634 | /** |
5ddc6d4e | 635 | * cpufreq_parse_governor - parse a governor string only for has_target() |
1da177e4 | 636 | */ |
ae0ff89f RW |
637 | static int cpufreq_parse_governor(char *str_governor, |
638 | struct cpufreq_policy *policy) | |
1da177e4 | 639 | { |
ab05d97a | 640 | struct cpufreq_governor *t; |
045149e6 | 641 | |
ab05d97a | 642 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 | 643 | |
ab05d97a YH |
644 | t = find_governor(str_governor); |
645 | if (!t) { | |
646 | int ret; | |
3bcb09a3 | 647 | |
ab05d97a | 648 | mutex_unlock(&cpufreq_governor_mutex); |
045149e6 | 649 | |
ab05d97a YH |
650 | ret = request_module("cpufreq_%s", str_governor); |
651 | if (ret) | |
652 | return -EINVAL; | |
045149e6 | 653 | |
ab05d97a | 654 | mutex_lock(&cpufreq_governor_mutex); |
ea714970 | 655 | |
ab05d97a YH |
656 | t = find_governor(str_governor); |
657 | } | |
658 | if (t && !try_module_get(t->owner)) | |
659 | t = NULL; | |
ea714970 | 660 | |
ab05d97a | 661 | mutex_unlock(&cpufreq_governor_mutex); |
045149e6 | 662 | |
ab05d97a YH |
663 | if (t) { |
664 | policy->governor = t; | |
665 | return 0; | |
1da177e4 | 666 | } |
045149e6 RW |
667 | |
668 | return -EINVAL; | |
1da177e4 | 669 | } |
1da177e4 | 670 | |
1da177e4 | 671 | /** |
e08f5f5b GS |
672 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
673 | * print out cpufreq information | |
1da177e4 LT |
674 | * |
675 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
676 | * "unsigned int". | |
677 | */ | |
678 | ||
32ee8c3e DJ |
679 | #define show_one(file_name, object) \ |
680 | static ssize_t show_##file_name \ | |
905d77cd | 681 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 682 | { \ |
29464f28 | 683 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
684 | } |
685 | ||
686 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
687 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 688 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
689 | show_one(scaling_min_freq, min); |
690 | show_one(scaling_max_freq, max); | |
c034b02e | 691 | |
f8475cef LB |
692 | __weak unsigned int arch_freq_get_on_cpu(int cpu) |
693 | { | |
694 | return 0; | |
695 | } | |
696 | ||
09347b29 | 697 | static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) |
c034b02e DB |
698 | { |
699 | ssize_t ret; | |
f8475cef | 700 | unsigned int freq; |
c034b02e | 701 | |
f8475cef LB |
702 | freq = arch_freq_get_on_cpu(policy->cpu); |
703 | if (freq) | |
704 | ret = sprintf(buf, "%u\n", freq); | |
705 | else if (cpufreq_driver && cpufreq_driver->setpolicy && | |
706 | cpufreq_driver->get) | |
c034b02e DB |
707 | ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); |
708 | else | |
709 | ret = sprintf(buf, "%u\n", policy->cur); | |
710 | return ret; | |
711 | } | |
1da177e4 LT |
712 | |
713 | /** | |
714 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
715 | */ | |
716 | #define store_one(file_name, object) \ | |
717 | static ssize_t store_##file_name \ | |
905d77cd | 718 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 719 | { \ |
619c144c | 720 | int ret, temp; \ |
1da177e4 LT |
721 | struct cpufreq_policy new_policy; \ |
722 | \ | |
8fa5b631 | 723 | memcpy(&new_policy, policy, sizeof(*policy)); \ |
c7d1f119 TW |
724 | new_policy.min = policy->user_policy.min; \ |
725 | new_policy.max = policy->user_policy.max; \ | |
1da177e4 | 726 | \ |
29464f28 | 727 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
728 | if (ret != 1) \ |
729 | return -EINVAL; \ | |
730 | \ | |
619c144c | 731 | temp = new_policy.object; \ |
037ce839 | 732 | ret = cpufreq_set_policy(policy, &new_policy); \ |
619c144c VH |
733 | if (!ret) \ |
734 | policy->user_policy.object = temp; \ | |
1da177e4 LT |
735 | \ |
736 | return ret ? ret : count; \ | |
737 | } | |
738 | ||
29464f28 DJ |
739 | store_one(scaling_min_freq, min); |
740 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
741 | |
742 | /** | |
743 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
744 | */ | |
905d77cd DJ |
745 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
746 | char *buf) | |
1da177e4 | 747 | { |
d92d50a4 | 748 | unsigned int cur_freq = __cpufreq_get(policy); |
9b4f603e RW |
749 | |
750 | if (cur_freq) | |
751 | return sprintf(buf, "%u\n", cur_freq); | |
752 | ||
753 | return sprintf(buf, "<unknown>\n"); | |
1da177e4 LT |
754 | } |
755 | ||
1da177e4 LT |
756 | /** |
757 | * show_scaling_governor - show the current policy for the specified CPU | |
758 | */ | |
905d77cd | 759 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 760 | { |
29464f28 | 761 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
762 | return sprintf(buf, "powersave\n"); |
763 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
764 | return sprintf(buf, "performance\n"); | |
765 | else if (policy->governor) | |
4b972f0b | 766 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 767 | policy->governor->name); |
1da177e4 LT |
768 | return -EINVAL; |
769 | } | |
770 | ||
1da177e4 LT |
771 | /** |
772 | * store_scaling_governor - store policy for the specified CPU | |
773 | */ | |
905d77cd DJ |
774 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
775 | const char *buf, size_t count) | |
1da177e4 | 776 | { |
5136fa56 | 777 | int ret; |
1da177e4 LT |
778 | char str_governor[16]; |
779 | struct cpufreq_policy new_policy; | |
780 | ||
8fa5b631 | 781 | memcpy(&new_policy, policy, sizeof(*policy)); |
1da177e4 | 782 | |
29464f28 | 783 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
784 | if (ret != 1) |
785 | return -EINVAL; | |
786 | ||
ab05d97a YH |
787 | if (cpufreq_driver->setpolicy) { |
788 | if (cpufreq_parse_policy(str_governor, &new_policy)) | |
789 | return -EINVAL; | |
790 | } else { | |
791 | if (cpufreq_parse_governor(str_governor, &new_policy)) | |
792 | return -EINVAL; | |
793 | } | |
1da177e4 | 794 | |
037ce839 | 795 | ret = cpufreq_set_policy(policy, &new_policy); |
a8b149d3 RW |
796 | |
797 | if (new_policy.governor) | |
798 | module_put(new_policy.governor->owner); | |
799 | ||
88dc4384 | 800 | return ret ? ret : count; |
1da177e4 LT |
801 | } |
802 | ||
803 | /** | |
804 | * show_scaling_driver - show the cpufreq driver currently loaded | |
805 | */ | |
905d77cd | 806 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 807 | { |
1c3d85dd | 808 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
809 | } |
810 | ||
811 | /** | |
812 | * show_scaling_available_governors - show the available CPUfreq governors | |
813 | */ | |
905d77cd DJ |
814 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
815 | char *buf) | |
1da177e4 LT |
816 | { |
817 | ssize_t i = 0; | |
818 | struct cpufreq_governor *t; | |
819 | ||
9c0ebcf7 | 820 | if (!has_target()) { |
1da177e4 LT |
821 | i += sprintf(buf, "performance powersave"); |
822 | goto out; | |
823 | } | |
824 | ||
f7b27061 | 825 | for_each_governor(t) { |
29464f28 DJ |
826 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
827 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 828 | goto out; |
4b972f0b | 829 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 830 | } |
7d5e350f | 831 | out: |
1da177e4 LT |
832 | i += sprintf(&buf[i], "\n"); |
833 | return i; | |
834 | } | |
e8628dd0 | 835 | |
f4fd3797 | 836 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
837 | { |
838 | ssize_t i = 0; | |
839 | unsigned int cpu; | |
840 | ||
835481d9 | 841 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
842 | if (i) |
843 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
844 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
845 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 846 | break; |
1da177e4 LT |
847 | } |
848 | i += sprintf(&buf[i], "\n"); | |
849 | return i; | |
850 | } | |
f4fd3797 | 851 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 852 | |
e8628dd0 DW |
853 | /** |
854 | * show_related_cpus - show the CPUs affected by each transition even if | |
855 | * hw coordination is in use | |
856 | */ | |
857 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
858 | { | |
f4fd3797 | 859 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
860 | } |
861 | ||
862 | /** | |
863 | * show_affected_cpus - show the CPUs affected by each transition | |
864 | */ | |
865 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
866 | { | |
f4fd3797 | 867 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
868 | } |
869 | ||
9e76988e | 870 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 871 | const char *buf, size_t count) |
9e76988e VP |
872 | { |
873 | unsigned int freq = 0; | |
874 | unsigned int ret; | |
875 | ||
879000f9 | 876 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
877 | return -EINVAL; |
878 | ||
879 | ret = sscanf(buf, "%u", &freq); | |
880 | if (ret != 1) | |
881 | return -EINVAL; | |
882 | ||
883 | policy->governor->store_setspeed(policy, freq); | |
884 | ||
885 | return count; | |
886 | } | |
887 | ||
888 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
889 | { | |
879000f9 | 890 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
891 | return sprintf(buf, "<unsupported>\n"); |
892 | ||
893 | return policy->governor->show_setspeed(policy, buf); | |
894 | } | |
1da177e4 | 895 | |
e2f74f35 | 896 | /** |
8bf1ac72 | 897 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
898 | */ |
899 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
900 | { | |
901 | unsigned int limit; | |
902 | int ret; | |
b23aa311 YH |
903 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); |
904 | if (!ret) | |
905 | return sprintf(buf, "%u\n", limit); | |
e2f74f35 TR |
906 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); |
907 | } | |
908 | ||
6dad2a29 BP |
909 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
910 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
911 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
912 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
913 | cpufreq_freq_attr_ro(scaling_available_governors); | |
914 | cpufreq_freq_attr_ro(scaling_driver); | |
915 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
916 | cpufreq_freq_attr_ro(bios_limit); | |
917 | cpufreq_freq_attr_ro(related_cpus); | |
918 | cpufreq_freq_attr_ro(affected_cpus); | |
919 | cpufreq_freq_attr_rw(scaling_min_freq); | |
920 | cpufreq_freq_attr_rw(scaling_max_freq); | |
921 | cpufreq_freq_attr_rw(scaling_governor); | |
922 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 923 | |
905d77cd | 924 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
925 | &cpuinfo_min_freq.attr, |
926 | &cpuinfo_max_freq.attr, | |
ed129784 | 927 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
928 | &scaling_min_freq.attr, |
929 | &scaling_max_freq.attr, | |
930 | &affected_cpus.attr, | |
e8628dd0 | 931 | &related_cpus.attr, |
1da177e4 LT |
932 | &scaling_governor.attr, |
933 | &scaling_driver.attr, | |
934 | &scaling_available_governors.attr, | |
9e76988e | 935 | &scaling_setspeed.attr, |
1da177e4 LT |
936 | NULL |
937 | }; | |
938 | ||
29464f28 DJ |
939 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
940 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 941 | |
29464f28 | 942 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 943 | { |
905d77cd DJ |
944 | struct cpufreq_policy *policy = to_policy(kobj); |
945 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 946 | ssize_t ret; |
6eed9404 | 947 | |
ad7722da | 948 | down_read(&policy->rwsem); |
6541aef0 | 949 | ret = fattr->show(policy, buf); |
ad7722da | 950 | up_read(&policy->rwsem); |
1b750e3b | 951 | |
1da177e4 LT |
952 | return ret; |
953 | } | |
954 | ||
905d77cd DJ |
955 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
956 | const char *buf, size_t count) | |
1da177e4 | 957 | { |
905d77cd DJ |
958 | struct cpufreq_policy *policy = to_policy(kobj); |
959 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 960 | ssize_t ret = -EINVAL; |
6eed9404 | 961 | |
9b3d9bb3 WL |
962 | /* |
963 | * cpus_read_trylock() is used here to work around a circular lock | |
964 | * dependency problem with respect to the cpufreq_register_driver(). | |
965 | */ | |
966 | if (!cpus_read_trylock()) | |
967 | return -EBUSY; | |
4f750c93 | 968 | |
6541aef0 RW |
969 | if (cpu_online(policy->cpu)) { |
970 | down_write(&policy->rwsem); | |
e08f5f5b | 971 | ret = fattr->store(policy, buf, count); |
6541aef0 RW |
972 | up_write(&policy->rwsem); |
973 | } | |
e08f5f5b | 974 | |
a92551e4 | 975 | cpus_read_unlock(); |
4f750c93 | 976 | |
1da177e4 LT |
977 | return ret; |
978 | } | |
979 | ||
905d77cd | 980 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 981 | { |
905d77cd | 982 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 983 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
984 | complete(&policy->kobj_unregister); |
985 | } | |
986 | ||
52cf25d0 | 987 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
988 | .show = show, |
989 | .store = store, | |
990 | }; | |
991 | ||
992 | static struct kobj_type ktype_cpufreq = { | |
993 | .sysfs_ops = &sysfs_ops, | |
994 | .default_attrs = default_attrs, | |
995 | .release = cpufreq_sysfs_release, | |
996 | }; | |
997 | ||
2f0ba790 | 998 | static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) |
87549141 | 999 | { |
2f0ba790 RW |
1000 | struct device *dev = get_cpu_device(cpu); |
1001 | ||
1002 | if (!dev) | |
1003 | return; | |
1004 | ||
1005 | if (cpumask_test_and_set_cpu(cpu, policy->real_cpus)) | |
1006 | return; | |
1007 | ||
26619804 | 1008 | dev_dbg(dev, "%s: Adding symlink\n", __func__); |
2f0ba790 RW |
1009 | if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq")) |
1010 | dev_err(dev, "cpufreq symlink creation failed\n"); | |
87549141 VK |
1011 | } |
1012 | ||
26619804 VK |
1013 | static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, |
1014 | struct device *dev) | |
87549141 | 1015 | { |
26619804 VK |
1016 | dev_dbg(dev, "%s: Removing symlink\n", __func__); |
1017 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
87549141 VK |
1018 | } |
1019 | ||
d9612a49 | 1020 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) |
909a694e DJ |
1021 | { |
1022 | struct freq_attr **drv_attr; | |
909a694e | 1023 | int ret = 0; |
909a694e | 1024 | |
909a694e | 1025 | /* set up files for this cpu device */ |
1c3d85dd | 1026 | drv_attr = cpufreq_driver->attr; |
f13f1184 | 1027 | while (drv_attr && *drv_attr) { |
909a694e DJ |
1028 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
1029 | if (ret) | |
6d4e81ed | 1030 | return ret; |
909a694e DJ |
1031 | drv_attr++; |
1032 | } | |
1c3d85dd | 1033 | if (cpufreq_driver->get) { |
909a694e DJ |
1034 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
1035 | if (ret) | |
6d4e81ed | 1036 | return ret; |
909a694e | 1037 | } |
c034b02e DB |
1038 | |
1039 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
1040 | if (ret) | |
6d4e81ed | 1041 | return ret; |
c034b02e | 1042 | |
1c3d85dd | 1043 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
1044 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
1045 | if (ret) | |
6d4e81ed | 1046 | return ret; |
e2f74f35 | 1047 | } |
909a694e | 1048 | |
26619804 | 1049 | return 0; |
e18f1682 SB |
1050 | } |
1051 | ||
de1df26b RW |
1052 | __weak struct cpufreq_governor *cpufreq_default_governor(void) |
1053 | { | |
1054 | return NULL; | |
1055 | } | |
1056 | ||
7f0fa40f | 1057 | static int cpufreq_init_policy(struct cpufreq_policy *policy) |
e18f1682 | 1058 | { |
ab05d97a | 1059 | struct cpufreq_governor *gov = NULL, *def_gov = NULL; |
e18f1682 | 1060 | struct cpufreq_policy new_policy; |
e18f1682 | 1061 | |
d5b73cd8 | 1062 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 1063 | |
ab05d97a YH |
1064 | def_gov = cpufreq_default_governor(); |
1065 | ||
1066 | if (has_target()) { | |
1067 | /* | |
1068 | * Update governor of new_policy to the governor used before | |
1069 | * hotplug | |
1070 | */ | |
1071 | gov = find_governor(policy->last_governor); | |
1072 | if (gov) { | |
1073 | pr_debug("Restoring governor %s for cpu %d\n", | |
6e2c89d1 | 1074 | policy->governor->name, policy->cpu); |
ab05d97a YH |
1075 | } else { |
1076 | if (!def_gov) | |
1077 | return -ENODATA; | |
1078 | gov = def_gov; | |
1079 | } | |
1080 | new_policy.governor = gov; | |
de1df26b | 1081 | } else { |
ab05d97a YH |
1082 | /* Use the default policy if there is no last_policy. */ |
1083 | if (policy->last_policy) { | |
69030dd1 | 1084 | new_policy.policy = policy->last_policy; |
ab05d97a YH |
1085 | } else { |
1086 | if (!def_gov) | |
1087 | return -ENODATA; | |
1088 | cpufreq_parse_policy(def_gov->name, &new_policy); | |
1089 | } | |
69030dd1 | 1090 | } |
ab05d97a | 1091 | |
7f0fa40f | 1092 | return cpufreq_set_policy(policy, &new_policy); |
909a694e DJ |
1093 | } |
1094 | ||
d9612a49 | 1095 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
fcf80582 | 1096 | { |
9c0ebcf7 | 1097 | int ret = 0; |
fcf80582 | 1098 | |
bb29ae15 VK |
1099 | /* Has this CPU been taken care of already? */ |
1100 | if (cpumask_test_cpu(cpu, policy->cpus)) | |
1101 | return 0; | |
1102 | ||
49f18560 | 1103 | down_write(&policy->rwsem); |
45482c70 RW |
1104 | if (has_target()) |
1105 | cpufreq_stop_governor(policy); | |
fcf80582 | 1106 | |
fcf80582 | 1107 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 1108 | |
9c0ebcf7 | 1109 | if (has_target()) { |
0a300767 | 1110 | ret = cpufreq_start_governor(policy); |
49f18560 | 1111 | if (ret) |
3de9bdeb | 1112 | pr_err("%s: Failed to start governor\n", __func__); |
820c6ca2 | 1113 | } |
49f18560 VK |
1114 | up_write(&policy->rwsem); |
1115 | return ret; | |
fcf80582 | 1116 | } |
1da177e4 | 1117 | |
70a59fde VK |
1118 | static void refresh_frequency_limits(struct cpufreq_policy *policy) |
1119 | { | |
1120 | struct cpufreq_policy new_policy = *policy; | |
1121 | ||
1122 | pr_debug("updating policy for CPU %u\n", policy->cpu); | |
1123 | ||
1124 | new_policy.min = policy->user_policy.min; | |
1125 | new_policy.max = policy->user_policy.max; | |
1126 | ||
1127 | cpufreq_set_policy(policy, &new_policy); | |
1128 | } | |
1129 | ||
11eb69b9 VK |
1130 | static void handle_update(struct work_struct *work) |
1131 | { | |
1132 | struct cpufreq_policy *policy = | |
1133 | container_of(work, struct cpufreq_policy, update); | |
70a59fde VK |
1134 | |
1135 | pr_debug("handle_update for cpu %u called\n", policy->cpu); | |
1136 | refresh_frequency_limits(policy); | |
fcf80582 | 1137 | } |
1da177e4 | 1138 | |
a34e63b1 | 1139 | static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) |
e9698cc5 SB |
1140 | { |
1141 | struct cpufreq_policy *policy; | |
edd4a893 | 1142 | int ret; |
e9698cc5 SB |
1143 | |
1144 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
1145 | if (!policy) | |
1146 | return NULL; | |
1147 | ||
1148 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1149 | goto err_free_policy; | |
1150 | ||
1151 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1152 | goto err_free_cpumask; | |
1153 | ||
559ed407 RW |
1154 | if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) |
1155 | goto err_free_rcpumask; | |
1156 | ||
edd4a893 VK |
1157 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
1158 | cpufreq_global_kobject, "policy%u", cpu); | |
1159 | if (ret) { | |
1160 | pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret); | |
2acb9bda RW |
1161 | /* |
1162 | * The entire policy object will be freed below, but the extra | |
1163 | * memory allocated for the kobject name needs to be freed by | |
1164 | * releasing the kobject. | |
1165 | */ | |
4ebe36c9 | 1166 | kobject_put(&policy->kobj); |
edd4a893 VK |
1167 | goto err_free_real_cpus; |
1168 | } | |
1169 | ||
c88a1f8b | 1170 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1171 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1172 | spin_lock_init(&policy->transition_lock); |
1173 | init_waitqueue_head(&policy->transition_wait); | |
818c5712 VK |
1174 | init_completion(&policy->kobj_unregister); |
1175 | INIT_WORK(&policy->update, handle_update); | |
ad7722da | 1176 | |
a34e63b1 | 1177 | policy->cpu = cpu; |
e9698cc5 SB |
1178 | return policy; |
1179 | ||
edd4a893 VK |
1180 | err_free_real_cpus: |
1181 | free_cpumask_var(policy->real_cpus); | |
2fc3384d VK |
1182 | err_free_rcpumask: |
1183 | free_cpumask_var(policy->related_cpus); | |
e9698cc5 SB |
1184 | err_free_cpumask: |
1185 | free_cpumask_var(policy->cpus); | |
1186 | err_free_policy: | |
1187 | kfree(policy); | |
1188 | ||
1189 | return NULL; | |
1190 | } | |
1191 | ||
f9f41e3e | 1192 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
42f921a6 VK |
1193 | { |
1194 | struct kobject *kobj; | |
1195 | struct completion *cmp; | |
1196 | ||
87549141 | 1197 | down_write(&policy->rwsem); |
1aefc75b | 1198 | cpufreq_stats_free_table(policy); |
42f921a6 VK |
1199 | kobj = &policy->kobj; |
1200 | cmp = &policy->kobj_unregister; | |
87549141 | 1201 | up_write(&policy->rwsem); |
42f921a6 VK |
1202 | kobject_put(kobj); |
1203 | ||
1204 | /* | |
1205 | * We need to make sure that the underlying kobj is | |
1206 | * actually not referenced anymore by anybody before we | |
1207 | * proceed with unloading. | |
1208 | */ | |
1209 | pr_debug("waiting for dropping of refcount\n"); | |
1210 | wait_for_completion(cmp); | |
1211 | pr_debug("wait complete\n"); | |
1212 | } | |
1213 | ||
f9f41e3e | 1214 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
e9698cc5 | 1215 | { |
988bed09 VK |
1216 | unsigned long flags; |
1217 | int cpu; | |
1218 | ||
1219 | /* Remove policy from list */ | |
1220 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1221 | list_del(&policy->policy_list); | |
1222 | ||
1223 | for_each_cpu(cpu, policy->related_cpus) | |
1224 | per_cpu(cpufreq_cpu_data, cpu) = NULL; | |
1225 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1226 | ||
f9f41e3e | 1227 | cpufreq_policy_put_kobj(policy); |
559ed407 | 1228 | free_cpumask_var(policy->real_cpus); |
e9698cc5 SB |
1229 | free_cpumask_var(policy->related_cpus); |
1230 | free_cpumask_var(policy->cpus); | |
1231 | kfree(policy); | |
1232 | } | |
1233 | ||
0b275352 | 1234 | static int cpufreq_online(unsigned int cpu) |
1da177e4 | 1235 | { |
7f0c020a | 1236 | struct cpufreq_policy *policy; |
194d99c7 | 1237 | bool new_policy; |
1da177e4 | 1238 | unsigned long flags; |
0b275352 RW |
1239 | unsigned int j; |
1240 | int ret; | |
87549141 | 1241 | |
0b275352 | 1242 | pr_debug("%s: bringing CPU%u online\n", __func__, cpu); |
6eed9404 | 1243 | |
bb29ae15 | 1244 | /* Check if this CPU already has a policy to manage it */ |
9104bb26 | 1245 | policy = per_cpu(cpufreq_cpu_data, cpu); |
11ce707e | 1246 | if (policy) { |
9104bb26 | 1247 | WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus)); |
11ce707e | 1248 | if (!policy_is_inactive(policy)) |
d9612a49 | 1249 | return cpufreq_add_policy_cpu(policy, cpu); |
1da177e4 | 1250 | |
11ce707e | 1251 | /* This is the only online CPU for the policy. Start over. */ |
194d99c7 | 1252 | new_policy = false; |
11ce707e RW |
1253 | down_write(&policy->rwsem); |
1254 | policy->cpu = cpu; | |
1255 | policy->governor = NULL; | |
1256 | up_write(&policy->rwsem); | |
1257 | } else { | |
194d99c7 | 1258 | new_policy = true; |
a34e63b1 | 1259 | policy = cpufreq_policy_alloc(cpu); |
72368d12 | 1260 | if (!policy) |
d4d854d6 | 1261 | return -ENOMEM; |
72368d12 | 1262 | } |
0d66b91e | 1263 | |
91a12e91 VK |
1264 | if (!new_policy && cpufreq_driver->online) { |
1265 | ret = cpufreq_driver->online(policy); | |
1266 | if (ret) { | |
1267 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1268 | __LINE__); | |
1269 | goto out_exit_policy; | |
1270 | } | |
1da177e4 | 1271 | |
91a12e91 VK |
1272 | /* Recover policy->cpus using related_cpus */ |
1273 | cpumask_copy(policy->cpus, policy->related_cpus); | |
1274 | } else { | |
1275 | cpumask_copy(policy->cpus, cpumask_of(cpu)); | |
643ae6e8 | 1276 | |
91a12e91 VK |
1277 | /* |
1278 | * Call driver. From then on the cpufreq must be able | |
1279 | * to accept all calls to ->verify and ->setpolicy for this CPU. | |
1280 | */ | |
1281 | ret = cpufreq_driver->init(policy); | |
1282 | if (ret) { | |
1283 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1284 | __LINE__); | |
1285 | goto out_free_policy; | |
1286 | } | |
d417e069 | 1287 | |
91a12e91 VK |
1288 | ret = cpufreq_table_validate_and_sort(policy); |
1289 | if (ret) | |
1290 | goto out_exit_policy; | |
6d4e81ed | 1291 | |
4d1f3a5b | 1292 | /* related_cpus should at least include policy->cpus. */ |
0998a03a | 1293 | cpumask_copy(policy->related_cpus, policy->cpus); |
4d1f3a5b | 1294 | } |
559ed407 | 1295 | |
91a12e91 | 1296 | down_write(&policy->rwsem); |
5a7e56a5 VK |
1297 | /* |
1298 | * affected cpus must always be the one, which are online. We aren't | |
1299 | * managing offline cpus here. | |
1300 | */ | |
1301 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1302 | ||
194d99c7 | 1303 | if (new_policy) { |
5a7e56a5 VK |
1304 | policy->user_policy.min = policy->min; |
1305 | policy->user_policy.max = policy->max; | |
6d4e81ed | 1306 | |
2f0ba790 | 1307 | for_each_cpu(j, policy->related_cpus) { |
988bed09 | 1308 | per_cpu(cpufreq_cpu_data, j) = policy; |
2f0ba790 RW |
1309 | add_cpu_dev_symlink(policy, j); |
1310 | } | |
ff010472 VK |
1311 | } else { |
1312 | policy->min = policy->user_policy.min; | |
1313 | policy->max = policy->user_policy.max; | |
988bed09 | 1314 | } |
652ed95d | 1315 | |
5ddc6d4e | 1316 | if (cpufreq_driver->get && has_target()) { |
da60ce9f VK |
1317 | policy->cur = cpufreq_driver->get(policy->cpu); |
1318 | if (!policy->cur) { | |
1319 | pr_err("%s: ->get() failed\n", __func__); | |
d417e069 | 1320 | goto out_destroy_policy; |
da60ce9f VK |
1321 | } |
1322 | } | |
1323 | ||
d3916691 VK |
1324 | /* |
1325 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1326 | * frequency table present with cpufreq core. In such cases CPU might be | |
1327 | * unstable if it has to run on that frequency for long duration of time | |
1328 | * and so its better to set it to a frequency which is specified in | |
1329 | * freq-table. This also makes cpufreq stats inconsistent as | |
1330 | * cpufreq-stats would fail to register because current frequency of CPU | |
1331 | * isn't found in freq-table. | |
1332 | * | |
1333 | * Because we don't want this change to effect boot process badly, we go | |
1334 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1335 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1336 | * is initialized to zero). | |
1337 | * | |
1338 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1339 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1340 | * equal to target-freq. | |
1341 | */ | |
1342 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1343 | && has_target()) { | |
1344 | /* Are we running at unknown frequency ? */ | |
1345 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1346 | if (ret == -EINVAL) { | |
1347 | /* Warn user and fix it */ | |
1348 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1349 | __func__, policy->cpu, policy->cur); | |
1350 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1351 | CPUFREQ_RELATION_L); | |
1352 | ||
1353 | /* | |
1354 | * Reaching here after boot in a few seconds may not | |
1355 | * mean that system will remain stable at "unknown" | |
1356 | * frequency for longer duration. Hence, a BUG_ON(). | |
1357 | */ | |
1358 | BUG_ON(ret); | |
1359 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1360 | __func__, policy->cpu, policy->cur); | |
1361 | } | |
1362 | } | |
1363 | ||
194d99c7 | 1364 | if (new_policy) { |
d9612a49 | 1365 | ret = cpufreq_add_dev_interface(policy); |
a82fab29 | 1366 | if (ret) |
d417e069 | 1367 | goto out_destroy_policy; |
1aefc75b RW |
1368 | |
1369 | cpufreq_stats_create_table(policy); | |
8ff69732 | 1370 | |
988bed09 VK |
1371 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1372 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1373 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1374 | } | |
9515f4d6 | 1375 | |
7f0fa40f VK |
1376 | ret = cpufreq_init_policy(policy); |
1377 | if (ret) { | |
1378 | pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", | |
1379 | __func__, cpu, ret); | |
d417e069 | 1380 | goto out_destroy_policy; |
08fd8c1c | 1381 | } |
e18f1682 | 1382 | |
4e97b631 | 1383 | up_write(&policy->rwsem); |
08fd8c1c | 1384 | |
038c5b3e | 1385 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
7c45cf31 | 1386 | |
7c45cf31 VK |
1387 | /* Callback for handling stuff after policy is ready */ |
1388 | if (cpufreq_driver->ready) | |
1389 | cpufreq_driver->ready(policy); | |
1390 | ||
bcc61569 | 1391 | if (cpufreq_thermal_control_enabled(cpufreq_driver)) |
5c238a8b AK |
1392 | policy->cdev = of_cpufreq_cooling_register(policy); |
1393 | ||
2d06d8c4 | 1394 | pr_debug("initialization complete\n"); |
87c32271 | 1395 | |
1da177e4 LT |
1396 | return 0; |
1397 | ||
d417e069 | 1398 | out_destroy_policy: |
b24b6478 VK |
1399 | for_each_cpu(j, policy->real_cpus) |
1400 | remove_cpu_dev_symlink(policy, get_cpu_device(j)); | |
1401 | ||
7106e02b PB |
1402 | up_write(&policy->rwsem); |
1403 | ||
d417e069 | 1404 | out_exit_policy: |
da60ce9f VK |
1405 | if (cpufreq_driver->exit) |
1406 | cpufreq_driver->exit(policy); | |
2f0ba790 | 1407 | |
8101f997 | 1408 | out_free_policy: |
f9f41e3e | 1409 | cpufreq_policy_free(policy); |
1da177e4 LT |
1410 | return ret; |
1411 | } | |
1412 | ||
0b275352 RW |
1413 | /** |
1414 | * cpufreq_add_dev - the cpufreq interface for a CPU device. | |
1415 | * @dev: CPU device. | |
1416 | * @sif: Subsystem interface structure pointer (not used) | |
1417 | */ | |
1418 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1419 | { | |
a794d613 | 1420 | struct cpufreq_policy *policy; |
0b275352 | 1421 | unsigned cpu = dev->id; |
26619804 | 1422 | int ret; |
0b275352 RW |
1423 | |
1424 | dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); | |
1425 | ||
26619804 VK |
1426 | if (cpu_online(cpu)) { |
1427 | ret = cpufreq_online(cpu); | |
1428 | if (ret) | |
1429 | return ret; | |
1430 | } | |
0b275352 | 1431 | |
26619804 | 1432 | /* Create sysfs link on CPU registration */ |
a794d613 | 1433 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2f0ba790 RW |
1434 | if (policy) |
1435 | add_cpu_dev_symlink(policy, cpu); | |
26619804 | 1436 | |
2f0ba790 | 1437 | return 0; |
1da177e4 LT |
1438 | } |
1439 | ||
27622b06 | 1440 | static int cpufreq_offline(unsigned int cpu) |
1da177e4 | 1441 | { |
3a3e9e06 | 1442 | struct cpufreq_policy *policy; |
69cee714 | 1443 | int ret; |
1da177e4 | 1444 | |
b8eed8af | 1445 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1446 | |
988bed09 | 1447 | policy = cpufreq_cpu_get_raw(cpu); |
3a3e9e06 | 1448 | if (!policy) { |
b8eed8af | 1449 | pr_debug("%s: No cpu_data found\n", __func__); |
27622b06 | 1450 | return 0; |
1da177e4 | 1451 | } |
1da177e4 | 1452 | |
49f18560 | 1453 | down_write(&policy->rwsem); |
45482c70 RW |
1454 | if (has_target()) |
1455 | cpufreq_stop_governor(policy); | |
1da177e4 | 1456 | |
9591becb | 1457 | cpumask_clear_cpu(cpu, policy->cpus); |
4573237b | 1458 | |
9591becb VK |
1459 | if (policy_is_inactive(policy)) { |
1460 | if (has_target()) | |
1461 | strncpy(policy->last_governor, policy->governor->name, | |
1462 | CPUFREQ_NAME_LEN); | |
69030dd1 SP |
1463 | else |
1464 | policy->last_policy = policy->policy; | |
9591becb VK |
1465 | } else if (cpu == policy->cpu) { |
1466 | /* Nominate new CPU */ | |
1467 | policy->cpu = cpumask_any(policy->cpus); | |
1468 | } | |
084f3493 | 1469 | |
9591becb VK |
1470 | /* Start governor again for active policy */ |
1471 | if (!policy_is_inactive(policy)) { | |
1472 | if (has_target()) { | |
0a300767 | 1473 | ret = cpufreq_start_governor(policy); |
9591becb VK |
1474 | if (ret) |
1475 | pr_err("%s: Failed to start governor\n", __func__); | |
1476 | } | |
cedb70af | 1477 | |
49f18560 | 1478 | goto unlock; |
cedb70af SB |
1479 | } |
1480 | ||
bcc61569 | 1481 | if (cpufreq_thermal_control_enabled(cpufreq_driver)) { |
5c238a8b AK |
1482 | cpufreq_cooling_unregister(policy->cdev); |
1483 | policy->cdev = NULL; | |
1484 | } | |
1485 | ||
69cee714 VK |
1486 | if (cpufreq_driver->stop_cpu) |
1487 | cpufreq_driver->stop_cpu(policy); | |
87549141 | 1488 | |
36be3418 RW |
1489 | if (has_target()) |
1490 | cpufreq_exit_governor(policy); | |
1da177e4 | 1491 | |
87549141 | 1492 | /* |
91a12e91 VK |
1493 | * Perform the ->offline() during light-weight tear-down, as |
1494 | * that allows fast recovery when the CPU comes back. | |
87549141 | 1495 | */ |
91a12e91 VK |
1496 | if (cpufreq_driver->offline) { |
1497 | cpufreq_driver->offline(policy); | |
1498 | } else if (cpufreq_driver->exit) { | |
87549141 | 1499 | cpufreq_driver->exit(policy); |
55582bcc SP |
1500 | policy->freq_table = NULL; |
1501 | } | |
49f18560 VK |
1502 | |
1503 | unlock: | |
1504 | up_write(&policy->rwsem); | |
27622b06 | 1505 | return 0; |
1da177e4 LT |
1506 | } |
1507 | ||
cedb70af | 1508 | /** |
27a862e9 | 1509 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1510 | * |
1511 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1512 | */ |
71db87ba | 1513 | static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1514 | { |
8a25a2fd | 1515 | unsigned int cpu = dev->id; |
559ed407 | 1516 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
87549141 | 1517 | |
559ed407 | 1518 | if (!policy) |
1af115d6 | 1519 | return; |
87549141 | 1520 | |
69cee714 VK |
1521 | if (cpu_online(cpu)) |
1522 | cpufreq_offline(cpu); | |
87549141 | 1523 | |
559ed407 | 1524 | cpumask_clear_cpu(cpu, policy->real_cpus); |
26619804 | 1525 | remove_cpu_dev_symlink(policy, dev); |
87549141 | 1526 | |
91a12e91 VK |
1527 | if (cpumask_empty(policy->real_cpus)) { |
1528 | /* We did light-weight exit earlier, do full tear down now */ | |
1529 | if (cpufreq_driver->offline) | |
1530 | cpufreq_driver->exit(policy); | |
1531 | ||
f9f41e3e | 1532 | cpufreq_policy_free(policy); |
91a12e91 | 1533 | } |
5a01f2e8 VP |
1534 | } |
1535 | ||
1da177e4 | 1536 | /** |
bb176f7d VK |
1537 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1538 | * in deep trouble. | |
a1e1dc41 | 1539 | * @policy: policy managing CPUs |
1da177e4 LT |
1540 | * @new_freq: CPU frequency the CPU actually runs at |
1541 | * | |
29464f28 DJ |
1542 | * We adjust to current frequency first, and need to clean up later. |
1543 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1544 | */ |
a1e1dc41 | 1545 | static void cpufreq_out_of_sync(struct cpufreq_policy *policy, |
e08f5f5b | 1546 | unsigned int new_freq) |
1da177e4 LT |
1547 | { |
1548 | struct cpufreq_freqs freqs; | |
b43a7ffb | 1549 | |
e837f9b5 | 1550 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
a1e1dc41 | 1551 | policy->cur, new_freq); |
1da177e4 | 1552 | |
a1e1dc41 | 1553 | freqs.old = policy->cur; |
1da177e4 | 1554 | freqs.new = new_freq; |
b43a7ffb | 1555 | |
8fec051e VK |
1556 | cpufreq_freq_transition_begin(policy, &freqs); |
1557 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1558 | } |
1559 | ||
5980752e VK |
1560 | static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update) |
1561 | { | |
1562 | unsigned int new_freq; | |
1563 | ||
1564 | new_freq = cpufreq_driver->get(policy->cpu); | |
1565 | if (!new_freq) | |
1566 | return 0; | |
1567 | ||
1568 | /* | |
1569 | * If fast frequency switching is used with the given policy, the check | |
1570 | * against policy->cur is pointless, so skip it in that case. | |
1571 | */ | |
1572 | if (policy->fast_switch_enabled || !has_target()) | |
1573 | return new_freq; | |
1574 | ||
1575 | if (policy->cur != new_freq) { | |
1576 | cpufreq_out_of_sync(policy, new_freq); | |
1577 | if (update) | |
1578 | schedule_work(&policy->update); | |
1579 | } | |
1580 | ||
1581 | return new_freq; | |
1582 | } | |
1583 | ||
32ee8c3e | 1584 | /** |
4ab70df4 | 1585 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1586 | * @cpu: CPU number |
1587 | * | |
1588 | * This is the last known freq, without actually getting it from the driver. | |
1589 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1590 | */ | |
1591 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1592 | { | |
9e21ba8b | 1593 | struct cpufreq_policy *policy; |
e08f5f5b | 1594 | unsigned int ret_freq = 0; |
c75361c0 | 1595 | unsigned long flags; |
95235ca2 | 1596 | |
c75361c0 RC |
1597 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1598 | ||
1599 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { | |
1600 | ret_freq = cpufreq_driver->get(cpu); | |
1601 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1602 | return ret_freq; | |
1603 | } | |
1604 | ||
1605 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
9e21ba8b DB |
1606 | |
1607 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1608 | if (policy) { |
e08f5f5b | 1609 | ret_freq = policy->cur; |
95235ca2 VP |
1610 | cpufreq_cpu_put(policy); |
1611 | } | |
1612 | ||
4d34a67d | 1613 | return ret_freq; |
95235ca2 VP |
1614 | } |
1615 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1616 | ||
3d737108 JB |
1617 | /** |
1618 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1619 | * @cpu: CPU number | |
1620 | * | |
1621 | * Just return the max possible frequency for a given CPU. | |
1622 | */ | |
1623 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1624 | { | |
1625 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1626 | unsigned int ret_freq = 0; | |
1627 | ||
1628 | if (policy) { | |
1629 | ret_freq = policy->max; | |
1630 | cpufreq_cpu_put(policy); | |
1631 | } | |
1632 | ||
1633 | return ret_freq; | |
1634 | } | |
1635 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1636 | ||
d92d50a4 | 1637 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy) |
1da177e4 | 1638 | { |
4db7c34c | 1639 | if (unlikely(policy_is_inactive(policy))) |
5980752e | 1640 | return 0; |
1da177e4 | 1641 | |
5980752e | 1642 | return cpufreq_verify_current_freq(policy, true); |
5a01f2e8 | 1643 | } |
1da177e4 | 1644 | |
5a01f2e8 VP |
1645 | /** |
1646 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1647 | * @cpu: CPU number | |
1648 | * | |
1649 | * Get the CPU current (static) CPU frequency | |
1650 | */ | |
1651 | unsigned int cpufreq_get(unsigned int cpu) | |
1652 | { | |
999976e0 | 1653 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1654 | unsigned int ret_freq = 0; |
5a01f2e8 | 1655 | |
999976e0 AP |
1656 | if (policy) { |
1657 | down_read(&policy->rwsem); | |
4db7c34c YH |
1658 | if (cpufreq_driver->get) |
1659 | ret_freq = __cpufreq_get(policy); | |
999976e0 | 1660 | up_read(&policy->rwsem); |
5a01f2e8 | 1661 | |
999976e0 AP |
1662 | cpufreq_cpu_put(policy); |
1663 | } | |
6eed9404 | 1664 | |
4d34a67d | 1665 | return ret_freq; |
1da177e4 LT |
1666 | } |
1667 | EXPORT_SYMBOL(cpufreq_get); | |
1668 | ||
8a25a2fd KS |
1669 | static struct subsys_interface cpufreq_interface = { |
1670 | .name = "cpufreq", | |
1671 | .subsys = &cpu_subsys, | |
1672 | .add_dev = cpufreq_add_dev, | |
1673 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1674 | }; |
1675 | ||
e28867ea VK |
1676 | /* |
1677 | * In case platform wants some specific frequency to be configured | |
1678 | * during suspend.. | |
1679 | */ | |
1680 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1681 | { | |
1682 | int ret; | |
1683 | ||
1684 | if (!policy->suspend_freq) { | |
201f3716 BZ |
1685 | pr_debug("%s: suspend_freq not defined\n", __func__); |
1686 | return 0; | |
e28867ea VK |
1687 | } |
1688 | ||
1689 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1690 | policy->suspend_freq); | |
1691 | ||
1692 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1693 | CPUFREQ_RELATION_H); | |
1694 | if (ret) | |
1695 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1696 | __func__, policy->suspend_freq, ret); | |
1697 | ||
1698 | return ret; | |
1699 | } | |
1700 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1701 | ||
42d4dc3f | 1702 | /** |
2f0aea93 | 1703 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1704 | * |
2f0aea93 VK |
1705 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1706 | * as some platforms can't change frequency after this point in suspend cycle. | |
1707 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1708 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1709 | */ |
2f0aea93 | 1710 | void cpufreq_suspend(void) |
42d4dc3f | 1711 | { |
3a3e9e06 | 1712 | struct cpufreq_policy *policy; |
42d4dc3f | 1713 | |
2f0aea93 VK |
1714 | if (!cpufreq_driver) |
1715 | return; | |
42d4dc3f | 1716 | |
ba41e1bc | 1717 | if (!has_target() && !cpufreq_driver->suspend) |
b1b12bab | 1718 | goto suspend; |
42d4dc3f | 1719 | |
2f0aea93 VK |
1720 | pr_debug("%s: Suspending Governors\n", __func__); |
1721 | ||
f963735a | 1722 | for_each_active_policy(policy) { |
ba41e1bc RW |
1723 | if (has_target()) { |
1724 | down_write(&policy->rwsem); | |
45482c70 | 1725 | cpufreq_stop_governor(policy); |
ba41e1bc | 1726 | up_write(&policy->rwsem); |
ba41e1bc RW |
1727 | } |
1728 | ||
1729 | if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) | |
2f0aea93 VK |
1730 | pr_err("%s: Failed to suspend driver: %p\n", __func__, |
1731 | policy); | |
42d4dc3f | 1732 | } |
b1b12bab VK |
1733 | |
1734 | suspend: | |
1735 | cpufreq_suspended = true; | |
42d4dc3f BH |
1736 | } |
1737 | ||
1da177e4 | 1738 | /** |
2f0aea93 | 1739 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1740 | * |
2f0aea93 VK |
1741 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1742 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1743 | */ |
2f0aea93 | 1744 | void cpufreq_resume(void) |
1da177e4 | 1745 | { |
3a3e9e06 | 1746 | struct cpufreq_policy *policy; |
49f18560 | 1747 | int ret; |
1da177e4 | 1748 | |
2f0aea93 | 1749 | if (!cpufreq_driver) |
703cbaa6 BY |
1750 | return; |
1751 | ||
1752 | if (unlikely(!cpufreq_suspended)) | |
2f0aea93 | 1753 | return; |
1da177e4 | 1754 | |
8e30444e LT |
1755 | cpufreq_suspended = false; |
1756 | ||
ba41e1bc | 1757 | if (!has_target() && !cpufreq_driver->resume) |
e00e56df | 1758 | return; |
1da177e4 | 1759 | |
2f0aea93 | 1760 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1761 | |
f963735a | 1762 | for_each_active_policy(policy) { |
49f18560 | 1763 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { |
0c5aa405 VK |
1764 | pr_err("%s: Failed to resume driver: %p\n", __func__, |
1765 | policy); | |
ba41e1bc | 1766 | } else if (has_target()) { |
49f18560 | 1767 | down_write(&policy->rwsem); |
0a300767 | 1768 | ret = cpufreq_start_governor(policy); |
49f18560 VK |
1769 | up_write(&policy->rwsem); |
1770 | ||
1771 | if (ret) | |
1772 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1773 | __func__, policy); | |
1774 | } | |
2f0aea93 VK |
1775 | } |
1776 | } | |
1da177e4 | 1777 | |
9d95046e BP |
1778 | /** |
1779 | * cpufreq_get_current_driver - return current driver's name | |
1780 | * | |
1781 | * Return the name string of the currently loaded cpufreq driver | |
1782 | * or NULL, if none. | |
1783 | */ | |
1784 | const char *cpufreq_get_current_driver(void) | |
1785 | { | |
1c3d85dd RW |
1786 | if (cpufreq_driver) |
1787 | return cpufreq_driver->name; | |
1788 | ||
1789 | return NULL; | |
9d95046e BP |
1790 | } |
1791 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 | 1792 | |
51315cdf TP |
1793 | /** |
1794 | * cpufreq_get_driver_data - return current driver data | |
1795 | * | |
1796 | * Return the private data of the currently loaded cpufreq | |
1797 | * driver, or NULL if no cpufreq driver is loaded. | |
1798 | */ | |
1799 | void *cpufreq_get_driver_data(void) | |
1800 | { | |
1801 | if (cpufreq_driver) | |
1802 | return cpufreq_driver->driver_data; | |
1803 | ||
1804 | return NULL; | |
1805 | } | |
1806 | EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); | |
1807 | ||
1da177e4 LT |
1808 | /********************************************************************* |
1809 | * NOTIFIER LISTS INTERFACE * | |
1810 | *********************************************************************/ | |
1811 | ||
1812 | /** | |
1813 | * cpufreq_register_notifier - register a driver with cpufreq | |
1814 | * @nb: notifier function to register | |
1815 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1816 | * | |
32ee8c3e | 1817 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1818 | * are notified about clock rate changes (once before and once after |
1819 | * the transition), or a list of drivers that are notified about | |
1820 | * changes in cpufreq policy. | |
1821 | * | |
1822 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1823 | * blocking_notifier_chain_register. |
1da177e4 LT |
1824 | */ |
1825 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1826 | { | |
1827 | int ret; | |
1828 | ||
d5aaffa9 DB |
1829 | if (cpufreq_disabled()) |
1830 | return -EINVAL; | |
1831 | ||
1da177e4 LT |
1832 | switch (list) { |
1833 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1834 | mutex_lock(&cpufreq_fast_switch_lock); |
1835 | ||
1836 | if (cpufreq_fast_switch_count > 0) { | |
1837 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1838 | return -EBUSY; | |
1839 | } | |
b4dfdbb3 | 1840 | ret = srcu_notifier_chain_register( |
e041c683 | 1841 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1842 | if (!ret) |
1843 | cpufreq_fast_switch_count--; | |
1844 | ||
1845 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1846 | break; |
1847 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1848 | ret = blocking_notifier_chain_register( |
1849 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1850 | break; |
1851 | default: | |
1852 | ret = -EINVAL; | |
1853 | } | |
1da177e4 LT |
1854 | |
1855 | return ret; | |
1856 | } | |
1857 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1858 | ||
1da177e4 LT |
1859 | /** |
1860 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1861 | * @nb: notifier block to be unregistered | |
bb176f7d | 1862 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1863 | * |
1864 | * Remove a driver from the CPU frequency notifier list. | |
1865 | * | |
1866 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1867 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1868 | */ |
1869 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1870 | { | |
1871 | int ret; | |
1872 | ||
d5aaffa9 DB |
1873 | if (cpufreq_disabled()) |
1874 | return -EINVAL; | |
1875 | ||
1da177e4 LT |
1876 | switch (list) { |
1877 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1878 | mutex_lock(&cpufreq_fast_switch_lock); |
1879 | ||
b4dfdbb3 | 1880 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1881 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1882 | if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) |
1883 | cpufreq_fast_switch_count++; | |
1884 | ||
1885 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1886 | break; |
1887 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1888 | ret = blocking_notifier_chain_unregister( |
1889 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1890 | break; |
1891 | default: | |
1892 | ret = -EINVAL; | |
1893 | } | |
1da177e4 LT |
1894 | |
1895 | return ret; | |
1896 | } | |
1897 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1898 | ||
1899 | ||
1900 | /********************************************************************* | |
1901 | * GOVERNORS * | |
1902 | *********************************************************************/ | |
1903 | ||
b7898fda RW |
1904 | /** |
1905 | * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. | |
1906 | * @policy: cpufreq policy to switch the frequency for. | |
1907 | * @target_freq: New frequency to set (may be approximate). | |
1908 | * | |
1909 | * Carry out a fast frequency switch without sleeping. | |
1910 | * | |
1911 | * The driver's ->fast_switch() callback invoked by this function must be | |
1912 | * suitable for being called from within RCU-sched read-side critical sections | |
1913 | * and it is expected to select the minimum available frequency greater than or | |
1914 | * equal to @target_freq (CPUFREQ_RELATION_L). | |
1915 | * | |
1916 | * This function must not be called if policy->fast_switch_enabled is unset. | |
1917 | * | |
1918 | * Governors calling this function must guarantee that it will never be invoked | |
1919 | * twice in parallel for the same policy and that it will never be called in | |
1920 | * parallel with either ->target() or ->target_index() for the same policy. | |
1921 | * | |
209887e6 VK |
1922 | * Returns the actual frequency set for the CPU. |
1923 | * | |
1924 | * If 0 is returned by the driver's ->fast_switch() callback to indicate an | |
1925 | * error condition, the hardware configuration must be preserved. | |
b7898fda RW |
1926 | */ |
1927 | unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, | |
1928 | unsigned int target_freq) | |
1929 | { | |
b9af6948 | 1930 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
b7898fda RW |
1931 | |
1932 | return cpufreq_driver->fast_switch(policy, target_freq); | |
1933 | } | |
1934 | EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); | |
1935 | ||
1c03a2d0 VK |
1936 | /* Must set freqs->new to intermediate frequency */ |
1937 | static int __target_intermediate(struct cpufreq_policy *policy, | |
1938 | struct cpufreq_freqs *freqs, int index) | |
1939 | { | |
1940 | int ret; | |
1941 | ||
1942 | freqs->new = cpufreq_driver->get_intermediate(policy, index); | |
1943 | ||
1944 | /* We don't need to switch to intermediate freq */ | |
1945 | if (!freqs->new) | |
1946 | return 0; | |
1947 | ||
1948 | pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", | |
1949 | __func__, policy->cpu, freqs->old, freqs->new); | |
1950 | ||
1951 | cpufreq_freq_transition_begin(policy, freqs); | |
1952 | ret = cpufreq_driver->target_intermediate(policy, index); | |
1953 | cpufreq_freq_transition_end(policy, freqs, ret); | |
1954 | ||
1955 | if (ret) | |
1956 | pr_err("%s: Failed to change to intermediate frequency: %d\n", | |
1957 | __func__, ret); | |
1958 | ||
1959 | return ret; | |
1960 | } | |
1961 | ||
23727845 | 1962 | static int __target_index(struct cpufreq_policy *policy, int index) |
8d65775d | 1963 | { |
1c03a2d0 VK |
1964 | struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
1965 | unsigned int intermediate_freq = 0; | |
23727845 | 1966 | unsigned int newfreq = policy->freq_table[index].frequency; |
8d65775d VK |
1967 | int retval = -EINVAL; |
1968 | bool notify; | |
1969 | ||
23727845 VK |
1970 | if (newfreq == policy->cur) |
1971 | return 0; | |
1972 | ||
8d65775d | 1973 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); |
8d65775d | 1974 | if (notify) { |
1c03a2d0 VK |
1975 | /* Handle switching to intermediate frequency */ |
1976 | if (cpufreq_driver->get_intermediate) { | |
1977 | retval = __target_intermediate(policy, &freqs, index); | |
1978 | if (retval) | |
1979 | return retval; | |
1980 | ||
1981 | intermediate_freq = freqs.new; | |
1982 | /* Set old freq to intermediate */ | |
1983 | if (intermediate_freq) | |
1984 | freqs.old = freqs.new; | |
1985 | } | |
8d65775d | 1986 | |
23727845 | 1987 | freqs.new = newfreq; |
8d65775d VK |
1988 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", |
1989 | __func__, policy->cpu, freqs.old, freqs.new); | |
1990 | ||
1991 | cpufreq_freq_transition_begin(policy, &freqs); | |
1992 | } | |
1993 | ||
1994 | retval = cpufreq_driver->target_index(policy, index); | |
1995 | if (retval) | |
1996 | pr_err("%s: Failed to change cpu frequency: %d\n", __func__, | |
1997 | retval); | |
1998 | ||
1c03a2d0 | 1999 | if (notify) { |
8d65775d VK |
2000 | cpufreq_freq_transition_end(policy, &freqs, retval); |
2001 | ||
1c03a2d0 VK |
2002 | /* |
2003 | * Failed after setting to intermediate freq? Driver should have | |
2004 | * reverted back to initial frequency and so should we. Check | |
2005 | * here for intermediate_freq instead of get_intermediate, in | |
58405af6 | 2006 | * case we haven't switched to intermediate freq at all. |
1c03a2d0 VK |
2007 | */ |
2008 | if (unlikely(retval && intermediate_freq)) { | |
2009 | freqs.old = intermediate_freq; | |
2010 | freqs.new = policy->restore_freq; | |
2011 | cpufreq_freq_transition_begin(policy, &freqs); | |
2012 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
2013 | } | |
2014 | } | |
2015 | ||
8d65775d VK |
2016 | return retval; |
2017 | } | |
2018 | ||
1da177e4 LT |
2019 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
2020 | unsigned int target_freq, | |
2021 | unsigned int relation) | |
2022 | { | |
7249924e | 2023 | unsigned int old_target_freq = target_freq; |
d218ed77 | 2024 | int index; |
c32b6b8e | 2025 | |
a7b422cd KRW |
2026 | if (cpufreq_disabled()) |
2027 | return -ENODEV; | |
2028 | ||
7249924e | 2029 | /* Make sure that target_freq is within supported range */ |
910c6e88 | 2030 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
7249924e VK |
2031 | |
2032 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 2033 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 2034 | |
9c0ebcf7 VK |
2035 | /* |
2036 | * This might look like a redundant call as we are checking it again | |
2037 | * after finding index. But it is left intentionally for cases where | |
2038 | * exactly same freq is called again and so we can save on few function | |
2039 | * calls. | |
2040 | */ | |
5a1c0228 VK |
2041 | if (target_freq == policy->cur) |
2042 | return 0; | |
2043 | ||
1c03a2d0 VK |
2044 | /* Save last value to restore later on errors */ |
2045 | policy->restore_freq = policy->cur; | |
2046 | ||
1c3d85dd | 2047 | if (cpufreq_driver->target) |
6019d23a | 2048 | return cpufreq_driver->target(policy, target_freq, relation); |
9c0ebcf7 | 2049 | |
6019d23a RW |
2050 | if (!cpufreq_driver->target_index) |
2051 | return -EINVAL; | |
9c0ebcf7 | 2052 | |
d218ed77 | 2053 | index = cpufreq_frequency_table_target(policy, target_freq, relation); |
6019d23a | 2054 | |
23727845 | 2055 | return __target_index(policy, index); |
1da177e4 LT |
2056 | } |
2057 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
2058 | ||
1da177e4 LT |
2059 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
2060 | unsigned int target_freq, | |
2061 | unsigned int relation) | |
2062 | { | |
f1829e4a | 2063 | int ret = -EINVAL; |
1da177e4 | 2064 | |
ad7722da | 2065 | down_write(&policy->rwsem); |
1da177e4 LT |
2066 | |
2067 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
2068 | ||
ad7722da | 2069 | up_write(&policy->rwsem); |
1da177e4 | 2070 | |
1da177e4 LT |
2071 | return ret; |
2072 | } | |
2073 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
2074 | ||
de1df26b RW |
2075 | __weak struct cpufreq_governor *cpufreq_fallback_governor(void) |
2076 | { | |
2077 | return NULL; | |
2078 | } | |
2079 | ||
a92604b4 | 2080 | static int cpufreq_init_governor(struct cpufreq_policy *policy) |
1da177e4 | 2081 | { |
cc993cab | 2082 | int ret; |
6afde10c | 2083 | |
2f0aea93 VK |
2084 | /* Don't start any governor operations if we are entering suspend */ |
2085 | if (cpufreq_suspended) | |
2086 | return 0; | |
cb57720b EZ |
2087 | /* |
2088 | * Governor might not be initiated here if ACPI _PPC changed | |
2089 | * notification happened, so check it. | |
2090 | */ | |
2091 | if (!policy->governor) | |
2092 | return -EINVAL; | |
2f0aea93 | 2093 | |
ed4676e2 VK |
2094 | /* Platform doesn't want dynamic frequency switching ? */ |
2095 | if (policy->governor->dynamic_switching && | |
fc4c709f | 2096 | cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) { |
de1df26b RW |
2097 | struct cpufreq_governor *gov = cpufreq_fallback_governor(); |
2098 | ||
2099 | if (gov) { | |
fe829ed8 | 2100 | pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n", |
e837f9b5 | 2101 | policy->governor->name, gov->name); |
6afde10c | 2102 | policy->governor = gov; |
de1df26b RW |
2103 | } else { |
2104 | return -EINVAL; | |
6afde10c | 2105 | } |
1c256245 | 2106 | } |
1da177e4 | 2107 | |
a92604b4 RW |
2108 | if (!try_module_get(policy->governor->owner)) |
2109 | return -EINVAL; | |
95731ebb | 2110 | |
a92604b4 | 2111 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
1da177e4 | 2112 | |
e788892b RW |
2113 | if (policy->governor->init) { |
2114 | ret = policy->governor->init(policy); | |
2115 | if (ret) { | |
36be3418 | 2116 | module_put(policy->governor->owner); |
e788892b RW |
2117 | return ret; |
2118 | } | |
36be3418 | 2119 | } |
1da177e4 | 2120 | |
a92604b4 RW |
2121 | return 0; |
2122 | } | |
2123 | ||
2124 | static void cpufreq_exit_governor(struct cpufreq_policy *policy) | |
2125 | { | |
2126 | if (cpufreq_suspended || !policy->governor) | |
2127 | return; | |
2128 | ||
2129 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2130 | ||
e788892b RW |
2131 | if (policy->governor->exit) |
2132 | policy->governor->exit(policy); | |
a92604b4 | 2133 | |
a92604b4 | 2134 | module_put(policy->governor->owner); |
1da177e4 LT |
2135 | } |
2136 | ||
0a300767 RW |
2137 | static int cpufreq_start_governor(struct cpufreq_policy *policy) |
2138 | { | |
2139 | int ret; | |
2140 | ||
a92604b4 RW |
2141 | if (cpufreq_suspended) |
2142 | return 0; | |
2143 | ||
2144 | if (!policy->governor) | |
2145 | return -EINVAL; | |
2146 | ||
2147 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2148 | ||
407d0fff | 2149 | if (cpufreq_driver->get) |
5980752e | 2150 | cpufreq_verify_current_freq(policy, false); |
3bbf8fe3 | 2151 | |
e788892b RW |
2152 | if (policy->governor->start) { |
2153 | ret = policy->governor->start(policy); | |
2154 | if (ret) | |
2155 | return ret; | |
2156 | } | |
2157 | ||
2158 | if (policy->governor->limits) | |
2159 | policy->governor->limits(policy); | |
d6ff44d6 | 2160 | |
d6ff44d6 | 2161 | return 0; |
0a300767 RW |
2162 | } |
2163 | ||
a92604b4 RW |
2164 | static void cpufreq_stop_governor(struct cpufreq_policy *policy) |
2165 | { | |
2166 | if (cpufreq_suspended || !policy->governor) | |
2167 | return; | |
2168 | ||
2169 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2170 | ||
e788892b RW |
2171 | if (policy->governor->stop) |
2172 | policy->governor->stop(policy); | |
a92604b4 RW |
2173 | } |
2174 | ||
2175 | static void cpufreq_governor_limits(struct cpufreq_policy *policy) | |
2176 | { | |
2177 | if (cpufreq_suspended || !policy->governor) | |
2178 | return; | |
2179 | ||
2180 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2181 | ||
e788892b RW |
2182 | if (policy->governor->limits) |
2183 | policy->governor->limits(policy); | |
0a300767 RW |
2184 | } |
2185 | ||
1da177e4 LT |
2186 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
2187 | { | |
3bcb09a3 | 2188 | int err; |
1da177e4 LT |
2189 | |
2190 | if (!governor) | |
2191 | return -EINVAL; | |
2192 | ||
a7b422cd KRW |
2193 | if (cpufreq_disabled()) |
2194 | return -ENODEV; | |
2195 | ||
3fc54d37 | 2196 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 2197 | |
3bcb09a3 | 2198 | err = -EBUSY; |
42f91fa1 | 2199 | if (!find_governor(governor->name)) { |
3bcb09a3 JF |
2200 | err = 0; |
2201 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2202 | } |
1da177e4 | 2203 | |
32ee8c3e | 2204 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2205 | return err; |
1da177e4 LT |
2206 | } |
2207 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2208 | ||
1da177e4 LT |
2209 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2210 | { | |
4573237b VK |
2211 | struct cpufreq_policy *policy; |
2212 | unsigned long flags; | |
90e41bac | 2213 | |
1da177e4 LT |
2214 | if (!governor) |
2215 | return; | |
2216 | ||
a7b422cd KRW |
2217 | if (cpufreq_disabled()) |
2218 | return; | |
2219 | ||
4573237b VK |
2220 | /* clear last_governor for all inactive policies */ |
2221 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
2222 | for_each_inactive_policy(policy) { | |
18bf3a12 VK |
2223 | if (!strcmp(policy->last_governor, governor->name)) { |
2224 | policy->governor = NULL; | |
4573237b | 2225 | strcpy(policy->last_governor, "\0"); |
18bf3a12 | 2226 | } |
90e41bac | 2227 | } |
4573237b | 2228 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
90e41bac | 2229 | |
3fc54d37 | 2230 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2231 | list_del(&governor->governor_list); |
3fc54d37 | 2232 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2233 | } |
2234 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2235 | ||
2236 | ||
1da177e4 LT |
2237 | /********************************************************************* |
2238 | * POLICY INTERFACE * | |
2239 | *********************************************************************/ | |
2240 | ||
2241 | /** | |
2242 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2243 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2244 | * is written | |
1da177e4 LT |
2245 | * |
2246 | * Reads the current cpufreq policy. | |
2247 | */ | |
2248 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2249 | { | |
2250 | struct cpufreq_policy *cpu_policy; | |
2251 | if (!policy) | |
2252 | return -EINVAL; | |
2253 | ||
2254 | cpu_policy = cpufreq_cpu_get(cpu); | |
2255 | if (!cpu_policy) | |
2256 | return -EINVAL; | |
2257 | ||
d5b73cd8 | 2258 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2259 | |
2260 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2261 | return 0; |
2262 | } | |
2263 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2264 | ||
a0dbb819 RW |
2265 | /** |
2266 | * cpufreq_set_policy - Modify cpufreq policy parameters. | |
2267 | * @policy: Policy object to modify. | |
2268 | * @new_policy: New policy data. | |
2269 | * | |
2270 | * Pass @new_policy to the cpufreq driver's ->verify() callback, run the | |
2271 | * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to | |
2272 | * the driver's ->verify() callback again and run the notifiers for it again | |
2273 | * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters | |
2274 | * of @new_policy to @policy and either invoke the driver's ->setpolicy() | |
2275 | * callback (if present) or carry out a governor update for @policy. That is, | |
2276 | * run the current governor's ->limits() callback (if the governor field in | |
2277 | * @new_policy points to the same object as the one in @policy) or replace the | |
2278 | * governor for @policy with the new one stored in @new_policy. | |
2279 | * | |
2280 | * The cpuinfo part of @policy is not updated by this function. | |
153d7f3f | 2281 | */ |
9083e498 RW |
2282 | int cpufreq_set_policy(struct cpufreq_policy *policy, |
2283 | struct cpufreq_policy *new_policy) | |
1da177e4 | 2284 | { |
d9a789c7 RW |
2285 | struct cpufreq_governor *old_gov; |
2286 | int ret; | |
1da177e4 | 2287 | |
e837f9b5 JP |
2288 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2289 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2290 | |
d5b73cd8 | 2291 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2292 | |
fba9573b PX |
2293 | /* |
2294 | * This check works well when we store new min/max freq attributes, | |
2295 | * because new_policy is a copy of policy with one field updated. | |
2296 | */ | |
2297 | if (new_policy->min > new_policy->max) | |
d9a789c7 | 2298 | return -EINVAL; |
9c9a43ed | 2299 | |
1da177e4 | 2300 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2301 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2302 | if (ret) |
d9a789c7 | 2303 | return ret; |
1da177e4 | 2304 | |
1da177e4 | 2305 | /* adjust if necessary - all reasons */ |
e041c683 | 2306 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2307 | CPUFREQ_ADJUST, new_policy); |
1da177e4 | 2308 | |
bb176f7d VK |
2309 | /* |
2310 | * verify the cpu speed can be set within this limit, which might be | |
2311 | * different to the first one | |
2312 | */ | |
3a3e9e06 | 2313 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2314 | if (ret) |
d9a789c7 | 2315 | return ret; |
1da177e4 LT |
2316 | |
2317 | /* notification of the new policy */ | |
e041c683 | 2318 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2319 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2320 | |
3a3e9e06 VK |
2321 | policy->min = new_policy->min; |
2322 | policy->max = new_policy->max; | |
601b2185 | 2323 | trace_cpu_frequency_limits(policy); |
1da177e4 | 2324 | |
e3c06236 SM |
2325 | policy->cached_target_freq = UINT_MAX; |
2326 | ||
2d06d8c4 | 2327 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2328 | policy->min, policy->max); |
1da177e4 | 2329 | |
1c3d85dd | 2330 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2331 | policy->policy = new_policy->policy; |
2d06d8c4 | 2332 | pr_debug("setting range\n"); |
167a38dc | 2333 | return cpufreq_driver->setpolicy(policy); |
d9a789c7 | 2334 | } |
1da177e4 | 2335 | |
0a300767 | 2336 | if (new_policy->governor == policy->governor) { |
2bb4059e | 2337 | pr_debug("governor limits update\n"); |
a92604b4 | 2338 | cpufreq_governor_limits(policy); |
d6ff44d6 | 2339 | return 0; |
0a300767 | 2340 | } |
7bd353a9 | 2341 | |
d9a789c7 RW |
2342 | pr_debug("governor switch\n"); |
2343 | ||
2344 | /* save old, working values */ | |
2345 | old_gov = policy->governor; | |
2346 | /* end old governor */ | |
2347 | if (old_gov) { | |
45482c70 | 2348 | cpufreq_stop_governor(policy); |
36be3418 | 2349 | cpufreq_exit_governor(policy); |
1da177e4 LT |
2350 | } |
2351 | ||
d9a789c7 RW |
2352 | /* start new governor */ |
2353 | policy->governor = new_policy->governor; | |
a92604b4 | 2354 | ret = cpufreq_init_governor(policy); |
4bc384ae | 2355 | if (!ret) { |
0a300767 RW |
2356 | ret = cpufreq_start_governor(policy); |
2357 | if (!ret) { | |
2bb4059e | 2358 | pr_debug("governor change\n"); |
531b5c9f | 2359 | sched_cpufreq_governor_change(policy, old_gov); |
0a300767 RW |
2360 | return 0; |
2361 | } | |
b7898fda | 2362 | cpufreq_exit_governor(policy); |
d9a789c7 RW |
2363 | } |
2364 | ||
2365 | /* new governor failed, so re-start old one */ | |
2366 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2367 | if (old_gov) { | |
2368 | policy->governor = old_gov; | |
a92604b4 | 2369 | if (cpufreq_init_governor(policy)) |
4bc384ae VK |
2370 | policy->governor = NULL; |
2371 | else | |
0a300767 | 2372 | cpufreq_start_governor(policy); |
d9a789c7 RW |
2373 | } |
2374 | ||
4bc384ae | 2375 | return ret; |
1da177e4 LT |
2376 | } |
2377 | ||
1da177e4 | 2378 | /** |
a0dbb819 RW |
2379 | * cpufreq_update_policy - Re-evaluate an existing cpufreq policy. |
2380 | * @cpu: CPU to re-evaluate the policy for. | |
1da177e4 | 2381 | * |
a0dbb819 RW |
2382 | * Update the current frequency for the cpufreq policy of @cpu and use |
2383 | * cpufreq_set_policy() to re-apply the min and max limits saved in the | |
2384 | * user_policy sub-structure of that policy, which triggers the evaluation | |
2385 | * of policy notifiers and the cpufreq driver's ->verify() callback for the | |
2386 | * policy in question, among other things. | |
1da177e4 | 2387 | */ |
30248fef | 2388 | void cpufreq_update_policy(unsigned int cpu) |
1da177e4 | 2389 | { |
540a3758 | 2390 | struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); |
1da177e4 | 2391 | |
fefa8ff8 | 2392 | if (!policy) |
30248fef | 2393 | return; |
1da177e4 | 2394 | |
bb176f7d VK |
2395 | /* |
2396 | * BIOS might change freq behind our back | |
2397 | * -> ask driver for current freq and notify governors about a change | |
2398 | */ | |
5ddc6d4e | 2399 | if (cpufreq_driver->get && has_target() && |
5980752e | 2400 | (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false)))) |
348a2ec5 | 2401 | goto unlock; |
30248fef | 2402 | |
70a59fde | 2403 | refresh_frequency_limits(policy); |
1da177e4 | 2404 | |
fefa8ff8 | 2405 | unlock: |
540a3758 | 2406 | cpufreq_cpu_release(policy); |
1da177e4 LT |
2407 | } |
2408 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2409 | ||
5a25e3f7 RW |
2410 | /** |
2411 | * cpufreq_update_limits - Update policy limits for a given CPU. | |
2412 | * @cpu: CPU to update the policy limits for. | |
2413 | * | |
2414 | * Invoke the driver's ->update_limits callback if present or call | |
2415 | * cpufreq_update_policy() for @cpu. | |
2416 | */ | |
2417 | void cpufreq_update_limits(unsigned int cpu) | |
2418 | { | |
2419 | if (cpufreq_driver->update_limits) | |
2420 | cpufreq_driver->update_limits(cpu); | |
2421 | else | |
2422 | cpufreq_update_policy(cpu); | |
2423 | } | |
2424 | EXPORT_SYMBOL_GPL(cpufreq_update_limits); | |
2425 | ||
6f19efc0 LM |
2426 | /********************************************************************* |
2427 | * BOOST * | |
2428 | *********************************************************************/ | |
2429 | static int cpufreq_boost_set_sw(int state) | |
2430 | { | |
6f19efc0 LM |
2431 | struct cpufreq_policy *policy; |
2432 | int ret = -EINVAL; | |
2433 | ||
f963735a | 2434 | for_each_active_policy(policy) { |
f8bfc116 VK |
2435 | if (!policy->freq_table) |
2436 | continue; | |
49f18560 | 2437 | |
f8bfc116 VK |
2438 | ret = cpufreq_frequency_table_cpuinfo(policy, |
2439 | policy->freq_table); | |
2440 | if (ret) { | |
2441 | pr_err("%s: Policy frequency update failed\n", | |
2442 | __func__); | |
2443 | break; | |
6f19efc0 | 2444 | } |
f8bfc116 VK |
2445 | |
2446 | down_write(&policy->rwsem); | |
2447 | policy->user_policy.max = policy->max; | |
2448 | cpufreq_governor_limits(policy); | |
2449 | up_write(&policy->rwsem); | |
6f19efc0 LM |
2450 | } |
2451 | ||
2452 | return ret; | |
2453 | } | |
2454 | ||
2455 | int cpufreq_boost_trigger_state(int state) | |
2456 | { | |
2457 | unsigned long flags; | |
2458 | int ret = 0; | |
2459 | ||
2460 | if (cpufreq_driver->boost_enabled == state) | |
2461 | return 0; | |
2462 | ||
2463 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2464 | cpufreq_driver->boost_enabled = state; | |
2465 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2466 | ||
2467 | ret = cpufreq_driver->set_boost(state); | |
2468 | if (ret) { | |
2469 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2470 | cpufreq_driver->boost_enabled = !state; | |
2471 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2472 | ||
e837f9b5 JP |
2473 | pr_err("%s: Cannot %s BOOST\n", |
2474 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2475 | } |
2476 | ||
2477 | return ret; | |
2478 | } | |
2479 | ||
41669da0 | 2480 | static bool cpufreq_boost_supported(void) |
6f19efc0 | 2481 | { |
89f98d7e | 2482 | return cpufreq_driver->set_boost; |
6f19efc0 | 2483 | } |
6f19efc0 | 2484 | |
44139ed4 VK |
2485 | static int create_boost_sysfs_file(void) |
2486 | { | |
2487 | int ret; | |
2488 | ||
c82bd444 | 2489 | ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2490 | if (ret) |
2491 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
2492 | __func__); | |
2493 | ||
2494 | return ret; | |
2495 | } | |
2496 | ||
2497 | static void remove_boost_sysfs_file(void) | |
2498 | { | |
2499 | if (cpufreq_boost_supported()) | |
c82bd444 | 2500 | sysfs_remove_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2501 | } |
2502 | ||
2503 | int cpufreq_enable_boost_support(void) | |
2504 | { | |
2505 | if (!cpufreq_driver) | |
2506 | return -EINVAL; | |
2507 | ||
2508 | if (cpufreq_boost_supported()) | |
2509 | return 0; | |
2510 | ||
7a6c79f2 | 2511 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; |
44139ed4 VK |
2512 | |
2513 | /* This will get removed on driver unregister */ | |
2514 | return create_boost_sysfs_file(); | |
2515 | } | |
2516 | EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support); | |
2517 | ||
6f19efc0 LM |
2518 | int cpufreq_boost_enabled(void) |
2519 | { | |
2520 | return cpufreq_driver->boost_enabled; | |
2521 | } | |
2522 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2523 | ||
1da177e4 LT |
2524 | /********************************************************************* |
2525 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2526 | *********************************************************************/ | |
27622b06 | 2527 | static enum cpuhp_state hp_online; |
1da177e4 | 2528 | |
c4a3fa26 CY |
2529 | static int cpuhp_cpufreq_online(unsigned int cpu) |
2530 | { | |
2531 | cpufreq_online(cpu); | |
2532 | ||
2533 | return 0; | |
2534 | } | |
2535 | ||
2536 | static int cpuhp_cpufreq_offline(unsigned int cpu) | |
2537 | { | |
2538 | cpufreq_offline(cpu); | |
2539 | ||
2540 | return 0; | |
2541 | } | |
2542 | ||
1da177e4 LT |
2543 | /** |
2544 | * cpufreq_register_driver - register a CPU Frequency driver | |
2545 | * @driver_data: A struct cpufreq_driver containing the values# | |
2546 | * submitted by the CPU Frequency driver. | |
2547 | * | |
bb176f7d | 2548 | * Registers a CPU Frequency driver to this core code. This code |
63af4055 | 2549 | * returns zero on success, -EEXIST when another driver got here first |
32ee8c3e | 2550 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2551 | * |
2552 | */ | |
221dee28 | 2553 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2554 | { |
2555 | unsigned long flags; | |
2556 | int ret; | |
2557 | ||
a7b422cd KRW |
2558 | if (cpufreq_disabled()) |
2559 | return -ENODEV; | |
2560 | ||
1da177e4 | 2561 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2562 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2563 | driver_data->target) || |
2564 | (driver_data->setpolicy && (driver_data->target_index || | |
1c03a2d0 | 2565 | driver_data->target)) || |
a9a22b57 | 2566 | (!driver_data->get_intermediate != !driver_data->target_intermediate) || |
91a12e91 | 2567 | (!driver_data->online != !driver_data->offline)) |
1da177e4 LT |
2568 | return -EINVAL; |
2569 | ||
2d06d8c4 | 2570 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 | 2571 | |
fdd320da | 2572 | /* Protect against concurrent CPU online/offline. */ |
a92551e4 | 2573 | cpus_read_lock(); |
fdd320da | 2574 | |
0d1857a1 | 2575 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2576 | if (cpufreq_driver) { |
0d1857a1 | 2577 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fdd320da RW |
2578 | ret = -EEXIST; |
2579 | goto out; | |
1da177e4 | 2580 | } |
1c3d85dd | 2581 | cpufreq_driver = driver_data; |
0d1857a1 | 2582 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2583 | |
bc68b7df VK |
2584 | if (driver_data->setpolicy) |
2585 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2586 | ||
7a6c79f2 RW |
2587 | if (cpufreq_boost_supported()) { |
2588 | ret = create_boost_sysfs_file(); | |
2589 | if (ret) | |
2590 | goto err_null_driver; | |
2591 | } | |
6f19efc0 | 2592 | |
8a25a2fd | 2593 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2594 | if (ret) |
6f19efc0 | 2595 | goto err_boost_unreg; |
1da177e4 | 2596 | |
ce1bcfe9 VK |
2597 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY) && |
2598 | list_empty(&cpufreq_policy_list)) { | |
1da177e4 | 2599 | /* if all ->init() calls failed, unregister */ |
6c770036 | 2600 | ret = -ENODEV; |
ce1bcfe9 VK |
2601 | pr_debug("%s: No CPU initialized for driver %s\n", __func__, |
2602 | driver_data->name); | |
2603 | goto err_if_unreg; | |
1da177e4 LT |
2604 | } |
2605 | ||
a92551e4 SAS |
2606 | ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, |
2607 | "cpufreq:online", | |
2608 | cpuhp_cpufreq_online, | |
2609 | cpuhp_cpufreq_offline); | |
27622b06 SAS |
2610 | if (ret < 0) |
2611 | goto err_if_unreg; | |
2612 | hp_online = ret; | |
5372e054 | 2613 | ret = 0; |
27622b06 | 2614 | |
2d06d8c4 | 2615 | pr_debug("driver %s up and running\n", driver_data->name); |
3834abb4 | 2616 | goto out; |
fdd320da | 2617 | |
8a25a2fd KS |
2618 | err_if_unreg: |
2619 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 | 2620 | err_boost_unreg: |
44139ed4 | 2621 | remove_boost_sysfs_file(); |
8f5bc2ab | 2622 | err_null_driver: |
0d1857a1 | 2623 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2624 | cpufreq_driver = NULL; |
0d1857a1 | 2625 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
3834abb4 | 2626 | out: |
a92551e4 | 2627 | cpus_read_unlock(); |
3834abb4 | 2628 | return ret; |
1da177e4 LT |
2629 | } |
2630 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2631 | ||
1da177e4 LT |
2632 | /** |
2633 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2634 | * | |
bb176f7d | 2635 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2636 | * the right to do so, i.e. if you have succeeded in initialising before! |
2637 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2638 | * currently not initialised. | |
2639 | */ | |
221dee28 | 2640 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2641 | { |
2642 | unsigned long flags; | |
2643 | ||
1c3d85dd | 2644 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2645 | return -EINVAL; |
1da177e4 | 2646 | |
2d06d8c4 | 2647 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2648 | |
454d3a25 | 2649 | /* Protect against concurrent cpu hotplug */ |
a92551e4 | 2650 | cpus_read_lock(); |
8a25a2fd | 2651 | subsys_interface_unregister(&cpufreq_interface); |
44139ed4 | 2652 | remove_boost_sysfs_file(); |
a92551e4 | 2653 | cpuhp_remove_state_nocalls_cpuslocked(hp_online); |
1da177e4 | 2654 | |
0d1857a1 | 2655 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2656 | |
1c3d85dd | 2657 | cpufreq_driver = NULL; |
6eed9404 | 2658 | |
0d1857a1 | 2659 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
a92551e4 | 2660 | cpus_read_unlock(); |
1da177e4 LT |
2661 | |
2662 | return 0; | |
2663 | } | |
2664 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 | 2665 | |
90de2a4a DA |
2666 | /* |
2667 | * Stop cpufreq at shutdown to make sure it isn't holding any locks | |
2668 | * or mutexes when secondary CPUs are halted. | |
2669 | */ | |
2670 | static struct syscore_ops cpufreq_syscore_ops = { | |
2671 | .shutdown = cpufreq_suspend, | |
2672 | }; | |
2673 | ||
c82bd444 VK |
2674 | struct kobject *cpufreq_global_kobject; |
2675 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
2676 | ||
5a01f2e8 VP |
2677 | static int __init cpufreq_core_init(void) |
2678 | { | |
a7b422cd KRW |
2679 | if (cpufreq_disabled()) |
2680 | return -ENODEV; | |
2681 | ||
8eec1020 | 2682 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 TR |
2683 | BUG_ON(!cpufreq_global_kobject); |
2684 | ||
90de2a4a DA |
2685 | register_syscore_ops(&cpufreq_syscore_ops); |
2686 | ||
5a01f2e8 VP |
2687 | return 0; |
2688 | } | |
d82f2692 | 2689 | module_param(off, int, 0444); |
5a01f2e8 | 2690 | core_initcall(cpufreq_core_init); |