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 | */ |
1c3d85dd | 362 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
20b5324d | 363 | if (policy->cur && (policy->cur != freqs->old)) { |
e837f9b5 JP |
364 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", |
365 | freqs->old, policy->cur); | |
e4472cb3 | 366 | freqs->old = policy->cur; |
1da177e4 LT |
367 | } |
368 | } | |
20b5324d | 369 | |
df24014a VK |
370 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
371 | CPUFREQ_PRECHANGE, freqs); | |
20b5324d | 372 | |
1da177e4 LT |
373 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
374 | break; | |
e4472cb3 | 375 | |
1da177e4 LT |
376 | case CPUFREQ_POSTCHANGE: |
377 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
20b5324d VK |
378 | pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new, |
379 | cpumask_pr_args(policy->cpus)); | |
380 | ||
df24014a VK |
381 | for_each_cpu(cpu, policy->cpus) |
382 | trace_cpu_frequency(freqs->new, cpu); | |
383 | ||
384 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
385 | CPUFREQ_POSTCHANGE, freqs); | |
20b5324d | 386 | |
1aefc75b | 387 | cpufreq_stats_record_transition(policy, freqs->new); |
20b5324d | 388 | policy->cur = freqs->new; |
1da177e4 | 389 | } |
1da177e4 | 390 | } |
bb176f7d | 391 | |
f7ba3b41 | 392 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 393 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
394 | struct cpufreq_freqs *freqs, int transition_failed) |
395 | { | |
396 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
397 | if (!transition_failed) | |
398 | return; | |
399 | ||
400 | swap(freqs->old, freqs->new); | |
401 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
402 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
403 | } | |
f7ba3b41 | 404 | |
12478cf0 SB |
405 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
406 | struct cpufreq_freqs *freqs) | |
407 | { | |
ca654dc3 SB |
408 | |
409 | /* | |
410 | * Catch double invocations of _begin() which lead to self-deadlock. | |
411 | * ASYNC_NOTIFICATION drivers are left out because the cpufreq core | |
412 | * doesn't invoke _begin() on their behalf, and hence the chances of | |
413 | * double invocations are very low. Moreover, there are scenarios | |
414 | * where these checks can emit false-positive warnings in these | |
415 | * drivers; so we avoid that by skipping them altogether. | |
416 | */ | |
417 | WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) | |
418 | && current == policy->transition_task); | |
419 | ||
12478cf0 SB |
420 | wait: |
421 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
422 | ||
423 | spin_lock(&policy->transition_lock); | |
424 | ||
425 | if (unlikely(policy->transition_ongoing)) { | |
426 | spin_unlock(&policy->transition_lock); | |
427 | goto wait; | |
428 | } | |
429 | ||
430 | policy->transition_ongoing = true; | |
ca654dc3 | 431 | policy->transition_task = current; |
12478cf0 SB |
432 | |
433 | spin_unlock(&policy->transition_lock); | |
434 | ||
435 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
436 | } | |
437 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
438 | ||
439 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
440 | struct cpufreq_freqs *freqs, int transition_failed) | |
441 | { | |
0e7ea2f3 | 442 | if (WARN_ON(!policy->transition_ongoing)) |
12478cf0 SB |
443 | return; |
444 | ||
445 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
446 | ||
447 | policy->transition_ongoing = false; | |
ca654dc3 | 448 | policy->transition_task = NULL; |
12478cf0 SB |
449 | |
450 | wake_up(&policy->transition_wait); | |
451 | } | |
452 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
453 | ||
b7898fda RW |
454 | /* |
455 | * Fast frequency switching status count. Positive means "enabled", negative | |
456 | * means "disabled" and 0 means "not decided yet". | |
457 | */ | |
458 | static int cpufreq_fast_switch_count; | |
459 | static DEFINE_MUTEX(cpufreq_fast_switch_lock); | |
460 | ||
461 | static void cpufreq_list_transition_notifiers(void) | |
462 | { | |
463 | struct notifier_block *nb; | |
464 | ||
465 | pr_info("Registered transition notifiers:\n"); | |
466 | ||
467 | mutex_lock(&cpufreq_transition_notifier_list.mutex); | |
468 | ||
469 | for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next) | |
470 | pr_info("%pF\n", nb->notifier_call); | |
471 | ||
472 | mutex_unlock(&cpufreq_transition_notifier_list.mutex); | |
473 | } | |
474 | ||
475 | /** | |
476 | * cpufreq_enable_fast_switch - Enable fast frequency switching for policy. | |
477 | * @policy: cpufreq policy to enable fast frequency switching for. | |
478 | * | |
479 | * Try to enable fast frequency switching for @policy. | |
480 | * | |
481 | * The attempt will fail if there is at least one transition notifier registered | |
482 | * at this point, as fast frequency switching is quite fundamentally at odds | |
483 | * with transition notifiers. Thus if successful, it will make registration of | |
484 | * transition notifiers fail going forward. | |
485 | */ | |
486 | void cpufreq_enable_fast_switch(struct cpufreq_policy *policy) | |
487 | { | |
488 | lockdep_assert_held(&policy->rwsem); | |
489 | ||
490 | if (!policy->fast_switch_possible) | |
491 | return; | |
492 | ||
493 | mutex_lock(&cpufreq_fast_switch_lock); | |
494 | if (cpufreq_fast_switch_count >= 0) { | |
495 | cpufreq_fast_switch_count++; | |
496 | policy->fast_switch_enabled = true; | |
497 | } else { | |
498 | pr_warn("CPU%u: Fast frequency switching not enabled\n", | |
499 | policy->cpu); | |
500 | cpufreq_list_transition_notifiers(); | |
501 | } | |
502 | mutex_unlock(&cpufreq_fast_switch_lock); | |
503 | } | |
504 | EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); | |
505 | ||
6c9d9c81 RW |
506 | /** |
507 | * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. | |
508 | * @policy: cpufreq policy to disable fast frequency switching for. | |
509 | */ | |
510 | void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) | |
b7898fda RW |
511 | { |
512 | mutex_lock(&cpufreq_fast_switch_lock); | |
513 | if (policy->fast_switch_enabled) { | |
514 | policy->fast_switch_enabled = false; | |
515 | if (!WARN_ON(cpufreq_fast_switch_count <= 0)) | |
516 | cpufreq_fast_switch_count--; | |
517 | } | |
518 | mutex_unlock(&cpufreq_fast_switch_lock); | |
519 | } | |
6c9d9c81 | 520 | EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); |
1da177e4 | 521 | |
e3c06236 SM |
522 | /** |
523 | * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported | |
524 | * one. | |
525 | * @target_freq: target frequency to resolve. | |
526 | * | |
527 | * The target to driver frequency mapping is cached in the policy. | |
528 | * | |
529 | * Return: Lowest driver-supported frequency greater than or equal to the | |
530 | * given target_freq, subject to policy (min/max) and driver limitations. | |
531 | */ | |
532 | unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, | |
533 | unsigned int target_freq) | |
534 | { | |
535 | target_freq = clamp_val(target_freq, policy->min, policy->max); | |
536 | policy->cached_target_freq = target_freq; | |
abe8bd02 VK |
537 | |
538 | if (cpufreq_driver->target_index) { | |
539 | int idx; | |
540 | ||
541 | idx = cpufreq_frequency_table_target(policy, target_freq, | |
542 | CPUFREQ_RELATION_L); | |
543 | policy->cached_resolved_idx = idx; | |
544 | return policy->freq_table[idx].frequency; | |
545 | } | |
546 | ||
e3c06236 SM |
547 | if (cpufreq_driver->resolve_freq) |
548 | return cpufreq_driver->resolve_freq(policy, target_freq); | |
abe8bd02 VK |
549 | |
550 | return target_freq; | |
e3c06236 | 551 | } |
ae2c1ca6 | 552 | EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); |
e3c06236 | 553 | |
aa7519af VK |
554 | unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy) |
555 | { | |
556 | unsigned int latency; | |
557 | ||
558 | if (policy->transition_delay_us) | |
559 | return policy->transition_delay_us; | |
560 | ||
561 | latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC; | |
e948bc8f VK |
562 | if (latency) { |
563 | /* | |
564 | * For platforms that can change the frequency very fast (< 10 | |
565 | * us), the above formula gives a decent transition delay. But | |
566 | * for platforms where transition_latency is in milliseconds, it | |
567 | * ends up giving unrealistic values. | |
568 | * | |
569 | * Cap the default transition delay to 10 ms, which seems to be | |
570 | * a reasonable amount of time after which we should reevaluate | |
571 | * the frequency. | |
572 | */ | |
573 | return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000); | |
574 | } | |
aa7519af VK |
575 | |
576 | return LATENCY_MULTIPLIER; | |
577 | } | |
578 | EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us); | |
579 | ||
1da177e4 LT |
580 | /********************************************************************* |
581 | * SYSFS INTERFACE * | |
582 | *********************************************************************/ | |
8a5c74a1 | 583 | static ssize_t show_boost(struct kobject *kobj, |
625c85a6 | 584 | struct kobj_attribute *attr, char *buf) |
6f19efc0 LM |
585 | { |
586 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
587 | } | |
588 | ||
625c85a6 VK |
589 | static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr, |
590 | const char *buf, size_t count) | |
6f19efc0 LM |
591 | { |
592 | int ret, enable; | |
593 | ||
594 | ret = sscanf(buf, "%d", &enable); | |
595 | if (ret != 1 || enable < 0 || enable > 1) | |
596 | return -EINVAL; | |
597 | ||
598 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
599 | pr_err("%s: Cannot %s BOOST!\n", |
600 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
601 | return -EINVAL; |
602 | } | |
603 | ||
e837f9b5 JP |
604 | pr_debug("%s: cpufreq BOOST %s\n", |
605 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
606 | |
607 | return count; | |
608 | } | |
609 | define_one_global_rw(boost); | |
1da177e4 | 610 | |
42f91fa1 | 611 | static struct cpufreq_governor *find_governor(const char *str_governor) |
3bcb09a3 JF |
612 | { |
613 | struct cpufreq_governor *t; | |
614 | ||
f7b27061 | 615 | for_each_governor(t) |
7c4f4539 | 616 | if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
617 | return t; |
618 | ||
619 | return NULL; | |
620 | } | |
621 | ||
1da177e4 LT |
622 | /** |
623 | * cpufreq_parse_governor - parse a governor string | |
624 | */ | |
ae0ff89f RW |
625 | static int cpufreq_parse_governor(char *str_governor, |
626 | struct cpufreq_policy *policy) | |
1da177e4 | 627 | { |
1c3d85dd | 628 | if (cpufreq_driver->setpolicy) { |
7c4f4539 | 629 | if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
ae0ff89f | 630 | policy->policy = CPUFREQ_POLICY_PERFORMANCE; |
045149e6 RW |
631 | return 0; |
632 | } | |
633 | ||
634 | if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { | |
ae0ff89f | 635 | policy->policy = CPUFREQ_POLICY_POWERSAVE; |
045149e6 | 636 | return 0; |
1da177e4 | 637 | } |
2e1cc3a5 | 638 | } else { |
1da177e4 | 639 | struct cpufreq_governor *t; |
3bcb09a3 | 640 | |
3fc54d37 | 641 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 | 642 | |
42f91fa1 | 643 | t = find_governor(str_governor); |
045149e6 | 644 | if (!t) { |
1a8e1463 | 645 | int ret; |
ea714970 | 646 | |
1a8e1463 | 647 | mutex_unlock(&cpufreq_governor_mutex); |
045149e6 | 648 | |
1a8e1463 | 649 | ret = request_module("cpufreq_%s", str_governor); |
045149e6 RW |
650 | if (ret) |
651 | return -EINVAL; | |
652 | ||
1a8e1463 | 653 | mutex_lock(&cpufreq_governor_mutex); |
ea714970 | 654 | |
045149e6 | 655 | t = find_governor(str_governor); |
ea714970 | 656 | } |
a8b149d3 RW |
657 | if (t && !try_module_get(t->owner)) |
658 | t = NULL; | |
ea714970 | 659 | |
045149e6 RW |
660 | mutex_unlock(&cpufreq_governor_mutex); |
661 | ||
662 | if (t) { | |
ae0ff89f | 663 | policy->governor = t; |
045149e6 | 664 | return 0; |
1da177e4 | 665 | } |
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 | ||
ae0ff89f | 787 | if (cpufreq_parse_governor(str_governor, &new_policy)) |
1da177e4 LT |
788 | return -EINVAL; |
789 | ||
037ce839 | 790 | ret = cpufreq_set_policy(policy, &new_policy); |
a8b149d3 RW |
791 | |
792 | if (new_policy.governor) | |
793 | module_put(new_policy.governor->owner); | |
794 | ||
88dc4384 | 795 | return ret ? ret : count; |
1da177e4 LT |
796 | } |
797 | ||
798 | /** | |
799 | * show_scaling_driver - show the cpufreq driver currently loaded | |
800 | */ | |
905d77cd | 801 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 802 | { |
1c3d85dd | 803 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
804 | } |
805 | ||
806 | /** | |
807 | * show_scaling_available_governors - show the available CPUfreq governors | |
808 | */ | |
905d77cd DJ |
809 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
810 | char *buf) | |
1da177e4 LT |
811 | { |
812 | ssize_t i = 0; | |
813 | struct cpufreq_governor *t; | |
814 | ||
9c0ebcf7 | 815 | if (!has_target()) { |
1da177e4 LT |
816 | i += sprintf(buf, "performance powersave"); |
817 | goto out; | |
818 | } | |
819 | ||
f7b27061 | 820 | for_each_governor(t) { |
29464f28 DJ |
821 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
822 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 823 | goto out; |
4b972f0b | 824 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 825 | } |
7d5e350f | 826 | out: |
1da177e4 LT |
827 | i += sprintf(&buf[i], "\n"); |
828 | return i; | |
829 | } | |
e8628dd0 | 830 | |
f4fd3797 | 831 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
832 | { |
833 | ssize_t i = 0; | |
834 | unsigned int cpu; | |
835 | ||
835481d9 | 836 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
837 | if (i) |
838 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
839 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
840 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 841 | break; |
1da177e4 LT |
842 | } |
843 | i += sprintf(&buf[i], "\n"); | |
844 | return i; | |
845 | } | |
f4fd3797 | 846 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 847 | |
e8628dd0 DW |
848 | /** |
849 | * show_related_cpus - show the CPUs affected by each transition even if | |
850 | * hw coordination is in use | |
851 | */ | |
852 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
853 | { | |
f4fd3797 | 854 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
855 | } |
856 | ||
857 | /** | |
858 | * show_affected_cpus - show the CPUs affected by each transition | |
859 | */ | |
860 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
861 | { | |
f4fd3797 | 862 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
863 | } |
864 | ||
9e76988e | 865 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 866 | const char *buf, size_t count) |
9e76988e VP |
867 | { |
868 | unsigned int freq = 0; | |
869 | unsigned int ret; | |
870 | ||
879000f9 | 871 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
872 | return -EINVAL; |
873 | ||
874 | ret = sscanf(buf, "%u", &freq); | |
875 | if (ret != 1) | |
876 | return -EINVAL; | |
877 | ||
878 | policy->governor->store_setspeed(policy, freq); | |
879 | ||
880 | return count; | |
881 | } | |
882 | ||
883 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
884 | { | |
879000f9 | 885 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
886 | return sprintf(buf, "<unsupported>\n"); |
887 | ||
888 | return policy->governor->show_setspeed(policy, buf); | |
889 | } | |
1da177e4 | 890 | |
e2f74f35 | 891 | /** |
8bf1ac72 | 892 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
893 | */ |
894 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
895 | { | |
896 | unsigned int limit; | |
897 | int ret; | |
b23aa311 YH |
898 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); |
899 | if (!ret) | |
900 | return sprintf(buf, "%u\n", limit); | |
e2f74f35 TR |
901 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); |
902 | } | |
903 | ||
6dad2a29 BP |
904 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
905 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
906 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
907 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
908 | cpufreq_freq_attr_ro(scaling_available_governors); | |
909 | cpufreq_freq_attr_ro(scaling_driver); | |
910 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
911 | cpufreq_freq_attr_ro(bios_limit); | |
912 | cpufreq_freq_attr_ro(related_cpus); | |
913 | cpufreq_freq_attr_ro(affected_cpus); | |
914 | cpufreq_freq_attr_rw(scaling_min_freq); | |
915 | cpufreq_freq_attr_rw(scaling_max_freq); | |
916 | cpufreq_freq_attr_rw(scaling_governor); | |
917 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 918 | |
905d77cd | 919 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
920 | &cpuinfo_min_freq.attr, |
921 | &cpuinfo_max_freq.attr, | |
ed129784 | 922 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
923 | &scaling_min_freq.attr, |
924 | &scaling_max_freq.attr, | |
925 | &affected_cpus.attr, | |
e8628dd0 | 926 | &related_cpus.attr, |
1da177e4 LT |
927 | &scaling_governor.attr, |
928 | &scaling_driver.attr, | |
929 | &scaling_available_governors.attr, | |
9e76988e | 930 | &scaling_setspeed.attr, |
1da177e4 LT |
931 | NULL |
932 | }; | |
933 | ||
29464f28 DJ |
934 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
935 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 936 | |
29464f28 | 937 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 938 | { |
905d77cd DJ |
939 | struct cpufreq_policy *policy = to_policy(kobj); |
940 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 941 | ssize_t ret; |
6eed9404 | 942 | |
ad7722da | 943 | down_read(&policy->rwsem); |
6541aef0 | 944 | ret = fattr->show(policy, buf); |
ad7722da | 945 | up_read(&policy->rwsem); |
1b750e3b | 946 | |
1da177e4 LT |
947 | return ret; |
948 | } | |
949 | ||
905d77cd DJ |
950 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
951 | const char *buf, size_t count) | |
1da177e4 | 952 | { |
905d77cd DJ |
953 | struct cpufreq_policy *policy = to_policy(kobj); |
954 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 955 | ssize_t ret = -EINVAL; |
6eed9404 | 956 | |
9b3d9bb3 WL |
957 | /* |
958 | * cpus_read_trylock() is used here to work around a circular lock | |
959 | * dependency problem with respect to the cpufreq_register_driver(). | |
960 | */ | |
961 | if (!cpus_read_trylock()) | |
962 | return -EBUSY; | |
4f750c93 | 963 | |
6541aef0 RW |
964 | if (cpu_online(policy->cpu)) { |
965 | down_write(&policy->rwsem); | |
e08f5f5b | 966 | ret = fattr->store(policy, buf, count); |
6541aef0 RW |
967 | up_write(&policy->rwsem); |
968 | } | |
e08f5f5b | 969 | |
a92551e4 | 970 | cpus_read_unlock(); |
4f750c93 | 971 | |
1da177e4 LT |
972 | return ret; |
973 | } | |
974 | ||
905d77cd | 975 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 976 | { |
905d77cd | 977 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 978 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
979 | complete(&policy->kobj_unregister); |
980 | } | |
981 | ||
52cf25d0 | 982 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
983 | .show = show, |
984 | .store = store, | |
985 | }; | |
986 | ||
987 | static struct kobj_type ktype_cpufreq = { | |
988 | .sysfs_ops = &sysfs_ops, | |
989 | .default_attrs = default_attrs, | |
990 | .release = cpufreq_sysfs_release, | |
991 | }; | |
992 | ||
2f0ba790 | 993 | static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) |
87549141 | 994 | { |
2f0ba790 RW |
995 | struct device *dev = get_cpu_device(cpu); |
996 | ||
997 | if (!dev) | |
998 | return; | |
999 | ||
1000 | if (cpumask_test_and_set_cpu(cpu, policy->real_cpus)) | |
1001 | return; | |
1002 | ||
26619804 | 1003 | dev_dbg(dev, "%s: Adding symlink\n", __func__); |
2f0ba790 RW |
1004 | if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq")) |
1005 | dev_err(dev, "cpufreq symlink creation failed\n"); | |
87549141 VK |
1006 | } |
1007 | ||
26619804 VK |
1008 | static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, |
1009 | struct device *dev) | |
87549141 | 1010 | { |
26619804 VK |
1011 | dev_dbg(dev, "%s: Removing symlink\n", __func__); |
1012 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
87549141 VK |
1013 | } |
1014 | ||
d9612a49 | 1015 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) |
909a694e DJ |
1016 | { |
1017 | struct freq_attr **drv_attr; | |
909a694e | 1018 | int ret = 0; |
909a694e | 1019 | |
909a694e | 1020 | /* set up files for this cpu device */ |
1c3d85dd | 1021 | drv_attr = cpufreq_driver->attr; |
f13f1184 | 1022 | while (drv_attr && *drv_attr) { |
909a694e DJ |
1023 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
1024 | if (ret) | |
6d4e81ed | 1025 | return ret; |
909a694e DJ |
1026 | drv_attr++; |
1027 | } | |
1c3d85dd | 1028 | if (cpufreq_driver->get) { |
909a694e DJ |
1029 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
1030 | if (ret) | |
6d4e81ed | 1031 | return ret; |
909a694e | 1032 | } |
c034b02e DB |
1033 | |
1034 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
1035 | if (ret) | |
6d4e81ed | 1036 | return ret; |
c034b02e | 1037 | |
1c3d85dd | 1038 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
1039 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
1040 | if (ret) | |
6d4e81ed | 1041 | return ret; |
e2f74f35 | 1042 | } |
909a694e | 1043 | |
26619804 | 1044 | return 0; |
e18f1682 SB |
1045 | } |
1046 | ||
de1df26b RW |
1047 | __weak struct cpufreq_governor *cpufreq_default_governor(void) |
1048 | { | |
1049 | return NULL; | |
1050 | } | |
1051 | ||
7f0fa40f | 1052 | static int cpufreq_init_policy(struct cpufreq_policy *policy) |
e18f1682 | 1053 | { |
6e2c89d1 | 1054 | struct cpufreq_governor *gov = NULL; |
e18f1682 | 1055 | struct cpufreq_policy new_policy; |
e18f1682 | 1056 | |
d5b73cd8 | 1057 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 1058 | |
6e2c89d1 | 1059 | /* Update governor of new_policy to the governor used before hotplug */ |
4573237b | 1060 | gov = find_governor(policy->last_governor); |
de1df26b | 1061 | if (gov) { |
6e2c89d1 | 1062 | pr_debug("Restoring governor %s for cpu %d\n", |
1063 | policy->governor->name, policy->cpu); | |
de1df26b RW |
1064 | } else { |
1065 | gov = cpufreq_default_governor(); | |
1066 | if (!gov) | |
1067 | return -ENODATA; | |
1068 | } | |
6e2c89d1 | 1069 | |
1070 | new_policy.governor = gov; | |
1071 | ||
69030dd1 SP |
1072 | /* Use the default policy if there is no last_policy. */ |
1073 | if (cpufreq_driver->setpolicy) { | |
1074 | if (policy->last_policy) | |
1075 | new_policy.policy = policy->last_policy; | |
1076 | else | |
ae0ff89f | 1077 | cpufreq_parse_governor(gov->name, &new_policy); |
69030dd1 | 1078 | } |
ecf7e461 | 1079 | /* set default policy */ |
7f0fa40f | 1080 | return cpufreq_set_policy(policy, &new_policy); |
909a694e DJ |
1081 | } |
1082 | ||
d9612a49 | 1083 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
fcf80582 | 1084 | { |
9c0ebcf7 | 1085 | int ret = 0; |
fcf80582 | 1086 | |
bb29ae15 VK |
1087 | /* Has this CPU been taken care of already? */ |
1088 | if (cpumask_test_cpu(cpu, policy->cpus)) | |
1089 | return 0; | |
1090 | ||
49f18560 | 1091 | down_write(&policy->rwsem); |
45482c70 RW |
1092 | if (has_target()) |
1093 | cpufreq_stop_governor(policy); | |
fcf80582 | 1094 | |
fcf80582 | 1095 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 1096 | |
9c0ebcf7 | 1097 | if (has_target()) { |
0a300767 | 1098 | ret = cpufreq_start_governor(policy); |
49f18560 | 1099 | if (ret) |
3de9bdeb | 1100 | pr_err("%s: Failed to start governor\n", __func__); |
820c6ca2 | 1101 | } |
49f18560 VK |
1102 | up_write(&policy->rwsem); |
1103 | return ret; | |
fcf80582 | 1104 | } |
1da177e4 | 1105 | |
11eb69b9 VK |
1106 | static void handle_update(struct work_struct *work) |
1107 | { | |
1108 | struct cpufreq_policy *policy = | |
1109 | container_of(work, struct cpufreq_policy, update); | |
1110 | unsigned int cpu = policy->cpu; | |
1111 | pr_debug("handle_update for cpu %u called\n", cpu); | |
1112 | cpufreq_update_policy(cpu); | |
fcf80582 | 1113 | } |
1da177e4 | 1114 | |
a34e63b1 | 1115 | static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) |
e9698cc5 SB |
1116 | { |
1117 | struct cpufreq_policy *policy; | |
edd4a893 | 1118 | int ret; |
e9698cc5 SB |
1119 | |
1120 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
1121 | if (!policy) | |
1122 | return NULL; | |
1123 | ||
1124 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1125 | goto err_free_policy; | |
1126 | ||
1127 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1128 | goto err_free_cpumask; | |
1129 | ||
559ed407 RW |
1130 | if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) |
1131 | goto err_free_rcpumask; | |
1132 | ||
edd4a893 VK |
1133 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
1134 | cpufreq_global_kobject, "policy%u", cpu); | |
1135 | if (ret) { | |
1136 | pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret); | |
2acb9bda RW |
1137 | /* |
1138 | * The entire policy object will be freed below, but the extra | |
1139 | * memory allocated for the kobject name needs to be freed by | |
1140 | * releasing the kobject. | |
1141 | */ | |
4ebe36c9 | 1142 | kobject_put(&policy->kobj); |
edd4a893 VK |
1143 | goto err_free_real_cpus; |
1144 | } | |
1145 | ||
c88a1f8b | 1146 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1147 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1148 | spin_lock_init(&policy->transition_lock); |
1149 | init_waitqueue_head(&policy->transition_wait); | |
818c5712 VK |
1150 | init_completion(&policy->kobj_unregister); |
1151 | INIT_WORK(&policy->update, handle_update); | |
ad7722da | 1152 | |
a34e63b1 | 1153 | policy->cpu = cpu; |
e9698cc5 SB |
1154 | return policy; |
1155 | ||
edd4a893 VK |
1156 | err_free_real_cpus: |
1157 | free_cpumask_var(policy->real_cpus); | |
2fc3384d VK |
1158 | err_free_rcpumask: |
1159 | free_cpumask_var(policy->related_cpus); | |
e9698cc5 SB |
1160 | err_free_cpumask: |
1161 | free_cpumask_var(policy->cpus); | |
1162 | err_free_policy: | |
1163 | kfree(policy); | |
1164 | ||
1165 | return NULL; | |
1166 | } | |
1167 | ||
f9f41e3e | 1168 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
42f921a6 VK |
1169 | { |
1170 | struct kobject *kobj; | |
1171 | struct completion *cmp; | |
1172 | ||
87549141 | 1173 | down_write(&policy->rwsem); |
1aefc75b | 1174 | cpufreq_stats_free_table(policy); |
42f921a6 VK |
1175 | kobj = &policy->kobj; |
1176 | cmp = &policy->kobj_unregister; | |
87549141 | 1177 | up_write(&policy->rwsem); |
42f921a6 VK |
1178 | kobject_put(kobj); |
1179 | ||
1180 | /* | |
1181 | * We need to make sure that the underlying kobj is | |
1182 | * actually not referenced anymore by anybody before we | |
1183 | * proceed with unloading. | |
1184 | */ | |
1185 | pr_debug("waiting for dropping of refcount\n"); | |
1186 | wait_for_completion(cmp); | |
1187 | pr_debug("wait complete\n"); | |
1188 | } | |
1189 | ||
f9f41e3e | 1190 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
e9698cc5 | 1191 | { |
988bed09 VK |
1192 | unsigned long flags; |
1193 | int cpu; | |
1194 | ||
1195 | /* Remove policy from list */ | |
1196 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1197 | list_del(&policy->policy_list); | |
1198 | ||
1199 | for_each_cpu(cpu, policy->related_cpus) | |
1200 | per_cpu(cpufreq_cpu_data, cpu) = NULL; | |
1201 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1202 | ||
f9f41e3e | 1203 | cpufreq_policy_put_kobj(policy); |
559ed407 | 1204 | free_cpumask_var(policy->real_cpus); |
e9698cc5 SB |
1205 | free_cpumask_var(policy->related_cpus); |
1206 | free_cpumask_var(policy->cpus); | |
1207 | kfree(policy); | |
1208 | } | |
1209 | ||
0b275352 | 1210 | static int cpufreq_online(unsigned int cpu) |
1da177e4 | 1211 | { |
7f0c020a | 1212 | struct cpufreq_policy *policy; |
194d99c7 | 1213 | bool new_policy; |
1da177e4 | 1214 | unsigned long flags; |
0b275352 RW |
1215 | unsigned int j; |
1216 | int ret; | |
87549141 | 1217 | |
0b275352 | 1218 | pr_debug("%s: bringing CPU%u online\n", __func__, cpu); |
6eed9404 | 1219 | |
bb29ae15 | 1220 | /* Check if this CPU already has a policy to manage it */ |
9104bb26 | 1221 | policy = per_cpu(cpufreq_cpu_data, cpu); |
11ce707e | 1222 | if (policy) { |
9104bb26 | 1223 | WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus)); |
11ce707e | 1224 | if (!policy_is_inactive(policy)) |
d9612a49 | 1225 | return cpufreq_add_policy_cpu(policy, cpu); |
1da177e4 | 1226 | |
11ce707e | 1227 | /* This is the only online CPU for the policy. Start over. */ |
194d99c7 | 1228 | new_policy = false; |
11ce707e RW |
1229 | down_write(&policy->rwsem); |
1230 | policy->cpu = cpu; | |
1231 | policy->governor = NULL; | |
1232 | up_write(&policy->rwsem); | |
1233 | } else { | |
194d99c7 | 1234 | new_policy = true; |
a34e63b1 | 1235 | policy = cpufreq_policy_alloc(cpu); |
72368d12 | 1236 | if (!policy) |
d4d854d6 | 1237 | return -ENOMEM; |
72368d12 | 1238 | } |
0d66b91e | 1239 | |
91a12e91 VK |
1240 | if (!new_policy && cpufreq_driver->online) { |
1241 | ret = cpufreq_driver->online(policy); | |
1242 | if (ret) { | |
1243 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1244 | __LINE__); | |
1245 | goto out_exit_policy; | |
1246 | } | |
1da177e4 | 1247 | |
91a12e91 VK |
1248 | /* Recover policy->cpus using related_cpus */ |
1249 | cpumask_copy(policy->cpus, policy->related_cpus); | |
1250 | } else { | |
1251 | cpumask_copy(policy->cpus, cpumask_of(cpu)); | |
643ae6e8 | 1252 | |
91a12e91 VK |
1253 | /* |
1254 | * Call driver. From then on the cpufreq must be able | |
1255 | * to accept all calls to ->verify and ->setpolicy for this CPU. | |
1256 | */ | |
1257 | ret = cpufreq_driver->init(policy); | |
1258 | if (ret) { | |
1259 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1260 | __LINE__); | |
1261 | goto out_free_policy; | |
1262 | } | |
d417e069 | 1263 | |
91a12e91 VK |
1264 | ret = cpufreq_table_validate_and_sort(policy); |
1265 | if (ret) | |
1266 | goto out_exit_policy; | |
6d4e81ed | 1267 | |
4d1f3a5b | 1268 | /* related_cpus should at least include policy->cpus. */ |
0998a03a | 1269 | cpumask_copy(policy->related_cpus, policy->cpus); |
4d1f3a5b | 1270 | } |
559ed407 | 1271 | |
91a12e91 | 1272 | down_write(&policy->rwsem); |
5a7e56a5 VK |
1273 | /* |
1274 | * affected cpus must always be the one, which are online. We aren't | |
1275 | * managing offline cpus here. | |
1276 | */ | |
1277 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1278 | ||
194d99c7 | 1279 | if (new_policy) { |
5a7e56a5 VK |
1280 | policy->user_policy.min = policy->min; |
1281 | policy->user_policy.max = policy->max; | |
6d4e81ed | 1282 | |
2f0ba790 | 1283 | for_each_cpu(j, policy->related_cpus) { |
988bed09 | 1284 | per_cpu(cpufreq_cpu_data, j) = policy; |
2f0ba790 RW |
1285 | add_cpu_dev_symlink(policy, j); |
1286 | } | |
ff010472 VK |
1287 | } else { |
1288 | policy->min = policy->user_policy.min; | |
1289 | policy->max = policy->user_policy.max; | |
988bed09 | 1290 | } |
652ed95d | 1291 | |
2ed99e39 | 1292 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
da60ce9f VK |
1293 | policy->cur = cpufreq_driver->get(policy->cpu); |
1294 | if (!policy->cur) { | |
1295 | pr_err("%s: ->get() failed\n", __func__); | |
d417e069 | 1296 | goto out_destroy_policy; |
da60ce9f VK |
1297 | } |
1298 | } | |
1299 | ||
d3916691 VK |
1300 | /* |
1301 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1302 | * frequency table present with cpufreq core. In such cases CPU might be | |
1303 | * unstable if it has to run on that frequency for long duration of time | |
1304 | * and so its better to set it to a frequency which is specified in | |
1305 | * freq-table. This also makes cpufreq stats inconsistent as | |
1306 | * cpufreq-stats would fail to register because current frequency of CPU | |
1307 | * isn't found in freq-table. | |
1308 | * | |
1309 | * Because we don't want this change to effect boot process badly, we go | |
1310 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1311 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1312 | * is initialized to zero). | |
1313 | * | |
1314 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1315 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1316 | * equal to target-freq. | |
1317 | */ | |
1318 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1319 | && has_target()) { | |
1320 | /* Are we running at unknown frequency ? */ | |
1321 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1322 | if (ret == -EINVAL) { | |
1323 | /* Warn user and fix it */ | |
1324 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1325 | __func__, policy->cpu, policy->cur); | |
1326 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1327 | CPUFREQ_RELATION_L); | |
1328 | ||
1329 | /* | |
1330 | * Reaching here after boot in a few seconds may not | |
1331 | * mean that system will remain stable at "unknown" | |
1332 | * frequency for longer duration. Hence, a BUG_ON(). | |
1333 | */ | |
1334 | BUG_ON(ret); | |
1335 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1336 | __func__, policy->cpu, policy->cur); | |
1337 | } | |
1338 | } | |
1339 | ||
194d99c7 | 1340 | if (new_policy) { |
d9612a49 | 1341 | ret = cpufreq_add_dev_interface(policy); |
a82fab29 | 1342 | if (ret) |
d417e069 | 1343 | goto out_destroy_policy; |
1aefc75b RW |
1344 | |
1345 | cpufreq_stats_create_table(policy); | |
8ff69732 | 1346 | |
988bed09 VK |
1347 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1348 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1349 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1350 | } | |
9515f4d6 | 1351 | |
7f0fa40f VK |
1352 | ret = cpufreq_init_policy(policy); |
1353 | if (ret) { | |
1354 | pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", | |
1355 | __func__, cpu, ret); | |
d417e069 | 1356 | goto out_destroy_policy; |
08fd8c1c | 1357 | } |
e18f1682 | 1358 | |
4e97b631 | 1359 | up_write(&policy->rwsem); |
08fd8c1c | 1360 | |
038c5b3e | 1361 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
7c45cf31 | 1362 | |
7c45cf31 VK |
1363 | /* Callback for handling stuff after policy is ready */ |
1364 | if (cpufreq_driver->ready) | |
1365 | cpufreq_driver->ready(policy); | |
1366 | ||
5c238a8b AK |
1367 | if (IS_ENABLED(CONFIG_CPU_THERMAL) && |
1368 | cpufreq_driver->flags & CPUFREQ_IS_COOLING_DEV) | |
1369 | policy->cdev = of_cpufreq_cooling_register(policy); | |
1370 | ||
2d06d8c4 | 1371 | pr_debug("initialization complete\n"); |
87c32271 | 1372 | |
1da177e4 LT |
1373 | return 0; |
1374 | ||
d417e069 | 1375 | out_destroy_policy: |
b24b6478 VK |
1376 | for_each_cpu(j, policy->real_cpus) |
1377 | remove_cpu_dev_symlink(policy, get_cpu_device(j)); | |
1378 | ||
7106e02b PB |
1379 | up_write(&policy->rwsem); |
1380 | ||
d417e069 | 1381 | out_exit_policy: |
da60ce9f VK |
1382 | if (cpufreq_driver->exit) |
1383 | cpufreq_driver->exit(policy); | |
2f0ba790 | 1384 | |
8101f997 | 1385 | out_free_policy: |
f9f41e3e | 1386 | cpufreq_policy_free(policy); |
1da177e4 LT |
1387 | return ret; |
1388 | } | |
1389 | ||
0b275352 RW |
1390 | /** |
1391 | * cpufreq_add_dev - the cpufreq interface for a CPU device. | |
1392 | * @dev: CPU device. | |
1393 | * @sif: Subsystem interface structure pointer (not used) | |
1394 | */ | |
1395 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1396 | { | |
a794d613 | 1397 | struct cpufreq_policy *policy; |
0b275352 | 1398 | unsigned cpu = dev->id; |
26619804 | 1399 | int ret; |
0b275352 RW |
1400 | |
1401 | dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); | |
1402 | ||
26619804 VK |
1403 | if (cpu_online(cpu)) { |
1404 | ret = cpufreq_online(cpu); | |
1405 | if (ret) | |
1406 | return ret; | |
1407 | } | |
0b275352 | 1408 | |
26619804 | 1409 | /* Create sysfs link on CPU registration */ |
a794d613 | 1410 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2f0ba790 RW |
1411 | if (policy) |
1412 | add_cpu_dev_symlink(policy, cpu); | |
26619804 | 1413 | |
2f0ba790 | 1414 | return 0; |
1da177e4 LT |
1415 | } |
1416 | ||
27622b06 | 1417 | static int cpufreq_offline(unsigned int cpu) |
1da177e4 | 1418 | { |
3a3e9e06 | 1419 | struct cpufreq_policy *policy; |
69cee714 | 1420 | int ret; |
1da177e4 | 1421 | |
b8eed8af | 1422 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1423 | |
988bed09 | 1424 | policy = cpufreq_cpu_get_raw(cpu); |
3a3e9e06 | 1425 | if (!policy) { |
b8eed8af | 1426 | pr_debug("%s: No cpu_data found\n", __func__); |
27622b06 | 1427 | return 0; |
1da177e4 | 1428 | } |
1da177e4 | 1429 | |
49f18560 | 1430 | down_write(&policy->rwsem); |
45482c70 RW |
1431 | if (has_target()) |
1432 | cpufreq_stop_governor(policy); | |
1da177e4 | 1433 | |
9591becb | 1434 | cpumask_clear_cpu(cpu, policy->cpus); |
4573237b | 1435 | |
9591becb VK |
1436 | if (policy_is_inactive(policy)) { |
1437 | if (has_target()) | |
1438 | strncpy(policy->last_governor, policy->governor->name, | |
1439 | CPUFREQ_NAME_LEN); | |
69030dd1 SP |
1440 | else |
1441 | policy->last_policy = policy->policy; | |
9591becb VK |
1442 | } else if (cpu == policy->cpu) { |
1443 | /* Nominate new CPU */ | |
1444 | policy->cpu = cpumask_any(policy->cpus); | |
1445 | } | |
084f3493 | 1446 | |
9591becb VK |
1447 | /* Start governor again for active policy */ |
1448 | if (!policy_is_inactive(policy)) { | |
1449 | if (has_target()) { | |
0a300767 | 1450 | ret = cpufreq_start_governor(policy); |
9591becb VK |
1451 | if (ret) |
1452 | pr_err("%s: Failed to start governor\n", __func__); | |
1453 | } | |
cedb70af | 1454 | |
49f18560 | 1455 | goto unlock; |
cedb70af SB |
1456 | } |
1457 | ||
5c238a8b AK |
1458 | if (IS_ENABLED(CONFIG_CPU_THERMAL) && |
1459 | cpufreq_driver->flags & CPUFREQ_IS_COOLING_DEV) { | |
1460 | cpufreq_cooling_unregister(policy->cdev); | |
1461 | policy->cdev = NULL; | |
1462 | } | |
1463 | ||
69cee714 VK |
1464 | if (cpufreq_driver->stop_cpu) |
1465 | cpufreq_driver->stop_cpu(policy); | |
87549141 | 1466 | |
36be3418 RW |
1467 | if (has_target()) |
1468 | cpufreq_exit_governor(policy); | |
1da177e4 | 1469 | |
87549141 | 1470 | /* |
91a12e91 VK |
1471 | * Perform the ->offline() during light-weight tear-down, as |
1472 | * that allows fast recovery when the CPU comes back. | |
87549141 | 1473 | */ |
91a12e91 VK |
1474 | if (cpufreq_driver->offline) { |
1475 | cpufreq_driver->offline(policy); | |
1476 | } else if (cpufreq_driver->exit) { | |
87549141 | 1477 | cpufreq_driver->exit(policy); |
55582bcc SP |
1478 | policy->freq_table = NULL; |
1479 | } | |
49f18560 VK |
1480 | |
1481 | unlock: | |
1482 | up_write(&policy->rwsem); | |
27622b06 | 1483 | return 0; |
1da177e4 LT |
1484 | } |
1485 | ||
cedb70af | 1486 | /** |
27a862e9 | 1487 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1488 | * |
1489 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1490 | */ |
71db87ba | 1491 | static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1492 | { |
8a25a2fd | 1493 | unsigned int cpu = dev->id; |
559ed407 | 1494 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
87549141 | 1495 | |
559ed407 | 1496 | if (!policy) |
1af115d6 | 1497 | return; |
87549141 | 1498 | |
69cee714 VK |
1499 | if (cpu_online(cpu)) |
1500 | cpufreq_offline(cpu); | |
87549141 | 1501 | |
559ed407 | 1502 | cpumask_clear_cpu(cpu, policy->real_cpus); |
26619804 | 1503 | remove_cpu_dev_symlink(policy, dev); |
87549141 | 1504 | |
91a12e91 VK |
1505 | if (cpumask_empty(policy->real_cpus)) { |
1506 | /* We did light-weight exit earlier, do full tear down now */ | |
1507 | if (cpufreq_driver->offline) | |
1508 | cpufreq_driver->exit(policy); | |
1509 | ||
f9f41e3e | 1510 | cpufreq_policy_free(policy); |
91a12e91 | 1511 | } |
5a01f2e8 VP |
1512 | } |
1513 | ||
1da177e4 | 1514 | /** |
bb176f7d VK |
1515 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1516 | * in deep trouble. | |
a1e1dc41 | 1517 | * @policy: policy managing CPUs |
1da177e4 LT |
1518 | * @new_freq: CPU frequency the CPU actually runs at |
1519 | * | |
29464f28 DJ |
1520 | * We adjust to current frequency first, and need to clean up later. |
1521 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1522 | */ |
a1e1dc41 | 1523 | static void cpufreq_out_of_sync(struct cpufreq_policy *policy, |
e08f5f5b | 1524 | unsigned int new_freq) |
1da177e4 LT |
1525 | { |
1526 | struct cpufreq_freqs freqs; | |
b43a7ffb | 1527 | |
e837f9b5 | 1528 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
a1e1dc41 | 1529 | policy->cur, new_freq); |
1da177e4 | 1530 | |
a1e1dc41 | 1531 | freqs.old = policy->cur; |
1da177e4 | 1532 | freqs.new = new_freq; |
b43a7ffb | 1533 | |
8fec051e VK |
1534 | cpufreq_freq_transition_begin(policy, &freqs); |
1535 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1536 | } |
1537 | ||
32ee8c3e | 1538 | /** |
4ab70df4 | 1539 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1540 | * @cpu: CPU number |
1541 | * | |
1542 | * This is the last known freq, without actually getting it from the driver. | |
1543 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1544 | */ | |
1545 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1546 | { | |
9e21ba8b | 1547 | struct cpufreq_policy *policy; |
e08f5f5b | 1548 | unsigned int ret_freq = 0; |
c75361c0 | 1549 | unsigned long flags; |
95235ca2 | 1550 | |
c75361c0 RC |
1551 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1552 | ||
1553 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { | |
1554 | ret_freq = cpufreq_driver->get(cpu); | |
1555 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1556 | return ret_freq; | |
1557 | } | |
1558 | ||
1559 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
9e21ba8b DB |
1560 | |
1561 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1562 | if (policy) { |
e08f5f5b | 1563 | ret_freq = policy->cur; |
95235ca2 VP |
1564 | cpufreq_cpu_put(policy); |
1565 | } | |
1566 | ||
4d34a67d | 1567 | return ret_freq; |
95235ca2 VP |
1568 | } |
1569 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1570 | ||
3d737108 JB |
1571 | /** |
1572 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1573 | * @cpu: CPU number | |
1574 | * | |
1575 | * Just return the max possible frequency for a given CPU. | |
1576 | */ | |
1577 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1578 | { | |
1579 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1580 | unsigned int ret_freq = 0; | |
1581 | ||
1582 | if (policy) { | |
1583 | ret_freq = policy->max; | |
1584 | cpufreq_cpu_put(policy); | |
1585 | } | |
1586 | ||
1587 | return ret_freq; | |
1588 | } | |
1589 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1590 | ||
d92d50a4 | 1591 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy) |
1da177e4 | 1592 | { |
e08f5f5b | 1593 | unsigned int ret_freq = 0; |
5800043b | 1594 | |
4db7c34c | 1595 | if (unlikely(policy_is_inactive(policy))) |
4d34a67d | 1596 | return ret_freq; |
1da177e4 | 1597 | |
d92d50a4 | 1598 | ret_freq = cpufreq_driver->get(policy->cpu); |
1da177e4 | 1599 | |
b7898fda | 1600 | /* |
2f661962 | 1601 | * If fast frequency switching is used with the given policy, the check |
b7898fda RW |
1602 | * against policy->cur is pointless, so skip it in that case too. |
1603 | */ | |
2f661962 | 1604 | if (policy->fast_switch_enabled) |
11e584cf VK |
1605 | return ret_freq; |
1606 | ||
e08f5f5b | 1607 | if (ret_freq && policy->cur && |
1c3d85dd | 1608 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1609 | /* verify no discrepancy between actual and |
1610 | saved value exists */ | |
1611 | if (unlikely(ret_freq != policy->cur)) { | |
a1e1dc41 | 1612 | cpufreq_out_of_sync(policy, ret_freq); |
1da177e4 LT |
1613 | schedule_work(&policy->update); |
1614 | } | |
1615 | } | |
1616 | ||
4d34a67d | 1617 | return ret_freq; |
5a01f2e8 | 1618 | } |
1da177e4 | 1619 | |
5a01f2e8 VP |
1620 | /** |
1621 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1622 | * @cpu: CPU number | |
1623 | * | |
1624 | * Get the CPU current (static) CPU frequency | |
1625 | */ | |
1626 | unsigned int cpufreq_get(unsigned int cpu) | |
1627 | { | |
999976e0 | 1628 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1629 | unsigned int ret_freq = 0; |
5a01f2e8 | 1630 | |
999976e0 AP |
1631 | if (policy) { |
1632 | down_read(&policy->rwsem); | |
4db7c34c YH |
1633 | if (cpufreq_driver->get) |
1634 | ret_freq = __cpufreq_get(policy); | |
999976e0 | 1635 | up_read(&policy->rwsem); |
5a01f2e8 | 1636 | |
999976e0 AP |
1637 | cpufreq_cpu_put(policy); |
1638 | } | |
6eed9404 | 1639 | |
4d34a67d | 1640 | return ret_freq; |
1da177e4 LT |
1641 | } |
1642 | EXPORT_SYMBOL(cpufreq_get); | |
1643 | ||
999f5729 RW |
1644 | static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy) |
1645 | { | |
1646 | unsigned int new_freq; | |
1647 | ||
1648 | new_freq = cpufreq_driver->get(policy->cpu); | |
1649 | if (!new_freq) | |
1650 | return 0; | |
1651 | ||
1652 | if (!policy->cur) { | |
1653 | pr_debug("cpufreq: Driver did not initialize current freq\n"); | |
1654 | policy->cur = new_freq; | |
1655 | } else if (policy->cur != new_freq && has_target()) { | |
1656 | cpufreq_out_of_sync(policy, new_freq); | |
1657 | } | |
1658 | ||
1659 | return new_freq; | |
1660 | } | |
1661 | ||
8a25a2fd KS |
1662 | static struct subsys_interface cpufreq_interface = { |
1663 | .name = "cpufreq", | |
1664 | .subsys = &cpu_subsys, | |
1665 | .add_dev = cpufreq_add_dev, | |
1666 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1667 | }; |
1668 | ||
e28867ea VK |
1669 | /* |
1670 | * In case platform wants some specific frequency to be configured | |
1671 | * during suspend.. | |
1672 | */ | |
1673 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1674 | { | |
1675 | int ret; | |
1676 | ||
1677 | if (!policy->suspend_freq) { | |
201f3716 BZ |
1678 | pr_debug("%s: suspend_freq not defined\n", __func__); |
1679 | return 0; | |
e28867ea VK |
1680 | } |
1681 | ||
1682 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1683 | policy->suspend_freq); | |
1684 | ||
1685 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1686 | CPUFREQ_RELATION_H); | |
1687 | if (ret) | |
1688 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1689 | __func__, policy->suspend_freq, ret); | |
1690 | ||
1691 | return ret; | |
1692 | } | |
1693 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1694 | ||
42d4dc3f | 1695 | /** |
2f0aea93 | 1696 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1697 | * |
2f0aea93 VK |
1698 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1699 | * as some platforms can't change frequency after this point in suspend cycle. | |
1700 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1701 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1702 | */ |
2f0aea93 | 1703 | void cpufreq_suspend(void) |
42d4dc3f | 1704 | { |
3a3e9e06 | 1705 | struct cpufreq_policy *policy; |
42d4dc3f | 1706 | |
2f0aea93 VK |
1707 | if (!cpufreq_driver) |
1708 | return; | |
42d4dc3f | 1709 | |
ba41e1bc | 1710 | if (!has_target() && !cpufreq_driver->suspend) |
b1b12bab | 1711 | goto suspend; |
42d4dc3f | 1712 | |
2f0aea93 VK |
1713 | pr_debug("%s: Suspending Governors\n", __func__); |
1714 | ||
f963735a | 1715 | for_each_active_policy(policy) { |
ba41e1bc RW |
1716 | if (has_target()) { |
1717 | down_write(&policy->rwsem); | |
45482c70 | 1718 | cpufreq_stop_governor(policy); |
ba41e1bc | 1719 | up_write(&policy->rwsem); |
ba41e1bc RW |
1720 | } |
1721 | ||
1722 | if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) | |
2f0aea93 VK |
1723 | pr_err("%s: Failed to suspend driver: %p\n", __func__, |
1724 | policy); | |
42d4dc3f | 1725 | } |
b1b12bab VK |
1726 | |
1727 | suspend: | |
1728 | cpufreq_suspended = true; | |
42d4dc3f BH |
1729 | } |
1730 | ||
1da177e4 | 1731 | /** |
2f0aea93 | 1732 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1733 | * |
2f0aea93 VK |
1734 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1735 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1736 | */ |
2f0aea93 | 1737 | void cpufreq_resume(void) |
1da177e4 | 1738 | { |
3a3e9e06 | 1739 | struct cpufreq_policy *policy; |
49f18560 | 1740 | int ret; |
1da177e4 | 1741 | |
2f0aea93 | 1742 | if (!cpufreq_driver) |
703cbaa6 BY |
1743 | return; |
1744 | ||
1745 | if (unlikely(!cpufreq_suspended)) | |
2f0aea93 | 1746 | return; |
1da177e4 | 1747 | |
8e30444e LT |
1748 | cpufreq_suspended = false; |
1749 | ||
ba41e1bc | 1750 | if (!has_target() && !cpufreq_driver->resume) |
e00e56df | 1751 | return; |
1da177e4 | 1752 | |
2f0aea93 | 1753 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1754 | |
f963735a | 1755 | for_each_active_policy(policy) { |
49f18560 | 1756 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { |
0c5aa405 VK |
1757 | pr_err("%s: Failed to resume driver: %p\n", __func__, |
1758 | policy); | |
ba41e1bc | 1759 | } else if (has_target()) { |
49f18560 | 1760 | down_write(&policy->rwsem); |
0a300767 | 1761 | ret = cpufreq_start_governor(policy); |
49f18560 VK |
1762 | up_write(&policy->rwsem); |
1763 | ||
1764 | if (ret) | |
1765 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1766 | __func__, policy); | |
1767 | } | |
2f0aea93 VK |
1768 | } |
1769 | } | |
1da177e4 | 1770 | |
9d95046e BP |
1771 | /** |
1772 | * cpufreq_get_current_driver - return current driver's name | |
1773 | * | |
1774 | * Return the name string of the currently loaded cpufreq driver | |
1775 | * or NULL, if none. | |
1776 | */ | |
1777 | const char *cpufreq_get_current_driver(void) | |
1778 | { | |
1c3d85dd RW |
1779 | if (cpufreq_driver) |
1780 | return cpufreq_driver->name; | |
1781 | ||
1782 | return NULL; | |
9d95046e BP |
1783 | } |
1784 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 | 1785 | |
51315cdf TP |
1786 | /** |
1787 | * cpufreq_get_driver_data - return current driver data | |
1788 | * | |
1789 | * Return the private data of the currently loaded cpufreq | |
1790 | * driver, or NULL if no cpufreq driver is loaded. | |
1791 | */ | |
1792 | void *cpufreq_get_driver_data(void) | |
1793 | { | |
1794 | if (cpufreq_driver) | |
1795 | return cpufreq_driver->driver_data; | |
1796 | ||
1797 | return NULL; | |
1798 | } | |
1799 | EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); | |
1800 | ||
1da177e4 LT |
1801 | /********************************************************************* |
1802 | * NOTIFIER LISTS INTERFACE * | |
1803 | *********************************************************************/ | |
1804 | ||
1805 | /** | |
1806 | * cpufreq_register_notifier - register a driver with cpufreq | |
1807 | * @nb: notifier function to register | |
1808 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1809 | * | |
32ee8c3e | 1810 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1811 | * are notified about clock rate changes (once before and once after |
1812 | * the transition), or a list of drivers that are notified about | |
1813 | * changes in cpufreq policy. | |
1814 | * | |
1815 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1816 | * blocking_notifier_chain_register. |
1da177e4 LT |
1817 | */ |
1818 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1819 | { | |
1820 | int ret; | |
1821 | ||
d5aaffa9 DB |
1822 | if (cpufreq_disabled()) |
1823 | return -EINVAL; | |
1824 | ||
1da177e4 LT |
1825 | switch (list) { |
1826 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1827 | mutex_lock(&cpufreq_fast_switch_lock); |
1828 | ||
1829 | if (cpufreq_fast_switch_count > 0) { | |
1830 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1831 | return -EBUSY; | |
1832 | } | |
b4dfdbb3 | 1833 | ret = srcu_notifier_chain_register( |
e041c683 | 1834 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1835 | if (!ret) |
1836 | cpufreq_fast_switch_count--; | |
1837 | ||
1838 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1839 | break; |
1840 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1841 | ret = blocking_notifier_chain_register( |
1842 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1843 | break; |
1844 | default: | |
1845 | ret = -EINVAL; | |
1846 | } | |
1da177e4 LT |
1847 | |
1848 | return ret; | |
1849 | } | |
1850 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1851 | ||
1da177e4 LT |
1852 | /** |
1853 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1854 | * @nb: notifier block to be unregistered | |
bb176f7d | 1855 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1856 | * |
1857 | * Remove a driver from the CPU frequency notifier list. | |
1858 | * | |
1859 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1860 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1861 | */ |
1862 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1863 | { | |
1864 | int ret; | |
1865 | ||
d5aaffa9 DB |
1866 | if (cpufreq_disabled()) |
1867 | return -EINVAL; | |
1868 | ||
1da177e4 LT |
1869 | switch (list) { |
1870 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1871 | mutex_lock(&cpufreq_fast_switch_lock); |
1872 | ||
b4dfdbb3 | 1873 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1874 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1875 | if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) |
1876 | cpufreq_fast_switch_count++; | |
1877 | ||
1878 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1879 | break; |
1880 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1881 | ret = blocking_notifier_chain_unregister( |
1882 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1883 | break; |
1884 | default: | |
1885 | ret = -EINVAL; | |
1886 | } | |
1da177e4 LT |
1887 | |
1888 | return ret; | |
1889 | } | |
1890 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1891 | ||
1892 | ||
1893 | /********************************************************************* | |
1894 | * GOVERNORS * | |
1895 | *********************************************************************/ | |
1896 | ||
b7898fda RW |
1897 | /** |
1898 | * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. | |
1899 | * @policy: cpufreq policy to switch the frequency for. | |
1900 | * @target_freq: New frequency to set (may be approximate). | |
1901 | * | |
1902 | * Carry out a fast frequency switch without sleeping. | |
1903 | * | |
1904 | * The driver's ->fast_switch() callback invoked by this function must be | |
1905 | * suitable for being called from within RCU-sched read-side critical sections | |
1906 | * and it is expected to select the minimum available frequency greater than or | |
1907 | * equal to @target_freq (CPUFREQ_RELATION_L). | |
1908 | * | |
1909 | * This function must not be called if policy->fast_switch_enabled is unset. | |
1910 | * | |
1911 | * Governors calling this function must guarantee that it will never be invoked | |
1912 | * twice in parallel for the same policy and that it will never be called in | |
1913 | * parallel with either ->target() or ->target_index() for the same policy. | |
1914 | * | |
209887e6 VK |
1915 | * Returns the actual frequency set for the CPU. |
1916 | * | |
1917 | * If 0 is returned by the driver's ->fast_switch() callback to indicate an | |
1918 | * error condition, the hardware configuration must be preserved. | |
b7898fda RW |
1919 | */ |
1920 | unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, | |
1921 | unsigned int target_freq) | |
1922 | { | |
b9af6948 | 1923 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
b7898fda RW |
1924 | |
1925 | return cpufreq_driver->fast_switch(policy, target_freq); | |
1926 | } | |
1927 | EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); | |
1928 | ||
1c03a2d0 VK |
1929 | /* Must set freqs->new to intermediate frequency */ |
1930 | static int __target_intermediate(struct cpufreq_policy *policy, | |
1931 | struct cpufreq_freqs *freqs, int index) | |
1932 | { | |
1933 | int ret; | |
1934 | ||
1935 | freqs->new = cpufreq_driver->get_intermediate(policy, index); | |
1936 | ||
1937 | /* We don't need to switch to intermediate freq */ | |
1938 | if (!freqs->new) | |
1939 | return 0; | |
1940 | ||
1941 | pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", | |
1942 | __func__, policy->cpu, freqs->old, freqs->new); | |
1943 | ||
1944 | cpufreq_freq_transition_begin(policy, freqs); | |
1945 | ret = cpufreq_driver->target_intermediate(policy, index); | |
1946 | cpufreq_freq_transition_end(policy, freqs, ret); | |
1947 | ||
1948 | if (ret) | |
1949 | pr_err("%s: Failed to change to intermediate frequency: %d\n", | |
1950 | __func__, ret); | |
1951 | ||
1952 | return ret; | |
1953 | } | |
1954 | ||
23727845 | 1955 | static int __target_index(struct cpufreq_policy *policy, int index) |
8d65775d | 1956 | { |
1c03a2d0 VK |
1957 | struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
1958 | unsigned int intermediate_freq = 0; | |
23727845 | 1959 | unsigned int newfreq = policy->freq_table[index].frequency; |
8d65775d VK |
1960 | int retval = -EINVAL; |
1961 | bool notify; | |
1962 | ||
23727845 VK |
1963 | if (newfreq == policy->cur) |
1964 | return 0; | |
1965 | ||
8d65775d | 1966 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); |
8d65775d | 1967 | if (notify) { |
1c03a2d0 VK |
1968 | /* Handle switching to intermediate frequency */ |
1969 | if (cpufreq_driver->get_intermediate) { | |
1970 | retval = __target_intermediate(policy, &freqs, index); | |
1971 | if (retval) | |
1972 | return retval; | |
1973 | ||
1974 | intermediate_freq = freqs.new; | |
1975 | /* Set old freq to intermediate */ | |
1976 | if (intermediate_freq) | |
1977 | freqs.old = freqs.new; | |
1978 | } | |
8d65775d | 1979 | |
23727845 | 1980 | freqs.new = newfreq; |
8d65775d VK |
1981 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", |
1982 | __func__, policy->cpu, freqs.old, freqs.new); | |
1983 | ||
1984 | cpufreq_freq_transition_begin(policy, &freqs); | |
1985 | } | |
1986 | ||
1987 | retval = cpufreq_driver->target_index(policy, index); | |
1988 | if (retval) | |
1989 | pr_err("%s: Failed to change cpu frequency: %d\n", __func__, | |
1990 | retval); | |
1991 | ||
1c03a2d0 | 1992 | if (notify) { |
8d65775d VK |
1993 | cpufreq_freq_transition_end(policy, &freqs, retval); |
1994 | ||
1c03a2d0 VK |
1995 | /* |
1996 | * Failed after setting to intermediate freq? Driver should have | |
1997 | * reverted back to initial frequency and so should we. Check | |
1998 | * here for intermediate_freq instead of get_intermediate, in | |
58405af6 | 1999 | * case we haven't switched to intermediate freq at all. |
1c03a2d0 VK |
2000 | */ |
2001 | if (unlikely(retval && intermediate_freq)) { | |
2002 | freqs.old = intermediate_freq; | |
2003 | freqs.new = policy->restore_freq; | |
2004 | cpufreq_freq_transition_begin(policy, &freqs); | |
2005 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
2006 | } | |
2007 | } | |
2008 | ||
8d65775d VK |
2009 | return retval; |
2010 | } | |
2011 | ||
1da177e4 LT |
2012 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
2013 | unsigned int target_freq, | |
2014 | unsigned int relation) | |
2015 | { | |
7249924e | 2016 | unsigned int old_target_freq = target_freq; |
d218ed77 | 2017 | int index; |
c32b6b8e | 2018 | |
a7b422cd KRW |
2019 | if (cpufreq_disabled()) |
2020 | return -ENODEV; | |
2021 | ||
7249924e | 2022 | /* Make sure that target_freq is within supported range */ |
910c6e88 | 2023 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
7249924e VK |
2024 | |
2025 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 2026 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 2027 | |
9c0ebcf7 VK |
2028 | /* |
2029 | * This might look like a redundant call as we are checking it again | |
2030 | * after finding index. But it is left intentionally for cases where | |
2031 | * exactly same freq is called again and so we can save on few function | |
2032 | * calls. | |
2033 | */ | |
5a1c0228 VK |
2034 | if (target_freq == policy->cur) |
2035 | return 0; | |
2036 | ||
1c03a2d0 VK |
2037 | /* Save last value to restore later on errors */ |
2038 | policy->restore_freq = policy->cur; | |
2039 | ||
1c3d85dd | 2040 | if (cpufreq_driver->target) |
6019d23a | 2041 | return cpufreq_driver->target(policy, target_freq, relation); |
9c0ebcf7 | 2042 | |
6019d23a RW |
2043 | if (!cpufreq_driver->target_index) |
2044 | return -EINVAL; | |
9c0ebcf7 | 2045 | |
d218ed77 | 2046 | index = cpufreq_frequency_table_target(policy, target_freq, relation); |
6019d23a | 2047 | |
23727845 | 2048 | return __target_index(policy, index); |
1da177e4 LT |
2049 | } |
2050 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
2051 | ||
1da177e4 LT |
2052 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
2053 | unsigned int target_freq, | |
2054 | unsigned int relation) | |
2055 | { | |
f1829e4a | 2056 | int ret = -EINVAL; |
1da177e4 | 2057 | |
ad7722da | 2058 | down_write(&policy->rwsem); |
1da177e4 LT |
2059 | |
2060 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
2061 | ||
ad7722da | 2062 | up_write(&policy->rwsem); |
1da177e4 | 2063 | |
1da177e4 LT |
2064 | return ret; |
2065 | } | |
2066 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
2067 | ||
de1df26b RW |
2068 | __weak struct cpufreq_governor *cpufreq_fallback_governor(void) |
2069 | { | |
2070 | return NULL; | |
2071 | } | |
2072 | ||
a92604b4 | 2073 | static int cpufreq_init_governor(struct cpufreq_policy *policy) |
1da177e4 | 2074 | { |
cc993cab | 2075 | int ret; |
6afde10c | 2076 | |
2f0aea93 VK |
2077 | /* Don't start any governor operations if we are entering suspend */ |
2078 | if (cpufreq_suspended) | |
2079 | return 0; | |
cb57720b EZ |
2080 | /* |
2081 | * Governor might not be initiated here if ACPI _PPC changed | |
2082 | * notification happened, so check it. | |
2083 | */ | |
2084 | if (!policy->governor) | |
2085 | return -EINVAL; | |
2f0aea93 | 2086 | |
ed4676e2 VK |
2087 | /* Platform doesn't want dynamic frequency switching ? */ |
2088 | if (policy->governor->dynamic_switching && | |
fc4c709f | 2089 | cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) { |
de1df26b RW |
2090 | struct cpufreq_governor *gov = cpufreq_fallback_governor(); |
2091 | ||
2092 | if (gov) { | |
fe829ed8 | 2093 | pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n", |
e837f9b5 | 2094 | policy->governor->name, gov->name); |
6afde10c | 2095 | policy->governor = gov; |
de1df26b RW |
2096 | } else { |
2097 | return -EINVAL; | |
6afde10c | 2098 | } |
1c256245 | 2099 | } |
1da177e4 | 2100 | |
a92604b4 RW |
2101 | if (!try_module_get(policy->governor->owner)) |
2102 | return -EINVAL; | |
95731ebb | 2103 | |
a92604b4 | 2104 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
1da177e4 | 2105 | |
e788892b RW |
2106 | if (policy->governor->init) { |
2107 | ret = policy->governor->init(policy); | |
2108 | if (ret) { | |
36be3418 | 2109 | module_put(policy->governor->owner); |
e788892b RW |
2110 | return ret; |
2111 | } | |
36be3418 | 2112 | } |
1da177e4 | 2113 | |
a92604b4 RW |
2114 | return 0; |
2115 | } | |
2116 | ||
2117 | static void cpufreq_exit_governor(struct cpufreq_policy *policy) | |
2118 | { | |
2119 | if (cpufreq_suspended || !policy->governor) | |
2120 | return; | |
2121 | ||
2122 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2123 | ||
e788892b RW |
2124 | if (policy->governor->exit) |
2125 | policy->governor->exit(policy); | |
a92604b4 | 2126 | |
a92604b4 | 2127 | module_put(policy->governor->owner); |
1da177e4 LT |
2128 | } |
2129 | ||
0a300767 RW |
2130 | static int cpufreq_start_governor(struct cpufreq_policy *policy) |
2131 | { | |
2132 | int ret; | |
2133 | ||
a92604b4 RW |
2134 | if (cpufreq_suspended) |
2135 | return 0; | |
2136 | ||
2137 | if (!policy->governor) | |
2138 | return -EINVAL; | |
2139 | ||
2140 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2141 | ||
3bbf8fe3 RW |
2142 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) |
2143 | cpufreq_update_current_freq(policy); | |
2144 | ||
e788892b RW |
2145 | if (policy->governor->start) { |
2146 | ret = policy->governor->start(policy); | |
2147 | if (ret) | |
2148 | return ret; | |
2149 | } | |
2150 | ||
2151 | if (policy->governor->limits) | |
2152 | policy->governor->limits(policy); | |
d6ff44d6 | 2153 | |
d6ff44d6 | 2154 | return 0; |
0a300767 RW |
2155 | } |
2156 | ||
a92604b4 RW |
2157 | static void cpufreq_stop_governor(struct cpufreq_policy *policy) |
2158 | { | |
2159 | if (cpufreq_suspended || !policy->governor) | |
2160 | return; | |
2161 | ||
2162 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2163 | ||
e788892b RW |
2164 | if (policy->governor->stop) |
2165 | policy->governor->stop(policy); | |
a92604b4 RW |
2166 | } |
2167 | ||
2168 | static void cpufreq_governor_limits(struct cpufreq_policy *policy) | |
2169 | { | |
2170 | if (cpufreq_suspended || !policy->governor) | |
2171 | return; | |
2172 | ||
2173 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2174 | ||
e788892b RW |
2175 | if (policy->governor->limits) |
2176 | policy->governor->limits(policy); | |
0a300767 RW |
2177 | } |
2178 | ||
1da177e4 LT |
2179 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
2180 | { | |
3bcb09a3 | 2181 | int err; |
1da177e4 LT |
2182 | |
2183 | if (!governor) | |
2184 | return -EINVAL; | |
2185 | ||
a7b422cd KRW |
2186 | if (cpufreq_disabled()) |
2187 | return -ENODEV; | |
2188 | ||
3fc54d37 | 2189 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 2190 | |
3bcb09a3 | 2191 | err = -EBUSY; |
42f91fa1 | 2192 | if (!find_governor(governor->name)) { |
3bcb09a3 JF |
2193 | err = 0; |
2194 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2195 | } |
1da177e4 | 2196 | |
32ee8c3e | 2197 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2198 | return err; |
1da177e4 LT |
2199 | } |
2200 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2201 | ||
1da177e4 LT |
2202 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2203 | { | |
4573237b VK |
2204 | struct cpufreq_policy *policy; |
2205 | unsigned long flags; | |
90e41bac | 2206 | |
1da177e4 LT |
2207 | if (!governor) |
2208 | return; | |
2209 | ||
a7b422cd KRW |
2210 | if (cpufreq_disabled()) |
2211 | return; | |
2212 | ||
4573237b VK |
2213 | /* clear last_governor for all inactive policies */ |
2214 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
2215 | for_each_inactive_policy(policy) { | |
18bf3a12 VK |
2216 | if (!strcmp(policy->last_governor, governor->name)) { |
2217 | policy->governor = NULL; | |
4573237b | 2218 | strcpy(policy->last_governor, "\0"); |
18bf3a12 | 2219 | } |
90e41bac | 2220 | } |
4573237b | 2221 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
90e41bac | 2222 | |
3fc54d37 | 2223 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2224 | list_del(&governor->governor_list); |
3fc54d37 | 2225 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2226 | } |
2227 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2228 | ||
2229 | ||
1da177e4 LT |
2230 | /********************************************************************* |
2231 | * POLICY INTERFACE * | |
2232 | *********************************************************************/ | |
2233 | ||
2234 | /** | |
2235 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2236 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2237 | * is written | |
1da177e4 LT |
2238 | * |
2239 | * Reads the current cpufreq policy. | |
2240 | */ | |
2241 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2242 | { | |
2243 | struct cpufreq_policy *cpu_policy; | |
2244 | if (!policy) | |
2245 | return -EINVAL; | |
2246 | ||
2247 | cpu_policy = cpufreq_cpu_get(cpu); | |
2248 | if (!cpu_policy) | |
2249 | return -EINVAL; | |
2250 | ||
d5b73cd8 | 2251 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2252 | |
2253 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2254 | return 0; |
2255 | } | |
2256 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2257 | ||
a0dbb819 RW |
2258 | /** |
2259 | * cpufreq_set_policy - Modify cpufreq policy parameters. | |
2260 | * @policy: Policy object to modify. | |
2261 | * @new_policy: New policy data. | |
2262 | * | |
2263 | * Pass @new_policy to the cpufreq driver's ->verify() callback, run the | |
2264 | * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to | |
2265 | * the driver's ->verify() callback again and run the notifiers for it again | |
2266 | * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters | |
2267 | * of @new_policy to @policy and either invoke the driver's ->setpolicy() | |
2268 | * callback (if present) or carry out a governor update for @policy. That is, | |
2269 | * run the current governor's ->limits() callback (if the governor field in | |
2270 | * @new_policy points to the same object as the one in @policy) or replace the | |
2271 | * governor for @policy with the new one stored in @new_policy. | |
2272 | * | |
2273 | * The cpuinfo part of @policy is not updated by this function. | |
153d7f3f | 2274 | */ |
9083e498 RW |
2275 | int cpufreq_set_policy(struct cpufreq_policy *policy, |
2276 | struct cpufreq_policy *new_policy) | |
1da177e4 | 2277 | { |
d9a789c7 RW |
2278 | struct cpufreq_governor *old_gov; |
2279 | int ret; | |
1da177e4 | 2280 | |
e837f9b5 JP |
2281 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2282 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2283 | |
d5b73cd8 | 2284 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2285 | |
fba9573b PX |
2286 | /* |
2287 | * This check works well when we store new min/max freq attributes, | |
2288 | * because new_policy is a copy of policy with one field updated. | |
2289 | */ | |
2290 | if (new_policy->min > new_policy->max) | |
d9a789c7 | 2291 | return -EINVAL; |
9c9a43ed | 2292 | |
1da177e4 | 2293 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2294 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2295 | if (ret) |
d9a789c7 | 2296 | return ret; |
1da177e4 | 2297 | |
1da177e4 | 2298 | /* adjust if necessary - all reasons */ |
e041c683 | 2299 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2300 | CPUFREQ_ADJUST, new_policy); |
1da177e4 | 2301 | |
bb176f7d VK |
2302 | /* |
2303 | * verify the cpu speed can be set within this limit, which might be | |
2304 | * different to the first one | |
2305 | */ | |
3a3e9e06 | 2306 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2307 | if (ret) |
d9a789c7 | 2308 | return ret; |
1da177e4 LT |
2309 | |
2310 | /* notification of the new policy */ | |
e041c683 | 2311 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2312 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2313 | |
3a3e9e06 VK |
2314 | policy->min = new_policy->min; |
2315 | policy->max = new_policy->max; | |
601b2185 | 2316 | trace_cpu_frequency_limits(policy); |
1da177e4 | 2317 | |
e3c06236 SM |
2318 | policy->cached_target_freq = UINT_MAX; |
2319 | ||
2d06d8c4 | 2320 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2321 | policy->min, policy->max); |
1da177e4 | 2322 | |
1c3d85dd | 2323 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2324 | policy->policy = new_policy->policy; |
2d06d8c4 | 2325 | pr_debug("setting range\n"); |
167a38dc | 2326 | return cpufreq_driver->setpolicy(policy); |
d9a789c7 | 2327 | } |
1da177e4 | 2328 | |
0a300767 | 2329 | if (new_policy->governor == policy->governor) { |
2bb4059e | 2330 | pr_debug("governor limits update\n"); |
a92604b4 | 2331 | cpufreq_governor_limits(policy); |
d6ff44d6 | 2332 | return 0; |
0a300767 | 2333 | } |
7bd353a9 | 2334 | |
d9a789c7 RW |
2335 | pr_debug("governor switch\n"); |
2336 | ||
2337 | /* save old, working values */ | |
2338 | old_gov = policy->governor; | |
2339 | /* end old governor */ | |
2340 | if (old_gov) { | |
45482c70 | 2341 | cpufreq_stop_governor(policy); |
36be3418 | 2342 | cpufreq_exit_governor(policy); |
1da177e4 LT |
2343 | } |
2344 | ||
d9a789c7 RW |
2345 | /* start new governor */ |
2346 | policy->governor = new_policy->governor; | |
a92604b4 | 2347 | ret = cpufreq_init_governor(policy); |
4bc384ae | 2348 | if (!ret) { |
0a300767 RW |
2349 | ret = cpufreq_start_governor(policy); |
2350 | if (!ret) { | |
2bb4059e | 2351 | pr_debug("governor change\n"); |
531b5c9f | 2352 | sched_cpufreq_governor_change(policy, old_gov); |
0a300767 RW |
2353 | return 0; |
2354 | } | |
b7898fda | 2355 | cpufreq_exit_governor(policy); |
d9a789c7 RW |
2356 | } |
2357 | ||
2358 | /* new governor failed, so re-start old one */ | |
2359 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2360 | if (old_gov) { | |
2361 | policy->governor = old_gov; | |
a92604b4 | 2362 | if (cpufreq_init_governor(policy)) |
4bc384ae VK |
2363 | policy->governor = NULL; |
2364 | else | |
0a300767 | 2365 | cpufreq_start_governor(policy); |
d9a789c7 RW |
2366 | } |
2367 | ||
4bc384ae | 2368 | return ret; |
1da177e4 LT |
2369 | } |
2370 | ||
1da177e4 | 2371 | /** |
a0dbb819 RW |
2372 | * cpufreq_update_policy - Re-evaluate an existing cpufreq policy. |
2373 | * @cpu: CPU to re-evaluate the policy for. | |
1da177e4 | 2374 | * |
a0dbb819 RW |
2375 | * Update the current frequency for the cpufreq policy of @cpu and use |
2376 | * cpufreq_set_policy() to re-apply the min and max limits saved in the | |
2377 | * user_policy sub-structure of that policy, which triggers the evaluation | |
2378 | * of policy notifiers and the cpufreq driver's ->verify() callback for the | |
2379 | * policy in question, among other things. | |
1da177e4 | 2380 | */ |
30248fef | 2381 | void cpufreq_update_policy(unsigned int cpu) |
1da177e4 | 2382 | { |
540a3758 | 2383 | struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); |
3a3e9e06 | 2384 | struct cpufreq_policy new_policy; |
1da177e4 | 2385 | |
fefa8ff8 | 2386 | if (!policy) |
30248fef | 2387 | return; |
1da177e4 | 2388 | |
bb176f7d VK |
2389 | /* |
2390 | * BIOS might change freq behind our back | |
2391 | * -> ask driver for current freq and notify governors about a change | |
2392 | */ | |
348a2ec5 RW |
2393 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy && |
2394 | (cpufreq_suspended || WARN_ON(!cpufreq_update_current_freq(policy)))) | |
2395 | goto unlock; | |
30248fef | 2396 | |
348a2ec5 RW |
2397 | pr_debug("updating policy for CPU %u\n", cpu); |
2398 | memcpy(&new_policy, policy, sizeof(*policy)); | |
2399 | new_policy.min = policy->user_policy.min; | |
2400 | new_policy.max = policy->user_policy.max; | |
0961dd0d | 2401 | |
30248fef | 2402 | cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2403 | |
fefa8ff8 | 2404 | unlock: |
540a3758 | 2405 | cpufreq_cpu_release(policy); |
1da177e4 LT |
2406 | } |
2407 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2408 | ||
5a25e3f7 RW |
2409 | /** |
2410 | * cpufreq_update_limits - Update policy limits for a given CPU. | |
2411 | * @cpu: CPU to update the policy limits for. | |
2412 | * | |
2413 | * Invoke the driver's ->update_limits callback if present or call | |
2414 | * cpufreq_update_policy() for @cpu. | |
2415 | */ | |
2416 | void cpufreq_update_limits(unsigned int cpu) | |
2417 | { | |
2418 | if (cpufreq_driver->update_limits) | |
2419 | cpufreq_driver->update_limits(cpu); | |
2420 | else | |
2421 | cpufreq_update_policy(cpu); | |
2422 | } | |
2423 | EXPORT_SYMBOL_GPL(cpufreq_update_limits); | |
2424 | ||
6f19efc0 LM |
2425 | /********************************************************************* |
2426 | * BOOST * | |
2427 | *********************************************************************/ | |
2428 | static int cpufreq_boost_set_sw(int state) | |
2429 | { | |
6f19efc0 LM |
2430 | struct cpufreq_policy *policy; |
2431 | int ret = -EINVAL; | |
2432 | ||
f963735a | 2433 | for_each_active_policy(policy) { |
f8bfc116 VK |
2434 | if (!policy->freq_table) |
2435 | continue; | |
49f18560 | 2436 | |
f8bfc116 VK |
2437 | ret = cpufreq_frequency_table_cpuinfo(policy, |
2438 | policy->freq_table); | |
2439 | if (ret) { | |
2440 | pr_err("%s: Policy frequency update failed\n", | |
2441 | __func__); | |
2442 | break; | |
6f19efc0 | 2443 | } |
f8bfc116 VK |
2444 | |
2445 | down_write(&policy->rwsem); | |
2446 | policy->user_policy.max = policy->max; | |
2447 | cpufreq_governor_limits(policy); | |
2448 | up_write(&policy->rwsem); | |
6f19efc0 LM |
2449 | } |
2450 | ||
2451 | return ret; | |
2452 | } | |
2453 | ||
2454 | int cpufreq_boost_trigger_state(int state) | |
2455 | { | |
2456 | unsigned long flags; | |
2457 | int ret = 0; | |
2458 | ||
2459 | if (cpufreq_driver->boost_enabled == state) | |
2460 | return 0; | |
2461 | ||
2462 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2463 | cpufreq_driver->boost_enabled = state; | |
2464 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2465 | ||
2466 | ret = cpufreq_driver->set_boost(state); | |
2467 | if (ret) { | |
2468 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2469 | cpufreq_driver->boost_enabled = !state; | |
2470 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2471 | ||
e837f9b5 JP |
2472 | pr_err("%s: Cannot %s BOOST\n", |
2473 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2474 | } |
2475 | ||
2476 | return ret; | |
2477 | } | |
2478 | ||
41669da0 | 2479 | static bool cpufreq_boost_supported(void) |
6f19efc0 | 2480 | { |
89f98d7e | 2481 | return cpufreq_driver->set_boost; |
6f19efc0 | 2482 | } |
6f19efc0 | 2483 | |
44139ed4 VK |
2484 | static int create_boost_sysfs_file(void) |
2485 | { | |
2486 | int ret; | |
2487 | ||
c82bd444 | 2488 | ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2489 | if (ret) |
2490 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
2491 | __func__); | |
2492 | ||
2493 | return ret; | |
2494 | } | |
2495 | ||
2496 | static void remove_boost_sysfs_file(void) | |
2497 | { | |
2498 | if (cpufreq_boost_supported()) | |
c82bd444 | 2499 | sysfs_remove_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2500 | } |
2501 | ||
2502 | int cpufreq_enable_boost_support(void) | |
2503 | { | |
2504 | if (!cpufreq_driver) | |
2505 | return -EINVAL; | |
2506 | ||
2507 | if (cpufreq_boost_supported()) | |
2508 | return 0; | |
2509 | ||
7a6c79f2 | 2510 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; |
44139ed4 VK |
2511 | |
2512 | /* This will get removed on driver unregister */ | |
2513 | return create_boost_sysfs_file(); | |
2514 | } | |
2515 | EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support); | |
2516 | ||
6f19efc0 LM |
2517 | int cpufreq_boost_enabled(void) |
2518 | { | |
2519 | return cpufreq_driver->boost_enabled; | |
2520 | } | |
2521 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2522 | ||
1da177e4 LT |
2523 | /********************************************************************* |
2524 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2525 | *********************************************************************/ | |
27622b06 | 2526 | static enum cpuhp_state hp_online; |
1da177e4 | 2527 | |
c4a3fa26 CY |
2528 | static int cpuhp_cpufreq_online(unsigned int cpu) |
2529 | { | |
2530 | cpufreq_online(cpu); | |
2531 | ||
2532 | return 0; | |
2533 | } | |
2534 | ||
2535 | static int cpuhp_cpufreq_offline(unsigned int cpu) | |
2536 | { | |
2537 | cpufreq_offline(cpu); | |
2538 | ||
2539 | return 0; | |
2540 | } | |
2541 | ||
1da177e4 LT |
2542 | /** |
2543 | * cpufreq_register_driver - register a CPU Frequency driver | |
2544 | * @driver_data: A struct cpufreq_driver containing the values# | |
2545 | * submitted by the CPU Frequency driver. | |
2546 | * | |
bb176f7d | 2547 | * Registers a CPU Frequency driver to this core code. This code |
63af4055 | 2548 | * returns zero on success, -EEXIST when another driver got here first |
32ee8c3e | 2549 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2550 | * |
2551 | */ | |
221dee28 | 2552 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2553 | { |
2554 | unsigned long flags; | |
2555 | int ret; | |
2556 | ||
a7b422cd KRW |
2557 | if (cpufreq_disabled()) |
2558 | return -ENODEV; | |
2559 | ||
1da177e4 | 2560 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2561 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2562 | driver_data->target) || |
2563 | (driver_data->setpolicy && (driver_data->target_index || | |
1c03a2d0 | 2564 | driver_data->target)) || |
a9a22b57 | 2565 | (!driver_data->get_intermediate != !driver_data->target_intermediate) || |
91a12e91 | 2566 | (!driver_data->online != !driver_data->offline)) |
1da177e4 LT |
2567 | return -EINVAL; |
2568 | ||
2d06d8c4 | 2569 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 | 2570 | |
fdd320da | 2571 | /* Protect against concurrent CPU online/offline. */ |
a92551e4 | 2572 | cpus_read_lock(); |
fdd320da | 2573 | |
0d1857a1 | 2574 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2575 | if (cpufreq_driver) { |
0d1857a1 | 2576 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fdd320da RW |
2577 | ret = -EEXIST; |
2578 | goto out; | |
1da177e4 | 2579 | } |
1c3d85dd | 2580 | cpufreq_driver = driver_data; |
0d1857a1 | 2581 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2582 | |
bc68b7df VK |
2583 | if (driver_data->setpolicy) |
2584 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2585 | ||
7a6c79f2 RW |
2586 | if (cpufreq_boost_supported()) { |
2587 | ret = create_boost_sysfs_file(); | |
2588 | if (ret) | |
2589 | goto err_null_driver; | |
2590 | } | |
6f19efc0 | 2591 | |
8a25a2fd | 2592 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2593 | if (ret) |
6f19efc0 | 2594 | goto err_boost_unreg; |
1da177e4 | 2595 | |
ce1bcfe9 VK |
2596 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY) && |
2597 | list_empty(&cpufreq_policy_list)) { | |
1da177e4 | 2598 | /* if all ->init() calls failed, unregister */ |
6c770036 | 2599 | ret = -ENODEV; |
ce1bcfe9 VK |
2600 | pr_debug("%s: No CPU initialized for driver %s\n", __func__, |
2601 | driver_data->name); | |
2602 | goto err_if_unreg; | |
1da177e4 LT |
2603 | } |
2604 | ||
a92551e4 SAS |
2605 | ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, |
2606 | "cpufreq:online", | |
2607 | cpuhp_cpufreq_online, | |
2608 | cpuhp_cpufreq_offline); | |
27622b06 SAS |
2609 | if (ret < 0) |
2610 | goto err_if_unreg; | |
2611 | hp_online = ret; | |
5372e054 | 2612 | ret = 0; |
27622b06 | 2613 | |
2d06d8c4 | 2614 | pr_debug("driver %s up and running\n", driver_data->name); |
3834abb4 | 2615 | goto out; |
fdd320da | 2616 | |
8a25a2fd KS |
2617 | err_if_unreg: |
2618 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 | 2619 | err_boost_unreg: |
44139ed4 | 2620 | remove_boost_sysfs_file(); |
8f5bc2ab | 2621 | err_null_driver: |
0d1857a1 | 2622 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2623 | cpufreq_driver = NULL; |
0d1857a1 | 2624 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
3834abb4 | 2625 | out: |
a92551e4 | 2626 | cpus_read_unlock(); |
3834abb4 | 2627 | return ret; |
1da177e4 LT |
2628 | } |
2629 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2630 | ||
1da177e4 LT |
2631 | /** |
2632 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2633 | * | |
bb176f7d | 2634 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2635 | * the right to do so, i.e. if you have succeeded in initialising before! |
2636 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2637 | * currently not initialised. | |
2638 | */ | |
221dee28 | 2639 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2640 | { |
2641 | unsigned long flags; | |
2642 | ||
1c3d85dd | 2643 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2644 | return -EINVAL; |
1da177e4 | 2645 | |
2d06d8c4 | 2646 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2647 | |
454d3a25 | 2648 | /* Protect against concurrent cpu hotplug */ |
a92551e4 | 2649 | cpus_read_lock(); |
8a25a2fd | 2650 | subsys_interface_unregister(&cpufreq_interface); |
44139ed4 | 2651 | remove_boost_sysfs_file(); |
a92551e4 | 2652 | cpuhp_remove_state_nocalls_cpuslocked(hp_online); |
1da177e4 | 2653 | |
0d1857a1 | 2654 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2655 | |
1c3d85dd | 2656 | cpufreq_driver = NULL; |
6eed9404 | 2657 | |
0d1857a1 | 2658 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
a92551e4 | 2659 | cpus_read_unlock(); |
1da177e4 LT |
2660 | |
2661 | return 0; | |
2662 | } | |
2663 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 | 2664 | |
90de2a4a DA |
2665 | /* |
2666 | * Stop cpufreq at shutdown to make sure it isn't holding any locks | |
2667 | * or mutexes when secondary CPUs are halted. | |
2668 | */ | |
2669 | static struct syscore_ops cpufreq_syscore_ops = { | |
2670 | .shutdown = cpufreq_suspend, | |
2671 | }; | |
2672 | ||
c82bd444 VK |
2673 | struct kobject *cpufreq_global_kobject; |
2674 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
2675 | ||
5a01f2e8 VP |
2676 | static int __init cpufreq_core_init(void) |
2677 | { | |
a7b422cd KRW |
2678 | if (cpufreq_disabled()) |
2679 | return -ENODEV; | |
2680 | ||
8eec1020 | 2681 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 TR |
2682 | BUG_ON(!cpufreq_global_kobject); |
2683 | ||
90de2a4a DA |
2684 | register_syscore_ops(&cpufreq_syscore_ops); |
2685 | ||
5a01f2e8 VP |
2686 | return 0; |
2687 | } | |
d82f2692 | 2688 | module_param(off, int, 0444); |
5a01f2e8 | 2689 | core_initcall(cpufreq_core_init); |