Commit | Line | Data |
---|---|---|
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> |
67d874c3 | 29 | #include <linux/pm_qos.h> |
5ff0a268 | 30 | #include <linux/slab.h> |
2f0aea93 | 31 | #include <linux/suspend.h> |
90de2a4a | 32 | #include <linux/syscore_ops.h> |
5ff0a268 | 33 | #include <linux/tick.h> |
6f4f2723 TR |
34 | #include <trace/events/power.h> |
35 | ||
b4f0676f | 36 | static LIST_HEAD(cpufreq_policy_list); |
f963735a | 37 | |
f963735a | 38 | /* Macros to iterate over CPU policies */ |
fd7dc7e6 EB |
39 | #define for_each_suitable_policy(__policy, __active) \ |
40 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \ | |
41 | if ((__active) == !policy_is_inactive(__policy)) | |
f963735a VK |
42 | |
43 | #define for_each_active_policy(__policy) \ | |
44 | for_each_suitable_policy(__policy, true) | |
45 | #define for_each_inactive_policy(__policy) \ | |
46 | for_each_suitable_policy(__policy, false) | |
47 | ||
48 | #define for_each_policy(__policy) \ | |
b4f0676f VK |
49 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) |
50 | ||
f7b27061 VK |
51 | /* Iterate over governors */ |
52 | static LIST_HEAD(cpufreq_governor_list); | |
53 | #define for_each_governor(__governor) \ | |
54 | list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) | |
55 | ||
1da177e4 | 56 | /** |
cd878479 | 57 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
58 | * level driver of CPUFreq support, and its spinlock. This lock |
59 | * also protects the cpufreq_cpu_data array. | |
60 | */ | |
1c3d85dd | 61 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 62 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
bb176f7d | 63 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
bb176f7d | 64 | |
2f0aea93 VK |
65 | /* Flag to suspend/resume CPUFreq governors */ |
66 | static bool cpufreq_suspended; | |
1da177e4 | 67 | |
9c0ebcf7 VK |
68 | static inline bool has_target(void) |
69 | { | |
70 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
71 | } | |
72 | ||
1da177e4 | 73 | /* internal prototypes */ |
d92d50a4 | 74 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy); |
a92604b4 RW |
75 | static int cpufreq_init_governor(struct cpufreq_policy *policy); |
76 | static void cpufreq_exit_governor(struct cpufreq_policy *policy); | |
0a300767 | 77 | static int cpufreq_start_governor(struct cpufreq_policy *policy); |
a92604b4 RW |
78 | static void cpufreq_stop_governor(struct cpufreq_policy *policy); |
79 | static void cpufreq_governor_limits(struct cpufreq_policy *policy); | |
45482c70 | 80 | |
1da177e4 | 81 | /** |
32ee8c3e DJ |
82 | * Two notifier lists: the "policy" list is involved in the |
83 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
84 | * "transition" list for kernel code that needs to handle |
85 | * changes to devices when the CPU clock speed changes. | |
86 | * The mutex locks both lists. | |
87 | */ | |
e041c683 | 88 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
cc85de36 | 89 | SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list); |
1da177e4 | 90 | |
a7b422cd | 91 | static int off __read_mostly; |
da584455 | 92 | static int cpufreq_disabled(void) |
a7b422cd KRW |
93 | { |
94 | return off; | |
95 | } | |
96 | void disable_cpufreq(void) | |
97 | { | |
98 | off = 1; | |
99 | } | |
29464f28 | 100 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 101 | |
4d5dcc42 VK |
102 | bool have_governor_per_policy(void) |
103 | { | |
0b981e70 | 104 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 105 | } |
3f869d6d | 106 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 107 | |
944e9a03 VK |
108 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
109 | { | |
110 | if (have_governor_per_policy()) | |
111 | return &policy->kobj; | |
112 | else | |
113 | return cpufreq_global_kobject; | |
114 | } | |
115 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
116 | ||
72a4ce34 VK |
117 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
118 | { | |
119 | u64 idle_time; | |
120 | u64 cur_wall_time; | |
121 | u64 busy_time; | |
122 | ||
7fb1327e | 123 | cur_wall_time = jiffies64_to_nsecs(get_jiffies_64()); |
72a4ce34 VK |
124 | |
125 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
126 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
127 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
128 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
129 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
130 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
131 | ||
132 | idle_time = cur_wall_time - busy_time; | |
133 | if (wall) | |
7fb1327e | 134 | *wall = div_u64(cur_wall_time, NSEC_PER_USEC); |
72a4ce34 | 135 | |
7fb1327e | 136 | return div_u64(idle_time, NSEC_PER_USEC); |
72a4ce34 VK |
137 | } |
138 | ||
139 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
140 | { | |
141 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
142 | ||
143 | if (idle_time == -1ULL) | |
144 | return get_cpu_idle_time_jiffy(cpu, wall); | |
145 | else if (!io_busy) | |
146 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
147 | ||
148 | return idle_time; | |
149 | } | |
150 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
151 | ||
e7d5459d DE |
152 | __weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, |
153 | unsigned long max_freq) | |
154 | { | |
155 | } | |
156 | EXPORT_SYMBOL_GPL(arch_set_freq_scale); | |
157 | ||
70e9e778 VK |
158 | /* |
159 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
160 | * drivers of SMP systems. It will do following: | |
161 | * - validate & show freq table passed | |
162 | * - set policies transition latency | |
163 | * - policy->cpus with all possible CPUs | |
164 | */ | |
165 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
166 | struct cpufreq_frequency_table *table, | |
167 | unsigned int transition_latency) | |
168 | { | |
92c99d15 | 169 | policy->freq_table = table; |
70e9e778 VK |
170 | policy->cpuinfo.transition_latency = transition_latency; |
171 | ||
172 | /* | |
58405af6 | 173 | * The driver only supports the SMP configuration where all processors |
70e9e778 VK |
174 | * share the clock and voltage and clock. |
175 | */ | |
176 | cpumask_setall(policy->cpus); | |
177 | ||
178 | return 0; | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
181 | ||
1f0bd44e | 182 | struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) |
652ed95d VK |
183 | { |
184 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
185 | ||
988bed09 VK |
186 | return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL; |
187 | } | |
1f0bd44e | 188 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw); |
988bed09 VK |
189 | |
190 | unsigned int cpufreq_generic_get(unsigned int cpu) | |
191 | { | |
192 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); | |
193 | ||
652ed95d | 194 | if (!policy || IS_ERR(policy->clk)) { |
e837f9b5 JP |
195 | pr_err("%s: No %s associated to cpu: %d\n", |
196 | __func__, policy ? "clk" : "policy", cpu); | |
652ed95d VK |
197 | return 0; |
198 | } | |
199 | ||
200 | return clk_get_rate(policy->clk) / 1000; | |
201 | } | |
202 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
203 | ||
50e9c852 | 204 | /** |
5d094fea RW |
205 | * cpufreq_cpu_get - Return policy for a CPU and mark it as busy. |
206 | * @cpu: CPU to find the policy for. | |
50e9c852 | 207 | * |
5d094fea RW |
208 | * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment |
209 | * the kobject reference counter of that policy. Return a valid policy on | |
210 | * success or NULL on failure. | |
50e9c852 | 211 | * |
5d094fea RW |
212 | * The policy returned by this function has to be released with the help of |
213 | * cpufreq_cpu_put() to balance its kobject reference counter properly. | |
50e9c852 | 214 | */ |
6eed9404 | 215 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 216 | { |
6eed9404 | 217 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
218 | unsigned long flags; |
219 | ||
1b947c90 | 220 | if (WARN_ON(cpu >= nr_cpu_ids)) |
6eed9404 VK |
221 | return NULL; |
222 | ||
1da177e4 | 223 | /* get the cpufreq driver */ |
1c3d85dd | 224 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 225 | |
6eed9404 VK |
226 | if (cpufreq_driver) { |
227 | /* get the CPU */ | |
988bed09 | 228 | policy = cpufreq_cpu_get_raw(cpu); |
6eed9404 VK |
229 | if (policy) |
230 | kobject_get(&policy->kobj); | |
231 | } | |
1da177e4 | 232 | |
6eed9404 | 233 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 234 | |
3a3e9e06 | 235 | return policy; |
a9144436 | 236 | } |
1da177e4 LT |
237 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
238 | ||
50e9c852 | 239 | /** |
5d094fea RW |
240 | * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy. |
241 | * @policy: cpufreq policy returned by cpufreq_cpu_get(). | |
50e9c852 | 242 | */ |
3a3e9e06 | 243 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 244 | { |
6eed9404 | 245 | kobject_put(&policy->kobj); |
1da177e4 LT |
246 | } |
247 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
248 | ||
540a3758 RW |
249 | /** |
250 | * cpufreq_cpu_release - Unlock a policy and decrement its usage counter. | |
251 | * @policy: cpufreq policy returned by cpufreq_cpu_acquire(). | |
252 | */ | |
9083e498 | 253 | void cpufreq_cpu_release(struct cpufreq_policy *policy) |
540a3758 RW |
254 | { |
255 | if (WARN_ON(!policy)) | |
256 | return; | |
257 | ||
258 | lockdep_assert_held(&policy->rwsem); | |
259 | ||
260 | up_write(&policy->rwsem); | |
261 | ||
262 | cpufreq_cpu_put(policy); | |
263 | } | |
264 | ||
265 | /** | |
266 | * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it. | |
267 | * @cpu: CPU to find the policy for. | |
268 | * | |
269 | * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and | |
270 | * if the policy returned by it is not NULL, acquire its rwsem for writing. | |
271 | * Return the policy if it is active or release it and return NULL otherwise. | |
272 | * | |
273 | * The policy returned by this function has to be released with the help of | |
274 | * cpufreq_cpu_release() in order to release its rwsem and balance its usage | |
275 | * counter properly. | |
276 | */ | |
9083e498 | 277 | struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu) |
540a3758 RW |
278 | { |
279 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
280 | ||
281 | if (!policy) | |
282 | return NULL; | |
283 | ||
284 | down_write(&policy->rwsem); | |
285 | ||
286 | if (policy_is_inactive(policy)) { | |
287 | cpufreq_cpu_release(policy); | |
288 | return NULL; | |
289 | } | |
290 | ||
291 | return policy; | |
292 | } | |
293 | ||
1da177e4 LT |
294 | /********************************************************************* |
295 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
296 | *********************************************************************/ | |
297 | ||
298 | /** | |
299 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
300 | * | |
301 | * This function alters the system "loops_per_jiffy" for the clock | |
302 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 303 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
304 | * per-CPU loops_per_jiffy value wherever possible. |
305 | */ | |
858119e1 | 306 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 | 307 | { |
39c132ee VK |
308 | #ifndef CONFIG_SMP |
309 | static unsigned long l_p_j_ref; | |
310 | static unsigned int l_p_j_ref_freq; | |
311 | ||
1da177e4 LT |
312 | if (ci->flags & CPUFREQ_CONST_LOOPS) |
313 | return; | |
314 | ||
315 | if (!l_p_j_ref_freq) { | |
316 | l_p_j_ref = loops_per_jiffy; | |
317 | l_p_j_ref_freq = ci->old; | |
e837f9b5 JP |
318 | pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", |
319 | l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 | 320 | } |
0b443ead | 321 | if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { |
e08f5f5b GS |
322 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
323 | ci->new); | |
e837f9b5 JP |
324 | pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", |
325 | loops_per_jiffy, ci->new); | |
1da177e4 | 326 | } |
1da177e4 | 327 | #endif |
39c132ee | 328 | } |
1da177e4 | 329 | |
20b5324d VK |
330 | /** |
331 | * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies. | |
332 | * @policy: cpufreq policy to enable fast frequency switching for. | |
333 | * @freqs: contain details of the frequency update. | |
334 | * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. | |
335 | * | |
336 | * This function calls the transition notifiers and the "adjust_jiffies" | |
337 | * function. It is called twice on all CPU frequency changes that have | |
338 | * external effects. | |
339 | */ | |
340 | static void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
341 | struct cpufreq_freqs *freqs, | |
342 | unsigned int state) | |
1da177e4 | 343 | { |
df24014a VK |
344 | int cpu; |
345 | ||
1da177e4 LT |
346 | BUG_ON(irqs_disabled()); |
347 | ||
d5aaffa9 DB |
348 | if (cpufreq_disabled()) |
349 | return; | |
350 | ||
df24014a | 351 | freqs->policy = policy; |
1c3d85dd | 352 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 353 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e837f9b5 | 354 | state, freqs->new); |
1da177e4 | 355 | |
1da177e4 LT |
356 | switch (state) { |
357 | case CPUFREQ_PRECHANGE: | |
20b5324d VK |
358 | /* |
359 | * Detect if the driver reported a value as "old frequency" | |
e4472cb3 DJ |
360 | * which is not equal to what the cpufreq core thinks is |
361 | * "old frequency". | |
1da177e4 | 362 | */ |
98015228 VK |
363 | if (policy->cur && policy->cur != freqs->old) { |
364 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", | |
365 | freqs->old, policy->cur); | |
366 | freqs->old = policy->cur; | |
1da177e4 | 367 | } |
20b5324d | 368 | |
df24014a VK |
369 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
370 | CPUFREQ_PRECHANGE, freqs); | |
20b5324d | 371 | |
1da177e4 LT |
372 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
373 | break; | |
e4472cb3 | 374 | |
1da177e4 LT |
375 | case CPUFREQ_POSTCHANGE: |
376 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
20b5324d VK |
377 | pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new, |
378 | cpumask_pr_args(policy->cpus)); | |
379 | ||
df24014a VK |
380 | for_each_cpu(cpu, policy->cpus) |
381 | trace_cpu_frequency(freqs->new, cpu); | |
382 | ||
383 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
384 | CPUFREQ_POSTCHANGE, freqs); | |
20b5324d | 385 | |
1aefc75b | 386 | cpufreq_stats_record_transition(policy, freqs->new); |
20b5324d | 387 | policy->cur = freqs->new; |
1da177e4 | 388 | } |
1da177e4 | 389 | } |
bb176f7d | 390 | |
f7ba3b41 | 391 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 392 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
393 | struct cpufreq_freqs *freqs, int transition_failed) |
394 | { | |
395 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
396 | if (!transition_failed) | |
397 | return; | |
398 | ||
399 | swap(freqs->old, freqs->new); | |
400 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
401 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
402 | } | |
f7ba3b41 | 403 | |
12478cf0 SB |
404 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
405 | struct cpufreq_freqs *freqs) | |
406 | { | |
ca654dc3 SB |
407 | |
408 | /* | |
409 | * Catch double invocations of _begin() which lead to self-deadlock. | |
410 | * ASYNC_NOTIFICATION drivers are left out because the cpufreq core | |
411 | * doesn't invoke _begin() on their behalf, and hence the chances of | |
412 | * double invocations are very low. Moreover, there are scenarios | |
413 | * where these checks can emit false-positive warnings in these | |
414 | * drivers; so we avoid that by skipping them altogether. | |
415 | */ | |
416 | WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) | |
417 | && current == policy->transition_task); | |
418 | ||
12478cf0 SB |
419 | wait: |
420 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
421 | ||
422 | spin_lock(&policy->transition_lock); | |
423 | ||
424 | if (unlikely(policy->transition_ongoing)) { | |
425 | spin_unlock(&policy->transition_lock); | |
426 | goto wait; | |
427 | } | |
428 | ||
429 | policy->transition_ongoing = true; | |
ca654dc3 | 430 | policy->transition_task = current; |
12478cf0 SB |
431 | |
432 | spin_unlock(&policy->transition_lock); | |
433 | ||
434 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
435 | } | |
436 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
437 | ||
438 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
439 | struct cpufreq_freqs *freqs, int transition_failed) | |
440 | { | |
0e7ea2f3 | 441 | if (WARN_ON(!policy->transition_ongoing)) |
12478cf0 SB |
442 | return; |
443 | ||
444 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
445 | ||
446 | policy->transition_ongoing = false; | |
ca654dc3 | 447 | policy->transition_task = NULL; |
12478cf0 SB |
448 | |
449 | wake_up(&policy->transition_wait); | |
450 | } | |
451 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
452 | ||
b7898fda RW |
453 | /* |
454 | * Fast frequency switching status count. Positive means "enabled", negative | |
455 | * means "disabled" and 0 means "not decided yet". | |
456 | */ | |
457 | static int cpufreq_fast_switch_count; | |
458 | static DEFINE_MUTEX(cpufreq_fast_switch_lock); | |
459 | ||
460 | static void cpufreq_list_transition_notifiers(void) | |
461 | { | |
462 | struct notifier_block *nb; | |
463 | ||
464 | pr_info("Registered transition notifiers:\n"); | |
465 | ||
466 | mutex_lock(&cpufreq_transition_notifier_list.mutex); | |
467 | ||
468 | for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next) | |
d75f773c | 469 | pr_info("%pS\n", nb->notifier_call); |
b7898fda RW |
470 | |
471 | mutex_unlock(&cpufreq_transition_notifier_list.mutex); | |
472 | } | |
473 | ||
474 | /** | |
475 | * cpufreq_enable_fast_switch - Enable fast frequency switching for policy. | |
476 | * @policy: cpufreq policy to enable fast frequency switching for. | |
477 | * | |
478 | * Try to enable fast frequency switching for @policy. | |
479 | * | |
480 | * The attempt will fail if there is at least one transition notifier registered | |
481 | * at this point, as fast frequency switching is quite fundamentally at odds | |
482 | * with transition notifiers. Thus if successful, it will make registration of | |
483 | * transition notifiers fail going forward. | |
484 | */ | |
485 | void cpufreq_enable_fast_switch(struct cpufreq_policy *policy) | |
486 | { | |
487 | lockdep_assert_held(&policy->rwsem); | |
488 | ||
489 | if (!policy->fast_switch_possible) | |
490 | return; | |
491 | ||
492 | mutex_lock(&cpufreq_fast_switch_lock); | |
493 | if (cpufreq_fast_switch_count >= 0) { | |
494 | cpufreq_fast_switch_count++; | |
495 | policy->fast_switch_enabled = true; | |
496 | } else { | |
497 | pr_warn("CPU%u: Fast frequency switching not enabled\n", | |
498 | policy->cpu); | |
499 | cpufreq_list_transition_notifiers(); | |
500 | } | |
501 | mutex_unlock(&cpufreq_fast_switch_lock); | |
502 | } | |
503 | EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); | |
504 | ||
6c9d9c81 RW |
505 | /** |
506 | * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. | |
507 | * @policy: cpufreq policy to disable fast frequency switching for. | |
508 | */ | |
509 | void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) | |
b7898fda RW |
510 | { |
511 | mutex_lock(&cpufreq_fast_switch_lock); | |
512 | if (policy->fast_switch_enabled) { | |
513 | policy->fast_switch_enabled = false; | |
514 | if (!WARN_ON(cpufreq_fast_switch_count <= 0)) | |
515 | cpufreq_fast_switch_count--; | |
516 | } | |
517 | mutex_unlock(&cpufreq_fast_switch_lock); | |
518 | } | |
6c9d9c81 | 519 | EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); |
1da177e4 | 520 | |
e3c06236 SM |
521 | /** |
522 | * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported | |
523 | * one. | |
524 | * @target_freq: target frequency to resolve. | |
525 | * | |
526 | * The target to driver frequency mapping is cached in the policy. | |
527 | * | |
528 | * Return: Lowest driver-supported frequency greater than or equal to the | |
529 | * given target_freq, subject to policy (min/max) and driver limitations. | |
530 | */ | |
531 | unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, | |
532 | unsigned int target_freq) | |
533 | { | |
534 | target_freq = clamp_val(target_freq, policy->min, policy->max); | |
535 | policy->cached_target_freq = target_freq; | |
abe8bd02 VK |
536 | |
537 | if (cpufreq_driver->target_index) { | |
538 | int idx; | |
539 | ||
540 | idx = cpufreq_frequency_table_target(policy, target_freq, | |
541 | CPUFREQ_RELATION_L); | |
542 | policy->cached_resolved_idx = idx; | |
543 | return policy->freq_table[idx].frequency; | |
544 | } | |
545 | ||
e3c06236 SM |
546 | if (cpufreq_driver->resolve_freq) |
547 | return cpufreq_driver->resolve_freq(policy, target_freq); | |
abe8bd02 VK |
548 | |
549 | return target_freq; | |
e3c06236 | 550 | } |
ae2c1ca6 | 551 | EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); |
e3c06236 | 552 | |
aa7519af VK |
553 | unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy) |
554 | { | |
555 | unsigned int latency; | |
556 | ||
557 | if (policy->transition_delay_us) | |
558 | return policy->transition_delay_us; | |
559 | ||
560 | latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC; | |
e948bc8f VK |
561 | if (latency) { |
562 | /* | |
563 | * For platforms that can change the frequency very fast (< 10 | |
564 | * us), the above formula gives a decent transition delay. But | |
565 | * for platforms where transition_latency is in milliseconds, it | |
566 | * ends up giving unrealistic values. | |
567 | * | |
568 | * Cap the default transition delay to 10 ms, which seems to be | |
569 | * a reasonable amount of time after which we should reevaluate | |
570 | * the frequency. | |
571 | */ | |
572 | return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000); | |
573 | } | |
aa7519af VK |
574 | |
575 | return LATENCY_MULTIPLIER; | |
576 | } | |
577 | EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us); | |
578 | ||
1da177e4 LT |
579 | /********************************************************************* |
580 | * SYSFS INTERFACE * | |
581 | *********************************************************************/ | |
8a5c74a1 | 582 | static ssize_t show_boost(struct kobject *kobj, |
625c85a6 | 583 | struct kobj_attribute *attr, char *buf) |
6f19efc0 LM |
584 | { |
585 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
586 | } | |
587 | ||
625c85a6 VK |
588 | static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr, |
589 | const char *buf, size_t count) | |
6f19efc0 LM |
590 | { |
591 | int ret, enable; | |
592 | ||
593 | ret = sscanf(buf, "%d", &enable); | |
594 | if (ret != 1 || enable < 0 || enable > 1) | |
595 | return -EINVAL; | |
596 | ||
597 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
598 | pr_err("%s: Cannot %s BOOST!\n", |
599 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
600 | return -EINVAL; |
601 | } | |
602 | ||
e837f9b5 JP |
603 | pr_debug("%s: cpufreq BOOST %s\n", |
604 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
605 | |
606 | return count; | |
607 | } | |
608 | define_one_global_rw(boost); | |
1da177e4 | 609 | |
42f91fa1 | 610 | static struct cpufreq_governor *find_governor(const char *str_governor) |
3bcb09a3 JF |
611 | { |
612 | struct cpufreq_governor *t; | |
613 | ||
f7b27061 | 614 | for_each_governor(t) |
7c4f4539 | 615 | if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
616 | return t; |
617 | ||
618 | return NULL; | |
619 | } | |
620 | ||
ab05d97a YH |
621 | static int cpufreq_parse_policy(char *str_governor, |
622 | struct cpufreq_policy *policy) | |
623 | { | |
624 | if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
625 | policy->policy = CPUFREQ_POLICY_PERFORMANCE; | |
626 | return 0; | |
627 | } | |
628 | if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { | |
629 | policy->policy = CPUFREQ_POLICY_POWERSAVE; | |
630 | return 0; | |
631 | } | |
632 | return -EINVAL; | |
633 | } | |
634 | ||
1da177e4 | 635 | /** |
5ddc6d4e | 636 | * cpufreq_parse_governor - parse a governor string only for has_target() |
1da177e4 | 637 | */ |
ae0ff89f RW |
638 | static int cpufreq_parse_governor(char *str_governor, |
639 | struct cpufreq_policy *policy) | |
1da177e4 | 640 | { |
ab05d97a | 641 | struct cpufreq_governor *t; |
045149e6 | 642 | |
ab05d97a | 643 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 | 644 | |
ab05d97a YH |
645 | t = find_governor(str_governor); |
646 | if (!t) { | |
647 | int ret; | |
3bcb09a3 | 648 | |
ab05d97a | 649 | mutex_unlock(&cpufreq_governor_mutex); |
045149e6 | 650 | |
ab05d97a YH |
651 | ret = request_module("cpufreq_%s", str_governor); |
652 | if (ret) | |
653 | return -EINVAL; | |
045149e6 | 654 | |
ab05d97a | 655 | mutex_lock(&cpufreq_governor_mutex); |
ea714970 | 656 | |
ab05d97a YH |
657 | t = find_governor(str_governor); |
658 | } | |
659 | if (t && !try_module_get(t->owner)) | |
660 | t = NULL; | |
ea714970 | 661 | |
ab05d97a | 662 | mutex_unlock(&cpufreq_governor_mutex); |
045149e6 | 663 | |
ab05d97a YH |
664 | if (t) { |
665 | policy->governor = t; | |
666 | return 0; | |
1da177e4 | 667 | } |
045149e6 RW |
668 | |
669 | return -EINVAL; | |
1da177e4 | 670 | } |
1da177e4 | 671 | |
1da177e4 | 672 | /** |
e08f5f5b GS |
673 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
674 | * print out cpufreq information | |
1da177e4 LT |
675 | * |
676 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
677 | * "unsigned int". | |
678 | */ | |
679 | ||
32ee8c3e DJ |
680 | #define show_one(file_name, object) \ |
681 | static ssize_t show_##file_name \ | |
905d77cd | 682 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 683 | { \ |
29464f28 | 684 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
685 | } |
686 | ||
687 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
688 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 689 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
690 | show_one(scaling_min_freq, min); |
691 | show_one(scaling_max_freq, max); | |
c034b02e | 692 | |
f8475cef LB |
693 | __weak unsigned int arch_freq_get_on_cpu(int cpu) |
694 | { | |
695 | return 0; | |
696 | } | |
697 | ||
09347b29 | 698 | static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) |
c034b02e DB |
699 | { |
700 | ssize_t ret; | |
f8475cef | 701 | unsigned int freq; |
c034b02e | 702 | |
f8475cef LB |
703 | freq = arch_freq_get_on_cpu(policy->cpu); |
704 | if (freq) | |
705 | ret = sprintf(buf, "%u\n", freq); | |
706 | else if (cpufreq_driver && cpufreq_driver->setpolicy && | |
707 | cpufreq_driver->get) | |
c034b02e DB |
708 | ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); |
709 | else | |
710 | ret = sprintf(buf, "%u\n", policy->cur); | |
711 | return ret; | |
712 | } | |
1da177e4 LT |
713 | |
714 | /** | |
715 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
716 | */ | |
717 | #define store_one(file_name, object) \ | |
718 | static ssize_t store_##file_name \ | |
905d77cd | 719 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 720 | { \ |
18c49926 VK |
721 | unsigned long val; \ |
722 | int ret; \ | |
1da177e4 | 723 | \ |
18c49926 | 724 | ret = sscanf(buf, "%lu", &val); \ |
1da177e4 LT |
725 | if (ret != 1) \ |
726 | return -EINVAL; \ | |
727 | \ | |
18c49926 VK |
728 | ret = dev_pm_qos_update_request(policy->object##_freq_req, val);\ |
729 | return ret >= 0 ? count : ret; \ | |
1da177e4 LT |
730 | } |
731 | ||
29464f28 DJ |
732 | store_one(scaling_min_freq, min); |
733 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
734 | |
735 | /** | |
736 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
737 | */ | |
905d77cd DJ |
738 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
739 | char *buf) | |
1da177e4 | 740 | { |
d92d50a4 | 741 | unsigned int cur_freq = __cpufreq_get(policy); |
9b4f603e RW |
742 | |
743 | if (cur_freq) | |
744 | return sprintf(buf, "%u\n", cur_freq); | |
745 | ||
746 | return sprintf(buf, "<unknown>\n"); | |
1da177e4 LT |
747 | } |
748 | ||
1da177e4 LT |
749 | /** |
750 | * show_scaling_governor - show the current policy for the specified CPU | |
751 | */ | |
905d77cd | 752 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 753 | { |
29464f28 | 754 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
755 | return sprintf(buf, "powersave\n"); |
756 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
757 | return sprintf(buf, "performance\n"); | |
758 | else if (policy->governor) | |
4b972f0b | 759 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 760 | policy->governor->name); |
1da177e4 LT |
761 | return -EINVAL; |
762 | } | |
763 | ||
1da177e4 LT |
764 | /** |
765 | * store_scaling_governor - store policy for the specified CPU | |
766 | */ | |
905d77cd DJ |
767 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
768 | const char *buf, size_t count) | |
1da177e4 | 769 | { |
5136fa56 | 770 | int ret; |
1da177e4 LT |
771 | char str_governor[16]; |
772 | struct cpufreq_policy new_policy; | |
773 | ||
8fa5b631 | 774 | memcpy(&new_policy, policy, sizeof(*policy)); |
1da177e4 | 775 | |
29464f28 | 776 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
777 | if (ret != 1) |
778 | return -EINVAL; | |
779 | ||
ab05d97a YH |
780 | if (cpufreq_driver->setpolicy) { |
781 | if (cpufreq_parse_policy(str_governor, &new_policy)) | |
782 | return -EINVAL; | |
783 | } else { | |
784 | if (cpufreq_parse_governor(str_governor, &new_policy)) | |
785 | return -EINVAL; | |
786 | } | |
1da177e4 | 787 | |
037ce839 | 788 | ret = cpufreq_set_policy(policy, &new_policy); |
a8b149d3 RW |
789 | |
790 | if (new_policy.governor) | |
791 | module_put(new_policy.governor->owner); | |
792 | ||
88dc4384 | 793 | return ret ? ret : count; |
1da177e4 LT |
794 | } |
795 | ||
796 | /** | |
797 | * show_scaling_driver - show the cpufreq driver currently loaded | |
798 | */ | |
905d77cd | 799 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 800 | { |
1c3d85dd | 801 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
802 | } |
803 | ||
804 | /** | |
805 | * show_scaling_available_governors - show the available CPUfreq governors | |
806 | */ | |
905d77cd DJ |
807 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
808 | char *buf) | |
1da177e4 LT |
809 | { |
810 | ssize_t i = 0; | |
811 | struct cpufreq_governor *t; | |
812 | ||
9c0ebcf7 | 813 | if (!has_target()) { |
1da177e4 LT |
814 | i += sprintf(buf, "performance powersave"); |
815 | goto out; | |
816 | } | |
817 | ||
f7b27061 | 818 | for_each_governor(t) { |
29464f28 DJ |
819 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
820 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 821 | goto out; |
4b972f0b | 822 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 823 | } |
7d5e350f | 824 | out: |
1da177e4 LT |
825 | i += sprintf(&buf[i], "\n"); |
826 | return i; | |
827 | } | |
e8628dd0 | 828 | |
f4fd3797 | 829 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
830 | { |
831 | ssize_t i = 0; | |
832 | unsigned int cpu; | |
833 | ||
835481d9 | 834 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
835 | if (i) |
836 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
837 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
838 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 839 | break; |
1da177e4 LT |
840 | } |
841 | i += sprintf(&buf[i], "\n"); | |
842 | return i; | |
843 | } | |
f4fd3797 | 844 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 845 | |
e8628dd0 DW |
846 | /** |
847 | * show_related_cpus - show the CPUs affected by each transition even if | |
848 | * hw coordination is in use | |
849 | */ | |
850 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
851 | { | |
f4fd3797 | 852 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
853 | } |
854 | ||
855 | /** | |
856 | * show_affected_cpus - show the CPUs affected by each transition | |
857 | */ | |
858 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
859 | { | |
f4fd3797 | 860 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
861 | } |
862 | ||
9e76988e | 863 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 864 | const char *buf, size_t count) |
9e76988e VP |
865 | { |
866 | unsigned int freq = 0; | |
867 | unsigned int ret; | |
868 | ||
879000f9 | 869 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
870 | return -EINVAL; |
871 | ||
872 | ret = sscanf(buf, "%u", &freq); | |
873 | if (ret != 1) | |
874 | return -EINVAL; | |
875 | ||
876 | policy->governor->store_setspeed(policy, freq); | |
877 | ||
878 | return count; | |
879 | } | |
880 | ||
881 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
882 | { | |
879000f9 | 883 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
884 | return sprintf(buf, "<unsupported>\n"); |
885 | ||
886 | return policy->governor->show_setspeed(policy, buf); | |
887 | } | |
1da177e4 | 888 | |
e2f74f35 | 889 | /** |
8bf1ac72 | 890 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
891 | */ |
892 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
893 | { | |
894 | unsigned int limit; | |
895 | int ret; | |
b23aa311 YH |
896 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); |
897 | if (!ret) | |
898 | return sprintf(buf, "%u\n", limit); | |
e2f74f35 TR |
899 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); |
900 | } | |
901 | ||
6dad2a29 BP |
902 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
903 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
904 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
905 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
906 | cpufreq_freq_attr_ro(scaling_available_governors); | |
907 | cpufreq_freq_attr_ro(scaling_driver); | |
908 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
909 | cpufreq_freq_attr_ro(bios_limit); | |
910 | cpufreq_freq_attr_ro(related_cpus); | |
911 | cpufreq_freq_attr_ro(affected_cpus); | |
912 | cpufreq_freq_attr_rw(scaling_min_freq); | |
913 | cpufreq_freq_attr_rw(scaling_max_freq); | |
914 | cpufreq_freq_attr_rw(scaling_governor); | |
915 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 916 | |
905d77cd | 917 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
918 | &cpuinfo_min_freq.attr, |
919 | &cpuinfo_max_freq.attr, | |
ed129784 | 920 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
921 | &scaling_min_freq.attr, |
922 | &scaling_max_freq.attr, | |
923 | &affected_cpus.attr, | |
e8628dd0 | 924 | &related_cpus.attr, |
1da177e4 LT |
925 | &scaling_governor.attr, |
926 | &scaling_driver.attr, | |
927 | &scaling_available_governors.attr, | |
9e76988e | 928 | &scaling_setspeed.attr, |
1da177e4 LT |
929 | NULL |
930 | }; | |
931 | ||
29464f28 DJ |
932 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
933 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 934 | |
29464f28 | 935 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 936 | { |
905d77cd DJ |
937 | struct cpufreq_policy *policy = to_policy(kobj); |
938 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 939 | ssize_t ret; |
6eed9404 | 940 | |
ad7722da | 941 | down_read(&policy->rwsem); |
6541aef0 | 942 | ret = fattr->show(policy, buf); |
ad7722da | 943 | up_read(&policy->rwsem); |
1b750e3b | 944 | |
1da177e4 LT |
945 | return ret; |
946 | } | |
947 | ||
905d77cd DJ |
948 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
949 | const char *buf, size_t count) | |
1da177e4 | 950 | { |
905d77cd DJ |
951 | struct cpufreq_policy *policy = to_policy(kobj); |
952 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 953 | ssize_t ret = -EINVAL; |
6eed9404 | 954 | |
9b3d9bb3 WL |
955 | /* |
956 | * cpus_read_trylock() is used here to work around a circular lock | |
957 | * dependency problem with respect to the cpufreq_register_driver(). | |
958 | */ | |
959 | if (!cpus_read_trylock()) | |
960 | return -EBUSY; | |
4f750c93 | 961 | |
6541aef0 RW |
962 | if (cpu_online(policy->cpu)) { |
963 | down_write(&policy->rwsem); | |
e08f5f5b | 964 | ret = fattr->store(policy, buf, count); |
6541aef0 RW |
965 | up_write(&policy->rwsem); |
966 | } | |
e08f5f5b | 967 | |
a92551e4 | 968 | cpus_read_unlock(); |
4f750c93 | 969 | |
1da177e4 LT |
970 | return ret; |
971 | } | |
972 | ||
905d77cd | 973 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 974 | { |
905d77cd | 975 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 976 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
977 | complete(&policy->kobj_unregister); |
978 | } | |
979 | ||
52cf25d0 | 980 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
981 | .show = show, |
982 | .store = store, | |
983 | }; | |
984 | ||
985 | static struct kobj_type ktype_cpufreq = { | |
986 | .sysfs_ops = &sysfs_ops, | |
987 | .default_attrs = default_attrs, | |
988 | .release = cpufreq_sysfs_release, | |
989 | }; | |
990 | ||
2f0ba790 | 991 | static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) |
87549141 | 992 | { |
2f0ba790 RW |
993 | struct device *dev = get_cpu_device(cpu); |
994 | ||
67d874c3 | 995 | if (unlikely(!dev)) |
2f0ba790 RW |
996 | return; |
997 | ||
998 | if (cpumask_test_and_set_cpu(cpu, policy->real_cpus)) | |
999 | return; | |
1000 | ||
26619804 | 1001 | dev_dbg(dev, "%s: Adding symlink\n", __func__); |
2f0ba790 RW |
1002 | if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq")) |
1003 | dev_err(dev, "cpufreq symlink creation failed\n"); | |
87549141 VK |
1004 | } |
1005 | ||
26619804 VK |
1006 | static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, |
1007 | struct device *dev) | |
87549141 | 1008 | { |
26619804 VK |
1009 | dev_dbg(dev, "%s: Removing symlink\n", __func__); |
1010 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
87549141 VK |
1011 | } |
1012 | ||
d9612a49 | 1013 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) |
909a694e DJ |
1014 | { |
1015 | struct freq_attr **drv_attr; | |
909a694e | 1016 | int ret = 0; |
909a694e | 1017 | |
909a694e | 1018 | /* set up files for this cpu device */ |
1c3d85dd | 1019 | drv_attr = cpufreq_driver->attr; |
f13f1184 | 1020 | while (drv_attr && *drv_attr) { |
909a694e DJ |
1021 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
1022 | if (ret) | |
6d4e81ed | 1023 | return ret; |
909a694e DJ |
1024 | drv_attr++; |
1025 | } | |
1c3d85dd | 1026 | if (cpufreq_driver->get) { |
909a694e DJ |
1027 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
1028 | if (ret) | |
6d4e81ed | 1029 | return ret; |
909a694e | 1030 | } |
c034b02e DB |
1031 | |
1032 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
1033 | if (ret) | |
6d4e81ed | 1034 | return ret; |
c034b02e | 1035 | |
1c3d85dd | 1036 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
1037 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
1038 | if (ret) | |
6d4e81ed | 1039 | return ret; |
e2f74f35 | 1040 | } |
909a694e | 1041 | |
26619804 | 1042 | return 0; |
e18f1682 SB |
1043 | } |
1044 | ||
de1df26b RW |
1045 | __weak struct cpufreq_governor *cpufreq_default_governor(void) |
1046 | { | |
1047 | return NULL; | |
1048 | } | |
1049 | ||
7f0fa40f | 1050 | static int cpufreq_init_policy(struct cpufreq_policy *policy) |
e18f1682 | 1051 | { |
ab05d97a | 1052 | struct cpufreq_governor *gov = NULL, *def_gov = NULL; |
e18f1682 | 1053 | struct cpufreq_policy new_policy; |
e18f1682 | 1054 | |
d5b73cd8 | 1055 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 1056 | |
ab05d97a YH |
1057 | def_gov = cpufreq_default_governor(); |
1058 | ||
1059 | if (has_target()) { | |
1060 | /* | |
1061 | * Update governor of new_policy to the governor used before | |
1062 | * hotplug | |
1063 | */ | |
1064 | gov = find_governor(policy->last_governor); | |
1065 | if (gov) { | |
1066 | pr_debug("Restoring governor %s for cpu %d\n", | |
6e2c89d1 | 1067 | policy->governor->name, policy->cpu); |
ab05d97a YH |
1068 | } else { |
1069 | if (!def_gov) | |
1070 | return -ENODATA; | |
1071 | gov = def_gov; | |
1072 | } | |
1073 | new_policy.governor = gov; | |
de1df26b | 1074 | } else { |
ab05d97a YH |
1075 | /* Use the default policy if there is no last_policy. */ |
1076 | if (policy->last_policy) { | |
69030dd1 | 1077 | new_policy.policy = policy->last_policy; |
ab05d97a YH |
1078 | } else { |
1079 | if (!def_gov) | |
1080 | return -ENODATA; | |
1081 | cpufreq_parse_policy(def_gov->name, &new_policy); | |
1082 | } | |
69030dd1 | 1083 | } |
ab05d97a | 1084 | |
7f0fa40f | 1085 | return cpufreq_set_policy(policy, &new_policy); |
909a694e DJ |
1086 | } |
1087 | ||
d9612a49 | 1088 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
fcf80582 | 1089 | { |
9c0ebcf7 | 1090 | int ret = 0; |
fcf80582 | 1091 | |
bb29ae15 VK |
1092 | /* Has this CPU been taken care of already? */ |
1093 | if (cpumask_test_cpu(cpu, policy->cpus)) | |
1094 | return 0; | |
1095 | ||
49f18560 | 1096 | down_write(&policy->rwsem); |
45482c70 RW |
1097 | if (has_target()) |
1098 | cpufreq_stop_governor(policy); | |
fcf80582 | 1099 | |
fcf80582 | 1100 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 1101 | |
9c0ebcf7 | 1102 | if (has_target()) { |
0a300767 | 1103 | ret = cpufreq_start_governor(policy); |
49f18560 | 1104 | if (ret) |
3de9bdeb | 1105 | pr_err("%s: Failed to start governor\n", __func__); |
820c6ca2 | 1106 | } |
49f18560 VK |
1107 | up_write(&policy->rwsem); |
1108 | return ret; | |
fcf80582 | 1109 | } |
1da177e4 | 1110 | |
c57b25bd | 1111 | void refresh_frequency_limits(struct cpufreq_policy *policy) |
70a59fde | 1112 | { |
67d874c3 | 1113 | struct cpufreq_policy new_policy; |
70a59fde | 1114 | |
67d874c3 VK |
1115 | if (!policy_is_inactive(policy)) { |
1116 | new_policy = *policy; | |
1117 | pr_debug("updating policy for CPU %u\n", policy->cpu); | |
70a59fde | 1118 | |
67d874c3 VK |
1119 | cpufreq_set_policy(policy, &new_policy); |
1120 | } | |
70a59fde | 1121 | } |
c57b25bd | 1122 | EXPORT_SYMBOL(refresh_frequency_limits); |
70a59fde | 1123 | |
11eb69b9 VK |
1124 | static void handle_update(struct work_struct *work) |
1125 | { | |
1126 | struct cpufreq_policy *policy = | |
1127 | container_of(work, struct cpufreq_policy, update); | |
70a59fde VK |
1128 | |
1129 | pr_debug("handle_update for cpu %u called\n", policy->cpu); | |
67d874c3 | 1130 | down_write(&policy->rwsem); |
70a59fde | 1131 | refresh_frequency_limits(policy); |
67d874c3 VK |
1132 | up_write(&policy->rwsem); |
1133 | } | |
1134 | ||
1135 | static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq, | |
1136 | void *data) | |
1137 | { | |
1138 | struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min); | |
1139 | ||
1140 | schedule_work(&policy->update); | |
1141 | return 0; | |
1142 | } | |
1143 | ||
1144 | static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq, | |
1145 | void *data) | |
1146 | { | |
1147 | struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max); | |
1148 | ||
1149 | schedule_work(&policy->update); | |
1150 | return 0; | |
1151 | } | |
1152 | ||
1153 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) | |
1154 | { | |
1155 | struct kobject *kobj; | |
1156 | struct completion *cmp; | |
1157 | ||
1158 | down_write(&policy->rwsem); | |
1159 | cpufreq_stats_free_table(policy); | |
1160 | kobj = &policy->kobj; | |
1161 | cmp = &policy->kobj_unregister; | |
1162 | up_write(&policy->rwsem); | |
1163 | kobject_put(kobj); | |
1164 | ||
1165 | /* | |
1166 | * We need to make sure that the underlying kobj is | |
1167 | * actually not referenced anymore by anybody before we | |
1168 | * proceed with unloading. | |
1169 | */ | |
1170 | pr_debug("waiting for dropping of refcount\n"); | |
1171 | wait_for_completion(cmp); | |
1172 | pr_debug("wait complete\n"); | |
fcf80582 | 1173 | } |
1da177e4 | 1174 | |
a34e63b1 | 1175 | static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) |
e9698cc5 SB |
1176 | { |
1177 | struct cpufreq_policy *policy; | |
67d874c3 | 1178 | struct device *dev = get_cpu_device(cpu); |
edd4a893 | 1179 | int ret; |
e9698cc5 | 1180 | |
67d874c3 VK |
1181 | if (!dev) |
1182 | return NULL; | |
1183 | ||
e9698cc5 SB |
1184 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); |
1185 | if (!policy) | |
1186 | return NULL; | |
1187 | ||
1188 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1189 | goto err_free_policy; | |
1190 | ||
1191 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1192 | goto err_free_cpumask; | |
1193 | ||
559ed407 RW |
1194 | if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) |
1195 | goto err_free_rcpumask; | |
1196 | ||
edd4a893 VK |
1197 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
1198 | cpufreq_global_kobject, "policy%u", cpu); | |
1199 | if (ret) { | |
67d874c3 | 1200 | dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret); |
2acb9bda RW |
1201 | /* |
1202 | * The entire policy object will be freed below, but the extra | |
1203 | * memory allocated for the kobject name needs to be freed by | |
1204 | * releasing the kobject. | |
1205 | */ | |
4ebe36c9 | 1206 | kobject_put(&policy->kobj); |
edd4a893 VK |
1207 | goto err_free_real_cpus; |
1208 | } | |
1209 | ||
67d874c3 VK |
1210 | policy->nb_min.notifier_call = cpufreq_notifier_min; |
1211 | policy->nb_max.notifier_call = cpufreq_notifier_max; | |
1212 | ||
1213 | ret = dev_pm_qos_add_notifier(dev, &policy->nb_min, | |
1214 | DEV_PM_QOS_MIN_FREQUENCY); | |
1215 | if (ret) { | |
1216 | dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n", | |
1217 | ret, cpumask_pr_args(policy->cpus)); | |
1218 | goto err_kobj_remove; | |
1219 | } | |
1220 | ||
1221 | ret = dev_pm_qos_add_notifier(dev, &policy->nb_max, | |
1222 | DEV_PM_QOS_MAX_FREQUENCY); | |
1223 | if (ret) { | |
1224 | dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n", | |
1225 | ret, cpumask_pr_args(policy->cpus)); | |
1226 | goto err_min_qos_notifier; | |
1227 | } | |
1228 | ||
c88a1f8b | 1229 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1230 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1231 | spin_lock_init(&policy->transition_lock); |
1232 | init_waitqueue_head(&policy->transition_wait); | |
818c5712 VK |
1233 | init_completion(&policy->kobj_unregister); |
1234 | INIT_WORK(&policy->update, handle_update); | |
ad7722da | 1235 | |
a34e63b1 | 1236 | policy->cpu = cpu; |
e9698cc5 SB |
1237 | return policy; |
1238 | ||
67d874c3 VK |
1239 | err_min_qos_notifier: |
1240 | dev_pm_qos_remove_notifier(dev, &policy->nb_min, | |
1241 | DEV_PM_QOS_MIN_FREQUENCY); | |
1242 | err_kobj_remove: | |
1243 | cpufreq_policy_put_kobj(policy); | |
edd4a893 VK |
1244 | err_free_real_cpus: |
1245 | free_cpumask_var(policy->real_cpus); | |
2fc3384d VK |
1246 | err_free_rcpumask: |
1247 | free_cpumask_var(policy->related_cpus); | |
e9698cc5 SB |
1248 | err_free_cpumask: |
1249 | free_cpumask_var(policy->cpus); | |
1250 | err_free_policy: | |
1251 | kfree(policy); | |
1252 | ||
1253 | return NULL; | |
1254 | } | |
1255 | ||
f9f41e3e | 1256 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
e9698cc5 | 1257 | { |
67d874c3 | 1258 | struct device *dev = get_cpu_device(policy->cpu); |
988bed09 VK |
1259 | unsigned long flags; |
1260 | int cpu; | |
1261 | ||
1262 | /* Remove policy from list */ | |
1263 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1264 | list_del(&policy->policy_list); | |
1265 | ||
1266 | for_each_cpu(cpu, policy->related_cpus) | |
1267 | per_cpu(cpufreq_cpu_data, cpu) = NULL; | |
1268 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1269 | ||
67d874c3 VK |
1270 | dev_pm_qos_remove_notifier(dev, &policy->nb_max, |
1271 | DEV_PM_QOS_MAX_FREQUENCY); | |
1272 | dev_pm_qos_remove_notifier(dev, &policy->nb_min, | |
1273 | DEV_PM_QOS_MIN_FREQUENCY); | |
18c49926 VK |
1274 | dev_pm_qos_remove_request(policy->max_freq_req); |
1275 | dev_pm_qos_remove_request(policy->min_freq_req); | |
1276 | kfree(policy->min_freq_req); | |
67d874c3 | 1277 | |
f9f41e3e | 1278 | cpufreq_policy_put_kobj(policy); |
559ed407 | 1279 | free_cpumask_var(policy->real_cpus); |
e9698cc5 SB |
1280 | free_cpumask_var(policy->related_cpus); |
1281 | free_cpumask_var(policy->cpus); | |
1282 | kfree(policy); | |
1283 | } | |
1284 | ||
0b275352 | 1285 | static int cpufreq_online(unsigned int cpu) |
1da177e4 | 1286 | { |
7f0c020a | 1287 | struct cpufreq_policy *policy; |
194d99c7 | 1288 | bool new_policy; |
1da177e4 | 1289 | unsigned long flags; |
0b275352 RW |
1290 | unsigned int j; |
1291 | int ret; | |
87549141 | 1292 | |
0b275352 | 1293 | pr_debug("%s: bringing CPU%u online\n", __func__, cpu); |
6eed9404 | 1294 | |
bb29ae15 | 1295 | /* Check if this CPU already has a policy to manage it */ |
9104bb26 | 1296 | policy = per_cpu(cpufreq_cpu_data, cpu); |
11ce707e | 1297 | if (policy) { |
9104bb26 | 1298 | WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus)); |
11ce707e | 1299 | if (!policy_is_inactive(policy)) |
d9612a49 | 1300 | return cpufreq_add_policy_cpu(policy, cpu); |
1da177e4 | 1301 | |
11ce707e | 1302 | /* This is the only online CPU for the policy. Start over. */ |
194d99c7 | 1303 | new_policy = false; |
11ce707e RW |
1304 | down_write(&policy->rwsem); |
1305 | policy->cpu = cpu; | |
1306 | policy->governor = NULL; | |
1307 | up_write(&policy->rwsem); | |
1308 | } else { | |
194d99c7 | 1309 | new_policy = true; |
a34e63b1 | 1310 | policy = cpufreq_policy_alloc(cpu); |
72368d12 | 1311 | if (!policy) |
d4d854d6 | 1312 | return -ENOMEM; |
72368d12 | 1313 | } |
0d66b91e | 1314 | |
91a12e91 VK |
1315 | if (!new_policy && cpufreq_driver->online) { |
1316 | ret = cpufreq_driver->online(policy); | |
1317 | if (ret) { | |
1318 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1319 | __LINE__); | |
1320 | goto out_exit_policy; | |
1321 | } | |
1da177e4 | 1322 | |
91a12e91 VK |
1323 | /* Recover policy->cpus using related_cpus */ |
1324 | cpumask_copy(policy->cpus, policy->related_cpus); | |
1325 | } else { | |
1326 | cpumask_copy(policy->cpus, cpumask_of(cpu)); | |
643ae6e8 | 1327 | |
91a12e91 VK |
1328 | /* |
1329 | * Call driver. From then on the cpufreq must be able | |
1330 | * to accept all calls to ->verify and ->setpolicy for this CPU. | |
1331 | */ | |
1332 | ret = cpufreq_driver->init(policy); | |
1333 | if (ret) { | |
1334 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1335 | __LINE__); | |
1336 | goto out_free_policy; | |
1337 | } | |
d417e069 | 1338 | |
91a12e91 VK |
1339 | ret = cpufreq_table_validate_and_sort(policy); |
1340 | if (ret) | |
1341 | goto out_exit_policy; | |
6d4e81ed | 1342 | |
4d1f3a5b | 1343 | /* related_cpus should at least include policy->cpus. */ |
0998a03a | 1344 | cpumask_copy(policy->related_cpus, policy->cpus); |
4d1f3a5b | 1345 | } |
559ed407 | 1346 | |
91a12e91 | 1347 | down_write(&policy->rwsem); |
5a7e56a5 VK |
1348 | /* |
1349 | * affected cpus must always be the one, which are online. We aren't | |
1350 | * managing offline cpus here. | |
1351 | */ | |
1352 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1353 | ||
194d99c7 | 1354 | if (new_policy) { |
18c49926 | 1355 | struct device *dev = get_cpu_device(cpu); |
6d4e81ed | 1356 | |
2f0ba790 | 1357 | for_each_cpu(j, policy->related_cpus) { |
988bed09 | 1358 | per_cpu(cpufreq_cpu_data, j) = policy; |
2f0ba790 RW |
1359 | add_cpu_dev_symlink(policy, j); |
1360 | } | |
18c49926 VK |
1361 | |
1362 | policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req), | |
1363 | GFP_KERNEL); | |
1364 | if (!policy->min_freq_req) | |
1365 | goto out_destroy_policy; | |
1366 | ||
1367 | ret = dev_pm_qos_add_request(dev, policy->min_freq_req, | |
1368 | DEV_PM_QOS_MIN_FREQUENCY, | |
1369 | policy->min); | |
1370 | if (ret < 0) { | |
1371 | /* | |
1372 | * So we don't call dev_pm_qos_remove_request() for an | |
1373 | * uninitialized request. | |
1374 | */ | |
1375 | kfree(policy->min_freq_req); | |
1376 | policy->min_freq_req = NULL; | |
1377 | ||
1378 | dev_err(dev, "Failed to add min-freq constraint (%d)\n", | |
1379 | ret); | |
1380 | goto out_destroy_policy; | |
1381 | } | |
1382 | ||
1383 | /* | |
1384 | * This must be initialized right here to avoid calling | |
1385 | * dev_pm_qos_remove_request() on uninitialized request in case | |
1386 | * of errors. | |
1387 | */ | |
1388 | policy->max_freq_req = policy->min_freq_req + 1; | |
1389 | ||
1390 | ret = dev_pm_qos_add_request(dev, policy->max_freq_req, | |
1391 | DEV_PM_QOS_MAX_FREQUENCY, | |
1392 | policy->max); | |
1393 | if (ret < 0) { | |
1394 | policy->max_freq_req = NULL; | |
1395 | dev_err(dev, "Failed to add max-freq constraint (%d)\n", | |
1396 | ret); | |
1397 | goto out_destroy_policy; | |
1398 | } | |
988bed09 | 1399 | } |
652ed95d | 1400 | |
5ddc6d4e | 1401 | if (cpufreq_driver->get && has_target()) { |
da60ce9f VK |
1402 | policy->cur = cpufreq_driver->get(policy->cpu); |
1403 | if (!policy->cur) { | |
1404 | pr_err("%s: ->get() failed\n", __func__); | |
d417e069 | 1405 | goto out_destroy_policy; |
da60ce9f VK |
1406 | } |
1407 | } | |
1408 | ||
d3916691 VK |
1409 | /* |
1410 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1411 | * frequency table present with cpufreq core. In such cases CPU might be | |
1412 | * unstable if it has to run on that frequency for long duration of time | |
1413 | * and so its better to set it to a frequency which is specified in | |
1414 | * freq-table. This also makes cpufreq stats inconsistent as | |
1415 | * cpufreq-stats would fail to register because current frequency of CPU | |
1416 | * isn't found in freq-table. | |
1417 | * | |
1418 | * Because we don't want this change to effect boot process badly, we go | |
1419 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1420 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1421 | * is initialized to zero). | |
1422 | * | |
1423 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1424 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1425 | * equal to target-freq. | |
1426 | */ | |
1427 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1428 | && has_target()) { | |
1429 | /* Are we running at unknown frequency ? */ | |
1430 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1431 | if (ret == -EINVAL) { | |
1432 | /* Warn user and fix it */ | |
1433 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1434 | __func__, policy->cpu, policy->cur); | |
1435 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1436 | CPUFREQ_RELATION_L); | |
1437 | ||
1438 | /* | |
1439 | * Reaching here after boot in a few seconds may not | |
1440 | * mean that system will remain stable at "unknown" | |
1441 | * frequency for longer duration. Hence, a BUG_ON(). | |
1442 | */ | |
1443 | BUG_ON(ret); | |
1444 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1445 | __func__, policy->cpu, policy->cur); | |
1446 | } | |
1447 | } | |
1448 | ||
194d99c7 | 1449 | if (new_policy) { |
d9612a49 | 1450 | ret = cpufreq_add_dev_interface(policy); |
a82fab29 | 1451 | if (ret) |
d417e069 | 1452 | goto out_destroy_policy; |
1aefc75b RW |
1453 | |
1454 | cpufreq_stats_create_table(policy); | |
8ff69732 | 1455 | |
988bed09 VK |
1456 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1457 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1458 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1459 | } | |
9515f4d6 | 1460 | |
7f0fa40f VK |
1461 | ret = cpufreq_init_policy(policy); |
1462 | if (ret) { | |
1463 | pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", | |
1464 | __func__, cpu, ret); | |
d417e069 | 1465 | goto out_destroy_policy; |
08fd8c1c | 1466 | } |
e18f1682 | 1467 | |
4e97b631 | 1468 | up_write(&policy->rwsem); |
08fd8c1c | 1469 | |
038c5b3e | 1470 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
7c45cf31 | 1471 | |
7c45cf31 VK |
1472 | /* Callback for handling stuff after policy is ready */ |
1473 | if (cpufreq_driver->ready) | |
1474 | cpufreq_driver->ready(policy); | |
1475 | ||
bcc61569 | 1476 | if (cpufreq_thermal_control_enabled(cpufreq_driver)) |
5c238a8b AK |
1477 | policy->cdev = of_cpufreq_cooling_register(policy); |
1478 | ||
2d06d8c4 | 1479 | pr_debug("initialization complete\n"); |
87c32271 | 1480 | |
1da177e4 LT |
1481 | return 0; |
1482 | ||
d417e069 | 1483 | out_destroy_policy: |
b24b6478 VK |
1484 | for_each_cpu(j, policy->real_cpus) |
1485 | remove_cpu_dev_symlink(policy, get_cpu_device(j)); | |
1486 | ||
7106e02b PB |
1487 | up_write(&policy->rwsem); |
1488 | ||
d417e069 | 1489 | out_exit_policy: |
da60ce9f VK |
1490 | if (cpufreq_driver->exit) |
1491 | cpufreq_driver->exit(policy); | |
2f0ba790 | 1492 | |
8101f997 | 1493 | out_free_policy: |
f9f41e3e | 1494 | cpufreq_policy_free(policy); |
1da177e4 LT |
1495 | return ret; |
1496 | } | |
1497 | ||
0b275352 RW |
1498 | /** |
1499 | * cpufreq_add_dev - the cpufreq interface for a CPU device. | |
1500 | * @dev: CPU device. | |
1501 | * @sif: Subsystem interface structure pointer (not used) | |
1502 | */ | |
1503 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1504 | { | |
a794d613 | 1505 | struct cpufreq_policy *policy; |
0b275352 | 1506 | unsigned cpu = dev->id; |
26619804 | 1507 | int ret; |
0b275352 RW |
1508 | |
1509 | dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); | |
1510 | ||
26619804 VK |
1511 | if (cpu_online(cpu)) { |
1512 | ret = cpufreq_online(cpu); | |
1513 | if (ret) | |
1514 | return ret; | |
1515 | } | |
0b275352 | 1516 | |
26619804 | 1517 | /* Create sysfs link on CPU registration */ |
a794d613 | 1518 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2f0ba790 RW |
1519 | if (policy) |
1520 | add_cpu_dev_symlink(policy, cpu); | |
26619804 | 1521 | |
2f0ba790 | 1522 | return 0; |
1da177e4 LT |
1523 | } |
1524 | ||
27622b06 | 1525 | static int cpufreq_offline(unsigned int cpu) |
1da177e4 | 1526 | { |
3a3e9e06 | 1527 | struct cpufreq_policy *policy; |
69cee714 | 1528 | int ret; |
1da177e4 | 1529 | |
b8eed8af | 1530 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1531 | |
988bed09 | 1532 | policy = cpufreq_cpu_get_raw(cpu); |
3a3e9e06 | 1533 | if (!policy) { |
b8eed8af | 1534 | pr_debug("%s: No cpu_data found\n", __func__); |
27622b06 | 1535 | return 0; |
1da177e4 | 1536 | } |
1da177e4 | 1537 | |
49f18560 | 1538 | down_write(&policy->rwsem); |
45482c70 RW |
1539 | if (has_target()) |
1540 | cpufreq_stop_governor(policy); | |
1da177e4 | 1541 | |
9591becb | 1542 | cpumask_clear_cpu(cpu, policy->cpus); |
4573237b | 1543 | |
9591becb VK |
1544 | if (policy_is_inactive(policy)) { |
1545 | if (has_target()) | |
1546 | strncpy(policy->last_governor, policy->governor->name, | |
1547 | CPUFREQ_NAME_LEN); | |
69030dd1 SP |
1548 | else |
1549 | policy->last_policy = policy->policy; | |
9591becb VK |
1550 | } else if (cpu == policy->cpu) { |
1551 | /* Nominate new CPU */ | |
1552 | policy->cpu = cpumask_any(policy->cpus); | |
1553 | } | |
084f3493 | 1554 | |
9591becb VK |
1555 | /* Start governor again for active policy */ |
1556 | if (!policy_is_inactive(policy)) { | |
1557 | if (has_target()) { | |
0a300767 | 1558 | ret = cpufreq_start_governor(policy); |
9591becb VK |
1559 | if (ret) |
1560 | pr_err("%s: Failed to start governor\n", __func__); | |
1561 | } | |
cedb70af | 1562 | |
49f18560 | 1563 | goto unlock; |
cedb70af SB |
1564 | } |
1565 | ||
bcc61569 | 1566 | if (cpufreq_thermal_control_enabled(cpufreq_driver)) { |
5c238a8b AK |
1567 | cpufreq_cooling_unregister(policy->cdev); |
1568 | policy->cdev = NULL; | |
1569 | } | |
1570 | ||
69cee714 VK |
1571 | if (cpufreq_driver->stop_cpu) |
1572 | cpufreq_driver->stop_cpu(policy); | |
87549141 | 1573 | |
36be3418 RW |
1574 | if (has_target()) |
1575 | cpufreq_exit_governor(policy); | |
1da177e4 | 1576 | |
87549141 | 1577 | /* |
91a12e91 VK |
1578 | * Perform the ->offline() during light-weight tear-down, as |
1579 | * that allows fast recovery when the CPU comes back. | |
87549141 | 1580 | */ |
91a12e91 VK |
1581 | if (cpufreq_driver->offline) { |
1582 | cpufreq_driver->offline(policy); | |
1583 | } else if (cpufreq_driver->exit) { | |
87549141 | 1584 | cpufreq_driver->exit(policy); |
55582bcc SP |
1585 | policy->freq_table = NULL; |
1586 | } | |
49f18560 VK |
1587 | |
1588 | unlock: | |
1589 | up_write(&policy->rwsem); | |
27622b06 | 1590 | return 0; |
1da177e4 LT |
1591 | } |
1592 | ||
cedb70af | 1593 | /** |
27a862e9 | 1594 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1595 | * |
1596 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1597 | */ |
71db87ba | 1598 | static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1599 | { |
8a25a2fd | 1600 | unsigned int cpu = dev->id; |
559ed407 | 1601 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
87549141 | 1602 | |
559ed407 | 1603 | if (!policy) |
1af115d6 | 1604 | return; |
87549141 | 1605 | |
69cee714 VK |
1606 | if (cpu_online(cpu)) |
1607 | cpufreq_offline(cpu); | |
87549141 | 1608 | |
559ed407 | 1609 | cpumask_clear_cpu(cpu, policy->real_cpus); |
26619804 | 1610 | remove_cpu_dev_symlink(policy, dev); |
87549141 | 1611 | |
91a12e91 VK |
1612 | if (cpumask_empty(policy->real_cpus)) { |
1613 | /* We did light-weight exit earlier, do full tear down now */ | |
1614 | if (cpufreq_driver->offline) | |
1615 | cpufreq_driver->exit(policy); | |
1616 | ||
f9f41e3e | 1617 | cpufreq_policy_free(policy); |
91a12e91 | 1618 | } |
5a01f2e8 VP |
1619 | } |
1620 | ||
1da177e4 | 1621 | /** |
bb176f7d VK |
1622 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1623 | * in deep trouble. | |
a1e1dc41 | 1624 | * @policy: policy managing CPUs |
1da177e4 LT |
1625 | * @new_freq: CPU frequency the CPU actually runs at |
1626 | * | |
29464f28 DJ |
1627 | * We adjust to current frequency first, and need to clean up later. |
1628 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1629 | */ |
a1e1dc41 | 1630 | static void cpufreq_out_of_sync(struct cpufreq_policy *policy, |
e08f5f5b | 1631 | unsigned int new_freq) |
1da177e4 LT |
1632 | { |
1633 | struct cpufreq_freqs freqs; | |
b43a7ffb | 1634 | |
e837f9b5 | 1635 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
a1e1dc41 | 1636 | policy->cur, new_freq); |
1da177e4 | 1637 | |
a1e1dc41 | 1638 | freqs.old = policy->cur; |
1da177e4 | 1639 | freqs.new = new_freq; |
b43a7ffb | 1640 | |
8fec051e VK |
1641 | cpufreq_freq_transition_begin(policy, &freqs); |
1642 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1643 | } |
1644 | ||
5980752e VK |
1645 | static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update) |
1646 | { | |
1647 | unsigned int new_freq; | |
1648 | ||
1649 | new_freq = cpufreq_driver->get(policy->cpu); | |
1650 | if (!new_freq) | |
1651 | return 0; | |
1652 | ||
1653 | /* | |
1654 | * If fast frequency switching is used with the given policy, the check | |
1655 | * against policy->cur is pointless, so skip it in that case. | |
1656 | */ | |
1657 | if (policy->fast_switch_enabled || !has_target()) | |
1658 | return new_freq; | |
1659 | ||
1660 | if (policy->cur != new_freq) { | |
1661 | cpufreq_out_of_sync(policy, new_freq); | |
1662 | if (update) | |
1663 | schedule_work(&policy->update); | |
1664 | } | |
1665 | ||
1666 | return new_freq; | |
1667 | } | |
1668 | ||
32ee8c3e | 1669 | /** |
4ab70df4 | 1670 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1671 | * @cpu: CPU number |
1672 | * | |
1673 | * This is the last known freq, without actually getting it from the driver. | |
1674 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1675 | */ | |
1676 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1677 | { | |
9e21ba8b | 1678 | struct cpufreq_policy *policy; |
e08f5f5b | 1679 | unsigned int ret_freq = 0; |
c75361c0 | 1680 | unsigned long flags; |
95235ca2 | 1681 | |
c75361c0 RC |
1682 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1683 | ||
1684 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { | |
1685 | ret_freq = cpufreq_driver->get(cpu); | |
1686 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1687 | return ret_freq; | |
1688 | } | |
1689 | ||
1690 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
9e21ba8b DB |
1691 | |
1692 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1693 | if (policy) { |
e08f5f5b | 1694 | ret_freq = policy->cur; |
95235ca2 VP |
1695 | cpufreq_cpu_put(policy); |
1696 | } | |
1697 | ||
4d34a67d | 1698 | return ret_freq; |
95235ca2 VP |
1699 | } |
1700 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1701 | ||
3d737108 JB |
1702 | /** |
1703 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1704 | * @cpu: CPU number | |
1705 | * | |
1706 | * Just return the max possible frequency for a given CPU. | |
1707 | */ | |
1708 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1709 | { | |
1710 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1711 | unsigned int ret_freq = 0; | |
1712 | ||
1713 | if (policy) { | |
1714 | ret_freq = policy->max; | |
1715 | cpufreq_cpu_put(policy); | |
1716 | } | |
1717 | ||
1718 | return ret_freq; | |
1719 | } | |
1720 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1721 | ||
d92d50a4 | 1722 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy) |
1da177e4 | 1723 | { |
4db7c34c | 1724 | if (unlikely(policy_is_inactive(policy))) |
5980752e | 1725 | return 0; |
1da177e4 | 1726 | |
5980752e | 1727 | return cpufreq_verify_current_freq(policy, true); |
5a01f2e8 | 1728 | } |
1da177e4 | 1729 | |
5a01f2e8 VP |
1730 | /** |
1731 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1732 | * @cpu: CPU number | |
1733 | * | |
1734 | * Get the CPU current (static) CPU frequency | |
1735 | */ | |
1736 | unsigned int cpufreq_get(unsigned int cpu) | |
1737 | { | |
999976e0 | 1738 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1739 | unsigned int ret_freq = 0; |
5a01f2e8 | 1740 | |
999976e0 AP |
1741 | if (policy) { |
1742 | down_read(&policy->rwsem); | |
4db7c34c YH |
1743 | if (cpufreq_driver->get) |
1744 | ret_freq = __cpufreq_get(policy); | |
999976e0 | 1745 | up_read(&policy->rwsem); |
5a01f2e8 | 1746 | |
999976e0 AP |
1747 | cpufreq_cpu_put(policy); |
1748 | } | |
6eed9404 | 1749 | |
4d34a67d | 1750 | return ret_freq; |
1da177e4 LT |
1751 | } |
1752 | EXPORT_SYMBOL(cpufreq_get); | |
1753 | ||
8a25a2fd KS |
1754 | static struct subsys_interface cpufreq_interface = { |
1755 | .name = "cpufreq", | |
1756 | .subsys = &cpu_subsys, | |
1757 | .add_dev = cpufreq_add_dev, | |
1758 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1759 | }; |
1760 | ||
e28867ea VK |
1761 | /* |
1762 | * In case platform wants some specific frequency to be configured | |
1763 | * during suspend.. | |
1764 | */ | |
1765 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1766 | { | |
1767 | int ret; | |
1768 | ||
1769 | if (!policy->suspend_freq) { | |
201f3716 BZ |
1770 | pr_debug("%s: suspend_freq not defined\n", __func__); |
1771 | return 0; | |
e28867ea VK |
1772 | } |
1773 | ||
1774 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1775 | policy->suspend_freq); | |
1776 | ||
1777 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1778 | CPUFREQ_RELATION_H); | |
1779 | if (ret) | |
1780 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1781 | __func__, policy->suspend_freq, ret); | |
1782 | ||
1783 | return ret; | |
1784 | } | |
1785 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1786 | ||
42d4dc3f | 1787 | /** |
2f0aea93 | 1788 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1789 | * |
2f0aea93 VK |
1790 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1791 | * as some platforms can't change frequency after this point in suspend cycle. | |
1792 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1793 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1794 | */ |
2f0aea93 | 1795 | void cpufreq_suspend(void) |
42d4dc3f | 1796 | { |
3a3e9e06 | 1797 | struct cpufreq_policy *policy; |
42d4dc3f | 1798 | |
2f0aea93 VK |
1799 | if (!cpufreq_driver) |
1800 | return; | |
42d4dc3f | 1801 | |
ba41e1bc | 1802 | if (!has_target() && !cpufreq_driver->suspend) |
b1b12bab | 1803 | goto suspend; |
42d4dc3f | 1804 | |
2f0aea93 VK |
1805 | pr_debug("%s: Suspending Governors\n", __func__); |
1806 | ||
f963735a | 1807 | for_each_active_policy(policy) { |
ba41e1bc RW |
1808 | if (has_target()) { |
1809 | down_write(&policy->rwsem); | |
45482c70 | 1810 | cpufreq_stop_governor(policy); |
ba41e1bc | 1811 | up_write(&policy->rwsem); |
ba41e1bc RW |
1812 | } |
1813 | ||
1814 | if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) | |
2f0aea93 VK |
1815 | pr_err("%s: Failed to suspend driver: %p\n", __func__, |
1816 | policy); | |
42d4dc3f | 1817 | } |
b1b12bab VK |
1818 | |
1819 | suspend: | |
1820 | cpufreq_suspended = true; | |
42d4dc3f BH |
1821 | } |
1822 | ||
1da177e4 | 1823 | /** |
2f0aea93 | 1824 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1825 | * |
2f0aea93 VK |
1826 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1827 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1828 | */ |
2f0aea93 | 1829 | void cpufreq_resume(void) |
1da177e4 | 1830 | { |
3a3e9e06 | 1831 | struct cpufreq_policy *policy; |
49f18560 | 1832 | int ret; |
1da177e4 | 1833 | |
2f0aea93 | 1834 | if (!cpufreq_driver) |
703cbaa6 BY |
1835 | return; |
1836 | ||
1837 | if (unlikely(!cpufreq_suspended)) | |
2f0aea93 | 1838 | return; |
1da177e4 | 1839 | |
8e30444e LT |
1840 | cpufreq_suspended = false; |
1841 | ||
ba41e1bc | 1842 | if (!has_target() && !cpufreq_driver->resume) |
e00e56df | 1843 | return; |
1da177e4 | 1844 | |
2f0aea93 | 1845 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1846 | |
f963735a | 1847 | for_each_active_policy(policy) { |
49f18560 | 1848 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { |
0c5aa405 VK |
1849 | pr_err("%s: Failed to resume driver: %p\n", __func__, |
1850 | policy); | |
ba41e1bc | 1851 | } else if (has_target()) { |
49f18560 | 1852 | down_write(&policy->rwsem); |
0a300767 | 1853 | ret = cpufreq_start_governor(policy); |
49f18560 VK |
1854 | up_write(&policy->rwsem); |
1855 | ||
1856 | if (ret) | |
1857 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1858 | __func__, policy); | |
1859 | } | |
2f0aea93 VK |
1860 | } |
1861 | } | |
1da177e4 | 1862 | |
9d95046e BP |
1863 | /** |
1864 | * cpufreq_get_current_driver - return current driver's name | |
1865 | * | |
1866 | * Return the name string of the currently loaded cpufreq driver | |
1867 | * or NULL, if none. | |
1868 | */ | |
1869 | const char *cpufreq_get_current_driver(void) | |
1870 | { | |
1c3d85dd RW |
1871 | if (cpufreq_driver) |
1872 | return cpufreq_driver->name; | |
1873 | ||
1874 | return NULL; | |
9d95046e BP |
1875 | } |
1876 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 | 1877 | |
51315cdf TP |
1878 | /** |
1879 | * cpufreq_get_driver_data - return current driver data | |
1880 | * | |
1881 | * Return the private data of the currently loaded cpufreq | |
1882 | * driver, or NULL if no cpufreq driver is loaded. | |
1883 | */ | |
1884 | void *cpufreq_get_driver_data(void) | |
1885 | { | |
1886 | if (cpufreq_driver) | |
1887 | return cpufreq_driver->driver_data; | |
1888 | ||
1889 | return NULL; | |
1890 | } | |
1891 | EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); | |
1892 | ||
1da177e4 LT |
1893 | /********************************************************************* |
1894 | * NOTIFIER LISTS INTERFACE * | |
1895 | *********************************************************************/ | |
1896 | ||
1897 | /** | |
1898 | * cpufreq_register_notifier - register a driver with cpufreq | |
1899 | * @nb: notifier function to register | |
1900 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1901 | * | |
32ee8c3e | 1902 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1903 | * are notified about clock rate changes (once before and once after |
1904 | * the transition), or a list of drivers that are notified about | |
1905 | * changes in cpufreq policy. | |
1906 | * | |
1907 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1908 | * blocking_notifier_chain_register. |
1da177e4 LT |
1909 | */ |
1910 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1911 | { | |
1912 | int ret; | |
1913 | ||
d5aaffa9 DB |
1914 | if (cpufreq_disabled()) |
1915 | return -EINVAL; | |
1916 | ||
1da177e4 LT |
1917 | switch (list) { |
1918 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1919 | mutex_lock(&cpufreq_fast_switch_lock); |
1920 | ||
1921 | if (cpufreq_fast_switch_count > 0) { | |
1922 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1923 | return -EBUSY; | |
1924 | } | |
b4dfdbb3 | 1925 | ret = srcu_notifier_chain_register( |
e041c683 | 1926 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1927 | if (!ret) |
1928 | cpufreq_fast_switch_count--; | |
1929 | ||
1930 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1931 | break; |
1932 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1933 | ret = blocking_notifier_chain_register( |
1934 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1935 | break; |
1936 | default: | |
1937 | ret = -EINVAL; | |
1938 | } | |
1da177e4 LT |
1939 | |
1940 | return ret; | |
1941 | } | |
1942 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1943 | ||
1da177e4 LT |
1944 | /** |
1945 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1946 | * @nb: notifier block to be unregistered | |
bb176f7d | 1947 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1948 | * |
1949 | * Remove a driver from the CPU frequency notifier list. | |
1950 | * | |
1951 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1952 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1953 | */ |
1954 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1955 | { | |
1956 | int ret; | |
1957 | ||
d5aaffa9 DB |
1958 | if (cpufreq_disabled()) |
1959 | return -EINVAL; | |
1960 | ||
1da177e4 LT |
1961 | switch (list) { |
1962 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1963 | mutex_lock(&cpufreq_fast_switch_lock); |
1964 | ||
b4dfdbb3 | 1965 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1966 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1967 | if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) |
1968 | cpufreq_fast_switch_count++; | |
1969 | ||
1970 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1971 | break; |
1972 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1973 | ret = blocking_notifier_chain_unregister( |
1974 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1975 | break; |
1976 | default: | |
1977 | ret = -EINVAL; | |
1978 | } | |
1da177e4 LT |
1979 | |
1980 | return ret; | |
1981 | } | |
1982 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1983 | ||
1984 | ||
1985 | /********************************************************************* | |
1986 | * GOVERNORS * | |
1987 | *********************************************************************/ | |
1988 | ||
b7898fda RW |
1989 | /** |
1990 | * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. | |
1991 | * @policy: cpufreq policy to switch the frequency for. | |
1992 | * @target_freq: New frequency to set (may be approximate). | |
1993 | * | |
1994 | * Carry out a fast frequency switch without sleeping. | |
1995 | * | |
1996 | * The driver's ->fast_switch() callback invoked by this function must be | |
1997 | * suitable for being called from within RCU-sched read-side critical sections | |
1998 | * and it is expected to select the minimum available frequency greater than or | |
1999 | * equal to @target_freq (CPUFREQ_RELATION_L). | |
2000 | * | |
2001 | * This function must not be called if policy->fast_switch_enabled is unset. | |
2002 | * | |
2003 | * Governors calling this function must guarantee that it will never be invoked | |
2004 | * twice in parallel for the same policy and that it will never be called in | |
2005 | * parallel with either ->target() or ->target_index() for the same policy. | |
2006 | * | |
209887e6 VK |
2007 | * Returns the actual frequency set for the CPU. |
2008 | * | |
2009 | * If 0 is returned by the driver's ->fast_switch() callback to indicate an | |
2010 | * error condition, the hardware configuration must be preserved. | |
b7898fda RW |
2011 | */ |
2012 | unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, | |
2013 | unsigned int target_freq) | |
2014 | { | |
b9af6948 | 2015 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
b7898fda RW |
2016 | |
2017 | return cpufreq_driver->fast_switch(policy, target_freq); | |
2018 | } | |
2019 | EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); | |
2020 | ||
1c03a2d0 VK |
2021 | /* Must set freqs->new to intermediate frequency */ |
2022 | static int __target_intermediate(struct cpufreq_policy *policy, | |
2023 | struct cpufreq_freqs *freqs, int index) | |
2024 | { | |
2025 | int ret; | |
2026 | ||
2027 | freqs->new = cpufreq_driver->get_intermediate(policy, index); | |
2028 | ||
2029 | /* We don't need to switch to intermediate freq */ | |
2030 | if (!freqs->new) | |
2031 | return 0; | |
2032 | ||
2033 | pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", | |
2034 | __func__, policy->cpu, freqs->old, freqs->new); | |
2035 | ||
2036 | cpufreq_freq_transition_begin(policy, freqs); | |
2037 | ret = cpufreq_driver->target_intermediate(policy, index); | |
2038 | cpufreq_freq_transition_end(policy, freqs, ret); | |
2039 | ||
2040 | if (ret) | |
2041 | pr_err("%s: Failed to change to intermediate frequency: %d\n", | |
2042 | __func__, ret); | |
2043 | ||
2044 | return ret; | |
2045 | } | |
2046 | ||
23727845 | 2047 | static int __target_index(struct cpufreq_policy *policy, int index) |
8d65775d | 2048 | { |
1c03a2d0 VK |
2049 | struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
2050 | unsigned int intermediate_freq = 0; | |
23727845 | 2051 | unsigned int newfreq = policy->freq_table[index].frequency; |
8d65775d VK |
2052 | int retval = -EINVAL; |
2053 | bool notify; | |
2054 | ||
23727845 VK |
2055 | if (newfreq == policy->cur) |
2056 | return 0; | |
2057 | ||
8d65775d | 2058 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); |
8d65775d | 2059 | if (notify) { |
1c03a2d0 VK |
2060 | /* Handle switching to intermediate frequency */ |
2061 | if (cpufreq_driver->get_intermediate) { | |
2062 | retval = __target_intermediate(policy, &freqs, index); | |
2063 | if (retval) | |
2064 | return retval; | |
2065 | ||
2066 | intermediate_freq = freqs.new; | |
2067 | /* Set old freq to intermediate */ | |
2068 | if (intermediate_freq) | |
2069 | freqs.old = freqs.new; | |
2070 | } | |
8d65775d | 2071 | |
23727845 | 2072 | freqs.new = newfreq; |
8d65775d VK |
2073 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", |
2074 | __func__, policy->cpu, freqs.old, freqs.new); | |
2075 | ||
2076 | cpufreq_freq_transition_begin(policy, &freqs); | |
2077 | } | |
2078 | ||
2079 | retval = cpufreq_driver->target_index(policy, index); | |
2080 | if (retval) | |
2081 | pr_err("%s: Failed to change cpu frequency: %d\n", __func__, | |
2082 | retval); | |
2083 | ||
1c03a2d0 | 2084 | if (notify) { |
8d65775d VK |
2085 | cpufreq_freq_transition_end(policy, &freqs, retval); |
2086 | ||
1c03a2d0 VK |
2087 | /* |
2088 | * Failed after setting to intermediate freq? Driver should have | |
2089 | * reverted back to initial frequency and so should we. Check | |
2090 | * here for intermediate_freq instead of get_intermediate, in | |
58405af6 | 2091 | * case we haven't switched to intermediate freq at all. |
1c03a2d0 VK |
2092 | */ |
2093 | if (unlikely(retval && intermediate_freq)) { | |
2094 | freqs.old = intermediate_freq; | |
2095 | freqs.new = policy->restore_freq; | |
2096 | cpufreq_freq_transition_begin(policy, &freqs); | |
2097 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
2098 | } | |
2099 | } | |
2100 | ||
8d65775d VK |
2101 | return retval; |
2102 | } | |
2103 | ||
1da177e4 LT |
2104 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
2105 | unsigned int target_freq, | |
2106 | unsigned int relation) | |
2107 | { | |
7249924e | 2108 | unsigned int old_target_freq = target_freq; |
d218ed77 | 2109 | int index; |
c32b6b8e | 2110 | |
a7b422cd KRW |
2111 | if (cpufreq_disabled()) |
2112 | return -ENODEV; | |
2113 | ||
7249924e | 2114 | /* Make sure that target_freq is within supported range */ |
910c6e88 | 2115 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
7249924e VK |
2116 | |
2117 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 2118 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 2119 | |
9c0ebcf7 VK |
2120 | /* |
2121 | * This might look like a redundant call as we are checking it again | |
2122 | * after finding index. But it is left intentionally for cases where | |
2123 | * exactly same freq is called again and so we can save on few function | |
2124 | * calls. | |
2125 | */ | |
5a1c0228 VK |
2126 | if (target_freq == policy->cur) |
2127 | return 0; | |
2128 | ||
1c03a2d0 VK |
2129 | /* Save last value to restore later on errors */ |
2130 | policy->restore_freq = policy->cur; | |
2131 | ||
1c3d85dd | 2132 | if (cpufreq_driver->target) |
6019d23a | 2133 | return cpufreq_driver->target(policy, target_freq, relation); |
9c0ebcf7 | 2134 | |
6019d23a RW |
2135 | if (!cpufreq_driver->target_index) |
2136 | return -EINVAL; | |
9c0ebcf7 | 2137 | |
d218ed77 | 2138 | index = cpufreq_frequency_table_target(policy, target_freq, relation); |
6019d23a | 2139 | |
23727845 | 2140 | return __target_index(policy, index); |
1da177e4 LT |
2141 | } |
2142 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
2143 | ||
1da177e4 LT |
2144 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
2145 | unsigned int target_freq, | |
2146 | unsigned int relation) | |
2147 | { | |
f1829e4a | 2148 | int ret = -EINVAL; |
1da177e4 | 2149 | |
ad7722da | 2150 | down_write(&policy->rwsem); |
1da177e4 LT |
2151 | |
2152 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
2153 | ||
ad7722da | 2154 | up_write(&policy->rwsem); |
1da177e4 | 2155 | |
1da177e4 LT |
2156 | return ret; |
2157 | } | |
2158 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
2159 | ||
de1df26b RW |
2160 | __weak struct cpufreq_governor *cpufreq_fallback_governor(void) |
2161 | { | |
2162 | return NULL; | |
2163 | } | |
2164 | ||
a92604b4 | 2165 | static int cpufreq_init_governor(struct cpufreq_policy *policy) |
1da177e4 | 2166 | { |
cc993cab | 2167 | int ret; |
6afde10c | 2168 | |
2f0aea93 VK |
2169 | /* Don't start any governor operations if we are entering suspend */ |
2170 | if (cpufreq_suspended) | |
2171 | return 0; | |
cb57720b EZ |
2172 | /* |
2173 | * Governor might not be initiated here if ACPI _PPC changed | |
2174 | * notification happened, so check it. | |
2175 | */ | |
2176 | if (!policy->governor) | |
2177 | return -EINVAL; | |
2f0aea93 | 2178 | |
ed4676e2 VK |
2179 | /* Platform doesn't want dynamic frequency switching ? */ |
2180 | if (policy->governor->dynamic_switching && | |
fc4c709f | 2181 | cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) { |
de1df26b RW |
2182 | struct cpufreq_governor *gov = cpufreq_fallback_governor(); |
2183 | ||
2184 | if (gov) { | |
fe829ed8 | 2185 | pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n", |
e837f9b5 | 2186 | policy->governor->name, gov->name); |
6afde10c | 2187 | policy->governor = gov; |
de1df26b RW |
2188 | } else { |
2189 | return -EINVAL; | |
6afde10c | 2190 | } |
1c256245 | 2191 | } |
1da177e4 | 2192 | |
a92604b4 RW |
2193 | if (!try_module_get(policy->governor->owner)) |
2194 | return -EINVAL; | |
95731ebb | 2195 | |
a92604b4 | 2196 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
1da177e4 | 2197 | |
e788892b RW |
2198 | if (policy->governor->init) { |
2199 | ret = policy->governor->init(policy); | |
2200 | if (ret) { | |
36be3418 | 2201 | module_put(policy->governor->owner); |
e788892b RW |
2202 | return ret; |
2203 | } | |
36be3418 | 2204 | } |
1da177e4 | 2205 | |
a92604b4 RW |
2206 | return 0; |
2207 | } | |
2208 | ||
2209 | static void cpufreq_exit_governor(struct cpufreq_policy *policy) | |
2210 | { | |
2211 | if (cpufreq_suspended || !policy->governor) | |
2212 | return; | |
2213 | ||
2214 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2215 | ||
e788892b RW |
2216 | if (policy->governor->exit) |
2217 | policy->governor->exit(policy); | |
a92604b4 | 2218 | |
a92604b4 | 2219 | module_put(policy->governor->owner); |
1da177e4 LT |
2220 | } |
2221 | ||
0a300767 RW |
2222 | static int cpufreq_start_governor(struct cpufreq_policy *policy) |
2223 | { | |
2224 | int ret; | |
2225 | ||
a92604b4 RW |
2226 | if (cpufreq_suspended) |
2227 | return 0; | |
2228 | ||
2229 | if (!policy->governor) | |
2230 | return -EINVAL; | |
2231 | ||
2232 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2233 | ||
407d0fff | 2234 | if (cpufreq_driver->get) |
5980752e | 2235 | cpufreq_verify_current_freq(policy, false); |
3bbf8fe3 | 2236 | |
e788892b RW |
2237 | if (policy->governor->start) { |
2238 | ret = policy->governor->start(policy); | |
2239 | if (ret) | |
2240 | return ret; | |
2241 | } | |
2242 | ||
2243 | if (policy->governor->limits) | |
2244 | policy->governor->limits(policy); | |
d6ff44d6 | 2245 | |
d6ff44d6 | 2246 | return 0; |
0a300767 RW |
2247 | } |
2248 | ||
a92604b4 RW |
2249 | static void cpufreq_stop_governor(struct cpufreq_policy *policy) |
2250 | { | |
2251 | if (cpufreq_suspended || !policy->governor) | |
2252 | return; | |
2253 | ||
2254 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2255 | ||
e788892b RW |
2256 | if (policy->governor->stop) |
2257 | policy->governor->stop(policy); | |
a92604b4 RW |
2258 | } |
2259 | ||
2260 | static void cpufreq_governor_limits(struct cpufreq_policy *policy) | |
2261 | { | |
2262 | if (cpufreq_suspended || !policy->governor) | |
2263 | return; | |
2264 | ||
2265 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2266 | ||
e788892b RW |
2267 | if (policy->governor->limits) |
2268 | policy->governor->limits(policy); | |
0a300767 RW |
2269 | } |
2270 | ||
1da177e4 LT |
2271 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
2272 | { | |
3bcb09a3 | 2273 | int err; |
1da177e4 LT |
2274 | |
2275 | if (!governor) | |
2276 | return -EINVAL; | |
2277 | ||
a7b422cd KRW |
2278 | if (cpufreq_disabled()) |
2279 | return -ENODEV; | |
2280 | ||
3fc54d37 | 2281 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 2282 | |
3bcb09a3 | 2283 | err = -EBUSY; |
42f91fa1 | 2284 | if (!find_governor(governor->name)) { |
3bcb09a3 JF |
2285 | err = 0; |
2286 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2287 | } |
1da177e4 | 2288 | |
32ee8c3e | 2289 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2290 | return err; |
1da177e4 LT |
2291 | } |
2292 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2293 | ||
1da177e4 LT |
2294 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2295 | { | |
4573237b VK |
2296 | struct cpufreq_policy *policy; |
2297 | unsigned long flags; | |
90e41bac | 2298 | |
1da177e4 LT |
2299 | if (!governor) |
2300 | return; | |
2301 | ||
a7b422cd KRW |
2302 | if (cpufreq_disabled()) |
2303 | return; | |
2304 | ||
4573237b VK |
2305 | /* clear last_governor for all inactive policies */ |
2306 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
2307 | for_each_inactive_policy(policy) { | |
18bf3a12 VK |
2308 | if (!strcmp(policy->last_governor, governor->name)) { |
2309 | policy->governor = NULL; | |
4573237b | 2310 | strcpy(policy->last_governor, "\0"); |
18bf3a12 | 2311 | } |
90e41bac | 2312 | } |
4573237b | 2313 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
90e41bac | 2314 | |
3fc54d37 | 2315 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2316 | list_del(&governor->governor_list); |
3fc54d37 | 2317 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2318 | } |
2319 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2320 | ||
2321 | ||
1da177e4 LT |
2322 | /********************************************************************* |
2323 | * POLICY INTERFACE * | |
2324 | *********************************************************************/ | |
2325 | ||
2326 | /** | |
2327 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2328 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2329 | * is written | |
1da177e4 LT |
2330 | * |
2331 | * Reads the current cpufreq policy. | |
2332 | */ | |
2333 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2334 | { | |
2335 | struct cpufreq_policy *cpu_policy; | |
2336 | if (!policy) | |
2337 | return -EINVAL; | |
2338 | ||
2339 | cpu_policy = cpufreq_cpu_get(cpu); | |
2340 | if (!cpu_policy) | |
2341 | return -EINVAL; | |
2342 | ||
d5b73cd8 | 2343 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2344 | |
2345 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2346 | return 0; |
2347 | } | |
2348 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2349 | ||
a0dbb819 RW |
2350 | /** |
2351 | * cpufreq_set_policy - Modify cpufreq policy parameters. | |
2352 | * @policy: Policy object to modify. | |
2353 | * @new_policy: New policy data. | |
2354 | * | |
2355 | * Pass @new_policy to the cpufreq driver's ->verify() callback, run the | |
2356 | * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to | |
2357 | * the driver's ->verify() callback again and run the notifiers for it again | |
2358 | * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters | |
2359 | * of @new_policy to @policy and either invoke the driver's ->setpolicy() | |
2360 | * callback (if present) or carry out a governor update for @policy. That is, | |
2361 | * run the current governor's ->limits() callback (if the governor field in | |
2362 | * @new_policy points to the same object as the one in @policy) or replace the | |
2363 | * governor for @policy with the new one stored in @new_policy. | |
2364 | * | |
2365 | * The cpuinfo part of @policy is not updated by this function. | |
153d7f3f | 2366 | */ |
9083e498 RW |
2367 | int cpufreq_set_policy(struct cpufreq_policy *policy, |
2368 | struct cpufreq_policy *new_policy) | |
1da177e4 | 2369 | { |
d9a789c7 | 2370 | struct cpufreq_governor *old_gov; |
67d874c3 | 2371 | struct device *cpu_dev = get_cpu_device(policy->cpu); |
d9a789c7 | 2372 | int ret; |
1da177e4 | 2373 | |
e837f9b5 JP |
2374 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2375 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2376 | |
d5b73cd8 | 2377 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2378 | |
67d874c3 VK |
2379 | /* |
2380 | * PM QoS framework collects all the requests from users and provide us | |
2381 | * the final aggregated value here. | |
2382 | */ | |
18c49926 VK |
2383 | new_policy->min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY); |
2384 | new_policy->max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY); | |
67d874c3 | 2385 | |
1da177e4 | 2386 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2387 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2388 | if (ret) |
d9a789c7 | 2389 | return ret; |
1da177e4 | 2390 | |
67d874c3 VK |
2391 | /* |
2392 | * The notifier-chain shall be removed once all the users of | |
2393 | * CPUFREQ_ADJUST are moved to use the QoS framework. | |
2394 | */ | |
1da177e4 | 2395 | /* adjust if necessary - all reasons */ |
e041c683 | 2396 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2397 | CPUFREQ_ADJUST, new_policy); |
1da177e4 | 2398 | |
bb176f7d VK |
2399 | /* |
2400 | * verify the cpu speed can be set within this limit, which might be | |
2401 | * different to the first one | |
2402 | */ | |
3a3e9e06 | 2403 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2404 | if (ret) |
d9a789c7 | 2405 | return ret; |
1da177e4 LT |
2406 | |
2407 | /* notification of the new policy */ | |
e041c683 | 2408 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2409 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2410 | |
3a3e9e06 VK |
2411 | policy->min = new_policy->min; |
2412 | policy->max = new_policy->max; | |
601b2185 | 2413 | trace_cpu_frequency_limits(policy); |
1da177e4 | 2414 | |
e3c06236 SM |
2415 | policy->cached_target_freq = UINT_MAX; |
2416 | ||
2d06d8c4 | 2417 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2418 | policy->min, policy->max); |
1da177e4 | 2419 | |
1c3d85dd | 2420 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2421 | policy->policy = new_policy->policy; |
2d06d8c4 | 2422 | pr_debug("setting range\n"); |
167a38dc | 2423 | return cpufreq_driver->setpolicy(policy); |
d9a789c7 | 2424 | } |
1da177e4 | 2425 | |
0a300767 | 2426 | if (new_policy->governor == policy->governor) { |
2bb4059e | 2427 | pr_debug("governor limits update\n"); |
a92604b4 | 2428 | cpufreq_governor_limits(policy); |
d6ff44d6 | 2429 | return 0; |
0a300767 | 2430 | } |
7bd353a9 | 2431 | |
d9a789c7 RW |
2432 | pr_debug("governor switch\n"); |
2433 | ||
2434 | /* save old, working values */ | |
2435 | old_gov = policy->governor; | |
2436 | /* end old governor */ | |
2437 | if (old_gov) { | |
45482c70 | 2438 | cpufreq_stop_governor(policy); |
36be3418 | 2439 | cpufreq_exit_governor(policy); |
1da177e4 LT |
2440 | } |
2441 | ||
d9a789c7 RW |
2442 | /* start new governor */ |
2443 | policy->governor = new_policy->governor; | |
a92604b4 | 2444 | ret = cpufreq_init_governor(policy); |
4bc384ae | 2445 | if (!ret) { |
0a300767 RW |
2446 | ret = cpufreq_start_governor(policy); |
2447 | if (!ret) { | |
2bb4059e | 2448 | pr_debug("governor change\n"); |
531b5c9f | 2449 | sched_cpufreq_governor_change(policy, old_gov); |
0a300767 RW |
2450 | return 0; |
2451 | } | |
b7898fda | 2452 | cpufreq_exit_governor(policy); |
d9a789c7 RW |
2453 | } |
2454 | ||
2455 | /* new governor failed, so re-start old one */ | |
2456 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2457 | if (old_gov) { | |
2458 | policy->governor = old_gov; | |
a92604b4 | 2459 | if (cpufreq_init_governor(policy)) |
4bc384ae VK |
2460 | policy->governor = NULL; |
2461 | else | |
0a300767 | 2462 | cpufreq_start_governor(policy); |
d9a789c7 RW |
2463 | } |
2464 | ||
4bc384ae | 2465 | return ret; |
1da177e4 LT |
2466 | } |
2467 | ||
1da177e4 | 2468 | /** |
a0dbb819 RW |
2469 | * cpufreq_update_policy - Re-evaluate an existing cpufreq policy. |
2470 | * @cpu: CPU to re-evaluate the policy for. | |
1da177e4 | 2471 | * |
a0dbb819 | 2472 | * Update the current frequency for the cpufreq policy of @cpu and use |
18c49926 VK |
2473 | * cpufreq_set_policy() to re-apply the min and max limits, which triggers the |
2474 | * evaluation of policy notifiers and the cpufreq driver's ->verify() callback | |
2475 | * for the policy in question, among other things. | |
1da177e4 | 2476 | */ |
30248fef | 2477 | void cpufreq_update_policy(unsigned int cpu) |
1da177e4 | 2478 | { |
540a3758 | 2479 | struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); |
1da177e4 | 2480 | |
fefa8ff8 | 2481 | if (!policy) |
30248fef | 2482 | return; |
1da177e4 | 2483 | |
bb176f7d VK |
2484 | /* |
2485 | * BIOS might change freq behind our back | |
2486 | * -> ask driver for current freq and notify governors about a change | |
2487 | */ | |
5ddc6d4e | 2488 | if (cpufreq_driver->get && has_target() && |
5980752e | 2489 | (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false)))) |
348a2ec5 | 2490 | goto unlock; |
30248fef | 2491 | |
70a59fde | 2492 | refresh_frequency_limits(policy); |
1da177e4 | 2493 | |
fefa8ff8 | 2494 | unlock: |
540a3758 | 2495 | cpufreq_cpu_release(policy); |
1da177e4 LT |
2496 | } |
2497 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2498 | ||
5a25e3f7 RW |
2499 | /** |
2500 | * cpufreq_update_limits - Update policy limits for a given CPU. | |
2501 | * @cpu: CPU to update the policy limits for. | |
2502 | * | |
2503 | * Invoke the driver's ->update_limits callback if present or call | |
2504 | * cpufreq_update_policy() for @cpu. | |
2505 | */ | |
2506 | void cpufreq_update_limits(unsigned int cpu) | |
2507 | { | |
2508 | if (cpufreq_driver->update_limits) | |
2509 | cpufreq_driver->update_limits(cpu); | |
2510 | else | |
2511 | cpufreq_update_policy(cpu); | |
2512 | } | |
2513 | EXPORT_SYMBOL_GPL(cpufreq_update_limits); | |
2514 | ||
6f19efc0 LM |
2515 | /********************************************************************* |
2516 | * BOOST * | |
2517 | *********************************************************************/ | |
2518 | static int cpufreq_boost_set_sw(int state) | |
2519 | { | |
6f19efc0 LM |
2520 | struct cpufreq_policy *policy; |
2521 | int ret = -EINVAL; | |
2522 | ||
f963735a | 2523 | for_each_active_policy(policy) { |
f8bfc116 VK |
2524 | if (!policy->freq_table) |
2525 | continue; | |
49f18560 | 2526 | |
f8bfc116 VK |
2527 | ret = cpufreq_frequency_table_cpuinfo(policy, |
2528 | policy->freq_table); | |
2529 | if (ret) { | |
2530 | pr_err("%s: Policy frequency update failed\n", | |
2531 | __func__); | |
2532 | break; | |
6f19efc0 | 2533 | } |
f8bfc116 | 2534 | |
18c49926 VK |
2535 | ret = dev_pm_qos_update_request(policy->max_freq_req, policy->max); |
2536 | if (ret) | |
2537 | break; | |
6f19efc0 LM |
2538 | } |
2539 | ||
2540 | return ret; | |
2541 | } | |
2542 | ||
2543 | int cpufreq_boost_trigger_state(int state) | |
2544 | { | |
2545 | unsigned long flags; | |
2546 | int ret = 0; | |
2547 | ||
2548 | if (cpufreq_driver->boost_enabled == state) | |
2549 | return 0; | |
2550 | ||
2551 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2552 | cpufreq_driver->boost_enabled = state; | |
2553 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2554 | ||
2555 | ret = cpufreq_driver->set_boost(state); | |
2556 | if (ret) { | |
2557 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2558 | cpufreq_driver->boost_enabled = !state; | |
2559 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2560 | ||
e837f9b5 JP |
2561 | pr_err("%s: Cannot %s BOOST\n", |
2562 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2563 | } |
2564 | ||
2565 | return ret; | |
2566 | } | |
2567 | ||
41669da0 | 2568 | static bool cpufreq_boost_supported(void) |
6f19efc0 | 2569 | { |
89f98d7e | 2570 | return cpufreq_driver->set_boost; |
6f19efc0 | 2571 | } |
6f19efc0 | 2572 | |
44139ed4 VK |
2573 | static int create_boost_sysfs_file(void) |
2574 | { | |
2575 | int ret; | |
2576 | ||
c82bd444 | 2577 | ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2578 | if (ret) |
2579 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
2580 | __func__); | |
2581 | ||
2582 | return ret; | |
2583 | } | |
2584 | ||
2585 | static void remove_boost_sysfs_file(void) | |
2586 | { | |
2587 | if (cpufreq_boost_supported()) | |
c82bd444 | 2588 | sysfs_remove_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2589 | } |
2590 | ||
2591 | int cpufreq_enable_boost_support(void) | |
2592 | { | |
2593 | if (!cpufreq_driver) | |
2594 | return -EINVAL; | |
2595 | ||
2596 | if (cpufreq_boost_supported()) | |
2597 | return 0; | |
2598 | ||
7a6c79f2 | 2599 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; |
44139ed4 VK |
2600 | |
2601 | /* This will get removed on driver unregister */ | |
2602 | return create_boost_sysfs_file(); | |
2603 | } | |
2604 | EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support); | |
2605 | ||
6f19efc0 LM |
2606 | int cpufreq_boost_enabled(void) |
2607 | { | |
2608 | return cpufreq_driver->boost_enabled; | |
2609 | } | |
2610 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2611 | ||
1da177e4 LT |
2612 | /********************************************************************* |
2613 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2614 | *********************************************************************/ | |
27622b06 | 2615 | static enum cpuhp_state hp_online; |
1da177e4 | 2616 | |
c4a3fa26 CY |
2617 | static int cpuhp_cpufreq_online(unsigned int cpu) |
2618 | { | |
2619 | cpufreq_online(cpu); | |
2620 | ||
2621 | return 0; | |
2622 | } | |
2623 | ||
2624 | static int cpuhp_cpufreq_offline(unsigned int cpu) | |
2625 | { | |
2626 | cpufreq_offline(cpu); | |
2627 | ||
2628 | return 0; | |
2629 | } | |
2630 | ||
1da177e4 LT |
2631 | /** |
2632 | * cpufreq_register_driver - register a CPU Frequency driver | |
2633 | * @driver_data: A struct cpufreq_driver containing the values# | |
2634 | * submitted by the CPU Frequency driver. | |
2635 | * | |
bb176f7d | 2636 | * Registers a CPU Frequency driver to this core code. This code |
63af4055 | 2637 | * returns zero on success, -EEXIST when another driver got here first |
32ee8c3e | 2638 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2639 | * |
2640 | */ | |
221dee28 | 2641 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2642 | { |
2643 | unsigned long flags; | |
2644 | int ret; | |
2645 | ||
a7b422cd KRW |
2646 | if (cpufreq_disabled()) |
2647 | return -ENODEV; | |
2648 | ||
1da177e4 | 2649 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2650 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2651 | driver_data->target) || |
2652 | (driver_data->setpolicy && (driver_data->target_index || | |
1c03a2d0 | 2653 | driver_data->target)) || |
a9a22b57 | 2654 | (!driver_data->get_intermediate != !driver_data->target_intermediate) || |
91a12e91 | 2655 | (!driver_data->online != !driver_data->offline)) |
1da177e4 LT |
2656 | return -EINVAL; |
2657 | ||
2d06d8c4 | 2658 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 | 2659 | |
fdd320da | 2660 | /* Protect against concurrent CPU online/offline. */ |
a92551e4 | 2661 | cpus_read_lock(); |
fdd320da | 2662 | |
0d1857a1 | 2663 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2664 | if (cpufreq_driver) { |
0d1857a1 | 2665 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fdd320da RW |
2666 | ret = -EEXIST; |
2667 | goto out; | |
1da177e4 | 2668 | } |
1c3d85dd | 2669 | cpufreq_driver = driver_data; |
0d1857a1 | 2670 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2671 | |
bc68b7df VK |
2672 | if (driver_data->setpolicy) |
2673 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2674 | ||
7a6c79f2 RW |
2675 | if (cpufreq_boost_supported()) { |
2676 | ret = create_boost_sysfs_file(); | |
2677 | if (ret) | |
2678 | goto err_null_driver; | |
2679 | } | |
6f19efc0 | 2680 | |
8a25a2fd | 2681 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2682 | if (ret) |
6f19efc0 | 2683 | goto err_boost_unreg; |
1da177e4 | 2684 | |
ce1bcfe9 VK |
2685 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY) && |
2686 | list_empty(&cpufreq_policy_list)) { | |
1da177e4 | 2687 | /* if all ->init() calls failed, unregister */ |
6c770036 | 2688 | ret = -ENODEV; |
ce1bcfe9 VK |
2689 | pr_debug("%s: No CPU initialized for driver %s\n", __func__, |
2690 | driver_data->name); | |
2691 | goto err_if_unreg; | |
1da177e4 LT |
2692 | } |
2693 | ||
a92551e4 SAS |
2694 | ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, |
2695 | "cpufreq:online", | |
2696 | cpuhp_cpufreq_online, | |
2697 | cpuhp_cpufreq_offline); | |
27622b06 SAS |
2698 | if (ret < 0) |
2699 | goto err_if_unreg; | |
2700 | hp_online = ret; | |
5372e054 | 2701 | ret = 0; |
27622b06 | 2702 | |
2d06d8c4 | 2703 | pr_debug("driver %s up and running\n", driver_data->name); |
3834abb4 | 2704 | goto out; |
fdd320da | 2705 | |
8a25a2fd KS |
2706 | err_if_unreg: |
2707 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 | 2708 | err_boost_unreg: |
44139ed4 | 2709 | remove_boost_sysfs_file(); |
8f5bc2ab | 2710 | err_null_driver: |
0d1857a1 | 2711 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2712 | cpufreq_driver = NULL; |
0d1857a1 | 2713 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
3834abb4 | 2714 | out: |
a92551e4 | 2715 | cpus_read_unlock(); |
3834abb4 | 2716 | return ret; |
1da177e4 LT |
2717 | } |
2718 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2719 | ||
1da177e4 LT |
2720 | /** |
2721 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2722 | * | |
bb176f7d | 2723 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2724 | * the right to do so, i.e. if you have succeeded in initialising before! |
2725 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2726 | * currently not initialised. | |
2727 | */ | |
221dee28 | 2728 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2729 | { |
2730 | unsigned long flags; | |
2731 | ||
1c3d85dd | 2732 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2733 | return -EINVAL; |
1da177e4 | 2734 | |
2d06d8c4 | 2735 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2736 | |
454d3a25 | 2737 | /* Protect against concurrent cpu hotplug */ |
a92551e4 | 2738 | cpus_read_lock(); |
8a25a2fd | 2739 | subsys_interface_unregister(&cpufreq_interface); |
44139ed4 | 2740 | remove_boost_sysfs_file(); |
a92551e4 | 2741 | cpuhp_remove_state_nocalls_cpuslocked(hp_online); |
1da177e4 | 2742 | |
0d1857a1 | 2743 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2744 | |
1c3d85dd | 2745 | cpufreq_driver = NULL; |
6eed9404 | 2746 | |
0d1857a1 | 2747 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
a92551e4 | 2748 | cpus_read_unlock(); |
1da177e4 LT |
2749 | |
2750 | return 0; | |
2751 | } | |
2752 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 | 2753 | |
90de2a4a DA |
2754 | /* |
2755 | * Stop cpufreq at shutdown to make sure it isn't holding any locks | |
2756 | * or mutexes when secondary CPUs are halted. | |
2757 | */ | |
2758 | static struct syscore_ops cpufreq_syscore_ops = { | |
2759 | .shutdown = cpufreq_suspend, | |
2760 | }; | |
2761 | ||
c82bd444 VK |
2762 | struct kobject *cpufreq_global_kobject; |
2763 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
2764 | ||
5a01f2e8 VP |
2765 | static int __init cpufreq_core_init(void) |
2766 | { | |
a7b422cd KRW |
2767 | if (cpufreq_disabled()) |
2768 | return -ENODEV; | |
2769 | ||
8eec1020 | 2770 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 TR |
2771 | BUG_ON(!cpufreq_global_kobject); |
2772 | ||
90de2a4a DA |
2773 | register_syscore_ops(&cpufreq_syscore_ops); |
2774 | ||
5a01f2e8 VP |
2775 | return 0; |
2776 | } | |
d82f2692 | 2777 | module_param(off, int, 0444); |
5a01f2e8 | 2778 | core_initcall(cpufreq_core_init); |