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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/drivers/cpufreq/cpufreq.c | |
4 | * | |
5 | * Copyright (C) 2001 Russell King | |
6 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
bb176f7d | 7 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> |
1da177e4 | 8 | * |
c32b6b8e | 9 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 10 | * Added handling for CPU hotplug |
8ff69732 DJ |
11 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
12 | * Fix handling for CPU hotplug -- affected CPUs | |
1da177e4 LT |
13 | */ |
14 | ||
db701151 VK |
15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
16 | ||
5ff0a268 | 17 | #include <linux/cpu.h> |
1da177e4 | 18 | #include <linux/cpufreq.h> |
5c238a8b | 19 | #include <linux/cpu_cooling.h> |
1da177e4 | 20 | #include <linux/delay.h> |
1da177e4 | 21 | #include <linux/device.h> |
5ff0a268 VK |
22 | #include <linux/init.h> |
23 | #include <linux/kernel_stat.h> | |
24 | #include <linux/module.h> | |
3fc54d37 | 25 | #include <linux/mutex.h> |
67d874c3 | 26 | #include <linux/pm_qos.h> |
5ff0a268 | 27 | #include <linux/slab.h> |
2f0aea93 | 28 | #include <linux/suspend.h> |
90de2a4a | 29 | #include <linux/syscore_ops.h> |
5ff0a268 | 30 | #include <linux/tick.h> |
6f4f2723 TR |
31 | #include <trace/events/power.h> |
32 | ||
b4f0676f | 33 | static LIST_HEAD(cpufreq_policy_list); |
f963735a | 34 | |
f963735a | 35 | /* Macros to iterate over CPU policies */ |
fd7dc7e6 EB |
36 | #define for_each_suitable_policy(__policy, __active) \ |
37 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \ | |
38 | if ((__active) == !policy_is_inactive(__policy)) | |
f963735a VK |
39 | |
40 | #define for_each_active_policy(__policy) \ | |
41 | for_each_suitable_policy(__policy, true) | |
42 | #define for_each_inactive_policy(__policy) \ | |
43 | for_each_suitable_policy(__policy, false) | |
44 | ||
45 | #define for_each_policy(__policy) \ | |
b4f0676f VK |
46 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) |
47 | ||
f7b27061 VK |
48 | /* Iterate over governors */ |
49 | static LIST_HEAD(cpufreq_governor_list); | |
50 | #define for_each_governor(__governor) \ | |
51 | list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) | |
52 | ||
1da177e4 | 53 | /** |
cd878479 | 54 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
55 | * level driver of CPUFreq support, and its spinlock. This lock |
56 | * also protects the cpufreq_cpu_data array. | |
57 | */ | |
1c3d85dd | 58 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 59 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
bb176f7d | 60 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
bb176f7d | 61 | |
2f0aea93 VK |
62 | /* Flag to suspend/resume CPUFreq governors */ |
63 | static bool cpufreq_suspended; | |
1da177e4 | 64 | |
9c0ebcf7 VK |
65 | static inline bool has_target(void) |
66 | { | |
67 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
68 | } | |
69 | ||
1da177e4 | 70 | /* internal prototypes */ |
d92d50a4 | 71 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy); |
a92604b4 RW |
72 | static int cpufreq_init_governor(struct cpufreq_policy *policy); |
73 | static void cpufreq_exit_governor(struct cpufreq_policy *policy); | |
0a300767 | 74 | static int cpufreq_start_governor(struct cpufreq_policy *policy); |
a92604b4 RW |
75 | static void cpufreq_stop_governor(struct cpufreq_policy *policy); |
76 | static void cpufreq_governor_limits(struct cpufreq_policy *policy); | |
1e4f63ae RW |
77 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
78 | struct cpufreq_governor *new_gov, | |
79 | unsigned int new_pol); | |
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 | |
183edb20 YL |
108 | static struct kobject *cpufreq_global_kobject; |
109 | ||
944e9a03 VK |
110 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
111 | { | |
112 | if (have_governor_per_policy()) | |
113 | return &policy->kobj; | |
114 | else | |
115 | return cpufreq_global_kobject; | |
116 | } | |
117 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
118 | ||
72a4ce34 VK |
119 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
120 | { | |
5720821b | 121 | struct kernel_cpustat kcpustat; |
72a4ce34 | 122 | u64 cur_wall_time; |
5720821b | 123 | u64 idle_time; |
72a4ce34 VK |
124 | u64 busy_time; |
125 | ||
7fb1327e | 126 | cur_wall_time = jiffies64_to_nsecs(get_jiffies_64()); |
72a4ce34 | 127 | |
5720821b FW |
128 | kcpustat_cpu_fetch(&kcpustat, cpu); |
129 | ||
130 | busy_time = kcpustat.cpustat[CPUTIME_USER]; | |
131 | busy_time += kcpustat.cpustat[CPUTIME_SYSTEM]; | |
132 | busy_time += kcpustat.cpustat[CPUTIME_IRQ]; | |
133 | busy_time += kcpustat.cpustat[CPUTIME_SOFTIRQ]; | |
134 | busy_time += kcpustat.cpustat[CPUTIME_STEAL]; | |
135 | busy_time += kcpustat.cpustat[CPUTIME_NICE]; | |
72a4ce34 VK |
136 | |
137 | idle_time = cur_wall_time - busy_time; | |
138 | if (wall) | |
7fb1327e | 139 | *wall = div_u64(cur_wall_time, NSEC_PER_USEC); |
72a4ce34 | 140 | |
7fb1327e | 141 | return div_u64(idle_time, NSEC_PER_USEC); |
72a4ce34 VK |
142 | } |
143 | ||
144 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
145 | { | |
146 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
147 | ||
148 | if (idle_time == -1ULL) | |
149 | return get_cpu_idle_time_jiffy(cpu, wall); | |
150 | else if (!io_busy) | |
151 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
152 | ||
153 | return idle_time; | |
154 | } | |
155 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
156 | ||
e7d5459d DE |
157 | __weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, |
158 | unsigned long max_freq) | |
159 | { | |
160 | } | |
161 | EXPORT_SYMBOL_GPL(arch_set_freq_scale); | |
162 | ||
70e9e778 VK |
163 | /* |
164 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
165 | * drivers of SMP systems. It will do following: | |
166 | * - validate & show freq table passed | |
167 | * - set policies transition latency | |
168 | * - policy->cpus with all possible CPUs | |
169 | */ | |
c4dcc8a1 | 170 | void cpufreq_generic_init(struct cpufreq_policy *policy, |
70e9e778 VK |
171 | struct cpufreq_frequency_table *table, |
172 | unsigned int transition_latency) | |
173 | { | |
92c99d15 | 174 | policy->freq_table = table; |
70e9e778 VK |
175 | policy->cpuinfo.transition_latency = transition_latency; |
176 | ||
177 | /* | |
58405af6 | 178 | * The driver only supports the SMP configuration where all processors |
70e9e778 VK |
179 | * share the clock and voltage and clock. |
180 | */ | |
181 | cpumask_setall(policy->cpus); | |
70e9e778 VK |
182 | } |
183 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
184 | ||
1f0bd44e | 185 | struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) |
652ed95d VK |
186 | { |
187 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
188 | ||
988bed09 VK |
189 | return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL; |
190 | } | |
1f0bd44e | 191 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw); |
988bed09 VK |
192 | |
193 | unsigned int cpufreq_generic_get(unsigned int cpu) | |
194 | { | |
195 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); | |
196 | ||
652ed95d | 197 | if (!policy || IS_ERR(policy->clk)) { |
e837f9b5 JP |
198 | pr_err("%s: No %s associated to cpu: %d\n", |
199 | __func__, policy ? "clk" : "policy", cpu); | |
652ed95d VK |
200 | return 0; |
201 | } | |
202 | ||
203 | return clk_get_rate(policy->clk) / 1000; | |
204 | } | |
205 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
206 | ||
50e9c852 | 207 | /** |
5d094fea RW |
208 | * cpufreq_cpu_get - Return policy for a CPU and mark it as busy. |
209 | * @cpu: CPU to find the policy for. | |
50e9c852 | 210 | * |
5d094fea RW |
211 | * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment |
212 | * the kobject reference counter of that policy. Return a valid policy on | |
213 | * success or NULL on failure. | |
50e9c852 | 214 | * |
5d094fea RW |
215 | * The policy returned by this function has to be released with the help of |
216 | * cpufreq_cpu_put() to balance its kobject reference counter properly. | |
50e9c852 | 217 | */ |
6eed9404 | 218 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 219 | { |
6eed9404 | 220 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
221 | unsigned long flags; |
222 | ||
1b947c90 | 223 | if (WARN_ON(cpu >= nr_cpu_ids)) |
6eed9404 VK |
224 | return NULL; |
225 | ||
1da177e4 | 226 | /* get the cpufreq driver */ |
1c3d85dd | 227 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 228 | |
6eed9404 VK |
229 | if (cpufreq_driver) { |
230 | /* get the CPU */ | |
988bed09 | 231 | policy = cpufreq_cpu_get_raw(cpu); |
6eed9404 VK |
232 | if (policy) |
233 | kobject_get(&policy->kobj); | |
234 | } | |
1da177e4 | 235 | |
6eed9404 | 236 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 237 | |
3a3e9e06 | 238 | return policy; |
a9144436 | 239 | } |
1da177e4 LT |
240 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
241 | ||
50e9c852 | 242 | /** |
5d094fea RW |
243 | * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy. |
244 | * @policy: cpufreq policy returned by cpufreq_cpu_get(). | |
50e9c852 | 245 | */ |
3a3e9e06 | 246 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 247 | { |
6eed9404 | 248 | kobject_put(&policy->kobj); |
1da177e4 LT |
249 | } |
250 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
251 | ||
540a3758 RW |
252 | /** |
253 | * cpufreq_cpu_release - Unlock a policy and decrement its usage counter. | |
254 | * @policy: cpufreq policy returned by cpufreq_cpu_acquire(). | |
255 | */ | |
9083e498 | 256 | void cpufreq_cpu_release(struct cpufreq_policy *policy) |
540a3758 RW |
257 | { |
258 | if (WARN_ON(!policy)) | |
259 | return; | |
260 | ||
261 | lockdep_assert_held(&policy->rwsem); | |
262 | ||
263 | up_write(&policy->rwsem); | |
264 | ||
265 | cpufreq_cpu_put(policy); | |
266 | } | |
267 | ||
268 | /** | |
269 | * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it. | |
270 | * @cpu: CPU to find the policy for. | |
271 | * | |
272 | * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and | |
273 | * if the policy returned by it is not NULL, acquire its rwsem for writing. | |
274 | * Return the policy if it is active or release it and return NULL otherwise. | |
275 | * | |
276 | * The policy returned by this function has to be released with the help of | |
277 | * cpufreq_cpu_release() in order to release its rwsem and balance its usage | |
278 | * counter properly. | |
279 | */ | |
9083e498 | 280 | struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu) |
540a3758 RW |
281 | { |
282 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
283 | ||
284 | if (!policy) | |
285 | return NULL; | |
286 | ||
287 | down_write(&policy->rwsem); | |
288 | ||
289 | if (policy_is_inactive(policy)) { | |
290 | cpufreq_cpu_release(policy); | |
291 | return NULL; | |
292 | } | |
293 | ||
294 | return policy; | |
295 | } | |
296 | ||
1da177e4 LT |
297 | /********************************************************************* |
298 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
299 | *********************************************************************/ | |
300 | ||
301 | /** | |
302 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
303 | * | |
304 | * This function alters the system "loops_per_jiffy" for the clock | |
305 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 306 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
307 | * per-CPU loops_per_jiffy value wherever possible. |
308 | */ | |
858119e1 | 309 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 | 310 | { |
39c132ee VK |
311 | #ifndef CONFIG_SMP |
312 | static unsigned long l_p_j_ref; | |
313 | static unsigned int l_p_j_ref_freq; | |
314 | ||
1da177e4 LT |
315 | if (ci->flags & CPUFREQ_CONST_LOOPS) |
316 | return; | |
317 | ||
318 | if (!l_p_j_ref_freq) { | |
319 | l_p_j_ref = loops_per_jiffy; | |
320 | l_p_j_ref_freq = ci->old; | |
e837f9b5 JP |
321 | pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", |
322 | l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 | 323 | } |
0b443ead | 324 | if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { |
e08f5f5b GS |
325 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
326 | ci->new); | |
e837f9b5 JP |
327 | pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", |
328 | loops_per_jiffy, ci->new); | |
1da177e4 | 329 | } |
1da177e4 | 330 | #endif |
39c132ee | 331 | } |
1da177e4 | 332 | |
20b5324d VK |
333 | /** |
334 | * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies. | |
335 | * @policy: cpufreq policy to enable fast frequency switching for. | |
336 | * @freqs: contain details of the frequency update. | |
337 | * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE. | |
338 | * | |
339 | * This function calls the transition notifiers and the "adjust_jiffies" | |
340 | * function. It is called twice on all CPU frequency changes that have | |
341 | * external effects. | |
342 | */ | |
343 | static void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
344 | struct cpufreq_freqs *freqs, | |
345 | unsigned int state) | |
1da177e4 | 346 | { |
df24014a VK |
347 | int cpu; |
348 | ||
1da177e4 LT |
349 | BUG_ON(irqs_disabled()); |
350 | ||
d5aaffa9 DB |
351 | if (cpufreq_disabled()) |
352 | return; | |
353 | ||
df24014a | 354 | freqs->policy = policy; |
1c3d85dd | 355 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 356 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e837f9b5 | 357 | state, freqs->new); |
1da177e4 | 358 | |
1da177e4 LT |
359 | switch (state) { |
360 | case CPUFREQ_PRECHANGE: | |
20b5324d VK |
361 | /* |
362 | * Detect if the driver reported a value as "old frequency" | |
e4472cb3 DJ |
363 | * which is not equal to what the cpufreq core thinks is |
364 | * "old frequency". | |
1da177e4 | 365 | */ |
98015228 VK |
366 | if (policy->cur && policy->cur != freqs->old) { |
367 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", | |
368 | freqs->old, policy->cur); | |
369 | freqs->old = policy->cur; | |
1da177e4 | 370 | } |
20b5324d | 371 | |
df24014a VK |
372 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
373 | CPUFREQ_PRECHANGE, freqs); | |
20b5324d | 374 | |
1da177e4 LT |
375 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
376 | break; | |
e4472cb3 | 377 | |
1da177e4 LT |
378 | case CPUFREQ_POSTCHANGE: |
379 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
20b5324d VK |
380 | pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new, |
381 | cpumask_pr_args(policy->cpus)); | |
382 | ||
df24014a VK |
383 | for_each_cpu(cpu, policy->cpus) |
384 | trace_cpu_frequency(freqs->new, cpu); | |
385 | ||
386 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
387 | CPUFREQ_POSTCHANGE, freqs); | |
20b5324d | 388 | |
1aefc75b | 389 | cpufreq_stats_record_transition(policy, freqs->new); |
20b5324d | 390 | policy->cur = freqs->new; |
1da177e4 | 391 | } |
1da177e4 | 392 | } |
bb176f7d | 393 | |
f7ba3b41 | 394 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 395 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
396 | struct cpufreq_freqs *freqs, int transition_failed) |
397 | { | |
398 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
399 | if (!transition_failed) | |
400 | return; | |
401 | ||
402 | swap(freqs->old, freqs->new); | |
403 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
404 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
405 | } | |
f7ba3b41 | 406 | |
12478cf0 SB |
407 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
408 | struct cpufreq_freqs *freqs) | |
409 | { | |
ca654dc3 SB |
410 | |
411 | /* | |
412 | * Catch double invocations of _begin() which lead to self-deadlock. | |
413 | * ASYNC_NOTIFICATION drivers are left out because the cpufreq core | |
414 | * doesn't invoke _begin() on their behalf, and hence the chances of | |
415 | * double invocations are very low. Moreover, there are scenarios | |
416 | * where these checks can emit false-positive warnings in these | |
417 | * drivers; so we avoid that by skipping them altogether. | |
418 | */ | |
419 | WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) | |
420 | && current == policy->transition_task); | |
421 | ||
12478cf0 SB |
422 | wait: |
423 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
424 | ||
425 | spin_lock(&policy->transition_lock); | |
426 | ||
427 | if (unlikely(policy->transition_ongoing)) { | |
428 | spin_unlock(&policy->transition_lock); | |
429 | goto wait; | |
430 | } | |
431 | ||
432 | policy->transition_ongoing = true; | |
ca654dc3 | 433 | policy->transition_task = current; |
12478cf0 SB |
434 | |
435 | spin_unlock(&policy->transition_lock); | |
436 | ||
437 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
438 | } | |
439 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
440 | ||
441 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
442 | struct cpufreq_freqs *freqs, int transition_failed) | |
443 | { | |
0e7ea2f3 | 444 | if (WARN_ON(!policy->transition_ongoing)) |
12478cf0 SB |
445 | return; |
446 | ||
447 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
448 | ||
449 | policy->transition_ongoing = false; | |
ca654dc3 | 450 | policy->transition_task = NULL; |
12478cf0 SB |
451 | |
452 | wake_up(&policy->transition_wait); | |
453 | } | |
454 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
455 | ||
b7898fda RW |
456 | /* |
457 | * Fast frequency switching status count. Positive means "enabled", negative | |
458 | * means "disabled" and 0 means "not decided yet". | |
459 | */ | |
460 | static int cpufreq_fast_switch_count; | |
461 | static DEFINE_MUTEX(cpufreq_fast_switch_lock); | |
462 | ||
463 | static void cpufreq_list_transition_notifiers(void) | |
464 | { | |
465 | struct notifier_block *nb; | |
466 | ||
467 | pr_info("Registered transition notifiers:\n"); | |
468 | ||
469 | mutex_lock(&cpufreq_transition_notifier_list.mutex); | |
470 | ||
471 | for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next) | |
d75f773c | 472 | pr_info("%pS\n", nb->notifier_call); |
b7898fda RW |
473 | |
474 | mutex_unlock(&cpufreq_transition_notifier_list.mutex); | |
475 | } | |
476 | ||
477 | /** | |
478 | * cpufreq_enable_fast_switch - Enable fast frequency switching for policy. | |
479 | * @policy: cpufreq policy to enable fast frequency switching for. | |
480 | * | |
481 | * Try to enable fast frequency switching for @policy. | |
482 | * | |
483 | * The attempt will fail if there is at least one transition notifier registered | |
484 | * at this point, as fast frequency switching is quite fundamentally at odds | |
485 | * with transition notifiers. Thus if successful, it will make registration of | |
486 | * transition notifiers fail going forward. | |
487 | */ | |
488 | void cpufreq_enable_fast_switch(struct cpufreq_policy *policy) | |
489 | { | |
490 | lockdep_assert_held(&policy->rwsem); | |
491 | ||
492 | if (!policy->fast_switch_possible) | |
493 | return; | |
494 | ||
495 | mutex_lock(&cpufreq_fast_switch_lock); | |
496 | if (cpufreq_fast_switch_count >= 0) { | |
497 | cpufreq_fast_switch_count++; | |
498 | policy->fast_switch_enabled = true; | |
499 | } else { | |
500 | pr_warn("CPU%u: Fast frequency switching not enabled\n", | |
501 | policy->cpu); | |
502 | cpufreq_list_transition_notifiers(); | |
503 | } | |
504 | mutex_unlock(&cpufreq_fast_switch_lock); | |
505 | } | |
506 | EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); | |
507 | ||
6c9d9c81 RW |
508 | /** |
509 | * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. | |
510 | * @policy: cpufreq policy to disable fast frequency switching for. | |
511 | */ | |
512 | void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) | |
b7898fda RW |
513 | { |
514 | mutex_lock(&cpufreq_fast_switch_lock); | |
515 | if (policy->fast_switch_enabled) { | |
516 | policy->fast_switch_enabled = false; | |
517 | if (!WARN_ON(cpufreq_fast_switch_count <= 0)) | |
518 | cpufreq_fast_switch_count--; | |
519 | } | |
520 | mutex_unlock(&cpufreq_fast_switch_lock); | |
521 | } | |
6c9d9c81 | 522 | EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); |
1da177e4 | 523 | |
e3c06236 SM |
524 | /** |
525 | * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported | |
526 | * one. | |
527 | * @target_freq: target frequency to resolve. | |
528 | * | |
529 | * The target to driver frequency mapping is cached in the policy. | |
530 | * | |
531 | * Return: Lowest driver-supported frequency greater than or equal to the | |
532 | * given target_freq, subject to policy (min/max) and driver limitations. | |
533 | */ | |
534 | unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, | |
535 | unsigned int target_freq) | |
536 | { | |
537 | target_freq = clamp_val(target_freq, policy->min, policy->max); | |
538 | policy->cached_target_freq = target_freq; | |
abe8bd02 VK |
539 | |
540 | if (cpufreq_driver->target_index) { | |
541 | int idx; | |
542 | ||
543 | idx = cpufreq_frequency_table_target(policy, target_freq, | |
544 | CPUFREQ_RELATION_L); | |
545 | policy->cached_resolved_idx = idx; | |
546 | return policy->freq_table[idx].frequency; | |
547 | } | |
548 | ||
e3c06236 SM |
549 | if (cpufreq_driver->resolve_freq) |
550 | return cpufreq_driver->resolve_freq(policy, target_freq); | |
abe8bd02 VK |
551 | |
552 | return target_freq; | |
e3c06236 | 553 | } |
ae2c1ca6 | 554 | EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); |
e3c06236 | 555 | |
aa7519af VK |
556 | unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy) |
557 | { | |
558 | unsigned int latency; | |
559 | ||
560 | if (policy->transition_delay_us) | |
561 | return policy->transition_delay_us; | |
562 | ||
563 | latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC; | |
e948bc8f VK |
564 | if (latency) { |
565 | /* | |
566 | * For platforms that can change the frequency very fast (< 10 | |
567 | * us), the above formula gives a decent transition delay. But | |
568 | * for platforms where transition_latency is in milliseconds, it | |
569 | * ends up giving unrealistic values. | |
570 | * | |
571 | * Cap the default transition delay to 10 ms, which seems to be | |
572 | * a reasonable amount of time after which we should reevaluate | |
573 | * the frequency. | |
574 | */ | |
575 | return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000); | |
576 | } | |
aa7519af VK |
577 | |
578 | return LATENCY_MULTIPLIER; | |
579 | } | |
580 | EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us); | |
581 | ||
1da177e4 LT |
582 | /********************************************************************* |
583 | * SYSFS INTERFACE * | |
584 | *********************************************************************/ | |
8a5c74a1 | 585 | static ssize_t show_boost(struct kobject *kobj, |
625c85a6 | 586 | struct kobj_attribute *attr, char *buf) |
6f19efc0 LM |
587 | { |
588 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
589 | } | |
590 | ||
625c85a6 VK |
591 | static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr, |
592 | const char *buf, size_t count) | |
6f19efc0 LM |
593 | { |
594 | int ret, enable; | |
595 | ||
596 | ret = sscanf(buf, "%d", &enable); | |
597 | if (ret != 1 || enable < 0 || enable > 1) | |
598 | return -EINVAL; | |
599 | ||
600 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
601 | pr_err("%s: Cannot %s BOOST!\n", |
602 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
603 | return -EINVAL; |
604 | } | |
605 | ||
e837f9b5 JP |
606 | pr_debug("%s: cpufreq BOOST %s\n", |
607 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
608 | |
609 | return count; | |
610 | } | |
611 | define_one_global_rw(boost); | |
1da177e4 | 612 | |
42f91fa1 | 613 | static struct cpufreq_governor *find_governor(const char *str_governor) |
3bcb09a3 JF |
614 | { |
615 | struct cpufreq_governor *t; | |
616 | ||
f7b27061 | 617 | for_each_governor(t) |
7c4f4539 | 618 | if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
619 | return t; |
620 | ||
621 | return NULL; | |
622 | } | |
623 | ||
1e4f63ae | 624 | static unsigned int cpufreq_parse_policy(char *str_governor) |
ab05d97a | 625 | { |
1e4f63ae RW |
626 | if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) |
627 | return CPUFREQ_POLICY_PERFORMANCE; | |
628 | ||
629 | if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) | |
630 | return CPUFREQ_POLICY_POWERSAVE; | |
631 | ||
632 | return CPUFREQ_POLICY_UNKNOWN; | |
ab05d97a YH |
633 | } |
634 | ||
1da177e4 | 635 | /** |
5ddc6d4e | 636 | * cpufreq_parse_governor - parse a governor string only for has_target() |
1e4f63ae | 637 | * @str_governor: Governor name. |
1da177e4 | 638 | */ |
1e4f63ae | 639 | static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor) |
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) | |
1e4f63ae | 653 | return NULL; |
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 | |
1e4f63ae | 664 | return t; |
1da177e4 | 665 | } |
1da177e4 | 666 | |
1da177e4 | 667 | /** |
e08f5f5b GS |
668 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
669 | * print out cpufreq information | |
1da177e4 LT |
670 | * |
671 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
672 | * "unsigned int". | |
673 | */ | |
674 | ||
32ee8c3e DJ |
675 | #define show_one(file_name, object) \ |
676 | static ssize_t show_##file_name \ | |
905d77cd | 677 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 678 | { \ |
29464f28 | 679 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
680 | } |
681 | ||
682 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
683 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 684 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
685 | show_one(scaling_min_freq, min); |
686 | show_one(scaling_max_freq, max); | |
c034b02e | 687 | |
f8475cef LB |
688 | __weak unsigned int arch_freq_get_on_cpu(int cpu) |
689 | { | |
690 | return 0; | |
691 | } | |
692 | ||
09347b29 | 693 | static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) |
c034b02e DB |
694 | { |
695 | ssize_t ret; | |
f8475cef | 696 | unsigned int freq; |
c034b02e | 697 | |
f8475cef LB |
698 | freq = arch_freq_get_on_cpu(policy->cpu); |
699 | if (freq) | |
700 | ret = sprintf(buf, "%u\n", freq); | |
701 | else if (cpufreq_driver && cpufreq_driver->setpolicy && | |
702 | cpufreq_driver->get) | |
c034b02e DB |
703 | ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); |
704 | else | |
705 | ret = sprintf(buf, "%u\n", policy->cur); | |
706 | return ret; | |
707 | } | |
1da177e4 LT |
708 | |
709 | /** | |
710 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
711 | */ | |
712 | #define store_one(file_name, object) \ | |
713 | static ssize_t store_##file_name \ | |
905d77cd | 714 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 715 | { \ |
18c49926 VK |
716 | unsigned long val; \ |
717 | int ret; \ | |
1da177e4 | 718 | \ |
18c49926 | 719 | ret = sscanf(buf, "%lu", &val); \ |
1da177e4 LT |
720 | if (ret != 1) \ |
721 | return -EINVAL; \ | |
722 | \ | |
3000ce3c | 723 | ret = freq_qos_update_request(policy->object##_freq_req, val);\ |
18c49926 | 724 | return ret >= 0 ? count : ret; \ |
1da177e4 LT |
725 | } |
726 | ||
29464f28 DJ |
727 | store_one(scaling_min_freq, min); |
728 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
729 | |
730 | /** | |
731 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
732 | */ | |
905d77cd DJ |
733 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
734 | char *buf) | |
1da177e4 | 735 | { |
d92d50a4 | 736 | unsigned int cur_freq = __cpufreq_get(policy); |
9b4f603e RW |
737 | |
738 | if (cur_freq) | |
739 | return sprintf(buf, "%u\n", cur_freq); | |
740 | ||
741 | return sprintf(buf, "<unknown>\n"); | |
1da177e4 LT |
742 | } |
743 | ||
1da177e4 LT |
744 | /** |
745 | * show_scaling_governor - show the current policy for the specified CPU | |
746 | */ | |
905d77cd | 747 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 748 | { |
29464f28 | 749 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
750 | return sprintf(buf, "powersave\n"); |
751 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
752 | return sprintf(buf, "performance\n"); | |
753 | else if (policy->governor) | |
4b972f0b | 754 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 755 | policy->governor->name); |
1da177e4 LT |
756 | return -EINVAL; |
757 | } | |
758 | ||
1da177e4 LT |
759 | /** |
760 | * store_scaling_governor - store policy for the specified CPU | |
761 | */ | |
905d77cd DJ |
762 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
763 | const char *buf, size_t count) | |
1da177e4 | 764 | { |
1e4f63ae | 765 | char str_governor[16]; |
5136fa56 | 766 | int ret; |
1da177e4 | 767 | |
29464f28 | 768 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
769 | if (ret != 1) |
770 | return -EINVAL; | |
771 | ||
ab05d97a | 772 | if (cpufreq_driver->setpolicy) { |
1e4f63ae RW |
773 | unsigned int new_pol; |
774 | ||
775 | new_pol = cpufreq_parse_policy(str_governor); | |
776 | if (!new_pol) | |
ab05d97a | 777 | return -EINVAL; |
1e4f63ae RW |
778 | |
779 | ret = cpufreq_set_policy(policy, NULL, new_pol); | |
ab05d97a | 780 | } else { |
1e4f63ae RW |
781 | struct cpufreq_governor *new_gov; |
782 | ||
783 | new_gov = cpufreq_parse_governor(str_governor); | |
784 | if (!new_gov) | |
ab05d97a | 785 | return -EINVAL; |
1da177e4 | 786 | |
1e4f63ae RW |
787 | ret = cpufreq_set_policy(policy, new_gov, |
788 | CPUFREQ_POLICY_UNKNOWN); | |
a8b149d3 | 789 | |
1e4f63ae RW |
790 | module_put(new_gov->owner); |
791 | } | |
a8b149d3 | 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 | |
e6e8df07 KS |
941 | if (!fattr->show) |
942 | return -EIO; | |
943 | ||
ad7722da | 944 | down_read(&policy->rwsem); |
6541aef0 | 945 | ret = fattr->show(policy, buf); |
ad7722da | 946 | up_read(&policy->rwsem); |
1b750e3b | 947 | |
1da177e4 LT |
948 | return ret; |
949 | } | |
950 | ||
905d77cd DJ |
951 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
952 | const char *buf, size_t count) | |
1da177e4 | 953 | { |
905d77cd DJ |
954 | struct cpufreq_policy *policy = to_policy(kobj); |
955 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 956 | ssize_t ret = -EINVAL; |
6eed9404 | 957 | |
e6e8df07 KS |
958 | if (!fattr->store) |
959 | return -EIO; | |
960 | ||
9b3d9bb3 WL |
961 | /* |
962 | * cpus_read_trylock() is used here to work around a circular lock | |
963 | * dependency problem with respect to the cpufreq_register_driver(). | |
964 | */ | |
965 | if (!cpus_read_trylock()) | |
966 | return -EBUSY; | |
4f750c93 | 967 | |
6541aef0 RW |
968 | if (cpu_online(policy->cpu)) { |
969 | down_write(&policy->rwsem); | |
e08f5f5b | 970 | ret = fattr->store(policy, buf, count); |
6541aef0 RW |
971 | up_write(&policy->rwsem); |
972 | } | |
e08f5f5b | 973 | |
a92551e4 | 974 | cpus_read_unlock(); |
4f750c93 | 975 | |
1da177e4 LT |
976 | return ret; |
977 | } | |
978 | ||
905d77cd | 979 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 980 | { |
905d77cd | 981 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 982 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
983 | complete(&policy->kobj_unregister); |
984 | } | |
985 | ||
52cf25d0 | 986 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
987 | .show = show, |
988 | .store = store, | |
989 | }; | |
990 | ||
991 | static struct kobj_type ktype_cpufreq = { | |
992 | .sysfs_ops = &sysfs_ops, | |
993 | .default_attrs = default_attrs, | |
994 | .release = cpufreq_sysfs_release, | |
995 | }; | |
996 | ||
2f0ba790 | 997 | static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) |
87549141 | 998 | { |
2f0ba790 RW |
999 | struct device *dev = get_cpu_device(cpu); |
1000 | ||
67d874c3 | 1001 | if (unlikely(!dev)) |
2f0ba790 RW |
1002 | return; |
1003 | ||
1004 | if (cpumask_test_and_set_cpu(cpu, policy->real_cpus)) | |
1005 | return; | |
1006 | ||
26619804 | 1007 | dev_dbg(dev, "%s: Adding symlink\n", __func__); |
2f0ba790 RW |
1008 | if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq")) |
1009 | dev_err(dev, "cpufreq symlink creation failed\n"); | |
87549141 VK |
1010 | } |
1011 | ||
26619804 VK |
1012 | static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, |
1013 | struct device *dev) | |
87549141 | 1014 | { |
26619804 VK |
1015 | dev_dbg(dev, "%s: Removing symlink\n", __func__); |
1016 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
87549141 VK |
1017 | } |
1018 | ||
d9612a49 | 1019 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) |
909a694e DJ |
1020 | { |
1021 | struct freq_attr **drv_attr; | |
909a694e | 1022 | int ret = 0; |
909a694e | 1023 | |
909a694e | 1024 | /* set up files for this cpu device */ |
1c3d85dd | 1025 | drv_attr = cpufreq_driver->attr; |
f13f1184 | 1026 | while (drv_attr && *drv_attr) { |
909a694e DJ |
1027 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
1028 | if (ret) | |
6d4e81ed | 1029 | return ret; |
909a694e DJ |
1030 | drv_attr++; |
1031 | } | |
1c3d85dd | 1032 | if (cpufreq_driver->get) { |
909a694e DJ |
1033 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
1034 | if (ret) | |
6d4e81ed | 1035 | return ret; |
909a694e | 1036 | } |
c034b02e DB |
1037 | |
1038 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
1039 | if (ret) | |
6d4e81ed | 1040 | return ret; |
c034b02e | 1041 | |
1c3d85dd | 1042 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
1043 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
1044 | if (ret) | |
6d4e81ed | 1045 | return ret; |
e2f74f35 | 1046 | } |
909a694e | 1047 | |
26619804 | 1048 | return 0; |
e18f1682 SB |
1049 | } |
1050 | ||
de1df26b RW |
1051 | __weak struct cpufreq_governor *cpufreq_default_governor(void) |
1052 | { | |
1053 | return NULL; | |
1054 | } | |
1055 | ||
7f0fa40f | 1056 | static int cpufreq_init_policy(struct cpufreq_policy *policy) |
e18f1682 | 1057 | { |
1e4f63ae RW |
1058 | struct cpufreq_governor *def_gov = cpufreq_default_governor(); |
1059 | struct cpufreq_governor *gov = NULL; | |
1060 | unsigned int pol = CPUFREQ_POLICY_UNKNOWN; | |
ab05d97a YH |
1061 | |
1062 | if (has_target()) { | |
1e4f63ae | 1063 | /* Update policy governor to the one used before hotplug. */ |
ab05d97a YH |
1064 | gov = find_governor(policy->last_governor); |
1065 | if (gov) { | |
1066 | pr_debug("Restoring governor %s for cpu %d\n", | |
1e4f63ae RW |
1067 | policy->governor->name, policy->cpu); |
1068 | } else if (def_gov) { | |
ab05d97a | 1069 | gov = def_gov; |
1e4f63ae RW |
1070 | } else { |
1071 | return -ENODATA; | |
ab05d97a | 1072 | } |
de1df26b | 1073 | } else { |
ab05d97a YH |
1074 | /* Use the default policy if there is no last_policy. */ |
1075 | if (policy->last_policy) { | |
1e4f63ae RW |
1076 | pol = policy->last_policy; |
1077 | } else if (def_gov) { | |
1078 | pol = cpufreq_parse_policy(def_gov->name); | |
f5739cb0 RW |
1079 | /* |
1080 | * In case the default governor is neiter "performance" | |
1081 | * nor "powersave", fall back to the initial policy | |
1082 | * value set by the driver. | |
1083 | */ | |
1084 | if (pol == CPUFREQ_POLICY_UNKNOWN) | |
1085 | pol = policy->policy; | |
ab05d97a | 1086 | } |
f5739cb0 RW |
1087 | if (pol != CPUFREQ_POLICY_PERFORMANCE && |
1088 | pol != CPUFREQ_POLICY_POWERSAVE) | |
1089 | return -ENODATA; | |
69030dd1 | 1090 | } |
ab05d97a | 1091 | |
1e4f63ae | 1092 | return cpufreq_set_policy(policy, gov, pol); |
909a694e DJ |
1093 | } |
1094 | ||
d9612a49 | 1095 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
fcf80582 | 1096 | { |
9c0ebcf7 | 1097 | int ret = 0; |
fcf80582 | 1098 | |
bb29ae15 VK |
1099 | /* Has this CPU been taken care of already? */ |
1100 | if (cpumask_test_cpu(cpu, policy->cpus)) | |
1101 | return 0; | |
1102 | ||
49f18560 | 1103 | down_write(&policy->rwsem); |
45482c70 RW |
1104 | if (has_target()) |
1105 | cpufreq_stop_governor(policy); | |
fcf80582 | 1106 | |
fcf80582 | 1107 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 1108 | |
9c0ebcf7 | 1109 | if (has_target()) { |
0a300767 | 1110 | ret = cpufreq_start_governor(policy); |
49f18560 | 1111 | if (ret) |
3de9bdeb | 1112 | pr_err("%s: Failed to start governor\n", __func__); |
820c6ca2 | 1113 | } |
49f18560 VK |
1114 | up_write(&policy->rwsem); |
1115 | return ret; | |
fcf80582 | 1116 | } |
1da177e4 | 1117 | |
c57b25bd | 1118 | void refresh_frequency_limits(struct cpufreq_policy *policy) |
70a59fde | 1119 | { |
67d874c3 | 1120 | if (!policy_is_inactive(policy)) { |
67d874c3 | 1121 | pr_debug("updating policy for CPU %u\n", policy->cpu); |
70a59fde | 1122 | |
1e4f63ae | 1123 | cpufreq_set_policy(policy, policy->governor, policy->policy); |
67d874c3 | 1124 | } |
70a59fde | 1125 | } |
c57b25bd | 1126 | EXPORT_SYMBOL(refresh_frequency_limits); |
70a59fde | 1127 | |
11eb69b9 VK |
1128 | static void handle_update(struct work_struct *work) |
1129 | { | |
1130 | struct cpufreq_policy *policy = | |
1131 | container_of(work, struct cpufreq_policy, update); | |
70a59fde VK |
1132 | |
1133 | pr_debug("handle_update for cpu %u called\n", policy->cpu); | |
67d874c3 | 1134 | down_write(&policy->rwsem); |
70a59fde | 1135 | refresh_frequency_limits(policy); |
67d874c3 VK |
1136 | up_write(&policy->rwsem); |
1137 | } | |
1138 | ||
1139 | static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq, | |
1140 | void *data) | |
1141 | { | |
1142 | struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min); | |
1143 | ||
1144 | schedule_work(&policy->update); | |
1145 | return 0; | |
1146 | } | |
1147 | ||
1148 | static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq, | |
1149 | void *data) | |
1150 | { | |
1151 | struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max); | |
1152 | ||
1153 | schedule_work(&policy->update); | |
1154 | return 0; | |
1155 | } | |
1156 | ||
1157 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) | |
1158 | { | |
1159 | struct kobject *kobj; | |
1160 | struct completion *cmp; | |
1161 | ||
1162 | down_write(&policy->rwsem); | |
1163 | cpufreq_stats_free_table(policy); | |
1164 | kobj = &policy->kobj; | |
1165 | cmp = &policy->kobj_unregister; | |
1166 | up_write(&policy->rwsem); | |
1167 | kobject_put(kobj); | |
1168 | ||
1169 | /* | |
1170 | * We need to make sure that the underlying kobj is | |
1171 | * actually not referenced anymore by anybody before we | |
1172 | * proceed with unloading. | |
1173 | */ | |
1174 | pr_debug("waiting for dropping of refcount\n"); | |
1175 | wait_for_completion(cmp); | |
1176 | pr_debug("wait complete\n"); | |
fcf80582 | 1177 | } |
1da177e4 | 1178 | |
a34e63b1 | 1179 | static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) |
e9698cc5 SB |
1180 | { |
1181 | struct cpufreq_policy *policy; | |
67d874c3 | 1182 | struct device *dev = get_cpu_device(cpu); |
edd4a893 | 1183 | int ret; |
e9698cc5 | 1184 | |
67d874c3 VK |
1185 | if (!dev) |
1186 | return NULL; | |
1187 | ||
e9698cc5 SB |
1188 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); |
1189 | if (!policy) | |
1190 | return NULL; | |
1191 | ||
1192 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1193 | goto err_free_policy; | |
1194 | ||
1195 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1196 | goto err_free_cpumask; | |
1197 | ||
559ed407 RW |
1198 | if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) |
1199 | goto err_free_rcpumask; | |
1200 | ||
edd4a893 VK |
1201 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
1202 | cpufreq_global_kobject, "policy%u", cpu); | |
1203 | if (ret) { | |
67d874c3 | 1204 | dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret); |
2acb9bda RW |
1205 | /* |
1206 | * The entire policy object will be freed below, but the extra | |
1207 | * memory allocated for the kobject name needs to be freed by | |
1208 | * releasing the kobject. | |
1209 | */ | |
4ebe36c9 | 1210 | kobject_put(&policy->kobj); |
edd4a893 VK |
1211 | goto err_free_real_cpus; |
1212 | } | |
1213 | ||
3000ce3c RW |
1214 | freq_constraints_init(&policy->constraints); |
1215 | ||
67d874c3 VK |
1216 | policy->nb_min.notifier_call = cpufreq_notifier_min; |
1217 | policy->nb_max.notifier_call = cpufreq_notifier_max; | |
1218 | ||
3000ce3c RW |
1219 | ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN, |
1220 | &policy->nb_min); | |
67d874c3 VK |
1221 | if (ret) { |
1222 | dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n", | |
1223 | ret, cpumask_pr_args(policy->cpus)); | |
1224 | goto err_kobj_remove; | |
1225 | } | |
1226 | ||
3000ce3c RW |
1227 | ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX, |
1228 | &policy->nb_max); | |
67d874c3 VK |
1229 | if (ret) { |
1230 | dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n", | |
1231 | ret, cpumask_pr_args(policy->cpus)); | |
1232 | goto err_min_qos_notifier; | |
1233 | } | |
1234 | ||
c88a1f8b | 1235 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1236 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1237 | spin_lock_init(&policy->transition_lock); |
1238 | init_waitqueue_head(&policy->transition_wait); | |
818c5712 VK |
1239 | init_completion(&policy->kobj_unregister); |
1240 | INIT_WORK(&policy->update, handle_update); | |
ad7722da | 1241 | |
a34e63b1 | 1242 | policy->cpu = cpu; |
e9698cc5 SB |
1243 | return policy; |
1244 | ||
67d874c3 | 1245 | err_min_qos_notifier: |
3000ce3c RW |
1246 | freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN, |
1247 | &policy->nb_min); | |
67d874c3 VK |
1248 | err_kobj_remove: |
1249 | cpufreq_policy_put_kobj(policy); | |
edd4a893 VK |
1250 | err_free_real_cpus: |
1251 | free_cpumask_var(policy->real_cpus); | |
2fc3384d VK |
1252 | err_free_rcpumask: |
1253 | free_cpumask_var(policy->related_cpus); | |
e9698cc5 SB |
1254 | err_free_cpumask: |
1255 | free_cpumask_var(policy->cpus); | |
1256 | err_free_policy: | |
1257 | kfree(policy); | |
1258 | ||
1259 | return NULL; | |
1260 | } | |
1261 | ||
f9f41e3e | 1262 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
e9698cc5 | 1263 | { |
988bed09 VK |
1264 | unsigned long flags; |
1265 | int cpu; | |
1266 | ||
1267 | /* Remove policy from list */ | |
1268 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1269 | list_del(&policy->policy_list); | |
1270 | ||
1271 | for_each_cpu(cpu, policy->related_cpus) | |
1272 | per_cpu(cpufreq_cpu_data, cpu) = NULL; | |
1273 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1274 | ||
3000ce3c RW |
1275 | freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX, |
1276 | &policy->nb_max); | |
1277 | freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN, | |
1278 | &policy->nb_min); | |
6a149036 | 1279 | |
6941051d SH |
1280 | /* Cancel any pending policy->update work before freeing the policy. */ |
1281 | cancel_work_sync(&policy->update); | |
6a149036 VK |
1282 | |
1283 | if (policy->max_freq_req) { | |
1284 | /* | |
1285 | * CPUFREQ_CREATE_POLICY notification is sent only after | |
1286 | * successfully adding max_freq_req request. | |
1287 | */ | |
1288 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1289 | CPUFREQ_REMOVE_POLICY, policy); | |
3000ce3c | 1290 | freq_qos_remove_request(policy->max_freq_req); |
6a149036 VK |
1291 | } |
1292 | ||
3000ce3c | 1293 | freq_qos_remove_request(policy->min_freq_req); |
18c49926 | 1294 | kfree(policy->min_freq_req); |
67d874c3 | 1295 | |
f9f41e3e | 1296 | cpufreq_policy_put_kobj(policy); |
559ed407 | 1297 | free_cpumask_var(policy->real_cpus); |
e9698cc5 SB |
1298 | free_cpumask_var(policy->related_cpus); |
1299 | free_cpumask_var(policy->cpus); | |
1300 | kfree(policy); | |
1301 | } | |
1302 | ||
0b275352 | 1303 | static int cpufreq_online(unsigned int cpu) |
1da177e4 | 1304 | { |
7f0c020a | 1305 | struct cpufreq_policy *policy; |
194d99c7 | 1306 | bool new_policy; |
1da177e4 | 1307 | unsigned long flags; |
0b275352 RW |
1308 | unsigned int j; |
1309 | int ret; | |
87549141 | 1310 | |
0b275352 | 1311 | pr_debug("%s: bringing CPU%u online\n", __func__, cpu); |
6eed9404 | 1312 | |
bb29ae15 | 1313 | /* Check if this CPU already has a policy to manage it */ |
9104bb26 | 1314 | policy = per_cpu(cpufreq_cpu_data, cpu); |
11ce707e | 1315 | if (policy) { |
9104bb26 | 1316 | WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus)); |
11ce707e | 1317 | if (!policy_is_inactive(policy)) |
d9612a49 | 1318 | return cpufreq_add_policy_cpu(policy, cpu); |
1da177e4 | 1319 | |
11ce707e | 1320 | /* This is the only online CPU for the policy. Start over. */ |
194d99c7 | 1321 | new_policy = false; |
11ce707e RW |
1322 | down_write(&policy->rwsem); |
1323 | policy->cpu = cpu; | |
1324 | policy->governor = NULL; | |
1325 | up_write(&policy->rwsem); | |
1326 | } else { | |
194d99c7 | 1327 | new_policy = true; |
a34e63b1 | 1328 | policy = cpufreq_policy_alloc(cpu); |
72368d12 | 1329 | if (!policy) |
d4d854d6 | 1330 | return -ENOMEM; |
72368d12 | 1331 | } |
0d66b91e | 1332 | |
91a12e91 VK |
1333 | if (!new_policy && cpufreq_driver->online) { |
1334 | ret = cpufreq_driver->online(policy); | |
1335 | if (ret) { | |
1336 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1337 | __LINE__); | |
1338 | goto out_exit_policy; | |
1339 | } | |
1da177e4 | 1340 | |
91a12e91 VK |
1341 | /* Recover policy->cpus using related_cpus */ |
1342 | cpumask_copy(policy->cpus, policy->related_cpus); | |
1343 | } else { | |
1344 | cpumask_copy(policy->cpus, cpumask_of(cpu)); | |
643ae6e8 | 1345 | |
91a12e91 VK |
1346 | /* |
1347 | * Call driver. From then on the cpufreq must be able | |
1348 | * to accept all calls to ->verify and ->setpolicy for this CPU. | |
1349 | */ | |
1350 | ret = cpufreq_driver->init(policy); | |
1351 | if (ret) { | |
1352 | pr_debug("%s: %d: initialization failed\n", __func__, | |
1353 | __LINE__); | |
1354 | goto out_free_policy; | |
1355 | } | |
d417e069 | 1356 | |
91a12e91 VK |
1357 | ret = cpufreq_table_validate_and_sort(policy); |
1358 | if (ret) | |
1359 | goto out_exit_policy; | |
6d4e81ed | 1360 | |
4d1f3a5b | 1361 | /* related_cpus should at least include policy->cpus. */ |
0998a03a | 1362 | cpumask_copy(policy->related_cpus, policy->cpus); |
4d1f3a5b | 1363 | } |
559ed407 | 1364 | |
91a12e91 | 1365 | down_write(&policy->rwsem); |
5a7e56a5 VK |
1366 | /* |
1367 | * affected cpus must always be the one, which are online. We aren't | |
1368 | * managing offline cpus here. | |
1369 | */ | |
1370 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1371 | ||
194d99c7 | 1372 | if (new_policy) { |
2f0ba790 | 1373 | for_each_cpu(j, policy->related_cpus) { |
988bed09 | 1374 | per_cpu(cpufreq_cpu_data, j) = policy; |
2f0ba790 RW |
1375 | add_cpu_dev_symlink(policy, j); |
1376 | } | |
18c49926 VK |
1377 | |
1378 | policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req), | |
1379 | GFP_KERNEL); | |
1380 | if (!policy->min_freq_req) | |
1381 | goto out_destroy_policy; | |
1382 | ||
3000ce3c RW |
1383 | ret = freq_qos_add_request(&policy->constraints, |
1384 | policy->min_freq_req, FREQ_QOS_MIN, | |
1385 | policy->min); | |
18c49926 VK |
1386 | if (ret < 0) { |
1387 | /* | |
3000ce3c | 1388 | * So we don't call freq_qos_remove_request() for an |
18c49926 VK |
1389 | * uninitialized request. |
1390 | */ | |
1391 | kfree(policy->min_freq_req); | |
1392 | policy->min_freq_req = NULL; | |
18c49926 VK |
1393 | goto out_destroy_policy; |
1394 | } | |
1395 | ||
1396 | /* | |
1397 | * This must be initialized right here to avoid calling | |
3000ce3c | 1398 | * freq_qos_remove_request() on uninitialized request in case |
18c49926 VK |
1399 | * of errors. |
1400 | */ | |
1401 | policy->max_freq_req = policy->min_freq_req + 1; | |
1402 | ||
3000ce3c RW |
1403 | ret = freq_qos_add_request(&policy->constraints, |
1404 | policy->max_freq_req, FREQ_QOS_MAX, | |
1405 | policy->max); | |
18c49926 VK |
1406 | if (ret < 0) { |
1407 | policy->max_freq_req = NULL; | |
18c49926 VK |
1408 | goto out_destroy_policy; |
1409 | } | |
6a149036 VK |
1410 | |
1411 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1412 | CPUFREQ_CREATE_POLICY, policy); | |
988bed09 | 1413 | } |
652ed95d | 1414 | |
5ddc6d4e | 1415 | if (cpufreq_driver->get && has_target()) { |
da60ce9f VK |
1416 | policy->cur = cpufreq_driver->get(policy->cpu); |
1417 | if (!policy->cur) { | |
1418 | pr_err("%s: ->get() failed\n", __func__); | |
d417e069 | 1419 | goto out_destroy_policy; |
da60ce9f VK |
1420 | } |
1421 | } | |
1422 | ||
d3916691 VK |
1423 | /* |
1424 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1425 | * frequency table present with cpufreq core. In such cases CPU might be | |
1426 | * unstable if it has to run on that frequency for long duration of time | |
1427 | * and so its better to set it to a frequency which is specified in | |
1428 | * freq-table. This also makes cpufreq stats inconsistent as | |
1429 | * cpufreq-stats would fail to register because current frequency of CPU | |
1430 | * isn't found in freq-table. | |
1431 | * | |
1432 | * Because we don't want this change to effect boot process badly, we go | |
1433 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1434 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1435 | * is initialized to zero). | |
1436 | * | |
1437 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1438 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1439 | * equal to target-freq. | |
1440 | */ | |
1441 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1442 | && has_target()) { | |
1443 | /* Are we running at unknown frequency ? */ | |
1444 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1445 | if (ret == -EINVAL) { | |
1446 | /* Warn user and fix it */ | |
1447 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1448 | __func__, policy->cpu, policy->cur); | |
1449 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1450 | CPUFREQ_RELATION_L); | |
1451 | ||
1452 | /* | |
1453 | * Reaching here after boot in a few seconds may not | |
1454 | * mean that system will remain stable at "unknown" | |
1455 | * frequency for longer duration. Hence, a BUG_ON(). | |
1456 | */ | |
1457 | BUG_ON(ret); | |
1458 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1459 | __func__, policy->cpu, policy->cur); | |
1460 | } | |
1461 | } | |
1462 | ||
194d99c7 | 1463 | if (new_policy) { |
d9612a49 | 1464 | ret = cpufreq_add_dev_interface(policy); |
a82fab29 | 1465 | if (ret) |
d417e069 | 1466 | goto out_destroy_policy; |
1aefc75b RW |
1467 | |
1468 | cpufreq_stats_create_table(policy); | |
8ff69732 | 1469 | |
988bed09 VK |
1470 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1471 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1472 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1473 | } | |
9515f4d6 | 1474 | |
7f0fa40f VK |
1475 | ret = cpufreq_init_policy(policy); |
1476 | if (ret) { | |
1477 | pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", | |
1478 | __func__, cpu, ret); | |
d417e069 | 1479 | goto out_destroy_policy; |
08fd8c1c | 1480 | } |
e18f1682 | 1481 | |
4e97b631 | 1482 | up_write(&policy->rwsem); |
08fd8c1c | 1483 | |
038c5b3e | 1484 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
7c45cf31 | 1485 | |
7c45cf31 VK |
1486 | /* Callback for handling stuff after policy is ready */ |
1487 | if (cpufreq_driver->ready) | |
1488 | cpufreq_driver->ready(policy); | |
1489 | ||
bcc61569 | 1490 | if (cpufreq_thermal_control_enabled(cpufreq_driver)) |
5c238a8b AK |
1491 | policy->cdev = of_cpufreq_cooling_register(policy); |
1492 | ||
2d06d8c4 | 1493 | pr_debug("initialization complete\n"); |
87c32271 | 1494 | |
1da177e4 LT |
1495 | return 0; |
1496 | ||
d417e069 | 1497 | out_destroy_policy: |
b24b6478 VK |
1498 | for_each_cpu(j, policy->real_cpus) |
1499 | remove_cpu_dev_symlink(policy, get_cpu_device(j)); | |
1500 | ||
7106e02b PB |
1501 | up_write(&policy->rwsem); |
1502 | ||
d417e069 | 1503 | out_exit_policy: |
da60ce9f VK |
1504 | if (cpufreq_driver->exit) |
1505 | cpufreq_driver->exit(policy); | |
2f0ba790 | 1506 | |
8101f997 | 1507 | out_free_policy: |
f9f41e3e | 1508 | cpufreq_policy_free(policy); |
1da177e4 LT |
1509 | return ret; |
1510 | } | |
1511 | ||
0b275352 RW |
1512 | /** |
1513 | * cpufreq_add_dev - the cpufreq interface for a CPU device. | |
1514 | * @dev: CPU device. | |
1515 | * @sif: Subsystem interface structure pointer (not used) | |
1516 | */ | |
1517 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1518 | { | |
a794d613 | 1519 | struct cpufreq_policy *policy; |
0b275352 | 1520 | unsigned cpu = dev->id; |
26619804 | 1521 | int ret; |
0b275352 RW |
1522 | |
1523 | dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); | |
1524 | ||
26619804 VK |
1525 | if (cpu_online(cpu)) { |
1526 | ret = cpufreq_online(cpu); | |
1527 | if (ret) | |
1528 | return ret; | |
1529 | } | |
0b275352 | 1530 | |
26619804 | 1531 | /* Create sysfs link on CPU registration */ |
a794d613 | 1532 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2f0ba790 RW |
1533 | if (policy) |
1534 | add_cpu_dev_symlink(policy, cpu); | |
26619804 | 1535 | |
2f0ba790 | 1536 | return 0; |
1da177e4 LT |
1537 | } |
1538 | ||
27622b06 | 1539 | static int cpufreq_offline(unsigned int cpu) |
1da177e4 | 1540 | { |
3a3e9e06 | 1541 | struct cpufreq_policy *policy; |
69cee714 | 1542 | int ret; |
1da177e4 | 1543 | |
b8eed8af | 1544 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1545 | |
988bed09 | 1546 | policy = cpufreq_cpu_get_raw(cpu); |
3a3e9e06 | 1547 | if (!policy) { |
b8eed8af | 1548 | pr_debug("%s: No cpu_data found\n", __func__); |
27622b06 | 1549 | return 0; |
1da177e4 | 1550 | } |
1da177e4 | 1551 | |
49f18560 | 1552 | down_write(&policy->rwsem); |
45482c70 RW |
1553 | if (has_target()) |
1554 | cpufreq_stop_governor(policy); | |
1da177e4 | 1555 | |
9591becb | 1556 | cpumask_clear_cpu(cpu, policy->cpus); |
4573237b | 1557 | |
9591becb VK |
1558 | if (policy_is_inactive(policy)) { |
1559 | if (has_target()) | |
1560 | strncpy(policy->last_governor, policy->governor->name, | |
1561 | CPUFREQ_NAME_LEN); | |
69030dd1 SP |
1562 | else |
1563 | policy->last_policy = policy->policy; | |
9591becb VK |
1564 | } else if (cpu == policy->cpu) { |
1565 | /* Nominate new CPU */ | |
1566 | policy->cpu = cpumask_any(policy->cpus); | |
1567 | } | |
084f3493 | 1568 | |
9591becb VK |
1569 | /* Start governor again for active policy */ |
1570 | if (!policy_is_inactive(policy)) { | |
1571 | if (has_target()) { | |
0a300767 | 1572 | ret = cpufreq_start_governor(policy); |
9591becb VK |
1573 | if (ret) |
1574 | pr_err("%s: Failed to start governor\n", __func__); | |
1575 | } | |
cedb70af | 1576 | |
49f18560 | 1577 | goto unlock; |
cedb70af SB |
1578 | } |
1579 | ||
bcc61569 | 1580 | if (cpufreq_thermal_control_enabled(cpufreq_driver)) { |
5c238a8b AK |
1581 | cpufreq_cooling_unregister(policy->cdev); |
1582 | policy->cdev = NULL; | |
1583 | } | |
1584 | ||
69cee714 VK |
1585 | if (cpufreq_driver->stop_cpu) |
1586 | cpufreq_driver->stop_cpu(policy); | |
87549141 | 1587 | |
36be3418 RW |
1588 | if (has_target()) |
1589 | cpufreq_exit_governor(policy); | |
1da177e4 | 1590 | |
87549141 | 1591 | /* |
91a12e91 VK |
1592 | * Perform the ->offline() during light-weight tear-down, as |
1593 | * that allows fast recovery when the CPU comes back. | |
87549141 | 1594 | */ |
91a12e91 VK |
1595 | if (cpufreq_driver->offline) { |
1596 | cpufreq_driver->offline(policy); | |
1597 | } else if (cpufreq_driver->exit) { | |
87549141 | 1598 | cpufreq_driver->exit(policy); |
55582bcc SP |
1599 | policy->freq_table = NULL; |
1600 | } | |
49f18560 VK |
1601 | |
1602 | unlock: | |
1603 | up_write(&policy->rwsem); | |
27622b06 | 1604 | return 0; |
1da177e4 LT |
1605 | } |
1606 | ||
cedb70af | 1607 | /** |
27a862e9 | 1608 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1609 | * |
1610 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1611 | */ |
71db87ba | 1612 | static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1613 | { |
8a25a2fd | 1614 | unsigned int cpu = dev->id; |
559ed407 | 1615 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
87549141 | 1616 | |
559ed407 | 1617 | if (!policy) |
1af115d6 | 1618 | return; |
87549141 | 1619 | |
69cee714 VK |
1620 | if (cpu_online(cpu)) |
1621 | cpufreq_offline(cpu); | |
87549141 | 1622 | |
559ed407 | 1623 | cpumask_clear_cpu(cpu, policy->real_cpus); |
26619804 | 1624 | remove_cpu_dev_symlink(policy, dev); |
87549141 | 1625 | |
91a12e91 VK |
1626 | if (cpumask_empty(policy->real_cpus)) { |
1627 | /* We did light-weight exit earlier, do full tear down now */ | |
1628 | if (cpufreq_driver->offline) | |
1629 | cpufreq_driver->exit(policy); | |
1630 | ||
f9f41e3e | 1631 | cpufreq_policy_free(policy); |
91a12e91 | 1632 | } |
5a01f2e8 VP |
1633 | } |
1634 | ||
1da177e4 | 1635 | /** |
bb176f7d VK |
1636 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1637 | * in deep trouble. | |
a1e1dc41 | 1638 | * @policy: policy managing CPUs |
1da177e4 LT |
1639 | * @new_freq: CPU frequency the CPU actually runs at |
1640 | * | |
29464f28 DJ |
1641 | * We adjust to current frequency first, and need to clean up later. |
1642 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1643 | */ |
a1e1dc41 | 1644 | static void cpufreq_out_of_sync(struct cpufreq_policy *policy, |
e08f5f5b | 1645 | unsigned int new_freq) |
1da177e4 LT |
1646 | { |
1647 | struct cpufreq_freqs freqs; | |
b43a7ffb | 1648 | |
e837f9b5 | 1649 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
a1e1dc41 | 1650 | policy->cur, new_freq); |
1da177e4 | 1651 | |
a1e1dc41 | 1652 | freqs.old = policy->cur; |
1da177e4 | 1653 | freqs.new = new_freq; |
b43a7ffb | 1654 | |
8fec051e VK |
1655 | cpufreq_freq_transition_begin(policy, &freqs); |
1656 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1657 | } |
1658 | ||
5980752e VK |
1659 | static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update) |
1660 | { | |
1661 | unsigned int new_freq; | |
1662 | ||
1663 | new_freq = cpufreq_driver->get(policy->cpu); | |
1664 | if (!new_freq) | |
1665 | return 0; | |
1666 | ||
1667 | /* | |
1668 | * If fast frequency switching is used with the given policy, the check | |
1669 | * against policy->cur is pointless, so skip it in that case. | |
1670 | */ | |
1671 | if (policy->fast_switch_enabled || !has_target()) | |
1672 | return new_freq; | |
1673 | ||
1674 | if (policy->cur != new_freq) { | |
1675 | cpufreq_out_of_sync(policy, new_freq); | |
1676 | if (update) | |
1677 | schedule_work(&policy->update); | |
1678 | } | |
1679 | ||
1680 | return new_freq; | |
1681 | } | |
1682 | ||
32ee8c3e | 1683 | /** |
4ab70df4 | 1684 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1685 | * @cpu: CPU number |
1686 | * | |
1687 | * This is the last known freq, without actually getting it from the driver. | |
1688 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1689 | */ | |
1690 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1691 | { | |
9e21ba8b | 1692 | struct cpufreq_policy *policy; |
e08f5f5b | 1693 | unsigned int ret_freq = 0; |
c75361c0 | 1694 | unsigned long flags; |
95235ca2 | 1695 | |
c75361c0 RC |
1696 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1697 | ||
1698 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { | |
1699 | ret_freq = cpufreq_driver->get(cpu); | |
1700 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1701 | return ret_freq; | |
1702 | } | |
1703 | ||
1704 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
9e21ba8b DB |
1705 | |
1706 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1707 | if (policy) { |
e08f5f5b | 1708 | ret_freq = policy->cur; |
95235ca2 VP |
1709 | cpufreq_cpu_put(policy); |
1710 | } | |
1711 | ||
4d34a67d | 1712 | return ret_freq; |
95235ca2 VP |
1713 | } |
1714 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1715 | ||
3d737108 JB |
1716 | /** |
1717 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1718 | * @cpu: CPU number | |
1719 | * | |
1720 | * Just return the max possible frequency for a given CPU. | |
1721 | */ | |
1722 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1723 | { | |
1724 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1725 | unsigned int ret_freq = 0; | |
1726 | ||
1727 | if (policy) { | |
1728 | ret_freq = policy->max; | |
1729 | cpufreq_cpu_put(policy); | |
1730 | } | |
1731 | ||
1732 | return ret_freq; | |
1733 | } | |
1734 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1735 | ||
bbce8eaa IV |
1736 | /** |
1737 | * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU | |
1738 | * @cpu: CPU number | |
1739 | * | |
1740 | * The default return value is the max_freq field of cpuinfo. | |
1741 | */ | |
1742 | __weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu) | |
1743 | { | |
1744 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1745 | unsigned int ret_freq = 0; | |
1746 | ||
1747 | if (policy) { | |
1748 | ret_freq = policy->cpuinfo.max_freq; | |
1749 | cpufreq_cpu_put(policy); | |
1750 | } | |
1751 | ||
1752 | return ret_freq; | |
1753 | } | |
1754 | EXPORT_SYMBOL(cpufreq_get_hw_max_freq); | |
1755 | ||
d92d50a4 | 1756 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy) |
1da177e4 | 1757 | { |
4db7c34c | 1758 | if (unlikely(policy_is_inactive(policy))) |
5980752e | 1759 | return 0; |
1da177e4 | 1760 | |
5980752e | 1761 | return cpufreq_verify_current_freq(policy, true); |
5a01f2e8 | 1762 | } |
1da177e4 | 1763 | |
5a01f2e8 VP |
1764 | /** |
1765 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1766 | * @cpu: CPU number | |
1767 | * | |
1768 | * Get the CPU current (static) CPU frequency | |
1769 | */ | |
1770 | unsigned int cpufreq_get(unsigned int cpu) | |
1771 | { | |
999976e0 | 1772 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1773 | unsigned int ret_freq = 0; |
5a01f2e8 | 1774 | |
999976e0 AP |
1775 | if (policy) { |
1776 | down_read(&policy->rwsem); | |
4db7c34c YH |
1777 | if (cpufreq_driver->get) |
1778 | ret_freq = __cpufreq_get(policy); | |
999976e0 | 1779 | up_read(&policy->rwsem); |
5a01f2e8 | 1780 | |
999976e0 AP |
1781 | cpufreq_cpu_put(policy); |
1782 | } | |
6eed9404 | 1783 | |
4d34a67d | 1784 | return ret_freq; |
1da177e4 LT |
1785 | } |
1786 | EXPORT_SYMBOL(cpufreq_get); | |
1787 | ||
8a25a2fd KS |
1788 | static struct subsys_interface cpufreq_interface = { |
1789 | .name = "cpufreq", | |
1790 | .subsys = &cpu_subsys, | |
1791 | .add_dev = cpufreq_add_dev, | |
1792 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1793 | }; |
1794 | ||
e28867ea VK |
1795 | /* |
1796 | * In case platform wants some specific frequency to be configured | |
1797 | * during suspend.. | |
1798 | */ | |
1799 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1800 | { | |
1801 | int ret; | |
1802 | ||
1803 | if (!policy->suspend_freq) { | |
201f3716 BZ |
1804 | pr_debug("%s: suspend_freq not defined\n", __func__); |
1805 | return 0; | |
e28867ea VK |
1806 | } |
1807 | ||
1808 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1809 | policy->suspend_freq); | |
1810 | ||
1811 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1812 | CPUFREQ_RELATION_H); | |
1813 | if (ret) | |
1814 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1815 | __func__, policy->suspend_freq, ret); | |
1816 | ||
1817 | return ret; | |
1818 | } | |
1819 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1820 | ||
42d4dc3f | 1821 | /** |
2f0aea93 | 1822 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1823 | * |
2f0aea93 VK |
1824 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1825 | * as some platforms can't change frequency after this point in suspend cycle. | |
1826 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1827 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1828 | */ |
2f0aea93 | 1829 | void cpufreq_suspend(void) |
42d4dc3f | 1830 | { |
3a3e9e06 | 1831 | struct cpufreq_policy *policy; |
42d4dc3f | 1832 | |
2f0aea93 VK |
1833 | if (!cpufreq_driver) |
1834 | return; | |
42d4dc3f | 1835 | |
ba41e1bc | 1836 | if (!has_target() && !cpufreq_driver->suspend) |
b1b12bab | 1837 | goto suspend; |
42d4dc3f | 1838 | |
2f0aea93 VK |
1839 | pr_debug("%s: Suspending Governors\n", __func__); |
1840 | ||
f963735a | 1841 | for_each_active_policy(policy) { |
ba41e1bc RW |
1842 | if (has_target()) { |
1843 | down_write(&policy->rwsem); | |
45482c70 | 1844 | cpufreq_stop_governor(policy); |
ba41e1bc | 1845 | up_write(&policy->rwsem); |
ba41e1bc RW |
1846 | } |
1847 | ||
1848 | if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) | |
e9a7cc1d FF |
1849 | pr_err("%s: Failed to suspend driver: %s\n", __func__, |
1850 | cpufreq_driver->name); | |
42d4dc3f | 1851 | } |
b1b12bab VK |
1852 | |
1853 | suspend: | |
1854 | cpufreq_suspended = true; | |
42d4dc3f BH |
1855 | } |
1856 | ||
1da177e4 | 1857 | /** |
2f0aea93 | 1858 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1859 | * |
2f0aea93 VK |
1860 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1861 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1862 | */ |
2f0aea93 | 1863 | void cpufreq_resume(void) |
1da177e4 | 1864 | { |
3a3e9e06 | 1865 | struct cpufreq_policy *policy; |
49f18560 | 1866 | int ret; |
1da177e4 | 1867 | |
2f0aea93 | 1868 | if (!cpufreq_driver) |
703cbaa6 BY |
1869 | return; |
1870 | ||
1871 | if (unlikely(!cpufreq_suspended)) | |
2f0aea93 | 1872 | return; |
1da177e4 | 1873 | |
8e30444e LT |
1874 | cpufreq_suspended = false; |
1875 | ||
ba41e1bc | 1876 | if (!has_target() && !cpufreq_driver->resume) |
e00e56df | 1877 | return; |
1da177e4 | 1878 | |
2f0aea93 | 1879 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1880 | |
f963735a | 1881 | for_each_active_policy(policy) { |
49f18560 | 1882 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { |
0c5aa405 VK |
1883 | pr_err("%s: Failed to resume driver: %p\n", __func__, |
1884 | policy); | |
ba41e1bc | 1885 | } else if (has_target()) { |
49f18560 | 1886 | down_write(&policy->rwsem); |
0a300767 | 1887 | ret = cpufreq_start_governor(policy); |
49f18560 VK |
1888 | up_write(&policy->rwsem); |
1889 | ||
1890 | if (ret) | |
1891 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1892 | __func__, policy); | |
1893 | } | |
2f0aea93 VK |
1894 | } |
1895 | } | |
1da177e4 | 1896 | |
9d95046e BP |
1897 | /** |
1898 | * cpufreq_get_current_driver - return current driver's name | |
1899 | * | |
1900 | * Return the name string of the currently loaded cpufreq driver | |
1901 | * or NULL, if none. | |
1902 | */ | |
1903 | const char *cpufreq_get_current_driver(void) | |
1904 | { | |
1c3d85dd RW |
1905 | if (cpufreq_driver) |
1906 | return cpufreq_driver->name; | |
1907 | ||
1908 | return NULL; | |
9d95046e BP |
1909 | } |
1910 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 | 1911 | |
51315cdf TP |
1912 | /** |
1913 | * cpufreq_get_driver_data - return current driver data | |
1914 | * | |
1915 | * Return the private data of the currently loaded cpufreq | |
1916 | * driver, or NULL if no cpufreq driver is loaded. | |
1917 | */ | |
1918 | void *cpufreq_get_driver_data(void) | |
1919 | { | |
1920 | if (cpufreq_driver) | |
1921 | return cpufreq_driver->driver_data; | |
1922 | ||
1923 | return NULL; | |
1924 | } | |
1925 | EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); | |
1926 | ||
1da177e4 LT |
1927 | /********************************************************************* |
1928 | * NOTIFIER LISTS INTERFACE * | |
1929 | *********************************************************************/ | |
1930 | ||
1931 | /** | |
1932 | * cpufreq_register_notifier - register a driver with cpufreq | |
1933 | * @nb: notifier function to register | |
1934 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1935 | * | |
32ee8c3e | 1936 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1937 | * are notified about clock rate changes (once before and once after |
1938 | * the transition), or a list of drivers that are notified about | |
1939 | * changes in cpufreq policy. | |
1940 | * | |
1941 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1942 | * blocking_notifier_chain_register. |
1da177e4 LT |
1943 | */ |
1944 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1945 | { | |
1946 | int ret; | |
1947 | ||
d5aaffa9 DB |
1948 | if (cpufreq_disabled()) |
1949 | return -EINVAL; | |
1950 | ||
1da177e4 LT |
1951 | switch (list) { |
1952 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1953 | mutex_lock(&cpufreq_fast_switch_lock); |
1954 | ||
1955 | if (cpufreq_fast_switch_count > 0) { | |
1956 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1957 | return -EBUSY; | |
1958 | } | |
b4dfdbb3 | 1959 | ret = srcu_notifier_chain_register( |
e041c683 | 1960 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1961 | if (!ret) |
1962 | cpufreq_fast_switch_count--; | |
1963 | ||
1964 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1965 | break; |
1966 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1967 | ret = blocking_notifier_chain_register( |
1968 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1969 | break; |
1970 | default: | |
1971 | ret = -EINVAL; | |
1972 | } | |
1da177e4 LT |
1973 | |
1974 | return ret; | |
1975 | } | |
1976 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1977 | ||
1da177e4 LT |
1978 | /** |
1979 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1980 | * @nb: notifier block to be unregistered | |
bb176f7d | 1981 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1982 | * |
1983 | * Remove a driver from the CPU frequency notifier list. | |
1984 | * | |
1985 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1986 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1987 | */ |
1988 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1989 | { | |
1990 | int ret; | |
1991 | ||
d5aaffa9 DB |
1992 | if (cpufreq_disabled()) |
1993 | return -EINVAL; | |
1994 | ||
1da177e4 LT |
1995 | switch (list) { |
1996 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1997 | mutex_lock(&cpufreq_fast_switch_lock); |
1998 | ||
b4dfdbb3 | 1999 | ret = srcu_notifier_chain_unregister( |
e041c683 | 2000 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
2001 | if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) |
2002 | cpufreq_fast_switch_count++; | |
2003 | ||
2004 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
2005 | break; |
2006 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
2007 | ret = blocking_notifier_chain_unregister( |
2008 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
2009 | break; |
2010 | default: | |
2011 | ret = -EINVAL; | |
2012 | } | |
1da177e4 LT |
2013 | |
2014 | return ret; | |
2015 | } | |
2016 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
2017 | ||
2018 | ||
2019 | /********************************************************************* | |
2020 | * GOVERNORS * | |
2021 | *********************************************************************/ | |
2022 | ||
b7898fda RW |
2023 | /** |
2024 | * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. | |
2025 | * @policy: cpufreq policy to switch the frequency for. | |
2026 | * @target_freq: New frequency to set (may be approximate). | |
2027 | * | |
2028 | * Carry out a fast frequency switch without sleeping. | |
2029 | * | |
2030 | * The driver's ->fast_switch() callback invoked by this function must be | |
2031 | * suitable for being called from within RCU-sched read-side critical sections | |
2032 | * and it is expected to select the minimum available frequency greater than or | |
2033 | * equal to @target_freq (CPUFREQ_RELATION_L). | |
2034 | * | |
2035 | * This function must not be called if policy->fast_switch_enabled is unset. | |
2036 | * | |
2037 | * Governors calling this function must guarantee that it will never be invoked | |
2038 | * twice in parallel for the same policy and that it will never be called in | |
2039 | * parallel with either ->target() or ->target_index() for the same policy. | |
2040 | * | |
209887e6 VK |
2041 | * Returns the actual frequency set for the CPU. |
2042 | * | |
2043 | * If 0 is returned by the driver's ->fast_switch() callback to indicate an | |
2044 | * error condition, the hardware configuration must be preserved. | |
b7898fda RW |
2045 | */ |
2046 | unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, | |
2047 | unsigned int target_freq) | |
2048 | { | |
b9af6948 | 2049 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
b7898fda RW |
2050 | |
2051 | return cpufreq_driver->fast_switch(policy, target_freq); | |
2052 | } | |
2053 | EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); | |
2054 | ||
1c03a2d0 VK |
2055 | /* Must set freqs->new to intermediate frequency */ |
2056 | static int __target_intermediate(struct cpufreq_policy *policy, | |
2057 | struct cpufreq_freqs *freqs, int index) | |
2058 | { | |
2059 | int ret; | |
2060 | ||
2061 | freqs->new = cpufreq_driver->get_intermediate(policy, index); | |
2062 | ||
2063 | /* We don't need to switch to intermediate freq */ | |
2064 | if (!freqs->new) | |
2065 | return 0; | |
2066 | ||
2067 | pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", | |
2068 | __func__, policy->cpu, freqs->old, freqs->new); | |
2069 | ||
2070 | cpufreq_freq_transition_begin(policy, freqs); | |
2071 | ret = cpufreq_driver->target_intermediate(policy, index); | |
2072 | cpufreq_freq_transition_end(policy, freqs, ret); | |
2073 | ||
2074 | if (ret) | |
2075 | pr_err("%s: Failed to change to intermediate frequency: %d\n", | |
2076 | __func__, ret); | |
2077 | ||
2078 | return ret; | |
2079 | } | |
2080 | ||
23727845 | 2081 | static int __target_index(struct cpufreq_policy *policy, int index) |
8d65775d | 2082 | { |
1c03a2d0 VK |
2083 | struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
2084 | unsigned int intermediate_freq = 0; | |
23727845 | 2085 | unsigned int newfreq = policy->freq_table[index].frequency; |
8d65775d VK |
2086 | int retval = -EINVAL; |
2087 | bool notify; | |
2088 | ||
23727845 VK |
2089 | if (newfreq == policy->cur) |
2090 | return 0; | |
2091 | ||
8d65775d | 2092 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); |
8d65775d | 2093 | if (notify) { |
1c03a2d0 VK |
2094 | /* Handle switching to intermediate frequency */ |
2095 | if (cpufreq_driver->get_intermediate) { | |
2096 | retval = __target_intermediate(policy, &freqs, index); | |
2097 | if (retval) | |
2098 | return retval; | |
2099 | ||
2100 | intermediate_freq = freqs.new; | |
2101 | /* Set old freq to intermediate */ | |
2102 | if (intermediate_freq) | |
2103 | freqs.old = freqs.new; | |
2104 | } | |
8d65775d | 2105 | |
23727845 | 2106 | freqs.new = newfreq; |
8d65775d VK |
2107 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", |
2108 | __func__, policy->cpu, freqs.old, freqs.new); | |
2109 | ||
2110 | cpufreq_freq_transition_begin(policy, &freqs); | |
2111 | } | |
2112 | ||
2113 | retval = cpufreq_driver->target_index(policy, index); | |
2114 | if (retval) | |
2115 | pr_err("%s: Failed to change cpu frequency: %d\n", __func__, | |
2116 | retval); | |
2117 | ||
1c03a2d0 | 2118 | if (notify) { |
8d65775d VK |
2119 | cpufreq_freq_transition_end(policy, &freqs, retval); |
2120 | ||
1c03a2d0 VK |
2121 | /* |
2122 | * Failed after setting to intermediate freq? Driver should have | |
2123 | * reverted back to initial frequency and so should we. Check | |
2124 | * here for intermediate_freq instead of get_intermediate, in | |
58405af6 | 2125 | * case we haven't switched to intermediate freq at all. |
1c03a2d0 VK |
2126 | */ |
2127 | if (unlikely(retval && intermediate_freq)) { | |
2128 | freqs.old = intermediate_freq; | |
2129 | freqs.new = policy->restore_freq; | |
2130 | cpufreq_freq_transition_begin(policy, &freqs); | |
2131 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
2132 | } | |
2133 | } | |
2134 | ||
8d65775d VK |
2135 | return retval; |
2136 | } | |
2137 | ||
1da177e4 LT |
2138 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
2139 | unsigned int target_freq, | |
2140 | unsigned int relation) | |
2141 | { | |
7249924e | 2142 | unsigned int old_target_freq = target_freq; |
d218ed77 | 2143 | int index; |
c32b6b8e | 2144 | |
a7b422cd KRW |
2145 | if (cpufreq_disabled()) |
2146 | return -ENODEV; | |
2147 | ||
7249924e | 2148 | /* Make sure that target_freq is within supported range */ |
910c6e88 | 2149 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
7249924e VK |
2150 | |
2151 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 2152 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 2153 | |
9c0ebcf7 VK |
2154 | /* |
2155 | * This might look like a redundant call as we are checking it again | |
2156 | * after finding index. But it is left intentionally for cases where | |
2157 | * exactly same freq is called again and so we can save on few function | |
2158 | * calls. | |
2159 | */ | |
5a1c0228 VK |
2160 | if (target_freq == policy->cur) |
2161 | return 0; | |
2162 | ||
1c03a2d0 VK |
2163 | /* Save last value to restore later on errors */ |
2164 | policy->restore_freq = policy->cur; | |
2165 | ||
1c3d85dd | 2166 | if (cpufreq_driver->target) |
6019d23a | 2167 | return cpufreq_driver->target(policy, target_freq, relation); |
9c0ebcf7 | 2168 | |
6019d23a RW |
2169 | if (!cpufreq_driver->target_index) |
2170 | return -EINVAL; | |
9c0ebcf7 | 2171 | |
d218ed77 | 2172 | index = cpufreq_frequency_table_target(policy, target_freq, relation); |
6019d23a | 2173 | |
23727845 | 2174 | return __target_index(policy, index); |
1da177e4 LT |
2175 | } |
2176 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
2177 | ||
1da177e4 LT |
2178 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
2179 | unsigned int target_freq, | |
2180 | unsigned int relation) | |
2181 | { | |
62c23a89 | 2182 | int ret; |
1da177e4 | 2183 | |
ad7722da | 2184 | down_write(&policy->rwsem); |
1da177e4 LT |
2185 | |
2186 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
2187 | ||
ad7722da | 2188 | up_write(&policy->rwsem); |
1da177e4 | 2189 | |
1da177e4 LT |
2190 | return ret; |
2191 | } | |
2192 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
2193 | ||
de1df26b RW |
2194 | __weak struct cpufreq_governor *cpufreq_fallback_governor(void) |
2195 | { | |
2196 | return NULL; | |
2197 | } | |
2198 | ||
a92604b4 | 2199 | static int cpufreq_init_governor(struct cpufreq_policy *policy) |
1da177e4 | 2200 | { |
cc993cab | 2201 | int ret; |
6afde10c | 2202 | |
2f0aea93 VK |
2203 | /* Don't start any governor operations if we are entering suspend */ |
2204 | if (cpufreq_suspended) | |
2205 | return 0; | |
cb57720b EZ |
2206 | /* |
2207 | * Governor might not be initiated here if ACPI _PPC changed | |
2208 | * notification happened, so check it. | |
2209 | */ | |
2210 | if (!policy->governor) | |
2211 | return -EINVAL; | |
2f0aea93 | 2212 | |
ed4676e2 VK |
2213 | /* Platform doesn't want dynamic frequency switching ? */ |
2214 | if (policy->governor->dynamic_switching && | |
fc4c709f | 2215 | cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) { |
de1df26b RW |
2216 | struct cpufreq_governor *gov = cpufreq_fallback_governor(); |
2217 | ||
2218 | if (gov) { | |
fe829ed8 | 2219 | pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n", |
e837f9b5 | 2220 | policy->governor->name, gov->name); |
6afde10c | 2221 | policy->governor = gov; |
de1df26b RW |
2222 | } else { |
2223 | return -EINVAL; | |
6afde10c | 2224 | } |
1c256245 | 2225 | } |
1da177e4 | 2226 | |
a92604b4 RW |
2227 | if (!try_module_get(policy->governor->owner)) |
2228 | return -EINVAL; | |
95731ebb | 2229 | |
a92604b4 | 2230 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
1da177e4 | 2231 | |
e788892b RW |
2232 | if (policy->governor->init) { |
2233 | ret = policy->governor->init(policy); | |
2234 | if (ret) { | |
36be3418 | 2235 | module_put(policy->governor->owner); |
e788892b RW |
2236 | return ret; |
2237 | } | |
36be3418 | 2238 | } |
1da177e4 | 2239 | |
a92604b4 RW |
2240 | return 0; |
2241 | } | |
2242 | ||
2243 | static void cpufreq_exit_governor(struct cpufreq_policy *policy) | |
2244 | { | |
2245 | if (cpufreq_suspended || !policy->governor) | |
2246 | return; | |
2247 | ||
2248 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2249 | ||
e788892b RW |
2250 | if (policy->governor->exit) |
2251 | policy->governor->exit(policy); | |
a92604b4 | 2252 | |
a92604b4 | 2253 | module_put(policy->governor->owner); |
1da177e4 LT |
2254 | } |
2255 | ||
0a300767 RW |
2256 | static int cpufreq_start_governor(struct cpufreq_policy *policy) |
2257 | { | |
2258 | int ret; | |
2259 | ||
a92604b4 RW |
2260 | if (cpufreq_suspended) |
2261 | return 0; | |
2262 | ||
2263 | if (!policy->governor) | |
2264 | return -EINVAL; | |
2265 | ||
2266 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2267 | ||
407d0fff | 2268 | if (cpufreq_driver->get) |
5980752e | 2269 | cpufreq_verify_current_freq(policy, false); |
3bbf8fe3 | 2270 | |
e788892b RW |
2271 | if (policy->governor->start) { |
2272 | ret = policy->governor->start(policy); | |
2273 | if (ret) | |
2274 | return ret; | |
2275 | } | |
2276 | ||
2277 | if (policy->governor->limits) | |
2278 | policy->governor->limits(policy); | |
d6ff44d6 | 2279 | |
d6ff44d6 | 2280 | return 0; |
0a300767 RW |
2281 | } |
2282 | ||
a92604b4 RW |
2283 | static void cpufreq_stop_governor(struct cpufreq_policy *policy) |
2284 | { | |
2285 | if (cpufreq_suspended || !policy->governor) | |
2286 | return; | |
2287 | ||
2288 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2289 | ||
e788892b RW |
2290 | if (policy->governor->stop) |
2291 | policy->governor->stop(policy); | |
a92604b4 RW |
2292 | } |
2293 | ||
2294 | static void cpufreq_governor_limits(struct cpufreq_policy *policy) | |
2295 | { | |
2296 | if (cpufreq_suspended || !policy->governor) | |
2297 | return; | |
2298 | ||
2299 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2300 | ||
e788892b RW |
2301 | if (policy->governor->limits) |
2302 | policy->governor->limits(policy); | |
0a300767 RW |
2303 | } |
2304 | ||
1da177e4 LT |
2305 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
2306 | { | |
3bcb09a3 | 2307 | int err; |
1da177e4 LT |
2308 | |
2309 | if (!governor) | |
2310 | return -EINVAL; | |
2311 | ||
a7b422cd KRW |
2312 | if (cpufreq_disabled()) |
2313 | return -ENODEV; | |
2314 | ||
3fc54d37 | 2315 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 2316 | |
3bcb09a3 | 2317 | err = -EBUSY; |
42f91fa1 | 2318 | if (!find_governor(governor->name)) { |
3bcb09a3 JF |
2319 | err = 0; |
2320 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2321 | } |
1da177e4 | 2322 | |
32ee8c3e | 2323 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2324 | return err; |
1da177e4 LT |
2325 | } |
2326 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2327 | ||
1da177e4 LT |
2328 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2329 | { | |
4573237b VK |
2330 | struct cpufreq_policy *policy; |
2331 | unsigned long flags; | |
90e41bac | 2332 | |
1da177e4 LT |
2333 | if (!governor) |
2334 | return; | |
2335 | ||
a7b422cd KRW |
2336 | if (cpufreq_disabled()) |
2337 | return; | |
2338 | ||
4573237b VK |
2339 | /* clear last_governor for all inactive policies */ |
2340 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
2341 | for_each_inactive_policy(policy) { | |
18bf3a12 VK |
2342 | if (!strcmp(policy->last_governor, governor->name)) { |
2343 | policy->governor = NULL; | |
4573237b | 2344 | strcpy(policy->last_governor, "\0"); |
18bf3a12 | 2345 | } |
90e41bac | 2346 | } |
4573237b | 2347 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
90e41bac | 2348 | |
3fc54d37 | 2349 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2350 | list_del(&governor->governor_list); |
3fc54d37 | 2351 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2352 | } |
2353 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2354 | ||
2355 | ||
1da177e4 LT |
2356 | /********************************************************************* |
2357 | * POLICY INTERFACE * | |
2358 | *********************************************************************/ | |
2359 | ||
2360 | /** | |
2361 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2362 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2363 | * is written | |
1da177e4 LT |
2364 | * |
2365 | * Reads the current cpufreq policy. | |
2366 | */ | |
2367 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2368 | { | |
2369 | struct cpufreq_policy *cpu_policy; | |
2370 | if (!policy) | |
2371 | return -EINVAL; | |
2372 | ||
2373 | cpu_policy = cpufreq_cpu_get(cpu); | |
2374 | if (!cpu_policy) | |
2375 | return -EINVAL; | |
2376 | ||
d5b73cd8 | 2377 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2378 | |
2379 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2380 | return 0; |
2381 | } | |
2382 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2383 | ||
a0dbb819 RW |
2384 | /** |
2385 | * cpufreq_set_policy - Modify cpufreq policy parameters. | |
2386 | * @policy: Policy object to modify. | |
1e4f63ae RW |
2387 | * @new_gov: Policy governor pointer. |
2388 | * @new_pol: Policy value (for drivers with built-in governors). | |
a0dbb819 | 2389 | * |
1e4f63ae RW |
2390 | * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency |
2391 | * limits to be set for the policy, update @policy with the verified limits | |
2392 | * values and either invoke the driver's ->setpolicy() callback (if present) or | |
2393 | * carry out a governor update for @policy. That is, run the current governor's | |
2394 | * ->limits() callback (if @new_gov points to the same object as the one in | |
2395 | * @policy) or replace the governor for @policy with @new_gov. | |
a0dbb819 RW |
2396 | * |
2397 | * The cpuinfo part of @policy is not updated by this function. | |
153d7f3f | 2398 | */ |
1e4f63ae RW |
2399 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
2400 | struct cpufreq_governor *new_gov, | |
2401 | unsigned int new_pol) | |
1da177e4 | 2402 | { |
1e4f63ae | 2403 | struct cpufreq_policy_data new_data; |
d9a789c7 RW |
2404 | struct cpufreq_governor *old_gov; |
2405 | int ret; | |
1da177e4 | 2406 | |
1e4f63ae RW |
2407 | memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
2408 | new_data.freq_table = policy->freq_table; | |
2409 | new_data.cpu = policy->cpu; | |
fba9573b | 2410 | /* |
67d874c3 VK |
2411 | * PM QoS framework collects all the requests from users and provide us |
2412 | * the final aggregated value here. | |
2413 | */ | |
1e4f63ae RW |
2414 | new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN); |
2415 | new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX); | |
2416 | ||
2417 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", | |
2418 | new_data.cpu, new_data.min, new_data.max); | |
9c9a43ed | 2419 | |
737ffb27 VK |
2420 | /* |
2421 | * Verify that the CPU speed can be set within these limits and make sure | |
2422 | * that min <= max. | |
2423 | */ | |
1e4f63ae | 2424 | ret = cpufreq_driver->verify(&new_data); |
1da177e4 | 2425 | if (ret) |
d9a789c7 | 2426 | return ret; |
1da177e4 | 2427 | |
1e4f63ae RW |
2428 | policy->min = new_data.min; |
2429 | policy->max = new_data.max; | |
601b2185 | 2430 | trace_cpu_frequency_limits(policy); |
1da177e4 | 2431 | |
e3c06236 SM |
2432 | policy->cached_target_freq = UINT_MAX; |
2433 | ||
2d06d8c4 | 2434 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2435 | policy->min, policy->max); |
1da177e4 | 2436 | |
1c3d85dd | 2437 | if (cpufreq_driver->setpolicy) { |
1e4f63ae | 2438 | policy->policy = new_pol; |
2d06d8c4 | 2439 | pr_debug("setting range\n"); |
167a38dc | 2440 | return cpufreq_driver->setpolicy(policy); |
d9a789c7 | 2441 | } |
1da177e4 | 2442 | |
1e4f63ae | 2443 | if (new_gov == policy->governor) { |
2bb4059e | 2444 | pr_debug("governor limits update\n"); |
a92604b4 | 2445 | cpufreq_governor_limits(policy); |
d6ff44d6 | 2446 | return 0; |
0a300767 | 2447 | } |
7bd353a9 | 2448 | |
d9a789c7 RW |
2449 | pr_debug("governor switch\n"); |
2450 | ||
2451 | /* save old, working values */ | |
2452 | old_gov = policy->governor; | |
2453 | /* end old governor */ | |
2454 | if (old_gov) { | |
45482c70 | 2455 | cpufreq_stop_governor(policy); |
36be3418 | 2456 | cpufreq_exit_governor(policy); |
1da177e4 LT |
2457 | } |
2458 | ||
d9a789c7 | 2459 | /* start new governor */ |
1e4f63ae | 2460 | policy->governor = new_gov; |
a92604b4 | 2461 | ret = cpufreq_init_governor(policy); |
4bc384ae | 2462 | if (!ret) { |
0a300767 RW |
2463 | ret = cpufreq_start_governor(policy); |
2464 | if (!ret) { | |
2bb4059e | 2465 | pr_debug("governor change\n"); |
531b5c9f | 2466 | sched_cpufreq_governor_change(policy, old_gov); |
0a300767 RW |
2467 | return 0; |
2468 | } | |
b7898fda | 2469 | cpufreq_exit_governor(policy); |
d9a789c7 RW |
2470 | } |
2471 | ||
2472 | /* new governor failed, so re-start old one */ | |
2473 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2474 | if (old_gov) { | |
2475 | policy->governor = old_gov; | |
a92604b4 | 2476 | if (cpufreq_init_governor(policy)) |
4bc384ae VK |
2477 | policy->governor = NULL; |
2478 | else | |
0a300767 | 2479 | cpufreq_start_governor(policy); |
d9a789c7 RW |
2480 | } |
2481 | ||
4bc384ae | 2482 | return ret; |
1da177e4 LT |
2483 | } |
2484 | ||
1da177e4 | 2485 | /** |
a0dbb819 RW |
2486 | * cpufreq_update_policy - Re-evaluate an existing cpufreq policy. |
2487 | * @cpu: CPU to re-evaluate the policy for. | |
1da177e4 | 2488 | * |
a0dbb819 | 2489 | * Update the current frequency for the cpufreq policy of @cpu and use |
18c49926 VK |
2490 | * cpufreq_set_policy() to re-apply the min and max limits, which triggers the |
2491 | * evaluation of policy notifiers and the cpufreq driver's ->verify() callback | |
2492 | * for the policy in question, among other things. | |
1da177e4 | 2493 | */ |
30248fef | 2494 | void cpufreq_update_policy(unsigned int cpu) |
1da177e4 | 2495 | { |
540a3758 | 2496 | struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu); |
1da177e4 | 2497 | |
fefa8ff8 | 2498 | if (!policy) |
30248fef | 2499 | return; |
1da177e4 | 2500 | |
bb176f7d VK |
2501 | /* |
2502 | * BIOS might change freq behind our back | |
2503 | * -> ask driver for current freq and notify governors about a change | |
2504 | */ | |
5ddc6d4e | 2505 | if (cpufreq_driver->get && has_target() && |
5980752e | 2506 | (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false)))) |
348a2ec5 | 2507 | goto unlock; |
30248fef | 2508 | |
70a59fde | 2509 | refresh_frequency_limits(policy); |
1da177e4 | 2510 | |
fefa8ff8 | 2511 | unlock: |
540a3758 | 2512 | cpufreq_cpu_release(policy); |
1da177e4 LT |
2513 | } |
2514 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2515 | ||
5a25e3f7 RW |
2516 | /** |
2517 | * cpufreq_update_limits - Update policy limits for a given CPU. | |
2518 | * @cpu: CPU to update the policy limits for. | |
2519 | * | |
2520 | * Invoke the driver's ->update_limits callback if present or call | |
2521 | * cpufreq_update_policy() for @cpu. | |
2522 | */ | |
2523 | void cpufreq_update_limits(unsigned int cpu) | |
2524 | { | |
2525 | if (cpufreq_driver->update_limits) | |
2526 | cpufreq_driver->update_limits(cpu); | |
2527 | else | |
2528 | cpufreq_update_policy(cpu); | |
2529 | } | |
2530 | EXPORT_SYMBOL_GPL(cpufreq_update_limits); | |
2531 | ||
6f19efc0 LM |
2532 | /********************************************************************* |
2533 | * BOOST * | |
2534 | *********************************************************************/ | |
2535 | static int cpufreq_boost_set_sw(int state) | |
2536 | { | |
6f19efc0 LM |
2537 | struct cpufreq_policy *policy; |
2538 | int ret = -EINVAL; | |
2539 | ||
f963735a | 2540 | for_each_active_policy(policy) { |
f8bfc116 VK |
2541 | if (!policy->freq_table) |
2542 | continue; | |
49f18560 | 2543 | |
f8bfc116 VK |
2544 | ret = cpufreq_frequency_table_cpuinfo(policy, |
2545 | policy->freq_table); | |
2546 | if (ret) { | |
2547 | pr_err("%s: Policy frequency update failed\n", | |
2548 | __func__); | |
2549 | break; | |
6f19efc0 | 2550 | } |
f8bfc116 | 2551 | |
3000ce3c | 2552 | ret = freq_qos_update_request(policy->max_freq_req, policy->max); |
e61a4125 | 2553 | if (ret < 0) |
18c49926 | 2554 | break; |
6f19efc0 LM |
2555 | } |
2556 | ||
2557 | return ret; | |
2558 | } | |
2559 | ||
2560 | int cpufreq_boost_trigger_state(int state) | |
2561 | { | |
2562 | unsigned long flags; | |
2563 | int ret = 0; | |
2564 | ||
2565 | if (cpufreq_driver->boost_enabled == state) | |
2566 | return 0; | |
2567 | ||
2568 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2569 | cpufreq_driver->boost_enabled = state; | |
2570 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2571 | ||
2572 | ret = cpufreq_driver->set_boost(state); | |
2573 | if (ret) { | |
2574 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2575 | cpufreq_driver->boost_enabled = !state; | |
2576 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2577 | ||
e837f9b5 JP |
2578 | pr_err("%s: Cannot %s BOOST\n", |
2579 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2580 | } |
2581 | ||
2582 | return ret; | |
2583 | } | |
2584 | ||
41669da0 | 2585 | static bool cpufreq_boost_supported(void) |
6f19efc0 | 2586 | { |
89f98d7e | 2587 | return cpufreq_driver->set_boost; |
6f19efc0 | 2588 | } |
6f19efc0 | 2589 | |
44139ed4 VK |
2590 | static int create_boost_sysfs_file(void) |
2591 | { | |
2592 | int ret; | |
2593 | ||
c82bd444 | 2594 | ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2595 | if (ret) |
2596 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
2597 | __func__); | |
2598 | ||
2599 | return ret; | |
2600 | } | |
2601 | ||
2602 | static void remove_boost_sysfs_file(void) | |
2603 | { | |
2604 | if (cpufreq_boost_supported()) | |
c82bd444 | 2605 | sysfs_remove_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2606 | } |
2607 | ||
2608 | int cpufreq_enable_boost_support(void) | |
2609 | { | |
2610 | if (!cpufreq_driver) | |
2611 | return -EINVAL; | |
2612 | ||
2613 | if (cpufreq_boost_supported()) | |
2614 | return 0; | |
2615 | ||
7a6c79f2 | 2616 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; |
44139ed4 VK |
2617 | |
2618 | /* This will get removed on driver unregister */ | |
2619 | return create_boost_sysfs_file(); | |
2620 | } | |
2621 | EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support); | |
2622 | ||
6f19efc0 LM |
2623 | int cpufreq_boost_enabled(void) |
2624 | { | |
2625 | return cpufreq_driver->boost_enabled; | |
2626 | } | |
2627 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2628 | ||
1da177e4 LT |
2629 | /********************************************************************* |
2630 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2631 | *********************************************************************/ | |
27622b06 | 2632 | static enum cpuhp_state hp_online; |
1da177e4 | 2633 | |
c4a3fa26 CY |
2634 | static int cpuhp_cpufreq_online(unsigned int cpu) |
2635 | { | |
2636 | cpufreq_online(cpu); | |
2637 | ||
2638 | return 0; | |
2639 | } | |
2640 | ||
2641 | static int cpuhp_cpufreq_offline(unsigned int cpu) | |
2642 | { | |
2643 | cpufreq_offline(cpu); | |
2644 | ||
2645 | return 0; | |
2646 | } | |
2647 | ||
1da177e4 LT |
2648 | /** |
2649 | * cpufreq_register_driver - register a CPU Frequency driver | |
2650 | * @driver_data: A struct cpufreq_driver containing the values# | |
2651 | * submitted by the CPU Frequency driver. | |
2652 | * | |
bb176f7d | 2653 | * Registers a CPU Frequency driver to this core code. This code |
63af4055 | 2654 | * returns zero on success, -EEXIST when another driver got here first |
32ee8c3e | 2655 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2656 | * |
2657 | */ | |
221dee28 | 2658 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2659 | { |
2660 | unsigned long flags; | |
2661 | int ret; | |
2662 | ||
a7b422cd KRW |
2663 | if (cpufreq_disabled()) |
2664 | return -ENODEV; | |
2665 | ||
46770be0 VK |
2666 | /* |
2667 | * The cpufreq core depends heavily on the availability of device | |
2668 | * structure, make sure they are available before proceeding further. | |
2669 | */ | |
2670 | if (!get_cpu_device(0)) | |
2671 | return -EPROBE_DEFER; | |
2672 | ||
1da177e4 | 2673 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2674 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2675 | driver_data->target) || |
2676 | (driver_data->setpolicy && (driver_data->target_index || | |
1c03a2d0 | 2677 | driver_data->target)) || |
a9a22b57 | 2678 | (!driver_data->get_intermediate != !driver_data->target_intermediate) || |
91a12e91 | 2679 | (!driver_data->online != !driver_data->offline)) |
1da177e4 LT |
2680 | return -EINVAL; |
2681 | ||
2d06d8c4 | 2682 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 | 2683 | |
fdd320da | 2684 | /* Protect against concurrent CPU online/offline. */ |
a92551e4 | 2685 | cpus_read_lock(); |
fdd320da | 2686 | |
0d1857a1 | 2687 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2688 | if (cpufreq_driver) { |
0d1857a1 | 2689 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fdd320da RW |
2690 | ret = -EEXIST; |
2691 | goto out; | |
1da177e4 | 2692 | } |
1c3d85dd | 2693 | cpufreq_driver = driver_data; |
0d1857a1 | 2694 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2695 | |
bc68b7df VK |
2696 | if (driver_data->setpolicy) |
2697 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2698 | ||
7a6c79f2 RW |
2699 | if (cpufreq_boost_supported()) { |
2700 | ret = create_boost_sysfs_file(); | |
2701 | if (ret) | |
2702 | goto err_null_driver; | |
2703 | } | |
6f19efc0 | 2704 | |
8a25a2fd | 2705 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2706 | if (ret) |
6f19efc0 | 2707 | goto err_boost_unreg; |
1da177e4 | 2708 | |
ce1bcfe9 VK |
2709 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY) && |
2710 | list_empty(&cpufreq_policy_list)) { | |
1da177e4 | 2711 | /* if all ->init() calls failed, unregister */ |
6c770036 | 2712 | ret = -ENODEV; |
ce1bcfe9 VK |
2713 | pr_debug("%s: No CPU initialized for driver %s\n", __func__, |
2714 | driver_data->name); | |
2715 | goto err_if_unreg; | |
1da177e4 LT |
2716 | } |
2717 | ||
a92551e4 SAS |
2718 | ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, |
2719 | "cpufreq:online", | |
2720 | cpuhp_cpufreq_online, | |
2721 | cpuhp_cpufreq_offline); | |
27622b06 SAS |
2722 | if (ret < 0) |
2723 | goto err_if_unreg; | |
2724 | hp_online = ret; | |
5372e054 | 2725 | ret = 0; |
27622b06 | 2726 | |
2d06d8c4 | 2727 | pr_debug("driver %s up and running\n", driver_data->name); |
3834abb4 | 2728 | goto out; |
fdd320da | 2729 | |
8a25a2fd KS |
2730 | err_if_unreg: |
2731 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 | 2732 | err_boost_unreg: |
44139ed4 | 2733 | remove_boost_sysfs_file(); |
8f5bc2ab | 2734 | err_null_driver: |
0d1857a1 | 2735 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2736 | cpufreq_driver = NULL; |
0d1857a1 | 2737 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
3834abb4 | 2738 | out: |
a92551e4 | 2739 | cpus_read_unlock(); |
3834abb4 | 2740 | return ret; |
1da177e4 LT |
2741 | } |
2742 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2743 | ||
1da177e4 LT |
2744 | /** |
2745 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2746 | * | |
bb176f7d | 2747 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2748 | * the right to do so, i.e. if you have succeeded in initialising before! |
2749 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2750 | * currently not initialised. | |
2751 | */ | |
221dee28 | 2752 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2753 | { |
2754 | unsigned long flags; | |
2755 | ||
1c3d85dd | 2756 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2757 | return -EINVAL; |
1da177e4 | 2758 | |
2d06d8c4 | 2759 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2760 | |
454d3a25 | 2761 | /* Protect against concurrent cpu hotplug */ |
a92551e4 | 2762 | cpus_read_lock(); |
8a25a2fd | 2763 | subsys_interface_unregister(&cpufreq_interface); |
44139ed4 | 2764 | remove_boost_sysfs_file(); |
a92551e4 | 2765 | cpuhp_remove_state_nocalls_cpuslocked(hp_online); |
1da177e4 | 2766 | |
0d1857a1 | 2767 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2768 | |
1c3d85dd | 2769 | cpufreq_driver = NULL; |
6eed9404 | 2770 | |
0d1857a1 | 2771 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
a92551e4 | 2772 | cpus_read_unlock(); |
1da177e4 LT |
2773 | |
2774 | return 0; | |
2775 | } | |
2776 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2777 | |
2778 | static int __init cpufreq_core_init(void) | |
2779 | { | |
a7b422cd KRW |
2780 | if (cpufreq_disabled()) |
2781 | return -ENODEV; | |
2782 | ||
8eec1020 | 2783 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 TR |
2784 | BUG_ON(!cpufreq_global_kobject); |
2785 | ||
5a01f2e8 VP |
2786 | return 0; |
2787 | } | |
d82f2692 | 2788 | module_param(off, int, 0444); |
5a01f2e8 | 2789 | core_initcall(cpufreq_core_init); |