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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
bb176f7d | 6 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> |
1da177e4 | 7 | * |
c32b6b8e | 8 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 9 | * Added handling for CPU hotplug |
8ff69732 DJ |
10 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
11 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 12 | * |
1da177e4 LT |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
1da177e4 LT |
16 | */ |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
5ff0a268 | 20 | #include <linux/cpu.h> |
1da177e4 LT |
21 | #include <linux/cpufreq.h> |
22 | #include <linux/delay.h> | |
1da177e4 | 23 | #include <linux/device.h> |
5ff0a268 VK |
24 | #include <linux/init.h> |
25 | #include <linux/kernel_stat.h> | |
26 | #include <linux/module.h> | |
3fc54d37 | 27 | #include <linux/mutex.h> |
5ff0a268 | 28 | #include <linux/slab.h> |
2f0aea93 | 29 | #include <linux/suspend.h> |
90de2a4a | 30 | #include <linux/syscore_ops.h> |
5ff0a268 | 31 | #include <linux/tick.h> |
6f4f2723 TR |
32 | #include <trace/events/power.h> |
33 | ||
b4f0676f | 34 | static LIST_HEAD(cpufreq_policy_list); |
f963735a VK |
35 | |
36 | static inline bool policy_is_inactive(struct cpufreq_policy *policy) | |
37 | { | |
38 | return cpumask_empty(policy->cpus); | |
39 | } | |
40 | ||
f963735a | 41 | /* Macros to iterate over CPU policies */ |
fd7dc7e6 EB |
42 | #define for_each_suitable_policy(__policy, __active) \ |
43 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \ | |
44 | if ((__active) == !policy_is_inactive(__policy)) | |
f963735a VK |
45 | |
46 | #define for_each_active_policy(__policy) \ | |
47 | for_each_suitable_policy(__policy, true) | |
48 | #define for_each_inactive_policy(__policy) \ | |
49 | for_each_suitable_policy(__policy, false) | |
50 | ||
51 | #define for_each_policy(__policy) \ | |
b4f0676f VK |
52 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) |
53 | ||
f7b27061 VK |
54 | /* Iterate over governors */ |
55 | static LIST_HEAD(cpufreq_governor_list); | |
56 | #define for_each_governor(__governor) \ | |
57 | list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) | |
58 | ||
1da177e4 | 59 | /** |
cd878479 | 60 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
61 | * level driver of CPUFreq support, and its spinlock. This lock |
62 | * also protects the cpufreq_cpu_data array. | |
63 | */ | |
1c3d85dd | 64 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 65 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
bb176f7d | 66 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
bb176f7d | 67 | |
2f0aea93 VK |
68 | /* Flag to suspend/resume CPUFreq governors */ |
69 | static bool cpufreq_suspended; | |
1da177e4 | 70 | |
9c0ebcf7 VK |
71 | static inline bool has_target(void) |
72 | { | |
73 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
74 | } | |
75 | ||
1da177e4 | 76 | /* internal prototypes */ |
d92d50a4 | 77 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy); |
a92604b4 RW |
78 | static int cpufreq_init_governor(struct cpufreq_policy *policy); |
79 | static void cpufreq_exit_governor(struct cpufreq_policy *policy); | |
0a300767 | 80 | static int cpufreq_start_governor(struct cpufreq_policy *policy); |
a92604b4 RW |
81 | static void cpufreq_stop_governor(struct cpufreq_policy *policy); |
82 | static void cpufreq_governor_limits(struct cpufreq_policy *policy); | |
45482c70 | 83 | |
1da177e4 | 84 | /** |
32ee8c3e DJ |
85 | * Two notifier lists: the "policy" list is involved in the |
86 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
87 | * "transition" list for kernel code that needs to handle |
88 | * changes to devices when the CPU clock speed changes. | |
89 | * The mutex locks both lists. | |
90 | */ | |
e041c683 | 91 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 92 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 93 | |
74212ca4 | 94 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
95 | static int __init init_cpufreq_transition_notifier_list(void) |
96 | { | |
97 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 98 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
99 | return 0; |
100 | } | |
b3438f82 | 101 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 102 | |
a7b422cd | 103 | static int off __read_mostly; |
da584455 | 104 | static int cpufreq_disabled(void) |
a7b422cd KRW |
105 | { |
106 | return off; | |
107 | } | |
108 | void disable_cpufreq(void) | |
109 | { | |
110 | off = 1; | |
111 | } | |
29464f28 | 112 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 113 | |
4d5dcc42 VK |
114 | bool have_governor_per_policy(void) |
115 | { | |
0b981e70 | 116 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 117 | } |
3f869d6d | 118 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 119 | |
944e9a03 VK |
120 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
121 | { | |
122 | if (have_governor_per_policy()) | |
123 | return &policy->kobj; | |
124 | else | |
125 | return cpufreq_global_kobject; | |
126 | } | |
127 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
128 | ||
72a4ce34 VK |
129 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
130 | { | |
131 | u64 idle_time; | |
132 | u64 cur_wall_time; | |
133 | u64 busy_time; | |
134 | ||
7fb1327e | 135 | cur_wall_time = jiffies64_to_nsecs(get_jiffies_64()); |
72a4ce34 VK |
136 | |
137 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
138 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
139 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
140 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
141 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
142 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
143 | ||
144 | idle_time = cur_wall_time - busy_time; | |
145 | if (wall) | |
7fb1327e | 146 | *wall = div_u64(cur_wall_time, NSEC_PER_USEC); |
72a4ce34 | 147 | |
7fb1327e | 148 | return div_u64(idle_time, NSEC_PER_USEC); |
72a4ce34 VK |
149 | } |
150 | ||
151 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
152 | { | |
153 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
154 | ||
155 | if (idle_time == -1ULL) | |
156 | return get_cpu_idle_time_jiffy(cpu, wall); | |
157 | else if (!io_busy) | |
158 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
159 | ||
160 | return idle_time; | |
161 | } | |
162 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
163 | ||
70e9e778 VK |
164 | /* |
165 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
166 | * drivers of SMP systems. It will do following: | |
167 | * - validate & show freq table passed | |
168 | * - set policies transition latency | |
169 | * - policy->cpus with all possible CPUs | |
170 | */ | |
171 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
172 | struct cpufreq_frequency_table *table, | |
173 | unsigned int transition_latency) | |
174 | { | |
175 | int ret; | |
176 | ||
177 | ret = cpufreq_table_validate_and_show(policy, table); | |
178 | if (ret) { | |
179 | pr_err("%s: invalid frequency table: %d\n", __func__, ret); | |
180 | return ret; | |
181 | } | |
182 | ||
183 | policy->cpuinfo.transition_latency = transition_latency; | |
184 | ||
185 | /* | |
58405af6 | 186 | * The driver only supports the SMP configuration where all processors |
70e9e778 VK |
187 | * share the clock and voltage and clock. |
188 | */ | |
189 | cpumask_setall(policy->cpus); | |
190 | ||
191 | return 0; | |
192 | } | |
193 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
194 | ||
1f0bd44e | 195 | struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) |
652ed95d VK |
196 | { |
197 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
198 | ||
988bed09 VK |
199 | return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL; |
200 | } | |
1f0bd44e | 201 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw); |
988bed09 VK |
202 | |
203 | unsigned int cpufreq_generic_get(unsigned int cpu) | |
204 | { | |
205 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); | |
206 | ||
652ed95d | 207 | if (!policy || IS_ERR(policy->clk)) { |
e837f9b5 JP |
208 | pr_err("%s: No %s associated to cpu: %d\n", |
209 | __func__, policy ? "clk" : "policy", cpu); | |
652ed95d VK |
210 | return 0; |
211 | } | |
212 | ||
213 | return clk_get_rate(policy->clk) / 1000; | |
214 | } | |
215 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
216 | ||
50e9c852 VK |
217 | /** |
218 | * cpufreq_cpu_get: returns policy for a cpu and marks it busy. | |
219 | * | |
220 | * @cpu: cpu to find policy for. | |
221 | * | |
222 | * This returns policy for 'cpu', returns NULL if it doesn't exist. | |
223 | * It also increments the kobject reference count to mark it busy and so would | |
224 | * require a corresponding call to cpufreq_cpu_put() to decrement it back. | |
225 | * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be | |
226 | * freed as that depends on the kobj count. | |
227 | * | |
50e9c852 VK |
228 | * Return: A valid policy on success, otherwise NULL on failure. |
229 | */ | |
6eed9404 | 230 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 231 | { |
6eed9404 | 232 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
233 | unsigned long flags; |
234 | ||
1b947c90 | 235 | if (WARN_ON(cpu >= nr_cpu_ids)) |
6eed9404 VK |
236 | return NULL; |
237 | ||
1da177e4 | 238 | /* get the cpufreq driver */ |
1c3d85dd | 239 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 240 | |
6eed9404 VK |
241 | if (cpufreq_driver) { |
242 | /* get the CPU */ | |
988bed09 | 243 | policy = cpufreq_cpu_get_raw(cpu); |
6eed9404 VK |
244 | if (policy) |
245 | kobject_get(&policy->kobj); | |
246 | } | |
1da177e4 | 247 | |
6eed9404 | 248 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 249 | |
3a3e9e06 | 250 | return policy; |
a9144436 | 251 | } |
1da177e4 LT |
252 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
253 | ||
50e9c852 VK |
254 | /** |
255 | * cpufreq_cpu_put: Decrements the usage count of a policy | |
256 | * | |
257 | * @policy: policy earlier returned by cpufreq_cpu_get(). | |
258 | * | |
259 | * This decrements the kobject reference count incremented earlier by calling | |
260 | * cpufreq_cpu_get(). | |
50e9c852 | 261 | */ |
3a3e9e06 | 262 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 263 | { |
6eed9404 | 264 | kobject_put(&policy->kobj); |
1da177e4 LT |
265 | } |
266 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
267 | ||
1da177e4 LT |
268 | /********************************************************************* |
269 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
270 | *********************************************************************/ | |
271 | ||
272 | /** | |
273 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
274 | * | |
275 | * This function alters the system "loops_per_jiffy" for the clock | |
276 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 277 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
278 | * per-CPU loops_per_jiffy value wherever possible. |
279 | */ | |
858119e1 | 280 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 | 281 | { |
39c132ee VK |
282 | #ifndef CONFIG_SMP |
283 | static unsigned long l_p_j_ref; | |
284 | static unsigned int l_p_j_ref_freq; | |
285 | ||
1da177e4 LT |
286 | if (ci->flags & CPUFREQ_CONST_LOOPS) |
287 | return; | |
288 | ||
289 | if (!l_p_j_ref_freq) { | |
290 | l_p_j_ref = loops_per_jiffy; | |
291 | l_p_j_ref_freq = ci->old; | |
e837f9b5 JP |
292 | pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", |
293 | l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 | 294 | } |
0b443ead | 295 | if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { |
e08f5f5b GS |
296 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
297 | ci->new); | |
e837f9b5 JP |
298 | pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", |
299 | loops_per_jiffy, ci->new); | |
1da177e4 | 300 | } |
1da177e4 | 301 | #endif |
39c132ee | 302 | } |
1da177e4 | 303 | |
0956df9c | 304 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 305 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
306 | { |
307 | BUG_ON(irqs_disabled()); | |
308 | ||
d5aaffa9 DB |
309 | if (cpufreq_disabled()) |
310 | return; | |
311 | ||
1c3d85dd | 312 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 313 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e837f9b5 | 314 | state, freqs->new); |
1da177e4 | 315 | |
1da177e4 | 316 | switch (state) { |
e4472cb3 | 317 | |
1da177e4 | 318 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 319 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
320 | * which is not equal to what the cpufreq core thinks is |
321 | * "old frequency". | |
1da177e4 | 322 | */ |
1c3d85dd | 323 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
324 | if ((policy) && (policy->cpu == freqs->cpu) && |
325 | (policy->cur) && (policy->cur != freqs->old)) { | |
e837f9b5 JP |
326 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", |
327 | freqs->old, policy->cur); | |
e4472cb3 | 328 | freqs->old = policy->cur; |
1da177e4 LT |
329 | } |
330 | } | |
b4dfdbb3 | 331 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 332 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
333 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
334 | break; | |
e4472cb3 | 335 | |
1da177e4 LT |
336 | case CPUFREQ_POSTCHANGE: |
337 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
e837f9b5 JP |
338 | pr_debug("FREQ: %lu - CPU: %lu\n", |
339 | (unsigned long)freqs->new, (unsigned long)freqs->cpu); | |
25e41933 | 340 | trace_cpu_frequency(freqs->new, freqs->cpu); |
1aefc75b | 341 | cpufreq_stats_record_transition(policy, freqs->new); |
b4dfdbb3 | 342 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 343 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
344 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
345 | policy->cur = freqs->new; | |
1da177e4 LT |
346 | break; |
347 | } | |
1da177e4 | 348 | } |
bb176f7d | 349 | |
b43a7ffb VK |
350 | /** |
351 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
352 | * on frequency transition. | |
353 | * | |
354 | * This function calls the transition notifiers and the "adjust_jiffies" | |
355 | * function. It is called twice on all CPU frequency changes that have | |
356 | * external effects. | |
357 | */ | |
236a9800 | 358 | static void cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb VK |
359 | struct cpufreq_freqs *freqs, unsigned int state) |
360 | { | |
361 | for_each_cpu(freqs->cpu, policy->cpus) | |
362 | __cpufreq_notify_transition(policy, freqs, state); | |
363 | } | |
1da177e4 | 364 | |
f7ba3b41 | 365 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 366 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
367 | struct cpufreq_freqs *freqs, int transition_failed) |
368 | { | |
369 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
370 | if (!transition_failed) | |
371 | return; | |
372 | ||
373 | swap(freqs->old, freqs->new); | |
374 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
375 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
376 | } | |
f7ba3b41 | 377 | |
12478cf0 SB |
378 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
379 | struct cpufreq_freqs *freqs) | |
380 | { | |
ca654dc3 SB |
381 | |
382 | /* | |
383 | * Catch double invocations of _begin() which lead to self-deadlock. | |
384 | * ASYNC_NOTIFICATION drivers are left out because the cpufreq core | |
385 | * doesn't invoke _begin() on their behalf, and hence the chances of | |
386 | * double invocations are very low. Moreover, there are scenarios | |
387 | * where these checks can emit false-positive warnings in these | |
388 | * drivers; so we avoid that by skipping them altogether. | |
389 | */ | |
390 | WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) | |
391 | && current == policy->transition_task); | |
392 | ||
12478cf0 SB |
393 | wait: |
394 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
395 | ||
396 | spin_lock(&policy->transition_lock); | |
397 | ||
398 | if (unlikely(policy->transition_ongoing)) { | |
399 | spin_unlock(&policy->transition_lock); | |
400 | goto wait; | |
401 | } | |
402 | ||
403 | policy->transition_ongoing = true; | |
ca654dc3 | 404 | policy->transition_task = current; |
12478cf0 SB |
405 | |
406 | spin_unlock(&policy->transition_lock); | |
407 | ||
408 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
409 | } | |
410 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
411 | ||
412 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
413 | struct cpufreq_freqs *freqs, int transition_failed) | |
414 | { | |
415 | if (unlikely(WARN_ON(!policy->transition_ongoing))) | |
416 | return; | |
417 | ||
418 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
419 | ||
420 | policy->transition_ongoing = false; | |
ca654dc3 | 421 | policy->transition_task = NULL; |
12478cf0 SB |
422 | |
423 | wake_up(&policy->transition_wait); | |
424 | } | |
425 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
426 | ||
b7898fda RW |
427 | /* |
428 | * Fast frequency switching status count. Positive means "enabled", negative | |
429 | * means "disabled" and 0 means "not decided yet". | |
430 | */ | |
431 | static int cpufreq_fast_switch_count; | |
432 | static DEFINE_MUTEX(cpufreq_fast_switch_lock); | |
433 | ||
434 | static void cpufreq_list_transition_notifiers(void) | |
435 | { | |
436 | struct notifier_block *nb; | |
437 | ||
438 | pr_info("Registered transition notifiers:\n"); | |
439 | ||
440 | mutex_lock(&cpufreq_transition_notifier_list.mutex); | |
441 | ||
442 | for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next) | |
443 | pr_info("%pF\n", nb->notifier_call); | |
444 | ||
445 | mutex_unlock(&cpufreq_transition_notifier_list.mutex); | |
446 | } | |
447 | ||
448 | /** | |
449 | * cpufreq_enable_fast_switch - Enable fast frequency switching for policy. | |
450 | * @policy: cpufreq policy to enable fast frequency switching for. | |
451 | * | |
452 | * Try to enable fast frequency switching for @policy. | |
453 | * | |
454 | * The attempt will fail if there is at least one transition notifier registered | |
455 | * at this point, as fast frequency switching is quite fundamentally at odds | |
456 | * with transition notifiers. Thus if successful, it will make registration of | |
457 | * transition notifiers fail going forward. | |
458 | */ | |
459 | void cpufreq_enable_fast_switch(struct cpufreq_policy *policy) | |
460 | { | |
461 | lockdep_assert_held(&policy->rwsem); | |
462 | ||
463 | if (!policy->fast_switch_possible) | |
464 | return; | |
465 | ||
466 | mutex_lock(&cpufreq_fast_switch_lock); | |
467 | if (cpufreq_fast_switch_count >= 0) { | |
468 | cpufreq_fast_switch_count++; | |
469 | policy->fast_switch_enabled = true; | |
470 | } else { | |
471 | pr_warn("CPU%u: Fast frequency switching not enabled\n", | |
472 | policy->cpu); | |
473 | cpufreq_list_transition_notifiers(); | |
474 | } | |
475 | mutex_unlock(&cpufreq_fast_switch_lock); | |
476 | } | |
477 | EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); | |
478 | ||
6c9d9c81 RW |
479 | /** |
480 | * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. | |
481 | * @policy: cpufreq policy to disable fast frequency switching for. | |
482 | */ | |
483 | void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) | |
b7898fda RW |
484 | { |
485 | mutex_lock(&cpufreq_fast_switch_lock); | |
486 | if (policy->fast_switch_enabled) { | |
487 | policy->fast_switch_enabled = false; | |
488 | if (!WARN_ON(cpufreq_fast_switch_count <= 0)) | |
489 | cpufreq_fast_switch_count--; | |
490 | } | |
491 | mutex_unlock(&cpufreq_fast_switch_lock); | |
492 | } | |
6c9d9c81 | 493 | EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); |
1da177e4 | 494 | |
e3c06236 SM |
495 | /** |
496 | * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported | |
497 | * one. | |
498 | * @target_freq: target frequency to resolve. | |
499 | * | |
500 | * The target to driver frequency mapping is cached in the policy. | |
501 | * | |
502 | * Return: Lowest driver-supported frequency greater than or equal to the | |
503 | * given target_freq, subject to policy (min/max) and driver limitations. | |
504 | */ | |
505 | unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, | |
506 | unsigned int target_freq) | |
507 | { | |
508 | target_freq = clamp_val(target_freq, policy->min, policy->max); | |
509 | policy->cached_target_freq = target_freq; | |
abe8bd02 VK |
510 | |
511 | if (cpufreq_driver->target_index) { | |
512 | int idx; | |
513 | ||
514 | idx = cpufreq_frequency_table_target(policy, target_freq, | |
515 | CPUFREQ_RELATION_L); | |
516 | policy->cached_resolved_idx = idx; | |
517 | return policy->freq_table[idx].frequency; | |
518 | } | |
519 | ||
e3c06236 SM |
520 | if (cpufreq_driver->resolve_freq) |
521 | return cpufreq_driver->resolve_freq(policy, target_freq); | |
abe8bd02 VK |
522 | |
523 | return target_freq; | |
e3c06236 | 524 | } |
ae2c1ca6 | 525 | EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); |
e3c06236 | 526 | |
1da177e4 LT |
527 | /********************************************************************* |
528 | * SYSFS INTERFACE * | |
529 | *********************************************************************/ | |
8a5c74a1 | 530 | static ssize_t show_boost(struct kobject *kobj, |
6f19efc0 LM |
531 | struct attribute *attr, char *buf) |
532 | { | |
533 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
534 | } | |
535 | ||
536 | static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, | |
537 | const char *buf, size_t count) | |
538 | { | |
539 | int ret, enable; | |
540 | ||
541 | ret = sscanf(buf, "%d", &enable); | |
542 | if (ret != 1 || enable < 0 || enable > 1) | |
543 | return -EINVAL; | |
544 | ||
545 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
546 | pr_err("%s: Cannot %s BOOST!\n", |
547 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
548 | return -EINVAL; |
549 | } | |
550 | ||
e837f9b5 JP |
551 | pr_debug("%s: cpufreq BOOST %s\n", |
552 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
553 | |
554 | return count; | |
555 | } | |
556 | define_one_global_rw(boost); | |
1da177e4 | 557 | |
42f91fa1 | 558 | static struct cpufreq_governor *find_governor(const char *str_governor) |
3bcb09a3 JF |
559 | { |
560 | struct cpufreq_governor *t; | |
561 | ||
f7b27061 | 562 | for_each_governor(t) |
7c4f4539 | 563 | if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
564 | return t; |
565 | ||
566 | return NULL; | |
567 | } | |
568 | ||
1da177e4 LT |
569 | /** |
570 | * cpufreq_parse_governor - parse a governor string | |
571 | */ | |
905d77cd | 572 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
573 | struct cpufreq_governor **governor) |
574 | { | |
3bcb09a3 | 575 | int err = -EINVAL; |
1c3d85dd | 576 | |
1c3d85dd | 577 | if (cpufreq_driver->setpolicy) { |
7c4f4539 | 578 | if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
1da177e4 | 579 | *policy = CPUFREQ_POLICY_PERFORMANCE; |
3bcb09a3 | 580 | err = 0; |
7c4f4539 | 581 | } else if (!strncasecmp(str_governor, "powersave", |
e08f5f5b | 582 | CPUFREQ_NAME_LEN)) { |
1da177e4 | 583 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 584 | err = 0; |
1da177e4 | 585 | } |
2e1cc3a5 | 586 | } else { |
1da177e4 | 587 | struct cpufreq_governor *t; |
3bcb09a3 | 588 | |
3fc54d37 | 589 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 | 590 | |
42f91fa1 | 591 | t = find_governor(str_governor); |
3bcb09a3 | 592 | |
ea714970 | 593 | if (t == NULL) { |
1a8e1463 | 594 | int ret; |
ea714970 | 595 | |
1a8e1463 KC |
596 | mutex_unlock(&cpufreq_governor_mutex); |
597 | ret = request_module("cpufreq_%s", str_governor); | |
598 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 599 | |
1a8e1463 | 600 | if (ret == 0) |
42f91fa1 | 601 | t = find_governor(str_governor); |
ea714970 JF |
602 | } |
603 | ||
3bcb09a3 JF |
604 | if (t != NULL) { |
605 | *governor = t; | |
606 | err = 0; | |
1da177e4 | 607 | } |
3bcb09a3 | 608 | |
3fc54d37 | 609 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 610 | } |
3bcb09a3 | 611 | return err; |
1da177e4 | 612 | } |
1da177e4 | 613 | |
1da177e4 | 614 | /** |
e08f5f5b GS |
615 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
616 | * print out cpufreq information | |
1da177e4 LT |
617 | * |
618 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
619 | * "unsigned int". | |
620 | */ | |
621 | ||
32ee8c3e DJ |
622 | #define show_one(file_name, object) \ |
623 | static ssize_t show_##file_name \ | |
905d77cd | 624 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 625 | { \ |
29464f28 | 626 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
627 | } |
628 | ||
629 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
630 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 631 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
632 | show_one(scaling_min_freq, min); |
633 | show_one(scaling_max_freq, max); | |
c034b02e | 634 | |
09347b29 | 635 | static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) |
c034b02e DB |
636 | { |
637 | ssize_t ret; | |
638 | ||
639 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) | |
640 | ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); | |
641 | else | |
642 | ret = sprintf(buf, "%u\n", policy->cur); | |
643 | return ret; | |
644 | } | |
1da177e4 | 645 | |
037ce839 | 646 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 647 | struct cpufreq_policy *new_policy); |
7970e08b | 648 | |
1da177e4 LT |
649 | /** |
650 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
651 | */ | |
652 | #define store_one(file_name, object) \ | |
653 | static ssize_t store_##file_name \ | |
905d77cd | 654 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 655 | { \ |
619c144c | 656 | int ret, temp; \ |
1da177e4 LT |
657 | struct cpufreq_policy new_policy; \ |
658 | \ | |
8fa5b631 | 659 | memcpy(&new_policy, policy, sizeof(*policy)); \ |
1da177e4 | 660 | \ |
29464f28 | 661 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
662 | if (ret != 1) \ |
663 | return -EINVAL; \ | |
664 | \ | |
619c144c | 665 | temp = new_policy.object; \ |
037ce839 | 666 | ret = cpufreq_set_policy(policy, &new_policy); \ |
619c144c VH |
667 | if (!ret) \ |
668 | policy->user_policy.object = temp; \ | |
1da177e4 LT |
669 | \ |
670 | return ret ? ret : count; \ | |
671 | } | |
672 | ||
29464f28 DJ |
673 | store_one(scaling_min_freq, min); |
674 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
675 | |
676 | /** | |
677 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
678 | */ | |
905d77cd DJ |
679 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
680 | char *buf) | |
1da177e4 | 681 | { |
d92d50a4 | 682 | unsigned int cur_freq = __cpufreq_get(policy); |
9b4f603e RW |
683 | |
684 | if (cur_freq) | |
685 | return sprintf(buf, "%u\n", cur_freq); | |
686 | ||
687 | return sprintf(buf, "<unknown>\n"); | |
1da177e4 LT |
688 | } |
689 | ||
1da177e4 LT |
690 | /** |
691 | * show_scaling_governor - show the current policy for the specified CPU | |
692 | */ | |
905d77cd | 693 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 694 | { |
29464f28 | 695 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
696 | return sprintf(buf, "powersave\n"); |
697 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
698 | return sprintf(buf, "performance\n"); | |
699 | else if (policy->governor) | |
4b972f0b | 700 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 701 | policy->governor->name); |
1da177e4 LT |
702 | return -EINVAL; |
703 | } | |
704 | ||
1da177e4 LT |
705 | /** |
706 | * store_scaling_governor - store policy for the specified CPU | |
707 | */ | |
905d77cd DJ |
708 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
709 | const char *buf, size_t count) | |
1da177e4 | 710 | { |
5136fa56 | 711 | int ret; |
1da177e4 LT |
712 | char str_governor[16]; |
713 | struct cpufreq_policy new_policy; | |
714 | ||
8fa5b631 | 715 | memcpy(&new_policy, policy, sizeof(*policy)); |
1da177e4 | 716 | |
29464f28 | 717 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
718 | if (ret != 1) |
719 | return -EINVAL; | |
720 | ||
e08f5f5b GS |
721 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
722 | &new_policy.governor)) | |
1da177e4 LT |
723 | return -EINVAL; |
724 | ||
037ce839 | 725 | ret = cpufreq_set_policy(policy, &new_policy); |
88dc4384 | 726 | return ret ? ret : count; |
1da177e4 LT |
727 | } |
728 | ||
729 | /** | |
730 | * show_scaling_driver - show the cpufreq driver currently loaded | |
731 | */ | |
905d77cd | 732 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 733 | { |
1c3d85dd | 734 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
735 | } |
736 | ||
737 | /** | |
738 | * show_scaling_available_governors - show the available CPUfreq governors | |
739 | */ | |
905d77cd DJ |
740 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
741 | char *buf) | |
1da177e4 LT |
742 | { |
743 | ssize_t i = 0; | |
744 | struct cpufreq_governor *t; | |
745 | ||
9c0ebcf7 | 746 | if (!has_target()) { |
1da177e4 LT |
747 | i += sprintf(buf, "performance powersave"); |
748 | goto out; | |
749 | } | |
750 | ||
f7b27061 | 751 | for_each_governor(t) { |
29464f28 DJ |
752 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
753 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 754 | goto out; |
4b972f0b | 755 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 756 | } |
7d5e350f | 757 | out: |
1da177e4 LT |
758 | i += sprintf(&buf[i], "\n"); |
759 | return i; | |
760 | } | |
e8628dd0 | 761 | |
f4fd3797 | 762 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
763 | { |
764 | ssize_t i = 0; | |
765 | unsigned int cpu; | |
766 | ||
835481d9 | 767 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
768 | if (i) |
769 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
770 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
771 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 772 | break; |
1da177e4 LT |
773 | } |
774 | i += sprintf(&buf[i], "\n"); | |
775 | return i; | |
776 | } | |
f4fd3797 | 777 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 778 | |
e8628dd0 DW |
779 | /** |
780 | * show_related_cpus - show the CPUs affected by each transition even if | |
781 | * hw coordination is in use | |
782 | */ | |
783 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
784 | { | |
f4fd3797 | 785 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
786 | } |
787 | ||
788 | /** | |
789 | * show_affected_cpus - show the CPUs affected by each transition | |
790 | */ | |
791 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
792 | { | |
f4fd3797 | 793 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
794 | } |
795 | ||
9e76988e | 796 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 797 | const char *buf, size_t count) |
9e76988e VP |
798 | { |
799 | unsigned int freq = 0; | |
800 | unsigned int ret; | |
801 | ||
879000f9 | 802 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
803 | return -EINVAL; |
804 | ||
805 | ret = sscanf(buf, "%u", &freq); | |
806 | if (ret != 1) | |
807 | return -EINVAL; | |
808 | ||
809 | policy->governor->store_setspeed(policy, freq); | |
810 | ||
811 | return count; | |
812 | } | |
813 | ||
814 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
815 | { | |
879000f9 | 816 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
817 | return sprintf(buf, "<unsupported>\n"); |
818 | ||
819 | return policy->governor->show_setspeed(policy, buf); | |
820 | } | |
1da177e4 | 821 | |
e2f74f35 | 822 | /** |
8bf1ac72 | 823 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
824 | */ |
825 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
826 | { | |
827 | unsigned int limit; | |
828 | int ret; | |
1c3d85dd RW |
829 | if (cpufreq_driver->bios_limit) { |
830 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
831 | if (!ret) |
832 | return sprintf(buf, "%u\n", limit); | |
833 | } | |
834 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
835 | } | |
836 | ||
6dad2a29 BP |
837 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
838 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
839 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
840 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
841 | cpufreq_freq_attr_ro(scaling_available_governors); | |
842 | cpufreq_freq_attr_ro(scaling_driver); | |
843 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
844 | cpufreq_freq_attr_ro(bios_limit); | |
845 | cpufreq_freq_attr_ro(related_cpus); | |
846 | cpufreq_freq_attr_ro(affected_cpus); | |
847 | cpufreq_freq_attr_rw(scaling_min_freq); | |
848 | cpufreq_freq_attr_rw(scaling_max_freq); | |
849 | cpufreq_freq_attr_rw(scaling_governor); | |
850 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 851 | |
905d77cd | 852 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
853 | &cpuinfo_min_freq.attr, |
854 | &cpuinfo_max_freq.attr, | |
ed129784 | 855 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
856 | &scaling_min_freq.attr, |
857 | &scaling_max_freq.attr, | |
858 | &affected_cpus.attr, | |
e8628dd0 | 859 | &related_cpus.attr, |
1da177e4 LT |
860 | &scaling_governor.attr, |
861 | &scaling_driver.attr, | |
862 | &scaling_available_governors.attr, | |
9e76988e | 863 | &scaling_setspeed.attr, |
1da177e4 LT |
864 | NULL |
865 | }; | |
866 | ||
29464f28 DJ |
867 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
868 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 869 | |
29464f28 | 870 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 871 | { |
905d77cd DJ |
872 | struct cpufreq_policy *policy = to_policy(kobj); |
873 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 874 | ssize_t ret; |
6eed9404 | 875 | |
ad7722da | 876 | down_read(&policy->rwsem); |
6541aef0 | 877 | ret = fattr->show(policy, buf); |
ad7722da | 878 | up_read(&policy->rwsem); |
1b750e3b | 879 | |
1da177e4 LT |
880 | return ret; |
881 | } | |
882 | ||
905d77cd DJ |
883 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
884 | const char *buf, size_t count) | |
1da177e4 | 885 | { |
905d77cd DJ |
886 | struct cpufreq_policy *policy = to_policy(kobj); |
887 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 888 | ssize_t ret = -EINVAL; |
6eed9404 | 889 | |
4f750c93 SB |
890 | get_online_cpus(); |
891 | ||
6541aef0 RW |
892 | if (cpu_online(policy->cpu)) { |
893 | down_write(&policy->rwsem); | |
e08f5f5b | 894 | ret = fattr->store(policy, buf, count); |
6541aef0 RW |
895 | up_write(&policy->rwsem); |
896 | } | |
e08f5f5b | 897 | |
4f750c93 SB |
898 | put_online_cpus(); |
899 | ||
1da177e4 LT |
900 | return ret; |
901 | } | |
902 | ||
905d77cd | 903 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 904 | { |
905d77cd | 905 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 906 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
907 | complete(&policy->kobj_unregister); |
908 | } | |
909 | ||
52cf25d0 | 910 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
911 | .show = show, |
912 | .store = store, | |
913 | }; | |
914 | ||
915 | static struct kobj_type ktype_cpufreq = { | |
916 | .sysfs_ops = &sysfs_ops, | |
917 | .default_attrs = default_attrs, | |
918 | .release = cpufreq_sysfs_release, | |
919 | }; | |
920 | ||
2f0ba790 | 921 | static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) |
87549141 | 922 | { |
2f0ba790 RW |
923 | struct device *dev = get_cpu_device(cpu); |
924 | ||
925 | if (!dev) | |
926 | return; | |
927 | ||
928 | if (cpumask_test_and_set_cpu(cpu, policy->real_cpus)) | |
929 | return; | |
930 | ||
26619804 | 931 | dev_dbg(dev, "%s: Adding symlink\n", __func__); |
2f0ba790 RW |
932 | if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq")) |
933 | dev_err(dev, "cpufreq symlink creation failed\n"); | |
87549141 VK |
934 | } |
935 | ||
26619804 VK |
936 | static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, |
937 | struct device *dev) | |
87549141 | 938 | { |
26619804 VK |
939 | dev_dbg(dev, "%s: Removing symlink\n", __func__); |
940 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
87549141 VK |
941 | } |
942 | ||
d9612a49 | 943 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) |
909a694e DJ |
944 | { |
945 | struct freq_attr **drv_attr; | |
909a694e | 946 | int ret = 0; |
909a694e | 947 | |
909a694e | 948 | /* set up files for this cpu device */ |
1c3d85dd | 949 | drv_attr = cpufreq_driver->attr; |
f13f1184 | 950 | while (drv_attr && *drv_attr) { |
909a694e DJ |
951 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
952 | if (ret) | |
6d4e81ed | 953 | return ret; |
909a694e DJ |
954 | drv_attr++; |
955 | } | |
1c3d85dd | 956 | if (cpufreq_driver->get) { |
909a694e DJ |
957 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
958 | if (ret) | |
6d4e81ed | 959 | return ret; |
909a694e | 960 | } |
c034b02e DB |
961 | |
962 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
963 | if (ret) | |
6d4e81ed | 964 | return ret; |
c034b02e | 965 | |
1c3d85dd | 966 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
967 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
968 | if (ret) | |
6d4e81ed | 969 | return ret; |
e2f74f35 | 970 | } |
909a694e | 971 | |
26619804 | 972 | return 0; |
e18f1682 SB |
973 | } |
974 | ||
de1df26b RW |
975 | __weak struct cpufreq_governor *cpufreq_default_governor(void) |
976 | { | |
977 | return NULL; | |
978 | } | |
979 | ||
7f0fa40f | 980 | static int cpufreq_init_policy(struct cpufreq_policy *policy) |
e18f1682 | 981 | { |
6e2c89d1 | 982 | struct cpufreq_governor *gov = NULL; |
e18f1682 | 983 | struct cpufreq_policy new_policy; |
e18f1682 | 984 | |
d5b73cd8 | 985 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 986 | |
6e2c89d1 | 987 | /* Update governor of new_policy to the governor used before hotplug */ |
4573237b | 988 | gov = find_governor(policy->last_governor); |
de1df26b | 989 | if (gov) { |
6e2c89d1 | 990 | pr_debug("Restoring governor %s for cpu %d\n", |
991 | policy->governor->name, policy->cpu); | |
de1df26b RW |
992 | } else { |
993 | gov = cpufreq_default_governor(); | |
994 | if (!gov) | |
995 | return -ENODATA; | |
996 | } | |
6e2c89d1 | 997 | |
998 | new_policy.governor = gov; | |
999 | ||
69030dd1 SP |
1000 | /* Use the default policy if there is no last_policy. */ |
1001 | if (cpufreq_driver->setpolicy) { | |
1002 | if (policy->last_policy) | |
1003 | new_policy.policy = policy->last_policy; | |
1004 | else | |
1005 | cpufreq_parse_governor(gov->name, &new_policy.policy, | |
1006 | NULL); | |
1007 | } | |
ecf7e461 | 1008 | /* set default policy */ |
7f0fa40f | 1009 | return cpufreq_set_policy(policy, &new_policy); |
909a694e DJ |
1010 | } |
1011 | ||
d9612a49 | 1012 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
fcf80582 | 1013 | { |
9c0ebcf7 | 1014 | int ret = 0; |
fcf80582 | 1015 | |
bb29ae15 VK |
1016 | /* Has this CPU been taken care of already? */ |
1017 | if (cpumask_test_cpu(cpu, policy->cpus)) | |
1018 | return 0; | |
1019 | ||
49f18560 | 1020 | down_write(&policy->rwsem); |
45482c70 RW |
1021 | if (has_target()) |
1022 | cpufreq_stop_governor(policy); | |
fcf80582 | 1023 | |
fcf80582 | 1024 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 1025 | |
9c0ebcf7 | 1026 | if (has_target()) { |
0a300767 | 1027 | ret = cpufreq_start_governor(policy); |
49f18560 | 1028 | if (ret) |
3de9bdeb | 1029 | pr_err("%s: Failed to start governor\n", __func__); |
820c6ca2 | 1030 | } |
49f18560 VK |
1031 | up_write(&policy->rwsem); |
1032 | return ret; | |
fcf80582 | 1033 | } |
1da177e4 | 1034 | |
11eb69b9 VK |
1035 | static void handle_update(struct work_struct *work) |
1036 | { | |
1037 | struct cpufreq_policy *policy = | |
1038 | container_of(work, struct cpufreq_policy, update); | |
1039 | unsigned int cpu = policy->cpu; | |
1040 | pr_debug("handle_update for cpu %u called\n", cpu); | |
1041 | cpufreq_update_policy(cpu); | |
fcf80582 | 1042 | } |
1da177e4 | 1043 | |
a34e63b1 | 1044 | static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) |
e9698cc5 SB |
1045 | { |
1046 | struct cpufreq_policy *policy; | |
edd4a893 | 1047 | int ret; |
e9698cc5 SB |
1048 | |
1049 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
1050 | if (!policy) | |
1051 | return NULL; | |
1052 | ||
1053 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1054 | goto err_free_policy; | |
1055 | ||
1056 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1057 | goto err_free_cpumask; | |
1058 | ||
559ed407 RW |
1059 | if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) |
1060 | goto err_free_rcpumask; | |
1061 | ||
edd4a893 VK |
1062 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
1063 | cpufreq_global_kobject, "policy%u", cpu); | |
1064 | if (ret) { | |
1065 | pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret); | |
1066 | goto err_free_real_cpus; | |
1067 | } | |
1068 | ||
c88a1f8b | 1069 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1070 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1071 | spin_lock_init(&policy->transition_lock); |
1072 | init_waitqueue_head(&policy->transition_wait); | |
818c5712 VK |
1073 | init_completion(&policy->kobj_unregister); |
1074 | INIT_WORK(&policy->update, handle_update); | |
ad7722da | 1075 | |
a34e63b1 | 1076 | policy->cpu = cpu; |
e9698cc5 SB |
1077 | return policy; |
1078 | ||
edd4a893 VK |
1079 | err_free_real_cpus: |
1080 | free_cpumask_var(policy->real_cpus); | |
2fc3384d VK |
1081 | err_free_rcpumask: |
1082 | free_cpumask_var(policy->related_cpus); | |
e9698cc5 SB |
1083 | err_free_cpumask: |
1084 | free_cpumask_var(policy->cpus); | |
1085 | err_free_policy: | |
1086 | kfree(policy); | |
1087 | ||
1088 | return NULL; | |
1089 | } | |
1090 | ||
f9f41e3e | 1091 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
42f921a6 VK |
1092 | { |
1093 | struct kobject *kobj; | |
1094 | struct completion *cmp; | |
1095 | ||
87549141 | 1096 | down_write(&policy->rwsem); |
1aefc75b | 1097 | cpufreq_stats_free_table(policy); |
42f921a6 VK |
1098 | kobj = &policy->kobj; |
1099 | cmp = &policy->kobj_unregister; | |
87549141 | 1100 | up_write(&policy->rwsem); |
42f921a6 VK |
1101 | kobject_put(kobj); |
1102 | ||
1103 | /* | |
1104 | * We need to make sure that the underlying kobj is | |
1105 | * actually not referenced anymore by anybody before we | |
1106 | * proceed with unloading. | |
1107 | */ | |
1108 | pr_debug("waiting for dropping of refcount\n"); | |
1109 | wait_for_completion(cmp); | |
1110 | pr_debug("wait complete\n"); | |
1111 | } | |
1112 | ||
f9f41e3e | 1113 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
e9698cc5 | 1114 | { |
988bed09 VK |
1115 | unsigned long flags; |
1116 | int cpu; | |
1117 | ||
1118 | /* Remove policy from list */ | |
1119 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1120 | list_del(&policy->policy_list); | |
1121 | ||
1122 | for_each_cpu(cpu, policy->related_cpus) | |
1123 | per_cpu(cpufreq_cpu_data, cpu) = NULL; | |
1124 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1125 | ||
f9f41e3e | 1126 | cpufreq_policy_put_kobj(policy); |
559ed407 | 1127 | free_cpumask_var(policy->real_cpus); |
e9698cc5 SB |
1128 | free_cpumask_var(policy->related_cpus); |
1129 | free_cpumask_var(policy->cpus); | |
1130 | kfree(policy); | |
1131 | } | |
1132 | ||
0b275352 | 1133 | static int cpufreq_online(unsigned int cpu) |
1da177e4 | 1134 | { |
7f0c020a | 1135 | struct cpufreq_policy *policy; |
194d99c7 | 1136 | bool new_policy; |
1da177e4 | 1137 | unsigned long flags; |
0b275352 RW |
1138 | unsigned int j; |
1139 | int ret; | |
87549141 | 1140 | |
0b275352 | 1141 | pr_debug("%s: bringing CPU%u online\n", __func__, cpu); |
6eed9404 | 1142 | |
bb29ae15 | 1143 | /* Check if this CPU already has a policy to manage it */ |
9104bb26 | 1144 | policy = per_cpu(cpufreq_cpu_data, cpu); |
11ce707e | 1145 | if (policy) { |
9104bb26 | 1146 | WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus)); |
11ce707e | 1147 | if (!policy_is_inactive(policy)) |
d9612a49 | 1148 | return cpufreq_add_policy_cpu(policy, cpu); |
1da177e4 | 1149 | |
11ce707e | 1150 | /* This is the only online CPU for the policy. Start over. */ |
194d99c7 | 1151 | new_policy = false; |
11ce707e RW |
1152 | down_write(&policy->rwsem); |
1153 | policy->cpu = cpu; | |
1154 | policy->governor = NULL; | |
1155 | up_write(&policy->rwsem); | |
1156 | } else { | |
194d99c7 | 1157 | new_policy = true; |
a34e63b1 | 1158 | policy = cpufreq_policy_alloc(cpu); |
72368d12 | 1159 | if (!policy) |
d4d854d6 | 1160 | return -ENOMEM; |
72368d12 | 1161 | } |
0d66b91e | 1162 | |
835481d9 | 1163 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1164 | |
1da177e4 LT |
1165 | /* call driver. From then on the cpufreq must be able |
1166 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1167 | */ | |
1c3d85dd | 1168 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1169 | if (ret) { |
2d06d8c4 | 1170 | pr_debug("initialization failed\n"); |
8101f997 | 1171 | goto out_free_policy; |
1da177e4 | 1172 | } |
643ae6e8 | 1173 | |
6d4e81ed TV |
1174 | down_write(&policy->rwsem); |
1175 | ||
194d99c7 | 1176 | if (new_policy) { |
4d1f3a5b | 1177 | /* related_cpus should at least include policy->cpus. */ |
0998a03a | 1178 | cpumask_copy(policy->related_cpus, policy->cpus); |
4d1f3a5b | 1179 | } |
559ed407 | 1180 | |
5a7e56a5 VK |
1181 | /* |
1182 | * affected cpus must always be the one, which are online. We aren't | |
1183 | * managing offline cpus here. | |
1184 | */ | |
1185 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1186 | ||
194d99c7 | 1187 | if (new_policy) { |
5a7e56a5 VK |
1188 | policy->user_policy.min = policy->min; |
1189 | policy->user_policy.max = policy->max; | |
6d4e81ed | 1190 | |
2f0ba790 | 1191 | for_each_cpu(j, policy->related_cpus) { |
988bed09 | 1192 | per_cpu(cpufreq_cpu_data, j) = policy; |
2f0ba790 RW |
1193 | add_cpu_dev_symlink(policy, j); |
1194 | } | |
ff010472 VK |
1195 | } else { |
1196 | policy->min = policy->user_policy.min; | |
1197 | policy->max = policy->user_policy.max; | |
988bed09 | 1198 | } |
652ed95d | 1199 | |
2ed99e39 | 1200 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
da60ce9f VK |
1201 | policy->cur = cpufreq_driver->get(policy->cpu); |
1202 | if (!policy->cur) { | |
1203 | pr_err("%s: ->get() failed\n", __func__); | |
8101f997 | 1204 | goto out_exit_policy; |
da60ce9f VK |
1205 | } |
1206 | } | |
1207 | ||
d3916691 VK |
1208 | /* |
1209 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1210 | * frequency table present with cpufreq core. In such cases CPU might be | |
1211 | * unstable if it has to run on that frequency for long duration of time | |
1212 | * and so its better to set it to a frequency which is specified in | |
1213 | * freq-table. This also makes cpufreq stats inconsistent as | |
1214 | * cpufreq-stats would fail to register because current frequency of CPU | |
1215 | * isn't found in freq-table. | |
1216 | * | |
1217 | * Because we don't want this change to effect boot process badly, we go | |
1218 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1219 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1220 | * is initialized to zero). | |
1221 | * | |
1222 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1223 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1224 | * equal to target-freq. | |
1225 | */ | |
1226 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1227 | && has_target()) { | |
1228 | /* Are we running at unknown frequency ? */ | |
1229 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1230 | if (ret == -EINVAL) { | |
1231 | /* Warn user and fix it */ | |
1232 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1233 | __func__, policy->cpu, policy->cur); | |
1234 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1235 | CPUFREQ_RELATION_L); | |
1236 | ||
1237 | /* | |
1238 | * Reaching here after boot in a few seconds may not | |
1239 | * mean that system will remain stable at "unknown" | |
1240 | * frequency for longer duration. Hence, a BUG_ON(). | |
1241 | */ | |
1242 | BUG_ON(ret); | |
1243 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1244 | __func__, policy->cpu, policy->cur); | |
1245 | } | |
1246 | } | |
1247 | ||
194d99c7 | 1248 | if (new_policy) { |
d9612a49 | 1249 | ret = cpufreq_add_dev_interface(policy); |
a82fab29 | 1250 | if (ret) |
8101f997 | 1251 | goto out_exit_policy; |
1aefc75b RW |
1252 | |
1253 | cpufreq_stats_create_table(policy); | |
8ff69732 | 1254 | |
988bed09 VK |
1255 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1256 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1257 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1258 | } | |
9515f4d6 | 1259 | |
7f0fa40f VK |
1260 | ret = cpufreq_init_policy(policy); |
1261 | if (ret) { | |
1262 | pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", | |
1263 | __func__, cpu, ret); | |
194d99c7 RW |
1264 | /* cpufreq_policy_free() will notify based on this */ |
1265 | new_policy = false; | |
1266 | goto out_exit_policy; | |
08fd8c1c | 1267 | } |
e18f1682 | 1268 | |
4e97b631 | 1269 | up_write(&policy->rwsem); |
08fd8c1c | 1270 | |
038c5b3e | 1271 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
7c45cf31 | 1272 | |
7c45cf31 VK |
1273 | /* Callback for handling stuff after policy is ready */ |
1274 | if (cpufreq_driver->ready) | |
1275 | cpufreq_driver->ready(policy); | |
1276 | ||
2d06d8c4 | 1277 | pr_debug("initialization complete\n"); |
87c32271 | 1278 | |
1da177e4 LT |
1279 | return 0; |
1280 | ||
8101f997 | 1281 | out_exit_policy: |
7106e02b PB |
1282 | up_write(&policy->rwsem); |
1283 | ||
da60ce9f VK |
1284 | if (cpufreq_driver->exit) |
1285 | cpufreq_driver->exit(policy); | |
2f0ba790 RW |
1286 | |
1287 | for_each_cpu(j, policy->real_cpus) | |
1288 | remove_cpu_dev_symlink(policy, get_cpu_device(j)); | |
1289 | ||
8101f997 | 1290 | out_free_policy: |
f9f41e3e | 1291 | cpufreq_policy_free(policy); |
1da177e4 LT |
1292 | return ret; |
1293 | } | |
1294 | ||
0b275352 RW |
1295 | /** |
1296 | * cpufreq_add_dev - the cpufreq interface for a CPU device. | |
1297 | * @dev: CPU device. | |
1298 | * @sif: Subsystem interface structure pointer (not used) | |
1299 | */ | |
1300 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1301 | { | |
a794d613 | 1302 | struct cpufreq_policy *policy; |
0b275352 | 1303 | unsigned cpu = dev->id; |
26619804 | 1304 | int ret; |
0b275352 RW |
1305 | |
1306 | dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); | |
1307 | ||
26619804 VK |
1308 | if (cpu_online(cpu)) { |
1309 | ret = cpufreq_online(cpu); | |
1310 | if (ret) | |
1311 | return ret; | |
1312 | } | |
0b275352 | 1313 | |
26619804 | 1314 | /* Create sysfs link on CPU registration */ |
a794d613 | 1315 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2f0ba790 RW |
1316 | if (policy) |
1317 | add_cpu_dev_symlink(policy, cpu); | |
26619804 | 1318 | |
2f0ba790 | 1319 | return 0; |
1da177e4 LT |
1320 | } |
1321 | ||
27622b06 | 1322 | static int cpufreq_offline(unsigned int cpu) |
1da177e4 | 1323 | { |
3a3e9e06 | 1324 | struct cpufreq_policy *policy; |
69cee714 | 1325 | int ret; |
1da177e4 | 1326 | |
b8eed8af | 1327 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1328 | |
988bed09 | 1329 | policy = cpufreq_cpu_get_raw(cpu); |
3a3e9e06 | 1330 | if (!policy) { |
b8eed8af | 1331 | pr_debug("%s: No cpu_data found\n", __func__); |
27622b06 | 1332 | return 0; |
1da177e4 | 1333 | } |
1da177e4 | 1334 | |
49f18560 | 1335 | down_write(&policy->rwsem); |
45482c70 RW |
1336 | if (has_target()) |
1337 | cpufreq_stop_governor(policy); | |
1da177e4 | 1338 | |
9591becb | 1339 | cpumask_clear_cpu(cpu, policy->cpus); |
4573237b | 1340 | |
9591becb VK |
1341 | if (policy_is_inactive(policy)) { |
1342 | if (has_target()) | |
1343 | strncpy(policy->last_governor, policy->governor->name, | |
1344 | CPUFREQ_NAME_LEN); | |
69030dd1 SP |
1345 | else |
1346 | policy->last_policy = policy->policy; | |
9591becb VK |
1347 | } else if (cpu == policy->cpu) { |
1348 | /* Nominate new CPU */ | |
1349 | policy->cpu = cpumask_any(policy->cpus); | |
1350 | } | |
084f3493 | 1351 | |
9591becb VK |
1352 | /* Start governor again for active policy */ |
1353 | if (!policy_is_inactive(policy)) { | |
1354 | if (has_target()) { | |
0a300767 | 1355 | ret = cpufreq_start_governor(policy); |
9591becb VK |
1356 | if (ret) |
1357 | pr_err("%s: Failed to start governor\n", __func__); | |
1358 | } | |
cedb70af | 1359 | |
49f18560 | 1360 | goto unlock; |
cedb70af SB |
1361 | } |
1362 | ||
69cee714 VK |
1363 | if (cpufreq_driver->stop_cpu) |
1364 | cpufreq_driver->stop_cpu(policy); | |
87549141 | 1365 | |
36be3418 RW |
1366 | if (has_target()) |
1367 | cpufreq_exit_governor(policy); | |
1da177e4 | 1368 | |
87549141 VK |
1369 | /* |
1370 | * Perform the ->exit() even during light-weight tear-down, | |
1371 | * since this is a core component, and is essential for the | |
1372 | * subsequent light-weight ->init() to succeed. | |
1373 | */ | |
55582bcc | 1374 | if (cpufreq_driver->exit) { |
87549141 | 1375 | cpufreq_driver->exit(policy); |
55582bcc SP |
1376 | policy->freq_table = NULL; |
1377 | } | |
49f18560 VK |
1378 | |
1379 | unlock: | |
1380 | up_write(&policy->rwsem); | |
27622b06 | 1381 | return 0; |
1da177e4 LT |
1382 | } |
1383 | ||
cedb70af | 1384 | /** |
27a862e9 | 1385 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1386 | * |
1387 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1388 | */ |
71db87ba | 1389 | static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1390 | { |
8a25a2fd | 1391 | unsigned int cpu = dev->id; |
559ed407 | 1392 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
87549141 | 1393 | |
559ed407 | 1394 | if (!policy) |
1af115d6 | 1395 | return; |
87549141 | 1396 | |
69cee714 VK |
1397 | if (cpu_online(cpu)) |
1398 | cpufreq_offline(cpu); | |
87549141 | 1399 | |
559ed407 | 1400 | cpumask_clear_cpu(cpu, policy->real_cpus); |
26619804 | 1401 | remove_cpu_dev_symlink(policy, dev); |
87549141 | 1402 | |
f344dae0 | 1403 | if (cpumask_empty(policy->real_cpus)) |
f9f41e3e | 1404 | cpufreq_policy_free(policy); |
5a01f2e8 VP |
1405 | } |
1406 | ||
1da177e4 | 1407 | /** |
bb176f7d VK |
1408 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1409 | * in deep trouble. | |
a1e1dc41 | 1410 | * @policy: policy managing CPUs |
1da177e4 LT |
1411 | * @new_freq: CPU frequency the CPU actually runs at |
1412 | * | |
29464f28 DJ |
1413 | * We adjust to current frequency first, and need to clean up later. |
1414 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1415 | */ |
a1e1dc41 | 1416 | static void cpufreq_out_of_sync(struct cpufreq_policy *policy, |
e08f5f5b | 1417 | unsigned int new_freq) |
1da177e4 LT |
1418 | { |
1419 | struct cpufreq_freqs freqs; | |
b43a7ffb | 1420 | |
e837f9b5 | 1421 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
a1e1dc41 | 1422 | policy->cur, new_freq); |
1da177e4 | 1423 | |
a1e1dc41 | 1424 | freqs.old = policy->cur; |
1da177e4 | 1425 | freqs.new = new_freq; |
b43a7ffb | 1426 | |
8fec051e VK |
1427 | cpufreq_freq_transition_begin(policy, &freqs); |
1428 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1429 | } |
1430 | ||
32ee8c3e | 1431 | /** |
4ab70df4 | 1432 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1433 | * @cpu: CPU number |
1434 | * | |
1435 | * This is the last known freq, without actually getting it from the driver. | |
1436 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1437 | */ | |
1438 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1439 | { | |
9e21ba8b | 1440 | struct cpufreq_policy *policy; |
e08f5f5b | 1441 | unsigned int ret_freq = 0; |
c75361c0 | 1442 | unsigned long flags; |
95235ca2 | 1443 | |
c75361c0 RC |
1444 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1445 | ||
1446 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { | |
1447 | ret_freq = cpufreq_driver->get(cpu); | |
1448 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1449 | return ret_freq; | |
1450 | } | |
1451 | ||
1452 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
9e21ba8b DB |
1453 | |
1454 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1455 | if (policy) { |
e08f5f5b | 1456 | ret_freq = policy->cur; |
95235ca2 VP |
1457 | cpufreq_cpu_put(policy); |
1458 | } | |
1459 | ||
4d34a67d | 1460 | return ret_freq; |
95235ca2 VP |
1461 | } |
1462 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1463 | ||
3d737108 JB |
1464 | /** |
1465 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1466 | * @cpu: CPU number | |
1467 | * | |
1468 | * Just return the max possible frequency for a given CPU. | |
1469 | */ | |
1470 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1471 | { | |
1472 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1473 | unsigned int ret_freq = 0; | |
1474 | ||
1475 | if (policy) { | |
1476 | ret_freq = policy->max; | |
1477 | cpufreq_cpu_put(policy); | |
1478 | } | |
1479 | ||
1480 | return ret_freq; | |
1481 | } | |
1482 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1483 | ||
d92d50a4 | 1484 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy) |
1da177e4 | 1485 | { |
e08f5f5b | 1486 | unsigned int ret_freq = 0; |
5800043b | 1487 | |
1c3d85dd | 1488 | if (!cpufreq_driver->get) |
4d34a67d | 1489 | return ret_freq; |
1da177e4 | 1490 | |
d92d50a4 | 1491 | ret_freq = cpufreq_driver->get(policy->cpu); |
1da177e4 | 1492 | |
b7898fda RW |
1493 | /* |
1494 | * Updating inactive policies is invalid, so avoid doing that. Also | |
1495 | * if fast frequency switching is used with the given policy, the check | |
1496 | * against policy->cur is pointless, so skip it in that case too. | |
1497 | */ | |
1498 | if (unlikely(policy_is_inactive(policy)) || policy->fast_switch_enabled) | |
11e584cf VK |
1499 | return ret_freq; |
1500 | ||
e08f5f5b | 1501 | if (ret_freq && policy->cur && |
1c3d85dd | 1502 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1503 | /* verify no discrepancy between actual and |
1504 | saved value exists */ | |
1505 | if (unlikely(ret_freq != policy->cur)) { | |
a1e1dc41 | 1506 | cpufreq_out_of_sync(policy, ret_freq); |
1da177e4 LT |
1507 | schedule_work(&policy->update); |
1508 | } | |
1509 | } | |
1510 | ||
4d34a67d | 1511 | return ret_freq; |
5a01f2e8 | 1512 | } |
1da177e4 | 1513 | |
5a01f2e8 VP |
1514 | /** |
1515 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1516 | * @cpu: CPU number | |
1517 | * | |
1518 | * Get the CPU current (static) CPU frequency | |
1519 | */ | |
1520 | unsigned int cpufreq_get(unsigned int cpu) | |
1521 | { | |
999976e0 | 1522 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1523 | unsigned int ret_freq = 0; |
5a01f2e8 | 1524 | |
999976e0 AP |
1525 | if (policy) { |
1526 | down_read(&policy->rwsem); | |
182e36af RW |
1527 | |
1528 | if (!policy_is_inactive(policy)) | |
1529 | ret_freq = __cpufreq_get(policy); | |
1530 | ||
999976e0 | 1531 | up_read(&policy->rwsem); |
5a01f2e8 | 1532 | |
999976e0 AP |
1533 | cpufreq_cpu_put(policy); |
1534 | } | |
6eed9404 | 1535 | |
4d34a67d | 1536 | return ret_freq; |
1da177e4 LT |
1537 | } |
1538 | EXPORT_SYMBOL(cpufreq_get); | |
1539 | ||
999f5729 RW |
1540 | static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy) |
1541 | { | |
1542 | unsigned int new_freq; | |
1543 | ||
1544 | new_freq = cpufreq_driver->get(policy->cpu); | |
1545 | if (!new_freq) | |
1546 | return 0; | |
1547 | ||
1548 | if (!policy->cur) { | |
1549 | pr_debug("cpufreq: Driver did not initialize current freq\n"); | |
1550 | policy->cur = new_freq; | |
1551 | } else if (policy->cur != new_freq && has_target()) { | |
1552 | cpufreq_out_of_sync(policy, new_freq); | |
1553 | } | |
1554 | ||
1555 | return new_freq; | |
1556 | } | |
1557 | ||
8a25a2fd KS |
1558 | static struct subsys_interface cpufreq_interface = { |
1559 | .name = "cpufreq", | |
1560 | .subsys = &cpu_subsys, | |
1561 | .add_dev = cpufreq_add_dev, | |
1562 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1563 | }; |
1564 | ||
e28867ea VK |
1565 | /* |
1566 | * In case platform wants some specific frequency to be configured | |
1567 | * during suspend.. | |
1568 | */ | |
1569 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1570 | { | |
1571 | int ret; | |
1572 | ||
1573 | if (!policy->suspend_freq) { | |
201f3716 BZ |
1574 | pr_debug("%s: suspend_freq not defined\n", __func__); |
1575 | return 0; | |
e28867ea VK |
1576 | } |
1577 | ||
1578 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1579 | policy->suspend_freq); | |
1580 | ||
1581 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1582 | CPUFREQ_RELATION_H); | |
1583 | if (ret) | |
1584 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1585 | __func__, policy->suspend_freq, ret); | |
1586 | ||
1587 | return ret; | |
1588 | } | |
1589 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1590 | ||
42d4dc3f | 1591 | /** |
2f0aea93 | 1592 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1593 | * |
2f0aea93 VK |
1594 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1595 | * as some platforms can't change frequency after this point in suspend cycle. | |
1596 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1597 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1598 | */ |
2f0aea93 | 1599 | void cpufreq_suspend(void) |
42d4dc3f | 1600 | { |
3a3e9e06 | 1601 | struct cpufreq_policy *policy; |
42d4dc3f | 1602 | |
2f0aea93 VK |
1603 | if (!cpufreq_driver) |
1604 | return; | |
42d4dc3f | 1605 | |
ba41e1bc | 1606 | if (!has_target() && !cpufreq_driver->suspend) |
b1b12bab | 1607 | goto suspend; |
42d4dc3f | 1608 | |
2f0aea93 VK |
1609 | pr_debug("%s: Suspending Governors\n", __func__); |
1610 | ||
f963735a | 1611 | for_each_active_policy(policy) { |
ba41e1bc RW |
1612 | if (has_target()) { |
1613 | down_write(&policy->rwsem); | |
45482c70 | 1614 | cpufreq_stop_governor(policy); |
ba41e1bc | 1615 | up_write(&policy->rwsem); |
ba41e1bc RW |
1616 | } |
1617 | ||
1618 | if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) | |
2f0aea93 VK |
1619 | pr_err("%s: Failed to suspend driver: %p\n", __func__, |
1620 | policy); | |
42d4dc3f | 1621 | } |
b1b12bab VK |
1622 | |
1623 | suspend: | |
1624 | cpufreq_suspended = true; | |
42d4dc3f BH |
1625 | } |
1626 | ||
1da177e4 | 1627 | /** |
2f0aea93 | 1628 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1629 | * |
2f0aea93 VK |
1630 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1631 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1632 | */ |
2f0aea93 | 1633 | void cpufreq_resume(void) |
1da177e4 | 1634 | { |
3a3e9e06 | 1635 | struct cpufreq_policy *policy; |
49f18560 | 1636 | int ret; |
1da177e4 | 1637 | |
2f0aea93 VK |
1638 | if (!cpufreq_driver) |
1639 | return; | |
1da177e4 | 1640 | |
8e30444e LT |
1641 | cpufreq_suspended = false; |
1642 | ||
ba41e1bc | 1643 | if (!has_target() && !cpufreq_driver->resume) |
e00e56df | 1644 | return; |
1da177e4 | 1645 | |
2f0aea93 | 1646 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1647 | |
f963735a | 1648 | for_each_active_policy(policy) { |
49f18560 | 1649 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { |
0c5aa405 VK |
1650 | pr_err("%s: Failed to resume driver: %p\n", __func__, |
1651 | policy); | |
ba41e1bc | 1652 | } else if (has_target()) { |
49f18560 | 1653 | down_write(&policy->rwsem); |
0a300767 | 1654 | ret = cpufreq_start_governor(policy); |
49f18560 VK |
1655 | up_write(&policy->rwsem); |
1656 | ||
1657 | if (ret) | |
1658 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1659 | __func__, policy); | |
1660 | } | |
2f0aea93 VK |
1661 | } |
1662 | } | |
1da177e4 | 1663 | |
9d95046e BP |
1664 | /** |
1665 | * cpufreq_get_current_driver - return current driver's name | |
1666 | * | |
1667 | * Return the name string of the currently loaded cpufreq driver | |
1668 | * or NULL, if none. | |
1669 | */ | |
1670 | const char *cpufreq_get_current_driver(void) | |
1671 | { | |
1c3d85dd RW |
1672 | if (cpufreq_driver) |
1673 | return cpufreq_driver->name; | |
1674 | ||
1675 | return NULL; | |
9d95046e BP |
1676 | } |
1677 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 | 1678 | |
51315cdf TP |
1679 | /** |
1680 | * cpufreq_get_driver_data - return current driver data | |
1681 | * | |
1682 | * Return the private data of the currently loaded cpufreq | |
1683 | * driver, or NULL if no cpufreq driver is loaded. | |
1684 | */ | |
1685 | void *cpufreq_get_driver_data(void) | |
1686 | { | |
1687 | if (cpufreq_driver) | |
1688 | return cpufreq_driver->driver_data; | |
1689 | ||
1690 | return NULL; | |
1691 | } | |
1692 | EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); | |
1693 | ||
1da177e4 LT |
1694 | /********************************************************************* |
1695 | * NOTIFIER LISTS INTERFACE * | |
1696 | *********************************************************************/ | |
1697 | ||
1698 | /** | |
1699 | * cpufreq_register_notifier - register a driver with cpufreq | |
1700 | * @nb: notifier function to register | |
1701 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1702 | * | |
32ee8c3e | 1703 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1704 | * are notified about clock rate changes (once before and once after |
1705 | * the transition), or a list of drivers that are notified about | |
1706 | * changes in cpufreq policy. | |
1707 | * | |
1708 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1709 | * blocking_notifier_chain_register. |
1da177e4 LT |
1710 | */ |
1711 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1712 | { | |
1713 | int ret; | |
1714 | ||
d5aaffa9 DB |
1715 | if (cpufreq_disabled()) |
1716 | return -EINVAL; | |
1717 | ||
74212ca4 CEB |
1718 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1719 | ||
1da177e4 LT |
1720 | switch (list) { |
1721 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1722 | mutex_lock(&cpufreq_fast_switch_lock); |
1723 | ||
1724 | if (cpufreq_fast_switch_count > 0) { | |
1725 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1726 | return -EBUSY; | |
1727 | } | |
b4dfdbb3 | 1728 | ret = srcu_notifier_chain_register( |
e041c683 | 1729 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1730 | if (!ret) |
1731 | cpufreq_fast_switch_count--; | |
1732 | ||
1733 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1734 | break; |
1735 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1736 | ret = blocking_notifier_chain_register( |
1737 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1738 | break; |
1739 | default: | |
1740 | ret = -EINVAL; | |
1741 | } | |
1da177e4 LT |
1742 | |
1743 | return ret; | |
1744 | } | |
1745 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1746 | ||
1da177e4 LT |
1747 | /** |
1748 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1749 | * @nb: notifier block to be unregistered | |
bb176f7d | 1750 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1751 | * |
1752 | * Remove a driver from the CPU frequency notifier list. | |
1753 | * | |
1754 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1755 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1756 | */ |
1757 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1758 | { | |
1759 | int ret; | |
1760 | ||
d5aaffa9 DB |
1761 | if (cpufreq_disabled()) |
1762 | return -EINVAL; | |
1763 | ||
1da177e4 LT |
1764 | switch (list) { |
1765 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1766 | mutex_lock(&cpufreq_fast_switch_lock); |
1767 | ||
b4dfdbb3 | 1768 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1769 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1770 | if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) |
1771 | cpufreq_fast_switch_count++; | |
1772 | ||
1773 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1774 | break; |
1775 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1776 | ret = blocking_notifier_chain_unregister( |
1777 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1778 | break; |
1779 | default: | |
1780 | ret = -EINVAL; | |
1781 | } | |
1da177e4 LT |
1782 | |
1783 | return ret; | |
1784 | } | |
1785 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1786 | ||
1787 | ||
1788 | /********************************************************************* | |
1789 | * GOVERNORS * | |
1790 | *********************************************************************/ | |
1791 | ||
b7898fda RW |
1792 | /** |
1793 | * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. | |
1794 | * @policy: cpufreq policy to switch the frequency for. | |
1795 | * @target_freq: New frequency to set (may be approximate). | |
1796 | * | |
1797 | * Carry out a fast frequency switch without sleeping. | |
1798 | * | |
1799 | * The driver's ->fast_switch() callback invoked by this function must be | |
1800 | * suitable for being called from within RCU-sched read-side critical sections | |
1801 | * and it is expected to select the minimum available frequency greater than or | |
1802 | * equal to @target_freq (CPUFREQ_RELATION_L). | |
1803 | * | |
1804 | * This function must not be called if policy->fast_switch_enabled is unset. | |
1805 | * | |
1806 | * Governors calling this function must guarantee that it will never be invoked | |
1807 | * twice in parallel for the same policy and that it will never be called in | |
1808 | * parallel with either ->target() or ->target_index() for the same policy. | |
1809 | * | |
1810 | * If CPUFREQ_ENTRY_INVALID is returned by the driver's ->fast_switch() | |
1811 | * callback to indicate an error condition, the hardware configuration must be | |
1812 | * preserved. | |
1813 | */ | |
1814 | unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, | |
1815 | unsigned int target_freq) | |
1816 | { | |
b9af6948 | 1817 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
b7898fda RW |
1818 | |
1819 | return cpufreq_driver->fast_switch(policy, target_freq); | |
1820 | } | |
1821 | EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); | |
1822 | ||
1c03a2d0 VK |
1823 | /* Must set freqs->new to intermediate frequency */ |
1824 | static int __target_intermediate(struct cpufreq_policy *policy, | |
1825 | struct cpufreq_freqs *freqs, int index) | |
1826 | { | |
1827 | int ret; | |
1828 | ||
1829 | freqs->new = cpufreq_driver->get_intermediate(policy, index); | |
1830 | ||
1831 | /* We don't need to switch to intermediate freq */ | |
1832 | if (!freqs->new) | |
1833 | return 0; | |
1834 | ||
1835 | pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", | |
1836 | __func__, policy->cpu, freqs->old, freqs->new); | |
1837 | ||
1838 | cpufreq_freq_transition_begin(policy, freqs); | |
1839 | ret = cpufreq_driver->target_intermediate(policy, index); | |
1840 | cpufreq_freq_transition_end(policy, freqs, ret); | |
1841 | ||
1842 | if (ret) | |
1843 | pr_err("%s: Failed to change to intermediate frequency: %d\n", | |
1844 | __func__, ret); | |
1845 | ||
1846 | return ret; | |
1847 | } | |
1848 | ||
23727845 | 1849 | static int __target_index(struct cpufreq_policy *policy, int index) |
8d65775d | 1850 | { |
1c03a2d0 VK |
1851 | struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
1852 | unsigned int intermediate_freq = 0; | |
23727845 | 1853 | unsigned int newfreq = policy->freq_table[index].frequency; |
8d65775d VK |
1854 | int retval = -EINVAL; |
1855 | bool notify; | |
1856 | ||
23727845 VK |
1857 | if (newfreq == policy->cur) |
1858 | return 0; | |
1859 | ||
8d65775d | 1860 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); |
8d65775d | 1861 | if (notify) { |
1c03a2d0 VK |
1862 | /* Handle switching to intermediate frequency */ |
1863 | if (cpufreq_driver->get_intermediate) { | |
1864 | retval = __target_intermediate(policy, &freqs, index); | |
1865 | if (retval) | |
1866 | return retval; | |
1867 | ||
1868 | intermediate_freq = freqs.new; | |
1869 | /* Set old freq to intermediate */ | |
1870 | if (intermediate_freq) | |
1871 | freqs.old = freqs.new; | |
1872 | } | |
8d65775d | 1873 | |
23727845 | 1874 | freqs.new = newfreq; |
8d65775d VK |
1875 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", |
1876 | __func__, policy->cpu, freqs.old, freqs.new); | |
1877 | ||
1878 | cpufreq_freq_transition_begin(policy, &freqs); | |
1879 | } | |
1880 | ||
1881 | retval = cpufreq_driver->target_index(policy, index); | |
1882 | if (retval) | |
1883 | pr_err("%s: Failed to change cpu frequency: %d\n", __func__, | |
1884 | retval); | |
1885 | ||
1c03a2d0 | 1886 | if (notify) { |
8d65775d VK |
1887 | cpufreq_freq_transition_end(policy, &freqs, retval); |
1888 | ||
1c03a2d0 VK |
1889 | /* |
1890 | * Failed after setting to intermediate freq? Driver should have | |
1891 | * reverted back to initial frequency and so should we. Check | |
1892 | * here for intermediate_freq instead of get_intermediate, in | |
58405af6 | 1893 | * case we haven't switched to intermediate freq at all. |
1c03a2d0 VK |
1894 | */ |
1895 | if (unlikely(retval && intermediate_freq)) { | |
1896 | freqs.old = intermediate_freq; | |
1897 | freqs.new = policy->restore_freq; | |
1898 | cpufreq_freq_transition_begin(policy, &freqs); | |
1899 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1900 | } | |
1901 | } | |
1902 | ||
8d65775d VK |
1903 | return retval; |
1904 | } | |
1905 | ||
1da177e4 LT |
1906 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1907 | unsigned int target_freq, | |
1908 | unsigned int relation) | |
1909 | { | |
7249924e | 1910 | unsigned int old_target_freq = target_freq; |
d218ed77 | 1911 | int index; |
c32b6b8e | 1912 | |
a7b422cd KRW |
1913 | if (cpufreq_disabled()) |
1914 | return -ENODEV; | |
1915 | ||
7249924e | 1916 | /* Make sure that target_freq is within supported range */ |
910c6e88 | 1917 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
7249924e VK |
1918 | |
1919 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 1920 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 1921 | |
9c0ebcf7 VK |
1922 | /* |
1923 | * This might look like a redundant call as we are checking it again | |
1924 | * after finding index. But it is left intentionally for cases where | |
1925 | * exactly same freq is called again and so we can save on few function | |
1926 | * calls. | |
1927 | */ | |
5a1c0228 VK |
1928 | if (target_freq == policy->cur) |
1929 | return 0; | |
1930 | ||
1c03a2d0 VK |
1931 | /* Save last value to restore later on errors */ |
1932 | policy->restore_freq = policy->cur; | |
1933 | ||
1c3d85dd | 1934 | if (cpufreq_driver->target) |
6019d23a | 1935 | return cpufreq_driver->target(policy, target_freq, relation); |
9c0ebcf7 | 1936 | |
6019d23a RW |
1937 | if (!cpufreq_driver->target_index) |
1938 | return -EINVAL; | |
9c0ebcf7 | 1939 | |
d218ed77 | 1940 | index = cpufreq_frequency_table_target(policy, target_freq, relation); |
6019d23a | 1941 | |
23727845 | 1942 | return __target_index(policy, index); |
1da177e4 LT |
1943 | } |
1944 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1945 | ||
1da177e4 LT |
1946 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1947 | unsigned int target_freq, | |
1948 | unsigned int relation) | |
1949 | { | |
f1829e4a | 1950 | int ret = -EINVAL; |
1da177e4 | 1951 | |
ad7722da | 1952 | down_write(&policy->rwsem); |
1da177e4 LT |
1953 | |
1954 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1955 | ||
ad7722da | 1956 | up_write(&policy->rwsem); |
1da177e4 | 1957 | |
1da177e4 LT |
1958 | return ret; |
1959 | } | |
1960 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1961 | ||
de1df26b RW |
1962 | __weak struct cpufreq_governor *cpufreq_fallback_governor(void) |
1963 | { | |
1964 | return NULL; | |
1965 | } | |
1966 | ||
a92604b4 | 1967 | static int cpufreq_init_governor(struct cpufreq_policy *policy) |
1da177e4 | 1968 | { |
cc993cab | 1969 | int ret; |
6afde10c | 1970 | |
2f0aea93 VK |
1971 | /* Don't start any governor operations if we are entering suspend */ |
1972 | if (cpufreq_suspended) | |
1973 | return 0; | |
cb57720b EZ |
1974 | /* |
1975 | * Governor might not be initiated here if ACPI _PPC changed | |
1976 | * notification happened, so check it. | |
1977 | */ | |
1978 | if (!policy->governor) | |
1979 | return -EINVAL; | |
2f0aea93 | 1980 | |
1c256245 TR |
1981 | if (policy->governor->max_transition_latency && |
1982 | policy->cpuinfo.transition_latency > | |
1983 | policy->governor->max_transition_latency) { | |
de1df26b RW |
1984 | struct cpufreq_governor *gov = cpufreq_fallback_governor(); |
1985 | ||
1986 | if (gov) { | |
e837f9b5 JP |
1987 | pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", |
1988 | policy->governor->name, gov->name); | |
6afde10c | 1989 | policy->governor = gov; |
de1df26b RW |
1990 | } else { |
1991 | return -EINVAL; | |
6afde10c | 1992 | } |
1c256245 | 1993 | } |
1da177e4 | 1994 | |
a92604b4 RW |
1995 | if (!try_module_get(policy->governor->owner)) |
1996 | return -EINVAL; | |
95731ebb | 1997 | |
a92604b4 | 1998 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
1da177e4 | 1999 | |
e788892b RW |
2000 | if (policy->governor->init) { |
2001 | ret = policy->governor->init(policy); | |
2002 | if (ret) { | |
36be3418 | 2003 | module_put(policy->governor->owner); |
e788892b RW |
2004 | return ret; |
2005 | } | |
36be3418 | 2006 | } |
1da177e4 | 2007 | |
a92604b4 RW |
2008 | return 0; |
2009 | } | |
2010 | ||
2011 | static void cpufreq_exit_governor(struct cpufreq_policy *policy) | |
2012 | { | |
2013 | if (cpufreq_suspended || !policy->governor) | |
2014 | return; | |
2015 | ||
2016 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2017 | ||
e788892b RW |
2018 | if (policy->governor->exit) |
2019 | policy->governor->exit(policy); | |
a92604b4 | 2020 | |
a92604b4 | 2021 | module_put(policy->governor->owner); |
1da177e4 LT |
2022 | } |
2023 | ||
0a300767 RW |
2024 | static int cpufreq_start_governor(struct cpufreq_policy *policy) |
2025 | { | |
2026 | int ret; | |
2027 | ||
a92604b4 RW |
2028 | if (cpufreq_suspended) |
2029 | return 0; | |
2030 | ||
2031 | if (!policy->governor) | |
2032 | return -EINVAL; | |
2033 | ||
2034 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2035 | ||
3bbf8fe3 RW |
2036 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) |
2037 | cpufreq_update_current_freq(policy); | |
2038 | ||
e788892b RW |
2039 | if (policy->governor->start) { |
2040 | ret = policy->governor->start(policy); | |
2041 | if (ret) | |
2042 | return ret; | |
2043 | } | |
2044 | ||
2045 | if (policy->governor->limits) | |
2046 | policy->governor->limits(policy); | |
d6ff44d6 | 2047 | |
d6ff44d6 | 2048 | return 0; |
0a300767 RW |
2049 | } |
2050 | ||
a92604b4 RW |
2051 | static void cpufreq_stop_governor(struct cpufreq_policy *policy) |
2052 | { | |
2053 | if (cpufreq_suspended || !policy->governor) | |
2054 | return; | |
2055 | ||
2056 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2057 | ||
e788892b RW |
2058 | if (policy->governor->stop) |
2059 | policy->governor->stop(policy); | |
a92604b4 RW |
2060 | } |
2061 | ||
2062 | static void cpufreq_governor_limits(struct cpufreq_policy *policy) | |
2063 | { | |
2064 | if (cpufreq_suspended || !policy->governor) | |
2065 | return; | |
2066 | ||
2067 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2068 | ||
e788892b RW |
2069 | if (policy->governor->limits) |
2070 | policy->governor->limits(policy); | |
0a300767 RW |
2071 | } |
2072 | ||
1da177e4 LT |
2073 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
2074 | { | |
3bcb09a3 | 2075 | int err; |
1da177e4 LT |
2076 | |
2077 | if (!governor) | |
2078 | return -EINVAL; | |
2079 | ||
a7b422cd KRW |
2080 | if (cpufreq_disabled()) |
2081 | return -ENODEV; | |
2082 | ||
3fc54d37 | 2083 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 2084 | |
3bcb09a3 | 2085 | err = -EBUSY; |
42f91fa1 | 2086 | if (!find_governor(governor->name)) { |
3bcb09a3 JF |
2087 | err = 0; |
2088 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2089 | } |
1da177e4 | 2090 | |
32ee8c3e | 2091 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2092 | return err; |
1da177e4 LT |
2093 | } |
2094 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2095 | ||
1da177e4 LT |
2096 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2097 | { | |
4573237b VK |
2098 | struct cpufreq_policy *policy; |
2099 | unsigned long flags; | |
90e41bac | 2100 | |
1da177e4 LT |
2101 | if (!governor) |
2102 | return; | |
2103 | ||
a7b422cd KRW |
2104 | if (cpufreq_disabled()) |
2105 | return; | |
2106 | ||
4573237b VK |
2107 | /* clear last_governor for all inactive policies */ |
2108 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
2109 | for_each_inactive_policy(policy) { | |
18bf3a12 VK |
2110 | if (!strcmp(policy->last_governor, governor->name)) { |
2111 | policy->governor = NULL; | |
4573237b | 2112 | strcpy(policy->last_governor, "\0"); |
18bf3a12 | 2113 | } |
90e41bac | 2114 | } |
4573237b | 2115 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
90e41bac | 2116 | |
3fc54d37 | 2117 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2118 | list_del(&governor->governor_list); |
3fc54d37 | 2119 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2120 | return; |
2121 | } | |
2122 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2123 | ||
2124 | ||
1da177e4 LT |
2125 | /********************************************************************* |
2126 | * POLICY INTERFACE * | |
2127 | *********************************************************************/ | |
2128 | ||
2129 | /** | |
2130 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2131 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2132 | * is written | |
1da177e4 LT |
2133 | * |
2134 | * Reads the current cpufreq policy. | |
2135 | */ | |
2136 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2137 | { | |
2138 | struct cpufreq_policy *cpu_policy; | |
2139 | if (!policy) | |
2140 | return -EINVAL; | |
2141 | ||
2142 | cpu_policy = cpufreq_cpu_get(cpu); | |
2143 | if (!cpu_policy) | |
2144 | return -EINVAL; | |
2145 | ||
d5b73cd8 | 2146 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2147 | |
2148 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2149 | return 0; |
2150 | } | |
2151 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2152 | ||
153d7f3f | 2153 | /* |
037ce839 VK |
2154 | * policy : current policy. |
2155 | * new_policy: policy to be set. | |
153d7f3f | 2156 | */ |
037ce839 | 2157 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 2158 | struct cpufreq_policy *new_policy) |
1da177e4 | 2159 | { |
d9a789c7 RW |
2160 | struct cpufreq_governor *old_gov; |
2161 | int ret; | |
1da177e4 | 2162 | |
e837f9b5 JP |
2163 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2164 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2165 | |
d5b73cd8 | 2166 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2167 | |
fba9573b PX |
2168 | /* |
2169 | * This check works well when we store new min/max freq attributes, | |
2170 | * because new_policy is a copy of policy with one field updated. | |
2171 | */ | |
2172 | if (new_policy->min > new_policy->max) | |
d9a789c7 | 2173 | return -EINVAL; |
9c9a43ed | 2174 | |
1da177e4 | 2175 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2176 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2177 | if (ret) |
d9a789c7 | 2178 | return ret; |
1da177e4 | 2179 | |
1da177e4 | 2180 | /* adjust if necessary - all reasons */ |
e041c683 | 2181 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2182 | CPUFREQ_ADJUST, new_policy); |
1da177e4 | 2183 | |
bb176f7d VK |
2184 | /* |
2185 | * verify the cpu speed can be set within this limit, which might be | |
2186 | * different to the first one | |
2187 | */ | |
3a3e9e06 | 2188 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2189 | if (ret) |
d9a789c7 | 2190 | return ret; |
1da177e4 LT |
2191 | |
2192 | /* notification of the new policy */ | |
e041c683 | 2193 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2194 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2195 | |
3a3e9e06 VK |
2196 | policy->min = new_policy->min; |
2197 | policy->max = new_policy->max; | |
1da177e4 | 2198 | |
e3c06236 SM |
2199 | policy->cached_target_freq = UINT_MAX; |
2200 | ||
2d06d8c4 | 2201 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2202 | policy->min, policy->max); |
1da177e4 | 2203 | |
1c3d85dd | 2204 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2205 | policy->policy = new_policy->policy; |
2d06d8c4 | 2206 | pr_debug("setting range\n"); |
d9a789c7 RW |
2207 | return cpufreq_driver->setpolicy(new_policy); |
2208 | } | |
1da177e4 | 2209 | |
0a300767 RW |
2210 | if (new_policy->governor == policy->governor) { |
2211 | pr_debug("cpufreq: governor limits update\n"); | |
a92604b4 | 2212 | cpufreq_governor_limits(policy); |
d6ff44d6 | 2213 | return 0; |
0a300767 | 2214 | } |
7bd353a9 | 2215 | |
d9a789c7 RW |
2216 | pr_debug("governor switch\n"); |
2217 | ||
2218 | /* save old, working values */ | |
2219 | old_gov = policy->governor; | |
2220 | /* end old governor */ | |
2221 | if (old_gov) { | |
45482c70 | 2222 | cpufreq_stop_governor(policy); |
36be3418 | 2223 | cpufreq_exit_governor(policy); |
1da177e4 LT |
2224 | } |
2225 | ||
d9a789c7 RW |
2226 | /* start new governor */ |
2227 | policy->governor = new_policy->governor; | |
a92604b4 | 2228 | ret = cpufreq_init_governor(policy); |
4bc384ae | 2229 | if (!ret) { |
0a300767 RW |
2230 | ret = cpufreq_start_governor(policy); |
2231 | if (!ret) { | |
2232 | pr_debug("cpufreq: governor change\n"); | |
2233 | return 0; | |
2234 | } | |
b7898fda | 2235 | cpufreq_exit_governor(policy); |
d9a789c7 RW |
2236 | } |
2237 | ||
2238 | /* new governor failed, so re-start old one */ | |
2239 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2240 | if (old_gov) { | |
2241 | policy->governor = old_gov; | |
a92604b4 | 2242 | if (cpufreq_init_governor(policy)) |
4bc384ae VK |
2243 | policy->governor = NULL; |
2244 | else | |
0a300767 | 2245 | cpufreq_start_governor(policy); |
d9a789c7 RW |
2246 | } |
2247 | ||
4bc384ae | 2248 | return ret; |
1da177e4 LT |
2249 | } |
2250 | ||
1da177e4 LT |
2251 | /** |
2252 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2253 | * @cpu: CPU which shall be re-evaluated | |
2254 | * | |
25985edc | 2255 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2256 | * at different times. |
2257 | */ | |
30248fef | 2258 | void cpufreq_update_policy(unsigned int cpu) |
1da177e4 | 2259 | { |
3a3e9e06 VK |
2260 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2261 | struct cpufreq_policy new_policy; | |
1da177e4 | 2262 | |
fefa8ff8 | 2263 | if (!policy) |
30248fef | 2264 | return; |
1da177e4 | 2265 | |
ad7722da | 2266 | down_write(&policy->rwsem); |
1da177e4 | 2267 | |
30248fef | 2268 | if (policy_is_inactive(policy)) |
182e36af | 2269 | goto unlock; |
182e36af | 2270 | |
2d06d8c4 | 2271 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2272 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2273 | new_policy.min = policy->user_policy.min; |
2274 | new_policy.max = policy->user_policy.max; | |
1da177e4 | 2275 | |
bb176f7d VK |
2276 | /* |
2277 | * BIOS might change freq behind our back | |
2278 | * -> ask driver for current freq and notify governors about a change | |
2279 | */ | |
2ed99e39 | 2280 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
30248fef | 2281 | if (cpufreq_suspended) |
742c87bf | 2282 | goto unlock; |
30248fef | 2283 | |
999f5729 | 2284 | new_policy.cur = cpufreq_update_current_freq(policy); |
30248fef | 2285 | if (WARN_ON(!new_policy.cur)) |
fefa8ff8 | 2286 | goto unlock; |
0961dd0d TR |
2287 | } |
2288 | ||
30248fef | 2289 | cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2290 | |
fefa8ff8 | 2291 | unlock: |
ad7722da | 2292 | up_write(&policy->rwsem); |
5a01f2e8 | 2293 | |
3a3e9e06 | 2294 | cpufreq_cpu_put(policy); |
1da177e4 LT |
2295 | } |
2296 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2297 | ||
6f19efc0 LM |
2298 | /********************************************************************* |
2299 | * BOOST * | |
2300 | *********************************************************************/ | |
2301 | static int cpufreq_boost_set_sw(int state) | |
2302 | { | |
6f19efc0 LM |
2303 | struct cpufreq_policy *policy; |
2304 | int ret = -EINVAL; | |
2305 | ||
f963735a | 2306 | for_each_active_policy(policy) { |
f8bfc116 VK |
2307 | if (!policy->freq_table) |
2308 | continue; | |
49f18560 | 2309 | |
f8bfc116 VK |
2310 | ret = cpufreq_frequency_table_cpuinfo(policy, |
2311 | policy->freq_table); | |
2312 | if (ret) { | |
2313 | pr_err("%s: Policy frequency update failed\n", | |
2314 | __func__); | |
2315 | break; | |
6f19efc0 | 2316 | } |
f8bfc116 VK |
2317 | |
2318 | down_write(&policy->rwsem); | |
2319 | policy->user_policy.max = policy->max; | |
2320 | cpufreq_governor_limits(policy); | |
2321 | up_write(&policy->rwsem); | |
6f19efc0 LM |
2322 | } |
2323 | ||
2324 | return ret; | |
2325 | } | |
2326 | ||
2327 | int cpufreq_boost_trigger_state(int state) | |
2328 | { | |
2329 | unsigned long flags; | |
2330 | int ret = 0; | |
2331 | ||
2332 | if (cpufreq_driver->boost_enabled == state) | |
2333 | return 0; | |
2334 | ||
2335 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2336 | cpufreq_driver->boost_enabled = state; | |
2337 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2338 | ||
2339 | ret = cpufreq_driver->set_boost(state); | |
2340 | if (ret) { | |
2341 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2342 | cpufreq_driver->boost_enabled = !state; | |
2343 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2344 | ||
e837f9b5 JP |
2345 | pr_err("%s: Cannot %s BOOST\n", |
2346 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2347 | } |
2348 | ||
2349 | return ret; | |
2350 | } | |
2351 | ||
41669da0 | 2352 | static bool cpufreq_boost_supported(void) |
6f19efc0 | 2353 | { |
7a6c79f2 | 2354 | return likely(cpufreq_driver) && cpufreq_driver->set_boost; |
6f19efc0 | 2355 | } |
6f19efc0 | 2356 | |
44139ed4 VK |
2357 | static int create_boost_sysfs_file(void) |
2358 | { | |
2359 | int ret; | |
2360 | ||
c82bd444 | 2361 | ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2362 | if (ret) |
2363 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
2364 | __func__); | |
2365 | ||
2366 | return ret; | |
2367 | } | |
2368 | ||
2369 | static void remove_boost_sysfs_file(void) | |
2370 | { | |
2371 | if (cpufreq_boost_supported()) | |
c82bd444 | 2372 | sysfs_remove_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2373 | } |
2374 | ||
2375 | int cpufreq_enable_boost_support(void) | |
2376 | { | |
2377 | if (!cpufreq_driver) | |
2378 | return -EINVAL; | |
2379 | ||
2380 | if (cpufreq_boost_supported()) | |
2381 | return 0; | |
2382 | ||
7a6c79f2 | 2383 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; |
44139ed4 VK |
2384 | |
2385 | /* This will get removed on driver unregister */ | |
2386 | return create_boost_sysfs_file(); | |
2387 | } | |
2388 | EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support); | |
2389 | ||
6f19efc0 LM |
2390 | int cpufreq_boost_enabled(void) |
2391 | { | |
2392 | return cpufreq_driver->boost_enabled; | |
2393 | } | |
2394 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2395 | ||
1da177e4 LT |
2396 | /********************************************************************* |
2397 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2398 | *********************************************************************/ | |
27622b06 | 2399 | static enum cpuhp_state hp_online; |
1da177e4 LT |
2400 | |
2401 | /** | |
2402 | * cpufreq_register_driver - register a CPU Frequency driver | |
2403 | * @driver_data: A struct cpufreq_driver containing the values# | |
2404 | * submitted by the CPU Frequency driver. | |
2405 | * | |
bb176f7d | 2406 | * Registers a CPU Frequency driver to this core code. This code |
63af4055 | 2407 | * returns zero on success, -EEXIST when another driver got here first |
32ee8c3e | 2408 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2409 | * |
2410 | */ | |
221dee28 | 2411 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2412 | { |
2413 | unsigned long flags; | |
2414 | int ret; | |
2415 | ||
a7b422cd KRW |
2416 | if (cpufreq_disabled()) |
2417 | return -ENODEV; | |
2418 | ||
1da177e4 | 2419 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2420 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2421 | driver_data->target) || |
2422 | (driver_data->setpolicy && (driver_data->target_index || | |
1c03a2d0 VK |
2423 | driver_data->target)) || |
2424 | (!!driver_data->get_intermediate != !!driver_data->target_intermediate)) | |
1da177e4 LT |
2425 | return -EINVAL; |
2426 | ||
2d06d8c4 | 2427 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 | 2428 | |
fdd320da RW |
2429 | /* Protect against concurrent CPU online/offline. */ |
2430 | get_online_cpus(); | |
2431 | ||
0d1857a1 | 2432 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2433 | if (cpufreq_driver) { |
0d1857a1 | 2434 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fdd320da RW |
2435 | ret = -EEXIST; |
2436 | goto out; | |
1da177e4 | 2437 | } |
1c3d85dd | 2438 | cpufreq_driver = driver_data; |
0d1857a1 | 2439 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2440 | |
bc68b7df VK |
2441 | if (driver_data->setpolicy) |
2442 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2443 | ||
7a6c79f2 RW |
2444 | if (cpufreq_boost_supported()) { |
2445 | ret = create_boost_sysfs_file(); | |
2446 | if (ret) | |
2447 | goto err_null_driver; | |
2448 | } | |
6f19efc0 | 2449 | |
8a25a2fd | 2450 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2451 | if (ret) |
6f19efc0 | 2452 | goto err_boost_unreg; |
1da177e4 | 2453 | |
ce1bcfe9 VK |
2454 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY) && |
2455 | list_empty(&cpufreq_policy_list)) { | |
1da177e4 | 2456 | /* if all ->init() calls failed, unregister */ |
ce1bcfe9 VK |
2457 | pr_debug("%s: No CPU initialized for driver %s\n", __func__, |
2458 | driver_data->name); | |
2459 | goto err_if_unreg; | |
1da177e4 LT |
2460 | } |
2461 | ||
27622b06 SAS |
2462 | ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "cpufreq:online", |
2463 | cpufreq_online, | |
2464 | cpufreq_offline); | |
2465 | if (ret < 0) | |
2466 | goto err_if_unreg; | |
2467 | hp_online = ret; | |
5372e054 | 2468 | ret = 0; |
27622b06 | 2469 | |
2d06d8c4 | 2470 | pr_debug("driver %s up and running\n", driver_data->name); |
3834abb4 | 2471 | goto out; |
fdd320da | 2472 | |
8a25a2fd KS |
2473 | err_if_unreg: |
2474 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 | 2475 | err_boost_unreg: |
44139ed4 | 2476 | remove_boost_sysfs_file(); |
8f5bc2ab | 2477 | err_null_driver: |
0d1857a1 | 2478 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2479 | cpufreq_driver = NULL; |
0d1857a1 | 2480 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
3834abb4 PG |
2481 | out: |
2482 | put_online_cpus(); | |
2483 | return ret; | |
1da177e4 LT |
2484 | } |
2485 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2486 | ||
1da177e4 LT |
2487 | /** |
2488 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2489 | * | |
bb176f7d | 2490 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2491 | * the right to do so, i.e. if you have succeeded in initialising before! |
2492 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2493 | * currently not initialised. | |
2494 | */ | |
221dee28 | 2495 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2496 | { |
2497 | unsigned long flags; | |
2498 | ||
1c3d85dd | 2499 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2500 | return -EINVAL; |
1da177e4 | 2501 | |
2d06d8c4 | 2502 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2503 | |
454d3a25 SAS |
2504 | /* Protect against concurrent cpu hotplug */ |
2505 | get_online_cpus(); | |
8a25a2fd | 2506 | subsys_interface_unregister(&cpufreq_interface); |
44139ed4 | 2507 | remove_boost_sysfs_file(); |
27622b06 | 2508 | cpuhp_remove_state_nocalls(hp_online); |
1da177e4 | 2509 | |
0d1857a1 | 2510 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2511 | |
1c3d85dd | 2512 | cpufreq_driver = NULL; |
6eed9404 | 2513 | |
0d1857a1 | 2514 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
454d3a25 | 2515 | put_online_cpus(); |
1da177e4 LT |
2516 | |
2517 | return 0; | |
2518 | } | |
2519 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 | 2520 | |
90de2a4a DA |
2521 | /* |
2522 | * Stop cpufreq at shutdown to make sure it isn't holding any locks | |
2523 | * or mutexes when secondary CPUs are halted. | |
2524 | */ | |
2525 | static struct syscore_ops cpufreq_syscore_ops = { | |
2526 | .shutdown = cpufreq_suspend, | |
2527 | }; | |
2528 | ||
c82bd444 VK |
2529 | struct kobject *cpufreq_global_kobject; |
2530 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
2531 | ||
5a01f2e8 VP |
2532 | static int __init cpufreq_core_init(void) |
2533 | { | |
a7b422cd KRW |
2534 | if (cpufreq_disabled()) |
2535 | return -ENODEV; | |
2536 | ||
8eec1020 | 2537 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 TR |
2538 | BUG_ON(!cpufreq_global_kobject); |
2539 | ||
90de2a4a DA |
2540 | register_syscore_ops(&cpufreq_syscore_ops); |
2541 | ||
5a01f2e8 VP |
2542 | return 0; |
2543 | } | |
d82f2692 | 2544 | module_param(off, int, 0444); |
5a01f2e8 | 2545 | core_initcall(cpufreq_core_init); |