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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> |
e00e56df | 29 | #include <linux/syscore_ops.h> |
5ff0a268 | 30 | #include <linux/tick.h> |
6f4f2723 TR |
31 | #include <trace/events/power.h> |
32 | ||
1da177e4 | 33 | /** |
cd878479 | 34 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
35 | * level driver of CPUFreq support, and its spinlock. This lock |
36 | * also protects the cpufreq_cpu_data array. | |
37 | */ | |
1c3d85dd | 38 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 39 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
8414809c | 40 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); |
bb176f7d VK |
41 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
42 | static DEFINE_MUTEX(cpufreq_governor_lock); | |
c88a1f8b | 43 | static LIST_HEAD(cpufreq_policy_list); |
bb176f7d | 44 | |
084f3493 TR |
45 | #ifdef CONFIG_HOTPLUG_CPU |
46 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 47 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 48 | #endif |
1da177e4 | 49 | |
9c0ebcf7 VK |
50 | static inline bool has_target(void) |
51 | { | |
52 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
53 | } | |
54 | ||
5a01f2e8 VP |
55 | /* |
56 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
57 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
58 | * | |
59 | * The rules for this semaphore: | |
60 | * - Any routine that wants to read from the policy structure will | |
61 | * do a down_read on this semaphore. | |
62 | * - Any routine that will write to the policy structure and/or may take away | |
63 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
64 | * mode before doing so. | |
65 | * | |
66 | * Additional rules: | |
5a01f2e8 VP |
67 | * - Governor routines that can be called in cpufreq hotplug path should not |
68 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
69 | * - Lock should not be held across |
70 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 71 | */ |
5a01f2e8 VP |
72 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
73 | ||
74 | #define lock_policy_rwsem(mode, cpu) \ | |
1b750e3b | 75 | static void lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 76 | { \ |
474deff7 VK |
77 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
78 | BUG_ON(!policy); \ | |
79 | down_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 VP |
80 | } |
81 | ||
82 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 83 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 84 | |
fa1d8af4 VK |
85 | #define unlock_policy_rwsem(mode, cpu) \ |
86 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
87 | { \ | |
474deff7 VK |
88 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
89 | BUG_ON(!policy); \ | |
90 | up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 | 91 | } |
5a01f2e8 | 92 | |
fa1d8af4 VK |
93 | unlock_policy_rwsem(read, cpu); |
94 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 95 | |
6eed9404 VK |
96 | /* |
97 | * rwsem to guarantee that cpufreq driver module doesn't unload during critical | |
98 | * sections | |
99 | */ | |
100 | static DECLARE_RWSEM(cpufreq_rwsem); | |
101 | ||
1da177e4 | 102 | /* internal prototypes */ |
29464f28 DJ |
103 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
104 | unsigned int event); | |
5a01f2e8 | 105 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 106 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
107 | |
108 | /** | |
32ee8c3e DJ |
109 | * Two notifier lists: the "policy" list is involved in the |
110 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
111 | * "transition" list for kernel code that needs to handle |
112 | * changes to devices when the CPU clock speed changes. | |
113 | * The mutex locks both lists. | |
114 | */ | |
e041c683 | 115 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 116 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 117 | |
74212ca4 | 118 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
119 | static int __init init_cpufreq_transition_notifier_list(void) |
120 | { | |
121 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 122 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
123 | return 0; |
124 | } | |
b3438f82 | 125 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 126 | |
a7b422cd | 127 | static int off __read_mostly; |
da584455 | 128 | static int cpufreq_disabled(void) |
a7b422cd KRW |
129 | { |
130 | return off; | |
131 | } | |
132 | void disable_cpufreq(void) | |
133 | { | |
134 | off = 1; | |
135 | } | |
1da177e4 | 136 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 137 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 138 | |
4d5dcc42 VK |
139 | bool have_governor_per_policy(void) |
140 | { | |
0b981e70 | 141 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 142 | } |
3f869d6d | 143 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 144 | |
944e9a03 VK |
145 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
146 | { | |
147 | if (have_governor_per_policy()) | |
148 | return &policy->kobj; | |
149 | else | |
150 | return cpufreq_global_kobject; | |
151 | } | |
152 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
153 | ||
72a4ce34 VK |
154 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
155 | { | |
156 | u64 idle_time; | |
157 | u64 cur_wall_time; | |
158 | u64 busy_time; | |
159 | ||
160 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
161 | ||
162 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
163 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
164 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
165 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
166 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
167 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
168 | ||
169 | idle_time = cur_wall_time - busy_time; | |
170 | if (wall) | |
171 | *wall = cputime_to_usecs(cur_wall_time); | |
172 | ||
173 | return cputime_to_usecs(idle_time); | |
174 | } | |
175 | ||
176 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
177 | { | |
178 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
179 | ||
180 | if (idle_time == -1ULL) | |
181 | return get_cpu_idle_time_jiffy(cpu, wall); | |
182 | else if (!io_busy) | |
183 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
184 | ||
185 | return idle_time; | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
188 | ||
70e9e778 VK |
189 | /* |
190 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
191 | * drivers of SMP systems. It will do following: | |
192 | * - validate & show freq table passed | |
193 | * - set policies transition latency | |
194 | * - policy->cpus with all possible CPUs | |
195 | */ | |
196 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
197 | struct cpufreq_frequency_table *table, | |
198 | unsigned int transition_latency) | |
199 | { | |
200 | int ret; | |
201 | ||
202 | ret = cpufreq_table_validate_and_show(policy, table); | |
203 | if (ret) { | |
204 | pr_err("%s: invalid frequency table: %d\n", __func__, ret); | |
205 | return ret; | |
206 | } | |
207 | ||
208 | policy->cpuinfo.transition_latency = transition_latency; | |
209 | ||
210 | /* | |
211 | * The driver only supports the SMP configuartion where all processors | |
212 | * share the clock and voltage and clock. | |
213 | */ | |
214 | cpumask_setall(policy->cpus); | |
215 | ||
216 | return 0; | |
217 | } | |
218 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
219 | ||
6eed9404 | 220 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 221 | { |
6eed9404 | 222 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
223 | unsigned long flags; |
224 | ||
6eed9404 VK |
225 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
226 | return NULL; | |
227 | ||
228 | if (!down_read_trylock(&cpufreq_rwsem)) | |
229 | return NULL; | |
1da177e4 LT |
230 | |
231 | /* get the cpufreq driver */ | |
1c3d85dd | 232 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 233 | |
6eed9404 VK |
234 | if (cpufreq_driver) { |
235 | /* get the CPU */ | |
236 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
237 | if (policy) | |
238 | kobject_get(&policy->kobj); | |
239 | } | |
1da177e4 | 240 | |
6eed9404 | 241 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 242 | |
3a3e9e06 | 243 | if (!policy) |
6eed9404 | 244 | up_read(&cpufreq_rwsem); |
1da177e4 | 245 | |
3a3e9e06 | 246 | return policy; |
a9144436 | 247 | } |
1da177e4 LT |
248 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
249 | ||
3a3e9e06 | 250 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 251 | { |
d5aaffa9 DB |
252 | if (cpufreq_disabled()) |
253 | return; | |
254 | ||
6eed9404 VK |
255 | kobject_put(&policy->kobj); |
256 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
257 | } |
258 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
259 | ||
1da177e4 LT |
260 | /********************************************************************* |
261 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
262 | *********************************************************************/ | |
263 | ||
264 | /** | |
265 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
266 | * | |
267 | * This function alters the system "loops_per_jiffy" for the clock | |
268 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 269 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
270 | * per-CPU loops_per_jiffy value wherever possible. |
271 | */ | |
272 | #ifndef CONFIG_SMP | |
273 | static unsigned long l_p_j_ref; | |
bb176f7d | 274 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 275 | |
858119e1 | 276 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
277 | { |
278 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
279 | return; | |
280 | ||
281 | if (!l_p_j_ref_freq) { | |
282 | l_p_j_ref = loops_per_jiffy; | |
283 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 284 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 285 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 286 | } |
bb176f7d | 287 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 288 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
289 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
290 | ci->new); | |
2d06d8c4 | 291 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 292 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
293 | } |
294 | } | |
295 | #else | |
e08f5f5b GS |
296 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
297 | { | |
298 | return; | |
299 | } | |
1da177e4 LT |
300 | #endif |
301 | ||
0956df9c | 302 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 303 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
304 | { |
305 | BUG_ON(irqs_disabled()); | |
306 | ||
d5aaffa9 DB |
307 | if (cpufreq_disabled()) |
308 | return; | |
309 | ||
1c3d85dd | 310 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 311 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 312 | state, freqs->new); |
1da177e4 | 313 | |
1da177e4 | 314 | switch (state) { |
e4472cb3 | 315 | |
1da177e4 | 316 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 317 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
318 | * which is not equal to what the cpufreq core thinks is |
319 | * "old frequency". | |
1da177e4 | 320 | */ |
1c3d85dd | 321 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
322 | if ((policy) && (policy->cpu == freqs->cpu) && |
323 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 324 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
325 | " %u, cpufreq assumed %u kHz.\n", |
326 | freqs->old, policy->cur); | |
327 | freqs->old = policy->cur; | |
1da177e4 LT |
328 | } |
329 | } | |
b4dfdbb3 | 330 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 331 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
332 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
333 | break; | |
e4472cb3 | 334 | |
1da177e4 LT |
335 | case CPUFREQ_POSTCHANGE: |
336 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 337 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 338 | (unsigned long)freqs->cpu); |
25e41933 | 339 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 340 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 341 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
342 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
343 | policy->cur = freqs->new; | |
1da177e4 LT |
344 | break; |
345 | } | |
1da177e4 | 346 | } |
bb176f7d | 347 | |
b43a7ffb VK |
348 | /** |
349 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
350 | * on frequency transition. | |
351 | * | |
352 | * This function calls the transition notifiers and the "adjust_jiffies" | |
353 | * function. It is called twice on all CPU frequency changes that have | |
354 | * external effects. | |
355 | */ | |
356 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
357 | struct cpufreq_freqs *freqs, unsigned int state) | |
358 | { | |
359 | for_each_cpu(freqs->cpu, policy->cpus) | |
360 | __cpufreq_notify_transition(policy, freqs, state); | |
361 | } | |
1da177e4 LT |
362 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
363 | ||
364 | ||
1da177e4 LT |
365 | /********************************************************************* |
366 | * SYSFS INTERFACE * | |
367 | *********************************************************************/ | |
368 | ||
3bcb09a3 JF |
369 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
370 | { | |
371 | struct cpufreq_governor *t; | |
372 | ||
373 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 374 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
375 | return t; |
376 | ||
377 | return NULL; | |
378 | } | |
379 | ||
1da177e4 LT |
380 | /** |
381 | * cpufreq_parse_governor - parse a governor string | |
382 | */ | |
905d77cd | 383 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
384 | struct cpufreq_governor **governor) |
385 | { | |
3bcb09a3 | 386 | int err = -EINVAL; |
1c3d85dd RW |
387 | |
388 | if (!cpufreq_driver) | |
3bcb09a3 JF |
389 | goto out; |
390 | ||
1c3d85dd | 391 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
392 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
393 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 394 | err = 0; |
e08f5f5b GS |
395 | } else if (!strnicmp(str_governor, "powersave", |
396 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 397 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 398 | err = 0; |
1da177e4 | 399 | } |
9c0ebcf7 | 400 | } else if (has_target()) { |
1da177e4 | 401 | struct cpufreq_governor *t; |
3bcb09a3 | 402 | |
3fc54d37 | 403 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
404 | |
405 | t = __find_governor(str_governor); | |
406 | ||
ea714970 | 407 | if (t == NULL) { |
1a8e1463 | 408 | int ret; |
ea714970 | 409 | |
1a8e1463 KC |
410 | mutex_unlock(&cpufreq_governor_mutex); |
411 | ret = request_module("cpufreq_%s", str_governor); | |
412 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 413 | |
1a8e1463 KC |
414 | if (ret == 0) |
415 | t = __find_governor(str_governor); | |
ea714970 JF |
416 | } |
417 | ||
3bcb09a3 JF |
418 | if (t != NULL) { |
419 | *governor = t; | |
420 | err = 0; | |
1da177e4 | 421 | } |
3bcb09a3 | 422 | |
3fc54d37 | 423 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 424 | } |
29464f28 | 425 | out: |
3bcb09a3 | 426 | return err; |
1da177e4 | 427 | } |
1da177e4 | 428 | |
1da177e4 | 429 | /** |
e08f5f5b GS |
430 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
431 | * print out cpufreq information | |
1da177e4 LT |
432 | * |
433 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
434 | * "unsigned int". | |
435 | */ | |
436 | ||
32ee8c3e DJ |
437 | #define show_one(file_name, object) \ |
438 | static ssize_t show_##file_name \ | |
905d77cd | 439 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 440 | { \ |
29464f28 | 441 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
442 | } |
443 | ||
444 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
445 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 446 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
447 | show_one(scaling_min_freq, min); |
448 | show_one(scaling_max_freq, max); | |
449 | show_one(scaling_cur_freq, cur); | |
450 | ||
037ce839 | 451 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 452 | struct cpufreq_policy *new_policy); |
7970e08b | 453 | |
1da177e4 LT |
454 | /** |
455 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
456 | */ | |
457 | #define store_one(file_name, object) \ | |
458 | static ssize_t store_##file_name \ | |
905d77cd | 459 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 460 | { \ |
5136fa56 | 461 | int ret; \ |
1da177e4 LT |
462 | struct cpufreq_policy new_policy; \ |
463 | \ | |
464 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
465 | if (ret) \ | |
466 | return -EINVAL; \ | |
467 | \ | |
29464f28 | 468 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
469 | if (ret != 1) \ |
470 | return -EINVAL; \ | |
471 | \ | |
037ce839 | 472 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 473 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
474 | \ |
475 | return ret ? ret : count; \ | |
476 | } | |
477 | ||
29464f28 DJ |
478 | store_one(scaling_min_freq, min); |
479 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
480 | |
481 | /** | |
482 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
483 | */ | |
905d77cd DJ |
484 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
485 | char *buf) | |
1da177e4 | 486 | { |
5a01f2e8 | 487 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
488 | if (!cur_freq) |
489 | return sprintf(buf, "<unknown>"); | |
490 | return sprintf(buf, "%u\n", cur_freq); | |
491 | } | |
492 | ||
1da177e4 LT |
493 | /** |
494 | * show_scaling_governor - show the current policy for the specified CPU | |
495 | */ | |
905d77cd | 496 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 497 | { |
29464f28 | 498 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
499 | return sprintf(buf, "powersave\n"); |
500 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
501 | return sprintf(buf, "performance\n"); | |
502 | else if (policy->governor) | |
4b972f0b | 503 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 504 | policy->governor->name); |
1da177e4 LT |
505 | return -EINVAL; |
506 | } | |
507 | ||
1da177e4 LT |
508 | /** |
509 | * store_scaling_governor - store policy for the specified CPU | |
510 | */ | |
905d77cd DJ |
511 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
512 | const char *buf, size_t count) | |
1da177e4 | 513 | { |
5136fa56 | 514 | int ret; |
1da177e4 LT |
515 | char str_governor[16]; |
516 | struct cpufreq_policy new_policy; | |
517 | ||
518 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
519 | if (ret) | |
520 | return ret; | |
521 | ||
29464f28 | 522 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
523 | if (ret != 1) |
524 | return -EINVAL; | |
525 | ||
e08f5f5b GS |
526 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
527 | &new_policy.governor)) | |
1da177e4 LT |
528 | return -EINVAL; |
529 | ||
037ce839 | 530 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
531 | |
532 | policy->user_policy.policy = policy->policy; | |
533 | policy->user_policy.governor = policy->governor; | |
7970e08b | 534 | |
e08f5f5b GS |
535 | if (ret) |
536 | return ret; | |
537 | else | |
538 | return count; | |
1da177e4 LT |
539 | } |
540 | ||
541 | /** | |
542 | * show_scaling_driver - show the cpufreq driver currently loaded | |
543 | */ | |
905d77cd | 544 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 545 | { |
1c3d85dd | 546 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
547 | } |
548 | ||
549 | /** | |
550 | * show_scaling_available_governors - show the available CPUfreq governors | |
551 | */ | |
905d77cd DJ |
552 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
553 | char *buf) | |
1da177e4 LT |
554 | { |
555 | ssize_t i = 0; | |
556 | struct cpufreq_governor *t; | |
557 | ||
9c0ebcf7 | 558 | if (!has_target()) { |
1da177e4 LT |
559 | i += sprintf(buf, "performance powersave"); |
560 | goto out; | |
561 | } | |
562 | ||
563 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
564 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
565 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 566 | goto out; |
4b972f0b | 567 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 568 | } |
7d5e350f | 569 | out: |
1da177e4 LT |
570 | i += sprintf(&buf[i], "\n"); |
571 | return i; | |
572 | } | |
e8628dd0 | 573 | |
f4fd3797 | 574 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
575 | { |
576 | ssize_t i = 0; | |
577 | unsigned int cpu; | |
578 | ||
835481d9 | 579 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
580 | if (i) |
581 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
582 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
583 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 584 | break; |
1da177e4 LT |
585 | } |
586 | i += sprintf(&buf[i], "\n"); | |
587 | return i; | |
588 | } | |
f4fd3797 | 589 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 590 | |
e8628dd0 DW |
591 | /** |
592 | * show_related_cpus - show the CPUs affected by each transition even if | |
593 | * hw coordination is in use | |
594 | */ | |
595 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
596 | { | |
f4fd3797 | 597 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
598 | } |
599 | ||
600 | /** | |
601 | * show_affected_cpus - show the CPUs affected by each transition | |
602 | */ | |
603 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
604 | { | |
f4fd3797 | 605 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
606 | } |
607 | ||
9e76988e | 608 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 609 | const char *buf, size_t count) |
9e76988e VP |
610 | { |
611 | unsigned int freq = 0; | |
612 | unsigned int ret; | |
613 | ||
879000f9 | 614 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
615 | return -EINVAL; |
616 | ||
617 | ret = sscanf(buf, "%u", &freq); | |
618 | if (ret != 1) | |
619 | return -EINVAL; | |
620 | ||
621 | policy->governor->store_setspeed(policy, freq); | |
622 | ||
623 | return count; | |
624 | } | |
625 | ||
626 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
627 | { | |
879000f9 | 628 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
629 | return sprintf(buf, "<unsupported>\n"); |
630 | ||
631 | return policy->governor->show_setspeed(policy, buf); | |
632 | } | |
1da177e4 | 633 | |
e2f74f35 | 634 | /** |
8bf1ac72 | 635 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
636 | */ |
637 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
638 | { | |
639 | unsigned int limit; | |
640 | int ret; | |
1c3d85dd RW |
641 | if (cpufreq_driver->bios_limit) { |
642 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
643 | if (!ret) |
644 | return sprintf(buf, "%u\n", limit); | |
645 | } | |
646 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
647 | } | |
648 | ||
6dad2a29 BP |
649 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
650 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
651 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
652 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
653 | cpufreq_freq_attr_ro(scaling_available_governors); | |
654 | cpufreq_freq_attr_ro(scaling_driver); | |
655 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
656 | cpufreq_freq_attr_ro(bios_limit); | |
657 | cpufreq_freq_attr_ro(related_cpus); | |
658 | cpufreq_freq_attr_ro(affected_cpus); | |
659 | cpufreq_freq_attr_rw(scaling_min_freq); | |
660 | cpufreq_freq_attr_rw(scaling_max_freq); | |
661 | cpufreq_freq_attr_rw(scaling_governor); | |
662 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 663 | |
905d77cd | 664 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
665 | &cpuinfo_min_freq.attr, |
666 | &cpuinfo_max_freq.attr, | |
ed129784 | 667 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
668 | &scaling_min_freq.attr, |
669 | &scaling_max_freq.attr, | |
670 | &affected_cpus.attr, | |
e8628dd0 | 671 | &related_cpus.attr, |
1da177e4 LT |
672 | &scaling_governor.attr, |
673 | &scaling_driver.attr, | |
674 | &scaling_available_governors.attr, | |
9e76988e | 675 | &scaling_setspeed.attr, |
1da177e4 LT |
676 | NULL |
677 | }; | |
678 | ||
29464f28 DJ |
679 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
680 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 681 | |
29464f28 | 682 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 683 | { |
905d77cd DJ |
684 | struct cpufreq_policy *policy = to_policy(kobj); |
685 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 686 | ssize_t ret; |
6eed9404 VK |
687 | |
688 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 689 | return -EINVAL; |
5a01f2e8 | 690 | |
1b750e3b | 691 | lock_policy_rwsem_read(policy->cpu); |
5a01f2e8 | 692 | |
e08f5f5b GS |
693 | if (fattr->show) |
694 | ret = fattr->show(policy, buf); | |
695 | else | |
696 | ret = -EIO; | |
697 | ||
5a01f2e8 | 698 | unlock_policy_rwsem_read(policy->cpu); |
6eed9404 | 699 | up_read(&cpufreq_rwsem); |
1b750e3b | 700 | |
1da177e4 LT |
701 | return ret; |
702 | } | |
703 | ||
905d77cd DJ |
704 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
705 | const char *buf, size_t count) | |
1da177e4 | 706 | { |
905d77cd DJ |
707 | struct cpufreq_policy *policy = to_policy(kobj); |
708 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 709 | ssize_t ret = -EINVAL; |
6eed9404 | 710 | |
4f750c93 SB |
711 | get_online_cpus(); |
712 | ||
713 | if (!cpu_online(policy->cpu)) | |
714 | goto unlock; | |
715 | ||
6eed9404 | 716 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 717 | goto unlock; |
5a01f2e8 | 718 | |
1b750e3b | 719 | lock_policy_rwsem_write(policy->cpu); |
5a01f2e8 | 720 | |
e08f5f5b GS |
721 | if (fattr->store) |
722 | ret = fattr->store(policy, buf, count); | |
723 | else | |
724 | ret = -EIO; | |
725 | ||
5a01f2e8 | 726 | unlock_policy_rwsem_write(policy->cpu); |
6eed9404 | 727 | |
6eed9404 | 728 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
729 | unlock: |
730 | put_online_cpus(); | |
731 | ||
1da177e4 LT |
732 | return ret; |
733 | } | |
734 | ||
905d77cd | 735 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 736 | { |
905d77cd | 737 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 738 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
739 | complete(&policy->kobj_unregister); |
740 | } | |
741 | ||
52cf25d0 | 742 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
743 | .show = show, |
744 | .store = store, | |
745 | }; | |
746 | ||
747 | static struct kobj_type ktype_cpufreq = { | |
748 | .sysfs_ops = &sysfs_ops, | |
749 | .default_attrs = default_attrs, | |
750 | .release = cpufreq_sysfs_release, | |
751 | }; | |
752 | ||
2361be23 VK |
753 | struct kobject *cpufreq_global_kobject; |
754 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
755 | ||
756 | static int cpufreq_global_kobject_usage; | |
757 | ||
758 | int cpufreq_get_global_kobject(void) | |
759 | { | |
760 | if (!cpufreq_global_kobject_usage++) | |
761 | return kobject_add(cpufreq_global_kobject, | |
762 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
763 | ||
764 | return 0; | |
765 | } | |
766 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
767 | ||
768 | void cpufreq_put_global_kobject(void) | |
769 | { | |
770 | if (!--cpufreq_global_kobject_usage) | |
771 | kobject_del(cpufreq_global_kobject); | |
772 | } | |
773 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
774 | ||
775 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
776 | { | |
777 | int ret = cpufreq_get_global_kobject(); | |
778 | ||
779 | if (!ret) { | |
780 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
781 | if (ret) | |
782 | cpufreq_put_global_kobject(); | |
783 | } | |
784 | ||
785 | return ret; | |
786 | } | |
787 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
788 | ||
789 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
790 | { | |
791 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
792 | cpufreq_put_global_kobject(); | |
793 | } | |
794 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
795 | ||
19d6f7ec | 796 | /* symlink affected CPUs */ |
308b60e7 | 797 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
798 | { |
799 | unsigned int j; | |
800 | int ret = 0; | |
801 | ||
802 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 803 | struct device *cpu_dev; |
19d6f7ec | 804 | |
308b60e7 | 805 | if (j == policy->cpu) |
19d6f7ec | 806 | continue; |
19d6f7ec | 807 | |
e8fdde10 | 808 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
809 | cpu_dev = get_cpu_device(j); |
810 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 811 | "cpufreq"); |
71c3461e RW |
812 | if (ret) |
813 | break; | |
19d6f7ec DJ |
814 | } |
815 | return ret; | |
816 | } | |
817 | ||
308b60e7 | 818 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 819 | struct device *dev) |
909a694e DJ |
820 | { |
821 | struct freq_attr **drv_attr; | |
909a694e | 822 | int ret = 0; |
909a694e DJ |
823 | |
824 | /* prepare interface data */ | |
825 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 826 | &dev->kobj, "cpufreq"); |
909a694e DJ |
827 | if (ret) |
828 | return ret; | |
829 | ||
830 | /* set up files for this cpu device */ | |
1c3d85dd | 831 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
832 | while ((drv_attr) && (*drv_attr)) { |
833 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
834 | if (ret) | |
1c3d85dd | 835 | goto err_out_kobj_put; |
909a694e DJ |
836 | drv_attr++; |
837 | } | |
1c3d85dd | 838 | if (cpufreq_driver->get) { |
909a694e DJ |
839 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
840 | if (ret) | |
1c3d85dd | 841 | goto err_out_kobj_put; |
909a694e | 842 | } |
9c0ebcf7 | 843 | if (has_target()) { |
909a694e DJ |
844 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
845 | if (ret) | |
1c3d85dd | 846 | goto err_out_kobj_put; |
909a694e | 847 | } |
1c3d85dd | 848 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
849 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
850 | if (ret) | |
1c3d85dd | 851 | goto err_out_kobj_put; |
e2f74f35 | 852 | } |
909a694e | 853 | |
308b60e7 | 854 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
855 | if (ret) |
856 | goto err_out_kobj_put; | |
857 | ||
e18f1682 SB |
858 | return ret; |
859 | ||
860 | err_out_kobj_put: | |
861 | kobject_put(&policy->kobj); | |
862 | wait_for_completion(&policy->kobj_unregister); | |
863 | return ret; | |
864 | } | |
865 | ||
866 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
867 | { | |
868 | struct cpufreq_policy new_policy; | |
869 | int ret = 0; | |
870 | ||
d5b73cd8 | 871 | memcpy(&new_policy, policy, sizeof(*policy)); |
037ce839 | 872 | /* assure that the starting sequence is run in cpufreq_set_policy */ |
ecf7e461 DJ |
873 | policy->governor = NULL; |
874 | ||
875 | /* set default policy */ | |
037ce839 | 876 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 DJ |
877 | policy->user_policy.policy = policy->policy; |
878 | policy->user_policy.governor = policy->governor; | |
879 | ||
880 | if (ret) { | |
2d06d8c4 | 881 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
882 | if (cpufreq_driver->exit) |
883 | cpufreq_driver->exit(policy); | |
ecf7e461 | 884 | } |
909a694e DJ |
885 | } |
886 | ||
fcf80582 | 887 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 VK |
888 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
889 | unsigned int cpu, struct device *dev, | |
890 | bool frozen) | |
fcf80582 | 891 | { |
9c0ebcf7 | 892 | int ret = 0; |
fcf80582 VK |
893 | unsigned long flags; |
894 | ||
9c0ebcf7 | 895 | if (has_target()) { |
3de9bdeb VK |
896 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
897 | if (ret) { | |
898 | pr_err("%s: Failed to stop governor\n", __func__); | |
899 | return ret; | |
900 | } | |
901 | } | |
fcf80582 | 902 | |
d8d3b471 | 903 | lock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 904 | |
0d1857a1 | 905 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 906 | |
fcf80582 VK |
907 | cpumask_set_cpu(cpu, policy->cpus); |
908 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 909 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 910 | |
d8d3b471 | 911 | unlock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 912 | |
9c0ebcf7 | 913 | if (has_target()) { |
3de9bdeb VK |
914 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
915 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
916 | pr_err("%s: Failed to start governor\n", __func__); | |
917 | return ret; | |
918 | } | |
820c6ca2 | 919 | } |
fcf80582 | 920 | |
a82fab29 | 921 | /* Don't touch sysfs links during light-weight init */ |
71c3461e RW |
922 | if (!frozen) |
923 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); | |
a82fab29 SB |
924 | |
925 | return ret; | |
fcf80582 VK |
926 | } |
927 | #endif | |
1da177e4 | 928 | |
8414809c SB |
929 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
930 | { | |
931 | struct cpufreq_policy *policy; | |
932 | unsigned long flags; | |
933 | ||
44871c9c | 934 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
935 | |
936 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
937 | ||
44871c9c | 938 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c SB |
939 | |
940 | return policy; | |
941 | } | |
942 | ||
e9698cc5 SB |
943 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
944 | { | |
945 | struct cpufreq_policy *policy; | |
946 | ||
947 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
948 | if (!policy) | |
949 | return NULL; | |
950 | ||
951 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
952 | goto err_free_policy; | |
953 | ||
954 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
955 | goto err_free_cpumask; | |
956 | ||
c88a1f8b | 957 | INIT_LIST_HEAD(&policy->policy_list); |
e9698cc5 SB |
958 | return policy; |
959 | ||
960 | err_free_cpumask: | |
961 | free_cpumask_var(policy->cpus); | |
962 | err_free_policy: | |
963 | kfree(policy); | |
964 | ||
965 | return NULL; | |
966 | } | |
967 | ||
968 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
969 | { | |
970 | free_cpumask_var(policy->related_cpus); | |
971 | free_cpumask_var(policy->cpus); | |
972 | kfree(policy); | |
973 | } | |
974 | ||
0d66b91e SB |
975 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
976 | { | |
99ec899e | 977 | if (WARN_ON(cpu == policy->cpu)) |
cb38ed5c SB |
978 | return; |
979 | ||
8efd5765 VK |
980 | /* |
981 | * Take direct locks as lock_policy_rwsem_write wouldn't work here. | |
982 | * Also lock for last cpu is enough here as contention will happen only | |
983 | * after policy->cpu is changed and after it is changed, other threads | |
984 | * will try to acquire lock for new cpu. And policy is already updated | |
985 | * by then. | |
986 | */ | |
987 | down_write(&per_cpu(cpu_policy_rwsem, policy->cpu)); | |
988 | ||
0d66b91e SB |
989 | policy->last_cpu = policy->cpu; |
990 | policy->cpu = cpu; | |
991 | ||
8efd5765 VK |
992 | up_write(&per_cpu(cpu_policy_rwsem, policy->last_cpu)); |
993 | ||
0d66b91e | 994 | cpufreq_frequency_table_update_policy_cpu(policy); |
0d66b91e SB |
995 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
996 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
997 | } | |
998 | ||
a82fab29 SB |
999 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, |
1000 | bool frozen) | |
1da177e4 | 1001 | { |
fcf80582 | 1002 | unsigned int j, cpu = dev->id; |
65922465 | 1003 | int ret = -ENOMEM; |
1da177e4 | 1004 | struct cpufreq_policy *policy; |
1da177e4 | 1005 | unsigned long flags; |
90e41bac | 1006 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 1007 | struct cpufreq_policy *tpolicy; |
fcf80582 | 1008 | struct cpufreq_governor *gov; |
90e41bac | 1009 | #endif |
1da177e4 | 1010 | |
c32b6b8e AR |
1011 | if (cpu_is_offline(cpu)) |
1012 | return 0; | |
1013 | ||
2d06d8c4 | 1014 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
1015 | |
1016 | #ifdef CONFIG_SMP | |
1017 | /* check whether a different CPU already registered this | |
1018 | * CPU because it is in the same boat. */ | |
1019 | policy = cpufreq_cpu_get(cpu); | |
1020 | if (unlikely(policy)) { | |
8ff69732 | 1021 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1022 | return 0; |
1023 | } | |
5025d628 | 1024 | #endif |
fcf80582 | 1025 | |
6eed9404 VK |
1026 | if (!down_read_trylock(&cpufreq_rwsem)) |
1027 | return 0; | |
1028 | ||
fcf80582 VK |
1029 | #ifdef CONFIG_HOTPLUG_CPU |
1030 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1031 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1032 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1033 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1034 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1b274294 | 1035 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev, frozen); |
6eed9404 VK |
1036 | up_read(&cpufreq_rwsem); |
1037 | return ret; | |
2eaa3e2d | 1038 | } |
fcf80582 | 1039 | } |
0d1857a1 | 1040 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1041 | #endif |
1042 | ||
8414809c SB |
1043 | if (frozen) |
1044 | /* Restore the saved policy when doing light-weight init */ | |
1045 | policy = cpufreq_policy_restore(cpu); | |
1046 | else | |
1047 | policy = cpufreq_policy_alloc(); | |
1048 | ||
059019a3 | 1049 | if (!policy) |
1da177e4 | 1050 | goto nomem_out; |
059019a3 | 1051 | |
0d66b91e SB |
1052 | |
1053 | /* | |
1054 | * In the resume path, since we restore a saved policy, the assignment | |
1055 | * to policy->cpu is like an update of the existing policy, rather than | |
1056 | * the creation of a brand new one. So we need to perform this update | |
1057 | * by invoking update_policy_cpu(). | |
1058 | */ | |
1059 | if (frozen && cpu != policy->cpu) | |
1060 | update_policy_cpu(policy, cpu); | |
1061 | else | |
1062 | policy->cpu = cpu; | |
1063 | ||
65922465 | 1064 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1065 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1066 | |
1da177e4 | 1067 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1068 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1069 | |
1070 | /* call driver. From then on the cpufreq must be able | |
1071 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1072 | */ | |
1c3d85dd | 1073 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1074 | if (ret) { |
2d06d8c4 | 1075 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1076 | goto err_set_policy_cpu; |
1da177e4 | 1077 | } |
643ae6e8 | 1078 | |
da60ce9f VK |
1079 | if (cpufreq_driver->get) { |
1080 | policy->cur = cpufreq_driver->get(policy->cpu); | |
1081 | if (!policy->cur) { | |
1082 | pr_err("%s: ->get() failed\n", __func__); | |
1083 | goto err_get_freq; | |
1084 | } | |
1085 | } | |
1086 | ||
fcf80582 VK |
1087 | /* related cpus should atleast have policy->cpus */ |
1088 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1089 | ||
643ae6e8 VK |
1090 | /* |
1091 | * affected cpus must always be the one, which are online. We aren't | |
1092 | * managing offline cpus here. | |
1093 | */ | |
1094 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1095 | ||
187d9f4e MC |
1096 | policy->user_policy.min = policy->min; |
1097 | policy->user_policy.max = policy->max; | |
1da177e4 | 1098 | |
a1531acd TR |
1099 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1100 | CPUFREQ_START, policy); | |
1101 | ||
fcf80582 VK |
1102 | #ifdef CONFIG_HOTPLUG_CPU |
1103 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1104 | if (gov) { | |
1105 | policy->governor = gov; | |
1106 | pr_debug("Restoring governor %s for cpu %d\n", | |
1107 | policy->governor->name, cpu); | |
4bfa042c | 1108 | } |
fcf80582 | 1109 | #endif |
1da177e4 | 1110 | |
e18f1682 | 1111 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1112 | for_each_cpu(j, policy->cpus) |
e18f1682 | 1113 | per_cpu(cpufreq_cpu_data, j) = policy; |
e18f1682 SB |
1114 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1115 | ||
a82fab29 | 1116 | if (!frozen) { |
308b60e7 | 1117 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1118 | if (ret) |
1119 | goto err_out_unregister; | |
1120 | } | |
8ff69732 | 1121 | |
9515f4d6 VK |
1122 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1123 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1124 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1125 | ||
e18f1682 SB |
1126 | cpufreq_init_policy(policy); |
1127 | ||
038c5b3e | 1128 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1129 | up_read(&cpufreq_rwsem); |
1130 | ||
2d06d8c4 | 1131 | pr_debug("initialization complete\n"); |
87c32271 | 1132 | |
1da177e4 LT |
1133 | return 0; |
1134 | ||
1da177e4 | 1135 | err_out_unregister: |
0d1857a1 | 1136 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1137 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1138 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1139 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1140 | |
da60ce9f VK |
1141 | err_get_freq: |
1142 | if (cpufreq_driver->exit) | |
1143 | cpufreq_driver->exit(policy); | |
2eaa3e2d | 1144 | err_set_policy_cpu: |
e9698cc5 | 1145 | cpufreq_policy_free(policy); |
1da177e4 | 1146 | nomem_out: |
6eed9404 VK |
1147 | up_read(&cpufreq_rwsem); |
1148 | ||
1da177e4 LT |
1149 | return ret; |
1150 | } | |
1151 | ||
a82fab29 SB |
1152 | /** |
1153 | * cpufreq_add_dev - add a CPU device | |
1154 | * | |
1155 | * Adds the cpufreq interface for a CPU device. | |
1156 | * | |
1157 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1158 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1159 | * mess up, but more thorough testing is needed. - Mathieu | |
1160 | */ | |
1161 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1162 | { | |
1163 | return __cpufreq_add_dev(dev, sif, false); | |
1164 | } | |
1165 | ||
3a3e9e06 | 1166 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
a82fab29 | 1167 | unsigned int old_cpu, bool frozen) |
f9ba680d SB |
1168 | { |
1169 | struct device *cpu_dev; | |
f9ba680d SB |
1170 | int ret; |
1171 | ||
1172 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1173 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 SB |
1174 | |
1175 | /* Don't touch sysfs files during light-weight tear-down */ | |
1176 | if (frozen) | |
1177 | return cpu_dev->id; | |
1178 | ||
f9ba680d | 1179 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1180 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d SB |
1181 | if (ret) { |
1182 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1183 | ||
1b750e3b | 1184 | lock_policy_rwsem_write(old_cpu); |
3a3e9e06 | 1185 | cpumask_set_cpu(old_cpu, policy->cpus); |
f9ba680d SB |
1186 | unlock_policy_rwsem_write(old_cpu); |
1187 | ||
3a3e9e06 | 1188 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1189 | "cpufreq"); |
1190 | ||
1191 | return -EINVAL; | |
1192 | } | |
1193 | ||
1194 | return cpu_dev->id; | |
1195 | } | |
1196 | ||
cedb70af SB |
1197 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
1198 | struct subsys_interface *sif, | |
1199 | bool frozen) | |
1da177e4 | 1200 | { |
f9ba680d | 1201 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1202 | int new_cpu, ret; |
1da177e4 | 1203 | unsigned long flags; |
3a3e9e06 | 1204 | struct cpufreq_policy *policy; |
1da177e4 | 1205 | |
b8eed8af | 1206 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1207 | |
0d1857a1 | 1208 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1209 | |
3a3e9e06 | 1210 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1211 | |
8414809c SB |
1212 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1213 | if (frozen) | |
3a3e9e06 | 1214 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1215 | |
0d1857a1 | 1216 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1217 | |
3a3e9e06 | 1218 | if (!policy) { |
b8eed8af | 1219 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1220 | return -EINVAL; |
1221 | } | |
1da177e4 | 1222 | |
9c0ebcf7 | 1223 | if (has_target()) { |
3de9bdeb VK |
1224 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1225 | if (ret) { | |
1226 | pr_err("%s: Failed to stop governor\n", __func__); | |
1227 | return ret; | |
1228 | } | |
1229 | } | |
1da177e4 | 1230 | |
084f3493 | 1231 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1232 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1233 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1234 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 LT |
1235 | #endif |
1236 | ||
9c8f1ee4 | 1237 | lock_policy_rwsem_read(cpu); |
3a3e9e06 | 1238 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 | 1239 | unlock_policy_rwsem_read(cpu); |
084f3493 | 1240 | |
61173f25 SB |
1241 | if (cpu != policy->cpu) { |
1242 | if (!frozen) | |
1243 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
73bf0fc2 | 1244 | } else if (cpus > 1) { |
3a3e9e06 | 1245 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen); |
f9ba680d | 1246 | if (new_cpu >= 0) { |
3a3e9e06 | 1247 | update_policy_cpu(policy, new_cpu); |
a82fab29 SB |
1248 | |
1249 | if (!frozen) { | |
75949c9a VK |
1250 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1251 | __func__, new_cpu, cpu); | |
a82fab29 | 1252 | } |
1da177e4 LT |
1253 | } |
1254 | } | |
1da177e4 | 1255 | |
cedb70af SB |
1256 | return 0; |
1257 | } | |
1258 | ||
1259 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
1260 | struct subsys_interface *sif, | |
1261 | bool frozen) | |
1262 | { | |
1263 | unsigned int cpu = dev->id, cpus; | |
1264 | int ret; | |
1265 | unsigned long flags; | |
1266 | struct cpufreq_policy *policy; | |
1267 | struct kobject *kobj; | |
1268 | struct completion *cmp; | |
1269 | ||
1270 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1271 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1272 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1273 | ||
1274 | if (!policy) { | |
1275 | pr_debug("%s: No cpu_data found\n", __func__); | |
1276 | return -EINVAL; | |
1277 | } | |
1278 | ||
1b750e3b | 1279 | lock_policy_rwsem_write(cpu); |
cedb70af | 1280 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1281 | |
1282 | if (cpus > 1) | |
1283 | cpumask_clear_cpu(cpu, policy->cpus); | |
1284 | unlock_policy_rwsem_write(cpu); | |
cedb70af | 1285 | |
b8eed8af VK |
1286 | /* If cpu is last user of policy, free policy */ |
1287 | if (cpus == 1) { | |
9c0ebcf7 | 1288 | if (has_target()) { |
3de9bdeb VK |
1289 | ret = __cpufreq_governor(policy, |
1290 | CPUFREQ_GOV_POLICY_EXIT); | |
1291 | if (ret) { | |
1292 | pr_err("%s: Failed to exit governor\n", | |
1293 | __func__); | |
1294 | return ret; | |
1295 | } | |
edab2fbc | 1296 | } |
2a998599 | 1297 | |
8414809c SB |
1298 | if (!frozen) { |
1299 | lock_policy_rwsem_read(cpu); | |
3a3e9e06 VK |
1300 | kobj = &policy->kobj; |
1301 | cmp = &policy->kobj_unregister; | |
8414809c SB |
1302 | unlock_policy_rwsem_read(cpu); |
1303 | kobject_put(kobj); | |
1304 | ||
1305 | /* | |
1306 | * We need to make sure that the underlying kobj is | |
1307 | * actually not referenced anymore by anybody before we | |
1308 | * proceed with unloading. | |
1309 | */ | |
1310 | pr_debug("waiting for dropping of refcount\n"); | |
1311 | wait_for_completion(cmp); | |
1312 | pr_debug("wait complete\n"); | |
1313 | } | |
7d26e2d5 | 1314 | |
8414809c SB |
1315 | /* |
1316 | * Perform the ->exit() even during light-weight tear-down, | |
1317 | * since this is a core component, and is essential for the | |
1318 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1319 | */ |
1c3d85dd | 1320 | if (cpufreq_driver->exit) |
3a3e9e06 | 1321 | cpufreq_driver->exit(policy); |
27ecddc2 | 1322 | |
9515f4d6 VK |
1323 | /* Remove policy from list of active policies */ |
1324 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1325 | list_del(&policy->policy_list); | |
1326 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1327 | ||
8414809c | 1328 | if (!frozen) |
3a3e9e06 | 1329 | cpufreq_policy_free(policy); |
2a998599 | 1330 | } else { |
9c0ebcf7 | 1331 | if (has_target()) { |
3de9bdeb VK |
1332 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
1333 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
1334 | pr_err("%s: Failed to start governor\n", | |
1335 | __func__); | |
1336 | return ret; | |
1337 | } | |
2a998599 | 1338 | } |
27ecddc2 | 1339 | } |
1da177e4 | 1340 | |
474deff7 | 1341 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1342 | return 0; |
1343 | } | |
1344 | ||
cedb70af | 1345 | /** |
27a862e9 | 1346 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1347 | * |
1348 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1349 | */ |
8a25a2fd | 1350 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1351 | { |
8a25a2fd | 1352 | unsigned int cpu = dev->id; |
27a862e9 | 1353 | int ret; |
ec28297a VP |
1354 | |
1355 | if (cpu_is_offline(cpu)) | |
1356 | return 0; | |
1357 | ||
27a862e9 VK |
1358 | ret = __cpufreq_remove_dev_prepare(dev, sif, false); |
1359 | ||
1360 | if (!ret) | |
1361 | ret = __cpufreq_remove_dev_finish(dev, sif, false); | |
1362 | ||
1363 | return ret; | |
5a01f2e8 VP |
1364 | } |
1365 | ||
65f27f38 | 1366 | static void handle_update(struct work_struct *work) |
1da177e4 | 1367 | { |
65f27f38 DH |
1368 | struct cpufreq_policy *policy = |
1369 | container_of(work, struct cpufreq_policy, update); | |
1370 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1371 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1372 | cpufreq_update_policy(cpu); |
1373 | } | |
1374 | ||
1375 | /** | |
bb176f7d VK |
1376 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1377 | * in deep trouble. | |
1da177e4 LT |
1378 | * @cpu: cpu number |
1379 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1380 | * @new_freq: CPU frequency the CPU actually runs at | |
1381 | * | |
29464f28 DJ |
1382 | * We adjust to current frequency first, and need to clean up later. |
1383 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1384 | */ |
e08f5f5b GS |
1385 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1386 | unsigned int new_freq) | |
1da177e4 | 1387 | { |
b43a7ffb | 1388 | struct cpufreq_policy *policy; |
1da177e4 | 1389 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1390 | unsigned long flags; |
1391 | ||
2d06d8c4 | 1392 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1393 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1394 | ||
1da177e4 LT |
1395 | freqs.old = old_freq; |
1396 | freqs.new = new_freq; | |
b43a7ffb VK |
1397 | |
1398 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1399 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1400 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1401 | ||
1402 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1403 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1404 | } |
1405 | ||
32ee8c3e | 1406 | /** |
4ab70df4 | 1407 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1408 | * @cpu: CPU number |
1409 | * | |
1410 | * This is the last known freq, without actually getting it from the driver. | |
1411 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1412 | */ | |
1413 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1414 | { | |
9e21ba8b | 1415 | struct cpufreq_policy *policy; |
e08f5f5b | 1416 | unsigned int ret_freq = 0; |
95235ca2 | 1417 | |
1c3d85dd RW |
1418 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1419 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1420 | |
1421 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1422 | if (policy) { |
e08f5f5b | 1423 | ret_freq = policy->cur; |
95235ca2 VP |
1424 | cpufreq_cpu_put(policy); |
1425 | } | |
1426 | ||
4d34a67d | 1427 | return ret_freq; |
95235ca2 VP |
1428 | } |
1429 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1430 | ||
3d737108 JB |
1431 | /** |
1432 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1433 | * @cpu: CPU number | |
1434 | * | |
1435 | * Just return the max possible frequency for a given CPU. | |
1436 | */ | |
1437 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1438 | { | |
1439 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1440 | unsigned int ret_freq = 0; | |
1441 | ||
1442 | if (policy) { | |
1443 | ret_freq = policy->max; | |
1444 | cpufreq_cpu_put(policy); | |
1445 | } | |
1446 | ||
1447 | return ret_freq; | |
1448 | } | |
1449 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1450 | ||
5a01f2e8 | 1451 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1452 | { |
7a6aedfa | 1453 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1454 | unsigned int ret_freq = 0; |
5800043b | 1455 | |
1c3d85dd | 1456 | if (!cpufreq_driver->get) |
4d34a67d | 1457 | return ret_freq; |
1da177e4 | 1458 | |
1c3d85dd | 1459 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1460 | |
e08f5f5b | 1461 | if (ret_freq && policy->cur && |
1c3d85dd | 1462 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1463 | /* verify no discrepancy between actual and |
1464 | saved value exists */ | |
1465 | if (unlikely(ret_freq != policy->cur)) { | |
1466 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1467 | schedule_work(&policy->update); |
1468 | } | |
1469 | } | |
1470 | ||
4d34a67d | 1471 | return ret_freq; |
5a01f2e8 | 1472 | } |
1da177e4 | 1473 | |
5a01f2e8 VP |
1474 | /** |
1475 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1476 | * @cpu: CPU number | |
1477 | * | |
1478 | * Get the CPU current (static) CPU frequency | |
1479 | */ | |
1480 | unsigned int cpufreq_get(unsigned int cpu) | |
1481 | { | |
1482 | unsigned int ret_freq = 0; | |
5a01f2e8 | 1483 | |
26ca8694 VK |
1484 | if (cpufreq_disabled() || !cpufreq_driver) |
1485 | return -ENOENT; | |
1486 | ||
6eed9404 VK |
1487 | if (!down_read_trylock(&cpufreq_rwsem)) |
1488 | return 0; | |
5a01f2e8 | 1489 | |
1b750e3b | 1490 | lock_policy_rwsem_read(cpu); |
5a01f2e8 VP |
1491 | |
1492 | ret_freq = __cpufreq_get(cpu); | |
1493 | ||
1494 | unlock_policy_rwsem_read(cpu); | |
6eed9404 VK |
1495 | up_read(&cpufreq_rwsem); |
1496 | ||
4d34a67d | 1497 | return ret_freq; |
1da177e4 LT |
1498 | } |
1499 | EXPORT_SYMBOL(cpufreq_get); | |
1500 | ||
8a25a2fd KS |
1501 | static struct subsys_interface cpufreq_interface = { |
1502 | .name = "cpufreq", | |
1503 | .subsys = &cpu_subsys, | |
1504 | .add_dev = cpufreq_add_dev, | |
1505 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1506 | }; |
1507 | ||
42d4dc3f | 1508 | /** |
e00e56df RW |
1509 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1510 | * | |
1511 | * This function is only executed for the boot processor. The other CPUs | |
1512 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1513 | */ |
e00e56df | 1514 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1515 | { |
e08f5f5b | 1516 | int ret = 0; |
4bc5d341 | 1517 | |
e00e56df | 1518 | int cpu = smp_processor_id(); |
3a3e9e06 | 1519 | struct cpufreq_policy *policy; |
42d4dc3f | 1520 | |
2d06d8c4 | 1521 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1522 | |
e00e56df | 1523 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1524 | policy = cpufreq_cpu_get(cpu); |
1525 | if (!policy) | |
e00e56df | 1526 | return 0; |
42d4dc3f | 1527 | |
1c3d85dd | 1528 | if (cpufreq_driver->suspend) { |
3a3e9e06 | 1529 | ret = cpufreq_driver->suspend(policy); |
ce6c3997 | 1530 | if (ret) |
42d4dc3f | 1531 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
3a3e9e06 | 1532 | "step on CPU %u\n", policy->cpu); |
42d4dc3f BH |
1533 | } |
1534 | ||
3a3e9e06 | 1535 | cpufreq_cpu_put(policy); |
c9060494 | 1536 | return ret; |
42d4dc3f BH |
1537 | } |
1538 | ||
1da177e4 | 1539 | /** |
e00e56df | 1540 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1541 | * |
1542 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1543 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1544 | * restored. It will verify that the current freq is in sync with | |
1545 | * what we believe it to be. This is a bit later than when it | |
1546 | * should be, but nonethteless it's better than calling | |
1547 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1548 | * |
1549 | * This function is only executed for the boot CPU. The other CPUs have not | |
1550 | * been turned on yet. | |
1da177e4 | 1551 | */ |
e00e56df | 1552 | static void cpufreq_bp_resume(void) |
1da177e4 | 1553 | { |
e08f5f5b | 1554 | int ret = 0; |
4bc5d341 | 1555 | |
e00e56df | 1556 | int cpu = smp_processor_id(); |
3a3e9e06 | 1557 | struct cpufreq_policy *policy; |
1da177e4 | 1558 | |
2d06d8c4 | 1559 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1560 | |
e00e56df | 1561 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1562 | policy = cpufreq_cpu_get(cpu); |
1563 | if (!policy) | |
e00e56df | 1564 | return; |
1da177e4 | 1565 | |
1c3d85dd | 1566 | if (cpufreq_driver->resume) { |
3a3e9e06 | 1567 | ret = cpufreq_driver->resume(policy); |
1da177e4 LT |
1568 | if (ret) { |
1569 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
3a3e9e06 | 1570 | "step on CPU %u\n", policy->cpu); |
c9060494 | 1571 | goto fail; |
1da177e4 LT |
1572 | } |
1573 | } | |
1574 | ||
3a3e9e06 | 1575 | schedule_work(&policy->update); |
ce6c3997 | 1576 | |
c9060494 | 1577 | fail: |
3a3e9e06 | 1578 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1579 | } |
1580 | ||
e00e56df RW |
1581 | static struct syscore_ops cpufreq_syscore_ops = { |
1582 | .suspend = cpufreq_bp_suspend, | |
1583 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1584 | }; |
1585 | ||
9d95046e BP |
1586 | /** |
1587 | * cpufreq_get_current_driver - return current driver's name | |
1588 | * | |
1589 | * Return the name string of the currently loaded cpufreq driver | |
1590 | * or NULL, if none. | |
1591 | */ | |
1592 | const char *cpufreq_get_current_driver(void) | |
1593 | { | |
1c3d85dd RW |
1594 | if (cpufreq_driver) |
1595 | return cpufreq_driver->name; | |
1596 | ||
1597 | return NULL; | |
9d95046e BP |
1598 | } |
1599 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1600 | |
1601 | /********************************************************************* | |
1602 | * NOTIFIER LISTS INTERFACE * | |
1603 | *********************************************************************/ | |
1604 | ||
1605 | /** | |
1606 | * cpufreq_register_notifier - register a driver with cpufreq | |
1607 | * @nb: notifier function to register | |
1608 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1609 | * | |
32ee8c3e | 1610 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1611 | * are notified about clock rate changes (once before and once after |
1612 | * the transition), or a list of drivers that are notified about | |
1613 | * changes in cpufreq policy. | |
1614 | * | |
1615 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1616 | * blocking_notifier_chain_register. |
1da177e4 LT |
1617 | */ |
1618 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1619 | { | |
1620 | int ret; | |
1621 | ||
d5aaffa9 DB |
1622 | if (cpufreq_disabled()) |
1623 | return -EINVAL; | |
1624 | ||
74212ca4 CEB |
1625 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1626 | ||
1da177e4 LT |
1627 | switch (list) { |
1628 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1629 | ret = srcu_notifier_chain_register( |
e041c683 | 1630 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1631 | break; |
1632 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1633 | ret = blocking_notifier_chain_register( |
1634 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1635 | break; |
1636 | default: | |
1637 | ret = -EINVAL; | |
1638 | } | |
1da177e4 LT |
1639 | |
1640 | return ret; | |
1641 | } | |
1642 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1643 | ||
1da177e4 LT |
1644 | /** |
1645 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1646 | * @nb: notifier block to be unregistered | |
bb176f7d | 1647 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1648 | * |
1649 | * Remove a driver from the CPU frequency notifier list. | |
1650 | * | |
1651 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1652 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1653 | */ |
1654 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1655 | { | |
1656 | int ret; | |
1657 | ||
d5aaffa9 DB |
1658 | if (cpufreq_disabled()) |
1659 | return -EINVAL; | |
1660 | ||
1da177e4 LT |
1661 | switch (list) { |
1662 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1663 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1664 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1665 | break; |
1666 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1667 | ret = blocking_notifier_chain_unregister( |
1668 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1669 | break; |
1670 | default: | |
1671 | ret = -EINVAL; | |
1672 | } | |
1da177e4 LT |
1673 | |
1674 | return ret; | |
1675 | } | |
1676 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1677 | ||
1678 | ||
1679 | /********************************************************************* | |
1680 | * GOVERNORS * | |
1681 | *********************************************************************/ | |
1682 | ||
1da177e4 LT |
1683 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1684 | unsigned int target_freq, | |
1685 | unsigned int relation) | |
1686 | { | |
1687 | int retval = -EINVAL; | |
7249924e | 1688 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1689 | |
a7b422cd KRW |
1690 | if (cpufreq_disabled()) |
1691 | return -ENODEV; | |
1692 | ||
7249924e VK |
1693 | /* Make sure that target_freq is within supported range */ |
1694 | if (target_freq > policy->max) | |
1695 | target_freq = policy->max; | |
1696 | if (target_freq < policy->min) | |
1697 | target_freq = policy->min; | |
1698 | ||
1699 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1700 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 | 1701 | |
9c0ebcf7 VK |
1702 | /* |
1703 | * This might look like a redundant call as we are checking it again | |
1704 | * after finding index. But it is left intentionally for cases where | |
1705 | * exactly same freq is called again and so we can save on few function | |
1706 | * calls. | |
1707 | */ | |
5a1c0228 VK |
1708 | if (target_freq == policy->cur) |
1709 | return 0; | |
1710 | ||
1c3d85dd RW |
1711 | if (cpufreq_driver->target) |
1712 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
9c0ebcf7 VK |
1713 | else if (cpufreq_driver->target_index) { |
1714 | struct cpufreq_frequency_table *freq_table; | |
1715 | int index; | |
90d45d17 | 1716 | |
9c0ebcf7 VK |
1717 | freq_table = cpufreq_frequency_get_table(policy->cpu); |
1718 | if (unlikely(!freq_table)) { | |
1719 | pr_err("%s: Unable to find freq_table\n", __func__); | |
1720 | goto out; | |
1721 | } | |
1722 | ||
1723 | retval = cpufreq_frequency_table_target(policy, freq_table, | |
1724 | target_freq, relation, &index); | |
1725 | if (unlikely(retval)) { | |
1726 | pr_err("%s: Unable to find matching freq\n", __func__); | |
1727 | goto out; | |
1728 | } | |
1729 | ||
1730 | if (freq_table[index].frequency == policy->cur) | |
1731 | retval = 0; | |
1732 | else | |
1733 | retval = cpufreq_driver->target_index(policy, index); | |
1734 | } | |
1735 | ||
1736 | out: | |
1da177e4 LT |
1737 | return retval; |
1738 | } | |
1739 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1740 | ||
1da177e4 LT |
1741 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1742 | unsigned int target_freq, | |
1743 | unsigned int relation) | |
1744 | { | |
f1829e4a | 1745 | int ret = -EINVAL; |
1da177e4 | 1746 | |
1b750e3b | 1747 | lock_policy_rwsem_write(policy->cpu); |
1da177e4 LT |
1748 | |
1749 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1750 | ||
5a01f2e8 | 1751 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1752 | |
1da177e4 LT |
1753 | return ret; |
1754 | } | |
1755 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1756 | ||
153d7f3f | 1757 | /* |
153d7f3f AV |
1758 | * when "event" is CPUFREQ_GOV_LIMITS |
1759 | */ | |
1da177e4 | 1760 | |
e08f5f5b GS |
1761 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1762 | unsigned int event) | |
1da177e4 | 1763 | { |
cc993cab | 1764 | int ret; |
6afde10c TR |
1765 | |
1766 | /* Only must be defined when default governor is known to have latency | |
1767 | restrictions, like e.g. conservative or ondemand. | |
1768 | That this is the case is already ensured in Kconfig | |
1769 | */ | |
1770 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1771 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1772 | #else | |
1773 | struct cpufreq_governor *gov = NULL; | |
1774 | #endif | |
1c256245 TR |
1775 | |
1776 | if (policy->governor->max_transition_latency && | |
1777 | policy->cpuinfo.transition_latency > | |
1778 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1779 | if (!gov) |
1780 | return -EINVAL; | |
1781 | else { | |
1782 | printk(KERN_WARNING "%s governor failed, too long" | |
1783 | " transition latency of HW, fallback" | |
1784 | " to %s governor\n", | |
1785 | policy->governor->name, | |
1786 | gov->name); | |
1787 | policy->governor = gov; | |
1788 | } | |
1c256245 | 1789 | } |
1da177e4 | 1790 | |
fe492f3f VK |
1791 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1792 | if (!try_module_get(policy->governor->owner)) | |
1793 | return -EINVAL; | |
1da177e4 | 1794 | |
2d06d8c4 | 1795 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1796 | policy->cpu, event); |
95731ebb XC |
1797 | |
1798 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1799 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1800 | || (!policy->governor_enabled |
1801 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1802 | mutex_unlock(&cpufreq_governor_lock); |
1803 | return -EBUSY; | |
1804 | } | |
1805 | ||
1806 | if (event == CPUFREQ_GOV_STOP) | |
1807 | policy->governor_enabled = false; | |
1808 | else if (event == CPUFREQ_GOV_START) | |
1809 | policy->governor_enabled = true; | |
1810 | ||
1811 | mutex_unlock(&cpufreq_governor_lock); | |
1812 | ||
1da177e4 LT |
1813 | ret = policy->governor->governor(policy, event); |
1814 | ||
4d5dcc42 VK |
1815 | if (!ret) { |
1816 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1817 | policy->governor->initialized++; | |
1818 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1819 | policy->governor->initialized--; | |
95731ebb XC |
1820 | } else { |
1821 | /* Restore original values */ | |
1822 | mutex_lock(&cpufreq_governor_lock); | |
1823 | if (event == CPUFREQ_GOV_STOP) | |
1824 | policy->governor_enabled = true; | |
1825 | else if (event == CPUFREQ_GOV_START) | |
1826 | policy->governor_enabled = false; | |
1827 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1828 | } |
b394058f | 1829 | |
fe492f3f VK |
1830 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1831 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1832 | module_put(policy->governor->owner); |
1833 | ||
1834 | return ret; | |
1835 | } | |
1836 | ||
1da177e4 LT |
1837 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1838 | { | |
3bcb09a3 | 1839 | int err; |
1da177e4 LT |
1840 | |
1841 | if (!governor) | |
1842 | return -EINVAL; | |
1843 | ||
a7b422cd KRW |
1844 | if (cpufreq_disabled()) |
1845 | return -ENODEV; | |
1846 | ||
3fc54d37 | 1847 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1848 | |
b394058f | 1849 | governor->initialized = 0; |
3bcb09a3 JF |
1850 | err = -EBUSY; |
1851 | if (__find_governor(governor->name) == NULL) { | |
1852 | err = 0; | |
1853 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1854 | } |
1da177e4 | 1855 | |
32ee8c3e | 1856 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1857 | return err; |
1da177e4 LT |
1858 | } |
1859 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1860 | ||
1da177e4 LT |
1861 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1862 | { | |
90e41bac PB |
1863 | #ifdef CONFIG_HOTPLUG_CPU |
1864 | int cpu; | |
1865 | #endif | |
1866 | ||
1da177e4 LT |
1867 | if (!governor) |
1868 | return; | |
1869 | ||
a7b422cd KRW |
1870 | if (cpufreq_disabled()) |
1871 | return; | |
1872 | ||
90e41bac PB |
1873 | #ifdef CONFIG_HOTPLUG_CPU |
1874 | for_each_present_cpu(cpu) { | |
1875 | if (cpu_online(cpu)) | |
1876 | continue; | |
1877 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1878 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1879 | } | |
1880 | #endif | |
1881 | ||
3fc54d37 | 1882 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1883 | list_del(&governor->governor_list); |
3fc54d37 | 1884 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1885 | return; |
1886 | } | |
1887 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1888 | ||
1889 | ||
1da177e4 LT |
1890 | /********************************************************************* |
1891 | * POLICY INTERFACE * | |
1892 | *********************************************************************/ | |
1893 | ||
1894 | /** | |
1895 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1896 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1897 | * is written | |
1da177e4 LT |
1898 | * |
1899 | * Reads the current cpufreq policy. | |
1900 | */ | |
1901 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1902 | { | |
1903 | struct cpufreq_policy *cpu_policy; | |
1904 | if (!policy) | |
1905 | return -EINVAL; | |
1906 | ||
1907 | cpu_policy = cpufreq_cpu_get(cpu); | |
1908 | if (!cpu_policy) | |
1909 | return -EINVAL; | |
1910 | ||
d5b73cd8 | 1911 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
1912 | |
1913 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1914 | return 0; |
1915 | } | |
1916 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1917 | ||
153d7f3f | 1918 | /* |
037ce839 VK |
1919 | * policy : current policy. |
1920 | * new_policy: policy to be set. | |
153d7f3f | 1921 | */ |
037ce839 | 1922 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 1923 | struct cpufreq_policy *new_policy) |
1da177e4 | 1924 | { |
7bd353a9 | 1925 | int ret = 0, failed = 1; |
1da177e4 | 1926 | |
3a3e9e06 VK |
1927 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, |
1928 | new_policy->min, new_policy->max); | |
1da177e4 | 1929 | |
d5b73cd8 | 1930 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 1931 | |
3a3e9e06 | 1932 | if (new_policy->min > policy->max || new_policy->max < policy->min) { |
9c9a43ed MD |
1933 | ret = -EINVAL; |
1934 | goto error_out; | |
1935 | } | |
1936 | ||
1da177e4 | 1937 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 1938 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 LT |
1939 | if (ret) |
1940 | goto error_out; | |
1941 | ||
1da177e4 | 1942 | /* adjust if necessary - all reasons */ |
e041c683 | 1943 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1944 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
1945 | |
1946 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 1947 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1948 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 1949 | |
bb176f7d VK |
1950 | /* |
1951 | * verify the cpu speed can be set within this limit, which might be | |
1952 | * different to the first one | |
1953 | */ | |
3a3e9e06 | 1954 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 1955 | if (ret) |
1da177e4 | 1956 | goto error_out; |
1da177e4 LT |
1957 | |
1958 | /* notification of the new policy */ | |
e041c683 | 1959 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1960 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 1961 | |
3a3e9e06 VK |
1962 | policy->min = new_policy->min; |
1963 | policy->max = new_policy->max; | |
1da177e4 | 1964 | |
2d06d8c4 | 1965 | pr_debug("new min and max freqs are %u - %u kHz\n", |
3a3e9e06 | 1966 | policy->min, policy->max); |
1da177e4 | 1967 | |
1c3d85dd | 1968 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 1969 | policy->policy = new_policy->policy; |
2d06d8c4 | 1970 | pr_debug("setting range\n"); |
3a3e9e06 | 1971 | ret = cpufreq_driver->setpolicy(new_policy); |
1da177e4 | 1972 | } else { |
3a3e9e06 | 1973 | if (new_policy->governor != policy->governor) { |
1da177e4 | 1974 | /* save old, working values */ |
3a3e9e06 | 1975 | struct cpufreq_governor *old_gov = policy->governor; |
1da177e4 | 1976 | |
2d06d8c4 | 1977 | pr_debug("governor switch\n"); |
1da177e4 LT |
1978 | |
1979 | /* end old governor */ | |
3a3e9e06 VK |
1980 | if (policy->governor) { |
1981 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1982 | unlock_policy_rwsem_write(new_policy->cpu); | |
1983 | __cpufreq_governor(policy, | |
7bd353a9 | 1984 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1985 | lock_policy_rwsem_write(new_policy->cpu); |
7bd353a9 | 1986 | } |
1da177e4 LT |
1987 | |
1988 | /* start new governor */ | |
3a3e9e06 VK |
1989 | policy->governor = new_policy->governor; |
1990 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
1991 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) { | |
7bd353a9 | 1992 | failed = 0; |
955ef483 | 1993 | } else { |
3a3e9e06 VK |
1994 | unlock_policy_rwsem_write(new_policy->cpu); |
1995 | __cpufreq_governor(policy, | |
7bd353a9 | 1996 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1997 | lock_policy_rwsem_write(new_policy->cpu); |
955ef483 | 1998 | } |
7bd353a9 VK |
1999 | } |
2000 | ||
2001 | if (failed) { | |
1da177e4 | 2002 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 2003 | pr_debug("starting governor %s failed\n", |
3a3e9e06 | 2004 | policy->governor->name); |
1da177e4 | 2005 | if (old_gov) { |
3a3e9e06 VK |
2006 | policy->governor = old_gov; |
2007 | __cpufreq_governor(policy, | |
7bd353a9 | 2008 | CPUFREQ_GOV_POLICY_INIT); |
3a3e9e06 | 2009 | __cpufreq_governor(policy, |
e08f5f5b | 2010 | CPUFREQ_GOV_START); |
1da177e4 LT |
2011 | } |
2012 | ret = -EINVAL; | |
2013 | goto error_out; | |
2014 | } | |
2015 | /* might be a policy change, too, so fall through */ | |
2016 | } | |
2d06d8c4 | 2017 | pr_debug("governor: change or update limits\n"); |
3de9bdeb | 2018 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
1da177e4 LT |
2019 | } |
2020 | ||
7d5e350f | 2021 | error_out: |
1da177e4 LT |
2022 | return ret; |
2023 | } | |
2024 | ||
1da177e4 LT |
2025 | /** |
2026 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2027 | * @cpu: CPU which shall be re-evaluated | |
2028 | * | |
25985edc | 2029 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2030 | * at different times. |
2031 | */ | |
2032 | int cpufreq_update_policy(unsigned int cpu) | |
2033 | { | |
3a3e9e06 VK |
2034 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2035 | struct cpufreq_policy new_policy; | |
f1829e4a | 2036 | int ret; |
1da177e4 | 2037 | |
3a3e9e06 | 2038 | if (!policy) { |
f1829e4a JL |
2039 | ret = -ENODEV; |
2040 | goto no_policy; | |
2041 | } | |
1da177e4 | 2042 | |
1b750e3b | 2043 | lock_policy_rwsem_write(cpu); |
1da177e4 | 2044 | |
2d06d8c4 | 2045 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2046 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2047 | new_policy.min = policy->user_policy.min; |
2048 | new_policy.max = policy->user_policy.max; | |
2049 | new_policy.policy = policy->user_policy.policy; | |
2050 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 2051 | |
bb176f7d VK |
2052 | /* |
2053 | * BIOS might change freq behind our back | |
2054 | * -> ask driver for current freq and notify governors about a change | |
2055 | */ | |
1c3d85dd | 2056 | if (cpufreq_driver->get) { |
3a3e9e06 VK |
2057 | new_policy.cur = cpufreq_driver->get(cpu); |
2058 | if (!policy->cur) { | |
2d06d8c4 | 2059 | pr_debug("Driver did not initialize current freq"); |
3a3e9e06 | 2060 | policy->cur = new_policy.cur; |
a85f7bd3 | 2061 | } else { |
9c0ebcf7 | 2062 | if (policy->cur != new_policy.cur && has_target()) |
3a3e9e06 VK |
2063 | cpufreq_out_of_sync(cpu, policy->cur, |
2064 | new_policy.cur); | |
a85f7bd3 | 2065 | } |
0961dd0d TR |
2066 | } |
2067 | ||
037ce839 | 2068 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2069 | |
5a01f2e8 VP |
2070 | unlock_policy_rwsem_write(cpu); |
2071 | ||
3a3e9e06 | 2072 | cpufreq_cpu_put(policy); |
f1829e4a | 2073 | no_policy: |
1da177e4 LT |
2074 | return ret; |
2075 | } | |
2076 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2077 | ||
2760984f | 2078 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2079 | unsigned long action, void *hcpu) |
2080 | { | |
2081 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2082 | struct device *dev; |
5302c3fb | 2083 | bool frozen = false; |
c32b6b8e | 2084 | |
8a25a2fd KS |
2085 | dev = get_cpu_device(cpu); |
2086 | if (dev) { | |
5302c3fb SB |
2087 | |
2088 | if (action & CPU_TASKS_FROZEN) | |
2089 | frozen = true; | |
2090 | ||
2091 | switch (action & ~CPU_TASKS_FROZEN) { | |
c32b6b8e | 2092 | case CPU_ONLINE: |
5302c3fb | 2093 | __cpufreq_add_dev(dev, NULL, frozen); |
23d32899 | 2094 | cpufreq_update_policy(cpu); |
c32b6b8e | 2095 | break; |
5302c3fb | 2096 | |
c32b6b8e | 2097 | case CPU_DOWN_PREPARE: |
cedb70af | 2098 | __cpufreq_remove_dev_prepare(dev, NULL, frozen); |
1aee40ac SB |
2099 | break; |
2100 | ||
2101 | case CPU_POST_DEAD: | |
cedb70af | 2102 | __cpufreq_remove_dev_finish(dev, NULL, frozen); |
c32b6b8e | 2103 | break; |
5302c3fb | 2104 | |
5a01f2e8 | 2105 | case CPU_DOWN_FAILED: |
5302c3fb | 2106 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2107 | break; |
2108 | } | |
2109 | } | |
2110 | return NOTIFY_OK; | |
2111 | } | |
2112 | ||
9c36f746 | 2113 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2114 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2115 | }; |
1da177e4 LT |
2116 | |
2117 | /********************************************************************* | |
2118 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2119 | *********************************************************************/ | |
2120 | ||
2121 | /** | |
2122 | * cpufreq_register_driver - register a CPU Frequency driver | |
2123 | * @driver_data: A struct cpufreq_driver containing the values# | |
2124 | * submitted by the CPU Frequency driver. | |
2125 | * | |
bb176f7d | 2126 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2127 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2128 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2129 | * |
2130 | */ | |
221dee28 | 2131 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2132 | { |
2133 | unsigned long flags; | |
2134 | int ret; | |
2135 | ||
a7b422cd KRW |
2136 | if (cpufreq_disabled()) |
2137 | return -ENODEV; | |
2138 | ||
1da177e4 | 2139 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 VK |
2140 | !(driver_data->setpolicy || driver_data->target_index || |
2141 | driver_data->target)) | |
1da177e4 LT |
2142 | return -EINVAL; |
2143 | ||
2d06d8c4 | 2144 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2145 | |
2146 | if (driver_data->setpolicy) | |
2147 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2148 | ||
0d1857a1 | 2149 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2150 | if (cpufreq_driver) { |
0d1857a1 | 2151 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2152 | return -EEXIST; |
1da177e4 | 2153 | } |
1c3d85dd | 2154 | cpufreq_driver = driver_data; |
0d1857a1 | 2155 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2156 | |
8a25a2fd | 2157 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2158 | if (ret) |
2159 | goto err_null_driver; | |
1da177e4 | 2160 | |
1c3d85dd | 2161 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2162 | int i; |
2163 | ret = -ENODEV; | |
2164 | ||
2165 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2166 | for (i = 0; i < nr_cpu_ids; i++) |
2167 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2168 | ret = 0; |
7a6aedfa MT |
2169 | break; |
2170 | } | |
1da177e4 LT |
2171 | |
2172 | /* if all ->init() calls failed, unregister */ | |
2173 | if (ret) { | |
2d06d8c4 | 2174 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2175 | driver_data->name); |
8a25a2fd | 2176 | goto err_if_unreg; |
1da177e4 LT |
2177 | } |
2178 | } | |
2179 | ||
8f5bc2ab | 2180 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2181 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2182 | |
8f5bc2ab | 2183 | return 0; |
8a25a2fd KS |
2184 | err_if_unreg: |
2185 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2186 | err_null_driver: |
0d1857a1 | 2187 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2188 | cpufreq_driver = NULL; |
0d1857a1 | 2189 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2190 | return ret; |
1da177e4 LT |
2191 | } |
2192 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2193 | ||
1da177e4 LT |
2194 | /** |
2195 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2196 | * | |
bb176f7d | 2197 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2198 | * the right to do so, i.e. if you have succeeded in initialising before! |
2199 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2200 | * currently not initialised. | |
2201 | */ | |
221dee28 | 2202 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2203 | { |
2204 | unsigned long flags; | |
2205 | ||
1c3d85dd | 2206 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2207 | return -EINVAL; |
1da177e4 | 2208 | |
2d06d8c4 | 2209 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2210 | |
8a25a2fd | 2211 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2212 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2213 | |
6eed9404 | 2214 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2215 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2216 | |
1c3d85dd | 2217 | cpufreq_driver = NULL; |
6eed9404 | 2218 | |
0d1857a1 | 2219 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2220 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2221 | |
2222 | return 0; | |
2223 | } | |
2224 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2225 | |
2226 | static int __init cpufreq_core_init(void) | |
2227 | { | |
2228 | int cpu; | |
2229 | ||
a7b422cd KRW |
2230 | if (cpufreq_disabled()) |
2231 | return -ENODEV; | |
2232 | ||
474deff7 | 2233 | for_each_possible_cpu(cpu) |
5a01f2e8 | 2234 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
8aa84ad8 | 2235 | |
2361be23 | 2236 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2237 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2238 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2239 | |
5a01f2e8 VP |
2240 | return 0; |
2241 | } | |
5a01f2e8 | 2242 | core_initcall(cpufreq_core_init); |