Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
bb176f7d | 6 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> |
1da177e4 | 7 | * |
c32b6b8e | 8 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 9 | * Added handling for CPU hotplug |
8ff69732 DJ |
10 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
11 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 12 | * |
1da177e4 LT |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
1da177e4 LT |
16 | */ |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
5ff0a268 | 20 | #include <linux/cpu.h> |
1da177e4 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 | |
5a01f2e8 VP |
50 | /* |
51 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
52 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
53 | * | |
54 | * The rules for this semaphore: | |
55 | * - Any routine that wants to read from the policy structure will | |
56 | * do a down_read on this semaphore. | |
57 | * - Any routine that will write to the policy structure and/or may take away | |
58 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
59 | * mode before doing so. | |
60 | * | |
61 | * Additional rules: | |
5a01f2e8 VP |
62 | * - Governor routines that can be called in cpufreq hotplug path should not |
63 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
64 | * - Lock should not be held across |
65 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 66 | */ |
5a01f2e8 VP |
67 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
68 | ||
69 | #define lock_policy_rwsem(mode, cpu) \ | |
fa1d8af4 | 70 | static int lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 71 | { \ |
474deff7 VK |
72 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
73 | BUG_ON(!policy); \ | |
74 | down_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 VP |
75 | \ |
76 | return 0; \ | |
77 | } | |
78 | ||
79 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 80 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 81 | |
fa1d8af4 VK |
82 | #define unlock_policy_rwsem(mode, cpu) \ |
83 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
84 | { \ | |
474deff7 VK |
85 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
86 | BUG_ON(!policy); \ | |
87 | up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 | 88 | } |
5a01f2e8 | 89 | |
fa1d8af4 VK |
90 | unlock_policy_rwsem(read, cpu); |
91 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 92 | |
6eed9404 VK |
93 | /* |
94 | * rwsem to guarantee that cpufreq driver module doesn't unload during critical | |
95 | * sections | |
96 | */ | |
97 | static DECLARE_RWSEM(cpufreq_rwsem); | |
98 | ||
1da177e4 | 99 | /* internal prototypes */ |
29464f28 DJ |
100 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
101 | unsigned int event); | |
5a01f2e8 | 102 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 103 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
104 | |
105 | /** | |
32ee8c3e DJ |
106 | * Two notifier lists: the "policy" list is involved in the |
107 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
108 | * "transition" list for kernel code that needs to handle |
109 | * changes to devices when the CPU clock speed changes. | |
110 | * The mutex locks both lists. | |
111 | */ | |
e041c683 | 112 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 113 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 114 | |
74212ca4 | 115 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
116 | static int __init init_cpufreq_transition_notifier_list(void) |
117 | { | |
118 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 119 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
120 | return 0; |
121 | } | |
b3438f82 | 122 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 123 | |
a7b422cd | 124 | static int off __read_mostly; |
da584455 | 125 | static int cpufreq_disabled(void) |
a7b422cd KRW |
126 | { |
127 | return off; | |
128 | } | |
129 | void disable_cpufreq(void) | |
130 | { | |
131 | off = 1; | |
132 | } | |
1da177e4 | 133 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 134 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 135 | |
4d5dcc42 VK |
136 | bool have_governor_per_policy(void) |
137 | { | |
1c3d85dd | 138 | return cpufreq_driver->have_governor_per_policy; |
4d5dcc42 | 139 | } |
3f869d6d | 140 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 141 | |
944e9a03 VK |
142 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
143 | { | |
144 | if (have_governor_per_policy()) | |
145 | return &policy->kobj; | |
146 | else | |
147 | return cpufreq_global_kobject; | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
150 | ||
72a4ce34 VK |
151 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
152 | { | |
153 | u64 idle_time; | |
154 | u64 cur_wall_time; | |
155 | u64 busy_time; | |
156 | ||
157 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
158 | ||
159 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
160 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
161 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
162 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
163 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
164 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
165 | ||
166 | idle_time = cur_wall_time - busy_time; | |
167 | if (wall) | |
168 | *wall = cputime_to_usecs(cur_wall_time); | |
169 | ||
170 | return cputime_to_usecs(idle_time); | |
171 | } | |
172 | ||
173 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
174 | { | |
175 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
176 | ||
177 | if (idle_time == -1ULL) | |
178 | return get_cpu_idle_time_jiffy(cpu, wall); | |
179 | else if (!io_busy) | |
180 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
181 | ||
182 | return idle_time; | |
183 | } | |
184 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
185 | ||
6eed9404 | 186 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 187 | { |
6eed9404 | 188 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
189 | unsigned long flags; |
190 | ||
6eed9404 VK |
191 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
192 | return NULL; | |
193 | ||
194 | if (!down_read_trylock(&cpufreq_rwsem)) | |
195 | return NULL; | |
1da177e4 LT |
196 | |
197 | /* get the cpufreq driver */ | |
1c3d85dd | 198 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 199 | |
6eed9404 VK |
200 | if (cpufreq_driver) { |
201 | /* get the CPU */ | |
202 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
203 | if (policy) | |
204 | kobject_get(&policy->kobj); | |
205 | } | |
1da177e4 | 206 | |
6eed9404 | 207 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 208 | |
3a3e9e06 | 209 | if (!policy) |
6eed9404 | 210 | up_read(&cpufreq_rwsem); |
1da177e4 | 211 | |
3a3e9e06 | 212 | return policy; |
a9144436 | 213 | } |
1da177e4 LT |
214 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
215 | ||
3a3e9e06 | 216 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 217 | { |
d5aaffa9 DB |
218 | if (cpufreq_disabled()) |
219 | return; | |
220 | ||
6eed9404 VK |
221 | kobject_put(&policy->kobj); |
222 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
223 | } |
224 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
225 | ||
1da177e4 LT |
226 | /********************************************************************* |
227 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
228 | *********************************************************************/ | |
229 | ||
230 | /** | |
231 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
232 | * | |
233 | * This function alters the system "loops_per_jiffy" for the clock | |
234 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 235 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
236 | * per-CPU loops_per_jiffy value wherever possible. |
237 | */ | |
238 | #ifndef CONFIG_SMP | |
239 | static unsigned long l_p_j_ref; | |
bb176f7d | 240 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 241 | |
858119e1 | 242 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
243 | { |
244 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
245 | return; | |
246 | ||
247 | if (!l_p_j_ref_freq) { | |
248 | l_p_j_ref = loops_per_jiffy; | |
249 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 250 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 251 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 252 | } |
bb176f7d | 253 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 254 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
255 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
256 | ci->new); | |
2d06d8c4 | 257 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 258 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
259 | } |
260 | } | |
261 | #else | |
e08f5f5b GS |
262 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
263 | { | |
264 | return; | |
265 | } | |
1da177e4 LT |
266 | #endif |
267 | ||
0956df9c | 268 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 269 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
270 | { |
271 | BUG_ON(irqs_disabled()); | |
272 | ||
d5aaffa9 DB |
273 | if (cpufreq_disabled()) |
274 | return; | |
275 | ||
1c3d85dd | 276 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 277 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 278 | state, freqs->new); |
1da177e4 | 279 | |
1da177e4 | 280 | switch (state) { |
e4472cb3 | 281 | |
1da177e4 | 282 | case CPUFREQ_PRECHANGE: |
266c13d7 VK |
283 | if (WARN(policy->transition_ongoing == |
284 | cpumask_weight(policy->cpus), | |
7c30ed53 VK |
285 | "In middle of another frequency transition\n")) |
286 | return; | |
287 | ||
266c13d7 | 288 | policy->transition_ongoing++; |
7c30ed53 | 289 | |
32ee8c3e | 290 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
291 | * which is not equal to what the cpufreq core thinks is |
292 | * "old frequency". | |
1da177e4 | 293 | */ |
1c3d85dd | 294 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
295 | if ((policy) && (policy->cpu == freqs->cpu) && |
296 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 297 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
298 | " %u, cpufreq assumed %u kHz.\n", |
299 | freqs->old, policy->cur); | |
300 | freqs->old = policy->cur; | |
1da177e4 LT |
301 | } |
302 | } | |
b4dfdbb3 | 303 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 304 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
305 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
306 | break; | |
e4472cb3 | 307 | |
1da177e4 | 308 | case CPUFREQ_POSTCHANGE: |
7c30ed53 VK |
309 | if (WARN(!policy->transition_ongoing, |
310 | "No frequency transition in progress\n")) | |
311 | return; | |
312 | ||
266c13d7 | 313 | policy->transition_ongoing--; |
7c30ed53 | 314 | |
1da177e4 | 315 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); |
2d06d8c4 | 316 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 317 | (unsigned long)freqs->cpu); |
25e41933 | 318 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 319 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 320 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
321 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
322 | policy->cur = freqs->new; | |
1da177e4 LT |
323 | break; |
324 | } | |
1da177e4 | 325 | } |
bb176f7d | 326 | |
b43a7ffb VK |
327 | /** |
328 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
329 | * on frequency transition. | |
330 | * | |
331 | * This function calls the transition notifiers and the "adjust_jiffies" | |
332 | * function. It is called twice on all CPU frequency changes that have | |
333 | * external effects. | |
334 | */ | |
335 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
336 | struct cpufreq_freqs *freqs, unsigned int state) | |
337 | { | |
338 | for_each_cpu(freqs->cpu, policy->cpus) | |
339 | __cpufreq_notify_transition(policy, freqs, state); | |
340 | } | |
1da177e4 LT |
341 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
342 | ||
343 | ||
1da177e4 LT |
344 | /********************************************************************* |
345 | * SYSFS INTERFACE * | |
346 | *********************************************************************/ | |
347 | ||
3bcb09a3 JF |
348 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
349 | { | |
350 | struct cpufreq_governor *t; | |
351 | ||
352 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 353 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
354 | return t; |
355 | ||
356 | return NULL; | |
357 | } | |
358 | ||
1da177e4 LT |
359 | /** |
360 | * cpufreq_parse_governor - parse a governor string | |
361 | */ | |
905d77cd | 362 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
363 | struct cpufreq_governor **governor) |
364 | { | |
3bcb09a3 | 365 | int err = -EINVAL; |
1c3d85dd RW |
366 | |
367 | if (!cpufreq_driver) | |
3bcb09a3 JF |
368 | goto out; |
369 | ||
1c3d85dd | 370 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
371 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
372 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 373 | err = 0; |
e08f5f5b GS |
374 | } else if (!strnicmp(str_governor, "powersave", |
375 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 376 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 377 | err = 0; |
1da177e4 | 378 | } |
1c3d85dd | 379 | } else if (cpufreq_driver->target) { |
1da177e4 | 380 | struct cpufreq_governor *t; |
3bcb09a3 | 381 | |
3fc54d37 | 382 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
383 | |
384 | t = __find_governor(str_governor); | |
385 | ||
ea714970 | 386 | if (t == NULL) { |
1a8e1463 | 387 | int ret; |
ea714970 | 388 | |
1a8e1463 KC |
389 | mutex_unlock(&cpufreq_governor_mutex); |
390 | ret = request_module("cpufreq_%s", str_governor); | |
391 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 392 | |
1a8e1463 KC |
393 | if (ret == 0) |
394 | t = __find_governor(str_governor); | |
ea714970 JF |
395 | } |
396 | ||
3bcb09a3 JF |
397 | if (t != NULL) { |
398 | *governor = t; | |
399 | err = 0; | |
1da177e4 | 400 | } |
3bcb09a3 | 401 | |
3fc54d37 | 402 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 403 | } |
29464f28 | 404 | out: |
3bcb09a3 | 405 | return err; |
1da177e4 | 406 | } |
1da177e4 | 407 | |
1da177e4 | 408 | /** |
e08f5f5b GS |
409 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
410 | * print out cpufreq information | |
1da177e4 LT |
411 | * |
412 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
413 | * "unsigned int". | |
414 | */ | |
415 | ||
32ee8c3e DJ |
416 | #define show_one(file_name, object) \ |
417 | static ssize_t show_##file_name \ | |
905d77cd | 418 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 419 | { \ |
29464f28 | 420 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
421 | } |
422 | ||
423 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
424 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 425 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
426 | show_one(scaling_min_freq, min); |
427 | show_one(scaling_max_freq, max); | |
428 | show_one(scaling_cur_freq, cur); | |
429 | ||
3a3e9e06 VK |
430 | static int __cpufreq_set_policy(struct cpufreq_policy *policy, |
431 | struct cpufreq_policy *new_policy); | |
7970e08b | 432 | |
1da177e4 LT |
433 | /** |
434 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
435 | */ | |
436 | #define store_one(file_name, object) \ | |
437 | static ssize_t store_##file_name \ | |
905d77cd | 438 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 439 | { \ |
f55c9c26 | 440 | unsigned int ret; \ |
1da177e4 LT |
441 | struct cpufreq_policy new_policy; \ |
442 | \ | |
443 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
444 | if (ret) \ | |
445 | return -EINVAL; \ | |
446 | \ | |
29464f28 | 447 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
448 | if (ret != 1) \ |
449 | return -EINVAL; \ | |
450 | \ | |
7970e08b TR |
451 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
452 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
453 | \ |
454 | return ret ? ret : count; \ | |
455 | } | |
456 | ||
29464f28 DJ |
457 | store_one(scaling_min_freq, min); |
458 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
459 | |
460 | /** | |
461 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
462 | */ | |
905d77cd DJ |
463 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
464 | char *buf) | |
1da177e4 | 465 | { |
5a01f2e8 | 466 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
467 | if (!cur_freq) |
468 | return sprintf(buf, "<unknown>"); | |
469 | return sprintf(buf, "%u\n", cur_freq); | |
470 | } | |
471 | ||
1da177e4 LT |
472 | /** |
473 | * show_scaling_governor - show the current policy for the specified CPU | |
474 | */ | |
905d77cd | 475 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 476 | { |
29464f28 | 477 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
478 | return sprintf(buf, "powersave\n"); |
479 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
480 | return sprintf(buf, "performance\n"); | |
481 | else if (policy->governor) | |
4b972f0b | 482 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 483 | policy->governor->name); |
1da177e4 LT |
484 | return -EINVAL; |
485 | } | |
486 | ||
1da177e4 LT |
487 | /** |
488 | * store_scaling_governor - store policy for the specified CPU | |
489 | */ | |
905d77cd DJ |
490 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
491 | const char *buf, size_t count) | |
1da177e4 | 492 | { |
f55c9c26 | 493 | unsigned int ret; |
1da177e4 LT |
494 | char str_governor[16]; |
495 | struct cpufreq_policy new_policy; | |
496 | ||
497 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
498 | if (ret) | |
499 | return ret; | |
500 | ||
29464f28 | 501 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
502 | if (ret != 1) |
503 | return -EINVAL; | |
504 | ||
e08f5f5b GS |
505 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
506 | &new_policy.governor)) | |
1da177e4 LT |
507 | return -EINVAL; |
508 | ||
bb176f7d VK |
509 | /* |
510 | * Do not use cpufreq_set_policy here or the user_policy.max | |
511 | * will be wrongly overridden | |
512 | */ | |
7970e08b TR |
513 | ret = __cpufreq_set_policy(policy, &new_policy); |
514 | ||
515 | policy->user_policy.policy = policy->policy; | |
516 | policy->user_policy.governor = policy->governor; | |
7970e08b | 517 | |
e08f5f5b GS |
518 | if (ret) |
519 | return ret; | |
520 | else | |
521 | return count; | |
1da177e4 LT |
522 | } |
523 | ||
524 | /** | |
525 | * show_scaling_driver - show the cpufreq driver currently loaded | |
526 | */ | |
905d77cd | 527 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 528 | { |
1c3d85dd | 529 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
530 | } |
531 | ||
532 | /** | |
533 | * show_scaling_available_governors - show the available CPUfreq governors | |
534 | */ | |
905d77cd DJ |
535 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
536 | char *buf) | |
1da177e4 LT |
537 | { |
538 | ssize_t i = 0; | |
539 | struct cpufreq_governor *t; | |
540 | ||
1c3d85dd | 541 | if (!cpufreq_driver->target) { |
1da177e4 LT |
542 | i += sprintf(buf, "performance powersave"); |
543 | goto out; | |
544 | } | |
545 | ||
546 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
547 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
548 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 549 | goto out; |
4b972f0b | 550 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 551 | } |
7d5e350f | 552 | out: |
1da177e4 LT |
553 | i += sprintf(&buf[i], "\n"); |
554 | return i; | |
555 | } | |
e8628dd0 | 556 | |
f4fd3797 | 557 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
558 | { |
559 | ssize_t i = 0; | |
560 | unsigned int cpu; | |
561 | ||
835481d9 | 562 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
563 | if (i) |
564 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
565 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
566 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 567 | break; |
1da177e4 LT |
568 | } |
569 | i += sprintf(&buf[i], "\n"); | |
570 | return i; | |
571 | } | |
f4fd3797 | 572 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 573 | |
e8628dd0 DW |
574 | /** |
575 | * show_related_cpus - show the CPUs affected by each transition even if | |
576 | * hw coordination is in use | |
577 | */ | |
578 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
579 | { | |
f4fd3797 | 580 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
581 | } |
582 | ||
583 | /** | |
584 | * show_affected_cpus - show the CPUs affected by each transition | |
585 | */ | |
586 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
587 | { | |
f4fd3797 | 588 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
589 | } |
590 | ||
9e76988e | 591 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 592 | const char *buf, size_t count) |
9e76988e VP |
593 | { |
594 | unsigned int freq = 0; | |
595 | unsigned int ret; | |
596 | ||
879000f9 | 597 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
598 | return -EINVAL; |
599 | ||
600 | ret = sscanf(buf, "%u", &freq); | |
601 | if (ret != 1) | |
602 | return -EINVAL; | |
603 | ||
604 | policy->governor->store_setspeed(policy, freq); | |
605 | ||
606 | return count; | |
607 | } | |
608 | ||
609 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
610 | { | |
879000f9 | 611 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
612 | return sprintf(buf, "<unsupported>\n"); |
613 | ||
614 | return policy->governor->show_setspeed(policy, buf); | |
615 | } | |
1da177e4 | 616 | |
e2f74f35 | 617 | /** |
8bf1ac72 | 618 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
619 | */ |
620 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
621 | { | |
622 | unsigned int limit; | |
623 | int ret; | |
1c3d85dd RW |
624 | if (cpufreq_driver->bios_limit) { |
625 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
626 | if (!ret) |
627 | return sprintf(buf, "%u\n", limit); | |
628 | } | |
629 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
630 | } | |
631 | ||
6dad2a29 BP |
632 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
633 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
634 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
635 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
636 | cpufreq_freq_attr_ro(scaling_available_governors); | |
637 | cpufreq_freq_attr_ro(scaling_driver); | |
638 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
639 | cpufreq_freq_attr_ro(bios_limit); | |
640 | cpufreq_freq_attr_ro(related_cpus); | |
641 | cpufreq_freq_attr_ro(affected_cpus); | |
642 | cpufreq_freq_attr_rw(scaling_min_freq); | |
643 | cpufreq_freq_attr_rw(scaling_max_freq); | |
644 | cpufreq_freq_attr_rw(scaling_governor); | |
645 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 646 | |
905d77cd | 647 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
648 | &cpuinfo_min_freq.attr, |
649 | &cpuinfo_max_freq.attr, | |
ed129784 | 650 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
651 | &scaling_min_freq.attr, |
652 | &scaling_max_freq.attr, | |
653 | &affected_cpus.attr, | |
e8628dd0 | 654 | &related_cpus.attr, |
1da177e4 LT |
655 | &scaling_governor.attr, |
656 | &scaling_driver.attr, | |
657 | &scaling_available_governors.attr, | |
9e76988e | 658 | &scaling_setspeed.attr, |
1da177e4 LT |
659 | NULL |
660 | }; | |
661 | ||
29464f28 DJ |
662 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
663 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 664 | |
29464f28 | 665 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 666 | { |
905d77cd DJ |
667 | struct cpufreq_policy *policy = to_policy(kobj); |
668 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 669 | ssize_t ret = -EINVAL; |
6eed9404 VK |
670 | |
671 | if (!down_read_trylock(&cpufreq_rwsem)) | |
672 | goto exit; | |
5a01f2e8 VP |
673 | |
674 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
6eed9404 | 675 | goto up_read; |
5a01f2e8 | 676 | |
e08f5f5b GS |
677 | if (fattr->show) |
678 | ret = fattr->show(policy, buf); | |
679 | else | |
680 | ret = -EIO; | |
681 | ||
5a01f2e8 | 682 | unlock_policy_rwsem_read(policy->cpu); |
6eed9404 VK |
683 | |
684 | up_read: | |
685 | up_read(&cpufreq_rwsem); | |
686 | exit: | |
1da177e4 LT |
687 | return ret; |
688 | } | |
689 | ||
905d77cd DJ |
690 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
691 | const char *buf, size_t count) | |
1da177e4 | 692 | { |
905d77cd DJ |
693 | struct cpufreq_policy *policy = to_policy(kobj); |
694 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 695 | ssize_t ret = -EINVAL; |
6eed9404 VK |
696 | |
697 | if (!down_read_trylock(&cpufreq_rwsem)) | |
698 | goto exit; | |
5a01f2e8 VP |
699 | |
700 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
6eed9404 | 701 | goto up_read; |
5a01f2e8 | 702 | |
e08f5f5b GS |
703 | if (fattr->store) |
704 | ret = fattr->store(policy, buf, count); | |
705 | else | |
706 | ret = -EIO; | |
707 | ||
5a01f2e8 | 708 | unlock_policy_rwsem_write(policy->cpu); |
6eed9404 VK |
709 | |
710 | up_read: | |
711 | up_read(&cpufreq_rwsem); | |
712 | exit: | |
1da177e4 LT |
713 | return ret; |
714 | } | |
715 | ||
905d77cd | 716 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 717 | { |
905d77cd | 718 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 719 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
720 | complete(&policy->kobj_unregister); |
721 | } | |
722 | ||
52cf25d0 | 723 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
724 | .show = show, |
725 | .store = store, | |
726 | }; | |
727 | ||
728 | static struct kobj_type ktype_cpufreq = { | |
729 | .sysfs_ops = &sysfs_ops, | |
730 | .default_attrs = default_attrs, | |
731 | .release = cpufreq_sysfs_release, | |
732 | }; | |
733 | ||
2361be23 VK |
734 | struct kobject *cpufreq_global_kobject; |
735 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
736 | ||
737 | static int cpufreq_global_kobject_usage; | |
738 | ||
739 | int cpufreq_get_global_kobject(void) | |
740 | { | |
741 | if (!cpufreq_global_kobject_usage++) | |
742 | return kobject_add(cpufreq_global_kobject, | |
743 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
744 | ||
745 | return 0; | |
746 | } | |
747 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
748 | ||
749 | void cpufreq_put_global_kobject(void) | |
750 | { | |
751 | if (!--cpufreq_global_kobject_usage) | |
752 | kobject_del(cpufreq_global_kobject); | |
753 | } | |
754 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
755 | ||
756 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
757 | { | |
758 | int ret = cpufreq_get_global_kobject(); | |
759 | ||
760 | if (!ret) { | |
761 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
762 | if (ret) | |
763 | cpufreq_put_global_kobject(); | |
764 | } | |
765 | ||
766 | return ret; | |
767 | } | |
768 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
769 | ||
770 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
771 | { | |
772 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
773 | cpufreq_put_global_kobject(); | |
774 | } | |
775 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
776 | ||
19d6f7ec | 777 | /* symlink affected CPUs */ |
308b60e7 | 778 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
779 | { |
780 | unsigned int j; | |
781 | int ret = 0; | |
782 | ||
783 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 784 | struct device *cpu_dev; |
19d6f7ec | 785 | |
308b60e7 | 786 | if (j == policy->cpu) |
19d6f7ec | 787 | continue; |
19d6f7ec | 788 | |
e8fdde10 | 789 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
790 | cpu_dev = get_cpu_device(j); |
791 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 792 | "cpufreq"); |
71c3461e RW |
793 | if (ret) |
794 | break; | |
19d6f7ec DJ |
795 | } |
796 | return ret; | |
797 | } | |
798 | ||
308b60e7 | 799 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 800 | struct device *dev) |
909a694e DJ |
801 | { |
802 | struct freq_attr **drv_attr; | |
909a694e | 803 | int ret = 0; |
909a694e DJ |
804 | |
805 | /* prepare interface data */ | |
806 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 807 | &dev->kobj, "cpufreq"); |
909a694e DJ |
808 | if (ret) |
809 | return ret; | |
810 | ||
811 | /* set up files for this cpu device */ | |
1c3d85dd | 812 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
813 | while ((drv_attr) && (*drv_attr)) { |
814 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
815 | if (ret) | |
1c3d85dd | 816 | goto err_out_kobj_put; |
909a694e DJ |
817 | drv_attr++; |
818 | } | |
1c3d85dd | 819 | if (cpufreq_driver->get) { |
909a694e DJ |
820 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
821 | if (ret) | |
1c3d85dd | 822 | goto err_out_kobj_put; |
909a694e | 823 | } |
1c3d85dd | 824 | if (cpufreq_driver->target) { |
909a694e DJ |
825 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
826 | if (ret) | |
1c3d85dd | 827 | goto err_out_kobj_put; |
909a694e | 828 | } |
1c3d85dd | 829 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
830 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
831 | if (ret) | |
1c3d85dd | 832 | goto err_out_kobj_put; |
e2f74f35 | 833 | } |
909a694e | 834 | |
308b60e7 | 835 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
836 | if (ret) |
837 | goto err_out_kobj_put; | |
838 | ||
e18f1682 SB |
839 | return ret; |
840 | ||
841 | err_out_kobj_put: | |
842 | kobject_put(&policy->kobj); | |
843 | wait_for_completion(&policy->kobj_unregister); | |
844 | return ret; | |
845 | } | |
846 | ||
847 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
848 | { | |
849 | struct cpufreq_policy new_policy; | |
850 | int ret = 0; | |
851 | ||
d5b73cd8 | 852 | memcpy(&new_policy, policy, sizeof(*policy)); |
ecf7e461 DJ |
853 | /* assure that the starting sequence is run in __cpufreq_set_policy */ |
854 | policy->governor = NULL; | |
855 | ||
856 | /* set default policy */ | |
857 | ret = __cpufreq_set_policy(policy, &new_policy); | |
858 | policy->user_policy.policy = policy->policy; | |
859 | policy->user_policy.governor = policy->governor; | |
860 | ||
861 | if (ret) { | |
2d06d8c4 | 862 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
863 | if (cpufreq_driver->exit) |
864 | cpufreq_driver->exit(policy); | |
ecf7e461 | 865 | } |
909a694e DJ |
866 | } |
867 | ||
fcf80582 | 868 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 VK |
869 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
870 | unsigned int cpu, struct device *dev, | |
871 | bool frozen) | |
fcf80582 | 872 | { |
1c3d85dd | 873 | int ret = 0, has_target = !!cpufreq_driver->target; |
fcf80582 VK |
874 | unsigned long flags; |
875 | ||
3de9bdeb VK |
876 | if (has_target) { |
877 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
878 | if (ret) { | |
879 | pr_err("%s: Failed to stop governor\n", __func__); | |
880 | return ret; | |
881 | } | |
882 | } | |
fcf80582 | 883 | |
d8d3b471 | 884 | lock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 885 | |
0d1857a1 | 886 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 887 | |
fcf80582 VK |
888 | cpumask_set_cpu(cpu, policy->cpus); |
889 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 890 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 891 | |
d8d3b471 | 892 | unlock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 893 | |
820c6ca2 | 894 | if (has_target) { |
3de9bdeb VK |
895 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
896 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
897 | pr_err("%s: Failed to start governor\n", __func__); | |
898 | return ret; | |
899 | } | |
820c6ca2 | 900 | } |
fcf80582 | 901 | |
a82fab29 | 902 | /* Don't touch sysfs links during light-weight init */ |
71c3461e RW |
903 | if (!frozen) |
904 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); | |
a82fab29 SB |
905 | |
906 | return ret; | |
fcf80582 VK |
907 | } |
908 | #endif | |
1da177e4 | 909 | |
8414809c SB |
910 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
911 | { | |
912 | struct cpufreq_policy *policy; | |
913 | unsigned long flags; | |
914 | ||
915 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
916 | ||
917 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
918 | ||
919 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
920 | ||
921 | return policy; | |
922 | } | |
923 | ||
e9698cc5 SB |
924 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
925 | { | |
926 | struct cpufreq_policy *policy; | |
927 | ||
928 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
929 | if (!policy) | |
930 | return NULL; | |
931 | ||
932 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
933 | goto err_free_policy; | |
934 | ||
935 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
936 | goto err_free_cpumask; | |
937 | ||
c88a1f8b | 938 | INIT_LIST_HEAD(&policy->policy_list); |
e9698cc5 SB |
939 | return policy; |
940 | ||
941 | err_free_cpumask: | |
942 | free_cpumask_var(policy->cpus); | |
943 | err_free_policy: | |
944 | kfree(policy); | |
945 | ||
946 | return NULL; | |
947 | } | |
948 | ||
949 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
950 | { | |
951 | free_cpumask_var(policy->related_cpus); | |
952 | free_cpumask_var(policy->cpus); | |
953 | kfree(policy); | |
954 | } | |
955 | ||
a82fab29 SB |
956 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, |
957 | bool frozen) | |
1da177e4 | 958 | { |
fcf80582 | 959 | unsigned int j, cpu = dev->id; |
65922465 | 960 | int ret = -ENOMEM; |
1da177e4 | 961 | struct cpufreq_policy *policy; |
1da177e4 | 962 | unsigned long flags; |
90e41bac | 963 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 964 | struct cpufreq_policy *tpolicy; |
fcf80582 | 965 | struct cpufreq_governor *gov; |
90e41bac | 966 | #endif |
1da177e4 | 967 | |
c32b6b8e AR |
968 | if (cpu_is_offline(cpu)) |
969 | return 0; | |
970 | ||
2d06d8c4 | 971 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
972 | |
973 | #ifdef CONFIG_SMP | |
974 | /* check whether a different CPU already registered this | |
975 | * CPU because it is in the same boat. */ | |
976 | policy = cpufreq_cpu_get(cpu); | |
977 | if (unlikely(policy)) { | |
8ff69732 | 978 | cpufreq_cpu_put(policy); |
1da177e4 LT |
979 | return 0; |
980 | } | |
5025d628 | 981 | #endif |
fcf80582 | 982 | |
6eed9404 VK |
983 | if (!down_read_trylock(&cpufreq_rwsem)) |
984 | return 0; | |
985 | ||
fcf80582 VK |
986 | #ifdef CONFIG_HOTPLUG_CPU |
987 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 988 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
989 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
990 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 991 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1b274294 | 992 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev, frozen); |
6eed9404 VK |
993 | up_read(&cpufreq_rwsem); |
994 | return ret; | |
2eaa3e2d | 995 | } |
fcf80582 | 996 | } |
0d1857a1 | 997 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
998 | #endif |
999 | ||
8414809c SB |
1000 | if (frozen) |
1001 | /* Restore the saved policy when doing light-weight init */ | |
1002 | policy = cpufreq_policy_restore(cpu); | |
1003 | else | |
1004 | policy = cpufreq_policy_alloc(); | |
1005 | ||
059019a3 | 1006 | if (!policy) |
1da177e4 | 1007 | goto nomem_out; |
059019a3 | 1008 | |
1da177e4 | 1009 | policy->cpu = cpu; |
65922465 | 1010 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1011 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1012 | |
1da177e4 | 1013 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1014 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1015 | |
1016 | /* call driver. From then on the cpufreq must be able | |
1017 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1018 | */ | |
1c3d85dd | 1019 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1020 | if (ret) { |
2d06d8c4 | 1021 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1022 | goto err_set_policy_cpu; |
1da177e4 | 1023 | } |
643ae6e8 | 1024 | |
fcf80582 VK |
1025 | /* related cpus should atleast have policy->cpus */ |
1026 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1027 | ||
643ae6e8 VK |
1028 | /* |
1029 | * affected cpus must always be the one, which are online. We aren't | |
1030 | * managing offline cpus here. | |
1031 | */ | |
1032 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1033 | ||
187d9f4e MC |
1034 | policy->user_policy.min = policy->min; |
1035 | policy->user_policy.max = policy->max; | |
1da177e4 | 1036 | |
a1531acd TR |
1037 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1038 | CPUFREQ_START, policy); | |
1039 | ||
fcf80582 VK |
1040 | #ifdef CONFIG_HOTPLUG_CPU |
1041 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1042 | if (gov) { | |
1043 | policy->governor = gov; | |
1044 | pr_debug("Restoring governor %s for cpu %d\n", | |
1045 | policy->governor->name, cpu); | |
4bfa042c | 1046 | } |
fcf80582 | 1047 | #endif |
1da177e4 | 1048 | |
e18f1682 | 1049 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1050 | for_each_cpu(j, policy->cpus) |
e18f1682 | 1051 | per_cpu(cpufreq_cpu_data, j) = policy; |
e18f1682 SB |
1052 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1053 | ||
a82fab29 | 1054 | if (!frozen) { |
308b60e7 | 1055 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1056 | if (ret) |
1057 | goto err_out_unregister; | |
1058 | } | |
8ff69732 | 1059 | |
9515f4d6 VK |
1060 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1061 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1062 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1063 | ||
e18f1682 SB |
1064 | cpufreq_init_policy(policy); |
1065 | ||
038c5b3e | 1066 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1067 | up_read(&cpufreq_rwsem); |
1068 | ||
2d06d8c4 | 1069 | pr_debug("initialization complete\n"); |
87c32271 | 1070 | |
1da177e4 LT |
1071 | return 0; |
1072 | ||
1da177e4 | 1073 | err_out_unregister: |
0d1857a1 | 1074 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1075 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1076 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1077 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1078 | |
2eaa3e2d | 1079 | err_set_policy_cpu: |
e9698cc5 | 1080 | cpufreq_policy_free(policy); |
1da177e4 | 1081 | nomem_out: |
6eed9404 VK |
1082 | up_read(&cpufreq_rwsem); |
1083 | ||
1da177e4 LT |
1084 | return ret; |
1085 | } | |
1086 | ||
a82fab29 SB |
1087 | /** |
1088 | * cpufreq_add_dev - add a CPU device | |
1089 | * | |
1090 | * Adds the cpufreq interface for a CPU device. | |
1091 | * | |
1092 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1093 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1094 | * mess up, but more thorough testing is needed. - Mathieu | |
1095 | */ | |
1096 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1097 | { | |
1098 | return __cpufreq_add_dev(dev, sif, false); | |
1099 | } | |
1100 | ||
b8eed8af VK |
1101 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1102 | { | |
b8eed8af VK |
1103 | policy->last_cpu = policy->cpu; |
1104 | policy->cpu = cpu; | |
1105 | ||
b8eed8af VK |
1106 | #ifdef CONFIG_CPU_FREQ_TABLE |
1107 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1108 | #endif | |
1109 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1110 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1111 | } | |
1da177e4 | 1112 | |
3a3e9e06 | 1113 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
a82fab29 | 1114 | unsigned int old_cpu, bool frozen) |
f9ba680d SB |
1115 | { |
1116 | struct device *cpu_dev; | |
f9ba680d SB |
1117 | int ret; |
1118 | ||
1119 | /* first sibling now owns the new sysfs dir */ | |
3a3e9e06 | 1120 | cpu_dev = get_cpu_device(cpumask_first(policy->cpus)); |
a82fab29 SB |
1121 | |
1122 | /* Don't touch sysfs files during light-weight tear-down */ | |
1123 | if (frozen) | |
1124 | return cpu_dev->id; | |
1125 | ||
f9ba680d | 1126 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1127 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d SB |
1128 | if (ret) { |
1129 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1130 | ||
1131 | WARN_ON(lock_policy_rwsem_write(old_cpu)); | |
3a3e9e06 | 1132 | cpumask_set_cpu(old_cpu, policy->cpus); |
f9ba680d SB |
1133 | unlock_policy_rwsem_write(old_cpu); |
1134 | ||
3a3e9e06 | 1135 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1136 | "cpufreq"); |
1137 | ||
1138 | return -EINVAL; | |
1139 | } | |
1140 | ||
1141 | return cpu_dev->id; | |
1142 | } | |
1143 | ||
1da177e4 | 1144 | /** |
5a01f2e8 | 1145 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1146 | * |
1147 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1148 | * Caller should already have policy_rwsem in write mode for this CPU. |
1149 | * This routine frees the rwsem before returning. | |
1da177e4 | 1150 | */ |
bb176f7d | 1151 | static int __cpufreq_remove_dev(struct device *dev, |
a82fab29 | 1152 | struct subsys_interface *sif, bool frozen) |
1da177e4 | 1153 | { |
f9ba680d | 1154 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1155 | int new_cpu, ret; |
1da177e4 | 1156 | unsigned long flags; |
3a3e9e06 | 1157 | struct cpufreq_policy *policy; |
499bca9b AW |
1158 | struct kobject *kobj; |
1159 | struct completion *cmp; | |
1da177e4 | 1160 | |
b8eed8af | 1161 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1162 | |
0d1857a1 | 1163 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1164 | |
3a3e9e06 | 1165 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1166 | |
8414809c SB |
1167 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1168 | if (frozen) | |
3a3e9e06 | 1169 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1170 | |
0d1857a1 | 1171 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1172 | |
3a3e9e06 | 1173 | if (!policy) { |
b8eed8af | 1174 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1175 | return -EINVAL; |
1176 | } | |
1da177e4 | 1177 | |
3de9bdeb VK |
1178 | if (cpufreq_driver->target) { |
1179 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1180 | if (ret) { | |
1181 | pr_err("%s: Failed to stop governor\n", __func__); | |
1182 | return ret; | |
1183 | } | |
1184 | } | |
1da177e4 | 1185 | |
084f3493 | 1186 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1187 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1188 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1189 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 LT |
1190 | #endif |
1191 | ||
2eaa3e2d | 1192 | WARN_ON(lock_policy_rwsem_write(cpu)); |
3a3e9e06 | 1193 | cpus = cpumask_weight(policy->cpus); |
e4969eba VK |
1194 | |
1195 | if (cpus > 1) | |
3a3e9e06 | 1196 | cpumask_clear_cpu(cpu, policy->cpus); |
2eaa3e2d | 1197 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1198 | |
3a3e9e06 | 1199 | if (cpu != policy->cpu && !frozen) { |
73bf0fc2 VK |
1200 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
1201 | } else if (cpus > 1) { | |
084f3493 | 1202 | |
3a3e9e06 | 1203 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen); |
f9ba680d | 1204 | if (new_cpu >= 0) { |
2eaa3e2d | 1205 | WARN_ON(lock_policy_rwsem_write(cpu)); |
3a3e9e06 | 1206 | update_policy_cpu(policy, new_cpu); |
499bca9b | 1207 | unlock_policy_rwsem_write(cpu); |
a82fab29 SB |
1208 | |
1209 | if (!frozen) { | |
1210 | pr_debug("%s: policy Kobject moved to cpu: %d " | |
1211 | "from: %d\n",__func__, new_cpu, cpu); | |
1212 | } | |
1da177e4 LT |
1213 | } |
1214 | } | |
1da177e4 | 1215 | |
b8eed8af VK |
1216 | /* If cpu is last user of policy, free policy */ |
1217 | if (cpus == 1) { | |
3de9bdeb VK |
1218 | if (cpufreq_driver->target) { |
1219 | ret = __cpufreq_governor(policy, | |
1220 | CPUFREQ_GOV_POLICY_EXIT); | |
1221 | if (ret) { | |
1222 | pr_err("%s: Failed to exit governor\n", | |
1223 | __func__); | |
1224 | return ret; | |
1225 | } | |
edab2fbc | 1226 | } |
2a998599 | 1227 | |
8414809c SB |
1228 | if (!frozen) { |
1229 | lock_policy_rwsem_read(cpu); | |
3a3e9e06 VK |
1230 | kobj = &policy->kobj; |
1231 | cmp = &policy->kobj_unregister; | |
8414809c SB |
1232 | unlock_policy_rwsem_read(cpu); |
1233 | kobject_put(kobj); | |
1234 | ||
1235 | /* | |
1236 | * We need to make sure that the underlying kobj is | |
1237 | * actually not referenced anymore by anybody before we | |
1238 | * proceed with unloading. | |
1239 | */ | |
1240 | pr_debug("waiting for dropping of refcount\n"); | |
1241 | wait_for_completion(cmp); | |
1242 | pr_debug("wait complete\n"); | |
1243 | } | |
7d26e2d5 | 1244 | |
8414809c SB |
1245 | /* |
1246 | * Perform the ->exit() even during light-weight tear-down, | |
1247 | * since this is a core component, and is essential for the | |
1248 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1249 | */ |
1c3d85dd | 1250 | if (cpufreq_driver->exit) |
3a3e9e06 | 1251 | cpufreq_driver->exit(policy); |
27ecddc2 | 1252 | |
9515f4d6 VK |
1253 | /* Remove policy from list of active policies */ |
1254 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1255 | list_del(&policy->policy_list); | |
1256 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1257 | ||
8414809c | 1258 | if (!frozen) |
3a3e9e06 | 1259 | cpufreq_policy_free(policy); |
2a998599 | 1260 | } else { |
2a998599 | 1261 | if (cpufreq_driver->target) { |
3de9bdeb VK |
1262 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
1263 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
1264 | pr_err("%s: Failed to start governor\n", | |
1265 | __func__); | |
1266 | return ret; | |
1267 | } | |
2a998599 | 1268 | } |
27ecddc2 | 1269 | } |
1da177e4 | 1270 | |
474deff7 | 1271 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1272 | return 0; |
1273 | } | |
1274 | ||
8a25a2fd | 1275 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1276 | { |
8a25a2fd | 1277 | unsigned int cpu = dev->id; |
5a01f2e8 | 1278 | int retval; |
ec28297a VP |
1279 | |
1280 | if (cpu_is_offline(cpu)) | |
1281 | return 0; | |
1282 | ||
a82fab29 | 1283 | retval = __cpufreq_remove_dev(dev, sif, false); |
5a01f2e8 VP |
1284 | return retval; |
1285 | } | |
1286 | ||
65f27f38 | 1287 | static void handle_update(struct work_struct *work) |
1da177e4 | 1288 | { |
65f27f38 DH |
1289 | struct cpufreq_policy *policy = |
1290 | container_of(work, struct cpufreq_policy, update); | |
1291 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1292 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1293 | cpufreq_update_policy(cpu); |
1294 | } | |
1295 | ||
1296 | /** | |
bb176f7d VK |
1297 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1298 | * in deep trouble. | |
1da177e4 LT |
1299 | * @cpu: cpu number |
1300 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1301 | * @new_freq: CPU frequency the CPU actually runs at | |
1302 | * | |
29464f28 DJ |
1303 | * We adjust to current frequency first, and need to clean up later. |
1304 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1305 | */ |
e08f5f5b GS |
1306 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1307 | unsigned int new_freq) | |
1da177e4 | 1308 | { |
b43a7ffb | 1309 | struct cpufreq_policy *policy; |
1da177e4 | 1310 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1311 | unsigned long flags; |
1312 | ||
2d06d8c4 | 1313 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1314 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1315 | ||
1da177e4 LT |
1316 | freqs.old = old_freq; |
1317 | freqs.new = new_freq; | |
b43a7ffb VK |
1318 | |
1319 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1320 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1321 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1322 | ||
1323 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1324 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1325 | } |
1326 | ||
32ee8c3e | 1327 | /** |
4ab70df4 | 1328 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1329 | * @cpu: CPU number |
1330 | * | |
1331 | * This is the last known freq, without actually getting it from the driver. | |
1332 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1333 | */ | |
1334 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1335 | { | |
9e21ba8b | 1336 | struct cpufreq_policy *policy; |
e08f5f5b | 1337 | unsigned int ret_freq = 0; |
95235ca2 | 1338 | |
1c3d85dd RW |
1339 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1340 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1341 | |
1342 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1343 | if (policy) { |
e08f5f5b | 1344 | ret_freq = policy->cur; |
95235ca2 VP |
1345 | cpufreq_cpu_put(policy); |
1346 | } | |
1347 | ||
4d34a67d | 1348 | return ret_freq; |
95235ca2 VP |
1349 | } |
1350 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1351 | ||
3d737108 JB |
1352 | /** |
1353 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1354 | * @cpu: CPU number | |
1355 | * | |
1356 | * Just return the max possible frequency for a given CPU. | |
1357 | */ | |
1358 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1359 | { | |
1360 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1361 | unsigned int ret_freq = 0; | |
1362 | ||
1363 | if (policy) { | |
1364 | ret_freq = policy->max; | |
1365 | cpufreq_cpu_put(policy); | |
1366 | } | |
1367 | ||
1368 | return ret_freq; | |
1369 | } | |
1370 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1371 | ||
5a01f2e8 | 1372 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1373 | { |
7a6aedfa | 1374 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1375 | unsigned int ret_freq = 0; |
5800043b | 1376 | |
1c3d85dd | 1377 | if (!cpufreq_driver->get) |
4d34a67d | 1378 | return ret_freq; |
1da177e4 | 1379 | |
1c3d85dd | 1380 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1381 | |
e08f5f5b | 1382 | if (ret_freq && policy->cur && |
1c3d85dd | 1383 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1384 | /* verify no discrepancy between actual and |
1385 | saved value exists */ | |
1386 | if (unlikely(ret_freq != policy->cur)) { | |
1387 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1388 | schedule_work(&policy->update); |
1389 | } | |
1390 | } | |
1391 | ||
4d34a67d | 1392 | return ret_freq; |
5a01f2e8 | 1393 | } |
1da177e4 | 1394 | |
5a01f2e8 VP |
1395 | /** |
1396 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1397 | * @cpu: CPU number | |
1398 | * | |
1399 | * Get the CPU current (static) CPU frequency | |
1400 | */ | |
1401 | unsigned int cpufreq_get(unsigned int cpu) | |
1402 | { | |
1403 | unsigned int ret_freq = 0; | |
5a01f2e8 | 1404 | |
6eed9404 VK |
1405 | if (!down_read_trylock(&cpufreq_rwsem)) |
1406 | return 0; | |
5a01f2e8 VP |
1407 | |
1408 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1409 | goto out_policy; | |
1410 | ||
1411 | ret_freq = __cpufreq_get(cpu); | |
1412 | ||
1413 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1414 | |
5a01f2e8 | 1415 | out_policy: |
6eed9404 VK |
1416 | up_read(&cpufreq_rwsem); |
1417 | ||
4d34a67d | 1418 | return ret_freq; |
1da177e4 LT |
1419 | } |
1420 | EXPORT_SYMBOL(cpufreq_get); | |
1421 | ||
8a25a2fd KS |
1422 | static struct subsys_interface cpufreq_interface = { |
1423 | .name = "cpufreq", | |
1424 | .subsys = &cpu_subsys, | |
1425 | .add_dev = cpufreq_add_dev, | |
1426 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1427 | }; |
1428 | ||
42d4dc3f | 1429 | /** |
e00e56df RW |
1430 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1431 | * | |
1432 | * This function is only executed for the boot processor. The other CPUs | |
1433 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1434 | */ |
e00e56df | 1435 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1436 | { |
e08f5f5b | 1437 | int ret = 0; |
4bc5d341 | 1438 | |
e00e56df | 1439 | int cpu = smp_processor_id(); |
3a3e9e06 | 1440 | struct cpufreq_policy *policy; |
42d4dc3f | 1441 | |
2d06d8c4 | 1442 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1443 | |
e00e56df | 1444 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1445 | policy = cpufreq_cpu_get(cpu); |
1446 | if (!policy) | |
e00e56df | 1447 | return 0; |
42d4dc3f | 1448 | |
1c3d85dd | 1449 | if (cpufreq_driver->suspend) { |
3a3e9e06 | 1450 | ret = cpufreq_driver->suspend(policy); |
ce6c3997 | 1451 | if (ret) |
42d4dc3f | 1452 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
3a3e9e06 | 1453 | "step on CPU %u\n", policy->cpu); |
42d4dc3f BH |
1454 | } |
1455 | ||
3a3e9e06 | 1456 | cpufreq_cpu_put(policy); |
c9060494 | 1457 | return ret; |
42d4dc3f BH |
1458 | } |
1459 | ||
1da177e4 | 1460 | /** |
e00e56df | 1461 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1462 | * |
1463 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1464 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1465 | * restored. It will verify that the current freq is in sync with | |
1466 | * what we believe it to be. This is a bit later than when it | |
1467 | * should be, but nonethteless it's better than calling | |
1468 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1469 | * |
1470 | * This function is only executed for the boot CPU. The other CPUs have not | |
1471 | * been turned on yet. | |
1da177e4 | 1472 | */ |
e00e56df | 1473 | static void cpufreq_bp_resume(void) |
1da177e4 | 1474 | { |
e08f5f5b | 1475 | int ret = 0; |
4bc5d341 | 1476 | |
e00e56df | 1477 | int cpu = smp_processor_id(); |
3a3e9e06 | 1478 | struct cpufreq_policy *policy; |
1da177e4 | 1479 | |
2d06d8c4 | 1480 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1481 | |
e00e56df | 1482 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1483 | policy = cpufreq_cpu_get(cpu); |
1484 | if (!policy) | |
e00e56df | 1485 | return; |
1da177e4 | 1486 | |
1c3d85dd | 1487 | if (cpufreq_driver->resume) { |
3a3e9e06 | 1488 | ret = cpufreq_driver->resume(policy); |
1da177e4 LT |
1489 | if (ret) { |
1490 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
3a3e9e06 | 1491 | "step on CPU %u\n", policy->cpu); |
c9060494 | 1492 | goto fail; |
1da177e4 LT |
1493 | } |
1494 | } | |
1495 | ||
3a3e9e06 | 1496 | schedule_work(&policy->update); |
ce6c3997 | 1497 | |
c9060494 | 1498 | fail: |
3a3e9e06 | 1499 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1500 | } |
1501 | ||
e00e56df RW |
1502 | static struct syscore_ops cpufreq_syscore_ops = { |
1503 | .suspend = cpufreq_bp_suspend, | |
1504 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1505 | }; |
1506 | ||
9d95046e BP |
1507 | /** |
1508 | * cpufreq_get_current_driver - return current driver's name | |
1509 | * | |
1510 | * Return the name string of the currently loaded cpufreq driver | |
1511 | * or NULL, if none. | |
1512 | */ | |
1513 | const char *cpufreq_get_current_driver(void) | |
1514 | { | |
1c3d85dd RW |
1515 | if (cpufreq_driver) |
1516 | return cpufreq_driver->name; | |
1517 | ||
1518 | return NULL; | |
9d95046e BP |
1519 | } |
1520 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1521 | |
1522 | /********************************************************************* | |
1523 | * NOTIFIER LISTS INTERFACE * | |
1524 | *********************************************************************/ | |
1525 | ||
1526 | /** | |
1527 | * cpufreq_register_notifier - register a driver with cpufreq | |
1528 | * @nb: notifier function to register | |
1529 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1530 | * | |
32ee8c3e | 1531 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1532 | * are notified about clock rate changes (once before and once after |
1533 | * the transition), or a list of drivers that are notified about | |
1534 | * changes in cpufreq policy. | |
1535 | * | |
1536 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1537 | * blocking_notifier_chain_register. |
1da177e4 LT |
1538 | */ |
1539 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1540 | { | |
1541 | int ret; | |
1542 | ||
d5aaffa9 DB |
1543 | if (cpufreq_disabled()) |
1544 | return -EINVAL; | |
1545 | ||
74212ca4 CEB |
1546 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1547 | ||
1da177e4 LT |
1548 | switch (list) { |
1549 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1550 | ret = srcu_notifier_chain_register( |
e041c683 | 1551 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1552 | break; |
1553 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1554 | ret = blocking_notifier_chain_register( |
1555 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1556 | break; |
1557 | default: | |
1558 | ret = -EINVAL; | |
1559 | } | |
1da177e4 LT |
1560 | |
1561 | return ret; | |
1562 | } | |
1563 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1564 | ||
1da177e4 LT |
1565 | /** |
1566 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1567 | * @nb: notifier block to be unregistered | |
bb176f7d | 1568 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1569 | * |
1570 | * Remove a driver from the CPU frequency notifier list. | |
1571 | * | |
1572 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1573 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1574 | */ |
1575 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1576 | { | |
1577 | int ret; | |
1578 | ||
d5aaffa9 DB |
1579 | if (cpufreq_disabled()) |
1580 | return -EINVAL; | |
1581 | ||
1da177e4 LT |
1582 | switch (list) { |
1583 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1584 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1585 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1586 | break; |
1587 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1588 | ret = blocking_notifier_chain_unregister( |
1589 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1590 | break; |
1591 | default: | |
1592 | ret = -EINVAL; | |
1593 | } | |
1da177e4 LT |
1594 | |
1595 | return ret; | |
1596 | } | |
1597 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1598 | ||
1599 | ||
1600 | /********************************************************************* | |
1601 | * GOVERNORS * | |
1602 | *********************************************************************/ | |
1603 | ||
1da177e4 LT |
1604 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1605 | unsigned int target_freq, | |
1606 | unsigned int relation) | |
1607 | { | |
1608 | int retval = -EINVAL; | |
7249924e | 1609 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1610 | |
a7b422cd KRW |
1611 | if (cpufreq_disabled()) |
1612 | return -ENODEV; | |
7c30ed53 VK |
1613 | if (policy->transition_ongoing) |
1614 | return -EBUSY; | |
a7b422cd | 1615 | |
7249924e VK |
1616 | /* Make sure that target_freq is within supported range */ |
1617 | if (target_freq > policy->max) | |
1618 | target_freq = policy->max; | |
1619 | if (target_freq < policy->min) | |
1620 | target_freq = policy->min; | |
1621 | ||
1622 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1623 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1624 | |
1625 | if (target_freq == policy->cur) | |
1626 | return 0; | |
1627 | ||
1c3d85dd RW |
1628 | if (cpufreq_driver->target) |
1629 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1630 | |
1da177e4 LT |
1631 | return retval; |
1632 | } | |
1633 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1634 | ||
1da177e4 LT |
1635 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1636 | unsigned int target_freq, | |
1637 | unsigned int relation) | |
1638 | { | |
f1829e4a | 1639 | int ret = -EINVAL; |
1da177e4 | 1640 | |
5a01f2e8 | 1641 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1642 | goto fail; |
1da177e4 LT |
1643 | |
1644 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1645 | ||
5a01f2e8 | 1646 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1647 | |
f1829e4a | 1648 | fail: |
1da177e4 LT |
1649 | return ret; |
1650 | } | |
1651 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1652 | ||
153d7f3f | 1653 | /* |
153d7f3f AV |
1654 | * when "event" is CPUFREQ_GOV_LIMITS |
1655 | */ | |
1da177e4 | 1656 | |
e08f5f5b GS |
1657 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1658 | unsigned int event) | |
1da177e4 | 1659 | { |
cc993cab | 1660 | int ret; |
6afde10c TR |
1661 | |
1662 | /* Only must be defined when default governor is known to have latency | |
1663 | restrictions, like e.g. conservative or ondemand. | |
1664 | That this is the case is already ensured in Kconfig | |
1665 | */ | |
1666 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1667 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1668 | #else | |
1669 | struct cpufreq_governor *gov = NULL; | |
1670 | #endif | |
1c256245 TR |
1671 | |
1672 | if (policy->governor->max_transition_latency && | |
1673 | policy->cpuinfo.transition_latency > | |
1674 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1675 | if (!gov) |
1676 | return -EINVAL; | |
1677 | else { | |
1678 | printk(KERN_WARNING "%s governor failed, too long" | |
1679 | " transition latency of HW, fallback" | |
1680 | " to %s governor\n", | |
1681 | policy->governor->name, | |
1682 | gov->name); | |
1683 | policy->governor = gov; | |
1684 | } | |
1c256245 | 1685 | } |
1da177e4 | 1686 | |
fe492f3f VK |
1687 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1688 | if (!try_module_get(policy->governor->owner)) | |
1689 | return -EINVAL; | |
1da177e4 | 1690 | |
2d06d8c4 | 1691 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1692 | policy->cpu, event); |
95731ebb XC |
1693 | |
1694 | mutex_lock(&cpufreq_governor_lock); | |
1695 | if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) || | |
1696 | (policy->governor_enabled && (event == CPUFREQ_GOV_START))) { | |
1697 | mutex_unlock(&cpufreq_governor_lock); | |
1698 | return -EBUSY; | |
1699 | } | |
1700 | ||
1701 | if (event == CPUFREQ_GOV_STOP) | |
1702 | policy->governor_enabled = false; | |
1703 | else if (event == CPUFREQ_GOV_START) | |
1704 | policy->governor_enabled = true; | |
1705 | ||
1706 | mutex_unlock(&cpufreq_governor_lock); | |
1707 | ||
1da177e4 LT |
1708 | ret = policy->governor->governor(policy, event); |
1709 | ||
4d5dcc42 VK |
1710 | if (!ret) { |
1711 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1712 | policy->governor->initialized++; | |
1713 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1714 | policy->governor->initialized--; | |
95731ebb XC |
1715 | } else { |
1716 | /* Restore original values */ | |
1717 | mutex_lock(&cpufreq_governor_lock); | |
1718 | if (event == CPUFREQ_GOV_STOP) | |
1719 | policy->governor_enabled = true; | |
1720 | else if (event == CPUFREQ_GOV_START) | |
1721 | policy->governor_enabled = false; | |
1722 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1723 | } |
b394058f | 1724 | |
fe492f3f VK |
1725 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1726 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1727 | module_put(policy->governor->owner); |
1728 | ||
1729 | return ret; | |
1730 | } | |
1731 | ||
1da177e4 LT |
1732 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1733 | { | |
3bcb09a3 | 1734 | int err; |
1da177e4 LT |
1735 | |
1736 | if (!governor) | |
1737 | return -EINVAL; | |
1738 | ||
a7b422cd KRW |
1739 | if (cpufreq_disabled()) |
1740 | return -ENODEV; | |
1741 | ||
3fc54d37 | 1742 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1743 | |
b394058f | 1744 | governor->initialized = 0; |
3bcb09a3 JF |
1745 | err = -EBUSY; |
1746 | if (__find_governor(governor->name) == NULL) { | |
1747 | err = 0; | |
1748 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1749 | } |
1da177e4 | 1750 | |
32ee8c3e | 1751 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1752 | return err; |
1da177e4 LT |
1753 | } |
1754 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1755 | ||
1da177e4 LT |
1756 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1757 | { | |
90e41bac PB |
1758 | #ifdef CONFIG_HOTPLUG_CPU |
1759 | int cpu; | |
1760 | #endif | |
1761 | ||
1da177e4 LT |
1762 | if (!governor) |
1763 | return; | |
1764 | ||
a7b422cd KRW |
1765 | if (cpufreq_disabled()) |
1766 | return; | |
1767 | ||
90e41bac PB |
1768 | #ifdef CONFIG_HOTPLUG_CPU |
1769 | for_each_present_cpu(cpu) { | |
1770 | if (cpu_online(cpu)) | |
1771 | continue; | |
1772 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1773 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1774 | } | |
1775 | #endif | |
1776 | ||
3fc54d37 | 1777 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1778 | list_del(&governor->governor_list); |
3fc54d37 | 1779 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1780 | return; |
1781 | } | |
1782 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1783 | ||
1784 | ||
1da177e4 LT |
1785 | /********************************************************************* |
1786 | * POLICY INTERFACE * | |
1787 | *********************************************************************/ | |
1788 | ||
1789 | /** | |
1790 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1791 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1792 | * is written | |
1da177e4 LT |
1793 | * |
1794 | * Reads the current cpufreq policy. | |
1795 | */ | |
1796 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1797 | { | |
1798 | struct cpufreq_policy *cpu_policy; | |
1799 | if (!policy) | |
1800 | return -EINVAL; | |
1801 | ||
1802 | cpu_policy = cpufreq_cpu_get(cpu); | |
1803 | if (!cpu_policy) | |
1804 | return -EINVAL; | |
1805 | ||
d5b73cd8 | 1806 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
1807 | |
1808 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1809 | return 0; |
1810 | } | |
1811 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1812 | ||
153d7f3f | 1813 | /* |
e08f5f5b GS |
1814 | * data : current policy. |
1815 | * policy : policy to be set. | |
153d7f3f | 1816 | */ |
3a3e9e06 VK |
1817 | static int __cpufreq_set_policy(struct cpufreq_policy *policy, |
1818 | struct cpufreq_policy *new_policy) | |
1da177e4 | 1819 | { |
7bd353a9 | 1820 | int ret = 0, failed = 1; |
1da177e4 | 1821 | |
3a3e9e06 VK |
1822 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, |
1823 | new_policy->min, new_policy->max); | |
1da177e4 | 1824 | |
d5b73cd8 | 1825 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 1826 | |
3a3e9e06 | 1827 | if (new_policy->min > policy->max || new_policy->max < policy->min) { |
9c9a43ed MD |
1828 | ret = -EINVAL; |
1829 | goto error_out; | |
1830 | } | |
1831 | ||
1da177e4 | 1832 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 1833 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 LT |
1834 | if (ret) |
1835 | goto error_out; | |
1836 | ||
1da177e4 | 1837 | /* adjust if necessary - all reasons */ |
e041c683 | 1838 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1839 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
1840 | |
1841 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 1842 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1843 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 1844 | |
bb176f7d VK |
1845 | /* |
1846 | * verify the cpu speed can be set within this limit, which might be | |
1847 | * different to the first one | |
1848 | */ | |
3a3e9e06 | 1849 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 1850 | if (ret) |
1da177e4 | 1851 | goto error_out; |
1da177e4 LT |
1852 | |
1853 | /* notification of the new policy */ | |
e041c683 | 1854 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1855 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 1856 | |
3a3e9e06 VK |
1857 | policy->min = new_policy->min; |
1858 | policy->max = new_policy->max; | |
1da177e4 | 1859 | |
2d06d8c4 | 1860 | pr_debug("new min and max freqs are %u - %u kHz\n", |
3a3e9e06 | 1861 | policy->min, policy->max); |
1da177e4 | 1862 | |
1c3d85dd | 1863 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 1864 | policy->policy = new_policy->policy; |
2d06d8c4 | 1865 | pr_debug("setting range\n"); |
3a3e9e06 | 1866 | ret = cpufreq_driver->setpolicy(new_policy); |
1da177e4 | 1867 | } else { |
3a3e9e06 | 1868 | if (new_policy->governor != policy->governor) { |
1da177e4 | 1869 | /* save old, working values */ |
3a3e9e06 | 1870 | struct cpufreq_governor *old_gov = policy->governor; |
1da177e4 | 1871 | |
2d06d8c4 | 1872 | pr_debug("governor switch\n"); |
1da177e4 LT |
1873 | |
1874 | /* end old governor */ | |
3a3e9e06 VK |
1875 | if (policy->governor) { |
1876 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1877 | unlock_policy_rwsem_write(new_policy->cpu); | |
1878 | __cpufreq_governor(policy, | |
7bd353a9 | 1879 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1880 | lock_policy_rwsem_write(new_policy->cpu); |
7bd353a9 | 1881 | } |
1da177e4 LT |
1882 | |
1883 | /* start new governor */ | |
3a3e9e06 VK |
1884 | policy->governor = new_policy->governor; |
1885 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
1886 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) { | |
7bd353a9 | 1887 | failed = 0; |
955ef483 | 1888 | } else { |
3a3e9e06 VK |
1889 | unlock_policy_rwsem_write(new_policy->cpu); |
1890 | __cpufreq_governor(policy, | |
7bd353a9 | 1891 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1892 | lock_policy_rwsem_write(new_policy->cpu); |
955ef483 | 1893 | } |
7bd353a9 VK |
1894 | } |
1895 | ||
1896 | if (failed) { | |
1da177e4 | 1897 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1898 | pr_debug("starting governor %s failed\n", |
3a3e9e06 | 1899 | policy->governor->name); |
1da177e4 | 1900 | if (old_gov) { |
3a3e9e06 VK |
1901 | policy->governor = old_gov; |
1902 | __cpufreq_governor(policy, | |
7bd353a9 | 1903 | CPUFREQ_GOV_POLICY_INIT); |
3a3e9e06 | 1904 | __cpufreq_governor(policy, |
e08f5f5b | 1905 | CPUFREQ_GOV_START); |
1da177e4 LT |
1906 | } |
1907 | ret = -EINVAL; | |
1908 | goto error_out; | |
1909 | } | |
1910 | /* might be a policy change, too, so fall through */ | |
1911 | } | |
2d06d8c4 | 1912 | pr_debug("governor: change or update limits\n"); |
3de9bdeb | 1913 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
1da177e4 LT |
1914 | } |
1915 | ||
7d5e350f | 1916 | error_out: |
1da177e4 LT |
1917 | return ret; |
1918 | } | |
1919 | ||
1da177e4 LT |
1920 | /** |
1921 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1922 | * @cpu: CPU which shall be re-evaluated | |
1923 | * | |
25985edc | 1924 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1925 | * at different times. |
1926 | */ | |
1927 | int cpufreq_update_policy(unsigned int cpu) | |
1928 | { | |
3a3e9e06 VK |
1929 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
1930 | struct cpufreq_policy new_policy; | |
f1829e4a | 1931 | int ret; |
1da177e4 | 1932 | |
3a3e9e06 | 1933 | if (!policy) { |
f1829e4a JL |
1934 | ret = -ENODEV; |
1935 | goto no_policy; | |
1936 | } | |
1da177e4 | 1937 | |
f1829e4a JL |
1938 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1939 | ret = -EINVAL; | |
1940 | goto fail; | |
1941 | } | |
1da177e4 | 1942 | |
2d06d8c4 | 1943 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 1944 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
1945 | new_policy.min = policy->user_policy.min; |
1946 | new_policy.max = policy->user_policy.max; | |
1947 | new_policy.policy = policy->user_policy.policy; | |
1948 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 1949 | |
bb176f7d VK |
1950 | /* |
1951 | * BIOS might change freq behind our back | |
1952 | * -> ask driver for current freq and notify governors about a change | |
1953 | */ | |
1c3d85dd | 1954 | if (cpufreq_driver->get) { |
3a3e9e06 VK |
1955 | new_policy.cur = cpufreq_driver->get(cpu); |
1956 | if (!policy->cur) { | |
2d06d8c4 | 1957 | pr_debug("Driver did not initialize current freq"); |
3a3e9e06 | 1958 | policy->cur = new_policy.cur; |
a85f7bd3 | 1959 | } else { |
3a3e9e06 VK |
1960 | if (policy->cur != new_policy.cur && cpufreq_driver->target) |
1961 | cpufreq_out_of_sync(cpu, policy->cur, | |
1962 | new_policy.cur); | |
a85f7bd3 | 1963 | } |
0961dd0d TR |
1964 | } |
1965 | ||
3a3e9e06 | 1966 | ret = __cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 1967 | |
5a01f2e8 VP |
1968 | unlock_policy_rwsem_write(cpu); |
1969 | ||
f1829e4a | 1970 | fail: |
3a3e9e06 | 1971 | cpufreq_cpu_put(policy); |
f1829e4a | 1972 | no_policy: |
1da177e4 LT |
1973 | return ret; |
1974 | } | |
1975 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1976 | ||
2760984f | 1977 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1978 | unsigned long action, void *hcpu) |
1979 | { | |
1980 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1981 | struct device *dev; |
5302c3fb | 1982 | bool frozen = false; |
c32b6b8e | 1983 | |
8a25a2fd KS |
1984 | dev = get_cpu_device(cpu); |
1985 | if (dev) { | |
5302c3fb SB |
1986 | |
1987 | if (action & CPU_TASKS_FROZEN) | |
1988 | frozen = true; | |
1989 | ||
1990 | switch (action & ~CPU_TASKS_FROZEN) { | |
c32b6b8e | 1991 | case CPU_ONLINE: |
5302c3fb | 1992 | __cpufreq_add_dev(dev, NULL, frozen); |
23d32899 | 1993 | cpufreq_update_policy(cpu); |
c32b6b8e | 1994 | break; |
5302c3fb | 1995 | |
c32b6b8e | 1996 | case CPU_DOWN_PREPARE: |
5302c3fb | 1997 | __cpufreq_remove_dev(dev, NULL, frozen); |
c32b6b8e | 1998 | break; |
5302c3fb | 1999 | |
5a01f2e8 | 2000 | case CPU_DOWN_FAILED: |
5302c3fb | 2001 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2002 | break; |
2003 | } | |
2004 | } | |
2005 | return NOTIFY_OK; | |
2006 | } | |
2007 | ||
9c36f746 | 2008 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2009 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2010 | }; |
1da177e4 LT |
2011 | |
2012 | /********************************************************************* | |
2013 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2014 | *********************************************************************/ | |
2015 | ||
2016 | /** | |
2017 | * cpufreq_register_driver - register a CPU Frequency driver | |
2018 | * @driver_data: A struct cpufreq_driver containing the values# | |
2019 | * submitted by the CPU Frequency driver. | |
2020 | * | |
bb176f7d | 2021 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2022 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2023 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2024 | * |
2025 | */ | |
221dee28 | 2026 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2027 | { |
2028 | unsigned long flags; | |
2029 | int ret; | |
2030 | ||
a7b422cd KRW |
2031 | if (cpufreq_disabled()) |
2032 | return -ENODEV; | |
2033 | ||
1da177e4 LT |
2034 | if (!driver_data || !driver_data->verify || !driver_data->init || |
2035 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2036 | return -EINVAL; | |
2037 | ||
2d06d8c4 | 2038 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2039 | |
2040 | if (driver_data->setpolicy) | |
2041 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2042 | ||
0d1857a1 | 2043 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2044 | if (cpufreq_driver) { |
0d1857a1 | 2045 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2046 | return -EBUSY; |
2047 | } | |
1c3d85dd | 2048 | cpufreq_driver = driver_data; |
0d1857a1 | 2049 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2050 | |
8a25a2fd | 2051 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2052 | if (ret) |
2053 | goto err_null_driver; | |
1da177e4 | 2054 | |
1c3d85dd | 2055 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2056 | int i; |
2057 | ret = -ENODEV; | |
2058 | ||
2059 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2060 | for (i = 0; i < nr_cpu_ids; i++) |
2061 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2062 | ret = 0; |
7a6aedfa MT |
2063 | break; |
2064 | } | |
1da177e4 LT |
2065 | |
2066 | /* if all ->init() calls failed, unregister */ | |
2067 | if (ret) { | |
2d06d8c4 | 2068 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2069 | driver_data->name); |
8a25a2fd | 2070 | goto err_if_unreg; |
1da177e4 LT |
2071 | } |
2072 | } | |
2073 | ||
8f5bc2ab | 2074 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2075 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2076 | |
8f5bc2ab | 2077 | return 0; |
8a25a2fd KS |
2078 | err_if_unreg: |
2079 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2080 | err_null_driver: |
0d1857a1 | 2081 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2082 | cpufreq_driver = NULL; |
0d1857a1 | 2083 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2084 | return ret; |
1da177e4 LT |
2085 | } |
2086 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2087 | ||
1da177e4 LT |
2088 | /** |
2089 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2090 | * | |
bb176f7d | 2091 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2092 | * the right to do so, i.e. if you have succeeded in initialising before! |
2093 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2094 | * currently not initialised. | |
2095 | */ | |
221dee28 | 2096 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2097 | { |
2098 | unsigned long flags; | |
2099 | ||
1c3d85dd | 2100 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2101 | return -EINVAL; |
1da177e4 | 2102 | |
2d06d8c4 | 2103 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2104 | |
8a25a2fd | 2105 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2106 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2107 | |
6eed9404 | 2108 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2109 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2110 | |
1c3d85dd | 2111 | cpufreq_driver = NULL; |
6eed9404 | 2112 | |
0d1857a1 | 2113 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2114 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2115 | |
2116 | return 0; | |
2117 | } | |
2118 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2119 | |
2120 | static int __init cpufreq_core_init(void) | |
2121 | { | |
2122 | int cpu; | |
2123 | ||
a7b422cd KRW |
2124 | if (cpufreq_disabled()) |
2125 | return -ENODEV; | |
2126 | ||
474deff7 | 2127 | for_each_possible_cpu(cpu) |
5a01f2e8 | 2128 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
8aa84ad8 | 2129 | |
2361be23 | 2130 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2131 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2132 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2133 | |
5a01f2e8 VP |
2134 | return 0; |
2135 | } | |
5a01f2e8 | 2136 | core_initcall(cpufreq_core_init); |