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); | |
43 | ||
084f3493 TR |
44 | #ifdef CONFIG_HOTPLUG_CPU |
45 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 46 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 47 | #endif |
1da177e4 | 48 | |
5a01f2e8 VP |
49 | /* |
50 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
51 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
52 | * | |
53 | * The rules for this semaphore: | |
54 | * - Any routine that wants to read from the policy structure will | |
55 | * do a down_read on this semaphore. | |
56 | * - Any routine that will write to the policy structure and/or may take away | |
57 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
58 | * mode before doing so. | |
59 | * | |
60 | * Additional rules: | |
5a01f2e8 VP |
61 | * - Governor routines that can be called in cpufreq hotplug path should not |
62 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
63 | * - Lock should not be held across |
64 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 65 | */ |
f1625066 | 66 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
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 | { \ |
f1625066 | 72 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
73 | BUG_ON(policy_cpu == -1); \ |
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 | { \ | |
85 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
86 | BUG_ON(policy_cpu == -1); \ | |
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 | |
1da177e4 | 93 | /* internal prototypes */ |
29464f28 DJ |
94 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
95 | unsigned int event); | |
5a01f2e8 | 96 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 97 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
98 | |
99 | /** | |
32ee8c3e DJ |
100 | * Two notifier lists: the "policy" list is involved in the |
101 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
102 | * "transition" list for kernel code that needs to handle |
103 | * changes to devices when the CPU clock speed changes. | |
104 | * The mutex locks both lists. | |
105 | */ | |
e041c683 | 106 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 107 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 108 | |
74212ca4 | 109 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
110 | static int __init init_cpufreq_transition_notifier_list(void) |
111 | { | |
112 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 113 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
114 | return 0; |
115 | } | |
b3438f82 | 116 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 117 | |
a7b422cd | 118 | static int off __read_mostly; |
da584455 | 119 | static int cpufreq_disabled(void) |
a7b422cd KRW |
120 | { |
121 | return off; | |
122 | } | |
123 | void disable_cpufreq(void) | |
124 | { | |
125 | off = 1; | |
126 | } | |
1da177e4 | 127 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 128 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 129 | |
4d5dcc42 VK |
130 | bool have_governor_per_policy(void) |
131 | { | |
1c3d85dd | 132 | return cpufreq_driver->have_governor_per_policy; |
4d5dcc42 | 133 | } |
3f869d6d | 134 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 135 | |
944e9a03 VK |
136 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
137 | { | |
138 | if (have_governor_per_policy()) | |
139 | return &policy->kobj; | |
140 | else | |
141 | return cpufreq_global_kobject; | |
142 | } | |
143 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
144 | ||
72a4ce34 VK |
145 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
146 | { | |
147 | u64 idle_time; | |
148 | u64 cur_wall_time; | |
149 | u64 busy_time; | |
150 | ||
151 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
152 | ||
153 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
154 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
155 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
156 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
157 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
158 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
159 | ||
160 | idle_time = cur_wall_time - busy_time; | |
161 | if (wall) | |
162 | *wall = cputime_to_usecs(cur_wall_time); | |
163 | ||
164 | return cputime_to_usecs(idle_time); | |
165 | } | |
166 | ||
167 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
168 | { | |
169 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
170 | ||
171 | if (idle_time == -1ULL) | |
172 | return get_cpu_idle_time_jiffy(cpu, wall); | |
173 | else if (!io_busy) | |
174 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
175 | ||
176 | return idle_time; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
179 | ||
a9144436 | 180 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 | 181 | { |
3a3e9e06 | 182 | struct cpufreq_policy *policy; |
1da177e4 LT |
183 | unsigned long flags; |
184 | ||
7a6aedfa | 185 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
186 | goto err_out; |
187 | ||
188 | /* get the cpufreq driver */ | |
1c3d85dd | 189 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 190 | |
1c3d85dd | 191 | if (!cpufreq_driver) |
1da177e4 LT |
192 | goto err_out_unlock; |
193 | ||
1c3d85dd | 194 | if (!try_module_get(cpufreq_driver->owner)) |
1da177e4 LT |
195 | goto err_out_unlock; |
196 | ||
1da177e4 | 197 | /* get the CPU */ |
3a3e9e06 | 198 | policy = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 | 199 | |
3a3e9e06 | 200 | if (!policy) |
1da177e4 LT |
201 | goto err_out_put_module; |
202 | ||
3a3e9e06 | 203 | if (!sysfs && !kobject_get(&policy->kobj)) |
1da177e4 LT |
204 | goto err_out_put_module; |
205 | ||
0d1857a1 | 206 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
3a3e9e06 | 207 | return policy; |
1da177e4 | 208 | |
7d5e350f | 209 | err_out_put_module: |
1c3d85dd | 210 | module_put(cpufreq_driver->owner); |
5800043b | 211 | err_out_unlock: |
1c3d85dd | 212 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 213 | err_out: |
1da177e4 LT |
214 | return NULL; |
215 | } | |
a9144436 SB |
216 | |
217 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
218 | { | |
d5aaffa9 DB |
219 | if (cpufreq_disabled()) |
220 | return NULL; | |
221 | ||
a9144436 SB |
222 | return __cpufreq_cpu_get(cpu, false); |
223 | } | |
1da177e4 LT |
224 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
225 | ||
a9144436 SB |
226 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
227 | { | |
228 | return __cpufreq_cpu_get(cpu, true); | |
229 | } | |
230 | ||
3a3e9e06 | 231 | static void __cpufreq_cpu_put(struct cpufreq_policy *policy, bool sysfs) |
a9144436 SB |
232 | { |
233 | if (!sysfs) | |
3a3e9e06 | 234 | kobject_put(&policy->kobj); |
1c3d85dd | 235 | module_put(cpufreq_driver->owner); |
a9144436 | 236 | } |
7d5e350f | 237 | |
3a3e9e06 | 238 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 239 | { |
d5aaffa9 DB |
240 | if (cpufreq_disabled()) |
241 | return; | |
242 | ||
3a3e9e06 | 243 | __cpufreq_cpu_put(policy, false); |
1da177e4 LT |
244 | } |
245 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
246 | ||
3a3e9e06 | 247 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *policy) |
a9144436 | 248 | { |
3a3e9e06 | 249 | __cpufreq_cpu_put(policy, true); |
a9144436 | 250 | } |
1da177e4 | 251 | |
1da177e4 LT |
252 | /********************************************************************* |
253 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
254 | *********************************************************************/ | |
255 | ||
256 | /** | |
257 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
258 | * | |
259 | * This function alters the system "loops_per_jiffy" for the clock | |
260 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 261 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
262 | * per-CPU loops_per_jiffy value wherever possible. |
263 | */ | |
264 | #ifndef CONFIG_SMP | |
265 | static unsigned long l_p_j_ref; | |
bb176f7d | 266 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 267 | |
858119e1 | 268 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
269 | { |
270 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
271 | return; | |
272 | ||
273 | if (!l_p_j_ref_freq) { | |
274 | l_p_j_ref = loops_per_jiffy; | |
275 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 276 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 277 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 278 | } |
bb176f7d | 279 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 280 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
281 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
282 | ci->new); | |
2d06d8c4 | 283 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 284 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
285 | } |
286 | } | |
287 | #else | |
e08f5f5b GS |
288 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
289 | { | |
290 | return; | |
291 | } | |
1da177e4 LT |
292 | #endif |
293 | ||
0956df9c | 294 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 295 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
296 | { |
297 | BUG_ON(irqs_disabled()); | |
298 | ||
d5aaffa9 DB |
299 | if (cpufreq_disabled()) |
300 | return; | |
301 | ||
1c3d85dd | 302 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 303 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 304 | state, freqs->new); |
1da177e4 | 305 | |
1da177e4 | 306 | switch (state) { |
e4472cb3 | 307 | |
1da177e4 | 308 | case CPUFREQ_PRECHANGE: |
266c13d7 VK |
309 | if (WARN(policy->transition_ongoing == |
310 | cpumask_weight(policy->cpus), | |
7c30ed53 VK |
311 | "In middle of another frequency transition\n")) |
312 | return; | |
313 | ||
266c13d7 | 314 | policy->transition_ongoing++; |
7c30ed53 | 315 | |
32ee8c3e | 316 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
317 | * which is not equal to what the cpufreq core thinks is |
318 | * "old frequency". | |
1da177e4 | 319 | */ |
1c3d85dd | 320 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
321 | if ((policy) && (policy->cpu == freqs->cpu) && |
322 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 323 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
324 | " %u, cpufreq assumed %u kHz.\n", |
325 | freqs->old, policy->cur); | |
326 | freqs->old = policy->cur; | |
1da177e4 LT |
327 | } |
328 | } | |
b4dfdbb3 | 329 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 330 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
331 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
332 | break; | |
e4472cb3 | 333 | |
1da177e4 | 334 | case CPUFREQ_POSTCHANGE: |
7c30ed53 VK |
335 | if (WARN(!policy->transition_ongoing, |
336 | "No frequency transition in progress\n")) | |
337 | return; | |
338 | ||
266c13d7 | 339 | policy->transition_ongoing--; |
7c30ed53 | 340 | |
1da177e4 | 341 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); |
2d06d8c4 | 342 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 343 | (unsigned long)freqs->cpu); |
25e41933 | 344 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 345 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 346 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
347 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
348 | policy->cur = freqs->new; | |
1da177e4 LT |
349 | break; |
350 | } | |
1da177e4 | 351 | } |
bb176f7d | 352 | |
b43a7ffb VK |
353 | /** |
354 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
355 | * on frequency transition. | |
356 | * | |
357 | * This function calls the transition notifiers and the "adjust_jiffies" | |
358 | * function. It is called twice on all CPU frequency changes that have | |
359 | * external effects. | |
360 | */ | |
361 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
362 | struct cpufreq_freqs *freqs, unsigned int state) | |
363 | { | |
364 | for_each_cpu(freqs->cpu, policy->cpus) | |
365 | __cpufreq_notify_transition(policy, freqs, state); | |
366 | } | |
1da177e4 LT |
367 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
368 | ||
369 | ||
1da177e4 LT |
370 | /********************************************************************* |
371 | * SYSFS INTERFACE * | |
372 | *********************************************************************/ | |
373 | ||
3bcb09a3 JF |
374 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
375 | { | |
376 | struct cpufreq_governor *t; | |
377 | ||
378 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 379 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
380 | return t; |
381 | ||
382 | return NULL; | |
383 | } | |
384 | ||
1da177e4 LT |
385 | /** |
386 | * cpufreq_parse_governor - parse a governor string | |
387 | */ | |
905d77cd | 388 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
389 | struct cpufreq_governor **governor) |
390 | { | |
3bcb09a3 | 391 | int err = -EINVAL; |
1c3d85dd RW |
392 | |
393 | if (!cpufreq_driver) | |
3bcb09a3 JF |
394 | goto out; |
395 | ||
1c3d85dd | 396 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
397 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
398 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 399 | err = 0; |
e08f5f5b GS |
400 | } else if (!strnicmp(str_governor, "powersave", |
401 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 402 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 403 | err = 0; |
1da177e4 | 404 | } |
1c3d85dd | 405 | } else if (cpufreq_driver->target) { |
1da177e4 | 406 | struct cpufreq_governor *t; |
3bcb09a3 | 407 | |
3fc54d37 | 408 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
409 | |
410 | t = __find_governor(str_governor); | |
411 | ||
ea714970 | 412 | if (t == NULL) { |
1a8e1463 | 413 | int ret; |
ea714970 | 414 | |
1a8e1463 KC |
415 | mutex_unlock(&cpufreq_governor_mutex); |
416 | ret = request_module("cpufreq_%s", str_governor); | |
417 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 418 | |
1a8e1463 KC |
419 | if (ret == 0) |
420 | t = __find_governor(str_governor); | |
ea714970 JF |
421 | } |
422 | ||
3bcb09a3 JF |
423 | if (t != NULL) { |
424 | *governor = t; | |
425 | err = 0; | |
1da177e4 | 426 | } |
3bcb09a3 | 427 | |
3fc54d37 | 428 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 429 | } |
29464f28 | 430 | out: |
3bcb09a3 | 431 | return err; |
1da177e4 | 432 | } |
1da177e4 | 433 | |
1da177e4 | 434 | /** |
e08f5f5b GS |
435 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
436 | * print out cpufreq information | |
1da177e4 LT |
437 | * |
438 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
439 | * "unsigned int". | |
440 | */ | |
441 | ||
32ee8c3e DJ |
442 | #define show_one(file_name, object) \ |
443 | static ssize_t show_##file_name \ | |
905d77cd | 444 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 445 | { \ |
29464f28 | 446 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
447 | } |
448 | ||
449 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
450 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 451 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
452 | show_one(scaling_min_freq, min); |
453 | show_one(scaling_max_freq, max); | |
454 | show_one(scaling_cur_freq, cur); | |
455 | ||
3a3e9e06 VK |
456 | static int __cpufreq_set_policy(struct cpufreq_policy *policy, |
457 | struct cpufreq_policy *new_policy); | |
7970e08b | 458 | |
1da177e4 LT |
459 | /** |
460 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
461 | */ | |
462 | #define store_one(file_name, object) \ | |
463 | static ssize_t store_##file_name \ | |
905d77cd | 464 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 465 | { \ |
f55c9c26 | 466 | unsigned int ret; \ |
1da177e4 LT |
467 | struct cpufreq_policy new_policy; \ |
468 | \ | |
469 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
470 | if (ret) \ | |
471 | return -EINVAL; \ | |
472 | \ | |
29464f28 | 473 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
474 | if (ret != 1) \ |
475 | return -EINVAL; \ | |
476 | \ | |
7970e08b TR |
477 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
478 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
479 | \ |
480 | return ret ? ret : count; \ | |
481 | } | |
482 | ||
29464f28 DJ |
483 | store_one(scaling_min_freq, min); |
484 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
485 | |
486 | /** | |
487 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
488 | */ | |
905d77cd DJ |
489 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
490 | char *buf) | |
1da177e4 | 491 | { |
5a01f2e8 | 492 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
493 | if (!cur_freq) |
494 | return sprintf(buf, "<unknown>"); | |
495 | return sprintf(buf, "%u\n", cur_freq); | |
496 | } | |
497 | ||
1da177e4 LT |
498 | /** |
499 | * show_scaling_governor - show the current policy for the specified CPU | |
500 | */ | |
905d77cd | 501 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 502 | { |
29464f28 | 503 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
504 | return sprintf(buf, "powersave\n"); |
505 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
506 | return sprintf(buf, "performance\n"); | |
507 | else if (policy->governor) | |
4b972f0b | 508 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 509 | policy->governor->name); |
1da177e4 LT |
510 | return -EINVAL; |
511 | } | |
512 | ||
1da177e4 LT |
513 | /** |
514 | * store_scaling_governor - store policy for the specified CPU | |
515 | */ | |
905d77cd DJ |
516 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
517 | const char *buf, size_t count) | |
1da177e4 | 518 | { |
f55c9c26 | 519 | unsigned int ret; |
1da177e4 LT |
520 | char str_governor[16]; |
521 | struct cpufreq_policy new_policy; | |
522 | ||
523 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
524 | if (ret) | |
525 | return ret; | |
526 | ||
29464f28 | 527 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
528 | if (ret != 1) |
529 | return -EINVAL; | |
530 | ||
e08f5f5b GS |
531 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
532 | &new_policy.governor)) | |
1da177e4 LT |
533 | return -EINVAL; |
534 | ||
bb176f7d VK |
535 | /* |
536 | * Do not use cpufreq_set_policy here or the user_policy.max | |
537 | * will be wrongly overridden | |
538 | */ | |
7970e08b TR |
539 | ret = __cpufreq_set_policy(policy, &new_policy); |
540 | ||
541 | policy->user_policy.policy = policy->policy; | |
542 | policy->user_policy.governor = policy->governor; | |
7970e08b | 543 | |
e08f5f5b GS |
544 | if (ret) |
545 | return ret; | |
546 | else | |
547 | return count; | |
1da177e4 LT |
548 | } |
549 | ||
550 | /** | |
551 | * show_scaling_driver - show the cpufreq driver currently loaded | |
552 | */ | |
905d77cd | 553 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 554 | { |
1c3d85dd | 555 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
556 | } |
557 | ||
558 | /** | |
559 | * show_scaling_available_governors - show the available CPUfreq governors | |
560 | */ | |
905d77cd DJ |
561 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
562 | char *buf) | |
1da177e4 LT |
563 | { |
564 | ssize_t i = 0; | |
565 | struct cpufreq_governor *t; | |
566 | ||
1c3d85dd | 567 | if (!cpufreq_driver->target) { |
1da177e4 LT |
568 | i += sprintf(buf, "performance powersave"); |
569 | goto out; | |
570 | } | |
571 | ||
572 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
573 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
574 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 575 | goto out; |
4b972f0b | 576 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 577 | } |
7d5e350f | 578 | out: |
1da177e4 LT |
579 | i += sprintf(&buf[i], "\n"); |
580 | return i; | |
581 | } | |
e8628dd0 | 582 | |
f4fd3797 | 583 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
584 | { |
585 | ssize_t i = 0; | |
586 | unsigned int cpu; | |
587 | ||
835481d9 | 588 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
589 | if (i) |
590 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
591 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
592 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 593 | break; |
1da177e4 LT |
594 | } |
595 | i += sprintf(&buf[i], "\n"); | |
596 | return i; | |
597 | } | |
f4fd3797 | 598 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 599 | |
e8628dd0 DW |
600 | /** |
601 | * show_related_cpus - show the CPUs affected by each transition even if | |
602 | * hw coordination is in use | |
603 | */ | |
604 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
605 | { | |
f4fd3797 | 606 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
607 | } |
608 | ||
609 | /** | |
610 | * show_affected_cpus - show the CPUs affected by each transition | |
611 | */ | |
612 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
613 | { | |
f4fd3797 | 614 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
615 | } |
616 | ||
9e76988e | 617 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 618 | const char *buf, size_t count) |
9e76988e VP |
619 | { |
620 | unsigned int freq = 0; | |
621 | unsigned int ret; | |
622 | ||
879000f9 | 623 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
624 | return -EINVAL; |
625 | ||
626 | ret = sscanf(buf, "%u", &freq); | |
627 | if (ret != 1) | |
628 | return -EINVAL; | |
629 | ||
630 | policy->governor->store_setspeed(policy, freq); | |
631 | ||
632 | return count; | |
633 | } | |
634 | ||
635 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
636 | { | |
879000f9 | 637 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
638 | return sprintf(buf, "<unsupported>\n"); |
639 | ||
640 | return policy->governor->show_setspeed(policy, buf); | |
641 | } | |
1da177e4 | 642 | |
e2f74f35 | 643 | /** |
8bf1ac72 | 644 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
645 | */ |
646 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
647 | { | |
648 | unsigned int limit; | |
649 | int ret; | |
1c3d85dd RW |
650 | if (cpufreq_driver->bios_limit) { |
651 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
652 | if (!ret) |
653 | return sprintf(buf, "%u\n", limit); | |
654 | } | |
655 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
656 | } | |
657 | ||
6dad2a29 BP |
658 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
659 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
660 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
661 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
662 | cpufreq_freq_attr_ro(scaling_available_governors); | |
663 | cpufreq_freq_attr_ro(scaling_driver); | |
664 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
665 | cpufreq_freq_attr_ro(bios_limit); | |
666 | cpufreq_freq_attr_ro(related_cpus); | |
667 | cpufreq_freq_attr_ro(affected_cpus); | |
668 | cpufreq_freq_attr_rw(scaling_min_freq); | |
669 | cpufreq_freq_attr_rw(scaling_max_freq); | |
670 | cpufreq_freq_attr_rw(scaling_governor); | |
671 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 672 | |
905d77cd | 673 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
674 | &cpuinfo_min_freq.attr, |
675 | &cpuinfo_max_freq.attr, | |
ed129784 | 676 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
677 | &scaling_min_freq.attr, |
678 | &scaling_max_freq.attr, | |
679 | &affected_cpus.attr, | |
e8628dd0 | 680 | &related_cpus.attr, |
1da177e4 LT |
681 | &scaling_governor.attr, |
682 | &scaling_driver.attr, | |
683 | &scaling_available_governors.attr, | |
9e76988e | 684 | &scaling_setspeed.attr, |
1da177e4 LT |
685 | NULL |
686 | }; | |
687 | ||
29464f28 DJ |
688 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
689 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 690 | |
29464f28 | 691 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 692 | { |
905d77cd DJ |
693 | struct cpufreq_policy *policy = to_policy(kobj); |
694 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 695 | ssize_t ret = -EINVAL; |
a9144436 | 696 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 697 | if (!policy) |
0db4a8a9 | 698 | goto no_policy; |
5a01f2e8 VP |
699 | |
700 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 701 | goto fail; |
5a01f2e8 | 702 | |
e08f5f5b GS |
703 | if (fattr->show) |
704 | ret = fattr->show(policy, buf); | |
705 | else | |
706 | ret = -EIO; | |
707 | ||
5a01f2e8 | 708 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 709 | fail: |
a9144436 | 710 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 711 | no_policy: |
1da177e4 LT |
712 | return ret; |
713 | } | |
714 | ||
905d77cd DJ |
715 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
716 | const char *buf, size_t count) | |
1da177e4 | 717 | { |
905d77cd DJ |
718 | struct cpufreq_policy *policy = to_policy(kobj); |
719 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 720 | ssize_t ret = -EINVAL; |
a9144436 | 721 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 722 | if (!policy) |
a07530b4 | 723 | goto no_policy; |
5a01f2e8 VP |
724 | |
725 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 726 | goto fail; |
5a01f2e8 | 727 | |
e08f5f5b GS |
728 | if (fattr->store) |
729 | ret = fattr->store(policy, buf, count); | |
730 | else | |
731 | ret = -EIO; | |
732 | ||
5a01f2e8 | 733 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 734 | fail: |
a9144436 | 735 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 736 | no_policy: |
1da177e4 LT |
737 | return ret; |
738 | } | |
739 | ||
905d77cd | 740 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 741 | { |
905d77cd | 742 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 743 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
744 | complete(&policy->kobj_unregister); |
745 | } | |
746 | ||
52cf25d0 | 747 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
748 | .show = show, |
749 | .store = store, | |
750 | }; | |
751 | ||
752 | static struct kobj_type ktype_cpufreq = { | |
753 | .sysfs_ops = &sysfs_ops, | |
754 | .default_attrs = default_attrs, | |
755 | .release = cpufreq_sysfs_release, | |
756 | }; | |
757 | ||
2361be23 VK |
758 | struct kobject *cpufreq_global_kobject; |
759 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
760 | ||
761 | static int cpufreq_global_kobject_usage; | |
762 | ||
763 | int cpufreq_get_global_kobject(void) | |
764 | { | |
765 | if (!cpufreq_global_kobject_usage++) | |
766 | return kobject_add(cpufreq_global_kobject, | |
767 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
768 | ||
769 | return 0; | |
770 | } | |
771 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
772 | ||
773 | void cpufreq_put_global_kobject(void) | |
774 | { | |
775 | if (!--cpufreq_global_kobject_usage) | |
776 | kobject_del(cpufreq_global_kobject); | |
777 | } | |
778 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
779 | ||
780 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
781 | { | |
782 | int ret = cpufreq_get_global_kobject(); | |
783 | ||
784 | if (!ret) { | |
785 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
786 | if (ret) | |
787 | cpufreq_put_global_kobject(); | |
788 | } | |
789 | ||
790 | return ret; | |
791 | } | |
792 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
793 | ||
794 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
795 | { | |
796 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
797 | cpufreq_put_global_kobject(); | |
798 | } | |
799 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
800 | ||
19d6f7ec | 801 | /* symlink affected CPUs */ |
308b60e7 | 802 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
803 | { |
804 | unsigned int j; | |
805 | int ret = 0; | |
806 | ||
807 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 808 | struct device *cpu_dev; |
19d6f7ec | 809 | |
308b60e7 | 810 | if (j == policy->cpu) |
19d6f7ec | 811 | continue; |
19d6f7ec | 812 | |
e8fdde10 | 813 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
814 | cpu_dev = get_cpu_device(j); |
815 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 816 | "cpufreq"); |
71c3461e RW |
817 | if (ret) |
818 | break; | |
19d6f7ec DJ |
819 | } |
820 | return ret; | |
821 | } | |
822 | ||
308b60e7 | 823 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 824 | struct device *dev) |
909a694e DJ |
825 | { |
826 | struct freq_attr **drv_attr; | |
909a694e | 827 | int ret = 0; |
909a694e DJ |
828 | |
829 | /* prepare interface data */ | |
830 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 831 | &dev->kobj, "cpufreq"); |
909a694e DJ |
832 | if (ret) |
833 | return ret; | |
834 | ||
835 | /* set up files for this cpu device */ | |
1c3d85dd | 836 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
837 | while ((drv_attr) && (*drv_attr)) { |
838 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
839 | if (ret) | |
1c3d85dd | 840 | goto err_out_kobj_put; |
909a694e DJ |
841 | drv_attr++; |
842 | } | |
1c3d85dd | 843 | if (cpufreq_driver->get) { |
909a694e DJ |
844 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
845 | if (ret) | |
1c3d85dd | 846 | goto err_out_kobj_put; |
909a694e | 847 | } |
1c3d85dd | 848 | if (cpufreq_driver->target) { |
909a694e DJ |
849 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
850 | if (ret) | |
1c3d85dd | 851 | goto err_out_kobj_put; |
909a694e | 852 | } |
1c3d85dd | 853 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
854 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
855 | if (ret) | |
1c3d85dd | 856 | goto err_out_kobj_put; |
e2f74f35 | 857 | } |
909a694e | 858 | |
308b60e7 | 859 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
860 | if (ret) |
861 | goto err_out_kobj_put; | |
862 | ||
e18f1682 SB |
863 | return ret; |
864 | ||
865 | err_out_kobj_put: | |
866 | kobject_put(&policy->kobj); | |
867 | wait_for_completion(&policy->kobj_unregister); | |
868 | return ret; | |
869 | } | |
870 | ||
871 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
872 | { | |
873 | struct cpufreq_policy new_policy; | |
874 | int ret = 0; | |
875 | ||
ecf7e461 DJ |
876 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
877 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
878 | policy->governor = NULL; | |
879 | ||
880 | /* set default policy */ | |
881 | ret = __cpufreq_set_policy(policy, &new_policy); | |
882 | policy->user_policy.policy = policy->policy; | |
883 | policy->user_policy.governor = policy->governor; | |
884 | ||
885 | if (ret) { | |
2d06d8c4 | 886 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
887 | if (cpufreq_driver->exit) |
888 | cpufreq_driver->exit(policy); | |
ecf7e461 | 889 | } |
909a694e DJ |
890 | } |
891 | ||
fcf80582 | 892 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 VK |
893 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
894 | unsigned int cpu, struct device *dev, | |
895 | bool frozen) | |
fcf80582 | 896 | { |
1c3d85dd | 897 | int ret = 0, has_target = !!cpufreq_driver->target; |
fcf80582 VK |
898 | unsigned long flags; |
899 | ||
820c6ca2 VK |
900 | if (has_target) |
901 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
fcf80582 | 902 | |
d8d3b471 | 903 | lock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 904 | |
0d1857a1 | 905 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 906 | |
fcf80582 | 907 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 908 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
fcf80582 | 909 | per_cpu(cpufreq_cpu_data, cpu) = policy; |
0d1857a1 | 910 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 911 | |
d8d3b471 | 912 | unlock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 913 | |
820c6ca2 VK |
914 | if (has_target) { |
915 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
916 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
917 | } | |
fcf80582 | 918 | |
a82fab29 | 919 | /* Don't touch sysfs links during light-weight init */ |
71c3461e RW |
920 | if (!frozen) |
921 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); | |
a82fab29 SB |
922 | |
923 | return ret; | |
fcf80582 VK |
924 | } |
925 | #endif | |
1da177e4 | 926 | |
8414809c SB |
927 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
928 | { | |
929 | struct cpufreq_policy *policy; | |
930 | unsigned long flags; | |
931 | ||
932 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
933 | ||
934 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
935 | ||
936 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
937 | ||
938 | return policy; | |
939 | } | |
940 | ||
e9698cc5 SB |
941 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
942 | { | |
943 | struct cpufreq_policy *policy; | |
944 | ||
945 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
946 | if (!policy) | |
947 | return NULL; | |
948 | ||
949 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
950 | goto err_free_policy; | |
951 | ||
952 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
953 | goto err_free_cpumask; | |
954 | ||
955 | return policy; | |
956 | ||
957 | err_free_cpumask: | |
958 | free_cpumask_var(policy->cpus); | |
959 | err_free_policy: | |
960 | kfree(policy); | |
961 | ||
962 | return NULL; | |
963 | } | |
964 | ||
965 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
966 | { | |
967 | free_cpumask_var(policy->related_cpus); | |
968 | free_cpumask_var(policy->cpus); | |
969 | kfree(policy); | |
970 | } | |
971 | ||
a82fab29 SB |
972 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, |
973 | bool frozen) | |
1da177e4 | 974 | { |
fcf80582 | 975 | unsigned int j, cpu = dev->id; |
65922465 | 976 | int ret = -ENOMEM; |
1da177e4 | 977 | struct cpufreq_policy *policy; |
1da177e4 | 978 | unsigned long flags; |
90e41bac | 979 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 980 | struct cpufreq_governor *gov; |
90e41bac PB |
981 | int sibling; |
982 | #endif | |
1da177e4 | 983 | |
c32b6b8e AR |
984 | if (cpu_is_offline(cpu)) |
985 | return 0; | |
986 | ||
2d06d8c4 | 987 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
988 | |
989 | #ifdef CONFIG_SMP | |
990 | /* check whether a different CPU already registered this | |
991 | * CPU because it is in the same boat. */ | |
992 | policy = cpufreq_cpu_get(cpu); | |
993 | if (unlikely(policy)) { | |
8ff69732 | 994 | cpufreq_cpu_put(policy); |
1da177e4 LT |
995 | return 0; |
996 | } | |
fcf80582 VK |
997 | |
998 | #ifdef CONFIG_HOTPLUG_CPU | |
999 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1000 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
1001 | for_each_online_cpu(sibling) { |
1002 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d | 1003 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
0d1857a1 | 1004 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
d8d3b471 | 1005 | return cpufreq_add_policy_cpu(cp, cpu, dev, frozen); |
2eaa3e2d | 1006 | } |
fcf80582 | 1007 | } |
0d1857a1 | 1008 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 1009 | #endif |
1da177e4 LT |
1010 | #endif |
1011 | ||
1c3d85dd | 1012 | if (!try_module_get(cpufreq_driver->owner)) { |
1da177e4 LT |
1013 | ret = -EINVAL; |
1014 | goto module_out; | |
1015 | } | |
1016 | ||
8414809c SB |
1017 | if (frozen) |
1018 | /* Restore the saved policy when doing light-weight init */ | |
1019 | policy = cpufreq_policy_restore(cpu); | |
1020 | else | |
1021 | policy = cpufreq_policy_alloc(); | |
1022 | ||
059019a3 | 1023 | if (!policy) |
1da177e4 | 1024 | goto nomem_out; |
059019a3 | 1025 | |
1da177e4 | 1026 | policy->cpu = cpu; |
65922465 | 1027 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1028 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1029 | |
5a01f2e8 | 1030 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 1031 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 1032 | |
1da177e4 | 1033 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1034 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1035 | |
1036 | /* call driver. From then on the cpufreq must be able | |
1037 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1038 | */ | |
1c3d85dd | 1039 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1040 | if (ret) { |
2d06d8c4 | 1041 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1042 | goto err_set_policy_cpu; |
1da177e4 | 1043 | } |
643ae6e8 | 1044 | |
fcf80582 VK |
1045 | /* related cpus should atleast have policy->cpus */ |
1046 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1047 | ||
643ae6e8 VK |
1048 | /* |
1049 | * affected cpus must always be the one, which are online. We aren't | |
1050 | * managing offline cpus here. | |
1051 | */ | |
1052 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1053 | ||
187d9f4e MC |
1054 | policy->user_policy.min = policy->min; |
1055 | policy->user_policy.max = policy->max; | |
1da177e4 | 1056 | |
a1531acd TR |
1057 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1058 | CPUFREQ_START, policy); | |
1059 | ||
fcf80582 VK |
1060 | #ifdef CONFIG_HOTPLUG_CPU |
1061 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1062 | if (gov) { | |
1063 | policy->governor = gov; | |
1064 | pr_debug("Restoring governor %s for cpu %d\n", | |
1065 | policy->governor->name, cpu); | |
4bfa042c | 1066 | } |
fcf80582 | 1067 | #endif |
1da177e4 | 1068 | |
e18f1682 SB |
1069 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1070 | for_each_cpu(j, policy->cpus) { | |
1071 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1072 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; | |
1073 | } | |
1074 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1075 | ||
a82fab29 | 1076 | if (!frozen) { |
308b60e7 | 1077 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1078 | if (ret) |
1079 | goto err_out_unregister; | |
1080 | } | |
8ff69732 | 1081 | |
e18f1682 SB |
1082 | cpufreq_init_policy(policy); |
1083 | ||
038c5b3e | 1084 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1c3d85dd | 1085 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 1086 | pr_debug("initialization complete\n"); |
87c32271 | 1087 | |
1da177e4 LT |
1088 | return 0; |
1089 | ||
1da177e4 | 1090 | err_out_unregister: |
0d1857a1 | 1091 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
e18f1682 | 1092 | for_each_cpu(j, policy->cpus) { |
7a6aedfa | 1093 | per_cpu(cpufreq_cpu_data, j) = NULL; |
e18f1682 SB |
1094 | if (j != cpu) |
1095 | per_cpu(cpufreq_policy_cpu, j) = -1; | |
1096 | } | |
0d1857a1 | 1097 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1098 | |
2eaa3e2d VK |
1099 | err_set_policy_cpu: |
1100 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
e9698cc5 | 1101 | cpufreq_policy_free(policy); |
1da177e4 | 1102 | nomem_out: |
1c3d85dd | 1103 | module_put(cpufreq_driver->owner); |
c32b6b8e | 1104 | module_out: |
1da177e4 LT |
1105 | return ret; |
1106 | } | |
1107 | ||
a82fab29 SB |
1108 | /** |
1109 | * cpufreq_add_dev - add a CPU device | |
1110 | * | |
1111 | * Adds the cpufreq interface for a CPU device. | |
1112 | * | |
1113 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1114 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1115 | * mess up, but more thorough testing is needed. - Mathieu | |
1116 | */ | |
1117 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1118 | { | |
1119 | return __cpufreq_add_dev(dev, sif, false); | |
1120 | } | |
1121 | ||
b8eed8af VK |
1122 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1123 | { | |
1124 | int j; | |
1125 | ||
1126 | policy->last_cpu = policy->cpu; | |
1127 | policy->cpu = cpu; | |
1128 | ||
3361b7b1 | 1129 | for_each_cpu(j, policy->cpus) |
b8eed8af | 1130 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
1131 | |
1132 | #ifdef CONFIG_CPU_FREQ_TABLE | |
1133 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1134 | #endif | |
1135 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1136 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1137 | } | |
1da177e4 | 1138 | |
3a3e9e06 | 1139 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
a82fab29 | 1140 | unsigned int old_cpu, bool frozen) |
f9ba680d SB |
1141 | { |
1142 | struct device *cpu_dev; | |
1143 | unsigned long flags; | |
1144 | int ret; | |
1145 | ||
1146 | /* first sibling now owns the new sysfs dir */ | |
3a3e9e06 | 1147 | cpu_dev = get_cpu_device(cpumask_first(policy->cpus)); |
a82fab29 SB |
1148 | |
1149 | /* Don't touch sysfs files during light-weight tear-down */ | |
1150 | if (frozen) | |
1151 | return cpu_dev->id; | |
1152 | ||
f9ba680d | 1153 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1154 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d SB |
1155 | if (ret) { |
1156 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1157 | ||
1158 | WARN_ON(lock_policy_rwsem_write(old_cpu)); | |
3a3e9e06 | 1159 | cpumask_set_cpu(old_cpu, policy->cpus); |
f9ba680d SB |
1160 | |
1161 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
3a3e9e06 | 1162 | per_cpu(cpufreq_cpu_data, old_cpu) = policy; |
f9ba680d SB |
1163 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1164 | ||
1165 | unlock_policy_rwsem_write(old_cpu); | |
1166 | ||
3a3e9e06 | 1167 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1168 | "cpufreq"); |
1169 | ||
1170 | return -EINVAL; | |
1171 | } | |
1172 | ||
1173 | return cpu_dev->id; | |
1174 | } | |
1175 | ||
1da177e4 | 1176 | /** |
5a01f2e8 | 1177 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1178 | * |
1179 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1180 | * Caller should already have policy_rwsem in write mode for this CPU. |
1181 | * This routine frees the rwsem before returning. | |
1da177e4 | 1182 | */ |
bb176f7d | 1183 | static int __cpufreq_remove_dev(struct device *dev, |
a82fab29 | 1184 | struct subsys_interface *sif, bool frozen) |
1da177e4 | 1185 | { |
f9ba680d SB |
1186 | unsigned int cpu = dev->id, cpus; |
1187 | int new_cpu; | |
1da177e4 | 1188 | unsigned long flags; |
3a3e9e06 | 1189 | struct cpufreq_policy *policy; |
499bca9b AW |
1190 | struct kobject *kobj; |
1191 | struct completion *cmp; | |
1da177e4 | 1192 | |
b8eed8af | 1193 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1194 | |
0d1857a1 | 1195 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1196 | |
3a3e9e06 | 1197 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1198 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1199 | ||
8414809c SB |
1200 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1201 | if (frozen) | |
3a3e9e06 | 1202 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1203 | |
0d1857a1 | 1204 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1205 | |
3a3e9e06 | 1206 | if (!policy) { |
b8eed8af | 1207 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1208 | return -EINVAL; |
1209 | } | |
1da177e4 | 1210 | |
1c3d85dd | 1211 | if (cpufreq_driver->target) |
3a3e9e06 | 1212 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1da177e4 | 1213 | |
084f3493 | 1214 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1215 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1216 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1217 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 LT |
1218 | #endif |
1219 | ||
2eaa3e2d | 1220 | WARN_ON(lock_policy_rwsem_write(cpu)); |
3a3e9e06 | 1221 | cpus = cpumask_weight(policy->cpus); |
e4969eba VK |
1222 | |
1223 | if (cpus > 1) | |
3a3e9e06 | 1224 | cpumask_clear_cpu(cpu, policy->cpus); |
2eaa3e2d | 1225 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1226 | |
3a3e9e06 | 1227 | if (cpu != policy->cpu && !frozen) { |
73bf0fc2 VK |
1228 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
1229 | } else if (cpus > 1) { | |
084f3493 | 1230 | |
3a3e9e06 | 1231 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen); |
f9ba680d | 1232 | if (new_cpu >= 0) { |
2eaa3e2d | 1233 | WARN_ON(lock_policy_rwsem_write(cpu)); |
3a3e9e06 | 1234 | update_policy_cpu(policy, new_cpu); |
499bca9b | 1235 | unlock_policy_rwsem_write(cpu); |
a82fab29 SB |
1236 | |
1237 | if (!frozen) { | |
1238 | pr_debug("%s: policy Kobject moved to cpu: %d " | |
1239 | "from: %d\n",__func__, new_cpu, cpu); | |
1240 | } | |
1da177e4 LT |
1241 | } |
1242 | } | |
1da177e4 | 1243 | |
b8eed8af VK |
1244 | /* If cpu is last user of policy, free policy */ |
1245 | if (cpus == 1) { | |
2a998599 | 1246 | if (cpufreq_driver->target) |
3a3e9e06 | 1247 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); |
2a998599 | 1248 | |
8414809c SB |
1249 | if (!frozen) { |
1250 | lock_policy_rwsem_read(cpu); | |
3a3e9e06 VK |
1251 | kobj = &policy->kobj; |
1252 | cmp = &policy->kobj_unregister; | |
8414809c SB |
1253 | unlock_policy_rwsem_read(cpu); |
1254 | kobject_put(kobj); | |
1255 | ||
1256 | /* | |
1257 | * We need to make sure that the underlying kobj is | |
1258 | * actually not referenced anymore by anybody before we | |
1259 | * proceed with unloading. | |
1260 | */ | |
1261 | pr_debug("waiting for dropping of refcount\n"); | |
1262 | wait_for_completion(cmp); | |
1263 | pr_debug("wait complete\n"); | |
1264 | } | |
7d26e2d5 | 1265 | |
8414809c SB |
1266 | /* |
1267 | * Perform the ->exit() even during light-weight tear-down, | |
1268 | * since this is a core component, and is essential for the | |
1269 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1270 | */ |
1c3d85dd | 1271 | if (cpufreq_driver->exit) |
3a3e9e06 | 1272 | cpufreq_driver->exit(policy); |
27ecddc2 | 1273 | |
8414809c | 1274 | if (!frozen) |
3a3e9e06 | 1275 | cpufreq_policy_free(policy); |
2a998599 | 1276 | } else { |
2a998599 | 1277 | if (cpufreq_driver->target) { |
3a3e9e06 VK |
1278 | __cpufreq_governor(policy, CPUFREQ_GOV_START); |
1279 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
2a998599 | 1280 | } |
27ecddc2 | 1281 | } |
1da177e4 | 1282 | |
2eaa3e2d | 1283 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
1da177e4 LT |
1284 | return 0; |
1285 | } | |
1286 | ||
8a25a2fd | 1287 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1288 | { |
8a25a2fd | 1289 | unsigned int cpu = dev->id; |
5a01f2e8 | 1290 | int retval; |
ec28297a VP |
1291 | |
1292 | if (cpu_is_offline(cpu)) | |
1293 | return 0; | |
1294 | ||
a82fab29 | 1295 | retval = __cpufreq_remove_dev(dev, sif, false); |
5a01f2e8 VP |
1296 | return retval; |
1297 | } | |
1298 | ||
65f27f38 | 1299 | static void handle_update(struct work_struct *work) |
1da177e4 | 1300 | { |
65f27f38 DH |
1301 | struct cpufreq_policy *policy = |
1302 | container_of(work, struct cpufreq_policy, update); | |
1303 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1304 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1305 | cpufreq_update_policy(cpu); |
1306 | } | |
1307 | ||
1308 | /** | |
bb176f7d VK |
1309 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1310 | * in deep trouble. | |
1da177e4 LT |
1311 | * @cpu: cpu number |
1312 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1313 | * @new_freq: CPU frequency the CPU actually runs at | |
1314 | * | |
29464f28 DJ |
1315 | * We adjust to current frequency first, and need to clean up later. |
1316 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1317 | */ |
e08f5f5b GS |
1318 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1319 | unsigned int new_freq) | |
1da177e4 | 1320 | { |
b43a7ffb | 1321 | struct cpufreq_policy *policy; |
1da177e4 | 1322 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1323 | unsigned long flags; |
1324 | ||
2d06d8c4 | 1325 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1326 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1327 | ||
1da177e4 LT |
1328 | freqs.old = old_freq; |
1329 | freqs.new = new_freq; | |
b43a7ffb VK |
1330 | |
1331 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1332 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1333 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1334 | ||
1335 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1336 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1337 | } |
1338 | ||
32ee8c3e | 1339 | /** |
4ab70df4 | 1340 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1341 | * @cpu: CPU number |
1342 | * | |
1343 | * This is the last known freq, without actually getting it from the driver. | |
1344 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1345 | */ | |
1346 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1347 | { | |
9e21ba8b | 1348 | struct cpufreq_policy *policy; |
e08f5f5b | 1349 | unsigned int ret_freq = 0; |
95235ca2 | 1350 | |
1c3d85dd RW |
1351 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1352 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1353 | |
1354 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1355 | if (policy) { |
e08f5f5b | 1356 | ret_freq = policy->cur; |
95235ca2 VP |
1357 | cpufreq_cpu_put(policy); |
1358 | } | |
1359 | ||
4d34a67d | 1360 | return ret_freq; |
95235ca2 VP |
1361 | } |
1362 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1363 | ||
3d737108 JB |
1364 | /** |
1365 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1366 | * @cpu: CPU number | |
1367 | * | |
1368 | * Just return the max possible frequency for a given CPU. | |
1369 | */ | |
1370 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1371 | { | |
1372 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1373 | unsigned int ret_freq = 0; | |
1374 | ||
1375 | if (policy) { | |
1376 | ret_freq = policy->max; | |
1377 | cpufreq_cpu_put(policy); | |
1378 | } | |
1379 | ||
1380 | return ret_freq; | |
1381 | } | |
1382 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1383 | ||
5a01f2e8 | 1384 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1385 | { |
7a6aedfa | 1386 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1387 | unsigned int ret_freq = 0; |
5800043b | 1388 | |
1c3d85dd | 1389 | if (!cpufreq_driver->get) |
4d34a67d | 1390 | return ret_freq; |
1da177e4 | 1391 | |
1c3d85dd | 1392 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1393 | |
e08f5f5b | 1394 | if (ret_freq && policy->cur && |
1c3d85dd | 1395 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1396 | /* verify no discrepancy between actual and |
1397 | saved value exists */ | |
1398 | if (unlikely(ret_freq != policy->cur)) { | |
1399 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1400 | schedule_work(&policy->update); |
1401 | } | |
1402 | } | |
1403 | ||
4d34a67d | 1404 | return ret_freq; |
5a01f2e8 | 1405 | } |
1da177e4 | 1406 | |
5a01f2e8 VP |
1407 | /** |
1408 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1409 | * @cpu: CPU number | |
1410 | * | |
1411 | * Get the CPU current (static) CPU frequency | |
1412 | */ | |
1413 | unsigned int cpufreq_get(unsigned int cpu) | |
1414 | { | |
1415 | unsigned int ret_freq = 0; | |
1416 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1417 | ||
1418 | if (!policy) | |
1419 | goto out; | |
1420 | ||
1421 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1422 | goto out_policy; | |
1423 | ||
1424 | ret_freq = __cpufreq_get(cpu); | |
1425 | ||
1426 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1427 | |
5a01f2e8 VP |
1428 | out_policy: |
1429 | cpufreq_cpu_put(policy); | |
1430 | out: | |
4d34a67d | 1431 | return ret_freq; |
1da177e4 LT |
1432 | } |
1433 | EXPORT_SYMBOL(cpufreq_get); | |
1434 | ||
8a25a2fd KS |
1435 | static struct subsys_interface cpufreq_interface = { |
1436 | .name = "cpufreq", | |
1437 | .subsys = &cpu_subsys, | |
1438 | .add_dev = cpufreq_add_dev, | |
1439 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1440 | }; |
1441 | ||
42d4dc3f | 1442 | /** |
e00e56df RW |
1443 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1444 | * | |
1445 | * This function is only executed for the boot processor. The other CPUs | |
1446 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1447 | */ |
e00e56df | 1448 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1449 | { |
e08f5f5b | 1450 | int ret = 0; |
4bc5d341 | 1451 | |
e00e56df | 1452 | int cpu = smp_processor_id(); |
3a3e9e06 | 1453 | struct cpufreq_policy *policy; |
42d4dc3f | 1454 | |
2d06d8c4 | 1455 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1456 | |
e00e56df | 1457 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1458 | policy = cpufreq_cpu_get(cpu); |
1459 | if (!policy) | |
e00e56df | 1460 | return 0; |
42d4dc3f | 1461 | |
1c3d85dd | 1462 | if (cpufreq_driver->suspend) { |
3a3e9e06 | 1463 | ret = cpufreq_driver->suspend(policy); |
ce6c3997 | 1464 | if (ret) |
42d4dc3f | 1465 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
3a3e9e06 | 1466 | "step on CPU %u\n", policy->cpu); |
42d4dc3f BH |
1467 | } |
1468 | ||
3a3e9e06 | 1469 | cpufreq_cpu_put(policy); |
c9060494 | 1470 | return ret; |
42d4dc3f BH |
1471 | } |
1472 | ||
1da177e4 | 1473 | /** |
e00e56df | 1474 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1475 | * |
1476 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1477 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1478 | * restored. It will verify that the current freq is in sync with | |
1479 | * what we believe it to be. This is a bit later than when it | |
1480 | * should be, but nonethteless it's better than calling | |
1481 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1482 | * |
1483 | * This function is only executed for the boot CPU. The other CPUs have not | |
1484 | * been turned on yet. | |
1da177e4 | 1485 | */ |
e00e56df | 1486 | static void cpufreq_bp_resume(void) |
1da177e4 | 1487 | { |
e08f5f5b | 1488 | int ret = 0; |
4bc5d341 | 1489 | |
e00e56df | 1490 | int cpu = smp_processor_id(); |
3a3e9e06 | 1491 | struct cpufreq_policy *policy; |
1da177e4 | 1492 | |
2d06d8c4 | 1493 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1494 | |
e00e56df | 1495 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1496 | policy = cpufreq_cpu_get(cpu); |
1497 | if (!policy) | |
e00e56df | 1498 | return; |
1da177e4 | 1499 | |
1c3d85dd | 1500 | if (cpufreq_driver->resume) { |
3a3e9e06 | 1501 | ret = cpufreq_driver->resume(policy); |
1da177e4 LT |
1502 | if (ret) { |
1503 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
3a3e9e06 | 1504 | "step on CPU %u\n", policy->cpu); |
c9060494 | 1505 | goto fail; |
1da177e4 LT |
1506 | } |
1507 | } | |
1508 | ||
3a3e9e06 | 1509 | schedule_work(&policy->update); |
ce6c3997 | 1510 | |
c9060494 | 1511 | fail: |
3a3e9e06 | 1512 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1513 | } |
1514 | ||
e00e56df RW |
1515 | static struct syscore_ops cpufreq_syscore_ops = { |
1516 | .suspend = cpufreq_bp_suspend, | |
1517 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1518 | }; |
1519 | ||
9d95046e BP |
1520 | /** |
1521 | * cpufreq_get_current_driver - return current driver's name | |
1522 | * | |
1523 | * Return the name string of the currently loaded cpufreq driver | |
1524 | * or NULL, if none. | |
1525 | */ | |
1526 | const char *cpufreq_get_current_driver(void) | |
1527 | { | |
1c3d85dd RW |
1528 | if (cpufreq_driver) |
1529 | return cpufreq_driver->name; | |
1530 | ||
1531 | return NULL; | |
9d95046e BP |
1532 | } |
1533 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1534 | |
1535 | /********************************************************************* | |
1536 | * NOTIFIER LISTS INTERFACE * | |
1537 | *********************************************************************/ | |
1538 | ||
1539 | /** | |
1540 | * cpufreq_register_notifier - register a driver with cpufreq | |
1541 | * @nb: notifier function to register | |
1542 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1543 | * | |
32ee8c3e | 1544 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1545 | * are notified about clock rate changes (once before and once after |
1546 | * the transition), or a list of drivers that are notified about | |
1547 | * changes in cpufreq policy. | |
1548 | * | |
1549 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1550 | * blocking_notifier_chain_register. |
1da177e4 LT |
1551 | */ |
1552 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1553 | { | |
1554 | int ret; | |
1555 | ||
d5aaffa9 DB |
1556 | if (cpufreq_disabled()) |
1557 | return -EINVAL; | |
1558 | ||
74212ca4 CEB |
1559 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1560 | ||
1da177e4 LT |
1561 | switch (list) { |
1562 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1563 | ret = srcu_notifier_chain_register( |
e041c683 | 1564 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1565 | break; |
1566 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1567 | ret = blocking_notifier_chain_register( |
1568 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1569 | break; |
1570 | default: | |
1571 | ret = -EINVAL; | |
1572 | } | |
1da177e4 LT |
1573 | |
1574 | return ret; | |
1575 | } | |
1576 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1577 | ||
1da177e4 LT |
1578 | /** |
1579 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1580 | * @nb: notifier block to be unregistered | |
bb176f7d | 1581 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1582 | * |
1583 | * Remove a driver from the CPU frequency notifier list. | |
1584 | * | |
1585 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1586 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1587 | */ |
1588 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1589 | { | |
1590 | int ret; | |
1591 | ||
d5aaffa9 DB |
1592 | if (cpufreq_disabled()) |
1593 | return -EINVAL; | |
1594 | ||
1da177e4 LT |
1595 | switch (list) { |
1596 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1597 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1598 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1599 | break; |
1600 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1601 | ret = blocking_notifier_chain_unregister( |
1602 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1603 | break; |
1604 | default: | |
1605 | ret = -EINVAL; | |
1606 | } | |
1da177e4 LT |
1607 | |
1608 | return ret; | |
1609 | } | |
1610 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1611 | ||
1612 | ||
1613 | /********************************************************************* | |
1614 | * GOVERNORS * | |
1615 | *********************************************************************/ | |
1616 | ||
1da177e4 LT |
1617 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1618 | unsigned int target_freq, | |
1619 | unsigned int relation) | |
1620 | { | |
1621 | int retval = -EINVAL; | |
7249924e | 1622 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1623 | |
a7b422cd KRW |
1624 | if (cpufreq_disabled()) |
1625 | return -ENODEV; | |
7c30ed53 VK |
1626 | if (policy->transition_ongoing) |
1627 | return -EBUSY; | |
a7b422cd | 1628 | |
7249924e VK |
1629 | /* Make sure that target_freq is within supported range */ |
1630 | if (target_freq > policy->max) | |
1631 | target_freq = policy->max; | |
1632 | if (target_freq < policy->min) | |
1633 | target_freq = policy->min; | |
1634 | ||
1635 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1636 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1637 | |
1638 | if (target_freq == policy->cur) | |
1639 | return 0; | |
1640 | ||
1c3d85dd RW |
1641 | if (cpufreq_driver->target) |
1642 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1643 | |
1da177e4 LT |
1644 | return retval; |
1645 | } | |
1646 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1647 | ||
1da177e4 LT |
1648 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1649 | unsigned int target_freq, | |
1650 | unsigned int relation) | |
1651 | { | |
f1829e4a | 1652 | int ret = -EINVAL; |
1da177e4 | 1653 | |
5a01f2e8 | 1654 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1655 | goto fail; |
1da177e4 LT |
1656 | |
1657 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1658 | ||
5a01f2e8 | 1659 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1660 | |
f1829e4a | 1661 | fail: |
1da177e4 LT |
1662 | return ret; |
1663 | } | |
1664 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1665 | ||
153d7f3f | 1666 | /* |
153d7f3f AV |
1667 | * when "event" is CPUFREQ_GOV_LIMITS |
1668 | */ | |
1da177e4 | 1669 | |
e08f5f5b GS |
1670 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1671 | unsigned int event) | |
1da177e4 | 1672 | { |
cc993cab | 1673 | int ret; |
6afde10c TR |
1674 | |
1675 | /* Only must be defined when default governor is known to have latency | |
1676 | restrictions, like e.g. conservative or ondemand. | |
1677 | That this is the case is already ensured in Kconfig | |
1678 | */ | |
1679 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1680 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1681 | #else | |
1682 | struct cpufreq_governor *gov = NULL; | |
1683 | #endif | |
1c256245 TR |
1684 | |
1685 | if (policy->governor->max_transition_latency && | |
1686 | policy->cpuinfo.transition_latency > | |
1687 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1688 | if (!gov) |
1689 | return -EINVAL; | |
1690 | else { | |
1691 | printk(KERN_WARNING "%s governor failed, too long" | |
1692 | " transition latency of HW, fallback" | |
1693 | " to %s governor\n", | |
1694 | policy->governor->name, | |
1695 | gov->name); | |
1696 | policy->governor = gov; | |
1697 | } | |
1c256245 | 1698 | } |
1da177e4 LT |
1699 | |
1700 | if (!try_module_get(policy->governor->owner)) | |
1701 | return -EINVAL; | |
1702 | ||
2d06d8c4 | 1703 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1704 | policy->cpu, event); |
95731ebb XC |
1705 | |
1706 | mutex_lock(&cpufreq_governor_lock); | |
1707 | if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) || | |
1708 | (policy->governor_enabled && (event == CPUFREQ_GOV_START))) { | |
1709 | mutex_unlock(&cpufreq_governor_lock); | |
1710 | return -EBUSY; | |
1711 | } | |
1712 | ||
1713 | if (event == CPUFREQ_GOV_STOP) | |
1714 | policy->governor_enabled = false; | |
1715 | else if (event == CPUFREQ_GOV_START) | |
1716 | policy->governor_enabled = true; | |
1717 | ||
1718 | mutex_unlock(&cpufreq_governor_lock); | |
1719 | ||
1da177e4 LT |
1720 | ret = policy->governor->governor(policy, event); |
1721 | ||
4d5dcc42 VK |
1722 | if (!ret) { |
1723 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1724 | policy->governor->initialized++; | |
1725 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1726 | policy->governor->initialized--; | |
95731ebb XC |
1727 | } else { |
1728 | /* Restore original values */ | |
1729 | mutex_lock(&cpufreq_governor_lock); | |
1730 | if (event == CPUFREQ_GOV_STOP) | |
1731 | policy->governor_enabled = true; | |
1732 | else if (event == CPUFREQ_GOV_START) | |
1733 | policy->governor_enabled = false; | |
1734 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1735 | } |
b394058f | 1736 | |
e08f5f5b GS |
1737 | /* we keep one module reference alive for |
1738 | each CPU governed by this CPU */ | |
1da177e4 LT |
1739 | if ((event != CPUFREQ_GOV_START) || ret) |
1740 | module_put(policy->governor->owner); | |
1741 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1742 | module_put(policy->governor->owner); | |
1743 | ||
1744 | return ret; | |
1745 | } | |
1746 | ||
1da177e4 LT |
1747 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1748 | { | |
3bcb09a3 | 1749 | int err; |
1da177e4 LT |
1750 | |
1751 | if (!governor) | |
1752 | return -EINVAL; | |
1753 | ||
a7b422cd KRW |
1754 | if (cpufreq_disabled()) |
1755 | return -ENODEV; | |
1756 | ||
3fc54d37 | 1757 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1758 | |
b394058f | 1759 | governor->initialized = 0; |
3bcb09a3 JF |
1760 | err = -EBUSY; |
1761 | if (__find_governor(governor->name) == NULL) { | |
1762 | err = 0; | |
1763 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1764 | } |
1da177e4 | 1765 | |
32ee8c3e | 1766 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1767 | return err; |
1da177e4 LT |
1768 | } |
1769 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1770 | ||
1da177e4 LT |
1771 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1772 | { | |
90e41bac PB |
1773 | #ifdef CONFIG_HOTPLUG_CPU |
1774 | int cpu; | |
1775 | #endif | |
1776 | ||
1da177e4 LT |
1777 | if (!governor) |
1778 | return; | |
1779 | ||
a7b422cd KRW |
1780 | if (cpufreq_disabled()) |
1781 | return; | |
1782 | ||
90e41bac PB |
1783 | #ifdef CONFIG_HOTPLUG_CPU |
1784 | for_each_present_cpu(cpu) { | |
1785 | if (cpu_online(cpu)) | |
1786 | continue; | |
1787 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1788 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1789 | } | |
1790 | #endif | |
1791 | ||
3fc54d37 | 1792 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1793 | list_del(&governor->governor_list); |
3fc54d37 | 1794 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1795 | return; |
1796 | } | |
1797 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1798 | ||
1799 | ||
1da177e4 LT |
1800 | /********************************************************************* |
1801 | * POLICY INTERFACE * | |
1802 | *********************************************************************/ | |
1803 | ||
1804 | /** | |
1805 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1806 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1807 | * is written | |
1da177e4 LT |
1808 | * |
1809 | * Reads the current cpufreq policy. | |
1810 | */ | |
1811 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1812 | { | |
1813 | struct cpufreq_policy *cpu_policy; | |
1814 | if (!policy) | |
1815 | return -EINVAL; | |
1816 | ||
1817 | cpu_policy = cpufreq_cpu_get(cpu); | |
1818 | if (!cpu_policy) | |
1819 | return -EINVAL; | |
1820 | ||
1da177e4 | 1821 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1822 | |
1823 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1824 | return 0; |
1825 | } | |
1826 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1827 | ||
153d7f3f | 1828 | /* |
e08f5f5b GS |
1829 | * data : current policy. |
1830 | * policy : policy to be set. | |
153d7f3f | 1831 | */ |
3a3e9e06 VK |
1832 | static int __cpufreq_set_policy(struct cpufreq_policy *policy, |
1833 | struct cpufreq_policy *new_policy) | |
1da177e4 | 1834 | { |
7bd353a9 | 1835 | int ret = 0, failed = 1; |
1da177e4 | 1836 | |
3a3e9e06 VK |
1837 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, |
1838 | new_policy->min, new_policy->max); | |
1da177e4 | 1839 | |
3a3e9e06 | 1840 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, |
e08f5f5b | 1841 | sizeof(struct cpufreq_cpuinfo)); |
1da177e4 | 1842 | |
3a3e9e06 | 1843 | if (new_policy->min > policy->max || new_policy->max < policy->min) { |
9c9a43ed MD |
1844 | ret = -EINVAL; |
1845 | goto error_out; | |
1846 | } | |
1847 | ||
1da177e4 | 1848 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 1849 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 LT |
1850 | if (ret) |
1851 | goto error_out; | |
1852 | ||
1da177e4 | 1853 | /* adjust if necessary - all reasons */ |
e041c683 | 1854 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1855 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
1856 | |
1857 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 1858 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1859 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 1860 | |
bb176f7d VK |
1861 | /* |
1862 | * verify the cpu speed can be set within this limit, which might be | |
1863 | * different to the first one | |
1864 | */ | |
3a3e9e06 | 1865 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 1866 | if (ret) |
1da177e4 | 1867 | goto error_out; |
1da177e4 LT |
1868 | |
1869 | /* notification of the new policy */ | |
e041c683 | 1870 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1871 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 1872 | |
3a3e9e06 VK |
1873 | policy->min = new_policy->min; |
1874 | policy->max = new_policy->max; | |
1da177e4 | 1875 | |
2d06d8c4 | 1876 | pr_debug("new min and max freqs are %u - %u kHz\n", |
3a3e9e06 | 1877 | policy->min, policy->max); |
1da177e4 | 1878 | |
1c3d85dd | 1879 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 1880 | policy->policy = new_policy->policy; |
2d06d8c4 | 1881 | pr_debug("setting range\n"); |
3a3e9e06 | 1882 | ret = cpufreq_driver->setpolicy(new_policy); |
1da177e4 | 1883 | } else { |
3a3e9e06 | 1884 | if (new_policy->governor != policy->governor) { |
1da177e4 | 1885 | /* save old, working values */ |
3a3e9e06 | 1886 | struct cpufreq_governor *old_gov = policy->governor; |
1da177e4 | 1887 | |
2d06d8c4 | 1888 | pr_debug("governor switch\n"); |
1da177e4 LT |
1889 | |
1890 | /* end old governor */ | |
3a3e9e06 VK |
1891 | if (policy->governor) { |
1892 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1893 | unlock_policy_rwsem_write(new_policy->cpu); | |
1894 | __cpufreq_governor(policy, | |
7bd353a9 | 1895 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1896 | lock_policy_rwsem_write(new_policy->cpu); |
7bd353a9 | 1897 | } |
1da177e4 LT |
1898 | |
1899 | /* start new governor */ | |
3a3e9e06 VK |
1900 | policy->governor = new_policy->governor; |
1901 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
1902 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) { | |
7bd353a9 | 1903 | failed = 0; |
955ef483 | 1904 | } else { |
3a3e9e06 VK |
1905 | unlock_policy_rwsem_write(new_policy->cpu); |
1906 | __cpufreq_governor(policy, | |
7bd353a9 | 1907 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1908 | lock_policy_rwsem_write(new_policy->cpu); |
955ef483 | 1909 | } |
7bd353a9 VK |
1910 | } |
1911 | ||
1912 | if (failed) { | |
1da177e4 | 1913 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1914 | pr_debug("starting governor %s failed\n", |
3a3e9e06 | 1915 | policy->governor->name); |
1da177e4 | 1916 | if (old_gov) { |
3a3e9e06 VK |
1917 | policy->governor = old_gov; |
1918 | __cpufreq_governor(policy, | |
7bd353a9 | 1919 | CPUFREQ_GOV_POLICY_INIT); |
3a3e9e06 | 1920 | __cpufreq_governor(policy, |
e08f5f5b | 1921 | CPUFREQ_GOV_START); |
1da177e4 LT |
1922 | } |
1923 | ret = -EINVAL; | |
1924 | goto error_out; | |
1925 | } | |
1926 | /* might be a policy change, too, so fall through */ | |
1927 | } | |
2d06d8c4 | 1928 | pr_debug("governor: change or update limits\n"); |
3a3e9e06 | 1929 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
1da177e4 LT |
1930 | } |
1931 | ||
7d5e350f | 1932 | error_out: |
1da177e4 LT |
1933 | return ret; |
1934 | } | |
1935 | ||
1da177e4 LT |
1936 | /** |
1937 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1938 | * @cpu: CPU which shall be re-evaluated | |
1939 | * | |
25985edc | 1940 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1941 | * at different times. |
1942 | */ | |
1943 | int cpufreq_update_policy(unsigned int cpu) | |
1944 | { | |
3a3e9e06 VK |
1945 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
1946 | struct cpufreq_policy new_policy; | |
f1829e4a | 1947 | int ret; |
1da177e4 | 1948 | |
3a3e9e06 | 1949 | if (!policy) { |
f1829e4a JL |
1950 | ret = -ENODEV; |
1951 | goto no_policy; | |
1952 | } | |
1da177e4 | 1953 | |
f1829e4a JL |
1954 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1955 | ret = -EINVAL; | |
1956 | goto fail; | |
1957 | } | |
1da177e4 | 1958 | |
2d06d8c4 | 1959 | pr_debug("updating policy for CPU %u\n", cpu); |
3a3e9e06 VK |
1960 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
1961 | new_policy.min = policy->user_policy.min; | |
1962 | new_policy.max = policy->user_policy.max; | |
1963 | new_policy.policy = policy->user_policy.policy; | |
1964 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 1965 | |
bb176f7d VK |
1966 | /* |
1967 | * BIOS might change freq behind our back | |
1968 | * -> ask driver for current freq and notify governors about a change | |
1969 | */ | |
1c3d85dd | 1970 | if (cpufreq_driver->get) { |
3a3e9e06 VK |
1971 | new_policy.cur = cpufreq_driver->get(cpu); |
1972 | if (!policy->cur) { | |
2d06d8c4 | 1973 | pr_debug("Driver did not initialize current freq"); |
3a3e9e06 | 1974 | policy->cur = new_policy.cur; |
a85f7bd3 | 1975 | } else { |
3a3e9e06 VK |
1976 | if (policy->cur != new_policy.cur && cpufreq_driver->target) |
1977 | cpufreq_out_of_sync(cpu, policy->cur, | |
1978 | new_policy.cur); | |
a85f7bd3 | 1979 | } |
0961dd0d TR |
1980 | } |
1981 | ||
3a3e9e06 | 1982 | ret = __cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 1983 | |
5a01f2e8 VP |
1984 | unlock_policy_rwsem_write(cpu); |
1985 | ||
f1829e4a | 1986 | fail: |
3a3e9e06 | 1987 | cpufreq_cpu_put(policy); |
f1829e4a | 1988 | no_policy: |
1da177e4 LT |
1989 | return ret; |
1990 | } | |
1991 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1992 | ||
2760984f | 1993 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1994 | unsigned long action, void *hcpu) |
1995 | { | |
1996 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1997 | struct device *dev; |
5302c3fb | 1998 | bool frozen = false; |
c32b6b8e | 1999 | |
8a25a2fd KS |
2000 | dev = get_cpu_device(cpu); |
2001 | if (dev) { | |
5302c3fb SB |
2002 | |
2003 | if (action & CPU_TASKS_FROZEN) | |
2004 | frozen = true; | |
2005 | ||
2006 | switch (action & ~CPU_TASKS_FROZEN) { | |
c32b6b8e | 2007 | case CPU_ONLINE: |
5302c3fb | 2008 | __cpufreq_add_dev(dev, NULL, frozen); |
23d32899 | 2009 | cpufreq_update_policy(cpu); |
c32b6b8e | 2010 | break; |
5302c3fb | 2011 | |
c32b6b8e | 2012 | case CPU_DOWN_PREPARE: |
5302c3fb | 2013 | __cpufreq_remove_dev(dev, NULL, frozen); |
c32b6b8e | 2014 | break; |
5302c3fb | 2015 | |
5a01f2e8 | 2016 | case CPU_DOWN_FAILED: |
5302c3fb | 2017 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2018 | break; |
2019 | } | |
2020 | } | |
2021 | return NOTIFY_OK; | |
2022 | } | |
2023 | ||
9c36f746 | 2024 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2025 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2026 | }; |
1da177e4 LT |
2027 | |
2028 | /********************************************************************* | |
2029 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2030 | *********************************************************************/ | |
2031 | ||
2032 | /** | |
2033 | * cpufreq_register_driver - register a CPU Frequency driver | |
2034 | * @driver_data: A struct cpufreq_driver containing the values# | |
2035 | * submitted by the CPU Frequency driver. | |
2036 | * | |
bb176f7d | 2037 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2038 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2039 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2040 | * |
2041 | */ | |
221dee28 | 2042 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2043 | { |
2044 | unsigned long flags; | |
2045 | int ret; | |
2046 | ||
a7b422cd KRW |
2047 | if (cpufreq_disabled()) |
2048 | return -ENODEV; | |
2049 | ||
1da177e4 LT |
2050 | if (!driver_data || !driver_data->verify || !driver_data->init || |
2051 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2052 | return -EINVAL; | |
2053 | ||
2d06d8c4 | 2054 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2055 | |
2056 | if (driver_data->setpolicy) | |
2057 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2058 | ||
0d1857a1 | 2059 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2060 | if (cpufreq_driver) { |
0d1857a1 | 2061 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2062 | return -EBUSY; |
2063 | } | |
1c3d85dd | 2064 | cpufreq_driver = driver_data; |
0d1857a1 | 2065 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2066 | |
8a25a2fd | 2067 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2068 | if (ret) |
2069 | goto err_null_driver; | |
1da177e4 | 2070 | |
1c3d85dd | 2071 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2072 | int i; |
2073 | ret = -ENODEV; | |
2074 | ||
2075 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2076 | for (i = 0; i < nr_cpu_ids; i++) |
2077 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2078 | ret = 0; |
7a6aedfa MT |
2079 | break; |
2080 | } | |
1da177e4 LT |
2081 | |
2082 | /* if all ->init() calls failed, unregister */ | |
2083 | if (ret) { | |
2d06d8c4 | 2084 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2085 | driver_data->name); |
8a25a2fd | 2086 | goto err_if_unreg; |
1da177e4 LT |
2087 | } |
2088 | } | |
2089 | ||
8f5bc2ab | 2090 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2091 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2092 | |
8f5bc2ab | 2093 | return 0; |
8a25a2fd KS |
2094 | err_if_unreg: |
2095 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2096 | err_null_driver: |
0d1857a1 | 2097 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2098 | cpufreq_driver = NULL; |
0d1857a1 | 2099 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2100 | return ret; |
1da177e4 LT |
2101 | } |
2102 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2103 | ||
1da177e4 LT |
2104 | /** |
2105 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2106 | * | |
bb176f7d | 2107 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2108 | * the right to do so, i.e. if you have succeeded in initialising before! |
2109 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2110 | * currently not initialised. | |
2111 | */ | |
221dee28 | 2112 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2113 | { |
2114 | unsigned long flags; | |
2115 | ||
1c3d85dd | 2116 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2117 | return -EINVAL; |
1da177e4 | 2118 | |
2d06d8c4 | 2119 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2120 | |
8a25a2fd | 2121 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2122 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2123 | |
0d1857a1 | 2124 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2125 | cpufreq_driver = NULL; |
0d1857a1 | 2126 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2127 | |
2128 | return 0; | |
2129 | } | |
2130 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2131 | |
2132 | static int __init cpufreq_core_init(void) | |
2133 | { | |
2134 | int cpu; | |
2135 | ||
a7b422cd KRW |
2136 | if (cpufreq_disabled()) |
2137 | return -ENODEV; | |
2138 | ||
5a01f2e8 | 2139 | for_each_possible_cpu(cpu) { |
f1625066 | 2140 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
2141 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
2142 | } | |
8aa84ad8 | 2143 | |
2361be23 | 2144 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2145 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2146 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2147 | |
5a01f2e8 VP |
2148 | return 0; |
2149 | } | |
5a01f2e8 | 2150 | core_initcall(cpufreq_core_init); |