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 | |
9c0ebcf7 VK |
50 | static inline bool has_target(void) |
51 | { | |
52 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
53 | } | |
54 | ||
6eed9404 VK |
55 | /* |
56 | * rwsem to guarantee that cpufreq driver module doesn't unload during critical | |
57 | * sections | |
58 | */ | |
59 | static DECLARE_RWSEM(cpufreq_rwsem); | |
60 | ||
1da177e4 | 61 | /* internal prototypes */ |
29464f28 DJ |
62 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
63 | unsigned int event); | |
5a01f2e8 | 64 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 65 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
66 | |
67 | /** | |
32ee8c3e DJ |
68 | * Two notifier lists: the "policy" list is involved in the |
69 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
70 | * "transition" list for kernel code that needs to handle |
71 | * changes to devices when the CPU clock speed changes. | |
72 | * The mutex locks both lists. | |
73 | */ | |
e041c683 | 74 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 75 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 76 | |
74212ca4 | 77 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
78 | static int __init init_cpufreq_transition_notifier_list(void) |
79 | { | |
80 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 81 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
82 | return 0; |
83 | } | |
b3438f82 | 84 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 85 | |
a7b422cd | 86 | static int off __read_mostly; |
da584455 | 87 | static int cpufreq_disabled(void) |
a7b422cd KRW |
88 | { |
89 | return off; | |
90 | } | |
91 | void disable_cpufreq(void) | |
92 | { | |
93 | off = 1; | |
94 | } | |
1da177e4 | 95 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 96 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 97 | |
4d5dcc42 VK |
98 | bool have_governor_per_policy(void) |
99 | { | |
0b981e70 | 100 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 101 | } |
3f869d6d | 102 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 103 | |
944e9a03 VK |
104 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
105 | { | |
106 | if (have_governor_per_policy()) | |
107 | return &policy->kobj; | |
108 | else | |
109 | return cpufreq_global_kobject; | |
110 | } | |
111 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
112 | ||
72a4ce34 VK |
113 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
114 | { | |
115 | u64 idle_time; | |
116 | u64 cur_wall_time; | |
117 | u64 busy_time; | |
118 | ||
119 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
120 | ||
121 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
122 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
123 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
124 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
125 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
126 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
127 | ||
128 | idle_time = cur_wall_time - busy_time; | |
129 | if (wall) | |
130 | *wall = cputime_to_usecs(cur_wall_time); | |
131 | ||
132 | return cputime_to_usecs(idle_time); | |
133 | } | |
134 | ||
135 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
136 | { | |
137 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
138 | ||
139 | if (idle_time == -1ULL) | |
140 | return get_cpu_idle_time_jiffy(cpu, wall); | |
141 | else if (!io_busy) | |
142 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
143 | ||
144 | return idle_time; | |
145 | } | |
146 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
147 | ||
70e9e778 VK |
148 | /* |
149 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
150 | * drivers of SMP systems. It will do following: | |
151 | * - validate & show freq table passed | |
152 | * - set policies transition latency | |
153 | * - policy->cpus with all possible CPUs | |
154 | */ | |
155 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
156 | struct cpufreq_frequency_table *table, | |
157 | unsigned int transition_latency) | |
158 | { | |
159 | int ret; | |
160 | ||
161 | ret = cpufreq_table_validate_and_show(policy, table); | |
162 | if (ret) { | |
163 | pr_err("%s: invalid frequency table: %d\n", __func__, ret); | |
164 | return ret; | |
165 | } | |
166 | ||
167 | policy->cpuinfo.transition_latency = transition_latency; | |
168 | ||
169 | /* | |
170 | * The driver only supports the SMP configuartion where all processors | |
171 | * share the clock and voltage and clock. | |
172 | */ | |
173 | cpumask_setall(policy->cpus); | |
174 | ||
175 | return 0; | |
176 | } | |
177 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
178 | ||
6eed9404 | 179 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 180 | { |
6eed9404 | 181 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
182 | unsigned long flags; |
183 | ||
6eed9404 VK |
184 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
185 | return NULL; | |
186 | ||
187 | if (!down_read_trylock(&cpufreq_rwsem)) | |
188 | return NULL; | |
1da177e4 LT |
189 | |
190 | /* get the cpufreq driver */ | |
1c3d85dd | 191 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 192 | |
6eed9404 VK |
193 | if (cpufreq_driver) { |
194 | /* get the CPU */ | |
195 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
196 | if (policy) | |
197 | kobject_get(&policy->kobj); | |
198 | } | |
1da177e4 | 199 | |
6eed9404 | 200 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 201 | |
3a3e9e06 | 202 | if (!policy) |
6eed9404 | 203 | up_read(&cpufreq_rwsem); |
1da177e4 | 204 | |
3a3e9e06 | 205 | return policy; |
a9144436 | 206 | } |
1da177e4 LT |
207 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
208 | ||
3a3e9e06 | 209 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 210 | { |
d5aaffa9 DB |
211 | if (cpufreq_disabled()) |
212 | return; | |
213 | ||
6eed9404 VK |
214 | kobject_put(&policy->kobj); |
215 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
216 | } |
217 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
218 | ||
1da177e4 LT |
219 | /********************************************************************* |
220 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
221 | *********************************************************************/ | |
222 | ||
223 | /** | |
224 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
225 | * | |
226 | * This function alters the system "loops_per_jiffy" for the clock | |
227 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 228 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
229 | * per-CPU loops_per_jiffy value wherever possible. |
230 | */ | |
231 | #ifndef CONFIG_SMP | |
232 | static unsigned long l_p_j_ref; | |
bb176f7d | 233 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 234 | |
858119e1 | 235 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
236 | { |
237 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
238 | return; | |
239 | ||
240 | if (!l_p_j_ref_freq) { | |
241 | l_p_j_ref = loops_per_jiffy; | |
242 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 243 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 244 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 245 | } |
bb176f7d | 246 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 247 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
248 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
249 | ci->new); | |
2d06d8c4 | 250 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 251 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
252 | } |
253 | } | |
254 | #else | |
e08f5f5b GS |
255 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
256 | { | |
257 | return; | |
258 | } | |
1da177e4 LT |
259 | #endif |
260 | ||
0956df9c | 261 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 262 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
263 | { |
264 | BUG_ON(irqs_disabled()); | |
265 | ||
d5aaffa9 DB |
266 | if (cpufreq_disabled()) |
267 | return; | |
268 | ||
1c3d85dd | 269 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 270 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 271 | state, freqs->new); |
1da177e4 | 272 | |
1da177e4 | 273 | switch (state) { |
e4472cb3 | 274 | |
1da177e4 | 275 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 276 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
277 | * which is not equal to what the cpufreq core thinks is |
278 | * "old frequency". | |
1da177e4 | 279 | */ |
1c3d85dd | 280 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
281 | if ((policy) && (policy->cpu == freqs->cpu) && |
282 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 283 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
284 | " %u, cpufreq assumed %u kHz.\n", |
285 | freqs->old, policy->cur); | |
286 | freqs->old = policy->cur; | |
1da177e4 LT |
287 | } |
288 | } | |
b4dfdbb3 | 289 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 290 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
291 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
292 | break; | |
e4472cb3 | 293 | |
1da177e4 LT |
294 | case CPUFREQ_POSTCHANGE: |
295 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 296 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 297 | (unsigned long)freqs->cpu); |
25e41933 | 298 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 299 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 300 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
301 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
302 | policy->cur = freqs->new; | |
1da177e4 LT |
303 | break; |
304 | } | |
1da177e4 | 305 | } |
bb176f7d | 306 | |
b43a7ffb VK |
307 | /** |
308 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
309 | * on frequency transition. | |
310 | * | |
311 | * This function calls the transition notifiers and the "adjust_jiffies" | |
312 | * function. It is called twice on all CPU frequency changes that have | |
313 | * external effects. | |
314 | */ | |
315 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
316 | struct cpufreq_freqs *freqs, unsigned int state) | |
317 | { | |
318 | for_each_cpu(freqs->cpu, policy->cpus) | |
319 | __cpufreq_notify_transition(policy, freqs, state); | |
320 | } | |
1da177e4 LT |
321 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
322 | ||
323 | ||
1da177e4 LT |
324 | /********************************************************************* |
325 | * SYSFS INTERFACE * | |
326 | *********************************************************************/ | |
327 | ||
3bcb09a3 JF |
328 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
329 | { | |
330 | struct cpufreq_governor *t; | |
331 | ||
332 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 333 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
334 | return t; |
335 | ||
336 | return NULL; | |
337 | } | |
338 | ||
1da177e4 LT |
339 | /** |
340 | * cpufreq_parse_governor - parse a governor string | |
341 | */ | |
905d77cd | 342 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
343 | struct cpufreq_governor **governor) |
344 | { | |
3bcb09a3 | 345 | int err = -EINVAL; |
1c3d85dd RW |
346 | |
347 | if (!cpufreq_driver) | |
3bcb09a3 JF |
348 | goto out; |
349 | ||
1c3d85dd | 350 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
351 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
352 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 353 | err = 0; |
e08f5f5b GS |
354 | } else if (!strnicmp(str_governor, "powersave", |
355 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 356 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 357 | err = 0; |
1da177e4 | 358 | } |
9c0ebcf7 | 359 | } else if (has_target()) { |
1da177e4 | 360 | struct cpufreq_governor *t; |
3bcb09a3 | 361 | |
3fc54d37 | 362 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
363 | |
364 | t = __find_governor(str_governor); | |
365 | ||
ea714970 | 366 | if (t == NULL) { |
1a8e1463 | 367 | int ret; |
ea714970 | 368 | |
1a8e1463 KC |
369 | mutex_unlock(&cpufreq_governor_mutex); |
370 | ret = request_module("cpufreq_%s", str_governor); | |
371 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 372 | |
1a8e1463 KC |
373 | if (ret == 0) |
374 | t = __find_governor(str_governor); | |
ea714970 JF |
375 | } |
376 | ||
3bcb09a3 JF |
377 | if (t != NULL) { |
378 | *governor = t; | |
379 | err = 0; | |
1da177e4 | 380 | } |
3bcb09a3 | 381 | |
3fc54d37 | 382 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 383 | } |
29464f28 | 384 | out: |
3bcb09a3 | 385 | return err; |
1da177e4 | 386 | } |
1da177e4 | 387 | |
1da177e4 | 388 | /** |
e08f5f5b GS |
389 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
390 | * print out cpufreq information | |
1da177e4 LT |
391 | * |
392 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
393 | * "unsigned int". | |
394 | */ | |
395 | ||
32ee8c3e DJ |
396 | #define show_one(file_name, object) \ |
397 | static ssize_t show_##file_name \ | |
905d77cd | 398 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 399 | { \ |
29464f28 | 400 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
401 | } |
402 | ||
403 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
404 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 405 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
406 | show_one(scaling_min_freq, min); |
407 | show_one(scaling_max_freq, max); | |
408 | show_one(scaling_cur_freq, cur); | |
409 | ||
037ce839 | 410 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 411 | struct cpufreq_policy *new_policy); |
7970e08b | 412 | |
1da177e4 LT |
413 | /** |
414 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
415 | */ | |
416 | #define store_one(file_name, object) \ | |
417 | static ssize_t store_##file_name \ | |
905d77cd | 418 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 419 | { \ |
5136fa56 | 420 | int ret; \ |
1da177e4 LT |
421 | struct cpufreq_policy new_policy; \ |
422 | \ | |
423 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
424 | if (ret) \ | |
425 | return -EINVAL; \ | |
426 | \ | |
29464f28 | 427 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
428 | if (ret != 1) \ |
429 | return -EINVAL; \ | |
430 | \ | |
037ce839 | 431 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 432 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
433 | \ |
434 | return ret ? ret : count; \ | |
435 | } | |
436 | ||
29464f28 DJ |
437 | store_one(scaling_min_freq, min); |
438 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
439 | |
440 | /** | |
441 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
442 | */ | |
905d77cd DJ |
443 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
444 | char *buf) | |
1da177e4 | 445 | { |
5a01f2e8 | 446 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
447 | if (!cur_freq) |
448 | return sprintf(buf, "<unknown>"); | |
449 | return sprintf(buf, "%u\n", cur_freq); | |
450 | } | |
451 | ||
1da177e4 LT |
452 | /** |
453 | * show_scaling_governor - show the current policy for the specified CPU | |
454 | */ | |
905d77cd | 455 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 456 | { |
29464f28 | 457 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
458 | return sprintf(buf, "powersave\n"); |
459 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
460 | return sprintf(buf, "performance\n"); | |
461 | else if (policy->governor) | |
4b972f0b | 462 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 463 | policy->governor->name); |
1da177e4 LT |
464 | return -EINVAL; |
465 | } | |
466 | ||
1da177e4 LT |
467 | /** |
468 | * store_scaling_governor - store policy for the specified CPU | |
469 | */ | |
905d77cd DJ |
470 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
471 | const char *buf, size_t count) | |
1da177e4 | 472 | { |
5136fa56 | 473 | int ret; |
1da177e4 LT |
474 | char str_governor[16]; |
475 | struct cpufreq_policy new_policy; | |
476 | ||
477 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
478 | if (ret) | |
479 | return ret; | |
480 | ||
29464f28 | 481 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
482 | if (ret != 1) |
483 | return -EINVAL; | |
484 | ||
e08f5f5b GS |
485 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
486 | &new_policy.governor)) | |
1da177e4 LT |
487 | return -EINVAL; |
488 | ||
037ce839 | 489 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
490 | |
491 | policy->user_policy.policy = policy->policy; | |
492 | policy->user_policy.governor = policy->governor; | |
7970e08b | 493 | |
e08f5f5b GS |
494 | if (ret) |
495 | return ret; | |
496 | else | |
497 | return count; | |
1da177e4 LT |
498 | } |
499 | ||
500 | /** | |
501 | * show_scaling_driver - show the cpufreq driver currently loaded | |
502 | */ | |
905d77cd | 503 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 504 | { |
1c3d85dd | 505 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
506 | } |
507 | ||
508 | /** | |
509 | * show_scaling_available_governors - show the available CPUfreq governors | |
510 | */ | |
905d77cd DJ |
511 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
512 | char *buf) | |
1da177e4 LT |
513 | { |
514 | ssize_t i = 0; | |
515 | struct cpufreq_governor *t; | |
516 | ||
9c0ebcf7 | 517 | if (!has_target()) { |
1da177e4 LT |
518 | i += sprintf(buf, "performance powersave"); |
519 | goto out; | |
520 | } | |
521 | ||
522 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
523 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
524 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 525 | goto out; |
4b972f0b | 526 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 527 | } |
7d5e350f | 528 | out: |
1da177e4 LT |
529 | i += sprintf(&buf[i], "\n"); |
530 | return i; | |
531 | } | |
e8628dd0 | 532 | |
f4fd3797 | 533 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
534 | { |
535 | ssize_t i = 0; | |
536 | unsigned int cpu; | |
537 | ||
835481d9 | 538 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
539 | if (i) |
540 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
541 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
542 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 543 | break; |
1da177e4 LT |
544 | } |
545 | i += sprintf(&buf[i], "\n"); | |
546 | return i; | |
547 | } | |
f4fd3797 | 548 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 549 | |
e8628dd0 DW |
550 | /** |
551 | * show_related_cpus - show the CPUs affected by each transition even if | |
552 | * hw coordination is in use | |
553 | */ | |
554 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
555 | { | |
f4fd3797 | 556 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
557 | } |
558 | ||
559 | /** | |
560 | * show_affected_cpus - show the CPUs affected by each transition | |
561 | */ | |
562 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
563 | { | |
f4fd3797 | 564 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
565 | } |
566 | ||
9e76988e | 567 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 568 | const char *buf, size_t count) |
9e76988e VP |
569 | { |
570 | unsigned int freq = 0; | |
571 | unsigned int ret; | |
572 | ||
879000f9 | 573 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
574 | return -EINVAL; |
575 | ||
576 | ret = sscanf(buf, "%u", &freq); | |
577 | if (ret != 1) | |
578 | return -EINVAL; | |
579 | ||
580 | policy->governor->store_setspeed(policy, freq); | |
581 | ||
582 | return count; | |
583 | } | |
584 | ||
585 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
586 | { | |
879000f9 | 587 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
588 | return sprintf(buf, "<unsupported>\n"); |
589 | ||
590 | return policy->governor->show_setspeed(policy, buf); | |
591 | } | |
1da177e4 | 592 | |
e2f74f35 | 593 | /** |
8bf1ac72 | 594 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
595 | */ |
596 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
597 | { | |
598 | unsigned int limit; | |
599 | int ret; | |
1c3d85dd RW |
600 | if (cpufreq_driver->bios_limit) { |
601 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
602 | if (!ret) |
603 | return sprintf(buf, "%u\n", limit); | |
604 | } | |
605 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
606 | } | |
607 | ||
6dad2a29 BP |
608 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
609 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
610 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
611 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
612 | cpufreq_freq_attr_ro(scaling_available_governors); | |
613 | cpufreq_freq_attr_ro(scaling_driver); | |
614 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
615 | cpufreq_freq_attr_ro(bios_limit); | |
616 | cpufreq_freq_attr_ro(related_cpus); | |
617 | cpufreq_freq_attr_ro(affected_cpus); | |
618 | cpufreq_freq_attr_rw(scaling_min_freq); | |
619 | cpufreq_freq_attr_rw(scaling_max_freq); | |
620 | cpufreq_freq_attr_rw(scaling_governor); | |
621 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 622 | |
905d77cd | 623 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
624 | &cpuinfo_min_freq.attr, |
625 | &cpuinfo_max_freq.attr, | |
ed129784 | 626 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
627 | &scaling_min_freq.attr, |
628 | &scaling_max_freq.attr, | |
629 | &affected_cpus.attr, | |
e8628dd0 | 630 | &related_cpus.attr, |
1da177e4 LT |
631 | &scaling_governor.attr, |
632 | &scaling_driver.attr, | |
633 | &scaling_available_governors.attr, | |
9e76988e | 634 | &scaling_setspeed.attr, |
1da177e4 LT |
635 | NULL |
636 | }; | |
637 | ||
29464f28 DJ |
638 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
639 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 640 | |
29464f28 | 641 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 642 | { |
905d77cd DJ |
643 | struct cpufreq_policy *policy = to_policy(kobj); |
644 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 645 | ssize_t ret; |
6eed9404 VK |
646 | |
647 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 648 | return -EINVAL; |
5a01f2e8 | 649 | |
ad7722da | 650 | down_read(&policy->rwsem); |
5a01f2e8 | 651 | |
e08f5f5b GS |
652 | if (fattr->show) |
653 | ret = fattr->show(policy, buf); | |
654 | else | |
655 | ret = -EIO; | |
656 | ||
ad7722da | 657 | up_read(&policy->rwsem); |
6eed9404 | 658 | up_read(&cpufreq_rwsem); |
1b750e3b | 659 | |
1da177e4 LT |
660 | return ret; |
661 | } | |
662 | ||
905d77cd DJ |
663 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
664 | const char *buf, size_t count) | |
1da177e4 | 665 | { |
905d77cd DJ |
666 | struct cpufreq_policy *policy = to_policy(kobj); |
667 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 668 | ssize_t ret = -EINVAL; |
6eed9404 | 669 | |
4f750c93 SB |
670 | get_online_cpus(); |
671 | ||
672 | if (!cpu_online(policy->cpu)) | |
673 | goto unlock; | |
674 | ||
6eed9404 | 675 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 676 | goto unlock; |
5a01f2e8 | 677 | |
ad7722da | 678 | down_write(&policy->rwsem); |
5a01f2e8 | 679 | |
e08f5f5b GS |
680 | if (fattr->store) |
681 | ret = fattr->store(policy, buf, count); | |
682 | else | |
683 | ret = -EIO; | |
684 | ||
ad7722da | 685 | up_write(&policy->rwsem); |
6eed9404 | 686 | |
6eed9404 | 687 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
688 | unlock: |
689 | put_online_cpus(); | |
690 | ||
1da177e4 LT |
691 | return ret; |
692 | } | |
693 | ||
905d77cd | 694 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 695 | { |
905d77cd | 696 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 697 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
698 | complete(&policy->kobj_unregister); |
699 | } | |
700 | ||
52cf25d0 | 701 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
702 | .show = show, |
703 | .store = store, | |
704 | }; | |
705 | ||
706 | static struct kobj_type ktype_cpufreq = { | |
707 | .sysfs_ops = &sysfs_ops, | |
708 | .default_attrs = default_attrs, | |
709 | .release = cpufreq_sysfs_release, | |
710 | }; | |
711 | ||
2361be23 VK |
712 | struct kobject *cpufreq_global_kobject; |
713 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
714 | ||
715 | static int cpufreq_global_kobject_usage; | |
716 | ||
717 | int cpufreq_get_global_kobject(void) | |
718 | { | |
719 | if (!cpufreq_global_kobject_usage++) | |
720 | return kobject_add(cpufreq_global_kobject, | |
721 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
722 | ||
723 | return 0; | |
724 | } | |
725 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
726 | ||
727 | void cpufreq_put_global_kobject(void) | |
728 | { | |
729 | if (!--cpufreq_global_kobject_usage) | |
730 | kobject_del(cpufreq_global_kobject); | |
731 | } | |
732 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
733 | ||
734 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
735 | { | |
736 | int ret = cpufreq_get_global_kobject(); | |
737 | ||
738 | if (!ret) { | |
739 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
740 | if (ret) | |
741 | cpufreq_put_global_kobject(); | |
742 | } | |
743 | ||
744 | return ret; | |
745 | } | |
746 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
747 | ||
748 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
749 | { | |
750 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
751 | cpufreq_put_global_kobject(); | |
752 | } | |
753 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
754 | ||
19d6f7ec | 755 | /* symlink affected CPUs */ |
308b60e7 | 756 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
757 | { |
758 | unsigned int j; | |
759 | int ret = 0; | |
760 | ||
761 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 762 | struct device *cpu_dev; |
19d6f7ec | 763 | |
308b60e7 | 764 | if (j == policy->cpu) |
19d6f7ec | 765 | continue; |
19d6f7ec | 766 | |
e8fdde10 | 767 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
768 | cpu_dev = get_cpu_device(j); |
769 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 770 | "cpufreq"); |
71c3461e RW |
771 | if (ret) |
772 | break; | |
19d6f7ec DJ |
773 | } |
774 | return ret; | |
775 | } | |
776 | ||
308b60e7 | 777 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 778 | struct device *dev) |
909a694e DJ |
779 | { |
780 | struct freq_attr **drv_attr; | |
909a694e | 781 | int ret = 0; |
909a694e DJ |
782 | |
783 | /* prepare interface data */ | |
784 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 785 | &dev->kobj, "cpufreq"); |
909a694e DJ |
786 | if (ret) |
787 | return ret; | |
788 | ||
789 | /* set up files for this cpu device */ | |
1c3d85dd | 790 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
791 | while ((drv_attr) && (*drv_attr)) { |
792 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
793 | if (ret) | |
1c3d85dd | 794 | goto err_out_kobj_put; |
909a694e DJ |
795 | drv_attr++; |
796 | } | |
1c3d85dd | 797 | if (cpufreq_driver->get) { |
909a694e DJ |
798 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
799 | if (ret) | |
1c3d85dd | 800 | goto err_out_kobj_put; |
909a694e | 801 | } |
9c0ebcf7 | 802 | if (has_target()) { |
909a694e DJ |
803 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
804 | if (ret) | |
1c3d85dd | 805 | goto err_out_kobj_put; |
909a694e | 806 | } |
1c3d85dd | 807 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
808 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
809 | if (ret) | |
1c3d85dd | 810 | goto err_out_kobj_put; |
e2f74f35 | 811 | } |
909a694e | 812 | |
308b60e7 | 813 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
814 | if (ret) |
815 | goto err_out_kobj_put; | |
816 | ||
e18f1682 SB |
817 | return ret; |
818 | ||
819 | err_out_kobj_put: | |
820 | kobject_put(&policy->kobj); | |
821 | wait_for_completion(&policy->kobj_unregister); | |
822 | return ret; | |
823 | } | |
824 | ||
825 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
826 | { | |
827 | struct cpufreq_policy new_policy; | |
828 | int ret = 0; | |
829 | ||
d5b73cd8 | 830 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 JB |
831 | |
832 | /* Use the default policy if its valid. */ | |
833 | if (cpufreq_driver->setpolicy) | |
834 | cpufreq_parse_governor(policy->governor->name, | |
835 | &new_policy.policy, NULL); | |
836 | ||
037ce839 | 837 | /* assure that the starting sequence is run in cpufreq_set_policy */ |
ecf7e461 DJ |
838 | policy->governor = NULL; |
839 | ||
840 | /* set default policy */ | |
037ce839 | 841 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 | 842 | if (ret) { |
2d06d8c4 | 843 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
844 | if (cpufreq_driver->exit) |
845 | cpufreq_driver->exit(policy); | |
ecf7e461 | 846 | } |
909a694e DJ |
847 | } |
848 | ||
fcf80582 | 849 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 | 850 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 851 | unsigned int cpu, struct device *dev) |
fcf80582 | 852 | { |
9c0ebcf7 | 853 | int ret = 0; |
fcf80582 VK |
854 | unsigned long flags; |
855 | ||
9c0ebcf7 | 856 | if (has_target()) { |
3de9bdeb VK |
857 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
858 | if (ret) { | |
859 | pr_err("%s: Failed to stop governor\n", __func__); | |
860 | return ret; | |
861 | } | |
862 | } | |
fcf80582 | 863 | |
ad7722da | 864 | down_write(&policy->rwsem); |
2eaa3e2d | 865 | |
0d1857a1 | 866 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 867 | |
fcf80582 VK |
868 | cpumask_set_cpu(cpu, policy->cpus); |
869 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 870 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 871 | |
ad7722da | 872 | up_write(&policy->rwsem); |
2eaa3e2d | 873 | |
9c0ebcf7 | 874 | if (has_target()) { |
3de9bdeb VK |
875 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
876 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
877 | pr_err("%s: Failed to start governor\n", __func__); | |
878 | return ret; | |
879 | } | |
820c6ca2 | 880 | } |
fcf80582 | 881 | |
42f921a6 | 882 | return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
fcf80582 VK |
883 | } |
884 | #endif | |
1da177e4 | 885 | |
8414809c SB |
886 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
887 | { | |
888 | struct cpufreq_policy *policy; | |
889 | unsigned long flags; | |
890 | ||
44871c9c | 891 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
892 | |
893 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
894 | ||
44871c9c | 895 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c SB |
896 | |
897 | return policy; | |
898 | } | |
899 | ||
e9698cc5 SB |
900 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
901 | { | |
902 | struct cpufreq_policy *policy; | |
903 | ||
904 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
905 | if (!policy) | |
906 | return NULL; | |
907 | ||
908 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
909 | goto err_free_policy; | |
910 | ||
911 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
912 | goto err_free_cpumask; | |
913 | ||
c88a1f8b | 914 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 915 | init_rwsem(&policy->rwsem); |
916 | ||
e9698cc5 SB |
917 | return policy; |
918 | ||
919 | err_free_cpumask: | |
920 | free_cpumask_var(policy->cpus); | |
921 | err_free_policy: | |
922 | kfree(policy); | |
923 | ||
924 | return NULL; | |
925 | } | |
926 | ||
42f921a6 VK |
927 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
928 | { | |
929 | struct kobject *kobj; | |
930 | struct completion *cmp; | |
931 | ||
932 | down_read(&policy->rwsem); | |
933 | kobj = &policy->kobj; | |
934 | cmp = &policy->kobj_unregister; | |
935 | up_read(&policy->rwsem); | |
936 | kobject_put(kobj); | |
937 | ||
938 | /* | |
939 | * We need to make sure that the underlying kobj is | |
940 | * actually not referenced anymore by anybody before we | |
941 | * proceed with unloading. | |
942 | */ | |
943 | pr_debug("waiting for dropping of refcount\n"); | |
944 | wait_for_completion(cmp); | |
945 | pr_debug("wait complete\n"); | |
946 | } | |
947 | ||
e9698cc5 SB |
948 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
949 | { | |
950 | free_cpumask_var(policy->related_cpus); | |
951 | free_cpumask_var(policy->cpus); | |
952 | kfree(policy); | |
953 | } | |
954 | ||
0d66b91e SB |
955 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
956 | { | |
99ec899e | 957 | if (WARN_ON(cpu == policy->cpu)) |
cb38ed5c SB |
958 | return; |
959 | ||
ad7722da | 960 | down_write(&policy->rwsem); |
8efd5765 | 961 | |
0d66b91e SB |
962 | policy->last_cpu = policy->cpu; |
963 | policy->cpu = cpu; | |
964 | ||
ad7722da | 965 | up_write(&policy->rwsem); |
8efd5765 | 966 | |
0d66b91e | 967 | cpufreq_frequency_table_update_policy_cpu(policy); |
0d66b91e SB |
968 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
969 | CPUFREQ_UPDATE_POLICY_CPU, 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 |
1b274294 | 980 | struct cpufreq_policy *tpolicy; |
fcf80582 | 981 | struct cpufreq_governor *gov; |
90e41bac | 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 | } | |
5025d628 | 997 | #endif |
fcf80582 | 998 | |
6eed9404 VK |
999 | if (!down_read_trylock(&cpufreq_rwsem)) |
1000 | return 0; | |
1001 | ||
fcf80582 VK |
1002 | #ifdef CONFIG_HOTPLUG_CPU |
1003 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1004 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1005 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1006 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1007 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
42f921a6 | 1008 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev); |
6eed9404 VK |
1009 | up_read(&cpufreq_rwsem); |
1010 | return ret; | |
2eaa3e2d | 1011 | } |
fcf80582 | 1012 | } |
0d1857a1 | 1013 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1014 | #endif |
1015 | ||
72368d12 RW |
1016 | /* |
1017 | * Restore the saved policy when doing light-weight init and fall back | |
1018 | * to the full init if that fails. | |
1019 | */ | |
1020 | policy = frozen ? cpufreq_policy_restore(cpu) : NULL; | |
1021 | if (!policy) { | |
1022 | frozen = false; | |
8414809c | 1023 | policy = cpufreq_policy_alloc(); |
72368d12 RW |
1024 | if (!policy) |
1025 | goto nomem_out; | |
1026 | } | |
0d66b91e SB |
1027 | |
1028 | /* | |
1029 | * In the resume path, since we restore a saved policy, the assignment | |
1030 | * to policy->cpu is like an update of the existing policy, rather than | |
1031 | * the creation of a brand new one. So we need to perform this update | |
1032 | * by invoking update_policy_cpu(). | |
1033 | */ | |
1034 | if (frozen && cpu != policy->cpu) | |
1035 | update_policy_cpu(policy, cpu); | |
1036 | else | |
1037 | policy->cpu = cpu; | |
1038 | ||
65922465 | 1039 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1040 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1041 | |
1da177e4 | 1042 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1043 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1044 | |
1045 | /* call driver. From then on the cpufreq must be able | |
1046 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1047 | */ | |
1c3d85dd | 1048 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1049 | if (ret) { |
2d06d8c4 | 1050 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1051 | goto err_set_policy_cpu; |
1da177e4 | 1052 | } |
643ae6e8 | 1053 | |
da60ce9f VK |
1054 | if (cpufreq_driver->get) { |
1055 | policy->cur = cpufreq_driver->get(policy->cpu); | |
1056 | if (!policy->cur) { | |
1057 | pr_err("%s: ->get() failed\n", __func__); | |
1058 | goto err_get_freq; | |
1059 | } | |
1060 | } | |
1061 | ||
fcf80582 VK |
1062 | /* related cpus should atleast have policy->cpus */ |
1063 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1064 | ||
643ae6e8 VK |
1065 | /* |
1066 | * affected cpus must always be the one, which are online. We aren't | |
1067 | * managing offline cpus here. | |
1068 | */ | |
1069 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1070 | ||
08fd8c1c VK |
1071 | if (!frozen) { |
1072 | policy->user_policy.min = policy->min; | |
1073 | policy->user_policy.max = policy->max; | |
1074 | } | |
1da177e4 | 1075 | |
a1531acd TR |
1076 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1077 | CPUFREQ_START, policy); | |
1078 | ||
fcf80582 VK |
1079 | #ifdef CONFIG_HOTPLUG_CPU |
1080 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1081 | if (gov) { | |
1082 | policy->governor = gov; | |
1083 | pr_debug("Restoring governor %s for cpu %d\n", | |
1084 | policy->governor->name, cpu); | |
4bfa042c | 1085 | } |
fcf80582 | 1086 | #endif |
1da177e4 | 1087 | |
e18f1682 | 1088 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1089 | for_each_cpu(j, policy->cpus) |
e18f1682 | 1090 | per_cpu(cpufreq_cpu_data, j) = policy; |
e18f1682 SB |
1091 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1092 | ||
a82fab29 | 1093 | if (!frozen) { |
308b60e7 | 1094 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1095 | if (ret) |
1096 | goto err_out_unregister; | |
1097 | } | |
8ff69732 | 1098 | |
9515f4d6 VK |
1099 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1100 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1101 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1102 | ||
e18f1682 SB |
1103 | cpufreq_init_policy(policy); |
1104 | ||
08fd8c1c VK |
1105 | if (!frozen) { |
1106 | policy->user_policy.policy = policy->policy; | |
1107 | policy->user_policy.governor = policy->governor; | |
1108 | } | |
1109 | ||
038c5b3e | 1110 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1111 | up_read(&cpufreq_rwsem); |
1112 | ||
2d06d8c4 | 1113 | pr_debug("initialization complete\n"); |
87c32271 | 1114 | |
1da177e4 LT |
1115 | return 0; |
1116 | ||
1da177e4 | 1117 | err_out_unregister: |
0d1857a1 | 1118 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1119 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1120 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1121 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1122 | |
da60ce9f VK |
1123 | err_get_freq: |
1124 | if (cpufreq_driver->exit) | |
1125 | cpufreq_driver->exit(policy); | |
2eaa3e2d | 1126 | err_set_policy_cpu: |
72368d12 RW |
1127 | if (frozen) { |
1128 | /* Do not leave stale fallback data behind. */ | |
1129 | per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; | |
42f921a6 | 1130 | cpufreq_policy_put_kobj(policy); |
72368d12 | 1131 | } |
e9698cc5 | 1132 | cpufreq_policy_free(policy); |
42f921a6 | 1133 | |
1da177e4 | 1134 | nomem_out: |
6eed9404 VK |
1135 | up_read(&cpufreq_rwsem); |
1136 | ||
1da177e4 LT |
1137 | return ret; |
1138 | } | |
1139 | ||
a82fab29 SB |
1140 | /** |
1141 | * cpufreq_add_dev - add a CPU device | |
1142 | * | |
1143 | * Adds the cpufreq interface for a CPU device. | |
1144 | * | |
1145 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1146 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1147 | * mess up, but more thorough testing is needed. - Mathieu | |
1148 | */ | |
1149 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1150 | { | |
1151 | return __cpufreq_add_dev(dev, sif, false); | |
1152 | } | |
1153 | ||
3a3e9e06 | 1154 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 1155 | unsigned int old_cpu) |
f9ba680d SB |
1156 | { |
1157 | struct device *cpu_dev; | |
f9ba680d SB |
1158 | int ret; |
1159 | ||
1160 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1161 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 | 1162 | |
f9ba680d | 1163 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1164 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d SB |
1165 | if (ret) { |
1166 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1167 | ||
ad7722da | 1168 | down_write(&policy->rwsem); |
3a3e9e06 | 1169 | cpumask_set_cpu(old_cpu, policy->cpus); |
ad7722da | 1170 | up_write(&policy->rwsem); |
f9ba680d | 1171 | |
3a3e9e06 | 1172 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1173 | "cpufreq"); |
1174 | ||
1175 | return -EINVAL; | |
1176 | } | |
1177 | ||
1178 | return cpu_dev->id; | |
1179 | } | |
1180 | ||
cedb70af SB |
1181 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
1182 | struct subsys_interface *sif, | |
1183 | bool frozen) | |
1da177e4 | 1184 | { |
f9ba680d | 1185 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1186 | int new_cpu, ret; |
1da177e4 | 1187 | unsigned long flags; |
3a3e9e06 | 1188 | struct cpufreq_policy *policy; |
1da177e4 | 1189 | |
b8eed8af | 1190 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1191 | |
0d1857a1 | 1192 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1193 | |
3a3e9e06 | 1194 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1195 | |
8414809c SB |
1196 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1197 | if (frozen) | |
3a3e9e06 | 1198 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1199 | |
0d1857a1 | 1200 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1201 | |
3a3e9e06 | 1202 | if (!policy) { |
b8eed8af | 1203 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1204 | return -EINVAL; |
1205 | } | |
1da177e4 | 1206 | |
9c0ebcf7 | 1207 | if (has_target()) { |
3de9bdeb VK |
1208 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1209 | if (ret) { | |
1210 | pr_err("%s: Failed to stop governor\n", __func__); | |
1211 | return ret; | |
1212 | } | |
1213 | } | |
1da177e4 | 1214 | |
084f3493 | 1215 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1216 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1217 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1218 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 LT |
1219 | #endif |
1220 | ||
ad7722da | 1221 | down_read(&policy->rwsem); |
3a3e9e06 | 1222 | cpus = cpumask_weight(policy->cpus); |
ad7722da | 1223 | up_read(&policy->rwsem); |
084f3493 | 1224 | |
61173f25 SB |
1225 | if (cpu != policy->cpu) { |
1226 | if (!frozen) | |
1227 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
73bf0fc2 | 1228 | } else if (cpus > 1) { |
42f921a6 | 1229 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu); |
f9ba680d | 1230 | if (new_cpu >= 0) { |
3a3e9e06 | 1231 | update_policy_cpu(policy, new_cpu); |
a82fab29 SB |
1232 | |
1233 | if (!frozen) { | |
75949c9a VK |
1234 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1235 | __func__, new_cpu, cpu); | |
a82fab29 | 1236 | } |
1da177e4 LT |
1237 | } |
1238 | } | |
1da177e4 | 1239 | |
cedb70af SB |
1240 | return 0; |
1241 | } | |
1242 | ||
1243 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
1244 | struct subsys_interface *sif, | |
1245 | bool frozen) | |
1246 | { | |
1247 | unsigned int cpu = dev->id, cpus; | |
1248 | int ret; | |
1249 | unsigned long flags; | |
1250 | struct cpufreq_policy *policy; | |
cedb70af SB |
1251 | |
1252 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1253 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1254 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1255 | ||
1256 | if (!policy) { | |
1257 | pr_debug("%s: No cpu_data found\n", __func__); | |
1258 | return -EINVAL; | |
1259 | } | |
1260 | ||
ad7722da | 1261 | down_write(&policy->rwsem); |
cedb70af | 1262 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1263 | |
1264 | if (cpus > 1) | |
1265 | cpumask_clear_cpu(cpu, policy->cpus); | |
ad7722da | 1266 | up_write(&policy->rwsem); |
cedb70af | 1267 | |
b8eed8af VK |
1268 | /* If cpu is last user of policy, free policy */ |
1269 | if (cpus == 1) { | |
9c0ebcf7 | 1270 | if (has_target()) { |
3de9bdeb VK |
1271 | ret = __cpufreq_governor(policy, |
1272 | CPUFREQ_GOV_POLICY_EXIT); | |
1273 | if (ret) { | |
1274 | pr_err("%s: Failed to exit governor\n", | |
1275 | __func__); | |
1276 | return ret; | |
1277 | } | |
edab2fbc | 1278 | } |
2a998599 | 1279 | |
42f921a6 VK |
1280 | if (!frozen) |
1281 | cpufreq_policy_put_kobj(policy); | |
7d26e2d5 | 1282 | |
8414809c SB |
1283 | /* |
1284 | * Perform the ->exit() even during light-weight tear-down, | |
1285 | * since this is a core component, and is essential for the | |
1286 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1287 | */ |
1c3d85dd | 1288 | if (cpufreq_driver->exit) |
3a3e9e06 | 1289 | cpufreq_driver->exit(policy); |
27ecddc2 | 1290 | |
9515f4d6 VK |
1291 | /* Remove policy from list of active policies */ |
1292 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1293 | list_del(&policy->policy_list); | |
1294 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1295 | ||
8414809c | 1296 | if (!frozen) |
3a3e9e06 | 1297 | cpufreq_policy_free(policy); |
2a998599 | 1298 | } else { |
9c0ebcf7 | 1299 | if (has_target()) { |
3de9bdeb VK |
1300 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
1301 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
1302 | pr_err("%s: Failed to start governor\n", | |
1303 | __func__); | |
1304 | return ret; | |
1305 | } | |
2a998599 | 1306 | } |
27ecddc2 | 1307 | } |
1da177e4 | 1308 | |
474deff7 | 1309 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1310 | return 0; |
1311 | } | |
1312 | ||
cedb70af | 1313 | /** |
27a862e9 | 1314 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1315 | * |
1316 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1317 | */ |
8a25a2fd | 1318 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1319 | { |
8a25a2fd | 1320 | unsigned int cpu = dev->id; |
27a862e9 | 1321 | int ret; |
ec28297a VP |
1322 | |
1323 | if (cpu_is_offline(cpu)) | |
1324 | return 0; | |
1325 | ||
27a862e9 VK |
1326 | ret = __cpufreq_remove_dev_prepare(dev, sif, false); |
1327 | ||
1328 | if (!ret) | |
1329 | ret = __cpufreq_remove_dev_finish(dev, sif, false); | |
1330 | ||
1331 | return ret; | |
5a01f2e8 VP |
1332 | } |
1333 | ||
65f27f38 | 1334 | static void handle_update(struct work_struct *work) |
1da177e4 | 1335 | { |
65f27f38 DH |
1336 | struct cpufreq_policy *policy = |
1337 | container_of(work, struct cpufreq_policy, update); | |
1338 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1339 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1340 | cpufreq_update_policy(cpu); |
1341 | } | |
1342 | ||
1343 | /** | |
bb176f7d VK |
1344 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1345 | * in deep trouble. | |
1da177e4 LT |
1346 | * @cpu: cpu number |
1347 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1348 | * @new_freq: CPU frequency the CPU actually runs at | |
1349 | * | |
29464f28 DJ |
1350 | * We adjust to current frequency first, and need to clean up later. |
1351 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1352 | */ |
e08f5f5b GS |
1353 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1354 | unsigned int new_freq) | |
1da177e4 | 1355 | { |
b43a7ffb | 1356 | struct cpufreq_policy *policy; |
1da177e4 | 1357 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1358 | unsigned long flags; |
1359 | ||
2d06d8c4 | 1360 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1361 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1362 | ||
1da177e4 LT |
1363 | freqs.old = old_freq; |
1364 | freqs.new = new_freq; | |
b43a7ffb VK |
1365 | |
1366 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1367 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1368 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1369 | ||
1370 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1371 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1372 | } |
1373 | ||
32ee8c3e | 1374 | /** |
4ab70df4 | 1375 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1376 | * @cpu: CPU number |
1377 | * | |
1378 | * This is the last known freq, without actually getting it from the driver. | |
1379 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1380 | */ | |
1381 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1382 | { | |
9e21ba8b | 1383 | struct cpufreq_policy *policy; |
e08f5f5b | 1384 | unsigned int ret_freq = 0; |
95235ca2 | 1385 | |
1c3d85dd RW |
1386 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1387 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1388 | |
1389 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1390 | if (policy) { |
e08f5f5b | 1391 | ret_freq = policy->cur; |
95235ca2 VP |
1392 | cpufreq_cpu_put(policy); |
1393 | } | |
1394 | ||
4d34a67d | 1395 | return ret_freq; |
95235ca2 VP |
1396 | } |
1397 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1398 | ||
3d737108 JB |
1399 | /** |
1400 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1401 | * @cpu: CPU number | |
1402 | * | |
1403 | * Just return the max possible frequency for a given CPU. | |
1404 | */ | |
1405 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1406 | { | |
1407 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1408 | unsigned int ret_freq = 0; | |
1409 | ||
1410 | if (policy) { | |
1411 | ret_freq = policy->max; | |
1412 | cpufreq_cpu_put(policy); | |
1413 | } | |
1414 | ||
1415 | return ret_freq; | |
1416 | } | |
1417 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1418 | ||
5a01f2e8 | 1419 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1420 | { |
7a6aedfa | 1421 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1422 | unsigned int ret_freq = 0; |
5800043b | 1423 | |
1c3d85dd | 1424 | if (!cpufreq_driver->get) |
4d34a67d | 1425 | return ret_freq; |
1da177e4 | 1426 | |
1c3d85dd | 1427 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1428 | |
e08f5f5b | 1429 | if (ret_freq && policy->cur && |
1c3d85dd | 1430 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1431 | /* verify no discrepancy between actual and |
1432 | saved value exists */ | |
1433 | if (unlikely(ret_freq != policy->cur)) { | |
1434 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1435 | schedule_work(&policy->update); |
1436 | } | |
1437 | } | |
1438 | ||
4d34a67d | 1439 | return ret_freq; |
5a01f2e8 | 1440 | } |
1da177e4 | 1441 | |
5a01f2e8 VP |
1442 | /** |
1443 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1444 | * @cpu: CPU number | |
1445 | * | |
1446 | * Get the CPU current (static) CPU frequency | |
1447 | */ | |
1448 | unsigned int cpufreq_get(unsigned int cpu) | |
1449 | { | |
ad7722da | 1450 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
5a01f2e8 | 1451 | unsigned int ret_freq = 0; |
5a01f2e8 | 1452 | |
26ca8694 VK |
1453 | if (cpufreq_disabled() || !cpufreq_driver) |
1454 | return -ENOENT; | |
1455 | ||
ad7722da | 1456 | BUG_ON(!policy); |
1457 | ||
6eed9404 VK |
1458 | if (!down_read_trylock(&cpufreq_rwsem)) |
1459 | return 0; | |
5a01f2e8 | 1460 | |
ad7722da | 1461 | down_read(&policy->rwsem); |
5a01f2e8 VP |
1462 | |
1463 | ret_freq = __cpufreq_get(cpu); | |
1464 | ||
ad7722da | 1465 | up_read(&policy->rwsem); |
6eed9404 VK |
1466 | up_read(&cpufreq_rwsem); |
1467 | ||
4d34a67d | 1468 | return ret_freq; |
1da177e4 LT |
1469 | } |
1470 | EXPORT_SYMBOL(cpufreq_get); | |
1471 | ||
8a25a2fd KS |
1472 | static struct subsys_interface cpufreq_interface = { |
1473 | .name = "cpufreq", | |
1474 | .subsys = &cpu_subsys, | |
1475 | .add_dev = cpufreq_add_dev, | |
1476 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1477 | }; |
1478 | ||
42d4dc3f | 1479 | /** |
e00e56df RW |
1480 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1481 | * | |
1482 | * This function is only executed for the boot processor. The other CPUs | |
1483 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1484 | */ |
e00e56df | 1485 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1486 | { |
e08f5f5b | 1487 | int ret = 0; |
4bc5d341 | 1488 | |
e00e56df | 1489 | int cpu = smp_processor_id(); |
3a3e9e06 | 1490 | struct cpufreq_policy *policy; |
42d4dc3f | 1491 | |
2d06d8c4 | 1492 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1493 | |
e00e56df | 1494 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1495 | policy = cpufreq_cpu_get(cpu); |
1496 | if (!policy) | |
e00e56df | 1497 | return 0; |
42d4dc3f | 1498 | |
1c3d85dd | 1499 | if (cpufreq_driver->suspend) { |
3a3e9e06 | 1500 | ret = cpufreq_driver->suspend(policy); |
ce6c3997 | 1501 | if (ret) |
42d4dc3f | 1502 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
3a3e9e06 | 1503 | "step on CPU %u\n", policy->cpu); |
42d4dc3f BH |
1504 | } |
1505 | ||
3a3e9e06 | 1506 | cpufreq_cpu_put(policy); |
c9060494 | 1507 | return ret; |
42d4dc3f BH |
1508 | } |
1509 | ||
1da177e4 | 1510 | /** |
e00e56df | 1511 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1512 | * |
1513 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1514 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1515 | * restored. It will verify that the current freq is in sync with | |
1516 | * what we believe it to be. This is a bit later than when it | |
1517 | * should be, but nonethteless it's better than calling | |
1518 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1519 | * |
1520 | * This function is only executed for the boot CPU. The other CPUs have not | |
1521 | * been turned on yet. | |
1da177e4 | 1522 | */ |
e00e56df | 1523 | static void cpufreq_bp_resume(void) |
1da177e4 | 1524 | { |
e08f5f5b | 1525 | int ret = 0; |
4bc5d341 | 1526 | |
e00e56df | 1527 | int cpu = smp_processor_id(); |
3a3e9e06 | 1528 | struct cpufreq_policy *policy; |
1da177e4 | 1529 | |
2d06d8c4 | 1530 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1531 | |
e00e56df | 1532 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1533 | policy = cpufreq_cpu_get(cpu); |
1534 | if (!policy) | |
e00e56df | 1535 | return; |
1da177e4 | 1536 | |
1c3d85dd | 1537 | if (cpufreq_driver->resume) { |
3a3e9e06 | 1538 | ret = cpufreq_driver->resume(policy); |
1da177e4 LT |
1539 | if (ret) { |
1540 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
3a3e9e06 | 1541 | "step on CPU %u\n", policy->cpu); |
c9060494 | 1542 | goto fail; |
1da177e4 LT |
1543 | } |
1544 | } | |
1545 | ||
3a3e9e06 | 1546 | schedule_work(&policy->update); |
ce6c3997 | 1547 | |
c9060494 | 1548 | fail: |
3a3e9e06 | 1549 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1550 | } |
1551 | ||
e00e56df RW |
1552 | static struct syscore_ops cpufreq_syscore_ops = { |
1553 | .suspend = cpufreq_bp_suspend, | |
1554 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1555 | }; |
1556 | ||
9d95046e BP |
1557 | /** |
1558 | * cpufreq_get_current_driver - return current driver's name | |
1559 | * | |
1560 | * Return the name string of the currently loaded cpufreq driver | |
1561 | * or NULL, if none. | |
1562 | */ | |
1563 | const char *cpufreq_get_current_driver(void) | |
1564 | { | |
1c3d85dd RW |
1565 | if (cpufreq_driver) |
1566 | return cpufreq_driver->name; | |
1567 | ||
1568 | return NULL; | |
9d95046e BP |
1569 | } |
1570 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1571 | |
1572 | /********************************************************************* | |
1573 | * NOTIFIER LISTS INTERFACE * | |
1574 | *********************************************************************/ | |
1575 | ||
1576 | /** | |
1577 | * cpufreq_register_notifier - register a driver with cpufreq | |
1578 | * @nb: notifier function to register | |
1579 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1580 | * | |
32ee8c3e | 1581 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1582 | * are notified about clock rate changes (once before and once after |
1583 | * the transition), or a list of drivers that are notified about | |
1584 | * changes in cpufreq policy. | |
1585 | * | |
1586 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1587 | * blocking_notifier_chain_register. |
1da177e4 LT |
1588 | */ |
1589 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1590 | { | |
1591 | int ret; | |
1592 | ||
d5aaffa9 DB |
1593 | if (cpufreq_disabled()) |
1594 | return -EINVAL; | |
1595 | ||
74212ca4 CEB |
1596 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1597 | ||
1da177e4 LT |
1598 | switch (list) { |
1599 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1600 | ret = srcu_notifier_chain_register( |
e041c683 | 1601 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1602 | break; |
1603 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1604 | ret = blocking_notifier_chain_register( |
1605 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1606 | break; |
1607 | default: | |
1608 | ret = -EINVAL; | |
1609 | } | |
1da177e4 LT |
1610 | |
1611 | return ret; | |
1612 | } | |
1613 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1614 | ||
1da177e4 LT |
1615 | /** |
1616 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1617 | * @nb: notifier block to be unregistered | |
bb176f7d | 1618 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1619 | * |
1620 | * Remove a driver from the CPU frequency notifier list. | |
1621 | * | |
1622 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1623 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1624 | */ |
1625 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1626 | { | |
1627 | int ret; | |
1628 | ||
d5aaffa9 DB |
1629 | if (cpufreq_disabled()) |
1630 | return -EINVAL; | |
1631 | ||
1da177e4 LT |
1632 | switch (list) { |
1633 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1634 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1635 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1636 | break; |
1637 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1638 | ret = blocking_notifier_chain_unregister( |
1639 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1640 | break; |
1641 | default: | |
1642 | ret = -EINVAL; | |
1643 | } | |
1da177e4 LT |
1644 | |
1645 | return ret; | |
1646 | } | |
1647 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1648 | ||
1649 | ||
1650 | /********************************************************************* | |
1651 | * GOVERNORS * | |
1652 | *********************************************************************/ | |
1653 | ||
1da177e4 LT |
1654 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1655 | unsigned int target_freq, | |
1656 | unsigned int relation) | |
1657 | { | |
1658 | int retval = -EINVAL; | |
7249924e | 1659 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1660 | |
a7b422cd KRW |
1661 | if (cpufreq_disabled()) |
1662 | return -ENODEV; | |
1663 | ||
7249924e VK |
1664 | /* Make sure that target_freq is within supported range */ |
1665 | if (target_freq > policy->max) | |
1666 | target_freq = policy->max; | |
1667 | if (target_freq < policy->min) | |
1668 | target_freq = policy->min; | |
1669 | ||
1670 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1671 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 | 1672 | |
9c0ebcf7 VK |
1673 | /* |
1674 | * This might look like a redundant call as we are checking it again | |
1675 | * after finding index. But it is left intentionally for cases where | |
1676 | * exactly same freq is called again and so we can save on few function | |
1677 | * calls. | |
1678 | */ | |
5a1c0228 VK |
1679 | if (target_freq == policy->cur) |
1680 | return 0; | |
1681 | ||
1c3d85dd RW |
1682 | if (cpufreq_driver->target) |
1683 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
9c0ebcf7 VK |
1684 | else if (cpufreq_driver->target_index) { |
1685 | struct cpufreq_frequency_table *freq_table; | |
d4019f0a VK |
1686 | struct cpufreq_freqs freqs; |
1687 | bool notify; | |
9c0ebcf7 | 1688 | int index; |
90d45d17 | 1689 | |
9c0ebcf7 VK |
1690 | freq_table = cpufreq_frequency_get_table(policy->cpu); |
1691 | if (unlikely(!freq_table)) { | |
1692 | pr_err("%s: Unable to find freq_table\n", __func__); | |
1693 | goto out; | |
1694 | } | |
1695 | ||
1696 | retval = cpufreq_frequency_table_target(policy, freq_table, | |
1697 | target_freq, relation, &index); | |
1698 | if (unlikely(retval)) { | |
1699 | pr_err("%s: Unable to find matching freq\n", __func__); | |
1700 | goto out; | |
1701 | } | |
1702 | ||
d4019f0a | 1703 | if (freq_table[index].frequency == policy->cur) { |
9c0ebcf7 | 1704 | retval = 0; |
d4019f0a VK |
1705 | goto out; |
1706 | } | |
1707 | ||
1708 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); | |
1709 | ||
1710 | if (notify) { | |
1711 | freqs.old = policy->cur; | |
1712 | freqs.new = freq_table[index].frequency; | |
1713 | freqs.flags = 0; | |
1714 | ||
1715 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", | |
1716 | __func__, policy->cpu, freqs.old, | |
1717 | freqs.new); | |
1718 | ||
1719 | cpufreq_notify_transition(policy, &freqs, | |
1720 | CPUFREQ_PRECHANGE); | |
1721 | } | |
1722 | ||
1723 | retval = cpufreq_driver->target_index(policy, index); | |
1724 | if (retval) | |
1725 | pr_err("%s: Failed to change cpu frequency: %d\n", | |
1726 | __func__, retval); | |
1727 | ||
1728 | if (notify) { | |
1729 | /* | |
1730 | * Notify with old freq in case we failed to change | |
1731 | * frequency | |
1732 | */ | |
1733 | if (retval) | |
1734 | freqs.new = freqs.old; | |
1735 | ||
1736 | cpufreq_notify_transition(policy, &freqs, | |
1737 | CPUFREQ_POSTCHANGE); | |
1738 | } | |
9c0ebcf7 VK |
1739 | } |
1740 | ||
1741 | out: | |
1da177e4 LT |
1742 | return retval; |
1743 | } | |
1744 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1745 | ||
1da177e4 LT |
1746 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1747 | unsigned int target_freq, | |
1748 | unsigned int relation) | |
1749 | { | |
f1829e4a | 1750 | int ret = -EINVAL; |
1da177e4 | 1751 | |
ad7722da | 1752 | down_write(&policy->rwsem); |
1da177e4 LT |
1753 | |
1754 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1755 | ||
ad7722da | 1756 | up_write(&policy->rwsem); |
1da177e4 | 1757 | |
1da177e4 LT |
1758 | return ret; |
1759 | } | |
1760 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1761 | ||
153d7f3f | 1762 | /* |
153d7f3f AV |
1763 | * when "event" is CPUFREQ_GOV_LIMITS |
1764 | */ | |
1da177e4 | 1765 | |
e08f5f5b GS |
1766 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1767 | unsigned int event) | |
1da177e4 | 1768 | { |
cc993cab | 1769 | int ret; |
6afde10c TR |
1770 | |
1771 | /* Only must be defined when default governor is known to have latency | |
1772 | restrictions, like e.g. conservative or ondemand. | |
1773 | That this is the case is already ensured in Kconfig | |
1774 | */ | |
1775 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1776 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1777 | #else | |
1778 | struct cpufreq_governor *gov = NULL; | |
1779 | #endif | |
1c256245 TR |
1780 | |
1781 | if (policy->governor->max_transition_latency && | |
1782 | policy->cpuinfo.transition_latency > | |
1783 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1784 | if (!gov) |
1785 | return -EINVAL; | |
1786 | else { | |
1787 | printk(KERN_WARNING "%s governor failed, too long" | |
1788 | " transition latency of HW, fallback" | |
1789 | " to %s governor\n", | |
1790 | policy->governor->name, | |
1791 | gov->name); | |
1792 | policy->governor = gov; | |
1793 | } | |
1c256245 | 1794 | } |
1da177e4 | 1795 | |
fe492f3f VK |
1796 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1797 | if (!try_module_get(policy->governor->owner)) | |
1798 | return -EINVAL; | |
1da177e4 | 1799 | |
2d06d8c4 | 1800 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1801 | policy->cpu, event); |
95731ebb XC |
1802 | |
1803 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1804 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1805 | || (!policy->governor_enabled |
1806 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1807 | mutex_unlock(&cpufreq_governor_lock); |
1808 | return -EBUSY; | |
1809 | } | |
1810 | ||
1811 | if (event == CPUFREQ_GOV_STOP) | |
1812 | policy->governor_enabled = false; | |
1813 | else if (event == CPUFREQ_GOV_START) | |
1814 | policy->governor_enabled = true; | |
1815 | ||
1816 | mutex_unlock(&cpufreq_governor_lock); | |
1817 | ||
1da177e4 LT |
1818 | ret = policy->governor->governor(policy, event); |
1819 | ||
4d5dcc42 VK |
1820 | if (!ret) { |
1821 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1822 | policy->governor->initialized++; | |
1823 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1824 | policy->governor->initialized--; | |
95731ebb XC |
1825 | } else { |
1826 | /* Restore original values */ | |
1827 | mutex_lock(&cpufreq_governor_lock); | |
1828 | if (event == CPUFREQ_GOV_STOP) | |
1829 | policy->governor_enabled = true; | |
1830 | else if (event == CPUFREQ_GOV_START) | |
1831 | policy->governor_enabled = false; | |
1832 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1833 | } |
b394058f | 1834 | |
fe492f3f VK |
1835 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1836 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1837 | module_put(policy->governor->owner); |
1838 | ||
1839 | return ret; | |
1840 | } | |
1841 | ||
1da177e4 LT |
1842 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1843 | { | |
3bcb09a3 | 1844 | int err; |
1da177e4 LT |
1845 | |
1846 | if (!governor) | |
1847 | return -EINVAL; | |
1848 | ||
a7b422cd KRW |
1849 | if (cpufreq_disabled()) |
1850 | return -ENODEV; | |
1851 | ||
3fc54d37 | 1852 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1853 | |
b394058f | 1854 | governor->initialized = 0; |
3bcb09a3 JF |
1855 | err = -EBUSY; |
1856 | if (__find_governor(governor->name) == NULL) { | |
1857 | err = 0; | |
1858 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1859 | } |
1da177e4 | 1860 | |
32ee8c3e | 1861 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1862 | return err; |
1da177e4 LT |
1863 | } |
1864 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1865 | ||
1da177e4 LT |
1866 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1867 | { | |
90e41bac PB |
1868 | #ifdef CONFIG_HOTPLUG_CPU |
1869 | int cpu; | |
1870 | #endif | |
1871 | ||
1da177e4 LT |
1872 | if (!governor) |
1873 | return; | |
1874 | ||
a7b422cd KRW |
1875 | if (cpufreq_disabled()) |
1876 | return; | |
1877 | ||
90e41bac PB |
1878 | #ifdef CONFIG_HOTPLUG_CPU |
1879 | for_each_present_cpu(cpu) { | |
1880 | if (cpu_online(cpu)) | |
1881 | continue; | |
1882 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1883 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1884 | } | |
1885 | #endif | |
1886 | ||
3fc54d37 | 1887 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1888 | list_del(&governor->governor_list); |
3fc54d37 | 1889 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1890 | return; |
1891 | } | |
1892 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1893 | ||
1894 | ||
1da177e4 LT |
1895 | /********************************************************************* |
1896 | * POLICY INTERFACE * | |
1897 | *********************************************************************/ | |
1898 | ||
1899 | /** | |
1900 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1901 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1902 | * is written | |
1da177e4 LT |
1903 | * |
1904 | * Reads the current cpufreq policy. | |
1905 | */ | |
1906 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1907 | { | |
1908 | struct cpufreq_policy *cpu_policy; | |
1909 | if (!policy) | |
1910 | return -EINVAL; | |
1911 | ||
1912 | cpu_policy = cpufreq_cpu_get(cpu); | |
1913 | if (!cpu_policy) | |
1914 | return -EINVAL; | |
1915 | ||
d5b73cd8 | 1916 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
1917 | |
1918 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1919 | return 0; |
1920 | } | |
1921 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1922 | ||
153d7f3f | 1923 | /* |
037ce839 VK |
1924 | * policy : current policy. |
1925 | * new_policy: policy to be set. | |
153d7f3f | 1926 | */ |
037ce839 | 1927 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 1928 | struct cpufreq_policy *new_policy) |
1da177e4 | 1929 | { |
7bd353a9 | 1930 | int ret = 0, failed = 1; |
1da177e4 | 1931 | |
3a3e9e06 VK |
1932 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, |
1933 | new_policy->min, new_policy->max); | |
1da177e4 | 1934 | |
d5b73cd8 | 1935 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 1936 | |
3a3e9e06 | 1937 | if (new_policy->min > policy->max || new_policy->max < policy->min) { |
9c9a43ed MD |
1938 | ret = -EINVAL; |
1939 | goto error_out; | |
1940 | } | |
1941 | ||
1da177e4 | 1942 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 1943 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 LT |
1944 | if (ret) |
1945 | goto error_out; | |
1946 | ||
1da177e4 | 1947 | /* adjust if necessary - all reasons */ |
e041c683 | 1948 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1949 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
1950 | |
1951 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 1952 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1953 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 1954 | |
bb176f7d VK |
1955 | /* |
1956 | * verify the cpu speed can be set within this limit, which might be | |
1957 | * different to the first one | |
1958 | */ | |
3a3e9e06 | 1959 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 1960 | if (ret) |
1da177e4 | 1961 | goto error_out; |
1da177e4 LT |
1962 | |
1963 | /* notification of the new policy */ | |
e041c683 | 1964 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1965 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 1966 | |
3a3e9e06 VK |
1967 | policy->min = new_policy->min; |
1968 | policy->max = new_policy->max; | |
1da177e4 | 1969 | |
2d06d8c4 | 1970 | pr_debug("new min and max freqs are %u - %u kHz\n", |
3a3e9e06 | 1971 | policy->min, policy->max); |
1da177e4 | 1972 | |
1c3d85dd | 1973 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 1974 | policy->policy = new_policy->policy; |
2d06d8c4 | 1975 | pr_debug("setting range\n"); |
3a3e9e06 | 1976 | ret = cpufreq_driver->setpolicy(new_policy); |
1da177e4 | 1977 | } else { |
3a3e9e06 | 1978 | if (new_policy->governor != policy->governor) { |
1da177e4 | 1979 | /* save old, working values */ |
3a3e9e06 | 1980 | struct cpufreq_governor *old_gov = policy->governor; |
1da177e4 | 1981 | |
2d06d8c4 | 1982 | pr_debug("governor switch\n"); |
1da177e4 LT |
1983 | |
1984 | /* end old governor */ | |
3a3e9e06 VK |
1985 | if (policy->governor) { |
1986 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
ad7722da | 1987 | up_write(&policy->rwsem); |
3a3e9e06 | 1988 | __cpufreq_governor(policy, |
7bd353a9 | 1989 | CPUFREQ_GOV_POLICY_EXIT); |
ad7722da | 1990 | down_write(&policy->rwsem); |
7bd353a9 | 1991 | } |
1da177e4 LT |
1992 | |
1993 | /* start new governor */ | |
3a3e9e06 VK |
1994 | policy->governor = new_policy->governor; |
1995 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
1996 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) { | |
7bd353a9 | 1997 | failed = 0; |
955ef483 | 1998 | } else { |
ad7722da | 1999 | up_write(&policy->rwsem); |
3a3e9e06 | 2000 | __cpufreq_governor(policy, |
7bd353a9 | 2001 | CPUFREQ_GOV_POLICY_EXIT); |
ad7722da | 2002 | down_write(&policy->rwsem); |
955ef483 | 2003 | } |
7bd353a9 VK |
2004 | } |
2005 | ||
2006 | if (failed) { | |
1da177e4 | 2007 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 2008 | pr_debug("starting governor %s failed\n", |
3a3e9e06 | 2009 | policy->governor->name); |
1da177e4 | 2010 | if (old_gov) { |
3a3e9e06 VK |
2011 | policy->governor = old_gov; |
2012 | __cpufreq_governor(policy, | |
7bd353a9 | 2013 | CPUFREQ_GOV_POLICY_INIT); |
3a3e9e06 | 2014 | __cpufreq_governor(policy, |
e08f5f5b | 2015 | CPUFREQ_GOV_START); |
1da177e4 LT |
2016 | } |
2017 | ret = -EINVAL; | |
2018 | goto error_out; | |
2019 | } | |
2020 | /* might be a policy change, too, so fall through */ | |
2021 | } | |
2d06d8c4 | 2022 | pr_debug("governor: change or update limits\n"); |
3de9bdeb | 2023 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
1da177e4 LT |
2024 | } |
2025 | ||
7d5e350f | 2026 | error_out: |
1da177e4 LT |
2027 | return ret; |
2028 | } | |
2029 | ||
1da177e4 LT |
2030 | /** |
2031 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2032 | * @cpu: CPU which shall be re-evaluated | |
2033 | * | |
25985edc | 2034 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2035 | * at different times. |
2036 | */ | |
2037 | int cpufreq_update_policy(unsigned int cpu) | |
2038 | { | |
3a3e9e06 VK |
2039 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2040 | struct cpufreq_policy new_policy; | |
f1829e4a | 2041 | int ret; |
1da177e4 | 2042 | |
3a3e9e06 | 2043 | if (!policy) { |
f1829e4a JL |
2044 | ret = -ENODEV; |
2045 | goto no_policy; | |
2046 | } | |
1da177e4 | 2047 | |
ad7722da | 2048 | down_write(&policy->rwsem); |
1da177e4 | 2049 | |
2d06d8c4 | 2050 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2051 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2052 | new_policy.min = policy->user_policy.min; |
2053 | new_policy.max = policy->user_policy.max; | |
2054 | new_policy.policy = policy->user_policy.policy; | |
2055 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 2056 | |
bb176f7d VK |
2057 | /* |
2058 | * BIOS might change freq behind our back | |
2059 | * -> ask driver for current freq and notify governors about a change | |
2060 | */ | |
1c3d85dd | 2061 | if (cpufreq_driver->get) { |
3a3e9e06 VK |
2062 | new_policy.cur = cpufreq_driver->get(cpu); |
2063 | if (!policy->cur) { | |
2d06d8c4 | 2064 | pr_debug("Driver did not initialize current freq"); |
3a3e9e06 | 2065 | policy->cur = new_policy.cur; |
a85f7bd3 | 2066 | } else { |
9c0ebcf7 | 2067 | if (policy->cur != new_policy.cur && has_target()) |
3a3e9e06 VK |
2068 | cpufreq_out_of_sync(cpu, policy->cur, |
2069 | new_policy.cur); | |
a85f7bd3 | 2070 | } |
0961dd0d TR |
2071 | } |
2072 | ||
037ce839 | 2073 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2074 | |
ad7722da | 2075 | up_write(&policy->rwsem); |
5a01f2e8 | 2076 | |
3a3e9e06 | 2077 | cpufreq_cpu_put(policy); |
f1829e4a | 2078 | no_policy: |
1da177e4 LT |
2079 | return ret; |
2080 | } | |
2081 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2082 | ||
2760984f | 2083 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2084 | unsigned long action, void *hcpu) |
2085 | { | |
2086 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2087 | struct device *dev; |
5302c3fb | 2088 | bool frozen = false; |
c32b6b8e | 2089 | |
8a25a2fd KS |
2090 | dev = get_cpu_device(cpu); |
2091 | if (dev) { | |
5302c3fb | 2092 | |
d4faadd5 RW |
2093 | if (action & CPU_TASKS_FROZEN) |
2094 | frozen = true; | |
2095 | ||
5302c3fb | 2096 | switch (action & ~CPU_TASKS_FROZEN) { |
c32b6b8e | 2097 | case CPU_ONLINE: |
5302c3fb | 2098 | __cpufreq_add_dev(dev, NULL, frozen); |
23d32899 | 2099 | cpufreq_update_policy(cpu); |
c32b6b8e | 2100 | break; |
5302c3fb | 2101 | |
c32b6b8e | 2102 | case CPU_DOWN_PREPARE: |
cedb70af | 2103 | __cpufreq_remove_dev_prepare(dev, NULL, frozen); |
1aee40ac SB |
2104 | break; |
2105 | ||
2106 | case CPU_POST_DEAD: | |
cedb70af | 2107 | __cpufreq_remove_dev_finish(dev, NULL, frozen); |
c32b6b8e | 2108 | break; |
5302c3fb | 2109 | |
5a01f2e8 | 2110 | case CPU_DOWN_FAILED: |
5302c3fb | 2111 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2112 | break; |
2113 | } | |
2114 | } | |
2115 | return NOTIFY_OK; | |
2116 | } | |
2117 | ||
9c36f746 | 2118 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2119 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2120 | }; |
1da177e4 LT |
2121 | |
2122 | /********************************************************************* | |
2123 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2124 | *********************************************************************/ | |
2125 | ||
2126 | /** | |
2127 | * cpufreq_register_driver - register a CPU Frequency driver | |
2128 | * @driver_data: A struct cpufreq_driver containing the values# | |
2129 | * submitted by the CPU Frequency driver. | |
2130 | * | |
bb176f7d | 2131 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2132 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2133 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2134 | * |
2135 | */ | |
221dee28 | 2136 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2137 | { |
2138 | unsigned long flags; | |
2139 | int ret; | |
2140 | ||
a7b422cd KRW |
2141 | if (cpufreq_disabled()) |
2142 | return -ENODEV; | |
2143 | ||
1da177e4 | 2144 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 VK |
2145 | !(driver_data->setpolicy || driver_data->target_index || |
2146 | driver_data->target)) | |
1da177e4 LT |
2147 | return -EINVAL; |
2148 | ||
2d06d8c4 | 2149 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2150 | |
2151 | if (driver_data->setpolicy) | |
2152 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2153 | ||
0d1857a1 | 2154 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2155 | if (cpufreq_driver) { |
0d1857a1 | 2156 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2157 | return -EEXIST; |
1da177e4 | 2158 | } |
1c3d85dd | 2159 | cpufreq_driver = driver_data; |
0d1857a1 | 2160 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2161 | |
8a25a2fd | 2162 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2163 | if (ret) |
2164 | goto err_null_driver; | |
1da177e4 | 2165 | |
1c3d85dd | 2166 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2167 | int i; |
2168 | ret = -ENODEV; | |
2169 | ||
2170 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2171 | for (i = 0; i < nr_cpu_ids; i++) |
2172 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2173 | ret = 0; |
7a6aedfa MT |
2174 | break; |
2175 | } | |
1da177e4 LT |
2176 | |
2177 | /* if all ->init() calls failed, unregister */ | |
2178 | if (ret) { | |
2d06d8c4 | 2179 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2180 | driver_data->name); |
8a25a2fd | 2181 | goto err_if_unreg; |
1da177e4 LT |
2182 | } |
2183 | } | |
2184 | ||
8f5bc2ab | 2185 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2186 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2187 | |
8f5bc2ab | 2188 | return 0; |
8a25a2fd KS |
2189 | err_if_unreg: |
2190 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2191 | err_null_driver: |
0d1857a1 | 2192 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2193 | cpufreq_driver = NULL; |
0d1857a1 | 2194 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2195 | return ret; |
1da177e4 LT |
2196 | } |
2197 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2198 | ||
1da177e4 LT |
2199 | /** |
2200 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2201 | * | |
bb176f7d | 2202 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2203 | * the right to do so, i.e. if you have succeeded in initialising before! |
2204 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2205 | * currently not initialised. | |
2206 | */ | |
221dee28 | 2207 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2208 | { |
2209 | unsigned long flags; | |
2210 | ||
1c3d85dd | 2211 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2212 | return -EINVAL; |
1da177e4 | 2213 | |
2d06d8c4 | 2214 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2215 | |
8a25a2fd | 2216 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2217 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2218 | |
6eed9404 | 2219 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2220 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2221 | |
1c3d85dd | 2222 | cpufreq_driver = NULL; |
6eed9404 | 2223 | |
0d1857a1 | 2224 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2225 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2226 | |
2227 | return 0; | |
2228 | } | |
2229 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2230 | |
2231 | static int __init cpufreq_core_init(void) | |
2232 | { | |
a7b422cd KRW |
2233 | if (cpufreq_disabled()) |
2234 | return -ENODEV; | |
2235 | ||
2361be23 | 2236 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2237 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2238 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2239 | |
5a01f2e8 VP |
2240 | return 0; |
2241 | } | |
5a01f2e8 | 2242 | core_initcall(cpufreq_core_init); |