Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
bb176f7d | 6 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> |
1da177e4 | 7 | * |
c32b6b8e | 8 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 9 | * Added handling for CPU hotplug |
8ff69732 DJ |
10 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
11 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 12 | * |
1da177e4 LT |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
1da177e4 LT |
16 | */ |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
5ff0a268 | 20 | #include <linux/cpu.h> |
1da177e4 LT |
21 | #include <linux/cpufreq.h> |
22 | #include <linux/delay.h> | |
1da177e4 | 23 | #include <linux/device.h> |
5ff0a268 VK |
24 | #include <linux/init.h> |
25 | #include <linux/kernel_stat.h> | |
26 | #include <linux/module.h> | |
3fc54d37 | 27 | #include <linux/mutex.h> |
5ff0a268 | 28 | #include <linux/slab.h> |
e00e56df | 29 | #include <linux/syscore_ops.h> |
5ff0a268 | 30 | #include <linux/tick.h> |
6f4f2723 TR |
31 | #include <trace/events/power.h> |
32 | ||
1da177e4 | 33 | /** |
cd878479 | 34 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
35 | * level driver of CPUFreq support, and its spinlock. This lock |
36 | * also protects the cpufreq_cpu_data array. | |
37 | */ | |
1c3d85dd | 38 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 39 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
8414809c | 40 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); |
bb176f7d VK |
41 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
42 | static DEFINE_MUTEX(cpufreq_governor_lock); | |
c88a1f8b | 43 | static LIST_HEAD(cpufreq_policy_list); |
bb176f7d | 44 | |
084f3493 TR |
45 | #ifdef CONFIG_HOTPLUG_CPU |
46 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 47 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 48 | #endif |
1da177e4 | 49 | |
5a01f2e8 VP |
50 | /* |
51 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
52 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
53 | * | |
54 | * The rules for this semaphore: | |
55 | * - Any routine that wants to read from the policy structure will | |
56 | * do a down_read on this semaphore. | |
57 | * - Any routine that will write to the policy structure and/or may take away | |
58 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
59 | * mode before doing so. | |
60 | * | |
61 | * Additional rules: | |
5a01f2e8 VP |
62 | * - Governor routines that can be called in cpufreq hotplug path should not |
63 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
64 | * - Lock should not be held across |
65 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 66 | */ |
5a01f2e8 VP |
67 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
68 | ||
69 | #define lock_policy_rwsem(mode, cpu) \ | |
1b750e3b | 70 | static void lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 71 | { \ |
474deff7 VK |
72 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
73 | BUG_ON(!policy); \ | |
74 | down_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 VP |
75 | } |
76 | ||
77 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 78 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 79 | |
fa1d8af4 VK |
80 | #define unlock_policy_rwsem(mode, cpu) \ |
81 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
82 | { \ | |
474deff7 VK |
83 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
84 | BUG_ON(!policy); \ | |
85 | up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 | 86 | } |
5a01f2e8 | 87 | |
fa1d8af4 VK |
88 | unlock_policy_rwsem(read, cpu); |
89 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 90 | |
6eed9404 VK |
91 | /* |
92 | * rwsem to guarantee that cpufreq driver module doesn't unload during critical | |
93 | * sections | |
94 | */ | |
95 | static DECLARE_RWSEM(cpufreq_rwsem); | |
96 | ||
1da177e4 | 97 | /* internal prototypes */ |
29464f28 DJ |
98 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
99 | unsigned int event); | |
5a01f2e8 | 100 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 101 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
102 | |
103 | /** | |
32ee8c3e DJ |
104 | * Two notifier lists: the "policy" list is involved in the |
105 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
106 | * "transition" list for kernel code that needs to handle |
107 | * changes to devices when the CPU clock speed changes. | |
108 | * The mutex locks both lists. | |
109 | */ | |
e041c683 | 110 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 111 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 112 | |
74212ca4 | 113 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
114 | static int __init init_cpufreq_transition_notifier_list(void) |
115 | { | |
116 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 117 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
118 | return 0; |
119 | } | |
b3438f82 | 120 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 121 | |
a7b422cd | 122 | static int off __read_mostly; |
da584455 | 123 | static int cpufreq_disabled(void) |
a7b422cd KRW |
124 | { |
125 | return off; | |
126 | } | |
127 | void disable_cpufreq(void) | |
128 | { | |
129 | off = 1; | |
130 | } | |
1da177e4 | 131 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 132 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 133 | |
4d5dcc42 VK |
134 | bool have_governor_per_policy(void) |
135 | { | |
0b981e70 | 136 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 137 | } |
3f869d6d | 138 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 139 | |
944e9a03 VK |
140 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
141 | { | |
142 | if (have_governor_per_policy()) | |
143 | return &policy->kobj; | |
144 | else | |
145 | return cpufreq_global_kobject; | |
146 | } | |
147 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
148 | ||
72a4ce34 VK |
149 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
150 | { | |
151 | u64 idle_time; | |
152 | u64 cur_wall_time; | |
153 | u64 busy_time; | |
154 | ||
155 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
156 | ||
157 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
158 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
159 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
160 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
161 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
162 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
163 | ||
164 | idle_time = cur_wall_time - busy_time; | |
165 | if (wall) | |
166 | *wall = cputime_to_usecs(cur_wall_time); | |
167 | ||
168 | return cputime_to_usecs(idle_time); | |
169 | } | |
170 | ||
171 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
172 | { | |
173 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
174 | ||
175 | if (idle_time == -1ULL) | |
176 | return get_cpu_idle_time_jiffy(cpu, wall); | |
177 | else if (!io_busy) | |
178 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
179 | ||
180 | return idle_time; | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
183 | ||
6eed9404 | 184 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 185 | { |
6eed9404 | 186 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
187 | unsigned long flags; |
188 | ||
6eed9404 VK |
189 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
190 | return NULL; | |
191 | ||
192 | if (!down_read_trylock(&cpufreq_rwsem)) | |
193 | return NULL; | |
1da177e4 LT |
194 | |
195 | /* get the cpufreq driver */ | |
1c3d85dd | 196 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 197 | |
6eed9404 VK |
198 | if (cpufreq_driver) { |
199 | /* get the CPU */ | |
200 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
201 | if (policy) | |
202 | kobject_get(&policy->kobj); | |
203 | } | |
1da177e4 | 204 | |
6eed9404 | 205 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 206 | |
3a3e9e06 | 207 | if (!policy) |
6eed9404 | 208 | up_read(&cpufreq_rwsem); |
1da177e4 | 209 | |
3a3e9e06 | 210 | return policy; |
a9144436 | 211 | } |
1da177e4 LT |
212 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
213 | ||
3a3e9e06 | 214 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 215 | { |
d5aaffa9 DB |
216 | if (cpufreq_disabled()) |
217 | return; | |
218 | ||
6eed9404 VK |
219 | kobject_put(&policy->kobj); |
220 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
221 | } |
222 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
223 | ||
1da177e4 LT |
224 | /********************************************************************* |
225 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
226 | *********************************************************************/ | |
227 | ||
228 | /** | |
229 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
230 | * | |
231 | * This function alters the system "loops_per_jiffy" for the clock | |
232 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 233 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
234 | * per-CPU loops_per_jiffy value wherever possible. |
235 | */ | |
236 | #ifndef CONFIG_SMP | |
237 | static unsigned long l_p_j_ref; | |
bb176f7d | 238 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 239 | |
858119e1 | 240 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
241 | { |
242 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
243 | return; | |
244 | ||
245 | if (!l_p_j_ref_freq) { | |
246 | l_p_j_ref = loops_per_jiffy; | |
247 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 248 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 249 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 250 | } |
bb176f7d | 251 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 252 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
253 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
254 | ci->new); | |
2d06d8c4 | 255 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 256 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
257 | } |
258 | } | |
259 | #else | |
e08f5f5b GS |
260 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
261 | { | |
262 | return; | |
263 | } | |
1da177e4 LT |
264 | #endif |
265 | ||
0956df9c | 266 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 267 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
268 | { |
269 | BUG_ON(irqs_disabled()); | |
270 | ||
d5aaffa9 DB |
271 | if (cpufreq_disabled()) |
272 | return; | |
273 | ||
1c3d85dd | 274 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 275 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 276 | state, freqs->new); |
1da177e4 | 277 | |
1da177e4 | 278 | switch (state) { |
e4472cb3 | 279 | |
1da177e4 | 280 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 281 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
282 | * which is not equal to what the cpufreq core thinks is |
283 | * "old frequency". | |
1da177e4 | 284 | */ |
1c3d85dd | 285 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
286 | if ((policy) && (policy->cpu == freqs->cpu) && |
287 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 288 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
289 | " %u, cpufreq assumed %u kHz.\n", |
290 | freqs->old, policy->cur); | |
291 | freqs->old = policy->cur; | |
1da177e4 LT |
292 | } |
293 | } | |
b4dfdbb3 | 294 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 295 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
296 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
297 | break; | |
e4472cb3 | 298 | |
1da177e4 LT |
299 | case CPUFREQ_POSTCHANGE: |
300 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 301 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 302 | (unsigned long)freqs->cpu); |
25e41933 | 303 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 304 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 305 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
306 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
307 | policy->cur = freqs->new; | |
1da177e4 LT |
308 | break; |
309 | } | |
1da177e4 | 310 | } |
bb176f7d | 311 | |
b43a7ffb VK |
312 | /** |
313 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
314 | * on frequency transition. | |
315 | * | |
316 | * This function calls the transition notifiers and the "adjust_jiffies" | |
317 | * function. It is called twice on all CPU frequency changes that have | |
318 | * external effects. | |
319 | */ | |
320 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
321 | struct cpufreq_freqs *freqs, unsigned int state) | |
322 | { | |
323 | for_each_cpu(freqs->cpu, policy->cpus) | |
324 | __cpufreq_notify_transition(policy, freqs, state); | |
325 | } | |
1da177e4 LT |
326 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
327 | ||
328 | ||
1da177e4 LT |
329 | /********************************************************************* |
330 | * SYSFS INTERFACE * | |
331 | *********************************************************************/ | |
332 | ||
3bcb09a3 JF |
333 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
334 | { | |
335 | struct cpufreq_governor *t; | |
336 | ||
337 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 338 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
339 | return t; |
340 | ||
341 | return NULL; | |
342 | } | |
343 | ||
1da177e4 LT |
344 | /** |
345 | * cpufreq_parse_governor - parse a governor string | |
346 | */ | |
905d77cd | 347 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
348 | struct cpufreq_governor **governor) |
349 | { | |
3bcb09a3 | 350 | int err = -EINVAL; |
1c3d85dd RW |
351 | |
352 | if (!cpufreq_driver) | |
3bcb09a3 JF |
353 | goto out; |
354 | ||
1c3d85dd | 355 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
356 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
357 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 358 | err = 0; |
e08f5f5b GS |
359 | } else if (!strnicmp(str_governor, "powersave", |
360 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 361 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 362 | err = 0; |
1da177e4 | 363 | } |
1c3d85dd | 364 | } else if (cpufreq_driver->target) { |
1da177e4 | 365 | struct cpufreq_governor *t; |
3bcb09a3 | 366 | |
3fc54d37 | 367 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
368 | |
369 | t = __find_governor(str_governor); | |
370 | ||
ea714970 | 371 | if (t == NULL) { |
1a8e1463 | 372 | int ret; |
ea714970 | 373 | |
1a8e1463 KC |
374 | mutex_unlock(&cpufreq_governor_mutex); |
375 | ret = request_module("cpufreq_%s", str_governor); | |
376 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 377 | |
1a8e1463 KC |
378 | if (ret == 0) |
379 | t = __find_governor(str_governor); | |
ea714970 JF |
380 | } |
381 | ||
3bcb09a3 JF |
382 | if (t != NULL) { |
383 | *governor = t; | |
384 | err = 0; | |
1da177e4 | 385 | } |
3bcb09a3 | 386 | |
3fc54d37 | 387 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 388 | } |
29464f28 | 389 | out: |
3bcb09a3 | 390 | return err; |
1da177e4 | 391 | } |
1da177e4 | 392 | |
1da177e4 | 393 | /** |
e08f5f5b GS |
394 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
395 | * print out cpufreq information | |
1da177e4 LT |
396 | * |
397 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
398 | * "unsigned int". | |
399 | */ | |
400 | ||
32ee8c3e DJ |
401 | #define show_one(file_name, object) \ |
402 | static ssize_t show_##file_name \ | |
905d77cd | 403 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 404 | { \ |
29464f28 | 405 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
406 | } |
407 | ||
408 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
409 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 410 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
411 | show_one(scaling_min_freq, min); |
412 | show_one(scaling_max_freq, max); | |
413 | show_one(scaling_cur_freq, cur); | |
414 | ||
037ce839 | 415 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 416 | struct cpufreq_policy *new_policy); |
7970e08b | 417 | |
1da177e4 LT |
418 | /** |
419 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
420 | */ | |
421 | #define store_one(file_name, object) \ | |
422 | static ssize_t store_##file_name \ | |
905d77cd | 423 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 424 | { \ |
5136fa56 | 425 | int ret; \ |
1da177e4 LT |
426 | struct cpufreq_policy new_policy; \ |
427 | \ | |
428 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
429 | if (ret) \ | |
430 | return -EINVAL; \ | |
431 | \ | |
29464f28 | 432 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
433 | if (ret != 1) \ |
434 | return -EINVAL; \ | |
435 | \ | |
037ce839 | 436 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 437 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
438 | \ |
439 | return ret ? ret : count; \ | |
440 | } | |
441 | ||
29464f28 DJ |
442 | store_one(scaling_min_freq, min); |
443 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
444 | |
445 | /** | |
446 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
447 | */ | |
905d77cd DJ |
448 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
449 | char *buf) | |
1da177e4 | 450 | { |
5a01f2e8 | 451 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
452 | if (!cur_freq) |
453 | return sprintf(buf, "<unknown>"); | |
454 | return sprintf(buf, "%u\n", cur_freq); | |
455 | } | |
456 | ||
1da177e4 LT |
457 | /** |
458 | * show_scaling_governor - show the current policy for the specified CPU | |
459 | */ | |
905d77cd | 460 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 461 | { |
29464f28 | 462 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
463 | return sprintf(buf, "powersave\n"); |
464 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
465 | return sprintf(buf, "performance\n"); | |
466 | else if (policy->governor) | |
4b972f0b | 467 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 468 | policy->governor->name); |
1da177e4 LT |
469 | return -EINVAL; |
470 | } | |
471 | ||
1da177e4 LT |
472 | /** |
473 | * store_scaling_governor - store policy for the specified CPU | |
474 | */ | |
905d77cd DJ |
475 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
476 | const char *buf, size_t count) | |
1da177e4 | 477 | { |
5136fa56 | 478 | int ret; |
1da177e4 LT |
479 | char str_governor[16]; |
480 | struct cpufreq_policy new_policy; | |
481 | ||
482 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
483 | if (ret) | |
484 | return ret; | |
485 | ||
29464f28 | 486 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
487 | if (ret != 1) |
488 | return -EINVAL; | |
489 | ||
e08f5f5b GS |
490 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
491 | &new_policy.governor)) | |
1da177e4 LT |
492 | return -EINVAL; |
493 | ||
037ce839 | 494 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
495 | |
496 | policy->user_policy.policy = policy->policy; | |
497 | policy->user_policy.governor = policy->governor; | |
7970e08b | 498 | |
e08f5f5b GS |
499 | if (ret) |
500 | return ret; | |
501 | else | |
502 | return count; | |
1da177e4 LT |
503 | } |
504 | ||
505 | /** | |
506 | * show_scaling_driver - show the cpufreq driver currently loaded | |
507 | */ | |
905d77cd | 508 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 509 | { |
1c3d85dd | 510 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
511 | } |
512 | ||
513 | /** | |
514 | * show_scaling_available_governors - show the available CPUfreq governors | |
515 | */ | |
905d77cd DJ |
516 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
517 | char *buf) | |
1da177e4 LT |
518 | { |
519 | ssize_t i = 0; | |
520 | struct cpufreq_governor *t; | |
521 | ||
1c3d85dd | 522 | if (!cpufreq_driver->target) { |
1da177e4 LT |
523 | i += sprintf(buf, "performance powersave"); |
524 | goto out; | |
525 | } | |
526 | ||
527 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
528 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
529 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 530 | goto out; |
4b972f0b | 531 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 532 | } |
7d5e350f | 533 | out: |
1da177e4 LT |
534 | i += sprintf(&buf[i], "\n"); |
535 | return i; | |
536 | } | |
e8628dd0 | 537 | |
f4fd3797 | 538 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
539 | { |
540 | ssize_t i = 0; | |
541 | unsigned int cpu; | |
542 | ||
835481d9 | 543 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
544 | if (i) |
545 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
546 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
547 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 548 | break; |
1da177e4 LT |
549 | } |
550 | i += sprintf(&buf[i], "\n"); | |
551 | return i; | |
552 | } | |
f4fd3797 | 553 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 554 | |
e8628dd0 DW |
555 | /** |
556 | * show_related_cpus - show the CPUs affected by each transition even if | |
557 | * hw coordination is in use | |
558 | */ | |
559 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
560 | { | |
f4fd3797 | 561 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
562 | } |
563 | ||
564 | /** | |
565 | * show_affected_cpus - show the CPUs affected by each transition | |
566 | */ | |
567 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
568 | { | |
f4fd3797 | 569 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
570 | } |
571 | ||
9e76988e | 572 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 573 | const char *buf, size_t count) |
9e76988e VP |
574 | { |
575 | unsigned int freq = 0; | |
576 | unsigned int ret; | |
577 | ||
879000f9 | 578 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
579 | return -EINVAL; |
580 | ||
581 | ret = sscanf(buf, "%u", &freq); | |
582 | if (ret != 1) | |
583 | return -EINVAL; | |
584 | ||
585 | policy->governor->store_setspeed(policy, freq); | |
586 | ||
587 | return count; | |
588 | } | |
589 | ||
590 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
591 | { | |
879000f9 | 592 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
593 | return sprintf(buf, "<unsupported>\n"); |
594 | ||
595 | return policy->governor->show_setspeed(policy, buf); | |
596 | } | |
1da177e4 | 597 | |
e2f74f35 | 598 | /** |
8bf1ac72 | 599 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
600 | */ |
601 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
602 | { | |
603 | unsigned int limit; | |
604 | int ret; | |
1c3d85dd RW |
605 | if (cpufreq_driver->bios_limit) { |
606 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
607 | if (!ret) |
608 | return sprintf(buf, "%u\n", limit); | |
609 | } | |
610 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
611 | } | |
612 | ||
6dad2a29 BP |
613 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
614 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
615 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
616 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
617 | cpufreq_freq_attr_ro(scaling_available_governors); | |
618 | cpufreq_freq_attr_ro(scaling_driver); | |
619 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
620 | cpufreq_freq_attr_ro(bios_limit); | |
621 | cpufreq_freq_attr_ro(related_cpus); | |
622 | cpufreq_freq_attr_ro(affected_cpus); | |
623 | cpufreq_freq_attr_rw(scaling_min_freq); | |
624 | cpufreq_freq_attr_rw(scaling_max_freq); | |
625 | cpufreq_freq_attr_rw(scaling_governor); | |
626 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 627 | |
905d77cd | 628 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
629 | &cpuinfo_min_freq.attr, |
630 | &cpuinfo_max_freq.attr, | |
ed129784 | 631 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
632 | &scaling_min_freq.attr, |
633 | &scaling_max_freq.attr, | |
634 | &affected_cpus.attr, | |
e8628dd0 | 635 | &related_cpus.attr, |
1da177e4 LT |
636 | &scaling_governor.attr, |
637 | &scaling_driver.attr, | |
638 | &scaling_available_governors.attr, | |
9e76988e | 639 | &scaling_setspeed.attr, |
1da177e4 LT |
640 | NULL |
641 | }; | |
642 | ||
29464f28 DJ |
643 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
644 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 645 | |
29464f28 | 646 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 647 | { |
905d77cd DJ |
648 | struct cpufreq_policy *policy = to_policy(kobj); |
649 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 650 | ssize_t ret; |
6eed9404 VK |
651 | |
652 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 653 | return -EINVAL; |
5a01f2e8 | 654 | |
1b750e3b | 655 | lock_policy_rwsem_read(policy->cpu); |
5a01f2e8 | 656 | |
e08f5f5b GS |
657 | if (fattr->show) |
658 | ret = fattr->show(policy, buf); | |
659 | else | |
660 | ret = -EIO; | |
661 | ||
5a01f2e8 | 662 | unlock_policy_rwsem_read(policy->cpu); |
6eed9404 | 663 | up_read(&cpufreq_rwsem); |
1b750e3b | 664 | |
1da177e4 LT |
665 | return ret; |
666 | } | |
667 | ||
905d77cd DJ |
668 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
669 | const char *buf, size_t count) | |
1da177e4 | 670 | { |
905d77cd DJ |
671 | struct cpufreq_policy *policy = to_policy(kobj); |
672 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 673 | ssize_t ret = -EINVAL; |
6eed9404 | 674 | |
4f750c93 SB |
675 | get_online_cpus(); |
676 | ||
677 | if (!cpu_online(policy->cpu)) | |
678 | goto unlock; | |
679 | ||
6eed9404 | 680 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 681 | goto unlock; |
5a01f2e8 | 682 | |
1b750e3b | 683 | lock_policy_rwsem_write(policy->cpu); |
5a01f2e8 | 684 | |
e08f5f5b GS |
685 | if (fattr->store) |
686 | ret = fattr->store(policy, buf, count); | |
687 | else | |
688 | ret = -EIO; | |
689 | ||
5a01f2e8 | 690 | unlock_policy_rwsem_write(policy->cpu); |
6eed9404 | 691 | |
6eed9404 | 692 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
693 | unlock: |
694 | put_online_cpus(); | |
695 | ||
1da177e4 LT |
696 | return ret; |
697 | } | |
698 | ||
905d77cd | 699 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 700 | { |
905d77cd | 701 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 702 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
703 | complete(&policy->kobj_unregister); |
704 | } | |
705 | ||
52cf25d0 | 706 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
707 | .show = show, |
708 | .store = store, | |
709 | }; | |
710 | ||
711 | static struct kobj_type ktype_cpufreq = { | |
712 | .sysfs_ops = &sysfs_ops, | |
713 | .default_attrs = default_attrs, | |
714 | .release = cpufreq_sysfs_release, | |
715 | }; | |
716 | ||
2361be23 VK |
717 | struct kobject *cpufreq_global_kobject; |
718 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
719 | ||
720 | static int cpufreq_global_kobject_usage; | |
721 | ||
722 | int cpufreq_get_global_kobject(void) | |
723 | { | |
724 | if (!cpufreq_global_kobject_usage++) | |
725 | return kobject_add(cpufreq_global_kobject, | |
726 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
727 | ||
728 | return 0; | |
729 | } | |
730 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
731 | ||
732 | void cpufreq_put_global_kobject(void) | |
733 | { | |
734 | if (!--cpufreq_global_kobject_usage) | |
735 | kobject_del(cpufreq_global_kobject); | |
736 | } | |
737 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
738 | ||
739 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
740 | { | |
741 | int ret = cpufreq_get_global_kobject(); | |
742 | ||
743 | if (!ret) { | |
744 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
745 | if (ret) | |
746 | cpufreq_put_global_kobject(); | |
747 | } | |
748 | ||
749 | return ret; | |
750 | } | |
751 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
752 | ||
753 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
754 | { | |
755 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
756 | cpufreq_put_global_kobject(); | |
757 | } | |
758 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
759 | ||
19d6f7ec | 760 | /* symlink affected CPUs */ |
308b60e7 | 761 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
762 | { |
763 | unsigned int j; | |
764 | int ret = 0; | |
765 | ||
766 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 767 | struct device *cpu_dev; |
19d6f7ec | 768 | |
308b60e7 | 769 | if (j == policy->cpu) |
19d6f7ec | 770 | continue; |
19d6f7ec | 771 | |
e8fdde10 | 772 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
773 | cpu_dev = get_cpu_device(j); |
774 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 775 | "cpufreq"); |
71c3461e RW |
776 | if (ret) |
777 | break; | |
19d6f7ec DJ |
778 | } |
779 | return ret; | |
780 | } | |
781 | ||
308b60e7 | 782 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 783 | struct device *dev) |
909a694e DJ |
784 | { |
785 | struct freq_attr **drv_attr; | |
909a694e | 786 | int ret = 0; |
909a694e DJ |
787 | |
788 | /* prepare interface data */ | |
789 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 790 | &dev->kobj, "cpufreq"); |
909a694e DJ |
791 | if (ret) |
792 | return ret; | |
793 | ||
794 | /* set up files for this cpu device */ | |
1c3d85dd | 795 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
796 | while ((drv_attr) && (*drv_attr)) { |
797 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
798 | if (ret) | |
1c3d85dd | 799 | goto err_out_kobj_put; |
909a694e DJ |
800 | drv_attr++; |
801 | } | |
1c3d85dd | 802 | if (cpufreq_driver->get) { |
909a694e DJ |
803 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
804 | if (ret) | |
1c3d85dd | 805 | goto err_out_kobj_put; |
909a694e | 806 | } |
1c3d85dd | 807 | if (cpufreq_driver->target) { |
909a694e DJ |
808 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
809 | if (ret) | |
1c3d85dd | 810 | goto err_out_kobj_put; |
909a694e | 811 | } |
1c3d85dd | 812 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
813 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
814 | if (ret) | |
1c3d85dd | 815 | goto err_out_kobj_put; |
e2f74f35 | 816 | } |
909a694e | 817 | |
308b60e7 | 818 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
819 | if (ret) |
820 | goto err_out_kobj_put; | |
821 | ||
e18f1682 SB |
822 | return ret; |
823 | ||
824 | err_out_kobj_put: | |
825 | kobject_put(&policy->kobj); | |
826 | wait_for_completion(&policy->kobj_unregister); | |
827 | return ret; | |
828 | } | |
829 | ||
830 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
831 | { | |
832 | struct cpufreq_policy new_policy; | |
833 | int ret = 0; | |
834 | ||
d5b73cd8 | 835 | memcpy(&new_policy, policy, sizeof(*policy)); |
037ce839 | 836 | /* assure that the starting sequence is run in cpufreq_set_policy */ |
ecf7e461 DJ |
837 | policy->governor = NULL; |
838 | ||
839 | /* set default policy */ | |
037ce839 | 840 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 DJ |
841 | policy->user_policy.policy = policy->policy; |
842 | policy->user_policy.governor = policy->governor; | |
843 | ||
844 | if (ret) { | |
2d06d8c4 | 845 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
846 | if (cpufreq_driver->exit) |
847 | cpufreq_driver->exit(policy); | |
ecf7e461 | 848 | } |
909a694e DJ |
849 | } |
850 | ||
fcf80582 | 851 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 VK |
852 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
853 | unsigned int cpu, struct device *dev, | |
854 | bool frozen) | |
fcf80582 | 855 | { |
1c3d85dd | 856 | int ret = 0, has_target = !!cpufreq_driver->target; |
fcf80582 VK |
857 | unsigned long flags; |
858 | ||
3de9bdeb VK |
859 | if (has_target) { |
860 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
861 | if (ret) { | |
862 | pr_err("%s: Failed to stop governor\n", __func__); | |
863 | return ret; | |
864 | } | |
865 | } | |
fcf80582 | 866 | |
d8d3b471 | 867 | lock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 868 | |
0d1857a1 | 869 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 870 | |
fcf80582 VK |
871 | cpumask_set_cpu(cpu, policy->cpus); |
872 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 873 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 874 | |
d8d3b471 | 875 | unlock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 876 | |
820c6ca2 | 877 | if (has_target) { |
3de9bdeb VK |
878 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
879 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
880 | pr_err("%s: Failed to start governor\n", __func__); | |
881 | return ret; | |
882 | } | |
820c6ca2 | 883 | } |
fcf80582 | 884 | |
a82fab29 | 885 | /* Don't touch sysfs links during light-weight init */ |
71c3461e RW |
886 | if (!frozen) |
887 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); | |
a82fab29 SB |
888 | |
889 | return ret; | |
fcf80582 VK |
890 | } |
891 | #endif | |
1da177e4 | 892 | |
8414809c SB |
893 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
894 | { | |
895 | struct cpufreq_policy *policy; | |
896 | unsigned long flags; | |
897 | ||
44871c9c | 898 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
899 | |
900 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
901 | ||
44871c9c | 902 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c SB |
903 | |
904 | return policy; | |
905 | } | |
906 | ||
e9698cc5 SB |
907 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
908 | { | |
909 | struct cpufreq_policy *policy; | |
910 | ||
911 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
912 | if (!policy) | |
913 | return NULL; | |
914 | ||
915 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
916 | goto err_free_policy; | |
917 | ||
918 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
919 | goto err_free_cpumask; | |
920 | ||
c88a1f8b | 921 | INIT_LIST_HEAD(&policy->policy_list); |
e9698cc5 SB |
922 | return policy; |
923 | ||
924 | err_free_cpumask: | |
925 | free_cpumask_var(policy->cpus); | |
926 | err_free_policy: | |
927 | kfree(policy); | |
928 | ||
929 | return NULL; | |
930 | } | |
931 | ||
932 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
933 | { | |
934 | free_cpumask_var(policy->related_cpus); | |
935 | free_cpumask_var(policy->cpus); | |
936 | kfree(policy); | |
937 | } | |
938 | ||
0d66b91e SB |
939 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
940 | { | |
cb38ed5c SB |
941 | if (cpu == policy->cpu) |
942 | return; | |
943 | ||
8efd5765 VK |
944 | /* |
945 | * Take direct locks as lock_policy_rwsem_write wouldn't work here. | |
946 | * Also lock for last cpu is enough here as contention will happen only | |
947 | * after policy->cpu is changed and after it is changed, other threads | |
948 | * will try to acquire lock for new cpu. And policy is already updated | |
949 | * by then. | |
950 | */ | |
951 | down_write(&per_cpu(cpu_policy_rwsem, policy->cpu)); | |
952 | ||
0d66b91e SB |
953 | policy->last_cpu = policy->cpu; |
954 | policy->cpu = cpu; | |
955 | ||
8efd5765 VK |
956 | up_write(&per_cpu(cpu_policy_rwsem, policy->last_cpu)); |
957 | ||
0d66b91e SB |
958 | #ifdef CONFIG_CPU_FREQ_TABLE |
959 | cpufreq_frequency_table_update_policy_cpu(policy); | |
960 | #endif | |
961 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
962 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
963 | } | |
964 | ||
a82fab29 SB |
965 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, |
966 | bool frozen) | |
1da177e4 | 967 | { |
fcf80582 | 968 | unsigned int j, cpu = dev->id; |
65922465 | 969 | int ret = -ENOMEM; |
1da177e4 | 970 | struct cpufreq_policy *policy; |
1da177e4 | 971 | unsigned long flags; |
90e41bac | 972 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 973 | struct cpufreq_policy *tpolicy; |
fcf80582 | 974 | struct cpufreq_governor *gov; |
90e41bac | 975 | #endif |
1da177e4 | 976 | |
c32b6b8e AR |
977 | if (cpu_is_offline(cpu)) |
978 | return 0; | |
979 | ||
2d06d8c4 | 980 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
981 | |
982 | #ifdef CONFIG_SMP | |
983 | /* check whether a different CPU already registered this | |
984 | * CPU because it is in the same boat. */ | |
985 | policy = cpufreq_cpu_get(cpu); | |
986 | if (unlikely(policy)) { | |
8ff69732 | 987 | cpufreq_cpu_put(policy); |
1da177e4 LT |
988 | return 0; |
989 | } | |
5025d628 | 990 | #endif |
fcf80582 | 991 | |
6eed9404 VK |
992 | if (!down_read_trylock(&cpufreq_rwsem)) |
993 | return 0; | |
994 | ||
fcf80582 VK |
995 | #ifdef CONFIG_HOTPLUG_CPU |
996 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 997 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
998 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
999 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1000 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1b274294 | 1001 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev, frozen); |
6eed9404 VK |
1002 | up_read(&cpufreq_rwsem); |
1003 | return ret; | |
2eaa3e2d | 1004 | } |
fcf80582 | 1005 | } |
0d1857a1 | 1006 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1007 | #endif |
1008 | ||
8414809c SB |
1009 | if (frozen) |
1010 | /* Restore the saved policy when doing light-weight init */ | |
1011 | policy = cpufreq_policy_restore(cpu); | |
1012 | else | |
1013 | policy = cpufreq_policy_alloc(); | |
1014 | ||
059019a3 | 1015 | if (!policy) |
1da177e4 | 1016 | goto nomem_out; |
059019a3 | 1017 | |
0d66b91e SB |
1018 | |
1019 | /* | |
1020 | * In the resume path, since we restore a saved policy, the assignment | |
1021 | * to policy->cpu is like an update of the existing policy, rather than | |
1022 | * the creation of a brand new one. So we need to perform this update | |
1023 | * by invoking update_policy_cpu(). | |
1024 | */ | |
1025 | if (frozen && cpu != policy->cpu) | |
1026 | update_policy_cpu(policy, cpu); | |
1027 | else | |
1028 | policy->cpu = cpu; | |
1029 | ||
65922465 | 1030 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1031 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 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 | 1069 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1070 | for_each_cpu(j, policy->cpus) |
e18f1682 | 1071 | per_cpu(cpufreq_cpu_data, j) = policy; |
e18f1682 SB |
1072 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1073 | ||
a82fab29 | 1074 | if (!frozen) { |
308b60e7 | 1075 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1076 | if (ret) |
1077 | goto err_out_unregister; | |
1078 | } | |
8ff69732 | 1079 | |
9515f4d6 VK |
1080 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1081 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1082 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1083 | ||
e18f1682 SB |
1084 | cpufreq_init_policy(policy); |
1085 | ||
038c5b3e | 1086 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1087 | up_read(&cpufreq_rwsem); |
1088 | ||
2d06d8c4 | 1089 | pr_debug("initialization complete\n"); |
87c32271 | 1090 | |
1da177e4 LT |
1091 | return 0; |
1092 | ||
1da177e4 | 1093 | err_out_unregister: |
0d1857a1 | 1094 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1095 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1096 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1097 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1098 | |
2eaa3e2d | 1099 | err_set_policy_cpu: |
e9698cc5 | 1100 | cpufreq_policy_free(policy); |
1da177e4 | 1101 | nomem_out: |
6eed9404 VK |
1102 | up_read(&cpufreq_rwsem); |
1103 | ||
1da177e4 LT |
1104 | return ret; |
1105 | } | |
1106 | ||
a82fab29 SB |
1107 | /** |
1108 | * cpufreq_add_dev - add a CPU device | |
1109 | * | |
1110 | * Adds the cpufreq interface for a CPU device. | |
1111 | * | |
1112 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1113 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1114 | * mess up, but more thorough testing is needed. - Mathieu | |
1115 | */ | |
1116 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1117 | { | |
1118 | return __cpufreq_add_dev(dev, sif, false); | |
1119 | } | |
1120 | ||
3a3e9e06 | 1121 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
a82fab29 | 1122 | unsigned int old_cpu, bool frozen) |
f9ba680d SB |
1123 | { |
1124 | struct device *cpu_dev; | |
f9ba680d SB |
1125 | int ret; |
1126 | ||
1127 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1128 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 SB |
1129 | |
1130 | /* Don't touch sysfs files during light-weight tear-down */ | |
1131 | if (frozen) | |
1132 | return cpu_dev->id; | |
1133 | ||
f9ba680d | 1134 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1135 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d SB |
1136 | if (ret) { |
1137 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1138 | ||
1b750e3b | 1139 | lock_policy_rwsem_write(old_cpu); |
3a3e9e06 | 1140 | cpumask_set_cpu(old_cpu, policy->cpus); |
f9ba680d SB |
1141 | unlock_policy_rwsem_write(old_cpu); |
1142 | ||
3a3e9e06 | 1143 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1144 | "cpufreq"); |
1145 | ||
1146 | return -EINVAL; | |
1147 | } | |
1148 | ||
1149 | return cpu_dev->id; | |
1150 | } | |
1151 | ||
cedb70af SB |
1152 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
1153 | struct subsys_interface *sif, | |
1154 | bool frozen) | |
1da177e4 | 1155 | { |
f9ba680d | 1156 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1157 | int new_cpu, ret; |
1da177e4 | 1158 | unsigned long flags; |
3a3e9e06 | 1159 | struct cpufreq_policy *policy; |
1da177e4 | 1160 | |
b8eed8af | 1161 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1162 | |
0d1857a1 | 1163 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1164 | |
3a3e9e06 | 1165 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1166 | |
8414809c SB |
1167 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1168 | if (frozen) | |
3a3e9e06 | 1169 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1170 | |
0d1857a1 | 1171 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1172 | |
3a3e9e06 | 1173 | if (!policy) { |
b8eed8af | 1174 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1175 | return -EINVAL; |
1176 | } | |
1da177e4 | 1177 | |
3de9bdeb VK |
1178 | if (cpufreq_driver->target) { |
1179 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1180 | if (ret) { | |
1181 | pr_err("%s: Failed to stop governor\n", __func__); | |
1182 | return ret; | |
1183 | } | |
1184 | } | |
1da177e4 | 1185 | |
084f3493 | 1186 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1187 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1188 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1189 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 LT |
1190 | #endif |
1191 | ||
9c8f1ee4 | 1192 | lock_policy_rwsem_read(cpu); |
3a3e9e06 | 1193 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 | 1194 | unlock_policy_rwsem_read(cpu); |
084f3493 | 1195 | |
61173f25 SB |
1196 | if (cpu != policy->cpu) { |
1197 | if (!frozen) | |
1198 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
73bf0fc2 | 1199 | } else if (cpus > 1) { |
3a3e9e06 | 1200 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen); |
f9ba680d | 1201 | if (new_cpu >= 0) { |
3a3e9e06 | 1202 | update_policy_cpu(policy, new_cpu); |
a82fab29 SB |
1203 | |
1204 | if (!frozen) { | |
75949c9a VK |
1205 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1206 | __func__, new_cpu, cpu); | |
a82fab29 | 1207 | } |
1da177e4 LT |
1208 | } |
1209 | } | |
1da177e4 | 1210 | |
cedb70af SB |
1211 | return 0; |
1212 | } | |
1213 | ||
1214 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
1215 | struct subsys_interface *sif, | |
1216 | bool frozen) | |
1217 | { | |
1218 | unsigned int cpu = dev->id, cpus; | |
1219 | int ret; | |
1220 | unsigned long flags; | |
1221 | struct cpufreq_policy *policy; | |
1222 | struct kobject *kobj; | |
1223 | struct completion *cmp; | |
1224 | ||
1225 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1226 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1227 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1228 | ||
1229 | if (!policy) { | |
1230 | pr_debug("%s: No cpu_data found\n", __func__); | |
1231 | return -EINVAL; | |
1232 | } | |
1233 | ||
1b750e3b | 1234 | lock_policy_rwsem_write(cpu); |
cedb70af | 1235 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1236 | |
1237 | if (cpus > 1) | |
1238 | cpumask_clear_cpu(cpu, policy->cpus); | |
1239 | unlock_policy_rwsem_write(cpu); | |
cedb70af | 1240 | |
b8eed8af VK |
1241 | /* If cpu is last user of policy, free policy */ |
1242 | if (cpus == 1) { | |
3de9bdeb VK |
1243 | if (cpufreq_driver->target) { |
1244 | ret = __cpufreq_governor(policy, | |
1245 | CPUFREQ_GOV_POLICY_EXIT); | |
1246 | if (ret) { | |
1247 | pr_err("%s: Failed to exit governor\n", | |
1248 | __func__); | |
1249 | return ret; | |
1250 | } | |
edab2fbc | 1251 | } |
2a998599 | 1252 | |
8414809c SB |
1253 | if (!frozen) { |
1254 | lock_policy_rwsem_read(cpu); | |
3a3e9e06 VK |
1255 | kobj = &policy->kobj; |
1256 | cmp = &policy->kobj_unregister; | |
8414809c SB |
1257 | unlock_policy_rwsem_read(cpu); |
1258 | kobject_put(kobj); | |
1259 | ||
1260 | /* | |
1261 | * We need to make sure that the underlying kobj is | |
1262 | * actually not referenced anymore by anybody before we | |
1263 | * proceed with unloading. | |
1264 | */ | |
1265 | pr_debug("waiting for dropping of refcount\n"); | |
1266 | wait_for_completion(cmp); | |
1267 | pr_debug("wait complete\n"); | |
1268 | } | |
7d26e2d5 | 1269 | |
8414809c SB |
1270 | /* |
1271 | * Perform the ->exit() even during light-weight tear-down, | |
1272 | * since this is a core component, and is essential for the | |
1273 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1274 | */ |
1c3d85dd | 1275 | if (cpufreq_driver->exit) |
3a3e9e06 | 1276 | cpufreq_driver->exit(policy); |
27ecddc2 | 1277 | |
9515f4d6 VK |
1278 | /* Remove policy from list of active policies */ |
1279 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1280 | list_del(&policy->policy_list); | |
1281 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1282 | ||
8414809c | 1283 | if (!frozen) |
3a3e9e06 | 1284 | cpufreq_policy_free(policy); |
2a998599 | 1285 | } else { |
2a998599 | 1286 | if (cpufreq_driver->target) { |
3de9bdeb VK |
1287 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
1288 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
1289 | pr_err("%s: Failed to start governor\n", | |
1290 | __func__); | |
1291 | return ret; | |
1292 | } | |
2a998599 | 1293 | } |
27ecddc2 | 1294 | } |
1da177e4 | 1295 | |
474deff7 | 1296 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1297 | return 0; |
1298 | } | |
1299 | ||
cedb70af | 1300 | /** |
27a862e9 | 1301 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1302 | * |
1303 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1304 | */ |
8a25a2fd | 1305 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1306 | { |
8a25a2fd | 1307 | unsigned int cpu = dev->id; |
27a862e9 | 1308 | int ret; |
ec28297a VP |
1309 | |
1310 | if (cpu_is_offline(cpu)) | |
1311 | return 0; | |
1312 | ||
27a862e9 VK |
1313 | ret = __cpufreq_remove_dev_prepare(dev, sif, false); |
1314 | ||
1315 | if (!ret) | |
1316 | ret = __cpufreq_remove_dev_finish(dev, sif, false); | |
1317 | ||
1318 | return ret; | |
5a01f2e8 VP |
1319 | } |
1320 | ||
65f27f38 | 1321 | static void handle_update(struct work_struct *work) |
1da177e4 | 1322 | { |
65f27f38 DH |
1323 | struct cpufreq_policy *policy = |
1324 | container_of(work, struct cpufreq_policy, update); | |
1325 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1326 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1327 | cpufreq_update_policy(cpu); |
1328 | } | |
1329 | ||
1330 | /** | |
bb176f7d VK |
1331 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1332 | * in deep trouble. | |
1da177e4 LT |
1333 | * @cpu: cpu number |
1334 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1335 | * @new_freq: CPU frequency the CPU actually runs at | |
1336 | * | |
29464f28 DJ |
1337 | * We adjust to current frequency first, and need to clean up later. |
1338 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1339 | */ |
e08f5f5b GS |
1340 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1341 | unsigned int new_freq) | |
1da177e4 | 1342 | { |
b43a7ffb | 1343 | struct cpufreq_policy *policy; |
1da177e4 | 1344 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1345 | unsigned long flags; |
1346 | ||
2d06d8c4 | 1347 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1348 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1349 | ||
1da177e4 LT |
1350 | freqs.old = old_freq; |
1351 | freqs.new = new_freq; | |
b43a7ffb VK |
1352 | |
1353 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1354 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1355 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1356 | ||
1357 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1358 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1359 | } |
1360 | ||
32ee8c3e | 1361 | /** |
4ab70df4 | 1362 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1363 | * @cpu: CPU number |
1364 | * | |
1365 | * This is the last known freq, without actually getting it from the driver. | |
1366 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1367 | */ | |
1368 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1369 | { | |
9e21ba8b | 1370 | struct cpufreq_policy *policy; |
e08f5f5b | 1371 | unsigned int ret_freq = 0; |
95235ca2 | 1372 | |
1c3d85dd RW |
1373 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1374 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1375 | |
1376 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1377 | if (policy) { |
e08f5f5b | 1378 | ret_freq = policy->cur; |
95235ca2 VP |
1379 | cpufreq_cpu_put(policy); |
1380 | } | |
1381 | ||
4d34a67d | 1382 | return ret_freq; |
95235ca2 VP |
1383 | } |
1384 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1385 | ||
3d737108 JB |
1386 | /** |
1387 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1388 | * @cpu: CPU number | |
1389 | * | |
1390 | * Just return the max possible frequency for a given CPU. | |
1391 | */ | |
1392 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1393 | { | |
1394 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1395 | unsigned int ret_freq = 0; | |
1396 | ||
1397 | if (policy) { | |
1398 | ret_freq = policy->max; | |
1399 | cpufreq_cpu_put(policy); | |
1400 | } | |
1401 | ||
1402 | return ret_freq; | |
1403 | } | |
1404 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1405 | ||
5a01f2e8 | 1406 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1407 | { |
7a6aedfa | 1408 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1409 | unsigned int ret_freq = 0; |
5800043b | 1410 | |
1c3d85dd | 1411 | if (!cpufreq_driver->get) |
4d34a67d | 1412 | return ret_freq; |
1da177e4 | 1413 | |
1c3d85dd | 1414 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1415 | |
e08f5f5b | 1416 | if (ret_freq && policy->cur && |
1c3d85dd | 1417 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1418 | /* verify no discrepancy between actual and |
1419 | saved value exists */ | |
1420 | if (unlikely(ret_freq != policy->cur)) { | |
1421 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1422 | schedule_work(&policy->update); |
1423 | } | |
1424 | } | |
1425 | ||
4d34a67d | 1426 | return ret_freq; |
5a01f2e8 | 1427 | } |
1da177e4 | 1428 | |
5a01f2e8 VP |
1429 | /** |
1430 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1431 | * @cpu: CPU number | |
1432 | * | |
1433 | * Get the CPU current (static) CPU frequency | |
1434 | */ | |
1435 | unsigned int cpufreq_get(unsigned int cpu) | |
1436 | { | |
1437 | unsigned int ret_freq = 0; | |
5a01f2e8 | 1438 | |
26ca8694 VK |
1439 | if (cpufreq_disabled() || !cpufreq_driver) |
1440 | return -ENOENT; | |
1441 | ||
6eed9404 VK |
1442 | if (!down_read_trylock(&cpufreq_rwsem)) |
1443 | return 0; | |
5a01f2e8 | 1444 | |
1b750e3b | 1445 | lock_policy_rwsem_read(cpu); |
5a01f2e8 VP |
1446 | |
1447 | ret_freq = __cpufreq_get(cpu); | |
1448 | ||
1449 | unlock_policy_rwsem_read(cpu); | |
6eed9404 VK |
1450 | up_read(&cpufreq_rwsem); |
1451 | ||
4d34a67d | 1452 | return ret_freq; |
1da177e4 LT |
1453 | } |
1454 | EXPORT_SYMBOL(cpufreq_get); | |
1455 | ||
8a25a2fd KS |
1456 | static struct subsys_interface cpufreq_interface = { |
1457 | .name = "cpufreq", | |
1458 | .subsys = &cpu_subsys, | |
1459 | .add_dev = cpufreq_add_dev, | |
1460 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1461 | }; |
1462 | ||
42d4dc3f | 1463 | /** |
e00e56df RW |
1464 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1465 | * | |
1466 | * This function is only executed for the boot processor. The other CPUs | |
1467 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1468 | */ |
e00e56df | 1469 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1470 | { |
e08f5f5b | 1471 | int ret = 0; |
4bc5d341 | 1472 | |
e00e56df | 1473 | int cpu = smp_processor_id(); |
3a3e9e06 | 1474 | struct cpufreq_policy *policy; |
42d4dc3f | 1475 | |
2d06d8c4 | 1476 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1477 | |
e00e56df | 1478 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1479 | policy = cpufreq_cpu_get(cpu); |
1480 | if (!policy) | |
e00e56df | 1481 | return 0; |
42d4dc3f | 1482 | |
1c3d85dd | 1483 | if (cpufreq_driver->suspend) { |
3a3e9e06 | 1484 | ret = cpufreq_driver->suspend(policy); |
ce6c3997 | 1485 | if (ret) |
42d4dc3f | 1486 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
3a3e9e06 | 1487 | "step on CPU %u\n", policy->cpu); |
42d4dc3f BH |
1488 | } |
1489 | ||
3a3e9e06 | 1490 | cpufreq_cpu_put(policy); |
c9060494 | 1491 | return ret; |
42d4dc3f BH |
1492 | } |
1493 | ||
1da177e4 | 1494 | /** |
e00e56df | 1495 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1496 | * |
1497 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1498 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1499 | * restored. It will verify that the current freq is in sync with | |
1500 | * what we believe it to be. This is a bit later than when it | |
1501 | * should be, but nonethteless it's better than calling | |
1502 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1503 | * |
1504 | * This function is only executed for the boot CPU. The other CPUs have not | |
1505 | * been turned on yet. | |
1da177e4 | 1506 | */ |
e00e56df | 1507 | static void cpufreq_bp_resume(void) |
1da177e4 | 1508 | { |
e08f5f5b | 1509 | int ret = 0; |
4bc5d341 | 1510 | |
e00e56df | 1511 | int cpu = smp_processor_id(); |
3a3e9e06 | 1512 | struct cpufreq_policy *policy; |
1da177e4 | 1513 | |
2d06d8c4 | 1514 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1515 | |
e00e56df | 1516 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1517 | policy = cpufreq_cpu_get(cpu); |
1518 | if (!policy) | |
e00e56df | 1519 | return; |
1da177e4 | 1520 | |
1c3d85dd | 1521 | if (cpufreq_driver->resume) { |
3a3e9e06 | 1522 | ret = cpufreq_driver->resume(policy); |
1da177e4 LT |
1523 | if (ret) { |
1524 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
3a3e9e06 | 1525 | "step on CPU %u\n", policy->cpu); |
c9060494 | 1526 | goto fail; |
1da177e4 LT |
1527 | } |
1528 | } | |
1529 | ||
3a3e9e06 | 1530 | schedule_work(&policy->update); |
ce6c3997 | 1531 | |
c9060494 | 1532 | fail: |
3a3e9e06 | 1533 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1534 | } |
1535 | ||
e00e56df RW |
1536 | static struct syscore_ops cpufreq_syscore_ops = { |
1537 | .suspend = cpufreq_bp_suspend, | |
1538 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1539 | }; |
1540 | ||
9d95046e BP |
1541 | /** |
1542 | * cpufreq_get_current_driver - return current driver's name | |
1543 | * | |
1544 | * Return the name string of the currently loaded cpufreq driver | |
1545 | * or NULL, if none. | |
1546 | */ | |
1547 | const char *cpufreq_get_current_driver(void) | |
1548 | { | |
1c3d85dd RW |
1549 | if (cpufreq_driver) |
1550 | return cpufreq_driver->name; | |
1551 | ||
1552 | return NULL; | |
9d95046e BP |
1553 | } |
1554 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1555 | |
1556 | /********************************************************************* | |
1557 | * NOTIFIER LISTS INTERFACE * | |
1558 | *********************************************************************/ | |
1559 | ||
1560 | /** | |
1561 | * cpufreq_register_notifier - register a driver with cpufreq | |
1562 | * @nb: notifier function to register | |
1563 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1564 | * | |
32ee8c3e | 1565 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1566 | * are notified about clock rate changes (once before and once after |
1567 | * the transition), or a list of drivers that are notified about | |
1568 | * changes in cpufreq policy. | |
1569 | * | |
1570 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1571 | * blocking_notifier_chain_register. |
1da177e4 LT |
1572 | */ |
1573 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1574 | { | |
1575 | int ret; | |
1576 | ||
d5aaffa9 DB |
1577 | if (cpufreq_disabled()) |
1578 | return -EINVAL; | |
1579 | ||
74212ca4 CEB |
1580 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1581 | ||
1da177e4 LT |
1582 | switch (list) { |
1583 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1584 | ret = srcu_notifier_chain_register( |
e041c683 | 1585 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1586 | break; |
1587 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1588 | ret = blocking_notifier_chain_register( |
1589 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1590 | break; |
1591 | default: | |
1592 | ret = -EINVAL; | |
1593 | } | |
1da177e4 LT |
1594 | |
1595 | return ret; | |
1596 | } | |
1597 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1598 | ||
1da177e4 LT |
1599 | /** |
1600 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1601 | * @nb: notifier block to be unregistered | |
bb176f7d | 1602 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1603 | * |
1604 | * Remove a driver from the CPU frequency notifier list. | |
1605 | * | |
1606 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1607 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1608 | */ |
1609 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1610 | { | |
1611 | int ret; | |
1612 | ||
d5aaffa9 DB |
1613 | if (cpufreq_disabled()) |
1614 | return -EINVAL; | |
1615 | ||
1da177e4 LT |
1616 | switch (list) { |
1617 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1618 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1619 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1620 | break; |
1621 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1622 | ret = blocking_notifier_chain_unregister( |
1623 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1624 | break; |
1625 | default: | |
1626 | ret = -EINVAL; | |
1627 | } | |
1da177e4 LT |
1628 | |
1629 | return ret; | |
1630 | } | |
1631 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1632 | ||
1633 | ||
1634 | /********************************************************************* | |
1635 | * GOVERNORS * | |
1636 | *********************************************************************/ | |
1637 | ||
1da177e4 LT |
1638 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1639 | unsigned int target_freq, | |
1640 | unsigned int relation) | |
1641 | { | |
1642 | int retval = -EINVAL; | |
7249924e | 1643 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1644 | |
a7b422cd KRW |
1645 | if (cpufreq_disabled()) |
1646 | return -ENODEV; | |
1647 | ||
7249924e VK |
1648 | /* Make sure that target_freq is within supported range */ |
1649 | if (target_freq > policy->max) | |
1650 | target_freq = policy->max; | |
1651 | if (target_freq < policy->min) | |
1652 | target_freq = policy->min; | |
1653 | ||
1654 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1655 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1656 | |
1657 | if (target_freq == policy->cur) | |
1658 | return 0; | |
1659 | ||
1c3d85dd RW |
1660 | if (cpufreq_driver->target) |
1661 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1662 | |
1da177e4 LT |
1663 | return retval; |
1664 | } | |
1665 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1666 | ||
1da177e4 LT |
1667 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1668 | unsigned int target_freq, | |
1669 | unsigned int relation) | |
1670 | { | |
f1829e4a | 1671 | int ret = -EINVAL; |
1da177e4 | 1672 | |
1b750e3b | 1673 | lock_policy_rwsem_write(policy->cpu); |
1da177e4 LT |
1674 | |
1675 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1676 | ||
5a01f2e8 | 1677 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1678 | |
1da177e4 LT |
1679 | return ret; |
1680 | } | |
1681 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1682 | ||
153d7f3f | 1683 | /* |
153d7f3f AV |
1684 | * when "event" is CPUFREQ_GOV_LIMITS |
1685 | */ | |
1da177e4 | 1686 | |
e08f5f5b GS |
1687 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1688 | unsigned int event) | |
1da177e4 | 1689 | { |
cc993cab | 1690 | int ret; |
6afde10c TR |
1691 | |
1692 | /* Only must be defined when default governor is known to have latency | |
1693 | restrictions, like e.g. conservative or ondemand. | |
1694 | That this is the case is already ensured in Kconfig | |
1695 | */ | |
1696 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1697 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1698 | #else | |
1699 | struct cpufreq_governor *gov = NULL; | |
1700 | #endif | |
1c256245 TR |
1701 | |
1702 | if (policy->governor->max_transition_latency && | |
1703 | policy->cpuinfo.transition_latency > | |
1704 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1705 | if (!gov) |
1706 | return -EINVAL; | |
1707 | else { | |
1708 | printk(KERN_WARNING "%s governor failed, too long" | |
1709 | " transition latency of HW, fallback" | |
1710 | " to %s governor\n", | |
1711 | policy->governor->name, | |
1712 | gov->name); | |
1713 | policy->governor = gov; | |
1714 | } | |
1c256245 | 1715 | } |
1da177e4 | 1716 | |
fe492f3f VK |
1717 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1718 | if (!try_module_get(policy->governor->owner)) | |
1719 | return -EINVAL; | |
1da177e4 | 1720 | |
2d06d8c4 | 1721 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1722 | policy->cpu, event); |
95731ebb XC |
1723 | |
1724 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1725 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1726 | || (!policy->governor_enabled |
1727 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1728 | mutex_unlock(&cpufreq_governor_lock); |
1729 | return -EBUSY; | |
1730 | } | |
1731 | ||
1732 | if (event == CPUFREQ_GOV_STOP) | |
1733 | policy->governor_enabled = false; | |
1734 | else if (event == CPUFREQ_GOV_START) | |
1735 | policy->governor_enabled = true; | |
1736 | ||
1737 | mutex_unlock(&cpufreq_governor_lock); | |
1738 | ||
1da177e4 LT |
1739 | ret = policy->governor->governor(policy, event); |
1740 | ||
4d5dcc42 VK |
1741 | if (!ret) { |
1742 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1743 | policy->governor->initialized++; | |
1744 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1745 | policy->governor->initialized--; | |
95731ebb XC |
1746 | } else { |
1747 | /* Restore original values */ | |
1748 | mutex_lock(&cpufreq_governor_lock); | |
1749 | if (event == CPUFREQ_GOV_STOP) | |
1750 | policy->governor_enabled = true; | |
1751 | else if (event == CPUFREQ_GOV_START) | |
1752 | policy->governor_enabled = false; | |
1753 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1754 | } |
b394058f | 1755 | |
fe492f3f VK |
1756 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1757 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1758 | module_put(policy->governor->owner); |
1759 | ||
1760 | return ret; | |
1761 | } | |
1762 | ||
1da177e4 LT |
1763 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1764 | { | |
3bcb09a3 | 1765 | int err; |
1da177e4 LT |
1766 | |
1767 | if (!governor) | |
1768 | return -EINVAL; | |
1769 | ||
a7b422cd KRW |
1770 | if (cpufreq_disabled()) |
1771 | return -ENODEV; | |
1772 | ||
3fc54d37 | 1773 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1774 | |
b394058f | 1775 | governor->initialized = 0; |
3bcb09a3 JF |
1776 | err = -EBUSY; |
1777 | if (__find_governor(governor->name) == NULL) { | |
1778 | err = 0; | |
1779 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1780 | } |
1da177e4 | 1781 | |
32ee8c3e | 1782 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1783 | return err; |
1da177e4 LT |
1784 | } |
1785 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1786 | ||
1da177e4 LT |
1787 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1788 | { | |
90e41bac PB |
1789 | #ifdef CONFIG_HOTPLUG_CPU |
1790 | int cpu; | |
1791 | #endif | |
1792 | ||
1da177e4 LT |
1793 | if (!governor) |
1794 | return; | |
1795 | ||
a7b422cd KRW |
1796 | if (cpufreq_disabled()) |
1797 | return; | |
1798 | ||
90e41bac PB |
1799 | #ifdef CONFIG_HOTPLUG_CPU |
1800 | for_each_present_cpu(cpu) { | |
1801 | if (cpu_online(cpu)) | |
1802 | continue; | |
1803 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1804 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1805 | } | |
1806 | #endif | |
1807 | ||
3fc54d37 | 1808 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1809 | list_del(&governor->governor_list); |
3fc54d37 | 1810 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1811 | return; |
1812 | } | |
1813 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1814 | ||
1815 | ||
1da177e4 LT |
1816 | /********************************************************************* |
1817 | * POLICY INTERFACE * | |
1818 | *********************************************************************/ | |
1819 | ||
1820 | /** | |
1821 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1822 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1823 | * is written | |
1da177e4 LT |
1824 | * |
1825 | * Reads the current cpufreq policy. | |
1826 | */ | |
1827 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1828 | { | |
1829 | struct cpufreq_policy *cpu_policy; | |
1830 | if (!policy) | |
1831 | return -EINVAL; | |
1832 | ||
1833 | cpu_policy = cpufreq_cpu_get(cpu); | |
1834 | if (!cpu_policy) | |
1835 | return -EINVAL; | |
1836 | ||
d5b73cd8 | 1837 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
1838 | |
1839 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1840 | return 0; |
1841 | } | |
1842 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1843 | ||
153d7f3f | 1844 | /* |
037ce839 VK |
1845 | * policy : current policy. |
1846 | * new_policy: policy to be set. | |
153d7f3f | 1847 | */ |
037ce839 | 1848 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 1849 | struct cpufreq_policy *new_policy) |
1da177e4 | 1850 | { |
7bd353a9 | 1851 | int ret = 0, failed = 1; |
1da177e4 | 1852 | |
3a3e9e06 VK |
1853 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, |
1854 | new_policy->min, new_policy->max); | |
1da177e4 | 1855 | |
d5b73cd8 | 1856 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 1857 | |
3a3e9e06 | 1858 | if (new_policy->min > policy->max || new_policy->max < policy->min) { |
9c9a43ed MD |
1859 | ret = -EINVAL; |
1860 | goto error_out; | |
1861 | } | |
1862 | ||
1da177e4 | 1863 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 1864 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 LT |
1865 | if (ret) |
1866 | goto error_out; | |
1867 | ||
1da177e4 | 1868 | /* adjust if necessary - all reasons */ |
e041c683 | 1869 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1870 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
1871 | |
1872 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 1873 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1874 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 1875 | |
bb176f7d VK |
1876 | /* |
1877 | * verify the cpu speed can be set within this limit, which might be | |
1878 | * different to the first one | |
1879 | */ | |
3a3e9e06 | 1880 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 1881 | if (ret) |
1da177e4 | 1882 | goto error_out; |
1da177e4 LT |
1883 | |
1884 | /* notification of the new policy */ | |
e041c683 | 1885 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1886 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 1887 | |
3a3e9e06 VK |
1888 | policy->min = new_policy->min; |
1889 | policy->max = new_policy->max; | |
1da177e4 | 1890 | |
2d06d8c4 | 1891 | pr_debug("new min and max freqs are %u - %u kHz\n", |
3a3e9e06 | 1892 | policy->min, policy->max); |
1da177e4 | 1893 | |
1c3d85dd | 1894 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 1895 | policy->policy = new_policy->policy; |
2d06d8c4 | 1896 | pr_debug("setting range\n"); |
3a3e9e06 | 1897 | ret = cpufreq_driver->setpolicy(new_policy); |
1da177e4 | 1898 | } else { |
3a3e9e06 | 1899 | if (new_policy->governor != policy->governor) { |
1da177e4 | 1900 | /* save old, working values */ |
3a3e9e06 | 1901 | struct cpufreq_governor *old_gov = policy->governor; |
1da177e4 | 1902 | |
2d06d8c4 | 1903 | pr_debug("governor switch\n"); |
1da177e4 LT |
1904 | |
1905 | /* end old governor */ | |
3a3e9e06 VK |
1906 | if (policy->governor) { |
1907 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1908 | unlock_policy_rwsem_write(new_policy->cpu); | |
1909 | __cpufreq_governor(policy, | |
7bd353a9 | 1910 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1911 | lock_policy_rwsem_write(new_policy->cpu); |
7bd353a9 | 1912 | } |
1da177e4 LT |
1913 | |
1914 | /* start new governor */ | |
3a3e9e06 VK |
1915 | policy->governor = new_policy->governor; |
1916 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
1917 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) { | |
7bd353a9 | 1918 | failed = 0; |
955ef483 | 1919 | } else { |
3a3e9e06 VK |
1920 | unlock_policy_rwsem_write(new_policy->cpu); |
1921 | __cpufreq_governor(policy, | |
7bd353a9 | 1922 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1923 | lock_policy_rwsem_write(new_policy->cpu); |
955ef483 | 1924 | } |
7bd353a9 VK |
1925 | } |
1926 | ||
1927 | if (failed) { | |
1da177e4 | 1928 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1929 | pr_debug("starting governor %s failed\n", |
3a3e9e06 | 1930 | policy->governor->name); |
1da177e4 | 1931 | if (old_gov) { |
3a3e9e06 VK |
1932 | policy->governor = old_gov; |
1933 | __cpufreq_governor(policy, | |
7bd353a9 | 1934 | CPUFREQ_GOV_POLICY_INIT); |
3a3e9e06 | 1935 | __cpufreq_governor(policy, |
e08f5f5b | 1936 | CPUFREQ_GOV_START); |
1da177e4 LT |
1937 | } |
1938 | ret = -EINVAL; | |
1939 | goto error_out; | |
1940 | } | |
1941 | /* might be a policy change, too, so fall through */ | |
1942 | } | |
2d06d8c4 | 1943 | pr_debug("governor: change or update limits\n"); |
3de9bdeb | 1944 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
1da177e4 LT |
1945 | } |
1946 | ||
7d5e350f | 1947 | error_out: |
1da177e4 LT |
1948 | return ret; |
1949 | } | |
1950 | ||
1da177e4 LT |
1951 | /** |
1952 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1953 | * @cpu: CPU which shall be re-evaluated | |
1954 | * | |
25985edc | 1955 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1956 | * at different times. |
1957 | */ | |
1958 | int cpufreq_update_policy(unsigned int cpu) | |
1959 | { | |
3a3e9e06 VK |
1960 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
1961 | struct cpufreq_policy new_policy; | |
f1829e4a | 1962 | int ret; |
1da177e4 | 1963 | |
3a3e9e06 | 1964 | if (!policy) { |
f1829e4a JL |
1965 | ret = -ENODEV; |
1966 | goto no_policy; | |
1967 | } | |
1da177e4 | 1968 | |
1b750e3b | 1969 | lock_policy_rwsem_write(cpu); |
1da177e4 | 1970 | |
2d06d8c4 | 1971 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 1972 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
1973 | new_policy.min = policy->user_policy.min; |
1974 | new_policy.max = policy->user_policy.max; | |
1975 | new_policy.policy = policy->user_policy.policy; | |
1976 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 1977 | |
bb176f7d VK |
1978 | /* |
1979 | * BIOS might change freq behind our back | |
1980 | * -> ask driver for current freq and notify governors about a change | |
1981 | */ | |
1c3d85dd | 1982 | if (cpufreq_driver->get) { |
3a3e9e06 VK |
1983 | new_policy.cur = cpufreq_driver->get(cpu); |
1984 | if (!policy->cur) { | |
2d06d8c4 | 1985 | pr_debug("Driver did not initialize current freq"); |
3a3e9e06 | 1986 | policy->cur = new_policy.cur; |
a85f7bd3 | 1987 | } else { |
3a3e9e06 VK |
1988 | if (policy->cur != new_policy.cur && cpufreq_driver->target) |
1989 | cpufreq_out_of_sync(cpu, policy->cur, | |
1990 | new_policy.cur); | |
a85f7bd3 | 1991 | } |
0961dd0d TR |
1992 | } |
1993 | ||
037ce839 | 1994 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 1995 | |
5a01f2e8 VP |
1996 | unlock_policy_rwsem_write(cpu); |
1997 | ||
3a3e9e06 | 1998 | cpufreq_cpu_put(policy); |
f1829e4a | 1999 | no_policy: |
1da177e4 LT |
2000 | return ret; |
2001 | } | |
2002 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2003 | ||
2760984f | 2004 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2005 | unsigned long action, void *hcpu) |
2006 | { | |
2007 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2008 | struct device *dev; |
5302c3fb | 2009 | bool frozen = false; |
c32b6b8e | 2010 | |
8a25a2fd KS |
2011 | dev = get_cpu_device(cpu); |
2012 | if (dev) { | |
5302c3fb SB |
2013 | |
2014 | if (action & CPU_TASKS_FROZEN) | |
2015 | frozen = true; | |
2016 | ||
2017 | switch (action & ~CPU_TASKS_FROZEN) { | |
c32b6b8e | 2018 | case CPU_ONLINE: |
5302c3fb | 2019 | __cpufreq_add_dev(dev, NULL, frozen); |
23d32899 | 2020 | cpufreq_update_policy(cpu); |
c32b6b8e | 2021 | break; |
5302c3fb | 2022 | |
c32b6b8e | 2023 | case CPU_DOWN_PREPARE: |
cedb70af | 2024 | __cpufreq_remove_dev_prepare(dev, NULL, frozen); |
1aee40ac SB |
2025 | break; |
2026 | ||
2027 | case CPU_POST_DEAD: | |
cedb70af | 2028 | __cpufreq_remove_dev_finish(dev, NULL, frozen); |
c32b6b8e | 2029 | break; |
5302c3fb | 2030 | |
5a01f2e8 | 2031 | case CPU_DOWN_FAILED: |
5302c3fb | 2032 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2033 | break; |
2034 | } | |
2035 | } | |
2036 | return NOTIFY_OK; | |
2037 | } | |
2038 | ||
9c36f746 | 2039 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2040 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2041 | }; |
1da177e4 LT |
2042 | |
2043 | /********************************************************************* | |
2044 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2045 | *********************************************************************/ | |
2046 | ||
2047 | /** | |
2048 | * cpufreq_register_driver - register a CPU Frequency driver | |
2049 | * @driver_data: A struct cpufreq_driver containing the values# | |
2050 | * submitted by the CPU Frequency driver. | |
2051 | * | |
bb176f7d | 2052 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2053 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2054 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2055 | * |
2056 | */ | |
221dee28 | 2057 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2058 | { |
2059 | unsigned long flags; | |
2060 | int ret; | |
2061 | ||
a7b422cd KRW |
2062 | if (cpufreq_disabled()) |
2063 | return -ENODEV; | |
2064 | ||
1da177e4 LT |
2065 | if (!driver_data || !driver_data->verify || !driver_data->init || |
2066 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2067 | return -EINVAL; | |
2068 | ||
2d06d8c4 | 2069 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2070 | |
2071 | if (driver_data->setpolicy) | |
2072 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2073 | ||
0d1857a1 | 2074 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2075 | if (cpufreq_driver) { |
0d1857a1 | 2076 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2077 | return -EEXIST; |
1da177e4 | 2078 | } |
1c3d85dd | 2079 | cpufreq_driver = driver_data; |
0d1857a1 | 2080 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2081 | |
8a25a2fd | 2082 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2083 | if (ret) |
2084 | goto err_null_driver; | |
1da177e4 | 2085 | |
1c3d85dd | 2086 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2087 | int i; |
2088 | ret = -ENODEV; | |
2089 | ||
2090 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2091 | for (i = 0; i < nr_cpu_ids; i++) |
2092 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2093 | ret = 0; |
7a6aedfa MT |
2094 | break; |
2095 | } | |
1da177e4 LT |
2096 | |
2097 | /* if all ->init() calls failed, unregister */ | |
2098 | if (ret) { | |
2d06d8c4 | 2099 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2100 | driver_data->name); |
8a25a2fd | 2101 | goto err_if_unreg; |
1da177e4 LT |
2102 | } |
2103 | } | |
2104 | ||
8f5bc2ab | 2105 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2106 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2107 | |
8f5bc2ab | 2108 | return 0; |
8a25a2fd KS |
2109 | err_if_unreg: |
2110 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2111 | err_null_driver: |
0d1857a1 | 2112 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2113 | cpufreq_driver = NULL; |
0d1857a1 | 2114 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2115 | return ret; |
1da177e4 LT |
2116 | } |
2117 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2118 | ||
1da177e4 LT |
2119 | /** |
2120 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2121 | * | |
bb176f7d | 2122 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2123 | * the right to do so, i.e. if you have succeeded in initialising before! |
2124 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2125 | * currently not initialised. | |
2126 | */ | |
221dee28 | 2127 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2128 | { |
2129 | unsigned long flags; | |
2130 | ||
1c3d85dd | 2131 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2132 | return -EINVAL; |
1da177e4 | 2133 | |
2d06d8c4 | 2134 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2135 | |
8a25a2fd | 2136 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2137 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2138 | |
6eed9404 | 2139 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2140 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2141 | |
1c3d85dd | 2142 | cpufreq_driver = NULL; |
6eed9404 | 2143 | |
0d1857a1 | 2144 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2145 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2146 | |
2147 | return 0; | |
2148 | } | |
2149 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2150 | |
2151 | static int __init cpufreq_core_init(void) | |
2152 | { | |
2153 | int cpu; | |
2154 | ||
a7b422cd KRW |
2155 | if (cpufreq_disabled()) |
2156 | return -ENODEV; | |
2157 | ||
474deff7 | 2158 | for_each_possible_cpu(cpu) |
5a01f2e8 | 2159 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
8aa84ad8 | 2160 | |
2361be23 | 2161 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2162 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2163 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2164 | |
5a01f2e8 VP |
2165 | return 0; |
2166 | } | |
5a01f2e8 | 2167 | core_initcall(cpufreq_core_init); |