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 | ||
72a4ce34 | 20 | #include <asm/cputime.h> |
1da177e4 | 21 | #include <linux/kernel.h> |
72a4ce34 | 22 | #include <linux/kernel_stat.h> |
1da177e4 LT |
23 | #include <linux/module.h> |
24 | #include <linux/init.h> | |
25 | #include <linux/notifier.h> | |
26 | #include <linux/cpufreq.h> | |
27 | #include <linux/delay.h> | |
28 | #include <linux/interrupt.h> | |
29 | #include <linux/spinlock.h> | |
72a4ce34 | 30 | #include <linux/tick.h> |
1da177e4 LT |
31 | #include <linux/device.h> |
32 | #include <linux/slab.h> | |
33 | #include <linux/cpu.h> | |
34 | #include <linux/completion.h> | |
3fc54d37 | 35 | #include <linux/mutex.h> |
e00e56df | 36 | #include <linux/syscore_ops.h> |
1da177e4 | 37 | |
6f4f2723 TR |
38 | #include <trace/events/power.h> |
39 | ||
1da177e4 | 40 | /** |
cd878479 | 41 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
42 | * level driver of CPUFreq support, and its spinlock. This lock |
43 | * also protects the cpufreq_cpu_data array. | |
44 | */ | |
1c3d85dd | 45 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 46 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
bb176f7d VK |
47 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
48 | static DEFINE_MUTEX(cpufreq_governor_lock); | |
49 | ||
084f3493 TR |
50 | #ifdef CONFIG_HOTPLUG_CPU |
51 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 52 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 53 | #endif |
1da177e4 | 54 | |
5a01f2e8 VP |
55 | /* |
56 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
57 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
58 | * | |
59 | * The rules for this semaphore: | |
60 | * - Any routine that wants to read from the policy structure will | |
61 | * do a down_read on this semaphore. | |
62 | * - Any routine that will write to the policy structure and/or may take away | |
63 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
64 | * mode before doing so. | |
65 | * | |
66 | * Additional rules: | |
5a01f2e8 VP |
67 | * - Governor routines that can be called in cpufreq hotplug path should not |
68 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
69 | * - Lock should not be held across |
70 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 71 | */ |
f1625066 | 72 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
73 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
74 | ||
75 | #define lock_policy_rwsem(mode, cpu) \ | |
fa1d8af4 | 76 | static int lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 77 | { \ |
f1625066 | 78 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
79 | BUG_ON(policy_cpu == -1); \ |
80 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 VP |
81 | \ |
82 | return 0; \ | |
83 | } | |
84 | ||
85 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 86 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 87 | |
fa1d8af4 VK |
88 | #define unlock_policy_rwsem(mode, cpu) \ |
89 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
90 | { \ | |
91 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
92 | BUG_ON(policy_cpu == -1); \ | |
93 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 | 94 | } |
5a01f2e8 | 95 | |
fa1d8af4 VK |
96 | unlock_policy_rwsem(read, cpu); |
97 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 98 | |
1da177e4 | 99 | /* internal prototypes */ |
29464f28 DJ |
100 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
101 | unsigned int event); | |
5a01f2e8 | 102 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 103 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
104 | |
105 | /** | |
32ee8c3e DJ |
106 | * Two notifier lists: the "policy" list is involved in the |
107 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
108 | * "transition" list for kernel code that needs to handle |
109 | * changes to devices when the CPU clock speed changes. | |
110 | * The mutex locks both lists. | |
111 | */ | |
e041c683 | 112 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 113 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 114 | |
74212ca4 | 115 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
116 | static int __init init_cpufreq_transition_notifier_list(void) |
117 | { | |
118 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 119 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
120 | return 0; |
121 | } | |
b3438f82 | 122 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 123 | |
a7b422cd | 124 | static int off __read_mostly; |
da584455 | 125 | static int cpufreq_disabled(void) |
a7b422cd KRW |
126 | { |
127 | return off; | |
128 | } | |
129 | void disable_cpufreq(void) | |
130 | { | |
131 | off = 1; | |
132 | } | |
1da177e4 | 133 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 134 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 135 | |
4d5dcc42 VK |
136 | bool have_governor_per_policy(void) |
137 | { | |
1c3d85dd | 138 | return cpufreq_driver->have_governor_per_policy; |
4d5dcc42 | 139 | } |
3f869d6d | 140 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 141 | |
944e9a03 VK |
142 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
143 | { | |
144 | if (have_governor_per_policy()) | |
145 | return &policy->kobj; | |
146 | else | |
147 | return cpufreq_global_kobject; | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
150 | ||
72a4ce34 VK |
151 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
152 | { | |
153 | u64 idle_time; | |
154 | u64 cur_wall_time; | |
155 | u64 busy_time; | |
156 | ||
157 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
158 | ||
159 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
160 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
161 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
162 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
163 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
164 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
165 | ||
166 | idle_time = cur_wall_time - busy_time; | |
167 | if (wall) | |
168 | *wall = cputime_to_usecs(cur_wall_time); | |
169 | ||
170 | return cputime_to_usecs(idle_time); | |
171 | } | |
172 | ||
173 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
174 | { | |
175 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
176 | ||
177 | if (idle_time == -1ULL) | |
178 | return get_cpu_idle_time_jiffy(cpu, wall); | |
179 | else if (!io_busy) | |
180 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
181 | ||
182 | return idle_time; | |
183 | } | |
184 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
185 | ||
a9144436 | 186 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
187 | { |
188 | struct cpufreq_policy *data; | |
189 | unsigned long flags; | |
190 | ||
7a6aedfa | 191 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
192 | goto err_out; |
193 | ||
194 | /* get the cpufreq driver */ | |
1c3d85dd | 195 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 196 | |
1c3d85dd | 197 | if (!cpufreq_driver) |
1da177e4 LT |
198 | goto err_out_unlock; |
199 | ||
1c3d85dd | 200 | if (!try_module_get(cpufreq_driver->owner)) |
1da177e4 LT |
201 | goto err_out_unlock; |
202 | ||
1da177e4 | 203 | /* get the CPU */ |
7a6aedfa | 204 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
205 | |
206 | if (!data) | |
207 | goto err_out_put_module; | |
208 | ||
a9144436 | 209 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
210 | goto err_out_put_module; |
211 | ||
0d1857a1 | 212 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
213 | return data; |
214 | ||
7d5e350f | 215 | err_out_put_module: |
1c3d85dd | 216 | module_put(cpufreq_driver->owner); |
5800043b | 217 | err_out_unlock: |
1c3d85dd | 218 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 219 | err_out: |
1da177e4 LT |
220 | return NULL; |
221 | } | |
a9144436 SB |
222 | |
223 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
224 | { | |
d5aaffa9 DB |
225 | if (cpufreq_disabled()) |
226 | return NULL; | |
227 | ||
a9144436 SB |
228 | return __cpufreq_cpu_get(cpu, false); |
229 | } | |
1da177e4 LT |
230 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
231 | ||
a9144436 SB |
232 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
233 | { | |
234 | return __cpufreq_cpu_get(cpu, true); | |
235 | } | |
236 | ||
237 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
238 | { | |
239 | if (!sysfs) | |
240 | kobject_put(&data->kobj); | |
1c3d85dd | 241 | module_put(cpufreq_driver->owner); |
a9144436 | 242 | } |
7d5e350f | 243 | |
1da177e4 LT |
244 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
245 | { | |
d5aaffa9 DB |
246 | if (cpufreq_disabled()) |
247 | return; | |
248 | ||
a9144436 | 249 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
250 | } |
251 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
252 | ||
a9144436 SB |
253 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
254 | { | |
255 | __cpufreq_cpu_put(data, true); | |
256 | } | |
1da177e4 | 257 | |
1da177e4 LT |
258 | /********************************************************************* |
259 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
260 | *********************************************************************/ | |
261 | ||
262 | /** | |
263 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
264 | * | |
265 | * This function alters the system "loops_per_jiffy" for the clock | |
266 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 267 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
268 | * per-CPU loops_per_jiffy value wherever possible. |
269 | */ | |
270 | #ifndef CONFIG_SMP | |
271 | static unsigned long l_p_j_ref; | |
bb176f7d | 272 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 273 | |
858119e1 | 274 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
275 | { |
276 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
277 | return; | |
278 | ||
279 | if (!l_p_j_ref_freq) { | |
280 | l_p_j_ref = loops_per_jiffy; | |
281 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 282 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 283 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 284 | } |
bb176f7d | 285 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 286 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
287 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
288 | ci->new); | |
2d06d8c4 | 289 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 290 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
291 | } |
292 | } | |
293 | #else | |
e08f5f5b GS |
294 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
295 | { | |
296 | return; | |
297 | } | |
1da177e4 LT |
298 | #endif |
299 | ||
0956df9c | 300 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 301 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
302 | { |
303 | BUG_ON(irqs_disabled()); | |
304 | ||
d5aaffa9 DB |
305 | if (cpufreq_disabled()) |
306 | return; | |
307 | ||
1c3d85dd | 308 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 309 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 310 | state, freqs->new); |
1da177e4 | 311 | |
1da177e4 | 312 | switch (state) { |
e4472cb3 | 313 | |
1da177e4 | 314 | case CPUFREQ_PRECHANGE: |
266c13d7 VK |
315 | if (WARN(policy->transition_ongoing == |
316 | cpumask_weight(policy->cpus), | |
7c30ed53 VK |
317 | "In middle of another frequency transition\n")) |
318 | return; | |
319 | ||
266c13d7 | 320 | policy->transition_ongoing++; |
7c30ed53 | 321 | |
32ee8c3e | 322 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
323 | * which is not equal to what the cpufreq core thinks is |
324 | * "old frequency". | |
1da177e4 | 325 | */ |
1c3d85dd | 326 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
327 | if ((policy) && (policy->cpu == freqs->cpu) && |
328 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 329 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
330 | " %u, cpufreq assumed %u kHz.\n", |
331 | freqs->old, policy->cur); | |
332 | freqs->old = policy->cur; | |
1da177e4 LT |
333 | } |
334 | } | |
b4dfdbb3 | 335 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 336 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
337 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
338 | break; | |
e4472cb3 | 339 | |
1da177e4 | 340 | case CPUFREQ_POSTCHANGE: |
7c30ed53 VK |
341 | if (WARN(!policy->transition_ongoing, |
342 | "No frequency transition in progress\n")) | |
343 | return; | |
344 | ||
266c13d7 | 345 | policy->transition_ongoing--; |
7c30ed53 | 346 | |
1da177e4 | 347 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); |
2d06d8c4 | 348 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 349 | (unsigned long)freqs->cpu); |
25e41933 | 350 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 351 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 352 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
353 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
354 | policy->cur = freqs->new; | |
1da177e4 LT |
355 | break; |
356 | } | |
1da177e4 | 357 | } |
bb176f7d | 358 | |
b43a7ffb VK |
359 | /** |
360 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
361 | * on frequency transition. | |
362 | * | |
363 | * This function calls the transition notifiers and the "adjust_jiffies" | |
364 | * function. It is called twice on all CPU frequency changes that have | |
365 | * external effects. | |
366 | */ | |
367 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
368 | struct cpufreq_freqs *freqs, unsigned int state) | |
369 | { | |
370 | for_each_cpu(freqs->cpu, policy->cpus) | |
371 | __cpufreq_notify_transition(policy, freqs, state); | |
372 | } | |
1da177e4 LT |
373 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
374 | ||
375 | ||
1da177e4 LT |
376 | /********************************************************************* |
377 | * SYSFS INTERFACE * | |
378 | *********************************************************************/ | |
379 | ||
3bcb09a3 JF |
380 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
381 | { | |
382 | struct cpufreq_governor *t; | |
383 | ||
384 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 385 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
386 | return t; |
387 | ||
388 | return NULL; | |
389 | } | |
390 | ||
1da177e4 LT |
391 | /** |
392 | * cpufreq_parse_governor - parse a governor string | |
393 | */ | |
905d77cd | 394 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
395 | struct cpufreq_governor **governor) |
396 | { | |
3bcb09a3 | 397 | int err = -EINVAL; |
1c3d85dd RW |
398 | |
399 | if (!cpufreq_driver) | |
3bcb09a3 JF |
400 | goto out; |
401 | ||
1c3d85dd | 402 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
403 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
404 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 405 | err = 0; |
e08f5f5b GS |
406 | } else if (!strnicmp(str_governor, "powersave", |
407 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 408 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 409 | err = 0; |
1da177e4 | 410 | } |
1c3d85dd | 411 | } else if (cpufreq_driver->target) { |
1da177e4 | 412 | struct cpufreq_governor *t; |
3bcb09a3 | 413 | |
3fc54d37 | 414 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
415 | |
416 | t = __find_governor(str_governor); | |
417 | ||
ea714970 | 418 | if (t == NULL) { |
1a8e1463 | 419 | int ret; |
ea714970 | 420 | |
1a8e1463 KC |
421 | mutex_unlock(&cpufreq_governor_mutex); |
422 | ret = request_module("cpufreq_%s", str_governor); | |
423 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 424 | |
1a8e1463 KC |
425 | if (ret == 0) |
426 | t = __find_governor(str_governor); | |
ea714970 JF |
427 | } |
428 | ||
3bcb09a3 JF |
429 | if (t != NULL) { |
430 | *governor = t; | |
431 | err = 0; | |
1da177e4 | 432 | } |
3bcb09a3 | 433 | |
3fc54d37 | 434 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 435 | } |
29464f28 | 436 | out: |
3bcb09a3 | 437 | return err; |
1da177e4 | 438 | } |
1da177e4 | 439 | |
1da177e4 | 440 | /** |
e08f5f5b GS |
441 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
442 | * print out cpufreq information | |
1da177e4 LT |
443 | * |
444 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
445 | * "unsigned int". | |
446 | */ | |
447 | ||
32ee8c3e DJ |
448 | #define show_one(file_name, object) \ |
449 | static ssize_t show_##file_name \ | |
905d77cd | 450 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 451 | { \ |
29464f28 | 452 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
453 | } |
454 | ||
455 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
456 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 457 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
458 | show_one(scaling_min_freq, min); |
459 | show_one(scaling_max_freq, max); | |
460 | show_one(scaling_cur_freq, cur); | |
461 | ||
e08f5f5b GS |
462 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
463 | struct cpufreq_policy *policy); | |
7970e08b | 464 | |
1da177e4 LT |
465 | /** |
466 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
467 | */ | |
468 | #define store_one(file_name, object) \ | |
469 | static ssize_t store_##file_name \ | |
905d77cd | 470 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 471 | { \ |
f55c9c26 | 472 | unsigned int ret; \ |
1da177e4 LT |
473 | struct cpufreq_policy new_policy; \ |
474 | \ | |
475 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
476 | if (ret) \ | |
477 | return -EINVAL; \ | |
478 | \ | |
29464f28 | 479 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
480 | if (ret != 1) \ |
481 | return -EINVAL; \ | |
482 | \ | |
7970e08b TR |
483 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
484 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
485 | \ |
486 | return ret ? ret : count; \ | |
487 | } | |
488 | ||
29464f28 DJ |
489 | store_one(scaling_min_freq, min); |
490 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
491 | |
492 | /** | |
493 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
494 | */ | |
905d77cd DJ |
495 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
496 | char *buf) | |
1da177e4 | 497 | { |
5a01f2e8 | 498 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
499 | if (!cur_freq) |
500 | return sprintf(buf, "<unknown>"); | |
501 | return sprintf(buf, "%u\n", cur_freq); | |
502 | } | |
503 | ||
1da177e4 LT |
504 | /** |
505 | * show_scaling_governor - show the current policy for the specified CPU | |
506 | */ | |
905d77cd | 507 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 508 | { |
29464f28 | 509 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
510 | return sprintf(buf, "powersave\n"); |
511 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
512 | return sprintf(buf, "performance\n"); | |
513 | else if (policy->governor) | |
4b972f0b | 514 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 515 | policy->governor->name); |
1da177e4 LT |
516 | return -EINVAL; |
517 | } | |
518 | ||
1da177e4 LT |
519 | /** |
520 | * store_scaling_governor - store policy for the specified CPU | |
521 | */ | |
905d77cd DJ |
522 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
523 | const char *buf, size_t count) | |
1da177e4 | 524 | { |
f55c9c26 | 525 | unsigned int ret; |
1da177e4 LT |
526 | char str_governor[16]; |
527 | struct cpufreq_policy new_policy; | |
528 | ||
529 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
530 | if (ret) | |
531 | return ret; | |
532 | ||
29464f28 | 533 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
534 | if (ret != 1) |
535 | return -EINVAL; | |
536 | ||
e08f5f5b GS |
537 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
538 | &new_policy.governor)) | |
1da177e4 LT |
539 | return -EINVAL; |
540 | ||
bb176f7d VK |
541 | /* |
542 | * Do not use cpufreq_set_policy here or the user_policy.max | |
543 | * will be wrongly overridden | |
544 | */ | |
7970e08b TR |
545 | ret = __cpufreq_set_policy(policy, &new_policy); |
546 | ||
547 | policy->user_policy.policy = policy->policy; | |
548 | policy->user_policy.governor = policy->governor; | |
7970e08b | 549 | |
e08f5f5b GS |
550 | if (ret) |
551 | return ret; | |
552 | else | |
553 | return count; | |
1da177e4 LT |
554 | } |
555 | ||
556 | /** | |
557 | * show_scaling_driver - show the cpufreq driver currently loaded | |
558 | */ | |
905d77cd | 559 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 560 | { |
1c3d85dd | 561 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
562 | } |
563 | ||
564 | /** | |
565 | * show_scaling_available_governors - show the available CPUfreq governors | |
566 | */ | |
905d77cd DJ |
567 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
568 | char *buf) | |
1da177e4 LT |
569 | { |
570 | ssize_t i = 0; | |
571 | struct cpufreq_governor *t; | |
572 | ||
1c3d85dd | 573 | if (!cpufreq_driver->target) { |
1da177e4 LT |
574 | i += sprintf(buf, "performance powersave"); |
575 | goto out; | |
576 | } | |
577 | ||
578 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
579 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
580 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 581 | goto out; |
4b972f0b | 582 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 583 | } |
7d5e350f | 584 | out: |
1da177e4 LT |
585 | i += sprintf(&buf[i], "\n"); |
586 | return i; | |
587 | } | |
e8628dd0 | 588 | |
f4fd3797 | 589 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
590 | { |
591 | ssize_t i = 0; | |
592 | unsigned int cpu; | |
593 | ||
835481d9 | 594 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
595 | if (i) |
596 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
597 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
598 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 599 | break; |
1da177e4 LT |
600 | } |
601 | i += sprintf(&buf[i], "\n"); | |
602 | return i; | |
603 | } | |
f4fd3797 | 604 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 605 | |
e8628dd0 DW |
606 | /** |
607 | * show_related_cpus - show the CPUs affected by each transition even if | |
608 | * hw coordination is in use | |
609 | */ | |
610 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
611 | { | |
f4fd3797 | 612 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
613 | } |
614 | ||
615 | /** | |
616 | * show_affected_cpus - show the CPUs affected by each transition | |
617 | */ | |
618 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
619 | { | |
f4fd3797 | 620 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
621 | } |
622 | ||
9e76988e | 623 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 624 | const char *buf, size_t count) |
9e76988e VP |
625 | { |
626 | unsigned int freq = 0; | |
627 | unsigned int ret; | |
628 | ||
879000f9 | 629 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
630 | return -EINVAL; |
631 | ||
632 | ret = sscanf(buf, "%u", &freq); | |
633 | if (ret != 1) | |
634 | return -EINVAL; | |
635 | ||
636 | policy->governor->store_setspeed(policy, freq); | |
637 | ||
638 | return count; | |
639 | } | |
640 | ||
641 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
642 | { | |
879000f9 | 643 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
644 | return sprintf(buf, "<unsupported>\n"); |
645 | ||
646 | return policy->governor->show_setspeed(policy, buf); | |
647 | } | |
1da177e4 | 648 | |
e2f74f35 | 649 | /** |
8bf1ac72 | 650 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
651 | */ |
652 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
653 | { | |
654 | unsigned int limit; | |
655 | int ret; | |
1c3d85dd RW |
656 | if (cpufreq_driver->bios_limit) { |
657 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
658 | if (!ret) |
659 | return sprintf(buf, "%u\n", limit); | |
660 | } | |
661 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
662 | } | |
663 | ||
6dad2a29 BP |
664 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
665 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
666 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
667 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
668 | cpufreq_freq_attr_ro(scaling_available_governors); | |
669 | cpufreq_freq_attr_ro(scaling_driver); | |
670 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
671 | cpufreq_freq_attr_ro(bios_limit); | |
672 | cpufreq_freq_attr_ro(related_cpus); | |
673 | cpufreq_freq_attr_ro(affected_cpus); | |
674 | cpufreq_freq_attr_rw(scaling_min_freq); | |
675 | cpufreq_freq_attr_rw(scaling_max_freq); | |
676 | cpufreq_freq_attr_rw(scaling_governor); | |
677 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 678 | |
905d77cd | 679 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
680 | &cpuinfo_min_freq.attr, |
681 | &cpuinfo_max_freq.attr, | |
ed129784 | 682 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
683 | &scaling_min_freq.attr, |
684 | &scaling_max_freq.attr, | |
685 | &affected_cpus.attr, | |
e8628dd0 | 686 | &related_cpus.attr, |
1da177e4 LT |
687 | &scaling_governor.attr, |
688 | &scaling_driver.attr, | |
689 | &scaling_available_governors.attr, | |
9e76988e | 690 | &scaling_setspeed.attr, |
1da177e4 LT |
691 | NULL |
692 | }; | |
693 | ||
29464f28 DJ |
694 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
695 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 696 | |
29464f28 | 697 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 698 | { |
905d77cd DJ |
699 | struct cpufreq_policy *policy = to_policy(kobj); |
700 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 701 | ssize_t ret = -EINVAL; |
a9144436 | 702 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 703 | if (!policy) |
0db4a8a9 | 704 | goto no_policy; |
5a01f2e8 VP |
705 | |
706 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 707 | goto fail; |
5a01f2e8 | 708 | |
e08f5f5b GS |
709 | if (fattr->show) |
710 | ret = fattr->show(policy, buf); | |
711 | else | |
712 | ret = -EIO; | |
713 | ||
5a01f2e8 | 714 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 715 | fail: |
a9144436 | 716 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 717 | no_policy: |
1da177e4 LT |
718 | return ret; |
719 | } | |
720 | ||
905d77cd DJ |
721 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
722 | const char *buf, size_t count) | |
1da177e4 | 723 | { |
905d77cd DJ |
724 | struct cpufreq_policy *policy = to_policy(kobj); |
725 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 726 | ssize_t ret = -EINVAL; |
a9144436 | 727 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 728 | if (!policy) |
a07530b4 | 729 | goto no_policy; |
5a01f2e8 VP |
730 | |
731 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 732 | goto fail; |
5a01f2e8 | 733 | |
e08f5f5b GS |
734 | if (fattr->store) |
735 | ret = fattr->store(policy, buf, count); | |
736 | else | |
737 | ret = -EIO; | |
738 | ||
5a01f2e8 | 739 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 740 | fail: |
a9144436 | 741 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 742 | no_policy: |
1da177e4 LT |
743 | return ret; |
744 | } | |
745 | ||
905d77cd | 746 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 747 | { |
905d77cd | 748 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 749 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
750 | complete(&policy->kobj_unregister); |
751 | } | |
752 | ||
52cf25d0 | 753 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
754 | .show = show, |
755 | .store = store, | |
756 | }; | |
757 | ||
758 | static struct kobj_type ktype_cpufreq = { | |
759 | .sysfs_ops = &sysfs_ops, | |
760 | .default_attrs = default_attrs, | |
761 | .release = cpufreq_sysfs_release, | |
762 | }; | |
763 | ||
2361be23 VK |
764 | struct kobject *cpufreq_global_kobject; |
765 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
766 | ||
767 | static int cpufreq_global_kobject_usage; | |
768 | ||
769 | int cpufreq_get_global_kobject(void) | |
770 | { | |
771 | if (!cpufreq_global_kobject_usage++) | |
772 | return kobject_add(cpufreq_global_kobject, | |
773 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
774 | ||
775 | return 0; | |
776 | } | |
777 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
778 | ||
779 | void cpufreq_put_global_kobject(void) | |
780 | { | |
781 | if (!--cpufreq_global_kobject_usage) | |
782 | kobject_del(cpufreq_global_kobject); | |
783 | } | |
784 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
785 | ||
786 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
787 | { | |
788 | int ret = cpufreq_get_global_kobject(); | |
789 | ||
790 | if (!ret) { | |
791 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
792 | if (ret) | |
793 | cpufreq_put_global_kobject(); | |
794 | } | |
795 | ||
796 | return ret; | |
797 | } | |
798 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
799 | ||
800 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
801 | { | |
802 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
803 | cpufreq_put_global_kobject(); | |
804 | } | |
805 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
806 | ||
19d6f7ec | 807 | /* symlink affected CPUs */ |
cf3289d0 AC |
808 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
809 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
810 | { |
811 | unsigned int j; | |
812 | int ret = 0; | |
813 | ||
814 | for_each_cpu(j, policy->cpus) { | |
815 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 816 | struct device *cpu_dev; |
19d6f7ec DJ |
817 | |
818 | if (j == cpu) | |
819 | continue; | |
19d6f7ec | 820 | |
2d06d8c4 | 821 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 822 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
823 | cpu_dev = get_cpu_device(j); |
824 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
825 | "cpufreq"); |
826 | if (ret) { | |
827 | cpufreq_cpu_put(managed_policy); | |
828 | return ret; | |
829 | } | |
830 | } | |
831 | return ret; | |
832 | } | |
833 | ||
cf3289d0 AC |
834 | static int cpufreq_add_dev_interface(unsigned int cpu, |
835 | struct cpufreq_policy *policy, | |
8a25a2fd | 836 | struct device *dev) |
909a694e DJ |
837 | { |
838 | struct freq_attr **drv_attr; | |
909a694e | 839 | int ret = 0; |
909a694e DJ |
840 | |
841 | /* prepare interface data */ | |
842 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 843 | &dev->kobj, "cpufreq"); |
909a694e DJ |
844 | if (ret) |
845 | return ret; | |
846 | ||
847 | /* set up files for this cpu device */ | |
1c3d85dd | 848 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
849 | while ((drv_attr) && (*drv_attr)) { |
850 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
851 | if (ret) | |
1c3d85dd | 852 | goto err_out_kobj_put; |
909a694e DJ |
853 | drv_attr++; |
854 | } | |
1c3d85dd | 855 | if (cpufreq_driver->get) { |
909a694e DJ |
856 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
857 | if (ret) | |
1c3d85dd | 858 | goto err_out_kobj_put; |
909a694e | 859 | } |
1c3d85dd | 860 | if (cpufreq_driver->target) { |
909a694e DJ |
861 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
862 | if (ret) | |
1c3d85dd | 863 | goto err_out_kobj_put; |
909a694e | 864 | } |
1c3d85dd | 865 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
866 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
867 | if (ret) | |
1c3d85dd | 868 | goto err_out_kobj_put; |
e2f74f35 | 869 | } |
909a694e | 870 | |
909a694e | 871 | ret = cpufreq_add_dev_symlink(cpu, policy); |
ecf7e461 DJ |
872 | if (ret) |
873 | goto err_out_kobj_put; | |
874 | ||
e18f1682 SB |
875 | return ret; |
876 | ||
877 | err_out_kobj_put: | |
878 | kobject_put(&policy->kobj); | |
879 | wait_for_completion(&policy->kobj_unregister); | |
880 | return ret; | |
881 | } | |
882 | ||
883 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
884 | { | |
885 | struct cpufreq_policy new_policy; | |
886 | int ret = 0; | |
887 | ||
ecf7e461 DJ |
888 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
889 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
890 | policy->governor = NULL; | |
891 | ||
892 | /* set default policy */ | |
893 | ret = __cpufreq_set_policy(policy, &new_policy); | |
894 | policy->user_policy.policy = policy->policy; | |
895 | policy->user_policy.governor = policy->governor; | |
896 | ||
897 | if (ret) { | |
2d06d8c4 | 898 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
899 | if (cpufreq_driver->exit) |
900 | cpufreq_driver->exit(policy); | |
ecf7e461 | 901 | } |
909a694e DJ |
902 | } |
903 | ||
fcf80582 VK |
904 | #ifdef CONFIG_HOTPLUG_CPU |
905 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
906 | struct device *dev) | |
907 | { | |
908 | struct cpufreq_policy *policy; | |
1c3d85dd | 909 | int ret = 0, has_target = !!cpufreq_driver->target; |
fcf80582 VK |
910 | unsigned long flags; |
911 | ||
912 | policy = cpufreq_cpu_get(sibling); | |
913 | WARN_ON(!policy); | |
914 | ||
820c6ca2 VK |
915 | if (has_target) |
916 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
fcf80582 | 917 | |
2eaa3e2d VK |
918 | lock_policy_rwsem_write(sibling); |
919 | ||
0d1857a1 | 920 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 921 | |
fcf80582 | 922 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 923 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; |
fcf80582 | 924 | per_cpu(cpufreq_cpu_data, cpu) = policy; |
0d1857a1 | 925 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 926 | |
2eaa3e2d VK |
927 | unlock_policy_rwsem_write(sibling); |
928 | ||
820c6ca2 VK |
929 | if (has_target) { |
930 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
931 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
932 | } | |
fcf80582 | 933 | |
fcf80582 VK |
934 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
935 | if (ret) { | |
936 | cpufreq_cpu_put(policy); | |
937 | return ret; | |
938 | } | |
939 | ||
940 | return 0; | |
941 | } | |
942 | #endif | |
1da177e4 | 943 | |
e9698cc5 SB |
944 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
945 | { | |
946 | struct cpufreq_policy *policy; | |
947 | ||
948 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
949 | if (!policy) | |
950 | return NULL; | |
951 | ||
952 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
953 | goto err_free_policy; | |
954 | ||
955 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
956 | goto err_free_cpumask; | |
957 | ||
958 | return policy; | |
959 | ||
960 | err_free_cpumask: | |
961 | free_cpumask_var(policy->cpus); | |
962 | err_free_policy: | |
963 | kfree(policy); | |
964 | ||
965 | return NULL; | |
966 | } | |
967 | ||
968 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
969 | { | |
970 | free_cpumask_var(policy->related_cpus); | |
971 | free_cpumask_var(policy->cpus); | |
972 | kfree(policy); | |
973 | } | |
974 | ||
1da177e4 LT |
975 | /** |
976 | * cpufreq_add_dev - add a CPU device | |
977 | * | |
32ee8c3e | 978 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
979 | * |
980 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
981 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
982 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 983 | */ |
8a25a2fd | 984 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 985 | { |
fcf80582 | 986 | unsigned int j, cpu = dev->id; |
65922465 | 987 | int ret = -ENOMEM; |
1da177e4 | 988 | struct cpufreq_policy *policy; |
1da177e4 | 989 | unsigned long flags; |
90e41bac | 990 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 991 | struct cpufreq_governor *gov; |
90e41bac PB |
992 | int sibling; |
993 | #endif | |
1da177e4 | 994 | |
c32b6b8e AR |
995 | if (cpu_is_offline(cpu)) |
996 | return 0; | |
997 | ||
2d06d8c4 | 998 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
999 | |
1000 | #ifdef CONFIG_SMP | |
1001 | /* check whether a different CPU already registered this | |
1002 | * CPU because it is in the same boat. */ | |
1003 | policy = cpufreq_cpu_get(cpu); | |
1004 | if (unlikely(policy)) { | |
8ff69732 | 1005 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1006 | return 0; |
1007 | } | |
fcf80582 VK |
1008 | |
1009 | #ifdef CONFIG_HOTPLUG_CPU | |
1010 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1011 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
1012 | for_each_online_cpu(sibling) { |
1013 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d | 1014 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
0d1857a1 | 1015 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 1016 | return cpufreq_add_policy_cpu(cpu, sibling, dev); |
2eaa3e2d | 1017 | } |
fcf80582 | 1018 | } |
0d1857a1 | 1019 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 1020 | #endif |
1da177e4 LT |
1021 | #endif |
1022 | ||
1c3d85dd | 1023 | if (!try_module_get(cpufreq_driver->owner)) { |
1da177e4 LT |
1024 | ret = -EINVAL; |
1025 | goto module_out; | |
1026 | } | |
1027 | ||
e9698cc5 | 1028 | policy = cpufreq_policy_alloc(); |
059019a3 | 1029 | if (!policy) |
1da177e4 | 1030 | goto nomem_out; |
059019a3 | 1031 | |
1da177e4 | 1032 | policy->cpu = cpu; |
65922465 | 1033 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1034 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1035 | |
5a01f2e8 | 1036 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 1037 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 1038 | |
1da177e4 | 1039 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1040 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1041 | |
1042 | /* call driver. From then on the cpufreq must be able | |
1043 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1044 | */ | |
1c3d85dd | 1045 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1046 | if (ret) { |
2d06d8c4 | 1047 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1048 | goto err_set_policy_cpu; |
1da177e4 | 1049 | } |
643ae6e8 | 1050 | |
fcf80582 VK |
1051 | /* related cpus should atleast have policy->cpus */ |
1052 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1053 | ||
643ae6e8 VK |
1054 | /* |
1055 | * affected cpus must always be the one, which are online. We aren't | |
1056 | * managing offline cpus here. | |
1057 | */ | |
1058 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1059 | ||
187d9f4e MC |
1060 | policy->user_policy.min = policy->min; |
1061 | policy->user_policy.max = policy->max; | |
1da177e4 | 1062 | |
a1531acd TR |
1063 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1064 | CPUFREQ_START, policy); | |
1065 | ||
fcf80582 VK |
1066 | #ifdef CONFIG_HOTPLUG_CPU |
1067 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1068 | if (gov) { | |
1069 | policy->governor = gov; | |
1070 | pr_debug("Restoring governor %s for cpu %d\n", | |
1071 | policy->governor->name, cpu); | |
4bfa042c | 1072 | } |
fcf80582 | 1073 | #endif |
1da177e4 | 1074 | |
e18f1682 SB |
1075 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1076 | for_each_cpu(j, policy->cpus) { | |
1077 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1078 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; | |
1079 | } | |
1080 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1081 | ||
8a25a2fd | 1082 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
1083 | if (ret) |
1084 | goto err_out_unregister; | |
8ff69732 | 1085 | |
e18f1682 SB |
1086 | cpufreq_init_policy(policy); |
1087 | ||
038c5b3e | 1088 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1c3d85dd | 1089 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 1090 | pr_debug("initialization complete\n"); |
87c32271 | 1091 | |
1da177e4 LT |
1092 | return 0; |
1093 | ||
1da177e4 | 1094 | err_out_unregister: |
0d1857a1 | 1095 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
e18f1682 | 1096 | for_each_cpu(j, policy->cpus) { |
7a6aedfa | 1097 | per_cpu(cpufreq_cpu_data, j) = NULL; |
e18f1682 SB |
1098 | if (j != cpu) |
1099 | per_cpu(cpufreq_policy_cpu, j) = -1; | |
1100 | } | |
0d1857a1 | 1101 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1102 | |
c10997f6 | 1103 | kobject_put(&policy->kobj); |
1da177e4 LT |
1104 | wait_for_completion(&policy->kobj_unregister); |
1105 | ||
2eaa3e2d VK |
1106 | err_set_policy_cpu: |
1107 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
e9698cc5 | 1108 | cpufreq_policy_free(policy); |
1da177e4 | 1109 | nomem_out: |
1c3d85dd | 1110 | module_put(cpufreq_driver->owner); |
c32b6b8e | 1111 | module_out: |
1da177e4 LT |
1112 | return ret; |
1113 | } | |
1114 | ||
b8eed8af VK |
1115 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1116 | { | |
1117 | int j; | |
1118 | ||
1119 | policy->last_cpu = policy->cpu; | |
1120 | policy->cpu = cpu; | |
1121 | ||
3361b7b1 | 1122 | for_each_cpu(j, policy->cpus) |
b8eed8af | 1123 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
1124 | |
1125 | #ifdef CONFIG_CPU_FREQ_TABLE | |
1126 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1127 | #endif | |
1128 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1129 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1130 | } | |
1da177e4 | 1131 | |
f9ba680d SB |
1132 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data, |
1133 | unsigned int old_cpu) | |
1134 | { | |
1135 | struct device *cpu_dev; | |
1136 | unsigned long flags; | |
1137 | int ret; | |
1138 | ||
1139 | /* first sibling now owns the new sysfs dir */ | |
1140 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1141 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1142 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1143 | if (ret) { | |
1144 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1145 | ||
1146 | WARN_ON(lock_policy_rwsem_write(old_cpu)); | |
1147 | cpumask_set_cpu(old_cpu, data->cpus); | |
1148 | ||
1149 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1150 | per_cpu(cpufreq_cpu_data, old_cpu) = data; | |
1151 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1152 | ||
1153 | unlock_policy_rwsem_write(old_cpu); | |
1154 | ||
1155 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, | |
1156 | "cpufreq"); | |
1157 | ||
1158 | return -EINVAL; | |
1159 | } | |
1160 | ||
1161 | return cpu_dev->id; | |
1162 | } | |
1163 | ||
1da177e4 | 1164 | /** |
5a01f2e8 | 1165 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1166 | * |
1167 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1168 | * Caller should already have policy_rwsem in write mode for this CPU. |
1169 | * This routine frees the rwsem before returning. | |
1da177e4 | 1170 | */ |
bb176f7d VK |
1171 | static int __cpufreq_remove_dev(struct device *dev, |
1172 | struct subsys_interface *sif) | |
1da177e4 | 1173 | { |
f9ba680d SB |
1174 | unsigned int cpu = dev->id, cpus; |
1175 | int new_cpu; | |
1da177e4 LT |
1176 | unsigned long flags; |
1177 | struct cpufreq_policy *data; | |
499bca9b AW |
1178 | struct kobject *kobj; |
1179 | struct completion *cmp; | |
1da177e4 | 1180 | |
b8eed8af | 1181 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1182 | |
0d1857a1 | 1183 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1184 | |
7a6aedfa | 1185 | data = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1186 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1187 | ||
0d1857a1 | 1188 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1189 | |
1190 | if (!data) { | |
b8eed8af | 1191 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1192 | return -EINVAL; |
1193 | } | |
1da177e4 | 1194 | |
1c3d85dd | 1195 | if (cpufreq_driver->target) |
f6a7409c | 1196 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1da177e4 | 1197 | |
084f3493 | 1198 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1199 | if (!cpufreq_driver->setpolicy) |
fa69e33f DB |
1200 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
1201 | data->governor->name, CPUFREQ_NAME_LEN); | |
1da177e4 LT |
1202 | #endif |
1203 | ||
2eaa3e2d | 1204 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1205 | cpus = cpumask_weight(data->cpus); |
e4969eba VK |
1206 | |
1207 | if (cpus > 1) | |
1208 | cpumask_clear_cpu(cpu, data->cpus); | |
2eaa3e2d | 1209 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1210 | |
73bf0fc2 VK |
1211 | if (cpu != data->cpu) { |
1212 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
1213 | } else if (cpus > 1) { | |
084f3493 | 1214 | |
f9ba680d SB |
1215 | new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu); |
1216 | if (new_cpu >= 0) { | |
2eaa3e2d | 1217 | WARN_ON(lock_policy_rwsem_write(cpu)); |
f9ba680d | 1218 | update_policy_cpu(data, new_cpu); |
499bca9b | 1219 | unlock_policy_rwsem_write(cpu); |
f9ba680d SB |
1220 | pr_debug("%s: policy Kobject moved to cpu: %d " |
1221 | "from: %d\n",__func__, new_cpu, cpu); | |
1da177e4 LT |
1222 | } |
1223 | } | |
1da177e4 | 1224 | |
b8eed8af VK |
1225 | /* If cpu is last user of policy, free policy */ |
1226 | if (cpus == 1) { | |
2a998599 RW |
1227 | if (cpufreq_driver->target) |
1228 | __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); | |
1229 | ||
2eaa3e2d | 1230 | lock_policy_rwsem_read(cpu); |
b8eed8af VK |
1231 | kobj = &data->kobj; |
1232 | cmp = &data->kobj_unregister; | |
2eaa3e2d | 1233 | unlock_policy_rwsem_read(cpu); |
b8eed8af | 1234 | kobject_put(kobj); |
7d26e2d5 | 1235 | |
b8eed8af VK |
1236 | /* we need to make sure that the underlying kobj is actually |
1237 | * not referenced anymore by anybody before we proceed with | |
1238 | * unloading. | |
1239 | */ | |
1240 | pr_debug("waiting for dropping of refcount\n"); | |
1241 | wait_for_completion(cmp); | |
1242 | pr_debug("wait complete\n"); | |
7d26e2d5 | 1243 | |
1c3d85dd RW |
1244 | if (cpufreq_driver->exit) |
1245 | cpufreq_driver->exit(data); | |
27ecddc2 | 1246 | |
e9698cc5 | 1247 | cpufreq_policy_free(data); |
2a998599 RW |
1248 | } else { |
1249 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); | |
1250 | cpufreq_cpu_put(data); | |
1251 | if (cpufreq_driver->target) { | |
1252 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1253 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1254 | } | |
27ecddc2 | 1255 | } |
1da177e4 | 1256 | |
2eaa3e2d | 1257 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
1da177e4 LT |
1258 | return 0; |
1259 | } | |
1260 | ||
8a25a2fd | 1261 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1262 | { |
8a25a2fd | 1263 | unsigned int cpu = dev->id; |
5a01f2e8 | 1264 | int retval; |
ec28297a VP |
1265 | |
1266 | if (cpu_is_offline(cpu)) | |
1267 | return 0; | |
1268 | ||
8a25a2fd | 1269 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1270 | return retval; |
1271 | } | |
1272 | ||
65f27f38 | 1273 | static void handle_update(struct work_struct *work) |
1da177e4 | 1274 | { |
65f27f38 DH |
1275 | struct cpufreq_policy *policy = |
1276 | container_of(work, struct cpufreq_policy, update); | |
1277 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1278 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1279 | cpufreq_update_policy(cpu); |
1280 | } | |
1281 | ||
1282 | /** | |
bb176f7d VK |
1283 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1284 | * in deep trouble. | |
1da177e4 LT |
1285 | * @cpu: cpu number |
1286 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1287 | * @new_freq: CPU frequency the CPU actually runs at | |
1288 | * | |
29464f28 DJ |
1289 | * We adjust to current frequency first, and need to clean up later. |
1290 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1291 | */ |
e08f5f5b GS |
1292 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1293 | unsigned int new_freq) | |
1da177e4 | 1294 | { |
b43a7ffb | 1295 | struct cpufreq_policy *policy; |
1da177e4 | 1296 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1297 | unsigned long flags; |
1298 | ||
2d06d8c4 | 1299 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1300 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1301 | ||
1da177e4 LT |
1302 | freqs.old = old_freq; |
1303 | freqs.new = new_freq; | |
b43a7ffb VK |
1304 | |
1305 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1306 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1307 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1308 | ||
1309 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1310 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1311 | } |
1312 | ||
32ee8c3e | 1313 | /** |
4ab70df4 | 1314 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1315 | * @cpu: CPU number |
1316 | * | |
1317 | * This is the last known freq, without actually getting it from the driver. | |
1318 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1319 | */ | |
1320 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1321 | { | |
9e21ba8b | 1322 | struct cpufreq_policy *policy; |
e08f5f5b | 1323 | unsigned int ret_freq = 0; |
95235ca2 | 1324 | |
1c3d85dd RW |
1325 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1326 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1327 | |
1328 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1329 | if (policy) { |
e08f5f5b | 1330 | ret_freq = policy->cur; |
95235ca2 VP |
1331 | cpufreq_cpu_put(policy); |
1332 | } | |
1333 | ||
4d34a67d | 1334 | return ret_freq; |
95235ca2 VP |
1335 | } |
1336 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1337 | ||
3d737108 JB |
1338 | /** |
1339 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1340 | * @cpu: CPU number | |
1341 | * | |
1342 | * Just return the max possible frequency for a given CPU. | |
1343 | */ | |
1344 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1345 | { | |
1346 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1347 | unsigned int ret_freq = 0; | |
1348 | ||
1349 | if (policy) { | |
1350 | ret_freq = policy->max; | |
1351 | cpufreq_cpu_put(policy); | |
1352 | } | |
1353 | ||
1354 | return ret_freq; | |
1355 | } | |
1356 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1357 | ||
5a01f2e8 | 1358 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1359 | { |
7a6aedfa | 1360 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1361 | unsigned int ret_freq = 0; |
5800043b | 1362 | |
1c3d85dd | 1363 | if (!cpufreq_driver->get) |
4d34a67d | 1364 | return ret_freq; |
1da177e4 | 1365 | |
1c3d85dd | 1366 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1367 | |
e08f5f5b | 1368 | if (ret_freq && policy->cur && |
1c3d85dd | 1369 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1370 | /* verify no discrepancy between actual and |
1371 | saved value exists */ | |
1372 | if (unlikely(ret_freq != policy->cur)) { | |
1373 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1374 | schedule_work(&policy->update); |
1375 | } | |
1376 | } | |
1377 | ||
4d34a67d | 1378 | return ret_freq; |
5a01f2e8 | 1379 | } |
1da177e4 | 1380 | |
5a01f2e8 VP |
1381 | /** |
1382 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1383 | * @cpu: CPU number | |
1384 | * | |
1385 | * Get the CPU current (static) CPU frequency | |
1386 | */ | |
1387 | unsigned int cpufreq_get(unsigned int cpu) | |
1388 | { | |
1389 | unsigned int ret_freq = 0; | |
1390 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1391 | ||
1392 | if (!policy) | |
1393 | goto out; | |
1394 | ||
1395 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1396 | goto out_policy; | |
1397 | ||
1398 | ret_freq = __cpufreq_get(cpu); | |
1399 | ||
1400 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1401 | |
5a01f2e8 VP |
1402 | out_policy: |
1403 | cpufreq_cpu_put(policy); | |
1404 | out: | |
4d34a67d | 1405 | return ret_freq; |
1da177e4 LT |
1406 | } |
1407 | EXPORT_SYMBOL(cpufreq_get); | |
1408 | ||
8a25a2fd KS |
1409 | static struct subsys_interface cpufreq_interface = { |
1410 | .name = "cpufreq", | |
1411 | .subsys = &cpu_subsys, | |
1412 | .add_dev = cpufreq_add_dev, | |
1413 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1414 | }; |
1415 | ||
42d4dc3f | 1416 | /** |
e00e56df RW |
1417 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1418 | * | |
1419 | * This function is only executed for the boot processor. The other CPUs | |
1420 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1421 | */ |
e00e56df | 1422 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1423 | { |
e08f5f5b | 1424 | int ret = 0; |
4bc5d341 | 1425 | |
e00e56df | 1426 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1427 | struct cpufreq_policy *cpu_policy; |
1428 | ||
2d06d8c4 | 1429 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1430 | |
e00e56df | 1431 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1432 | cpu_policy = cpufreq_cpu_get(cpu); |
1433 | if (!cpu_policy) | |
e00e56df | 1434 | return 0; |
42d4dc3f | 1435 | |
1c3d85dd RW |
1436 | if (cpufreq_driver->suspend) { |
1437 | ret = cpufreq_driver->suspend(cpu_policy); | |
ce6c3997 | 1438 | if (ret) |
42d4dc3f BH |
1439 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1440 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1441 | } |
1442 | ||
42d4dc3f | 1443 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1444 | return ret; |
42d4dc3f BH |
1445 | } |
1446 | ||
1da177e4 | 1447 | /** |
e00e56df | 1448 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1449 | * |
1450 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1451 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1452 | * restored. It will verify that the current freq is in sync with | |
1453 | * what we believe it to be. This is a bit later than when it | |
1454 | * should be, but nonethteless it's better than calling | |
1455 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1456 | * |
1457 | * This function is only executed for the boot CPU. The other CPUs have not | |
1458 | * been turned on yet. | |
1da177e4 | 1459 | */ |
e00e56df | 1460 | static void cpufreq_bp_resume(void) |
1da177e4 | 1461 | { |
e08f5f5b | 1462 | int ret = 0; |
4bc5d341 | 1463 | |
e00e56df | 1464 | int cpu = smp_processor_id(); |
1da177e4 LT |
1465 | struct cpufreq_policy *cpu_policy; |
1466 | ||
2d06d8c4 | 1467 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1468 | |
e00e56df | 1469 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1470 | cpu_policy = cpufreq_cpu_get(cpu); |
1471 | if (!cpu_policy) | |
e00e56df | 1472 | return; |
1da177e4 | 1473 | |
1c3d85dd RW |
1474 | if (cpufreq_driver->resume) { |
1475 | ret = cpufreq_driver->resume(cpu_policy); | |
1da177e4 LT |
1476 | if (ret) { |
1477 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1478 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1479 | goto fail; |
1da177e4 LT |
1480 | } |
1481 | } | |
1482 | ||
1da177e4 | 1483 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1484 | |
c9060494 | 1485 | fail: |
1da177e4 | 1486 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1487 | } |
1488 | ||
e00e56df RW |
1489 | static struct syscore_ops cpufreq_syscore_ops = { |
1490 | .suspend = cpufreq_bp_suspend, | |
1491 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1492 | }; |
1493 | ||
9d95046e BP |
1494 | /** |
1495 | * cpufreq_get_current_driver - return current driver's name | |
1496 | * | |
1497 | * Return the name string of the currently loaded cpufreq driver | |
1498 | * or NULL, if none. | |
1499 | */ | |
1500 | const char *cpufreq_get_current_driver(void) | |
1501 | { | |
1c3d85dd RW |
1502 | if (cpufreq_driver) |
1503 | return cpufreq_driver->name; | |
1504 | ||
1505 | return NULL; | |
9d95046e BP |
1506 | } |
1507 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1508 | |
1509 | /********************************************************************* | |
1510 | * NOTIFIER LISTS INTERFACE * | |
1511 | *********************************************************************/ | |
1512 | ||
1513 | /** | |
1514 | * cpufreq_register_notifier - register a driver with cpufreq | |
1515 | * @nb: notifier function to register | |
1516 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1517 | * | |
32ee8c3e | 1518 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1519 | * are notified about clock rate changes (once before and once after |
1520 | * the transition), or a list of drivers that are notified about | |
1521 | * changes in cpufreq policy. | |
1522 | * | |
1523 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1524 | * blocking_notifier_chain_register. |
1da177e4 LT |
1525 | */ |
1526 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1527 | { | |
1528 | int ret; | |
1529 | ||
d5aaffa9 DB |
1530 | if (cpufreq_disabled()) |
1531 | return -EINVAL; | |
1532 | ||
74212ca4 CEB |
1533 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1534 | ||
1da177e4 LT |
1535 | switch (list) { |
1536 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1537 | ret = srcu_notifier_chain_register( |
e041c683 | 1538 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1539 | break; |
1540 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1541 | ret = blocking_notifier_chain_register( |
1542 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1543 | break; |
1544 | default: | |
1545 | ret = -EINVAL; | |
1546 | } | |
1da177e4 LT |
1547 | |
1548 | return ret; | |
1549 | } | |
1550 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1551 | ||
1da177e4 LT |
1552 | /** |
1553 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1554 | * @nb: notifier block to be unregistered | |
bb176f7d | 1555 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1556 | * |
1557 | * Remove a driver from the CPU frequency notifier list. | |
1558 | * | |
1559 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1560 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1561 | */ |
1562 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1563 | { | |
1564 | int ret; | |
1565 | ||
d5aaffa9 DB |
1566 | if (cpufreq_disabled()) |
1567 | return -EINVAL; | |
1568 | ||
1da177e4 LT |
1569 | switch (list) { |
1570 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1571 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1572 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1573 | break; |
1574 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1575 | ret = blocking_notifier_chain_unregister( |
1576 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1577 | break; |
1578 | default: | |
1579 | ret = -EINVAL; | |
1580 | } | |
1da177e4 LT |
1581 | |
1582 | return ret; | |
1583 | } | |
1584 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1585 | ||
1586 | ||
1587 | /********************************************************************* | |
1588 | * GOVERNORS * | |
1589 | *********************************************************************/ | |
1590 | ||
1da177e4 LT |
1591 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1592 | unsigned int target_freq, | |
1593 | unsigned int relation) | |
1594 | { | |
1595 | int retval = -EINVAL; | |
7249924e | 1596 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1597 | |
a7b422cd KRW |
1598 | if (cpufreq_disabled()) |
1599 | return -ENODEV; | |
7c30ed53 VK |
1600 | if (policy->transition_ongoing) |
1601 | return -EBUSY; | |
a7b422cd | 1602 | |
7249924e VK |
1603 | /* Make sure that target_freq is within supported range */ |
1604 | if (target_freq > policy->max) | |
1605 | target_freq = policy->max; | |
1606 | if (target_freq < policy->min) | |
1607 | target_freq = policy->min; | |
1608 | ||
1609 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1610 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1611 | |
1612 | if (target_freq == policy->cur) | |
1613 | return 0; | |
1614 | ||
1c3d85dd RW |
1615 | if (cpufreq_driver->target) |
1616 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1617 | |
1da177e4 LT |
1618 | return retval; |
1619 | } | |
1620 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1621 | ||
1da177e4 LT |
1622 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1623 | unsigned int target_freq, | |
1624 | unsigned int relation) | |
1625 | { | |
f1829e4a | 1626 | int ret = -EINVAL; |
1da177e4 | 1627 | |
5a01f2e8 | 1628 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1629 | goto fail; |
1da177e4 LT |
1630 | |
1631 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1632 | ||
5a01f2e8 | 1633 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1634 | |
f1829e4a | 1635 | fail: |
1da177e4 LT |
1636 | return ret; |
1637 | } | |
1638 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1639 | ||
bf0b90e3 | 1640 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 | 1641 | { |
d5aaffa9 | 1642 | if (cpufreq_disabled()) |
a262e94c | 1643 | return 0; |
d5aaffa9 | 1644 | |
1c3d85dd | 1645 | if (!cpufreq_driver->getavg) |
0676f7f2 VK |
1646 | return 0; |
1647 | ||
a262e94c | 1648 | return cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1649 | } |
5a01f2e8 | 1650 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1651 | |
153d7f3f | 1652 | /* |
153d7f3f AV |
1653 | * when "event" is CPUFREQ_GOV_LIMITS |
1654 | */ | |
1da177e4 | 1655 | |
e08f5f5b GS |
1656 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1657 | unsigned int event) | |
1da177e4 | 1658 | { |
cc993cab | 1659 | int ret; |
6afde10c TR |
1660 | |
1661 | /* Only must be defined when default governor is known to have latency | |
1662 | restrictions, like e.g. conservative or ondemand. | |
1663 | That this is the case is already ensured in Kconfig | |
1664 | */ | |
1665 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1666 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1667 | #else | |
1668 | struct cpufreq_governor *gov = NULL; | |
1669 | #endif | |
1c256245 TR |
1670 | |
1671 | if (policy->governor->max_transition_latency && | |
1672 | policy->cpuinfo.transition_latency > | |
1673 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1674 | if (!gov) |
1675 | return -EINVAL; | |
1676 | else { | |
1677 | printk(KERN_WARNING "%s governor failed, too long" | |
1678 | " transition latency of HW, fallback" | |
1679 | " to %s governor\n", | |
1680 | policy->governor->name, | |
1681 | gov->name); | |
1682 | policy->governor = gov; | |
1683 | } | |
1c256245 | 1684 | } |
1da177e4 LT |
1685 | |
1686 | if (!try_module_get(policy->governor->owner)) | |
1687 | return -EINVAL; | |
1688 | ||
2d06d8c4 | 1689 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1690 | policy->cpu, event); |
95731ebb XC |
1691 | |
1692 | mutex_lock(&cpufreq_governor_lock); | |
1693 | if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) || | |
1694 | (policy->governor_enabled && (event == CPUFREQ_GOV_START))) { | |
1695 | mutex_unlock(&cpufreq_governor_lock); | |
1696 | return -EBUSY; | |
1697 | } | |
1698 | ||
1699 | if (event == CPUFREQ_GOV_STOP) | |
1700 | policy->governor_enabled = false; | |
1701 | else if (event == CPUFREQ_GOV_START) | |
1702 | policy->governor_enabled = true; | |
1703 | ||
1704 | mutex_unlock(&cpufreq_governor_lock); | |
1705 | ||
1da177e4 LT |
1706 | ret = policy->governor->governor(policy, event); |
1707 | ||
4d5dcc42 VK |
1708 | if (!ret) { |
1709 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1710 | policy->governor->initialized++; | |
1711 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1712 | policy->governor->initialized--; | |
95731ebb XC |
1713 | } else { |
1714 | /* Restore original values */ | |
1715 | mutex_lock(&cpufreq_governor_lock); | |
1716 | if (event == CPUFREQ_GOV_STOP) | |
1717 | policy->governor_enabled = true; | |
1718 | else if (event == CPUFREQ_GOV_START) | |
1719 | policy->governor_enabled = false; | |
1720 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1721 | } |
b394058f | 1722 | |
e08f5f5b GS |
1723 | /* we keep one module reference alive for |
1724 | each CPU governed by this CPU */ | |
1da177e4 LT |
1725 | if ((event != CPUFREQ_GOV_START) || ret) |
1726 | module_put(policy->governor->owner); | |
1727 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1728 | module_put(policy->governor->owner); | |
1729 | ||
1730 | return ret; | |
1731 | } | |
1732 | ||
1da177e4 LT |
1733 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1734 | { | |
3bcb09a3 | 1735 | int err; |
1da177e4 LT |
1736 | |
1737 | if (!governor) | |
1738 | return -EINVAL; | |
1739 | ||
a7b422cd KRW |
1740 | if (cpufreq_disabled()) |
1741 | return -ENODEV; | |
1742 | ||
3fc54d37 | 1743 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1744 | |
b394058f | 1745 | governor->initialized = 0; |
3bcb09a3 JF |
1746 | err = -EBUSY; |
1747 | if (__find_governor(governor->name) == NULL) { | |
1748 | err = 0; | |
1749 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1750 | } |
1da177e4 | 1751 | |
32ee8c3e | 1752 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1753 | return err; |
1da177e4 LT |
1754 | } |
1755 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1756 | ||
1da177e4 LT |
1757 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1758 | { | |
90e41bac PB |
1759 | #ifdef CONFIG_HOTPLUG_CPU |
1760 | int cpu; | |
1761 | #endif | |
1762 | ||
1da177e4 LT |
1763 | if (!governor) |
1764 | return; | |
1765 | ||
a7b422cd KRW |
1766 | if (cpufreq_disabled()) |
1767 | return; | |
1768 | ||
90e41bac PB |
1769 | #ifdef CONFIG_HOTPLUG_CPU |
1770 | for_each_present_cpu(cpu) { | |
1771 | if (cpu_online(cpu)) | |
1772 | continue; | |
1773 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1774 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1775 | } | |
1776 | #endif | |
1777 | ||
3fc54d37 | 1778 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1779 | list_del(&governor->governor_list); |
3fc54d37 | 1780 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1781 | return; |
1782 | } | |
1783 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1784 | ||
1785 | ||
1da177e4 LT |
1786 | /********************************************************************* |
1787 | * POLICY INTERFACE * | |
1788 | *********************************************************************/ | |
1789 | ||
1790 | /** | |
1791 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1792 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1793 | * is written | |
1da177e4 LT |
1794 | * |
1795 | * Reads the current cpufreq policy. | |
1796 | */ | |
1797 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1798 | { | |
1799 | struct cpufreq_policy *cpu_policy; | |
1800 | if (!policy) | |
1801 | return -EINVAL; | |
1802 | ||
1803 | cpu_policy = cpufreq_cpu_get(cpu); | |
1804 | if (!cpu_policy) | |
1805 | return -EINVAL; | |
1806 | ||
1da177e4 | 1807 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1808 | |
1809 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1810 | return 0; |
1811 | } | |
1812 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1813 | ||
153d7f3f | 1814 | /* |
e08f5f5b GS |
1815 | * data : current policy. |
1816 | * policy : policy to be set. | |
153d7f3f | 1817 | */ |
e08f5f5b GS |
1818 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1819 | struct cpufreq_policy *policy) | |
1da177e4 | 1820 | { |
7bd353a9 | 1821 | int ret = 0, failed = 1; |
1da177e4 | 1822 | |
2d06d8c4 | 1823 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1824 | policy->min, policy->max); |
1825 | ||
e08f5f5b GS |
1826 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1827 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1828 | |
53391fa2 | 1829 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1830 | ret = -EINVAL; |
1831 | goto error_out; | |
1832 | } | |
1833 | ||
1da177e4 | 1834 | /* verify the cpu speed can be set within this limit */ |
1c3d85dd | 1835 | ret = cpufreq_driver->verify(policy); |
1da177e4 LT |
1836 | if (ret) |
1837 | goto error_out; | |
1838 | ||
1da177e4 | 1839 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1840 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1841 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1842 | |
1843 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1844 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1845 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 | 1846 | |
bb176f7d VK |
1847 | /* |
1848 | * verify the cpu speed can be set within this limit, which might be | |
1849 | * different to the first one | |
1850 | */ | |
1c3d85dd | 1851 | ret = cpufreq_driver->verify(policy); |
e041c683 | 1852 | if (ret) |
1da177e4 | 1853 | goto error_out; |
1da177e4 LT |
1854 | |
1855 | /* notification of the new policy */ | |
e041c683 AS |
1856 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1857 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1858 | |
7d5e350f DJ |
1859 | data->min = policy->min; |
1860 | data->max = policy->max; | |
1da177e4 | 1861 | |
2d06d8c4 | 1862 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1863 | data->min, data->max); |
1da177e4 | 1864 | |
1c3d85dd | 1865 | if (cpufreq_driver->setpolicy) { |
1da177e4 | 1866 | data->policy = policy->policy; |
2d06d8c4 | 1867 | pr_debug("setting range\n"); |
1c3d85dd | 1868 | ret = cpufreq_driver->setpolicy(policy); |
1da177e4 LT |
1869 | } else { |
1870 | if (policy->governor != data->governor) { | |
1871 | /* save old, working values */ | |
1872 | struct cpufreq_governor *old_gov = data->governor; | |
1873 | ||
2d06d8c4 | 1874 | pr_debug("governor switch\n"); |
1da177e4 LT |
1875 | |
1876 | /* end old governor */ | |
7bd353a9 | 1877 | if (data->governor) { |
1da177e4 | 1878 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
955ef483 | 1879 | unlock_policy_rwsem_write(policy->cpu); |
7bd353a9 VK |
1880 | __cpufreq_governor(data, |
1881 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 | 1882 | lock_policy_rwsem_write(policy->cpu); |
7bd353a9 | 1883 | } |
1da177e4 LT |
1884 | |
1885 | /* start new governor */ | |
1886 | data->governor = policy->governor; | |
7bd353a9 | 1887 | if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { |
955ef483 | 1888 | if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) { |
7bd353a9 | 1889 | failed = 0; |
955ef483 VK |
1890 | } else { |
1891 | unlock_policy_rwsem_write(policy->cpu); | |
7bd353a9 VK |
1892 | __cpufreq_governor(data, |
1893 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 VK |
1894 | lock_policy_rwsem_write(policy->cpu); |
1895 | } | |
7bd353a9 VK |
1896 | } |
1897 | ||
1898 | if (failed) { | |
1da177e4 | 1899 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1900 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1901 | data->governor->name); |
1da177e4 LT |
1902 | if (old_gov) { |
1903 | data->governor = old_gov; | |
7bd353a9 VK |
1904 | __cpufreq_governor(data, |
1905 | CPUFREQ_GOV_POLICY_INIT); | |
e08f5f5b GS |
1906 | __cpufreq_governor(data, |
1907 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1908 | } |
1909 | ret = -EINVAL; | |
1910 | goto error_out; | |
1911 | } | |
1912 | /* might be a policy change, too, so fall through */ | |
1913 | } | |
2d06d8c4 | 1914 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1915 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1916 | } | |
1917 | ||
7d5e350f | 1918 | error_out: |
1da177e4 LT |
1919 | return ret; |
1920 | } | |
1921 | ||
1da177e4 LT |
1922 | /** |
1923 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1924 | * @cpu: CPU which shall be re-evaluated | |
1925 | * | |
25985edc | 1926 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1927 | * at different times. |
1928 | */ | |
1929 | int cpufreq_update_policy(unsigned int cpu) | |
1930 | { | |
1931 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1932 | struct cpufreq_policy policy; | |
f1829e4a | 1933 | int ret; |
1da177e4 | 1934 | |
f1829e4a JL |
1935 | if (!data) { |
1936 | ret = -ENODEV; | |
1937 | goto no_policy; | |
1938 | } | |
1da177e4 | 1939 | |
f1829e4a JL |
1940 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1941 | ret = -EINVAL; | |
1942 | goto fail; | |
1943 | } | |
1da177e4 | 1944 | |
2d06d8c4 | 1945 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1946 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1947 | policy.min = data->user_policy.min; |
1948 | policy.max = data->user_policy.max; | |
1949 | policy.policy = data->user_policy.policy; | |
1950 | policy.governor = data->user_policy.governor; | |
1951 | ||
bb176f7d VK |
1952 | /* |
1953 | * BIOS might change freq behind our back | |
1954 | * -> ask driver for current freq and notify governors about a change | |
1955 | */ | |
1c3d85dd RW |
1956 | if (cpufreq_driver->get) { |
1957 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1958 | if (!data->cur) { |
2d06d8c4 | 1959 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1960 | data->cur = policy.cur; |
1961 | } else { | |
1c3d85dd | 1962 | if (data->cur != policy.cur && cpufreq_driver->target) |
e08f5f5b GS |
1963 | cpufreq_out_of_sync(cpu, data->cur, |
1964 | policy.cur); | |
a85f7bd3 | 1965 | } |
0961dd0d TR |
1966 | } |
1967 | ||
1da177e4 LT |
1968 | ret = __cpufreq_set_policy(data, &policy); |
1969 | ||
5a01f2e8 VP |
1970 | unlock_policy_rwsem_write(cpu); |
1971 | ||
f1829e4a | 1972 | fail: |
1da177e4 | 1973 | cpufreq_cpu_put(data); |
f1829e4a | 1974 | no_policy: |
1da177e4 LT |
1975 | return ret; |
1976 | } | |
1977 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1978 | ||
2760984f | 1979 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1980 | unsigned long action, void *hcpu) |
1981 | { | |
1982 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1983 | struct device *dev; |
c32b6b8e | 1984 | |
8a25a2fd KS |
1985 | dev = get_cpu_device(cpu); |
1986 | if (dev) { | |
c32b6b8e AR |
1987 | switch (action) { |
1988 | case CPU_ONLINE: | |
aae760ed | 1989 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1990 | cpufreq_add_dev(dev, NULL); |
23d32899 | 1991 | cpufreq_update_policy(cpu); |
c32b6b8e AR |
1992 | break; |
1993 | case CPU_DOWN_PREPARE: | |
aae760ed | 1994 | case CPU_DOWN_PREPARE_FROZEN: |
8a25a2fd | 1995 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1996 | break; |
5a01f2e8 | 1997 | case CPU_DOWN_FAILED: |
aae760ed | 1998 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1999 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
2000 | break; |
2001 | } | |
2002 | } | |
2003 | return NOTIFY_OK; | |
2004 | } | |
2005 | ||
9c36f746 | 2006 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2007 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2008 | }; |
1da177e4 LT |
2009 | |
2010 | /********************************************************************* | |
2011 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2012 | *********************************************************************/ | |
2013 | ||
2014 | /** | |
2015 | * cpufreq_register_driver - register a CPU Frequency driver | |
2016 | * @driver_data: A struct cpufreq_driver containing the values# | |
2017 | * submitted by the CPU Frequency driver. | |
2018 | * | |
bb176f7d | 2019 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2020 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2021 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2022 | * |
2023 | */ | |
221dee28 | 2024 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2025 | { |
2026 | unsigned long flags; | |
2027 | int ret; | |
2028 | ||
a7b422cd KRW |
2029 | if (cpufreq_disabled()) |
2030 | return -ENODEV; | |
2031 | ||
1da177e4 LT |
2032 | if (!driver_data || !driver_data->verify || !driver_data->init || |
2033 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2034 | return -EINVAL; | |
2035 | ||
2d06d8c4 | 2036 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2037 | |
2038 | if (driver_data->setpolicy) | |
2039 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2040 | ||
0d1857a1 | 2041 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2042 | if (cpufreq_driver) { |
0d1857a1 | 2043 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2044 | return -EBUSY; |
2045 | } | |
1c3d85dd | 2046 | cpufreq_driver = driver_data; |
0d1857a1 | 2047 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2048 | |
8a25a2fd | 2049 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2050 | if (ret) |
2051 | goto err_null_driver; | |
1da177e4 | 2052 | |
1c3d85dd | 2053 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2054 | int i; |
2055 | ret = -ENODEV; | |
2056 | ||
2057 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2058 | for (i = 0; i < nr_cpu_ids; i++) |
2059 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2060 | ret = 0; |
7a6aedfa MT |
2061 | break; |
2062 | } | |
1da177e4 LT |
2063 | |
2064 | /* if all ->init() calls failed, unregister */ | |
2065 | if (ret) { | |
2d06d8c4 | 2066 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2067 | driver_data->name); |
8a25a2fd | 2068 | goto err_if_unreg; |
1da177e4 LT |
2069 | } |
2070 | } | |
2071 | ||
8f5bc2ab | 2072 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2073 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2074 | |
8f5bc2ab | 2075 | return 0; |
8a25a2fd KS |
2076 | err_if_unreg: |
2077 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2078 | err_null_driver: |
0d1857a1 | 2079 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2080 | cpufreq_driver = NULL; |
0d1857a1 | 2081 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2082 | return ret; |
1da177e4 LT |
2083 | } |
2084 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2085 | ||
1da177e4 LT |
2086 | /** |
2087 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2088 | * | |
bb176f7d | 2089 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2090 | * the right to do so, i.e. if you have succeeded in initialising before! |
2091 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2092 | * currently not initialised. | |
2093 | */ | |
221dee28 | 2094 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2095 | { |
2096 | unsigned long flags; | |
2097 | ||
1c3d85dd | 2098 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2099 | return -EINVAL; |
1da177e4 | 2100 | |
2d06d8c4 | 2101 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2102 | |
8a25a2fd | 2103 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2104 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2105 | |
0d1857a1 | 2106 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2107 | cpufreq_driver = NULL; |
0d1857a1 | 2108 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2109 | |
2110 | return 0; | |
2111 | } | |
2112 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2113 | |
2114 | static int __init cpufreq_core_init(void) | |
2115 | { | |
2116 | int cpu; | |
2117 | ||
a7b422cd KRW |
2118 | if (cpufreq_disabled()) |
2119 | return -ENODEV; | |
2120 | ||
5a01f2e8 | 2121 | for_each_possible_cpu(cpu) { |
f1625066 | 2122 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
2123 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
2124 | } | |
8aa84ad8 | 2125 | |
2361be23 | 2126 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2127 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2128 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2129 | |
5a01f2e8 VP |
2130 | return 0; |
2131 | } | |
5a01f2e8 | 2132 | core_initcall(cpufreq_core_init); |