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Commit | Line | Data |
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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); |
8414809c | 47 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); |
bb176f7d VK |
48 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
49 | static DEFINE_MUTEX(cpufreq_governor_lock); | |
50 | ||
084f3493 TR |
51 | #ifdef CONFIG_HOTPLUG_CPU |
52 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 53 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 54 | #endif |
1da177e4 | 55 | |
5a01f2e8 VP |
56 | /* |
57 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
58 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
59 | * | |
60 | * The rules for this semaphore: | |
61 | * - Any routine that wants to read from the policy structure will | |
62 | * do a down_read on this semaphore. | |
63 | * - Any routine that will write to the policy structure and/or may take away | |
64 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
65 | * mode before doing so. | |
66 | * | |
67 | * Additional rules: | |
5a01f2e8 VP |
68 | * - Governor routines that can be called in cpufreq hotplug path should not |
69 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
70 | * - Lock should not be held across |
71 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 72 | */ |
f1625066 | 73 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
74 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
75 | ||
76 | #define lock_policy_rwsem(mode, cpu) \ | |
fa1d8af4 | 77 | static int lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 78 | { \ |
f1625066 | 79 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
80 | BUG_ON(policy_cpu == -1); \ |
81 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 VP |
82 | \ |
83 | return 0; \ | |
84 | } | |
85 | ||
86 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 87 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 88 | |
fa1d8af4 VK |
89 | #define unlock_policy_rwsem(mode, cpu) \ |
90 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
91 | { \ | |
92 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
93 | BUG_ON(policy_cpu == -1); \ | |
94 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
5a01f2e8 | 95 | } |
5a01f2e8 | 96 | |
fa1d8af4 VK |
97 | unlock_policy_rwsem(read, cpu); |
98 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 99 | |
1da177e4 | 100 | /* internal prototypes */ |
29464f28 DJ |
101 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
102 | unsigned int event); | |
5a01f2e8 | 103 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 104 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
105 | |
106 | /** | |
32ee8c3e DJ |
107 | * Two notifier lists: the "policy" list is involved in the |
108 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
109 | * "transition" list for kernel code that needs to handle |
110 | * changes to devices when the CPU clock speed changes. | |
111 | * The mutex locks both lists. | |
112 | */ | |
e041c683 | 113 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 114 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 115 | |
74212ca4 | 116 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
117 | static int __init init_cpufreq_transition_notifier_list(void) |
118 | { | |
119 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 120 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
121 | return 0; |
122 | } | |
b3438f82 | 123 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 124 | |
a7b422cd | 125 | static int off __read_mostly; |
da584455 | 126 | static int cpufreq_disabled(void) |
a7b422cd KRW |
127 | { |
128 | return off; | |
129 | } | |
130 | void disable_cpufreq(void) | |
131 | { | |
132 | off = 1; | |
133 | } | |
1da177e4 | 134 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 135 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 136 | |
4d5dcc42 VK |
137 | bool have_governor_per_policy(void) |
138 | { | |
1c3d85dd | 139 | return cpufreq_driver->have_governor_per_policy; |
4d5dcc42 | 140 | } |
3f869d6d | 141 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 142 | |
944e9a03 VK |
143 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
144 | { | |
145 | if (have_governor_per_policy()) | |
146 | return &policy->kobj; | |
147 | else | |
148 | return cpufreq_global_kobject; | |
149 | } | |
150 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
151 | ||
72a4ce34 VK |
152 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
153 | { | |
154 | u64 idle_time; | |
155 | u64 cur_wall_time; | |
156 | u64 busy_time; | |
157 | ||
158 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
159 | ||
160 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
161 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
162 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
163 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
164 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
165 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
166 | ||
167 | idle_time = cur_wall_time - busy_time; | |
168 | if (wall) | |
169 | *wall = cputime_to_usecs(cur_wall_time); | |
170 | ||
171 | return cputime_to_usecs(idle_time); | |
172 | } | |
173 | ||
174 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
175 | { | |
176 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
177 | ||
178 | if (idle_time == -1ULL) | |
179 | return get_cpu_idle_time_jiffy(cpu, wall); | |
180 | else if (!io_busy) | |
181 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
182 | ||
183 | return idle_time; | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
186 | ||
a9144436 | 187 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
188 | { |
189 | struct cpufreq_policy *data; | |
190 | unsigned long flags; | |
191 | ||
7a6aedfa | 192 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
193 | goto err_out; |
194 | ||
195 | /* get the cpufreq driver */ | |
1c3d85dd | 196 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 197 | |
1c3d85dd | 198 | if (!cpufreq_driver) |
1da177e4 LT |
199 | goto err_out_unlock; |
200 | ||
1c3d85dd | 201 | if (!try_module_get(cpufreq_driver->owner)) |
1da177e4 LT |
202 | goto err_out_unlock; |
203 | ||
1da177e4 | 204 | /* get the CPU */ |
7a6aedfa | 205 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
206 | |
207 | if (!data) | |
208 | goto err_out_put_module; | |
209 | ||
a9144436 | 210 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
211 | goto err_out_put_module; |
212 | ||
0d1857a1 | 213 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
214 | return data; |
215 | ||
7d5e350f | 216 | err_out_put_module: |
1c3d85dd | 217 | module_put(cpufreq_driver->owner); |
5800043b | 218 | err_out_unlock: |
1c3d85dd | 219 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 220 | err_out: |
1da177e4 LT |
221 | return NULL; |
222 | } | |
a9144436 SB |
223 | |
224 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
225 | { | |
d5aaffa9 DB |
226 | if (cpufreq_disabled()) |
227 | return NULL; | |
228 | ||
a9144436 SB |
229 | return __cpufreq_cpu_get(cpu, false); |
230 | } | |
1da177e4 LT |
231 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
232 | ||
a9144436 SB |
233 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
234 | { | |
235 | return __cpufreq_cpu_get(cpu, true); | |
236 | } | |
237 | ||
238 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
239 | { | |
240 | if (!sysfs) | |
241 | kobject_put(&data->kobj); | |
1c3d85dd | 242 | module_put(cpufreq_driver->owner); |
a9144436 | 243 | } |
7d5e350f | 244 | |
1da177e4 LT |
245 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
246 | { | |
d5aaffa9 DB |
247 | if (cpufreq_disabled()) |
248 | return; | |
249 | ||
a9144436 | 250 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
251 | } |
252 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
253 | ||
a9144436 SB |
254 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
255 | { | |
256 | __cpufreq_cpu_put(data, true); | |
257 | } | |
1da177e4 | 258 | |
1da177e4 LT |
259 | /********************************************************************* |
260 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
261 | *********************************************************************/ | |
262 | ||
263 | /** | |
264 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
265 | * | |
266 | * This function alters the system "loops_per_jiffy" for the clock | |
267 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 268 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
269 | * per-CPU loops_per_jiffy value wherever possible. |
270 | */ | |
271 | #ifndef CONFIG_SMP | |
272 | static unsigned long l_p_j_ref; | |
bb176f7d | 273 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 274 | |
858119e1 | 275 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
276 | { |
277 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
278 | return; | |
279 | ||
280 | if (!l_p_j_ref_freq) { | |
281 | l_p_j_ref = loops_per_jiffy; | |
282 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 283 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 284 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 285 | } |
bb176f7d | 286 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 287 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
288 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
289 | ci->new); | |
2d06d8c4 | 290 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 291 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
292 | } |
293 | } | |
294 | #else | |
e08f5f5b GS |
295 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
296 | { | |
297 | return; | |
298 | } | |
1da177e4 LT |
299 | #endif |
300 | ||
0956df9c | 301 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 302 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
303 | { |
304 | BUG_ON(irqs_disabled()); | |
305 | ||
d5aaffa9 DB |
306 | if (cpufreq_disabled()) |
307 | return; | |
308 | ||
1c3d85dd | 309 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 310 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 311 | state, freqs->new); |
1da177e4 | 312 | |
1da177e4 | 313 | switch (state) { |
e4472cb3 | 314 | |
1da177e4 | 315 | case CPUFREQ_PRECHANGE: |
266c13d7 VK |
316 | if (WARN(policy->transition_ongoing == |
317 | cpumask_weight(policy->cpus), | |
7c30ed53 VK |
318 | "In middle of another frequency transition\n")) |
319 | return; | |
320 | ||
266c13d7 | 321 | policy->transition_ongoing++; |
7c30ed53 | 322 | |
32ee8c3e | 323 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
324 | * which is not equal to what the cpufreq core thinks is |
325 | * "old frequency". | |
1da177e4 | 326 | */ |
1c3d85dd | 327 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
328 | if ((policy) && (policy->cpu == freqs->cpu) && |
329 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 330 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
331 | " %u, cpufreq assumed %u kHz.\n", |
332 | freqs->old, policy->cur); | |
333 | freqs->old = policy->cur; | |
1da177e4 LT |
334 | } |
335 | } | |
b4dfdbb3 | 336 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 337 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
338 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
339 | break; | |
e4472cb3 | 340 | |
1da177e4 | 341 | case CPUFREQ_POSTCHANGE: |
7c30ed53 VK |
342 | if (WARN(!policy->transition_ongoing, |
343 | "No frequency transition in progress\n")) | |
344 | return; | |
345 | ||
266c13d7 | 346 | policy->transition_ongoing--; |
7c30ed53 | 347 | |
1da177e4 | 348 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); |
2d06d8c4 | 349 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 350 | (unsigned long)freqs->cpu); |
25e41933 | 351 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 352 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 353 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
354 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
355 | policy->cur = freqs->new; | |
1da177e4 LT |
356 | break; |
357 | } | |
1da177e4 | 358 | } |
bb176f7d | 359 | |
b43a7ffb VK |
360 | /** |
361 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
362 | * on frequency transition. | |
363 | * | |
364 | * This function calls the transition notifiers and the "adjust_jiffies" | |
365 | * function. It is called twice on all CPU frequency changes that have | |
366 | * external effects. | |
367 | */ | |
368 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
369 | struct cpufreq_freqs *freqs, unsigned int state) | |
370 | { | |
371 | for_each_cpu(freqs->cpu, policy->cpus) | |
372 | __cpufreq_notify_transition(policy, freqs, state); | |
373 | } | |
1da177e4 LT |
374 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
375 | ||
376 | ||
1da177e4 LT |
377 | /********************************************************************* |
378 | * SYSFS INTERFACE * | |
379 | *********************************************************************/ | |
380 | ||
3bcb09a3 JF |
381 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
382 | { | |
383 | struct cpufreq_governor *t; | |
384 | ||
385 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 386 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
387 | return t; |
388 | ||
389 | return NULL; | |
390 | } | |
391 | ||
1da177e4 LT |
392 | /** |
393 | * cpufreq_parse_governor - parse a governor string | |
394 | */ | |
905d77cd | 395 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
396 | struct cpufreq_governor **governor) |
397 | { | |
3bcb09a3 | 398 | int err = -EINVAL; |
1c3d85dd RW |
399 | |
400 | if (!cpufreq_driver) | |
3bcb09a3 JF |
401 | goto out; |
402 | ||
1c3d85dd | 403 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
404 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
405 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 406 | err = 0; |
e08f5f5b GS |
407 | } else if (!strnicmp(str_governor, "powersave", |
408 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 409 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 410 | err = 0; |
1da177e4 | 411 | } |
1c3d85dd | 412 | } else if (cpufreq_driver->target) { |
1da177e4 | 413 | struct cpufreq_governor *t; |
3bcb09a3 | 414 | |
3fc54d37 | 415 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
416 | |
417 | t = __find_governor(str_governor); | |
418 | ||
ea714970 | 419 | if (t == NULL) { |
1a8e1463 | 420 | int ret; |
ea714970 | 421 | |
1a8e1463 KC |
422 | mutex_unlock(&cpufreq_governor_mutex); |
423 | ret = request_module("cpufreq_%s", str_governor); | |
424 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 425 | |
1a8e1463 KC |
426 | if (ret == 0) |
427 | t = __find_governor(str_governor); | |
ea714970 JF |
428 | } |
429 | ||
3bcb09a3 JF |
430 | if (t != NULL) { |
431 | *governor = t; | |
432 | err = 0; | |
1da177e4 | 433 | } |
3bcb09a3 | 434 | |
3fc54d37 | 435 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 436 | } |
29464f28 | 437 | out: |
3bcb09a3 | 438 | return err; |
1da177e4 | 439 | } |
1da177e4 | 440 | |
1da177e4 | 441 | /** |
e08f5f5b GS |
442 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
443 | * print out cpufreq information | |
1da177e4 LT |
444 | * |
445 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
446 | * "unsigned int". | |
447 | */ | |
448 | ||
32ee8c3e DJ |
449 | #define show_one(file_name, object) \ |
450 | static ssize_t show_##file_name \ | |
905d77cd | 451 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 452 | { \ |
29464f28 | 453 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
454 | } |
455 | ||
456 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
457 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 458 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
459 | show_one(scaling_min_freq, min); |
460 | show_one(scaling_max_freq, max); | |
461 | show_one(scaling_cur_freq, cur); | |
462 | ||
e08f5f5b GS |
463 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
464 | struct cpufreq_policy *policy); | |
7970e08b | 465 | |
1da177e4 LT |
466 | /** |
467 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
468 | */ | |
469 | #define store_one(file_name, object) \ | |
470 | static ssize_t store_##file_name \ | |
905d77cd | 471 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 472 | { \ |
f55c9c26 | 473 | unsigned int ret; \ |
1da177e4 LT |
474 | struct cpufreq_policy new_policy; \ |
475 | \ | |
476 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
477 | if (ret) \ | |
478 | return -EINVAL; \ | |
479 | \ | |
29464f28 | 480 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
481 | if (ret != 1) \ |
482 | return -EINVAL; \ | |
483 | \ | |
7970e08b TR |
484 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
485 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
486 | \ |
487 | return ret ? ret : count; \ | |
488 | } | |
489 | ||
29464f28 DJ |
490 | store_one(scaling_min_freq, min); |
491 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
492 | |
493 | /** | |
494 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
495 | */ | |
905d77cd DJ |
496 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
497 | char *buf) | |
1da177e4 | 498 | { |
5a01f2e8 | 499 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
500 | if (!cur_freq) |
501 | return sprintf(buf, "<unknown>"); | |
502 | return sprintf(buf, "%u\n", cur_freq); | |
503 | } | |
504 | ||
1da177e4 LT |
505 | /** |
506 | * show_scaling_governor - show the current policy for the specified CPU | |
507 | */ | |
905d77cd | 508 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 509 | { |
29464f28 | 510 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
511 | return sprintf(buf, "powersave\n"); |
512 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
513 | return sprintf(buf, "performance\n"); | |
514 | else if (policy->governor) | |
4b972f0b | 515 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 516 | policy->governor->name); |
1da177e4 LT |
517 | return -EINVAL; |
518 | } | |
519 | ||
1da177e4 LT |
520 | /** |
521 | * store_scaling_governor - store policy for the specified CPU | |
522 | */ | |
905d77cd DJ |
523 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
524 | const char *buf, size_t count) | |
1da177e4 | 525 | { |
f55c9c26 | 526 | unsigned int ret; |
1da177e4 LT |
527 | char str_governor[16]; |
528 | struct cpufreq_policy new_policy; | |
529 | ||
530 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
531 | if (ret) | |
532 | return ret; | |
533 | ||
29464f28 | 534 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
535 | if (ret != 1) |
536 | return -EINVAL; | |
537 | ||
e08f5f5b GS |
538 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
539 | &new_policy.governor)) | |
1da177e4 LT |
540 | return -EINVAL; |
541 | ||
bb176f7d VK |
542 | /* |
543 | * Do not use cpufreq_set_policy here or the user_policy.max | |
544 | * will be wrongly overridden | |
545 | */ | |
7970e08b TR |
546 | ret = __cpufreq_set_policy(policy, &new_policy); |
547 | ||
548 | policy->user_policy.policy = policy->policy; | |
549 | policy->user_policy.governor = policy->governor; | |
7970e08b | 550 | |
e08f5f5b GS |
551 | if (ret) |
552 | return ret; | |
553 | else | |
554 | return count; | |
1da177e4 LT |
555 | } |
556 | ||
557 | /** | |
558 | * show_scaling_driver - show the cpufreq driver currently loaded | |
559 | */ | |
905d77cd | 560 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 561 | { |
1c3d85dd | 562 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
563 | } |
564 | ||
565 | /** | |
566 | * show_scaling_available_governors - show the available CPUfreq governors | |
567 | */ | |
905d77cd DJ |
568 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
569 | char *buf) | |
1da177e4 LT |
570 | { |
571 | ssize_t i = 0; | |
572 | struct cpufreq_governor *t; | |
573 | ||
1c3d85dd | 574 | if (!cpufreq_driver->target) { |
1da177e4 LT |
575 | i += sprintf(buf, "performance powersave"); |
576 | goto out; | |
577 | } | |
578 | ||
579 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
580 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
581 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 582 | goto out; |
4b972f0b | 583 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 584 | } |
7d5e350f | 585 | out: |
1da177e4 LT |
586 | i += sprintf(&buf[i], "\n"); |
587 | return i; | |
588 | } | |
e8628dd0 | 589 | |
f4fd3797 | 590 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
591 | { |
592 | ssize_t i = 0; | |
593 | unsigned int cpu; | |
594 | ||
835481d9 | 595 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
596 | if (i) |
597 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
598 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
599 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 600 | break; |
1da177e4 LT |
601 | } |
602 | i += sprintf(&buf[i], "\n"); | |
603 | return i; | |
604 | } | |
f4fd3797 | 605 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 606 | |
e8628dd0 DW |
607 | /** |
608 | * show_related_cpus - show the CPUs affected by each transition even if | |
609 | * hw coordination is in use | |
610 | */ | |
611 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
612 | { | |
f4fd3797 | 613 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
614 | } |
615 | ||
616 | /** | |
617 | * show_affected_cpus - show the CPUs affected by each transition | |
618 | */ | |
619 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
620 | { | |
f4fd3797 | 621 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
622 | } |
623 | ||
9e76988e | 624 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 625 | const char *buf, size_t count) |
9e76988e VP |
626 | { |
627 | unsigned int freq = 0; | |
628 | unsigned int ret; | |
629 | ||
879000f9 | 630 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
631 | return -EINVAL; |
632 | ||
633 | ret = sscanf(buf, "%u", &freq); | |
634 | if (ret != 1) | |
635 | return -EINVAL; | |
636 | ||
637 | policy->governor->store_setspeed(policy, freq); | |
638 | ||
639 | return count; | |
640 | } | |
641 | ||
642 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
643 | { | |
879000f9 | 644 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
645 | return sprintf(buf, "<unsupported>\n"); |
646 | ||
647 | return policy->governor->show_setspeed(policy, buf); | |
648 | } | |
1da177e4 | 649 | |
e2f74f35 | 650 | /** |
8bf1ac72 | 651 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
652 | */ |
653 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
654 | { | |
655 | unsigned int limit; | |
656 | int ret; | |
1c3d85dd RW |
657 | if (cpufreq_driver->bios_limit) { |
658 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
659 | if (!ret) |
660 | return sprintf(buf, "%u\n", limit); | |
661 | } | |
662 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
663 | } | |
664 | ||
6dad2a29 BP |
665 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
666 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
667 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
668 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
669 | cpufreq_freq_attr_ro(scaling_available_governors); | |
670 | cpufreq_freq_attr_ro(scaling_driver); | |
671 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
672 | cpufreq_freq_attr_ro(bios_limit); | |
673 | cpufreq_freq_attr_ro(related_cpus); | |
674 | cpufreq_freq_attr_ro(affected_cpus); | |
675 | cpufreq_freq_attr_rw(scaling_min_freq); | |
676 | cpufreq_freq_attr_rw(scaling_max_freq); | |
677 | cpufreq_freq_attr_rw(scaling_governor); | |
678 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 679 | |
905d77cd | 680 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
681 | &cpuinfo_min_freq.attr, |
682 | &cpuinfo_max_freq.attr, | |
ed129784 | 683 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
684 | &scaling_min_freq.attr, |
685 | &scaling_max_freq.attr, | |
686 | &affected_cpus.attr, | |
e8628dd0 | 687 | &related_cpus.attr, |
1da177e4 LT |
688 | &scaling_governor.attr, |
689 | &scaling_driver.attr, | |
690 | &scaling_available_governors.attr, | |
9e76988e | 691 | &scaling_setspeed.attr, |
1da177e4 LT |
692 | NULL |
693 | }; | |
694 | ||
29464f28 DJ |
695 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
696 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 697 | |
29464f28 | 698 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 699 | { |
905d77cd DJ |
700 | struct cpufreq_policy *policy = to_policy(kobj); |
701 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 702 | ssize_t ret = -EINVAL; |
a9144436 | 703 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 704 | if (!policy) |
0db4a8a9 | 705 | goto no_policy; |
5a01f2e8 VP |
706 | |
707 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 708 | goto fail; |
5a01f2e8 | 709 | |
e08f5f5b GS |
710 | if (fattr->show) |
711 | ret = fattr->show(policy, buf); | |
712 | else | |
713 | ret = -EIO; | |
714 | ||
5a01f2e8 | 715 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 716 | fail: |
a9144436 | 717 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 718 | no_policy: |
1da177e4 LT |
719 | return ret; |
720 | } | |
721 | ||
905d77cd DJ |
722 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
723 | const char *buf, size_t count) | |
1da177e4 | 724 | { |
905d77cd DJ |
725 | struct cpufreq_policy *policy = to_policy(kobj); |
726 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 727 | ssize_t ret = -EINVAL; |
a9144436 | 728 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 729 | if (!policy) |
a07530b4 | 730 | goto no_policy; |
5a01f2e8 VP |
731 | |
732 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 733 | goto fail; |
5a01f2e8 | 734 | |
e08f5f5b GS |
735 | if (fattr->store) |
736 | ret = fattr->store(policy, buf, count); | |
737 | else | |
738 | ret = -EIO; | |
739 | ||
5a01f2e8 | 740 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 741 | fail: |
a9144436 | 742 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 743 | no_policy: |
1da177e4 LT |
744 | return ret; |
745 | } | |
746 | ||
905d77cd | 747 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 748 | { |
905d77cd | 749 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 750 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
751 | complete(&policy->kobj_unregister); |
752 | } | |
753 | ||
52cf25d0 | 754 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
755 | .show = show, |
756 | .store = store, | |
757 | }; | |
758 | ||
759 | static struct kobj_type ktype_cpufreq = { | |
760 | .sysfs_ops = &sysfs_ops, | |
761 | .default_attrs = default_attrs, | |
762 | .release = cpufreq_sysfs_release, | |
763 | }; | |
764 | ||
2361be23 VK |
765 | struct kobject *cpufreq_global_kobject; |
766 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
767 | ||
768 | static int cpufreq_global_kobject_usage; | |
769 | ||
770 | int cpufreq_get_global_kobject(void) | |
771 | { | |
772 | if (!cpufreq_global_kobject_usage++) | |
773 | return kobject_add(cpufreq_global_kobject, | |
774 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
775 | ||
776 | return 0; | |
777 | } | |
778 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
779 | ||
780 | void cpufreq_put_global_kobject(void) | |
781 | { | |
782 | if (!--cpufreq_global_kobject_usage) | |
783 | kobject_del(cpufreq_global_kobject); | |
784 | } | |
785 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
786 | ||
787 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
788 | { | |
789 | int ret = cpufreq_get_global_kobject(); | |
790 | ||
791 | if (!ret) { | |
792 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
793 | if (ret) | |
794 | cpufreq_put_global_kobject(); | |
795 | } | |
796 | ||
797 | return ret; | |
798 | } | |
799 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
800 | ||
801 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
802 | { | |
803 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
804 | cpufreq_put_global_kobject(); | |
805 | } | |
806 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
807 | ||
19d6f7ec | 808 | /* symlink affected CPUs */ |
cf3289d0 AC |
809 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
810 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
811 | { |
812 | unsigned int j; | |
813 | int ret = 0; | |
814 | ||
815 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 816 | struct device *cpu_dev; |
19d6f7ec DJ |
817 | |
818 | if (j == cpu) | |
819 | continue; | |
19d6f7ec | 820 | |
e8fdde10 VK |
821 | pr_debug("Adding link for CPU: %u\n", j); |
822 | 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) { | |
e8fdde10 | 827 | cpufreq_cpu_put(policy); |
19d6f7ec DJ |
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, | |
a82fab29 | 906 | struct device *dev, bool frozen) |
fcf80582 VK |
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 | |
a82fab29 SB |
934 | /* Don't touch sysfs links during light-weight init */ |
935 | if (frozen) { | |
936 | /* Drop the extra refcount that we took above */ | |
fcf80582 | 937 | cpufreq_cpu_put(policy); |
a82fab29 | 938 | return 0; |
fcf80582 VK |
939 | } |
940 | ||
a82fab29 SB |
941 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
942 | if (ret) | |
943 | cpufreq_cpu_put(policy); | |
944 | ||
945 | return ret; | |
fcf80582 VK |
946 | } |
947 | #endif | |
1da177e4 | 948 | |
8414809c SB |
949 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
950 | { | |
951 | struct cpufreq_policy *policy; | |
952 | unsigned long flags; | |
953 | ||
954 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
955 | ||
956 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
957 | ||
958 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
959 | ||
960 | return policy; | |
961 | } | |
962 | ||
e9698cc5 SB |
963 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
964 | { | |
965 | struct cpufreq_policy *policy; | |
966 | ||
967 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
968 | if (!policy) | |
969 | return NULL; | |
970 | ||
971 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
972 | goto err_free_policy; | |
973 | ||
974 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
975 | goto err_free_cpumask; | |
976 | ||
977 | return policy; | |
978 | ||
979 | err_free_cpumask: | |
980 | free_cpumask_var(policy->cpus); | |
981 | err_free_policy: | |
982 | kfree(policy); | |
983 | ||
984 | return NULL; | |
985 | } | |
986 | ||
987 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
988 | { | |
989 | free_cpumask_var(policy->related_cpus); | |
990 | free_cpumask_var(policy->cpus); | |
991 | kfree(policy); | |
992 | } | |
993 | ||
a82fab29 SB |
994 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, |
995 | bool frozen) | |
1da177e4 | 996 | { |
fcf80582 | 997 | unsigned int j, cpu = dev->id; |
65922465 | 998 | int ret = -ENOMEM; |
1da177e4 | 999 | struct cpufreq_policy *policy; |
1da177e4 | 1000 | unsigned long flags; |
90e41bac | 1001 | #ifdef CONFIG_HOTPLUG_CPU |
fcf80582 | 1002 | struct cpufreq_governor *gov; |
90e41bac PB |
1003 | int sibling; |
1004 | #endif | |
1da177e4 | 1005 | |
c32b6b8e AR |
1006 | if (cpu_is_offline(cpu)) |
1007 | return 0; | |
1008 | ||
2d06d8c4 | 1009 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
1010 | |
1011 | #ifdef CONFIG_SMP | |
1012 | /* check whether a different CPU already registered this | |
1013 | * CPU because it is in the same boat. */ | |
1014 | policy = cpufreq_cpu_get(cpu); | |
1015 | if (unlikely(policy)) { | |
8ff69732 | 1016 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1017 | return 0; |
1018 | } | |
fcf80582 VK |
1019 | |
1020 | #ifdef CONFIG_HOTPLUG_CPU | |
1021 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1022 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
fcf80582 VK |
1023 | for_each_online_cpu(sibling) { |
1024 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
2eaa3e2d | 1025 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { |
0d1857a1 | 1026 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
a82fab29 SB |
1027 | return cpufreq_add_policy_cpu(cpu, sibling, dev, |
1028 | frozen); | |
2eaa3e2d | 1029 | } |
fcf80582 | 1030 | } |
0d1857a1 | 1031 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 1032 | #endif |
1da177e4 LT |
1033 | #endif |
1034 | ||
1c3d85dd | 1035 | if (!try_module_get(cpufreq_driver->owner)) { |
1da177e4 LT |
1036 | ret = -EINVAL; |
1037 | goto module_out; | |
1038 | } | |
1039 | ||
8414809c SB |
1040 | if (frozen) |
1041 | /* Restore the saved policy when doing light-weight init */ | |
1042 | policy = cpufreq_policy_restore(cpu); | |
1043 | else | |
1044 | policy = cpufreq_policy_alloc(); | |
1045 | ||
059019a3 | 1046 | if (!policy) |
1da177e4 | 1047 | goto nomem_out; |
059019a3 | 1048 | |
1da177e4 | 1049 | policy->cpu = cpu; |
65922465 | 1050 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1051 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1052 | |
5a01f2e8 | 1053 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 1054 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
5a01f2e8 | 1055 | |
1da177e4 | 1056 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1057 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1058 | |
1059 | /* call driver. From then on the cpufreq must be able | |
1060 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1061 | */ | |
1c3d85dd | 1062 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1063 | if (ret) { |
2d06d8c4 | 1064 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1065 | goto err_set_policy_cpu; |
1da177e4 | 1066 | } |
643ae6e8 | 1067 | |
fcf80582 VK |
1068 | /* related cpus should atleast have policy->cpus */ |
1069 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1070 | ||
643ae6e8 VK |
1071 | /* |
1072 | * affected cpus must always be the one, which are online. We aren't | |
1073 | * managing offline cpus here. | |
1074 | */ | |
1075 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1076 | ||
187d9f4e MC |
1077 | policy->user_policy.min = policy->min; |
1078 | policy->user_policy.max = policy->max; | |
1da177e4 | 1079 | |
a1531acd TR |
1080 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1081 | CPUFREQ_START, policy); | |
1082 | ||
fcf80582 VK |
1083 | #ifdef CONFIG_HOTPLUG_CPU |
1084 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1085 | if (gov) { | |
1086 | policy->governor = gov; | |
1087 | pr_debug("Restoring governor %s for cpu %d\n", | |
1088 | policy->governor->name, cpu); | |
4bfa042c | 1089 | } |
fcf80582 | 1090 | #endif |
1da177e4 | 1091 | |
e18f1682 SB |
1092 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1093 | for_each_cpu(j, policy->cpus) { | |
1094 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1095 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; | |
1096 | } | |
1097 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1098 | ||
a82fab29 SB |
1099 | if (!frozen) { |
1100 | ret = cpufreq_add_dev_interface(cpu, policy, dev); | |
1101 | if (ret) | |
1102 | goto err_out_unregister; | |
1103 | } | |
8ff69732 | 1104 | |
e18f1682 SB |
1105 | cpufreq_init_policy(policy); |
1106 | ||
038c5b3e | 1107 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1c3d85dd | 1108 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 1109 | pr_debug("initialization complete\n"); |
87c32271 | 1110 | |
1da177e4 LT |
1111 | return 0; |
1112 | ||
1da177e4 | 1113 | err_out_unregister: |
0d1857a1 | 1114 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
e18f1682 | 1115 | for_each_cpu(j, policy->cpus) { |
7a6aedfa | 1116 | per_cpu(cpufreq_cpu_data, j) = NULL; |
e18f1682 SB |
1117 | if (j != cpu) |
1118 | per_cpu(cpufreq_policy_cpu, j) = -1; | |
1119 | } | |
0d1857a1 | 1120 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1121 | |
c10997f6 | 1122 | kobject_put(&policy->kobj); |
1da177e4 LT |
1123 | wait_for_completion(&policy->kobj_unregister); |
1124 | ||
2eaa3e2d VK |
1125 | err_set_policy_cpu: |
1126 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
e9698cc5 | 1127 | cpufreq_policy_free(policy); |
1da177e4 | 1128 | nomem_out: |
1c3d85dd | 1129 | module_put(cpufreq_driver->owner); |
c32b6b8e | 1130 | module_out: |
1da177e4 LT |
1131 | return ret; |
1132 | } | |
1133 | ||
a82fab29 SB |
1134 | /** |
1135 | * cpufreq_add_dev - add a CPU device | |
1136 | * | |
1137 | * Adds the cpufreq interface for a CPU device. | |
1138 | * | |
1139 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1140 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1141 | * mess up, but more thorough testing is needed. - Mathieu | |
1142 | */ | |
1143 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1144 | { | |
1145 | return __cpufreq_add_dev(dev, sif, false); | |
1146 | } | |
1147 | ||
b8eed8af VK |
1148 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1149 | { | |
1150 | int j; | |
1151 | ||
1152 | policy->last_cpu = policy->cpu; | |
1153 | policy->cpu = cpu; | |
1154 | ||
3361b7b1 | 1155 | for_each_cpu(j, policy->cpus) |
b8eed8af | 1156 | per_cpu(cpufreq_policy_cpu, j) = cpu; |
b8eed8af VK |
1157 | |
1158 | #ifdef CONFIG_CPU_FREQ_TABLE | |
1159 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1160 | #endif | |
1161 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1162 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1163 | } | |
1da177e4 | 1164 | |
f9ba680d | 1165 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data, |
a82fab29 | 1166 | unsigned int old_cpu, bool frozen) |
f9ba680d SB |
1167 | { |
1168 | struct device *cpu_dev; | |
1169 | unsigned long flags; | |
1170 | int ret; | |
1171 | ||
1172 | /* first sibling now owns the new sysfs dir */ | |
1173 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
a82fab29 SB |
1174 | |
1175 | /* Don't touch sysfs files during light-weight tear-down */ | |
1176 | if (frozen) | |
1177 | return cpu_dev->id; | |
1178 | ||
f9ba680d SB |
1179 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
1180 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1181 | if (ret) { | |
1182 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1183 | ||
1184 | WARN_ON(lock_policy_rwsem_write(old_cpu)); | |
1185 | cpumask_set_cpu(old_cpu, data->cpus); | |
1186 | ||
1187 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1188 | per_cpu(cpufreq_cpu_data, old_cpu) = data; | |
1189 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1190 | ||
1191 | unlock_policy_rwsem_write(old_cpu); | |
1192 | ||
1193 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, | |
1194 | "cpufreq"); | |
1195 | ||
1196 | return -EINVAL; | |
1197 | } | |
1198 | ||
1199 | return cpu_dev->id; | |
1200 | } | |
1201 | ||
1da177e4 | 1202 | /** |
5a01f2e8 | 1203 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1204 | * |
1205 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1206 | * Caller should already have policy_rwsem in write mode for this CPU. |
1207 | * This routine frees the rwsem before returning. | |
1da177e4 | 1208 | */ |
bb176f7d | 1209 | static int __cpufreq_remove_dev(struct device *dev, |
a82fab29 | 1210 | struct subsys_interface *sif, bool frozen) |
1da177e4 | 1211 | { |
f9ba680d SB |
1212 | unsigned int cpu = dev->id, cpus; |
1213 | int new_cpu; | |
1da177e4 LT |
1214 | unsigned long flags; |
1215 | struct cpufreq_policy *data; | |
499bca9b AW |
1216 | struct kobject *kobj; |
1217 | struct completion *cmp; | |
1da177e4 | 1218 | |
b8eed8af | 1219 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1220 | |
0d1857a1 | 1221 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1222 | |
7a6aedfa | 1223 | data = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d VK |
1224 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1225 | ||
8414809c SB |
1226 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1227 | if (frozen) | |
1228 | per_cpu(cpufreq_cpu_data_fallback, cpu) = data; | |
1229 | ||
0d1857a1 | 1230 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1231 | |
1232 | if (!data) { | |
b8eed8af | 1233 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1234 | return -EINVAL; |
1235 | } | |
1da177e4 | 1236 | |
1c3d85dd | 1237 | if (cpufreq_driver->target) |
f6a7409c | 1238 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1da177e4 | 1239 | |
084f3493 | 1240 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1241 | if (!cpufreq_driver->setpolicy) |
fa69e33f DB |
1242 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
1243 | data->governor->name, CPUFREQ_NAME_LEN); | |
1da177e4 LT |
1244 | #endif |
1245 | ||
2eaa3e2d | 1246 | WARN_ON(lock_policy_rwsem_write(cpu)); |
b8eed8af | 1247 | cpus = cpumask_weight(data->cpus); |
e4969eba VK |
1248 | |
1249 | if (cpus > 1) | |
1250 | cpumask_clear_cpu(cpu, data->cpus); | |
2eaa3e2d | 1251 | unlock_policy_rwsem_write(cpu); |
084f3493 | 1252 | |
a82fab29 | 1253 | if (cpu != data->cpu && !frozen) { |
73bf0fc2 VK |
1254 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
1255 | } else if (cpus > 1) { | |
084f3493 | 1256 | |
a82fab29 | 1257 | new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu, frozen); |
f9ba680d | 1258 | if (new_cpu >= 0) { |
2eaa3e2d | 1259 | WARN_ON(lock_policy_rwsem_write(cpu)); |
f9ba680d | 1260 | update_policy_cpu(data, new_cpu); |
499bca9b | 1261 | unlock_policy_rwsem_write(cpu); |
a82fab29 SB |
1262 | |
1263 | if (!frozen) { | |
1264 | pr_debug("%s: policy Kobject moved to cpu: %d " | |
1265 | "from: %d\n",__func__, new_cpu, cpu); | |
1266 | } | |
1da177e4 LT |
1267 | } |
1268 | } | |
1da177e4 | 1269 | |
b8eed8af VK |
1270 | /* If cpu is last user of policy, free policy */ |
1271 | if (cpus == 1) { | |
2a998599 RW |
1272 | if (cpufreq_driver->target) |
1273 | __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); | |
1274 | ||
8414809c SB |
1275 | if (!frozen) { |
1276 | lock_policy_rwsem_read(cpu); | |
1277 | kobj = &data->kobj; | |
1278 | cmp = &data->kobj_unregister; | |
1279 | unlock_policy_rwsem_read(cpu); | |
1280 | kobject_put(kobj); | |
1281 | ||
1282 | /* | |
1283 | * We need to make sure that the underlying kobj is | |
1284 | * actually not referenced anymore by anybody before we | |
1285 | * proceed with unloading. | |
1286 | */ | |
1287 | pr_debug("waiting for dropping of refcount\n"); | |
1288 | wait_for_completion(cmp); | |
1289 | pr_debug("wait complete\n"); | |
1290 | } | |
7d26e2d5 | 1291 | |
8414809c SB |
1292 | /* |
1293 | * Perform the ->exit() even during light-weight tear-down, | |
1294 | * since this is a core component, and is essential for the | |
1295 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1296 | */ |
1c3d85dd RW |
1297 | if (cpufreq_driver->exit) |
1298 | cpufreq_driver->exit(data); | |
27ecddc2 | 1299 | |
8414809c SB |
1300 | if (!frozen) |
1301 | cpufreq_policy_free(data); | |
2a998599 | 1302 | } else { |
8414809c SB |
1303 | |
1304 | if (!frozen) { | |
1305 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); | |
1306 | cpufreq_cpu_put(data); | |
1307 | } | |
1308 | ||
2a998599 RW |
1309 | if (cpufreq_driver->target) { |
1310 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1311 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1312 | } | |
27ecddc2 | 1313 | } |
1da177e4 | 1314 | |
2eaa3e2d | 1315 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
1da177e4 LT |
1316 | return 0; |
1317 | } | |
1318 | ||
8a25a2fd | 1319 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1320 | { |
8a25a2fd | 1321 | unsigned int cpu = dev->id; |
5a01f2e8 | 1322 | int retval; |
ec28297a VP |
1323 | |
1324 | if (cpu_is_offline(cpu)) | |
1325 | return 0; | |
1326 | ||
a82fab29 | 1327 | retval = __cpufreq_remove_dev(dev, sif, false); |
5a01f2e8 VP |
1328 | return retval; |
1329 | } | |
1330 | ||
65f27f38 | 1331 | static void handle_update(struct work_struct *work) |
1da177e4 | 1332 | { |
65f27f38 DH |
1333 | struct cpufreq_policy *policy = |
1334 | container_of(work, struct cpufreq_policy, update); | |
1335 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1336 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1337 | cpufreq_update_policy(cpu); |
1338 | } | |
1339 | ||
1340 | /** | |
bb176f7d VK |
1341 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1342 | * in deep trouble. | |
1da177e4 LT |
1343 | * @cpu: cpu number |
1344 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1345 | * @new_freq: CPU frequency the CPU actually runs at | |
1346 | * | |
29464f28 DJ |
1347 | * We adjust to current frequency first, and need to clean up later. |
1348 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1349 | */ |
e08f5f5b GS |
1350 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1351 | unsigned int new_freq) | |
1da177e4 | 1352 | { |
b43a7ffb | 1353 | struct cpufreq_policy *policy; |
1da177e4 | 1354 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1355 | unsigned long flags; |
1356 | ||
2d06d8c4 | 1357 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1358 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1359 | ||
1da177e4 LT |
1360 | freqs.old = old_freq; |
1361 | freqs.new = new_freq; | |
b43a7ffb VK |
1362 | |
1363 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1364 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1365 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1366 | ||
1367 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1368 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1369 | } |
1370 | ||
32ee8c3e | 1371 | /** |
4ab70df4 | 1372 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1373 | * @cpu: CPU number |
1374 | * | |
1375 | * This is the last known freq, without actually getting it from the driver. | |
1376 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1377 | */ | |
1378 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1379 | { | |
9e21ba8b | 1380 | struct cpufreq_policy *policy; |
e08f5f5b | 1381 | unsigned int ret_freq = 0; |
95235ca2 | 1382 | |
1c3d85dd RW |
1383 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1384 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1385 | |
1386 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1387 | if (policy) { |
e08f5f5b | 1388 | ret_freq = policy->cur; |
95235ca2 VP |
1389 | cpufreq_cpu_put(policy); |
1390 | } | |
1391 | ||
4d34a67d | 1392 | return ret_freq; |
95235ca2 VP |
1393 | } |
1394 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1395 | ||
3d737108 JB |
1396 | /** |
1397 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1398 | * @cpu: CPU number | |
1399 | * | |
1400 | * Just return the max possible frequency for a given CPU. | |
1401 | */ | |
1402 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1403 | { | |
1404 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1405 | unsigned int ret_freq = 0; | |
1406 | ||
1407 | if (policy) { | |
1408 | ret_freq = policy->max; | |
1409 | cpufreq_cpu_put(policy); | |
1410 | } | |
1411 | ||
1412 | return ret_freq; | |
1413 | } | |
1414 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1415 | ||
5a01f2e8 | 1416 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1417 | { |
7a6aedfa | 1418 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1419 | unsigned int ret_freq = 0; |
5800043b | 1420 | |
1c3d85dd | 1421 | if (!cpufreq_driver->get) |
4d34a67d | 1422 | return ret_freq; |
1da177e4 | 1423 | |
1c3d85dd | 1424 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1425 | |
e08f5f5b | 1426 | if (ret_freq && policy->cur && |
1c3d85dd | 1427 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1428 | /* verify no discrepancy between actual and |
1429 | saved value exists */ | |
1430 | if (unlikely(ret_freq != policy->cur)) { | |
1431 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1432 | schedule_work(&policy->update); |
1433 | } | |
1434 | } | |
1435 | ||
4d34a67d | 1436 | return ret_freq; |
5a01f2e8 | 1437 | } |
1da177e4 | 1438 | |
5a01f2e8 VP |
1439 | /** |
1440 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1441 | * @cpu: CPU number | |
1442 | * | |
1443 | * Get the CPU current (static) CPU frequency | |
1444 | */ | |
1445 | unsigned int cpufreq_get(unsigned int cpu) | |
1446 | { | |
1447 | unsigned int ret_freq = 0; | |
1448 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1449 | ||
1450 | if (!policy) | |
1451 | goto out; | |
1452 | ||
1453 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1454 | goto out_policy; | |
1455 | ||
1456 | ret_freq = __cpufreq_get(cpu); | |
1457 | ||
1458 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1459 | |
5a01f2e8 VP |
1460 | out_policy: |
1461 | cpufreq_cpu_put(policy); | |
1462 | out: | |
4d34a67d | 1463 | return ret_freq; |
1da177e4 LT |
1464 | } |
1465 | EXPORT_SYMBOL(cpufreq_get); | |
1466 | ||
8a25a2fd KS |
1467 | static struct subsys_interface cpufreq_interface = { |
1468 | .name = "cpufreq", | |
1469 | .subsys = &cpu_subsys, | |
1470 | .add_dev = cpufreq_add_dev, | |
1471 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1472 | }; |
1473 | ||
42d4dc3f | 1474 | /** |
e00e56df RW |
1475 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1476 | * | |
1477 | * This function is only executed for the boot processor. The other CPUs | |
1478 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1479 | */ |
e00e56df | 1480 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1481 | { |
e08f5f5b | 1482 | int ret = 0; |
4bc5d341 | 1483 | |
e00e56df | 1484 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1485 | struct cpufreq_policy *cpu_policy; |
1486 | ||
2d06d8c4 | 1487 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1488 | |
e00e56df | 1489 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1490 | cpu_policy = cpufreq_cpu_get(cpu); |
1491 | if (!cpu_policy) | |
e00e56df | 1492 | return 0; |
42d4dc3f | 1493 | |
1c3d85dd RW |
1494 | if (cpufreq_driver->suspend) { |
1495 | ret = cpufreq_driver->suspend(cpu_policy); | |
ce6c3997 | 1496 | if (ret) |
42d4dc3f BH |
1497 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1498 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1499 | } |
1500 | ||
42d4dc3f | 1501 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1502 | return ret; |
42d4dc3f BH |
1503 | } |
1504 | ||
1da177e4 | 1505 | /** |
e00e56df | 1506 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1507 | * |
1508 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1509 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1510 | * restored. It will verify that the current freq is in sync with | |
1511 | * what we believe it to be. This is a bit later than when it | |
1512 | * should be, but nonethteless it's better than calling | |
1513 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1514 | * |
1515 | * This function is only executed for the boot CPU. The other CPUs have not | |
1516 | * been turned on yet. | |
1da177e4 | 1517 | */ |
e00e56df | 1518 | static void cpufreq_bp_resume(void) |
1da177e4 | 1519 | { |
e08f5f5b | 1520 | int ret = 0; |
4bc5d341 | 1521 | |
e00e56df | 1522 | int cpu = smp_processor_id(); |
1da177e4 LT |
1523 | struct cpufreq_policy *cpu_policy; |
1524 | ||
2d06d8c4 | 1525 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1526 | |
e00e56df | 1527 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1528 | cpu_policy = cpufreq_cpu_get(cpu); |
1529 | if (!cpu_policy) | |
e00e56df | 1530 | return; |
1da177e4 | 1531 | |
1c3d85dd RW |
1532 | if (cpufreq_driver->resume) { |
1533 | ret = cpufreq_driver->resume(cpu_policy); | |
1da177e4 LT |
1534 | if (ret) { |
1535 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1536 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1537 | goto fail; |
1da177e4 LT |
1538 | } |
1539 | } | |
1540 | ||
1da177e4 | 1541 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1542 | |
c9060494 | 1543 | fail: |
1da177e4 | 1544 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1545 | } |
1546 | ||
e00e56df RW |
1547 | static struct syscore_ops cpufreq_syscore_ops = { |
1548 | .suspend = cpufreq_bp_suspend, | |
1549 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1550 | }; |
1551 | ||
9d95046e BP |
1552 | /** |
1553 | * cpufreq_get_current_driver - return current driver's name | |
1554 | * | |
1555 | * Return the name string of the currently loaded cpufreq driver | |
1556 | * or NULL, if none. | |
1557 | */ | |
1558 | const char *cpufreq_get_current_driver(void) | |
1559 | { | |
1c3d85dd RW |
1560 | if (cpufreq_driver) |
1561 | return cpufreq_driver->name; | |
1562 | ||
1563 | return NULL; | |
9d95046e BP |
1564 | } |
1565 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1566 | |
1567 | /********************************************************************* | |
1568 | * NOTIFIER LISTS INTERFACE * | |
1569 | *********************************************************************/ | |
1570 | ||
1571 | /** | |
1572 | * cpufreq_register_notifier - register a driver with cpufreq | |
1573 | * @nb: notifier function to register | |
1574 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1575 | * | |
32ee8c3e | 1576 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1577 | * are notified about clock rate changes (once before and once after |
1578 | * the transition), or a list of drivers that are notified about | |
1579 | * changes in cpufreq policy. | |
1580 | * | |
1581 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1582 | * blocking_notifier_chain_register. |
1da177e4 LT |
1583 | */ |
1584 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1585 | { | |
1586 | int ret; | |
1587 | ||
d5aaffa9 DB |
1588 | if (cpufreq_disabled()) |
1589 | return -EINVAL; | |
1590 | ||
74212ca4 CEB |
1591 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1592 | ||
1da177e4 LT |
1593 | switch (list) { |
1594 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1595 | ret = srcu_notifier_chain_register( |
e041c683 | 1596 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1597 | break; |
1598 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1599 | ret = blocking_notifier_chain_register( |
1600 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1601 | break; |
1602 | default: | |
1603 | ret = -EINVAL; | |
1604 | } | |
1da177e4 LT |
1605 | |
1606 | return ret; | |
1607 | } | |
1608 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1609 | ||
1da177e4 LT |
1610 | /** |
1611 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1612 | * @nb: notifier block to be unregistered | |
bb176f7d | 1613 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1614 | * |
1615 | * Remove a driver from the CPU frequency notifier list. | |
1616 | * | |
1617 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1618 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1619 | */ |
1620 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1621 | { | |
1622 | int ret; | |
1623 | ||
d5aaffa9 DB |
1624 | if (cpufreq_disabled()) |
1625 | return -EINVAL; | |
1626 | ||
1da177e4 LT |
1627 | switch (list) { |
1628 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1629 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1630 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1631 | break; |
1632 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1633 | ret = blocking_notifier_chain_unregister( |
1634 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1635 | break; |
1636 | default: | |
1637 | ret = -EINVAL; | |
1638 | } | |
1da177e4 LT |
1639 | |
1640 | return ret; | |
1641 | } | |
1642 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1643 | ||
1644 | ||
1645 | /********************************************************************* | |
1646 | * GOVERNORS * | |
1647 | *********************************************************************/ | |
1648 | ||
1da177e4 LT |
1649 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1650 | unsigned int target_freq, | |
1651 | unsigned int relation) | |
1652 | { | |
1653 | int retval = -EINVAL; | |
7249924e | 1654 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1655 | |
a7b422cd KRW |
1656 | if (cpufreq_disabled()) |
1657 | return -ENODEV; | |
7c30ed53 VK |
1658 | if (policy->transition_ongoing) |
1659 | return -EBUSY; | |
a7b422cd | 1660 | |
7249924e VK |
1661 | /* Make sure that target_freq is within supported range */ |
1662 | if (target_freq > policy->max) | |
1663 | target_freq = policy->max; | |
1664 | if (target_freq < policy->min) | |
1665 | target_freq = policy->min; | |
1666 | ||
1667 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1668 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1669 | |
1670 | if (target_freq == policy->cur) | |
1671 | return 0; | |
1672 | ||
1c3d85dd RW |
1673 | if (cpufreq_driver->target) |
1674 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1675 | |
1da177e4 LT |
1676 | return retval; |
1677 | } | |
1678 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1679 | ||
1da177e4 LT |
1680 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1681 | unsigned int target_freq, | |
1682 | unsigned int relation) | |
1683 | { | |
f1829e4a | 1684 | int ret = -EINVAL; |
1da177e4 | 1685 | |
5a01f2e8 | 1686 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1687 | goto fail; |
1da177e4 LT |
1688 | |
1689 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1690 | ||
5a01f2e8 | 1691 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1692 | |
f1829e4a | 1693 | fail: |
1da177e4 LT |
1694 | return ret; |
1695 | } | |
1696 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1697 | ||
bf0b90e3 | 1698 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 | 1699 | { |
d5aaffa9 | 1700 | if (cpufreq_disabled()) |
a262e94c | 1701 | return 0; |
d5aaffa9 | 1702 | |
1c3d85dd | 1703 | if (!cpufreq_driver->getavg) |
0676f7f2 VK |
1704 | return 0; |
1705 | ||
a262e94c | 1706 | return cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1707 | } |
5a01f2e8 | 1708 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1709 | |
153d7f3f | 1710 | /* |
153d7f3f AV |
1711 | * when "event" is CPUFREQ_GOV_LIMITS |
1712 | */ | |
1da177e4 | 1713 | |
e08f5f5b GS |
1714 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1715 | unsigned int event) | |
1da177e4 | 1716 | { |
cc993cab | 1717 | int ret; |
6afde10c TR |
1718 | |
1719 | /* Only must be defined when default governor is known to have latency | |
1720 | restrictions, like e.g. conservative or ondemand. | |
1721 | That this is the case is already ensured in Kconfig | |
1722 | */ | |
1723 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1724 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1725 | #else | |
1726 | struct cpufreq_governor *gov = NULL; | |
1727 | #endif | |
1c256245 TR |
1728 | |
1729 | if (policy->governor->max_transition_latency && | |
1730 | policy->cpuinfo.transition_latency > | |
1731 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1732 | if (!gov) |
1733 | return -EINVAL; | |
1734 | else { | |
1735 | printk(KERN_WARNING "%s governor failed, too long" | |
1736 | " transition latency of HW, fallback" | |
1737 | " to %s governor\n", | |
1738 | policy->governor->name, | |
1739 | gov->name); | |
1740 | policy->governor = gov; | |
1741 | } | |
1c256245 | 1742 | } |
1da177e4 LT |
1743 | |
1744 | if (!try_module_get(policy->governor->owner)) | |
1745 | return -EINVAL; | |
1746 | ||
2d06d8c4 | 1747 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1748 | policy->cpu, event); |
95731ebb XC |
1749 | |
1750 | mutex_lock(&cpufreq_governor_lock); | |
1751 | if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) || | |
1752 | (policy->governor_enabled && (event == CPUFREQ_GOV_START))) { | |
1753 | mutex_unlock(&cpufreq_governor_lock); | |
1754 | return -EBUSY; | |
1755 | } | |
1756 | ||
1757 | if (event == CPUFREQ_GOV_STOP) | |
1758 | policy->governor_enabled = false; | |
1759 | else if (event == CPUFREQ_GOV_START) | |
1760 | policy->governor_enabled = true; | |
1761 | ||
1762 | mutex_unlock(&cpufreq_governor_lock); | |
1763 | ||
1da177e4 LT |
1764 | ret = policy->governor->governor(policy, event); |
1765 | ||
4d5dcc42 VK |
1766 | if (!ret) { |
1767 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1768 | policy->governor->initialized++; | |
1769 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1770 | policy->governor->initialized--; | |
95731ebb XC |
1771 | } else { |
1772 | /* Restore original values */ | |
1773 | mutex_lock(&cpufreq_governor_lock); | |
1774 | if (event == CPUFREQ_GOV_STOP) | |
1775 | policy->governor_enabled = true; | |
1776 | else if (event == CPUFREQ_GOV_START) | |
1777 | policy->governor_enabled = false; | |
1778 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1779 | } |
b394058f | 1780 | |
e08f5f5b GS |
1781 | /* we keep one module reference alive for |
1782 | each CPU governed by this CPU */ | |
1da177e4 LT |
1783 | if ((event != CPUFREQ_GOV_START) || ret) |
1784 | module_put(policy->governor->owner); | |
1785 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1786 | module_put(policy->governor->owner); | |
1787 | ||
1788 | return ret; | |
1789 | } | |
1790 | ||
1da177e4 LT |
1791 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1792 | { | |
3bcb09a3 | 1793 | int err; |
1da177e4 LT |
1794 | |
1795 | if (!governor) | |
1796 | return -EINVAL; | |
1797 | ||
a7b422cd KRW |
1798 | if (cpufreq_disabled()) |
1799 | return -ENODEV; | |
1800 | ||
3fc54d37 | 1801 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1802 | |
b394058f | 1803 | governor->initialized = 0; |
3bcb09a3 JF |
1804 | err = -EBUSY; |
1805 | if (__find_governor(governor->name) == NULL) { | |
1806 | err = 0; | |
1807 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1808 | } |
1da177e4 | 1809 | |
32ee8c3e | 1810 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1811 | return err; |
1da177e4 LT |
1812 | } |
1813 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1814 | ||
1da177e4 LT |
1815 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1816 | { | |
90e41bac PB |
1817 | #ifdef CONFIG_HOTPLUG_CPU |
1818 | int cpu; | |
1819 | #endif | |
1820 | ||
1da177e4 LT |
1821 | if (!governor) |
1822 | return; | |
1823 | ||
a7b422cd KRW |
1824 | if (cpufreq_disabled()) |
1825 | return; | |
1826 | ||
90e41bac PB |
1827 | #ifdef CONFIG_HOTPLUG_CPU |
1828 | for_each_present_cpu(cpu) { | |
1829 | if (cpu_online(cpu)) | |
1830 | continue; | |
1831 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1832 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1833 | } | |
1834 | #endif | |
1835 | ||
3fc54d37 | 1836 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1837 | list_del(&governor->governor_list); |
3fc54d37 | 1838 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1839 | return; |
1840 | } | |
1841 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1842 | ||
1843 | ||
1da177e4 LT |
1844 | /********************************************************************* |
1845 | * POLICY INTERFACE * | |
1846 | *********************************************************************/ | |
1847 | ||
1848 | /** | |
1849 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1850 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1851 | * is written | |
1da177e4 LT |
1852 | * |
1853 | * Reads the current cpufreq policy. | |
1854 | */ | |
1855 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1856 | { | |
1857 | struct cpufreq_policy *cpu_policy; | |
1858 | if (!policy) | |
1859 | return -EINVAL; | |
1860 | ||
1861 | cpu_policy = cpufreq_cpu_get(cpu); | |
1862 | if (!cpu_policy) | |
1863 | return -EINVAL; | |
1864 | ||
1da177e4 | 1865 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1866 | |
1867 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1868 | return 0; |
1869 | } | |
1870 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1871 | ||
153d7f3f | 1872 | /* |
e08f5f5b GS |
1873 | * data : current policy. |
1874 | * policy : policy to be set. | |
153d7f3f | 1875 | */ |
e08f5f5b GS |
1876 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1877 | struct cpufreq_policy *policy) | |
1da177e4 | 1878 | { |
7bd353a9 | 1879 | int ret = 0, failed = 1; |
1da177e4 | 1880 | |
2d06d8c4 | 1881 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1882 | policy->min, policy->max); |
1883 | ||
e08f5f5b GS |
1884 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1885 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1886 | |
53391fa2 | 1887 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1888 | ret = -EINVAL; |
1889 | goto error_out; | |
1890 | } | |
1891 | ||
1da177e4 | 1892 | /* verify the cpu speed can be set within this limit */ |
1c3d85dd | 1893 | ret = cpufreq_driver->verify(policy); |
1da177e4 LT |
1894 | if (ret) |
1895 | goto error_out; | |
1896 | ||
1da177e4 | 1897 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1898 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1899 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1900 | |
1901 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1902 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1903 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 | 1904 | |
bb176f7d VK |
1905 | /* |
1906 | * verify the cpu speed can be set within this limit, which might be | |
1907 | * different to the first one | |
1908 | */ | |
1c3d85dd | 1909 | ret = cpufreq_driver->verify(policy); |
e041c683 | 1910 | if (ret) |
1da177e4 | 1911 | goto error_out; |
1da177e4 LT |
1912 | |
1913 | /* notification of the new policy */ | |
e041c683 AS |
1914 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1915 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1916 | |
7d5e350f DJ |
1917 | data->min = policy->min; |
1918 | data->max = policy->max; | |
1da177e4 | 1919 | |
2d06d8c4 | 1920 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1921 | data->min, data->max); |
1da177e4 | 1922 | |
1c3d85dd | 1923 | if (cpufreq_driver->setpolicy) { |
1da177e4 | 1924 | data->policy = policy->policy; |
2d06d8c4 | 1925 | pr_debug("setting range\n"); |
1c3d85dd | 1926 | ret = cpufreq_driver->setpolicy(policy); |
1da177e4 LT |
1927 | } else { |
1928 | if (policy->governor != data->governor) { | |
1929 | /* save old, working values */ | |
1930 | struct cpufreq_governor *old_gov = data->governor; | |
1931 | ||
2d06d8c4 | 1932 | pr_debug("governor switch\n"); |
1da177e4 LT |
1933 | |
1934 | /* end old governor */ | |
7bd353a9 | 1935 | if (data->governor) { |
1da177e4 | 1936 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
955ef483 | 1937 | unlock_policy_rwsem_write(policy->cpu); |
7bd353a9 VK |
1938 | __cpufreq_governor(data, |
1939 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 | 1940 | lock_policy_rwsem_write(policy->cpu); |
7bd353a9 | 1941 | } |
1da177e4 LT |
1942 | |
1943 | /* start new governor */ | |
1944 | data->governor = policy->governor; | |
7bd353a9 | 1945 | if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { |
955ef483 | 1946 | if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) { |
7bd353a9 | 1947 | failed = 0; |
955ef483 VK |
1948 | } else { |
1949 | unlock_policy_rwsem_write(policy->cpu); | |
7bd353a9 VK |
1950 | __cpufreq_governor(data, |
1951 | CPUFREQ_GOV_POLICY_EXIT); | |
955ef483 VK |
1952 | lock_policy_rwsem_write(policy->cpu); |
1953 | } | |
7bd353a9 VK |
1954 | } |
1955 | ||
1956 | if (failed) { | |
1da177e4 | 1957 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1958 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1959 | data->governor->name); |
1da177e4 LT |
1960 | if (old_gov) { |
1961 | data->governor = old_gov; | |
7bd353a9 VK |
1962 | __cpufreq_governor(data, |
1963 | CPUFREQ_GOV_POLICY_INIT); | |
e08f5f5b GS |
1964 | __cpufreq_governor(data, |
1965 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1966 | } |
1967 | ret = -EINVAL; | |
1968 | goto error_out; | |
1969 | } | |
1970 | /* might be a policy change, too, so fall through */ | |
1971 | } | |
2d06d8c4 | 1972 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1973 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1974 | } | |
1975 | ||
7d5e350f | 1976 | error_out: |
1da177e4 LT |
1977 | return ret; |
1978 | } | |
1979 | ||
1da177e4 LT |
1980 | /** |
1981 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1982 | * @cpu: CPU which shall be re-evaluated | |
1983 | * | |
25985edc | 1984 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1985 | * at different times. |
1986 | */ | |
1987 | int cpufreq_update_policy(unsigned int cpu) | |
1988 | { | |
1989 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1990 | struct cpufreq_policy policy; | |
f1829e4a | 1991 | int ret; |
1da177e4 | 1992 | |
f1829e4a JL |
1993 | if (!data) { |
1994 | ret = -ENODEV; | |
1995 | goto no_policy; | |
1996 | } | |
1da177e4 | 1997 | |
f1829e4a JL |
1998 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1999 | ret = -EINVAL; | |
2000 | goto fail; | |
2001 | } | |
1da177e4 | 2002 | |
2d06d8c4 | 2003 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 2004 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
2005 | policy.min = data->user_policy.min; |
2006 | policy.max = data->user_policy.max; | |
2007 | policy.policy = data->user_policy.policy; | |
2008 | policy.governor = data->user_policy.governor; | |
2009 | ||
bb176f7d VK |
2010 | /* |
2011 | * BIOS might change freq behind our back | |
2012 | * -> ask driver for current freq and notify governors about a change | |
2013 | */ | |
1c3d85dd RW |
2014 | if (cpufreq_driver->get) { |
2015 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 2016 | if (!data->cur) { |
2d06d8c4 | 2017 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
2018 | data->cur = policy.cur; |
2019 | } else { | |
1c3d85dd | 2020 | if (data->cur != policy.cur && cpufreq_driver->target) |
e08f5f5b GS |
2021 | cpufreq_out_of_sync(cpu, data->cur, |
2022 | policy.cur); | |
a85f7bd3 | 2023 | } |
0961dd0d TR |
2024 | } |
2025 | ||
1da177e4 LT |
2026 | ret = __cpufreq_set_policy(data, &policy); |
2027 | ||
5a01f2e8 VP |
2028 | unlock_policy_rwsem_write(cpu); |
2029 | ||
f1829e4a | 2030 | fail: |
1da177e4 | 2031 | cpufreq_cpu_put(data); |
f1829e4a | 2032 | no_policy: |
1da177e4 LT |
2033 | return ret; |
2034 | } | |
2035 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2036 | ||
2760984f | 2037 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2038 | unsigned long action, void *hcpu) |
2039 | { | |
2040 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2041 | struct device *dev; |
5302c3fb | 2042 | bool frozen = false; |
c32b6b8e | 2043 | |
8a25a2fd KS |
2044 | dev = get_cpu_device(cpu); |
2045 | if (dev) { | |
5302c3fb SB |
2046 | |
2047 | if (action & CPU_TASKS_FROZEN) | |
2048 | frozen = true; | |
2049 | ||
2050 | switch (action & ~CPU_TASKS_FROZEN) { | |
c32b6b8e | 2051 | case CPU_ONLINE: |
5302c3fb | 2052 | __cpufreq_add_dev(dev, NULL, frozen); |
23d32899 | 2053 | cpufreq_update_policy(cpu); |
c32b6b8e | 2054 | break; |
5302c3fb | 2055 | |
c32b6b8e | 2056 | case CPU_DOWN_PREPARE: |
5302c3fb | 2057 | __cpufreq_remove_dev(dev, NULL, frozen); |
c32b6b8e | 2058 | break; |
5302c3fb | 2059 | |
5a01f2e8 | 2060 | case CPU_DOWN_FAILED: |
5302c3fb | 2061 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2062 | break; |
2063 | } | |
2064 | } | |
2065 | return NOTIFY_OK; | |
2066 | } | |
2067 | ||
9c36f746 | 2068 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2069 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2070 | }; |
1da177e4 LT |
2071 | |
2072 | /********************************************************************* | |
2073 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2074 | *********************************************************************/ | |
2075 | ||
2076 | /** | |
2077 | * cpufreq_register_driver - register a CPU Frequency driver | |
2078 | * @driver_data: A struct cpufreq_driver containing the values# | |
2079 | * submitted by the CPU Frequency driver. | |
2080 | * | |
bb176f7d | 2081 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2082 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2083 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2084 | * |
2085 | */ | |
221dee28 | 2086 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2087 | { |
2088 | unsigned long flags; | |
2089 | int ret; | |
2090 | ||
a7b422cd KRW |
2091 | if (cpufreq_disabled()) |
2092 | return -ENODEV; | |
2093 | ||
1da177e4 LT |
2094 | if (!driver_data || !driver_data->verify || !driver_data->init || |
2095 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2096 | return -EINVAL; | |
2097 | ||
2d06d8c4 | 2098 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2099 | |
2100 | if (driver_data->setpolicy) | |
2101 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2102 | ||
0d1857a1 | 2103 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2104 | if (cpufreq_driver) { |
0d1857a1 | 2105 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2106 | return -EBUSY; |
2107 | } | |
1c3d85dd | 2108 | cpufreq_driver = driver_data; |
0d1857a1 | 2109 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2110 | |
8a25a2fd | 2111 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2112 | if (ret) |
2113 | goto err_null_driver; | |
1da177e4 | 2114 | |
1c3d85dd | 2115 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2116 | int i; |
2117 | ret = -ENODEV; | |
2118 | ||
2119 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2120 | for (i = 0; i < nr_cpu_ids; i++) |
2121 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2122 | ret = 0; |
7a6aedfa MT |
2123 | break; |
2124 | } | |
1da177e4 LT |
2125 | |
2126 | /* if all ->init() calls failed, unregister */ | |
2127 | if (ret) { | |
2d06d8c4 | 2128 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2129 | driver_data->name); |
8a25a2fd | 2130 | goto err_if_unreg; |
1da177e4 LT |
2131 | } |
2132 | } | |
2133 | ||
8f5bc2ab | 2134 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2135 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2136 | |
8f5bc2ab | 2137 | return 0; |
8a25a2fd KS |
2138 | err_if_unreg: |
2139 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2140 | err_null_driver: |
0d1857a1 | 2141 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2142 | cpufreq_driver = NULL; |
0d1857a1 | 2143 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2144 | return ret; |
1da177e4 LT |
2145 | } |
2146 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2147 | ||
1da177e4 LT |
2148 | /** |
2149 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2150 | * | |
bb176f7d | 2151 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2152 | * the right to do so, i.e. if you have succeeded in initialising before! |
2153 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2154 | * currently not initialised. | |
2155 | */ | |
221dee28 | 2156 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2157 | { |
2158 | unsigned long flags; | |
2159 | ||
1c3d85dd | 2160 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2161 | return -EINVAL; |
1da177e4 | 2162 | |
2d06d8c4 | 2163 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2164 | |
8a25a2fd | 2165 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2166 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2167 | |
0d1857a1 | 2168 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2169 | cpufreq_driver = NULL; |
0d1857a1 | 2170 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
2171 | |
2172 | return 0; | |
2173 | } | |
2174 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2175 | |
2176 | static int __init cpufreq_core_init(void) | |
2177 | { | |
2178 | int cpu; | |
2179 | ||
a7b422cd KRW |
2180 | if (cpufreq_disabled()) |
2181 | return -ENODEV; | |
2182 | ||
5a01f2e8 | 2183 | for_each_possible_cpu(cpu) { |
f1625066 | 2184 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
2185 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
2186 | } | |
8aa84ad8 | 2187 | |
2361be23 | 2188 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2189 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2190 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2191 | |
5a01f2e8 VP |
2192 | return 0; |
2193 | } | |
5a01f2e8 | 2194 | core_initcall(cpufreq_core_init); |