]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
bb176f7d | 6 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> |
1da177e4 | 7 | * |
c32b6b8e | 8 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 9 | * Added handling for CPU hotplug |
8ff69732 DJ |
10 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
11 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 12 | * |
1da177e4 LT |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
1da177e4 LT |
16 | */ |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
5ff0a268 | 20 | #include <linux/cpu.h> |
1da177e4 LT |
21 | #include <linux/cpufreq.h> |
22 | #include <linux/delay.h> | |
1da177e4 | 23 | #include <linux/device.h> |
5ff0a268 VK |
24 | #include <linux/init.h> |
25 | #include <linux/kernel_stat.h> | |
26 | #include <linux/module.h> | |
3fc54d37 | 27 | #include <linux/mutex.h> |
5ff0a268 | 28 | #include <linux/slab.h> |
e00e56df | 29 | #include <linux/syscore_ops.h> |
5ff0a268 | 30 | #include <linux/tick.h> |
6f4f2723 TR |
31 | #include <trace/events/power.h> |
32 | ||
1da177e4 | 33 | /** |
cd878479 | 34 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
35 | * level driver of CPUFreq support, and its spinlock. This lock |
36 | * also protects the cpufreq_cpu_data array. | |
37 | */ | |
1c3d85dd | 38 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 39 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
8414809c | 40 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback); |
bb176f7d VK |
41 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
42 | static DEFINE_MUTEX(cpufreq_governor_lock); | |
c88a1f8b | 43 | static LIST_HEAD(cpufreq_policy_list); |
bb176f7d | 44 | |
084f3493 TR |
45 | #ifdef CONFIG_HOTPLUG_CPU |
46 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 47 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 48 | #endif |
1da177e4 | 49 | |
5a01f2e8 VP |
50 | /* |
51 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
52 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
53 | * | |
54 | * The rules for this semaphore: | |
55 | * - Any routine that wants to read from the policy structure will | |
56 | * do a down_read on this semaphore. | |
57 | * - Any routine that will write to the policy structure and/or may take away | |
58 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
59 | * mode before doing so. | |
60 | * | |
61 | * Additional rules: | |
5a01f2e8 VP |
62 | * - Governor routines that can be called in cpufreq hotplug path should not |
63 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
64 | * - Lock should not be held across |
65 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 66 | */ |
5a01f2e8 VP |
67 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
68 | ||
69 | #define lock_policy_rwsem(mode, cpu) \ | |
1b750e3b | 70 | static void lock_policy_rwsem_##mode(int cpu) \ |
5a01f2e8 | 71 | { \ |
474deff7 VK |
72 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
73 | BUG_ON(!policy); \ | |
74 | down_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 VP |
75 | } |
76 | ||
77 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 | 78 | lock_policy_rwsem(write, cpu); |
5a01f2e8 | 79 | |
fa1d8af4 VK |
80 | #define unlock_policy_rwsem(mode, cpu) \ |
81 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
82 | { \ | |
474deff7 VK |
83 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \ |
84 | BUG_ON(!policy); \ | |
85 | up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu)); \ | |
5a01f2e8 | 86 | } |
5a01f2e8 | 87 | |
fa1d8af4 VK |
88 | unlock_policy_rwsem(read, cpu); |
89 | unlock_policy_rwsem(write, cpu); | |
5a01f2e8 | 90 | |
6eed9404 VK |
91 | /* |
92 | * rwsem to guarantee that cpufreq driver module doesn't unload during critical | |
93 | * sections | |
94 | */ | |
95 | static DECLARE_RWSEM(cpufreq_rwsem); | |
96 | ||
1da177e4 | 97 | /* internal prototypes */ |
29464f28 DJ |
98 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
99 | unsigned int event); | |
5a01f2e8 | 100 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 101 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
102 | |
103 | /** | |
32ee8c3e DJ |
104 | * Two notifier lists: the "policy" list is involved in the |
105 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
106 | * "transition" list for kernel code that needs to handle |
107 | * changes to devices when the CPU clock speed changes. | |
108 | * The mutex locks both lists. | |
109 | */ | |
e041c683 | 110 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 111 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 112 | |
74212ca4 | 113 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
114 | static int __init init_cpufreq_transition_notifier_list(void) |
115 | { | |
116 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 117 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
118 | return 0; |
119 | } | |
b3438f82 | 120 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 121 | |
a7b422cd | 122 | static int off __read_mostly; |
da584455 | 123 | static int cpufreq_disabled(void) |
a7b422cd KRW |
124 | { |
125 | return off; | |
126 | } | |
127 | void disable_cpufreq(void) | |
128 | { | |
129 | off = 1; | |
130 | } | |
1da177e4 | 131 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 132 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 133 | |
4d5dcc42 VK |
134 | bool have_governor_per_policy(void) |
135 | { | |
1c3d85dd | 136 | return cpufreq_driver->have_governor_per_policy; |
4d5dcc42 | 137 | } |
3f869d6d | 138 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 139 | |
944e9a03 VK |
140 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
141 | { | |
142 | if (have_governor_per_policy()) | |
143 | return &policy->kobj; | |
144 | else | |
145 | return cpufreq_global_kobject; | |
146 | } | |
147 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
148 | ||
72a4ce34 VK |
149 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
150 | { | |
151 | u64 idle_time; | |
152 | u64 cur_wall_time; | |
153 | u64 busy_time; | |
154 | ||
155 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
156 | ||
157 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
158 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
159 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
160 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
161 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
162 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
163 | ||
164 | idle_time = cur_wall_time - busy_time; | |
165 | if (wall) | |
166 | *wall = cputime_to_usecs(cur_wall_time); | |
167 | ||
168 | return cputime_to_usecs(idle_time); | |
169 | } | |
170 | ||
171 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
172 | { | |
173 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
174 | ||
175 | if (idle_time == -1ULL) | |
176 | return get_cpu_idle_time_jiffy(cpu, wall); | |
177 | else if (!io_busy) | |
178 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
179 | ||
180 | return idle_time; | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
183 | ||
6eed9404 | 184 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 185 | { |
6eed9404 | 186 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
187 | unsigned long flags; |
188 | ||
6eed9404 VK |
189 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
190 | return NULL; | |
191 | ||
192 | if (!down_read_trylock(&cpufreq_rwsem)) | |
193 | return NULL; | |
1da177e4 LT |
194 | |
195 | /* get the cpufreq driver */ | |
1c3d85dd | 196 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 197 | |
6eed9404 VK |
198 | if (cpufreq_driver) { |
199 | /* get the CPU */ | |
200 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
201 | if (policy) | |
202 | kobject_get(&policy->kobj); | |
203 | } | |
1da177e4 | 204 | |
6eed9404 | 205 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 206 | |
3a3e9e06 | 207 | if (!policy) |
6eed9404 | 208 | up_read(&cpufreq_rwsem); |
1da177e4 | 209 | |
3a3e9e06 | 210 | return policy; |
a9144436 | 211 | } |
1da177e4 LT |
212 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
213 | ||
3a3e9e06 | 214 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 215 | { |
d5aaffa9 DB |
216 | if (cpufreq_disabled()) |
217 | return; | |
218 | ||
6eed9404 VK |
219 | kobject_put(&policy->kobj); |
220 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
221 | } |
222 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
223 | ||
1da177e4 LT |
224 | /********************************************************************* |
225 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
226 | *********************************************************************/ | |
227 | ||
228 | /** | |
229 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
230 | * | |
231 | * This function alters the system "loops_per_jiffy" for the clock | |
232 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 233 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
234 | * per-CPU loops_per_jiffy value wherever possible. |
235 | */ | |
236 | #ifndef CONFIG_SMP | |
237 | static unsigned long l_p_j_ref; | |
bb176f7d | 238 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 239 | |
858119e1 | 240 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
241 | { |
242 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
243 | return; | |
244 | ||
245 | if (!l_p_j_ref_freq) { | |
246 | l_p_j_ref = loops_per_jiffy; | |
247 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 248 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 249 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 250 | } |
bb176f7d | 251 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 252 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
253 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
254 | ci->new); | |
2d06d8c4 | 255 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 256 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
257 | } |
258 | } | |
259 | #else | |
e08f5f5b GS |
260 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
261 | { | |
262 | return; | |
263 | } | |
1da177e4 LT |
264 | #endif |
265 | ||
0956df9c | 266 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 267 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
268 | { |
269 | BUG_ON(irqs_disabled()); | |
270 | ||
d5aaffa9 DB |
271 | if (cpufreq_disabled()) |
272 | return; | |
273 | ||
1c3d85dd | 274 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 275 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 276 | state, freqs->new); |
1da177e4 | 277 | |
1da177e4 | 278 | switch (state) { |
e4472cb3 | 279 | |
1da177e4 | 280 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 281 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
282 | * which is not equal to what the cpufreq core thinks is |
283 | * "old frequency". | |
1da177e4 | 284 | */ |
1c3d85dd | 285 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
286 | if ((policy) && (policy->cpu == freqs->cpu) && |
287 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 288 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
289 | " %u, cpufreq assumed %u kHz.\n", |
290 | freqs->old, policy->cur); | |
291 | freqs->old = policy->cur; | |
1da177e4 LT |
292 | } |
293 | } | |
b4dfdbb3 | 294 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 295 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
296 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
297 | break; | |
e4472cb3 | 298 | |
1da177e4 LT |
299 | case CPUFREQ_POSTCHANGE: |
300 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 301 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 | 302 | (unsigned long)freqs->cpu); |
25e41933 | 303 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 304 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 305 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
306 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
307 | policy->cur = freqs->new; | |
1da177e4 LT |
308 | break; |
309 | } | |
1da177e4 | 310 | } |
bb176f7d | 311 | |
b43a7ffb VK |
312 | /** |
313 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
314 | * on frequency transition. | |
315 | * | |
316 | * This function calls the transition notifiers and the "adjust_jiffies" | |
317 | * function. It is called twice on all CPU frequency changes that have | |
318 | * external effects. | |
319 | */ | |
320 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
321 | struct cpufreq_freqs *freqs, unsigned int state) | |
322 | { | |
323 | for_each_cpu(freqs->cpu, policy->cpus) | |
324 | __cpufreq_notify_transition(policy, freqs, state); | |
325 | } | |
1da177e4 LT |
326 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); |
327 | ||
328 | ||
1da177e4 LT |
329 | /********************************************************************* |
330 | * SYSFS INTERFACE * | |
331 | *********************************************************************/ | |
332 | ||
3bcb09a3 JF |
333 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
334 | { | |
335 | struct cpufreq_governor *t; | |
336 | ||
337 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 338 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
339 | return t; |
340 | ||
341 | return NULL; | |
342 | } | |
343 | ||
1da177e4 LT |
344 | /** |
345 | * cpufreq_parse_governor - parse a governor string | |
346 | */ | |
905d77cd | 347 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
348 | struct cpufreq_governor **governor) |
349 | { | |
3bcb09a3 | 350 | int err = -EINVAL; |
1c3d85dd RW |
351 | |
352 | if (!cpufreq_driver) | |
3bcb09a3 JF |
353 | goto out; |
354 | ||
1c3d85dd | 355 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
356 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
357 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 358 | err = 0; |
e08f5f5b GS |
359 | } else if (!strnicmp(str_governor, "powersave", |
360 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 361 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 362 | err = 0; |
1da177e4 | 363 | } |
1c3d85dd | 364 | } else if (cpufreq_driver->target) { |
1da177e4 | 365 | struct cpufreq_governor *t; |
3bcb09a3 | 366 | |
3fc54d37 | 367 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
368 | |
369 | t = __find_governor(str_governor); | |
370 | ||
ea714970 | 371 | if (t == NULL) { |
1a8e1463 | 372 | int ret; |
ea714970 | 373 | |
1a8e1463 KC |
374 | mutex_unlock(&cpufreq_governor_mutex); |
375 | ret = request_module("cpufreq_%s", str_governor); | |
376 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 377 | |
1a8e1463 KC |
378 | if (ret == 0) |
379 | t = __find_governor(str_governor); | |
ea714970 JF |
380 | } |
381 | ||
3bcb09a3 JF |
382 | if (t != NULL) { |
383 | *governor = t; | |
384 | err = 0; | |
1da177e4 | 385 | } |
3bcb09a3 | 386 | |
3fc54d37 | 387 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 388 | } |
29464f28 | 389 | out: |
3bcb09a3 | 390 | return err; |
1da177e4 | 391 | } |
1da177e4 | 392 | |
1da177e4 | 393 | /** |
e08f5f5b GS |
394 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
395 | * print out cpufreq information | |
1da177e4 LT |
396 | * |
397 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
398 | * "unsigned int". | |
399 | */ | |
400 | ||
32ee8c3e DJ |
401 | #define show_one(file_name, object) \ |
402 | static ssize_t show_##file_name \ | |
905d77cd | 403 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 404 | { \ |
29464f28 | 405 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
406 | } |
407 | ||
408 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
409 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 410 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
411 | show_one(scaling_min_freq, min); |
412 | show_one(scaling_max_freq, max); | |
413 | show_one(scaling_cur_freq, cur); | |
414 | ||
3a3e9e06 VK |
415 | static int __cpufreq_set_policy(struct cpufreq_policy *policy, |
416 | struct cpufreq_policy *new_policy); | |
7970e08b | 417 | |
1da177e4 LT |
418 | /** |
419 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
420 | */ | |
421 | #define store_one(file_name, object) \ | |
422 | static ssize_t store_##file_name \ | |
905d77cd | 423 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 424 | { \ |
5136fa56 | 425 | int ret; \ |
1da177e4 LT |
426 | struct cpufreq_policy new_policy; \ |
427 | \ | |
428 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
429 | if (ret) \ | |
430 | return -EINVAL; \ | |
431 | \ | |
29464f28 | 432 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
433 | if (ret != 1) \ |
434 | return -EINVAL; \ | |
435 | \ | |
7970e08b TR |
436 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
437 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
438 | \ |
439 | return ret ? ret : count; \ | |
440 | } | |
441 | ||
29464f28 DJ |
442 | store_one(scaling_min_freq, min); |
443 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
444 | |
445 | /** | |
446 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
447 | */ | |
905d77cd DJ |
448 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
449 | char *buf) | |
1da177e4 | 450 | { |
5a01f2e8 | 451 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
452 | if (!cur_freq) |
453 | return sprintf(buf, "<unknown>"); | |
454 | return sprintf(buf, "%u\n", cur_freq); | |
455 | } | |
456 | ||
1da177e4 LT |
457 | /** |
458 | * show_scaling_governor - show the current policy for the specified CPU | |
459 | */ | |
905d77cd | 460 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 461 | { |
29464f28 | 462 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
463 | return sprintf(buf, "powersave\n"); |
464 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
465 | return sprintf(buf, "performance\n"); | |
466 | else if (policy->governor) | |
4b972f0b | 467 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 468 | policy->governor->name); |
1da177e4 LT |
469 | return -EINVAL; |
470 | } | |
471 | ||
1da177e4 LT |
472 | /** |
473 | * store_scaling_governor - store policy for the specified CPU | |
474 | */ | |
905d77cd DJ |
475 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
476 | const char *buf, size_t count) | |
1da177e4 | 477 | { |
5136fa56 | 478 | int ret; |
1da177e4 LT |
479 | char str_governor[16]; |
480 | struct cpufreq_policy new_policy; | |
481 | ||
482 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
483 | if (ret) | |
484 | return ret; | |
485 | ||
29464f28 | 486 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
487 | if (ret != 1) |
488 | return -EINVAL; | |
489 | ||
e08f5f5b GS |
490 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
491 | &new_policy.governor)) | |
1da177e4 LT |
492 | return -EINVAL; |
493 | ||
bb176f7d VK |
494 | /* |
495 | * Do not use cpufreq_set_policy here or the user_policy.max | |
496 | * will be wrongly overridden | |
497 | */ | |
7970e08b TR |
498 | ret = __cpufreq_set_policy(policy, &new_policy); |
499 | ||
500 | policy->user_policy.policy = policy->policy; | |
501 | policy->user_policy.governor = policy->governor; | |
7970e08b | 502 | |
e08f5f5b GS |
503 | if (ret) |
504 | return ret; | |
505 | else | |
506 | return count; | |
1da177e4 LT |
507 | } |
508 | ||
509 | /** | |
510 | * show_scaling_driver - show the cpufreq driver currently loaded | |
511 | */ | |
905d77cd | 512 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 513 | { |
1c3d85dd | 514 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
515 | } |
516 | ||
517 | /** | |
518 | * show_scaling_available_governors - show the available CPUfreq governors | |
519 | */ | |
905d77cd DJ |
520 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
521 | char *buf) | |
1da177e4 LT |
522 | { |
523 | ssize_t i = 0; | |
524 | struct cpufreq_governor *t; | |
525 | ||
1c3d85dd | 526 | if (!cpufreq_driver->target) { |
1da177e4 LT |
527 | i += sprintf(buf, "performance powersave"); |
528 | goto out; | |
529 | } | |
530 | ||
531 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
532 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
533 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 534 | goto out; |
4b972f0b | 535 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 536 | } |
7d5e350f | 537 | out: |
1da177e4 LT |
538 | i += sprintf(&buf[i], "\n"); |
539 | return i; | |
540 | } | |
e8628dd0 | 541 | |
f4fd3797 | 542 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
543 | { |
544 | ssize_t i = 0; | |
545 | unsigned int cpu; | |
546 | ||
835481d9 | 547 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
548 | if (i) |
549 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
550 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
551 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 552 | break; |
1da177e4 LT |
553 | } |
554 | i += sprintf(&buf[i], "\n"); | |
555 | return i; | |
556 | } | |
f4fd3797 | 557 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 558 | |
e8628dd0 DW |
559 | /** |
560 | * show_related_cpus - show the CPUs affected by each transition even if | |
561 | * hw coordination is in use | |
562 | */ | |
563 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
564 | { | |
f4fd3797 | 565 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
566 | } |
567 | ||
568 | /** | |
569 | * show_affected_cpus - show the CPUs affected by each transition | |
570 | */ | |
571 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
572 | { | |
f4fd3797 | 573 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
574 | } |
575 | ||
9e76988e | 576 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 577 | const char *buf, size_t count) |
9e76988e VP |
578 | { |
579 | unsigned int freq = 0; | |
580 | unsigned int ret; | |
581 | ||
879000f9 | 582 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
583 | return -EINVAL; |
584 | ||
585 | ret = sscanf(buf, "%u", &freq); | |
586 | if (ret != 1) | |
587 | return -EINVAL; | |
588 | ||
589 | policy->governor->store_setspeed(policy, freq); | |
590 | ||
591 | return count; | |
592 | } | |
593 | ||
594 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
595 | { | |
879000f9 | 596 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
597 | return sprintf(buf, "<unsupported>\n"); |
598 | ||
599 | return policy->governor->show_setspeed(policy, buf); | |
600 | } | |
1da177e4 | 601 | |
e2f74f35 | 602 | /** |
8bf1ac72 | 603 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
604 | */ |
605 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
606 | { | |
607 | unsigned int limit; | |
608 | int ret; | |
1c3d85dd RW |
609 | if (cpufreq_driver->bios_limit) { |
610 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
611 | if (!ret) |
612 | return sprintf(buf, "%u\n", limit); | |
613 | } | |
614 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
615 | } | |
616 | ||
6dad2a29 BP |
617 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
618 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
619 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
620 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
621 | cpufreq_freq_attr_ro(scaling_available_governors); | |
622 | cpufreq_freq_attr_ro(scaling_driver); | |
623 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
624 | cpufreq_freq_attr_ro(bios_limit); | |
625 | cpufreq_freq_attr_ro(related_cpus); | |
626 | cpufreq_freq_attr_ro(affected_cpus); | |
627 | cpufreq_freq_attr_rw(scaling_min_freq); | |
628 | cpufreq_freq_attr_rw(scaling_max_freq); | |
629 | cpufreq_freq_attr_rw(scaling_governor); | |
630 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 631 | |
905d77cd | 632 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
633 | &cpuinfo_min_freq.attr, |
634 | &cpuinfo_max_freq.attr, | |
ed129784 | 635 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
636 | &scaling_min_freq.attr, |
637 | &scaling_max_freq.attr, | |
638 | &affected_cpus.attr, | |
e8628dd0 | 639 | &related_cpus.attr, |
1da177e4 LT |
640 | &scaling_governor.attr, |
641 | &scaling_driver.attr, | |
642 | &scaling_available_governors.attr, | |
9e76988e | 643 | &scaling_setspeed.attr, |
1da177e4 LT |
644 | NULL |
645 | }; | |
646 | ||
29464f28 DJ |
647 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
648 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 649 | |
29464f28 | 650 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 651 | { |
905d77cd DJ |
652 | struct cpufreq_policy *policy = to_policy(kobj); |
653 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 654 | ssize_t ret; |
6eed9404 VK |
655 | |
656 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 657 | return -EINVAL; |
5a01f2e8 | 658 | |
1b750e3b | 659 | lock_policy_rwsem_read(policy->cpu); |
5a01f2e8 | 660 | |
e08f5f5b GS |
661 | if (fattr->show) |
662 | ret = fattr->show(policy, buf); | |
663 | else | |
664 | ret = -EIO; | |
665 | ||
5a01f2e8 | 666 | unlock_policy_rwsem_read(policy->cpu); |
6eed9404 | 667 | up_read(&cpufreq_rwsem); |
1b750e3b | 668 | |
1da177e4 LT |
669 | return ret; |
670 | } | |
671 | ||
905d77cd DJ |
672 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
673 | const char *buf, size_t count) | |
1da177e4 | 674 | { |
905d77cd DJ |
675 | struct cpufreq_policy *policy = to_policy(kobj); |
676 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 677 | ssize_t ret = -EINVAL; |
6eed9404 | 678 | |
4f750c93 SB |
679 | get_online_cpus(); |
680 | ||
681 | if (!cpu_online(policy->cpu)) | |
682 | goto unlock; | |
683 | ||
6eed9404 | 684 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 685 | goto unlock; |
5a01f2e8 | 686 | |
1b750e3b | 687 | lock_policy_rwsem_write(policy->cpu); |
5a01f2e8 | 688 | |
e08f5f5b GS |
689 | if (fattr->store) |
690 | ret = fattr->store(policy, buf, count); | |
691 | else | |
692 | ret = -EIO; | |
693 | ||
5a01f2e8 | 694 | unlock_policy_rwsem_write(policy->cpu); |
6eed9404 | 695 | |
6eed9404 | 696 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
697 | unlock: |
698 | put_online_cpus(); | |
699 | ||
1da177e4 LT |
700 | return ret; |
701 | } | |
702 | ||
905d77cd | 703 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 704 | { |
905d77cd | 705 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 706 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
707 | complete(&policy->kobj_unregister); |
708 | } | |
709 | ||
52cf25d0 | 710 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
711 | .show = show, |
712 | .store = store, | |
713 | }; | |
714 | ||
715 | static struct kobj_type ktype_cpufreq = { | |
716 | .sysfs_ops = &sysfs_ops, | |
717 | .default_attrs = default_attrs, | |
718 | .release = cpufreq_sysfs_release, | |
719 | }; | |
720 | ||
2361be23 VK |
721 | struct kobject *cpufreq_global_kobject; |
722 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
723 | ||
724 | static int cpufreq_global_kobject_usage; | |
725 | ||
726 | int cpufreq_get_global_kobject(void) | |
727 | { | |
728 | if (!cpufreq_global_kobject_usage++) | |
729 | return kobject_add(cpufreq_global_kobject, | |
730 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
731 | ||
732 | return 0; | |
733 | } | |
734 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
735 | ||
736 | void cpufreq_put_global_kobject(void) | |
737 | { | |
738 | if (!--cpufreq_global_kobject_usage) | |
739 | kobject_del(cpufreq_global_kobject); | |
740 | } | |
741 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
742 | ||
743 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
744 | { | |
745 | int ret = cpufreq_get_global_kobject(); | |
746 | ||
747 | if (!ret) { | |
748 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
749 | if (ret) | |
750 | cpufreq_put_global_kobject(); | |
751 | } | |
752 | ||
753 | return ret; | |
754 | } | |
755 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
756 | ||
757 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
758 | { | |
759 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
760 | cpufreq_put_global_kobject(); | |
761 | } | |
762 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
763 | ||
19d6f7ec | 764 | /* symlink affected CPUs */ |
308b60e7 | 765 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
766 | { |
767 | unsigned int j; | |
768 | int ret = 0; | |
769 | ||
770 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 771 | struct device *cpu_dev; |
19d6f7ec | 772 | |
308b60e7 | 773 | if (j == policy->cpu) |
19d6f7ec | 774 | continue; |
19d6f7ec | 775 | |
e8fdde10 | 776 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
777 | cpu_dev = get_cpu_device(j); |
778 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 779 | "cpufreq"); |
71c3461e RW |
780 | if (ret) |
781 | break; | |
19d6f7ec DJ |
782 | } |
783 | return ret; | |
784 | } | |
785 | ||
308b60e7 | 786 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 787 | struct device *dev) |
909a694e DJ |
788 | { |
789 | struct freq_attr **drv_attr; | |
909a694e | 790 | int ret = 0; |
909a694e DJ |
791 | |
792 | /* prepare interface data */ | |
793 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 794 | &dev->kobj, "cpufreq"); |
909a694e DJ |
795 | if (ret) |
796 | return ret; | |
797 | ||
798 | /* set up files for this cpu device */ | |
1c3d85dd | 799 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
800 | while ((drv_attr) && (*drv_attr)) { |
801 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
802 | if (ret) | |
1c3d85dd | 803 | goto err_out_kobj_put; |
909a694e DJ |
804 | drv_attr++; |
805 | } | |
1c3d85dd | 806 | if (cpufreq_driver->get) { |
909a694e DJ |
807 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
808 | if (ret) | |
1c3d85dd | 809 | goto err_out_kobj_put; |
909a694e | 810 | } |
1c3d85dd | 811 | if (cpufreq_driver->target) { |
909a694e DJ |
812 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
813 | if (ret) | |
1c3d85dd | 814 | goto err_out_kobj_put; |
909a694e | 815 | } |
1c3d85dd | 816 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
817 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
818 | if (ret) | |
1c3d85dd | 819 | goto err_out_kobj_put; |
e2f74f35 | 820 | } |
909a694e | 821 | |
308b60e7 | 822 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
823 | if (ret) |
824 | goto err_out_kobj_put; | |
825 | ||
e18f1682 SB |
826 | return ret; |
827 | ||
828 | err_out_kobj_put: | |
829 | kobject_put(&policy->kobj); | |
830 | wait_for_completion(&policy->kobj_unregister); | |
831 | return ret; | |
832 | } | |
833 | ||
834 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
835 | { | |
836 | struct cpufreq_policy new_policy; | |
837 | int ret = 0; | |
838 | ||
d5b73cd8 | 839 | memcpy(&new_policy, policy, sizeof(*policy)); |
ecf7e461 DJ |
840 | /* assure that the starting sequence is run in __cpufreq_set_policy */ |
841 | policy->governor = NULL; | |
842 | ||
843 | /* set default policy */ | |
844 | ret = __cpufreq_set_policy(policy, &new_policy); | |
845 | policy->user_policy.policy = policy->policy; | |
846 | policy->user_policy.governor = policy->governor; | |
847 | ||
848 | if (ret) { | |
2d06d8c4 | 849 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
850 | if (cpufreq_driver->exit) |
851 | cpufreq_driver->exit(policy); | |
ecf7e461 | 852 | } |
909a694e DJ |
853 | } |
854 | ||
fcf80582 | 855 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 VK |
856 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
857 | unsigned int cpu, struct device *dev, | |
858 | bool frozen) | |
fcf80582 | 859 | { |
1c3d85dd | 860 | int ret = 0, has_target = !!cpufreq_driver->target; |
fcf80582 VK |
861 | unsigned long flags; |
862 | ||
3de9bdeb VK |
863 | if (has_target) { |
864 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
865 | if (ret) { | |
866 | pr_err("%s: Failed to stop governor\n", __func__); | |
867 | return ret; | |
868 | } | |
869 | } | |
fcf80582 | 870 | |
d8d3b471 | 871 | lock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 872 | |
0d1857a1 | 873 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 874 | |
fcf80582 VK |
875 | cpumask_set_cpu(cpu, policy->cpus); |
876 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 877 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 878 | |
d8d3b471 | 879 | unlock_policy_rwsem_write(policy->cpu); |
2eaa3e2d | 880 | |
820c6ca2 | 881 | if (has_target) { |
3de9bdeb VK |
882 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
883 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
884 | pr_err("%s: Failed to start governor\n", __func__); | |
885 | return ret; | |
886 | } | |
820c6ca2 | 887 | } |
fcf80582 | 888 | |
a82fab29 | 889 | /* Don't touch sysfs links during light-weight init */ |
71c3461e RW |
890 | if (!frozen) |
891 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); | |
a82fab29 SB |
892 | |
893 | return ret; | |
fcf80582 VK |
894 | } |
895 | #endif | |
1da177e4 | 896 | |
8414809c SB |
897 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
898 | { | |
899 | struct cpufreq_policy *policy; | |
900 | unsigned long flags; | |
901 | ||
44871c9c | 902 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
903 | |
904 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
905 | ||
44871c9c | 906 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c SB |
907 | |
908 | return policy; | |
909 | } | |
910 | ||
e9698cc5 SB |
911 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
912 | { | |
913 | struct cpufreq_policy *policy; | |
914 | ||
915 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
916 | if (!policy) | |
917 | return NULL; | |
918 | ||
919 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
920 | goto err_free_policy; | |
921 | ||
922 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
923 | goto err_free_cpumask; | |
924 | ||
c88a1f8b | 925 | INIT_LIST_HEAD(&policy->policy_list); |
e9698cc5 SB |
926 | return policy; |
927 | ||
928 | err_free_cpumask: | |
929 | free_cpumask_var(policy->cpus); | |
930 | err_free_policy: | |
931 | kfree(policy); | |
932 | ||
933 | return NULL; | |
934 | } | |
935 | ||
936 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
937 | { | |
938 | free_cpumask_var(policy->related_cpus); | |
939 | free_cpumask_var(policy->cpus); | |
940 | kfree(policy); | |
941 | } | |
942 | ||
0d66b91e SB |
943 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
944 | { | |
cb38ed5c SB |
945 | if (cpu == policy->cpu) |
946 | return; | |
947 | ||
8efd5765 VK |
948 | /* |
949 | * Take direct locks as lock_policy_rwsem_write wouldn't work here. | |
950 | * Also lock for last cpu is enough here as contention will happen only | |
951 | * after policy->cpu is changed and after it is changed, other threads | |
952 | * will try to acquire lock for new cpu. And policy is already updated | |
953 | * by then. | |
954 | */ | |
955 | down_write(&per_cpu(cpu_policy_rwsem, policy->cpu)); | |
956 | ||
0d66b91e SB |
957 | policy->last_cpu = policy->cpu; |
958 | policy->cpu = cpu; | |
959 | ||
8efd5765 VK |
960 | up_write(&per_cpu(cpu_policy_rwsem, policy->last_cpu)); |
961 | ||
0d66b91e SB |
962 | #ifdef CONFIG_CPU_FREQ_TABLE |
963 | cpufreq_frequency_table_update_policy_cpu(policy); | |
964 | #endif | |
965 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
966 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
967 | } | |
968 | ||
a82fab29 SB |
969 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif, |
970 | bool frozen) | |
1da177e4 | 971 | { |
fcf80582 | 972 | unsigned int j, cpu = dev->id; |
65922465 | 973 | int ret = -ENOMEM; |
1da177e4 | 974 | struct cpufreq_policy *policy; |
1da177e4 | 975 | unsigned long flags; |
90e41bac | 976 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 977 | struct cpufreq_policy *tpolicy; |
fcf80582 | 978 | struct cpufreq_governor *gov; |
90e41bac | 979 | #endif |
1da177e4 | 980 | |
c32b6b8e AR |
981 | if (cpu_is_offline(cpu)) |
982 | return 0; | |
983 | ||
2d06d8c4 | 984 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
985 | |
986 | #ifdef CONFIG_SMP | |
987 | /* check whether a different CPU already registered this | |
988 | * CPU because it is in the same boat. */ | |
989 | policy = cpufreq_cpu_get(cpu); | |
990 | if (unlikely(policy)) { | |
8ff69732 | 991 | cpufreq_cpu_put(policy); |
1da177e4 LT |
992 | return 0; |
993 | } | |
5025d628 | 994 | #endif |
fcf80582 | 995 | |
6eed9404 VK |
996 | if (!down_read_trylock(&cpufreq_rwsem)) |
997 | return 0; | |
998 | ||
fcf80582 VK |
999 | #ifdef CONFIG_HOTPLUG_CPU |
1000 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1001 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1002 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1003 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1004 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1b274294 | 1005 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev, frozen); |
6eed9404 VK |
1006 | up_read(&cpufreq_rwsem); |
1007 | return ret; | |
2eaa3e2d | 1008 | } |
fcf80582 | 1009 | } |
0d1857a1 | 1010 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1011 | #endif |
1012 | ||
8414809c SB |
1013 | if (frozen) |
1014 | /* Restore the saved policy when doing light-weight init */ | |
1015 | policy = cpufreq_policy_restore(cpu); | |
1016 | else | |
1017 | policy = cpufreq_policy_alloc(); | |
1018 | ||
059019a3 | 1019 | if (!policy) |
1da177e4 | 1020 | goto nomem_out; |
059019a3 | 1021 | |
0d66b91e SB |
1022 | |
1023 | /* | |
1024 | * In the resume path, since we restore a saved policy, the assignment | |
1025 | * to policy->cpu is like an update of the existing policy, rather than | |
1026 | * the creation of a brand new one. So we need to perform this update | |
1027 | * by invoking update_policy_cpu(). | |
1028 | */ | |
1029 | if (frozen && cpu != policy->cpu) | |
1030 | update_policy_cpu(policy, cpu); | |
1031 | else | |
1032 | policy->cpu = cpu; | |
1033 | ||
65922465 | 1034 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; |
835481d9 | 1035 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1036 | |
1da177e4 | 1037 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1038 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1039 | |
1040 | /* call driver. From then on the cpufreq must be able | |
1041 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1042 | */ | |
1c3d85dd | 1043 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1044 | if (ret) { |
2d06d8c4 | 1045 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1046 | goto err_set_policy_cpu; |
1da177e4 | 1047 | } |
643ae6e8 | 1048 | |
fcf80582 VK |
1049 | /* related cpus should atleast have policy->cpus */ |
1050 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1051 | ||
643ae6e8 VK |
1052 | /* |
1053 | * affected cpus must always be the one, which are online. We aren't | |
1054 | * managing offline cpus here. | |
1055 | */ | |
1056 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1057 | ||
187d9f4e MC |
1058 | policy->user_policy.min = policy->min; |
1059 | policy->user_policy.max = policy->max; | |
1da177e4 | 1060 | |
a1531acd TR |
1061 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1062 | CPUFREQ_START, policy); | |
1063 | ||
fcf80582 VK |
1064 | #ifdef CONFIG_HOTPLUG_CPU |
1065 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1066 | if (gov) { | |
1067 | policy->governor = gov; | |
1068 | pr_debug("Restoring governor %s for cpu %d\n", | |
1069 | policy->governor->name, cpu); | |
4bfa042c | 1070 | } |
fcf80582 | 1071 | #endif |
1da177e4 | 1072 | |
e18f1682 | 1073 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1074 | for_each_cpu(j, policy->cpus) |
e18f1682 | 1075 | per_cpu(cpufreq_cpu_data, j) = policy; |
e18f1682 SB |
1076 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1077 | ||
a82fab29 | 1078 | if (!frozen) { |
308b60e7 | 1079 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1080 | if (ret) |
1081 | goto err_out_unregister; | |
1082 | } | |
8ff69732 | 1083 | |
9515f4d6 VK |
1084 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1085 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1086 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1087 | ||
e18f1682 SB |
1088 | cpufreq_init_policy(policy); |
1089 | ||
038c5b3e | 1090 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1091 | up_read(&cpufreq_rwsem); |
1092 | ||
2d06d8c4 | 1093 | pr_debug("initialization complete\n"); |
87c32271 | 1094 | |
1da177e4 LT |
1095 | return 0; |
1096 | ||
1da177e4 | 1097 | err_out_unregister: |
0d1857a1 | 1098 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1099 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1100 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1101 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1102 | |
2eaa3e2d | 1103 | err_set_policy_cpu: |
e9698cc5 | 1104 | cpufreq_policy_free(policy); |
1da177e4 | 1105 | nomem_out: |
6eed9404 VK |
1106 | up_read(&cpufreq_rwsem); |
1107 | ||
1da177e4 LT |
1108 | return ret; |
1109 | } | |
1110 | ||
a82fab29 SB |
1111 | /** |
1112 | * cpufreq_add_dev - add a CPU device | |
1113 | * | |
1114 | * Adds the cpufreq interface for a CPU device. | |
1115 | * | |
1116 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1117 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1118 | * mess up, but more thorough testing is needed. - Mathieu | |
1119 | */ | |
1120 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1121 | { | |
1122 | return __cpufreq_add_dev(dev, sif, false); | |
1123 | } | |
1124 | ||
3a3e9e06 | 1125 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
a82fab29 | 1126 | unsigned int old_cpu, bool frozen) |
f9ba680d SB |
1127 | { |
1128 | struct device *cpu_dev; | |
f9ba680d SB |
1129 | int ret; |
1130 | ||
1131 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1132 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 SB |
1133 | |
1134 | /* Don't touch sysfs files during light-weight tear-down */ | |
1135 | if (frozen) | |
1136 | return cpu_dev->id; | |
1137 | ||
f9ba680d | 1138 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1139 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d SB |
1140 | if (ret) { |
1141 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1142 | ||
1b750e3b | 1143 | lock_policy_rwsem_write(old_cpu); |
3a3e9e06 | 1144 | cpumask_set_cpu(old_cpu, policy->cpus); |
f9ba680d SB |
1145 | unlock_policy_rwsem_write(old_cpu); |
1146 | ||
3a3e9e06 | 1147 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1148 | "cpufreq"); |
1149 | ||
1150 | return -EINVAL; | |
1151 | } | |
1152 | ||
1153 | return cpu_dev->id; | |
1154 | } | |
1155 | ||
cedb70af SB |
1156 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
1157 | struct subsys_interface *sif, | |
1158 | bool frozen) | |
1da177e4 | 1159 | { |
f9ba680d | 1160 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1161 | int new_cpu, ret; |
1da177e4 | 1162 | unsigned long flags; |
3a3e9e06 | 1163 | struct cpufreq_policy *policy; |
1da177e4 | 1164 | |
b8eed8af | 1165 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1166 | |
0d1857a1 | 1167 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1168 | |
3a3e9e06 | 1169 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1170 | |
8414809c SB |
1171 | /* Save the policy somewhere when doing a light-weight tear-down */ |
1172 | if (frozen) | |
3a3e9e06 | 1173 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1174 | |
0d1857a1 | 1175 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1176 | |
3a3e9e06 | 1177 | if (!policy) { |
b8eed8af | 1178 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1179 | return -EINVAL; |
1180 | } | |
1da177e4 | 1181 | |
3de9bdeb VK |
1182 | if (cpufreq_driver->target) { |
1183 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1184 | if (ret) { | |
1185 | pr_err("%s: Failed to stop governor\n", __func__); | |
1186 | return ret; | |
1187 | } | |
1188 | } | |
1da177e4 | 1189 | |
084f3493 | 1190 | #ifdef CONFIG_HOTPLUG_CPU |
1c3d85dd | 1191 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1192 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1193 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 LT |
1194 | #endif |
1195 | ||
9c8f1ee4 | 1196 | lock_policy_rwsem_read(cpu); |
3a3e9e06 | 1197 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 | 1198 | unlock_policy_rwsem_read(cpu); |
084f3493 | 1199 | |
61173f25 SB |
1200 | if (cpu != policy->cpu) { |
1201 | if (!frozen) | |
1202 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
73bf0fc2 | 1203 | } else if (cpus > 1) { |
3a3e9e06 | 1204 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen); |
f9ba680d | 1205 | if (new_cpu >= 0) { |
3a3e9e06 | 1206 | update_policy_cpu(policy, new_cpu); |
a82fab29 SB |
1207 | |
1208 | if (!frozen) { | |
75949c9a VK |
1209 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
1210 | __func__, new_cpu, cpu); | |
a82fab29 | 1211 | } |
1da177e4 LT |
1212 | } |
1213 | } | |
1da177e4 | 1214 | |
cedb70af SB |
1215 | return 0; |
1216 | } | |
1217 | ||
1218 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
1219 | struct subsys_interface *sif, | |
1220 | bool frozen) | |
1221 | { | |
1222 | unsigned int cpu = dev->id, cpus; | |
1223 | int ret; | |
1224 | unsigned long flags; | |
1225 | struct cpufreq_policy *policy; | |
1226 | struct kobject *kobj; | |
1227 | struct completion *cmp; | |
1228 | ||
1229 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1230 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1231 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1232 | ||
1233 | if (!policy) { | |
1234 | pr_debug("%s: No cpu_data found\n", __func__); | |
1235 | return -EINVAL; | |
1236 | } | |
1237 | ||
1b750e3b | 1238 | lock_policy_rwsem_write(cpu); |
cedb70af | 1239 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1240 | |
1241 | if (cpus > 1) | |
1242 | cpumask_clear_cpu(cpu, policy->cpus); | |
1243 | unlock_policy_rwsem_write(cpu); | |
cedb70af | 1244 | |
b8eed8af VK |
1245 | /* If cpu is last user of policy, free policy */ |
1246 | if (cpus == 1) { | |
3de9bdeb VK |
1247 | if (cpufreq_driver->target) { |
1248 | ret = __cpufreq_governor(policy, | |
1249 | CPUFREQ_GOV_POLICY_EXIT); | |
1250 | if (ret) { | |
1251 | pr_err("%s: Failed to exit governor\n", | |
1252 | __func__); | |
1253 | return ret; | |
1254 | } | |
edab2fbc | 1255 | } |
2a998599 | 1256 | |
8414809c SB |
1257 | if (!frozen) { |
1258 | lock_policy_rwsem_read(cpu); | |
3a3e9e06 VK |
1259 | kobj = &policy->kobj; |
1260 | cmp = &policy->kobj_unregister; | |
8414809c SB |
1261 | unlock_policy_rwsem_read(cpu); |
1262 | kobject_put(kobj); | |
1263 | ||
1264 | /* | |
1265 | * We need to make sure that the underlying kobj is | |
1266 | * actually not referenced anymore by anybody before we | |
1267 | * proceed with unloading. | |
1268 | */ | |
1269 | pr_debug("waiting for dropping of refcount\n"); | |
1270 | wait_for_completion(cmp); | |
1271 | pr_debug("wait complete\n"); | |
1272 | } | |
7d26e2d5 | 1273 | |
8414809c SB |
1274 | /* |
1275 | * Perform the ->exit() even during light-weight tear-down, | |
1276 | * since this is a core component, and is essential for the | |
1277 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1278 | */ |
1c3d85dd | 1279 | if (cpufreq_driver->exit) |
3a3e9e06 | 1280 | cpufreq_driver->exit(policy); |
27ecddc2 | 1281 | |
9515f4d6 VK |
1282 | /* Remove policy from list of active policies */ |
1283 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1284 | list_del(&policy->policy_list); | |
1285 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1286 | ||
8414809c | 1287 | if (!frozen) |
3a3e9e06 | 1288 | cpufreq_policy_free(policy); |
2a998599 | 1289 | } else { |
2a998599 | 1290 | if (cpufreq_driver->target) { |
3de9bdeb VK |
1291 | if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) || |
1292 | (ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) { | |
1293 | pr_err("%s: Failed to start governor\n", | |
1294 | __func__); | |
1295 | return ret; | |
1296 | } | |
2a998599 | 1297 | } |
27ecddc2 | 1298 | } |
1da177e4 | 1299 | |
474deff7 | 1300 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1301 | return 0; |
1302 | } | |
1303 | ||
cedb70af | 1304 | /** |
27a862e9 | 1305 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1306 | * |
1307 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1308 | */ |
8a25a2fd | 1309 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1310 | { |
8a25a2fd | 1311 | unsigned int cpu = dev->id; |
27a862e9 | 1312 | int ret; |
ec28297a VP |
1313 | |
1314 | if (cpu_is_offline(cpu)) | |
1315 | return 0; | |
1316 | ||
27a862e9 VK |
1317 | ret = __cpufreq_remove_dev_prepare(dev, sif, false); |
1318 | ||
1319 | if (!ret) | |
1320 | ret = __cpufreq_remove_dev_finish(dev, sif, false); | |
1321 | ||
1322 | return ret; | |
5a01f2e8 VP |
1323 | } |
1324 | ||
65f27f38 | 1325 | static void handle_update(struct work_struct *work) |
1da177e4 | 1326 | { |
65f27f38 DH |
1327 | struct cpufreq_policy *policy = |
1328 | container_of(work, struct cpufreq_policy, update); | |
1329 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1330 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1331 | cpufreq_update_policy(cpu); |
1332 | } | |
1333 | ||
1334 | /** | |
bb176f7d VK |
1335 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1336 | * in deep trouble. | |
1da177e4 LT |
1337 | * @cpu: cpu number |
1338 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1339 | * @new_freq: CPU frequency the CPU actually runs at | |
1340 | * | |
29464f28 DJ |
1341 | * We adjust to current frequency first, and need to clean up later. |
1342 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1343 | */ |
e08f5f5b GS |
1344 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1345 | unsigned int new_freq) | |
1da177e4 | 1346 | { |
b43a7ffb | 1347 | struct cpufreq_policy *policy; |
1da177e4 | 1348 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1349 | unsigned long flags; |
1350 | ||
2d06d8c4 | 1351 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1352 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1353 | ||
1da177e4 LT |
1354 | freqs.old = old_freq; |
1355 | freqs.new = new_freq; | |
b43a7ffb VK |
1356 | |
1357 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1358 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1359 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1360 | ||
1361 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1362 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1da177e4 LT |
1363 | } |
1364 | ||
32ee8c3e | 1365 | /** |
4ab70df4 | 1366 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1367 | * @cpu: CPU number |
1368 | * | |
1369 | * This is the last known freq, without actually getting it from the driver. | |
1370 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1371 | */ | |
1372 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1373 | { | |
9e21ba8b | 1374 | struct cpufreq_policy *policy; |
e08f5f5b | 1375 | unsigned int ret_freq = 0; |
95235ca2 | 1376 | |
1c3d85dd RW |
1377 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1378 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1379 | |
1380 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1381 | if (policy) { |
e08f5f5b | 1382 | ret_freq = policy->cur; |
95235ca2 VP |
1383 | cpufreq_cpu_put(policy); |
1384 | } | |
1385 | ||
4d34a67d | 1386 | return ret_freq; |
95235ca2 VP |
1387 | } |
1388 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1389 | ||
3d737108 JB |
1390 | /** |
1391 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1392 | * @cpu: CPU number | |
1393 | * | |
1394 | * Just return the max possible frequency for a given CPU. | |
1395 | */ | |
1396 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1397 | { | |
1398 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1399 | unsigned int ret_freq = 0; | |
1400 | ||
1401 | if (policy) { | |
1402 | ret_freq = policy->max; | |
1403 | cpufreq_cpu_put(policy); | |
1404 | } | |
1405 | ||
1406 | return ret_freq; | |
1407 | } | |
1408 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1409 | ||
5a01f2e8 | 1410 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1411 | { |
7a6aedfa | 1412 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1413 | unsigned int ret_freq = 0; |
5800043b | 1414 | |
1c3d85dd | 1415 | if (!cpufreq_driver->get) |
4d34a67d | 1416 | return ret_freq; |
1da177e4 | 1417 | |
1c3d85dd | 1418 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1419 | |
e08f5f5b | 1420 | if (ret_freq && policy->cur && |
1c3d85dd | 1421 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1422 | /* verify no discrepancy between actual and |
1423 | saved value exists */ | |
1424 | if (unlikely(ret_freq != policy->cur)) { | |
1425 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1426 | schedule_work(&policy->update); |
1427 | } | |
1428 | } | |
1429 | ||
4d34a67d | 1430 | return ret_freq; |
5a01f2e8 | 1431 | } |
1da177e4 | 1432 | |
5a01f2e8 VP |
1433 | /** |
1434 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1435 | * @cpu: CPU number | |
1436 | * | |
1437 | * Get the CPU current (static) CPU frequency | |
1438 | */ | |
1439 | unsigned int cpufreq_get(unsigned int cpu) | |
1440 | { | |
1441 | unsigned int ret_freq = 0; | |
5a01f2e8 | 1442 | |
26ca8694 VK |
1443 | if (cpufreq_disabled() || !cpufreq_driver) |
1444 | return -ENOENT; | |
1445 | ||
6eed9404 VK |
1446 | if (!down_read_trylock(&cpufreq_rwsem)) |
1447 | return 0; | |
5a01f2e8 | 1448 | |
1b750e3b | 1449 | lock_policy_rwsem_read(cpu); |
5a01f2e8 VP |
1450 | |
1451 | ret_freq = __cpufreq_get(cpu); | |
1452 | ||
1453 | unlock_policy_rwsem_read(cpu); | |
6eed9404 VK |
1454 | up_read(&cpufreq_rwsem); |
1455 | ||
4d34a67d | 1456 | return ret_freq; |
1da177e4 LT |
1457 | } |
1458 | EXPORT_SYMBOL(cpufreq_get); | |
1459 | ||
8a25a2fd KS |
1460 | static struct subsys_interface cpufreq_interface = { |
1461 | .name = "cpufreq", | |
1462 | .subsys = &cpu_subsys, | |
1463 | .add_dev = cpufreq_add_dev, | |
1464 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1465 | }; |
1466 | ||
42d4dc3f | 1467 | /** |
e00e56df RW |
1468 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1469 | * | |
1470 | * This function is only executed for the boot processor. The other CPUs | |
1471 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1472 | */ |
e00e56df | 1473 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1474 | { |
e08f5f5b | 1475 | int ret = 0; |
4bc5d341 | 1476 | |
e00e56df | 1477 | int cpu = smp_processor_id(); |
3a3e9e06 | 1478 | struct cpufreq_policy *policy; |
42d4dc3f | 1479 | |
2d06d8c4 | 1480 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1481 | |
e00e56df | 1482 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1483 | policy = cpufreq_cpu_get(cpu); |
1484 | if (!policy) | |
e00e56df | 1485 | return 0; |
42d4dc3f | 1486 | |
1c3d85dd | 1487 | if (cpufreq_driver->suspend) { |
3a3e9e06 | 1488 | ret = cpufreq_driver->suspend(policy); |
ce6c3997 | 1489 | if (ret) |
42d4dc3f | 1490 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
3a3e9e06 | 1491 | "step on CPU %u\n", policy->cpu); |
42d4dc3f BH |
1492 | } |
1493 | ||
3a3e9e06 | 1494 | cpufreq_cpu_put(policy); |
c9060494 | 1495 | return ret; |
42d4dc3f BH |
1496 | } |
1497 | ||
1da177e4 | 1498 | /** |
e00e56df | 1499 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1500 | * |
1501 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1502 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1503 | * restored. It will verify that the current freq is in sync with | |
1504 | * what we believe it to be. This is a bit later than when it | |
1505 | * should be, but nonethteless it's better than calling | |
1506 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1507 | * |
1508 | * This function is only executed for the boot CPU. The other CPUs have not | |
1509 | * been turned on yet. | |
1da177e4 | 1510 | */ |
e00e56df | 1511 | static void cpufreq_bp_resume(void) |
1da177e4 | 1512 | { |
e08f5f5b | 1513 | int ret = 0; |
4bc5d341 | 1514 | |
e00e56df | 1515 | int cpu = smp_processor_id(); |
3a3e9e06 | 1516 | struct cpufreq_policy *policy; |
1da177e4 | 1517 | |
2d06d8c4 | 1518 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1519 | |
e00e56df | 1520 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
3a3e9e06 VK |
1521 | policy = cpufreq_cpu_get(cpu); |
1522 | if (!policy) | |
e00e56df | 1523 | return; |
1da177e4 | 1524 | |
1c3d85dd | 1525 | if (cpufreq_driver->resume) { |
3a3e9e06 | 1526 | ret = cpufreq_driver->resume(policy); |
1da177e4 LT |
1527 | if (ret) { |
1528 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
3a3e9e06 | 1529 | "step on CPU %u\n", policy->cpu); |
c9060494 | 1530 | goto fail; |
1da177e4 LT |
1531 | } |
1532 | } | |
1533 | ||
3a3e9e06 | 1534 | schedule_work(&policy->update); |
ce6c3997 | 1535 | |
c9060494 | 1536 | fail: |
3a3e9e06 | 1537 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1538 | } |
1539 | ||
e00e56df RW |
1540 | static struct syscore_ops cpufreq_syscore_ops = { |
1541 | .suspend = cpufreq_bp_suspend, | |
1542 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1543 | }; |
1544 | ||
9d95046e BP |
1545 | /** |
1546 | * cpufreq_get_current_driver - return current driver's name | |
1547 | * | |
1548 | * Return the name string of the currently loaded cpufreq driver | |
1549 | * or NULL, if none. | |
1550 | */ | |
1551 | const char *cpufreq_get_current_driver(void) | |
1552 | { | |
1c3d85dd RW |
1553 | if (cpufreq_driver) |
1554 | return cpufreq_driver->name; | |
1555 | ||
1556 | return NULL; | |
9d95046e BP |
1557 | } |
1558 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1559 | |
1560 | /********************************************************************* | |
1561 | * NOTIFIER LISTS INTERFACE * | |
1562 | *********************************************************************/ | |
1563 | ||
1564 | /** | |
1565 | * cpufreq_register_notifier - register a driver with cpufreq | |
1566 | * @nb: notifier function to register | |
1567 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1568 | * | |
32ee8c3e | 1569 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1570 | * are notified about clock rate changes (once before and once after |
1571 | * the transition), or a list of drivers that are notified about | |
1572 | * changes in cpufreq policy. | |
1573 | * | |
1574 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1575 | * blocking_notifier_chain_register. |
1da177e4 LT |
1576 | */ |
1577 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1578 | { | |
1579 | int ret; | |
1580 | ||
d5aaffa9 DB |
1581 | if (cpufreq_disabled()) |
1582 | return -EINVAL; | |
1583 | ||
74212ca4 CEB |
1584 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1585 | ||
1da177e4 LT |
1586 | switch (list) { |
1587 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1588 | ret = srcu_notifier_chain_register( |
e041c683 | 1589 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1590 | break; |
1591 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1592 | ret = blocking_notifier_chain_register( |
1593 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1594 | break; |
1595 | default: | |
1596 | ret = -EINVAL; | |
1597 | } | |
1da177e4 LT |
1598 | |
1599 | return ret; | |
1600 | } | |
1601 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1602 | ||
1da177e4 LT |
1603 | /** |
1604 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1605 | * @nb: notifier block to be unregistered | |
bb176f7d | 1606 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1607 | * |
1608 | * Remove a driver from the CPU frequency notifier list. | |
1609 | * | |
1610 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1611 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1612 | */ |
1613 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1614 | { | |
1615 | int ret; | |
1616 | ||
d5aaffa9 DB |
1617 | if (cpufreq_disabled()) |
1618 | return -EINVAL; | |
1619 | ||
1da177e4 LT |
1620 | switch (list) { |
1621 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1622 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1623 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1624 | break; |
1625 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1626 | ret = blocking_notifier_chain_unregister( |
1627 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1628 | break; |
1629 | default: | |
1630 | ret = -EINVAL; | |
1631 | } | |
1da177e4 LT |
1632 | |
1633 | return ret; | |
1634 | } | |
1635 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1636 | ||
1637 | ||
1638 | /********************************************************************* | |
1639 | * GOVERNORS * | |
1640 | *********************************************************************/ | |
1641 | ||
1da177e4 LT |
1642 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1643 | unsigned int target_freq, | |
1644 | unsigned int relation) | |
1645 | { | |
1646 | int retval = -EINVAL; | |
7249924e | 1647 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1648 | |
a7b422cd KRW |
1649 | if (cpufreq_disabled()) |
1650 | return -ENODEV; | |
1651 | ||
7249924e VK |
1652 | /* Make sure that target_freq is within supported range */ |
1653 | if (target_freq > policy->max) | |
1654 | target_freq = policy->max; | |
1655 | if (target_freq < policy->min) | |
1656 | target_freq = policy->min; | |
1657 | ||
1658 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1659 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1660 | |
1661 | if (target_freq == policy->cur) | |
1662 | return 0; | |
1663 | ||
1c3d85dd RW |
1664 | if (cpufreq_driver->target) |
1665 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1666 | |
1da177e4 LT |
1667 | return retval; |
1668 | } | |
1669 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1670 | ||
1da177e4 LT |
1671 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1672 | unsigned int target_freq, | |
1673 | unsigned int relation) | |
1674 | { | |
f1829e4a | 1675 | int ret = -EINVAL; |
1da177e4 | 1676 | |
1b750e3b | 1677 | lock_policy_rwsem_write(policy->cpu); |
1da177e4 LT |
1678 | |
1679 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1680 | ||
5a01f2e8 | 1681 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1682 | |
1da177e4 LT |
1683 | return ret; |
1684 | } | |
1685 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1686 | ||
153d7f3f | 1687 | /* |
153d7f3f AV |
1688 | * when "event" is CPUFREQ_GOV_LIMITS |
1689 | */ | |
1da177e4 | 1690 | |
e08f5f5b GS |
1691 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1692 | unsigned int event) | |
1da177e4 | 1693 | { |
cc993cab | 1694 | int ret; |
6afde10c TR |
1695 | |
1696 | /* Only must be defined when default governor is known to have latency | |
1697 | restrictions, like e.g. conservative or ondemand. | |
1698 | That this is the case is already ensured in Kconfig | |
1699 | */ | |
1700 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1701 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1702 | #else | |
1703 | struct cpufreq_governor *gov = NULL; | |
1704 | #endif | |
1c256245 TR |
1705 | |
1706 | if (policy->governor->max_transition_latency && | |
1707 | policy->cpuinfo.transition_latency > | |
1708 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1709 | if (!gov) |
1710 | return -EINVAL; | |
1711 | else { | |
1712 | printk(KERN_WARNING "%s governor failed, too long" | |
1713 | " transition latency of HW, fallback" | |
1714 | " to %s governor\n", | |
1715 | policy->governor->name, | |
1716 | gov->name); | |
1717 | policy->governor = gov; | |
1718 | } | |
1c256245 | 1719 | } |
1da177e4 | 1720 | |
fe492f3f VK |
1721 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1722 | if (!try_module_get(policy->governor->owner)) | |
1723 | return -EINVAL; | |
1da177e4 | 1724 | |
2d06d8c4 | 1725 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1726 | policy->cpu, event); |
95731ebb XC |
1727 | |
1728 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1729 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1730 | || (!policy->governor_enabled |
1731 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1732 | mutex_unlock(&cpufreq_governor_lock); |
1733 | return -EBUSY; | |
1734 | } | |
1735 | ||
1736 | if (event == CPUFREQ_GOV_STOP) | |
1737 | policy->governor_enabled = false; | |
1738 | else if (event == CPUFREQ_GOV_START) | |
1739 | policy->governor_enabled = true; | |
1740 | ||
1741 | mutex_unlock(&cpufreq_governor_lock); | |
1742 | ||
1da177e4 LT |
1743 | ret = policy->governor->governor(policy, event); |
1744 | ||
4d5dcc42 VK |
1745 | if (!ret) { |
1746 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1747 | policy->governor->initialized++; | |
1748 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1749 | policy->governor->initialized--; | |
95731ebb XC |
1750 | } else { |
1751 | /* Restore original values */ | |
1752 | mutex_lock(&cpufreq_governor_lock); | |
1753 | if (event == CPUFREQ_GOV_STOP) | |
1754 | policy->governor_enabled = true; | |
1755 | else if (event == CPUFREQ_GOV_START) | |
1756 | policy->governor_enabled = false; | |
1757 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1758 | } |
b394058f | 1759 | |
fe492f3f VK |
1760 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1761 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1762 | module_put(policy->governor->owner); |
1763 | ||
1764 | return ret; | |
1765 | } | |
1766 | ||
1da177e4 LT |
1767 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1768 | { | |
3bcb09a3 | 1769 | int err; |
1da177e4 LT |
1770 | |
1771 | if (!governor) | |
1772 | return -EINVAL; | |
1773 | ||
a7b422cd KRW |
1774 | if (cpufreq_disabled()) |
1775 | return -ENODEV; | |
1776 | ||
3fc54d37 | 1777 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1778 | |
b394058f | 1779 | governor->initialized = 0; |
3bcb09a3 JF |
1780 | err = -EBUSY; |
1781 | if (__find_governor(governor->name) == NULL) { | |
1782 | err = 0; | |
1783 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1784 | } |
1da177e4 | 1785 | |
32ee8c3e | 1786 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1787 | return err; |
1da177e4 LT |
1788 | } |
1789 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1790 | ||
1da177e4 LT |
1791 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
1792 | { | |
90e41bac PB |
1793 | #ifdef CONFIG_HOTPLUG_CPU |
1794 | int cpu; | |
1795 | #endif | |
1796 | ||
1da177e4 LT |
1797 | if (!governor) |
1798 | return; | |
1799 | ||
a7b422cd KRW |
1800 | if (cpufreq_disabled()) |
1801 | return; | |
1802 | ||
90e41bac PB |
1803 | #ifdef CONFIG_HOTPLUG_CPU |
1804 | for_each_present_cpu(cpu) { | |
1805 | if (cpu_online(cpu)) | |
1806 | continue; | |
1807 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1808 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1809 | } | |
1810 | #endif | |
1811 | ||
3fc54d37 | 1812 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1813 | list_del(&governor->governor_list); |
3fc54d37 | 1814 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1815 | return; |
1816 | } | |
1817 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1818 | ||
1819 | ||
1da177e4 LT |
1820 | /********************************************************************* |
1821 | * POLICY INTERFACE * | |
1822 | *********************************************************************/ | |
1823 | ||
1824 | /** | |
1825 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1826 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1827 | * is written | |
1da177e4 LT |
1828 | * |
1829 | * Reads the current cpufreq policy. | |
1830 | */ | |
1831 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1832 | { | |
1833 | struct cpufreq_policy *cpu_policy; | |
1834 | if (!policy) | |
1835 | return -EINVAL; | |
1836 | ||
1837 | cpu_policy = cpufreq_cpu_get(cpu); | |
1838 | if (!cpu_policy) | |
1839 | return -EINVAL; | |
1840 | ||
d5b73cd8 | 1841 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
1842 | |
1843 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1844 | return 0; |
1845 | } | |
1846 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1847 | ||
153d7f3f | 1848 | /* |
e08f5f5b GS |
1849 | * data : current policy. |
1850 | * policy : policy to be set. | |
153d7f3f | 1851 | */ |
3a3e9e06 VK |
1852 | static int __cpufreq_set_policy(struct cpufreq_policy *policy, |
1853 | struct cpufreq_policy *new_policy) | |
1da177e4 | 1854 | { |
7bd353a9 | 1855 | int ret = 0, failed = 1; |
1da177e4 | 1856 | |
3a3e9e06 VK |
1857 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", new_policy->cpu, |
1858 | new_policy->min, new_policy->max); | |
1da177e4 | 1859 | |
d5b73cd8 | 1860 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 1861 | |
3a3e9e06 | 1862 | if (new_policy->min > policy->max || new_policy->max < policy->min) { |
9c9a43ed MD |
1863 | ret = -EINVAL; |
1864 | goto error_out; | |
1865 | } | |
1866 | ||
1da177e4 | 1867 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 1868 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 LT |
1869 | if (ret) |
1870 | goto error_out; | |
1871 | ||
1da177e4 | 1872 | /* adjust if necessary - all reasons */ |
e041c683 | 1873 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1874 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
1875 | |
1876 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 1877 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1878 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 1879 | |
bb176f7d VK |
1880 | /* |
1881 | * verify the cpu speed can be set within this limit, which might be | |
1882 | * different to the first one | |
1883 | */ | |
3a3e9e06 | 1884 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 1885 | if (ret) |
1da177e4 | 1886 | goto error_out; |
1da177e4 LT |
1887 | |
1888 | /* notification of the new policy */ | |
e041c683 | 1889 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 1890 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 1891 | |
3a3e9e06 VK |
1892 | policy->min = new_policy->min; |
1893 | policy->max = new_policy->max; | |
1da177e4 | 1894 | |
2d06d8c4 | 1895 | pr_debug("new min and max freqs are %u - %u kHz\n", |
3a3e9e06 | 1896 | policy->min, policy->max); |
1da177e4 | 1897 | |
1c3d85dd | 1898 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 1899 | policy->policy = new_policy->policy; |
2d06d8c4 | 1900 | pr_debug("setting range\n"); |
3a3e9e06 | 1901 | ret = cpufreq_driver->setpolicy(new_policy); |
1da177e4 | 1902 | } else { |
3a3e9e06 | 1903 | if (new_policy->governor != policy->governor) { |
1da177e4 | 1904 | /* save old, working values */ |
3a3e9e06 | 1905 | struct cpufreq_governor *old_gov = policy->governor; |
1da177e4 | 1906 | |
2d06d8c4 | 1907 | pr_debug("governor switch\n"); |
1da177e4 LT |
1908 | |
1909 | /* end old governor */ | |
3a3e9e06 VK |
1910 | if (policy->governor) { |
1911 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
1912 | unlock_policy_rwsem_write(new_policy->cpu); | |
1913 | __cpufreq_governor(policy, | |
7bd353a9 | 1914 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1915 | lock_policy_rwsem_write(new_policy->cpu); |
7bd353a9 | 1916 | } |
1da177e4 LT |
1917 | |
1918 | /* start new governor */ | |
3a3e9e06 VK |
1919 | policy->governor = new_policy->governor; |
1920 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
1921 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) { | |
7bd353a9 | 1922 | failed = 0; |
955ef483 | 1923 | } else { |
3a3e9e06 VK |
1924 | unlock_policy_rwsem_write(new_policy->cpu); |
1925 | __cpufreq_governor(policy, | |
7bd353a9 | 1926 | CPUFREQ_GOV_POLICY_EXIT); |
3a3e9e06 | 1927 | lock_policy_rwsem_write(new_policy->cpu); |
955ef483 | 1928 | } |
7bd353a9 VK |
1929 | } |
1930 | ||
1931 | if (failed) { | |
1da177e4 | 1932 | /* new governor failed, so re-start old one */ |
2d06d8c4 | 1933 | pr_debug("starting governor %s failed\n", |
3a3e9e06 | 1934 | policy->governor->name); |
1da177e4 | 1935 | if (old_gov) { |
3a3e9e06 VK |
1936 | policy->governor = old_gov; |
1937 | __cpufreq_governor(policy, | |
7bd353a9 | 1938 | CPUFREQ_GOV_POLICY_INIT); |
3a3e9e06 | 1939 | __cpufreq_governor(policy, |
e08f5f5b | 1940 | CPUFREQ_GOV_START); |
1da177e4 LT |
1941 | } |
1942 | ret = -EINVAL; | |
1943 | goto error_out; | |
1944 | } | |
1945 | /* might be a policy change, too, so fall through */ | |
1946 | } | |
2d06d8c4 | 1947 | pr_debug("governor: change or update limits\n"); |
3de9bdeb | 1948 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); |
1da177e4 LT |
1949 | } |
1950 | ||
7d5e350f | 1951 | error_out: |
1da177e4 LT |
1952 | return ret; |
1953 | } | |
1954 | ||
1da177e4 LT |
1955 | /** |
1956 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1957 | * @cpu: CPU which shall be re-evaluated | |
1958 | * | |
25985edc | 1959 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1960 | * at different times. |
1961 | */ | |
1962 | int cpufreq_update_policy(unsigned int cpu) | |
1963 | { | |
3a3e9e06 VK |
1964 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
1965 | struct cpufreq_policy new_policy; | |
f1829e4a | 1966 | int ret; |
1da177e4 | 1967 | |
3a3e9e06 | 1968 | if (!policy) { |
f1829e4a JL |
1969 | ret = -ENODEV; |
1970 | goto no_policy; | |
1971 | } | |
1da177e4 | 1972 | |
1b750e3b | 1973 | lock_policy_rwsem_write(cpu); |
1da177e4 | 1974 | |
2d06d8c4 | 1975 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 1976 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
1977 | new_policy.min = policy->user_policy.min; |
1978 | new_policy.max = policy->user_policy.max; | |
1979 | new_policy.policy = policy->user_policy.policy; | |
1980 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 1981 | |
bb176f7d VK |
1982 | /* |
1983 | * BIOS might change freq behind our back | |
1984 | * -> ask driver for current freq and notify governors about a change | |
1985 | */ | |
1c3d85dd | 1986 | if (cpufreq_driver->get) { |
3a3e9e06 VK |
1987 | new_policy.cur = cpufreq_driver->get(cpu); |
1988 | if (!policy->cur) { | |
2d06d8c4 | 1989 | pr_debug("Driver did not initialize current freq"); |
3a3e9e06 | 1990 | policy->cur = new_policy.cur; |
a85f7bd3 | 1991 | } else { |
3a3e9e06 VK |
1992 | if (policy->cur != new_policy.cur && cpufreq_driver->target) |
1993 | cpufreq_out_of_sync(cpu, policy->cur, | |
1994 | new_policy.cur); | |
a85f7bd3 | 1995 | } |
0961dd0d TR |
1996 | } |
1997 | ||
3a3e9e06 | 1998 | ret = __cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 1999 | |
5a01f2e8 VP |
2000 | unlock_policy_rwsem_write(cpu); |
2001 | ||
3a3e9e06 | 2002 | cpufreq_cpu_put(policy); |
f1829e4a | 2003 | no_policy: |
1da177e4 LT |
2004 | return ret; |
2005 | } | |
2006 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2007 | ||
2760984f | 2008 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2009 | unsigned long action, void *hcpu) |
2010 | { | |
2011 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2012 | struct device *dev; |
5302c3fb | 2013 | bool frozen = false; |
c32b6b8e | 2014 | |
8a25a2fd KS |
2015 | dev = get_cpu_device(cpu); |
2016 | if (dev) { | |
5302c3fb SB |
2017 | |
2018 | if (action & CPU_TASKS_FROZEN) | |
2019 | frozen = true; | |
2020 | ||
2021 | switch (action & ~CPU_TASKS_FROZEN) { | |
c32b6b8e | 2022 | case CPU_ONLINE: |
5302c3fb | 2023 | __cpufreq_add_dev(dev, NULL, frozen); |
23d32899 | 2024 | cpufreq_update_policy(cpu); |
c32b6b8e | 2025 | break; |
5302c3fb | 2026 | |
c32b6b8e | 2027 | case CPU_DOWN_PREPARE: |
cedb70af | 2028 | __cpufreq_remove_dev_prepare(dev, NULL, frozen); |
1aee40ac SB |
2029 | break; |
2030 | ||
2031 | case CPU_POST_DEAD: | |
cedb70af | 2032 | __cpufreq_remove_dev_finish(dev, NULL, frozen); |
c32b6b8e | 2033 | break; |
5302c3fb | 2034 | |
5a01f2e8 | 2035 | case CPU_DOWN_FAILED: |
5302c3fb | 2036 | __cpufreq_add_dev(dev, NULL, frozen); |
c32b6b8e AR |
2037 | break; |
2038 | } | |
2039 | } | |
2040 | return NOTIFY_OK; | |
2041 | } | |
2042 | ||
9c36f746 | 2043 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2044 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2045 | }; |
1da177e4 LT |
2046 | |
2047 | /********************************************************************* | |
2048 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2049 | *********************************************************************/ | |
2050 | ||
2051 | /** | |
2052 | * cpufreq_register_driver - register a CPU Frequency driver | |
2053 | * @driver_data: A struct cpufreq_driver containing the values# | |
2054 | * submitted by the CPU Frequency driver. | |
2055 | * | |
bb176f7d | 2056 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2057 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2058 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2059 | * |
2060 | */ | |
221dee28 | 2061 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2062 | { |
2063 | unsigned long flags; | |
2064 | int ret; | |
2065 | ||
a7b422cd KRW |
2066 | if (cpufreq_disabled()) |
2067 | return -ENODEV; | |
2068 | ||
1da177e4 LT |
2069 | if (!driver_data || !driver_data->verify || !driver_data->init || |
2070 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2071 | return -EINVAL; | |
2072 | ||
2d06d8c4 | 2073 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2074 | |
2075 | if (driver_data->setpolicy) | |
2076 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2077 | ||
0d1857a1 | 2078 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2079 | if (cpufreq_driver) { |
0d1857a1 | 2080 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2081 | return -EEXIST; |
1da177e4 | 2082 | } |
1c3d85dd | 2083 | cpufreq_driver = driver_data; |
0d1857a1 | 2084 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2085 | |
8a25a2fd | 2086 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
2087 | if (ret) |
2088 | goto err_null_driver; | |
1da177e4 | 2089 | |
1c3d85dd | 2090 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2091 | int i; |
2092 | ret = -ENODEV; | |
2093 | ||
2094 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2095 | for (i = 0; i < nr_cpu_ids; i++) |
2096 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2097 | ret = 0; |
7a6aedfa MT |
2098 | break; |
2099 | } | |
1da177e4 LT |
2100 | |
2101 | /* if all ->init() calls failed, unregister */ | |
2102 | if (ret) { | |
2d06d8c4 | 2103 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 2104 | driver_data->name); |
8a25a2fd | 2105 | goto err_if_unreg; |
1da177e4 LT |
2106 | } |
2107 | } | |
2108 | ||
8f5bc2ab | 2109 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2110 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2111 | |
8f5bc2ab | 2112 | return 0; |
8a25a2fd KS |
2113 | err_if_unreg: |
2114 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab | 2115 | err_null_driver: |
0d1857a1 | 2116 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2117 | cpufreq_driver = NULL; |
0d1857a1 | 2118 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2119 | return ret; |
1da177e4 LT |
2120 | } |
2121 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2122 | ||
1da177e4 LT |
2123 | /** |
2124 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2125 | * | |
bb176f7d | 2126 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2127 | * the right to do so, i.e. if you have succeeded in initialising before! |
2128 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2129 | * currently not initialised. | |
2130 | */ | |
221dee28 | 2131 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2132 | { |
2133 | unsigned long flags; | |
2134 | ||
1c3d85dd | 2135 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2136 | return -EINVAL; |
1da177e4 | 2137 | |
2d06d8c4 | 2138 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2139 | |
8a25a2fd | 2140 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 2141 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2142 | |
6eed9404 | 2143 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2144 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2145 | |
1c3d85dd | 2146 | cpufreq_driver = NULL; |
6eed9404 | 2147 | |
0d1857a1 | 2148 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2149 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2150 | |
2151 | return 0; | |
2152 | } | |
2153 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2154 | |
2155 | static int __init cpufreq_core_init(void) | |
2156 | { | |
2157 | int cpu; | |
2158 | ||
a7b422cd KRW |
2159 | if (cpufreq_disabled()) |
2160 | return -ENODEV; | |
2161 | ||
474deff7 | 2162 | for_each_possible_cpu(cpu) |
5a01f2e8 | 2163 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
8aa84ad8 | 2164 | |
2361be23 | 2165 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 | 2166 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 2167 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 2168 | |
5a01f2e8 VP |
2169 | return 0; |
2170 | } | |
5a01f2e8 | 2171 | core_initcall(cpufreq_core_init); |