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> |
2f0aea93 | 29 | #include <linux/suspend.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 | 41 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
6f1e4efd | 42 | DEFINE_MUTEX(cpufreq_governor_lock); |
c88a1f8b | 43 | static LIST_HEAD(cpufreq_policy_list); |
bb176f7d | 44 | |
084f3493 | 45 | /* This one keeps track of the previously set governor of a removed CPU */ |
e77b89f1 | 46 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
1da177e4 | 47 | |
2f0aea93 VK |
48 | /* Flag to suspend/resume CPUFreq governors */ |
49 | static bool cpufreq_suspended; | |
1da177e4 | 50 | |
9c0ebcf7 VK |
51 | static inline bool has_target(void) |
52 | { | |
53 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
54 | } | |
55 | ||
6eed9404 VK |
56 | /* |
57 | * rwsem to guarantee that cpufreq driver module doesn't unload during critical | |
58 | * sections | |
59 | */ | |
60 | static DECLARE_RWSEM(cpufreq_rwsem); | |
61 | ||
1da177e4 | 62 | /* internal prototypes */ |
29464f28 DJ |
63 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
64 | unsigned int event); | |
5a01f2e8 | 65 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 66 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
67 | |
68 | /** | |
32ee8c3e DJ |
69 | * Two notifier lists: the "policy" list is involved in the |
70 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
71 | * "transition" list for kernel code that needs to handle |
72 | * changes to devices when the CPU clock speed changes. | |
73 | * The mutex locks both lists. | |
74 | */ | |
e041c683 | 75 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 76 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 77 | |
74212ca4 | 78 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
79 | static int __init init_cpufreq_transition_notifier_list(void) |
80 | { | |
81 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 82 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
83 | return 0; |
84 | } | |
b3438f82 | 85 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 86 | |
a7b422cd | 87 | static int off __read_mostly; |
da584455 | 88 | static int cpufreq_disabled(void) |
a7b422cd KRW |
89 | { |
90 | return off; | |
91 | } | |
92 | void disable_cpufreq(void) | |
93 | { | |
94 | off = 1; | |
95 | } | |
1da177e4 | 96 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 97 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 98 | |
4d5dcc42 VK |
99 | bool have_governor_per_policy(void) |
100 | { | |
0b981e70 | 101 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 102 | } |
3f869d6d | 103 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 104 | |
944e9a03 VK |
105 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
106 | { | |
107 | if (have_governor_per_policy()) | |
108 | return &policy->kobj; | |
109 | else | |
110 | return cpufreq_global_kobject; | |
111 | } | |
112 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
113 | ||
72a4ce34 VK |
114 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
115 | { | |
116 | u64 idle_time; | |
117 | u64 cur_wall_time; | |
118 | u64 busy_time; | |
119 | ||
120 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
121 | ||
122 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
123 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
124 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
125 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
126 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
127 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
128 | ||
129 | idle_time = cur_wall_time - busy_time; | |
130 | if (wall) | |
131 | *wall = cputime_to_usecs(cur_wall_time); | |
132 | ||
133 | return cputime_to_usecs(idle_time); | |
134 | } | |
135 | ||
136 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
137 | { | |
138 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
139 | ||
140 | if (idle_time == -1ULL) | |
141 | return get_cpu_idle_time_jiffy(cpu, wall); | |
142 | else if (!io_busy) | |
143 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
144 | ||
145 | return idle_time; | |
146 | } | |
147 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
148 | ||
70e9e778 VK |
149 | /* |
150 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
151 | * drivers of SMP systems. It will do following: | |
152 | * - validate & show freq table passed | |
153 | * - set policies transition latency | |
154 | * - policy->cpus with all possible CPUs | |
155 | */ | |
156 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
157 | struct cpufreq_frequency_table *table, | |
158 | unsigned int transition_latency) | |
159 | { | |
160 | int ret; | |
161 | ||
162 | ret = cpufreq_table_validate_and_show(policy, table); | |
163 | if (ret) { | |
164 | pr_err("%s: invalid frequency table: %d\n", __func__, ret); | |
165 | return ret; | |
166 | } | |
167 | ||
168 | policy->cpuinfo.transition_latency = transition_latency; | |
169 | ||
170 | /* | |
171 | * The driver only supports the SMP configuartion where all processors | |
172 | * share the clock and voltage and clock. | |
173 | */ | |
174 | cpumask_setall(policy->cpus); | |
175 | ||
176 | return 0; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
179 | ||
652ed95d VK |
180 | unsigned int cpufreq_generic_get(unsigned int cpu) |
181 | { | |
182 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
183 | ||
184 | if (!policy || IS_ERR(policy->clk)) { | |
e837f9b5 JP |
185 | pr_err("%s: No %s associated to cpu: %d\n", |
186 | __func__, policy ? "clk" : "policy", cpu); | |
652ed95d VK |
187 | return 0; |
188 | } | |
189 | ||
190 | return clk_get_rate(policy->clk) / 1000; | |
191 | } | |
192 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
193 | ||
e0b3165b VK |
194 | /* Only for cpufreq core internal use */ |
195 | struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) | |
196 | { | |
197 | return per_cpu(cpufreq_cpu_data, cpu); | |
198 | } | |
199 | ||
6eed9404 | 200 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 201 | { |
6eed9404 | 202 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
203 | unsigned long flags; |
204 | ||
6eed9404 VK |
205 | if (cpufreq_disabled() || (cpu >= nr_cpu_ids)) |
206 | return NULL; | |
207 | ||
208 | if (!down_read_trylock(&cpufreq_rwsem)) | |
209 | return NULL; | |
1da177e4 LT |
210 | |
211 | /* get the cpufreq driver */ | |
1c3d85dd | 212 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 213 | |
6eed9404 VK |
214 | if (cpufreq_driver) { |
215 | /* get the CPU */ | |
216 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
217 | if (policy) | |
218 | kobject_get(&policy->kobj); | |
219 | } | |
1da177e4 | 220 | |
6eed9404 | 221 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 222 | |
3a3e9e06 | 223 | if (!policy) |
6eed9404 | 224 | up_read(&cpufreq_rwsem); |
1da177e4 | 225 | |
3a3e9e06 | 226 | return policy; |
a9144436 | 227 | } |
1da177e4 LT |
228 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
229 | ||
3a3e9e06 | 230 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 231 | { |
d5aaffa9 DB |
232 | if (cpufreq_disabled()) |
233 | return; | |
234 | ||
6eed9404 VK |
235 | kobject_put(&policy->kobj); |
236 | up_read(&cpufreq_rwsem); | |
1da177e4 LT |
237 | } |
238 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
239 | ||
1da177e4 LT |
240 | /********************************************************************* |
241 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
242 | *********************************************************************/ | |
243 | ||
244 | /** | |
245 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
246 | * | |
247 | * This function alters the system "loops_per_jiffy" for the clock | |
248 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 249 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
250 | * per-CPU loops_per_jiffy value wherever possible. |
251 | */ | |
252 | #ifndef CONFIG_SMP | |
253 | static unsigned long l_p_j_ref; | |
bb176f7d | 254 | static unsigned int l_p_j_ref_freq; |
1da177e4 | 255 | |
858119e1 | 256 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
257 | { |
258 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
259 | return; | |
260 | ||
261 | if (!l_p_j_ref_freq) { | |
262 | l_p_j_ref = loops_per_jiffy; | |
263 | l_p_j_ref_freq = ci->old; | |
e837f9b5 JP |
264 | pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", |
265 | l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 | 266 | } |
0b443ead | 267 | if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { |
e08f5f5b GS |
268 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
269 | ci->new); | |
e837f9b5 JP |
270 | pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", |
271 | loops_per_jiffy, ci->new); | |
1da177e4 LT |
272 | } |
273 | } | |
274 | #else | |
e08f5f5b GS |
275 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
276 | { | |
277 | return; | |
278 | } | |
1da177e4 LT |
279 | #endif |
280 | ||
0956df9c | 281 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 282 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
283 | { |
284 | BUG_ON(irqs_disabled()); | |
285 | ||
d5aaffa9 DB |
286 | if (cpufreq_disabled()) |
287 | return; | |
288 | ||
1c3d85dd | 289 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 290 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e837f9b5 | 291 | state, freqs->new); |
1da177e4 | 292 | |
1da177e4 | 293 | switch (state) { |
e4472cb3 | 294 | |
1da177e4 | 295 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 296 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
297 | * which is not equal to what the cpufreq core thinks is |
298 | * "old frequency". | |
1da177e4 | 299 | */ |
1c3d85dd | 300 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
301 | if ((policy) && (policy->cpu == freqs->cpu) && |
302 | (policy->cur) && (policy->cur != freqs->old)) { | |
e837f9b5 JP |
303 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", |
304 | freqs->old, policy->cur); | |
e4472cb3 | 305 | freqs->old = policy->cur; |
1da177e4 LT |
306 | } |
307 | } | |
b4dfdbb3 | 308 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 309 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
310 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
311 | break; | |
e4472cb3 | 312 | |
1da177e4 LT |
313 | case CPUFREQ_POSTCHANGE: |
314 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
e837f9b5 JP |
315 | pr_debug("FREQ: %lu - CPU: %lu\n", |
316 | (unsigned long)freqs->new, (unsigned long)freqs->cpu); | |
25e41933 | 317 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 318 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 319 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
320 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
321 | policy->cur = freqs->new; | |
1da177e4 LT |
322 | break; |
323 | } | |
1da177e4 | 324 | } |
bb176f7d | 325 | |
b43a7ffb VK |
326 | /** |
327 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
328 | * on frequency transition. | |
329 | * | |
330 | * This function calls the transition notifiers and the "adjust_jiffies" | |
331 | * function. It is called twice on all CPU frequency changes that have | |
332 | * external effects. | |
333 | */ | |
236a9800 | 334 | static void cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb VK |
335 | struct cpufreq_freqs *freqs, unsigned int state) |
336 | { | |
337 | for_each_cpu(freqs->cpu, policy->cpus) | |
338 | __cpufreq_notify_transition(policy, freqs, state); | |
339 | } | |
1da177e4 | 340 | |
f7ba3b41 | 341 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 342 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
343 | struct cpufreq_freqs *freqs, int transition_failed) |
344 | { | |
345 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
346 | if (!transition_failed) | |
347 | return; | |
348 | ||
349 | swap(freqs->old, freqs->new); | |
350 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
351 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
352 | } | |
f7ba3b41 | 353 | |
12478cf0 SB |
354 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
355 | struct cpufreq_freqs *freqs) | |
356 | { | |
357 | wait: | |
358 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
359 | ||
360 | spin_lock(&policy->transition_lock); | |
361 | ||
362 | if (unlikely(policy->transition_ongoing)) { | |
363 | spin_unlock(&policy->transition_lock); | |
364 | goto wait; | |
365 | } | |
366 | ||
367 | policy->transition_ongoing = true; | |
368 | ||
369 | spin_unlock(&policy->transition_lock); | |
370 | ||
371 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
372 | } | |
373 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
374 | ||
375 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
376 | struct cpufreq_freqs *freqs, int transition_failed) | |
377 | { | |
378 | if (unlikely(WARN_ON(!policy->transition_ongoing))) | |
379 | return; | |
380 | ||
381 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
382 | ||
383 | policy->transition_ongoing = false; | |
384 | ||
385 | wake_up(&policy->transition_wait); | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
388 | ||
1da177e4 | 389 | |
1da177e4 LT |
390 | /********************************************************************* |
391 | * SYSFS INTERFACE * | |
392 | *********************************************************************/ | |
8a5c74a1 | 393 | static ssize_t show_boost(struct kobject *kobj, |
6f19efc0 LM |
394 | struct attribute *attr, char *buf) |
395 | { | |
396 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
397 | } | |
398 | ||
399 | static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, | |
400 | const char *buf, size_t count) | |
401 | { | |
402 | int ret, enable; | |
403 | ||
404 | ret = sscanf(buf, "%d", &enable); | |
405 | if (ret != 1 || enable < 0 || enable > 1) | |
406 | return -EINVAL; | |
407 | ||
408 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
409 | pr_err("%s: Cannot %s BOOST!\n", |
410 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
411 | return -EINVAL; |
412 | } | |
413 | ||
e837f9b5 JP |
414 | pr_debug("%s: cpufreq BOOST %s\n", |
415 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
416 | |
417 | return count; | |
418 | } | |
419 | define_one_global_rw(boost); | |
1da177e4 | 420 | |
3bcb09a3 JF |
421 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
422 | { | |
423 | struct cpufreq_governor *t; | |
424 | ||
425 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 426 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
427 | return t; |
428 | ||
429 | return NULL; | |
430 | } | |
431 | ||
1da177e4 LT |
432 | /** |
433 | * cpufreq_parse_governor - parse a governor string | |
434 | */ | |
905d77cd | 435 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
436 | struct cpufreq_governor **governor) |
437 | { | |
3bcb09a3 | 438 | int err = -EINVAL; |
1c3d85dd RW |
439 | |
440 | if (!cpufreq_driver) | |
3bcb09a3 JF |
441 | goto out; |
442 | ||
1c3d85dd | 443 | if (cpufreq_driver->setpolicy) { |
1da177e4 LT |
444 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
445 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 446 | err = 0; |
e08f5f5b GS |
447 | } else if (!strnicmp(str_governor, "powersave", |
448 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 449 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 450 | err = 0; |
1da177e4 | 451 | } |
9c0ebcf7 | 452 | } else if (has_target()) { |
1da177e4 | 453 | struct cpufreq_governor *t; |
3bcb09a3 | 454 | |
3fc54d37 | 455 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
456 | |
457 | t = __find_governor(str_governor); | |
458 | ||
ea714970 | 459 | if (t == NULL) { |
1a8e1463 | 460 | int ret; |
ea714970 | 461 | |
1a8e1463 KC |
462 | mutex_unlock(&cpufreq_governor_mutex); |
463 | ret = request_module("cpufreq_%s", str_governor); | |
464 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 465 | |
1a8e1463 KC |
466 | if (ret == 0) |
467 | t = __find_governor(str_governor); | |
ea714970 JF |
468 | } |
469 | ||
3bcb09a3 JF |
470 | if (t != NULL) { |
471 | *governor = t; | |
472 | err = 0; | |
1da177e4 | 473 | } |
3bcb09a3 | 474 | |
3fc54d37 | 475 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 476 | } |
29464f28 | 477 | out: |
3bcb09a3 | 478 | return err; |
1da177e4 | 479 | } |
1da177e4 | 480 | |
1da177e4 | 481 | /** |
e08f5f5b GS |
482 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
483 | * print out cpufreq information | |
1da177e4 LT |
484 | * |
485 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
486 | * "unsigned int". | |
487 | */ | |
488 | ||
32ee8c3e DJ |
489 | #define show_one(file_name, object) \ |
490 | static ssize_t show_##file_name \ | |
905d77cd | 491 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 492 | { \ |
29464f28 | 493 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
494 | } |
495 | ||
496 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
497 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 498 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
499 | show_one(scaling_min_freq, min); |
500 | show_one(scaling_max_freq, max); | |
501 | show_one(scaling_cur_freq, cur); | |
502 | ||
037ce839 | 503 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 504 | struct cpufreq_policy *new_policy); |
7970e08b | 505 | |
1da177e4 LT |
506 | /** |
507 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
508 | */ | |
509 | #define store_one(file_name, object) \ | |
510 | static ssize_t store_##file_name \ | |
905d77cd | 511 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 512 | { \ |
5136fa56 | 513 | int ret; \ |
1da177e4 LT |
514 | struct cpufreq_policy new_policy; \ |
515 | \ | |
516 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
517 | if (ret) \ | |
518 | return -EINVAL; \ | |
519 | \ | |
29464f28 | 520 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
521 | if (ret != 1) \ |
522 | return -EINVAL; \ | |
523 | \ | |
037ce839 | 524 | ret = cpufreq_set_policy(policy, &new_policy); \ |
7970e08b | 525 | policy->user_policy.object = policy->object; \ |
1da177e4 LT |
526 | \ |
527 | return ret ? ret : count; \ | |
528 | } | |
529 | ||
29464f28 DJ |
530 | store_one(scaling_min_freq, min); |
531 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
532 | |
533 | /** | |
534 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
535 | */ | |
905d77cd DJ |
536 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
537 | char *buf) | |
1da177e4 | 538 | { |
5a01f2e8 | 539 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
540 | if (!cur_freq) |
541 | return sprintf(buf, "<unknown>"); | |
542 | return sprintf(buf, "%u\n", cur_freq); | |
543 | } | |
544 | ||
1da177e4 LT |
545 | /** |
546 | * show_scaling_governor - show the current policy for the specified CPU | |
547 | */ | |
905d77cd | 548 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 549 | { |
29464f28 | 550 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
551 | return sprintf(buf, "powersave\n"); |
552 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
553 | return sprintf(buf, "performance\n"); | |
554 | else if (policy->governor) | |
4b972f0b | 555 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 556 | policy->governor->name); |
1da177e4 LT |
557 | return -EINVAL; |
558 | } | |
559 | ||
1da177e4 LT |
560 | /** |
561 | * store_scaling_governor - store policy for the specified CPU | |
562 | */ | |
905d77cd DJ |
563 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
564 | const char *buf, size_t count) | |
1da177e4 | 565 | { |
5136fa56 | 566 | int ret; |
1da177e4 LT |
567 | char str_governor[16]; |
568 | struct cpufreq_policy new_policy; | |
569 | ||
570 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
571 | if (ret) | |
572 | return ret; | |
573 | ||
29464f28 | 574 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
575 | if (ret != 1) |
576 | return -EINVAL; | |
577 | ||
e08f5f5b GS |
578 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
579 | &new_policy.governor)) | |
1da177e4 LT |
580 | return -EINVAL; |
581 | ||
037ce839 | 582 | ret = cpufreq_set_policy(policy, &new_policy); |
7970e08b TR |
583 | |
584 | policy->user_policy.policy = policy->policy; | |
585 | policy->user_policy.governor = policy->governor; | |
7970e08b | 586 | |
e08f5f5b GS |
587 | if (ret) |
588 | return ret; | |
589 | else | |
590 | return count; | |
1da177e4 LT |
591 | } |
592 | ||
593 | /** | |
594 | * show_scaling_driver - show the cpufreq driver currently loaded | |
595 | */ | |
905d77cd | 596 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 597 | { |
1c3d85dd | 598 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
599 | } |
600 | ||
601 | /** | |
602 | * show_scaling_available_governors - show the available CPUfreq governors | |
603 | */ | |
905d77cd DJ |
604 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
605 | char *buf) | |
1da177e4 LT |
606 | { |
607 | ssize_t i = 0; | |
608 | struct cpufreq_governor *t; | |
609 | ||
9c0ebcf7 | 610 | if (!has_target()) { |
1da177e4 LT |
611 | i += sprintf(buf, "performance powersave"); |
612 | goto out; | |
613 | } | |
614 | ||
615 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
616 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
617 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 618 | goto out; |
4b972f0b | 619 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 620 | } |
7d5e350f | 621 | out: |
1da177e4 LT |
622 | i += sprintf(&buf[i], "\n"); |
623 | return i; | |
624 | } | |
e8628dd0 | 625 | |
f4fd3797 | 626 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
627 | { |
628 | ssize_t i = 0; | |
629 | unsigned int cpu; | |
630 | ||
835481d9 | 631 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
632 | if (i) |
633 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
634 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
635 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 636 | break; |
1da177e4 LT |
637 | } |
638 | i += sprintf(&buf[i], "\n"); | |
639 | return i; | |
640 | } | |
f4fd3797 | 641 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 642 | |
e8628dd0 DW |
643 | /** |
644 | * show_related_cpus - show the CPUs affected by each transition even if | |
645 | * hw coordination is in use | |
646 | */ | |
647 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
648 | { | |
f4fd3797 | 649 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
650 | } |
651 | ||
652 | /** | |
653 | * show_affected_cpus - show the CPUs affected by each transition | |
654 | */ | |
655 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
656 | { | |
f4fd3797 | 657 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
658 | } |
659 | ||
9e76988e | 660 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 661 | const char *buf, size_t count) |
9e76988e VP |
662 | { |
663 | unsigned int freq = 0; | |
664 | unsigned int ret; | |
665 | ||
879000f9 | 666 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
667 | return -EINVAL; |
668 | ||
669 | ret = sscanf(buf, "%u", &freq); | |
670 | if (ret != 1) | |
671 | return -EINVAL; | |
672 | ||
673 | policy->governor->store_setspeed(policy, freq); | |
674 | ||
675 | return count; | |
676 | } | |
677 | ||
678 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
679 | { | |
879000f9 | 680 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
681 | return sprintf(buf, "<unsupported>\n"); |
682 | ||
683 | return policy->governor->show_setspeed(policy, buf); | |
684 | } | |
1da177e4 | 685 | |
e2f74f35 | 686 | /** |
8bf1ac72 | 687 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
688 | */ |
689 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
690 | { | |
691 | unsigned int limit; | |
692 | int ret; | |
1c3d85dd RW |
693 | if (cpufreq_driver->bios_limit) { |
694 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
695 | if (!ret) |
696 | return sprintf(buf, "%u\n", limit); | |
697 | } | |
698 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
699 | } | |
700 | ||
6dad2a29 BP |
701 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
702 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
703 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
704 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
705 | cpufreq_freq_attr_ro(scaling_available_governors); | |
706 | cpufreq_freq_attr_ro(scaling_driver); | |
707 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
708 | cpufreq_freq_attr_ro(bios_limit); | |
709 | cpufreq_freq_attr_ro(related_cpus); | |
710 | cpufreq_freq_attr_ro(affected_cpus); | |
711 | cpufreq_freq_attr_rw(scaling_min_freq); | |
712 | cpufreq_freq_attr_rw(scaling_max_freq); | |
713 | cpufreq_freq_attr_rw(scaling_governor); | |
714 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 715 | |
905d77cd | 716 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
717 | &cpuinfo_min_freq.attr, |
718 | &cpuinfo_max_freq.attr, | |
ed129784 | 719 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
720 | &scaling_min_freq.attr, |
721 | &scaling_max_freq.attr, | |
722 | &affected_cpus.attr, | |
e8628dd0 | 723 | &related_cpus.attr, |
1da177e4 LT |
724 | &scaling_governor.attr, |
725 | &scaling_driver.attr, | |
726 | &scaling_available_governors.attr, | |
9e76988e | 727 | &scaling_setspeed.attr, |
1da177e4 LT |
728 | NULL |
729 | }; | |
730 | ||
29464f28 DJ |
731 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
732 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 733 | |
29464f28 | 734 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 735 | { |
905d77cd DJ |
736 | struct cpufreq_policy *policy = to_policy(kobj); |
737 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 738 | ssize_t ret; |
6eed9404 VK |
739 | |
740 | if (!down_read_trylock(&cpufreq_rwsem)) | |
1b750e3b | 741 | return -EINVAL; |
5a01f2e8 | 742 | |
ad7722da | 743 | down_read(&policy->rwsem); |
5a01f2e8 | 744 | |
e08f5f5b GS |
745 | if (fattr->show) |
746 | ret = fattr->show(policy, buf); | |
747 | else | |
748 | ret = -EIO; | |
749 | ||
ad7722da | 750 | up_read(&policy->rwsem); |
6eed9404 | 751 | up_read(&cpufreq_rwsem); |
1b750e3b | 752 | |
1da177e4 LT |
753 | return ret; |
754 | } | |
755 | ||
905d77cd DJ |
756 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
757 | const char *buf, size_t count) | |
1da177e4 | 758 | { |
905d77cd DJ |
759 | struct cpufreq_policy *policy = to_policy(kobj); |
760 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 761 | ssize_t ret = -EINVAL; |
6eed9404 | 762 | |
4f750c93 SB |
763 | get_online_cpus(); |
764 | ||
765 | if (!cpu_online(policy->cpu)) | |
766 | goto unlock; | |
767 | ||
6eed9404 | 768 | if (!down_read_trylock(&cpufreq_rwsem)) |
4f750c93 | 769 | goto unlock; |
5a01f2e8 | 770 | |
ad7722da | 771 | down_write(&policy->rwsem); |
5a01f2e8 | 772 | |
e08f5f5b GS |
773 | if (fattr->store) |
774 | ret = fattr->store(policy, buf, count); | |
775 | else | |
776 | ret = -EIO; | |
777 | ||
ad7722da | 778 | up_write(&policy->rwsem); |
6eed9404 | 779 | |
6eed9404 | 780 | up_read(&cpufreq_rwsem); |
4f750c93 SB |
781 | unlock: |
782 | put_online_cpus(); | |
783 | ||
1da177e4 LT |
784 | return ret; |
785 | } | |
786 | ||
905d77cd | 787 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 788 | { |
905d77cd | 789 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 790 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
791 | complete(&policy->kobj_unregister); |
792 | } | |
793 | ||
52cf25d0 | 794 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
795 | .show = show, |
796 | .store = store, | |
797 | }; | |
798 | ||
799 | static struct kobj_type ktype_cpufreq = { | |
800 | .sysfs_ops = &sysfs_ops, | |
801 | .default_attrs = default_attrs, | |
802 | .release = cpufreq_sysfs_release, | |
803 | }; | |
804 | ||
2361be23 VK |
805 | struct kobject *cpufreq_global_kobject; |
806 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
807 | ||
808 | static int cpufreq_global_kobject_usage; | |
809 | ||
810 | int cpufreq_get_global_kobject(void) | |
811 | { | |
812 | if (!cpufreq_global_kobject_usage++) | |
813 | return kobject_add(cpufreq_global_kobject, | |
814 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
815 | ||
816 | return 0; | |
817 | } | |
818 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
819 | ||
820 | void cpufreq_put_global_kobject(void) | |
821 | { | |
822 | if (!--cpufreq_global_kobject_usage) | |
823 | kobject_del(cpufreq_global_kobject); | |
824 | } | |
825 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
826 | ||
827 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
828 | { | |
829 | int ret = cpufreq_get_global_kobject(); | |
830 | ||
831 | if (!ret) { | |
832 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
833 | if (ret) | |
834 | cpufreq_put_global_kobject(); | |
835 | } | |
836 | ||
837 | return ret; | |
838 | } | |
839 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
840 | ||
841 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
842 | { | |
843 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
844 | cpufreq_put_global_kobject(); | |
845 | } | |
846 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
847 | ||
19d6f7ec | 848 | /* symlink affected CPUs */ |
308b60e7 | 849 | static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy) |
19d6f7ec DJ |
850 | { |
851 | unsigned int j; | |
852 | int ret = 0; | |
853 | ||
854 | for_each_cpu(j, policy->cpus) { | |
8a25a2fd | 855 | struct device *cpu_dev; |
19d6f7ec | 856 | |
308b60e7 | 857 | if (j == policy->cpu) |
19d6f7ec | 858 | continue; |
19d6f7ec | 859 | |
e8fdde10 | 860 | pr_debug("Adding link for CPU: %u\n", j); |
8a25a2fd KS |
861 | cpu_dev = get_cpu_device(j); |
862 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec | 863 | "cpufreq"); |
71c3461e RW |
864 | if (ret) |
865 | break; | |
19d6f7ec DJ |
866 | } |
867 | return ret; | |
868 | } | |
869 | ||
308b60e7 | 870 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, |
8a25a2fd | 871 | struct device *dev) |
909a694e DJ |
872 | { |
873 | struct freq_attr **drv_attr; | |
909a694e | 874 | int ret = 0; |
909a694e DJ |
875 | |
876 | /* prepare interface data */ | |
877 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 878 | &dev->kobj, "cpufreq"); |
909a694e DJ |
879 | if (ret) |
880 | return ret; | |
881 | ||
882 | /* set up files for this cpu device */ | |
1c3d85dd | 883 | drv_attr = cpufreq_driver->attr; |
909a694e DJ |
884 | while ((drv_attr) && (*drv_attr)) { |
885 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
886 | if (ret) | |
1c3d85dd | 887 | goto err_out_kobj_put; |
909a694e DJ |
888 | drv_attr++; |
889 | } | |
1c3d85dd | 890 | if (cpufreq_driver->get) { |
909a694e DJ |
891 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
892 | if (ret) | |
1c3d85dd | 893 | goto err_out_kobj_put; |
909a694e | 894 | } |
9c0ebcf7 | 895 | if (has_target()) { |
909a694e DJ |
896 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); |
897 | if (ret) | |
1c3d85dd | 898 | goto err_out_kobj_put; |
909a694e | 899 | } |
1c3d85dd | 900 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
901 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
902 | if (ret) | |
1c3d85dd | 903 | goto err_out_kobj_put; |
e2f74f35 | 904 | } |
909a694e | 905 | |
308b60e7 | 906 | ret = cpufreq_add_dev_symlink(policy); |
ecf7e461 DJ |
907 | if (ret) |
908 | goto err_out_kobj_put; | |
909 | ||
e18f1682 SB |
910 | return ret; |
911 | ||
912 | err_out_kobj_put: | |
913 | kobject_put(&policy->kobj); | |
914 | wait_for_completion(&policy->kobj_unregister); | |
915 | return ret; | |
916 | } | |
917 | ||
918 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
919 | { | |
6e2c89d1 | 920 | struct cpufreq_governor *gov = NULL; |
e18f1682 SB |
921 | struct cpufreq_policy new_policy; |
922 | int ret = 0; | |
923 | ||
d5b73cd8 | 924 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 925 | |
6e2c89d1 | 926 | /* Update governor of new_policy to the governor used before hotplug */ |
927 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu)); | |
928 | if (gov) | |
929 | pr_debug("Restoring governor %s for cpu %d\n", | |
930 | policy->governor->name, policy->cpu); | |
931 | else | |
932 | gov = CPUFREQ_DEFAULT_GOVERNOR; | |
933 | ||
934 | new_policy.governor = gov; | |
935 | ||
a27a9ab7 JB |
936 | /* Use the default policy if its valid. */ |
937 | if (cpufreq_driver->setpolicy) | |
6e2c89d1 | 938 | cpufreq_parse_governor(gov->name, &new_policy.policy, NULL); |
ecf7e461 DJ |
939 | |
940 | /* set default policy */ | |
037ce839 | 941 | ret = cpufreq_set_policy(policy, &new_policy); |
ecf7e461 | 942 | if (ret) { |
2d06d8c4 | 943 | pr_debug("setting policy failed\n"); |
1c3d85dd RW |
944 | if (cpufreq_driver->exit) |
945 | cpufreq_driver->exit(policy); | |
ecf7e461 | 946 | } |
909a694e DJ |
947 | } |
948 | ||
fcf80582 | 949 | #ifdef CONFIG_HOTPLUG_CPU |
d8d3b471 | 950 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 951 | unsigned int cpu, struct device *dev) |
fcf80582 | 952 | { |
9c0ebcf7 | 953 | int ret = 0; |
fcf80582 VK |
954 | unsigned long flags; |
955 | ||
9c0ebcf7 | 956 | if (has_target()) { |
3de9bdeb VK |
957 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
958 | if (ret) { | |
959 | pr_err("%s: Failed to stop governor\n", __func__); | |
960 | return ret; | |
961 | } | |
962 | } | |
fcf80582 | 963 | |
ad7722da | 964 | down_write(&policy->rwsem); |
2eaa3e2d | 965 | |
0d1857a1 | 966 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 967 | |
fcf80582 VK |
968 | cpumask_set_cpu(cpu, policy->cpus); |
969 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
0d1857a1 | 970 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fcf80582 | 971 | |
ad7722da | 972 | up_write(&policy->rwsem); |
2eaa3e2d | 973 | |
9c0ebcf7 | 974 | if (has_target()) { |
e5c87b76 SK |
975 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); |
976 | if (!ret) | |
977 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
978 | ||
979 | if (ret) { | |
3de9bdeb VK |
980 | pr_err("%s: Failed to start governor\n", __func__); |
981 | return ret; | |
982 | } | |
820c6ca2 | 983 | } |
fcf80582 | 984 | |
42f921a6 | 985 | return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); |
fcf80582 VK |
986 | } |
987 | #endif | |
1da177e4 | 988 | |
8414809c SB |
989 | static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu) |
990 | { | |
991 | struct cpufreq_policy *policy; | |
992 | unsigned long flags; | |
993 | ||
44871c9c | 994 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
8414809c SB |
995 | |
996 | policy = per_cpu(cpufreq_cpu_data_fallback, cpu); | |
997 | ||
44871c9c | 998 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
8414809c | 999 | |
6e2c89d1 | 1000 | policy->governor = NULL; |
1001 | ||
8414809c SB |
1002 | return policy; |
1003 | } | |
1004 | ||
e9698cc5 SB |
1005 | static struct cpufreq_policy *cpufreq_policy_alloc(void) |
1006 | { | |
1007 | struct cpufreq_policy *policy; | |
1008 | ||
1009 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
1010 | if (!policy) | |
1011 | return NULL; | |
1012 | ||
1013 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1014 | goto err_free_policy; | |
1015 | ||
1016 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1017 | goto err_free_cpumask; | |
1018 | ||
c88a1f8b | 1019 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1020 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1021 | spin_lock_init(&policy->transition_lock); |
1022 | init_waitqueue_head(&policy->transition_wait); | |
ad7722da | 1023 | |
e9698cc5 SB |
1024 | return policy; |
1025 | ||
1026 | err_free_cpumask: | |
1027 | free_cpumask_var(policy->cpus); | |
1028 | err_free_policy: | |
1029 | kfree(policy); | |
1030 | ||
1031 | return NULL; | |
1032 | } | |
1033 | ||
42f921a6 VK |
1034 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
1035 | { | |
1036 | struct kobject *kobj; | |
1037 | struct completion *cmp; | |
1038 | ||
fcd7af91 VK |
1039 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1040 | CPUFREQ_REMOVE_POLICY, policy); | |
1041 | ||
42f921a6 VK |
1042 | down_read(&policy->rwsem); |
1043 | kobj = &policy->kobj; | |
1044 | cmp = &policy->kobj_unregister; | |
1045 | up_read(&policy->rwsem); | |
1046 | kobject_put(kobj); | |
1047 | ||
1048 | /* | |
1049 | * We need to make sure that the underlying kobj is | |
1050 | * actually not referenced anymore by anybody before we | |
1051 | * proceed with unloading. | |
1052 | */ | |
1053 | pr_debug("waiting for dropping of refcount\n"); | |
1054 | wait_for_completion(cmp); | |
1055 | pr_debug("wait complete\n"); | |
1056 | } | |
1057 | ||
e9698cc5 SB |
1058 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
1059 | { | |
1060 | free_cpumask_var(policy->related_cpus); | |
1061 | free_cpumask_var(policy->cpus); | |
1062 | kfree(policy); | |
1063 | } | |
1064 | ||
0d66b91e SB |
1065 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1066 | { | |
99ec899e | 1067 | if (WARN_ON(cpu == policy->cpu)) |
cb38ed5c SB |
1068 | return; |
1069 | ||
ad7722da | 1070 | down_write(&policy->rwsem); |
8efd5765 | 1071 | |
0d66b91e SB |
1072 | policy->last_cpu = policy->cpu; |
1073 | policy->cpu = cpu; | |
1074 | ||
ad7722da | 1075 | up_write(&policy->rwsem); |
8efd5765 | 1076 | |
0d66b91e SB |
1077 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1078 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1079 | } | |
1080 | ||
96bbbe4a | 1081 | static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1082 | { |
fcf80582 | 1083 | unsigned int j, cpu = dev->id; |
65922465 | 1084 | int ret = -ENOMEM; |
1da177e4 | 1085 | struct cpufreq_policy *policy; |
1da177e4 | 1086 | unsigned long flags; |
96bbbe4a | 1087 | bool recover_policy = cpufreq_suspended; |
90e41bac | 1088 | #ifdef CONFIG_HOTPLUG_CPU |
1b274294 | 1089 | struct cpufreq_policy *tpolicy; |
90e41bac | 1090 | #endif |
1da177e4 | 1091 | |
c32b6b8e AR |
1092 | if (cpu_is_offline(cpu)) |
1093 | return 0; | |
1094 | ||
2d06d8c4 | 1095 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
1096 | |
1097 | #ifdef CONFIG_SMP | |
1098 | /* check whether a different CPU already registered this | |
1099 | * CPU because it is in the same boat. */ | |
1100 | policy = cpufreq_cpu_get(cpu); | |
1101 | if (unlikely(policy)) { | |
8ff69732 | 1102 | cpufreq_cpu_put(policy); |
1da177e4 LT |
1103 | return 0; |
1104 | } | |
5025d628 | 1105 | #endif |
fcf80582 | 1106 | |
6eed9404 VK |
1107 | if (!down_read_trylock(&cpufreq_rwsem)) |
1108 | return 0; | |
1109 | ||
fcf80582 VK |
1110 | #ifdef CONFIG_HOTPLUG_CPU |
1111 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
0d1857a1 | 1112 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1b274294 VK |
1113 | list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) { |
1114 | if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) { | |
0d1857a1 | 1115 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
42f921a6 | 1116 | ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev); |
6eed9404 VK |
1117 | up_read(&cpufreq_rwsem); |
1118 | return ret; | |
2eaa3e2d | 1119 | } |
fcf80582 | 1120 | } |
0d1857a1 | 1121 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
1122 | #endif |
1123 | ||
72368d12 RW |
1124 | /* |
1125 | * Restore the saved policy when doing light-weight init and fall back | |
1126 | * to the full init if that fails. | |
1127 | */ | |
96bbbe4a | 1128 | policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL; |
72368d12 | 1129 | if (!policy) { |
96bbbe4a | 1130 | recover_policy = false; |
8414809c | 1131 | policy = cpufreq_policy_alloc(); |
72368d12 RW |
1132 | if (!policy) |
1133 | goto nomem_out; | |
1134 | } | |
0d66b91e SB |
1135 | |
1136 | /* | |
1137 | * In the resume path, since we restore a saved policy, the assignment | |
1138 | * to policy->cpu is like an update of the existing policy, rather than | |
1139 | * the creation of a brand new one. So we need to perform this update | |
1140 | * by invoking update_policy_cpu(). | |
1141 | */ | |
96bbbe4a | 1142 | if (recover_policy && cpu != policy->cpu) |
0d66b91e SB |
1143 | update_policy_cpu(policy, cpu); |
1144 | else | |
1145 | policy->cpu = cpu; | |
1146 | ||
835481d9 | 1147 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1148 | |
1da177e4 | 1149 | init_completion(&policy->kobj_unregister); |
65f27f38 | 1150 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
1151 | |
1152 | /* call driver. From then on the cpufreq must be able | |
1153 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1154 | */ | |
1c3d85dd | 1155 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1156 | if (ret) { |
2d06d8c4 | 1157 | pr_debug("initialization failed\n"); |
2eaa3e2d | 1158 | goto err_set_policy_cpu; |
1da177e4 | 1159 | } |
643ae6e8 | 1160 | |
5a7e56a5 VK |
1161 | /* related cpus should atleast have policy->cpus */ |
1162 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1163 | ||
1164 | /* | |
1165 | * affected cpus must always be the one, which are online. We aren't | |
1166 | * managing offline cpus here. | |
1167 | */ | |
1168 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1169 | ||
96bbbe4a | 1170 | if (!recover_policy) { |
5a7e56a5 VK |
1171 | policy->user_policy.min = policy->min; |
1172 | policy->user_policy.max = policy->max; | |
1173 | } | |
1174 | ||
4e97b631 | 1175 | down_write(&policy->rwsem); |
652ed95d VK |
1176 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1177 | for_each_cpu(j, policy->cpus) | |
1178 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1179 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1180 | ||
2ed99e39 | 1181 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
da60ce9f VK |
1182 | policy->cur = cpufreq_driver->get(policy->cpu); |
1183 | if (!policy->cur) { | |
1184 | pr_err("%s: ->get() failed\n", __func__); | |
1185 | goto err_get_freq; | |
1186 | } | |
1187 | } | |
1188 | ||
d3916691 VK |
1189 | /* |
1190 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1191 | * frequency table present with cpufreq core. In such cases CPU might be | |
1192 | * unstable if it has to run on that frequency for long duration of time | |
1193 | * and so its better to set it to a frequency which is specified in | |
1194 | * freq-table. This also makes cpufreq stats inconsistent as | |
1195 | * cpufreq-stats would fail to register because current frequency of CPU | |
1196 | * isn't found in freq-table. | |
1197 | * | |
1198 | * Because we don't want this change to effect boot process badly, we go | |
1199 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1200 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1201 | * is initialized to zero). | |
1202 | * | |
1203 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1204 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1205 | * equal to target-freq. | |
1206 | */ | |
1207 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1208 | && has_target()) { | |
1209 | /* Are we running at unknown frequency ? */ | |
1210 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1211 | if (ret == -EINVAL) { | |
1212 | /* Warn user and fix it */ | |
1213 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1214 | __func__, policy->cpu, policy->cur); | |
1215 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1216 | CPUFREQ_RELATION_L); | |
1217 | ||
1218 | /* | |
1219 | * Reaching here after boot in a few seconds may not | |
1220 | * mean that system will remain stable at "unknown" | |
1221 | * frequency for longer duration. Hence, a BUG_ON(). | |
1222 | */ | |
1223 | BUG_ON(ret); | |
1224 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1225 | __func__, policy->cpu, policy->cur); | |
1226 | } | |
1227 | } | |
1228 | ||
a1531acd TR |
1229 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1230 | CPUFREQ_START, policy); | |
1231 | ||
96bbbe4a | 1232 | if (!recover_policy) { |
308b60e7 | 1233 | ret = cpufreq_add_dev_interface(policy, dev); |
a82fab29 SB |
1234 | if (ret) |
1235 | goto err_out_unregister; | |
fcd7af91 VK |
1236 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1237 | CPUFREQ_CREATE_POLICY, policy); | |
a82fab29 | 1238 | } |
8ff69732 | 1239 | |
9515f4d6 VK |
1240 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1241 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1242 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1243 | ||
e18f1682 SB |
1244 | cpufreq_init_policy(policy); |
1245 | ||
96bbbe4a | 1246 | if (!recover_policy) { |
08fd8c1c VK |
1247 | policy->user_policy.policy = policy->policy; |
1248 | policy->user_policy.governor = policy->governor; | |
1249 | } | |
4e97b631 | 1250 | up_write(&policy->rwsem); |
08fd8c1c | 1251 | |
038c5b3e | 1252 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
6eed9404 VK |
1253 | up_read(&cpufreq_rwsem); |
1254 | ||
2d06d8c4 | 1255 | pr_debug("initialization complete\n"); |
87c32271 | 1256 | |
1da177e4 LT |
1257 | return 0; |
1258 | ||
1da177e4 | 1259 | err_out_unregister: |
652ed95d | 1260 | err_get_freq: |
0d1857a1 | 1261 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
474deff7 | 1262 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1263 | per_cpu(cpufreq_cpu_data, j) = NULL; |
0d1857a1 | 1264 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1265 | |
da60ce9f VK |
1266 | if (cpufreq_driver->exit) |
1267 | cpufreq_driver->exit(policy); | |
2eaa3e2d | 1268 | err_set_policy_cpu: |
96bbbe4a | 1269 | if (recover_policy) { |
72368d12 RW |
1270 | /* Do not leave stale fallback data behind. */ |
1271 | per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL; | |
42f921a6 | 1272 | cpufreq_policy_put_kobj(policy); |
72368d12 | 1273 | } |
e9698cc5 | 1274 | cpufreq_policy_free(policy); |
42f921a6 | 1275 | |
1da177e4 | 1276 | nomem_out: |
6eed9404 VK |
1277 | up_read(&cpufreq_rwsem); |
1278 | ||
1da177e4 LT |
1279 | return ret; |
1280 | } | |
1281 | ||
a82fab29 SB |
1282 | /** |
1283 | * cpufreq_add_dev - add a CPU device | |
1284 | * | |
1285 | * Adds the cpufreq interface for a CPU device. | |
1286 | * | |
1287 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
1288 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
1289 | * mess up, but more thorough testing is needed. - Mathieu | |
1290 | */ | |
1291 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1292 | { | |
96bbbe4a | 1293 | return __cpufreq_add_dev(dev, sif); |
a82fab29 SB |
1294 | } |
1295 | ||
3a3e9e06 | 1296 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy, |
42f921a6 | 1297 | unsigned int old_cpu) |
f9ba680d SB |
1298 | { |
1299 | struct device *cpu_dev; | |
f9ba680d SB |
1300 | int ret; |
1301 | ||
1302 | /* first sibling now owns the new sysfs dir */ | |
9c8f1ee4 | 1303 | cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu)); |
a82fab29 | 1304 | |
f9ba680d | 1305 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); |
3a3e9e06 | 1306 | ret = kobject_move(&policy->kobj, &cpu_dev->kobj); |
f9ba680d | 1307 | if (ret) { |
e837f9b5 | 1308 | pr_err("%s: Failed to move kobj: %d\n", __func__, ret); |
f9ba680d | 1309 | |
ad7722da | 1310 | down_write(&policy->rwsem); |
3a3e9e06 | 1311 | cpumask_set_cpu(old_cpu, policy->cpus); |
ad7722da | 1312 | up_write(&policy->rwsem); |
f9ba680d | 1313 | |
3a3e9e06 | 1314 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, |
f9ba680d SB |
1315 | "cpufreq"); |
1316 | ||
1317 | return -EINVAL; | |
1318 | } | |
1319 | ||
1320 | return cpu_dev->id; | |
1321 | } | |
1322 | ||
cedb70af | 1323 | static int __cpufreq_remove_dev_prepare(struct device *dev, |
96bbbe4a | 1324 | struct subsys_interface *sif) |
1da177e4 | 1325 | { |
f9ba680d | 1326 | unsigned int cpu = dev->id, cpus; |
3de9bdeb | 1327 | int new_cpu, ret; |
1da177e4 | 1328 | unsigned long flags; |
3a3e9e06 | 1329 | struct cpufreq_policy *policy; |
1da177e4 | 1330 | |
b8eed8af | 1331 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1332 | |
0d1857a1 | 1333 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
2eaa3e2d | 1334 | |
3a3e9e06 | 1335 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2eaa3e2d | 1336 | |
8414809c | 1337 | /* Save the policy somewhere when doing a light-weight tear-down */ |
96bbbe4a | 1338 | if (cpufreq_suspended) |
3a3e9e06 | 1339 | per_cpu(cpufreq_cpu_data_fallback, cpu) = policy; |
8414809c | 1340 | |
0d1857a1 | 1341 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 1342 | |
3a3e9e06 | 1343 | if (!policy) { |
b8eed8af | 1344 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 LT |
1345 | return -EINVAL; |
1346 | } | |
1da177e4 | 1347 | |
9c0ebcf7 | 1348 | if (has_target()) { |
3de9bdeb VK |
1349 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP); |
1350 | if (ret) { | |
1351 | pr_err("%s: Failed to stop governor\n", __func__); | |
1352 | return ret; | |
1353 | } | |
1354 | } | |
1da177e4 | 1355 | |
1c3d85dd | 1356 | if (!cpufreq_driver->setpolicy) |
fa69e33f | 1357 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), |
3a3e9e06 | 1358 | policy->governor->name, CPUFREQ_NAME_LEN); |
1da177e4 | 1359 | |
ad7722da | 1360 | down_read(&policy->rwsem); |
3a3e9e06 | 1361 | cpus = cpumask_weight(policy->cpus); |
ad7722da | 1362 | up_read(&policy->rwsem); |
084f3493 | 1363 | |
61173f25 | 1364 | if (cpu != policy->cpu) { |
6964d91d | 1365 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
73bf0fc2 | 1366 | } else if (cpus > 1) { |
42f921a6 | 1367 | new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu); |
f9ba680d | 1368 | if (new_cpu >= 0) { |
3a3e9e06 | 1369 | update_policy_cpu(policy, new_cpu); |
a82fab29 | 1370 | |
bda9f552 | 1371 | if (!cpufreq_suspended) |
75949c9a | 1372 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", |
e837f9b5 | 1373 | __func__, new_cpu, cpu); |
1da177e4 | 1374 | } |
367dc4aa DB |
1375 | } else if (cpufreq_driver->stop_cpu && cpufreq_driver->setpolicy) { |
1376 | cpufreq_driver->stop_cpu(policy); | |
1da177e4 | 1377 | } |
1da177e4 | 1378 | |
cedb70af SB |
1379 | return 0; |
1380 | } | |
1381 | ||
1382 | static int __cpufreq_remove_dev_finish(struct device *dev, | |
96bbbe4a | 1383 | struct subsys_interface *sif) |
cedb70af SB |
1384 | { |
1385 | unsigned int cpu = dev->id, cpus; | |
1386 | int ret; | |
1387 | unsigned long flags; | |
1388 | struct cpufreq_policy *policy; | |
cedb70af SB |
1389 | |
1390 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1391 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1392 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1393 | ||
1394 | if (!policy) { | |
1395 | pr_debug("%s: No cpu_data found\n", __func__); | |
1396 | return -EINVAL; | |
1397 | } | |
1398 | ||
ad7722da | 1399 | down_write(&policy->rwsem); |
cedb70af | 1400 | cpus = cpumask_weight(policy->cpus); |
9c8f1ee4 VK |
1401 | |
1402 | if (cpus > 1) | |
1403 | cpumask_clear_cpu(cpu, policy->cpus); | |
ad7722da | 1404 | up_write(&policy->rwsem); |
cedb70af | 1405 | |
b8eed8af VK |
1406 | /* If cpu is last user of policy, free policy */ |
1407 | if (cpus == 1) { | |
9c0ebcf7 | 1408 | if (has_target()) { |
3de9bdeb VK |
1409 | ret = __cpufreq_governor(policy, |
1410 | CPUFREQ_GOV_POLICY_EXIT); | |
1411 | if (ret) { | |
1412 | pr_err("%s: Failed to exit governor\n", | |
e837f9b5 | 1413 | __func__); |
3de9bdeb VK |
1414 | return ret; |
1415 | } | |
edab2fbc | 1416 | } |
2a998599 | 1417 | |
96bbbe4a | 1418 | if (!cpufreq_suspended) |
42f921a6 | 1419 | cpufreq_policy_put_kobj(policy); |
7d26e2d5 | 1420 | |
8414809c SB |
1421 | /* |
1422 | * Perform the ->exit() even during light-weight tear-down, | |
1423 | * since this is a core component, and is essential for the | |
1424 | * subsequent light-weight ->init() to succeed. | |
b8eed8af | 1425 | */ |
1c3d85dd | 1426 | if (cpufreq_driver->exit) |
3a3e9e06 | 1427 | cpufreq_driver->exit(policy); |
27ecddc2 | 1428 | |
9515f4d6 VK |
1429 | /* Remove policy from list of active policies */ |
1430 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1431 | list_del(&policy->policy_list); | |
1432 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1433 | ||
96bbbe4a | 1434 | if (!cpufreq_suspended) |
3a3e9e06 | 1435 | cpufreq_policy_free(policy); |
e5c87b76 SK |
1436 | } else if (has_target()) { |
1437 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
1438 | if (!ret) | |
1439 | ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1440 | ||
1441 | if (ret) { | |
1442 | pr_err("%s: Failed to start governor\n", __func__); | |
1443 | return ret; | |
2a998599 | 1444 | } |
27ecddc2 | 1445 | } |
1da177e4 | 1446 | |
474deff7 | 1447 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1da177e4 LT |
1448 | return 0; |
1449 | } | |
1450 | ||
cedb70af | 1451 | /** |
27a862e9 | 1452 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1453 | * |
1454 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1455 | */ |
8a25a2fd | 1456 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1457 | { |
8a25a2fd | 1458 | unsigned int cpu = dev->id; |
27a862e9 | 1459 | int ret; |
ec28297a VP |
1460 | |
1461 | if (cpu_is_offline(cpu)) | |
1462 | return 0; | |
1463 | ||
96bbbe4a | 1464 | ret = __cpufreq_remove_dev_prepare(dev, sif); |
27a862e9 VK |
1465 | |
1466 | if (!ret) | |
96bbbe4a | 1467 | ret = __cpufreq_remove_dev_finish(dev, sif); |
27a862e9 VK |
1468 | |
1469 | return ret; | |
5a01f2e8 VP |
1470 | } |
1471 | ||
65f27f38 | 1472 | static void handle_update(struct work_struct *work) |
1da177e4 | 1473 | { |
65f27f38 DH |
1474 | struct cpufreq_policy *policy = |
1475 | container_of(work, struct cpufreq_policy, update); | |
1476 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1477 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1478 | cpufreq_update_policy(cpu); |
1479 | } | |
1480 | ||
1481 | /** | |
bb176f7d VK |
1482 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1483 | * in deep trouble. | |
1da177e4 LT |
1484 | * @cpu: cpu number |
1485 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1486 | * @new_freq: CPU frequency the CPU actually runs at | |
1487 | * | |
29464f28 DJ |
1488 | * We adjust to current frequency first, and need to clean up later. |
1489 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1490 | */ |
e08f5f5b GS |
1491 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1492 | unsigned int new_freq) | |
1da177e4 | 1493 | { |
b43a7ffb | 1494 | struct cpufreq_policy *policy; |
1da177e4 | 1495 | struct cpufreq_freqs freqs; |
b43a7ffb VK |
1496 | unsigned long flags; |
1497 | ||
e837f9b5 JP |
1498 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
1499 | old_freq, new_freq); | |
1da177e4 | 1500 | |
1da177e4 LT |
1501 | freqs.old = old_freq; |
1502 | freqs.new = new_freq; | |
b43a7ffb VK |
1503 | |
1504 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1505 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1506 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1507 | ||
8fec051e VK |
1508 | cpufreq_freq_transition_begin(policy, &freqs); |
1509 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1510 | } |
1511 | ||
32ee8c3e | 1512 | /** |
4ab70df4 | 1513 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1514 | * @cpu: CPU number |
1515 | * | |
1516 | * This is the last known freq, without actually getting it from the driver. | |
1517 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1518 | */ | |
1519 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1520 | { | |
9e21ba8b | 1521 | struct cpufreq_policy *policy; |
e08f5f5b | 1522 | unsigned int ret_freq = 0; |
95235ca2 | 1523 | |
1c3d85dd RW |
1524 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) |
1525 | return cpufreq_driver->get(cpu); | |
9e21ba8b DB |
1526 | |
1527 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1528 | if (policy) { |
e08f5f5b | 1529 | ret_freq = policy->cur; |
95235ca2 VP |
1530 | cpufreq_cpu_put(policy); |
1531 | } | |
1532 | ||
4d34a67d | 1533 | return ret_freq; |
95235ca2 VP |
1534 | } |
1535 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1536 | ||
3d737108 JB |
1537 | /** |
1538 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1539 | * @cpu: CPU number | |
1540 | * | |
1541 | * Just return the max possible frequency for a given CPU. | |
1542 | */ | |
1543 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1544 | { | |
1545 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1546 | unsigned int ret_freq = 0; | |
1547 | ||
1548 | if (policy) { | |
1549 | ret_freq = policy->max; | |
1550 | cpufreq_cpu_put(policy); | |
1551 | } | |
1552 | ||
1553 | return ret_freq; | |
1554 | } | |
1555 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1556 | ||
5a01f2e8 | 1557 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1558 | { |
7a6aedfa | 1559 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1560 | unsigned int ret_freq = 0; |
5800043b | 1561 | |
1c3d85dd | 1562 | if (!cpufreq_driver->get) |
4d34a67d | 1563 | return ret_freq; |
1da177e4 | 1564 | |
1c3d85dd | 1565 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1566 | |
e08f5f5b | 1567 | if (ret_freq && policy->cur && |
1c3d85dd | 1568 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1569 | /* verify no discrepancy between actual and |
1570 | saved value exists */ | |
1571 | if (unlikely(ret_freq != policy->cur)) { | |
1572 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1573 | schedule_work(&policy->update); |
1574 | } | |
1575 | } | |
1576 | ||
4d34a67d | 1577 | return ret_freq; |
5a01f2e8 | 1578 | } |
1da177e4 | 1579 | |
5a01f2e8 VP |
1580 | /** |
1581 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1582 | * @cpu: CPU number | |
1583 | * | |
1584 | * Get the CPU current (static) CPU frequency | |
1585 | */ | |
1586 | unsigned int cpufreq_get(unsigned int cpu) | |
1587 | { | |
999976e0 | 1588 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1589 | unsigned int ret_freq = 0; |
5a01f2e8 | 1590 | |
999976e0 AP |
1591 | if (policy) { |
1592 | down_read(&policy->rwsem); | |
1593 | ret_freq = __cpufreq_get(cpu); | |
1594 | up_read(&policy->rwsem); | |
5a01f2e8 | 1595 | |
999976e0 AP |
1596 | cpufreq_cpu_put(policy); |
1597 | } | |
6eed9404 | 1598 | |
4d34a67d | 1599 | return ret_freq; |
1da177e4 LT |
1600 | } |
1601 | EXPORT_SYMBOL(cpufreq_get); | |
1602 | ||
8a25a2fd KS |
1603 | static struct subsys_interface cpufreq_interface = { |
1604 | .name = "cpufreq", | |
1605 | .subsys = &cpu_subsys, | |
1606 | .add_dev = cpufreq_add_dev, | |
1607 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1608 | }; |
1609 | ||
e28867ea VK |
1610 | /* |
1611 | * In case platform wants some specific frequency to be configured | |
1612 | * during suspend.. | |
1613 | */ | |
1614 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1615 | { | |
1616 | int ret; | |
1617 | ||
1618 | if (!policy->suspend_freq) { | |
1619 | pr_err("%s: suspend_freq can't be zero\n", __func__); | |
1620 | return -EINVAL; | |
1621 | } | |
1622 | ||
1623 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1624 | policy->suspend_freq); | |
1625 | ||
1626 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1627 | CPUFREQ_RELATION_H); | |
1628 | if (ret) | |
1629 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1630 | __func__, policy->suspend_freq, ret); | |
1631 | ||
1632 | return ret; | |
1633 | } | |
1634 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1635 | ||
42d4dc3f | 1636 | /** |
2f0aea93 | 1637 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1638 | * |
2f0aea93 VK |
1639 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1640 | * as some platforms can't change frequency after this point in suspend cycle. | |
1641 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1642 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1643 | */ |
2f0aea93 | 1644 | void cpufreq_suspend(void) |
42d4dc3f | 1645 | { |
3a3e9e06 | 1646 | struct cpufreq_policy *policy; |
42d4dc3f | 1647 | |
2f0aea93 VK |
1648 | if (!cpufreq_driver) |
1649 | return; | |
42d4dc3f | 1650 | |
2f0aea93 VK |
1651 | if (!has_target()) |
1652 | return; | |
42d4dc3f | 1653 | |
2f0aea93 VK |
1654 | pr_debug("%s: Suspending Governors\n", __func__); |
1655 | ||
1656 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
1657 | if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) | |
1658 | pr_err("%s: Failed to stop governor for policy: %p\n", | |
1659 | __func__, policy); | |
1660 | else if (cpufreq_driver->suspend | |
1661 | && cpufreq_driver->suspend(policy)) | |
1662 | pr_err("%s: Failed to suspend driver: %p\n", __func__, | |
1663 | policy); | |
42d4dc3f BH |
1664 | } |
1665 | ||
2f0aea93 | 1666 | cpufreq_suspended = true; |
42d4dc3f BH |
1667 | } |
1668 | ||
1da177e4 | 1669 | /** |
2f0aea93 | 1670 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1671 | * |
2f0aea93 VK |
1672 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1673 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1674 | */ |
2f0aea93 | 1675 | void cpufreq_resume(void) |
1da177e4 | 1676 | { |
3a3e9e06 | 1677 | struct cpufreq_policy *policy; |
1da177e4 | 1678 | |
2f0aea93 VK |
1679 | if (!cpufreq_driver) |
1680 | return; | |
1da177e4 | 1681 | |
2f0aea93 | 1682 | if (!has_target()) |
e00e56df | 1683 | return; |
1da177e4 | 1684 | |
2f0aea93 | 1685 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1686 | |
2f0aea93 | 1687 | cpufreq_suspended = false; |
ce6c3997 | 1688 | |
2f0aea93 | 1689 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { |
0c5aa405 VK |
1690 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) |
1691 | pr_err("%s: Failed to resume driver: %p\n", __func__, | |
1692 | policy); | |
1693 | else if (__cpufreq_governor(policy, CPUFREQ_GOV_START) | |
2f0aea93 VK |
1694 | || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS)) |
1695 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1696 | __func__, policy); | |
1da177e4 | 1697 | |
2f0aea93 VK |
1698 | /* |
1699 | * schedule call cpufreq_update_policy() for boot CPU, i.e. last | |
1700 | * policy in list. It will verify that the current freq is in | |
1701 | * sync with what we believe it to be. | |
1702 | */ | |
1703 | if (list_is_last(&policy->policy_list, &cpufreq_policy_list)) | |
1704 | schedule_work(&policy->update); | |
1705 | } | |
1706 | } | |
1da177e4 | 1707 | |
9d95046e BP |
1708 | /** |
1709 | * cpufreq_get_current_driver - return current driver's name | |
1710 | * | |
1711 | * Return the name string of the currently loaded cpufreq driver | |
1712 | * or NULL, if none. | |
1713 | */ | |
1714 | const char *cpufreq_get_current_driver(void) | |
1715 | { | |
1c3d85dd RW |
1716 | if (cpufreq_driver) |
1717 | return cpufreq_driver->name; | |
1718 | ||
1719 | return NULL; | |
9d95046e BP |
1720 | } |
1721 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1722 | |
1723 | /********************************************************************* | |
1724 | * NOTIFIER LISTS INTERFACE * | |
1725 | *********************************************************************/ | |
1726 | ||
1727 | /** | |
1728 | * cpufreq_register_notifier - register a driver with cpufreq | |
1729 | * @nb: notifier function to register | |
1730 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1731 | * | |
32ee8c3e | 1732 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1733 | * are notified about clock rate changes (once before and once after |
1734 | * the transition), or a list of drivers that are notified about | |
1735 | * changes in cpufreq policy. | |
1736 | * | |
1737 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1738 | * blocking_notifier_chain_register. |
1da177e4 LT |
1739 | */ |
1740 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1741 | { | |
1742 | int ret; | |
1743 | ||
d5aaffa9 DB |
1744 | if (cpufreq_disabled()) |
1745 | return -EINVAL; | |
1746 | ||
74212ca4 CEB |
1747 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1748 | ||
1da177e4 LT |
1749 | switch (list) { |
1750 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1751 | ret = srcu_notifier_chain_register( |
e041c683 | 1752 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1753 | break; |
1754 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1755 | ret = blocking_notifier_chain_register( |
1756 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1757 | break; |
1758 | default: | |
1759 | ret = -EINVAL; | |
1760 | } | |
1da177e4 LT |
1761 | |
1762 | return ret; | |
1763 | } | |
1764 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1765 | ||
1da177e4 LT |
1766 | /** |
1767 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1768 | * @nb: notifier block to be unregistered | |
bb176f7d | 1769 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1770 | * |
1771 | * Remove a driver from the CPU frequency notifier list. | |
1772 | * | |
1773 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1774 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1775 | */ |
1776 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1777 | { | |
1778 | int ret; | |
1779 | ||
d5aaffa9 DB |
1780 | if (cpufreq_disabled()) |
1781 | return -EINVAL; | |
1782 | ||
1da177e4 LT |
1783 | switch (list) { |
1784 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1785 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1786 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1787 | break; |
1788 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1789 | ret = blocking_notifier_chain_unregister( |
1790 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1791 | break; |
1792 | default: | |
1793 | ret = -EINVAL; | |
1794 | } | |
1da177e4 LT |
1795 | |
1796 | return ret; | |
1797 | } | |
1798 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1799 | ||
1800 | ||
1801 | /********************************************************************* | |
1802 | * GOVERNORS * | |
1803 | *********************************************************************/ | |
1804 | ||
1da177e4 LT |
1805 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1806 | unsigned int target_freq, | |
1807 | unsigned int relation) | |
1808 | { | |
1809 | int retval = -EINVAL; | |
7249924e | 1810 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1811 | |
a7b422cd KRW |
1812 | if (cpufreq_disabled()) |
1813 | return -ENODEV; | |
1814 | ||
7249924e VK |
1815 | /* Make sure that target_freq is within supported range */ |
1816 | if (target_freq > policy->max) | |
1817 | target_freq = policy->max; | |
1818 | if (target_freq < policy->min) | |
1819 | target_freq = policy->min; | |
1820 | ||
1821 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 1822 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 1823 | |
9c0ebcf7 VK |
1824 | /* |
1825 | * This might look like a redundant call as we are checking it again | |
1826 | * after finding index. But it is left intentionally for cases where | |
1827 | * exactly same freq is called again and so we can save on few function | |
1828 | * calls. | |
1829 | */ | |
5a1c0228 VK |
1830 | if (target_freq == policy->cur) |
1831 | return 0; | |
1832 | ||
1c3d85dd RW |
1833 | if (cpufreq_driver->target) |
1834 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
9c0ebcf7 VK |
1835 | else if (cpufreq_driver->target_index) { |
1836 | struct cpufreq_frequency_table *freq_table; | |
d4019f0a VK |
1837 | struct cpufreq_freqs freqs; |
1838 | bool notify; | |
9c0ebcf7 | 1839 | int index; |
90d45d17 | 1840 | |
9c0ebcf7 VK |
1841 | freq_table = cpufreq_frequency_get_table(policy->cpu); |
1842 | if (unlikely(!freq_table)) { | |
1843 | pr_err("%s: Unable to find freq_table\n", __func__); | |
1844 | goto out; | |
1845 | } | |
1846 | ||
1847 | retval = cpufreq_frequency_table_target(policy, freq_table, | |
1848 | target_freq, relation, &index); | |
1849 | if (unlikely(retval)) { | |
1850 | pr_err("%s: Unable to find matching freq\n", __func__); | |
1851 | goto out; | |
1852 | } | |
1853 | ||
d4019f0a | 1854 | if (freq_table[index].frequency == policy->cur) { |
9c0ebcf7 | 1855 | retval = 0; |
d4019f0a VK |
1856 | goto out; |
1857 | } | |
1858 | ||
1859 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); | |
1860 | ||
1861 | if (notify) { | |
1862 | freqs.old = policy->cur; | |
1863 | freqs.new = freq_table[index].frequency; | |
1864 | freqs.flags = 0; | |
1865 | ||
1866 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", | |
e837f9b5 | 1867 | __func__, policy->cpu, freqs.old, freqs.new); |
d4019f0a | 1868 | |
8fec051e | 1869 | cpufreq_freq_transition_begin(policy, &freqs); |
d4019f0a VK |
1870 | } |
1871 | ||
1872 | retval = cpufreq_driver->target_index(policy, index); | |
1873 | if (retval) | |
1874 | pr_err("%s: Failed to change cpu frequency: %d\n", | |
e837f9b5 | 1875 | __func__, retval); |
d4019f0a | 1876 | |
ab1b1c4e | 1877 | if (notify) |
8fec051e | 1878 | cpufreq_freq_transition_end(policy, &freqs, retval); |
9c0ebcf7 VK |
1879 | } |
1880 | ||
1881 | out: | |
1da177e4 LT |
1882 | return retval; |
1883 | } | |
1884 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1885 | ||
1da177e4 LT |
1886 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1887 | unsigned int target_freq, | |
1888 | unsigned int relation) | |
1889 | { | |
f1829e4a | 1890 | int ret = -EINVAL; |
1da177e4 | 1891 | |
ad7722da | 1892 | down_write(&policy->rwsem); |
1da177e4 LT |
1893 | |
1894 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1895 | ||
ad7722da | 1896 | up_write(&policy->rwsem); |
1da177e4 | 1897 | |
1da177e4 LT |
1898 | return ret; |
1899 | } | |
1900 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1901 | ||
153d7f3f | 1902 | /* |
153d7f3f AV |
1903 | * when "event" is CPUFREQ_GOV_LIMITS |
1904 | */ | |
1da177e4 | 1905 | |
e08f5f5b GS |
1906 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1907 | unsigned int event) | |
1da177e4 | 1908 | { |
cc993cab | 1909 | int ret; |
6afde10c TR |
1910 | |
1911 | /* Only must be defined when default governor is known to have latency | |
1912 | restrictions, like e.g. conservative or ondemand. | |
1913 | That this is the case is already ensured in Kconfig | |
1914 | */ | |
1915 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1916 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1917 | #else | |
1918 | struct cpufreq_governor *gov = NULL; | |
1919 | #endif | |
1c256245 | 1920 | |
2f0aea93 VK |
1921 | /* Don't start any governor operations if we are entering suspend */ |
1922 | if (cpufreq_suspended) | |
1923 | return 0; | |
1924 | ||
1c256245 TR |
1925 | if (policy->governor->max_transition_latency && |
1926 | policy->cpuinfo.transition_latency > | |
1927 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1928 | if (!gov) |
1929 | return -EINVAL; | |
1930 | else { | |
e837f9b5 JP |
1931 | pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", |
1932 | policy->governor->name, gov->name); | |
6afde10c TR |
1933 | policy->governor = gov; |
1934 | } | |
1c256245 | 1935 | } |
1da177e4 | 1936 | |
fe492f3f VK |
1937 | if (event == CPUFREQ_GOV_POLICY_INIT) |
1938 | if (!try_module_get(policy->governor->owner)) | |
1939 | return -EINVAL; | |
1da177e4 | 1940 | |
2d06d8c4 | 1941 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e837f9b5 | 1942 | policy->cpu, event); |
95731ebb XC |
1943 | |
1944 | mutex_lock(&cpufreq_governor_lock); | |
56d07db2 | 1945 | if ((policy->governor_enabled && event == CPUFREQ_GOV_START) |
f73d3933 VK |
1946 | || (!policy->governor_enabled |
1947 | && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { | |
95731ebb XC |
1948 | mutex_unlock(&cpufreq_governor_lock); |
1949 | return -EBUSY; | |
1950 | } | |
1951 | ||
1952 | if (event == CPUFREQ_GOV_STOP) | |
1953 | policy->governor_enabled = false; | |
1954 | else if (event == CPUFREQ_GOV_START) | |
1955 | policy->governor_enabled = true; | |
1956 | ||
1957 | mutex_unlock(&cpufreq_governor_lock); | |
1958 | ||
1da177e4 LT |
1959 | ret = policy->governor->governor(policy, event); |
1960 | ||
4d5dcc42 VK |
1961 | if (!ret) { |
1962 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1963 | policy->governor->initialized++; | |
1964 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1965 | policy->governor->initialized--; | |
95731ebb XC |
1966 | } else { |
1967 | /* Restore original values */ | |
1968 | mutex_lock(&cpufreq_governor_lock); | |
1969 | if (event == CPUFREQ_GOV_STOP) | |
1970 | policy->governor_enabled = true; | |
1971 | else if (event == CPUFREQ_GOV_START) | |
1972 | policy->governor_enabled = false; | |
1973 | mutex_unlock(&cpufreq_governor_lock); | |
4d5dcc42 | 1974 | } |
b394058f | 1975 | |
fe492f3f VK |
1976 | if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) || |
1977 | ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret)) | |
1da177e4 LT |
1978 | module_put(policy->governor->owner); |
1979 | ||
1980 | return ret; | |
1981 | } | |
1982 | ||
1da177e4 LT |
1983 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1984 | { | |
3bcb09a3 | 1985 | int err; |
1da177e4 LT |
1986 | |
1987 | if (!governor) | |
1988 | return -EINVAL; | |
1989 | ||
a7b422cd KRW |
1990 | if (cpufreq_disabled()) |
1991 | return -ENODEV; | |
1992 | ||
3fc54d37 | 1993 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1994 | |
b394058f | 1995 | governor->initialized = 0; |
3bcb09a3 JF |
1996 | err = -EBUSY; |
1997 | if (__find_governor(governor->name) == NULL) { | |
1998 | err = 0; | |
1999 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2000 | } |
1da177e4 | 2001 | |
32ee8c3e | 2002 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2003 | return err; |
1da177e4 LT |
2004 | } |
2005 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2006 | ||
1da177e4 LT |
2007 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2008 | { | |
90e41bac | 2009 | int cpu; |
90e41bac | 2010 | |
1da177e4 LT |
2011 | if (!governor) |
2012 | return; | |
2013 | ||
a7b422cd KRW |
2014 | if (cpufreq_disabled()) |
2015 | return; | |
2016 | ||
90e41bac PB |
2017 | for_each_present_cpu(cpu) { |
2018 | if (cpu_online(cpu)) | |
2019 | continue; | |
2020 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
2021 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
2022 | } | |
90e41bac | 2023 | |
3fc54d37 | 2024 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2025 | list_del(&governor->governor_list); |
3fc54d37 | 2026 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2027 | return; |
2028 | } | |
2029 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2030 | ||
2031 | ||
1da177e4 LT |
2032 | /********************************************************************* |
2033 | * POLICY INTERFACE * | |
2034 | *********************************************************************/ | |
2035 | ||
2036 | /** | |
2037 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2038 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2039 | * is written | |
1da177e4 LT |
2040 | * |
2041 | * Reads the current cpufreq policy. | |
2042 | */ | |
2043 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2044 | { | |
2045 | struct cpufreq_policy *cpu_policy; | |
2046 | if (!policy) | |
2047 | return -EINVAL; | |
2048 | ||
2049 | cpu_policy = cpufreq_cpu_get(cpu); | |
2050 | if (!cpu_policy) | |
2051 | return -EINVAL; | |
2052 | ||
d5b73cd8 | 2053 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2054 | |
2055 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2056 | return 0; |
2057 | } | |
2058 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2059 | ||
153d7f3f | 2060 | /* |
037ce839 VK |
2061 | * policy : current policy. |
2062 | * new_policy: policy to be set. | |
153d7f3f | 2063 | */ |
037ce839 | 2064 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 2065 | struct cpufreq_policy *new_policy) |
1da177e4 | 2066 | { |
d9a789c7 RW |
2067 | struct cpufreq_governor *old_gov; |
2068 | int ret; | |
1da177e4 | 2069 | |
e837f9b5 JP |
2070 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2071 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2072 | |
d5b73cd8 | 2073 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2074 | |
d9a789c7 RW |
2075 | if (new_policy->min > policy->max || new_policy->max < policy->min) |
2076 | return -EINVAL; | |
9c9a43ed | 2077 | |
1da177e4 | 2078 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2079 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2080 | if (ret) |
d9a789c7 | 2081 | return ret; |
1da177e4 | 2082 | |
1da177e4 | 2083 | /* adjust if necessary - all reasons */ |
e041c683 | 2084 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2085 | CPUFREQ_ADJUST, new_policy); |
1da177e4 LT |
2086 | |
2087 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 | 2088 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2089 | CPUFREQ_INCOMPATIBLE, new_policy); |
1da177e4 | 2090 | |
bb176f7d VK |
2091 | /* |
2092 | * verify the cpu speed can be set within this limit, which might be | |
2093 | * different to the first one | |
2094 | */ | |
3a3e9e06 | 2095 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2096 | if (ret) |
d9a789c7 | 2097 | return ret; |
1da177e4 LT |
2098 | |
2099 | /* notification of the new policy */ | |
e041c683 | 2100 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2101 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2102 | |
3a3e9e06 VK |
2103 | policy->min = new_policy->min; |
2104 | policy->max = new_policy->max; | |
1da177e4 | 2105 | |
2d06d8c4 | 2106 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2107 | policy->min, policy->max); |
1da177e4 | 2108 | |
1c3d85dd | 2109 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2110 | policy->policy = new_policy->policy; |
2d06d8c4 | 2111 | pr_debug("setting range\n"); |
d9a789c7 RW |
2112 | return cpufreq_driver->setpolicy(new_policy); |
2113 | } | |
1da177e4 | 2114 | |
d9a789c7 RW |
2115 | if (new_policy->governor == policy->governor) |
2116 | goto out; | |
7bd353a9 | 2117 | |
d9a789c7 RW |
2118 | pr_debug("governor switch\n"); |
2119 | ||
2120 | /* save old, working values */ | |
2121 | old_gov = policy->governor; | |
2122 | /* end old governor */ | |
2123 | if (old_gov) { | |
2124 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
2125 | up_write(&policy->rwsem); | |
e5c87b76 | 2126 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); |
d9a789c7 | 2127 | down_write(&policy->rwsem); |
1da177e4 LT |
2128 | } |
2129 | ||
d9a789c7 RW |
2130 | /* start new governor */ |
2131 | policy->governor = new_policy->governor; | |
2132 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) { | |
2133 | if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) | |
2134 | goto out; | |
2135 | ||
2136 | up_write(&policy->rwsem); | |
2137 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); | |
2138 | down_write(&policy->rwsem); | |
2139 | } | |
2140 | ||
2141 | /* new governor failed, so re-start old one */ | |
2142 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2143 | if (old_gov) { | |
2144 | policy->governor = old_gov; | |
2145 | __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT); | |
2146 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
2147 | } | |
2148 | ||
2149 | return -EINVAL; | |
2150 | ||
2151 | out: | |
2152 | pr_debug("governor: change or update limits\n"); | |
2153 | return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
1da177e4 LT |
2154 | } |
2155 | ||
1da177e4 LT |
2156 | /** |
2157 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2158 | * @cpu: CPU which shall be re-evaluated | |
2159 | * | |
25985edc | 2160 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2161 | * at different times. |
2162 | */ | |
2163 | int cpufreq_update_policy(unsigned int cpu) | |
2164 | { | |
3a3e9e06 VK |
2165 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2166 | struct cpufreq_policy new_policy; | |
f1829e4a | 2167 | int ret; |
1da177e4 | 2168 | |
3a3e9e06 | 2169 | if (!policy) { |
f1829e4a JL |
2170 | ret = -ENODEV; |
2171 | goto no_policy; | |
2172 | } | |
1da177e4 | 2173 | |
ad7722da | 2174 | down_write(&policy->rwsem); |
1da177e4 | 2175 | |
2d06d8c4 | 2176 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2177 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2178 | new_policy.min = policy->user_policy.min; |
2179 | new_policy.max = policy->user_policy.max; | |
2180 | new_policy.policy = policy->user_policy.policy; | |
2181 | new_policy.governor = policy->user_policy.governor; | |
1da177e4 | 2182 | |
bb176f7d VK |
2183 | /* |
2184 | * BIOS might change freq behind our back | |
2185 | * -> ask driver for current freq and notify governors about a change | |
2186 | */ | |
2ed99e39 | 2187 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
3a3e9e06 | 2188 | new_policy.cur = cpufreq_driver->get(cpu); |
bd0fa9bb VK |
2189 | if (WARN_ON(!new_policy.cur)) { |
2190 | ret = -EIO; | |
2191 | goto no_policy; | |
2192 | } | |
2193 | ||
3a3e9e06 | 2194 | if (!policy->cur) { |
e837f9b5 | 2195 | pr_debug("Driver did not initialize current freq\n"); |
3a3e9e06 | 2196 | policy->cur = new_policy.cur; |
a85f7bd3 | 2197 | } else { |
9c0ebcf7 | 2198 | if (policy->cur != new_policy.cur && has_target()) |
3a3e9e06 VK |
2199 | cpufreq_out_of_sync(cpu, policy->cur, |
2200 | new_policy.cur); | |
a85f7bd3 | 2201 | } |
0961dd0d TR |
2202 | } |
2203 | ||
037ce839 | 2204 | ret = cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2205 | |
ad7722da | 2206 | up_write(&policy->rwsem); |
5a01f2e8 | 2207 | |
3a3e9e06 | 2208 | cpufreq_cpu_put(policy); |
f1829e4a | 2209 | no_policy: |
1da177e4 LT |
2210 | return ret; |
2211 | } | |
2212 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2213 | ||
2760984f | 2214 | static int cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
2215 | unsigned long action, void *hcpu) |
2216 | { | |
2217 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 2218 | struct device *dev; |
c32b6b8e | 2219 | |
8a25a2fd KS |
2220 | dev = get_cpu_device(cpu); |
2221 | if (dev) { | |
5302c3fb | 2222 | switch (action & ~CPU_TASKS_FROZEN) { |
c32b6b8e | 2223 | case CPU_ONLINE: |
96bbbe4a | 2224 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e | 2225 | break; |
5302c3fb | 2226 | |
c32b6b8e | 2227 | case CPU_DOWN_PREPARE: |
96bbbe4a | 2228 | __cpufreq_remove_dev_prepare(dev, NULL); |
1aee40ac SB |
2229 | break; |
2230 | ||
2231 | case CPU_POST_DEAD: | |
96bbbe4a | 2232 | __cpufreq_remove_dev_finish(dev, NULL); |
c32b6b8e | 2233 | break; |
5302c3fb | 2234 | |
5a01f2e8 | 2235 | case CPU_DOWN_FAILED: |
96bbbe4a | 2236 | __cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
2237 | break; |
2238 | } | |
2239 | } | |
2240 | return NOTIFY_OK; | |
2241 | } | |
2242 | ||
9c36f746 | 2243 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
bb176f7d | 2244 | .notifier_call = cpufreq_cpu_callback, |
c32b6b8e | 2245 | }; |
1da177e4 | 2246 | |
6f19efc0 LM |
2247 | /********************************************************************* |
2248 | * BOOST * | |
2249 | *********************************************************************/ | |
2250 | static int cpufreq_boost_set_sw(int state) | |
2251 | { | |
2252 | struct cpufreq_frequency_table *freq_table; | |
2253 | struct cpufreq_policy *policy; | |
2254 | int ret = -EINVAL; | |
2255 | ||
2256 | list_for_each_entry(policy, &cpufreq_policy_list, policy_list) { | |
2257 | freq_table = cpufreq_frequency_get_table(policy->cpu); | |
2258 | if (freq_table) { | |
2259 | ret = cpufreq_frequency_table_cpuinfo(policy, | |
2260 | freq_table); | |
2261 | if (ret) { | |
2262 | pr_err("%s: Policy frequency update failed\n", | |
2263 | __func__); | |
2264 | break; | |
2265 | } | |
2266 | policy->user_policy.max = policy->max; | |
2267 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
2268 | } | |
2269 | } | |
2270 | ||
2271 | return ret; | |
2272 | } | |
2273 | ||
2274 | int cpufreq_boost_trigger_state(int state) | |
2275 | { | |
2276 | unsigned long flags; | |
2277 | int ret = 0; | |
2278 | ||
2279 | if (cpufreq_driver->boost_enabled == state) | |
2280 | return 0; | |
2281 | ||
2282 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2283 | cpufreq_driver->boost_enabled = state; | |
2284 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2285 | ||
2286 | ret = cpufreq_driver->set_boost(state); | |
2287 | if (ret) { | |
2288 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2289 | cpufreq_driver->boost_enabled = !state; | |
2290 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2291 | ||
e837f9b5 JP |
2292 | pr_err("%s: Cannot %s BOOST\n", |
2293 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2294 | } |
2295 | ||
2296 | return ret; | |
2297 | } | |
2298 | ||
2299 | int cpufreq_boost_supported(void) | |
2300 | { | |
2301 | if (likely(cpufreq_driver)) | |
2302 | return cpufreq_driver->boost_supported; | |
2303 | ||
2304 | return 0; | |
2305 | } | |
2306 | EXPORT_SYMBOL_GPL(cpufreq_boost_supported); | |
2307 | ||
2308 | int cpufreq_boost_enabled(void) | |
2309 | { | |
2310 | return cpufreq_driver->boost_enabled; | |
2311 | } | |
2312 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2313 | ||
1da177e4 LT |
2314 | /********************************************************************* |
2315 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2316 | *********************************************************************/ | |
2317 | ||
2318 | /** | |
2319 | * cpufreq_register_driver - register a CPU Frequency driver | |
2320 | * @driver_data: A struct cpufreq_driver containing the values# | |
2321 | * submitted by the CPU Frequency driver. | |
2322 | * | |
bb176f7d | 2323 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 2324 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 2325 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2326 | * |
2327 | */ | |
221dee28 | 2328 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2329 | { |
2330 | unsigned long flags; | |
2331 | int ret; | |
2332 | ||
a7b422cd KRW |
2333 | if (cpufreq_disabled()) |
2334 | return -ENODEV; | |
2335 | ||
1da177e4 | 2336 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2337 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2338 | driver_data->target) || |
2339 | (driver_data->setpolicy && (driver_data->target_index || | |
2340 | driver_data->target))) | |
1da177e4 LT |
2341 | return -EINVAL; |
2342 | ||
2d06d8c4 | 2343 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
2344 | |
2345 | if (driver_data->setpolicy) | |
2346 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2347 | ||
0d1857a1 | 2348 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2349 | if (cpufreq_driver) { |
0d1857a1 | 2350 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4dea5806 | 2351 | return -EEXIST; |
1da177e4 | 2352 | } |
1c3d85dd | 2353 | cpufreq_driver = driver_data; |
0d1857a1 | 2354 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2355 | |
6f19efc0 LM |
2356 | if (cpufreq_boost_supported()) { |
2357 | /* | |
2358 | * Check if driver provides function to enable boost - | |
2359 | * if not, use cpufreq_boost_set_sw as default | |
2360 | */ | |
2361 | if (!cpufreq_driver->set_boost) | |
2362 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; | |
2363 | ||
2364 | ret = cpufreq_sysfs_create_file(&boost.attr); | |
2365 | if (ret) { | |
2366 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
e837f9b5 | 2367 | __func__); |
6f19efc0 LM |
2368 | goto err_null_driver; |
2369 | } | |
2370 | } | |
2371 | ||
8a25a2fd | 2372 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2373 | if (ret) |
6f19efc0 | 2374 | goto err_boost_unreg; |
1da177e4 | 2375 | |
1c3d85dd | 2376 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
2377 | int i; |
2378 | ret = -ENODEV; | |
2379 | ||
2380 | /* check for at least one working CPU */ | |
7a6aedfa MT |
2381 | for (i = 0; i < nr_cpu_ids; i++) |
2382 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 2383 | ret = 0; |
7a6aedfa MT |
2384 | break; |
2385 | } | |
1da177e4 LT |
2386 | |
2387 | /* if all ->init() calls failed, unregister */ | |
2388 | if (ret) { | |
2d06d8c4 | 2389 | pr_debug("no CPU initialized for driver %s\n", |
e837f9b5 | 2390 | driver_data->name); |
8a25a2fd | 2391 | goto err_if_unreg; |
1da177e4 LT |
2392 | } |
2393 | } | |
2394 | ||
8f5bc2ab | 2395 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 2396 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 2397 | |
8f5bc2ab | 2398 | return 0; |
8a25a2fd KS |
2399 | err_if_unreg: |
2400 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 LM |
2401 | err_boost_unreg: |
2402 | if (cpufreq_boost_supported()) | |
2403 | cpufreq_sysfs_remove_file(&boost.attr); | |
8f5bc2ab | 2404 | err_null_driver: |
0d1857a1 | 2405 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2406 | cpufreq_driver = NULL; |
0d1857a1 | 2407 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
4d34a67d | 2408 | return ret; |
1da177e4 LT |
2409 | } |
2410 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2411 | ||
1da177e4 LT |
2412 | /** |
2413 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2414 | * | |
bb176f7d | 2415 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2416 | * the right to do so, i.e. if you have succeeded in initialising before! |
2417 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2418 | * currently not initialised. | |
2419 | */ | |
221dee28 | 2420 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2421 | { |
2422 | unsigned long flags; | |
2423 | ||
1c3d85dd | 2424 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2425 | return -EINVAL; |
1da177e4 | 2426 | |
2d06d8c4 | 2427 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2428 | |
8a25a2fd | 2429 | subsys_interface_unregister(&cpufreq_interface); |
6f19efc0 LM |
2430 | if (cpufreq_boost_supported()) |
2431 | cpufreq_sysfs_remove_file(&boost.attr); | |
2432 | ||
65edc68c | 2433 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 | 2434 | |
6eed9404 | 2435 | down_write(&cpufreq_rwsem); |
0d1857a1 | 2436 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2437 | |
1c3d85dd | 2438 | cpufreq_driver = NULL; |
6eed9404 | 2439 | |
0d1857a1 | 2440 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
6eed9404 | 2441 | up_write(&cpufreq_rwsem); |
1da177e4 LT |
2442 | |
2443 | return 0; | |
2444 | } | |
2445 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
2446 | |
2447 | static int __init cpufreq_core_init(void) | |
2448 | { | |
a7b422cd KRW |
2449 | if (cpufreq_disabled()) |
2450 | return -ENODEV; | |
2451 | ||
2361be23 | 2452 | cpufreq_global_kobject = kobject_create(); |
8aa84ad8 TR |
2453 | BUG_ON(!cpufreq_global_kobject); |
2454 | ||
5a01f2e8 VP |
2455 | return 0; |
2456 | } | |
5a01f2e8 | 2457 | core_initcall(cpufreq_core_init); |