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1/*
2 * drivers/cpufreq/cpufreq_stats.c
3 *
4 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
5 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/sysdev.h>
15#include <linux/cpu.h>
16#include <linux/sysfs.h>
17#include <linux/cpufreq.h>
18#include <linux/jiffies.h>
19#include <linux/percpu.h>
20#include <linux/kobject.h>
21#include <linux/spinlock.h>
22#include <linux/notifier.h>
23#include <asm/cputime.h>
24
25static spinlock_t cpufreq_stats_lock;
26
27#define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
28static struct freq_attr _attr_##_name = {\
29 .attr = {.name = __stringify(_name), .mode = _mode, }, \
30 .show = _show,\
31};
32
33struct cpufreq_stats {
34 unsigned int cpu;
35 unsigned int total_trans;
36 unsigned long long last_time;
37 unsigned int max_state;
38 unsigned int state_num;
39 unsigned int last_index;
40 cputime64_t *time_in_state;
41 unsigned int *freq_table;
42#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
43 unsigned int *trans_table;
44#endif
45};
46
47static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
48
49struct cpufreq_stats_attribute {
50 struct attribute attr;
51 ssize_t(*show) (struct cpufreq_stats *, char *);
52};
53
54static int cpufreq_stats_update(unsigned int cpu)
55{
56 struct cpufreq_stats *stat;
57 unsigned long long cur_time;
58
59 cur_time = get_jiffies_64();
60 spin_lock(&cpufreq_stats_lock);
61 stat = per_cpu(cpufreq_stats_table, cpu);
62 if (stat->time_in_state)
63 stat->time_in_state[stat->last_index] =
64 cputime64_add(stat->time_in_state[stat->last_index],
65 cputime_sub(cur_time, stat->last_time));
66 stat->last_time = cur_time;
67 spin_unlock(&cpufreq_stats_lock);
68 return 0;
69}
70
71static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
72{
73 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
74 if (!stat)
75 return 0;
76 return sprintf(buf, "%d\n",
77 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
78}
79
80static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
81{
82 ssize_t len = 0;
83 int i;
84 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
85 if (!stat)
86 return 0;
87 cpufreq_stats_update(stat->cpu);
88 for (i = 0; i < stat->state_num; i++) {
89 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
90 (unsigned long long)
91 cputime64_to_clock_t(stat->time_in_state[i]));
92 }
93 return len;
94}
95
96#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
97static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
98{
99 ssize_t len = 0;
100 int i, j;
101
102 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
103 if (!stat)
104 return 0;
105 cpufreq_stats_update(stat->cpu);
106 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
107 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
108 for (i = 0; i < stat->state_num; i++) {
109 if (len >= PAGE_SIZE)
110 break;
111 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
112 stat->freq_table[i]);
113 }
114 if (len >= PAGE_SIZE)
115 return PAGE_SIZE;
116
117 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
118
119 for (i = 0; i < stat->state_num; i++) {
120 if (len >= PAGE_SIZE)
121 break;
122
123 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
124 stat->freq_table[i]);
125
126 for (j = 0; j < stat->state_num; j++) {
127 if (len >= PAGE_SIZE)
128 break;
129 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
130 stat->trans_table[i*stat->max_state+j]);
131 }
132 if (len >= PAGE_SIZE)
133 break;
134 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
135 }
136 if (len >= PAGE_SIZE)
137 return PAGE_SIZE;
138 return len;
139}
140CPUFREQ_STATDEVICE_ATTR(trans_table, 0444, show_trans_table);
141#endif
142
143CPUFREQ_STATDEVICE_ATTR(total_trans, 0444, show_total_trans);
144CPUFREQ_STATDEVICE_ATTR(time_in_state, 0444, show_time_in_state);
145
146static struct attribute *default_attrs[] = {
147 &_attr_total_trans.attr,
148 &_attr_time_in_state.attr,
149#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
150 &_attr_trans_table.attr,
151#endif
152 NULL
153};
154static struct attribute_group stats_attr_group = {
155 .attrs = default_attrs,
156 .name = "stats"
157};
158
159static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
160{
161 int index;
162 for (index = 0; index < stat->max_state; index++)
163 if (stat->freq_table[index] == freq)
164 return index;
165 return -1;
166}
167
168/* should be called late in the CPU removal sequence so that the stats
169 * memory is still available in case someone tries to use it.
170 */
171static void cpufreq_stats_free_table(unsigned int cpu)
172{
173 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
174 if (stat) {
175 kfree(stat->time_in_state);
176 kfree(stat);
177 }
178 per_cpu(cpufreq_stats_table, cpu) = NULL;
179}
180
181/* must be called early in the CPU removal sequence (before
182 * cpufreq_remove_dev) so that policy is still valid.
183 */
184static void cpufreq_stats_free_sysfs(unsigned int cpu)
185{
186 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
187 if (policy && policy->cpu == cpu)
188 sysfs_remove_group(&policy->kobj, &stats_attr_group);
189 if (policy)
190 cpufreq_cpu_put(policy);
191}
192
193static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
194 struct cpufreq_frequency_table *table)
195{
196 unsigned int i, j, count = 0, ret = 0;
197 struct cpufreq_stats *stat;
198 struct cpufreq_policy *data;
199 unsigned int alloc_size;
200 unsigned int cpu = policy->cpu;
201 if (per_cpu(cpufreq_stats_table, cpu))
202 return -EBUSY;
203 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
204 if ((stat) == NULL)
205 return -ENOMEM;
206
207 data = cpufreq_cpu_get(cpu);
208 if (data == NULL) {
209 ret = -EINVAL;
210 goto error_get_fail;
211 }
212
213 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
214 if (ret)
215 goto error_out;
216
217 stat->cpu = cpu;
218 per_cpu(cpufreq_stats_table, cpu) = stat;
219
220 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
221 unsigned int freq = table[i].frequency;
222 if (freq == CPUFREQ_ENTRY_INVALID)
223 continue;
224 count++;
225 }
226
227 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
228
229#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
230 alloc_size += count * count * sizeof(int);
231#endif
232 stat->max_state = count;
233 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
234 if (!stat->time_in_state) {
235 ret = -ENOMEM;
236 goto error_out;
237 }
238 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
239
240#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
241 stat->trans_table = stat->freq_table + count;
242#endif
243 j = 0;
244 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
245 unsigned int freq = table[i].frequency;
246 if (freq == CPUFREQ_ENTRY_INVALID)
247 continue;
248 if (freq_table_get_index(stat, freq) == -1)
249 stat->freq_table[j++] = freq;
250 }
251 stat->state_num = j;
252 spin_lock(&cpufreq_stats_lock);
253 stat->last_time = get_jiffies_64();
254 stat->last_index = freq_table_get_index(stat, policy->cur);
255 spin_unlock(&cpufreq_stats_lock);
256 cpufreq_cpu_put(data);
257 return 0;
258error_out:
259 cpufreq_cpu_put(data);
260error_get_fail:
261 kfree(stat);
262 per_cpu(cpufreq_stats_table, cpu) = NULL;
263 return ret;
264}
265
266static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
267 unsigned long val, void *data)
268{
269 int ret;
270 struct cpufreq_policy *policy = data;
271 struct cpufreq_frequency_table *table;
272 unsigned int cpu = policy->cpu;
273 if (val != CPUFREQ_NOTIFY)
274 return 0;
275 table = cpufreq_frequency_get_table(cpu);
276 if (!table)
277 return 0;
278 ret = cpufreq_stats_create_table(policy, table);
279 if (ret)
280 return ret;
281 return 0;
282}
283
284static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
285 unsigned long val, void *data)
286{
287 struct cpufreq_freqs *freq = data;
288 struct cpufreq_stats *stat;
289 int old_index, new_index;
290
291 if (val != CPUFREQ_POSTCHANGE)
292 return 0;
293
294 stat = per_cpu(cpufreq_stats_table, freq->cpu);
295 if (!stat)
296 return 0;
297
298 old_index = stat->last_index;
299 new_index = freq_table_get_index(stat, freq->new);
300
301 /* We can't do stat->time_in_state[-1]= .. */
302 if (old_index == -1 || new_index == -1)
303 return 0;
304
305 cpufreq_stats_update(freq->cpu);
306
307 if (old_index == new_index)
308 return 0;
309
310 spin_lock(&cpufreq_stats_lock);
311 stat->last_index = new_index;
312#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
313 stat->trans_table[old_index * stat->max_state + new_index]++;
314#endif
315 stat->total_trans++;
316 spin_unlock(&cpufreq_stats_lock);
317 return 0;
318}
319
320static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
321 unsigned long action,
322 void *hcpu)
323{
324 unsigned int cpu = (unsigned long)hcpu;
325
326 switch (action) {
327 case CPU_ONLINE:
328 case CPU_ONLINE_FROZEN:
329 cpufreq_update_policy(cpu);
330 break;
331 case CPU_DOWN_PREPARE:
332 cpufreq_stats_free_sysfs(cpu);
333 break;
334 case CPU_DEAD:
335 case CPU_DEAD_FROZEN:
336 cpufreq_stats_free_table(cpu);
337 break;
338 }
339 return NOTIFY_OK;
340}
341
342/* priority=1 so this will get called before cpufreq_remove_dev */
343static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
344 .notifier_call = cpufreq_stat_cpu_callback,
345 .priority = 1,
346};
347
348static struct notifier_block notifier_policy_block = {
349 .notifier_call = cpufreq_stat_notifier_policy
350};
351
352static struct notifier_block notifier_trans_block = {
353 .notifier_call = cpufreq_stat_notifier_trans
354};
355
356static int __init cpufreq_stats_init(void)
357{
358 int ret;
359 unsigned int cpu;
360
361 spin_lock_init(&cpufreq_stats_lock);
362 ret = cpufreq_register_notifier(¬ifier_policy_block,
363 CPUFREQ_POLICY_NOTIFIER);
364 if (ret)
365 return ret;
366
367 ret = cpufreq_register_notifier(¬ifier_trans_block,
368 CPUFREQ_TRANSITION_NOTIFIER);
369 if (ret) {
370 cpufreq_unregister_notifier(¬ifier_policy_block,
371 CPUFREQ_POLICY_NOTIFIER);
372 return ret;
373 }
374
375 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
376 for_each_online_cpu(cpu) {
377 cpufreq_update_policy(cpu);
378 }
379 return 0;
380}
381static void __exit cpufreq_stats_exit(void)
382{
383 unsigned int cpu;
384
385 cpufreq_unregister_notifier(¬ifier_policy_block,
386 CPUFREQ_POLICY_NOTIFIER);
387 cpufreq_unregister_notifier(¬ifier_trans_block,
388 CPUFREQ_TRANSITION_NOTIFIER);
389 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
390 for_each_online_cpu(cpu) {
391 cpufreq_stats_free_table(cpu);
392 cpufreq_stats_free_sysfs(cpu);
393 }
394}
395
396MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
397MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
398 "through sysfs filesystem");
399MODULE_LICENSE("GPL");
400
401module_init(cpufreq_stats_init);
402module_exit(cpufreq_stats_exit);
1/*
2 * drivers/cpufreq/cpufreq_stats.c
3 *
4 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
5 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/cpu.h>
15#include <linux/sysfs.h>
16#include <linux/cpufreq.h>
17#include <linux/module.h>
18#include <linux/jiffies.h>
19#include <linux/percpu.h>
20#include <linux/kobject.h>
21#include <linux/spinlock.h>
22#include <linux/notifier.h>
23#include <asm/cputime.h>
24
25static spinlock_t cpufreq_stats_lock;
26
27#define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
28static struct freq_attr _attr_##_name = {\
29 .attr = {.name = __stringify(_name), .mode = _mode, }, \
30 .show = _show,\
31};
32
33struct cpufreq_stats {
34 unsigned int cpu;
35 unsigned int total_trans;
36 unsigned long long last_time;
37 unsigned int max_state;
38 unsigned int state_num;
39 unsigned int last_index;
40 cputime64_t *time_in_state;
41 unsigned int *freq_table;
42#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
43 unsigned int *trans_table;
44#endif
45};
46
47static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
48
49struct cpufreq_stats_attribute {
50 struct attribute attr;
51 ssize_t(*show) (struct cpufreq_stats *, char *);
52};
53
54static int cpufreq_stats_update(unsigned int cpu)
55{
56 struct cpufreq_stats *stat;
57 unsigned long long cur_time;
58
59 cur_time = get_jiffies_64();
60 spin_lock(&cpufreq_stats_lock);
61 stat = per_cpu(cpufreq_stats_table, cpu);
62 if (stat->time_in_state)
63 stat->time_in_state[stat->last_index] +=
64 cur_time - stat->last_time;
65 stat->last_time = cur_time;
66 spin_unlock(&cpufreq_stats_lock);
67 return 0;
68}
69
70static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
71{
72 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
73 if (!stat)
74 return 0;
75 return sprintf(buf, "%d\n",
76 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
77}
78
79static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
80{
81 ssize_t len = 0;
82 int i;
83 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
84 if (!stat)
85 return 0;
86 cpufreq_stats_update(stat->cpu);
87 for (i = 0; i < stat->state_num; i++) {
88 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
89 (unsigned long long)
90 cputime64_to_clock_t(stat->time_in_state[i]));
91 }
92 return len;
93}
94
95#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
96static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
97{
98 ssize_t len = 0;
99 int i, j;
100
101 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
102 if (!stat)
103 return 0;
104 cpufreq_stats_update(stat->cpu);
105 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
106 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
107 for (i = 0; i < stat->state_num; i++) {
108 if (len >= PAGE_SIZE)
109 break;
110 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
111 stat->freq_table[i]);
112 }
113 if (len >= PAGE_SIZE)
114 return PAGE_SIZE;
115
116 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
117
118 for (i = 0; i < stat->state_num; i++) {
119 if (len >= PAGE_SIZE)
120 break;
121
122 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
123 stat->freq_table[i]);
124
125 for (j = 0; j < stat->state_num; j++) {
126 if (len >= PAGE_SIZE)
127 break;
128 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
129 stat->trans_table[i*stat->max_state+j]);
130 }
131 if (len >= PAGE_SIZE)
132 break;
133 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
134 }
135 if (len >= PAGE_SIZE)
136 return PAGE_SIZE;
137 return len;
138}
139CPUFREQ_STATDEVICE_ATTR(trans_table, 0444, show_trans_table);
140#endif
141
142CPUFREQ_STATDEVICE_ATTR(total_trans, 0444, show_total_trans);
143CPUFREQ_STATDEVICE_ATTR(time_in_state, 0444, show_time_in_state);
144
145static struct attribute *default_attrs[] = {
146 &_attr_total_trans.attr,
147 &_attr_time_in_state.attr,
148#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
149 &_attr_trans_table.attr,
150#endif
151 NULL
152};
153static struct attribute_group stats_attr_group = {
154 .attrs = default_attrs,
155 .name = "stats"
156};
157
158static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
159{
160 int index;
161 for (index = 0; index < stat->max_state; index++)
162 if (stat->freq_table[index] == freq)
163 return index;
164 return -1;
165}
166
167/* should be called late in the CPU removal sequence so that the stats
168 * memory is still available in case someone tries to use it.
169 */
170static void cpufreq_stats_free_table(unsigned int cpu)
171{
172 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
173 if (stat) {
174 kfree(stat->time_in_state);
175 kfree(stat);
176 }
177 per_cpu(cpufreq_stats_table, cpu) = NULL;
178}
179
180/* must be called early in the CPU removal sequence (before
181 * cpufreq_remove_dev) so that policy is still valid.
182 */
183static void cpufreq_stats_free_sysfs(unsigned int cpu)
184{
185 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
186 if (policy && policy->cpu == cpu)
187 sysfs_remove_group(&policy->kobj, &stats_attr_group);
188 if (policy)
189 cpufreq_cpu_put(policy);
190}
191
192static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
193 struct cpufreq_frequency_table *table)
194{
195 unsigned int i, j, count = 0, ret = 0;
196 struct cpufreq_stats *stat;
197 struct cpufreq_policy *data;
198 unsigned int alloc_size;
199 unsigned int cpu = policy->cpu;
200 if (per_cpu(cpufreq_stats_table, cpu))
201 return -EBUSY;
202 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
203 if ((stat) == NULL)
204 return -ENOMEM;
205
206 data = cpufreq_cpu_get(cpu);
207 if (data == NULL) {
208 ret = -EINVAL;
209 goto error_get_fail;
210 }
211
212 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
213 if (ret)
214 goto error_out;
215
216 stat->cpu = cpu;
217 per_cpu(cpufreq_stats_table, cpu) = stat;
218
219 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
220 unsigned int freq = table[i].frequency;
221 if (freq == CPUFREQ_ENTRY_INVALID)
222 continue;
223 count++;
224 }
225
226 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
227
228#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
229 alloc_size += count * count * sizeof(int);
230#endif
231 stat->max_state = count;
232 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
233 if (!stat->time_in_state) {
234 ret = -ENOMEM;
235 goto error_out;
236 }
237 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
238
239#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
240 stat->trans_table = stat->freq_table + count;
241#endif
242 j = 0;
243 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
244 unsigned int freq = table[i].frequency;
245 if (freq == CPUFREQ_ENTRY_INVALID)
246 continue;
247 if (freq_table_get_index(stat, freq) == -1)
248 stat->freq_table[j++] = freq;
249 }
250 stat->state_num = j;
251 spin_lock(&cpufreq_stats_lock);
252 stat->last_time = get_jiffies_64();
253 stat->last_index = freq_table_get_index(stat, policy->cur);
254 spin_unlock(&cpufreq_stats_lock);
255 cpufreq_cpu_put(data);
256 return 0;
257error_out:
258 cpufreq_cpu_put(data);
259error_get_fail:
260 kfree(stat);
261 per_cpu(cpufreq_stats_table, cpu) = NULL;
262 return ret;
263}
264
265static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
266 unsigned long val, void *data)
267{
268 int ret;
269 struct cpufreq_policy *policy = data;
270 struct cpufreq_frequency_table *table;
271 unsigned int cpu = policy->cpu;
272 if (val != CPUFREQ_NOTIFY)
273 return 0;
274 table = cpufreq_frequency_get_table(cpu);
275 if (!table)
276 return 0;
277 ret = cpufreq_stats_create_table(policy, table);
278 if (ret)
279 return ret;
280 return 0;
281}
282
283static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
284 unsigned long val, void *data)
285{
286 struct cpufreq_freqs *freq = data;
287 struct cpufreq_stats *stat;
288 int old_index, new_index;
289
290 if (val != CPUFREQ_POSTCHANGE)
291 return 0;
292
293 stat = per_cpu(cpufreq_stats_table, freq->cpu);
294 if (!stat)
295 return 0;
296
297 old_index = stat->last_index;
298 new_index = freq_table_get_index(stat, freq->new);
299
300 /* We can't do stat->time_in_state[-1]= .. */
301 if (old_index == -1 || new_index == -1)
302 return 0;
303
304 cpufreq_stats_update(freq->cpu);
305
306 if (old_index == new_index)
307 return 0;
308
309 spin_lock(&cpufreq_stats_lock);
310 stat->last_index = new_index;
311#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
312 stat->trans_table[old_index * stat->max_state + new_index]++;
313#endif
314 stat->total_trans++;
315 spin_unlock(&cpufreq_stats_lock);
316 return 0;
317}
318
319static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
320 unsigned long action,
321 void *hcpu)
322{
323 unsigned int cpu = (unsigned long)hcpu;
324
325 switch (action) {
326 case CPU_ONLINE:
327 case CPU_ONLINE_FROZEN:
328 cpufreq_update_policy(cpu);
329 break;
330 case CPU_DOWN_PREPARE:
331 cpufreq_stats_free_sysfs(cpu);
332 break;
333 case CPU_DEAD:
334 case CPU_DEAD_FROZEN:
335 cpufreq_stats_free_table(cpu);
336 break;
337 }
338 return NOTIFY_OK;
339}
340
341/* priority=1 so this will get called before cpufreq_remove_dev */
342static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
343 .notifier_call = cpufreq_stat_cpu_callback,
344 .priority = 1,
345};
346
347static struct notifier_block notifier_policy_block = {
348 .notifier_call = cpufreq_stat_notifier_policy
349};
350
351static struct notifier_block notifier_trans_block = {
352 .notifier_call = cpufreq_stat_notifier_trans
353};
354
355static int __init cpufreq_stats_init(void)
356{
357 int ret;
358 unsigned int cpu;
359
360 spin_lock_init(&cpufreq_stats_lock);
361 ret = cpufreq_register_notifier(¬ifier_policy_block,
362 CPUFREQ_POLICY_NOTIFIER);
363 if (ret)
364 return ret;
365
366 ret = cpufreq_register_notifier(¬ifier_trans_block,
367 CPUFREQ_TRANSITION_NOTIFIER);
368 if (ret) {
369 cpufreq_unregister_notifier(¬ifier_policy_block,
370 CPUFREQ_POLICY_NOTIFIER);
371 return ret;
372 }
373
374 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
375 for_each_online_cpu(cpu) {
376 cpufreq_update_policy(cpu);
377 }
378 return 0;
379}
380static void __exit cpufreq_stats_exit(void)
381{
382 unsigned int cpu;
383
384 cpufreq_unregister_notifier(¬ifier_policy_block,
385 CPUFREQ_POLICY_NOTIFIER);
386 cpufreq_unregister_notifier(¬ifier_trans_block,
387 CPUFREQ_TRANSITION_NOTIFIER);
388 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
389 for_each_online_cpu(cpu) {
390 cpufreq_stats_free_table(cpu);
391 cpufreq_stats_free_sysfs(cpu);
392 }
393}
394
395MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
396MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
397 "through sysfs filesystem");
398MODULE_LICENSE("GPL");
399
400module_init(cpufreq_stats_init);
401module_exit(cpufreq_stats_exit);