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1da177e4 LT |
1 | /* |
2 | * drivers/cpufreq/cpufreq_stats.c | |
3 | * | |
4 | * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>. | |
32ee8c3e | 5 | * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>. |
1da177e4 LT |
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 | ||
1da177e4 LT |
12 | #include <linux/kernel.h> |
13 | #include <linux/sysdev.h> | |
14 | #include <linux/cpu.h> | |
15 | #include <linux/sysfs.h> | |
16 | #include <linux/cpufreq.h> | |
17 | #include <linux/jiffies.h> | |
18 | #include <linux/percpu.h> | |
19 | #include <linux/kobject.h> | |
20 | #include <linux/spinlock.h> | |
c32b6b8e | 21 | #include <linux/notifier.h> |
58f1df25 | 22 | #include <asm/cputime.h> |
1da177e4 LT |
23 | |
24 | static spinlock_t cpufreq_stats_lock; | |
25 | ||
26 | #define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \ | |
27 | static struct freq_attr _attr_##_name = {\ | |
7b595756 | 28 | .attr = {.name = __stringify(_name), .mode = _mode, }, \ |
1da177e4 LT |
29 | .show = _show,\ |
30 | }; | |
31 | ||
1da177e4 LT |
32 | struct cpufreq_stats { |
33 | unsigned int cpu; | |
34 | unsigned int total_trans; | |
58f1df25 | 35 | unsigned long long last_time; |
1da177e4 LT |
36 | unsigned int max_state; |
37 | unsigned int state_num; | |
38 | unsigned int last_index; | |
58f1df25 | 39 | cputime64_t *time_in_state; |
1da177e4 LT |
40 | unsigned int *freq_table; |
41 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
42 | unsigned int *trans_table; | |
43 | #endif | |
44 | }; | |
45 | ||
46 | static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS]; | |
47 | ||
48 | struct cpufreq_stats_attribute { | |
49 | struct attribute attr; | |
50 | ssize_t(*show) (struct cpufreq_stats *, char *); | |
51 | }; | |
52 | ||
53 | static int | |
54 | cpufreq_stats_update (unsigned int cpu) | |
55 | { | |
56 | struct cpufreq_stats *stat; | |
58f1df25 VP |
57 | unsigned long long cur_time; |
58 | ||
59 | cur_time = get_jiffies_64(); | |
1da177e4 LT |
60 | spin_lock(&cpufreq_stats_lock); |
61 | stat = cpufreq_stats_table[cpu]; | |
62 | if (stat->time_in_state) | |
58f1df25 VP |
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; | |
1da177e4 LT |
67 | spin_unlock(&cpufreq_stats_lock); |
68 | return 0; | |
69 | } | |
70 | ||
71 | static ssize_t | |
72 | show_total_trans(struct cpufreq_policy *policy, char *buf) | |
73 | { | |
74 | struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; | |
511e9ee1 | 75 | if (!stat) |
1da177e4 LT |
76 | return 0; |
77 | return sprintf(buf, "%d\n", | |
78 | cpufreq_stats_table[stat->cpu]->total_trans); | |
79 | } | |
80 | ||
81 | static ssize_t | |
82 | show_time_in_state(struct cpufreq_policy *policy, char *buf) | |
83 | { | |
84 | ssize_t len = 0; | |
85 | int i; | |
86 | struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; | |
511e9ee1 | 87 | if (!stat) |
1da177e4 LT |
88 | return 0; |
89 | cpufreq_stats_update(stat->cpu); | |
90 | for (i = 0; i < stat->state_num; i++) { | |
32ee8c3e | 91 | len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i], |
58f1df25 | 92 | (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i])); |
1da177e4 LT |
93 | } |
94 | return len; | |
95 | } | |
96 | ||
97 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
98 | static ssize_t | |
99 | show_trans_table(struct cpufreq_policy *policy, char *buf) | |
100 | { | |
101 | ssize_t len = 0; | |
102 | int i, j; | |
103 | ||
104 | struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; | |
511e9ee1 | 105 | if (!stat) |
1da177e4 LT |
106 | return 0; |
107 | cpufreq_stats_update(stat->cpu); | |
58f1df25 VP |
108 | len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); |
109 | len += snprintf(buf + len, PAGE_SIZE - len, " : "); | |
110 | for (i = 0; i < stat->state_num; i++) { | |
111 | if (len >= PAGE_SIZE) | |
112 | break; | |
113 | len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", | |
114 | stat->freq_table[i]); | |
115 | } | |
116 | if (len >= PAGE_SIZE) | |
25aca347 | 117 | return PAGE_SIZE; |
58f1df25 VP |
118 | |
119 | len += snprintf(buf + len, PAGE_SIZE - len, "\n"); | |
120 | ||
1da177e4 LT |
121 | for (i = 0; i < stat->state_num; i++) { |
122 | if (len >= PAGE_SIZE) | |
123 | break; | |
58f1df25 VP |
124 | |
125 | len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", | |
1da177e4 LT |
126 | stat->freq_table[i]); |
127 | ||
128 | for (j = 0; j < stat->state_num; j++) { | |
129 | if (len >= PAGE_SIZE) | |
130 | break; | |
58f1df25 | 131 | len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", |
1da177e4 LT |
132 | stat->trans_table[i*stat->max_state+j]); |
133 | } | |
25aca347 CEB |
134 | if (len >= PAGE_SIZE) |
135 | break; | |
1da177e4 LT |
136 | len += snprintf(buf + len, PAGE_SIZE - len, "\n"); |
137 | } | |
25aca347 CEB |
138 | if (len >= PAGE_SIZE) |
139 | return PAGE_SIZE; | |
1da177e4 LT |
140 | return len; |
141 | } | |
142 | CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table); | |
143 | #endif | |
144 | ||
145 | CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans); | |
146 | CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state); | |
147 | ||
148 | static struct attribute *default_attrs[] = { | |
149 | &_attr_total_trans.attr, | |
150 | &_attr_time_in_state.attr, | |
151 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
152 | &_attr_trans_table.attr, | |
153 | #endif | |
154 | NULL | |
155 | }; | |
156 | static struct attribute_group stats_attr_group = { | |
157 | .attrs = default_attrs, | |
158 | .name = "stats" | |
159 | }; | |
160 | ||
161 | static int | |
162 | freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq) | |
163 | { | |
164 | int index; | |
165 | for (index = 0; index < stat->max_state; index++) | |
166 | if (stat->freq_table[index] == freq) | |
167 | return index; | |
168 | return -1; | |
169 | } | |
170 | ||
a3323473 | 171 | static void cpufreq_stats_free_table(unsigned int cpu) |
1da177e4 LT |
172 | { |
173 | struct cpufreq_stats *stat = cpufreq_stats_table[cpu]; | |
174 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
32ee8c3e | 175 | if (policy && policy->cpu == cpu) |
1da177e4 LT |
176 | sysfs_remove_group(&policy->kobj, &stats_attr_group); |
177 | if (stat) { | |
178 | kfree(stat->time_in_state); | |
179 | kfree(stat); | |
180 | } | |
181 | cpufreq_stats_table[cpu] = NULL; | |
182 | if (policy) | |
183 | cpufreq_cpu_put(policy); | |
184 | } | |
185 | ||
186 | static int | |
187 | cpufreq_stats_create_table (struct cpufreq_policy *policy, | |
188 | struct cpufreq_frequency_table *table) | |
189 | { | |
190 | unsigned int i, j, count = 0, ret = 0; | |
191 | struct cpufreq_stats *stat; | |
192 | struct cpufreq_policy *data; | |
193 | unsigned int alloc_size; | |
194 | unsigned int cpu = policy->cpu; | |
195 | if (cpufreq_stats_table[cpu]) | |
196 | return -EBUSY; | |
e98df50c | 197 | if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL) |
1da177e4 | 198 | return -ENOMEM; |
1da177e4 LT |
199 | |
200 | data = cpufreq_cpu_get(cpu); | |
bc7b26fd DJ |
201 | if (data == NULL) { |
202 | ret = -EINVAL; | |
203 | goto error_get_fail; | |
204 | } | |
205 | ||
1da177e4 LT |
206 | if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group))) |
207 | goto error_out; | |
208 | ||
209 | stat->cpu = cpu; | |
210 | cpufreq_stats_table[cpu] = stat; | |
211 | ||
212 | for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) { | |
213 | unsigned int freq = table[i].frequency; | |
214 | if (freq == CPUFREQ_ENTRY_INVALID) | |
215 | continue; | |
216 | count++; | |
217 | } | |
218 | ||
58f1df25 | 219 | alloc_size = count * sizeof(int) + count * sizeof(cputime64_t); |
1da177e4 LT |
220 | |
221 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
222 | alloc_size += count * count * sizeof(int); | |
223 | #endif | |
224 | stat->max_state = count; | |
e98df50c | 225 | stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL); |
1da177e4 LT |
226 | if (!stat->time_in_state) { |
227 | ret = -ENOMEM; | |
228 | goto error_out; | |
229 | } | |
1da177e4 LT |
230 | stat->freq_table = (unsigned int *)(stat->time_in_state + count); |
231 | ||
232 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
233 | stat->trans_table = stat->freq_table + count; | |
234 | #endif | |
235 | j = 0; | |
236 | for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { | |
237 | unsigned int freq = table[i].frequency; | |
238 | if (freq == CPUFREQ_ENTRY_INVALID) | |
239 | continue; | |
240 | if (freq_table_get_index(stat, freq) == -1) | |
241 | stat->freq_table[j++] = freq; | |
242 | } | |
243 | stat->state_num = j; | |
244 | spin_lock(&cpufreq_stats_lock); | |
58f1df25 | 245 | stat->last_time = get_jiffies_64(); |
1da177e4 LT |
246 | stat->last_index = freq_table_get_index(stat, policy->cur); |
247 | spin_unlock(&cpufreq_stats_lock); | |
248 | cpufreq_cpu_put(data); | |
249 | return 0; | |
250 | error_out: | |
251 | cpufreq_cpu_put(data); | |
b7fb358c | 252 | error_get_fail: |
1da177e4 LT |
253 | kfree(stat); |
254 | cpufreq_stats_table[cpu] = NULL; | |
255 | return ret; | |
256 | } | |
257 | ||
258 | static int | |
259 | cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val, | |
260 | void *data) | |
261 | { | |
262 | int ret; | |
263 | struct cpufreq_policy *policy = data; | |
264 | struct cpufreq_frequency_table *table; | |
265 | unsigned int cpu = policy->cpu; | |
266 | if (val != CPUFREQ_NOTIFY) | |
267 | return 0; | |
268 | table = cpufreq_frequency_get_table(cpu); | |
269 | if (!table) | |
270 | return 0; | |
271 | if ((ret = cpufreq_stats_create_table(policy, table))) | |
272 | return ret; | |
273 | return 0; | |
274 | } | |
275 | ||
276 | static int | |
277 | cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val, | |
278 | void *data) | |
279 | { | |
280 | struct cpufreq_freqs *freq = data; | |
281 | struct cpufreq_stats *stat; | |
282 | int old_index, new_index; | |
283 | ||
284 | if (val != CPUFREQ_POSTCHANGE) | |
285 | return 0; | |
286 | ||
287 | stat = cpufreq_stats_table[freq->cpu]; | |
288 | if (!stat) | |
289 | return 0; | |
8edc59d9 | 290 | |
6501faf8 | 291 | old_index = stat->last_index; |
1da177e4 LT |
292 | new_index = freq_table_get_index(stat, freq->new); |
293 | ||
294 | cpufreq_stats_update(freq->cpu); | |
295 | if (old_index == new_index) | |
296 | return 0; | |
297 | ||
8edc59d9 VP |
298 | if (old_index == -1 || new_index == -1) |
299 | return 0; | |
300 | ||
1da177e4 LT |
301 | spin_lock(&cpufreq_stats_lock); |
302 | stat->last_index = new_index; | |
303 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
304 | stat->trans_table[old_index * stat->max_state + new_index]++; | |
305 | #endif | |
306 | stat->total_trans++; | |
307 | spin_unlock(&cpufreq_stats_lock); | |
308 | return 0; | |
309 | } | |
310 | ||
55395ae7 SS |
311 | static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb, |
312 | unsigned long action, | |
313 | void *hcpu) | |
c32b6b8e AR |
314 | { |
315 | unsigned int cpu = (unsigned long)hcpu; | |
316 | ||
317 | switch (action) { | |
318 | case CPU_ONLINE: | |
8bb78442 | 319 | case CPU_ONLINE_FROZEN: |
c32b6b8e AR |
320 | cpufreq_update_policy(cpu); |
321 | break; | |
322 | case CPU_DEAD: | |
8bb78442 | 323 | case CPU_DEAD_FROZEN: |
c32b6b8e AR |
324 | cpufreq_stats_free_table(cpu); |
325 | break; | |
326 | } | |
327 | return NOTIFY_OK; | |
328 | } | |
329 | ||
f6ebef30 | 330 | static struct notifier_block cpufreq_stat_cpu_notifier __refdata = |
c32b6b8e AR |
331 | { |
332 | .notifier_call = cpufreq_stat_cpu_callback, | |
333 | }; | |
334 | ||
1da177e4 LT |
335 | static struct notifier_block notifier_policy_block = { |
336 | .notifier_call = cpufreq_stat_notifier_policy | |
337 | }; | |
338 | ||
339 | static struct notifier_block notifier_trans_block = { | |
340 | .notifier_call = cpufreq_stat_notifier_trans | |
341 | }; | |
342 | ||
343 | static int | |
344 | __init cpufreq_stats_init(void) | |
345 | { | |
346 | int ret; | |
347 | unsigned int cpu; | |
c32b6b8e | 348 | |
1da177e4 LT |
349 | spin_lock_init(&cpufreq_stats_lock); |
350 | if ((ret = cpufreq_register_notifier(¬ifier_policy_block, | |
351 | CPUFREQ_POLICY_NOTIFIER))) | |
352 | return ret; | |
353 | ||
354 | if ((ret = cpufreq_register_notifier(¬ifier_trans_block, | |
355 | CPUFREQ_TRANSITION_NOTIFIER))) { | |
356 | cpufreq_unregister_notifier(¬ifier_policy_block, | |
357 | CPUFREQ_POLICY_NOTIFIER); | |
358 | return ret; | |
359 | } | |
360 | ||
65edc68c | 361 | register_hotcpu_notifier(&cpufreq_stat_cpu_notifier); |
c32b6b8e | 362 | for_each_online_cpu(cpu) { |
55395ae7 | 363 | cpufreq_update_policy(cpu); |
c32b6b8e | 364 | } |
1da177e4 LT |
365 | return 0; |
366 | } | |
367 | static void | |
368 | __exit cpufreq_stats_exit(void) | |
369 | { | |
370 | unsigned int cpu; | |
c32b6b8e | 371 | |
1da177e4 LT |
372 | cpufreq_unregister_notifier(¬ifier_policy_block, |
373 | CPUFREQ_POLICY_NOTIFIER); | |
374 | cpufreq_unregister_notifier(¬ifier_trans_block, | |
375 | CPUFREQ_TRANSITION_NOTIFIER); | |
65edc68c | 376 | unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier); |
c32b6b8e | 377 | for_each_online_cpu(cpu) { |
55395ae7 | 378 | cpufreq_stats_free_table(cpu); |
c32b6b8e | 379 | } |
1da177e4 LT |
380 | } |
381 | ||
382 | MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>"); | |
55395ae7 | 383 | MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats " |
e08f5f5b | 384 | "through sysfs filesystem"); |
1da177e4 LT |
385 | MODULE_LICENSE ("GPL"); |
386 | ||
387 | module_init(cpufreq_stats_init); | |
388 | module_exit(cpufreq_stats_exit); |