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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>. | |
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/config.h> | |
13 | #include <linux/kernel.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> | |
c32b6b8e | 22 | #include <linux/notifier.h> |
58f1df25 | 23 | #include <asm/cputime.h> |
1da177e4 LT |
24 | |
25 | static spinlock_t cpufreq_stats_lock; | |
26 | ||
27 | #define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \ | |
28 | static struct freq_attr _attr_##_name = {\ | |
29 | .attr = {.name = __stringify(_name), .owner = THIS_MODULE, \ | |
30 | .mode = _mode, }, \ | |
31 | .show = _show,\ | |
32 | }; | |
33 | ||
1da177e4 LT |
34 | struct cpufreq_stats { |
35 | unsigned int cpu; | |
36 | unsigned int total_trans; | |
58f1df25 | 37 | unsigned long long last_time; |
1da177e4 LT |
38 | unsigned int max_state; |
39 | unsigned int state_num; | |
40 | unsigned int last_index; | |
58f1df25 | 41 | cputime64_t *time_in_state; |
1da177e4 LT |
42 | unsigned int *freq_table; |
43 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
44 | unsigned int *trans_table; | |
45 | #endif | |
46 | }; | |
47 | ||
48 | static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS]; | |
49 | ||
50 | struct cpufreq_stats_attribute { | |
51 | struct attribute attr; | |
52 | ssize_t(*show) (struct cpufreq_stats *, char *); | |
53 | }; | |
54 | ||
55 | static int | |
56 | cpufreq_stats_update (unsigned int cpu) | |
57 | { | |
58 | struct cpufreq_stats *stat; | |
58f1df25 VP |
59 | unsigned long long cur_time; |
60 | ||
61 | cur_time = get_jiffies_64(); | |
1da177e4 LT |
62 | spin_lock(&cpufreq_stats_lock); |
63 | stat = cpufreq_stats_table[cpu]; | |
64 | if (stat->time_in_state) | |
58f1df25 VP |
65 | stat->time_in_state[stat->last_index] = |
66 | cputime64_add(stat->time_in_state[stat->last_index], | |
67 | cputime_sub(cur_time, stat->last_time)); | |
68 | stat->last_time = cur_time; | |
1da177e4 LT |
69 | spin_unlock(&cpufreq_stats_lock); |
70 | return 0; | |
71 | } | |
72 | ||
73 | static ssize_t | |
74 | show_total_trans(struct cpufreq_policy *policy, char *buf) | |
75 | { | |
76 | struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; | |
77 | if(!stat) | |
78 | return 0; | |
79 | return sprintf(buf, "%d\n", | |
80 | cpufreq_stats_table[stat->cpu]->total_trans); | |
81 | } | |
82 | ||
83 | static ssize_t | |
84 | show_time_in_state(struct cpufreq_policy *policy, char *buf) | |
85 | { | |
86 | ssize_t len = 0; | |
87 | int i; | |
88 | struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; | |
89 | if(!stat) | |
90 | return 0; | |
91 | cpufreq_stats_update(stat->cpu); | |
92 | for (i = 0; i < stat->state_num; i++) { | |
58f1df25 VP |
93 | len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i], |
94 | (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i])); | |
1da177e4 LT |
95 | } |
96 | return len; | |
97 | } | |
98 | ||
99 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
100 | static ssize_t | |
101 | show_trans_table(struct cpufreq_policy *policy, char *buf) | |
102 | { | |
103 | ssize_t len = 0; | |
104 | int i, j; | |
105 | ||
106 | struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; | |
107 | if(!stat) | |
108 | return 0; | |
109 | cpufreq_stats_update(stat->cpu); | |
58f1df25 VP |
110 | len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); |
111 | len += snprintf(buf + len, PAGE_SIZE - len, " : "); | |
112 | for (i = 0; i < stat->state_num; i++) { | |
113 | if (len >= PAGE_SIZE) | |
114 | break; | |
115 | len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", | |
116 | stat->freq_table[i]); | |
117 | } | |
118 | if (len >= PAGE_SIZE) | |
119 | return len; | |
120 | ||
121 | len += snprintf(buf + len, PAGE_SIZE - len, "\n"); | |
122 | ||
1da177e4 LT |
123 | for (i = 0; i < stat->state_num; i++) { |
124 | if (len >= PAGE_SIZE) | |
125 | break; | |
58f1df25 VP |
126 | |
127 | len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", | |
1da177e4 LT |
128 | stat->freq_table[i]); |
129 | ||
130 | for (j = 0; j < stat->state_num; j++) { | |
131 | if (len >= PAGE_SIZE) | |
132 | break; | |
58f1df25 | 133 | len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", |
1da177e4 LT |
134 | stat->trans_table[i*stat->max_state+j]); |
135 | } | |
136 | len += snprintf(buf + len, PAGE_SIZE - len, "\n"); | |
137 | } | |
138 | return len; | |
139 | } | |
140 | CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table); | |
141 | #endif | |
142 | ||
143 | CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans); | |
144 | CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state); | |
145 | ||
146 | static 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 | }; | |
154 | static struct attribute_group stats_attr_group = { | |
155 | .attrs = default_attrs, | |
156 | .name = "stats" | |
157 | }; | |
158 | ||
159 | static int | |
160 | freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq) | |
161 | { | |
162 | int index; | |
163 | for (index = 0; index < stat->max_state; index++) | |
164 | if (stat->freq_table[index] == freq) | |
165 | return index; | |
166 | return -1; | |
167 | } | |
168 | ||
169 | static void | |
170 | cpufreq_stats_free_table (unsigned int cpu) | |
171 | { | |
172 | struct cpufreq_stats *stat = cpufreq_stats_table[cpu]; | |
173 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
174 | if (policy && policy->cpu == cpu) | |
175 | sysfs_remove_group(&policy->kobj, &stats_attr_group); | |
176 | if (stat) { | |
177 | kfree(stat->time_in_state); | |
178 | kfree(stat); | |
179 | } | |
180 | cpufreq_stats_table[cpu] = NULL; | |
181 | if (policy) | |
182 | cpufreq_cpu_put(policy); | |
183 | } | |
184 | ||
185 | static int | |
186 | cpufreq_stats_create_table (struct cpufreq_policy *policy, | |
187 | struct cpufreq_frequency_table *table) | |
188 | { | |
189 | unsigned int i, j, count = 0, ret = 0; | |
190 | struct cpufreq_stats *stat; | |
191 | struct cpufreq_policy *data; | |
192 | unsigned int alloc_size; | |
193 | unsigned int cpu = policy->cpu; | |
194 | if (cpufreq_stats_table[cpu]) | |
195 | return -EBUSY; | |
e98df50c | 196 | if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL) |
1da177e4 | 197 | return -ENOMEM; |
1da177e4 LT |
198 | |
199 | data = cpufreq_cpu_get(cpu); | |
bc7b26fd DJ |
200 | if (data == NULL) { |
201 | ret = -EINVAL; | |
202 | goto error_get_fail; | |
203 | } | |
204 | ||
1da177e4 LT |
205 | if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group))) |
206 | goto error_out; | |
207 | ||
208 | stat->cpu = cpu; | |
209 | cpufreq_stats_table[cpu] = stat; | |
210 | ||
211 | for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) { | |
212 | unsigned int freq = table[i].frequency; | |
213 | if (freq == CPUFREQ_ENTRY_INVALID) | |
214 | continue; | |
215 | count++; | |
216 | } | |
217 | ||
58f1df25 | 218 | alloc_size = count * sizeof(int) + count * sizeof(cputime64_t); |
1da177e4 LT |
219 | |
220 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
221 | alloc_size += count * count * sizeof(int); | |
222 | #endif | |
223 | stat->max_state = count; | |
e98df50c | 224 | stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL); |
1da177e4 LT |
225 | if (!stat->time_in_state) { |
226 | ret = -ENOMEM; | |
227 | goto error_out; | |
228 | } | |
1da177e4 LT |
229 | stat->freq_table = (unsigned int *)(stat->time_in_state + count); |
230 | ||
231 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
232 | stat->trans_table = stat->freq_table + count; | |
233 | #endif | |
234 | j = 0; | |
235 | for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { | |
236 | unsigned int freq = table[i].frequency; | |
237 | if (freq == CPUFREQ_ENTRY_INVALID) | |
238 | continue; | |
239 | if (freq_table_get_index(stat, freq) == -1) | |
240 | stat->freq_table[j++] = freq; | |
241 | } | |
242 | stat->state_num = j; | |
243 | spin_lock(&cpufreq_stats_lock); | |
58f1df25 | 244 | stat->last_time = get_jiffies_64(); |
1da177e4 LT |
245 | stat->last_index = freq_table_get_index(stat, policy->cur); |
246 | spin_unlock(&cpufreq_stats_lock); | |
247 | cpufreq_cpu_put(data); | |
248 | return 0; | |
249 | error_out: | |
250 | cpufreq_cpu_put(data); | |
b7fb358c | 251 | error_get_fail: |
1da177e4 LT |
252 | kfree(stat); |
253 | cpufreq_stats_table[cpu] = NULL; | |
254 | return ret; | |
255 | } | |
256 | ||
257 | static int | |
258 | cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val, | |
259 | void *data) | |
260 | { | |
261 | int ret; | |
262 | struct cpufreq_policy *policy = data; | |
263 | struct cpufreq_frequency_table *table; | |
264 | unsigned int cpu = policy->cpu; | |
265 | if (val != CPUFREQ_NOTIFY) | |
266 | return 0; | |
267 | table = cpufreq_frequency_get_table(cpu); | |
268 | if (!table) | |
269 | return 0; | |
270 | if ((ret = cpufreq_stats_create_table(policy, table))) | |
271 | return ret; | |
272 | return 0; | |
273 | } | |
274 | ||
275 | static int | |
276 | cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val, | |
277 | void *data) | |
278 | { | |
279 | struct cpufreq_freqs *freq = data; | |
280 | struct cpufreq_stats *stat; | |
281 | int old_index, new_index; | |
282 | ||
283 | if (val != CPUFREQ_POSTCHANGE) | |
284 | return 0; | |
285 | ||
286 | stat = cpufreq_stats_table[freq->cpu]; | |
287 | if (!stat) | |
288 | return 0; | |
289 | old_index = freq_table_get_index(stat, freq->old); | |
290 | new_index = freq_table_get_index(stat, freq->new); | |
291 | ||
292 | cpufreq_stats_update(freq->cpu); | |
293 | if (old_index == new_index) | |
294 | return 0; | |
295 | ||
296 | spin_lock(&cpufreq_stats_lock); | |
297 | stat->last_index = new_index; | |
298 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS | |
299 | stat->trans_table[old_index * stat->max_state + new_index]++; | |
300 | #endif | |
301 | stat->total_trans++; | |
302 | spin_unlock(&cpufreq_stats_lock); | |
303 | return 0; | |
304 | } | |
305 | ||
c32b6b8e AR |
306 | static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb, |
307 | unsigned long action, void *hcpu) | |
308 | { | |
309 | unsigned int cpu = (unsigned long)hcpu; | |
310 | ||
311 | switch (action) { | |
312 | case CPU_ONLINE: | |
313 | cpufreq_update_policy(cpu); | |
314 | break; | |
315 | case CPU_DEAD: | |
316 | cpufreq_stats_free_table(cpu); | |
317 | break; | |
318 | } | |
319 | return NOTIFY_OK; | |
320 | } | |
321 | ||
322 | static struct notifier_block cpufreq_stat_cpu_notifier = | |
323 | { | |
324 | .notifier_call = cpufreq_stat_cpu_callback, | |
325 | }; | |
326 | ||
1da177e4 LT |
327 | static struct notifier_block notifier_policy_block = { |
328 | .notifier_call = cpufreq_stat_notifier_policy | |
329 | }; | |
330 | ||
331 | static struct notifier_block notifier_trans_block = { | |
332 | .notifier_call = cpufreq_stat_notifier_trans | |
333 | }; | |
334 | ||
335 | static int | |
336 | __init cpufreq_stats_init(void) | |
337 | { | |
338 | int ret; | |
339 | unsigned int cpu; | |
c32b6b8e | 340 | |
1da177e4 LT |
341 | spin_lock_init(&cpufreq_stats_lock); |
342 | if ((ret = cpufreq_register_notifier(¬ifier_policy_block, | |
343 | CPUFREQ_POLICY_NOTIFIER))) | |
344 | return ret; | |
345 | ||
346 | if ((ret = cpufreq_register_notifier(¬ifier_trans_block, | |
347 | CPUFREQ_TRANSITION_NOTIFIER))) { | |
348 | cpufreq_unregister_notifier(¬ifier_policy_block, | |
349 | CPUFREQ_POLICY_NOTIFIER); | |
350 | return ret; | |
351 | } | |
352 | ||
c32b6b8e AR |
353 | register_cpu_notifier(&cpufreq_stat_cpu_notifier); |
354 | lock_cpu_hotplug(); | |
355 | for_each_online_cpu(cpu) { | |
356 | cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE, | |
357 | (void *)(long)cpu); | |
358 | } | |
359 | unlock_cpu_hotplug(); | |
1da177e4 LT |
360 | return 0; |
361 | } | |
362 | static void | |
363 | __exit cpufreq_stats_exit(void) | |
364 | { | |
365 | unsigned int cpu; | |
c32b6b8e | 366 | |
1da177e4 LT |
367 | cpufreq_unregister_notifier(¬ifier_policy_block, |
368 | CPUFREQ_POLICY_NOTIFIER); | |
369 | cpufreq_unregister_notifier(¬ifier_trans_block, | |
370 | CPUFREQ_TRANSITION_NOTIFIER); | |
c32b6b8e AR |
371 | unregister_cpu_notifier(&cpufreq_stat_cpu_notifier); |
372 | lock_cpu_hotplug(); | |
373 | for_each_online_cpu(cpu) { | |
374 | cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD, | |
375 | (void *)(long)cpu); | |
376 | } | |
377 | unlock_cpu_hotplug(); | |
1da177e4 LT |
378 | } |
379 | ||
380 | MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>"); | |
381 | MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem"); | |
382 | MODULE_LICENSE ("GPL"); | |
383 | ||
384 | module_init(cpufreq_stats_init); | |
385 | module_exit(cpufreq_stats_exit); |