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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * drivers/cpufreq/cpufreq_stats.c
3 *
4 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
Dave Jones32ee8c32006-02-28 00:43:23 -05005 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#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>
Ashok Rajc32b6b82005-10-30 14:59:54 -080021#include <linux/notifier.h>
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070022#include <asm/cputime.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
24static spinlock_t cpufreq_stats_lock;
25
26#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
27static struct freq_attr _attr_##_name = {\
Tejun Heo7b595752007-06-14 03:45:17 +090028 .attr = {.name = __stringify(_name), .mode = _mode, }, \
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 .show = _show,\
30};
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032struct cpufreq_stats {
33 unsigned int cpu;
34 unsigned int total_trans;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070035 unsigned long long last_time;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 unsigned int max_state;
37 unsigned int state_num;
38 unsigned int last_index;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070039 cputime64_t *time_in_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 unsigned int *freq_table;
41#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
42 unsigned int *trans_table;
43#endif
44};
45
46static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
47
48struct cpufreq_stats_attribute {
49 struct attribute attr;
50 ssize_t(*show) (struct cpufreq_stats *, char *);
51};
52
53static int
54cpufreq_stats_update (unsigned int cpu)
55{
56 struct cpufreq_stats *stat;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070057 unsigned long long cur_time;
58
59 cur_time = get_jiffies_64();
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 spin_lock(&cpufreq_stats_lock);
61 stat = cpufreq_stats_table[cpu];
62 if (stat->time_in_state)
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070063 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 spin_unlock(&cpufreq_stats_lock);
68 return 0;
69}
70
71static ssize_t
72show_total_trans(struct cpufreq_policy *policy, char *buf)
73{
74 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
Dave Jones511e9ee2006-05-30 17:57:14 -040075 if (!stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 return 0;
77 return sprintf(buf, "%d\n",
78 cpufreq_stats_table[stat->cpu]->total_trans);
79}
80
81static ssize_t
82show_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];
Dave Jones511e9ee2006-05-30 17:57:14 -040087 if (!stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 return 0;
89 cpufreq_stats_update(stat->cpu);
90 for (i = 0; i < stat->state_num; i++) {
Dave Jones32ee8c32006-02-28 00:43:23 -050091 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070092 (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 }
94 return len;
95}
96
97#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
98static ssize_t
99show_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];
Dave Jones511e9ee2006-05-30 17:57:14 -0400105 if (!stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 return 0;
107 cpufreq_stats_update(stat->cpu);
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700108 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
109 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 for (i = 0; i < stat->state_num; i++) {
111 if (len >= PAGE_SIZE)
112 break;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700113 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
114 stat->freq_table[i]);
115 }
116 if (len >= PAGE_SIZE)
117 return len;
118
119 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
120
121 for (i = 0; i < stat->state_num; i++) {
122 if (len >= PAGE_SIZE)
123 break;
124
125 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 stat->freq_table[i]);
127
128 for (j = 0; j < stat->state_num; j++) {
129 if (len >= PAGE_SIZE)
130 break;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700131 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 stat->trans_table[i*stat->max_state+j]);
133 }
134 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
135 }
136 return len;
137}
138CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
139#endif
140
141CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
142CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
143
144static struct attribute *default_attrs[] = {
145 &_attr_total_trans.attr,
146 &_attr_time_in_state.attr,
147#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
148 &_attr_trans_table.attr,
149#endif
150 NULL
151};
152static struct attribute_group stats_attr_group = {
153 .attrs = default_attrs,
154 .name = "stats"
155};
156
157static int
158freq_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
Adrian Bunka3323472007-12-17 16:20:03 -0800167static void cpufreq_stats_free_table(unsigned int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168{
169 struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
170 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
Dave Jones32ee8c32006-02-28 00:43:23 -0500171 if (policy && policy->cpu == cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 sysfs_remove_group(&policy->kobj, &stats_attr_group);
173 if (stat) {
174 kfree(stat->time_in_state);
175 kfree(stat);
176 }
177 cpufreq_stats_table[cpu] = NULL;
178 if (policy)
179 cpufreq_cpu_put(policy);
180}
181
182static int
183cpufreq_stats_create_table (struct cpufreq_policy *policy,
184 struct cpufreq_frequency_table *table)
185{
186 unsigned int i, j, count = 0, ret = 0;
187 struct cpufreq_stats *stat;
188 struct cpufreq_policy *data;
189 unsigned int alloc_size;
190 unsigned int cpu = policy->cpu;
191 if (cpufreq_stats_table[cpu])
192 return -EBUSY;
Dave Jonese98df502005-10-20 15:17:43 -0700193 if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196 data = cpufreq_cpu_get(cpu);
Dave Jonesbc7b26f2005-10-27 16:02:06 -0700197 if (data == NULL) {
198 ret = -EINVAL;
199 goto error_get_fail;
200 }
201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
203 goto error_out;
204
205 stat->cpu = cpu;
206 cpufreq_stats_table[cpu] = stat;
207
208 for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
209 unsigned int freq = table[i].frequency;
210 if (freq == CPUFREQ_ENTRY_INVALID)
211 continue;
212 count++;
213 }
214
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700215 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
217#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
218 alloc_size += count * count * sizeof(int);
219#endif
220 stat->max_state = count;
Dave Jonese98df502005-10-20 15:17:43 -0700221 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 if (!stat->time_in_state) {
223 ret = -ENOMEM;
224 goto error_out;
225 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
227
228#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
229 stat->trans_table = stat->freq_table + count;
230#endif
231 j = 0;
232 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
233 unsigned int freq = table[i].frequency;
234 if (freq == CPUFREQ_ENTRY_INVALID)
235 continue;
236 if (freq_table_get_index(stat, freq) == -1)
237 stat->freq_table[j++] = freq;
238 }
239 stat->state_num = j;
240 spin_lock(&cpufreq_stats_lock);
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700241 stat->last_time = get_jiffies_64();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 stat->last_index = freq_table_get_index(stat, policy->cur);
243 spin_unlock(&cpufreq_stats_lock);
244 cpufreq_cpu_put(data);
245 return 0;
246error_out:
247 cpufreq_cpu_put(data);
Dave Jonesb7fb3582005-11-01 23:13:45 -0800248error_get_fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 kfree(stat);
250 cpufreq_stats_table[cpu] = NULL;
251 return ret;
252}
253
254static int
255cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
256 void *data)
257{
258 int ret;
259 struct cpufreq_policy *policy = data;
260 struct cpufreq_frequency_table *table;
261 unsigned int cpu = policy->cpu;
262 if (val != CPUFREQ_NOTIFY)
263 return 0;
264 table = cpufreq_frequency_get_table(cpu);
265 if (!table)
266 return 0;
267 if ((ret = cpufreq_stats_create_table(policy, table)))
268 return ret;
269 return 0;
270}
271
272static int
273cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
274 void *data)
275{
276 struct cpufreq_freqs *freq = data;
277 struct cpufreq_stats *stat;
278 int old_index, new_index;
279
280 if (val != CPUFREQ_POSTCHANGE)
281 return 0;
282
283 stat = cpufreq_stats_table[freq->cpu];
284 if (!stat)
285 return 0;
Venkatesh Pallipadi8edc59d92006-12-19 12:58:55 -0800286
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 old_index = freq_table_get_index(stat, freq->old);
288 new_index = freq_table_get_index(stat, freq->new);
289
290 cpufreq_stats_update(freq->cpu);
291 if (old_index == new_index)
292 return 0;
293
Venkatesh Pallipadi8edc59d92006-12-19 12:58:55 -0800294 if (old_index == -1 || new_index == -1)
295 return 0;
296
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 spin_lock(&cpufreq_stats_lock);
298 stat->last_index = new_index;
299#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
300 stat->trans_table[old_index * stat->max_state + new_index]++;
301#endif
302 stat->total_trans++;
303 spin_unlock(&cpufreq_stats_lock);
304 return 0;
305}
306
Satyam Sharma55395ae2007-10-02 13:28:15 -0700307static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
308 unsigned long action,
309 void *hcpu)
Ashok Rajc32b6b82005-10-30 14:59:54 -0800310{
311 unsigned int cpu = (unsigned long)hcpu;
312
313 switch (action) {
314 case CPU_ONLINE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700315 case CPU_ONLINE_FROZEN:
Ashok Rajc32b6b82005-10-30 14:59:54 -0800316 cpufreq_update_policy(cpu);
317 break;
318 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700319 case CPU_DEAD_FROZEN:
Ashok Rajc32b6b82005-10-30 14:59:54 -0800320 cpufreq_stats_free_table(cpu);
321 break;
322 }
323 return NOTIFY_OK;
324}
325
Satyam Sharma55395ae2007-10-02 13:28:15 -0700326static struct notifier_block cpufreq_stat_cpu_notifier __cpuinitdata =
Ashok Rajc32b6b82005-10-30 14:59:54 -0800327{
328 .notifier_call = cpufreq_stat_cpu_callback,
329};
330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331static struct notifier_block notifier_policy_block = {
332 .notifier_call = cpufreq_stat_notifier_policy
333};
334
335static struct notifier_block notifier_trans_block = {
336 .notifier_call = cpufreq_stat_notifier_trans
337};
338
339static int
340__init cpufreq_stats_init(void)
341{
342 int ret;
343 unsigned int cpu;
Ashok Rajc32b6b82005-10-30 14:59:54 -0800344
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 spin_lock_init(&cpufreq_stats_lock);
346 if ((ret = cpufreq_register_notifier(&notifier_policy_block,
347 CPUFREQ_POLICY_NOTIFIER)))
348 return ret;
349
350 if ((ret = cpufreq_register_notifier(&notifier_trans_block,
351 CPUFREQ_TRANSITION_NOTIFIER))) {
352 cpufreq_unregister_notifier(&notifier_policy_block,
353 CPUFREQ_POLICY_NOTIFIER);
354 return ret;
355 }
356
Chandra Seetharaman65edc682006-06-27 02:54:08 -0700357 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800358 for_each_online_cpu(cpu) {
Satyam Sharma55395ae2007-10-02 13:28:15 -0700359 cpufreq_update_policy(cpu);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800360 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 return 0;
362}
363static void
364__exit cpufreq_stats_exit(void)
365{
366 unsigned int cpu;
Ashok Rajc32b6b82005-10-30 14:59:54 -0800367
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 cpufreq_unregister_notifier(&notifier_policy_block,
369 CPUFREQ_POLICY_NOTIFIER);
370 cpufreq_unregister_notifier(&notifier_trans_block,
371 CPUFREQ_TRANSITION_NOTIFIER);
Chandra Seetharaman65edc682006-06-27 02:54:08 -0700372 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800373 for_each_online_cpu(cpu) {
Satyam Sharma55395ae2007-10-02 13:28:15 -0700374 cpufreq_stats_free_table(cpu);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800375 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376}
377
378MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
Satyam Sharma55395ae2007-10-02 13:28:15 -0700379MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats "
Gautham R Shenoye08f5f52006-10-26 16:20:58 +0530380 "through sysfs filesystem");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381MODULE_LICENSE ("GPL");
382
383module_init(cpufreq_stats_init);
384module_exit(cpufreq_stats_exit);