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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)
Cesar Eduardo Barros25aca342008-02-16 08:41:25 -0200117 return PAGE_SIZE;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700118
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 }
Cesar Eduardo Barros25aca342008-02-16 08:41:25 -0200134 if (len >= PAGE_SIZE)
135 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
137 }
Cesar Eduardo Barros25aca342008-02-16 08:41:25 -0200138 if (len >= PAGE_SIZE)
139 return PAGE_SIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 return len;
141}
142CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
143#endif
144
145CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
146CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
147
148static 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};
156static struct attribute_group stats_attr_group = {
157 .attrs = default_attrs,
158 .name = "stats"
159};
160
161static int
162freq_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
Adrian Bunka3323472007-12-17 16:20:03 -0800171static void cpufreq_stats_free_table(unsigned int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172{
173 struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
174 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
Dave Jones32ee8c32006-02-28 00:43:23 -0500175 if (policy && policy->cpu == cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 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
186static int
187cpufreq_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;
Dave Jonese98df502005-10-20 15:17:43 -0700197 if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200 data = cpufreq_cpu_get(cpu);
Dave Jonesbc7b26f2005-10-27 16:02:06 -0700201 if (data == NULL) {
202 ret = -EINVAL;
203 goto error_get_fail;
204 }
205
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 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
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700219 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
222 alloc_size += count * count * sizeof(int);
223#endif
224 stat->max_state = count;
Dave Jonese98df502005-10-20 15:17:43 -0700225 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 if (!stat->time_in_state) {
227 ret = -ENOMEM;
228 goto error_out;
229 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 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);
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700245 stat->last_time = get_jiffies_64();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 stat->last_index = freq_table_get_index(stat, policy->cur);
247 spin_unlock(&cpufreq_stats_lock);
248 cpufreq_cpu_put(data);
249 return 0;
250error_out:
251 cpufreq_cpu_put(data);
Dave Jonesb7fb3582005-11-01 23:13:45 -0800252error_get_fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 kfree(stat);
254 cpufreq_stats_table[cpu] = NULL;
255 return ret;
256}
257
258static int
259cpufreq_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
276static int
277cpufreq_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;
Venkatesh Pallipadi8edc59d92006-12-19 12:58:55 -0800290
Shaohua Li6501faf2008-04-27 13:46:56 -0700291 old_index = stat->last_index;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 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
Venkatesh Pallipadi8edc59d92006-12-19 12:58:55 -0800298 if (old_index == -1 || new_index == -1)
299 return 0;
300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 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
Satyam Sharma55395ae2007-10-02 13:28:15 -0700311static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
312 unsigned long action,
313 void *hcpu)
Ashok Rajc32b6b82005-10-30 14:59:54 -0800314{
315 unsigned int cpu = (unsigned long)hcpu;
316
317 switch (action) {
318 case CPU_ONLINE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700319 case CPU_ONLINE_FROZEN:
Ashok Rajc32b6b82005-10-30 14:59:54 -0800320 cpufreq_update_policy(cpu);
321 break;
322 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700323 case CPU_DEAD_FROZEN:
Ashok Rajc32b6b82005-10-30 14:59:54 -0800324 cpufreq_stats_free_table(cpu);
325 break;
326 }
327 return NOTIFY_OK;
328}
329
Sam Ravnborgf6ebef32008-02-17 13:22:52 +0100330static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
Ashok Rajc32b6b82005-10-30 14:59:54 -0800331{
332 .notifier_call = cpufreq_stat_cpu_callback,
333};
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335static struct notifier_block notifier_policy_block = {
336 .notifier_call = cpufreq_stat_notifier_policy
337};
338
339static struct notifier_block notifier_trans_block = {
340 .notifier_call = cpufreq_stat_notifier_trans
341};
342
343static int
344__init cpufreq_stats_init(void)
345{
346 int ret;
347 unsigned int cpu;
Ashok Rajc32b6b82005-10-30 14:59:54 -0800348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 spin_lock_init(&cpufreq_stats_lock);
350 if ((ret = cpufreq_register_notifier(&notifier_policy_block,
351 CPUFREQ_POLICY_NOTIFIER)))
352 return ret;
353
354 if ((ret = cpufreq_register_notifier(&notifier_trans_block,
355 CPUFREQ_TRANSITION_NOTIFIER))) {
356 cpufreq_unregister_notifier(&notifier_policy_block,
357 CPUFREQ_POLICY_NOTIFIER);
358 return ret;
359 }
360
Chandra Seetharaman65edc682006-06-27 02:54:08 -0700361 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800362 for_each_online_cpu(cpu) {
Satyam Sharma55395ae2007-10-02 13:28:15 -0700363 cpufreq_update_policy(cpu);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800364 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 return 0;
366}
367static void
368__exit cpufreq_stats_exit(void)
369{
370 unsigned int cpu;
Ashok Rajc32b6b82005-10-30 14:59:54 -0800371
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 cpufreq_unregister_notifier(&notifier_policy_block,
373 CPUFREQ_POLICY_NOTIFIER);
374 cpufreq_unregister_notifier(&notifier_trans_block,
375 CPUFREQ_TRANSITION_NOTIFIER);
Chandra Seetharaman65edc682006-06-27 02:54:08 -0700376 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800377 for_each_online_cpu(cpu) {
Satyam Sharma55395ae2007-10-02 13:28:15 -0700378 cpufreq_stats_free_table(cpu);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800379 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380}
381
382MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
Satyam Sharma55395ae2007-10-02 13:28:15 -0700383MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats "
Gautham R Shenoye08f5f52006-10-26 16:20:58 +0530384 "through sysfs filesystem");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385MODULE_LICENSE ("GPL");
386
387module_init(cpufreq_stats_init);
388module_exit(cpufreq_stats_exit);