blob: d1c7cac9316cc4e7729f8445c9ba8ebc07d858b7 [file] [log] [blame]
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 = {\
28 .attr = {.name = __stringify(_name), .owner = THIS_MODULE, \
29 .mode = _mode, }, \
30 .show = _show,\
31};
32
Linus Torvalds1da177e2005-04-16 15:20:36 -070033struct cpufreq_stats {
34 unsigned int cpu;
35 unsigned int total_trans;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070036 unsigned long long last_time;
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 unsigned int max_state;
38 unsigned int state_num;
39 unsigned int last_index;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070040 cputime64_t *time_in_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 unsigned int *freq_table;
42#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
43 unsigned int *trans_table;
44#endif
45};
46
47static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
48
49struct cpufreq_stats_attribute {
50 struct attribute attr;
51 ssize_t(*show) (struct cpufreq_stats *, char *);
52};
53
54static int
55cpufreq_stats_update (unsigned int cpu)
56{
57 struct cpufreq_stats *stat;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070058 unsigned long long cur_time;
59
60 cur_time = get_jiffies_64();
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 spin_lock(&cpufreq_stats_lock);
62 stat = cpufreq_stats_table[cpu];
63 if (stat->time_in_state)
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070064 stat->time_in_state[stat->last_index] =
65 cputime64_add(stat->time_in_state[stat->last_index],
66 cputime_sub(cur_time, stat->last_time));
67 stat->last_time = cur_time;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 spin_unlock(&cpufreq_stats_lock);
69 return 0;
70}
71
72static ssize_t
73show_total_trans(struct cpufreq_policy *policy, char *buf)
74{
75 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
Dave Jones511e9ee2006-05-30 17:57:14 -040076 if (!stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 return 0;
78 return sprintf(buf, "%d\n",
79 cpufreq_stats_table[stat->cpu]->total_trans);
80}
81
82static ssize_t
83show_time_in_state(struct cpufreq_policy *policy, char *buf)
84{
85 ssize_t len = 0;
86 int i;
87 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
Dave Jones511e9ee2006-05-30 17:57:14 -040088 if (!stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 return 0;
90 cpufreq_stats_update(stat->cpu);
91 for (i = 0; i < stat->state_num; i++) {
Dave Jones32ee8c32006-02-28 00:43:23 -050092 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070093 (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 }
95 return len;
96}
97
98#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
99static ssize_t
100show_trans_table(struct cpufreq_policy *policy, char *buf)
101{
102 ssize_t len = 0;
103 int i, j;
104
105 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
Dave Jones511e9ee2006-05-30 17:57:14 -0400106 if (!stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 return 0;
108 cpufreq_stats_update(stat->cpu);
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700109 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
110 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 for (i = 0; i < stat->state_num; i++) {
112 if (len >= PAGE_SIZE)
113 break;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700114 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
115 stat->freq_table[i]);
116 }
117 if (len >= PAGE_SIZE)
118 return len;
119
120 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
121
122 for (i = 0; i < stat->state_num; i++) {
123 if (len >= PAGE_SIZE)
124 break;
125
126 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 stat->freq_table[i]);
128
129 for (j = 0; j < stat->state_num; j++) {
130 if (len >= PAGE_SIZE)
131 break;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700132 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 stat->trans_table[i*stat->max_state+j]);
134 }
135 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
136 }
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
159freq_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
168static void
169cpufreq_stats_free_table (unsigned int cpu)
170{
171 struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
172 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
Dave Jones32ee8c32006-02-28 00:43:23 -0500173 if (policy && policy->cpu == cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 sysfs_remove_group(&policy->kobj, &stats_attr_group);
175 if (stat) {
176 kfree(stat->time_in_state);
177 kfree(stat);
178 }
179 cpufreq_stats_table[cpu] = NULL;
180 if (policy)
181 cpufreq_cpu_put(policy);
182}
183
184static int
185cpufreq_stats_create_table (struct cpufreq_policy *policy,
186 struct cpufreq_frequency_table *table)
187{
188 unsigned int i, j, count = 0, ret = 0;
189 struct cpufreq_stats *stat;
190 struct cpufreq_policy *data;
191 unsigned int alloc_size;
192 unsigned int cpu = policy->cpu;
193 if (cpufreq_stats_table[cpu])
194 return -EBUSY;
Dave Jonese98df502005-10-20 15:17:43 -0700195 if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
198 data = cpufreq_cpu_get(cpu);
Dave Jonesbc7b26f2005-10-27 16:02:06 -0700199 if (data == NULL) {
200 ret = -EINVAL;
201 goto error_get_fail;
202 }
203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
205 goto error_out;
206
207 stat->cpu = cpu;
208 cpufreq_stats_table[cpu] = stat;
209
210 for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
211 unsigned int freq = table[i].frequency;
212 if (freq == CPUFREQ_ENTRY_INVALID)
213 continue;
214 count++;
215 }
216
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700217 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
219#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
220 alloc_size += count * count * sizeof(int);
221#endif
222 stat->max_state = count;
Dave Jonese98df502005-10-20 15:17:43 -0700223 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 if (!stat->time_in_state) {
225 ret = -ENOMEM;
226 goto error_out;
227 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
229
230#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
231 stat->trans_table = stat->freq_table + count;
232#endif
233 j = 0;
234 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
235 unsigned int freq = table[i].frequency;
236 if (freq == CPUFREQ_ENTRY_INVALID)
237 continue;
238 if (freq_table_get_index(stat, freq) == -1)
239 stat->freq_table[j++] = freq;
240 }
241 stat->state_num = j;
242 spin_lock(&cpufreq_stats_lock);
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700243 stat->last_time = get_jiffies_64();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 stat->last_index = freq_table_get_index(stat, policy->cur);
245 spin_unlock(&cpufreq_stats_lock);
246 cpufreq_cpu_put(data);
247 return 0;
248error_out:
249 cpufreq_cpu_put(data);
Dave Jonesb7fb3582005-11-01 23:13:45 -0800250error_get_fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 kfree(stat);
252 cpufreq_stats_table[cpu] = NULL;
253 return ret;
254}
255
256static int
257cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
258 void *data)
259{
260 int ret;
261 struct cpufreq_policy *policy = data;
262 struct cpufreq_frequency_table *table;
263 unsigned int cpu = policy->cpu;
264 if (val != CPUFREQ_NOTIFY)
265 return 0;
266 table = cpufreq_frequency_get_table(cpu);
267 if (!table)
268 return 0;
269 if ((ret = cpufreq_stats_create_table(policy, table)))
270 return ret;
271 return 0;
272}
273
274static int
275cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
276 void *data)
277{
278 struct cpufreq_freqs *freq = data;
279 struct cpufreq_stats *stat;
280 int old_index, new_index;
281
282 if (val != CPUFREQ_POSTCHANGE)
283 return 0;
284
285 stat = cpufreq_stats_table[freq->cpu];
286 if (!stat)
287 return 0;
Venkatesh Pallipadi8edc59d92006-12-19 12:58:55 -0800288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 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
Venkatesh Pallipadi8edc59d92006-12-19 12:58:55 -0800296 if (old_index == -1 || new_index == -1)
297 return 0;
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 spin_lock(&cpufreq_stats_lock);
300 stat->last_index = new_index;
301#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
302 stat->trans_table[old_index * stat->max_state + new_index]++;
303#endif
304 stat->total_trans++;
305 spin_unlock(&cpufreq_stats_lock);
306 return 0;
307}
308
Sam Ravnborgbb1a8132006-03-11 19:22:53 +0100309static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
Ashok Rajc32b6b82005-10-30 14:59:54 -0800310 unsigned long action, void *hcpu)
311{
312 unsigned int cpu = (unsigned long)hcpu;
313
314 switch (action) {
315 case CPU_ONLINE:
316 cpufreq_update_policy(cpu);
317 break;
318 case CPU_DEAD:
319 cpufreq_stats_free_table(cpu);
320 break;
321 }
322 return NOTIFY_OK;
323}
324
325static struct notifier_block cpufreq_stat_cpu_notifier =
326{
327 .notifier_call = cpufreq_stat_cpu_callback,
328};
329
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330static struct notifier_block notifier_policy_block = {
331 .notifier_call = cpufreq_stat_notifier_policy
332};
333
334static struct notifier_block notifier_trans_block = {
335 .notifier_call = cpufreq_stat_notifier_trans
336};
337
338static int
339__init cpufreq_stats_init(void)
340{
341 int ret;
342 unsigned int cpu;
Ashok Rajc32b6b82005-10-30 14:59:54 -0800343
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 spin_lock_init(&cpufreq_stats_lock);
345 if ((ret = cpufreq_register_notifier(&notifier_policy_block,
346 CPUFREQ_POLICY_NOTIFIER)))
347 return ret;
348
349 if ((ret = cpufreq_register_notifier(&notifier_trans_block,
350 CPUFREQ_TRANSITION_NOTIFIER))) {
351 cpufreq_unregister_notifier(&notifier_policy_block,
352 CPUFREQ_POLICY_NOTIFIER);
353 return ret;
354 }
355
Chandra Seetharaman65edc682006-06-27 02:54:08 -0700356 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800357 for_each_online_cpu(cpu) {
Gautham R Shenoye08f5f52006-10-26 16:20:58 +0530358 cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier,
359 CPU_ONLINE, (void *)(long)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) {
Gautham R Shenoye08f5f52006-10-26 16:20:58 +0530374 cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier,
375 CPU_DEAD, (void *)(long)cpu);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800376 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377}
378
379MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
Gautham R Shenoye08f5f52006-10-26 16:20:58 +0530380MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats"
381 "through sysfs filesystem");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382MODULE_LICENSE ("GPL");
383
384module_init(cpufreq_stats_init);
385module_exit(cpufreq_stats_exit);