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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>.
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>
Ashok Rajc32b6b82005-10-30 14:59:54 -080022#include <linux/notifier.h>
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070023#include <asm/cputime.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25static spinlock_t cpufreq_stats_lock;
26
27#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
28static struct freq_attr _attr_##_name = {\
29 .attr = {.name = __stringify(_name), .owner = THIS_MODULE, \
30 .mode = _mode, }, \
31 .show = _show,\
32};
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034struct cpufreq_stats {
35 unsigned int cpu;
36 unsigned int total_trans;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070037 unsigned long long last_time;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 unsigned int max_state;
39 unsigned int state_num;
40 unsigned int last_index;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070041 cputime64_t *time_in_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 unsigned int *freq_table;
43#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
44 unsigned int *trans_table;
45#endif
46};
47
48static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
49
50struct cpufreq_stats_attribute {
51 struct attribute attr;
52 ssize_t(*show) (struct cpufreq_stats *, char *);
53};
54
55static int
56cpufreq_stats_update (unsigned int cpu)
57{
58 struct cpufreq_stats *stat;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070059 unsigned long long cur_time;
60
61 cur_time = get_jiffies_64();
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 spin_lock(&cpufreq_stats_lock);
63 stat = cpufreq_stats_table[cpu];
64 if (stat->time_in_state)
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070065 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 spin_unlock(&cpufreq_stats_lock);
70 return 0;
71}
72
73static ssize_t
74show_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
83static ssize_t
84show_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++) {
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -070093 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
94 (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 }
96 return len;
97}
98
99#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
100static ssize_t
101show_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);
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700110 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
111 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 for (i = 0; i < stat->state_num; i++) {
113 if (len >= PAGE_SIZE)
114 break;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700115 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
123 for (i = 0; i < stat->state_num; i++) {
124 if (len >= PAGE_SIZE)
125 break;
126
127 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 stat->freq_table[i]);
129
130 for (j = 0; j < stat->state_num; j++) {
131 if (len >= PAGE_SIZE)
132 break;
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700133 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 stat->trans_table[i*stat->max_state+j]);
135 }
136 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
137 }
138 return len;
139}
140CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
141#endif
142
143CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
144CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
145
146static 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};
154static struct attribute_group stats_attr_group = {
155 .attrs = default_attrs,
156 .name = "stats"
157};
158
159static int
160freq_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
169static void
170cpufreq_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
185static int
186cpufreq_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;
Dave Jonese98df502005-10-20 15:17:43 -0700196 if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199 data = cpufreq_cpu_get(cpu);
Dave Jonesbc7b26f2005-10-27 16:02:06 -0700200 if (data == NULL) {
201 ret = -EINVAL;
202 goto error_get_fail;
203 }
204
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 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
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700218 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
221 alloc_size += count * count * sizeof(int);
222#endif
223 stat->max_state = count;
Dave Jonese98df502005-10-20 15:17:43 -0700224 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 if (!stat->time_in_state) {
226 ret = -ENOMEM;
227 goto error_out;
228 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 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);
Venkatesh Pallipadi58f1df22005-05-25 14:46:50 -0700244 stat->last_time = get_jiffies_64();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 stat->last_index = freq_table_get_index(stat, policy->cur);
246 spin_unlock(&cpufreq_stats_lock);
247 cpufreq_cpu_put(data);
248 return 0;
249error_out:
250 cpufreq_cpu_put(data);
Dave Jonesb7fb3582005-11-01 23:13:45 -0800251error_get_fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 kfree(stat);
253 cpufreq_stats_table[cpu] = NULL;
254 return ret;
255}
256
257static int
258cpufreq_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
275static int
276cpufreq_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
Ashok Rajc32b6b82005-10-30 14:59:54 -0800306static 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
322static struct notifier_block cpufreq_stat_cpu_notifier =
323{
324 .notifier_call = cpufreq_stat_cpu_callback,
325};
326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327static struct notifier_block notifier_policy_block = {
328 .notifier_call = cpufreq_stat_notifier_policy
329};
330
331static struct notifier_block notifier_trans_block = {
332 .notifier_call = cpufreq_stat_notifier_trans
333};
334
335static int
336__init cpufreq_stats_init(void)
337{
338 int ret;
339 unsigned int cpu;
Ashok Rajc32b6b82005-10-30 14:59:54 -0800340
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 spin_lock_init(&cpufreq_stats_lock);
342 if ((ret = cpufreq_register_notifier(&notifier_policy_block,
343 CPUFREQ_POLICY_NOTIFIER)))
344 return ret;
345
346 if ((ret = cpufreq_register_notifier(&notifier_trans_block,
347 CPUFREQ_TRANSITION_NOTIFIER))) {
348 cpufreq_unregister_notifier(&notifier_policy_block,
349 CPUFREQ_POLICY_NOTIFIER);
350 return ret;
351 }
352
Ashok Rajc32b6b82005-10-30 14:59:54 -0800353 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();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 return 0;
361}
362static void
363__exit cpufreq_stats_exit(void)
364{
365 unsigned int cpu;
Ashok Rajc32b6b82005-10-30 14:59:54 -0800366
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 cpufreq_unregister_notifier(&notifier_policy_block,
368 CPUFREQ_POLICY_NOTIFIER);
369 cpufreq_unregister_notifier(&notifier_trans_block,
370 CPUFREQ_TRANSITION_NOTIFIER);
Ashok Rajc32b6b82005-10-30 14:59:54 -0800371 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();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378}
379
380MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
381MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem");
382MODULE_LICENSE ("GPL");
383
384module_init(cpufreq_stats_init);
385module_exit(cpufreq_stats_exit);