2 * drivers/cpufreq/cpufreq_stats.c
4 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
5 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
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.
12 #include <linux/cpu.h>
13 #include <linux/cpufreq.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/cputime.h>
18 static spinlock_t cpufreq_stats_lock
;
20 struct cpufreq_stats
{
22 unsigned int total_trans
;
23 unsigned long long last_time
;
24 unsigned int max_state
;
25 unsigned int state_num
;
26 unsigned int last_index
;
28 unsigned int *freq_table
;
29 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
30 unsigned int *trans_table
;
34 static DEFINE_PER_CPU(struct cpufreq_stats
*, cpufreq_stats_table
);
36 struct cpufreq_stats_attribute
{
37 struct attribute attr
;
38 ssize_t(*show
) (struct cpufreq_stats
*, char *);
41 static int cpufreq_stats_update(unsigned int cpu
)
43 struct cpufreq_stats
*stat
;
44 unsigned long long cur_time
;
46 cur_time
= get_jiffies_64();
47 spin_lock(&cpufreq_stats_lock
);
48 stat
= per_cpu(cpufreq_stats_table
, cpu
);
49 if (stat
->time_in_state
)
50 stat
->time_in_state
[stat
->last_index
] +=
51 cur_time
- stat
->last_time
;
52 stat
->last_time
= cur_time
;
53 spin_unlock(&cpufreq_stats_lock
);
57 static ssize_t
show_total_trans(struct cpufreq_policy
*policy
, char *buf
)
59 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
62 return sprintf(buf
, "%d\n",
63 per_cpu(cpufreq_stats_table
, stat
->cpu
)->total_trans
);
66 static ssize_t
show_time_in_state(struct cpufreq_policy
*policy
, char *buf
)
70 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
73 cpufreq_stats_update(stat
->cpu
);
74 for (i
= 0; i
< stat
->state_num
; i
++) {
75 len
+= sprintf(buf
+ len
, "%u %llu\n", stat
->freq_table
[i
],
77 jiffies_64_to_clock_t(stat
->time_in_state
[i
]));
82 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
83 static ssize_t
show_trans_table(struct cpufreq_policy
*policy
, char *buf
)
88 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
91 cpufreq_stats_update(stat
->cpu
);
92 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " From : To\n");
93 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " : ");
94 for (i
= 0; i
< stat
->state_num
; i
++) {
97 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
100 if (len
>= PAGE_SIZE
)
103 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
105 for (i
= 0; i
< stat
->state_num
; i
++) {
106 if (len
>= PAGE_SIZE
)
109 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u: ",
110 stat
->freq_table
[i
]);
112 for (j
= 0; j
< stat
->state_num
; j
++) {
113 if (len
>= PAGE_SIZE
)
115 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
116 stat
->trans_table
[i
*stat
->max_state
+j
]);
118 if (len
>= PAGE_SIZE
)
120 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
122 if (len
>= PAGE_SIZE
)
126 cpufreq_freq_attr_ro(trans_table
);
129 cpufreq_freq_attr_ro(total_trans
);
130 cpufreq_freq_attr_ro(time_in_state
);
132 static struct attribute
*default_attrs
[] = {
135 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
140 static struct attribute_group stats_attr_group
= {
141 .attrs
= default_attrs
,
145 static int freq_table_get_index(struct cpufreq_stats
*stat
, unsigned int freq
)
148 for (index
= 0; index
< stat
->max_state
; index
++)
149 if (stat
->freq_table
[index
] == freq
)
154 static void __cpufreq_stats_free_table(struct cpufreq_policy
*policy
)
156 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
161 pr_debug("%s: Free stat table\n", __func__
);
163 sysfs_remove_group(&policy
->kobj
, &stats_attr_group
);
164 kfree(stat
->time_in_state
);
166 per_cpu(cpufreq_stats_table
, policy
->cpu
) = NULL
;
169 static void cpufreq_stats_free_table(unsigned int cpu
)
171 struct cpufreq_policy
*policy
;
173 policy
= cpufreq_cpu_get(cpu
);
177 if (cpufreq_frequency_get_table(policy
->cpu
))
178 __cpufreq_stats_free_table(policy
);
180 cpufreq_cpu_put(policy
);
183 static int __cpufreq_stats_create_table(struct cpufreq_policy
*policy
)
185 unsigned int i
, count
= 0, ret
= 0;
186 struct cpufreq_stats
*stat
;
187 unsigned int alloc_size
;
188 unsigned int cpu
= policy
->cpu
;
189 struct cpufreq_frequency_table
*pos
, *table
;
191 table
= cpufreq_frequency_get_table(cpu
);
192 if (unlikely(!table
))
195 if (per_cpu(cpufreq_stats_table
, cpu
))
197 stat
= kzalloc(sizeof(*stat
), GFP_KERNEL
);
201 ret
= sysfs_create_group(&policy
->kobj
, &stats_attr_group
);
206 per_cpu(cpufreq_stats_table
, cpu
) = stat
;
208 cpufreq_for_each_valid_entry(pos
, table
)
211 alloc_size
= count
* sizeof(int) + count
* sizeof(u64
);
213 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
214 alloc_size
+= count
* count
* sizeof(int);
216 stat
->max_state
= count
;
217 stat
->time_in_state
= kzalloc(alloc_size
, GFP_KERNEL
);
218 if (!stat
->time_in_state
) {
222 stat
->freq_table
= (unsigned int *)(stat
->time_in_state
+ count
);
224 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
225 stat
->trans_table
= stat
->freq_table
+ count
;
228 cpufreq_for_each_valid_entry(pos
, table
)
229 if (freq_table_get_index(stat
, pos
->frequency
) == -1)
230 stat
->freq_table
[i
++] = pos
->frequency
;
232 spin_lock(&cpufreq_stats_lock
);
233 stat
->last_time
= get_jiffies_64();
234 stat
->last_index
= freq_table_get_index(stat
, policy
->cur
);
235 spin_unlock(&cpufreq_stats_lock
);
238 sysfs_remove_group(&policy
->kobj
, &stats_attr_group
);
241 per_cpu(cpufreq_stats_table
, cpu
) = NULL
;
245 static void cpufreq_stats_create_table(unsigned int cpu
)
247 struct cpufreq_policy
*policy
;
250 * "likely(!policy)" because normally cpufreq_stats will be registered
251 * before cpufreq driver
253 policy
= cpufreq_cpu_get(cpu
);
257 __cpufreq_stats_create_table(policy
);
259 cpufreq_cpu_put(policy
);
262 static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy
*policy
)
264 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
,
267 pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
268 policy
->cpu
, policy
->last_cpu
);
269 per_cpu(cpufreq_stats_table
, policy
->cpu
) = per_cpu(cpufreq_stats_table
,
271 per_cpu(cpufreq_stats_table
, policy
->last_cpu
) = NULL
;
272 stat
->cpu
= policy
->cpu
;
275 static int cpufreq_stat_notifier_policy(struct notifier_block
*nb
,
276 unsigned long val
, void *data
)
279 struct cpufreq_policy
*policy
= data
;
281 if (val
== CPUFREQ_UPDATE_POLICY_CPU
) {
282 cpufreq_stats_update_policy_cpu(policy
);
286 if (val
== CPUFREQ_CREATE_POLICY
)
287 ret
= __cpufreq_stats_create_table(policy
);
288 else if (val
== CPUFREQ_REMOVE_POLICY
)
289 __cpufreq_stats_free_table(policy
);
294 static int cpufreq_stat_notifier_trans(struct notifier_block
*nb
,
295 unsigned long val
, void *data
)
297 struct cpufreq_freqs
*freq
= data
;
298 struct cpufreq_stats
*stat
;
299 int old_index
, new_index
;
301 if (val
!= CPUFREQ_POSTCHANGE
)
304 stat
= per_cpu(cpufreq_stats_table
, freq
->cpu
);
308 old_index
= stat
->last_index
;
309 new_index
= freq_table_get_index(stat
, freq
->new);
311 /* We can't do stat->time_in_state[-1]= .. */
312 if (old_index
== -1 || new_index
== -1)
315 cpufreq_stats_update(freq
->cpu
);
317 if (old_index
== new_index
)
320 spin_lock(&cpufreq_stats_lock
);
321 stat
->last_index
= new_index
;
322 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
323 stat
->trans_table
[old_index
* stat
->max_state
+ new_index
]++;
326 spin_unlock(&cpufreq_stats_lock
);
330 static struct notifier_block notifier_policy_block
= {
331 .notifier_call
= cpufreq_stat_notifier_policy
334 static struct notifier_block notifier_trans_block
= {
335 .notifier_call
= cpufreq_stat_notifier_trans
338 static int __init
cpufreq_stats_init(void)
343 spin_lock_init(&cpufreq_stats_lock
);
344 ret
= cpufreq_register_notifier(¬ifier_policy_block
,
345 CPUFREQ_POLICY_NOTIFIER
);
349 for_each_online_cpu(cpu
)
350 cpufreq_stats_create_table(cpu
);
352 ret
= cpufreq_register_notifier(¬ifier_trans_block
,
353 CPUFREQ_TRANSITION_NOTIFIER
);
355 cpufreq_unregister_notifier(¬ifier_policy_block
,
356 CPUFREQ_POLICY_NOTIFIER
);
357 for_each_online_cpu(cpu
)
358 cpufreq_stats_free_table(cpu
);
364 static void __exit
cpufreq_stats_exit(void)
368 cpufreq_unregister_notifier(¬ifier_policy_block
,
369 CPUFREQ_POLICY_NOTIFIER
);
370 cpufreq_unregister_notifier(¬ifier_trans_block
,
371 CPUFREQ_TRANSITION_NOTIFIER
);
372 for_each_online_cpu(cpu
)
373 cpufreq_stats_free_table(cpu
);
376 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
377 MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
378 "through sysfs filesystem");
379 MODULE_LICENSE("GPL");
381 module_init(cpufreq_stats_init
);
382 module_exit(cpufreq_stats_exit
);