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 static int cpufreq_stats_update(unsigned int cpu
)
38 struct cpufreq_stats
*stat
;
39 unsigned long long cur_time
= get_jiffies_64();
41 spin_lock(&cpufreq_stats_lock
);
42 stat
= per_cpu(cpufreq_stats_table
, cpu
);
43 if (stat
->time_in_state
)
44 stat
->time_in_state
[stat
->last_index
] +=
45 cur_time
- stat
->last_time
;
46 stat
->last_time
= cur_time
;
47 spin_unlock(&cpufreq_stats_lock
);
51 static ssize_t
show_total_trans(struct cpufreq_policy
*policy
, char *buf
)
53 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
56 return sprintf(buf
, "%d\n",
57 per_cpu(cpufreq_stats_table
, stat
->cpu
)->total_trans
);
60 static ssize_t
show_time_in_state(struct cpufreq_policy
*policy
, char *buf
)
64 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
67 cpufreq_stats_update(stat
->cpu
);
68 for (i
= 0; i
< stat
->state_num
; i
++) {
69 len
+= sprintf(buf
+ len
, "%u %llu\n", stat
->freq_table
[i
],
71 jiffies_64_to_clock_t(stat
->time_in_state
[i
]));
76 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
77 static ssize_t
show_trans_table(struct cpufreq_policy
*policy
, char *buf
)
82 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
85 cpufreq_stats_update(stat
->cpu
);
86 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " From : To\n");
87 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " : ");
88 for (i
= 0; i
< stat
->state_num
; i
++) {
91 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
97 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
99 for (i
= 0; i
< stat
->state_num
; i
++) {
100 if (len
>= PAGE_SIZE
)
103 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u: ",
104 stat
->freq_table
[i
]);
106 for (j
= 0; j
< stat
->state_num
; j
++) {
107 if (len
>= PAGE_SIZE
)
109 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
110 stat
->trans_table
[i
*stat
->max_state
+j
]);
112 if (len
>= PAGE_SIZE
)
114 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
116 if (len
>= PAGE_SIZE
)
120 cpufreq_freq_attr_ro(trans_table
);
123 cpufreq_freq_attr_ro(total_trans
);
124 cpufreq_freq_attr_ro(time_in_state
);
126 static struct attribute
*default_attrs
[] = {
129 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
134 static struct attribute_group stats_attr_group
= {
135 .attrs
= default_attrs
,
139 static int freq_table_get_index(struct cpufreq_stats
*stat
, unsigned int freq
)
142 for (index
= 0; index
< stat
->max_state
; index
++)
143 if (stat
->freq_table
[index
] == freq
)
148 static void __cpufreq_stats_free_table(struct cpufreq_policy
*policy
)
150 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
155 pr_debug("%s: Free stat table\n", __func__
);
157 sysfs_remove_group(&policy
->kobj
, &stats_attr_group
);
158 kfree(stat
->time_in_state
);
160 per_cpu(cpufreq_stats_table
, policy
->cpu
) = NULL
;
163 static void cpufreq_stats_free_table(unsigned int cpu
)
165 struct cpufreq_policy
*policy
;
167 policy
= cpufreq_cpu_get(cpu
);
171 __cpufreq_stats_free_table(policy
);
173 cpufreq_cpu_put(policy
);
176 static int __cpufreq_stats_create_table(struct cpufreq_policy
*policy
)
178 unsigned int i
, count
= 0, ret
= 0;
179 struct cpufreq_stats
*stat
;
180 unsigned int alloc_size
;
181 unsigned int cpu
= policy
->cpu
;
182 struct cpufreq_frequency_table
*pos
, *table
;
184 table
= cpufreq_frequency_get_table(cpu
);
185 if (unlikely(!table
))
188 /* stats already initialized */
189 if (per_cpu(cpufreq_stats_table
, cpu
))
192 stat
= kzalloc(sizeof(*stat
), GFP_KERNEL
);
196 ret
= sysfs_create_group(&policy
->kobj
, &stats_attr_group
);
201 per_cpu(cpufreq_stats_table
, cpu
) = stat
;
203 cpufreq_for_each_valid_entry(pos
, table
)
206 alloc_size
= count
* sizeof(int) + count
* sizeof(u64
);
208 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
209 alloc_size
+= count
* count
* sizeof(int);
211 stat
->max_state
= count
;
212 stat
->time_in_state
= kzalloc(alloc_size
, GFP_KERNEL
);
213 if (!stat
->time_in_state
) {
217 stat
->freq_table
= (unsigned int *)(stat
->time_in_state
+ count
);
219 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
220 stat
->trans_table
= stat
->freq_table
+ count
;
223 cpufreq_for_each_valid_entry(pos
, table
)
224 if (freq_table_get_index(stat
, pos
->frequency
) == -1)
225 stat
->freq_table
[i
++] = pos
->frequency
;
227 spin_lock(&cpufreq_stats_lock
);
228 stat
->last_time
= get_jiffies_64();
229 stat
->last_index
= freq_table_get_index(stat
, policy
->cur
);
230 spin_unlock(&cpufreq_stats_lock
);
233 sysfs_remove_group(&policy
->kobj
, &stats_attr_group
);
236 per_cpu(cpufreq_stats_table
, cpu
) = NULL
;
240 static void cpufreq_stats_create_table(unsigned int cpu
)
242 struct cpufreq_policy
*policy
;
245 * "likely(!policy)" because normally cpufreq_stats will be registered
246 * before cpufreq driver
248 policy
= cpufreq_cpu_get(cpu
);
252 __cpufreq_stats_create_table(policy
);
254 cpufreq_cpu_put(policy
);
257 static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy
*policy
)
259 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
,
262 pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
263 policy
->cpu
, policy
->last_cpu
);
264 per_cpu(cpufreq_stats_table
, policy
->cpu
) = per_cpu(cpufreq_stats_table
,
266 per_cpu(cpufreq_stats_table
, policy
->last_cpu
) = NULL
;
267 stat
->cpu
= policy
->cpu
;
270 static int cpufreq_stat_notifier_policy(struct notifier_block
*nb
,
271 unsigned long val
, void *data
)
274 struct cpufreq_policy
*policy
= data
;
276 if (val
== CPUFREQ_UPDATE_POLICY_CPU
) {
277 cpufreq_stats_update_policy_cpu(policy
);
281 if (val
== CPUFREQ_CREATE_POLICY
)
282 ret
= __cpufreq_stats_create_table(policy
);
283 else if (val
== CPUFREQ_REMOVE_POLICY
)
284 __cpufreq_stats_free_table(policy
);
289 static int cpufreq_stat_notifier_trans(struct notifier_block
*nb
,
290 unsigned long val
, void *data
)
292 struct cpufreq_freqs
*freq
= data
;
293 struct cpufreq_stats
*stat
;
294 int old_index
, new_index
;
296 if (val
!= CPUFREQ_POSTCHANGE
)
299 stat
= per_cpu(cpufreq_stats_table
, freq
->cpu
);
303 old_index
= stat
->last_index
;
304 new_index
= freq_table_get_index(stat
, freq
->new);
306 /* We can't do stat->time_in_state[-1]= .. */
307 if (old_index
== -1 || new_index
== -1)
310 cpufreq_stats_update(freq
->cpu
);
312 if (old_index
== new_index
)
315 spin_lock(&cpufreq_stats_lock
);
316 stat
->last_index
= new_index
;
317 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
318 stat
->trans_table
[old_index
* stat
->max_state
+ new_index
]++;
321 spin_unlock(&cpufreq_stats_lock
);
325 static struct notifier_block notifier_policy_block
= {
326 .notifier_call
= cpufreq_stat_notifier_policy
329 static struct notifier_block notifier_trans_block
= {
330 .notifier_call
= cpufreq_stat_notifier_trans
333 static int __init
cpufreq_stats_init(void)
338 spin_lock_init(&cpufreq_stats_lock
);
339 ret
= cpufreq_register_notifier(¬ifier_policy_block
,
340 CPUFREQ_POLICY_NOTIFIER
);
344 for_each_online_cpu(cpu
)
345 cpufreq_stats_create_table(cpu
);
347 ret
= cpufreq_register_notifier(¬ifier_trans_block
,
348 CPUFREQ_TRANSITION_NOTIFIER
);
350 cpufreq_unregister_notifier(¬ifier_policy_block
,
351 CPUFREQ_POLICY_NOTIFIER
);
352 for_each_online_cpu(cpu
)
353 cpufreq_stats_free_table(cpu
);
359 static void __exit
cpufreq_stats_exit(void)
363 cpufreq_unregister_notifier(¬ifier_policy_block
,
364 CPUFREQ_POLICY_NOTIFIER
);
365 cpufreq_unregister_notifier(¬ifier_trans_block
,
366 CPUFREQ_TRANSITION_NOTIFIER
);
367 for_each_online_cpu(cpu
)
368 cpufreq_stats_free_table(cpu
);
371 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
372 MODULE_DESCRIPTION("Export cpufreq stats via sysfs");
373 MODULE_LICENSE("GPL");
375 module_init(cpufreq_stats_init
);
376 module_exit(cpufreq_stats_exit
);