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/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/sysdev.h>
15 #include <linux/cpu.h>
16 #include <linux/sysfs.h>
17 #include <linux/cpufreq.h>
18 #include <linux/module.h>
19 #include <linux/jiffies.h>
20 #include <linux/percpu.h>
21 #include <linux/kobject.h>
22 #include <linux/spinlock.h>
23 #include <linux/notifier.h>
24 #include <asm/cputime.h>
26 static spinlock_t cpufreq_stats_lock
;
28 #define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
29 static struct freq_attr _attr_##_name = {\
30 .attr = {.name = __stringify(_name), .mode = _mode, }, \
34 struct cpufreq_stats
{
36 unsigned int total_trans
;
37 unsigned long long last_time
;
38 unsigned int max_state
;
39 unsigned int state_num
;
40 unsigned int last_index
;
41 cputime64_t
*time_in_state
;
42 unsigned int *freq_table
;
43 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
44 unsigned int *trans_table
;
48 static DEFINE_PER_CPU(struct cpufreq_stats
*, cpufreq_stats_table
);
50 struct cpufreq_stats_attribute
{
51 struct attribute attr
;
52 ssize_t(*show
) (struct cpufreq_stats
*, char *);
55 static int cpufreq_stats_update(unsigned int cpu
)
57 struct cpufreq_stats
*stat
;
58 unsigned long long cur_time
;
60 cur_time
= get_jiffies_64();
61 spin_lock(&cpufreq_stats_lock
);
62 stat
= per_cpu(cpufreq_stats_table
, cpu
);
63 if (stat
->time_in_state
)
64 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
;
68 spin_unlock(&cpufreq_stats_lock
);
72 static ssize_t
show_total_trans(struct cpufreq_policy
*policy
, char *buf
)
74 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
77 return sprintf(buf
, "%d\n",
78 per_cpu(cpufreq_stats_table
, stat
->cpu
)->total_trans
);
81 static ssize_t
show_time_in_state(struct cpufreq_policy
*policy
, char *buf
)
85 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
88 cpufreq_stats_update(stat
->cpu
);
89 for (i
= 0; i
< stat
->state_num
; i
++) {
90 len
+= sprintf(buf
+ len
, "%u %llu\n", stat
->freq_table
[i
],
92 cputime64_to_clock_t(stat
->time_in_state
[i
]));
97 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
98 static ssize_t
show_trans_table(struct cpufreq_policy
*policy
, char *buf
)
103 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, policy
->cpu
);
106 cpufreq_stats_update(stat
->cpu
);
107 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " From : To\n");
108 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " : ");
109 for (i
= 0; i
< stat
->state_num
; i
++) {
110 if (len
>= PAGE_SIZE
)
112 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
113 stat
->freq_table
[i
]);
115 if (len
>= PAGE_SIZE
)
118 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
120 for (i
= 0; i
< stat
->state_num
; i
++) {
121 if (len
>= PAGE_SIZE
)
124 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u: ",
125 stat
->freq_table
[i
]);
127 for (j
= 0; j
< stat
->state_num
; j
++) {
128 if (len
>= PAGE_SIZE
)
130 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
131 stat
->trans_table
[i
*stat
->max_state
+j
]);
133 if (len
>= PAGE_SIZE
)
135 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
137 if (len
>= PAGE_SIZE
)
141 CPUFREQ_STATDEVICE_ATTR(trans_table
, 0444, show_trans_table
);
144 CPUFREQ_STATDEVICE_ATTR(total_trans
, 0444, show_total_trans
);
145 CPUFREQ_STATDEVICE_ATTR(time_in_state
, 0444, show_time_in_state
);
147 static struct attribute
*default_attrs
[] = {
148 &_attr_total_trans
.attr
,
149 &_attr_time_in_state
.attr
,
150 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
151 &_attr_trans_table
.attr
,
155 static struct attribute_group stats_attr_group
= {
156 .attrs
= default_attrs
,
160 static int freq_table_get_index(struct cpufreq_stats
*stat
, unsigned int freq
)
163 for (index
= 0; index
< stat
->max_state
; index
++)
164 if (stat
->freq_table
[index
] == freq
)
169 /* should be called late in the CPU removal sequence so that the stats
170 * memory is still available in case someone tries to use it.
172 static void cpufreq_stats_free_table(unsigned int cpu
)
174 struct cpufreq_stats
*stat
= per_cpu(cpufreq_stats_table
, cpu
);
176 kfree(stat
->time_in_state
);
179 per_cpu(cpufreq_stats_table
, cpu
) = NULL
;
182 /* must be called early in the CPU removal sequence (before
183 * cpufreq_remove_dev) so that policy is still valid.
185 static void cpufreq_stats_free_sysfs(unsigned int cpu
)
187 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
188 if (policy
&& policy
->cpu
== cpu
)
189 sysfs_remove_group(&policy
->kobj
, &stats_attr_group
);
191 cpufreq_cpu_put(policy
);
194 static int cpufreq_stats_create_table(struct cpufreq_policy
*policy
,
195 struct cpufreq_frequency_table
*table
)
197 unsigned int i
, j
, count
= 0, ret
= 0;
198 struct cpufreq_stats
*stat
;
199 struct cpufreq_policy
*data
;
200 unsigned int alloc_size
;
201 unsigned int cpu
= policy
->cpu
;
202 if (per_cpu(cpufreq_stats_table
, cpu
))
204 stat
= kzalloc(sizeof(struct cpufreq_stats
), GFP_KERNEL
);
208 data
= cpufreq_cpu_get(cpu
);
214 ret
= sysfs_create_group(&data
->kobj
, &stats_attr_group
);
219 per_cpu(cpufreq_stats_table
, cpu
) = stat
;
221 for (i
= 0; table
[i
].frequency
!= CPUFREQ_TABLE_END
; i
++) {
222 unsigned int freq
= table
[i
].frequency
;
223 if (freq
== CPUFREQ_ENTRY_INVALID
)
228 alloc_size
= count
* sizeof(int) + count
* sizeof(cputime64_t
);
230 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
231 alloc_size
+= count
* count
* sizeof(int);
233 stat
->max_state
= count
;
234 stat
->time_in_state
= kzalloc(alloc_size
, GFP_KERNEL
);
235 if (!stat
->time_in_state
) {
239 stat
->freq_table
= (unsigned int *)(stat
->time_in_state
+ count
);
241 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
242 stat
->trans_table
= stat
->freq_table
+ count
;
245 for (i
= 0; table
[i
].frequency
!= CPUFREQ_TABLE_END
; i
++) {
246 unsigned int freq
= table
[i
].frequency
;
247 if (freq
== CPUFREQ_ENTRY_INVALID
)
249 if (freq_table_get_index(stat
, freq
) == -1)
250 stat
->freq_table
[j
++] = freq
;
253 spin_lock(&cpufreq_stats_lock
);
254 stat
->last_time
= get_jiffies_64();
255 stat
->last_index
= freq_table_get_index(stat
, policy
->cur
);
256 spin_unlock(&cpufreq_stats_lock
);
257 cpufreq_cpu_put(data
);
260 cpufreq_cpu_put(data
);
263 per_cpu(cpufreq_stats_table
, cpu
) = NULL
;
267 static int cpufreq_stat_notifier_policy(struct notifier_block
*nb
,
268 unsigned long val
, void *data
)
271 struct cpufreq_policy
*policy
= data
;
272 struct cpufreq_frequency_table
*table
;
273 unsigned int cpu
= policy
->cpu
;
274 if (val
!= CPUFREQ_NOTIFY
)
276 table
= cpufreq_frequency_get_table(cpu
);
279 ret
= cpufreq_stats_create_table(policy
, table
);
285 static int cpufreq_stat_notifier_trans(struct notifier_block
*nb
,
286 unsigned long val
, void *data
)
288 struct cpufreq_freqs
*freq
= data
;
289 struct cpufreq_stats
*stat
;
290 int old_index
, new_index
;
292 if (val
!= CPUFREQ_POSTCHANGE
)
295 stat
= per_cpu(cpufreq_stats_table
, freq
->cpu
);
299 old_index
= stat
->last_index
;
300 new_index
= freq_table_get_index(stat
, freq
->new);
302 /* We can't do stat->time_in_state[-1]= .. */
303 if (old_index
== -1 || new_index
== -1)
306 cpufreq_stats_update(freq
->cpu
);
308 if (old_index
== new_index
)
311 spin_lock(&cpufreq_stats_lock
);
312 stat
->last_index
= new_index
;
313 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
314 stat
->trans_table
[old_index
* stat
->max_state
+ new_index
]++;
317 spin_unlock(&cpufreq_stats_lock
);
321 static int __cpuinit
cpufreq_stat_cpu_callback(struct notifier_block
*nfb
,
322 unsigned long action
,
325 unsigned int cpu
= (unsigned long)hcpu
;
329 case CPU_ONLINE_FROZEN
:
330 cpufreq_update_policy(cpu
);
332 case CPU_DOWN_PREPARE
:
333 cpufreq_stats_free_sysfs(cpu
);
336 case CPU_DEAD_FROZEN
:
337 cpufreq_stats_free_table(cpu
);
343 /* priority=1 so this will get called before cpufreq_remove_dev */
344 static struct notifier_block cpufreq_stat_cpu_notifier __refdata
= {
345 .notifier_call
= cpufreq_stat_cpu_callback
,
349 static struct notifier_block notifier_policy_block
= {
350 .notifier_call
= cpufreq_stat_notifier_policy
353 static struct notifier_block notifier_trans_block
= {
354 .notifier_call
= cpufreq_stat_notifier_trans
357 static int __init
cpufreq_stats_init(void)
362 spin_lock_init(&cpufreq_stats_lock
);
363 ret
= cpufreq_register_notifier(¬ifier_policy_block
,
364 CPUFREQ_POLICY_NOTIFIER
);
368 ret
= cpufreq_register_notifier(¬ifier_trans_block
,
369 CPUFREQ_TRANSITION_NOTIFIER
);
371 cpufreq_unregister_notifier(¬ifier_policy_block
,
372 CPUFREQ_POLICY_NOTIFIER
);
376 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier
);
377 for_each_online_cpu(cpu
) {
378 cpufreq_update_policy(cpu
);
382 static void __exit
cpufreq_stats_exit(void)
386 cpufreq_unregister_notifier(¬ifier_policy_block
,
387 CPUFREQ_POLICY_NOTIFIER
);
388 cpufreq_unregister_notifier(¬ifier_trans_block
,
389 CPUFREQ_TRANSITION_NOTIFIER
);
390 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier
);
391 for_each_online_cpu(cpu
) {
392 cpufreq_stats_free_table(cpu
);
393 cpufreq_stats_free_sysfs(cpu
);
397 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
398 MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
399 "through sysfs filesystem");
400 MODULE_LICENSE("GPL");
402 module_init(cpufreq_stats_init
);
403 module_exit(cpufreq_stats_exit
);