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>
17 static DEFINE_SPINLOCK(cpufreq_stats_lock
);
19 struct cpufreq_stats
{
20 unsigned int total_trans
;
21 unsigned long long last_time
;
22 unsigned int max_state
;
23 unsigned int state_num
;
24 unsigned int last_index
;
26 unsigned int *freq_table
;
27 unsigned int *trans_table
;
30 static int cpufreq_stats_update(struct cpufreq_stats
*stats
)
32 unsigned long long cur_time
= get_jiffies_64();
34 spin_lock(&cpufreq_stats_lock
);
35 stats
->time_in_state
[stats
->last_index
] += cur_time
- stats
->last_time
;
36 stats
->last_time
= cur_time
;
37 spin_unlock(&cpufreq_stats_lock
);
41 static void cpufreq_stats_clear_table(struct cpufreq_stats
*stats
)
43 unsigned int count
= stats
->max_state
;
45 memset(stats
->time_in_state
, 0, count
* sizeof(u64
));
46 memset(stats
->trans_table
, 0, count
* count
* sizeof(int));
47 stats
->last_time
= get_jiffies_64();
48 stats
->total_trans
= 0;
51 static ssize_t
show_total_trans(struct cpufreq_policy
*policy
, char *buf
)
53 return sprintf(buf
, "%d\n", policy
->stats
->total_trans
);
56 static ssize_t
show_time_in_state(struct cpufreq_policy
*policy
, char *buf
)
58 struct cpufreq_stats
*stats
= policy
->stats
;
62 if (policy
->fast_switch_enabled
)
65 cpufreq_stats_update(stats
);
66 for (i
= 0; i
< stats
->state_num
; i
++) {
67 len
+= sprintf(buf
+ len
, "%u %llu\n", stats
->freq_table
[i
],
69 jiffies_64_to_clock_t(stats
->time_in_state
[i
]));
74 static ssize_t
store_reset(struct cpufreq_policy
*policy
, const char *buf
,
77 /* We don't care what is written to the attribute. */
78 cpufreq_stats_clear_table(policy
->stats
);
82 static ssize_t
show_trans_table(struct cpufreq_policy
*policy
, char *buf
)
84 struct cpufreq_stats
*stats
= policy
->stats
;
88 if (policy
->fast_switch_enabled
)
91 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " From : To\n");
92 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " : ");
93 for (i
= 0; i
< stats
->state_num
; i
++) {
96 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
97 stats
->freq_table
[i
]);
102 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
104 for (i
= 0; i
< stats
->state_num
; i
++) {
105 if (len
>= PAGE_SIZE
)
108 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u: ",
109 stats
->freq_table
[i
]);
111 for (j
= 0; j
< stats
->state_num
; j
++) {
112 if (len
>= PAGE_SIZE
)
114 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
115 stats
->trans_table
[i
*stats
->max_state
+j
]);
117 if (len
>= PAGE_SIZE
)
119 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
122 if (len
>= PAGE_SIZE
) {
123 pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
128 cpufreq_freq_attr_ro(trans_table
);
130 cpufreq_freq_attr_ro(total_trans
);
131 cpufreq_freq_attr_ro(time_in_state
);
132 cpufreq_freq_attr_wo(reset
);
134 static struct attribute
*default_attrs
[] = {
141 static const struct attribute_group stats_attr_group
= {
142 .attrs
= default_attrs
,
146 static int freq_table_get_index(struct cpufreq_stats
*stats
, unsigned int freq
)
149 for (index
= 0; index
< stats
->max_state
; index
++)
150 if (stats
->freq_table
[index
] == freq
)
155 void cpufreq_stats_free_table(struct cpufreq_policy
*policy
)
157 struct cpufreq_stats
*stats
= policy
->stats
;
163 pr_debug("%s: Free stats table\n", __func__
);
165 sysfs_remove_group(&policy
->kobj
, &stats_attr_group
);
166 kfree(stats
->time_in_state
);
168 policy
->stats
= NULL
;
171 void cpufreq_stats_create_table(struct cpufreq_policy
*policy
)
173 unsigned int i
= 0, count
= 0, ret
= -ENOMEM
;
174 struct cpufreq_stats
*stats
;
175 unsigned int alloc_size
;
176 struct cpufreq_frequency_table
*pos
;
178 count
= cpufreq_table_count_valid_entries(policy
);
182 /* stats already initialized */
186 stats
= kzalloc(sizeof(*stats
), GFP_KERNEL
);
190 alloc_size
= count
* sizeof(int) + count
* sizeof(u64
);
192 alloc_size
+= count
* count
* sizeof(int);
194 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
195 stats
->time_in_state
= kzalloc(alloc_size
, GFP_KERNEL
);
196 if (!stats
->time_in_state
)
199 stats
->freq_table
= (unsigned int *)(stats
->time_in_state
+ count
);
201 stats
->trans_table
= stats
->freq_table
+ count
;
203 stats
->max_state
= count
;
205 /* Find valid-unique entries */
206 cpufreq_for_each_valid_entry(pos
, policy
->freq_table
)
207 if (freq_table_get_index(stats
, pos
->frequency
) == -1)
208 stats
->freq_table
[i
++] = pos
->frequency
;
210 stats
->state_num
= i
;
211 stats
->last_time
= get_jiffies_64();
212 stats
->last_index
= freq_table_get_index(stats
, policy
->cur
);
214 policy
->stats
= stats
;
215 ret
= sysfs_create_group(&policy
->kobj
, &stats_attr_group
);
219 /* We failed, release resources */
220 policy
->stats
= NULL
;
221 kfree(stats
->time_in_state
);
226 void cpufreq_stats_record_transition(struct cpufreq_policy
*policy
,
227 unsigned int new_freq
)
229 struct cpufreq_stats
*stats
= policy
->stats
;
230 int old_index
, new_index
;
233 pr_debug("%s: No stats found\n", __func__
);
237 old_index
= stats
->last_index
;
238 new_index
= freq_table_get_index(stats
, new_freq
);
240 /* We can't do stats->time_in_state[-1]= .. */
241 if (old_index
== -1 || new_index
== -1 || old_index
== new_index
)
244 cpufreq_stats_update(stats
);
246 stats
->last_index
= new_index
;
247 stats
->trans_table
[old_index
* stats
->max_state
+ new_index
]++;
248 stats
->total_trans
++;