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 DEFINE_SPINLOCK(cpufreq_stats_lock
);
20 struct cpufreq_stats
{
21 unsigned int total_trans
;
22 unsigned long long last_time
;
23 unsigned int max_state
;
24 unsigned int state_num
;
25 unsigned int last_index
;
27 unsigned int *freq_table
;
28 unsigned int *trans_table
;
31 static int cpufreq_stats_update(struct cpufreq_stats
*stats
)
33 unsigned long long cur_time
= get_jiffies_64();
35 spin_lock(&cpufreq_stats_lock
);
36 stats
->time_in_state
[stats
->last_index
] += cur_time
- stats
->last_time
;
37 stats
->last_time
= cur_time
;
38 spin_unlock(&cpufreq_stats_lock
);
42 static void cpufreq_stats_clear_table(struct cpufreq_stats
*stats
)
44 unsigned int count
= stats
->max_state
;
46 memset(stats
->time_in_state
, 0, count
* sizeof(u64
));
47 memset(stats
->trans_table
, 0, count
* count
* sizeof(int));
48 stats
->last_time
= get_jiffies_64();
49 stats
->total_trans
= 0;
52 static ssize_t
show_total_trans(struct cpufreq_policy
*policy
, char *buf
)
54 return sprintf(buf
, "%d\n", policy
->stats
->total_trans
);
57 static ssize_t
show_time_in_state(struct cpufreq_policy
*policy
, char *buf
)
59 struct cpufreq_stats
*stats
= policy
->stats
;
63 if (policy
->fast_switch_enabled
)
66 cpufreq_stats_update(stats
);
67 for (i
= 0; i
< stats
->state_num
; i
++) {
68 len
+= sprintf(buf
+ len
, "%u %llu\n", stats
->freq_table
[i
],
70 jiffies_64_to_clock_t(stats
->time_in_state
[i
]));
75 static ssize_t
store_reset(struct cpufreq_policy
*policy
, const char *buf
,
78 /* We don't care what is written to the attribute. */
79 cpufreq_stats_clear_table(policy
->stats
);
83 static ssize_t
show_trans_table(struct cpufreq_policy
*policy
, char *buf
)
85 struct cpufreq_stats
*stats
= policy
->stats
;
89 if (policy
->fast_switch_enabled
)
92 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " From : To\n");
93 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, " : ");
94 for (i
= 0; i
< stats
->state_num
; i
++) {
97 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
98 stats
->freq_table
[i
]);
100 if (len
>= PAGE_SIZE
)
103 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "\n");
105 for (i
= 0; i
< stats
->state_num
; i
++) {
106 if (len
>= PAGE_SIZE
)
109 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u: ",
110 stats
->freq_table
[i
]);
112 for (j
= 0; j
< stats
->state_num
; j
++) {
113 if (len
>= PAGE_SIZE
)
115 len
+= snprintf(buf
+ len
, PAGE_SIZE
- len
, "%9u ",
116 stats
->trans_table
[i
*stats
->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
);
128 cpufreq_freq_attr_ro(total_trans
);
129 cpufreq_freq_attr_ro(time_in_state
);
130 cpufreq_freq_attr_wo(reset
);
132 static struct attribute
*default_attrs
[] = {
139 static struct attribute_group stats_attr_group
= {
140 .attrs
= default_attrs
,
144 static int freq_table_get_index(struct cpufreq_stats
*stats
, unsigned int freq
)
147 for (index
= 0; index
< stats
->max_state
; index
++)
148 if (stats
->freq_table
[index
] == freq
)
153 void cpufreq_stats_free_table(struct cpufreq_policy
*policy
)
155 struct cpufreq_stats
*stats
= policy
->stats
;
161 pr_debug("%s: Free stats table\n", __func__
);
163 sysfs_remove_group(&policy
->kobj
, &stats_attr_group
);
164 kfree(stats
->time_in_state
);
166 policy
->stats
= NULL
;
169 void cpufreq_stats_create_table(struct cpufreq_policy
*policy
)
171 unsigned int i
= 0, count
= 0, ret
= -ENOMEM
;
172 struct cpufreq_stats
*stats
;
173 unsigned int alloc_size
;
174 struct cpufreq_frequency_table
*pos
, *table
;
176 /* We need cpufreq table for creating stats table */
177 table
= policy
->freq_table
;
178 if (unlikely(!table
))
181 /* stats already initialized */
185 stats
= kzalloc(sizeof(*stats
), GFP_KERNEL
);
189 /* Find total allocation size */
190 cpufreq_for_each_valid_entry(pos
, table
)
193 alloc_size
= count
* sizeof(int) + count
* sizeof(u64
);
195 alloc_size
+= count
* count
* sizeof(int);
197 /* Allocate memory for time_in_state/freq_table/trans_table in one go */
198 stats
->time_in_state
= kzalloc(alloc_size
, GFP_KERNEL
);
199 if (!stats
->time_in_state
)
202 stats
->freq_table
= (unsigned int *)(stats
->time_in_state
+ count
);
204 stats
->trans_table
= stats
->freq_table
+ count
;
206 stats
->max_state
= count
;
208 /* Find valid-unique entries */
209 cpufreq_for_each_valid_entry(pos
, table
)
210 if (freq_table_get_index(stats
, pos
->frequency
) == -1)
211 stats
->freq_table
[i
++] = pos
->frequency
;
213 stats
->state_num
= i
;
214 stats
->last_time
= get_jiffies_64();
215 stats
->last_index
= freq_table_get_index(stats
, policy
->cur
);
217 policy
->stats
= stats
;
218 ret
= sysfs_create_group(&policy
->kobj
, &stats_attr_group
);
222 /* We failed, release resources */
223 policy
->stats
= NULL
;
224 kfree(stats
->time_in_state
);
229 void cpufreq_stats_record_transition(struct cpufreq_policy
*policy
,
230 unsigned int new_freq
)
232 struct cpufreq_stats
*stats
= policy
->stats
;
233 int old_index
, new_index
;
236 pr_debug("%s: No stats found\n", __func__
);
240 old_index
= stats
->last_index
;
241 new_index
= freq_table_get_index(stats
, new_freq
);
243 /* We can't do stats->time_in_state[-1]= .. */
244 if (old_index
== -1 || new_index
== -1 || old_index
== new_index
)
247 cpufreq_stats_update(stats
);
249 stats
->last_index
= new_index
;
250 stats
->trans_table
[old_index
* stats
->max_state
+ new_index
]++;
251 stats
->total_trans
++;