ia64/kvm: compilation fix. export account_system_vtime.
[pv_ops_mirror.git] / drivers / cpufreq / cpufreq_stats.c
blobae70d63a8b26eabb2b02d8c2ea28721fcd934b2a
1 /*
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/sysdev.h>
14 #include <linux/cpu.h>
15 #include <linux/sysfs.h>
16 #include <linux/cpufreq.h>
17 #include <linux/jiffies.h>
18 #include <linux/percpu.h>
19 #include <linux/kobject.h>
20 #include <linux/spinlock.h>
21 #include <linux/notifier.h>
22 #include <asm/cputime.h>
24 static spinlock_t cpufreq_stats_lock;
26 #define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
27 static struct freq_attr _attr_##_name = {\
28 .attr = {.name = __stringify(_name), .mode = _mode, }, \
29 .show = _show,\
32 struct cpufreq_stats {
33 unsigned int cpu;
34 unsigned int total_trans;
35 unsigned long long last_time;
36 unsigned int max_state;
37 unsigned int state_num;
38 unsigned int last_index;
39 cputime64_t *time_in_state;
40 unsigned int *freq_table;
41 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
42 unsigned int *trans_table;
43 #endif
46 static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
48 struct cpufreq_stats_attribute {
49 struct attribute attr;
50 ssize_t(*show) (struct cpufreq_stats *, char *);
53 static int
54 cpufreq_stats_update (unsigned int cpu)
56 struct cpufreq_stats *stat;
57 unsigned long long cur_time;
59 cur_time = get_jiffies_64();
60 spin_lock(&cpufreq_stats_lock);
61 stat = cpufreq_stats_table[cpu];
62 if (stat->time_in_state)
63 stat->time_in_state[stat->last_index] =
64 cputime64_add(stat->time_in_state[stat->last_index],
65 cputime_sub(cur_time, stat->last_time));
66 stat->last_time = cur_time;
67 spin_unlock(&cpufreq_stats_lock);
68 return 0;
71 static ssize_t
72 show_total_trans(struct cpufreq_policy *policy, char *buf)
74 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
75 if (!stat)
76 return 0;
77 return sprintf(buf, "%d\n",
78 cpufreq_stats_table[stat->cpu]->total_trans);
81 static ssize_t
82 show_time_in_state(struct cpufreq_policy *policy, char *buf)
84 ssize_t len = 0;
85 int i;
86 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
87 if (!stat)
88 return 0;
89 cpufreq_stats_update(stat->cpu);
90 for (i = 0; i < stat->state_num; i++) {
91 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
92 (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
94 return len;
97 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
98 static ssize_t
99 show_trans_table(struct cpufreq_policy *policy, char *buf)
101 ssize_t len = 0;
102 int i, j;
104 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
105 if (!stat)
106 return 0;
107 cpufreq_stats_update(stat->cpu);
108 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
109 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
110 for (i = 0; i < stat->state_num; i++) {
111 if (len >= PAGE_SIZE)
112 break;
113 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
114 stat->freq_table[i]);
116 if (len >= PAGE_SIZE)
117 return PAGE_SIZE;
119 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
121 for (i = 0; i < stat->state_num; i++) {
122 if (len >= PAGE_SIZE)
123 break;
125 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
126 stat->freq_table[i]);
128 for (j = 0; j < stat->state_num; j++) {
129 if (len >= PAGE_SIZE)
130 break;
131 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
132 stat->trans_table[i*stat->max_state+j]);
134 if (len >= PAGE_SIZE)
135 break;
136 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
138 if (len >= PAGE_SIZE)
139 return PAGE_SIZE;
140 return len;
142 CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
143 #endif
145 CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
146 CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
148 static struct attribute *default_attrs[] = {
149 &_attr_total_trans.attr,
150 &_attr_time_in_state.attr,
151 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
152 &_attr_trans_table.attr,
153 #endif
154 NULL
156 static struct attribute_group stats_attr_group = {
157 .attrs = default_attrs,
158 .name = "stats"
161 static int
162 freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
164 int index;
165 for (index = 0; index < stat->max_state; index++)
166 if (stat->freq_table[index] == freq)
167 return index;
168 return -1;
171 static void cpufreq_stats_free_table(unsigned int cpu)
173 struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
174 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
175 if (policy && policy->cpu == cpu)
176 sysfs_remove_group(&policy->kobj, &stats_attr_group);
177 if (stat) {
178 kfree(stat->time_in_state);
179 kfree(stat);
181 cpufreq_stats_table[cpu] = NULL;
182 if (policy)
183 cpufreq_cpu_put(policy);
186 static int
187 cpufreq_stats_create_table (struct cpufreq_policy *policy,
188 struct cpufreq_frequency_table *table)
190 unsigned int i, j, count = 0, ret = 0;
191 struct cpufreq_stats *stat;
192 struct cpufreq_policy *data;
193 unsigned int alloc_size;
194 unsigned int cpu = policy->cpu;
195 if (cpufreq_stats_table[cpu])
196 return -EBUSY;
197 if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
198 return -ENOMEM;
200 data = cpufreq_cpu_get(cpu);
201 if (data == NULL) {
202 ret = -EINVAL;
203 goto error_get_fail;
206 if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
207 goto error_out;
209 stat->cpu = cpu;
210 cpufreq_stats_table[cpu] = stat;
212 for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
213 unsigned int freq = table[i].frequency;
214 if (freq == CPUFREQ_ENTRY_INVALID)
215 continue;
216 count++;
219 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
221 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
222 alloc_size += count * count * sizeof(int);
223 #endif
224 stat->max_state = count;
225 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
226 if (!stat->time_in_state) {
227 ret = -ENOMEM;
228 goto error_out;
230 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
232 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
233 stat->trans_table = stat->freq_table + count;
234 #endif
235 j = 0;
236 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
237 unsigned int freq = table[i].frequency;
238 if (freq == CPUFREQ_ENTRY_INVALID)
239 continue;
240 if (freq_table_get_index(stat, freq) == -1)
241 stat->freq_table[j++] = freq;
243 stat->state_num = j;
244 spin_lock(&cpufreq_stats_lock);
245 stat->last_time = get_jiffies_64();
246 stat->last_index = freq_table_get_index(stat, policy->cur);
247 spin_unlock(&cpufreq_stats_lock);
248 cpufreq_cpu_put(data);
249 return 0;
250 error_out:
251 cpufreq_cpu_put(data);
252 error_get_fail:
253 kfree(stat);
254 cpufreq_stats_table[cpu] = NULL;
255 return ret;
258 static int
259 cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
260 void *data)
262 int ret;
263 struct cpufreq_policy *policy = data;
264 struct cpufreq_frequency_table *table;
265 unsigned int cpu = policy->cpu;
266 if (val != CPUFREQ_NOTIFY)
267 return 0;
268 table = cpufreq_frequency_get_table(cpu);
269 if (!table)
270 return 0;
271 if ((ret = cpufreq_stats_create_table(policy, table)))
272 return ret;
273 return 0;
276 static int
277 cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
278 void *data)
280 struct cpufreq_freqs *freq = data;
281 struct cpufreq_stats *stat;
282 int old_index, new_index;
284 if (val != CPUFREQ_POSTCHANGE)
285 return 0;
287 stat = cpufreq_stats_table[freq->cpu];
288 if (!stat)
289 return 0;
291 old_index = stat->last_index;
292 new_index = freq_table_get_index(stat, freq->new);
294 cpufreq_stats_update(freq->cpu);
295 if (old_index == new_index)
296 return 0;
298 if (old_index == -1 || new_index == -1)
299 return 0;
301 spin_lock(&cpufreq_stats_lock);
302 stat->last_index = new_index;
303 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
304 stat->trans_table[old_index * stat->max_state + new_index]++;
305 #endif
306 stat->total_trans++;
307 spin_unlock(&cpufreq_stats_lock);
308 return 0;
311 static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
312 unsigned long action,
313 void *hcpu)
315 unsigned int cpu = (unsigned long)hcpu;
317 switch (action) {
318 case CPU_ONLINE:
319 case CPU_ONLINE_FROZEN:
320 cpufreq_update_policy(cpu);
321 break;
322 case CPU_DEAD:
323 case CPU_DEAD_FROZEN:
324 cpufreq_stats_free_table(cpu);
325 break;
327 return NOTIFY_OK;
330 static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
332 .notifier_call = cpufreq_stat_cpu_callback,
335 static struct notifier_block notifier_policy_block = {
336 .notifier_call = cpufreq_stat_notifier_policy
339 static struct notifier_block notifier_trans_block = {
340 .notifier_call = cpufreq_stat_notifier_trans
343 static int
344 __init cpufreq_stats_init(void)
346 int ret;
347 unsigned int cpu;
349 spin_lock_init(&cpufreq_stats_lock);
350 if ((ret = cpufreq_register_notifier(&notifier_policy_block,
351 CPUFREQ_POLICY_NOTIFIER)))
352 return ret;
354 if ((ret = cpufreq_register_notifier(&notifier_trans_block,
355 CPUFREQ_TRANSITION_NOTIFIER))) {
356 cpufreq_unregister_notifier(&notifier_policy_block,
357 CPUFREQ_POLICY_NOTIFIER);
358 return ret;
361 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
362 for_each_online_cpu(cpu) {
363 cpufreq_update_policy(cpu);
365 return 0;
367 static void
368 __exit cpufreq_stats_exit(void)
370 unsigned int cpu;
372 cpufreq_unregister_notifier(&notifier_policy_block,
373 CPUFREQ_POLICY_NOTIFIER);
374 cpufreq_unregister_notifier(&notifier_trans_block,
375 CPUFREQ_TRANSITION_NOTIFIER);
376 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
377 for_each_online_cpu(cpu) {
378 cpufreq_stats_free_table(cpu);
382 MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
383 MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats "
384 "through sysfs filesystem");
385 MODULE_LICENSE ("GPL");
387 module_init(cpufreq_stats_init);
388 module_exit(cpufreq_stats_exit);