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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>
23
24static spinlock_t cpufreq_stats_lock;
25
26#define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
27static struct freq_attr _attr_##_name = {\
28 .attr = {.name = __stringify(_name), .mode = _mode, }, \
29 .show = _show,\
30};
31
32struct 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
44};
45
46static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
47
48struct cpufreq_stats_attribute {
49 struct attribute attr;
50 ssize_t(*show) (struct cpufreq_stats *, char *);
51};
52
53static int cpufreq_stats_update(unsigned int cpu)
54{
55 struct cpufreq_stats *stat;
56 unsigned long long cur_time;
57
58 cur_time = get_jiffies_64();
59 spin_lock(&cpufreq_stats_lock);
60 stat = per_cpu(cpufreq_stats_table, cpu);
61 if (stat->time_in_state)
62 stat->time_in_state[stat->last_index] =
63 cputime64_add(stat->time_in_state[stat->last_index],
64 cputime_sub(cur_time, stat->last_time));
65 stat->last_time = cur_time;
66 spin_unlock(&cpufreq_stats_lock);
67 return 0;
68}
69
70static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
71{
72 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
73 if (!stat)
74 return 0;
75 return sprintf(buf, "%d\n",
76 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
77}
78
79static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
80{
81 ssize_t len = 0;
82 int i;
83 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
84 if (!stat)
85 return 0;
86 cpufreq_stats_update(stat->cpu);
87 for (i = 0; i < stat->state_num; i++) {
88 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
89 (unsigned long long)
90 cputime64_to_clock_t(stat->time_in_state[i]));
91 }
92 return len;
93}
94
95#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
96static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
97{
98 ssize_t len = 0;
99 int i, j;
100
101 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
102 if (!stat)
103 return 0;
104 cpufreq_stats_update(stat->cpu);
105 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
106 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
107 for (i = 0; i < stat->state_num; i++) {
108 if (len >= PAGE_SIZE)
109 break;
110 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
111 stat->freq_table[i]);
112 }
113 if (len >= PAGE_SIZE)
114 return PAGE_SIZE;
115
116 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
117
118 for (i = 0; i < stat->state_num; i++) {
119 if (len >= PAGE_SIZE)
120 break;
121
122 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
123 stat->freq_table[i]);
124
125 for (j = 0; j < stat->state_num; j++) {
126 if (len >= PAGE_SIZE)
127 break;
128 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
129 stat->trans_table[i*stat->max_state+j]);
130 }
131 if (len >= PAGE_SIZE)
132 break;
133 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
134 }
135 if (len >= PAGE_SIZE)
136 return PAGE_SIZE;
137 return len;
138}
139CPUFREQ_STATDEVICE_ATTR(trans_table, 0444, show_trans_table);
140#endif
141
142CPUFREQ_STATDEVICE_ATTR(total_trans, 0444, show_total_trans);
143CPUFREQ_STATDEVICE_ATTR(time_in_state, 0444, show_time_in_state);
144
145static struct attribute *default_attrs[] = {
146 &_attr_total_trans.attr,
147 &_attr_time_in_state.attr,
148#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
149 &_attr_trans_table.attr,
150#endif
151 NULL
152};
153static struct attribute_group stats_attr_group = {
154 .attrs = default_attrs,
155 .name = "stats"
156};
157
158static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
159{
160 int index;
161 for (index = 0; index < stat->max_state; index++)
162 if (stat->freq_table[index] == freq)
163 return index;
164 return -1;
165}
166
167static void cpufreq_stats_free_table(unsigned int cpu)
168{
169 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
170 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
171 if (policy && policy->cpu == cpu)
172 sysfs_remove_group(&policy->kobj, &stats_attr_group);
173 if (stat) {
174 kfree(stat->time_in_state);
175 kfree(stat);
176 }
177 per_cpu(cpufreq_stats_table, cpu) = NULL;
178 if (policy)
179 cpufreq_cpu_put(policy);
180}
181
182static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
183 struct cpufreq_frequency_table *table)
184{
185 unsigned int i, j, count = 0, ret = 0;
186 struct cpufreq_stats *stat;
187 struct cpufreq_policy *data;
188 unsigned int alloc_size;
189 unsigned int cpu = policy->cpu;
190 if (per_cpu(cpufreq_stats_table, cpu))
191 return -EBUSY;
192 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
193 if ((stat) == NULL)
194 return -ENOMEM;
195
196 data = cpufreq_cpu_get(cpu);
197 if (data == NULL) {
198 ret = -EINVAL;
199 goto error_get_fail;
200 }
201
202 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
203 if (ret)
204 goto error_out;
205
206 stat->cpu = cpu;
207 per_cpu(cpufreq_stats_table, cpu) = stat;
208
209 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
210 unsigned int freq = table[i].frequency;
211 if (freq == CPUFREQ_ENTRY_INVALID)
212 continue;
213 count++;
214 }
215
216 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
217
218#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
219 alloc_size += count * count * sizeof(int);
220#endif
221 stat->max_state = count;
222 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
223 if (!stat->time_in_state) {
224 ret = -ENOMEM;
225 goto error_out;
226 }
227 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
228
229#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
230 stat->trans_table = stat->freq_table + count;
231#endif
232 j = 0;
233 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
234 unsigned int freq = table[i].frequency;
235 if (freq == CPUFREQ_ENTRY_INVALID)
236 continue;
237 if (freq_table_get_index(stat, freq) == -1)
238 stat->freq_table[j++] = freq;
239 }
240 stat->state_num = j;
241 spin_lock(&cpufreq_stats_lock);
242 stat->last_time = get_jiffies_64();
243 stat->last_index = freq_table_get_index(stat, policy->cur);
244 spin_unlock(&cpufreq_stats_lock);
245 cpufreq_cpu_put(data);
246 return 0;
247error_out:
248 cpufreq_cpu_put(data);
249error_get_fail:
250 kfree(stat);
251 per_cpu(cpufreq_stats_table, cpu) = NULL;
252 return ret;
253}
254
255static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
256 unsigned long val, void *data)
257{
258 int ret;
259 struct cpufreq_policy *policy = data;
260 struct cpufreq_frequency_table *table;
261 unsigned int cpu = policy->cpu;
262 if (val != CPUFREQ_NOTIFY)
263 return 0;
264 table = cpufreq_frequency_get_table(cpu);
265 if (!table)
266 return 0;
267 ret = cpufreq_stats_create_table(policy, table);
268 if (ret)
269 return ret;
270 return 0;
271}
272
273static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
274 unsigned long val, void *data)
275{
276 struct cpufreq_freqs *freq = data;
277 struct cpufreq_stats *stat;
278 int old_index, new_index;
279
280 if (val != CPUFREQ_POSTCHANGE)
281 return 0;
282
283 stat = per_cpu(cpufreq_stats_table, freq->cpu);
284 if (!stat)
285 return 0;
286
287 old_index = stat->last_index;
288 new_index = freq_table_get_index(stat, freq->new);
289
290 cpufreq_stats_update(freq->cpu);
291 if (old_index == new_index)
292 return 0;
293
294 if (old_index == -1 || new_index == -1)
295 return 0;
296
297 spin_lock(&cpufreq_stats_lock);
298 stat->last_index = new_index;
299#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
300 stat->trans_table[old_index * stat->max_state + new_index]++;
301#endif
302 stat->total_trans++;
303 spin_unlock(&cpufreq_stats_lock);
304 return 0;
305}
306
307static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
308 unsigned long action,
309 void *hcpu)
310{
311 unsigned int cpu = (unsigned long)hcpu;
312
313 switch (action) {
314 case CPU_ONLINE:
315 case CPU_ONLINE_FROZEN:
316 cpufreq_update_policy(cpu);
317 break;
318 case CPU_DEAD:
319 case CPU_DEAD_FROZEN:
320 cpufreq_stats_free_table(cpu);
321 break;
322 }
323 return NOTIFY_OK;
324}
325
326static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
327{
328 .notifier_call = cpufreq_stat_cpu_callback,
329};
330
331static struct notifier_block notifier_policy_block = {
332 .notifier_call = cpufreq_stat_notifier_policy
333};
334
335static struct notifier_block notifier_trans_block = {
336 .notifier_call = cpufreq_stat_notifier_trans
337};
338
339static int __init cpufreq_stats_init(void)
340{
341 int ret;
342 unsigned int cpu;
343
344 spin_lock_init(&cpufreq_stats_lock);
345 ret = cpufreq_register_notifier(¬ifier_policy_block,
346 CPUFREQ_POLICY_NOTIFIER);
347 if (ret)
348 return ret;
349
350 ret = cpufreq_register_notifier(¬ifier_trans_block,
351 CPUFREQ_TRANSITION_NOTIFIER);
352 if (ret) {
353 cpufreq_unregister_notifier(¬ifier_policy_block,
354 CPUFREQ_POLICY_NOTIFIER);
355 return ret;
356 }
357
358 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
359 for_each_online_cpu(cpu) {
360 cpufreq_update_policy(cpu);
361 }
362 return 0;
363}
364static void __exit cpufreq_stats_exit(void)
365{
366 unsigned int cpu;
367
368 cpufreq_unregister_notifier(¬ifier_policy_block,
369 CPUFREQ_POLICY_NOTIFIER);
370 cpufreq_unregister_notifier(¬ifier_trans_block,
371 CPUFREQ_TRANSITION_NOTIFIER);
372 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
373 for_each_online_cpu(cpu) {
374 cpufreq_stats_free_table(cpu);
375 }
376}
377
378MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
379MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
380 "through sysfs filesystem");
381MODULE_LICENSE("GPL");
382
383module_init(cpufreq_stats_init);
384module_exit(cpufreq_stats_exit);
385
