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12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/cpu.h>
15#include <linux/sysfs.h>
16#include <linux/cpufreq.h>
17#include <linux/module.h>
18#include <linux/jiffies.h>
19#include <linux/percpu.h>
20#include <linux/kobject.h>
21#include <linux/spinlock.h>
22#include <linux/notifier.h>
23#include <asm/cputime.h>
24
25static spinlock_t cpufreq_stats_lock;
26
27struct cpufreq_stats {
28 unsigned int cpu;
29 unsigned int total_trans;
30 unsigned long long last_time;
31 unsigned int max_state;
32 unsigned int state_num;
33 unsigned int last_index;
34 u64 *time_in_state;
35 unsigned int *freq_table;
36#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
37 unsigned int *trans_table;
38#endif
39};
40
41static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
42
43struct cpufreq_stats_attribute {
44 struct attribute attr;
45 ssize_t(*show) (struct cpufreq_stats *, char *);
46};
47
48static int cpufreq_stats_update(unsigned int cpu)
49{
50 struct cpufreq_stats *stat;
51 unsigned long long cur_time;
52
53 cur_time = get_jiffies_64();
54 spin_lock(&cpufreq_stats_lock);
55 stat = per_cpu(cpufreq_stats_table, cpu);
56 if (stat->time_in_state)
57 stat->time_in_state[stat->last_index] +=
58 cur_time - stat->last_time;
59 stat->last_time = cur_time;
60 spin_unlock(&cpufreq_stats_lock);
61 return 0;
62}
63
64static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
65{
66 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
67 if (!stat)
68 return 0;
69 return sprintf(buf, "%d\n",
70 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
71}
72
73static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
74{
75 ssize_t len = 0;
76 int i;
77 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
78 if (!stat)
79 return 0;
80 cpufreq_stats_update(stat->cpu);
81 for (i = 0; i < stat->state_num; i++) {
82 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
83 (unsigned long long)
84 cputime64_to_clock_t(stat->time_in_state[i]));
85 }
86 return len;
87}
88
89#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
90static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
91{
92 ssize_t len = 0;
93 int i, j;
94
95 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
96 if (!stat)
97 return 0;
98 cpufreq_stats_update(stat->cpu);
99 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
100 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
101 for (i = 0; i < stat->state_num; i++) {
102 if (len >= PAGE_SIZE)
103 break;
104 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
105 stat->freq_table[i]);
106 }
107 if (len >= PAGE_SIZE)
108 return PAGE_SIZE;
109
110 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
111
112 for (i = 0; i < stat->state_num; i++) {
113 if (len >= PAGE_SIZE)
114 break;
115
116 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
117 stat->freq_table[i]);
118
119 for (j = 0; j < stat->state_num; j++) {
120 if (len >= PAGE_SIZE)
121 break;
122 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
123 stat->trans_table[i*stat->max_state+j]);
124 }
125 if (len >= PAGE_SIZE)
126 break;
127 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
128 }
129 if (len >= PAGE_SIZE)
130 return PAGE_SIZE;
131 return len;
132}
133cpufreq_freq_attr_ro(trans_table);
134#endif
135
136cpufreq_freq_attr_ro(total_trans);
137cpufreq_freq_attr_ro(time_in_state);
138
139static struct attribute *default_attrs[] = {
140 &total_trans.attr,
141 &time_in_state.attr,
142#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
143 &trans_table.attr,
144#endif
145 NULL
146};
147static struct attribute_group stats_attr_group = {
148 .attrs = default_attrs,
149 .name = "stats"
150};
151
152static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
153{
154 int index;
155 for (index = 0; index < stat->max_state; index++)
156 if (stat->freq_table[index] == freq)
157 return index;
158 return -1;
159}
160
161
162
163
164static void cpufreq_stats_free_table(unsigned int cpu)
165{
166 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
167
168 if (stat) {
169 pr_debug("%s: Free stat table\n", __func__);
170 kfree(stat->time_in_state);
171 kfree(stat);
172 per_cpu(cpufreq_stats_table, cpu) = NULL;
173 }
174}
175
176
177
178
179static void cpufreq_stats_free_sysfs(unsigned int cpu)
180{
181 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
182
183 if (!policy)
184 return;
185
186 if (!cpufreq_frequency_get_table(cpu))
187 goto put_ref;
188
189 if (!policy_is_shared(policy)) {
190 pr_debug("%s: Free sysfs stat\n", __func__);
191 sysfs_remove_group(&policy->kobj, &stats_attr_group);
192 }
193
194put_ref:
195 cpufreq_cpu_put(policy);
196}
197
198static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
199 struct cpufreq_frequency_table *table)
200{
201 unsigned int i, j, count = 0, ret = 0;
202 struct cpufreq_stats *stat;
203 struct cpufreq_policy *data;
204 unsigned int alloc_size;
205 unsigned int cpu = policy->cpu;
206 if (per_cpu(cpufreq_stats_table, cpu))
207 return -EBUSY;
208 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
209 if ((stat) == NULL)
210 return -ENOMEM;
211
212 data = cpufreq_cpu_get(cpu);
213 if (data == NULL) {
214 ret = -EINVAL;
215 goto error_get_fail;
216 }
217
218 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
219 if (ret)
220 goto error_out;
221
222 stat->cpu = cpu;
223 per_cpu(cpufreq_stats_table, cpu) = stat;
224
225 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
226 unsigned int freq = table[i].frequency;
227 if (freq == CPUFREQ_ENTRY_INVALID)
228 continue;
229 count++;
230 }
231
232 alloc_size = count * sizeof(int) + count * sizeof(u64);
233
234#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
235 alloc_size += count * count * sizeof(int);
236#endif
237 stat->max_state = count;
238 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
239 if (!stat->time_in_state) {
240 ret = -ENOMEM;
241 goto error_out;
242 }
243 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
244
245#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
246 stat->trans_table = stat->freq_table + count;
247#endif
248 j = 0;
249 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
250 unsigned int freq = table[i].frequency;
251 if (freq == CPUFREQ_ENTRY_INVALID)
252 continue;
253 if (freq_table_get_index(stat, freq) == -1)
254 stat->freq_table[j++] = freq;
255 }
256 stat->state_num = j;
257 spin_lock(&cpufreq_stats_lock);
258 stat->last_time = get_jiffies_64();
259 stat->last_index = freq_table_get_index(stat, policy->cur);
260 spin_unlock(&cpufreq_stats_lock);
261 cpufreq_cpu_put(data);
262 return 0;
263error_out:
264 cpufreq_cpu_put(data);
265error_get_fail:
266 kfree(stat);
267 per_cpu(cpufreq_stats_table, cpu) = NULL;
268 return ret;
269}
270
271static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
272{
273 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
274 policy->last_cpu);
275
276 pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
277 policy->cpu, policy->last_cpu);
278 per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
279 policy->last_cpu);
280 per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
281 stat->cpu = policy->cpu;
282}
283
284static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
285 unsigned long val, void *data)
286{
287 int ret;
288 struct cpufreq_policy *policy = data;
289 struct cpufreq_frequency_table *table;
290 unsigned int cpu = policy->cpu;
291
292 if (val == CPUFREQ_UPDATE_POLICY_CPU) {
293 cpufreq_stats_update_policy_cpu(policy);
294 return 0;
295 }
296
297 if (val != CPUFREQ_NOTIFY)
298 return 0;
299 table = cpufreq_frequency_get_table(cpu);
300 if (!table)
301 return 0;
302 ret = cpufreq_stats_create_table(policy, table);
303 if (ret)
304 return ret;
305 return 0;
306}
307
308static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
309 unsigned long val, void *data)
310{
311 struct cpufreq_freqs *freq = data;
312 struct cpufreq_stats *stat;
313 int old_index, new_index;
314
315 if (val != CPUFREQ_POSTCHANGE)
316 return 0;
317
318 stat = per_cpu(cpufreq_stats_table, freq->cpu);
319 if (!stat)
320 return 0;
321
322 old_index = stat->last_index;
323 new_index = freq_table_get_index(stat, freq->new);
324
325
326 if (old_index == -1 || new_index == -1)
327 return 0;
328
329 cpufreq_stats_update(freq->cpu);
330
331 if (old_index == new_index)
332 return 0;
333
334 spin_lock(&cpufreq_stats_lock);
335 stat->last_index = new_index;
336#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
337 stat->trans_table[old_index * stat->max_state + new_index]++;
338#endif
339 stat->total_trans++;
340 spin_unlock(&cpufreq_stats_lock);
341 return 0;
342}
343
344static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
345 unsigned long action,
346 void *hcpu)
347{
348 unsigned int cpu = (unsigned long)hcpu;
349
350 switch (action) {
351 case CPU_ONLINE:
352 case CPU_ONLINE_FROZEN:
353 cpufreq_update_policy(cpu);
354 break;
355 case CPU_DOWN_PREPARE:
356 case CPU_DOWN_PREPARE_FROZEN:
357 cpufreq_stats_free_sysfs(cpu);
358 break;
359 case CPU_DEAD:
360 case CPU_DEAD_FROZEN:
361 cpufreq_stats_free_table(cpu);
362 break;
363 }
364 return NOTIFY_OK;
365}
366
367
368static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
369 .notifier_call = cpufreq_stat_cpu_callback,
370 .priority = 1,
371};
372
373static struct notifier_block notifier_policy_block = {
374 .notifier_call = cpufreq_stat_notifier_policy
375};
376
377static struct notifier_block notifier_trans_block = {
378 .notifier_call = cpufreq_stat_notifier_trans
379};
380
381static int __init cpufreq_stats_init(void)
382{
383 int ret;
384 unsigned int cpu;
385
386 spin_lock_init(&cpufreq_stats_lock);
387 ret = cpufreq_register_notifier(¬ifier_policy_block,
388 CPUFREQ_POLICY_NOTIFIER);
389 if (ret)
390 return ret;
391
392 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
393 for_each_online_cpu(cpu)
394 cpufreq_update_policy(cpu);
395
396 ret = cpufreq_register_notifier(¬ifier_trans_block,
397 CPUFREQ_TRANSITION_NOTIFIER);
398 if (ret) {
399 cpufreq_unregister_notifier(¬ifier_policy_block,
400 CPUFREQ_POLICY_NOTIFIER);
401 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
402 for_each_online_cpu(cpu)
403 cpufreq_stats_free_table(cpu);
404 return ret;
405 }
406
407 return 0;
408}
409static void __exit cpufreq_stats_exit(void)
410{
411 unsigned int cpu;
412
413 cpufreq_unregister_notifier(¬ifier_policy_block,
414 CPUFREQ_POLICY_NOTIFIER);
415 cpufreq_unregister_notifier(¬ifier_trans_block,
416 CPUFREQ_TRANSITION_NOTIFIER);
417 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
418 for_each_online_cpu(cpu) {
419 cpufreq_stats_free_table(cpu);
420 cpufreq_stats_free_sysfs(cpu);
421 }
422}
423
424MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
425MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
426 "through sysfs filesystem");
427MODULE_LICENSE("GPL");
428
429module_init(cpufreq_stats_init);
430module_exit(cpufreq_stats_exit);
431
