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12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/sysdev.h>
15#include <linux/cpu.h>
16#include <linux/sysfs.h>
17#include <linux/cpufreq.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
27#define CPUFREQ_STATDEVICE_ATTR(_name, _mode, _show) \
28static struct freq_attr _attr_##_name = {\
29 .attr = {.name = __stringify(_name), .mode = _mode, }, \
30 .show = _show,\
31};
32
33struct cpufreq_stats {
34 unsigned int cpu;
35 unsigned int total_trans;
36 unsigned long long last_time;
37 unsigned int max_state;
38 unsigned int state_num;
39 unsigned int last_index;
40 cputime64_t *time_in_state;
41 unsigned int *freq_table;
42#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
43 unsigned int *trans_table;
44#endif
45};
46
47static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
48
49struct cpufreq_stats_attribute {
50 struct attribute attr;
51 ssize_t(*show) (struct cpufreq_stats *, char *);
52};
53
54static int cpufreq_stats_update(unsigned int cpu)
55{
56 struct cpufreq_stats *stat;
57 unsigned long long cur_time;
58
59 cur_time = get_jiffies_64();
60 spin_lock(&cpufreq_stats_lock);
61 stat = per_cpu(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;
69}
70
71static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
72{
73 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
74 if (!stat)
75 return 0;
76 return sprintf(buf, "%d\n",
77 per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
78}
79
80static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
81{
82 ssize_t len = 0;
83 int i;
84 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
85 if (!stat)
86 return 0;
87 cpufreq_stats_update(stat->cpu);
88 for (i = 0; i < stat->state_num; i++) {
89 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
90 (unsigned long long)
91 cputime64_to_clock_t(stat->time_in_state[i]));
92 }
93 return len;
94}
95
96#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
97static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
98{
99 ssize_t len = 0;
100 int i, j;
101
102 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
103 if (!stat)
104 return 0;
105 cpufreq_stats_update(stat->cpu);
106 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
107 len += snprintf(buf + len, PAGE_SIZE - len, " : ");
108 for (i = 0; i < stat->state_num; i++) {
109 if (len >= PAGE_SIZE)
110 break;
111 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
112 stat->freq_table[i]);
113 }
114 if (len >= PAGE_SIZE)
115 return PAGE_SIZE;
116
117 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
118
119 for (i = 0; i < stat->state_num; i++) {
120 if (len >= PAGE_SIZE)
121 break;
122
123 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
124 stat->freq_table[i]);
125
126 for (j = 0; j < stat->state_num; j++) {
127 if (len >= PAGE_SIZE)
128 break;
129 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
130 stat->trans_table[i*stat->max_state+j]);
131 }
132 if (len >= PAGE_SIZE)
133 break;
134 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
135 }
136 if (len >= PAGE_SIZE)
137 return PAGE_SIZE;
138 return len;
139}
140CPUFREQ_STATDEVICE_ATTR(trans_table, 0444, show_trans_table);
141#endif
142
143CPUFREQ_STATDEVICE_ATTR(total_trans, 0444, show_total_trans);
144CPUFREQ_STATDEVICE_ATTR(time_in_state, 0444, show_time_in_state);
145
146static struct attribute *default_attrs[] = {
147 &_attr_total_trans.attr,
148 &_attr_time_in_state.attr,
149#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
150 &_attr_trans_table.attr,
151#endif
152 NULL
153};
154static struct attribute_group stats_attr_group = {
155 .attrs = default_attrs,
156 .name = "stats"
157};
158
159static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
160{
161 int index;
162 for (index = 0; index < stat->max_state; index++)
163 if (stat->freq_table[index] == freq)
164 return index;
165 return -1;
166}
167
168static void cpufreq_stats_free_table(unsigned int cpu)
169{
170 struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
171 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
172 if (policy && policy->cpu == cpu)
173 sysfs_remove_group(&policy->kobj, &stats_attr_group);
174 if (stat) {
175 kfree(stat->time_in_state);
176 kfree(stat);
177 }
178 per_cpu(cpufreq_stats_table, cpu) = NULL;
179 if (policy)
180 cpufreq_cpu_put(policy);
181}
182
183static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
184 struct cpufreq_frequency_table *table)
185{
186 unsigned int i, j, count = 0, ret = 0;
187 struct cpufreq_stats *stat;
188 struct cpufreq_policy *data;
189 unsigned int alloc_size;
190 unsigned int cpu = policy->cpu;
191 if (per_cpu(cpufreq_stats_table, cpu))
192 return -EBUSY;
193 stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
194 if ((stat) == NULL)
195 return -ENOMEM;
196
197 data = cpufreq_cpu_get(cpu);
198 if (data == NULL) {
199 ret = -EINVAL;
200 goto error_get_fail;
201 }
202
203 ret = sysfs_create_group(&data->kobj, &stats_attr_group);
204 if (ret)
205 goto error_out;
206
207 stat->cpu = cpu;
208 per_cpu(cpufreq_stats_table, cpu) = stat;
209
210 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
211 unsigned int freq = table[i].frequency;
212 if (freq == CPUFREQ_ENTRY_INVALID)
213 continue;
214 count++;
215 }
216
217 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
218
219#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
220 alloc_size += count * count * sizeof(int);
221#endif
222 stat->max_state = count;
223 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
224 if (!stat->time_in_state) {
225 ret = -ENOMEM;
226 goto error_out;
227 }
228 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
229
230#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
231 stat->trans_table = stat->freq_table + count;
232#endif
233 j = 0;
234 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
235 unsigned int freq = table[i].frequency;
236 if (freq == CPUFREQ_ENTRY_INVALID)
237 continue;
238 if (freq_table_get_index(stat, freq) == -1)
239 stat->freq_table[j++] = freq;
240 }
241 stat->state_num = j;
242 spin_lock(&cpufreq_stats_lock);
243 stat->last_time = get_jiffies_64();
244 stat->last_index = freq_table_get_index(stat, policy->cur);
245 spin_unlock(&cpufreq_stats_lock);
246 cpufreq_cpu_put(data);
247 return 0;
248error_out:
249 cpufreq_cpu_put(data);
250error_get_fail:
251 kfree(stat);
252 per_cpu(cpufreq_stats_table, cpu) = NULL;
253 return ret;
254}
255
256static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
257 unsigned long val, void *data)
258{
259 int ret;
260 struct cpufreq_policy *policy = data;
261 struct cpufreq_frequency_table *table;
262 unsigned int cpu = policy->cpu;
263 if (val != CPUFREQ_NOTIFY)
264 return 0;
265 table = cpufreq_frequency_get_table(cpu);
266 if (!table)
267 return 0;
268 ret = cpufreq_stats_create_table(policy, table);
269 if (ret)
270 return ret;
271 return 0;
272}
273
274static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
275 unsigned long val, void *data)
276{
277 struct cpufreq_freqs *freq = data;
278 struct cpufreq_stats *stat;
279 int old_index, new_index;
280
281 if (val != CPUFREQ_POSTCHANGE)
282 return 0;
283
284 stat = per_cpu(cpufreq_stats_table, freq->cpu);
285 if (!stat)
286 return 0;
287
288 old_index = stat->last_index;
289 new_index = freq_table_get_index(stat, freq->new);
290
291 cpufreq_stats_update(freq->cpu);
292 if (old_index == new_index)
293 return 0;
294
295 if (old_index == -1 || new_index == -1)
296 return 0;
297
298 spin_lock(&cpufreq_stats_lock);
299 stat->last_index = new_index;
300#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
301 stat->trans_table[old_index * stat->max_state + new_index]++;
302#endif
303 stat->total_trans++;
304 spin_unlock(&cpufreq_stats_lock);
305 return 0;
306}
307
308static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
309 unsigned long action,
310 void *hcpu)
311{
312 unsigned int cpu = (unsigned long)hcpu;
313
314 switch (action) {
315 case CPU_ONLINE:
316 case CPU_ONLINE_FROZEN:
317 cpufreq_update_policy(cpu);
318 break;
319 case CPU_DEAD:
320 case CPU_DEAD_FROZEN:
321 cpufreq_stats_free_table(cpu);
322 break;
323 }
324 return NOTIFY_OK;
325}
326
327static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
328{
329 .notifier_call = cpufreq_stat_cpu_callback,
330};
331
332static struct notifier_block notifier_policy_block = {
333 .notifier_call = cpufreq_stat_notifier_policy
334};
335
336static struct notifier_block notifier_trans_block = {
337 .notifier_call = cpufreq_stat_notifier_trans
338};
339
340static int __init cpufreq_stats_init(void)
341{
342 int ret;
343 unsigned int cpu;
344
345 spin_lock_init(&cpufreq_stats_lock);
346 ret = cpufreq_register_notifier(¬ifier_policy_block,
347 CPUFREQ_POLICY_NOTIFIER);
348 if (ret)
349 return ret;
350
351 ret = cpufreq_register_notifier(¬ifier_trans_block,
352 CPUFREQ_TRANSITION_NOTIFIER);
353 if (ret) {
354 cpufreq_unregister_notifier(¬ifier_policy_block,
355 CPUFREQ_POLICY_NOTIFIER);
356 return ret;
357 }
358
359 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
360 for_each_online_cpu(cpu) {
361 cpufreq_update_policy(cpu);
362 }
363 return 0;
364}
365static void __exit cpufreq_stats_exit(void)
366{
367 unsigned int cpu;
368
369 cpufreq_unregister_notifier(¬ifier_policy_block,
370 CPUFREQ_POLICY_NOTIFIER);
371 cpufreq_unregister_notifier(¬ifier_trans_block,
372 CPUFREQ_TRANSITION_NOTIFIER);
373 unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
374 for_each_online_cpu(cpu) {
375 cpufreq_stats_free_table(cpu);
376 }
377}
378
379MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
380MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
381 "through sysfs filesystem");
382MODULE_LICENSE("GPL");
383
384module_init(cpufreq_stats_init);
385module_exit(cpufreq_stats_exit);
386
