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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 struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
47
48struct cpufreq_stats_attribute {
49 struct attribute attr;
50 ssize_t(*show) (struct cpufreq_stats *, char *);
51};
52
53static int
54cpufreq_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 = 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
72show_total_trans(struct cpufreq_policy *policy, char *buf)
73{
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);
79}
80
81static ssize_t
82show_time_in_state(struct cpufreq_policy *policy, char *buf)
83{
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]));
93 }
94 return len;
95}
96
97#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
98static ssize_t
99show_trans_table(struct cpufreq_policy *policy, char *buf)
100{
101 ssize_t len = 0;
102 int i, j;
103
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]);
115 }
116 if (len >= PAGE_SIZE)
117 return len;
118
119 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
120
121 for (i = 0; i < stat->state_num; i++) {
122 if (len >= PAGE_SIZE)
123 break;
124
125 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
126 stat->freq_table[i]);
127
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]);
133 }
134 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
135 }
136 return len;
137}
138CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
139#endif
140
141CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
142CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
143
144static struct attribute *default_attrs[] = {
145 &_attr_total_trans.attr,
146 &_attr_time_in_state.attr,
147#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
148 &_attr_trans_table.attr,
149#endif
150 NULL
151};
152static struct attribute_group stats_attr_group = {
153 .attrs = default_attrs,
154 .name = "stats"
155};
156
157static int
158freq_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 = 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 cpufreq_stats_table[cpu] = NULL;
178 if (policy)
179 cpufreq_cpu_put(policy);
180}
181
182static int
183cpufreq_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 (cpufreq_stats_table[cpu])
192 return -EBUSY;
193 if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == 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 if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
203 goto error_out;
204
205 stat->cpu = cpu;
206 cpufreq_stats_table[cpu] = stat;
207
208 for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
209 unsigned int freq = table[i].frequency;
210 if (freq == CPUFREQ_ENTRY_INVALID)
211 continue;
212 count++;
213 }
214
215 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
216
217#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
218 alloc_size += count * count * sizeof(int);
219#endif
220 stat->max_state = count;
221 stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
222 if (!stat->time_in_state) {
223 ret = -ENOMEM;
224 goto error_out;
225 }
226 stat->freq_table = (unsigned int *)(stat->time_in_state + count);
227
228#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
229 stat->trans_table = stat->freq_table + count;
230#endif
231 j = 0;
232 for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
233 unsigned int freq = table[i].frequency;
234 if (freq == CPUFREQ_ENTRY_INVALID)
235 continue;
236 if (freq_table_get_index(stat, freq) == -1)
237 stat->freq_table[j++] = freq;
238 }
239 stat->state_num = j;
240 spin_lock(&cpufreq_stats_lock);
241 stat->last_time = get_jiffies_64();
242 stat->last_index = freq_table_get_index(stat, policy->cur);
243 spin_unlock(&cpufreq_stats_lock);
244 cpufreq_cpu_put(data);
245 return 0;
246error_out:
247 cpufreq_cpu_put(data);
248error_get_fail:
249 kfree(stat);
250 cpufreq_stats_table[cpu] = NULL;
251 return ret;
252}
253
254static int
255cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
256 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 if ((ret = cpufreq_stats_create_table(policy, table)))
268 return ret;
269 return 0;
270}
271
272static int
273cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
274 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 = cpufreq_stats_table[freq->cpu];
284 if (!stat)
285 return 0;
286
287 old_index = freq_table_get_index(stat, freq->old);
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 __cpuinitdata =
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
340__init cpufreq_stats_init(void)
341{
342 int ret;
343 unsigned int cpu;
344
345 spin_lock_init(&cpufreq_stats_lock);
346 if ((ret = cpufreq_register_notifier(¬ifier_policy_block,
347 CPUFREQ_POLICY_NOTIFIER)))
348 return ret;
349
350 if ((ret = cpufreq_register_notifier(¬ifier_trans_block,
351 CPUFREQ_TRANSITION_NOTIFIER))) {
352 cpufreq_unregister_notifier(¬ifier_policy_block,
353 CPUFREQ_POLICY_NOTIFIER);
354 return ret;
355 }
356
357 register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
358 for_each_online_cpu(cpu) {
359 cpufreq_update_policy(cpu);
360 }
361 return 0;
362}
363static void
364__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
