1 /* 2 * drivers/cpufreq/cpufreq_stats.c 3 * 4 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>. 5 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>. 6 * 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. 10 */ 11 12 #include <linux/config.h> 13 #include <linux/kernel.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 25 static spinlock_t cpufreq_stats_lock; 26 27 #define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \ 28 static struct freq_attr _attr_##_name = {\ 29 .attr = {.name = __stringify(_name), .owner = THIS_MODULE, \ 30 .mode = _mode, }, \ 31 .show = _show,\ 32 }; 33 34 struct cpufreq_stats { 35 unsigned int cpu; 36 unsigned int total_trans; 37 unsigned long long last_time; 38 unsigned int max_state; 39 unsigned int state_num; 40 unsigned int last_index; 41 cputime64_t *time_in_state; 42 unsigned int *freq_table; 43 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS 44 unsigned int *trans_table; 45 #endif 46 }; 47 48 static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS]; 49 50 struct cpufreq_stats_attribute { 51 struct attribute attr; 52 ssize_t(*show) (struct cpufreq_stats *, char *); 53 }; 54 55 static int 56 cpufreq_stats_update (unsigned int cpu) 57 { 58 struct cpufreq_stats *stat; 59 unsigned long long cur_time; 60 61 cur_time = get_jiffies_64(); 62 spin_lock(&cpufreq_stats_lock); 63 stat = cpufreq_stats_table[cpu]; 64 if (stat->time_in_state) 65 stat->time_in_state[stat->last_index] = 66 cputime64_add(stat->time_in_state[stat->last_index], 67 cputime_sub(cur_time, stat->last_time)); 68 stat->last_time = cur_time; 69 spin_unlock(&cpufreq_stats_lock); 70 return 0; 71 } 72 73 static ssize_t 74 show_total_trans(struct cpufreq_policy *policy, char *buf) 75 { 76 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; 77 if(!stat) 78 return 0; 79 return sprintf(buf, "%d\n", 80 cpufreq_stats_table[stat->cpu]->total_trans); 81 } 82 83 static ssize_t 84 show_time_in_state(struct cpufreq_policy *policy, char *buf) 85 { 86 ssize_t len = 0; 87 int i; 88 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; 89 if(!stat) 90 return 0; 91 cpufreq_stats_update(stat->cpu); 92 for (i = 0; i < stat->state_num; i++) { 93 len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i], 94 (unsigned long long)cputime64_to_clock_t(stat->time_in_state[i])); 95 } 96 return len; 97 } 98 99 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS 100 static ssize_t 101 show_trans_table(struct cpufreq_policy *policy, char *buf) 102 { 103 ssize_t len = 0; 104 int i, j; 105 106 struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu]; 107 if(!stat) 108 return 0; 109 cpufreq_stats_update(stat->cpu); 110 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); 111 len += snprintf(buf + len, PAGE_SIZE - len, " : "); 112 for (i = 0; i < stat->state_num; i++) { 113 if (len >= PAGE_SIZE) 114 break; 115 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 116 stat->freq_table[i]); 117 } 118 if (len >= PAGE_SIZE) 119 return len; 120 121 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 122 123 for (i = 0; i < stat->state_num; i++) { 124 if (len >= PAGE_SIZE) 125 break; 126 127 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", 128 stat->freq_table[i]); 129 130 for (j = 0; j < stat->state_num; j++) { 131 if (len >= PAGE_SIZE) 132 break; 133 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 134 stat->trans_table[i*stat->max_state+j]); 135 } 136 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 137 } 138 return len; 139 } 140 CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table); 141 #endif 142 143 CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans); 144 CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state); 145 146 static 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 }; 154 static struct attribute_group stats_attr_group = { 155 .attrs = default_attrs, 156 .name = "stats" 157 }; 158 159 static int 160 freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq) 161 { 162 int index; 163 for (index = 0; index < stat->max_state; index++) 164 if (stat->freq_table[index] == freq) 165 return index; 166 return -1; 167 } 168 169 static void 170 cpufreq_stats_free_table (unsigned int cpu) 171 { 172 struct cpufreq_stats *stat = cpufreq_stats_table[cpu]; 173 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); 174 if (policy && policy->cpu == cpu) 175 sysfs_remove_group(&policy->kobj, &stats_attr_group); 176 if (stat) { 177 kfree(stat->time_in_state); 178 kfree(stat); 179 } 180 cpufreq_stats_table[cpu] = NULL; 181 if (policy) 182 cpufreq_cpu_put(policy); 183 } 184 185 static int 186 cpufreq_stats_create_table (struct cpufreq_policy *policy, 187 struct cpufreq_frequency_table *table) 188 { 189 unsigned int i, j, count = 0, ret = 0; 190 struct cpufreq_stats *stat; 191 struct cpufreq_policy *data; 192 unsigned int alloc_size; 193 unsigned int cpu = policy->cpu; 194 if (cpufreq_stats_table[cpu]) 195 return -EBUSY; 196 if ((stat = kmalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL) 197 return -ENOMEM; 198 memset(stat, 0, sizeof (struct cpufreq_stats)); 199 200 data = cpufreq_cpu_get(cpu); 201 if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group))) 202 goto error_out; 203 204 stat->cpu = cpu; 205 cpufreq_stats_table[cpu] = stat; 206 207 for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) { 208 unsigned int freq = table[i].frequency; 209 if (freq == CPUFREQ_ENTRY_INVALID) 210 continue; 211 count++; 212 } 213 214 alloc_size = count * sizeof(int) + count * sizeof(cputime64_t); 215 216 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS 217 alloc_size += count * count * sizeof(int); 218 #endif 219 stat->max_state = count; 220 stat->time_in_state = kmalloc(alloc_size, GFP_KERNEL); 221 if (!stat->time_in_state) { 222 ret = -ENOMEM; 223 goto error_out; 224 } 225 memset(stat->time_in_state, 0, alloc_size); 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; 246 error_out: 247 cpufreq_cpu_put(data); 248 kfree(stat); 249 cpufreq_stats_table[cpu] = NULL; 250 return ret; 251 } 252 253 static int 254 cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val, 255 void *data) 256 { 257 int ret; 258 struct cpufreq_policy *policy = data; 259 struct cpufreq_frequency_table *table; 260 unsigned int cpu = policy->cpu; 261 if (val != CPUFREQ_NOTIFY) 262 return 0; 263 table = cpufreq_frequency_get_table(cpu); 264 if (!table) 265 return 0; 266 if ((ret = cpufreq_stats_create_table(policy, table))) 267 return ret; 268 return 0; 269 } 270 271 static int 272 cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val, 273 void *data) 274 { 275 struct cpufreq_freqs *freq = data; 276 struct cpufreq_stats *stat; 277 int old_index, new_index; 278 279 if (val != CPUFREQ_POSTCHANGE) 280 return 0; 281 282 stat = cpufreq_stats_table[freq->cpu]; 283 if (!stat) 284 return 0; 285 old_index = freq_table_get_index(stat, freq->old); 286 new_index = freq_table_get_index(stat, freq->new); 287 288 cpufreq_stats_update(freq->cpu); 289 if (old_index == new_index) 290 return 0; 291 292 spin_lock(&cpufreq_stats_lock); 293 stat->last_index = new_index; 294 #ifdef CONFIG_CPU_FREQ_STAT_DETAILS 295 stat->trans_table[old_index * stat->max_state + new_index]++; 296 #endif 297 stat->total_trans++; 298 spin_unlock(&cpufreq_stats_lock); 299 return 0; 300 } 301 302 static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb, 303 unsigned long action, void *hcpu) 304 { 305 unsigned int cpu = (unsigned long)hcpu; 306 307 switch (action) { 308 case CPU_ONLINE: 309 cpufreq_update_policy(cpu); 310 break; 311 case CPU_DEAD: 312 cpufreq_stats_free_table(cpu); 313 break; 314 } 315 return NOTIFY_OK; 316 } 317 318 static struct notifier_block cpufreq_stat_cpu_notifier = 319 { 320 .notifier_call = cpufreq_stat_cpu_callback, 321 }; 322 323 static struct notifier_block notifier_policy_block = { 324 .notifier_call = cpufreq_stat_notifier_policy 325 }; 326 327 static struct notifier_block notifier_trans_block = { 328 .notifier_call = cpufreq_stat_notifier_trans 329 }; 330 331 static int 332 __init cpufreq_stats_init(void) 333 { 334 int ret; 335 unsigned int cpu; 336 337 spin_lock_init(&cpufreq_stats_lock); 338 if ((ret = cpufreq_register_notifier(¬ifier_policy_block, 339 CPUFREQ_POLICY_NOTIFIER))) 340 return ret; 341 342 if ((ret = cpufreq_register_notifier(¬ifier_trans_block, 343 CPUFREQ_TRANSITION_NOTIFIER))) { 344 cpufreq_unregister_notifier(¬ifier_policy_block, 345 CPUFREQ_POLICY_NOTIFIER); 346 return ret; 347 } 348 349 register_cpu_notifier(&cpufreq_stat_cpu_notifier); 350 lock_cpu_hotplug(); 351 for_each_online_cpu(cpu) { 352 cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE, 353 (void *)(long)cpu); 354 } 355 unlock_cpu_hotplug(); 356 return 0; 357 } 358 static void 359 __exit cpufreq_stats_exit(void) 360 { 361 unsigned int cpu; 362 363 cpufreq_unregister_notifier(¬ifier_policy_block, 364 CPUFREQ_POLICY_NOTIFIER); 365 cpufreq_unregister_notifier(¬ifier_trans_block, 366 CPUFREQ_TRANSITION_NOTIFIER); 367 unregister_cpu_notifier(&cpufreq_stat_cpu_notifier); 368 lock_cpu_hotplug(); 369 for_each_online_cpu(cpu) { 370 cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_DEAD, 371 (void *)(long)cpu); 372 } 373 unlock_cpu_hotplug(); 374 } 375 376 MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>"); 377 MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem"); 378 MODULE_LICENSE ("GPL"); 379 380 module_init(cpufreq_stats_init); 381 module_exit(cpufreq_stats_exit); 382