Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 23 | static spinlock_t cpufreq_stats_lock; |
| 24 | |
| 25 | #define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \ |
| 26 | static struct freq_attr _attr_##_name = {\ |
| 27 | .attr = {.name = __stringify(_name), .owner = THIS_MODULE, \ |
| 28 | .mode = _mode, }, \ |
| 29 | .show = _show,\ |
| 30 | }; |
| 31 | |
| 32 | static unsigned long |
| 33 | delta_time(unsigned long old, unsigned long new) |
| 34 | { |
| 35 | return (old > new) ? (old - new): (new + ~old + 1); |
| 36 | } |
| 37 | |
| 38 | struct cpufreq_stats { |
| 39 | unsigned int cpu; |
| 40 | unsigned int total_trans; |
| 41 | unsigned long long last_time; |
| 42 | unsigned int max_state; |
| 43 | unsigned int state_num; |
| 44 | unsigned int last_index; |
| 45 | unsigned long long *time_in_state; |
| 46 | unsigned int *freq_table; |
| 47 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS |
| 48 | unsigned int *trans_table; |
| 49 | #endif |
| 50 | }; |
| 51 | |
| 52 | static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS]; |
| 53 | |
| 54 | struct cpufreq_stats_attribute { |
| 55 | struct attribute attr; |
| 56 | ssize_t(*show) (struct cpufreq_stats *, char *); |
| 57 | }; |
| 58 | |
| 59 | static int |
| 60 | cpufreq_stats_update (unsigned int cpu) |
| 61 | { |
| 62 | struct cpufreq_stats *stat; |
| 63 | spin_lock(&cpufreq_stats_lock); |
| 64 | stat = cpufreq_stats_table[cpu]; |
| 65 | if (stat->time_in_state) |
| 66 | stat->time_in_state[stat->last_index] += |
| 67 | delta_time(stat->last_time, jiffies); |
| 68 | stat->last_time = jiffies; |
| 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", |
| 94 | stat->freq_table[i], 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 | for (i = 0; i < stat->state_num; i++) { |
| 111 | if (len >= PAGE_SIZE) |
| 112 | break; |
| 113 | len += snprintf(buf + len, PAGE_SIZE - len, "%9u:\t", |
| 114 | stat->freq_table[i]); |
| 115 | |
| 116 | for (j = 0; j < stat->state_num; j++) { |
| 117 | if (len >= PAGE_SIZE) |
| 118 | break; |
| 119 | len += snprintf(buf + len, PAGE_SIZE - len, "%u\t", |
| 120 | stat->trans_table[i*stat->max_state+j]); |
| 121 | } |
| 122 | len += snprintf(buf + len, PAGE_SIZE - len, "\n"); |
| 123 | } |
| 124 | return len; |
| 125 | } |
| 126 | CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table); |
| 127 | #endif |
| 128 | |
| 129 | CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans); |
| 130 | CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state); |
| 131 | |
| 132 | static struct attribute *default_attrs[] = { |
| 133 | &_attr_total_trans.attr, |
| 134 | &_attr_time_in_state.attr, |
| 135 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS |
| 136 | &_attr_trans_table.attr, |
| 137 | #endif |
| 138 | NULL |
| 139 | }; |
| 140 | static struct attribute_group stats_attr_group = { |
| 141 | .attrs = default_attrs, |
| 142 | .name = "stats" |
| 143 | }; |
| 144 | |
| 145 | static int |
| 146 | freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq) |
| 147 | { |
| 148 | int index; |
| 149 | for (index = 0; index < stat->max_state; index++) |
| 150 | if (stat->freq_table[index] == freq) |
| 151 | return index; |
| 152 | return -1; |
| 153 | } |
| 154 | |
| 155 | static void |
| 156 | cpufreq_stats_free_table (unsigned int cpu) |
| 157 | { |
| 158 | struct cpufreq_stats *stat = cpufreq_stats_table[cpu]; |
| 159 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
| 160 | if (policy && policy->cpu == cpu) |
| 161 | sysfs_remove_group(&policy->kobj, &stats_attr_group); |
| 162 | if (stat) { |
| 163 | kfree(stat->time_in_state); |
| 164 | kfree(stat); |
| 165 | } |
| 166 | cpufreq_stats_table[cpu] = NULL; |
| 167 | if (policy) |
| 168 | cpufreq_cpu_put(policy); |
| 169 | } |
| 170 | |
| 171 | static int |
| 172 | cpufreq_stats_create_table (struct cpufreq_policy *policy, |
| 173 | struct cpufreq_frequency_table *table) |
| 174 | { |
| 175 | unsigned int i, j, count = 0, ret = 0; |
| 176 | struct cpufreq_stats *stat; |
| 177 | struct cpufreq_policy *data; |
| 178 | unsigned int alloc_size; |
| 179 | unsigned int cpu = policy->cpu; |
| 180 | if (cpufreq_stats_table[cpu]) |
| 181 | return -EBUSY; |
| 182 | if ((stat = kmalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL) |
| 183 | return -ENOMEM; |
| 184 | memset(stat, 0, sizeof (struct cpufreq_stats)); |
| 185 | |
| 186 | data = cpufreq_cpu_get(cpu); |
| 187 | if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group))) |
| 188 | goto error_out; |
| 189 | |
| 190 | stat->cpu = cpu; |
| 191 | cpufreq_stats_table[cpu] = stat; |
| 192 | |
| 193 | for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) { |
| 194 | unsigned int freq = table[i].frequency; |
| 195 | if (freq == CPUFREQ_ENTRY_INVALID) |
| 196 | continue; |
| 197 | count++; |
| 198 | } |
| 199 | |
| 200 | alloc_size = count * sizeof(int) + count * sizeof(long long); |
| 201 | |
| 202 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS |
| 203 | alloc_size += count * count * sizeof(int); |
| 204 | #endif |
| 205 | stat->max_state = count; |
| 206 | stat->time_in_state = kmalloc(alloc_size, GFP_KERNEL); |
| 207 | if (!stat->time_in_state) { |
| 208 | ret = -ENOMEM; |
| 209 | goto error_out; |
| 210 | } |
| 211 | memset(stat->time_in_state, 0, alloc_size); |
| 212 | stat->freq_table = (unsigned int *)(stat->time_in_state + count); |
| 213 | |
| 214 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS |
| 215 | stat->trans_table = stat->freq_table + count; |
| 216 | #endif |
| 217 | j = 0; |
| 218 | for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { |
| 219 | unsigned int freq = table[i].frequency; |
| 220 | if (freq == CPUFREQ_ENTRY_INVALID) |
| 221 | continue; |
| 222 | if (freq_table_get_index(stat, freq) == -1) |
| 223 | stat->freq_table[j++] = freq; |
| 224 | } |
| 225 | stat->state_num = j; |
| 226 | spin_lock(&cpufreq_stats_lock); |
| 227 | stat->last_time = jiffies; |
| 228 | stat->last_index = freq_table_get_index(stat, policy->cur); |
| 229 | spin_unlock(&cpufreq_stats_lock); |
| 230 | cpufreq_cpu_put(data); |
| 231 | return 0; |
| 232 | error_out: |
| 233 | cpufreq_cpu_put(data); |
| 234 | kfree(stat); |
| 235 | cpufreq_stats_table[cpu] = NULL; |
| 236 | return ret; |
| 237 | } |
| 238 | |
| 239 | static int |
| 240 | cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val, |
| 241 | void *data) |
| 242 | { |
| 243 | int ret; |
| 244 | struct cpufreq_policy *policy = data; |
| 245 | struct cpufreq_frequency_table *table; |
| 246 | unsigned int cpu = policy->cpu; |
| 247 | if (val != CPUFREQ_NOTIFY) |
| 248 | return 0; |
| 249 | table = cpufreq_frequency_get_table(cpu); |
| 250 | if (!table) |
| 251 | return 0; |
| 252 | if ((ret = cpufreq_stats_create_table(policy, table))) |
| 253 | return ret; |
| 254 | return 0; |
| 255 | } |
| 256 | |
| 257 | static int |
| 258 | cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val, |
| 259 | void *data) |
| 260 | { |
| 261 | struct cpufreq_freqs *freq = data; |
| 262 | struct cpufreq_stats *stat; |
| 263 | int old_index, new_index; |
| 264 | |
| 265 | if (val != CPUFREQ_POSTCHANGE) |
| 266 | return 0; |
| 267 | |
| 268 | stat = cpufreq_stats_table[freq->cpu]; |
| 269 | if (!stat) |
| 270 | return 0; |
| 271 | old_index = freq_table_get_index(stat, freq->old); |
| 272 | new_index = freq_table_get_index(stat, freq->new); |
| 273 | |
| 274 | cpufreq_stats_update(freq->cpu); |
| 275 | if (old_index == new_index) |
| 276 | return 0; |
| 277 | |
| 278 | spin_lock(&cpufreq_stats_lock); |
| 279 | stat->last_index = new_index; |
| 280 | #ifdef CONFIG_CPU_FREQ_STAT_DETAILS |
| 281 | stat->trans_table[old_index * stat->max_state + new_index]++; |
| 282 | #endif |
| 283 | stat->total_trans++; |
| 284 | spin_unlock(&cpufreq_stats_lock); |
| 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | static struct notifier_block notifier_policy_block = { |
| 289 | .notifier_call = cpufreq_stat_notifier_policy |
| 290 | }; |
| 291 | |
| 292 | static struct notifier_block notifier_trans_block = { |
| 293 | .notifier_call = cpufreq_stat_notifier_trans |
| 294 | }; |
| 295 | |
| 296 | static int |
| 297 | __init cpufreq_stats_init(void) |
| 298 | { |
| 299 | int ret; |
| 300 | unsigned int cpu; |
| 301 | spin_lock_init(&cpufreq_stats_lock); |
| 302 | if ((ret = cpufreq_register_notifier(¬ifier_policy_block, |
| 303 | CPUFREQ_POLICY_NOTIFIER))) |
| 304 | return ret; |
| 305 | |
| 306 | if ((ret = cpufreq_register_notifier(¬ifier_trans_block, |
| 307 | CPUFREQ_TRANSITION_NOTIFIER))) { |
| 308 | cpufreq_unregister_notifier(¬ifier_policy_block, |
| 309 | CPUFREQ_POLICY_NOTIFIER); |
| 310 | return ret; |
| 311 | } |
| 312 | |
| 313 | for_each_cpu(cpu) |
| 314 | cpufreq_update_policy(cpu); |
| 315 | return 0; |
| 316 | } |
| 317 | static void |
| 318 | __exit cpufreq_stats_exit(void) |
| 319 | { |
| 320 | unsigned int cpu; |
| 321 | cpufreq_unregister_notifier(¬ifier_policy_block, |
| 322 | CPUFREQ_POLICY_NOTIFIER); |
| 323 | cpufreq_unregister_notifier(¬ifier_trans_block, |
| 324 | CPUFREQ_TRANSITION_NOTIFIER); |
| 325 | for_each_cpu(cpu) |
| 326 | cpufreq_stats_free_table(cpu); |
| 327 | } |
| 328 | |
| 329 | MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>"); |
| 330 | MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats through sysfs filesystem"); |
| 331 | MODULE_LICENSE ("GPL"); |
| 332 | |
| 333 | module_init(cpufreq_stats_init); |
| 334 | module_exit(cpufreq_stats_exit); |