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/cpu.h> 13 #include <linux/cpufreq.h> 14 #include <linux/module.h> 15 #include <linux/slab.h> 16 17 18 struct cpufreq_stats { 19 unsigned int total_trans; 20 unsigned long long last_time; 21 unsigned int max_state; 22 unsigned int state_num; 23 unsigned int last_index; 24 u64 *time_in_state; 25 spinlock_t lock; 26 unsigned int *freq_table; 27 unsigned int *trans_table; 28 }; 29 30 static void cpufreq_stats_update(struct cpufreq_stats *stats) 31 { 32 unsigned long long cur_time = get_jiffies_64(); 33 34 stats->time_in_state[stats->last_index] += cur_time - stats->last_time; 35 stats->last_time = cur_time; 36 } 37 38 static void cpufreq_stats_clear_table(struct cpufreq_stats *stats) 39 { 40 unsigned int count = stats->max_state; 41 42 spin_lock(&stats->lock); 43 memset(stats->time_in_state, 0, count * sizeof(u64)); 44 memset(stats->trans_table, 0, count * count * sizeof(int)); 45 stats->last_time = get_jiffies_64(); 46 stats->total_trans = 0; 47 spin_unlock(&stats->lock); 48 } 49 50 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) 51 { 52 return sprintf(buf, "%d\n", policy->stats->total_trans); 53 } 54 cpufreq_freq_attr_ro(total_trans); 55 56 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) 57 { 58 struct cpufreq_stats *stats = policy->stats; 59 ssize_t len = 0; 60 int i; 61 62 if (policy->fast_switch_enabled) 63 return 0; 64 65 spin_lock(&stats->lock); 66 cpufreq_stats_update(stats); 67 spin_unlock(&stats->lock); 68 69 for (i = 0; i < stats->state_num; i++) { 70 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i], 71 (unsigned long long) 72 jiffies_64_to_clock_t(stats->time_in_state[i])); 73 } 74 return len; 75 } 76 cpufreq_freq_attr_ro(time_in_state); 77 78 static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf, 79 size_t count) 80 { 81 /* We don't care what is written to the attribute. */ 82 cpufreq_stats_clear_table(policy->stats); 83 return count; 84 } 85 cpufreq_freq_attr_wo(reset); 86 87 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf) 88 { 89 struct cpufreq_stats *stats = policy->stats; 90 ssize_t len = 0; 91 int i, j; 92 93 if (policy->fast_switch_enabled) 94 return 0; 95 96 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); 97 len += snprintf(buf + len, PAGE_SIZE - len, " : "); 98 for (i = 0; i < stats->state_num; i++) { 99 if (len >= PAGE_SIZE) 100 break; 101 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 102 stats->freq_table[i]); 103 } 104 if (len >= PAGE_SIZE) 105 return PAGE_SIZE; 106 107 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 108 109 for (i = 0; i < stats->state_num; i++) { 110 if (len >= PAGE_SIZE) 111 break; 112 113 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", 114 stats->freq_table[i]); 115 116 for (j = 0; j < stats->state_num; j++) { 117 if (len >= PAGE_SIZE) 118 break; 119 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 120 stats->trans_table[i*stats->max_state+j]); 121 } 122 if (len >= PAGE_SIZE) 123 break; 124 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 125 } 126 127 if (len >= PAGE_SIZE) { 128 pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n"); 129 return -EFBIG; 130 } 131 return len; 132 } 133 cpufreq_freq_attr_ro(trans_table); 134 135 static struct attribute *default_attrs[] = { 136 &total_trans.attr, 137 &time_in_state.attr, 138 &reset.attr, 139 &trans_table.attr, 140 NULL 141 }; 142 static const struct attribute_group stats_attr_group = { 143 .attrs = default_attrs, 144 .name = "stats" 145 }; 146 147 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq) 148 { 149 int index; 150 for (index = 0; index < stats->max_state; index++) 151 if (stats->freq_table[index] == freq) 152 return index; 153 return -1; 154 } 155 156 void cpufreq_stats_free_table(struct cpufreq_policy *policy) 157 { 158 struct cpufreq_stats *stats = policy->stats; 159 160 /* Already freed */ 161 if (!stats) 162 return; 163 164 pr_debug("%s: Free stats table\n", __func__); 165 166 sysfs_remove_group(&policy->kobj, &stats_attr_group); 167 kfree(stats->time_in_state); 168 kfree(stats); 169 policy->stats = NULL; 170 } 171 172 void cpufreq_stats_create_table(struct cpufreq_policy *policy) 173 { 174 unsigned int i = 0, count = 0, ret = -ENOMEM; 175 struct cpufreq_stats *stats; 176 unsigned int alloc_size; 177 struct cpufreq_frequency_table *pos; 178 179 count = cpufreq_table_count_valid_entries(policy); 180 if (!count) 181 return; 182 183 /* stats already initialized */ 184 if (policy->stats) 185 return; 186 187 stats = kzalloc(sizeof(*stats), GFP_KERNEL); 188 if (!stats) 189 return; 190 191 alloc_size = count * sizeof(int) + count * sizeof(u64); 192 193 alloc_size += count * count * sizeof(int); 194 195 /* Allocate memory for time_in_state/freq_table/trans_table in one go */ 196 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL); 197 if (!stats->time_in_state) 198 goto free_stat; 199 200 stats->freq_table = (unsigned int *)(stats->time_in_state + count); 201 202 stats->trans_table = stats->freq_table + count; 203 204 stats->max_state = count; 205 206 /* Find valid-unique entries */ 207 cpufreq_for_each_valid_entry(pos, policy->freq_table) 208 if (freq_table_get_index(stats, pos->frequency) == -1) 209 stats->freq_table[i++] = pos->frequency; 210 211 stats->state_num = i; 212 stats->last_time = get_jiffies_64(); 213 stats->last_index = freq_table_get_index(stats, policy->cur); 214 spin_lock_init(&stats->lock); 215 216 policy->stats = stats; 217 ret = sysfs_create_group(&policy->kobj, &stats_attr_group); 218 if (!ret) 219 return; 220 221 /* We failed, release resources */ 222 policy->stats = NULL; 223 kfree(stats->time_in_state); 224 free_stat: 225 kfree(stats); 226 } 227 228 void cpufreq_stats_record_transition(struct cpufreq_policy *policy, 229 unsigned int new_freq) 230 { 231 struct cpufreq_stats *stats = policy->stats; 232 int old_index, new_index; 233 234 if (!stats) { 235 pr_debug("%s: No stats found\n", __func__); 236 return; 237 } 238 239 old_index = stats->last_index; 240 new_index = freq_table_get_index(stats, new_freq); 241 242 /* We can't do stats->time_in_state[-1]= .. */ 243 if (old_index == -1 || new_index == -1 || old_index == new_index) 244 return; 245 246 spin_lock(&stats->lock); 247 cpufreq_stats_update(stats); 248 249 stats->last_index = new_index; 250 stats->trans_table[old_index * stats->max_state + new_index]++; 251 stats->total_trans++; 252 spin_unlock(&stats->lock); 253 } 254