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