1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * drivers/cpufreq/cpufreq_stats.c 4 * 5 * Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>. 6 * (C) 2004 Zou Nan hai <nanhai.zou@intel.com>. 7 */ 8 9 #include <linux/cpu.h> 10 #include <linux/cpufreq.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 14 15 struct cpufreq_stats { 16 unsigned int total_trans; 17 unsigned long long last_time; 18 unsigned int max_state; 19 unsigned int state_num; 20 unsigned int last_index; 21 u64 *time_in_state; 22 spinlock_t lock; 23 unsigned int *freq_table; 24 unsigned int *trans_table; 25 }; 26 27 static void cpufreq_stats_update(struct cpufreq_stats *stats) 28 { 29 unsigned long long cur_time = get_jiffies_64(); 30 31 stats->time_in_state[stats->last_index] += cur_time - stats->last_time; 32 stats->last_time = cur_time; 33 } 34 35 static void cpufreq_stats_clear_table(struct cpufreq_stats *stats) 36 { 37 unsigned int count = stats->max_state; 38 39 spin_lock(&stats->lock); 40 memset(stats->time_in_state, 0, count * sizeof(u64)); 41 memset(stats->trans_table, 0, count * count * sizeof(int)); 42 stats->last_time = get_jiffies_64(); 43 stats->total_trans = 0; 44 spin_unlock(&stats->lock); 45 } 46 47 static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf) 48 { 49 return sprintf(buf, "%d\n", policy->stats->total_trans); 50 } 51 cpufreq_freq_attr_ro(total_trans); 52 53 static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf) 54 { 55 struct cpufreq_stats *stats = policy->stats; 56 ssize_t len = 0; 57 int i; 58 59 if (policy->fast_switch_enabled) 60 return 0; 61 62 spin_lock(&stats->lock); 63 cpufreq_stats_update(stats); 64 spin_unlock(&stats->lock); 65 66 for (i = 0; i < stats->state_num; i++) { 67 len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i], 68 (unsigned long long) 69 jiffies_64_to_clock_t(stats->time_in_state[i])); 70 } 71 return len; 72 } 73 cpufreq_freq_attr_ro(time_in_state); 74 75 static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf, 76 size_t count) 77 { 78 /* We don't care what is written to the attribute. */ 79 cpufreq_stats_clear_table(policy->stats); 80 return count; 81 } 82 cpufreq_freq_attr_wo(reset); 83 84 static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf) 85 { 86 struct cpufreq_stats *stats = policy->stats; 87 ssize_t len = 0; 88 int i, j; 89 90 if (policy->fast_switch_enabled) 91 return 0; 92 93 len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n"); 94 len += snprintf(buf + len, PAGE_SIZE - len, " : "); 95 for (i = 0; i < stats->state_num; i++) { 96 if (len >= PAGE_SIZE) 97 break; 98 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 99 stats->freq_table[i]); 100 } 101 if (len >= PAGE_SIZE) 102 return PAGE_SIZE; 103 104 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 105 106 for (i = 0; i < stats->state_num; i++) { 107 if (len >= PAGE_SIZE) 108 break; 109 110 len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ", 111 stats->freq_table[i]); 112 113 for (j = 0; j < stats->state_num; j++) { 114 if (len >= PAGE_SIZE) 115 break; 116 len += snprintf(buf + len, PAGE_SIZE - len, "%9u ", 117 stats->trans_table[i*stats->max_state+j]); 118 } 119 if (len >= PAGE_SIZE) 120 break; 121 len += snprintf(buf + len, PAGE_SIZE - len, "\n"); 122 } 123 124 if (len >= PAGE_SIZE) { 125 pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n"); 126 return -EFBIG; 127 } 128 return len; 129 } 130 cpufreq_freq_attr_ro(trans_table); 131 132 static struct attribute *default_attrs[] = { 133 &total_trans.attr, 134 &time_in_state.attr, 135 &reset.attr, 136 &trans_table.attr, 137 NULL 138 }; 139 static const struct attribute_group stats_attr_group = { 140 .attrs = default_attrs, 141 .name = "stats" 142 }; 143 144 static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq) 145 { 146 int index; 147 for (index = 0; index < stats->max_state; index++) 148 if (stats->freq_table[index] == freq) 149 return index; 150 return -1; 151 } 152 153 void cpufreq_stats_free_table(struct cpufreq_policy *policy) 154 { 155 struct cpufreq_stats *stats = policy->stats; 156 157 /* Already freed */ 158 if (!stats) 159 return; 160 161 pr_debug("%s: Free stats table\n", __func__); 162 163 sysfs_remove_group(&policy->kobj, &stats_attr_group); 164 kfree(stats->time_in_state); 165 kfree(stats); 166 policy->stats = NULL; 167 } 168 169 void cpufreq_stats_create_table(struct cpufreq_policy *policy) 170 { 171 unsigned int i = 0, count = 0, ret = -ENOMEM; 172 struct cpufreq_stats *stats; 173 unsigned int alloc_size; 174 struct cpufreq_frequency_table *pos; 175 176 count = cpufreq_table_count_valid_entries(policy); 177 if (!count) 178 return; 179 180 /* stats already initialized */ 181 if (policy->stats) 182 return; 183 184 stats = kzalloc(sizeof(*stats), GFP_KERNEL); 185 if (!stats) 186 return; 187 188 alloc_size = count * sizeof(int) + count * sizeof(u64); 189 190 alloc_size += count * count * sizeof(int); 191 192 /* Allocate memory for time_in_state/freq_table/trans_table in one go */ 193 stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL); 194 if (!stats->time_in_state) 195 goto free_stat; 196 197 stats->freq_table = (unsigned int *)(stats->time_in_state + count); 198 199 stats->trans_table = stats->freq_table + count; 200 201 stats->max_state = count; 202 203 /* Find valid-unique entries */ 204 cpufreq_for_each_valid_entry(pos, policy->freq_table) 205 if (freq_table_get_index(stats, pos->frequency) == -1) 206 stats->freq_table[i++] = pos->frequency; 207 208 stats->state_num = i; 209 stats->last_time = get_jiffies_64(); 210 stats->last_index = freq_table_get_index(stats, policy->cur); 211 spin_lock_init(&stats->lock); 212 213 policy->stats = stats; 214 ret = sysfs_create_group(&policy->kobj, &stats_attr_group); 215 if (!ret) 216 return; 217 218 /* We failed, release resources */ 219 policy->stats = NULL; 220 kfree(stats->time_in_state); 221 free_stat: 222 kfree(stats); 223 } 224 225 void cpufreq_stats_record_transition(struct cpufreq_policy *policy, 226 unsigned int new_freq) 227 { 228 struct cpufreq_stats *stats = policy->stats; 229 int old_index, new_index; 230 231 if (!stats) { 232 pr_debug("%s: No stats found\n", __func__); 233 return; 234 } 235 236 old_index = stats->last_index; 237 new_index = freq_table_get_index(stats, new_freq); 238 239 /* We can't do stats->time_in_state[-1]= .. */ 240 if (old_index == -1 || new_index == -1 || old_index == new_index) 241 return; 242 243 spin_lock(&stats->lock); 244 cpufreq_stats_update(stats); 245 246 stats->last_index = new_index; 247 stats->trans_table[old_index * stats->max_state + new_index]++; 248 stats->total_trans++; 249 spin_unlock(&stats->lock); 250 } 251