drivers/cpufreq/freq_table.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/drivers/cpufreq/freq_table.c
   4  *
   5  * Copyright (C) 2002 - 2003 Dominik Brodowski
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/cpufreq.h>
  11 #include <linux/module.h>
  12
  13 /*********************************************************************
  14  *                     FREQUENCY TABLE HELPERS                       *
  15  *********************************************************************/
  16
  17 bool policy_has_boost_freq(struct cpufreq_policy *policy)
  18 {
  19         struct cpufreq_frequency_table *pos, *table = policy->freq_table;
  20
  21         if (!table)
  22                 return false;
  23
  24         cpufreq_for_each_valid_entry(pos, table)
  25                 if (pos->flags & CPUFREQ_BOOST_FREQ)
  26                         return true;
  27
  28         return false;
  29 }
  30 EXPORT_SYMBOL_GPL(policy_has_boost_freq);
  31
  32 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
  33                                     struct cpufreq_frequency_table *table)
  34 {
  35         struct cpufreq_frequency_table *pos;
  36         unsigned int min_freq = ~0;
  37         unsigned int max_freq = 0;
  38         unsigned int freq;
  39
  40         cpufreq_for_each_valid_entry(pos, table) {
  41                 freq = pos->frequency;
  42
  43                 if (!cpufreq_boost_enabled()
  44                     && (pos->flags & CPUFREQ_BOOST_FREQ))
  45                         continue;
  46
  47                 pr_debug("table entry %u: %u kHz\n", (int)(pos - table), freq);
  48                 if (freq < min_freq)
  49                         min_freq = freq;
  50                 if (freq > max_freq)
  51                         max_freq = freq;
  52         }
  53
  54         policy->min = policy->cpuinfo.min_freq = min_freq;
  55         policy->max = max_freq;
  56         /*
  57          * If the driver has set its own cpuinfo.max_freq above max_freq, leave
  58          * it as is.
  59          */
  60         if (policy->cpuinfo.max_freq < max_freq)
  61                 policy->max = policy->cpuinfo.max_freq = max_freq;
  62
  63         if (policy->min == ~0)
  64                 return -EINVAL;
  65         else
  66                 return 0;
  67 }
  68
  69 int cpufreq_frequency_table_verify(struct cpufreq_policy_data *policy,
  70                                    struct cpufreq_frequency_table *table)
  71 {
  72         struct cpufreq_frequency_table *pos;
  73         unsigned int freq, next_larger = ~0;
  74         bool found = false;
  75
  76         pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
  77                                         policy->min, policy->max, policy->cpu);
  78
  79         cpufreq_verify_within_cpu_limits(policy);
  80
  81         cpufreq_for_each_valid_entry(pos, table) {
  82                 freq = pos->frequency;
  83
  84                 if ((freq >= policy->min) && (freq <= policy->max)) {
  85                         found = true;
  86                         break;
  87                 }
  88
  89                 if ((next_larger > freq) && (freq > policy->max))
  90                         next_larger = freq;
  91         }
  92
  93         if (!found) {
  94                 policy->max = next_larger;
  95                 cpufreq_verify_within_cpu_limits(policy);
  96         }
  97
  98         pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
  99                                 policy->min, policy->max, policy->cpu);
 100
 101         return 0;
 102 }
 103 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
 104
 105 /*
 106  * Generic routine to verify policy & frequency table, requires driver to set
 107  * policy->freq_table prior to it.
 108  */
 109 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy_data *policy)
 110 {
 111         if (!policy->freq_table)
 112                 return -ENODEV;
 113
 114         return cpufreq_frequency_table_verify(policy, policy->freq_table);
 115 }
 116 EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
 117
 118 int cpufreq_table_index_unsorted(struct cpufreq_policy *policy,
 119                                  unsigned int target_freq,
 120                                  unsigned int relation)
 121 {
 122         struct cpufreq_frequency_table optimal = {
 123                 .driver_data = ~0,
 124                 .frequency = 0,
 125         };
 126         struct cpufreq_frequency_table suboptimal = {
 127                 .driver_data = ~0,
 128                 .frequency = 0,
 129         };
 130         struct cpufreq_frequency_table *pos;
 131         struct cpufreq_frequency_table *table = policy->freq_table;
 132         unsigned int freq, diff, i = 0;
 133         int index;
 134
 135         pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
 136                                         target_freq, relation, policy->cpu);
 137
 138         switch (relation) {
 139         case CPUFREQ_RELATION_H:
 140                 suboptimal.frequency = ~0;
 141                 break;
 142         case CPUFREQ_RELATION_L:
 143         case CPUFREQ_RELATION_C:
 144                 optimal.frequency = ~0;
 145                 break;
 146         }
 147
 148         cpufreq_for_each_valid_entry_idx(pos, table, i) {
 149                 freq = pos->frequency;
 150
 151                 if ((freq < policy->min) || (freq > policy->max))
 152                         continue;
 153                 if (freq == target_freq) {
 154                         optimal.driver_data = i;
 155                         break;
 156                 }
 157                 switch (relation) {
 158                 case CPUFREQ_RELATION_H:
 159                         if (freq < target_freq) {
 160                                 if (freq >= optimal.frequency) {
 161                                         optimal.frequency = freq;
 162                                         optimal.driver_data = i;
 163                                 }
 164                         } else {
 165                                 if (freq <= suboptimal.frequency) {
 166                                         suboptimal.frequency = freq;
 167                                         suboptimal.driver_data = i;
 168                                 }
 169                         }
 170                         break;
 171                 case CPUFREQ_RELATION_L:
 172                         if (freq > target_freq) {
 173                                 if (freq <= optimal.frequency) {
 174                                         optimal.frequency = freq;
 175                                         optimal.driver_data = i;
 176                                 }
 177                         } else {
 178                                 if (freq >= suboptimal.frequency) {
 179                                         suboptimal.frequency = freq;
 180                                         suboptimal.driver_data = i;
 181                                 }
 182                         }
 183                         break;
 184                 case CPUFREQ_RELATION_C:
 185                         diff = abs(freq - target_freq);
 186                         if (diff < optimal.frequency ||
 187                             (diff == optimal.frequency &&
 188                              freq > table[optimal.driver_data].frequency)) {
 189                                 optimal.frequency = diff;
 190                                 optimal.driver_data = i;
 191                         }
 192                         break;
 193                 }
 194         }
 195         if (optimal.driver_data > i) {
 196                 if (suboptimal.driver_data > i) {
 197                         WARN(1, "Invalid frequency table: %d\n", policy->cpu);
 198                         return 0;
 199                 }
 200
 201                 index = suboptimal.driver_data;
 202         } else
 203                 index = optimal.driver_data;
 204
 205         pr_debug("target index is %u, freq is:%u kHz\n", index,
 206                  table[index].frequency);
 207         return index;
 208 }
 209 EXPORT_SYMBOL_GPL(cpufreq_table_index_unsorted);
 210
 211 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 212                 unsigned int freq)
 213 {
 214         struct cpufreq_frequency_table *pos, *table = policy->freq_table;
 215         int idx;
 216
 217         if (unlikely(!table)) {
 218                 pr_debug("%s: Unable to find frequency table\n", __func__);
 219                 return -ENOENT;
 220         }
 221
 222         cpufreq_for_each_valid_entry_idx(pos, table, idx)
 223                 if (pos->frequency == freq)
 224                         return idx;
 225
 226         return -EINVAL;
 227 }
 228 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_index);
 229
 230 /*
 231  * show_available_freqs - show available frequencies for the specified CPU
 232  */
 233 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf,
 234                                     bool show_boost)
 235 {
 236         ssize_t count = 0;
 237         struct cpufreq_frequency_table *pos, *table = policy->freq_table;
 238
 239         if (!table)
 240                 return -ENODEV;
 241
 242         cpufreq_for_each_valid_entry(pos, table) {
 243                 /*
 244                  * show_boost = true and driver_data = BOOST freq
 245                  * display BOOST freqs
 246                  *
 247                  * show_boost = false and driver_data = BOOST freq
 248                  * show_boost = true and driver_data != BOOST freq
 249                  * continue - do not display anything
 250                  *
 251                  * show_boost = false and driver_data != BOOST freq
 252                  * display NON BOOST freqs
 253                  */
 254                 if (show_boost ^ (pos->flags & CPUFREQ_BOOST_FREQ))
 255                         continue;
 256
 257                 count += sprintf(&buf[count], "%d ", pos->frequency);
 258         }
 259         count += sprintf(&buf[count], "\n");
 260
 261         return count;
 262
 263 }
 264
 265 #define cpufreq_attr_available_freq(_name)        \
 266 struct freq_attr cpufreq_freq_attr_##_name##_freqs =     \
 267 __ATTR_RO(_name##_frequencies)
 268
 269 /*
 270  * scaling_available_frequencies_show - show available normal frequencies for
 271  * the specified CPU
 272  */
 273 static ssize_t scaling_available_frequencies_show(struct cpufreq_policy *policy,
 274                                                   char *buf)
 275 {
 276         return show_available_freqs(policy, buf, false);
 277 }
 278 cpufreq_attr_available_freq(scaling_available);
 279 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
 280
 281 /*
 282  * scaling_boost_frequencies_show - show available boost frequencies for
 283  * the specified CPU
 284  */
 285 static ssize_t scaling_boost_frequencies_show(struct cpufreq_policy *policy,
 286                                               char *buf)
 287 {
 288         return show_available_freqs(policy, buf, true);
 289 }
 290 cpufreq_attr_available_freq(scaling_boost);
 291 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_boost_freqs);
 292
 293 struct freq_attr *cpufreq_generic_attr[] = {
 294         &cpufreq_freq_attr_scaling_available_freqs,
 295         NULL,
 296 };
 297 EXPORT_SYMBOL_GPL(cpufreq_generic_attr);
 298
 299 static int set_freq_table_sorted(struct cpufreq_policy *policy)
 300 {
 301         struct cpufreq_frequency_table *pos, *table = policy->freq_table;
 302         struct cpufreq_frequency_table *prev = NULL;
 303         int ascending = 0;
 304
 305         policy->freq_table_sorted = CPUFREQ_TABLE_UNSORTED;
 306
 307         cpufreq_for_each_valid_entry(pos, table) {
 308                 if (!prev) {
 309                         prev = pos;
 310                         continue;
 311                 }
 312
 313                 if (pos->frequency == prev->frequency) {
 314                         pr_warn("Duplicate freq-table entries: %u\n",
 315                                 pos->frequency);
 316                         return -EINVAL;
 317                 }
 318
 319                 /* Frequency increased from prev to pos */
 320                 if (pos->frequency > prev->frequency) {
 321                         /* But frequency was decreasing earlier */
 322                         if (ascending < 0) {
 323                                 pr_debug("Freq table is unsorted\n");
 324                                 return 0;
 325                         }
 326
 327                         ascending++;
 328                 } else {
 329                         /* Frequency decreased from prev to pos */
 330
 331                         /* But frequency was increasing earlier */
 332                         if (ascending > 0) {
 333                                 pr_debug("Freq table is unsorted\n");
 334                                 return 0;
 335                         }
 336
 337                         ascending--;
 338                 }
 339
 340                 prev = pos;
 341         }
 342
 343         if (ascending > 0)
 344                 policy->freq_table_sorted = CPUFREQ_TABLE_SORTED_ASCENDING;
 345         else
 346                 policy->freq_table_sorted = CPUFREQ_TABLE_SORTED_DESCENDING;
 347
 348         pr_debug("Freq table is sorted in %s order\n",
 349                  ascending > 0 ? "ascending" : "descending");
 350
 351         return 0;
 352 }
 353
 354 int cpufreq_table_validate_and_sort(struct cpufreq_policy *policy)
 355 {
 356         int ret;
 357
 358         if (!policy->freq_table) {
 359                 /* Freq table must be passed by drivers with target_index() */
 360                 if (has_target_index())
 361                         return -EINVAL;
 362
 363                 return 0;
 364         }
 365
 366         ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
 367         if (ret)
 368                 return ret;
 369
 370         return set_freq_table_sorted(policy);
 371 }
 372
 373 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
 374 MODULE_DESCRIPTION("CPUfreq frequency table helpers");