drivers/cpufreq/freq_table.c

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