GNU Linux-libre 5.19-rc6-gnu
[releases.git] / 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                 return 0;
360
361         ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
362         if (ret)
363                 return ret;
364
365         return set_freq_table_sorted(policy);
366 }
367
368 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
369 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
370 MODULE_LICENSE("GPL");