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
policy_has_boost_freq(struct cpufreq_policy * policy)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
cpufreq_frequency_table_cpuinfo(struct cpufreq_policy * policy,struct cpufreq_frequency_table * table)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
cpufreq_frequency_table_verify(struct cpufreq_policy_data * policy,struct cpufreq_frequency_table * table)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 */
cpufreq_generic_frequency_table_verify(struct cpufreq_policy_data * policy)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
cpufreq_table_index_unsorted(struct cpufreq_policy * policy,unsigned int target_freq,unsigned int relation)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
cpufreq_frequency_table_get_index(struct cpufreq_policy * policy,unsigned int freq)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 */
show_available_freqs(struct cpufreq_policy * policy,char * buf,bool show_boost)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 */
scaling_available_frequencies_show(struct cpufreq_policy * policy,char * buf)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 */
scaling_boost_frequencies_show(struct cpufreq_policy * policy,char * buf)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
set_freq_table_sorted(struct cpufreq_policy * policy)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
cpufreq_table_validate_and_sort(struct cpufreq_policy * policy)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");
375