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 static 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
cpufreq_frequency_table_cpuinfo(struct cpufreq_policy * policy,struct cpufreq_frequency_table * table)31 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
32 struct cpufreq_frequency_table *table)
33 {
34 struct cpufreq_frequency_table *pos;
35 unsigned int min_freq = ~0;
36 unsigned int max_freq = 0;
37 unsigned int freq;
38
39 cpufreq_for_each_valid_entry(pos, table) {
40 freq = pos->frequency;
41
42 if ((!cpufreq_boost_enabled() || !policy->boost_enabled)
43 && (pos->flags & CPUFREQ_BOOST_FREQ))
44 continue;
45
46 pr_debug("table entry %u: %u kHz\n", (int)(pos - table), freq);
47 if (freq < min_freq)
48 min_freq = freq;
49 if (freq > max_freq)
50 max_freq = freq;
51 }
52
53 policy->min = policy->cpuinfo.min_freq = min_freq;
54 policy->max = max_freq;
55 /*
56 * If the driver has set its own cpuinfo.max_freq above max_freq, leave
57 * it as is.
58 */
59 if (policy->cpuinfo.max_freq < max_freq)
60 policy->max = policy->cpuinfo.max_freq = max_freq;
61
62 if (policy->min == ~0)
63 return -EINVAL;
64 else
65 return 0;
66 }
67
cpufreq_frequency_table_verify(struct cpufreq_policy_data * policy,struct cpufreq_frequency_table * table)68 int cpufreq_frequency_table_verify(struct cpufreq_policy_data *policy,
69 struct cpufreq_frequency_table *table)
70 {
71 struct cpufreq_frequency_table *pos;
72 unsigned int freq, prev_smaller = 0;
73 bool found = false;
74
75 pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
76 policy->min, policy->max, policy->cpu);
77
78 cpufreq_verify_within_cpu_limits(policy);
79
80 cpufreq_for_each_valid_entry(pos, table) {
81 freq = pos->frequency;
82
83 if ((freq >= policy->min) && (freq <= policy->max)) {
84 found = true;
85 break;
86 }
87
88 if ((prev_smaller < freq) && (freq <= policy->max))
89 prev_smaller = freq;
90 }
91
92 if (!found) {
93 policy->max = prev_smaller;
94 cpufreq_verify_within_cpu_limits(policy);
95 }
96
97 pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
98 policy->min, policy->max, policy->cpu);
99
100 return 0;
101 }
102 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
103
104 /*
105 * Generic routine to verify policy & frequency table, requires driver to set
106 * policy->freq_table prior to it.
107 */
cpufreq_generic_frequency_table_verify(struct cpufreq_policy_data * policy)108 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy_data *policy)
109 {
110 if (!policy->freq_table)
111 return -ENODEV;
112
113 return cpufreq_frequency_table_verify(policy, policy->freq_table);
114 }
115 EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
116
cpufreq_table_index_unsorted(struct cpufreq_policy * policy,unsigned int target_freq,unsigned int min,unsigned int max,unsigned int relation)117 int cpufreq_table_index_unsorted(struct cpufreq_policy *policy,
118 unsigned int target_freq, unsigned int min,
119 unsigned int max, unsigned int relation)
120 {
121 struct cpufreq_frequency_table optimal = {
122 .driver_data = ~0,
123 .frequency = 0,
124 };
125 struct cpufreq_frequency_table suboptimal = {
126 .driver_data = ~0,
127 .frequency = 0,
128 };
129 struct cpufreq_frequency_table *pos;
130 struct cpufreq_frequency_table *table = policy->freq_table;
131 unsigned int freq, diff, i = 0;
132 int index;
133
134 pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
135 target_freq, relation, policy->cpu);
136
137 switch (relation) {
138 case CPUFREQ_RELATION_H:
139 suboptimal.frequency = ~0;
140 break;
141 case CPUFREQ_RELATION_L:
142 case CPUFREQ_RELATION_C:
143 optimal.frequency = ~0;
144 break;
145 }
146
147 cpufreq_for_each_valid_entry_idx(pos, table, i) {
148 freq = pos->frequency;
149
150 if (freq < min || freq > 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: %u\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
cpufreq_frequency_table_get_index(struct cpufreq_policy * policy,unsigned int freq)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 int idx;
215
216 if (unlikely(!table)) {
217 pr_debug("%s: Unable to find frequency table\n", __func__);
218 return -ENOENT;
219 }
220
221 cpufreq_for_each_valid_entry_idx(pos, table, idx)
222 if (pos->frequency == freq)
223 return idx;
224
225 return -EINVAL;
226 }
227 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_index);
228
229 /*
230 * show_available_freqs - show available frequencies for the specified CPU
231 */
show_available_freqs(struct cpufreq_policy * policy,char * buf,bool show_boost)232 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf,
233 bool show_boost)
234 {
235 ssize_t count = 0;
236 struct cpufreq_frequency_table *pos, *table = policy->freq_table;
237
238 if (!table)
239 return -ENODEV;
240
241 cpufreq_for_each_valid_entry(pos, table) {
242 /*
243 * show_boost = true and driver_data = BOOST freq
244 * display BOOST freqs
245 *
246 * show_boost = false and driver_data = BOOST freq
247 * show_boost = true and driver_data != BOOST freq
248 * continue - do not display anything
249 *
250 * show_boost = false and driver_data != BOOST freq
251 * display NON BOOST freqs
252 */
253 if (show_boost ^ (pos->flags & CPUFREQ_BOOST_FREQ))
254 continue;
255
256 count += sprintf(&buf[count], "%u ", pos->frequency);
257 }
258 count += sprintf(&buf[count], "\n");
259
260 return count;
261
262 }
263
264 #define cpufreq_attr_available_freq(_name) \
265 struct freq_attr cpufreq_freq_attr_##_name##_freqs = \
266 __ATTR_RO(_name##_frequencies)
267
268 /*
269 * scaling_available_frequencies_show - show available normal frequencies for
270 * the specified CPU
271 */
scaling_available_frequencies_show(struct cpufreq_policy * policy,char * buf)272 static ssize_t scaling_available_frequencies_show(struct cpufreq_policy *policy,
273 char *buf)
274 {
275 return show_available_freqs(policy, buf, false);
276 }
277 cpufreq_attr_available_freq(scaling_available);
278
279 /*
280 * scaling_boost_frequencies_show - show available boost frequencies for
281 * the specified CPU
282 */
scaling_boost_frequencies_show(struct cpufreq_policy * policy,char * buf)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
set_freq_table_sorted(struct cpufreq_policy * policy)290 static int set_freq_table_sorted(struct cpufreq_policy *policy)
291 {
292 struct cpufreq_frequency_table *pos, *table = policy->freq_table;
293 struct cpufreq_frequency_table *prev = NULL;
294 int ascending = 0;
295
296 policy->freq_table_sorted = CPUFREQ_TABLE_UNSORTED;
297
298 cpufreq_for_each_valid_entry(pos, table) {
299 if (!prev) {
300 prev = pos;
301 continue;
302 }
303
304 if (pos->frequency == prev->frequency) {
305 pr_warn("Duplicate freq-table entries: %u\n",
306 pos->frequency);
307 return -EINVAL;
308 }
309
310 /* Frequency increased from prev to pos */
311 if (pos->frequency > prev->frequency) {
312 /* But frequency was decreasing earlier */
313 if (ascending < 0) {
314 pr_debug("Freq table is unsorted\n");
315 return 0;
316 }
317
318 ascending++;
319 } else {
320 /* Frequency decreased from prev to pos */
321
322 /* But frequency was increasing earlier */
323 if (ascending > 0) {
324 pr_debug("Freq table is unsorted\n");
325 return 0;
326 }
327
328 ascending--;
329 }
330
331 prev = pos;
332 }
333
334 if (ascending > 0)
335 policy->freq_table_sorted = CPUFREQ_TABLE_SORTED_ASCENDING;
336 else
337 policy->freq_table_sorted = CPUFREQ_TABLE_SORTED_DESCENDING;
338
339 pr_debug("Freq table is sorted in %s order\n",
340 ascending > 0 ? "ascending" : "descending");
341
342 return 0;
343 }
344
cpufreq_table_validate_and_sort(struct cpufreq_policy * policy)345 int cpufreq_table_validate_and_sort(struct cpufreq_policy *policy)
346 {
347 int ret;
348
349 if (!policy->freq_table) {
350 /* Freq table must be passed by drivers with target_index() */
351 if (has_target_index())
352 return -EINVAL;
353
354 return 0;
355 }
356
357 ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
358 if (ret)
359 return ret;
360
361 /* Driver's may have set this field already */
362 if (policy_has_boost_freq(policy))
363 policy->boost_supported = true;
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