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