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 
policy_has_boost_freq(struct cpufreq_policy * policy)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 
cpufreq_frequency_table_cpuinfo(struct cpufreq_policy * policy,struct cpufreq_frequency_table * table)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 
cpufreq_frequency_table_verify(struct cpufreq_policy * policy,struct cpufreq_frequency_table * table)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  */
cpufreq_generic_frequency_table_verify(struct cpufreq_policy * policy)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 
cpufreq_table_index_unsorted(struct cpufreq_policy * policy,unsigned int target_freq,unsigned int relation)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_idx(pos, table, i) {
147 		freq = pos->frequency;
148 
149 		if ((freq < policy->min) || (freq > policy->max))
150 			continue;
151 		if (freq == target_freq) {
152 			optimal.driver_data = i;
153 			break;
154 		}
155 		switch (relation) {
156 		case CPUFREQ_RELATION_H:
157 			if (freq < target_freq) {
158 				if (freq >= optimal.frequency) {
159 					optimal.frequency = freq;
160 					optimal.driver_data = i;
161 				}
162 			} else {
163 				if (freq <= suboptimal.frequency) {
164 					suboptimal.frequency = freq;
165 					suboptimal.driver_data = i;
166 				}
167 			}
168 			break;
169 		case CPUFREQ_RELATION_L:
170 			if (freq > target_freq) {
171 				if (freq <= optimal.frequency) {
172 					optimal.frequency = freq;
173 					optimal.driver_data = i;
174 				}
175 			} else {
176 				if (freq >= suboptimal.frequency) {
177 					suboptimal.frequency = freq;
178 					suboptimal.driver_data = i;
179 				}
180 			}
181 			break;
182 		case CPUFREQ_RELATION_C:
183 			diff = abs(freq - target_freq);
184 			if (diff < optimal.frequency ||
185 			    (diff == optimal.frequency &&
186 			     freq > table[optimal.driver_data].frequency)) {
187 				optimal.frequency = diff;
188 				optimal.driver_data = i;
189 			}
190 			break;
191 		}
192 	}
193 	if (optimal.driver_data > i) {
194 		if (suboptimal.driver_data > i) {
195 			WARN(1, "Invalid frequency table: %d\n", policy->cpu);
196 			return 0;
197 		}
198 
199 		index = suboptimal.driver_data;
200 	} else
201 		index = optimal.driver_data;
202 
203 	pr_debug("target index is %u, freq is:%u kHz\n", index,
204 		 table[index].frequency);
205 	return index;
206 }
207 EXPORT_SYMBOL_GPL(cpufreq_table_index_unsorted);
208 
cpufreq_frequency_table_get_index(struct cpufreq_policy * policy,unsigned int freq)209 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
210 		unsigned int freq)
211 {
212 	struct cpufreq_frequency_table *pos, *table = policy->freq_table;
213 	int idx;
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_idx(pos, table, idx)
221 		if (pos->frequency == freq)
222 			return idx;
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  */
show_available_freqs(struct cpufreq_policy * policy,char * buf,bool show_boost)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  */
scaling_available_frequencies_show(struct cpufreq_policy * policy,char * buf)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  */
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 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 
set_freq_table_sorted(struct cpufreq_policy * policy)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 
cpufreq_table_validate_and_sort(struct cpufreq_policy * policy)355 int cpufreq_table_validate_and_sort(struct cpufreq_policy *policy)
356 {
357 	int ret;
358 
359 	if (!policy->freq_table)
360 		return 0;
361 
362 	ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
363 	if (ret)
364 		return ret;
365 
366 	return set_freq_table_sorted(policy);
367 }
368 
369 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
370 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
371 MODULE_LICENSE("GPL");
372