xref: /openbmc/linux/drivers/cpufreq/freq_table.c (revision 37be287c)
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 
21 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
22 				    struct cpufreq_frequency_table *table)
23 {
24 	unsigned int min_freq = ~0;
25 	unsigned int max_freq = 0;
26 	unsigned int i;
27 
28 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
29 		unsigned int freq = table[i].frequency;
30 		if (freq == CPUFREQ_ENTRY_INVALID) {
31 			pr_debug("table entry %u is invalid, skipping\n", i);
32 
33 			continue;
34 		}
35 		if (!cpufreq_boost_enabled()
36 		    && table[i].driver_data == CPUFREQ_BOOST_FREQ)
37 			continue;
38 
39 		pr_debug("table entry %u: %u kHz, %u driver_data\n",
40 					i, freq, table[i].driver_data);
41 		if (freq < min_freq)
42 			min_freq = freq;
43 		if (freq > max_freq)
44 			max_freq = freq;
45 	}
46 
47 	policy->min = policy->cpuinfo.min_freq = min_freq;
48 	policy->max = policy->cpuinfo.max_freq = max_freq;
49 
50 	if (policy->min == ~0)
51 		return -EINVAL;
52 	else
53 		return 0;
54 }
55 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
56 
57 
58 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
59 				   struct cpufreq_frequency_table *table)
60 {
61 	unsigned int next_larger = ~0, freq, i = 0;
62 	bool found = false;
63 
64 	pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
65 					policy->min, policy->max, policy->cpu);
66 
67 	cpufreq_verify_within_cpu_limits(policy);
68 
69 	for (; freq = table[i].frequency, freq != CPUFREQ_TABLE_END; i++) {
70 		if (freq == CPUFREQ_ENTRY_INVALID)
71 			continue;
72 		if ((freq >= policy->min) && (freq <= policy->max)) {
73 			found = true;
74 			break;
75 		}
76 
77 		if ((next_larger > freq) && (freq > policy->max))
78 			next_larger = freq;
79 	}
80 
81 	if (!found) {
82 		policy->max = next_larger;
83 		cpufreq_verify_within_cpu_limits(policy);
84 	}
85 
86 	pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
87 				policy->min, policy->max, policy->cpu);
88 
89 	return 0;
90 }
91 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
92 
93 /*
94  * Generic routine to verify policy & frequency table, requires driver to call
95  * cpufreq_frequency_table_get_attr() prior to it.
96  */
97 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy)
98 {
99 	struct cpufreq_frequency_table *table =
100 		cpufreq_frequency_get_table(policy->cpu);
101 	if (!table)
102 		return -ENODEV;
103 
104 	return cpufreq_frequency_table_verify(policy, table);
105 }
106 EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
107 
108 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
109 				   struct cpufreq_frequency_table *table,
110 				   unsigned int target_freq,
111 				   unsigned int relation,
112 				   unsigned int *index)
113 {
114 	struct cpufreq_frequency_table optimal = {
115 		.driver_data = ~0,
116 		.frequency = 0,
117 	};
118 	struct cpufreq_frequency_table suboptimal = {
119 		.driver_data = ~0,
120 		.frequency = 0,
121 	};
122 	unsigned int i;
123 
124 	pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
125 					target_freq, relation, policy->cpu);
126 
127 	switch (relation) {
128 	case CPUFREQ_RELATION_H:
129 		suboptimal.frequency = ~0;
130 		break;
131 	case CPUFREQ_RELATION_L:
132 		optimal.frequency = ~0;
133 		break;
134 	}
135 
136 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
137 		unsigned int freq = table[i].frequency;
138 		if (freq == CPUFREQ_ENTRY_INVALID)
139 			continue;
140 		if ((freq < policy->min) || (freq > policy->max))
141 			continue;
142 		switch (relation) {
143 		case CPUFREQ_RELATION_H:
144 			if (freq <= target_freq) {
145 				if (freq >= optimal.frequency) {
146 					optimal.frequency = freq;
147 					optimal.driver_data = i;
148 				}
149 			} else {
150 				if (freq <= suboptimal.frequency) {
151 					suboptimal.frequency = freq;
152 					suboptimal.driver_data = i;
153 				}
154 			}
155 			break;
156 		case CPUFREQ_RELATION_L:
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 		}
170 	}
171 	if (optimal.driver_data > i) {
172 		if (suboptimal.driver_data > i)
173 			return -EINVAL;
174 		*index = suboptimal.driver_data;
175 	} else
176 		*index = optimal.driver_data;
177 
178 	pr_debug("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
179 		table[*index].driver_data);
180 
181 	return 0;
182 }
183 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
184 
185 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
186 		unsigned int freq)
187 {
188 	struct cpufreq_frequency_table *table;
189 	int i;
190 
191 	table = cpufreq_frequency_get_table(policy->cpu);
192 	if (unlikely(!table)) {
193 		pr_debug("%s: Unable to find frequency table\n", __func__);
194 		return -ENOENT;
195 	}
196 
197 	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
198 		if (table[i].frequency == freq)
199 			return i;
200 	}
201 
202 	return -EINVAL;
203 }
204 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_index);
205 
206 static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table);
207 
208 /**
209  * show_available_freqs - show available frequencies for the specified CPU
210  */
211 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf,
212 				    bool show_boost)
213 {
214 	unsigned int i = 0;
215 	unsigned int cpu = policy->cpu;
216 	ssize_t count = 0;
217 	struct cpufreq_frequency_table *table;
218 
219 	if (!per_cpu(cpufreq_show_table, cpu))
220 		return -ENODEV;
221 
222 	table = per_cpu(cpufreq_show_table, cpu);
223 
224 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
225 		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
226 			continue;
227 		/*
228 		 * show_boost = true and driver_data = BOOST freq
229 		 * display BOOST freqs
230 		 *
231 		 * show_boost = false and driver_data = BOOST freq
232 		 * show_boost = true and driver_data != BOOST freq
233 		 * continue - do not display anything
234 		 *
235 		 * show_boost = false and driver_data != BOOST freq
236 		 * display NON BOOST freqs
237 		 */
238 		if (show_boost ^ (table[i].driver_data == CPUFREQ_BOOST_FREQ))
239 			continue;
240 
241 		count += sprintf(&buf[count], "%d ", table[i].frequency);
242 	}
243 	count += sprintf(&buf[count], "\n");
244 
245 	return count;
246 
247 }
248 
249 #define cpufreq_attr_available_freq(_name)	  \
250 struct freq_attr cpufreq_freq_attr_##_name##_freqs =     \
251 __ATTR_RO(_name##_frequencies)
252 
253 /**
254  * show_scaling_available_frequencies - show available normal frequencies for
255  * the specified CPU
256  */
257 static ssize_t scaling_available_frequencies_show(struct cpufreq_policy *policy,
258 						  char *buf)
259 {
260 	return show_available_freqs(policy, buf, false);
261 }
262 cpufreq_attr_available_freq(scaling_available);
263 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
264 
265 /**
266  * show_available_boost_freqs - show available boost frequencies for
267  * the specified CPU
268  */
269 static ssize_t scaling_boost_frequencies_show(struct cpufreq_policy *policy,
270 					      char *buf)
271 {
272 	return show_available_freqs(policy, buf, true);
273 }
274 cpufreq_attr_available_freq(scaling_boost);
275 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_boost_freqs);
276 
277 struct freq_attr *cpufreq_generic_attr[] = {
278 	&cpufreq_freq_attr_scaling_available_freqs,
279 #ifdef CONFIG_CPU_FREQ_BOOST_SW
280 	&cpufreq_freq_attr_scaling_boost_freqs,
281 #endif
282 	NULL,
283 };
284 EXPORT_SYMBOL_GPL(cpufreq_generic_attr);
285 
286 /*
287  * if you use these, you must assure that the frequency table is valid
288  * all the time between get_attr and put_attr!
289  */
290 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
291 				      unsigned int cpu)
292 {
293 	pr_debug("setting show_table for cpu %u to %p\n", cpu, table);
294 	per_cpu(cpufreq_show_table, cpu) = table;
295 }
296 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
297 
298 void cpufreq_frequency_table_put_attr(unsigned int cpu)
299 {
300 	pr_debug("clearing show_table for cpu %u\n", cpu);
301 	per_cpu(cpufreq_show_table, cpu) = NULL;
302 }
303 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
304 
305 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
306 				      struct cpufreq_frequency_table *table)
307 {
308 	int ret = cpufreq_frequency_table_cpuinfo(policy, table);
309 
310 	if (!ret)
311 		cpufreq_frequency_table_get_attr(table, policy->cpu);
312 
313 	return ret;
314 }
315 EXPORT_SYMBOL_GPL(cpufreq_table_validate_and_show);
316 
317 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy)
318 {
319 	pr_debug("Updating show_table for new_cpu %u from last_cpu %u\n",
320 			policy->cpu, policy->last_cpu);
321 	per_cpu(cpufreq_show_table, policy->cpu) = per_cpu(cpufreq_show_table,
322 			policy->last_cpu);
323 	per_cpu(cpufreq_show_table, policy->last_cpu) = NULL;
324 }
325 
326 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
327 {
328 	return per_cpu(cpufreq_show_table, cpu);
329 }
330 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
331 
332 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
333 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
334 MODULE_LICENSE("GPL");
335