xref: /openbmc/linux/drivers/cpufreq/freq_table.c (revision b34e08d5)
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].flags & CPUFREQ_BOOST_FREQ))
37 			continue;
38 
39 		pr_debug("table entry %u: %u kHz\n", i, freq);
40 		if (freq < min_freq)
41 			min_freq = freq;
42 		if (freq > max_freq)
43 			max_freq = freq;
44 	}
45 
46 	policy->min = policy->cpuinfo.min_freq = min_freq;
47 	policy->max = policy->cpuinfo.max_freq = max_freq;
48 
49 	if (policy->min == ~0)
50 		return -EINVAL;
51 	else
52 		return 0;
53 }
54 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
55 
56 
57 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
58 				   struct cpufreq_frequency_table *table)
59 {
60 	unsigned int next_larger = ~0, freq, i = 0;
61 	bool found = false;
62 
63 	pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
64 					policy->min, policy->max, policy->cpu);
65 
66 	cpufreq_verify_within_cpu_limits(policy);
67 
68 	for (; freq = table[i].frequency, freq != CPUFREQ_TABLE_END; i++) {
69 		if (freq == CPUFREQ_ENTRY_INVALID)
70 			continue;
71 		if ((freq >= policy->min) && (freq <= policy->max)) {
72 			found = true;
73 			break;
74 		}
75 
76 		if ((next_larger > freq) && (freq > policy->max))
77 			next_larger = freq;
78 	}
79 
80 	if (!found) {
81 		policy->max = next_larger;
82 		cpufreq_verify_within_cpu_limits(policy);
83 	}
84 
85 	pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
86 				policy->min, policy->max, policy->cpu);
87 
88 	return 0;
89 }
90 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
91 
92 /*
93  * Generic routine to verify policy & frequency table, requires driver to set
94  * policy->freq_table prior to it.
95  */
96 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy)
97 {
98 	struct cpufreq_frequency_table *table =
99 		cpufreq_frequency_get_table(policy->cpu);
100 	if (!table)
101 		return -ENODEV;
102 
103 	return cpufreq_frequency_table_verify(policy, table);
104 }
105 EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
106 
107 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
108 				   struct cpufreq_frequency_table *table,
109 				   unsigned int target_freq,
110 				   unsigned int relation,
111 				   unsigned int *index)
112 {
113 	struct cpufreq_frequency_table optimal = {
114 		.driver_data = ~0,
115 		.frequency = 0,
116 	};
117 	struct cpufreq_frequency_table suboptimal = {
118 		.driver_data = ~0,
119 		.frequency = 0,
120 	};
121 	unsigned int i;
122 
123 	pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
124 					target_freq, relation, policy->cpu);
125 
126 	switch (relation) {
127 	case CPUFREQ_RELATION_H:
128 		suboptimal.frequency = ~0;
129 		break;
130 	case CPUFREQ_RELATION_L:
131 		optimal.frequency = ~0;
132 		break;
133 	}
134 
135 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
136 		unsigned int freq = table[i].frequency;
137 		if (freq == CPUFREQ_ENTRY_INVALID)
138 			continue;
139 		if ((freq < policy->min) || (freq > policy->max))
140 			continue;
141 		switch (relation) {
142 		case CPUFREQ_RELATION_H:
143 			if (freq <= target_freq) {
144 				if (freq >= optimal.frequency) {
145 					optimal.frequency = freq;
146 					optimal.driver_data = i;
147 				}
148 			} else {
149 				if (freq <= suboptimal.frequency) {
150 					suboptimal.frequency = freq;
151 					suboptimal.driver_data = i;
152 				}
153 			}
154 			break;
155 		case CPUFREQ_RELATION_L:
156 			if (freq >= target_freq) {
157 				if (freq <= optimal.frequency) {
158 					optimal.frequency = freq;
159 					optimal.driver_data = i;
160 				}
161 			} else {
162 				if (freq >= suboptimal.frequency) {
163 					suboptimal.frequency = freq;
164 					suboptimal.driver_data = i;
165 				}
166 			}
167 			break;
168 		}
169 	}
170 	if (optimal.driver_data > i) {
171 		if (suboptimal.driver_data > i)
172 			return -EINVAL;
173 		*index = suboptimal.driver_data;
174 	} else
175 		*index = optimal.driver_data;
176 
177 	pr_debug("target index is %u, freq is:%u kHz\n", *index,
178 		 table[*index].frequency);
179 
180 	return 0;
181 }
182 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
183 
184 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
185 		unsigned int freq)
186 {
187 	struct cpufreq_frequency_table *table;
188 	int i;
189 
190 	table = cpufreq_frequency_get_table(policy->cpu);
191 	if (unlikely(!table)) {
192 		pr_debug("%s: Unable to find frequency table\n", __func__);
193 		return -ENOENT;
194 	}
195 
196 	for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
197 		if (table[i].frequency == freq)
198 			return i;
199 	}
200 
201 	return -EINVAL;
202 }
203 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_index);
204 
205 /**
206  * show_available_freqs - show available frequencies for the specified CPU
207  */
208 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf,
209 				    bool show_boost)
210 {
211 	unsigned int i = 0;
212 	ssize_t count = 0;
213 	struct cpufreq_frequency_table *table = policy->freq_table;
214 
215 	if (!table)
216 		return -ENODEV;
217 
218 	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
219 		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
220 			continue;
221 		/*
222 		 * show_boost = true and driver_data = BOOST freq
223 		 * display BOOST freqs
224 		 *
225 		 * show_boost = false and driver_data = BOOST freq
226 		 * show_boost = true and driver_data != BOOST freq
227 		 * continue - do not display anything
228 		 *
229 		 * show_boost = false and driver_data != BOOST freq
230 		 * display NON BOOST freqs
231 		 */
232 		if (show_boost ^ (table[i].flags & CPUFREQ_BOOST_FREQ))
233 			continue;
234 
235 		count += sprintf(&buf[count], "%d ", table[i].frequency);
236 	}
237 	count += sprintf(&buf[count], "\n");
238 
239 	return count;
240 
241 }
242 
243 #define cpufreq_attr_available_freq(_name)	  \
244 struct freq_attr cpufreq_freq_attr_##_name##_freqs =     \
245 __ATTR_RO(_name##_frequencies)
246 
247 /**
248  * show_scaling_available_frequencies - show available normal frequencies for
249  * the specified CPU
250  */
251 static ssize_t scaling_available_frequencies_show(struct cpufreq_policy *policy,
252 						  char *buf)
253 {
254 	return show_available_freqs(policy, buf, false);
255 }
256 cpufreq_attr_available_freq(scaling_available);
257 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
258 
259 /**
260  * show_available_boost_freqs - show available boost frequencies for
261  * the specified CPU
262  */
263 static ssize_t scaling_boost_frequencies_show(struct cpufreq_policy *policy,
264 					      char *buf)
265 {
266 	return show_available_freqs(policy, buf, true);
267 }
268 cpufreq_attr_available_freq(scaling_boost);
269 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_boost_freqs);
270 
271 struct freq_attr *cpufreq_generic_attr[] = {
272 	&cpufreq_freq_attr_scaling_available_freqs,
273 #ifdef CONFIG_CPU_FREQ_BOOST_SW
274 	&cpufreq_freq_attr_scaling_boost_freqs,
275 #endif
276 	NULL,
277 };
278 EXPORT_SYMBOL_GPL(cpufreq_generic_attr);
279 
280 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
281 				      struct cpufreq_frequency_table *table)
282 {
283 	int ret = cpufreq_frequency_table_cpuinfo(policy, table);
284 
285 	if (!ret)
286 		policy->freq_table = table;
287 
288 	return ret;
289 }
290 EXPORT_SYMBOL_GPL(cpufreq_table_validate_and_show);
291 
292 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
293 
294 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
295 {
296 	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
297 	return policy ? policy->freq_table : NULL;
298 }
299 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
300 
301 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
302 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
303 MODULE_LICENSE("GPL");
304