xref: /linux/tools/power/cpupower/utils/cpufreq-set.c (revision 2fd3b83cacfb9160b896fb26117328eeb0598c54)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  (C) 2004-2009  Dominik Brodowski <linux@dominikbrodowski.de>
4  */
5 
6 
7 #include <unistd.h>
8 #include <stdio.h>
9 #include <errno.h>
10 #include <stdlib.h>
11 #include <limits.h>
12 #include <string.h>
13 #include <ctype.h>
14 
15 #include <getopt.h>
16 
17 #include "cpufreq.h"
18 #include "cpuidle.h"
19 #include "helpers/helpers.h"
20 
21 #define NORM_FREQ_LEN 32
22 
23 static struct option set_opts[] = {
24 	{"min",		required_argument,	NULL, 'd'},
25 	{"max",		required_argument,	NULL, 'u'},
26 	{"governor",	required_argument,	NULL, 'g'},
27 	{"freq",	required_argument,	NULL, 'f'},
28 	{"related",	no_argument,		NULL, 'r'},
29 	{ },
30 };
31 
32 static void print_error(void)
33 {
34 	printf(_("Error setting new values. Common errors:\n"
35 			"- Do you have proper administration rights? (super-user?)\n"
36 			"- Is the governor you requested available and modprobed?\n"
37 			"- Trying to set an invalid policy?\n"
38 			"- Trying to set a specific frequency, but userspace governor is not available,\n"
39 			"   for example because of hardware which cannot be set to a specific frequency\n"
40 			"   or because the userspace governor isn't loaded?\n"));
41 };
42 
43 struct freq_units {
44 	char		*str_unit;
45 	int		power_of_ten;
46 };
47 
48 const struct freq_units def_units[] = {
49 	{"hz", -3},
50 	{"khz", 0}, /* default */
51 	{"mhz", 3},
52 	{"ghz", 6},
53 	{"thz", 9},
54 	{NULL, 0}
55 };
56 
57 static void print_unknown_arg(void)
58 {
59 	printf(_("invalid or unknown argument\n"));
60 }
61 
62 static unsigned long string_to_frequency(const char *str)
63 {
64 	char normalized[NORM_FREQ_LEN];
65 	const struct freq_units *unit;
66 	const char *scan;
67 	char *end;
68 	unsigned long freq;
69 	int power = 0, match_count = 0, i, cp, pad;
70 
71 	while (*str == '0')
72 		str++;
73 
74 	for (scan = str; isdigit(*scan) || *scan == '.'; scan++) {
75 		if (*scan == '.' && match_count == 0)
76 			match_count = 1;
77 		else if (*scan == '.' && match_count == 1)
78 			return 0;
79 	}
80 
81 	if (*scan) {
82 		match_count = 0;
83 		for (unit = def_units; unit->str_unit; unit++) {
84 			for (i = 0;
85 			     scan[i] && tolower(scan[i]) == unit->str_unit[i];
86 			     ++i)
87 				continue;
88 			if (scan[i])
89 				continue;
90 			match_count++;
91 			power = unit->power_of_ten;
92 		}
93 		if (match_count != 1)
94 			return 0;
95 	}
96 
97 	/* count the number of digits to be copied */
98 	for (cp = 0; isdigit(str[cp]); cp++)
99 		continue;
100 
101 	if (str[cp] == '.') {
102 		while (power > -1 && isdigit(str[cp+1])) {
103 			cp++;
104 			power--;
105 		}
106 	}
107 	if (power >= -1) {		/* not enough => pad */
108 		pad = power + 1;
109 	} else {			/* too much => strip */
110 		pad = 0;
111 		cp += power + 1;
112 	}
113 	/* check bounds */
114 	if (cp <= 0 || cp + pad > NORM_FREQ_LEN - 1)
115 		return 0;
116 
117 	/* copy digits */
118 	for (i = 0; i < cp; i++, str++) {
119 		if (*str == '.')
120 			str++;
121 		normalized[i] = *str;
122 	}
123 	/* and pad */
124 	for (; i < cp + pad; i++)
125 		normalized[i] = '0';
126 
127 	/* round up, down ? */
128 	match_count = (normalized[i-1] >= '5');
129 	/* and drop the decimal part */
130 	normalized[i-1] = 0; /* cp > 0 && pad >= 0 ==> i > 0 */
131 
132 	/* final conversion (and applying rounding) */
133 	errno = 0;
134 	freq = strtoul(normalized, &end, 10);
135 	if (errno)
136 		return 0;
137 	else {
138 		if (match_count && freq != ULONG_MAX)
139 			freq++;
140 		return freq;
141 	}
142 }
143 
144 static int do_new_policy(unsigned int cpu, struct cpufreq_policy *new_pol)
145 {
146 	struct cpufreq_policy *cur_pol = cpufreq_get_policy(cpu);
147 	int ret;
148 
149 	if (!cur_pol) {
150 		printf(_("wrong, unknown or unhandled CPU?\n"));
151 		return -EINVAL;
152 	}
153 
154 	if (!new_pol->min)
155 		new_pol->min = cur_pol->min;
156 
157 	if (!new_pol->max)
158 		new_pol->max = cur_pol->max;
159 
160 	if (!new_pol->governor)
161 		new_pol->governor = cur_pol->governor;
162 
163 	ret = cpufreq_set_policy(cpu, new_pol);
164 
165 	cpufreq_put_policy(cur_pol);
166 
167 	return ret;
168 }
169 
170 
171 static int do_one_cpu(unsigned int cpu, struct cpufreq_policy *new_pol,
172 		unsigned long freq, unsigned int pc)
173 {
174 	switch (pc) {
175 	case 0:
176 		return cpufreq_set_frequency(cpu, freq);
177 
178 	case 1:
179 		/* if only one value of a policy is to be changed, we can
180 		 * use a "fast path".
181 		 */
182 		if (new_pol->min)
183 			return cpufreq_modify_policy_min(cpu, new_pol->min);
184 		else if (new_pol->max)
185 			return cpufreq_modify_policy_max(cpu, new_pol->max);
186 		else if (new_pol->governor)
187 			return cpufreq_modify_policy_governor(cpu,
188 							new_pol->governor);
189 
190 	default:
191 		/* slow path */
192 		return do_new_policy(cpu, new_pol);
193 	}
194 }
195 
196 int cmd_freq_set(int argc, char **argv)
197 {
198 	int ret = 0, cont = 1;
199 	int double_parm = 0, related = 0, policychange = 0;
200 	unsigned long freq = 0;
201 	char gov[20];
202 	unsigned int cpu;
203 
204 	struct cpufreq_policy new_pol = {
205 		.min = 0,
206 		.max = 0,
207 		.governor = NULL,
208 	};
209 
210 	/* parameter parsing */
211 	do {
212 		ret = getopt_long(argc, argv, "d:u:g:f:r", set_opts, NULL);
213 		switch (ret) {
214 		case '?':
215 			print_unknown_arg();
216 			return -EINVAL;
217 		case -1:
218 			cont = 0;
219 			break;
220 		case 'r':
221 			if (related)
222 				double_parm++;
223 			related++;
224 			break;
225 		case 'd':
226 			if (new_pol.min)
227 				double_parm++;
228 			policychange++;
229 			new_pol.min = string_to_frequency(optarg);
230 			if (new_pol.min == 0) {
231 				print_unknown_arg();
232 				return -EINVAL;
233 			}
234 			break;
235 		case 'u':
236 			if (new_pol.max)
237 				double_parm++;
238 			policychange++;
239 			new_pol.max = string_to_frequency(optarg);
240 			if (new_pol.max == 0) {
241 				print_unknown_arg();
242 				return -EINVAL;
243 			}
244 			break;
245 		case 'f':
246 			if (freq)
247 				double_parm++;
248 			freq = string_to_frequency(optarg);
249 			if (freq == 0) {
250 				print_unknown_arg();
251 				return -EINVAL;
252 			}
253 			break;
254 		case 'g':
255 			if (new_pol.governor)
256 				double_parm++;
257 			policychange++;
258 			if ((strlen(optarg) < 3) || (strlen(optarg) > 18)) {
259 				print_unknown_arg();
260 				return -EINVAL;
261 			}
262 			if ((sscanf(optarg, "%19s", gov)) != 1) {
263 				print_unknown_arg();
264 				return -EINVAL;
265 			}
266 			new_pol.governor = gov;
267 			break;
268 		}
269 	} while (cont);
270 
271 	/* parameter checking */
272 	if (double_parm) {
273 		printf("the same parameter was passed more than once\n");
274 		return -EINVAL;
275 	}
276 
277 	if (freq && policychange) {
278 		printf(_("the -f/--freq parameter cannot be combined with -d/--min, -u/--max or\n"
279 				"-g/--governor parameters\n"));
280 		return -EINVAL;
281 	}
282 
283 	if (!freq && !policychange) {
284 		printf(_("At least one parameter out of -f/--freq, -d/--min, -u/--max, and\n"
285 				"-g/--governor must be passed\n"));
286 		return -EINVAL;
287 	}
288 
289 	/* Default is: set all CPUs */
290 	if (bitmask_isallclear(cpus_chosen))
291 		bitmask_setall(cpus_chosen);
292 
293 	/* Also set frequency settings for related CPUs if -r is passed */
294 	if (related) {
295 		for (cpu = bitmask_first(cpus_chosen);
296 		     cpu <= bitmask_last(cpus_chosen); cpu++) {
297 			struct cpufreq_affected_cpus *cpus;
298 
299 			if (!bitmask_isbitset(cpus_chosen, cpu) ||
300 			    cpupower_is_cpu_online(cpu) != 1)
301 				continue;
302 
303 			cpus = cpufreq_get_related_cpus(cpu);
304 			if (!cpus)
305 				break;
306 			while (cpus->next) {
307 				bitmask_setbit(cpus_chosen, cpus->cpu);
308 				cpus = cpus->next;
309 			}
310 			/* Set the last cpu in related cpus list */
311 			bitmask_setbit(cpus_chosen, cpus->cpu);
312 			cpufreq_put_related_cpus(cpus);
313 		}
314 	}
315 
316 	get_cpustate();
317 
318 	/* loop over CPUs */
319 	for (cpu = bitmask_first(cpus_chosen);
320 	     cpu <= bitmask_last(cpus_chosen); cpu++) {
321 
322 		if (!bitmask_isbitset(cpus_chosen, cpu) ||
323 		    cpupower_is_cpu_online(cpu) != 1)
324 			continue;
325 
326 		printf(_("Setting cpu: %d\n"), cpu);
327 		ret = do_one_cpu(cpu, &new_pol, freq, policychange);
328 		if (ret) {
329 			print_error();
330 			return ret;
331 		}
332 	}
333 
334 	print_offline_cpus();
335 
336 	return 0;
337 }
338