Commit | Line | Data |
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7fe2f639 DB |
1 | /* |
2 | * (C) 2004-2009 Dominik Brodowski <linux@dominikbrodowski.de> | |
3 | * (C) 2011 Thomas Renninger <trenn@novell.com> Novell Inc. | |
4 | * | |
5 | * Licensed under the terms of the GNU GPL License version 2. | |
6 | */ | |
7 | ||
8 | #include <stdio.h> | |
9 | #include <errno.h> | |
10 | #include <stdlib.h> | |
11 | #include <string.h> | |
12 | #include <sys/types.h> | |
13 | #include <sys/stat.h> | |
14 | #include <fcntl.h> | |
15 | #include <unistd.h> | |
16 | ||
17 | #include "helpers/sysfs.h" | |
18 | ||
19 | unsigned int sysfs_read_file(const char *path, char *buf, size_t buflen) | |
20 | { | |
21 | int fd; | |
22 | size_t numread; | |
23 | ||
24 | if ( ( fd = open(path, O_RDONLY) ) == -1 ) | |
25 | return 0; | |
26 | ||
27 | numread = read(fd, buf, buflen - 1); | |
28 | if ( numread < 1 ) | |
29 | { | |
30 | close(fd); | |
31 | return 0; | |
32 | } | |
33 | ||
34 | buf[numread] = '\0'; | |
35 | close(fd); | |
36 | ||
37 | return numread; | |
38 | } | |
39 | ||
40 | static unsigned int sysfs_write_file(const char *path, | |
41 | const char *value, size_t len) | |
42 | { | |
43 | int fd; | |
44 | size_t numwrite; | |
45 | ||
46 | if ( ( fd = open(path, O_WRONLY) ) == -1 ) | |
47 | return 0; | |
48 | ||
49 | numwrite = write(fd, value, len); | |
50 | if ( numwrite < 1 ) | |
51 | { | |
52 | close(fd); | |
53 | return 0; | |
54 | } | |
55 | close(fd); | |
56 | return numwrite; | |
57 | } | |
58 | ||
59 | /* CPUidle idlestate specific /sys/devices/system/cpu/cpuX/cpuidle/ access */ | |
60 | ||
61 | /* | |
62 | * helper function to read file from /sys into given buffer | |
63 | * fname is a relative path under "cpuX/cpuidle/stateX/" dir | |
64 | * cstates starting with 0, C0 is not counted as cstate. | |
65 | * This means if you want C1 info, pass 0 as idlestate param | |
66 | */ | |
67 | unsigned int sysfs_idlestate_read_file(unsigned int cpu, unsigned int idlestate, | |
68 | const char *fname, char *buf, size_t buflen) | |
69 | { | |
70 | char path[SYSFS_PATH_MAX]; | |
71 | int fd; | |
72 | size_t numread; | |
73 | ||
74 | snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpuidle/state%u/%s", | |
75 | cpu, idlestate, fname); | |
76 | ||
77 | if ( ( fd = open(path, O_RDONLY) ) == -1 ) | |
78 | return 0; | |
79 | ||
80 | numread = read(fd, buf, buflen - 1); | |
81 | if ( numread < 1 ) | |
82 | { | |
83 | close(fd); | |
84 | return 0; | |
85 | } | |
86 | ||
87 | buf[numread] = '\0'; | |
88 | close(fd); | |
89 | ||
90 | return numread; | |
91 | } | |
92 | ||
93 | /* read access to files which contain one numeric value */ | |
94 | ||
95 | enum idlestate_value { | |
96 | IDLESTATE_USAGE, | |
97 | IDLESTATE_POWER, | |
98 | IDLESTATE_LATENCY, | |
99 | IDLESTATE_TIME, | |
100 | MAX_IDLESTATE_VALUE_FILES | |
101 | }; | |
102 | ||
103 | static const char *idlestate_value_files[MAX_IDLESTATE_VALUE_FILES] = { | |
104 | [IDLESTATE_USAGE] = "usage", | |
105 | [IDLESTATE_POWER] = "power", | |
106 | [IDLESTATE_LATENCY] = "latency", | |
107 | [IDLESTATE_TIME] = "time", | |
108 | }; | |
109 | ||
110 | static unsigned long long sysfs_idlestate_get_one_value(unsigned int cpu, | |
111 | unsigned int idlestate, | |
112 | enum idlestate_value which) | |
113 | { | |
114 | unsigned long long value; | |
115 | unsigned int len; | |
116 | char linebuf[MAX_LINE_LEN]; | |
117 | char *endp; | |
118 | ||
119 | if ( which >= MAX_IDLESTATE_VALUE_FILES ) | |
120 | return 0; | |
121 | ||
122 | if ( ( len = sysfs_idlestate_read_file(cpu, idlestate, | |
123 | idlestate_value_files[which], | |
124 | linebuf, sizeof(linebuf))) == 0 ) | |
125 | { | |
126 | return 0; | |
127 | } | |
128 | ||
129 | value = strtoull(linebuf, &endp, 0); | |
130 | ||
131 | if ( endp == linebuf || errno == ERANGE ) | |
132 | return 0; | |
133 | ||
134 | return value; | |
135 | } | |
136 | ||
137 | /* read access to files which contain one string */ | |
138 | ||
139 | enum idlestate_string { | |
140 | IDLESTATE_DESC, | |
141 | IDLESTATE_NAME, | |
142 | MAX_IDLESTATE_STRING_FILES | |
143 | }; | |
144 | ||
145 | static const char *idlestate_string_files[MAX_IDLESTATE_STRING_FILES] = { | |
146 | [IDLESTATE_DESC] = "desc", | |
147 | [IDLESTATE_NAME] = "name", | |
148 | }; | |
149 | ||
150 | ||
151 | static char * sysfs_idlestate_get_one_string(unsigned int cpu, | |
152 | unsigned int idlestate, | |
153 | enum idlestate_string which) | |
154 | { | |
155 | char linebuf[MAX_LINE_LEN]; | |
156 | char *result; | |
157 | unsigned int len; | |
158 | ||
159 | if (which >= MAX_IDLESTATE_STRING_FILES) | |
160 | return NULL; | |
161 | ||
162 | if ( ( len = sysfs_idlestate_read_file(cpu, idlestate, | |
163 | idlestate_string_files[which], | |
164 | linebuf, sizeof(linebuf))) == 0 ) | |
165 | return NULL; | |
166 | ||
167 | if ( ( result = strdup(linebuf) ) == NULL ) | |
168 | return NULL; | |
169 | ||
170 | if (result[strlen(result) - 1] == '\n') | |
171 | result[strlen(result) - 1] = '\0'; | |
172 | ||
173 | return result; | |
174 | } | |
175 | ||
176 | unsigned long sysfs_get_idlestate_latency(unsigned int cpu, unsigned int idlestate) | |
177 | { | |
178 | return sysfs_idlestate_get_one_value(cpu, idlestate, IDLESTATE_LATENCY); | |
179 | } | |
180 | ||
181 | unsigned long sysfs_get_idlestate_usage(unsigned int cpu, unsigned int idlestate) | |
182 | { | |
183 | return sysfs_idlestate_get_one_value(cpu, idlestate, IDLESTATE_USAGE); | |
184 | } | |
185 | ||
186 | unsigned long long sysfs_get_idlestate_time(unsigned int cpu, unsigned int idlestate) | |
187 | { | |
188 | return sysfs_idlestate_get_one_value(cpu, idlestate, IDLESTATE_TIME); | |
189 | } | |
190 | ||
191 | char * sysfs_get_idlestate_name(unsigned int cpu, unsigned int idlestate) | |
192 | { | |
193 | return sysfs_idlestate_get_one_string(cpu, idlestate, IDLESTATE_NAME); | |
194 | } | |
195 | ||
196 | char * sysfs_get_idlestate_desc(unsigned int cpu, unsigned int idlestate) | |
197 | { | |
198 | return sysfs_idlestate_get_one_string(cpu, idlestate, IDLESTATE_DESC); | |
199 | } | |
200 | ||
201 | /* | |
202 | * Returns number of supported C-states of CPU core cpu | |
203 | * Negativ in error case | |
204 | * Zero if cpuidle does not export any C-states | |
205 | */ | |
206 | int sysfs_get_idlestate_count(unsigned int cpu) | |
207 | { | |
208 | char file[SYSFS_PATH_MAX]; | |
209 | struct stat statbuf; | |
210 | int idlestates = 1; | |
211 | ||
212 | ||
213 | snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU "cpuidle"); | |
214 | if ( stat(file, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) | |
215 | return -ENODEV; | |
216 | ||
217 | snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU "cpu%u/cpuidle/state0", cpu); | |
218 | if ( stat(file, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) | |
219 | return 0; | |
220 | ||
221 | while(stat(file, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) { | |
222 | snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU | |
223 | "cpu%u/cpuidle/state%d", cpu, idlestates); | |
224 | idlestates++; | |
225 | } | |
226 | idlestates--; | |
227 | return idlestates; | |
228 | } | |
229 | ||
230 | /* CPUidle general /sys/devices/system/cpu/cpuidle/ sysfs access ********/ | |
231 | ||
232 | /* | |
233 | * helper function to read file from /sys into given buffer | |
234 | * fname is a relative path under "cpu/cpuidle/" dir | |
235 | */ | |
236 | static unsigned int sysfs_cpuidle_read_file(const char *fname, char *buf, | |
237 | size_t buflen) | |
238 | { | |
239 | char path[SYSFS_PATH_MAX]; | |
240 | ||
241 | snprintf(path, sizeof(path), PATH_TO_CPU "cpuidle/%s", fname); | |
242 | ||
243 | return sysfs_read_file(path, buf, buflen); | |
244 | } | |
245 | ||
246 | ||
247 | ||
248 | /* read access to files which contain one string */ | |
249 | ||
250 | enum cpuidle_string { | |
251 | CPUIDLE_GOVERNOR, | |
252 | CPUIDLE_GOVERNOR_RO, | |
253 | CPUIDLE_DRIVER, | |
254 | MAX_CPUIDLE_STRING_FILES | |
255 | }; | |
256 | ||
257 | static const char *cpuidle_string_files[MAX_CPUIDLE_STRING_FILES] = { | |
258 | [CPUIDLE_GOVERNOR] = "current_governor", | |
259 | [CPUIDLE_GOVERNOR_RO] = "current_governor_ro", | |
260 | [CPUIDLE_DRIVER] = "current_driver", | |
261 | }; | |
262 | ||
263 | ||
264 | static char * sysfs_cpuidle_get_one_string(enum cpuidle_string which) | |
265 | { | |
266 | char linebuf[MAX_LINE_LEN]; | |
267 | char *result; | |
268 | unsigned int len; | |
269 | ||
270 | if (which >= MAX_CPUIDLE_STRING_FILES) | |
271 | return NULL; | |
272 | ||
273 | if ( ( len = sysfs_cpuidle_read_file(cpuidle_string_files[which], | |
274 | linebuf, sizeof(linebuf))) == 0 ) | |
275 | return NULL; | |
276 | ||
277 | if ( ( result = strdup(linebuf) ) == NULL ) | |
278 | return NULL; | |
279 | ||
280 | if (result[strlen(result) - 1] == '\n') | |
281 | result[strlen(result) - 1] = '\0'; | |
282 | ||
283 | return result; | |
284 | } | |
285 | ||
286 | char * sysfs_get_cpuidle_governor(void) | |
287 | { | |
288 | char *tmp = sysfs_cpuidle_get_one_string(CPUIDLE_GOVERNOR_RO); | |
289 | if (!tmp) | |
290 | return sysfs_cpuidle_get_one_string(CPUIDLE_GOVERNOR); | |
291 | else | |
292 | return tmp; | |
293 | } | |
294 | ||
295 | char * sysfs_get_cpuidle_driver(void) | |
296 | { | |
297 | return sysfs_cpuidle_get_one_string(CPUIDLE_DRIVER); | |
298 | } | |
299 | /* CPUidle idlestate specific /sys/devices/system/cpu/cpuX/cpuidle/ access */ | |
300 | ||
301 | /* | |
302 | * Get sched_mc or sched_smt settings | |
303 | * Pass "mc" or "smt" as argument | |
304 | * | |
305 | * Returns negative value on failure | |
306 | */ | |
307 | int sysfs_get_sched(const char* smt_mc) | |
308 | { | |
309 | unsigned long value; | |
310 | char linebuf[MAX_LINE_LEN]; | |
311 | char *endp; | |
312 | char path[SYSFS_PATH_MAX]; | |
313 | ||
314 | if (strcmp("mc", smt_mc) && strcmp("smt", smt_mc)) | |
315 | return -EINVAL; | |
316 | ||
317 | snprintf(path, sizeof(path), PATH_TO_CPU "sched_%s_power_savings", smt_mc); | |
318 | if (sysfs_read_file(path, linebuf, MAX_LINE_LEN) == 0 ) | |
319 | return -1; | |
320 | value = strtoul(linebuf, &endp, 0); | |
321 | if ( endp == linebuf || errno == ERANGE ) | |
322 | return -1; | |
323 | return value; | |
324 | } | |
325 | ||
326 | /* | |
327 | * Get sched_mc or sched_smt settings | |
328 | * Pass "mc" or "smt" as argument | |
329 | * | |
330 | * Returns negative value on failure | |
331 | */ | |
332 | int sysfs_set_sched(const char* smt_mc, int val) | |
333 | { | |
334 | char linebuf[MAX_LINE_LEN]; | |
335 | char path[SYSFS_PATH_MAX]; | |
336 | struct stat statbuf; | |
337 | ||
338 | if (strcmp("mc", smt_mc) && strcmp("smt", smt_mc)) | |
339 | return -EINVAL; | |
340 | ||
341 | snprintf(path, sizeof(path), PATH_TO_CPU "sched_%s_power_savings", smt_mc); | |
342 | sprintf(linebuf, "%d", val); | |
343 | ||
344 | if ( stat(path, &statbuf) != 0 ) | |
345 | return -ENODEV; | |
346 | ||
347 | if (sysfs_write_file(path, linebuf, MAX_LINE_LEN) == 0 ) | |
348 | return -1; | |
349 | return 0; | |
350 | } |