1 | /* $NetBSD: sysmon.c,v 1.28 2015/05/05 09:22:33 pgoyette Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2000 Zembu Labs, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * Author: Jason R. Thorpe <thorpej@zembu.com> |
8 | * |
9 | * Redistribution and use in source and binary forms, with or without |
10 | * modification, are permitted provided that the following conditions |
11 | * are met: |
12 | * 1. Redistributions of source code must retain the above copyright |
13 | * notice, this list of conditions and the following disclaimer. |
14 | * 2. Redistributions in binary form must reproduce the above copyright |
15 | * notice, this list of conditions and the following disclaimer in the |
16 | * documentation and/or other materials provided with the distribution. |
17 | * 3. All advertising materials mentioning features or use of this software |
18 | * must display the following acknowledgement: |
19 | * This product includes software developed by Zembu Labs, Inc. |
20 | * 4. Neither the name of Zembu Labs nor the names of its employees may |
21 | * be used to endorse or promote products derived from this software |
22 | * without specific prior written permission. |
23 | * |
24 | * THIS SOFTWARE IS PROVIDED BY ZEMBU LABS, INC. ``AS IS'' AND ANY EXPRESS |
25 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAR- |
26 | * RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DIS- |
27 | * CLAIMED. IN NO EVENT SHALL ZEMBU LABS BE LIABLE FOR ANY DIRECT, INDIRECT, |
28 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
29 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
30 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
31 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
32 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
33 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
34 | */ |
35 | |
36 | /* |
37 | * Clearing house for system monitoring hardware. We currently |
38 | * handle environmental sensors, watchdog timers, and power management. |
39 | */ |
40 | |
41 | #include <sys/cdefs.h> |
42 | __KERNEL_RCSID(0, "$NetBSD: sysmon.c,v 1.28 2015/05/05 09:22:33 pgoyette Exp $" ); |
43 | |
44 | #include <sys/param.h> |
45 | #include <sys/conf.h> |
46 | #include <sys/errno.h> |
47 | #include <sys/fcntl.h> |
48 | #include <sys/callout.h> |
49 | #include <sys/kernel.h> |
50 | #include <sys/systm.h> |
51 | #include <sys/proc.h> |
52 | #include <sys/module.h> |
53 | #include <sys/mutex.h> |
54 | #include <sys/device.h> |
55 | #include <sys/once.h> |
56 | |
57 | #include <dev/sysmon/sysmonvar.h> |
58 | |
59 | dev_type_open(sysmonopen); |
60 | dev_type_close(sysmonclose); |
61 | dev_type_ioctl(sysmonioctl); |
62 | dev_type_read(sysmonread); |
63 | dev_type_poll(sysmonpoll); |
64 | dev_type_kqfilter(sysmonkqfilter); |
65 | |
66 | const struct cdevsw sysmon_cdevsw = { |
67 | .d_open = sysmonopen, |
68 | .d_close = sysmonclose, |
69 | .d_read = sysmonread, |
70 | .d_write = nowrite, |
71 | .d_ioctl = sysmonioctl, |
72 | .d_stop = nostop, |
73 | .d_tty = notty, |
74 | .d_poll = sysmonpoll, |
75 | .d_mmap = nommap, |
76 | .d_kqfilter = sysmonkqfilter, |
77 | .d_discard = nodiscard, |
78 | .d_flag = D_OTHER | D_MPSAFE |
79 | }; |
80 | |
81 | static int sysmon_modcmd(modcmd_t, void *); |
82 | static int sm_init_once(void); |
83 | |
84 | /* |
85 | * Info about our minor "devices" |
86 | */ |
87 | static struct sysmon_opvec *sysmon_opvec_table[] = { NULL, NULL, NULL }; |
88 | static int sysmon_refcnt[] = { 0, 0, 0 }; |
89 | static const char *sysmon_mod[] = { "sysmon_envsys" , |
90 | "sysmon_wdog" , |
91 | "sysmon_power" }; |
92 | static kmutex_t sysmon_minor_mtx; |
93 | |
94 | #ifdef _MODULE |
95 | static bool sm_is_attached; |
96 | #endif |
97 | |
98 | ONCE_DECL(once_sm); |
99 | |
100 | /* |
101 | * sysmon_attach_minor |
102 | * |
103 | * Attach a minor device for wdog, power, or envsys. Manage a |
104 | * reference count so we can prevent the device from being |
105 | * detached if there are still users with the minor device opened. |
106 | * |
107 | * If the opvec argument is NULL, this is a request to detach the |
108 | * minor device - make sure the refcnt is zero! |
109 | */ |
110 | int |
111 | sysmon_attach_minor(int minor, struct sysmon_opvec *opvec) |
112 | { |
113 | int ret; |
114 | |
115 | mutex_enter(&sysmon_minor_mtx); |
116 | if (opvec) { |
117 | if (sysmon_opvec_table[minor] == NULL) { |
118 | sysmon_refcnt[minor] = 0; |
119 | sysmon_opvec_table[minor] = opvec; |
120 | ret = 0; |
121 | } else |
122 | ret = EEXIST; |
123 | } else { |
124 | if (sysmon_refcnt[minor] == 0) { |
125 | sysmon_opvec_table[minor] = NULL; |
126 | ret = 0; |
127 | } else |
128 | ret = EBUSY; |
129 | } |
130 | |
131 | mutex_exit(&sysmon_minor_mtx); |
132 | return ret; |
133 | } |
134 | |
135 | /* |
136 | * sysmonopen: |
137 | * |
138 | * Open the system monitor device. |
139 | */ |
140 | int |
141 | sysmonopen(dev_t dev, int flag, int mode, struct lwp *l) |
142 | { |
143 | int error; |
144 | |
145 | mutex_enter(&sysmon_minor_mtx); |
146 | |
147 | switch (minor(dev)) { |
148 | case SYSMON_MINOR_ENVSYS: |
149 | case SYSMON_MINOR_WDOG: |
150 | case SYSMON_MINOR_POWER: |
151 | if (sysmon_opvec_table[minor(dev)] == NULL) { |
152 | mutex_exit(&sysmon_minor_mtx); |
153 | error = module_autoload(sysmon_mod[minor(dev)], |
154 | MODULE_CLASS_MISC); |
155 | if (error) |
156 | return error; |
157 | mutex_enter(&sysmon_minor_mtx); |
158 | if (sysmon_opvec_table[minor(dev)] == NULL) { |
159 | error = ENODEV; |
160 | break; |
161 | } |
162 | } |
163 | error = (sysmon_opvec_table[minor(dev)]->so_open)(dev, flag, |
164 | mode, l); |
165 | if (error == 0) |
166 | sysmon_refcnt[minor(dev)]++; |
167 | break; |
168 | default: |
169 | error = ENODEV; |
170 | } |
171 | |
172 | mutex_exit(&sysmon_minor_mtx); |
173 | return error; |
174 | } |
175 | |
176 | /* |
177 | * sysmonclose: |
178 | * |
179 | * Close the system monitor device. |
180 | */ |
181 | int |
182 | sysmonclose(dev_t dev, int flag, int mode, struct lwp *l) |
183 | { |
184 | int error; |
185 | |
186 | switch (minor(dev)) { |
187 | case SYSMON_MINOR_ENVSYS: |
188 | case SYSMON_MINOR_WDOG: |
189 | case SYSMON_MINOR_POWER: |
190 | if (sysmon_opvec_table[minor(dev)] == NULL) |
191 | error = ENODEV; |
192 | else { |
193 | error = (sysmon_opvec_table[minor(dev)]->so_close)(dev, |
194 | flag, mode, l); |
195 | if (error == 0) { |
196 | sysmon_refcnt[minor(dev)]--; |
197 | KASSERT(sysmon_refcnt[minor(dev)] >= 0); |
198 | } |
199 | } |
200 | break; |
201 | default: |
202 | error = ENODEV; |
203 | } |
204 | |
205 | return (error); |
206 | } |
207 | |
208 | /* |
209 | * sysmonioctl: |
210 | * |
211 | * Perform a control request. |
212 | */ |
213 | int |
214 | sysmonioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) |
215 | { |
216 | int error; |
217 | |
218 | switch (minor(dev)) { |
219 | case SYSMON_MINOR_ENVSYS: |
220 | case SYSMON_MINOR_WDOG: |
221 | case SYSMON_MINOR_POWER: |
222 | if (sysmon_opvec_table[minor(dev)] == NULL) |
223 | error = ENODEV; |
224 | else |
225 | error = (sysmon_opvec_table[minor(dev)]->so_ioctl)(dev, |
226 | cmd, data, flag, l); |
227 | break; |
228 | default: |
229 | error = ENODEV; |
230 | } |
231 | |
232 | return (error); |
233 | } |
234 | |
235 | /* |
236 | * sysmonread: |
237 | * |
238 | * Perform a read request. |
239 | */ |
240 | int |
241 | sysmonread(dev_t dev, struct uio *uio, int flags) |
242 | { |
243 | int error; |
244 | |
245 | switch (minor(dev)) { |
246 | case SYSMON_MINOR_POWER: |
247 | if (sysmon_opvec_table[minor(dev)] == NULL) |
248 | error = ENODEV; |
249 | else |
250 | error = (sysmon_opvec_table[minor(dev)]->so_read)(dev, |
251 | uio, flags); |
252 | break; |
253 | default: |
254 | error = ENODEV; |
255 | } |
256 | |
257 | return (error); |
258 | } |
259 | |
260 | /* |
261 | * sysmonpoll: |
262 | * |
263 | * Poll the system monitor device. |
264 | */ |
265 | int |
266 | sysmonpoll(dev_t dev, int events, struct lwp *l) |
267 | { |
268 | int rv; |
269 | |
270 | switch (minor(dev)) { |
271 | case SYSMON_MINOR_POWER: |
272 | if (sysmon_opvec_table[minor(dev)] == NULL) |
273 | rv = events; |
274 | else |
275 | rv = (sysmon_opvec_table[minor(dev)]->so_poll)(dev, |
276 | events, l); |
277 | break; |
278 | default: |
279 | rv = events; |
280 | } |
281 | |
282 | return (rv); |
283 | } |
284 | |
285 | /* |
286 | * sysmonkqfilter: |
287 | * |
288 | * Kqueue filter for the system monitor device. |
289 | */ |
290 | int |
291 | sysmonkqfilter(dev_t dev, struct knote *kn) |
292 | { |
293 | int error; |
294 | |
295 | switch (minor(dev)) { |
296 | case SYSMON_MINOR_POWER: |
297 | if (sysmon_opvec_table[minor(dev)] == NULL) |
298 | error = ENODEV; |
299 | else |
300 | error = (sysmon_opvec_table[minor(dev)]->so_filter)(dev, |
301 | kn); |
302 | break; |
303 | default: |
304 | error = 1; |
305 | } |
306 | |
307 | return (error); |
308 | } |
309 | |
310 | MODULE(MODULE_CLASS_DRIVER, sysmon, "" ); |
311 | |
312 | static int |
313 | sm_init_once(void) |
314 | { |
315 | |
316 | mutex_init(&sysmon_minor_mtx, MUTEX_DEFAULT, IPL_NONE); |
317 | |
318 | return 0; |
319 | } |
320 | |
321 | int |
322 | sysmon_init(void) |
323 | { |
324 | int error; |
325 | #ifdef _MODULE |
326 | devmajor_t bmajor, cmajor; |
327 | #endif |
328 | |
329 | error = RUN_ONCE(&once_sm, sm_init_once); |
330 | |
331 | #ifdef _MODULE |
332 | mutex_enter(&sysmon_minor_mtx); |
333 | if (!sm_is_attached) { |
334 | bmajor = cmajor = -1; |
335 | error = devsw_attach("sysmon" , NULL, &bmajor, |
336 | &sysmon_cdevsw, &cmajor); |
337 | sm_is_attached = (error != 0); |
338 | } |
339 | mutex_exit(&sysmon_minor_mtx); |
340 | #endif |
341 | |
342 | return error; |
343 | } |
344 | |
345 | int |
346 | sysmon_fini(void) |
347 | { |
348 | int error = 0; |
349 | |
350 | if ((sysmon_opvec_table[SYSMON_MINOR_ENVSYS] != NULL) || |
351 | (sysmon_opvec_table[SYSMON_MINOR_WDOG] != NULL) || |
352 | (sysmon_opvec_table[SYSMON_MINOR_POWER] != NULL)) |
353 | error = EBUSY; |
354 | |
355 | #ifdef _MODULE |
356 | if (error == 0) { |
357 | mutex_enter(&sysmon_minor_mtx); |
358 | sm_is_attached = false; |
359 | error = devsw_detach(NULL, &sysmon_cdevsw); |
360 | mutex_exit(&sysmon_minor_mtx); |
361 | } |
362 | #endif |
363 | |
364 | return error; |
365 | } |
366 | |
367 | static |
368 | int |
369 | sysmon_modcmd(modcmd_t cmd, void *arg) |
370 | { |
371 | int ret; |
372 | |
373 | switch (cmd) { |
374 | case MODULE_CMD_INIT: |
375 | ret = sysmon_init(); |
376 | break; |
377 | |
378 | case MODULE_CMD_FINI: |
379 | ret = sysmon_fini(); |
380 | break; |
381 | |
382 | case MODULE_CMD_STAT: |
383 | default: |
384 | ret = ENOTTY; |
385 | } |
386 | |
387 | return ret; |
388 | } |
389 | |