FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_todr.c
1 /* $NetBSD: kern_todr.c,v 1.24 2006/09/24 18:24:55 peter Exp $ */
2
3 /*
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * the Systems Programming Group of the University of Utah Computer
9 * Science Department and Ralph Campbell.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * from: Utah Hdr: clock.c 1.18 91/01/21
36 *
37 * @(#)clock.c 8.1 (Berkeley) 6/10/93
38 */
39 /*
40 * Copyright (c) 1988 University of Utah.
41 *
42 * This code is derived from software contributed to Berkeley by
43 * the Systems Programming Group of the University of Utah Computer
44 * Science Department and Ralph Campbell.
45 *
46 * Redistribution and use in source and binary forms, with or without
47 * modification, are permitted provided that the following conditions
48 * are met:
49 * 1. Redistributions of source code must retain the above copyright
50 * notice, this list of conditions and the following disclaimer.
51 * 2. Redistributions in binary form must reproduce the above copyright
52 * notice, this list of conditions and the following disclaimer in the
53 * documentation and/or other materials provided with the distribution.
54 * 3. All advertising materials mentioning features or use of this software
55 * must display the following acknowledgement:
56 * This product includes software developed by the University of
57 * California, Berkeley and its contributors.
58 * 4. Neither the name of the University nor the names of its contributors
59 * may be used to endorse or promote products derived from this software
60 * without specific prior written permission.
61 *
62 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
63 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
64 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
65 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
66 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
67 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
68 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
69 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
70 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
71 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
72 * SUCH DAMAGE.
73 *
74 * from: Utah Hdr: clock.c 1.18 91/01/21
75 *
76 * @(#)clock.c 8.1 (Berkeley) 6/10/93
77 */
78 #include <sys/cdefs.h>
79 __KERNEL_RCSID(0, "$NetBSD: kern_todr.c,v 1.24 2006/09/24 18:24:55 peter Exp $");
80
81 #include <sys/param.h>
82 #include <sys/kernel.h>
83 #include <sys/systm.h>
84 #include <sys/device.h>
85 #include <sys/timetc.h>
86 #include <dev/clock_subr.h> /* hmm.. this should probably move to sys */
87
88 #ifdef __HAVE_GENERIC_TODR
89
90 static todr_chip_handle_t todr_handle = NULL;
91
92 /*
93 * Attach the clock device to todr_handle.
94 */
95 void
96 todr_attach(todr_chip_handle_t todr)
97 {
98
99 if (todr_handle) {
100 printf("todr_attach: TOD already configured\n");
101 return;
102 }
103 todr_handle = todr;
104 }
105
106 static int timeset = 0;
107
108 /*
109 * Set up the system's time, given a `reasonable' time value.
110 */
111 void
112 inittodr(time_t base)
113 {
114 int badbase = 0, waszero = (base == 0), goodtime = 0, badrtc = 0;
115 int s;
116 #ifdef __HAVE_TIMECOUNTER
117 struct timespec ts;
118 #endif
119 struct timeval tv;
120
121 if (base < 5 * SECYR) {
122 struct clock_ymdhms basedate;
123
124 /*
125 * If base is 0, assume filesystem time is just unknown
126 * instead of preposterous. Don't bark.
127 */
128 if (base != 0)
129 printf("WARNING: preposterous time in file system\n");
130 /* not going to use it anyway, if the chip is readable */
131 basedate.dt_year = 2006;
132 basedate.dt_mon = 1;
133 basedate.dt_day = 1;
134 basedate.dt_hour = 12;
135 basedate.dt_min = 0;
136 basedate.dt_sec = 0;
137 base = clock_ymdhms_to_secs(&basedate);
138 badbase = 1;
139 }
140
141 /*
142 * Some ports need to be supplied base in order to fabricate a time_t.
143 */
144 if (todr_handle)
145 todr_handle->base_time = base;
146
147 if ((todr_handle == NULL) ||
148 (todr_gettime(todr_handle, &tv) != 0) ||
149 (tv.tv_sec < (25 * SECYR))) {
150
151 if (todr_handle != NULL)
152 printf("WARNING: preposterous TOD clock time\n");
153 else
154 printf("WARNING: no TOD clock present\n");
155 badrtc = 1;
156 } else {
157 int deltat = tv.tv_sec - base;
158
159 if (deltat < 0)
160 deltat = -deltat;
161
162 if ((badbase == 0) && deltat >= 2 * SECDAY) {
163
164 if (tv.tv_sec < base) {
165 /*
166 * The clock should never go backwards
167 * relative to filesystem time. If it
168 * does by more than the threshold,
169 * believe the filesystem.
170 */
171 printf("WARNING: clock lost %d days\n",
172 deltat / SECDAY);
173 badrtc = 1;
174 } else {
175 printf("WARNING: clock gained %d days\n",
176 deltat / SECDAY);
177 }
178 } else {
179 goodtime = 1;
180 }
181 }
182
183 /* if the rtc time is bad, use the filesystem time */
184 if (badrtc) {
185 if (badbase) {
186 printf("WARNING: using default initial time\n");
187 } else {
188 printf("WARNING: using filesystem time\n");
189 }
190 tv.tv_sec = base;
191 tv.tv_usec = 0;
192 }
193
194 timeset = 1;
195
196 s = splclock();
197 #ifdef __HAVE_TIMECOUNTER
198 ts.tv_sec = tv.tv_sec;
199 ts.tv_nsec = tv.tv_usec * 1000;
200 tc_setclock(&ts);
201 #else
202 time = tv;
203 #endif
204 splx(s);
205
206 if (waszero || goodtime)
207 return;
208
209 printf("WARNING: CHECK AND RESET THE DATE!\n");
210 }
211
212 /*
213 * Reset the TODR based on the time value; used when the TODR
214 * has a preposterous value and also when the time is reset
215 * by the stime system call. Also called when the TODR goes past
216 * TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
217 * to wrap the TODR around.
218 */
219 void
220 resettodr(void)
221 {
222 #ifdef __HAVE_TIMECOUNTER
223 struct timeval time;
224 #endif
225
226 /*
227 * We might have been called by boot() due to a crash early
228 * on. Don't reset the clock chip if we don't know what time
229 * it is.
230 */
231 if (!timeset)
232 return;
233
234 #ifdef __HAVE_TIMECOUNTER
235 getmicrotime(&time);
236 #endif
237
238 if (time.tv_sec == 0)
239 return;
240
241 if (todr_handle)
242 if (todr_settime(todr_handle, &time) != 0)
243 printf("Cannot set TOD clock time\n");
244 }
245
246 #endif /* __HAVE_GENERIC_TODR */
247
248 #ifdef TODR_DEBUG
249 static void
250 todr_debug(const char *prefix, int rv, struct clock_ymdhms *dt,
251 volatile struct timeval *tvp)
252 {
253 struct timeval tv_val;
254 struct clock_ymdhms dt_val;
255
256 if (dt == NULL) {
257 clock_secs_to_ymdhms(tvp->tv_sec, &dt_val);
258 dt = &dt_val;
259 }
260 if (tvp == NULL) {
261 tvp = &tv_val;
262 tvp->tv_sec = clock_ymdhms_to_secs(dt);
263 tvp->tv_usec = 0;
264 }
265 printf("%s: rv = %d\n", prefix, rv);
266 printf("%s: rtc_offset = %d\n", prefix, rtc_offset);
267 printf("%s: %4u/%02u/%02u %02u:%02u:%02u, (wday %d) (epoch %u.%06u)\n",
268 prefix,
269 dt->dt_year, dt->dt_mon, dt->dt_day,
270 dt->dt_hour, dt->dt_min, dt->dt_sec,
271 dt->dt_wday, (unsigned)tvp->tv_sec, (unsigned)tvp->tv_usec);
272 }
273 #else /* !TODR_DEBUG */
274 #define todr_debug(prefix, rv, dt, tvp)
275 #endif /* TODR_DEBUG */
276
277
278 int
279 todr_gettime(todr_chip_handle_t tch, volatile struct timeval *tvp)
280 {
281 struct clock_ymdhms dt;
282 int rv;
283
284 if (tch->todr_gettime) {
285 rv = tch->todr_gettime(tch, tvp);
286 /*
287 * Some unconverted ports have their own references to
288 * rtc_offset. A converted port must not do that.
289 */
290 #ifdef __HAVE_GENERIC_TODR
291 if (rv == 0)
292 tvp->tv_sec += rtc_offset * 60;
293 #endif
294 todr_debug("TODR-GET-SECS", rv, NULL, tvp);
295 return rv;
296 } else if (tch->todr_gettime_ymdhms) {
297 rv = tch->todr_gettime_ymdhms(tch, &dt);
298 todr_debug("TODR-GET-YMDHMS", rv, &dt, NULL);
299 if (rv)
300 return rv;
301
302 /*
303 * Formerly we had code here that explicitly checked
304 * for 2038 year rollover.
305 *
306 * However, clock_ymdhms_to_secs performs the same
307 * check for us, so we need not worry about it. Note
308 * that this assumes that the tvp->tv_sec member is
309 * a time_t.
310 */
311
312 /*
313 * Simple sanity checks. Note that this includes a
314 * value for clocks that can return a leap second.
315 * Note that we don't support double leap seconds,
316 * since this was apparently an error/misunderstanding
317 * on the part of the ISO C committee, and can never
318 * actually occur. If your clock issues us a double
319 * leap second, it must be broken. Ultimately, you'd
320 * have to be trying to read time at precisely that
321 * instant to even notice, so even broken clocks will
322 * work the vast majority of the time. In such a case
323 * it is recommended correction be applied in the
324 * clock driver.
325 */
326 if (dt.dt_mon < 1 || dt.dt_mon > 12 ||
327 dt.dt_day < 1 || dt.dt_day > 31 ||
328 dt.dt_hour > 23 || dt.dt_min > 59 || dt.dt_sec > 60) {
329 return EINVAL;
330 }
331 tvp->tv_sec = clock_ymdhms_to_secs(&dt) + rtc_offset * 60;
332 tvp->tv_usec = 0;
333 return tvp->tv_sec < 0 ? EINVAL : 0;
334 }
335
336 return ENXIO;
337 }
338
339 int
340 todr_settime(todr_chip_handle_t tch, volatile struct timeval *tvp)
341 {
342 struct clock_ymdhms dt;
343 int rv;
344
345 if (tch->todr_settime) {
346 /* See comments above in gettime why this is ifdef'd */
347 #ifdef __HAVE_GENERIC_TODR
348 struct timeval copy = *tvp;
349 copy.tv_sec -= rtc_offset * 60;
350 rv = tch->todr_settime(tch, ©);
351 #else
352 rv = tch->todr_settime(tch, tvp);
353 #endif
354 todr_debug("TODR-SET-SECS", rv, NULL, tvp);
355 return rv;
356 } else if (tch->todr_settime_ymdhms) {
357 time_t sec = tvp->tv_sec - rtc_offset * 60;
358 if (tvp->tv_usec >= 500000)
359 sec++;
360 clock_secs_to_ymdhms(sec, &dt);
361 rv = tch->todr_settime_ymdhms(tch, &dt);
362 todr_debug("TODR-SET-YMDHMS", rv, &dt, NULL);
363 return rv;
364 } else {
365 return ENXIO;
366 }
367 }
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