clock.c revision 1.37
1 /* $NetBSD: clock.c,v 1.37 2020/04/25 15:26:18 bouyer Exp $ */ 2 3 /*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * William Jolitz and Don Ahn. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)clock.c 7.2 (Berkeley) 5/12/91 35 */ 36 /*- 37 * Copyright (c) 1993, 1994 Charles M. Hannum. 38 * 39 * This code is derived from software contributed to Berkeley by 40 * William Jolitz and Don Ahn. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. All advertising materials mentioning features or use of this software 51 * must display the following acknowledgement: 52 * This product includes software developed by the University of 53 * California, Berkeley and its contributors. 54 * 4. Neither the name of the University nor the names of its contributors 55 * may be used to endorse or promote products derived from this software 56 * without specific prior written permission. 57 * 58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 68 * SUCH DAMAGE. 69 * 70 * @(#)clock.c 7.2 (Berkeley) 5/12/91 71 */ 72 /* 73 * Mach Operating System 74 * Copyright (c) 1991,1990,1989 Carnegie Mellon University 75 * All Rights Reserved. 76 * 77 * Permission to use, copy, modify and distribute this software and its 78 * documentation is hereby granted, provided that both the copyright 79 * notice and this permission notice appear in all copies of the 80 * software, derivative works or modified versions, and any portions 81 * thereof, and that both notices appear in supporting documentation. 82 * 83 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 84 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 85 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 86 * 87 * Carnegie Mellon requests users of this software to return to 88 * 89 * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU 90 * School of Computer Science 91 * Carnegie Mellon University 92 * Pittsburgh PA 15213-3890 93 * 94 * any improvements or extensions that they make and grant Carnegie Mellon 95 * the rights to redistribute these changes. 96 */ 97 /* 98 Copyright 1988, 1989 by Intel Corporation, Santa Clara, California. 99 100 All Rights Reserved 101 102 Permission to use, copy, modify, and distribute this software and 103 its documentation for any purpose and without fee is hereby 104 granted, provided that the above copyright notice appears in all 105 copies and that both the copyright notice and this permission notice 106 appear in supporting documentation, and that the name of Intel 107 not be used in advertising or publicity pertaining to distribution 108 of the software without specific, written prior permission. 109 110 INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 111 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, 112 IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 113 CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 114 LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 115 NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 116 WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 117 */ 118 119 /* 120 * Primitive clock interrupt routines. 121 */ 122 123 #include <sys/cdefs.h> 124 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.37 2020/04/25 15:26:18 bouyer Exp $"); 125 126 /* #define CLOCKDEBUG */ 127 /* #define CLOCK_PARANOIA */ 128 129 #include "opt_multiprocessor.h" 130 #include "opt_ntp.h" 131 132 #include <sys/param.h> 133 #include <sys/systm.h> 134 #include <sys/time.h> 135 #include <sys/timetc.h> 136 #include <sys/kernel.h> 137 #include <sys/device.h> 138 #include <sys/mutex.h> 139 #include <sys/cpu.h> 140 #include <sys/intr.h> 141 142 #include <machine/pio.h> 143 #include <machine/cpufunc.h> 144 #include <machine/lock.h> 145 146 #include <dev/isa/isareg.h> 147 #include <dev/isa/isavar.h> 148 #include <dev/ic/mc146818reg.h> 149 #include <dev/ic/i8253reg.h> 150 #include <i386/isa/nvram.h> 151 #include <x86/x86/tsc.h> 152 #include <x86/lock.h> 153 #include <machine/specialreg.h> 154 #include <x86/rtc.h> 155 156 #ifndef __x86_64__ 157 #include "mca.h" 158 #endif 159 #if NMCA > 0 160 #include <machine/mca_machdep.h> /* for MCA_system */ 161 #endif 162 163 #include "pcppi.h" 164 #if (NPCPPI > 0) 165 #include <dev/isa/pcppivar.h> 166 167 int sysbeepmatch(device_t, cfdata_t, void *); 168 void sysbeepattach(device_t, device_t, void *); 169 int sysbeepdetach(device_t, int); 170 171 CFATTACH_DECL3_NEW(sysbeep, 0, 172 sysbeepmatch, sysbeepattach, sysbeepdetach, NULL, NULL, NULL, 173 DVF_DETACH_SHUTDOWN); 174 175 static int ppi_attached; 176 static pcppi_tag_t ppicookie; 177 #endif /* PCPPI */ 178 179 #ifdef CLOCKDEBUG 180 int clock_debug = 0; 181 #define DPRINTF(arg) if (clock_debug) printf arg 182 #else 183 #define DPRINTF(arg) 184 #endif 185 186 void (*x86_delay)(unsigned int) = i8254_delay; 187 188 void sysbeep(int, int); 189 static void tickle_tc(void); 190 191 static int clockintr(void *, struct intrframe *); 192 193 int sysbeepdetach(device_t, int); 194 195 static unsigned int gettick_broken_latch(void); 196 197 static volatile uint32_t i8254_lastcount; 198 static volatile uint32_t i8254_offset; 199 static volatile int i8254_ticked; 200 201 /* to protect TC timer variables */ 202 static __cpu_simple_lock_t tmr_lock = __SIMPLELOCK_UNLOCKED; 203 204 u_int i8254_get_timecount(struct timecounter *); 205 206 static struct timecounter i8254_timecounter = { 207 i8254_get_timecount, /* get_timecount */ 208 0, /* no poll_pps */ 209 ~0u, /* counter_mask */ 210 TIMER_FREQ, /* frequency */ 211 "i8254", /* name */ 212 100, /* quality */ 213 NULL, /* private data */ 214 NULL, /* next */ 215 }; 216 217 u_long x86_rtclock_tval; /* i8254 reload value for countdown */ 218 int rtclock_init = 0; 219 220 int clock_broken_latch = 0; 221 222 #ifdef CLOCK_PARANOIA 223 static int ticks[6]; 224 #endif 225 /* 226 * i8254 latch check routine: 227 * National Geode (formerly Cyrix MediaGX) has a serious bug in 228 * its built-in i8254-compatible clock module. 229 * machdep sets the variable 'clock_broken_latch' to indicate it. 230 */ 231 232 static unsigned int 233 gettick_broken_latch(void) 234 { 235 int v1, v2, v3; 236 int w1, w2, w3; 237 int s; 238 239 /* Don't want someone screwing with the counter while we're here. */ 240 s = splhigh(); 241 __cpu_simple_lock(&tmr_lock); 242 v1 = inb(IO_TIMER1+TIMER_CNTR0); 243 v1 |= inb(IO_TIMER1+TIMER_CNTR0) << 8; 244 v2 = inb(IO_TIMER1+TIMER_CNTR0); 245 v2 |= inb(IO_TIMER1+TIMER_CNTR0) << 8; 246 v3 = inb(IO_TIMER1+TIMER_CNTR0); 247 v3 |= inb(IO_TIMER1+TIMER_CNTR0) << 8; 248 __cpu_simple_unlock(&tmr_lock); 249 splx(s); 250 251 #ifdef CLOCK_PARANOIA 252 if (clock_debug) { 253 ticks[0] = ticks[3]; 254 ticks[1] = ticks[4]; 255 ticks[2] = ticks[5]; 256 ticks[3] = v1; 257 ticks[4] = v2; 258 ticks[5] = v3; 259 } 260 #endif 261 262 if (v1 >= v2 && v2 >= v3 && v1 - v3 < 0x200) 263 return (v2); 264 265 #define _swap_val(a, b) do { \ 266 int c = a; \ 267 a = b; \ 268 b = c; \ 269 } while (0) 270 271 /* 272 * sort v1 v2 v3 273 */ 274 if (v1 < v2) 275 _swap_val(v1, v2); 276 if (v2 < v3) 277 _swap_val(v2, v3); 278 if (v1 < v2) 279 _swap_val(v1, v2); 280 281 /* 282 * compute the middle value 283 */ 284 285 if (v1 - v3 < 0x200) 286 return (v2); 287 288 w1 = v2 - v3; 289 w2 = v3 - v1 + x86_rtclock_tval; 290 w3 = v1 - v2; 291 if (w1 >= w2) { 292 if (w1 >= w3) 293 return (v1); 294 } else { 295 if (w2 >= w3) 296 return (v2); 297 } 298 return (v3); 299 } 300 301 /* minimal initialization, enough for delay() */ 302 void 303 initrtclock(u_long freq) 304 { 305 u_long tval; 306 307 /* 308 * Compute timer_count, the count-down count the timer will be 309 * set to. Also, correctly round 310 * this by carrying an extra bit through the division. 311 */ 312 tval = (freq * 2) / (u_long) hz; 313 tval = (tval / 2) + (tval & 0x1); 314 315 /* initialize 8254 clock */ 316 outb(IO_TIMER1+TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT); 317 318 /* Correct rounding will buy us a better precision in timekeeping */ 319 outb(IO_TIMER1+TIMER_CNTR0, tval % 256); 320 outb(IO_TIMER1+TIMER_CNTR0, tval / 256); 321 322 x86_rtclock_tval = tval ? tval : 0xFFFF; 323 rtclock_init = 1; 324 } 325 326 void 327 startrtclock(void) 328 { 329 int s; 330 331 if (!rtclock_init) 332 initrtclock(TIMER_FREQ); 333 334 /* Check diagnostic status */ 335 if ((s = mc146818_read(NULL, NVRAM_DIAG)) != 0) { /* XXX softc */ 336 char bits[128]; 337 snprintb(bits, sizeof(bits), NVRAM_DIAG_BITS, s); 338 printf("RTC BIOS diagnostic error %s\n", bits); 339 } 340 341 tc_init(&i8254_timecounter); 342 rtc_register(); 343 } 344 345 /* 346 * Must be called at splsched(). 347 */ 348 static void 349 tickle_tc(void) 350 { 351 #if defined(MULTIPROCESSOR) 352 struct cpu_info *ci = curcpu(); 353 /* 354 * If we are not the primary CPU, we're not allowed to do 355 * any more work. 356 */ 357 if (CPU_IS_PRIMARY(ci) == 0) 358 return; 359 #endif 360 if (x86_rtclock_tval && 361 timecounter->tc_get_timecount == i8254_get_timecount) { 362 __cpu_simple_lock(&tmr_lock); 363 if (i8254_ticked) 364 i8254_ticked = 0; 365 else { 366 i8254_offset += x86_rtclock_tval; 367 i8254_lastcount = 0; 368 } 369 __cpu_simple_unlock(&tmr_lock); 370 } 371 372 } 373 374 static int 375 clockintr(void *arg, struct intrframe *frame) 376 { 377 tickle_tc(); 378 379 hardclock((struct clockframe *)frame); 380 381 #if NMCA > 0 382 if (MCA_system) { 383 /* Reset PS/2 clock interrupt by asserting bit 7 of port 0x61 */ 384 outb(0x61, inb(0x61) | 0x80); 385 } 386 #endif 387 return -1; 388 } 389 390 u_int 391 i8254_get_timecount(struct timecounter *tc) 392 { 393 u_int count; 394 uint16_t rdval; 395 u_long psl; 396 397 /* Don't want someone screwing with the counter while we're here. */ 398 psl = x86_read_psl(); 399 x86_disable_intr(); 400 __cpu_simple_lock(&tmr_lock); 401 /* Select timer0 and latch counter value. */ 402 outb(IO_TIMER1 + TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); 403 /* insb to make the read atomic */ 404 rdval = inb(IO_TIMER1+TIMER_CNTR0); 405 rdval |= (inb(IO_TIMER1+TIMER_CNTR0) << 8); 406 count = x86_rtclock_tval - rdval; 407 if (x86_rtclock_tval && (count < i8254_lastcount && 408 (!i8254_ticked || x86_rtclock_tval == 0xFFFF))) { 409 i8254_ticked = 1; 410 i8254_offset += x86_rtclock_tval; 411 } 412 i8254_lastcount = count; 413 count += i8254_offset; 414 __cpu_simple_unlock(&tmr_lock); 415 x86_write_psl(psl); 416 417 return (count); 418 } 419 420 unsigned int 421 gettick(void) 422 { 423 uint16_t rdval; 424 u_long psl; 425 426 if (clock_broken_latch) 427 return (gettick_broken_latch()); 428 429 /* Don't want someone screwing with the counter while we're here. */ 430 psl = x86_read_psl(); 431 x86_disable_intr(); 432 __cpu_simple_lock(&tmr_lock); 433 /* Select counter 0 and latch it. */ 434 outb(IO_TIMER1+TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); 435 rdval = inb(IO_TIMER1+TIMER_CNTR0); 436 rdval |= (inb(IO_TIMER1+TIMER_CNTR0) << 8); 437 __cpu_simple_unlock(&tmr_lock); 438 x86_write_psl(psl); 439 440 return rdval; 441 } 442 443 /* 444 * Wait approximately `n' microseconds. 445 * Relies on timer 1 counting down from (TIMER_FREQ / hz) at TIMER_FREQ Hz. 446 * Note: timer had better have been programmed before this is first used! 447 * (Note that we use `rate generator' mode, which counts at 1:1; `square 448 * wave' mode counts at 2:1). 449 * Don't rely on this being particularly accurate. 450 */ 451 void 452 i8254_delay(unsigned int n) 453 { 454 unsigned int cur_tick, initial_tick; 455 int remaining; 456 457 /* allow DELAY() to be used before startrtclock() */ 458 if (!rtclock_init) 459 initrtclock(TIMER_FREQ); 460 461 /* 462 * Read the counter first, so that the rest of the setup overhead is 463 * counted. 464 */ 465 initial_tick = gettick(); 466 467 if (n <= UINT_MAX / TIMER_FREQ) { 468 /* 469 * For unsigned arithmetic, division can be replaced with 470 * multiplication with the inverse and a shift. 471 */ 472 remaining = n * TIMER_FREQ / 1000000; 473 } else { 474 /* This is a very long delay. 475 * Being slow here doesn't matter. 476 */ 477 remaining = (unsigned long long) n * TIMER_FREQ / 1000000; 478 } 479 480 while (remaining > 1) { 481 #ifdef CLOCK_PARANOIA 482 int delta; 483 cur_tick = gettick(); 484 if (cur_tick > initial_tick) 485 delta = x86_rtclock_tval - (cur_tick - initial_tick); 486 else 487 delta = initial_tick - cur_tick; 488 if (delta < 0 || delta >= x86_rtclock_tval / 2) { 489 DPRINTF(("delay: ignore ticks %.4x-%.4x", 490 initial_tick, cur_tick)); 491 if (clock_broken_latch) { 492 DPRINTF((" (%.4x %.4x %.4x %.4x %.4x %.4x)\n", 493 ticks[0], ticks[1], ticks[2], 494 ticks[3], ticks[4], ticks[5])); 495 } else { 496 DPRINTF(("\n")); 497 } 498 } else 499 remaining -= delta; 500 #else 501 cur_tick = gettick(); 502 if (cur_tick > initial_tick) 503 remaining -= x86_rtclock_tval - (cur_tick - initial_tick); 504 else 505 remaining -= initial_tick - cur_tick; 506 #endif 507 initial_tick = cur_tick; 508 } 509 } 510 511 #if (NPCPPI > 0) 512 int 513 sysbeepmatch(device_t parent, cfdata_t match, void *aux) 514 { 515 return (!ppi_attached); 516 } 517 518 void 519 sysbeepattach(device_t parent, device_t self, void *aux) 520 { 521 aprint_naive("\n"); 522 aprint_normal("\n"); 523 524 ppicookie = ((struct pcppi_attach_args *)aux)->pa_cookie; 525 ppi_attached = 1; 526 527 if (!pmf_device_register(self, NULL, NULL)) 528 aprint_error_dev(self, "couldn't establish power handler\n"); 529 } 530 531 int 532 sysbeepdetach(device_t self, int flags) 533 { 534 pmf_device_deregister(self); 535 ppi_attached = 0; 536 return 0; 537 } 538 #endif 539 540 void 541 sysbeep(int pitch, int period) 542 { 543 #if (NPCPPI > 0) 544 if (ppi_attached) 545 pcppi_bell(ppicookie, pitch, period, 0); 546 #endif 547 } 548 549 void 550 i8254_initclocks(void) 551 { 552 553 /* 554 * XXX If you're doing strange things with multiple clocks, you might 555 * want to keep track of clock handlers. 556 */ 557 (void)isa_intr_establish(NULL, 0, IST_PULSE, IPL_CLOCK, 558 __FPTRCAST(int (*)(void *), clockintr), 0); 559 } 560 561 void 562 setstatclockrate(int arg) 563 { 564 } 565
Indexes created Thu Sep 25 16:09:42 GMT 2025