1 /*- 2 * Copyright (c) 2000, 2001 Michael Smith 3 * Copyright (c) 2000 BSDi 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "opt_acpi.h" 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/eventhandler.h> 35 #include <sys/kernel.h> 36 #include <sys/module.h> 37 #include <sys/sysctl.h> 38 #include <sys/timetc.h> 39 40 #include <machine/bus.h> 41 #include <machine/resource.h> 42 #include <sys/rman.h> 43 44 #include <contrib/dev/acpica/include/acpi.h> 45 #include <contrib/dev/acpica/include/accommon.h> 46 47 #include <dev/acpica/acpivar.h> 48 #include <dev/pci/pcivar.h> 49 50 /* 51 * A timecounter based on the free-running ACPI timer. 52 * 53 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 54 */ 55 56 /* Hooks for the ACPI CA debugging infrastructure */ 57 #define _COMPONENT ACPI_TIMER 58 ACPI_MODULE_NAME("TIMER") 59 60 static device_t acpi_timer_dev; 61 static struct resource *acpi_timer_reg; 62 static bus_space_handle_t acpi_timer_bsh; 63 static bus_space_tag_t acpi_timer_bst; 64 static eventhandler_tag acpi_timer_eh; 65 66 static u_int acpi_timer_frequency = 14318182 / 4; 67 68 /* Knob to disable acpi_timer device */ 69 bool acpi_timer_disabled = false; 70 71 static void acpi_timer_identify(driver_t *driver, device_t parent); 72 static int acpi_timer_probe(device_t dev); 73 static int acpi_timer_attach(device_t dev); 74 static void acpi_timer_resume_handler(struct timecounter *); 75 static void acpi_timer_suspend_handler(struct timecounter *); 76 static u_int acpi_timer_get_timecount(struct timecounter *tc); 77 static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 78 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 79 static void acpi_timer_boot_test(void); 80 81 static int acpi_timer_test(void); 82 static int acpi_timer_test_enabled = 0; 83 TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled); 84 85 static device_method_t acpi_timer_methods[] = { 86 DEVMETHOD(device_identify, acpi_timer_identify), 87 DEVMETHOD(device_probe, acpi_timer_probe), 88 DEVMETHOD(device_attach, acpi_timer_attach), 89 90 DEVMETHOD_END 91 }; 92 93 static driver_t acpi_timer_driver = { 94 "acpi_timer", 95 acpi_timer_methods, 96 0, 97 }; 98 99 static devclass_t acpi_timer_devclass; 100 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 101 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 102 103 static struct timecounter acpi_timer_timecounter = { 104 acpi_timer_get_timecount_safe, /* get_timecount function */ 105 0, /* no poll_pps */ 106 0, /* no default counter_mask */ 107 0, /* no default frequency */ 108 "ACPI", /* name */ 109 -1 /* quality (chosen later) */ 110 }; 111 112 static __inline uint32_t 113 acpi_timer_read(void) 114 { 115 116 return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 117 } 118 119 /* 120 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 121 * we will be using. 122 */ 123 static void 124 acpi_timer_identify(driver_t *driver, device_t parent) 125 { 126 device_t dev; 127 rman_res_t rlen, rstart; 128 int rid, rtype; 129 130 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 131 132 if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || 133 acpi_timer_dev || acpi_timer_disabled || 134 AcpiGbl_FADT.PmTimerLength == 0) 135 return_VOID; 136 137 if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) { 138 device_printf(parent, "could not add acpi_timer0\n"); 139 return_VOID; 140 } 141 acpi_timer_dev = dev; 142 143 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 144 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 145 rtype = SYS_RES_MEMORY; 146 break; 147 case ACPI_ADR_SPACE_SYSTEM_IO: 148 rtype = SYS_RES_IOPORT; 149 break; 150 default: 151 return_VOID; 152 } 153 rid = 0; 154 rlen = AcpiGbl_FADT.PmTimerLength; 155 rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 156 if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 157 device_printf(dev, "couldn't set resource (%s 0x%jx+0x%jx)\n", 158 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 159 return_VOID; 160 } 161 162 static int 163 acpi_timer_probe(device_t dev) 164 { 165 char desc[40]; 166 int i, j, rid, rtype; 167 168 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 169 170 if (dev != acpi_timer_dev) 171 return (ENXIO); 172 173 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 174 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 175 rtype = SYS_RES_MEMORY; 176 break; 177 case ACPI_ADR_SPACE_SYSTEM_IO: 178 rtype = SYS_RES_IOPORT; 179 break; 180 default: 181 return (ENXIO); 182 } 183 rid = 0; 184 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 185 if (acpi_timer_reg == NULL) { 186 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 187 (rtype == SYS_RES_IOPORT) ? "port" : "mem", 188 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 189 return (ENXIO); 190 } 191 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 192 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 193 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 194 acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 195 else 196 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 197 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 198 acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE; 199 if (testenv("debug.acpi.timer_test")) 200 acpi_timer_boot_test(); 201 202 /* 203 * If all tests of the counter succeed, use the ACPI-fast method. If 204 * at least one failed, default to using the safe routine, which reads 205 * the timer multiple times to get a consistent value before returning. 206 */ 207 j = 0; 208 if (bootverbose) 209 printf("ACPI timer:"); 210 for (i = 0; i < 10; i++) 211 j += acpi_timer_test(); 212 if (bootverbose) 213 printf(" -> %d\n", j); 214 if (j == 10) { 215 acpi_timer_timecounter.tc_name = "ACPI-fast"; 216 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 217 acpi_timer_timecounter.tc_quality = 900; 218 } else { 219 acpi_timer_timecounter.tc_name = "ACPI-safe"; 220 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 221 acpi_timer_timecounter.tc_quality = 850; 222 } 223 tc_init(&acpi_timer_timecounter); 224 225 sprintf(desc, "%d-bit timer at %u.%06uMHz", 226 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, 227 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); 228 device_set_desc_copy(dev, desc); 229 230 /* Release the resource, we'll allocate it again during attach. */ 231 bus_release_resource(dev, rtype, rid, acpi_timer_reg); 232 return (0); 233 } 234 235 static int 236 acpi_timer_attach(device_t dev) 237 { 238 int rid, rtype; 239 240 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 241 242 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 243 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 244 rtype = SYS_RES_MEMORY; 245 break; 246 case ACPI_ADR_SPACE_SYSTEM_IO: 247 rtype = SYS_RES_IOPORT; 248 break; 249 default: 250 return (ENXIO); 251 } 252 rid = 0; 253 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 254 if (acpi_timer_reg == NULL) 255 return (ENXIO); 256 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 257 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 258 259 /* Register suspend event handler. */ 260 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler, 261 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL) 262 device_printf(dev, "failed to register suspend event handler\n"); 263 264 return (0); 265 } 266 267 static void 268 acpi_timer_resume_handler(struct timecounter *newtc) 269 { 270 struct timecounter *tc; 271 272 tc = timecounter; 273 if (tc != newtc) { 274 if (bootverbose) 275 device_printf(acpi_timer_dev, 276 "restoring timecounter, %s -> %s\n", 277 tc->tc_name, newtc->tc_name); 278 (void)newtc->tc_get_timecount(newtc); 279 timecounter = newtc; 280 } 281 } 282 283 static void 284 acpi_timer_suspend_handler(struct timecounter *newtc) 285 { 286 struct timecounter *tc; 287 288 /* Deregister existing resume event handler. */ 289 if (acpi_timer_eh != NULL) { 290 EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh); 291 acpi_timer_eh = NULL; 292 } 293 294 if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) { 295 /* 296 * If we are using a suspend safe timecounter, don't 297 * save/restore it across suspend/resume. 298 */ 299 return; 300 } 301 302 KASSERT(newtc == &acpi_timer_timecounter, 303 ("acpi_timer_suspend_handler: wrong timecounter")); 304 305 tc = timecounter; 306 if (tc != newtc) { 307 if (bootverbose) 308 device_printf(acpi_timer_dev, 309 "switching timecounter, %s -> %s\n", 310 tc->tc_name, newtc->tc_name); 311 (void)acpi_timer_read(); 312 (void)acpi_timer_read(); 313 timecounter = newtc; 314 acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume, 315 acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST); 316 } 317 } 318 319 /* 320 * Fetch current time value from reliable hardware. 321 */ 322 static u_int 323 acpi_timer_get_timecount(struct timecounter *tc) 324 { 325 return (acpi_timer_read()); 326 } 327 328 /* 329 * Fetch current time value from hardware that may not correctly 330 * latch the counter. We need to read until we have three monotonic 331 * samples and then use the middle one, otherwise we are not protected 332 * against the fact that the bits can be wrong in two directions. If 333 * we only cared about monosity, two reads would be enough. 334 */ 335 static u_int 336 acpi_timer_get_timecount_safe(struct timecounter *tc) 337 { 338 u_int u1, u2, u3; 339 340 u2 = acpi_timer_read(); 341 u3 = acpi_timer_read(); 342 do { 343 u1 = u2; 344 u2 = u3; 345 u3 = acpi_timer_read(); 346 } while (u1 > u2 || u2 > u3); 347 348 return (u2); 349 } 350 351 /* 352 * Timecounter freqency adjustment interface. 353 */ 354 static int 355 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 356 { 357 int error; 358 u_int freq; 359 360 if (acpi_timer_timecounter.tc_frequency == 0) 361 return (EOPNOTSUPP); 362 freq = acpi_timer_frequency; 363 error = sysctl_handle_int(oidp, &freq, 0, req); 364 if (error == 0 && req->newptr != NULL) { 365 acpi_timer_frequency = freq; 366 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 367 } 368 369 return (error); 370 } 371 372 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, 373 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(u_int), 374 acpi_timer_sysctl_freq, "I", 375 "ACPI timer frequency"); 376 377 /* 378 * Some ACPI timers are known or believed to suffer from implementation 379 * problems which can lead to erroneous values being read. This function 380 * tests for consistent results from the timer and returns 1 if it believes 381 * the timer is consistent, otherwise it returns 0. 382 * 383 * It appears the cause is that the counter is not latched to the PCI bus 384 * clock when read: 385 * 386 * ] 20. ACPI Timer Errata 387 * ] 388 * ] Problem: The power management timer may return improper result when 389 * ] read. Although the timer value settles properly after incrementing, 390 * ] while incrementing there is a 3nS window every 69.8nS where the 391 * ] timer value is indeterminate (a 4.2% chance that the data will be 392 * ] incorrect when read). As a result, the ACPI free running count up 393 * ] timer specification is violated due to erroneous reads. Implication: 394 * ] System hangs due to the "inaccuracy" of the timer when used by 395 * ] software for time critical events and delays. 396 * ] 397 * ] Workaround: Read the register twice and compare. 398 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 399 * ] in the PIIX4M. 400 */ 401 #define N 2000 402 static int 403 acpi_timer_test() 404 { 405 uint32_t last, this; 406 int delta, max, max2, min, n; 407 register_t s; 408 409 /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */ 410 if (!acpi_timer_test_enabled) 411 return (1); 412 413 TSENTER(); 414 415 min = INT32_MAX; 416 max = max2 = 0; 417 418 /* Test the timer with interrupts disabled to get accurate results. */ 419 s = intr_disable(); 420 last = acpi_timer_read(); 421 for (n = 0; n < N; n++) { 422 this = acpi_timer_read(); 423 delta = acpi_TimerDelta(this, last); 424 if (delta > max) { 425 max2 = max; 426 max = delta; 427 } else if (delta > max2) 428 max2 = delta; 429 if (delta < min) 430 min = delta; 431 last = this; 432 } 433 intr_restore(s); 434 435 delta = max2 - min; 436 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) 437 n = 0; 438 else if (min < 0 || max == 0 || max2 == 0) 439 n = 0; 440 else 441 n = 1; 442 if (bootverbose) 443 printf(" %d/%d", n, delta); 444 445 TSEXIT(); 446 447 return (n); 448 } 449 #undef N 450 451 /* 452 * Test harness for verifying ACPI timer behaviour. 453 * Boot with debug.acpi.timer_test set to invoke this. 454 */ 455 static void 456 acpi_timer_boot_test(void) 457 { 458 uint32_t u1, u2, u3; 459 460 u1 = acpi_timer_read(); 461 u2 = acpi_timer_read(); 462 u3 = acpi_timer_read(); 463 464 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 465 for (;;) { 466 /* 467 * The failure case is where u3 > u1, but u2 does not fall between 468 * the two, ie. it contains garbage. 469 */ 470 if (u3 > u1) { 471 if (u2 < u1 || u2 > u3) 472 device_printf(acpi_timer_dev, 473 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 474 u1, u2, u3); 475 } 476 u1 = u2; 477 u2 = u3; 478 u3 = acpi_timer_read(); 479 } 480 } 481