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