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: releng/10.3/sys/dev/acpica/acpi_timer.c 255726 2013-09-20 05:06:03Z gibbs $"); 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 58ACPI_MODULE_NAME("TIMER") 59 60static device_t acpi_timer_dev; 61static struct resource *acpi_timer_reg; 62static bus_space_handle_t acpi_timer_bsh; 63static bus_space_tag_t acpi_timer_bst; 64static eventhandler_tag acpi_timer_eh; 65 66static u_int acpi_timer_frequency = 14318182 / 4; 67 68static void acpi_timer_identify(driver_t *driver, device_t parent); 69static int acpi_timer_probe(device_t dev); 70static int acpi_timer_attach(device_t dev); 71static void acpi_timer_resume_handler(struct timecounter *); 72static void acpi_timer_suspend_handler(struct timecounter *); 73static u_int acpi_timer_get_timecount(struct timecounter *tc); 74static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 75static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 76static void acpi_timer_boot_test(void); 77 78static int acpi_timer_test(void); 79 80static device_method_t acpi_timer_methods[] = { 81 DEVMETHOD(device_identify, acpi_timer_identify), 82 DEVMETHOD(device_probe, acpi_timer_probe), 83 DEVMETHOD(device_attach, acpi_timer_attach), 84 85 DEVMETHOD_END 86}; 87 88static driver_t acpi_timer_driver = { 89 "acpi_timer", 90 acpi_timer_methods, 91 0, 92}; 93 94static devclass_t acpi_timer_devclass; 95DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 96MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 97 98static struct timecounter acpi_timer_timecounter = { 99 acpi_timer_get_timecount_safe, /* get_timecount function */ 100 0, /* no poll_pps */ 101 0, /* no default counter_mask */ 102 0, /* no default frequency */ 103 "ACPI", /* name */ 104 -1 /* quality (chosen later) */ 105}; 106 107static __inline uint32_t 108acpi_timer_read(void) 109{ 110 111 return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 112} 113 114/* 115 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 116 * we will be using. 117 */ 118static void 119acpi_timer_identify(driver_t *driver, device_t parent) 120{ 121 device_t dev; 122 u_long rlen, rstart; 123 int rid, rtype; 124 125 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 126 127 if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || 128 acpi_timer_dev) 129 return_VOID; 130 131 if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) { 132 device_printf(parent, "could not add acpi_timer0\n"); 133 return_VOID; 134 } 135 acpi_timer_dev = dev; 136 137 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 138 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 139 rtype = SYS_RES_MEMORY; 140 break; 141 case ACPI_ADR_SPACE_SYSTEM_IO: 142 rtype = SYS_RES_IOPORT; 143 break; 144 default: 145 return_VOID; 146 } 147 rid = 0; 148 rlen = AcpiGbl_FADT.PmTimerLength; 149 rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 150 if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 151 device_printf(dev, "couldn't set resource (%s 0x%lx+0x%lx)\n", 152 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 153 return_VOID; 154} 155 156static int 157acpi_timer_probe(device_t dev) 158{ 159 char desc[40]; 160 int i, j, rid, rtype; 161 162 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 163 164 if (dev != acpi_timer_dev) 165 return (ENXIO); 166 167 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 168 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 169 rtype = SYS_RES_MEMORY; 170 break; 171 case ACPI_ADR_SPACE_SYSTEM_IO: 172 rtype = SYS_RES_IOPORT; 173 break; 174 default: 175 return (ENXIO); 176 } 177 rid = 0; 178 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 179 if (acpi_timer_reg == NULL) { 180 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 181 (rtype == SYS_RES_IOPORT) ? "port" : "mem", 182 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 183 return (ENXIO); 184 } 185 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 186 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 187 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 188 acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 189 else 190 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 191 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 192 acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE; 193 if (testenv("debug.acpi.timer_test")) 194 acpi_timer_boot_test(); 195 196 /* 197 * If all tests of the counter succeed, use the ACPI-fast method. If 198 * at least one failed, default to using the safe routine, which reads 199 * the timer multiple times to get a consistent value before returning. 200 */ 201 j = 0; 202 if (bootverbose) 203 printf("ACPI timer:"); 204 for (i = 0; i < 10; i++) 205 j += acpi_timer_test(); 206 if (bootverbose) 207 printf(" -> %d\n", j); 208 if (j == 10) { 209 acpi_timer_timecounter.tc_name = "ACPI-fast"; 210 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 211 acpi_timer_timecounter.tc_quality = 900; 212 } else { 213 acpi_timer_timecounter.tc_name = "ACPI-safe"; 214 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 215 acpi_timer_timecounter.tc_quality = 850; 216 } 217 tc_init(&acpi_timer_timecounter); 218 219 sprintf(desc, "%d-bit timer at %u.%06uMHz", 220 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, 221 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); 222 device_set_desc_copy(dev, desc); 223 224 /* Release the resource, we'll allocate it again during attach. */ 225 bus_release_resource(dev, rtype, rid, acpi_timer_reg); 226 return (0); 227} 228 229static int 230acpi_timer_attach(device_t dev) 231{ 232 int rid, rtype; 233 234 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 235 236 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 237 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 238 rtype = SYS_RES_MEMORY; 239 break; 240 case ACPI_ADR_SPACE_SYSTEM_IO: 241 rtype = SYS_RES_IOPORT; 242 break; 243 default: 244 return (ENXIO); 245 } 246 rid = 0; 247 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 248 if (acpi_timer_reg == NULL) 249 return (ENXIO); 250 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 251 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 252 253 /* Register suspend event handler. */ 254 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler, 255 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL) 256 device_printf(dev, "failed to register suspend event handler\n"); 257 258 return (0); 259} 260 261static void 262acpi_timer_resume_handler(struct timecounter *newtc) 263{ 264 struct timecounter *tc; 265 266 tc = timecounter; 267 if (tc != newtc) { 268 if (bootverbose) 269 device_printf(acpi_timer_dev, 270 "restoring timecounter, %s -> %s\n", 271 tc->tc_name, newtc->tc_name); 272 (void)newtc->tc_get_timecount(newtc); 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, CTLTYPE_INT | CTLFLAG_RW, 368 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "ACPI timer frequency"); 369 370/* 371 * Some ACPI timers are known or believed to suffer from implementation 372 * problems which can lead to erroneous values being read. This function 373 * tests for consistent results from the timer and returns 1 if it believes 374 * the timer is consistent, otherwise it returns 0. 375 * 376 * It appears the cause is that the counter is not latched to the PCI bus 377 * clock when read: 378 * 379 * ] 20. ACPI Timer Errata 380 * ] 381 * ] Problem: The power management timer may return improper result when 382 * ] read. Although the timer value settles properly after incrementing, 383 * ] while incrementing there is a 3nS window every 69.8nS where the 384 * ] timer value is indeterminate (a 4.2% chance that the data will be 385 * ] incorrect when read). As a result, the ACPI free running count up 386 * ] timer specification is violated due to erroneous reads. Implication: 387 * ] System hangs due to the "inaccuracy" of the timer when used by 388 * ] software for time critical events and delays. 389 * ] 390 * ] Workaround: Read the register twice and compare. 391 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 392 * ] in the PIIX4M. 393 */ 394#define N 2000 395static int 396acpi_timer_test() 397{ 398 uint32_t last, this; 399 int delta, max, max2, min, n; 400 register_t s; 401 402 min = INT32_MAX; 403 max = max2 = 0; 404 405 /* Test the timer with interrupts disabled to get accurate results. */ 406 s = intr_disable(); 407 last = acpi_timer_read(); 408 for (n = 0; n < N; n++) { 409 this = acpi_timer_read(); 410 delta = acpi_TimerDelta(this, last); 411 if (delta > max) { 412 max2 = max; 413 max = delta; 414 } else if (delta > max2) 415 max2 = delta; 416 if (delta < min) 417 min = delta; 418 last = this; 419 } 420 intr_restore(s); 421 422 delta = max2 - min; 423 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) 424 n = 0; 425 else if (min < 0 || max == 0 || max2 == 0) 426 n = 0; 427 else 428 n = 1; 429 if (bootverbose) 430 printf(" %d/%d", n, delta); 431 432 return (n); 433} 434#undef N 435 436/* 437 * Test harness for verifying ACPI timer behaviour. 438 * Boot with debug.acpi.timer_test set to invoke this. 439 */ 440static void 441acpi_timer_boot_test(void) 442{ 443 uint32_t u1, u2, u3; 444 445 u1 = acpi_timer_read(); 446 u2 = acpi_timer_read(); 447 u3 = acpi_timer_read(); 448 449 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 450 for (;;) { 451 /* 452 * The failure case is where u3 > u1, but u2 does not fall between 453 * the two, ie. it contains garbage. 454 */ 455 if (u3 > u1) { 456 if (u2 < u1 || u2 > u3) 457 device_printf(acpi_timer_dev, 458 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 459 u1, u2, u3); 460 } 461 u1 = u2; 462 u2 = u3; 463 u3 = acpi_timer_read(); 464 } 465} 466