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 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, 0, 0); 100 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 101 102 static struct timecounter acpi_timer_timecounter = { 103 acpi_timer_get_timecount_safe, /* get_timecount function */ 104 0, /* no poll_pps */ 105 0, /* no default counter_mask */ 106 0, /* no default frequency */ 107 "ACPI", /* name */ 108 -1 /* quality (chosen later) */ 109 }; 110 111 static __inline uint32_t 112 acpi_timer_read(void) 113 { 114 115 return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 116 } 117 118 /* 119 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 120 * we will be using. 121 */ 122 static void 123 acpi_timer_identify(driver_t *driver, device_t parent) 124 { 125 device_t dev; 126 rman_res_t rlen, rstart; 127 int rid, rtype; 128 129 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 130 131 if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || 132 acpi_timer_dev || acpi_timer_disabled || 133 AcpiGbl_FADT.PmTimerLength == 0) 134 return_VOID; 135 136 if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) { 137 device_printf(parent, "could not add acpi_timer0\n"); 138 return_VOID; 139 } 140 acpi_timer_dev = dev; 141 142 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 143 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 144 rtype = SYS_RES_MEMORY; 145 break; 146 case ACPI_ADR_SPACE_SYSTEM_IO: 147 rtype = SYS_RES_IOPORT; 148 break; 149 default: 150 return_VOID; 151 } 152 rid = 0; 153 rlen = AcpiGbl_FADT.PmTimerLength; 154 rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 155 if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 156 device_printf(dev, "couldn't set resource (%s 0x%jx+0x%jx)\n", 157 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 158 return_VOID; 159 } 160 161 static int 162 acpi_timer_probe(device_t dev) 163 { 164 char desc[40]; 165 int i, j, rid, rtype; 166 167 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 168 169 if (dev != acpi_timer_dev) 170 return (ENXIO); 171 172 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 173 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 174 rtype = SYS_RES_MEMORY; 175 break; 176 case ACPI_ADR_SPACE_SYSTEM_IO: 177 rtype = SYS_RES_IOPORT; 178 break; 179 default: 180 return (ENXIO); 181 } 182 rid = 0; 183 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 184 if (acpi_timer_reg == NULL) { 185 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 186 (rtype == SYS_RES_IOPORT) ? "port" : "mem", 187 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 188 return (ENXIO); 189 } 190 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 191 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 192 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 193 acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 194 else 195 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 196 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 197 acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE; 198 if (testenv("debug.acpi.timer_test")) 199 acpi_timer_boot_test(); 200 201 /* 202 * If all tests of the counter succeed, use the ACPI-fast method. If 203 * at least one failed, default to using the safe routine, which reads 204 * the timer multiple times to get a consistent value before returning. 205 */ 206 j = 0; 207 if (bootverbose) 208 printf("ACPI timer:"); 209 for (i = 0; i < 10; i++) 210 j += acpi_timer_test(); 211 if (bootverbose) 212 printf(" -> %d\n", j); 213 if (j == 10) { 214 acpi_timer_timecounter.tc_name = "ACPI-fast"; 215 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 216 acpi_timer_timecounter.tc_quality = 900; 217 } else { 218 acpi_timer_timecounter.tc_name = "ACPI-safe"; 219 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 220 acpi_timer_timecounter.tc_quality = 850; 221 } 222 tc_init(&acpi_timer_timecounter); 223 224 sprintf(desc, "%d-bit timer at %u.%06uMHz", 225 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, 226 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); 227 device_set_desc_copy(dev, desc); 228 229 /* Release the resource, we'll allocate it again during attach. */ 230 bus_release_resource(dev, rtype, rid, acpi_timer_reg); 231 return (0); 232 } 233 234 static int 235 acpi_timer_attach(device_t dev) 236 { 237 int rid, rtype; 238 239 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 240 241 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 242 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 243 rtype = SYS_RES_MEMORY; 244 break; 245 case ACPI_ADR_SPACE_SYSTEM_IO: 246 rtype = SYS_RES_IOPORT; 247 break; 248 default: 249 return (ENXIO); 250 } 251 rid = 0; 252 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 253 if (acpi_timer_reg == NULL) 254 return (ENXIO); 255 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 256 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 257 258 /* Register suspend event handler. */ 259 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler, 260 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL) 261 device_printf(dev, "failed to register suspend event handler\n"); 262 263 return (0); 264 } 265 266 static void 267 acpi_timer_resume_handler(struct timecounter *newtc) 268 { 269 struct timecounter *tc; 270 271 tc = timecounter; 272 if (tc != newtc) { 273 if (bootverbose) 274 device_printf(acpi_timer_dev, 275 "restoring timecounter, %s -> %s\n", 276 tc->tc_name, newtc->tc_name); 277 (void)newtc->tc_get_timecount(newtc); 278 timecounter = newtc; 279 } 280 } 281 282 static void 283 acpi_timer_suspend_handler(struct timecounter *newtc) 284 { 285 struct timecounter *tc; 286 287 /* Deregister existing resume event handler. */ 288 if (acpi_timer_eh != NULL) { 289 EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh); 290 acpi_timer_eh = NULL; 291 } 292 293 if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) { 294 /* 295 * If we are using a suspend safe timecounter, don't 296 * save/restore it across suspend/resume. 297 */ 298 return; 299 } 300 301 KASSERT(newtc == &acpi_timer_timecounter, 302 ("acpi_timer_suspend_handler: wrong timecounter")); 303 304 tc = timecounter; 305 if (tc != newtc) { 306 if (bootverbose) 307 device_printf(acpi_timer_dev, 308 "switching timecounter, %s -> %s\n", 309 tc->tc_name, newtc->tc_name); 310 (void)acpi_timer_read(); 311 (void)acpi_timer_read(); 312 timecounter = newtc; 313 acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume, 314 acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST); 315 } 316 } 317 318 /* 319 * Fetch current time value from reliable hardware. 320 */ 321 static u_int 322 acpi_timer_get_timecount(struct timecounter *tc) 323 { 324 return (acpi_timer_read()); 325 } 326 327 /* 328 * Fetch current time value from hardware that may not correctly 329 * latch the counter. We need to read until we have three monotonic 330 * samples and then use the middle one, otherwise we are not protected 331 * against the fact that the bits can be wrong in two directions. If 332 * we only cared about monosity, two reads would be enough. 333 */ 334 static u_int 335 acpi_timer_get_timecount_safe(struct timecounter *tc) 336 { 337 u_int u1, u2, u3; 338 339 u2 = acpi_timer_read(); 340 u3 = acpi_timer_read(); 341 do { 342 u1 = u2; 343 u2 = u3; 344 u3 = acpi_timer_read(); 345 } while (u1 > u2 || u2 > u3); 346 347 return (u2); 348 } 349 350 /* 351 * Timecounter freqency adjustment interface. 352 */ 353 static int 354 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 355 { 356 int error; 357 u_int freq; 358 359 if (acpi_timer_timecounter.tc_frequency == 0) 360 return (EOPNOTSUPP); 361 freq = acpi_timer_frequency; 362 error = sysctl_handle_int(oidp, &freq, 0, req); 363 if (error == 0 && req->newptr != NULL) { 364 acpi_timer_frequency = freq; 365 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 366 } 367 368 return (error); 369 } 370 371 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, 372 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, 373 acpi_timer_sysctl_freq, "I", 374 "ACPI timer frequency"); 375 376 /* 377 * Some ACPI timers are known or believed to suffer from implementation 378 * problems which can lead to erroneous values being read. This function 379 * tests for consistent results from the timer and returns 1 if it believes 380 * the timer is consistent, otherwise it returns 0. 381 * 382 * It appears the cause is that the counter is not latched to the PCI bus 383 * clock when read: 384 * 385 * ] 20. ACPI Timer Errata 386 * ] 387 * ] Problem: The power management timer may return improper result when 388 * ] read. Although the timer value settles properly after incrementing, 389 * ] while incrementing there is a 3nS window every 69.8nS where the 390 * ] timer value is indeterminate (a 4.2% chance that the data will be 391 * ] incorrect when read). As a result, the ACPI free running count up 392 * ] timer specification is violated due to erroneous reads. Implication: 393 * ] System hangs due to the "inaccuracy" of the timer when used by 394 * ] software for time critical events and delays. 395 * ] 396 * ] Workaround: Read the register twice and compare. 397 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 398 * ] in the PIIX4M. 399 */ 400 #define N 2000 401 static int 402 acpi_timer_test(void) 403 { 404 uint32_t last, this; 405 int delta, max, max2, min, n; 406 register_t s; 407 408 /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */ 409 if (!acpi_timer_test_enabled) 410 return (1); 411 412 TSENTER(); 413 414 min = INT32_MAX; 415 max = max2 = 0; 416 417 /* Test the timer with interrupts disabled to get accurate results. */ 418 s = intr_disable(); 419 last = acpi_timer_read(); 420 for (n = 0; n < N; n++) { 421 this = acpi_timer_read(); 422 delta = acpi_TimerDelta(this, last); 423 if (delta > max) { 424 max2 = max; 425 max = delta; 426 } else if (delta > max2) 427 max2 = delta; 428 if (delta < min) 429 min = delta; 430 last = this; 431 } 432 intr_restore(s); 433 434 delta = max2 - min; 435 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) 436 n = 0; 437 else if (min < 0 || max == 0 || max2 == 0) 438 n = 0; 439 else 440 n = 1; 441 if (bootverbose) 442 printf(" %d/%d", n, delta); 443 444 TSEXIT(); 445 446 return (n); 447 } 448 #undef N 449 450 /* 451 * Test harness for verifying ACPI timer behaviour. 452 * Boot with debug.acpi.timer_test set to invoke this. 453 */ 454 static void 455 acpi_timer_boot_test(void) 456 { 457 uint32_t u1, u2, u3; 458 459 u1 = acpi_timer_read(); 460 u2 = acpi_timer_read(); 461 u3 = acpi_timer_read(); 462 463 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 464 for (;;) { 465 /* 466 * The failure case is where u3 > u1, but u2 does not fall between 467 * the two, ie. it contains garbage. 468 */ 469 if (u3 > u1) { 470 if (u2 < u1 || u2 > u3) 471 device_printf(acpi_timer_dev, 472 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 473 u1, u2, u3); 474 } 475 u1 = u2; 476 u2 = u3; 477 u3 = acpi_timer_read(); 478 } 479 } 480