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 <[email protected]>. 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 #ifdef __i386__ 83 static int acpi_timer_test_enabled = 1; 84 #else 85 static int acpi_timer_test_enabled = 0; 86 #endif 87 TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled); 88 89 static device_method_t acpi_timer_methods[] = { 90 DEVMETHOD(device_identify, acpi_timer_identify), 91 DEVMETHOD(device_probe, acpi_timer_probe), 92 DEVMETHOD(device_attach, acpi_timer_attach), 93 94 DEVMETHOD_END 95 }; 96 97 static driver_t acpi_timer_driver = { 98 "acpi_timer", 99 acpi_timer_methods, 100 0, 101 }; 102 103 static devclass_t acpi_timer_devclass; 104 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 105 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 106 107 static struct timecounter acpi_timer_timecounter = { 108 acpi_timer_get_timecount_safe, /* get_timecount function */ 109 0, /* no poll_pps */ 110 0, /* no default counter_mask */ 111 0, /* no default frequency */ 112 "ACPI", /* name */ 113 -1 /* quality (chosen later) */ 114 }; 115 116 static __inline uint32_t 117 acpi_timer_read(void) 118 { 119 120 return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 121 } 122 123 /* 124 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 125 * we will be using. 126 */ 127 static void 128 acpi_timer_identify(driver_t *driver, device_t parent) 129 { 130 device_t dev; 131 rman_res_t rlen, rstart; 132 int rid, rtype; 133 134 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 135 136 if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || 137 acpi_timer_dev || acpi_timer_disabled || 138 AcpiGbl_FADT.PmTimerLength == 0) 139 return_VOID; 140 141 if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) { 142 device_printf(parent, "could not add acpi_timer0\n"); 143 return_VOID; 144 } 145 acpi_timer_dev = dev; 146 147 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 148 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 149 rtype = SYS_RES_MEMORY; 150 break; 151 case ACPI_ADR_SPACE_SYSTEM_IO: 152 rtype = SYS_RES_IOPORT; 153 break; 154 default: 155 return_VOID; 156 } 157 rid = 0; 158 rlen = AcpiGbl_FADT.PmTimerLength; 159 rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 160 if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 161 device_printf(dev, "couldn't set resource (%s 0x%jx+0x%jx)\n", 162 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 163 return_VOID; 164 } 165 166 static int 167 acpi_timer_probe(device_t dev) 168 { 169 char desc[40]; 170 int i, j, rid, rtype; 171 172 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 173 174 if (dev != acpi_timer_dev) 175 return (ENXIO); 176 177 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 178 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 179 rtype = SYS_RES_MEMORY; 180 break; 181 case ACPI_ADR_SPACE_SYSTEM_IO: 182 rtype = SYS_RES_IOPORT; 183 break; 184 default: 185 return (ENXIO); 186 } 187 rid = 0; 188 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 189 if (acpi_timer_reg == NULL) { 190 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 191 (rtype == SYS_RES_IOPORT) ? "port" : "mem", 192 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 193 return (ENXIO); 194 } 195 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 196 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 197 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 198 acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 199 else 200 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 201 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 202 acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE; 203 if (testenv("debug.acpi.timer_test")) 204 acpi_timer_boot_test(); 205 206 /* 207 * If all tests of the counter succeed, use the ACPI-fast method. If 208 * at least one failed, default to using the safe routine, which reads 209 * the timer multiple times to get a consistent value before returning. 210 */ 211 j = 0; 212 if (bootverbose) 213 printf("ACPI timer:"); 214 for (i = 0; i < 10; i++) 215 j += acpi_timer_test(); 216 if (bootverbose) 217 printf(" -> %d\n", j); 218 if (j == 10) { 219 acpi_timer_timecounter.tc_name = "ACPI-fast"; 220 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 221 acpi_timer_timecounter.tc_quality = 900; 222 } else { 223 acpi_timer_timecounter.tc_name = "ACPI-safe"; 224 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 225 acpi_timer_timecounter.tc_quality = 850; 226 } 227 tc_init(&acpi_timer_timecounter); 228 229 sprintf(desc, "%d-bit timer at %u.%06uMHz", 230 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, 231 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); 232 device_set_desc_copy(dev, desc); 233 234 /* Release the resource, we'll allocate it again during attach. */ 235 bus_release_resource(dev, rtype, rid, acpi_timer_reg); 236 return (0); 237 } 238 239 static int 240 acpi_timer_attach(device_t dev) 241 { 242 int rid, rtype; 243 244 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 245 246 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 247 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 248 rtype = SYS_RES_MEMORY; 249 break; 250 case ACPI_ADR_SPACE_SYSTEM_IO: 251 rtype = SYS_RES_IOPORT; 252 break; 253 default: 254 return (ENXIO); 255 } 256 rid = 0; 257 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 258 if (acpi_timer_reg == NULL) 259 return (ENXIO); 260 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 261 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 262 263 /* Register suspend event handler. */ 264 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler, 265 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL) 266 device_printf(dev, "failed to register suspend event handler\n"); 267 268 return (0); 269 } 270 271 static void 272 acpi_timer_resume_handler(struct timecounter *newtc) 273 { 274 struct timecounter *tc; 275 276 tc = timecounter; 277 if (tc != newtc) { 278 if (bootverbose) 279 device_printf(acpi_timer_dev, 280 "restoring timecounter, %s -> %s\n", 281 tc->tc_name, newtc->tc_name); 282 (void)newtc->tc_get_timecount(newtc); 283 timecounter = newtc; 284 } 285 } 286 287 static void 288 acpi_timer_suspend_handler(struct timecounter *newtc) 289 { 290 struct timecounter *tc; 291 292 /* Deregister existing resume event handler. */ 293 if (acpi_timer_eh != NULL) { 294 EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh); 295 acpi_timer_eh = NULL; 296 } 297 298 if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) { 299 /* 300 * If we are using a suspend safe timecounter, don't 301 * save/restore it across suspend/resume. 302 */ 303 return; 304 } 305 306 KASSERT(newtc == &acpi_timer_timecounter, 307 ("acpi_timer_suspend_handler: wrong timecounter")); 308 309 tc = timecounter; 310 if (tc != newtc) { 311 if (bootverbose) 312 device_printf(acpi_timer_dev, 313 "switching timecounter, %s -> %s\n", 314 tc->tc_name, newtc->tc_name); 315 (void)acpi_timer_read(); 316 (void)acpi_timer_read(); 317 timecounter = newtc; 318 acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume, 319 acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST); 320 } 321 } 322 323 /* 324 * Fetch current time value from reliable hardware. 325 */ 326 static u_int 327 acpi_timer_get_timecount(struct timecounter *tc) 328 { 329 return (acpi_timer_read()); 330 } 331 332 /* 333 * Fetch current time value from hardware that may not correctly 334 * latch the counter. We need to read until we have three monotonic 335 * samples and then use the middle one, otherwise we are not protected 336 * against the fact that the bits can be wrong in two directions. If 337 * we only cared about monosity, two reads would be enough. 338 */ 339 static u_int 340 acpi_timer_get_timecount_safe(struct timecounter *tc) 341 { 342 u_int u1, u2, u3; 343 344 u2 = acpi_timer_read(); 345 u3 = acpi_timer_read(); 346 do { 347 u1 = u2; 348 u2 = u3; 349 u3 = acpi_timer_read(); 350 } while (u1 > u2 || u2 > u3); 351 352 return (u2); 353 } 354 355 /* 356 * Timecounter freqency adjustment interface. 357 */ 358 static int 359 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 360 { 361 int error; 362 u_int freq; 363 364 if (acpi_timer_timecounter.tc_frequency == 0) 365 return (EOPNOTSUPP); 366 freq = acpi_timer_frequency; 367 error = sysctl_handle_int(oidp, &freq, 0, req); 368 if (error == 0 && req->newptr != NULL) { 369 acpi_timer_frequency = freq; 370 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 371 } 372 373 return (error); 374 } 375 376 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, 377 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, 378 acpi_timer_sysctl_freq, "I", 379 "ACPI timer frequency"); 380 381 /* 382 * Some ACPI timers are known or believed to suffer from implementation 383 * problems which can lead to erroneous values being read. This function 384 * tests for consistent results from the timer and returns 1 if it believes 385 * the timer is consistent, otherwise it returns 0. 386 * 387 * It appears the cause is that the counter is not latched to the PCI bus 388 * clock when read: 389 * 390 * ] 20. ACPI Timer Errata 391 * ] 392 * ] Problem: The power management timer may return improper result when 393 * ] read. Although the timer value settles properly after incrementing, 394 * ] while incrementing there is a 3nS window every 69.8nS where the 395 * ] timer value is indeterminate (a 4.2% chance that the data will be 396 * ] incorrect when read). As a result, the ACPI free running count up 397 * ] timer specification is violated due to erroneous reads. Implication: 398 * ] System hangs due to the "inaccuracy" of the timer when used by 399 * ] software for time critical events and delays. 400 * ] 401 * ] Workaround: Read the register twice and compare. 402 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 403 * ] in the PIIX4M. 404 */ 405 #define N 2000 406 static int 407 acpi_timer_test() 408 { 409 uint32_t last, this; 410 int delta, max, max2, min, n; 411 register_t s; 412 413 /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */ 414 if (!acpi_timer_test_enabled) 415 return (1); 416 417 TSENTER(); 418 419 min = INT32_MAX; 420 max = max2 = 0; 421 422 /* Test the timer with interrupts disabled to get accurate results. */ 423 s = intr_disable(); 424 last = acpi_timer_read(); 425 for (n = 0; n < N; n++) { 426 this = acpi_timer_read(); 427 delta = acpi_TimerDelta(this, last); 428 if (delta > max) { 429 max2 = max; 430 max = delta; 431 } else if (delta > max2) 432 max2 = delta; 433 if (delta < min) 434 min = delta; 435 last = this; 436 } 437 intr_restore(s); 438 439 delta = max2 - min; 440 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) 441 n = 0; 442 else if (min < 0 || max == 0 || max2 == 0) 443 n = 0; 444 else 445 n = 1; 446 if (bootverbose) 447 printf(" %d/%d", n, delta); 448 449 TSEXIT(); 450 451 return (n); 452 } 453 #undef N 454 455 /* 456 * Test harness for verifying ACPI timer behaviour. 457 * Boot with debug.acpi.timer_test set to invoke this. 458 */ 459 static void 460 acpi_timer_boot_test(void) 461 { 462 uint32_t u1, u2, u3; 463 464 u1 = acpi_timer_read(); 465 u2 = acpi_timer_read(); 466 u3 = acpi_timer_read(); 467 468 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 469 for (;;) { 470 /* 471 * The failure case is where u3 > u1, but u2 does not fall between 472 * the two, ie. it contains garbage. 473 */ 474 if (u3 > u1) { 475 if (u2 < u1 || u2 > u3) 476 device_printf(acpi_timer_dev, 477 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 478 u1, u2, u3); 479 } 480 u1 = u2; 481 u2 = u3; 482 u3 = acpi_timer_read(); 483 } 484 } 485