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 56 ACPI_MODULE_NAME("TIMER") 57 58 static device_t acpi_timer_dev; 59 static struct resource *acpi_timer_reg; 60 static bus_space_handle_t acpi_timer_bsh; 61 static bus_space_tag_t acpi_timer_bst; 62 static eventhandler_tag acpi_timer_eh; 63 64 static u_int acpi_timer_frequency = 14318182 / 4; 65 66 /* Knob to disable acpi_timer device */ 67 bool acpi_timer_disabled = false; 68 69 static void acpi_timer_identify(driver_t *driver, device_t parent); 70 static int acpi_timer_probe(device_t dev); 71 static int acpi_timer_attach(device_t dev); 72 static void acpi_timer_resume_handler(struct timecounter *); 73 static void acpi_timer_suspend_handler(struct timecounter *); 74 static u_int acpi_timer_get_timecount(struct timecounter *tc); 75 static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 76 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 77 static void acpi_timer_boot_test(void); 78 79 static int acpi_timer_test(void); 80 static int acpi_timer_test_enabled = 0; 81 TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled); 82 83 static 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 91 static driver_t acpi_timer_driver = { 92 "acpi_timer", 93 acpi_timer_methods, 94 0, 95 }; 96 97 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, 0, 0); 98 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 99 100 static 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 }; 108 109 static __inline uint32_t 110 acpi_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 */ 120 static void 121 acpi_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 } 158 159 static int 160 acpi_timer_probe(device_t dev) 161 { 162 char desc[40]; 163 int i, j, rid, rtype; 164 165 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 166 167 if (dev != acpi_timer_dev) 168 return (ENXIO); 169 170 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 171 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 172 rtype = SYS_RES_MEMORY; 173 break; 174 case ACPI_ADR_SPACE_SYSTEM_IO: 175 rtype = SYS_RES_IOPORT; 176 break; 177 default: 178 return (ENXIO); 179 } 180 rid = 0; 181 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 182 if (acpi_timer_reg == NULL) { 183 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 184 (rtype == SYS_RES_IOPORT) ? "port" : "mem", 185 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 186 return (ENXIO); 187 } 188 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 189 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 190 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 191 acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 192 else 193 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 194 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 195 acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE; 196 if (testenv("debug.acpi.timer_test")) 197 acpi_timer_boot_test(); 198 199 /* 200 * If all tests of the counter succeed, use the ACPI-fast method. If 201 * at least one failed, default to using the safe routine, which reads 202 * the timer multiple times to get a consistent value before returning. 203 */ 204 j = 0; 205 if (bootverbose) 206 printf("ACPI timer:"); 207 for (i = 0; i < 10; i++) 208 j += acpi_timer_test(); 209 if (bootverbose) 210 printf(" -> %d\n", j); 211 if (j == 10) { 212 acpi_timer_timecounter.tc_name = "ACPI-fast"; 213 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 214 acpi_timer_timecounter.tc_quality = 900; 215 } else { 216 acpi_timer_timecounter.tc_name = "ACPI-safe"; 217 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 218 acpi_timer_timecounter.tc_quality = 850; 219 } 220 tc_init(&acpi_timer_timecounter); 221 222 sprintf(desc, "%d-bit timer at %u.%06uMHz", 223 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, 224 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); 225 device_set_desc_copy(dev, desc); 226 227 /* Release the resource, we'll allocate it again during attach. */ 228 bus_release_resource(dev, rtype, rid, acpi_timer_reg); 229 return (0); 230 } 231 232 static int 233 acpi_timer_attach(device_t dev) 234 { 235 int rid, rtype; 236 237 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 238 239 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 240 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 241 rtype = SYS_RES_MEMORY; 242 break; 243 case ACPI_ADR_SPACE_SYSTEM_IO: 244 rtype = SYS_RES_IOPORT; 245 break; 246 default: 247 return (ENXIO); 248 } 249 rid = 0; 250 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 251 if (acpi_timer_reg == NULL) 252 return (ENXIO); 253 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 254 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 255 256 /* Register suspend event handler. */ 257 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler, 258 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL) 259 device_printf(dev, "failed to register suspend event handler\n"); 260 261 return (0); 262 } 263 264 static void 265 acpi_timer_resume_handler(struct timecounter *newtc) 266 { 267 struct timecounter *tc; 268 269 tc = timecounter; 270 if (tc != newtc) { 271 if (bootverbose) 272 device_printf(acpi_timer_dev, 273 "restoring timecounter, %s -> %s\n", 274 tc->tc_name, newtc->tc_name); 275 (void)newtc->tc_get_timecount(newtc); 276 timecounter = newtc; 277 } 278 } 279 280 static void 281 acpi_timer_suspend_handler(struct timecounter *newtc) 282 { 283 struct timecounter *tc; 284 285 /* Deregister existing resume event handler. */ 286 if (acpi_timer_eh != NULL) { 287 EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh); 288 acpi_timer_eh = NULL; 289 } 290 291 if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) { 292 /* 293 * If we are using a suspend safe timecounter, don't 294 * save/restore it across suspend/resume. 295 */ 296 return; 297 } 298 299 KASSERT(newtc == &acpi_timer_timecounter, 300 ("acpi_timer_suspend_handler: wrong timecounter")); 301 302 tc = timecounter; 303 if (tc != newtc) { 304 if (bootverbose) 305 device_printf(acpi_timer_dev, 306 "switching timecounter, %s -> %s\n", 307 tc->tc_name, newtc->tc_name); 308 (void)acpi_timer_read(); 309 (void)acpi_timer_read(); 310 timecounter = newtc; 311 acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume, 312 acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST); 313 } 314 } 315 316 /* 317 * Fetch current time value from reliable hardware. 318 */ 319 static u_int 320 acpi_timer_get_timecount(struct timecounter *tc) 321 { 322 return (acpi_timer_read()); 323 } 324 325 /* 326 * Fetch current time value from hardware that may not correctly 327 * latch the counter. We need to read until we have three monotonic 328 * samples and then use the middle one, otherwise we are not protected 329 * against the fact that the bits can be wrong in two directions. If 330 * we only cared about monosity, two reads would be enough. 331 */ 332 static u_int 333 acpi_timer_get_timecount_safe(struct timecounter *tc) 334 { 335 u_int u1, u2, u3; 336 337 u2 = acpi_timer_read(); 338 u3 = acpi_timer_read(); 339 do { 340 u1 = u2; 341 u2 = u3; 342 u3 = acpi_timer_read(); 343 } while (u1 > u2 || u2 > u3); 344 345 return (u2); 346 } 347 348 /* 349 * Timecounter freqency adjustment interface. 350 */ 351 static int 352 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 353 { 354 int error; 355 u_int freq; 356 357 if (acpi_timer_timecounter.tc_frequency == 0) 358 return (EOPNOTSUPP); 359 freq = acpi_timer_frequency; 360 error = sysctl_handle_int(oidp, &freq, 0, req); 361 if (error == 0 && req->newptr != NULL) { 362 acpi_timer_frequency = freq; 363 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 364 } 365 366 return (error); 367 } 368 369 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, 370 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, 371 acpi_timer_sysctl_freq, "I", 372 "ACPI timer frequency"); 373 374 /* 375 * Some ACPI timers are known or believed to suffer from implementation 376 * problems which can lead to erroneous values being read. This function 377 * tests for consistent results from the timer and returns 1 if it believes 378 * the timer is consistent, otherwise it returns 0. 379 * 380 * It appears the cause is that the counter is not latched to the PCI bus 381 * clock when read: 382 * 383 * ] 20. ACPI Timer Errata 384 * ] 385 * ] Problem: The power management timer may return improper result when 386 * ] read. Although the timer value settles properly after incrementing, 387 * ] while incrementing there is a 3nS window every 69.8nS where the 388 * ] timer value is indeterminate (a 4.2% chance that the data will be 389 * ] incorrect when read). As a result, the ACPI free running count up 390 * ] timer specification is violated due to erroneous reads. Implication: 391 * ] System hangs due to the "inaccuracy" of the timer when used by 392 * ] software for time critical events and delays. 393 * ] 394 * ] Workaround: Read the register twice and compare. 395 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 396 * ] in the PIIX4M. 397 */ 398 #define N 2000 399 static int 400 acpi_timer_test(void) 401 { 402 uint32_t last, this; 403 int delta, max, max2, min, n; 404 register_t s; 405 406 /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */ 407 if (!acpi_timer_test_enabled) 408 return (1); 409 410 TSENTER(); 411 412 min = INT32_MAX; 413 max = max2 = 0; 414 415 /* Test the timer with interrupts disabled to get accurate results. */ 416 s = intr_disable(); 417 last = acpi_timer_read(); 418 for (n = 0; n < N; n++) { 419 this = acpi_timer_read(); 420 delta = acpi_TimerDelta(this, last); 421 if (delta > max) { 422 max2 = max; 423 max = delta; 424 } else if (delta > max2) 425 max2 = delta; 426 if (delta < min) 427 min = delta; 428 last = this; 429 } 430 intr_restore(s); 431 432 delta = max2 - min; 433 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) 434 n = 0; 435 else if (min < 0 || max == 0 || max2 == 0) 436 n = 0; 437 else 438 n = 1; 439 if (bootverbose) 440 printf(" %d/%d", n, delta); 441 442 TSEXIT(); 443 444 return (n); 445 } 446 #undef N 447 448 /* 449 * Test harness for verifying ACPI timer behaviour. 450 * Boot with debug.acpi.timer_test set to invoke this. 451 */ 452 static void 453 acpi_timer_boot_test(void) 454 { 455 uint32_t u1, u2, u3; 456 457 u1 = acpi_timer_read(); 458 u2 = acpi_timer_read(); 459 u3 = acpi_timer_read(); 460 461 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 462 for (;;) { 463 /* 464 * The failure case is where u3 > u1, but u2 does not fall between 465 * the two, ie. it contains garbage. 466 */ 467 if (u3 > u1) { 468 if (u2 < u1 || u2 > u3) 469 device_printf(acpi_timer_dev, 470 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 471 u1, u2, u3); 472 } 473 u1 = u2; 474 u2 = u3; 475 u3 = acpi_timer_read(); 476 } 477 } 478