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 static void acpi_timer_identify(driver_t *driver, device_t parent); 69 static int acpi_timer_probe(device_t dev); 70 static int acpi_timer_attach(device_t dev); 71 static void acpi_timer_resume_handler(struct timecounter *); 72 static void acpi_timer_suspend_handler(struct timecounter *); 73 static u_int acpi_timer_get_timecount(struct timecounter *tc); 74 static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 75 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 76 static void acpi_timer_boot_test(void); 77 78 static int acpi_timer_test(void); 79 80 static 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 88 static driver_t acpi_timer_driver = { 89 "acpi_timer", 90 acpi_timer_methods, 91 0, 92 }; 93 94 static devclass_t acpi_timer_devclass; 95 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 96 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 97 98 static 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 }; 106 107 static __inline uint32_t 108 acpi_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 */ 118 static void 119 acpi_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 } 155 156 static int 157 acpi_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 if (testenv("debug.acpi.timer_test")) 193 acpi_timer_boot_test(); 194 195 /* 196 * If all tests of the counter succeed, use the ACPI-fast method. If 197 * at least one failed, default to using the safe routine, which reads 198 * the timer multiple times to get a consistent value before returning. 199 */ 200 j = 0; 201 if (bootverbose) 202 printf("ACPI timer:"); 203 for (i = 0; i < 10; i++) 204 j += acpi_timer_test(); 205 if (bootverbose) 206 printf(" -> %d\n", j); 207 if (j == 10) { 208 acpi_timer_timecounter.tc_name = "ACPI-fast"; 209 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 210 acpi_timer_timecounter.tc_quality = 900; 211 } else { 212 acpi_timer_timecounter.tc_name = "ACPI-safe"; 213 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 214 acpi_timer_timecounter.tc_quality = 850; 215 } 216 tc_init(&acpi_timer_timecounter); 217 218 sprintf(desc, "%d-bit timer at %u.%06uMHz", 219 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, 220 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); 221 device_set_desc_copy(dev, desc); 222 223 /* Release the resource, we'll allocate it again during attach. */ 224 bus_release_resource(dev, rtype, rid, acpi_timer_reg); 225 return (0); 226 } 227 228 static int 229 acpi_timer_attach(device_t dev) 230 { 231 int rid, rtype; 232 233 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 234 235 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 236 case ACPI_ADR_SPACE_SYSTEM_MEMORY: 237 rtype = SYS_RES_MEMORY; 238 break; 239 case ACPI_ADR_SPACE_SYSTEM_IO: 240 rtype = SYS_RES_IOPORT; 241 break; 242 default: 243 return (ENXIO); 244 } 245 rid = 0; 246 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 247 if (acpi_timer_reg == NULL) 248 return (ENXIO); 249 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 250 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 251 252 /* Register suspend event handler. */ 253 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler, 254 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL) 255 device_printf(dev, "failed to register suspend event handler\n"); 256 257 return (0); 258 } 259 260 static void 261 acpi_timer_resume_handler(struct timecounter *newtc) 262 { 263 struct timecounter *tc; 264 265 tc = timecounter; 266 if (tc != newtc) { 267 if (bootverbose) 268 device_printf(acpi_timer_dev, 269 "restoring timecounter, %s -> %s\n", 270 tc->tc_name, newtc->tc_name); 271 (void)newtc->tc_get_timecount(newtc); 272 (void)newtc->tc_get_timecount(newtc); 273 timecounter = newtc; 274 } 275 } 276 277 static void 278 acpi_timer_suspend_handler(struct timecounter *newtc) 279 { 280 struct timecounter *tc; 281 282 /* Deregister existing resume event handler. */ 283 if (acpi_timer_eh != NULL) { 284 EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh); 285 acpi_timer_eh = NULL; 286 } 287 288 KASSERT(newtc == &acpi_timer_timecounter, 289 ("acpi_timer_suspend_handler: wrong timecounter")); 290 291 tc = timecounter; 292 if (tc != newtc) { 293 if (bootverbose) 294 device_printf(acpi_timer_dev, 295 "switching timecounter, %s -> %s\n", 296 tc->tc_name, newtc->tc_name); 297 (void)acpi_timer_read(); 298 (void)acpi_timer_read(); 299 timecounter = newtc; 300 acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume, 301 acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST); 302 } 303 } 304 305 /* 306 * Fetch current time value from reliable hardware. 307 */ 308 static u_int 309 acpi_timer_get_timecount(struct timecounter *tc) 310 { 311 return (acpi_timer_read()); 312 } 313 314 /* 315 * Fetch current time value from hardware that may not correctly 316 * latch the counter. We need to read until we have three monotonic 317 * samples and then use the middle one, otherwise we are not protected 318 * against the fact that the bits can be wrong in two directions. If 319 * we only cared about monosity, two reads would be enough. 320 */ 321 static u_int 322 acpi_timer_get_timecount_safe(struct timecounter *tc) 323 { 324 u_int u1, u2, u3; 325 326 u2 = acpi_timer_read(); 327 u3 = acpi_timer_read(); 328 do { 329 u1 = u2; 330 u2 = u3; 331 u3 = acpi_timer_read(); 332 } while (u1 > u2 || u2 > u3); 333 334 return (u2); 335 } 336 337 /* 338 * Timecounter freqency adjustment interface. 339 */ 340 static int 341 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 342 { 343 int error; 344 u_int freq; 345 346 if (acpi_timer_timecounter.tc_frequency == 0) 347 return (EOPNOTSUPP); 348 freq = acpi_timer_frequency; 349 error = sysctl_handle_int(oidp, &freq, 0, req); 350 if (error == 0 && req->newptr != NULL) { 351 acpi_timer_frequency = freq; 352 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 353 } 354 355 return (error); 356 } 357 358 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 359 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "ACPI timer frequency"); 360 361 /* 362 * Some ACPI timers are known or believed to suffer from implementation 363 * problems which can lead to erroneous values being read. This function 364 * tests for consistent results from the timer and returns 1 if it believes 365 * the timer is consistent, otherwise it returns 0. 366 * 367 * It appears the cause is that the counter is not latched to the PCI bus 368 * clock when read: 369 * 370 * ] 20. ACPI Timer Errata 371 * ] 372 * ] Problem: The power management timer may return improper result when 373 * ] read. Although the timer value settles properly after incrementing, 374 * ] while incrementing there is a 3nS window every 69.8nS where the 375 * ] timer value is indeterminate (a 4.2% chance that the data will be 376 * ] incorrect when read). As a result, the ACPI free running count up 377 * ] timer specification is violated due to erroneous reads. Implication: 378 * ] System hangs due to the "inaccuracy" of the timer when used by 379 * ] software for time critical events and delays. 380 * ] 381 * ] Workaround: Read the register twice and compare. 382 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 383 * ] in the PIIX4M. 384 */ 385 #define N 2000 386 static int 387 acpi_timer_test() 388 { 389 uint32_t last, this; 390 int delta, max, max2, min, n; 391 register_t s; 392 393 min = INT32_MAX; 394 max = max2 = 0; 395 396 /* Test the timer with interrupts disabled to get accurate results. */ 397 s = intr_disable(); 398 last = acpi_timer_read(); 399 for (n = 0; n < N; n++) { 400 this = acpi_timer_read(); 401 delta = acpi_TimerDelta(this, last); 402 if (delta > max) { 403 max2 = max; 404 max = delta; 405 } else if (delta > max2) 406 max2 = delta; 407 if (delta < min) 408 min = delta; 409 last = this; 410 } 411 intr_restore(s); 412 413 delta = max2 - min; 414 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) 415 n = 0; 416 else if (min < 0 || max == 0 || max2 == 0) 417 n = 0; 418 else 419 n = 1; 420 if (bootverbose) 421 printf(" %d/%d", n, delta); 422 423 return (n); 424 } 425 #undef N 426 427 /* 428 * Test harness for verifying ACPI timer behaviour. 429 * Boot with debug.acpi.timer_test set to invoke this. 430 */ 431 static void 432 acpi_timer_boot_test(void) 433 { 434 uint32_t u1, u2, u3; 435 436 u1 = acpi_timer_read(); 437 u2 = acpi_timer_read(); 438 u3 = acpi_timer_read(); 439 440 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 441 for (;;) { 442 /* 443 * The failure case is where u3 > u1, but u2 does not fall between 444 * the two, ie. it contains garbage. 445 */ 446 if (u3 > u1) { 447 if (u2 < u1 || u2 > u3) 448 device_printf(acpi_timer_dev, 449 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 450 u1, u2, u3); 451 } 452 u1 = u2; 453 u2 = u3; 454 u3 = acpi_timer_read(); 455 } 456 } 457