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 * $FreeBSD: src/sys/dev/acpica/acpi_timer.c,v 1.24.2.1 2003/08/22 20:49:20 jhb Exp $ 28 * $DragonFly: src/sys/dev/acpica/Attic/acpi_timer.c,v 1.3 2004/02/13 00:25:17 joerg Exp $ 29 */ 30 31 #ifdef NOTDEF /* Disabled */ 32 33 #include "opt_acpi.h" 34 #include <sys/param.h> 35 #include <sys/bus.h> 36 #include <sys/kernel.h> 37 #include <sys/sysctl.h> 38 #if defined(__FreeBSD__) && __FreeBSD_version >= 500000 39 #include <sys/timetc.h> 40 #else 41 #include <sys/time.h> 42 #endif 43 44 #include <machine/bus.h> 45 #include <machine/resource.h> 46 #include <sys/rman.h> 47 48 #include "acpi.h" 49 50 #include <dev/acpica/acpivar.h> 51 #include <bus/pci/pcivar.h> 52 53 /* 54 * A timecounter based on the free-running ACPI timer. 55 * 56 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 57 */ 58 59 /* 60 * Hooks for the ACPI CA debugging infrastructure 61 */ 62 #define _COMPONENT ACPI_SYSTEM 63 ACPI_MODULE_NAME("TIMER") 64 65 static device_t acpi_timer_dev; 66 struct resource *acpi_timer_reg; 67 68 static u_int acpi_timer_frequency = 14318182/4; 69 70 static void acpi_timer_identify(driver_t *driver, device_t parent); 71 static int acpi_timer_probe(device_t dev); 72 static int acpi_timer_attach(device_t dev); 73 static unsigned acpi_timer_get_timecount(struct timecounter *tc); 74 static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc); 75 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 76 static void acpi_timer_test(void); 77 78 static u_int32_t read_counter(void); 79 static int test_counter(void); 80 81 /* 82 * Driver hung off ACPI. 83 */ 84 static device_method_t acpi_timer_methods[] = { 85 DEVMETHOD(device_identify, acpi_timer_identify), 86 DEVMETHOD(device_probe, acpi_timer_probe), 87 DEVMETHOD(device_attach, acpi_timer_attach), 88 89 {0, 0} 90 }; 91 92 static driver_t acpi_timer_driver = { 93 "acpi_timer", 94 acpi_timer_methods, 95 0, 96 }; 97 98 static devclass_t acpi_timer_devclass; 99 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 100 101 /* 102 * Timecounter. 103 */ 104 static struct timecounter acpi_timer_timecounter = { 105 acpi_timer_get_timecount_safe, 106 0, 107 0xffffff, 108 0, 109 "ACPI" 110 }; 111 112 113 static u_int32_t 114 read_counter() 115 { 116 bus_space_handle_t bsh; 117 bus_space_tag_t bst; 118 u_int32_t tv; 119 120 bsh = rman_get_bushandle(acpi_timer_reg); 121 bst = rman_get_bustag(acpi_timer_reg); 122 tv = bus_space_read_4(bst, bsh, 0); 123 bus_space_barrier(bst, bsh, 0, 4, BUS_SPACE_BARRIER_READ); 124 return (tv); 125 } 126 127 #define N 2000 128 static int 129 test_counter() 130 { 131 int min, max, n, delta; 132 unsigned last, this; 133 134 min = 10000000; 135 max = 0; 136 last = read_counter(); 137 for (n = 0; n < N; n++) { 138 this = read_counter(); 139 delta = (this - last) & 0xffffff; 140 if (delta > max) 141 max = delta; 142 else if (delta < min) 143 min = delta; 144 last = this; 145 } 146 if (max - min > 2) 147 n = 0; 148 else if (min < 0 || max == 0) 149 n = 0; 150 else 151 n = 1; 152 if (bootverbose) 153 printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", 154 n ? "GOOD" : "BAD ", 155 min, max, max - min); 156 return (n); 157 } 158 159 /* 160 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 161 * we will be using. 162 */ 163 static void 164 acpi_timer_identify(driver_t *driver, device_t parent) 165 { 166 device_t dev; 167 char desc[40]; 168 u_long rlen, rstart; 169 int i, j, rid, rtype; 170 171 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 172 173 if (acpi_disabled("timer")) 174 return_VOID; 175 176 if (AcpiGbl_FADT == NULL) 177 return_VOID; 178 179 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 180 device_printf(parent, "could not add acpi_timer0\n"); 181 return_VOID; 182 } 183 acpi_timer_dev = dev; 184 185 rid = 0; 186 rlen = AcpiGbl_FADT->PmTmLen; 187 rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId) 188 ? SYS_RES_IOPORT : SYS_RES_MEMORY; 189 rstart = AcpiGbl_FADT->XPmTmrBlk.Address; 190 bus_set_resource(dev, rtype, rid, rstart, rlen); 191 acpi_timer_reg = bus_alloc_resource(dev, rtype, &rid, 0, ~0, 1, RF_ACTIVE); 192 if (acpi_timer_reg == NULL) { 193 device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n", 194 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart); 195 return_VOID; 196 } 197 if (testenv("debug.acpi.timer_test")) 198 acpi_timer_test(); 199 200 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 201 j = 0; 202 for(i = 0; i < 10; i++) 203 j += test_counter(); 204 if (j == 10) { 205 acpi_timer_timecounter.tc_name = "ACPI-fast"; 206 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 207 } else { 208 acpi_timer_timecounter.tc_name = "ACPI-safe"; 209 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 210 } 211 tc_init(&acpi_timer_timecounter); 212 213 sprintf(desc, "%d-bit timer at 3.579545MHz", (AcpiGbl_FADT->TmrValExt) 214 ? 32 : 24); 215 device_set_desc_copy(dev, desc); 216 217 return_VOID; 218 } 219 220 static int 221 acpi_timer_probe(device_t dev) 222 { 223 if (dev == acpi_timer_dev) 224 return(0); 225 return(ENXIO); 226 } 227 228 static int 229 acpi_timer_attach(device_t dev) 230 { 231 return(0); 232 } 233 234 /* 235 * Fetch current time value from reliable hardware. 236 */ 237 static unsigned 238 acpi_timer_get_timecount(struct timecounter *tc) 239 { 240 return (read_counter()); 241 } 242 243 /* 244 * Fetch current time value from hardware that may not correctly 245 * latch the counter. 246 */ 247 static unsigned 248 acpi_timer_get_timecount_safe(struct timecounter *tc) 249 { 250 unsigned u1, u2, u3; 251 252 u2 = read_counter(); 253 u3 = read_counter(); 254 do { 255 u1 = u2; 256 u2 = u3; 257 u3 = read_counter(); 258 } while (u1 > u2 || u2 > u3 || (u3 - u1) > 15); 259 return (u2); 260 } 261 262 /* 263 * Timecounter freqency adjustment interface. 264 */ 265 static int 266 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 267 { 268 int error; 269 u_int freq; 270 271 if (acpi_timer_timecounter.tc_frequency == 0) 272 return (EOPNOTSUPP); 273 freq = acpi_timer_frequency; 274 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 275 if (error == 0 && req->newptr != NULL) { 276 acpi_timer_frequency = freq; 277 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 278 } 279 return (error); 280 } 281 282 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 283 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 284 285 /* 286 * Test harness for verifying ACPI timer behaviour. 287 * Boot with debug.acpi.timer_test set to invoke this. 288 */ 289 static void 290 acpi_timer_test(void) 291 { 292 u_int32_t u1, u2, u3; 293 294 u1 = read_counter(); 295 u2 = read_counter(); 296 u3 = read_counter(); 297 298 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 299 for (;;) { 300 /* 301 * The failure case is where u3 > u1, but u2 does not fall between the two, 302 * ie. it contains garbage. 303 */ 304 if (u3 > u1) { 305 if ((u2 < u1) || (u2 > u3)) 306 device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 307 u1, u2, u3); 308 } 309 u1 = u2; 310 u2 = u3; 311 u3 = read_counter(); 312 } 313 } 314 315 /* 316 * Chipset workaround driver hung off PCI. 317 * 318 * Some ACPI timers are known or believed to suffer from implementation 319 * problems which can lead to erroneous values being read from the timer. 320 * 321 * Since we can't trust unknown chipsets, we default to a timer-read 322 * routine which compensates for the most common problem (as detailed 323 * in the excerpt from the Intel PIIX4 datasheet below). 324 * 325 * When we detect a known-functional chipset, we disable the workaround 326 * to improve speed. 327 * 328 * ] 20. ACPI Timer Errata 329 * ] 330 * ] Problem: The power management timer may return improper result when 331 * ] read. Although the timer value settles properly after incrementing, 332 * ] while incrementing there is a 3nS window every 69.8nS where the 333 * ] timer value is indeterminate (a 4.2% chance that the data will be 334 * ] incorrect when read). As a result, the ACPI free running count up 335 * ] timer specification is violated due to erroneous reads. Implication: 336 * ] System hangs due to the "inaccuracy" of the timer when used by 337 * ] software for time critical events and delays. 338 * ] 339 * ] Workaround: Read the register twice and compare. 340 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 341 * ] in the PIIX4M. 342 * 343 * The counter is in other words not latched to the PCI bus clock when 344 * read. Notice the workaround isn't: We need to read until we have 345 * three monotonic samples and then use the middle one, otherwise we are 346 * not protected against the fact that the bits can be wrong in two 347 * directions. If we only cared about monosity two reads would be enough. 348 */ 349 350 #if 0 351 static int acpi_timer_pci_probe(device_t dev); 352 353 static device_method_t acpi_timer_pci_methods[] = { 354 DEVMETHOD(device_probe, acpi_timer_pci_probe), 355 {0, 0} 356 }; 357 358 static driver_t acpi_timer_pci_driver = { 359 "acpi_timer_pci", 360 acpi_timer_pci_methods, 361 0, 362 }; 363 364 devclass_t acpi_timer_pci_devclass; 365 DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0); 366 367 /* 368 * Look at PCI devices going past; if we detect one we know contains 369 * a functional ACPI timer device, enable the faster timecounter read 370 * routine. 371 */ 372 static int 373 acpi_timer_pci_probe(device_t dev) 374 { 375 int vendor, device, revid; 376 377 vendor = pci_get_vendor(dev); 378 device = pci_get_device(dev); 379 revid = pci_get_revid(dev); 380 381 if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */ 382 ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */ 383 0) { 384 385 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 386 acpi_timer_timecounter.tc_name = "ACPI-fast"; 387 if (bootverbose) 388 device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n"); 389 } 390 391 return(ENXIO); /* we never match anything */ 392 } 393 #endif 394 395 #endif 396