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 1.1 2003/09/24 03:32:16 drhodus Exp $ 29 */ 30 #include "opt_acpi.h" 31 #include <sys/param.h> 32 #include <sys/bus.h> 33 #include <sys/kernel.h> 34 #include <sys/sysctl.h> 35 #if __FreeBSD_version >= 500000 36 #include <sys/timetc.h> 37 #else 38 #include <sys/time.h> 39 #endif 40 41 #include <machine/bus.h> 42 #include <machine/resource.h> 43 #include <sys/rman.h> 44 45 #include "acpi.h" 46 47 #include <dev/acpica/acpivar.h> 48 #include <bus/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 /* 57 * Hooks for the ACPI CA debugging infrastructure 58 */ 59 #define _COMPONENT ACPI_SYSTEM 60 ACPI_MODULE_NAME("TIMER") 61 62 static device_t acpi_timer_dev; 63 struct resource *acpi_timer_reg; 64 65 static u_int acpi_timer_frequency = 14318182/4; 66 67 static void acpi_timer_identify(driver_t *driver, device_t parent); 68 static int acpi_timer_probe(device_t dev); 69 static int acpi_timer_attach(device_t dev); 70 static unsigned acpi_timer_get_timecount(struct timecounter *tc); 71 static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc); 72 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 73 static void acpi_timer_test(void); 74 75 static u_int32_t read_counter(void); 76 static int test_counter(void); 77 78 /* 79 * Driver hung off ACPI. 80 */ 81 static device_method_t acpi_timer_methods[] = { 82 DEVMETHOD(device_identify, acpi_timer_identify), 83 DEVMETHOD(device_probe, acpi_timer_probe), 84 DEVMETHOD(device_attach, acpi_timer_attach), 85 86 {0, 0} 87 }; 88 89 static driver_t acpi_timer_driver = { 90 "acpi_timer", 91 acpi_timer_methods, 92 0, 93 }; 94 95 static devclass_t acpi_timer_devclass; 96 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 97 98 /* 99 * Timecounter. 100 */ 101 static struct timecounter acpi_timer_timecounter = { 102 acpi_timer_get_timecount_safe, 103 0, 104 0xffffff, 105 0, 106 "ACPI" 107 }; 108 109 110 static u_int32_t 111 read_counter() 112 { 113 bus_space_handle_t bsh; 114 bus_space_tag_t bst; 115 u_int32_t tv; 116 117 bsh = rman_get_bushandle(acpi_timer_reg); 118 bst = rman_get_bustag(acpi_timer_reg); 119 tv = bus_space_read_4(bst, bsh, 0); 120 bus_space_barrier(bst, bsh, 0, 4, BUS_SPACE_BARRIER_READ); 121 return (tv); 122 } 123 124 #define N 2000 125 static int 126 test_counter() 127 { 128 int min, max, n, delta; 129 unsigned last, this; 130 131 min = 10000000; 132 max = 0; 133 last = read_counter(); 134 for (n = 0; n < N; n++) { 135 this = read_counter(); 136 delta = (this - last) & 0xffffff; 137 if (delta > max) 138 max = delta; 139 else if (delta < min) 140 min = delta; 141 last = this; 142 } 143 if (max - min > 2) 144 n = 0; 145 else if (min < 0 || max == 0) 146 n = 0; 147 else 148 n = 1; 149 if (bootverbose) 150 printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", 151 n ? "GOOD" : "BAD ", 152 min, max, max - min); 153 return (n); 154 } 155 156 /* 157 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 158 * we will be using. 159 */ 160 static void 161 acpi_timer_identify(driver_t *driver, device_t parent) 162 { 163 device_t dev; 164 char desc[40]; 165 u_long rlen, rstart; 166 int i, j, rid, rtype; 167 168 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 169 170 if (acpi_disabled("timer")) 171 return_VOID; 172 173 if (AcpiGbl_FADT == NULL) 174 return_VOID; 175 176 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 177 device_printf(parent, "could not add acpi_timer0\n"); 178 return_VOID; 179 } 180 acpi_timer_dev = dev; 181 182 rid = 0; 183 rlen = AcpiGbl_FADT->PmTmLen; 184 rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId) 185 ? SYS_RES_IOPORT : SYS_RES_MEMORY; 186 rstart = AcpiGbl_FADT->XPmTmrBlk.Address; 187 bus_set_resource(dev, rtype, rid, rstart, rlen); 188 acpi_timer_reg = bus_alloc_resource(dev, rtype, &rid, 0, ~0, 1, RF_ACTIVE); 189 if (acpi_timer_reg == NULL) { 190 device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n", 191 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart); 192 return_VOID; 193 } 194 if (testenv("debug.acpi.timer_test")) 195 acpi_timer_test(); 196 197 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 198 j = 0; 199 for(i = 0; i < 10; i++) 200 j += test_counter(); 201 if (j == 10) { 202 acpi_timer_timecounter.tc_name = "ACPI-fast"; 203 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 204 } else { 205 acpi_timer_timecounter.tc_name = "ACPI-safe"; 206 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 207 } 208 tc_init(&acpi_timer_timecounter); 209 210 sprintf(desc, "%d-bit timer at 3.579545MHz", (AcpiGbl_FADT->TmrValExt) 211 ? 32 : 24); 212 device_set_desc_copy(dev, desc); 213 214 return_VOID; 215 } 216 217 static int 218 acpi_timer_probe(device_t dev) 219 { 220 if (dev == acpi_timer_dev) 221 return(0); 222 return(ENXIO); 223 } 224 225 static int 226 acpi_timer_attach(device_t dev) 227 { 228 return(0); 229 } 230 231 /* 232 * Fetch current time value from reliable hardware. 233 */ 234 static unsigned 235 acpi_timer_get_timecount(struct timecounter *tc) 236 { 237 return (read_counter()); 238 } 239 240 /* 241 * Fetch current time value from hardware that may not correctly 242 * latch the counter. 243 */ 244 static unsigned 245 acpi_timer_get_timecount_safe(struct timecounter *tc) 246 { 247 unsigned u1, u2, u3; 248 249 u2 = read_counter(); 250 u3 = read_counter(); 251 do { 252 u1 = u2; 253 u2 = u3; 254 u3 = read_counter(); 255 } while (u1 > u2 || u2 > u3 || (u3 - u1) > 15); 256 return (u2); 257 } 258 259 /* 260 * Timecounter freqency adjustment interface. 261 */ 262 static int 263 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 264 { 265 int error; 266 u_int freq; 267 268 if (acpi_timer_timecounter.tc_frequency == 0) 269 return (EOPNOTSUPP); 270 freq = acpi_timer_frequency; 271 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 272 if (error == 0 && req->newptr != NULL) { 273 acpi_timer_frequency = freq; 274 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 275 } 276 return (error); 277 } 278 279 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 280 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 281 282 /* 283 * Test harness for verifying ACPI timer behaviour. 284 * Boot with debug.acpi.timer_test set to invoke this. 285 */ 286 static void 287 acpi_timer_test(void) 288 { 289 u_int32_t u1, u2, u3; 290 291 u1 = read_counter(); 292 u2 = read_counter(); 293 u3 = read_counter(); 294 295 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 296 for (;;) { 297 /* 298 * The failure case is where u3 > u1, but u2 does not fall between the two, 299 * ie. it contains garbage. 300 */ 301 if (u3 > u1) { 302 if ((u2 < u1) || (u2 > u3)) 303 device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 304 u1, u2, u3); 305 } 306 u1 = u2; 307 u2 = u3; 308 u3 = read_counter(); 309 } 310 } 311 312 /* 313 * Chipset workaround driver hung off PCI. 314 * 315 * Some ACPI timers are known or believed to suffer from implementation 316 * problems which can lead to erroneous values being read from the timer. 317 * 318 * Since we can't trust unknown chipsets, we default to a timer-read 319 * routine which compensates for the most common problem (as detailed 320 * in the excerpt from the Intel PIIX4 datasheet below). 321 * 322 * When we detect a known-functional chipset, we disable the workaround 323 * to improve speed. 324 * 325 * ] 20. ACPI Timer Errata 326 * ] 327 * ] Problem: The power management timer may return improper result when 328 * ] read. Although the timer value settles properly after incrementing, 329 * ] while incrementing there is a 3nS window every 69.8nS where the 330 * ] timer value is indeterminate (a 4.2% chance that the data will be 331 * ] incorrect when read). As a result, the ACPI free running count up 332 * ] timer specification is violated due to erroneous reads. Implication: 333 * ] System hangs due to the "inaccuracy" of the timer when used by 334 * ] software for time critical events and delays. 335 * ] 336 * ] Workaround: Read the register twice and compare. 337 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 338 * ] in the PIIX4M. 339 * 340 * The counter is in other words not latched to the PCI bus clock when 341 * read. Notice the workaround isn't: We need to read until we have 342 * three monotonic samples and then use the middle one, otherwise we are 343 * not protected against the fact that the bits can be wrong in two 344 * directions. If we only cared about monosity two reads would be enough. 345 */ 346 347 #if 0 348 static int acpi_timer_pci_probe(device_t dev); 349 350 static device_method_t acpi_timer_pci_methods[] = { 351 DEVMETHOD(device_probe, acpi_timer_pci_probe), 352 {0, 0} 353 }; 354 355 static driver_t acpi_timer_pci_driver = { 356 "acpi_timer_pci", 357 acpi_timer_pci_methods, 358 0, 359 }; 360 361 devclass_t acpi_timer_pci_devclass; 362 DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0); 363 364 /* 365 * Look at PCI devices going past; if we detect one we know contains 366 * a functional ACPI timer device, enable the faster timecounter read 367 * routine. 368 */ 369 static int 370 acpi_timer_pci_probe(device_t dev) 371 { 372 int vendor, device, revid; 373 374 vendor = pci_get_vendor(dev); 375 device = pci_get_device(dev); 376 revid = pci_get_revid(dev); 377 378 if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */ 379 ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */ 380 0) { 381 382 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 383 acpi_timer_timecounter.tc_name = "ACPI-fast"; 384 if (bootverbose) 385 device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n"); 386 } 387 388 return(ENXIO); /* we never match anything */ 389 } 390 #endif 391