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/kernel.h> 35 #include <sys/module.h> 36 #include <sys/sysctl.h> 37 #include <sys/timetc.h> 38 39 #include <machine/bus.h> 40 #include <machine/resource.h> 41 #include <sys/rman.h> 42 43 #include <contrib/dev/acpica/include/acpi.h> 44 #include <contrib/dev/acpica/include/accommon.h> 45 46 #include <dev/acpica/acpivar.h> 47 #include <dev/pci/pcivar.h> 48 49 /* 50 * A timecounter based on the free-running ACPI timer. 51 * 52 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 53 */ 54 55 /* Hooks for the ACPI CA debugging infrastructure */ 56 #define _COMPONENT ACPI_TIMER 57 ACPI_MODULE_NAME("TIMER") 58 59 static device_t acpi_timer_dev; 60 static struct resource *acpi_timer_reg; 61 static bus_space_handle_t acpi_timer_bsh; 62 static bus_space_tag_t acpi_timer_bst; 63 64 static u_int acpi_timer_frequency = 14318182 / 4; 65 66 static void acpi_timer_identify(driver_t *driver, device_t parent); 67 static int acpi_timer_probe(device_t dev); 68 static int acpi_timer_attach(device_t dev); 69 static u_int acpi_timer_get_timecount(struct timecounter *tc); 70 static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 71 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 72 static void acpi_timer_boot_test(void); 73 74 static u_int acpi_timer_read(void); 75 static int acpi_timer_test(void); 76 77 static device_method_t acpi_timer_methods[] = { 78 DEVMETHOD(device_identify, acpi_timer_identify), 79 DEVMETHOD(device_probe, acpi_timer_probe), 80 DEVMETHOD(device_attach, acpi_timer_attach), 81 82 {0, 0} 83 }; 84 85 static driver_t acpi_timer_driver = { 86 "acpi_timer", 87 acpi_timer_methods, 88 0, 89 }; 90 91 static devclass_t acpi_timer_devclass; 92 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 93 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 94 95 static struct timecounter acpi_timer_timecounter = { 96 acpi_timer_get_timecount_safe, /* get_timecount function */ 97 0, /* no poll_pps */ 98 0, /* no default counter_mask */ 99 0, /* no default frequency */ 100 "ACPI", /* name */ 101 -1 /* quality (chosen later) */ 102 }; 103 104 static u_int 105 acpi_timer_read() 106 { 107 return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 108 } 109 110 /* 111 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 112 * we will be using. 113 */ 114 static void 115 acpi_timer_identify(driver_t *driver, device_t parent) 116 { 117 device_t dev; 118 u_long rlen, rstart; 119 int rid, rtype; 120 121 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 122 123 if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || 124 acpi_timer_dev) 125 return_VOID; 126 127 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 128 device_printf(parent, "could not add acpi_timer0\n"); 129 return_VOID; 130 } 131 acpi_timer_dev = dev; 132 133 rid = 0; 134 rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 135 SYS_RES_IOPORT : SYS_RES_MEMORY; 136 rlen = AcpiGbl_FADT.PmTimerLength; 137 rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 138 if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 139 device_printf(dev, "couldn't set resource (%s 0x%lx+0x%lx)\n", 140 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 141 return_VOID; 142 } 143 144 static int 145 acpi_timer_probe(device_t dev) 146 { 147 char desc[40]; 148 int i, j, rid, rtype; 149 150 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 151 152 if (dev != acpi_timer_dev) 153 return (ENXIO); 154 155 rid = 0; 156 rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 157 SYS_RES_IOPORT : SYS_RES_MEMORY; 158 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 159 if (acpi_timer_reg == NULL) { 160 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 161 (rtype == SYS_RES_IOPORT) ? "port" : "mem", 162 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 163 return (ENXIO); 164 } 165 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 166 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 167 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 168 acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 169 else 170 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 171 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 172 if (testenv("debug.acpi.timer_test")) 173 acpi_timer_boot_test(); 174 175 /* 176 * If all tests of the counter succeed, use the ACPI-fast method. If 177 * at least one failed, default to using the safe routine, which reads 178 * the timer multiple times to get a consistent value before returning. 179 */ 180 j = 0; 181 if (bootverbose) 182 printf("ACPI timer:"); 183 for (i = 0; i < 10; i++) 184 j += acpi_timer_test(); 185 if (bootverbose) 186 printf(" -> %d\n", j); 187 if (j == 10) { 188 acpi_timer_timecounter.tc_name = "ACPI-fast"; 189 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 190 acpi_timer_timecounter.tc_quality = 1000; 191 } else { 192 acpi_timer_timecounter.tc_name = "ACPI-safe"; 193 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 194 acpi_timer_timecounter.tc_quality = 850; 195 } 196 tc_init(&acpi_timer_timecounter); 197 198 sprintf(desc, "%d-bit timer at 3.579545MHz", 199 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) ? 32 : 24); 200 device_set_desc_copy(dev, desc); 201 202 /* Release the resource, we'll allocate it again during attach. */ 203 bus_release_resource(dev, rtype, rid, acpi_timer_reg); 204 return (0); 205 } 206 207 static int 208 acpi_timer_attach(device_t dev) 209 { 210 int rid, rtype; 211 212 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 213 214 rid = 0; 215 rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 216 SYS_RES_IOPORT : SYS_RES_MEMORY; 217 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 218 if (acpi_timer_reg == NULL) 219 return (ENXIO); 220 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 221 acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 222 return (0); 223 } 224 225 /* 226 * Fetch current time value from reliable hardware. 227 */ 228 static u_int 229 acpi_timer_get_timecount(struct timecounter *tc) 230 { 231 return (acpi_timer_read()); 232 } 233 234 /* 235 * Fetch current time value from hardware that may not correctly 236 * latch the counter. We need to read until we have three monotonic 237 * samples and then use the middle one, otherwise we are not protected 238 * against the fact that the bits can be wrong in two directions. If 239 * we only cared about monosity, two reads would be enough. 240 */ 241 static u_int 242 acpi_timer_get_timecount_safe(struct timecounter *tc) 243 { 244 u_int u1, u2, u3; 245 246 u2 = acpi_timer_read(); 247 u3 = acpi_timer_read(); 248 do { 249 u1 = u2; 250 u2 = u3; 251 u3 = acpi_timer_read(); 252 } while (u1 > u2 || u2 > u3); 253 254 return (u2); 255 } 256 257 /* 258 * Timecounter freqency adjustment interface. 259 */ 260 static int 261 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 262 { 263 int error; 264 u_int freq; 265 266 if (acpi_timer_timecounter.tc_frequency == 0) 267 return (EOPNOTSUPP); 268 freq = acpi_timer_frequency; 269 error = sysctl_handle_int(oidp, &freq, 0, req); 270 if (error == 0 && req->newptr != NULL) { 271 acpi_timer_frequency = freq; 272 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 273 } 274 275 return (error); 276 } 277 278 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 279 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 280 281 /* 282 * Some ACPI timers are known or believed to suffer from implementation 283 * problems which can lead to erroneous values being read. This function 284 * tests for consistent results from the timer and returns 1 if it believes 285 * the timer is consistent, otherwise it returns 0. 286 * 287 * It appears the cause is that the counter is not latched to the PCI bus 288 * clock when read: 289 * 290 * ] 20. ACPI Timer Errata 291 * ] 292 * ] Problem: The power management timer may return improper result when 293 * ] read. Although the timer value settles properly after incrementing, 294 * ] while incrementing there is a 3nS window every 69.8nS where the 295 * ] timer value is indeterminate (a 4.2% chance that the data will be 296 * ] incorrect when read). As a result, the ACPI free running count up 297 * ] timer specification is violated due to erroneous reads. Implication: 298 * ] System hangs due to the "inaccuracy" of the timer when used by 299 * ] software for time critical events and delays. 300 * ] 301 * ] Workaround: Read the register twice and compare. 302 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 303 * ] in the PIIX4M. 304 */ 305 #define N 2000 306 static int 307 acpi_timer_test() 308 { 309 uint32_t last, this; 310 int min, max, n, delta; 311 register_t s; 312 313 min = 10000000; 314 max = 0; 315 316 /* Test the timer with interrupts disabled to get accurate results. */ 317 s = intr_disable(); 318 last = acpi_timer_read(); 319 for (n = 0; n < N; n++) { 320 this = acpi_timer_read(); 321 delta = acpi_TimerDelta(this, last); 322 if (delta > max) 323 max = delta; 324 else if (delta < min) 325 min = delta; 326 last = this; 327 } 328 intr_restore(s); 329 330 if (max - min > 2) 331 n = 0; 332 else if (min < 0 || max == 0) 333 n = 0; 334 else 335 n = 1; 336 if (bootverbose) 337 printf(" %d/%d", n, max-min); 338 339 return (n); 340 } 341 #undef N 342 343 /* 344 * Test harness for verifying ACPI timer behaviour. 345 * Boot with debug.acpi.timer_test set to invoke this. 346 */ 347 static void 348 acpi_timer_boot_test(void) 349 { 350 uint32_t u1, u2, u3; 351 352 u1 = acpi_timer_read(); 353 u2 = acpi_timer_read(); 354 u3 = acpi_timer_read(); 355 356 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 357 for (;;) { 358 /* 359 * The failure case is where u3 > u1, but u2 does not fall between 360 * the two, ie. it contains garbage. 361 */ 362 if (u3 > u1) { 363 if (u2 < u1 || u2 > u3) 364 device_printf(acpi_timer_dev, 365 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 366 u1, u2, u3); 367 } 368 u1 = u2; 369 u2 = u3; 370 u3 = acpi_timer_read(); 371 } 372 } 373