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 * $FreeBSD$ 28 */ 29 #include "opt_acpi.h" 30 #include <sys/param.h> 31 #include <sys/bus.h> 32 #include <sys/kernel.h> 33 #include <sys/sysctl.h> 34 #include <sys/timetc.h> 35 36 #include <machine/bus_pio.h> 37 #include <machine/bus.h> 38 #include <machine/resource.h> 39 #include <sys/rman.h> 40 41 #include "acpi.h" 42 43 #include <acpica/acpivar.h> 44 #include <pci/pcivar.h> 45 46 /* 47 * A timecounter based on the free-running ACPI timer. 48 * 49 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 50 */ 51 52 /* 53 * Hooks for the ACPI CA debugging infrastructure 54 */ 55 #define _COMPONENT ACPI_SYSTEM 56 ACPI_MODULE_NAME("TIMER") 57 58 static device_t acpi_timer_dev; 59 struct resource *acpi_timer_reg; 60 #define TIMER_READ bus_space_read_4(rman_get_bustag(acpi_timer_reg), \ 61 rman_get_bushandle(acpi_timer_reg), \ 62 0) 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 unsigned acpi_timer_get_timecount(struct timecounter *tc); 70 static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc); 71 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 72 static void acpi_timer_test(void); 73 74 /* 75 * Driver hung off ACPI. 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 94 /* 95 * Timecounter. 96 */ 97 static struct timecounter acpi_timer_timecounter = { 98 acpi_timer_get_timecount_safe, 99 0, 100 0xffffff, 101 0, 102 "ACPI" 103 }; 104 105 SYSCTL_OPAQUE(_debug, OID_AUTO, acpi_timecounter, CTLFLAG_RD, 106 &acpi_timer_timecounter, sizeof(acpi_timer_timecounter), "S,timecounter", ""); 107 static int test_counter(void); 108 109 #define N 2000 110 static int 111 test_counter() 112 { 113 int min, max, n, delta; 114 unsigned last, this; 115 116 min = 10000000; 117 max = 0; 118 last = TIMER_READ; 119 for (n = 0; n < N; n++) { 120 this = TIMER_READ; 121 delta = (this - last) & 0xffffff; 122 if (delta > max) 123 max = delta; 124 else if (delta < min) 125 min = delta; 126 last = this; 127 } 128 if (max - min > 2) 129 n = 0; 130 else if (min < 0) 131 n = 0; 132 else 133 n = 1; 134 if (bootverbose) 135 printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", 136 n ? "GOOD" : "BAD ", 137 min, max, max - min + 1); 138 return (n); 139 } 140 141 /* 142 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 143 * we will be using. 144 */ 145 static void 146 acpi_timer_identify(driver_t *driver, device_t parent) 147 { 148 device_t dev; 149 char desc[40]; 150 int rid, i, j; 151 152 ACPI_FUNCTION_TRACE(__func__); 153 154 if (acpi_disabled("timer")) 155 return_VOID; 156 157 if (AcpiGbl_FADT == NULL) 158 return_VOID; 159 160 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 161 device_printf(parent, "could not add acpi_timer0\n"); 162 return_VOID; 163 } 164 acpi_timer_dev = dev; 165 rid = 0; 166 bus_set_resource(dev, SYS_RES_IOPORT, rid, AcpiGbl_FADT->V1_PmTmrBlk, sizeof(u_int32_t)); 167 if ((acpi_timer_reg = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid, 0, ~0, 1, RF_ACTIVE)) == NULL) { 168 device_printf(dev, "couldn't allocate I/O resource (port 0x%x)\n", AcpiGbl_FADT->V1_PmTmrBlk); 169 return_VOID; 170 } 171 if (getenv("debug.acpi.timer_test") != NULL) 172 acpi_timer_test(); 173 174 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 175 j = 0; 176 for(i = 0; i < 10; i++) 177 j += test_counter(); 178 if (j == 10) { 179 acpi_timer_timecounter.tc_name = "ACPI-fast"; 180 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 181 } else { 182 acpi_timer_timecounter.tc_name = "ACPI-safe"; 183 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 184 } 185 tc_init(&acpi_timer_timecounter); 186 187 sprintf(desc, "%d-bit timer at 3.579545MHz", AcpiGbl_FADT->TmrValExt ? 32 : 24); 188 device_set_desc_copy(dev, desc); 189 190 return_VOID; 191 } 192 193 static int 194 acpi_timer_probe(device_t dev) 195 { 196 if (dev == acpi_timer_dev) 197 return(0); 198 return(ENXIO); 199 } 200 201 static int 202 acpi_timer_attach(device_t dev) 203 { 204 return(0); 205 } 206 207 /* 208 * Fetch current time value from reliable hardware. 209 */ 210 static unsigned 211 acpi_timer_get_timecount(struct timecounter *tc) 212 { 213 return(TIMER_READ); 214 } 215 216 /* 217 * Fetch current time value from hardware that may not correctly 218 * latch the counter. 219 */ 220 static unsigned 221 acpi_timer_get_timecount_safe(struct timecounter *tc) 222 { 223 unsigned u1, u2, u3; 224 225 u2 = TIMER_READ; 226 u3 = TIMER_READ; 227 do { 228 u1 = u2; 229 u2 = u3; 230 u3 = TIMER_READ; 231 } while (u1 > u2 || u2 > u3 || (u3 - u1) > 15); 232 return (u2); 233 } 234 235 /* 236 * Timecounter freqency adjustment interface. 237 */ 238 static int 239 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 240 { 241 int error; 242 u_int freq; 243 244 if (acpi_timer_timecounter.tc_frequency == 0) 245 return (EOPNOTSUPP); 246 freq = acpi_timer_frequency; 247 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 248 if (error == 0 && req->newptr != NULL) { 249 acpi_timer_frequency = freq; 250 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 251 tc_update(&acpi_timer_timecounter); 252 } 253 return (error); 254 } 255 256 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 257 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 258 259 /* 260 * Test harness for verifying ACPI timer behaviour. 261 * Boot with debug.acpi.timer_test set to invoke this. 262 */ 263 static void 264 acpi_timer_test(void) 265 { 266 u_int32_t u1, u2, u3; 267 268 u1 = TIMER_READ; 269 u2 = TIMER_READ; 270 u3 = TIMER_READ; 271 272 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 273 for (;;) { 274 /* 275 * The failure case is where u3 > u1, but u2 does not fall between the two, 276 * ie. it contains garbage. 277 */ 278 if (u3 > u1) { 279 if ((u2 < u1) || (u2 > u3)) 280 device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 281 u1, u2, u3); 282 } 283 u1 = u2; 284 u2 = u3; 285 u3 = TIMER_READ; 286 } 287 } 288 289 /* 290 * Chipset workaround driver hung off PCI. 291 * 292 * Some ACPI timers are known or believed to suffer from implementation 293 * problems which can lead to erroneous values being read from the timer. 294 * 295 * Since we can't trust unknown chipsets, we default to a timer-read 296 * routine which compensates for the most common problem (as detailed 297 * in the excerpt from the Intel PIIX4 datasheet below). 298 * 299 * When we detect a known-functional chipset, we disable the workaround 300 * to improve speed. 301 * 302 * ] 20. ACPI Timer Errata 303 * ] 304 * ] Problem: The power management timer may return improper result when 305 * ] read. Although the timer value settles properly after incrementing, 306 * ] while incrementing there is a 3nS window every 69.8nS where the 307 * ] timer value is indeterminate (a 4.2% chance that the data will be 308 * ] incorrect when read). As a result, the ACPI free running count up 309 * ] timer specification is violated due to erroneous reads. Implication: 310 * ] System hangs due to the "inaccuracy" of the timer when used by 311 * ] software for time critical events and delays. 312 * ] 313 * ] Workaround: Read the register twice and compare. 314 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 315 * ] in the PIIX4M. 316 * 317 * The counter is in other words not latched to the PCI bus clock when 318 * read. Notice the workaround isn't: We need to read until we have 319 * three monotonic samples and then use the middle one, otherwise we are 320 * not protected against the fact that the bits can be wrong in two 321 * directions. If we only cared about monosity two reads would be enough. 322 */ 323 324 #if 0 325 static int acpi_timer_pci_probe(device_t dev); 326 327 static device_method_t acpi_timer_pci_methods[] = { 328 DEVMETHOD(device_probe, acpi_timer_pci_probe), 329 {0, 0} 330 }; 331 332 static driver_t acpi_timer_pci_driver = { 333 "acpi_timer_pci", 334 acpi_timer_pci_methods, 335 0, 336 }; 337 338 devclass_t acpi_timer_pci_devclass; 339 DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0); 340 341 /* 342 * Look at PCI devices going past; if we detect one we know contains 343 * a functional ACPI timer device, enable the faster timecounter read 344 * routine. 345 */ 346 static int 347 acpi_timer_pci_probe(device_t dev) 348 { 349 int vendor, device, revid; 350 351 vendor = pci_get_vendor(dev); 352 device = pci_get_device(dev); 353 revid = pci_get_revid(dev); 354 355 if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */ 356 ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */ 357 0) { 358 359 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 360 acpi_timer_timecounter.tc_name = "ACPI-fast"; 361 if (bootverbose) 362 device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n"); 363 } 364 365 return(ENXIO); /* we never match anything */ 366 } 367 #endif 368