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", ""); 107 108 /* 109 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 110 * we will be using. 111 */ 112 static void 113 acpi_timer_identify(driver_t *driver, device_t parent) 114 { 115 device_t dev; 116 char desc[40]; 117 int rid; 118 119 ACPI_FUNCTION_TRACE(__func__); 120 121 if (acpi_disabled("timer")) 122 return_VOID; 123 124 if (AcpiGbl_FADT == NULL) 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 rid = 0; 133 bus_set_resource(dev, SYS_RES_IOPORT, rid, AcpiGbl_FADT->V1_PmTmrBlk, sizeof(u_int32_t)); 134 if ((acpi_timer_reg = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid, 0, ~0, 1, RF_ACTIVE)) == NULL) { 135 device_printf(dev, "couldn't allocate I/O resource (port 0x%x)\n", AcpiGbl_FADT->V1_PmTmrBlk); 136 return_VOID; 137 } 138 if (getenv("debug.acpi.timer_test") != NULL) 139 acpi_timer_test(); 140 141 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 142 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 143 tc_init(&acpi_timer_timecounter); 144 145 sprintf(desc, "%d-bit timer at 3.579545MHz", AcpiGbl_FADT->TmrValExt ? 32 : 24); 146 device_set_desc_copy(dev, desc); 147 148 #if 0 149 { 150 u_int64_t first; 151 152 first = rdtsc(); 153 acpi_timer_get_timecount(NULL); 154 printf("acpi_timer_get_timecount %lld cycles\n", rdtsc() - first); 155 156 first = rdtsc(); 157 acpi_timer_get_timecount_safe(NULL); 158 printf("acpi_timer_get_timecount_safe %lld cycles\n", rdtsc() - first); 159 } 160 #endif 161 162 return_VOID; 163 } 164 165 static int 166 acpi_timer_probe(device_t dev) 167 { 168 if (dev == acpi_timer_dev) 169 return(0); 170 return(ENXIO); 171 } 172 173 static int 174 acpi_timer_attach(device_t dev) 175 { 176 return(0); 177 } 178 179 /* 180 * Fetch current time value from reliable hardware. 181 */ 182 static unsigned 183 acpi_timer_get_timecount(struct timecounter *tc) 184 { 185 return(TIMER_READ); 186 } 187 188 /* 189 * Fetch current time value from hardware that may not correctly 190 * latch the counter. 191 */ 192 static unsigned 193 acpi_timer_get_timecount_safe(struct timecounter *tc) 194 { 195 unsigned u1, u2, u3; 196 197 u2 = TIMER_READ; 198 u3 = TIMER_READ; 199 do { 200 u1 = u2; 201 u2 = u3; 202 u3 = TIMER_READ; 203 } while (u1 > u2 || u2 > u3); 204 return (u2); 205 } 206 207 /* 208 * Timecounter freqency adjustment interface. 209 */ 210 static int 211 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 212 { 213 int error; 214 u_int freq; 215 216 if (acpi_timer_timecounter.tc_frequency == 0) 217 return (EOPNOTSUPP); 218 freq = acpi_timer_frequency; 219 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 220 if (error == 0 && req->newptr != NULL) { 221 acpi_timer_frequency = freq; 222 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 223 tc_update(&acpi_timer_timecounter); 224 } 225 return (error); 226 } 227 228 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 229 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 230 231 /* 232 * Test harness for verifying ACPI timer behaviour. 233 * Boot with debug.acpi.timer_test set to invoke this. 234 */ 235 static void 236 acpi_timer_test(void) 237 { 238 u_int32_t u1, u2, u3; 239 240 u1 = TIMER_READ; 241 u2 = TIMER_READ; 242 u3 = TIMER_READ; 243 244 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 245 for (;;) { 246 /* 247 * The failure case is where u3 > u1, but u2 does not fall between the two, 248 * ie. it contains garbage. 249 */ 250 if (u3 > u1) { 251 if ((u2 < u1) || (u2 > u3)) 252 device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 253 u1, u2, u3); 254 } 255 u1 = u2; 256 u2 = u3; 257 u3 = TIMER_READ; 258 } 259 } 260 261 /* 262 * Chipset workaround driver hung off PCI. 263 * 264 * Some ACPI timers are known or believed to suffer from implementation 265 * problems which can lead to erroneous values being read from the timer. 266 * 267 * Since we can't trust unknown chipsets, we default to a timer-read 268 * routine which compensates for the most common problem (as detailed 269 * in the excerpt from the Intel PIIX4 datasheet below). 270 * 271 * When we detect a known-functional chipset, we disable the workaround 272 * to improve speed. 273 * 274 * ] 20. ACPI Timer Errata 275 * ] 276 * ] Problem: The power management timer may return improper result when 277 * ] read. Although the timer value settles properly after incrementing, 278 * ] while incrementing there is a 3nS window every 69.8nS where the 279 * ] timer value is indeterminate (a 4.2% chance that the data will be 280 * ] incorrect when read). As a result, the ACPI free running count up 281 * ] timer specification is violated due to erroneous reads. Implication: 282 * ] System hangs due to the "inaccuracy" of the timer when used by 283 * ] software for time critical events and delays. 284 * ] 285 * ] Workaround: Read the register twice and compare. 286 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 287 * ] in the PIIX4M. 288 * 289 * The counter is in other words not latched to the PCI bus clock when 290 * read. Notice the workaround isn't: We need to read until we have 291 * three monotonic samples and then use the middle one, otherwise we are 292 * not protected against the fact that the bits can be wrong in two 293 * directions. If we only cared about monosity two reads would be enough. 294 */ 295 296 static int acpi_timer_pci_probe(device_t dev); 297 298 static device_method_t acpi_timer_pci_methods[] = { 299 DEVMETHOD(device_probe, acpi_timer_pci_probe), 300 {0, 0} 301 }; 302 303 static driver_t acpi_timer_pci_driver = { 304 "acpi_timer_pci", 305 acpi_timer_pci_methods, 306 0, 307 }; 308 309 devclass_t acpi_timer_pci_devclass; 310 DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0); 311 312 /* 313 * Look at PCI devices going past; if we detect one we know contains 314 * a functional ACPI timer device, enable the faster timecounter read 315 * routine. 316 */ 317 static int 318 acpi_timer_pci_probe(device_t dev) 319 { 320 int vendor, device, revid; 321 322 vendor = pci_get_vendor(dev); 323 device = pci_get_device(dev); 324 revid = pci_get_revid(dev); 325 326 if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */ 327 ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */ 328 0) { 329 330 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 331 acpi_timer_timecounter.tc_name = "ACPI-fast"; 332 if (bootverbose) 333 device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n"); 334 } 335 336 return(ENXIO); /* we never match anything */ 337 } 338