acpi_timer.c revision 128506
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: head/sys/dev/acpica/acpi_timer.c 128506 2004-04-21 00:48:16Z njl $ 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.h> 37#include <machine/resource.h> 38#include <sys/rman.h> 39 40#include "acpi.h" 41#include <dev/acpica/acpivar.h> 42#include <dev/pci/pcivar.h> 43 44/* 45 * A timecounter based on the free-running ACPI timer. 46 * 47 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 48 */ 49 50/* Hooks for the ACPI CA debugging infrastructure */ 51#define _COMPONENT ACPI_TIMER 52ACPI_MODULE_NAME("TIMER") 53 54static device_t acpi_timer_dev; 55struct resource *acpi_timer_reg; 56 57static u_int acpi_timer_frequency = 14318182 / 4; 58 59static void acpi_timer_identify(driver_t *driver, device_t parent); 60static int acpi_timer_probe(device_t dev); 61static int acpi_timer_attach(device_t dev); 62static u_int acpi_timer_get_timecount(struct timecounter *tc); 63static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 64static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 65static void acpi_timer_test(void); 66 67static u_int read_counter(void); 68static int test_counter(void); 69 70static device_method_t acpi_timer_methods[] = { 71 DEVMETHOD(device_identify, acpi_timer_identify), 72 DEVMETHOD(device_probe, acpi_timer_probe), 73 DEVMETHOD(device_attach, acpi_timer_attach), 74 75 {0, 0} 76}; 77 78static driver_t acpi_timer_driver = { 79 "acpi_timer", 80 acpi_timer_methods, 81 0, 82}; 83 84static devclass_t acpi_timer_devclass; 85DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 86MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 87 88static struct timecounter acpi_timer_timecounter = { 89 .tc_get_timecount = acpi_timer_get_timecount_safe, 90 .tc_poll_pps = 0, 91 .tc_counter_mask = 0, 92 .tc_frequency = 0, 93 .tc_name = "ACPI", 94 .tc_quality = 1000 95}; 96 97static u_int 98read_counter() 99{ 100 bus_space_handle_t bsh; 101 bus_space_tag_t bst; 102 uint32_t tv; 103 104 bsh = rman_get_bushandle(acpi_timer_reg); 105 bst = rman_get_bustag(acpi_timer_reg); 106 tv = bus_space_read_4(bst, bsh, 0); 107 bus_space_barrier(bst, bsh, 0, 4, BUS_SPACE_BARRIER_READ); 108 109 return (tv); 110} 111 112#define N 2000 113static int 114test_counter() 115{ 116 uint32_t last, this; 117 int min, max, n, delta; 118 119 min = 10000000; 120 max = 0; 121 last = read_counter(); 122 for (n = 0; n < N; n++) { 123 this = read_counter(); 124 delta = acpi_TimerDelta(this, last); 125 if (delta > max) 126 max = delta; 127 else if (delta < min) 128 min = delta; 129 last = this; 130 } 131 if (max - min > 2) 132 n = 0; 133 else if (min < 0 || max == 0) 134 n = 0; 135 else 136 n = 1; 137 if (bootverbose) { 138 printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", 139 n ? "GOOD" : "BAD ", 140 min, max, max - min); 141 } 142 143 return (n); 144} 145#undef N 146 147/* 148 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 149 * we will be using. 150 */ 151static void 152acpi_timer_identify(driver_t *driver, device_t parent) 153{ 154 device_t dev; 155 char desc[40]; 156 u_long rlen, rstart; 157 int i, j, rid, rtype; 158 159 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 160 161 if (acpi_disabled("timer") || AcpiGbl_FADT == NULL) 162 return_VOID; 163 164 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 165 device_printf(parent, "could not add acpi_timer0\n"); 166 return_VOID; 167 } 168 acpi_timer_dev = dev; 169 170 rid = 0; 171 rlen = AcpiGbl_FADT->PmTmLen; 172 rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId) 173 ? SYS_RES_IOPORT : SYS_RES_MEMORY; 174 rstart = AcpiGbl_FADT->XPmTmrBlk.Address; 175 bus_set_resource(dev, rtype, rid, rstart, rlen); 176 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 177 if (acpi_timer_reg == NULL) { 178 device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n", 179 rtype == SYS_RES_IOPORT ? "port" : "mem", rstart); 180 return_VOID; 181 } 182 if (AcpiGbl_FADT->TmrValExt != 0) 183 acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 184 else 185 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 186 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 187 if (testenv("debug.acpi.timer_test")) 188 acpi_timer_test(); 189 190 j = 0; 191 for (i = 0; i < 10; i++) 192 j += test_counter(); 193 if (j == 10) { 194 acpi_timer_timecounter.tc_name = "ACPI-fast"; 195 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 196 } else { 197 acpi_timer_timecounter.tc_name = "ACPI-safe"; 198 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 199 } 200 tc_init(&acpi_timer_timecounter); 201 202 sprintf(desc, "%d-bit timer at 3.579545MHz", 203 AcpiGbl_FADT->TmrValExt ? 32 : 24); 204 device_set_desc_copy(dev, desc); 205 206 return_VOID; 207} 208 209static int 210acpi_timer_probe(device_t dev) 211{ 212 if (dev == acpi_timer_dev) 213 return (0); 214 215 return (ENXIO); 216} 217 218static int 219acpi_timer_attach(device_t dev) 220{ 221 return (0); 222} 223 224/* 225 * Fetch current time value from reliable hardware. 226 */ 227static u_int 228acpi_timer_get_timecount(struct timecounter *tc) 229{ 230 return (read_counter()); 231} 232 233/* 234 * Fetch current time value from hardware that may not correctly 235 * latch the counter. 236 */ 237static u_int 238acpi_timer_get_timecount_safe(struct timecounter *tc) 239{ 240 u_int u1, u2, u3; 241 242 u2 = read_counter(); 243 u3 = read_counter(); 244 do { 245 u1 = u2; 246 u2 = u3; 247 u3 = read_counter(); 248 } while (u1 > u2 || u2 > u3 || u3 - u1 > 15); 249 250 return (u2); 251} 252 253/* 254 * Timecounter freqency adjustment interface. 255 */ 256static int 257acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 258{ 259 int error; 260 u_int freq; 261 262 if (acpi_timer_timecounter.tc_frequency == 0) 263 return (EOPNOTSUPP); 264 freq = acpi_timer_frequency; 265 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 266 if (error == 0 && req->newptr != NULL) { 267 acpi_timer_frequency = freq; 268 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 269 } 270 271 return (error); 272} 273 274SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 275 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 276 277/* 278 * Test harness for verifying ACPI timer behaviour. 279 * Boot with debug.acpi.timer_test set to invoke this. 280 */ 281static void 282acpi_timer_test(void) 283{ 284 uint32_t u1, u2, u3; 285 286 u1 = read_counter(); 287 u2 = read_counter(); 288 u3 = read_counter(); 289 290 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 291 for (;;) { 292 /* 293 * The failure case is where u3 > u1, but u2 does not fall between 294 * the two, ie. it contains garbage. 295 */ 296 if (u3 > u1) { 297 if (u2 < u1 || u2 > u3) 298 device_printf(acpi_timer_dev, 299 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 300 u1, u2, u3); 301 } 302 u1 = u2; 303 u2 = u3; 304 u3 = read_counter(); 305 } 306} 307