| 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 1.32 2004/04/24 16:25:00 njl Exp $ |
| 28 | * $DragonFly: src/sys/dev/acpica5/acpi_timer.c,v 1.2 2004/06/27 08:52:39 dillon 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 | #include <bus/pci/pcivar.h> |
| 45 | |
| 46 | #include "acpi.h" |
| 47 | #include "acpivar.h" |
| 48 | |
| 49 | #if 0 |
| 50 | |
| 51 | /* |
| 52 | * A timecounter based on the free-running ACPI timer. |
| 53 | * |
| 54 | * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. |
| 55 | */ |
| 56 | |
| 57 | /* Hooks for the ACPI CA debugging infrastructure */ |
| 58 | #define _COMPONENT ACPI_TIMER |
| 59 | ACPI_MODULE_NAME("TIMER") |
| 60 | |
| 61 | static device_t acpi_timer_dev; |
| 62 | static struct resource *acpi_timer_reg; |
| 63 | static bus_space_handle_t acpi_timer_bsh; |
| 64 | static bus_space_tag_t acpi_timer_bst; |
| 65 | |
| 66 | static u_int acpi_timer_frequency = 14318182 / 4; |
| 67 | |
| 68 | static void acpi_timer_identify(driver_t *driver, device_t parent); |
| 69 | static int acpi_timer_probe(device_t dev); |
| 70 | static int acpi_timer_attach(device_t dev); |
| 71 | static u_int acpi_timer_get_timecount(struct timecounter *tc); |
| 72 | static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); |
| 73 | static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); |
| 74 | static void acpi_timer_boot_test(void); |
| 75 | |
| 76 | static u_int acpi_timer_read(void); |
| 77 | static int acpi_timer_test(void); |
| 78 | |
| 79 | static device_method_t acpi_timer_methods[] = { |
| 80 | DEVMETHOD(device_identify, acpi_timer_identify), |
| 81 | DEVMETHOD(device_probe, acpi_timer_probe), |
| 82 | DEVMETHOD(device_attach, acpi_timer_attach), |
| 83 | |
| 84 | {0, 0} |
| 85 | }; |
| 86 | |
| 87 | static driver_t acpi_timer_driver = { |
| 88 | "acpi_timer", |
| 89 | acpi_timer_methods, |
| 90 | 0, |
| 91 | }; |
| 92 | |
| 93 | static devclass_t acpi_timer_devclass; |
| 94 | DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); |
| 95 | MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); |
| 96 | |
| 97 | static struct timecounter acpi_timer_timecounter = { |
| 98 | acpi_timer_get_timecount_safe, /* get_timecount function */ |
| 99 | 0, /* no poll_pps */ |
| 100 | 0, /* no default counter_mask */ |
| 101 | 0, /* no default frequency */ |
| 102 | "ACPI", /* name */ |
| 103 | 1000 /* quality */ |
| 104 | }; |
| 105 | |
| 106 | static u_int |
| 107 | acpi_timer_read() |
| 108 | { |
| 109 | return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * Locate the ACPI timer using the FADT, set up and allocate the I/O resources |
| 114 | * we will be using. |
| 115 | */ |
| 116 | static void |
| 117 | acpi_timer_identify(driver_t *driver, device_t parent) |
| 118 | { |
| 119 | device_t dev; |
| 120 | char desc[40]; |
| 121 | u_long rlen, rstart; |
| 122 | int i, j, rid, rtype; |
| 123 | |
| 124 | ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); |
| 125 | |
| 126 | if (acpi_disabled("timer") || AcpiGbl_FADT == NULL) |
| 127 | return_VOID; |
| 128 | |
| 129 | if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { |
| 130 | device_printf(parent, "could not add acpi_timer0\n"); |
| 131 | return_VOID; |
| 132 | } |
| 133 | acpi_timer_dev = dev; |
| 134 | |
| 135 | rid = 0; |
| 136 | rlen = AcpiGbl_FADT->PmTmLen; |
| 137 | rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId) |
| 138 | ? SYS_RES_IOPORT : SYS_RES_MEMORY; |
| 139 | rstart = AcpiGbl_FADT->XPmTmrBlk.Address; |
| 140 | bus_set_resource(dev, rtype, rid, rstart, rlen); |
| 141 | acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); |
| 142 | if (acpi_timer_reg == NULL) { |
| 143 | device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n", |
| 144 | rtype == SYS_RES_IOPORT ? "port" : "mem", rstart); |
| 145 | return_VOID; |
| 146 | } |
| 147 | acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); |
| 148 | acpi_timer_bst = rman_get_bustag(acpi_timer_reg); |
| 149 | if (AcpiGbl_FADT->TmrValExt != 0) |
| 150 | acpi_timer_timecounter.tc_counter_mask = 0xffffffff; |
| 151 | else |
| 152 | acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; |
| 153 | acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; |
| 154 | if (testenv("debug.acpi.timer_test")) |
| 155 | acpi_timer_boot_test(); |
| 156 | |
| 157 | /* |
| 158 | * If all tests of the counter succeed, use the ACPI-fast method. If |
| 159 | * at least one failed, default to using the safe routine, which reads |
| 160 | * the timer multiple times to get a consistent value before returning. |
| 161 | */ |
| 162 | j = 0; |
| 163 | for (i = 0; i < 10; i++) |
| 164 | j += acpi_timer_test(); |
| 165 | if (j == 10) { |
| 166 | acpi_timer_timecounter.tc_name = "ACPI-fast"; |
| 167 | acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; |
| 168 | } else { |
| 169 | acpi_timer_timecounter.tc_name = "ACPI-safe"; |
| 170 | acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; |
| 171 | } |
| 172 | tc_init(&acpi_timer_timecounter); |
| 173 | |
| 174 | sprintf(desc, "%d-bit timer at 3.579545MHz", |
| 175 | AcpiGbl_FADT->TmrValExt ? 32 : 24); |
| 176 | device_set_desc_copy(dev, desc); |
| 177 | |
| 178 | return_VOID; |
| 179 | } |
| 180 | |
| 181 | static int |
| 182 | acpi_timer_probe(device_t dev) |
| 183 | { |
| 184 | if (dev == acpi_timer_dev) |
| 185 | return (0); |
| 186 | |
| 187 | return (ENXIO); |
| 188 | } |
| 189 | |
| 190 | static int |
| 191 | acpi_timer_attach(device_t dev) |
| 192 | { |
| 193 | return (0); |
| 194 | } |
| 195 | |
| 196 | /* |
| 197 | * Fetch current time value from reliable hardware. |
| 198 | */ |
| 199 | static u_int |
| 200 | acpi_timer_get_timecount(struct timecounter *tc) |
| 201 | { |
| 202 | return (acpi_timer_read()); |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Fetch current time value from hardware that may not correctly |
| 207 | * latch the counter. We need to read until we have three monotonic |
| 208 | * samples and then use the middle one, otherwise we are not protected |
| 209 | * against the fact that the bits can be wrong in two directions. If |
| 210 | * we only cared about monosity, two reads would be enough. |
| 211 | */ |
| 212 | static u_int |
| 213 | acpi_timer_get_timecount_safe(struct timecounter *tc) |
| 214 | { |
| 215 | u_int u1, u2, u3; |
| 216 | |
| 217 | u2 = acpi_timer_read(); |
| 218 | u3 = acpi_timer_read(); |
| 219 | do { |
| 220 | u1 = u2; |
| 221 | u2 = u3; |
| 222 | u3 = acpi_timer_read(); |
| 223 | } while (u1 > u2 || u2 > u3); |
| 224 | |
| 225 | return (u2); |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | * Timecounter freqency adjustment interface. |
| 230 | */ |
| 231 | static int |
| 232 | acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) |
| 233 | { |
| 234 | int error; |
| 235 | u_int freq; |
| 236 | |
| 237 | if (acpi_timer_timecounter.tc_frequency == 0) |
| 238 | return (EOPNOTSUPP); |
| 239 | freq = acpi_timer_frequency; |
| 240 | error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); |
| 241 | if (error == 0 && req->newptr != NULL) { |
| 242 | acpi_timer_frequency = freq; |
| 243 | acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; |
| 244 | } |
| 245 | |
| 246 | return (error); |
| 247 | } |
| 248 | |
| 249 | SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, |
| 250 | 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); |
| 251 | |
| 252 | /* |
| 253 | * Some ACPI timers are known or believed to suffer from implementation |
| 254 | * problems which can lead to erroneous values being read. This function |
| 255 | * tests for consistent results from the timer and returns 1 if it believes |
| 256 | * the timer is consistent, otherwise it returns 0. |
| 257 | * |
| 258 | * It appears the cause is that the counter is not latched to the PCI bus |
| 259 | * clock when read: |
| 260 | * |
| 261 | * ] 20. ACPI Timer Errata |
| 262 | * ] |
| 263 | * ] Problem: The power management timer may return improper result when |
| 264 | * ] read. Although the timer value settles properly after incrementing, |
| 265 | * ] while incrementing there is a 3nS window every 69.8nS where the |
| 266 | * ] timer value is indeterminate (a 4.2% chance that the data will be |
| 267 | * ] incorrect when read). As a result, the ACPI free running count up |
| 268 | * ] timer specification is violated due to erroneous reads. Implication: |
| 269 | * ] System hangs due to the "inaccuracy" of the timer when used by |
| 270 | * ] software for time critical events and delays. |
| 271 | * ] |
| 272 | * ] Workaround: Read the register twice and compare. |
| 273 | * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed |
| 274 | * ] in the PIIX4M. |
| 275 | */ |
| 276 | #define N 2000 |
| 277 | static int |
| 278 | acpi_timer_test() |
| 279 | { |
| 280 | uint32_t last, this; |
| 281 | int min, max, n, delta; |
| 282 | register_t s; |
| 283 | |
| 284 | min = 10000000; |
| 285 | max = 0; |
| 286 | |
| 287 | /* Test the timer with interrupts disabled to get accurate results. */ |
| 288 | s = intr_disable(); |
| 289 | last = acpi_timer_read(); |
| 290 | for (n = 0; n < N; n++) { |
| 291 | this = acpi_timer_read(); |
| 292 | delta = acpi_TimerDelta(this, last); |
| 293 | if (delta > max) |
| 294 | max = delta; |
| 295 | else if (delta < min) |
| 296 | min = delta; |
| 297 | last = this; |
| 298 | } |
| 299 | intr_restore(s); |
| 300 | |
| 301 | if (max - min > 2) |
| 302 | n = 0; |
| 303 | else if (min < 0 || max == 0) |
| 304 | n = 0; |
| 305 | else |
| 306 | n = 1; |
| 307 | if (bootverbose) { |
| 308 | printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", |
| 309 | n ? "GOOD" : "BAD ", |
| 310 | min, max, max - min); |
| 311 | } |
| 312 | |
| 313 | return (n); |
| 314 | } |
| 315 | #undef N |
| 316 | |
| 317 | /* |
| 318 | * Test harness for verifying ACPI timer behaviour. |
| 319 | * Boot with debug.acpi.timer_test set to invoke this. |
| 320 | */ |
| 321 | static void |
| 322 | acpi_timer_boot_test(void) |
| 323 | { |
| 324 | uint32_t u1, u2, u3; |
| 325 | |
| 326 | u1 = acpi_timer_read(); |
| 327 | u2 = acpi_timer_read(); |
| 328 | u3 = acpi_timer_read(); |
| 329 | |
| 330 | device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); |
| 331 | for (;;) { |
| 332 | /* |
| 333 | * The failure case is where u3 > u1, but u2 does not fall between |
| 334 | * the two, ie. it contains garbage. |
| 335 | */ |
| 336 | if (u3 > u1) { |
| 337 | if (u2 < u1 || u2 > u3) |
| 338 | device_printf(acpi_timer_dev, |
| 339 | "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", |
| 340 | u1, u2, u3); |
| 341 | } |
| 342 | u1 = u2; |
| 343 | u2 = u3; |
| 344 | u3 = acpi_timer_read(); |
| 345 | } |
| 346 | } |
| 347 | |
| 348 | #endif /* 0 */ |