acpi_timer.c revision 222222
167761Smsmith/*- 280070Smsmith * Copyright (c) 2000, 2001 Michael Smith 367761Smsmith * Copyright (c) 2000 BSDi 467761Smsmith * All rights reserved. 567761Smsmith * 667761Smsmith * Redistribution and use in source and binary forms, with or without 767761Smsmith * modification, are permitted provided that the following conditions 867761Smsmith * are met: 967761Smsmith * 1. Redistributions of source code must retain the above copyright 1067761Smsmith * notice, this list of conditions and the following disclaimer. 1167761Smsmith * 2. Redistributions in binary form must reproduce the above copyright 1267761Smsmith * notice, this list of conditions and the following disclaimer in the 1367761Smsmith * documentation and/or other materials provided with the distribution. 1467761Smsmith * 1567761Smsmith * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1667761Smsmith * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1767761Smsmith * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1867761Smsmith * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1967761Smsmith * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2067761Smsmith * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2167761Smsmith * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2267761Smsmith * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2367761Smsmith * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2467761Smsmith * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2567761Smsmith * SUCH DAMAGE. 2667761Smsmith */ 27143002Sobrien 28143002Sobrien#include <sys/cdefs.h> 29143002Sobrien__FBSDID("$FreeBSD: head/sys/dev/acpica/acpi_timer.c 222222 2011-05-23 20:12:36Z jkim $"); 30143002Sobrien 3167761Smsmith#include "opt_acpi.h" 3267761Smsmith#include <sys/param.h> 3380070Smsmith#include <sys/bus.h> 3467761Smsmith#include <sys/kernel.h> 35129879Sphk#include <sys/module.h> 3680070Smsmith#include <sys/sysctl.h> 3780070Smsmith#include <sys/timetc.h> 3867761Smsmith 3980070Smsmith#include <machine/bus.h> 4080070Smsmith#include <machine/resource.h> 4180070Smsmith#include <sys/rman.h> 4280070Smsmith 43193530Sjkim#include <contrib/dev/acpica/include/acpi.h> 44193530Sjkim#include <contrib/dev/acpica/include/accommon.h> 45193530Sjkim 46104726Sjhb#include <dev/acpica/acpivar.h> 47119281Simp#include <dev/pci/pcivar.h> 4867761Smsmith 4969744Smsmith/* 5080070Smsmith * A timecounter based on the free-running ACPI timer. 5180070Smsmith * 5280070Smsmith * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 5380070Smsmith */ 5480070Smsmith 55119529Snjl/* Hooks for the ACPI CA debugging infrastructure */ 56126517Snjl#define _COMPONENT ACPI_TIMER 5791128SmsmithACPI_MODULE_NAME("TIMER") 5869744Smsmith 59128528Snjlstatic device_t acpi_timer_dev; 60128528Snjlstatic struct resource *acpi_timer_reg; 61128543Snjlstatic bus_space_handle_t acpi_timer_bsh; 62128543Snjlstatic bus_space_tag_t acpi_timer_bst; 6367761Smsmith 64119529Snjlstatic u_int acpi_timer_frequency = 14318182 / 4; 6567761Smsmith 6667761Smsmithstatic void acpi_timer_identify(driver_t *driver, device_t parent); 6767761Smsmithstatic int acpi_timer_probe(device_t dev); 6867761Smsmithstatic int acpi_timer_attach(device_t dev); 69128506Snjlstatic u_int acpi_timer_get_timecount(struct timecounter *tc); 70128506Snjlstatic u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 7180070Smsmithstatic int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 72128543Snjlstatic void acpi_timer_boot_test(void); 7367761Smsmith 74128543Snjlstatic int acpi_timer_test(void); 75114277Smarcel 7667761Smsmithstatic device_method_t acpi_timer_methods[] = { 7767761Smsmith DEVMETHOD(device_identify, acpi_timer_identify), 7867761Smsmith DEVMETHOD(device_probe, acpi_timer_probe), 7967761Smsmith DEVMETHOD(device_attach, acpi_timer_attach), 8067761Smsmith 8167761Smsmith {0, 0} 8267761Smsmith}; 8367761Smsmith 8467761Smsmithstatic driver_t acpi_timer_driver = { 8567761Smsmith "acpi_timer", 8667761Smsmith acpi_timer_methods, 8780070Smsmith 0, 8867761Smsmith}; 8967761Smsmith 9089054Smsmithstatic devclass_t acpi_timer_devclass; 9167761SmsmithDRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 92128071SnjlMODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 9367761Smsmith 9480070Smsmithstatic struct timecounter acpi_timer_timecounter = { 95128543Snjl acpi_timer_get_timecount_safe, /* get_timecount function */ 96128543Snjl 0, /* no poll_pps */ 97128543Snjl 0, /* no default counter_mask */ 98128543Snjl 0, /* no default frequency */ 99128543Snjl "ACPI", /* name */ 100171657Snjl -1 /* quality (chosen later) */ 10180070Smsmith}; 10280070Smsmith 103220331Sjkimstatic __inline uint32_t 104220331Sjkimacpi_timer_read(void) 105114277Smarcel{ 106220331Sjkim 107128607Snjl return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 108114277Smarcel} 109114277Smarcel 11080070Smsmith/* 11180070Smsmith * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 11280070Smsmith * we will be using. 11380070Smsmith */ 11467761Smsmithstatic void 11567761Smsmithacpi_timer_identify(driver_t *driver, device_t parent) 11667761Smsmith{ 117132527Snjl device_t dev; 118132527Snjl u_long rlen, rstart; 119132527Snjl int rid, rtype; 12067761Smsmith 12196926Speter ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 12269744Smsmith 123136270Snjl if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || 124167814Sjkim acpi_timer_dev) 12569744Smsmith return_VOID; 126128506Snjl 12767761Smsmith if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 12867761Smsmith device_printf(parent, "could not add acpi_timer0\n"); 12969744Smsmith return_VOID; 13067761Smsmith } 13180070Smsmith acpi_timer_dev = dev; 132114277Smarcel 133220805Sjkim switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 134220805Sjkim case ACPI_ADR_SPACE_SYSTEM_MEMORY: 135220805Sjkim rtype = SYS_RES_MEMORY; 136220805Sjkim break; 137220805Sjkim case ACPI_ADR_SPACE_SYSTEM_IO: 138220805Sjkim rtype = SYS_RES_IOPORT; 139220805Sjkim break; 140220805Sjkim default: 141220805Sjkim return_VOID; 142220805Sjkim } 14380070Smsmith rid = 0; 144167814Sjkim rlen = AcpiGbl_FADT.PmTimerLength; 145167814Sjkim rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 146132527Snjl if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 147132527Snjl device_printf(dev, "couldn't set resource (%s 0x%lx+0x%lx)\n", 148132527Snjl (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 149132527Snjl return_VOID; 150132527Snjl} 151132527Snjl 152132527Snjlstatic int 153132527Snjlacpi_timer_probe(device_t dev) 154132527Snjl{ 155132527Snjl char desc[40]; 156132527Snjl int i, j, rid, rtype; 157132527Snjl 158132527Snjl ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 159132527Snjl 160132527Snjl if (dev != acpi_timer_dev) 161132527Snjl return (ENXIO); 162132527Snjl 163220805Sjkim switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 164220805Sjkim case ACPI_ADR_SPACE_SYSTEM_MEMORY: 165220805Sjkim rtype = SYS_RES_MEMORY; 166220805Sjkim break; 167220805Sjkim case ACPI_ADR_SPACE_SYSTEM_IO: 168220805Sjkim rtype = SYS_RES_IOPORT; 169220805Sjkim break; 170220805Sjkim default: 171220805Sjkim return (ENXIO); 172220805Sjkim } 173132527Snjl rid = 0; 174127135Snjl acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 175114277Smarcel if (acpi_timer_reg == NULL) { 176132527Snjl device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 177132527Snjl (rtype == SYS_RES_IOPORT) ? "port" : "mem", 178167814Sjkim (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 179132527Snjl return (ENXIO); 18067761Smsmith } 181132528Snjl acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 182132528Snjl acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 183167814Sjkim if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 184128506Snjl acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 185128506Snjl else 186128506Snjl acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 187128506Snjl acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 18894936Smux if (testenv("debug.acpi.timer_test")) 189128543Snjl acpi_timer_boot_test(); 19067761Smsmith 191128528Snjl /* 192128528Snjl * If all tests of the counter succeed, use the ACPI-fast method. If 193128528Snjl * at least one failed, default to using the safe routine, which reads 194128528Snjl * the timer multiple times to get a consistent value before returning. 195128528Snjl */ 19691237Sphk j = 0; 197137151Sphk if (bootverbose) 198137151Sphk printf("ACPI timer:"); 199128506Snjl for (i = 0; i < 10; i++) 200128543Snjl j += acpi_timer_test(); 201137151Sphk if (bootverbose) 202137151Sphk printf(" -> %d\n", j); 20391237Sphk if (j == 10) { 20491237Sphk acpi_timer_timecounter.tc_name = "ACPI-fast"; 20591237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 206222222Sjkim acpi_timer_timecounter.tc_quality = 900; 20791237Sphk } else { 20891237Sphk acpi_timer_timecounter.tc_name = "ACPI-safe"; 20991237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 210171657Snjl acpi_timer_timecounter.tc_quality = 850; 21191237Sphk } 21280070Smsmith tc_init(&acpi_timer_timecounter); 21380070Smsmith 214220805Sjkim sprintf(desc, "%d-bit timer at %u.%06uMHz", 215220805Sjkim (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, 216220805Sjkim acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); 21767761Smsmith device_set_desc_copy(dev, desc); 21869744Smsmith 219132527Snjl /* Release the resource, we'll allocate it again during attach. */ 220132527Snjl bus_release_resource(dev, rtype, rid, acpi_timer_reg); 221132527Snjl return (0); 22267761Smsmith} 22367761Smsmith 22467761Smsmithstatic int 225132527Snjlacpi_timer_attach(device_t dev) 22667761Smsmith{ 227132527Snjl int rid, rtype; 228119529Snjl 229132527Snjl ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 23067761Smsmith 231220805Sjkim switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { 232220805Sjkim case ACPI_ADR_SPACE_SYSTEM_MEMORY: 233220805Sjkim rtype = SYS_RES_MEMORY; 234220805Sjkim break; 235220805Sjkim case ACPI_ADR_SPACE_SYSTEM_IO: 236220805Sjkim rtype = SYS_RES_IOPORT; 237220805Sjkim break; 238220805Sjkim default: 239220805Sjkim return (ENXIO); 240220805Sjkim } 241132527Snjl rid = 0; 242132527Snjl acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 243132527Snjl if (acpi_timer_reg == NULL) 244132527Snjl return (ENXIO); 245132527Snjl acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 246132527Snjl acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 247119529Snjl return (0); 24880070Smsmith} 24967761Smsmith 25080070Smsmith/* 25181096Smsmith * Fetch current time value from reliable hardware. 25280070Smsmith */ 253128506Snjlstatic u_int 25480070Smsmithacpi_timer_get_timecount(struct timecounter *tc) 25580070Smsmith{ 256128543Snjl return (acpi_timer_read()); 25767761Smsmith} 25880070Smsmith 25980070Smsmith/* 26081096Smsmith * Fetch current time value from hardware that may not correctly 261128528Snjl * latch the counter. We need to read until we have three monotonic 262128528Snjl * samples and then use the middle one, otherwise we are not protected 263128528Snjl * against the fact that the bits can be wrong in two directions. If 264128528Snjl * we only cared about monosity, two reads would be enough. 26581096Smsmith */ 266128506Snjlstatic u_int 26781096Smsmithacpi_timer_get_timecount_safe(struct timecounter *tc) 26881096Smsmith{ 269128506Snjl u_int u1, u2, u3; 27081096Smsmith 271128543Snjl u2 = acpi_timer_read(); 272128543Snjl u3 = acpi_timer_read(); 27381096Smsmith do { 27481096Smsmith u1 = u2; 27581096Smsmith u2 = u3; 276128543Snjl u3 = acpi_timer_read(); 277128543Snjl } while (u1 > u2 || u2 > u3); 278119529Snjl 27981096Smsmith return (u2); 28081096Smsmith} 28181096Smsmith 28281096Smsmith/* 28380070Smsmith * Timecounter freqency adjustment interface. 28480070Smsmith */ 28580070Smsmithstatic int 28680070Smsmithacpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 28780070Smsmith{ 28880070Smsmith int error; 28980070Smsmith u_int freq; 29080070Smsmith 29180070Smsmith if (acpi_timer_timecounter.tc_frequency == 0) 29280070Smsmith return (EOPNOTSUPP); 29380070Smsmith freq = acpi_timer_frequency; 294170289Sdwmalone error = sysctl_handle_int(oidp, &freq, 0, req); 29580070Smsmith if (error == 0 && req->newptr != NULL) { 29680070Smsmith acpi_timer_frequency = freq; 29780070Smsmith acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 29880070Smsmith } 299119529Snjl 30080070Smsmith return (error); 30180070Smsmith} 30280070Smsmith 30380070SmsmithSYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 304220613Sjkim 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "ACPI timer frequency"); 30580070Smsmith 30680070Smsmith/* 307128528Snjl * Some ACPI timers are known or believed to suffer from implementation 308128528Snjl * problems which can lead to erroneous values being read. This function 309128528Snjl * tests for consistent results from the timer and returns 1 if it believes 310128528Snjl * the timer is consistent, otherwise it returns 0. 311128528Snjl * 312128528Snjl * It appears the cause is that the counter is not latched to the PCI bus 313128528Snjl * clock when read: 314128528Snjl * 315128528Snjl * ] 20. ACPI Timer Errata 316128528Snjl * ] 317128528Snjl * ] Problem: The power management timer may return improper result when 318128528Snjl * ] read. Although the timer value settles properly after incrementing, 319128528Snjl * ] while incrementing there is a 3nS window every 69.8nS where the 320128528Snjl * ] timer value is indeterminate (a 4.2% chance that the data will be 321128528Snjl * ] incorrect when read). As a result, the ACPI free running count up 322128528Snjl * ] timer specification is violated due to erroneous reads. Implication: 323128528Snjl * ] System hangs due to the "inaccuracy" of the timer when used by 324128528Snjl * ] software for time critical events and delays. 325128528Snjl * ] 326128528Snjl * ] Workaround: Read the register twice and compare. 327128528Snjl * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 328128528Snjl * ] in the PIIX4M. 329128528Snjl */ 330128528Snjl#define N 2000 331128528Snjlstatic int 332128543Snjlacpi_timer_test() 333128528Snjl{ 334220369Sjkim uint32_t last, this; 335220369Sjkim int delta, max, max2, min, n; 336220369Sjkim register_t s; 337128528Snjl 338220336Sjkim min = INT32_MAX; 339220369Sjkim max = max2 = 0; 340128607Snjl 341128607Snjl /* Test the timer with interrupts disabled to get accurate results. */ 342128607Snjl s = intr_disable(); 343128543Snjl last = acpi_timer_read(); 344128528Snjl for (n = 0; n < N; n++) { 345128543Snjl this = acpi_timer_read(); 346128528Snjl delta = acpi_TimerDelta(this, last); 347220369Sjkim if (delta > max) { 348220369Sjkim max2 = max; 349128528Snjl max = delta; 350220369Sjkim } else if (delta > max2) 351220369Sjkim max2 = delta; 352220336Sjkim if (delta < min) 353128528Snjl min = delta; 354128528Snjl last = this; 355128528Snjl } 356128607Snjl intr_restore(s); 357128607Snjl 358220369Sjkim delta = max2 - min; 359220369Sjkim if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) 360128528Snjl n = 0; 361220369Sjkim else if (min < 0 || max == 0 || max2 == 0) 362128528Snjl n = 0; 363128528Snjl else 364128528Snjl n = 1; 365137151Sphk if (bootverbose) 366220333Sjkim printf(" %d/%d", n, delta); 367128528Snjl 368128528Snjl return (n); 369128528Snjl} 370128528Snjl#undef N 371128528Snjl 372128528Snjl/* 37380070Smsmith * Test harness for verifying ACPI timer behaviour. 37480070Smsmith * Boot with debug.acpi.timer_test set to invoke this. 37580070Smsmith */ 37680070Smsmithstatic void 377128543Snjlacpi_timer_boot_test(void) 37880070Smsmith{ 379128506Snjl uint32_t u1, u2, u3; 380128506Snjl 381128543Snjl u1 = acpi_timer_read(); 382128543Snjl u2 = acpi_timer_read(); 383128543Snjl u3 = acpi_timer_read(); 384128506Snjl 38580070Smsmith device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 38680070Smsmith for (;;) { 38780070Smsmith /* 388119529Snjl * The failure case is where u3 > u1, but u2 does not fall between 389119529Snjl * the two, ie. it contains garbage. 39080070Smsmith */ 39180070Smsmith if (u3 > u1) { 392119529Snjl if (u2 < u1 || u2 > u3) 393119529Snjl device_printf(acpi_timer_dev, 394119529Snjl "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 39580070Smsmith u1, u2, u3); 39680070Smsmith } 39780070Smsmith u1 = u2; 39880070Smsmith u2 = u3; 399128543Snjl u3 = acpi_timer_read(); 40080070Smsmith } 40180070Smsmith} 402