acpi_timer.c revision 220333
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 220333 2011-04-04 17:00:50Z 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 13380070Smsmith rid = 0; 134167814Sjkim rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 135132527Snjl SYS_RES_IOPORT : SYS_RES_MEMORY; 136167814Sjkim rlen = AcpiGbl_FADT.PmTimerLength; 137167814Sjkim rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 138132527Snjl if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 139132527Snjl device_printf(dev, "couldn't set resource (%s 0x%lx+0x%lx)\n", 140132527Snjl (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 141132527Snjl return_VOID; 142132527Snjl} 143132527Snjl 144132527Snjlstatic int 145132527Snjlacpi_timer_probe(device_t dev) 146132527Snjl{ 147132527Snjl char desc[40]; 148132527Snjl int i, j, rid, rtype; 149132527Snjl 150132527Snjl ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 151132527Snjl 152132527Snjl if (dev != acpi_timer_dev) 153132527Snjl return (ENXIO); 154132527Snjl 155132527Snjl rid = 0; 156167814Sjkim rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 157132527Snjl SYS_RES_IOPORT : SYS_RES_MEMORY; 158127135Snjl acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 159114277Smarcel if (acpi_timer_reg == NULL) { 160132527Snjl device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 161132527Snjl (rtype == SYS_RES_IOPORT) ? "port" : "mem", 162167814Sjkim (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 163132527Snjl return (ENXIO); 16467761Smsmith } 165132528Snjl acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 166132528Snjl acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 167167814Sjkim if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 168128506Snjl acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 169128506Snjl else 170128506Snjl acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 171128506Snjl acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 17294936Smux if (testenv("debug.acpi.timer_test")) 173128543Snjl acpi_timer_boot_test(); 17467761Smsmith 175128528Snjl /* 176128528Snjl * If all tests of the counter succeed, use the ACPI-fast method. If 177128528Snjl * at least one failed, default to using the safe routine, which reads 178128528Snjl * the timer multiple times to get a consistent value before returning. 179128528Snjl */ 18091237Sphk j = 0; 181137151Sphk if (bootverbose) 182137151Sphk printf("ACPI timer:"); 183128506Snjl for (i = 0; i < 10; i++) 184128543Snjl j += acpi_timer_test(); 185137151Sphk if (bootverbose) 186137151Sphk printf(" -> %d\n", j); 18791237Sphk if (j == 10) { 18891237Sphk acpi_timer_timecounter.tc_name = "ACPI-fast"; 18991237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 190171657Snjl acpi_timer_timecounter.tc_quality = 1000; 19191237Sphk } else { 19291237Sphk acpi_timer_timecounter.tc_name = "ACPI-safe"; 19391237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 194171657Snjl acpi_timer_timecounter.tc_quality = 850; 19591237Sphk } 19680070Smsmith tc_init(&acpi_timer_timecounter); 19780070Smsmith 198119529Snjl sprintf(desc, "%d-bit timer at 3.579545MHz", 199167814Sjkim (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) ? 32 : 24); 20067761Smsmith device_set_desc_copy(dev, desc); 20169744Smsmith 202132527Snjl /* Release the resource, we'll allocate it again during attach. */ 203132527Snjl bus_release_resource(dev, rtype, rid, acpi_timer_reg); 204132527Snjl return (0); 20567761Smsmith} 20667761Smsmith 20767761Smsmithstatic int 208132527Snjlacpi_timer_attach(device_t dev) 20967761Smsmith{ 210132527Snjl int rid, rtype; 211119529Snjl 212132527Snjl ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 21367761Smsmith 214132527Snjl rid = 0; 215167814Sjkim rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 216132527Snjl SYS_RES_IOPORT : SYS_RES_MEMORY; 217132527Snjl acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 218132527Snjl if (acpi_timer_reg == NULL) 219132527Snjl return (ENXIO); 220132527Snjl acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 221132527Snjl acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 222119529Snjl return (0); 22380070Smsmith} 22467761Smsmith 22580070Smsmith/* 22681096Smsmith * Fetch current time value from reliable hardware. 22780070Smsmith */ 228128506Snjlstatic u_int 22980070Smsmithacpi_timer_get_timecount(struct timecounter *tc) 23080070Smsmith{ 231128543Snjl return (acpi_timer_read()); 23267761Smsmith} 23380070Smsmith 23480070Smsmith/* 23581096Smsmith * Fetch current time value from hardware that may not correctly 236128528Snjl * latch the counter. We need to read until we have three monotonic 237128528Snjl * samples and then use the middle one, otherwise we are not protected 238128528Snjl * against the fact that the bits can be wrong in two directions. If 239128528Snjl * we only cared about monosity, two reads would be enough. 24081096Smsmith */ 241128506Snjlstatic u_int 24281096Smsmithacpi_timer_get_timecount_safe(struct timecounter *tc) 24381096Smsmith{ 244128506Snjl u_int u1, u2, u3; 24581096Smsmith 246128543Snjl u2 = acpi_timer_read(); 247128543Snjl u3 = acpi_timer_read(); 24881096Smsmith do { 24981096Smsmith u1 = u2; 25081096Smsmith u2 = u3; 251128543Snjl u3 = acpi_timer_read(); 252128543Snjl } while (u1 > u2 || u2 > u3); 253119529Snjl 25481096Smsmith return (u2); 25581096Smsmith} 25681096Smsmith 25781096Smsmith/* 25880070Smsmith * Timecounter freqency adjustment interface. 25980070Smsmith */ 26080070Smsmithstatic int 26180070Smsmithacpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 26280070Smsmith{ 26380070Smsmith int error; 26480070Smsmith u_int freq; 26580070Smsmith 26680070Smsmith if (acpi_timer_timecounter.tc_frequency == 0) 26780070Smsmith return (EOPNOTSUPP); 26880070Smsmith freq = acpi_timer_frequency; 269170289Sdwmalone error = sysctl_handle_int(oidp, &freq, 0, req); 27080070Smsmith if (error == 0 && req->newptr != NULL) { 27180070Smsmith acpi_timer_frequency = freq; 27280070Smsmith acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 27380070Smsmith } 274119529Snjl 27580070Smsmith return (error); 27680070Smsmith} 27780070Smsmith 27880070SmsmithSYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 27980070Smsmith 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 28080070Smsmith 28180070Smsmith/* 282128528Snjl * Some ACPI timers are known or believed to suffer from implementation 283128528Snjl * problems which can lead to erroneous values being read. This function 284128528Snjl * tests for consistent results from the timer and returns 1 if it believes 285128528Snjl * the timer is consistent, otherwise it returns 0. 286128528Snjl * 287128528Snjl * It appears the cause is that the counter is not latched to the PCI bus 288128528Snjl * clock when read: 289128528Snjl * 290128528Snjl * ] 20. ACPI Timer Errata 291128528Snjl * ] 292128528Snjl * ] Problem: The power management timer may return improper result when 293128528Snjl * ] read. Although the timer value settles properly after incrementing, 294128528Snjl * ] while incrementing there is a 3nS window every 69.8nS where the 295128528Snjl * ] timer value is indeterminate (a 4.2% chance that the data will be 296128528Snjl * ] incorrect when read). As a result, the ACPI free running count up 297128528Snjl * ] timer specification is violated due to erroneous reads. Implication: 298128528Snjl * ] System hangs due to the "inaccuracy" of the timer when used by 299128528Snjl * ] software for time critical events and delays. 300128528Snjl * ] 301128528Snjl * ] Workaround: Read the register twice and compare. 302128528Snjl * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 303128528Snjl * ] in the PIIX4M. 304128528Snjl */ 305128528Snjl#define N 2000 306128528Snjlstatic int 307128543Snjlacpi_timer_test() 308128528Snjl{ 309128528Snjl uint32_t last, this; 310128528Snjl int min, max, n, delta; 311128607Snjl register_t s; 312128528Snjl 313128528Snjl min = 10000000; 314128528Snjl max = 0; 315128607Snjl 316128607Snjl /* Test the timer with interrupts disabled to get accurate results. */ 317128607Snjl s = intr_disable(); 318128543Snjl last = acpi_timer_read(); 319128528Snjl for (n = 0; n < N; n++) { 320128543Snjl this = acpi_timer_read(); 321128528Snjl delta = acpi_TimerDelta(this, last); 322128528Snjl if (delta > max) 323128528Snjl max = delta; 324128528Snjl else if (delta < min) 325128528Snjl min = delta; 326128528Snjl last = this; 327128528Snjl } 328128607Snjl intr_restore(s); 329128607Snjl 330220333Sjkim delta = max - min; 331220333Sjkim if (delta > 2 && vm_guest == VM_GUEST_NO) 332128528Snjl n = 0; 333128528Snjl else if (min < 0 || max == 0) 334128528Snjl n = 0; 335128528Snjl else 336128528Snjl n = 1; 337137151Sphk if (bootverbose) 338220333Sjkim printf(" %d/%d", n, delta); 339128528Snjl 340128528Snjl return (n); 341128528Snjl} 342128528Snjl#undef N 343128528Snjl 344128528Snjl/* 34580070Smsmith * Test harness for verifying ACPI timer behaviour. 34680070Smsmith * Boot with debug.acpi.timer_test set to invoke this. 34780070Smsmith */ 34880070Smsmithstatic void 349128543Snjlacpi_timer_boot_test(void) 35080070Smsmith{ 351128506Snjl uint32_t u1, u2, u3; 352128506Snjl 353128543Snjl u1 = acpi_timer_read(); 354128543Snjl u2 = acpi_timer_read(); 355128543Snjl u3 = acpi_timer_read(); 356128506Snjl 35780070Smsmith device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 35880070Smsmith for (;;) { 35980070Smsmith /* 360119529Snjl * The failure case is where u3 > u1, but u2 does not fall between 361119529Snjl * the two, ie. it contains garbage. 36280070Smsmith */ 36380070Smsmith if (u3 > u1) { 364119529Snjl if (u2 < u1 || u2 > u3) 365119529Snjl device_printf(acpi_timer_dev, 366119529Snjl "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 36780070Smsmith u1, u2, u3); 36880070Smsmith } 36980070Smsmith u1 = u2; 37080070Smsmith u2 = u3; 371128543Snjl u3 = acpi_timer_read(); 37280070Smsmith } 37380070Smsmith} 374