acpi_timer.c revision 167814
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 167814 2007-03-22 18:16:43Z 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 43150003Sobrien#include <contrib/dev/acpica/acpi.h> 44104726Sjhb#include <dev/acpica/acpivar.h> 45119281Simp#include <dev/pci/pcivar.h> 4667761Smsmith 4769744Smsmith/* 4880070Smsmith * A timecounter based on the free-running ACPI timer. 4980070Smsmith * 5080070Smsmith * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 5180070Smsmith */ 5280070Smsmith 53119529Snjl/* Hooks for the ACPI CA debugging infrastructure */ 54126517Snjl#define _COMPONENT ACPI_TIMER 5591128SmsmithACPI_MODULE_NAME("TIMER") 5669744Smsmith 57128528Snjlstatic device_t acpi_timer_dev; 58128528Snjlstatic struct resource *acpi_timer_reg; 59128543Snjlstatic bus_space_handle_t acpi_timer_bsh; 60128543Snjlstatic bus_space_tag_t acpi_timer_bst; 6167761Smsmith 62119529Snjlstatic u_int acpi_timer_frequency = 14318182 / 4; 6367761Smsmith 6467761Smsmithstatic void acpi_timer_identify(driver_t *driver, device_t parent); 6567761Smsmithstatic int acpi_timer_probe(device_t dev); 6667761Smsmithstatic int acpi_timer_attach(device_t dev); 67128506Snjlstatic u_int acpi_timer_get_timecount(struct timecounter *tc); 68128506Snjlstatic u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 6980070Smsmithstatic int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 70128543Snjlstatic void acpi_timer_boot_test(void); 7167761Smsmith 72128543Snjlstatic u_int acpi_timer_read(void); 73128543Snjlstatic int acpi_timer_test(void); 74114277Smarcel 7567761Smsmithstatic device_method_t acpi_timer_methods[] = { 7667761Smsmith DEVMETHOD(device_identify, acpi_timer_identify), 7767761Smsmith DEVMETHOD(device_probe, acpi_timer_probe), 7867761Smsmith DEVMETHOD(device_attach, acpi_timer_attach), 7967761Smsmith 8067761Smsmith {0, 0} 8167761Smsmith}; 8267761Smsmith 8367761Smsmithstatic driver_t acpi_timer_driver = { 8467761Smsmith "acpi_timer", 8567761Smsmith acpi_timer_methods, 8680070Smsmith 0, 8767761Smsmith}; 8867761Smsmith 8989054Smsmithstatic devclass_t acpi_timer_devclass; 9067761SmsmithDRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 91128071SnjlMODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 9267761Smsmith 9380070Smsmithstatic struct timecounter acpi_timer_timecounter = { 94128543Snjl acpi_timer_get_timecount_safe, /* get_timecount function */ 95128543Snjl 0, /* no poll_pps */ 96128543Snjl 0, /* no default counter_mask */ 97128543Snjl 0, /* no default frequency */ 98128543Snjl "ACPI", /* name */ 99128543Snjl 1000 /* quality */ 10080070Smsmith}; 10180070Smsmith 102128506Snjlstatic u_int 103128543Snjlacpi_timer_read() 104114277Smarcel{ 105128607Snjl return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 106114277Smarcel} 107114277Smarcel 10880070Smsmith/* 10980070Smsmith * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 11080070Smsmith * we will be using. 11180070Smsmith */ 11267761Smsmithstatic void 11367761Smsmithacpi_timer_identify(driver_t *driver, device_t parent) 11467761Smsmith{ 115132527Snjl device_t dev; 116132527Snjl u_long rlen, rstart; 117132527Snjl int rid, rtype; 11867761Smsmith 11996926Speter ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 12069744Smsmith 121136270Snjl if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || 122167814Sjkim acpi_timer_dev) 12369744Smsmith return_VOID; 124128506Snjl 12567761Smsmith if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 12667761Smsmith device_printf(parent, "could not add acpi_timer0\n"); 12769744Smsmith return_VOID; 12867761Smsmith } 12980070Smsmith acpi_timer_dev = dev; 130114277Smarcel 13180070Smsmith rid = 0; 132167814Sjkim rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 133132527Snjl SYS_RES_IOPORT : SYS_RES_MEMORY; 134167814Sjkim rlen = AcpiGbl_FADT.PmTimerLength; 135167814Sjkim rstart = AcpiGbl_FADT.XPmTimerBlock.Address; 136132527Snjl if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 137132527Snjl device_printf(dev, "couldn't set resource (%s 0x%lx+0x%lx)\n", 138132527Snjl (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 139132527Snjl return_VOID; 140132527Snjl} 141132527Snjl 142132527Snjlstatic int 143132527Snjlacpi_timer_probe(device_t dev) 144132527Snjl{ 145132527Snjl char desc[40]; 146132527Snjl int i, j, rid, rtype; 147132527Snjl 148132527Snjl ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 149132527Snjl 150132527Snjl if (dev != acpi_timer_dev) 151132527Snjl return (ENXIO); 152132527Snjl 153132527Snjl rid = 0; 154167814Sjkim rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 155132527Snjl SYS_RES_IOPORT : SYS_RES_MEMORY; 156127135Snjl acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 157114277Smarcel if (acpi_timer_reg == NULL) { 158132527Snjl device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 159132527Snjl (rtype == SYS_RES_IOPORT) ? "port" : "mem", 160167814Sjkim (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); 161132527Snjl return (ENXIO); 16267761Smsmith } 163132528Snjl acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 164132528Snjl acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 165167814Sjkim if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) 166128506Snjl acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 167128506Snjl else 168128506Snjl acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 169128506Snjl acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 17094936Smux if (testenv("debug.acpi.timer_test")) 171128543Snjl acpi_timer_boot_test(); 17267761Smsmith 173128528Snjl /* 174128528Snjl * If all tests of the counter succeed, use the ACPI-fast method. If 175128528Snjl * at least one failed, default to using the safe routine, which reads 176128528Snjl * the timer multiple times to get a consistent value before returning. 177128528Snjl */ 17891237Sphk j = 0; 179137151Sphk if (bootverbose) 180137151Sphk printf("ACPI timer:"); 181128506Snjl for (i = 0; i < 10; i++) 182128543Snjl j += acpi_timer_test(); 183137151Sphk if (bootverbose) 184137151Sphk printf(" -> %d\n", j); 18591237Sphk if (j == 10) { 18691237Sphk acpi_timer_timecounter.tc_name = "ACPI-fast"; 18791237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 18891237Sphk } else { 18991237Sphk acpi_timer_timecounter.tc_name = "ACPI-safe"; 19091237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 19191237Sphk } 19280070Smsmith tc_init(&acpi_timer_timecounter); 19380070Smsmith 194119529Snjl sprintf(desc, "%d-bit timer at 3.579545MHz", 195167814Sjkim (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) ? 32 : 24); 19667761Smsmith device_set_desc_copy(dev, desc); 19769744Smsmith 198132527Snjl /* Release the resource, we'll allocate it again during attach. */ 199132527Snjl bus_release_resource(dev, rtype, rid, acpi_timer_reg); 200132527Snjl return (0); 20167761Smsmith} 20267761Smsmith 20367761Smsmithstatic int 204132527Snjlacpi_timer_attach(device_t dev) 20567761Smsmith{ 206132527Snjl int rid, rtype; 207119529Snjl 208132527Snjl ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 20967761Smsmith 210132527Snjl rid = 0; 211167814Sjkim rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ? 212132527Snjl SYS_RES_IOPORT : SYS_RES_MEMORY; 213132527Snjl acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 214132527Snjl if (acpi_timer_reg == NULL) 215132527Snjl return (ENXIO); 216132527Snjl acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 217132527Snjl acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 218119529Snjl return (0); 21980070Smsmith} 22067761Smsmith 22180070Smsmith/* 22281096Smsmith * Fetch current time value from reliable hardware. 22380070Smsmith */ 224128506Snjlstatic u_int 22580070Smsmithacpi_timer_get_timecount(struct timecounter *tc) 22680070Smsmith{ 227128543Snjl return (acpi_timer_read()); 22867761Smsmith} 22980070Smsmith 23080070Smsmith/* 23181096Smsmith * Fetch current time value from hardware that may not correctly 232128528Snjl * latch the counter. We need to read until we have three monotonic 233128528Snjl * samples and then use the middle one, otherwise we are not protected 234128528Snjl * against the fact that the bits can be wrong in two directions. If 235128528Snjl * we only cared about monosity, two reads would be enough. 23681096Smsmith */ 237128506Snjlstatic u_int 23881096Smsmithacpi_timer_get_timecount_safe(struct timecounter *tc) 23981096Smsmith{ 240128506Snjl u_int u1, u2, u3; 24181096Smsmith 242128543Snjl u2 = acpi_timer_read(); 243128543Snjl u3 = acpi_timer_read(); 24481096Smsmith do { 24581096Smsmith u1 = u2; 24681096Smsmith u2 = u3; 247128543Snjl u3 = acpi_timer_read(); 248128543Snjl } while (u1 > u2 || u2 > u3); 249119529Snjl 25081096Smsmith return (u2); 25181096Smsmith} 25281096Smsmith 25381096Smsmith/* 25480070Smsmith * Timecounter freqency adjustment interface. 25580070Smsmith */ 25680070Smsmithstatic int 25780070Smsmithacpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 25880070Smsmith{ 25980070Smsmith int error; 26080070Smsmith u_int freq; 26180070Smsmith 26280070Smsmith if (acpi_timer_timecounter.tc_frequency == 0) 26380070Smsmith return (EOPNOTSUPP); 26480070Smsmith freq = acpi_timer_frequency; 26580070Smsmith error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 26680070Smsmith if (error == 0 && req->newptr != NULL) { 26780070Smsmith acpi_timer_frequency = freq; 26880070Smsmith acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 26980070Smsmith } 270119529Snjl 27180070Smsmith return (error); 27280070Smsmith} 27380070Smsmith 27480070SmsmithSYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 27580070Smsmith 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 27680070Smsmith 27780070Smsmith/* 278128528Snjl * Some ACPI timers are known or believed to suffer from implementation 279128528Snjl * problems which can lead to erroneous values being read. This function 280128528Snjl * tests for consistent results from the timer and returns 1 if it believes 281128528Snjl * the timer is consistent, otherwise it returns 0. 282128528Snjl * 283128528Snjl * It appears the cause is that the counter is not latched to the PCI bus 284128528Snjl * clock when read: 285128528Snjl * 286128528Snjl * ] 20. ACPI Timer Errata 287128528Snjl * ] 288128528Snjl * ] Problem: The power management timer may return improper result when 289128528Snjl * ] read. Although the timer value settles properly after incrementing, 290128528Snjl * ] while incrementing there is a 3nS window every 69.8nS where the 291128528Snjl * ] timer value is indeterminate (a 4.2% chance that the data will be 292128528Snjl * ] incorrect when read). As a result, the ACPI free running count up 293128528Snjl * ] timer specification is violated due to erroneous reads. Implication: 294128528Snjl * ] System hangs due to the "inaccuracy" of the timer when used by 295128528Snjl * ] software for time critical events and delays. 296128528Snjl * ] 297128528Snjl * ] Workaround: Read the register twice and compare. 298128528Snjl * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 299128528Snjl * ] in the PIIX4M. 300128528Snjl */ 301128528Snjl#define N 2000 302128528Snjlstatic int 303128543Snjlacpi_timer_test() 304128528Snjl{ 305128528Snjl uint32_t last, this; 306128528Snjl int min, max, n, delta; 307128607Snjl register_t s; 308128528Snjl 309128528Snjl min = 10000000; 310128528Snjl max = 0; 311128607Snjl 312128607Snjl /* Test the timer with interrupts disabled to get accurate results. */ 313128607Snjl s = intr_disable(); 314128543Snjl last = acpi_timer_read(); 315128528Snjl for (n = 0; n < N; n++) { 316128543Snjl this = acpi_timer_read(); 317128528Snjl delta = acpi_TimerDelta(this, last); 318128528Snjl if (delta > max) 319128528Snjl max = delta; 320128528Snjl else if (delta < min) 321128528Snjl min = delta; 322128528Snjl last = this; 323128528Snjl } 324128607Snjl intr_restore(s); 325128607Snjl 326128528Snjl if (max - min > 2) 327128528Snjl n = 0; 328128528Snjl else if (min < 0 || max == 0) 329128528Snjl n = 0; 330128528Snjl else 331128528Snjl n = 1; 332137151Sphk if (bootverbose) 333137151Sphk printf(" %d/%d", n, max-min); 334128528Snjl 335128528Snjl return (n); 336128528Snjl} 337128528Snjl#undef N 338128528Snjl 339128528Snjl/* 34080070Smsmith * Test harness for verifying ACPI timer behaviour. 34180070Smsmith * Boot with debug.acpi.timer_test set to invoke this. 34280070Smsmith */ 34380070Smsmithstatic void 344128543Snjlacpi_timer_boot_test(void) 34580070Smsmith{ 346128506Snjl uint32_t u1, u2, u3; 347128506Snjl 348128543Snjl u1 = acpi_timer_read(); 349128543Snjl u2 = acpi_timer_read(); 350128543Snjl u3 = acpi_timer_read(); 351128506Snjl 35280070Smsmith device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 35380070Smsmith for (;;) { 35480070Smsmith /* 355119529Snjl * The failure case is where u3 > u1, but u2 does not fall between 356119529Snjl * the two, ie. it contains garbage. 35780070Smsmith */ 35880070Smsmith if (u3 > u1) { 359119529Snjl if (u2 < u1 || u2 > u3) 360119529Snjl device_printf(acpi_timer_dev, 361119529Snjl "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 36280070Smsmith u1, u2, u3); 36380070Smsmith } 36480070Smsmith u1 = u2; 36580070Smsmith u2 = u3; 366128543Snjl u3 = acpi_timer_read(); 36780070Smsmith } 36880070Smsmith} 369