acpi_timer.c revision 132527
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 * 2767761Smsmith * $FreeBSD: head/sys/dev/acpica/acpi_timer.c 132527 2004-07-22 05:32:56Z njl $ 2867761Smsmith */ 2967761Smsmith#include "opt_acpi.h" 3067761Smsmith#include <sys/param.h> 3180070Smsmith#include <sys/bus.h> 3267761Smsmith#include <sys/kernel.h> 3380070Smsmith#include <sys/module.h> 34105281Sjhb#include <sys/sysctl.h> 3580070Smsmith#include <sys/timetc.h> 36105281Sjhb 37105281Sjhb#include <machine/bus.h> 38105281Sjhb#include <machine/resource.h> 3967761Smsmith#include <sys/rman.h> 4080070Smsmith 4180070Smsmith#include "acpi.h" 4280070Smsmith#include <dev/acpica/acpivar.h> 4380070Smsmith#include <dev/pci/pcivar.h> 4467761Smsmith 4567761Smsmith/* 46104726Sjhb * A timecounter based on the free-running ACPI timer. 4780070Smsmith * 4867761Smsmith * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 4969744Smsmith */ 5080070Smsmith 5180070Smsmith/* Hooks for the ACPI CA debugging infrastructure */ 5280070Smsmith#define _COMPONENT ACPI_TIMER 5380070SmsmithACPI_MODULE_NAME("TIMER") 5480070Smsmith 5580070Smsmithstatic device_t acpi_timer_dev; 5669744Smsmithstatic struct resource *acpi_timer_reg; 5769744Smsmithstatic bus_space_handle_t acpi_timer_bsh; 5877432Smsmithstatic bus_space_tag_t acpi_timer_bst; 5991128Smsmith 6069744Smsmithstatic u_int acpi_timer_frequency = 14318182 / 4; 6180070Smsmith 6280070Smsmithstatic void acpi_timer_identify(driver_t *driver, device_t parent); 6367761Smsmithstatic int acpi_timer_probe(device_t dev); 6480070Smsmithstatic int acpi_timer_attach(device_t dev); 6567761Smsmithstatic u_int acpi_timer_get_timecount(struct timecounter *tc); 6667761Smsmithstatic u_int acpi_timer_get_timecount_safe(struct timecounter *tc); 6767761Smsmithstatic int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 6867761Smsmithstatic void acpi_timer_boot_test(void); 6980070Smsmith 7081096Smsmithstatic u_int acpi_timer_read(void); 7180070Smsmithstatic int acpi_timer_test(void); 7280070Smsmith 7367761Smsmithstatic device_method_t acpi_timer_methods[] = { 74114277Smarcel DEVMETHOD(device_identify, acpi_timer_identify), 75114277Smarcel DEVMETHOD(device_probe, acpi_timer_probe), 76114277Smarcel DEVMETHOD(device_attach, acpi_timer_attach), 7780070Smsmith 7880070Smsmith {0, 0} 7980070Smsmith}; 8067761Smsmith 8167761Smsmithstatic driver_t acpi_timer_driver = { 8267761Smsmith "acpi_timer", 8367761Smsmith acpi_timer_methods, 8467761Smsmith 0, 8567761Smsmith}; 8667761Smsmith 8767761Smsmithstatic devclass_t acpi_timer_devclass; 8867761SmsmithDRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 8967761SmsmithMODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 9067761Smsmith 9180070Smsmithstatic struct timecounter acpi_timer_timecounter = { 9267761Smsmith acpi_timer_get_timecount_safe, /* get_timecount function */ 9367761Smsmith 0, /* no poll_pps */ 9489054Smsmith 0, /* no default counter_mask */ 9567761Smsmith 0, /* no default frequency */ 9667761Smsmith "ACPI", /* name */ 9780070Smsmith 1000 /* quality */ 9880070Smsmith}; 9980070Smsmith 10080070Smsmithstatic u_int 10181096Smsmithacpi_timer_read() 10280070Smsmith{ 10380070Smsmith return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); 10480070Smsmith} 10580070Smsmith 10680070Smsmith/* 10780070Smsmith * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 10880070Smsmith * we will be using. 109114277Smarcel */ 110114277Smarcelstatic void 111114277Smarcelacpi_timer_identify(driver_t *driver, device_t parent) 112114277Smarcel{ 113114277Smarcel device_t dev; 114114277Smarcel u_long rlen, rstart; 115114277Smarcel int rid, rtype; 116114277Smarcel 117114277Smarcel ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 118114277Smarcel 119114277Smarcel if (acpi_disabled("timer") || AcpiGbl_FADT == NULL || acpi_timer_dev) 120114277Smarcel return_VOID; 121114277Smarcel 122114277Smarcel if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 12391237Sphk device_printf(parent, "could not add acpi_timer0\n"); 12491237Sphk return_VOID; 12591237Sphk } 12691237Sphk acpi_timer_dev = dev; 12791237Sphk 12891237Sphk rid = 0; 12991237Sphk rtype = AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId ? 13091237Sphk SYS_RES_IOPORT : SYS_RES_MEMORY; 13191237Sphk rlen = AcpiGbl_FADT->PmTmLen; 132114277Smarcel rstart = AcpiGbl_FADT->XPmTmrBlk.Address; 13391237Sphk if (bus_set_resource(dev, rtype, rid, rstart, rlen)) 134114277Smarcel device_printf(dev, "couldn't set resource (%s 0x%lx+0x%lx)\n", 13591237Sphk (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); 13691237Sphk return_VOID; 13791237Sphk} 13891237Sphk 13991237Sphkstatic int 14091237Sphkacpi_timer_probe(device_t dev) 14191237Sphk{ 14291237Sphk char desc[40]; 14391237Sphk int i, j, rid, rtype; 144114277Smarcel 14591237Sphk ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 14691237Sphk 14791237Sphk if (dev != acpi_timer_dev) 14893093Sphk return (ENXIO); 14993093Sphk 15093093Sphk rid = 0; 151114277Smarcel rtype = AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId ? 15291237Sphk SYS_RES_IOPORT : SYS_RES_MEMORY; 15391237Sphk acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 15491237Sphk if (acpi_timer_reg == NULL) { 15580070Smsmith device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", 15680070Smsmith (rtype == SYS_RES_IOPORT) ? "port" : "mem", 15780070Smsmith (u_long)AcpiGbl_FADT->XPmTmrBlk.Address); 15880070Smsmith return (ENXIO); 15967761Smsmith } 16067761Smsmith if (AcpiGbl_FADT->TmrValExt != 0) 16167761Smsmith acpi_timer_timecounter.tc_counter_mask = 0xffffffff; 16280070Smsmith else 16380070Smsmith acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; 164114277Smarcel acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 165114277Smarcel if (testenv("debug.acpi.timer_test")) 16667761Smsmith acpi_timer_boot_test(); 16796926Speter 16869744Smsmith /* 16969744Smsmith * If all tests of the counter succeed, use the ACPI-fast method. If 17069744Smsmith * at least one failed, default to using the safe routine, which reads 17169744Smsmith * the timer multiple times to get a consistent value before returning. 17271872Smsmith */ 17369744Smsmith j = 0; 17471872Smsmith for (i = 0; i < 10; i++) 17567761Smsmith j += acpi_timer_test(); 17667761Smsmith if (j == 10) { 17769744Smsmith acpi_timer_timecounter.tc_name = "ACPI-fast"; 17867761Smsmith acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 17980070Smsmith } else { 180114277Smarcel acpi_timer_timecounter.tc_name = "ACPI-safe"; 18180070Smsmith acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 182114277Smarcel } 183114277Smarcel tc_init(&acpi_timer_timecounter); 184114277Smarcel 185114277Smarcel sprintf(desc, "%d-bit timer at 3.579545MHz", 186114277Smarcel AcpiGbl_FADT->TmrValExt ? 32 : 24); 187114277Smarcel device_set_desc_copy(dev, desc); 188114277Smarcel 189114277Smarcel /* Release the resource, we'll allocate it again during attach. */ 190114277Smarcel bus_release_resource(dev, rtype, rid, acpi_timer_reg); 19169744Smsmith return (0); 19267761Smsmith} 19394936Smux 19480070Smsmithstatic int 19567761Smsmithacpi_timer_attach(device_t dev) 19680070Smsmith{ 19791237Sphk int rid, rtype; 19891237Sphk 19991237Sphk ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 20091237Sphk 20191237Sphk rid = 0; 20291237Sphk rtype = AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId ? 20391237Sphk SYS_RES_IOPORT : SYS_RES_MEMORY; 20491237Sphk acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 20591237Sphk if (acpi_timer_reg == NULL) 20691237Sphk return (ENXIO); 20780070Smsmith acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); 20880070Smsmith acpi_timer_bst = rman_get_bustag(acpi_timer_reg); 209114277Smarcel return (0); 210114277Smarcel} 21167761Smsmith 21269744Smsmith/* 21369744Smsmith * Fetch current time value from reliable hardware. 21467761Smsmith */ 21567761Smsmithstatic u_int 21667761Smsmithacpi_timer_get_timecount(struct timecounter *tc) 21767761Smsmith{ 21867761Smsmith return (acpi_timer_read()); 21980070Smsmith} 22067761Smsmith 22167761Smsmith/* 22267761Smsmith * Fetch current time value from hardware that may not correctly 22367761Smsmith * latch the counter. We need to read until we have three monotonic 22467761Smsmith * samples and then use the middle one, otherwise we are not protected 22567761Smsmith * against the fact that the bits can be wrong in two directions. If 22667761Smsmith * we only cared about monosity, two reads would be enough. 22780070Smsmith */ 22880070Smsmithstatic u_int 22967761Smsmithacpi_timer_get_timecount_safe(struct timecounter *tc) 23080070Smsmith{ 23181096Smsmith u_int u1, u2, u3; 23280070Smsmith 23380070Smsmith u2 = acpi_timer_read(); 23480070Smsmith u3 = acpi_timer_read(); 23580070Smsmith do { 236114277Smarcel u1 = u2; 23767761Smsmith u2 = u3; 23880070Smsmith u3 = acpi_timer_read(); 23980070Smsmith } while (u1 > u2 || u2 > u3); 24081096Smsmith 24181096Smsmith return (u2); 24281096Smsmith} 24381096Smsmith 24481096Smsmith/* 24581096Smsmith * Timecounter freqency adjustment interface. 24681096Smsmith */ 24781096Smsmithstatic int 248114277Smarcelacpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 249114277Smarcel{ 25081096Smsmith int error; 25181096Smsmith u_int freq; 25281096Smsmith 253114277Smarcel if (acpi_timer_timecounter.tc_frequency == 0) 25491237Sphk return (EOPNOTSUPP); 25581096Smsmith freq = acpi_timer_frequency; 25681096Smsmith error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 25781096Smsmith if (error == 0 && req->newptr != NULL) { 25881096Smsmith acpi_timer_frequency = freq; 25980070Smsmith acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 26080070Smsmith } 26180070Smsmith 26280070Smsmith return (error); 26380070Smsmith} 26480070Smsmith 26580070SmsmithSYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 26680070Smsmith 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 26780070Smsmith 26880070Smsmith/* 26980070Smsmith * Some ACPI timers are known or believed to suffer from implementation 27080070Smsmith * problems which can lead to erroneous values being read. This function 27180070Smsmith * tests for consistent results from the timer and returns 1 if it believes 27280070Smsmith * the timer is consistent, otherwise it returns 0. 27380070Smsmith * 27480070Smsmith * It appears the cause is that the counter is not latched to the PCI bus 27580070Smsmith * clock when read: 27680070Smsmith * 27780070Smsmith * ] 20. ACPI Timer Errata 27880070Smsmith * ] 27980070Smsmith * ] Problem: The power management timer may return improper result when 28080070Smsmith * ] read. Although the timer value settles properly after incrementing, 28180070Smsmith * ] while incrementing there is a 3nS window every 69.8nS where the 28280070Smsmith * ] timer value is indeterminate (a 4.2% chance that the data will be 28380070Smsmith * ] incorrect when read). As a result, the ACPI free running count up 28480070Smsmith * ] timer specification is violated due to erroneous reads. Implication: 28580070Smsmith * ] System hangs due to the "inaccuracy" of the timer when used by 28680070Smsmith * ] software for time critical events and delays. 28780070Smsmith * ] 28880070Smsmith * ] Workaround: Read the register twice and compare. 28980070Smsmith * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 290114277Smarcel * ] in the PIIX4M. 291114277Smarcel */ 292114277Smarcel#define N 2000 29380070Smsmithstatic int 29480070Smsmithacpi_timer_test() 29580070Smsmith{ 29680070Smsmith uint32_t last, this; 29780070Smsmith int min, max, n, delta; 29880070Smsmith register_t s; 29980070Smsmith 30080070Smsmith min = 10000000; 30180070Smsmith max = 0; 30280070Smsmith 30380070Smsmith /* Test the timer with interrupts disabled to get accurate results. */ 30480070Smsmith s = intr_disable(); 30580070Smsmith last = acpi_timer_read(); 30680070Smsmith for (n = 0; n < N; n++) { 307114277Smarcel this = acpi_timer_read(); 30880070Smsmith delta = acpi_TimerDelta(this, last); 30980070Smsmith if (delta > max) 31080070Smsmith max = delta; 31180602Smsmith else if (delta < min) 31280602Smsmith min = delta; 31380602Smsmith last = this; 31481096Smsmith } 31581096Smsmith intr_restore(s); 31681096Smsmith 31781096Smsmith if (max - min > 2) 31881096Smsmith n = 0; 31981096Smsmith else if (min < 0 || max == 0) 32081096Smsmith n = 0; 32181096Smsmith else 32281096Smsmith n = 1; 32381096Smsmith if (bootverbose) { 32480602Smsmith printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", 32580602Smsmith n ? "GOOD" : "BAD ", 32680602Smsmith min, max, max - min); 32780602Smsmith } 32880602Smsmith 32980602Smsmith return (n); 33080602Smsmith} 33180602Smsmith#undef N 33280602Smsmith 33380602Smsmith/* 33480602Smsmith * Test harness for verifying ACPI timer behaviour. 33580602Smsmith * Boot with debug.acpi.timer_test set to invoke this. 33680602Smsmith */ 33780602Smsmithstatic void 33880602Smsmithacpi_timer_boot_test(void) 33980602Smsmith{ 34080602Smsmith uint32_t u1, u2, u3; 34180602Smsmith 34280602Smsmith u1 = acpi_timer_read(); 34380602Smsmith u2 = acpi_timer_read(); 34480602Smsmith u3 = acpi_timer_read(); 34580602Smsmith 34691237Sphk device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 34780602Smsmith for (;;) { 34880602Smsmith /* 34980602Smsmith * The failure case is where u3 > u1, but u2 does not fall between 35080602Smsmith * the two, ie. it contains garbage. 35180602Smsmith */ 35280602Smsmith if (u3 > u1) { 35380602Smsmith if (u2 < u1 || u2 > u3) 35480602Smsmith device_printf(acpi_timer_dev, 35580602Smsmith "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 35680602Smsmith u1, u2, u3); 35780602Smsmith } 35880602Smsmith u1 = u2; 35980602Smsmith u2 = u3; 36080602Smsmith u3 = acpi_timer_read(); 36180602Smsmith } 36280602Smsmith} 36380602Smsmith