acpi_timer.c revision 94936
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 94936 2002-04-17 13:06:36Z mux $ 2867761Smsmith */ 2967761Smsmith#include "opt_acpi.h" 3067761Smsmith#include <sys/param.h> 3180070Smsmith#include <sys/bus.h> 3267761Smsmith#include <sys/kernel.h> 3380070Smsmith#include <sys/sysctl.h> 3480070Smsmith#include <sys/timetc.h> 3567761Smsmith 3680070Smsmith#include <machine/bus_pio.h> 3780070Smsmith#include <machine/bus.h> 3880070Smsmith#include <machine/resource.h> 3980070Smsmith#include <sys/rman.h> 4080070Smsmith 4167761Smsmith#include "acpi.h" 4267761Smsmith 4380070Smsmith#include <acpica/acpivar.h> 4480070Smsmith#include <pci/pcivar.h> 4567761Smsmith 4669744Smsmith/* 4780070Smsmith * A timecounter based on the free-running ACPI timer. 4880070Smsmith * 4980070Smsmith * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 5080070Smsmith */ 5180070Smsmith 5280070Smsmith/* 5369744Smsmith * Hooks for the ACPI CA debugging infrastructure 5469744Smsmith */ 5577432Smsmith#define _COMPONENT ACPI_SYSTEM 5691128SmsmithACPI_MODULE_NAME("TIMER") 5769744Smsmith 5880070Smsmithstatic device_t acpi_timer_dev; 5980070Smsmithstruct resource *acpi_timer_reg; 6080070Smsmith#define TIMER_READ bus_space_read_4(rman_get_bustag(acpi_timer_reg), \ 6180070Smsmith rman_get_bushandle(acpi_timer_reg), \ 6280070Smsmith 0) 6367761Smsmith 6480070Smsmithstatic 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); 6980070Smsmithstatic unsigned acpi_timer_get_timecount(struct timecounter *tc); 7081096Smsmithstatic unsigned acpi_timer_get_timecount_safe(struct timecounter *tc); 7180070Smsmithstatic int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 7280070Smsmithstatic void acpi_timer_test(void); 7367761Smsmith 7480070Smsmith/* 7580070Smsmith * Driver hung off ACPI. 7680070Smsmith */ 7767761Smsmithstatic device_method_t acpi_timer_methods[] = { 7867761Smsmith DEVMETHOD(device_identify, acpi_timer_identify), 7967761Smsmith DEVMETHOD(device_probe, acpi_timer_probe), 8067761Smsmith DEVMETHOD(device_attach, acpi_timer_attach), 8167761Smsmith 8267761Smsmith {0, 0} 8367761Smsmith}; 8467761Smsmith 8567761Smsmithstatic driver_t acpi_timer_driver = { 8667761Smsmith "acpi_timer", 8767761Smsmith acpi_timer_methods, 8880070Smsmith 0, 8967761Smsmith}; 9067761Smsmith 9189054Smsmithstatic devclass_t acpi_timer_devclass; 9267761SmsmithDRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 9367761Smsmith 9480070Smsmith/* 9580070Smsmith * Timecounter. 9680070Smsmith */ 9780070Smsmithstatic struct timecounter acpi_timer_timecounter = { 9881096Smsmith acpi_timer_get_timecount_safe, 9980070Smsmith 0, 10080070Smsmith 0xffffff, 10180070Smsmith 0, 10280070Smsmith "ACPI" 10380070Smsmith}; 10480070Smsmith 10580070SmsmithSYSCTL_OPAQUE(_debug, OID_AUTO, acpi_timecounter, CTLFLAG_RD, 10680070Smsmith &acpi_timer_timecounter, sizeof(acpi_timer_timecounter), "S,timecounter", ""); 10791237Sphkstatic int test_counter(void); 10880070Smsmith 10991237Sphk#define N 2000 11091237Sphkstatic int 11191237Sphktest_counter() 11291237Sphk{ 11391237Sphk int min, max, n, delta; 11491237Sphk unsigned last, this; 11591237Sphk 11691237Sphk min = 10000000; 11791237Sphk max = 0; 11891237Sphk last = TIMER_READ; 11991237Sphk for (n = 0; n < N; n++) { 12091237Sphk this = TIMER_READ; 12191237Sphk delta = (this - last) & 0xffffff; 12291237Sphk if (delta > max) 12391237Sphk max = delta; 12491237Sphk else if (delta < min) 12591237Sphk min = delta; 12691237Sphk last = this; 12791237Sphk } 12891237Sphk if (max - min > 2) 12991237Sphk n = 0; 13091237Sphk else if (min < 0) 13191237Sphk n = 0; 13291237Sphk else 13391237Sphk n = 1; 13493093Sphk if (bootverbose) 13593093Sphk printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", 13693093Sphk n ? "GOOD" : "BAD ", 13793093Sphk min, max, max - min + 1); 13891237Sphk return (n); 13991237Sphk} 14091237Sphk 14180070Smsmith/* 14280070Smsmith * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 14380070Smsmith * we will be using. 14480070Smsmith */ 14567761Smsmithstatic void 14667761Smsmithacpi_timer_identify(driver_t *driver, device_t parent) 14767761Smsmith{ 14880070Smsmith device_t dev; 14980070Smsmith char desc[40]; 15091237Sphk int rid, i, j; 15167761Smsmith 15291128Smsmith ACPI_FUNCTION_TRACE(__func__); 15369744Smsmith 15469744Smsmith if (acpi_disabled("timer")) 15569744Smsmith return_VOID; 15669744Smsmith 15771872Smsmith if (AcpiGbl_FADT == NULL) 15869744Smsmith return_VOID; 15971872Smsmith 16067761Smsmith if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 16167761Smsmith device_printf(parent, "could not add acpi_timer0\n"); 16269744Smsmith return_VOID; 16367761Smsmith } 16480070Smsmith acpi_timer_dev = dev; 16580070Smsmith rid = 0; 16680070Smsmith bus_set_resource(dev, SYS_RES_IOPORT, rid, AcpiGbl_FADT->V1_PmTmrBlk, sizeof(u_int32_t)); 16780070Smsmith if ((acpi_timer_reg = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid, 0, ~0, 1, RF_ACTIVE)) == NULL) { 16880070Smsmith device_printf(dev, "couldn't allocate I/O resource (port 0x%x)\n", AcpiGbl_FADT->V1_PmTmrBlk); 16969744Smsmith return_VOID; 17067761Smsmith } 17194936Smux if (testenv("debug.acpi.timer_test")) 17280070Smsmith acpi_timer_test(); 17367761Smsmith 17480070Smsmith acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 17591237Sphk j = 0; 17691237Sphk for(i = 0; i < 10; i++) 17791237Sphk j += test_counter(); 17891237Sphk if (j == 10) { 17991237Sphk acpi_timer_timecounter.tc_name = "ACPI-fast"; 18091237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 18191237Sphk } else { 18291237Sphk acpi_timer_timecounter.tc_name = "ACPI-safe"; 18391237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 18491237Sphk } 18580070Smsmith tc_init(&acpi_timer_timecounter); 18680070Smsmith 18771872Smsmith sprintf(desc, "%d-bit timer at 3.579545MHz", AcpiGbl_FADT->TmrValExt ? 32 : 24); 18867761Smsmith device_set_desc_copy(dev, desc); 18969744Smsmith 19069744Smsmith return_VOID; 19167761Smsmith} 19267761Smsmith 19367761Smsmithstatic int 19467761Smsmithacpi_timer_probe(device_t dev) 19567761Smsmith{ 19680070Smsmith if (dev == acpi_timer_dev) 19767761Smsmith return(0); 19867761Smsmith return(ENXIO); 19967761Smsmith} 20067761Smsmith 20167761Smsmithstatic int 20267761Smsmithacpi_timer_attach(device_t dev) 20367761Smsmith{ 20480070Smsmith return(0); 20580070Smsmith} 20667761Smsmith 20780070Smsmith/* 20881096Smsmith * Fetch current time value from reliable hardware. 20980070Smsmith */ 21080070Smsmithstatic unsigned 21180070Smsmithacpi_timer_get_timecount(struct timecounter *tc) 21280070Smsmith{ 21380602Smsmith return(TIMER_READ); 21467761Smsmith} 21580070Smsmith 21680070Smsmith/* 21781096Smsmith * Fetch current time value from hardware that may not correctly 21881096Smsmith * latch the counter. 21981096Smsmith */ 22081096Smsmithstatic unsigned 22181096Smsmithacpi_timer_get_timecount_safe(struct timecounter *tc) 22281096Smsmith{ 22381096Smsmith unsigned u1, u2, u3; 22481096Smsmith 22581096Smsmith u2 = TIMER_READ; 22681096Smsmith u3 = TIMER_READ; 22781096Smsmith do { 22881096Smsmith u1 = u2; 22981096Smsmith u2 = u3; 23081096Smsmith u3 = TIMER_READ; 23191237Sphk } while (u1 > u2 || u2 > u3 || (u3 - u1) > 15); 23281096Smsmith return (u2); 23381096Smsmith} 23481096Smsmith 23581096Smsmith/* 23680070Smsmith * Timecounter freqency adjustment interface. 23780070Smsmith */ 23880070Smsmithstatic int 23980070Smsmithacpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) 24080070Smsmith{ 24180070Smsmith int error; 24280070Smsmith u_int freq; 24380070Smsmith 24480070Smsmith if (acpi_timer_timecounter.tc_frequency == 0) 24580070Smsmith return (EOPNOTSUPP); 24680070Smsmith freq = acpi_timer_frequency; 24780070Smsmith error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 24880070Smsmith if (error == 0 && req->newptr != NULL) { 24980070Smsmith acpi_timer_frequency = freq; 25080070Smsmith acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 25180070Smsmith tc_update(&acpi_timer_timecounter); 25280070Smsmith } 25380070Smsmith return (error); 25480070Smsmith} 25580070Smsmith 25680070SmsmithSYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, 25780070Smsmith 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); 25880070Smsmith 25980070Smsmith/* 26080070Smsmith * Test harness for verifying ACPI timer behaviour. 26180070Smsmith * Boot with debug.acpi.timer_test set to invoke this. 26280070Smsmith */ 26380070Smsmithstatic void 26480070Smsmithacpi_timer_test(void) 26580070Smsmith{ 26680070Smsmith u_int32_t u1, u2, u3; 26780070Smsmith 26880070Smsmith u1 = TIMER_READ; 26980070Smsmith u2 = TIMER_READ; 27080070Smsmith u3 = TIMER_READ; 27180070Smsmith 27280070Smsmith device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 27380070Smsmith for (;;) { 27480070Smsmith /* 27580070Smsmith * The failure case is where u3 > u1, but u2 does not fall between the two, 27680070Smsmith * ie. it contains garbage. 27780070Smsmith */ 27880070Smsmith if (u3 > u1) { 27980070Smsmith if ((u2 < u1) || (u2 > u3)) 28080070Smsmith device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 28180070Smsmith u1, u2, u3); 28280070Smsmith } 28380070Smsmith u1 = u2; 28480070Smsmith u2 = u3; 28580070Smsmith u3 = TIMER_READ; 28680070Smsmith } 28780070Smsmith} 28880070Smsmith 28980602Smsmith/* 29080602Smsmith * Chipset workaround driver hung off PCI. 29180602Smsmith * 29281096Smsmith * Some ACPI timers are known or believed to suffer from implementation 29381096Smsmith * problems which can lead to erroneous values being read from the timer. 29481096Smsmith * 29581096Smsmith * Since we can't trust unknown chipsets, we default to a timer-read 29681096Smsmith * routine which compensates for the most common problem (as detailed 29781096Smsmith * in the excerpt from the Intel PIIX4 datasheet below). 29881096Smsmith * 29981096Smsmith * When we detect a known-functional chipset, we disable the workaround 30081096Smsmith * to improve speed. 30181096Smsmith * 30280602Smsmith * ] 20. ACPI Timer Errata 30380602Smsmith * ] 30480602Smsmith * ] Problem: The power management timer may return improper result when 30580602Smsmith * ] read. Although the timer value settles properly after incrementing, 30680602Smsmith * ] while incrementing there is a 3nS window every 69.8nS where the 30780602Smsmith * ] timer value is indeterminate (a 4.2% chance that the data will be 30880602Smsmith * ] incorrect when read). As a result, the ACPI free running count up 30980602Smsmith * ] timer specification is violated due to erroneous reads. Implication: 31080602Smsmith * ] System hangs due to the "inaccuracy" of the timer when used by 31180602Smsmith * ] software for time critical events and delays. 31280602Smsmith * ] 31380602Smsmith * ] Workaround: Read the register twice and compare. 31480602Smsmith * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 31580602Smsmith * ] in the PIIX4M. 31680602Smsmith * 31780602Smsmith * The counter is in other words not latched to the PCI bus clock when 31880602Smsmith * read. Notice the workaround isn't: We need to read until we have 31980602Smsmith * three monotonic samples and then use the middle one, otherwise we are 32080602Smsmith * not protected against the fact that the bits can be wrong in two 32180602Smsmith * directions. If we only cared about monosity two reads would be enough. 32280602Smsmith */ 32380602Smsmith 32491237Sphk#if 0 32580602Smsmithstatic int acpi_timer_pci_probe(device_t dev); 32680602Smsmith 32780602Smsmithstatic device_method_t acpi_timer_pci_methods[] = { 32880602Smsmith DEVMETHOD(device_probe, acpi_timer_pci_probe), 32980602Smsmith {0, 0} 33080602Smsmith}; 33180602Smsmith 33280602Smsmithstatic driver_t acpi_timer_pci_driver = { 33380602Smsmith "acpi_timer_pci", 33480602Smsmith acpi_timer_pci_methods, 33580602Smsmith 0, 33680602Smsmith}; 33780602Smsmith 33880602Smsmithdevclass_t acpi_timer_pci_devclass; 33980602SmsmithDRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0); 34080602Smsmith 34180602Smsmith/* 34281096Smsmith * Look at PCI devices going past; if we detect one we know contains 34381096Smsmith * a functional ACPI timer device, enable the faster timecounter read 34481096Smsmith * routine. 34580602Smsmith */ 34680602Smsmithstatic int 34780602Smsmithacpi_timer_pci_probe(device_t dev) 34880602Smsmith{ 34981172Smsmith int vendor, device, revid; 35081172Smsmith 35181172Smsmith vendor = pci_get_vendor(dev); 35281172Smsmith device = pci_get_device(dev); 35381172Smsmith revid = pci_get_revid(dev); 35481172Smsmith 35581172Smsmith if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */ 35681172Smsmith ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */ 35781172Smsmith 0) { 35881172Smsmith 35981096Smsmith acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 36081172Smsmith acpi_timer_timecounter.tc_name = "ACPI-fast"; 36181096Smsmith if (bootverbose) 36281172Smsmith device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n"); 36380602Smsmith } 36480602Smsmith 36580602Smsmith return(ENXIO); /* we never match anything */ 36680602Smsmith} 36791237Sphk#endif 368