acpi_timer.c revision 128071
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 128071 2004-04-09 18:14:32Z 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/sysctl.h> 34105281Sjhb#if __FreeBSD_version >= 500000 3580070Smsmith#include <sys/timetc.h> 36105281Sjhb#else 37105281Sjhb#include <sys/time.h> 38105281Sjhb#endif 3967761Smsmith 4080070Smsmith#include <machine/bus.h> 4180070Smsmith#include <machine/resource.h> 4280070Smsmith#include <sys/rman.h> 4380070Smsmith 4467761Smsmith#include "acpi.h" 45104726Sjhb#include <dev/acpica/acpivar.h> 46119281Simp#include <dev/pci/pcivar.h> 4767761Smsmith 4869744Smsmith/* 4980070Smsmith * A timecounter based on the free-running ACPI timer. 5080070Smsmith * 5180070Smsmith * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. 5280070Smsmith */ 5380070Smsmith 54119529Snjl/* Hooks for the ACPI CA debugging infrastructure */ 55126517Snjl#define _COMPONENT ACPI_TIMER 5691128SmsmithACPI_MODULE_NAME("TIMER") 5769744Smsmith 5880070Smsmithstatic device_t acpi_timer_dev; 5980070Smsmithstruct resource *acpi_timer_reg; 6067761Smsmith 61119529Snjlstatic u_int acpi_timer_frequency = 14318182 / 4; 6267761Smsmith 6367761Smsmithstatic void acpi_timer_identify(driver_t *driver, device_t parent); 6467761Smsmithstatic int acpi_timer_probe(device_t dev); 6567761Smsmithstatic int acpi_timer_attach(device_t dev); 6680070Smsmithstatic unsigned acpi_timer_get_timecount(struct timecounter *tc); 6781096Smsmithstatic unsigned acpi_timer_get_timecount_safe(struct timecounter *tc); 6880070Smsmithstatic int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); 6980070Smsmithstatic void acpi_timer_test(void); 7067761Smsmith 71119529Snjlstatic uint32_t read_counter(void); 72119529Snjlstatic int test_counter(void); 73114277Smarcel 7467761Smsmithstatic device_method_t acpi_timer_methods[] = { 7567761Smsmith DEVMETHOD(device_identify, acpi_timer_identify), 7667761Smsmith DEVMETHOD(device_probe, acpi_timer_probe), 7767761Smsmith DEVMETHOD(device_attach, acpi_timer_attach), 7867761Smsmith 7967761Smsmith {0, 0} 8067761Smsmith}; 8167761Smsmith 8267761Smsmithstatic driver_t acpi_timer_driver = { 8367761Smsmith "acpi_timer", 8467761Smsmith acpi_timer_methods, 8580070Smsmith 0, 8667761Smsmith}; 8767761Smsmith 8889054Smsmithstatic devclass_t acpi_timer_devclass; 8967761SmsmithDRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); 90128071SnjlMODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); 9167761Smsmith 9280070Smsmithstatic struct timecounter acpi_timer_timecounter = { 93118987Sphk acpi_timer_get_timecount_safe, 94118987Sphk 0, 95118987Sphk 0xffffff, 96118987Sphk 0, 97118987Sphk "ACPI", 98118987Sphk 1000 9980070Smsmith}; 10080070Smsmith 101119529Snjlstatic uint32_t 102114277Smarcelread_counter() 103114277Smarcel{ 104119529Snjl bus_space_handle_t bsh; 105119529Snjl bus_space_tag_t bst; 106119529Snjl u_int32_t tv; 107114277Smarcel 108119529Snjl bsh = rman_get_bushandle(acpi_timer_reg); 109119529Snjl bst = rman_get_bustag(acpi_timer_reg); 110119529Snjl tv = bus_space_read_4(bst, bsh, 0); 111119529Snjl bus_space_barrier(bst, bsh, 0, 4, BUS_SPACE_BARRIER_READ); 112119529Snjl 113119529Snjl return (tv); 114114277Smarcel} 115114277Smarcel 11691237Sphk#define N 2000 11791237Sphkstatic int 11891237Sphktest_counter() 11991237Sphk{ 120119529Snjl u_int last, this; 121119529Snjl int min, max, n, delta; 12291237Sphk 123119529Snjl min = 10000000; 124119529Snjl max = 0; 125119529Snjl last = read_counter(); 126119529Snjl for (n = 0; n < N; n++) { 127119529Snjl this = read_counter(); 128119529Snjl delta = (this - last) & 0xffffff; 129119529Snjl if (delta > max) 130119529Snjl max = delta; 131119529Snjl else if (delta < min) 132119529Snjl min = delta; 133119529Snjl last = this; 134119529Snjl } 135119529Snjl if (max - min > 2) 136119529Snjl n = 0; 137119529Snjl else if (min < 0 || max == 0) 138119529Snjl n = 0; 139119529Snjl else 140119529Snjl n = 1; 141119529Snjl if (bootverbose) { 142119529Snjl printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", 143119529Snjl n ? "GOOD" : "BAD ", 144119529Snjl min, max, max - min); 145119529Snjl } 146119529Snjl 147119529Snjl return (n); 14891237Sphk} 149119529Snjl#undef N 15091237Sphk 15180070Smsmith/* 15280070Smsmith * Locate the ACPI timer using the FADT, set up and allocate the I/O resources 15380070Smsmith * we will be using. 15480070Smsmith */ 15567761Smsmithstatic void 15667761Smsmithacpi_timer_identify(driver_t *driver, device_t parent) 15767761Smsmith{ 15880070Smsmith device_t dev; 15980070Smsmith char desc[40]; 160114277Smarcel u_long rlen, rstart; 161114277Smarcel int i, j, rid, rtype; 16267761Smsmith 16396926Speter ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 16469744Smsmith 165119529Snjl if (acpi_disabled("timer") || AcpiGbl_FADT == NULL) 16669744Smsmith return_VOID; 16771872Smsmith 16867761Smsmith if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { 16967761Smsmith device_printf(parent, "could not add acpi_timer0\n"); 17069744Smsmith return_VOID; 17167761Smsmith } 17280070Smsmith acpi_timer_dev = dev; 173114277Smarcel 17480070Smsmith rid = 0; 175114277Smarcel rlen = AcpiGbl_FADT->PmTmLen; 176114277Smarcel rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId) 177114277Smarcel ? SYS_RES_IOPORT : SYS_RES_MEMORY; 178114277Smarcel rstart = AcpiGbl_FADT->XPmTmrBlk.Address; 179114277Smarcel bus_set_resource(dev, rtype, rid, rstart, rlen); 180127135Snjl acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); 181114277Smarcel if (acpi_timer_reg == NULL) { 182114277Smarcel device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n", 183119529Snjl rtype == SYS_RES_IOPORT ? "port" : "mem", rstart); 18469744Smsmith return_VOID; 18567761Smsmith } 18694936Smux if (testenv("debug.acpi.timer_test")) 18780070Smsmith acpi_timer_test(); 18867761Smsmith 18980070Smsmith acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; 19091237Sphk j = 0; 19191237Sphk for(i = 0; i < 10; i++) 19291237Sphk j += test_counter(); 19391237Sphk if (j == 10) { 19491237Sphk acpi_timer_timecounter.tc_name = "ACPI-fast"; 19591237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 19691237Sphk } else { 19791237Sphk acpi_timer_timecounter.tc_name = "ACPI-safe"; 19891237Sphk acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; 19991237Sphk } 20080070Smsmith tc_init(&acpi_timer_timecounter); 20180070Smsmith 202119529Snjl sprintf(desc, "%d-bit timer at 3.579545MHz", 203119529Snjl AcpiGbl_FADT->TmrValExt ? 32 : 24); 20467761Smsmith device_set_desc_copy(dev, desc); 20569744Smsmith 20669744Smsmith return_VOID; 20767761Smsmith} 20867761Smsmith 20967761Smsmithstatic int 21067761Smsmithacpi_timer_probe(device_t dev) 21167761Smsmith{ 21280070Smsmith if (dev == acpi_timer_dev) 213119529Snjl return (0); 214119529Snjl 215119529Snjl return (ENXIO); 21667761Smsmith} 21767761Smsmith 21867761Smsmithstatic int 21967761Smsmithacpi_timer_attach(device_t dev) 22067761Smsmith{ 221119529Snjl return (0); 22280070Smsmith} 22367761Smsmith 22480070Smsmith/* 22581096Smsmith * Fetch current time value from reliable hardware. 22680070Smsmith */ 22780070Smsmithstatic unsigned 22880070Smsmithacpi_timer_get_timecount(struct timecounter *tc) 22980070Smsmith{ 230114277Smarcel return (read_counter()); 23167761Smsmith} 23280070Smsmith 23380070Smsmith/* 23481096Smsmith * Fetch current time value from hardware that may not correctly 23581096Smsmith * latch the counter. 23681096Smsmith */ 23781096Smsmithstatic unsigned 23881096Smsmithacpi_timer_get_timecount_safe(struct timecounter *tc) 23981096Smsmith{ 24081096Smsmith unsigned u1, u2, u3; 24181096Smsmith 242114277Smarcel u2 = read_counter(); 243114277Smarcel u3 = read_counter(); 24481096Smsmith do { 24581096Smsmith u1 = u2; 24681096Smsmith u2 = u3; 247114277Smarcel u3 = read_counter(); 248119529Snjl } while (u1 > u2 || u2 > u3 || u3 - u1 > 15); 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/* 27880070Smsmith * Test harness for verifying ACPI timer behaviour. 27980070Smsmith * Boot with debug.acpi.timer_test set to invoke this. 28080070Smsmith */ 28180070Smsmithstatic void 28280070Smsmithacpi_timer_test(void) 28380070Smsmith{ 28480070Smsmith u_int32_t u1, u2, u3; 28580070Smsmith 286114277Smarcel u1 = read_counter(); 287114277Smarcel u2 = read_counter(); 288114277Smarcel u3 = read_counter(); 28980070Smsmith 29080070Smsmith device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); 29180070Smsmith for (;;) { 29280070Smsmith /* 293119529Snjl * The failure case is where u3 > u1, but u2 does not fall between 294119529Snjl * the two, ie. it contains garbage. 29580070Smsmith */ 29680070Smsmith if (u3 > u1) { 297119529Snjl if (u2 < u1 || u2 > u3) 298119529Snjl device_printf(acpi_timer_dev, 299119529Snjl "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", 30080070Smsmith u1, u2, u3); 30180070Smsmith } 30280070Smsmith u1 = u2; 30380070Smsmith u2 = u3; 304114277Smarcel u3 = read_counter(); 30580070Smsmith } 30680070Smsmith} 30780070Smsmith 30880602Smsmith/* 30980602Smsmith * Chipset workaround driver hung off PCI. 31080602Smsmith * 31181096Smsmith * Some ACPI timers are known or believed to suffer from implementation 31281096Smsmith * problems which can lead to erroneous values being read from the timer. 31381096Smsmith * 31481096Smsmith * Since we can't trust unknown chipsets, we default to a timer-read 31581096Smsmith * routine which compensates for the most common problem (as detailed 31681096Smsmith * in the excerpt from the Intel PIIX4 datasheet below). 31781096Smsmith * 31881096Smsmith * When we detect a known-functional chipset, we disable the workaround 31981096Smsmith * to improve speed. 32081096Smsmith * 32180602Smsmith * ] 20. ACPI Timer Errata 32280602Smsmith * ] 32380602Smsmith * ] Problem: The power management timer may return improper result when 32480602Smsmith * ] read. Although the timer value settles properly after incrementing, 32580602Smsmith * ] while incrementing there is a 3nS window every 69.8nS where the 32680602Smsmith * ] timer value is indeterminate (a 4.2% chance that the data will be 32780602Smsmith * ] incorrect when read). As a result, the ACPI free running count up 32880602Smsmith * ] timer specification is violated due to erroneous reads. Implication: 32980602Smsmith * ] System hangs due to the "inaccuracy" of the timer when used by 33080602Smsmith * ] software for time critical events and delays. 33180602Smsmith * ] 33280602Smsmith * ] Workaround: Read the register twice and compare. 33380602Smsmith * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed 33480602Smsmith * ] in the PIIX4M. 33580602Smsmith * 33680602Smsmith * The counter is in other words not latched to the PCI bus clock when 33780602Smsmith * read. Notice the workaround isn't: We need to read until we have 33880602Smsmith * three monotonic samples and then use the middle one, otherwise we are 33980602Smsmith * not protected against the fact that the bits can be wrong in two 34080602Smsmith * directions. If we only cared about monosity two reads would be enough. 34180602Smsmith */ 34280602Smsmith 34391237Sphk#if 0 34480602Smsmithstatic int acpi_timer_pci_probe(device_t dev); 34580602Smsmith 34680602Smsmithstatic device_method_t acpi_timer_pci_methods[] = { 34780602Smsmith DEVMETHOD(device_probe, acpi_timer_pci_probe), 34880602Smsmith {0, 0} 34980602Smsmith}; 35080602Smsmith 35180602Smsmithstatic driver_t acpi_timer_pci_driver = { 35280602Smsmith "acpi_timer_pci", 35380602Smsmith acpi_timer_pci_methods, 35480602Smsmith 0, 35580602Smsmith}; 35680602Smsmith 35780602Smsmithdevclass_t acpi_timer_pci_devclass; 358119529SnjlDRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, 359119529Snjl acpi_timer_pci_devclass, 0, 0); 36080602Smsmith 36180602Smsmith/* 36281096Smsmith * Look at PCI devices going past; if we detect one we know contains 36381096Smsmith * a functional ACPI timer device, enable the faster timecounter read 36481096Smsmith * routine. 36580602Smsmith */ 36680602Smsmithstatic int 36780602Smsmithacpi_timer_pci_probe(device_t dev) 36880602Smsmith{ 36981172Smsmith int vendor, device, revid; 37081172Smsmith 37181172Smsmith vendor = pci_get_vendor(dev); 37281172Smsmith device = pci_get_device(dev); 37381172Smsmith revid = pci_get_revid(dev); 37481172Smsmith 375119529Snjl /* Detect the PIIX4M and i440MX, respectively */ 376119529Snjl if ((vendor == 0x8086 && device == 0x7113 && revid >= 0x03) || 377119529Snjl (vendor == 0x8086 && device == 0x719b)) { 37881172Smsmith 37981096Smsmith acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; 38081172Smsmith acpi_timer_timecounter.tc_name = "ACPI-fast"; 381119529Snjl if (bootverbose) { 382119529Snjl device_printf(acpi_timer_dev,"functional ACPI timer detected, " 383119529Snjl "enabling fast timecount interface\n"); 384119529Snjl } 38580602Smsmith } 38680602Smsmith 387119529Snjl /* We never match anything */ 388119529Snjl return (ENXIO); 38980602Smsmith} 39091237Sphk#endif 391