/*- * Copyright (c) 2000, 2001 Michael Smith * Copyright (c) 2000 BSDi * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include "opt_acpi.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * A timecounter based on the free-running ACPI timer. * * Based on the i386-only mp_clock.c by . */ /* Hooks for the ACPI CA debugging infrastructure */ #define _COMPONENT ACPI_TIMER ACPI_MODULE_NAME("TIMER") static device_t acpi_timer_dev; static struct resource *acpi_timer_reg; static bus_space_handle_t acpi_timer_bsh; static bus_space_tag_t acpi_timer_bst; static eventhandler_tag acpi_timer_eh; static u_int acpi_timer_frequency = 14318182 / 4; /* Knob to disable acpi_timer device */ bool acpi_timer_disabled = false; static void acpi_timer_identify(driver_t *driver, device_t parent); static int acpi_timer_probe(device_t dev); static int acpi_timer_attach(device_t dev); static void acpi_timer_resume_handler(struct timecounter *); static void acpi_timer_suspend_handler(struct timecounter *); static u_int acpi_timer_get_timecount(struct timecounter *tc); static u_int acpi_timer_get_timecount_safe(struct timecounter *tc); static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); static void acpi_timer_boot_test(void); static int acpi_timer_test(void); static int acpi_timer_test_enabled = 0; TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled); static device_method_t acpi_timer_methods[] = { DEVMETHOD(device_identify, acpi_timer_identify), DEVMETHOD(device_probe, acpi_timer_probe), DEVMETHOD(device_attach, acpi_timer_attach), DEVMETHOD_END }; static driver_t acpi_timer_driver = { "acpi_timer", acpi_timer_methods, 0, }; DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, 0, 0); MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1); static struct timecounter acpi_timer_timecounter = { acpi_timer_get_timecount_safe, /* get_timecount function */ 0, /* no poll_pps */ 0, /* no default counter_mask */ 0, /* no default frequency */ "ACPI", /* name */ -1 /* quality (chosen later) */ }; static __inline uint32_t acpi_timer_read(void) { return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0)); } /* * Locate the ACPI timer using the FADT, set up and allocate the I/O resources * we will be using. */ static void acpi_timer_identify(driver_t *driver, device_t parent) { device_t dev; rman_res_t rlen, rstart; int rid, rtype; ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) || acpi_timer_dev || acpi_timer_disabled || AcpiGbl_FADT.PmTimerLength == 0) return_VOID; if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) { device_printf(parent, "could not add acpi_timer0\n"); return_VOID; } acpi_timer_dev = dev; switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { case ACPI_ADR_SPACE_SYSTEM_MEMORY: rtype = SYS_RES_MEMORY; break; case ACPI_ADR_SPACE_SYSTEM_IO: rtype = SYS_RES_IOPORT; break; default: return_VOID; } rid = 0; rlen = AcpiGbl_FADT.PmTimerLength; rstart = AcpiGbl_FADT.XPmTimerBlock.Address; if (bus_set_resource(dev, rtype, rid, rstart, rlen)) device_printf(dev, "couldn't set resource (%s 0x%jx+0x%jx)\n", (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen); return_VOID; } static int acpi_timer_probe(device_t dev) { char desc[40]; int i, j, rid, rtype; ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); if (dev != acpi_timer_dev) return (ENXIO); switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { case ACPI_ADR_SPACE_SYSTEM_MEMORY: rtype = SYS_RES_MEMORY; break; case ACPI_ADR_SPACE_SYSTEM_IO: rtype = SYS_RES_IOPORT; break; default: return (ENXIO); } rid = 0; acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); if (acpi_timer_reg == NULL) { device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n", (rtype == SYS_RES_IOPORT) ? "port" : "mem", (u_long)AcpiGbl_FADT.XPmTimerBlock.Address); return (ENXIO); } acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); acpi_timer_bst = rman_get_bustag(acpi_timer_reg); if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) acpi_timer_timecounter.tc_counter_mask = 0xffffffff; else acpi_timer_timecounter.tc_counter_mask = 0x00ffffff; acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE; if (testenv("debug.acpi.timer_test")) acpi_timer_boot_test(); /* * If all tests of the counter succeed, use the ACPI-fast method. If * at least one failed, default to using the safe routine, which reads * the timer multiple times to get a consistent value before returning. */ j = 0; if (bootverbose) printf("ACPI timer:"); for (i = 0; i < 10; i++) j += acpi_timer_test(); if (bootverbose) printf(" -> %d\n", j); if (j == 10) { acpi_timer_timecounter.tc_name = "ACPI-fast"; acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; acpi_timer_timecounter.tc_quality = 900; } else { acpi_timer_timecounter.tc_name = "ACPI-safe"; acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; acpi_timer_timecounter.tc_quality = 850; } tc_init(&acpi_timer_timecounter); sprintf(desc, "%d-bit timer at %u.%06uMHz", (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24, acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000); device_set_desc_copy(dev, desc); /* Release the resource, we'll allocate it again during attach. */ bus_release_resource(dev, rtype, rid, acpi_timer_reg); return (0); } static int acpi_timer_attach(device_t dev) { int rid, rtype; ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) { case ACPI_ADR_SPACE_SYSTEM_MEMORY: rtype = SYS_RES_MEMORY; break; case ACPI_ADR_SPACE_SYSTEM_IO: rtype = SYS_RES_IOPORT; break; default: return (ENXIO); } rid = 0; acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE); if (acpi_timer_reg == NULL) return (ENXIO); acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg); acpi_timer_bst = rman_get_bustag(acpi_timer_reg); /* Register suspend event handler. */ if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler, &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL) device_printf(dev, "failed to register suspend event handler\n"); return (0); } static void acpi_timer_resume_handler(struct timecounter *newtc) { struct timecounter *tc; tc = timecounter; if (tc != newtc) { if (bootverbose) device_printf(acpi_timer_dev, "restoring timecounter, %s -> %s\n", tc->tc_name, newtc->tc_name); (void)newtc->tc_get_timecount(newtc); timecounter = newtc; } } static void acpi_timer_suspend_handler(struct timecounter *newtc) { struct timecounter *tc; /* Deregister existing resume event handler. */ if (acpi_timer_eh != NULL) { EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh); acpi_timer_eh = NULL; } if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) { /* * If we are using a suspend safe timecounter, don't * save/restore it across suspend/resume. */ return; } KASSERT(newtc == &acpi_timer_timecounter, ("acpi_timer_suspend_handler: wrong timecounter")); tc = timecounter; if (tc != newtc) { if (bootverbose) device_printf(acpi_timer_dev, "switching timecounter, %s -> %s\n", tc->tc_name, newtc->tc_name); (void)acpi_timer_read(); (void)acpi_timer_read(); timecounter = newtc; acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume, acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST); } } /* * Fetch current time value from reliable hardware. */ static u_int acpi_timer_get_timecount(struct timecounter *tc) { return (acpi_timer_read()); } /* * Fetch current time value from hardware that may not correctly * latch the counter. We need to read until we have three monotonic * samples and then use the middle one, otherwise we are not protected * against the fact that the bits can be wrong in two directions. If * we only cared about monosity, two reads would be enough. */ static u_int acpi_timer_get_timecount_safe(struct timecounter *tc) { u_int u1, u2, u3; u2 = acpi_timer_read(); u3 = acpi_timer_read(); do { u1 = u2; u2 = u3; u3 = acpi_timer_read(); } while (u1 > u2 || u2 > u3); return (u2); } /* * Timecounter freqency adjustment interface. */ static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) { int error; u_int freq; if (acpi_timer_timecounter.tc_frequency == 0) return (EOPNOTSUPP); freq = acpi_timer_frequency; error = sysctl_handle_int(oidp, &freq, 0, req); if (error == 0 && req->newptr != NULL) { acpi_timer_frequency = freq; acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; } return (error); } SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, acpi_timer_sysctl_freq, "I", "ACPI timer frequency"); /* * Some ACPI timers are known or believed to suffer from implementation * problems which can lead to erroneous values being read. This function * tests for consistent results from the timer and returns 1 if it believes * the timer is consistent, otherwise it returns 0. * * It appears the cause is that the counter is not latched to the PCI bus * clock when read: * * ] 20. ACPI Timer Errata * ] * ] Problem: The power management timer may return improper result when * ] read. Although the timer value settles properly after incrementing, * ] while incrementing there is a 3nS window every 69.8nS where the * ] timer value is indeterminate (a 4.2% chance that the data will be * ] incorrect when read). As a result, the ACPI free running count up * ] timer specification is violated due to erroneous reads. Implication: * ] System hangs due to the "inaccuracy" of the timer when used by * ] software for time critical events and delays. * ] * ] Workaround: Read the register twice and compare. * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed * ] in the PIIX4M. */ #define N 2000 static int acpi_timer_test(void) { uint32_t last, this; int delta, max, max2, min, n; register_t s; /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */ if (!acpi_timer_test_enabled) return (1); TSENTER(); min = INT32_MAX; max = max2 = 0; /* Test the timer with interrupts disabled to get accurate results. */ s = intr_disable(); last = acpi_timer_read(); for (n = 0; n < N; n++) { this = acpi_timer_read(); delta = acpi_TimerDelta(this, last); if (delta > max) { max2 = max; max = delta; } else if (delta > max2) max2 = delta; if (delta < min) min = delta; last = this; } intr_restore(s); delta = max2 - min; if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO) n = 0; else if (min < 0 || max == 0 || max2 == 0) n = 0; else n = 1; if (bootverbose) printf(" %d/%d", n, delta); TSEXIT(); return (n); } #undef N /* * Test harness for verifying ACPI timer behaviour. * Boot with debug.acpi.timer_test set to invoke this. */ static void acpi_timer_boot_test(void) { uint32_t u1, u2, u3; u1 = acpi_timer_read(); u2 = acpi_timer_read(); u3 = acpi_timer_read(); device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); for (;;) { /* * The failure case is where u3 > u1, but u2 does not fall between * the two, ie. it contains garbage. */ if (u3 > u1) { if (u2 < u1 || u2 > u3) device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", u1, u2, u3); } u1 = u2; u2 = u3; u3 = acpi_timer_read(); } }