Index: head/sys/dev/hyperv/vmbus/hv_et.c =================================================================== --- head/sys/dev/hyperv/vmbus/hv_et.c (revision 300986) +++ head/sys/dev/hyperv/vmbus/hv_et.c (revision 300987) @@ -1,175 +1,194 @@ /*- * Copyright (c) 2015,2016 Microsoft Corp. * 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 #include #include #include #include #include #include #include #include #include #include #include #define HV_TIMER_FREQUENCY (10 * 1000 * 1000LL) /* 100ns period */ #define HV_MAX_DELTA_TICKS 0xffffffffLL #define HV_MIN_DELTA_TICKS 1LL #define MSR_HV_STIMER0_CFG_SINT \ ((((uint64_t)HV_VMBUS_TIMER_SINT) << MSR_HV_STIMER_CFG_SINT_SHIFT) & \ MSR_HV_STIMER_CFG_SINT_MASK) /* * Two additionally required features: * - SynIC is needed for interrupt generation. * - Time reference counter is needed to set ABS reference count to * STIMER0_COUNT. */ #define CPUID_HV_ET_MASK (CPUID_HV_MSR_TIME_REFCNT | \ CPUID_HV_MSR_SYNIC | \ CPUID_HV_MSR_SYNTIMER) static struct eventtimer *et; -static inline uint64_t +static __inline uint64_t sbintime2tick(sbintime_t time) { struct timespec val; val = sbttots(time); - return val.tv_sec * HV_TIMER_FREQUENCY + val.tv_nsec / 100; + return (val.tv_sec * HV_TIMER_FREQUENCY) + (val.tv_nsec / 100); } static int hv_et_start(struct eventtimer *et, sbintime_t firsttime, sbintime_t periodtime) { - uint64_t current, config; + uint64_t current; - config = MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT; - current = rdmsr(MSR_HV_TIME_REF_COUNT); current += sbintime2tick(firsttime); - - wrmsr(MSR_HV_STIMER0_CONFIG, config); wrmsr(MSR_HV_STIMER0_COUNT, current); return (0); } -static int -hv_et_stop(struct eventtimer *et) -{ - wrmsr(MSR_HV_STIMER0_CONFIG, 0); - wrmsr(MSR_HV_STIMER0_COUNT, 0); - - return (0); -} - void hv_et_intr(struct trapframe *frame) { struct trapframe *oldframe; struct thread *td; if (et->et_active) { td = curthread; td->td_intr_nesting_level++; oldframe = td->td_intr_frame; td->td_intr_frame = frame; et->et_event_cb(et, et->et_arg); td->td_intr_frame = oldframe; td->td_intr_nesting_level--; } } static void hv_et_identify(driver_t *driver, device_t parent) { if (device_find_child(parent, "hv_et", -1) != NULL || (hyperv_features & CPUID_HV_ET_MASK) != CPUID_HV_ET_MASK) return; device_add_child(parent, "hv_et", -1); } static int hv_et_probe(device_t dev) { device_set_desc(dev, "Hyper-V event timer"); return (BUS_PROBE_NOWILDCARD); } +static void +vmbus_et_config(void *arg __unused) +{ + /* + * Make sure that STIMER0 is really disabled before writing + * to STIMER0_CONFIG. + * + * "Writing to the configuration register of a timer that + * is already enabled may result in undefined behaviour." + */ + for (;;) { + uint64_t val; + + /* Stop counting, and this also implies disabling STIMER0 */ + wrmsr(MSR_HV_STIMER0_COUNT, 0); + + val = rdmsr(MSR_HV_STIMER0_CONFIG); + if ((val & MSR_HV_STIMER_CFG_ENABLE) == 0) + break; + cpu_spinwait(); + } + wrmsr(MSR_HV_STIMER0_CONFIG, + MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT); +} + static int hv_et_attach(device_t dev) { /* XXX: need allocate SINT and remove global et */ et = device_get_softc(dev); et->et_name = "Hyper-V"; et->et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU; et->et_quality = 1000; et->et_frequency = HV_TIMER_FREQUENCY; et->et_min_period = HV_MIN_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY); et->et_max_period = HV_MAX_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY); et->et_start = hv_et_start; - et->et_stop = hv_et_stop; et->et_priv = dev; + + /* + * Delay a bit to make sure that MSR_HV_TIME_REF_COUNT will + * not return 0, since writing 0 to STIMER0_COUNT will disable + * STIMER0. + */ + DELAY(100); + smp_rendezvous(NULL, vmbus_et_config, NULL, NULL); return (et_register(et)); } static int hv_et_detach(device_t dev) { return (et_deregister(et)); } static device_method_t hv_et_methods[] = { DEVMETHOD(device_identify, hv_et_identify), DEVMETHOD(device_probe, hv_et_probe), DEVMETHOD(device_attach, hv_et_attach), DEVMETHOD(device_detach, hv_et_detach), DEVMETHOD_END }; static driver_t hv_et_driver = { "hv_et", hv_et_methods, sizeof(struct eventtimer) }; static devclass_t hv_et_devclass; DRIVER_MODULE(hv_et, vmbus, hv_et_driver, hv_et_devclass, NULL, 0); MODULE_VERSION(hv_et, 1);