vmbus_et.c revision 311373
1161246Spjd/*- 2161246Spjd * Copyright (c) 2015,2016 Microsoft Corp. 3161246Spjd * All rights reserved. 4161246Spjd * 5161246Spjd * Redistribution and use in source and binary forms, with or without 6161246Spjd * modification, are permitted provided that the following conditions 7161246Spjd * are met: 8161246Spjd * 1. Redistributions of source code must retain the above copyright 9161246Spjd * notice, this list of conditions and the following disclaimer. 10161246Spjd * 2. Redistributions in binary form must reproduce the above copyright 11161246Spjd * notice, this list of conditions and the following disclaimer in the 12161246Spjd * documentation and/or other materials provided with the distribution. 13161246Spjd * 14161246Spjd * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15161246Spjd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16161246Spjd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17161246Spjd * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18161246Spjd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19161246Spjd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20161246Spjd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21161246Spjd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22161246Spjd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23161246Spjd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24161246Spjd * SUCH DAMAGE. 25161246Spjd */ 26161246Spjd 27161246Spjd#include <sys/cdefs.h> 28161246Spjd__FBSDID("$FreeBSD: stable/11/sys/dev/hyperv/vmbus/vmbus_et.c 311373 2017-01-05 06:19:07Z sephe $"); 29161246Spjd 30161246Spjd#include <sys/param.h> 31161246Spjd#include <sys/bus.h> 32161246Spjd#include <sys/kernel.h> 33161246Spjd#include <sys/module.h> 34161246Spjd#include <sys/proc.h> 35161246Spjd#include <sys/smp.h> 36161246Spjd#include <sys/systm.h> 37161246Spjd#include <sys/timeet.h> 38161246Spjd 39161246Spjd#include <dev/hyperv/include/hyperv.h> 40161246Spjd#include <dev/hyperv/vmbus/hyperv_reg.h> 41162834Spjd#include <dev/hyperv/vmbus/hyperv_var.h> 42161246Spjd#include <dev/hyperv/vmbus/vmbus_var.h> 43161246Spjd 44161246Spjd#define VMBUS_ET_NAME "hvet" 45161246Spjd 46161246Spjd#define MSR_HV_STIMER0_CFG_SINT \ 47161246Spjd ((((uint64_t)VMBUS_SINT_TIMER) << MSR_HV_STIMER_CFG_SINT_SHIFT) & \ 48161246Spjd MSR_HV_STIMER_CFG_SINT_MASK) 49161246Spjd 50161246Spjd/* 51161246Spjd * Two additionally required features: 52161246Spjd * - SynIC is needed for interrupt generation. 53161246Spjd * - Time reference counter is needed to set ABS reference count to 54161246Spjd * STIMER0_COUNT. 55161246Spjd */ 56161246Spjd#define CPUID_HV_ET_MASK (CPUID_HV_MSR_TIME_REFCNT | \ 57161246Spjd CPUID_HV_MSR_SYNIC | \ 58161246Spjd CPUID_HV_MSR_SYNTIMER) 59161246Spjd 60161246Spjdstatic void vmbus_et_identify(driver_t *, device_t); 61161246Spjdstatic int vmbus_et_probe(device_t); 62161246Spjdstatic int vmbus_et_attach(device_t); 63161246Spjdstatic int vmbus_et_detach(device_t); 64161246Spjdstatic int vmbus_et_start(struct eventtimer *, sbintime_t, 65161246Spjd sbintime_t); 66161246Spjd 67161246Spjdstatic struct eventtimer vmbus_et; 68161246Spjd 69161246Spjdstatic device_method_t vmbus_et_methods[] = { 70161246Spjd DEVMETHOD(device_identify, vmbus_et_identify), 71161246Spjd DEVMETHOD(device_probe, vmbus_et_probe), 72161246Spjd DEVMETHOD(device_attach, vmbus_et_attach), 73161246Spjd DEVMETHOD(device_detach, vmbus_et_detach), 74161246Spjd 75161246Spjd DEVMETHOD_END 76161246Spjd}; 77162834Spjd 78161246Spjdstatic driver_t vmbus_et_driver = { 79161246Spjd VMBUS_ET_NAME, 80161246Spjd vmbus_et_methods, 81161246Spjd 0 82161246Spjd}; 83161246Spjd 84161246Spjdstatic devclass_t vmbus_et_devclass; 85161246Spjd 86161246SpjdDRIVER_MODULE(hv_et, vmbus, vmbus_et_driver, vmbus_et_devclass, NULL, NULL); 87161246SpjdMODULE_VERSION(hv_et, 1); 88161246Spjd 89161246Spjdstatic __inline uint64_t 90161246Spjdhyperv_sbintime2count(sbintime_t time) 91161246Spjd{ 92161246Spjd struct timespec val; 93161246Spjd 94161246Spjd val = sbttots(time); 95161246Spjd return (val.tv_sec * HYPERV_TIMER_FREQ) + 96161246Spjd (val.tv_nsec / HYPERV_TIMER_NS_FACTOR); 97161246Spjd} 98161246Spjd 99161246Spjdstatic int 100161246Spjdvmbus_et_start(struct eventtimer *et __unused, sbintime_t first, 101161246Spjd sbintime_t period __unused) 102161246Spjd{ 103161246Spjd uint64_t current; 104161246Spjd 105161246Spjd current = rdmsr(MSR_HV_TIME_REF_COUNT); 106161246Spjd current += hyperv_sbintime2count(first); 107161246Spjd wrmsr(MSR_HV_STIMER0_COUNT, current); 108161246Spjd 109161246Spjd return (0); 110161246Spjd} 111161246Spjd 112161246Spjdvoid 113162834Spjdvmbus_et_intr(struct trapframe *frame) 114161246Spjd{ 115161246Spjd struct trapframe *oldframe; 116161246Spjd struct thread *td; 117161246Spjd 118161246Spjd if (vmbus_et.et_active) { 119161246Spjd td = curthread; 120161246Spjd td->td_intr_nesting_level++; 121161246Spjd oldframe = td->td_intr_frame; 122161246Spjd td->td_intr_frame = frame; 123161246Spjd vmbus_et.et_event_cb(&vmbus_et, vmbus_et.et_arg); 124161246Spjd td->td_intr_frame = oldframe; 125161246Spjd td->td_intr_nesting_level--; 126161246Spjd } 127161246Spjd} 128161246Spjd 129161246Spjdstatic void 130161246Spjdvmbus_et_identify(driver_t *driver, device_t parent) 131161246Spjd{ 132161246Spjd if (device_get_unit(parent) != 0 || 133161246Spjd device_find_child(parent, VMBUS_ET_NAME, -1) != NULL || 134161246Spjd (hyperv_features & CPUID_HV_ET_MASK) != CPUID_HV_ET_MASK) 135161246Spjd return; 136161246Spjd 137161246Spjd device_add_child(parent, VMBUS_ET_NAME, -1); 138161246Spjd} 139161246Spjd 140161246Spjdstatic int 141vmbus_et_probe(device_t dev) 142{ 143 if (resource_disabled(VMBUS_ET_NAME, 0)) 144 return (ENXIO); 145 146 device_set_desc(dev, "Hyper-V event timer"); 147 148 return (BUS_PROBE_NOWILDCARD); 149} 150 151static void 152vmbus_et_config(void *arg __unused) 153{ 154 /* 155 * Make sure that STIMER0 is really disabled before writing 156 * to STIMER0_CONFIG. 157 * 158 * "Writing to the configuration register of a timer that 159 * is already enabled may result in undefined behaviour." 160 */ 161 for (;;) { 162 uint64_t val; 163 164 /* Stop counting, and this also implies disabling STIMER0 */ 165 wrmsr(MSR_HV_STIMER0_COUNT, 0); 166 167 val = rdmsr(MSR_HV_STIMER0_CONFIG); 168 if ((val & MSR_HV_STIMER_CFG_ENABLE) == 0) 169 break; 170 cpu_spinwait(); 171 } 172 wrmsr(MSR_HV_STIMER0_CONFIG, 173 MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT); 174} 175 176static int 177vmbus_et_attach(device_t dev) 178{ 179 /* TODO: use independent IDT vector */ 180 181 vmbus_et.et_name = "Hyper-V"; 182 vmbus_et.et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU; 183 vmbus_et.et_quality = 1000; 184 vmbus_et.et_frequency = HYPERV_TIMER_FREQ; 185 vmbus_et.et_min_period = (0x00000001ULL << 32) / HYPERV_TIMER_FREQ; 186 vmbus_et.et_max_period = (0xfffffffeULL << 32) / HYPERV_TIMER_FREQ; 187 vmbus_et.et_start = vmbus_et_start; 188 189 /* 190 * Delay a bit to make sure that MSR_HV_TIME_REF_COUNT will 191 * not return 0, since writing 0 to STIMER0_COUNT will disable 192 * STIMER0. 193 */ 194 DELAY(100); 195 smp_rendezvous(NULL, vmbus_et_config, NULL, NULL); 196 197 return (et_register(&vmbus_et)); 198} 199 200static int 201vmbus_et_detach(device_t dev) 202{ 203 return (et_deregister(&vmbus_et)); 204} 205