1 /*- 2 * Copyright (c) 2015,2016 Microsoft Corp. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/bus.h> 32 #include <sys/kernel.h> 33 #include <sys/module.h> 34 #include <sys/proc.h> 35 #include <sys/systm.h> 36 #include <sys/smp.h> 37 #include <sys/time.h> 38 #include <sys/timeet.h> 39 40 #include <dev/hyperv/vmbus/hyperv_reg.h> 41 #include <dev/hyperv/vmbus/hyperv_var.h> 42 #include <dev/hyperv/vmbus/vmbus_var.h> 43 44 #define VMBUS_ET_NAME "hvet" 45 46 #define MSR_HV_STIMER0_CFG_SINT \ 47 ((((uint64_t)VMBUS_SINT_TIMER) << MSR_HV_STIMER_CFG_SINT_SHIFT) & \ 48 MSR_HV_STIMER_CFG_SINT_MASK) 49 50 /* 51 * Two additionally required features: 52 * - SynIC is needed for interrupt generation. 53 * - Time reference counter is needed to set ABS reference count to 54 * STIMER0_COUNT. 55 */ 56 #define CPUID_HV_ET_MASK (CPUID_HV_MSR_TIME_REFCNT | \ 57 CPUID_HV_MSR_SYNIC | \ 58 CPUID_HV_MSR_SYNTIMER) 59 60 static struct eventtimer vmbus_et; 61 62 static __inline uint64_t 63 hyperv_sbintime2count(sbintime_t time) 64 { 65 struct timespec val; 66 67 val = sbttots(time); 68 return (val.tv_sec * HYPERV_TIMER_FREQ) + 69 (val.tv_nsec / HYPERV_TIMER_NS_FACTOR); 70 } 71 72 static int 73 vmbus_et_start(struct eventtimer *et __unused, sbintime_t first, 74 sbintime_t period __unused) 75 { 76 uint64_t current; 77 78 current = rdmsr(MSR_HV_TIME_REF_COUNT); 79 current += hyperv_sbintime2count(first); 80 wrmsr(MSR_HV_STIMER0_COUNT, current); 81 82 return (0); 83 } 84 85 void 86 vmbus_et_intr(struct trapframe *frame) 87 { 88 struct trapframe *oldframe; 89 struct thread *td; 90 91 if (vmbus_et.et_active) { 92 td = curthread; 93 td->td_intr_nesting_level++; 94 oldframe = td->td_intr_frame; 95 td->td_intr_frame = frame; 96 vmbus_et.et_event_cb(&vmbus_et, vmbus_et.et_arg); 97 td->td_intr_frame = oldframe; 98 td->td_intr_nesting_level--; 99 } 100 } 101 102 static void 103 vmbus_et_identify(driver_t *driver, device_t parent) 104 { 105 if (device_get_unit(parent) != 0 || 106 device_find_child(parent, VMBUS_ET_NAME, -1) != NULL || 107 (hyperv_features & CPUID_HV_ET_MASK) != CPUID_HV_ET_MASK) 108 return; 109 110 device_add_child(parent, VMBUS_ET_NAME, -1); 111 } 112 113 static int 114 vmbus_et_probe(device_t dev) 115 { 116 if (resource_disabled(VMBUS_ET_NAME, 0)) 117 return (ENXIO); 118 119 device_set_desc(dev, "Hyper-V event timer"); 120 121 return (BUS_PROBE_NOWILDCARD); 122 } 123 124 static void 125 vmbus_et_config(void *arg __unused) 126 { 127 /* 128 * Make sure that STIMER0 is really disabled before writing 129 * to STIMER0_CONFIG. 130 * 131 * "Writing to the configuration register of a timer that 132 * is already enabled may result in undefined behaviour." 133 */ 134 for (;;) { 135 uint64_t val; 136 137 /* Stop counting, and this also implies disabling STIMER0 */ 138 wrmsr(MSR_HV_STIMER0_COUNT, 0); 139 140 val = rdmsr(MSR_HV_STIMER0_CONFIG); 141 if ((val & MSR_HV_STIMER_CFG_ENABLE) == 0) 142 break; 143 cpu_spinwait(); 144 } 145 wrmsr(MSR_HV_STIMER0_CONFIG, 146 MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT); 147 } 148 149 static int 150 vmbus_et_attach(device_t dev) 151 { 152 /* TODO: use independent IDT vector */ 153 154 vmbus_et.et_name = "Hyper-V"; 155 vmbus_et.et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU; 156 vmbus_et.et_quality = 1000; 157 vmbus_et.et_frequency = HYPERV_TIMER_FREQ; 158 vmbus_et.et_min_period = (0x00000001ULL << 32) / HYPERV_TIMER_FREQ; 159 vmbus_et.et_max_period = (0xfffffffeULL << 32) / HYPERV_TIMER_FREQ; 160 vmbus_et.et_start = vmbus_et_start; 161 162 /* 163 * Delay a bit to make sure that MSR_HV_TIME_REF_COUNT will 164 * not return 0, since writing 0 to STIMER0_COUNT will disable 165 * STIMER0. 166 */ 167 DELAY(100); 168 smp_rendezvous(NULL, vmbus_et_config, NULL, NULL); 169 170 return (et_register(&vmbus_et)); 171 } 172 173 static int 174 vmbus_et_detach(device_t dev) 175 { 176 return (et_deregister(&vmbus_et)); 177 } 178 179 static device_method_t vmbus_et_methods[] = { 180 DEVMETHOD(device_identify, vmbus_et_identify), 181 DEVMETHOD(device_probe, vmbus_et_probe), 182 DEVMETHOD(device_attach, vmbus_et_attach), 183 DEVMETHOD(device_detach, vmbus_et_detach), 184 185 DEVMETHOD_END 186 }; 187 188 static driver_t vmbus_et_driver = { 189 VMBUS_ET_NAME, 190 vmbus_et_methods, 191 0 192 }; 193 194 static devclass_t vmbus_et_devclass; 195 DRIVER_MODULE(hv_et, vmbus, vmbus_et_driver, vmbus_et_devclass, NULL, NULL); 196 MODULE_VERSION(hv_et, 1); 197