1 /*- 2 * Copyright (c) 2015,2016-2017 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/smp.h> 36 #include <sys/systm.h> 37 #include <sys/timeet.h> 38 39 #include <dev/hyperv/include/hyperv.h> 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 * Additionally required feature: 52 * - SynIC is needed for interrupt generation. 53 */ 54 #define CPUID_HV_ET_MASK (CPUID_HV_MSR_SYNIC | \ 55 CPUID_HV_MSR_SYNTIMER) 56 57 static void vmbus_et_identify(driver_t *, device_t); 58 static int vmbus_et_probe(device_t); 59 static int vmbus_et_attach(device_t); 60 static int vmbus_et_detach(device_t); 61 static int vmbus_et_start(struct eventtimer *, sbintime_t, 62 sbintime_t); 63 64 static struct eventtimer vmbus_et; 65 66 static device_method_t vmbus_et_methods[] = { 67 DEVMETHOD(device_identify, vmbus_et_identify), 68 DEVMETHOD(device_probe, vmbus_et_probe), 69 DEVMETHOD(device_attach, vmbus_et_attach), 70 DEVMETHOD(device_detach, vmbus_et_detach), 71 72 DEVMETHOD_END 73 }; 74 75 static driver_t vmbus_et_driver = { 76 VMBUS_ET_NAME, 77 vmbus_et_methods, 78 0 79 }; 80 81 static devclass_t vmbus_et_devclass; 82 83 DRIVER_MODULE(hv_et, vmbus, vmbus_et_driver, vmbus_et_devclass, NULL, NULL); 84 MODULE_VERSION(hv_et, 1); 85 86 static __inline uint64_t 87 hyperv_sbintime2count(sbintime_t time) 88 { 89 struct timespec val; 90 91 val = sbttots(time); 92 return (val.tv_sec * HYPERV_TIMER_FREQ) + 93 (val.tv_nsec / HYPERV_TIMER_NS_FACTOR); 94 } 95 96 static int 97 vmbus_et_start(struct eventtimer *et __unused, sbintime_t first, 98 sbintime_t period __unused) 99 { 100 uint64_t current; 101 102 current = hyperv_tc64(); 103 current += hyperv_sbintime2count(first); 104 wrmsr(MSR_HV_STIMER0_COUNT, current); 105 106 return (0); 107 } 108 109 void 110 vmbus_et_intr(struct trapframe *frame) 111 { 112 struct trapframe *oldframe; 113 struct thread *td; 114 115 if (vmbus_et.et_active) { 116 td = curthread; 117 td->td_intr_nesting_level++; 118 oldframe = td->td_intr_frame; 119 td->td_intr_frame = frame; 120 vmbus_et.et_event_cb(&vmbus_et, vmbus_et.et_arg); 121 td->td_intr_frame = oldframe; 122 td->td_intr_nesting_level--; 123 } 124 } 125 126 static void 127 vmbus_et_identify(driver_t *driver, device_t parent) 128 { 129 if (device_get_unit(parent) != 0 || 130 device_find_child(parent, VMBUS_ET_NAME, -1) != NULL || 131 (hyperv_features & CPUID_HV_ET_MASK) != CPUID_HV_ET_MASK || 132 hyperv_tc64 == NULL) 133 return; 134 135 device_add_child(parent, VMBUS_ET_NAME, -1); 136 } 137 138 static int 139 vmbus_et_probe(device_t dev) 140 { 141 if (resource_disabled(VMBUS_ET_NAME, 0)) 142 return (ENXIO); 143 144 device_set_desc(dev, "Hyper-V event timer"); 145 146 return (BUS_PROBE_NOWILDCARD); 147 } 148 149 static void 150 vmbus_et_config(void *arg __unused) 151 { 152 /* 153 * Make sure that STIMER0 is really disabled before writing 154 * to STIMER0_CONFIG. 155 * 156 * "Writing to the configuration register of a timer that 157 * is already enabled may result in undefined behaviour." 158 */ 159 for (;;) { 160 uint64_t val; 161 162 /* Stop counting, and this also implies disabling STIMER0 */ 163 wrmsr(MSR_HV_STIMER0_COUNT, 0); 164 165 val = rdmsr(MSR_HV_STIMER0_CONFIG); 166 if ((val & MSR_HV_STIMER_CFG_ENABLE) == 0) 167 break; 168 cpu_spinwait(); 169 } 170 wrmsr(MSR_HV_STIMER0_CONFIG, 171 MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT); 172 } 173 174 static int 175 vmbus_et_attach(device_t dev) 176 { 177 /* TODO: use independent IDT vector */ 178 179 vmbus_et.et_name = "Hyper-V"; 180 vmbus_et.et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU; 181 vmbus_et.et_quality = 1000; 182 vmbus_et.et_frequency = HYPERV_TIMER_FREQ; 183 vmbus_et.et_min_period = (0x00000001ULL << 32) / HYPERV_TIMER_FREQ; 184 vmbus_et.et_max_period = (0xfffffffeULL << 32) / HYPERV_TIMER_FREQ; 185 vmbus_et.et_start = vmbus_et_start; 186 187 /* 188 * Delay a bit to make sure that hyperv_tc64 will not return 0, 189 * since writing 0 to STIMER0_COUNT will disable STIMER0. 190 */ 191 DELAY(100); 192 smp_rendezvous(NULL, vmbus_et_config, NULL, NULL); 193 194 return (et_register(&vmbus_et)); 195 } 196 197 static int 198 vmbus_et_detach(device_t dev) 199 { 200 return (et_deregister(&vmbus_et)); 201 } 202