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/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 * 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 void vmbus_et_identify(driver_t *, device_t); 61 static int vmbus_et_probe(device_t); 62 static int vmbus_et_attach(device_t); 63 static int vmbus_et_detach(device_t); 64 static int vmbus_et_start(struct eventtimer *, sbintime_t, 65 sbintime_t); 66 67 static struct eventtimer vmbus_et; 68 69 static device_method_t vmbus_et_methods[] = { 70 DEVMETHOD(device_identify, vmbus_et_identify), 71 DEVMETHOD(device_probe, vmbus_et_probe), 72 DEVMETHOD(device_attach, vmbus_et_attach), 73 DEVMETHOD(device_detach, vmbus_et_detach), 74 75 DEVMETHOD_END 76 }; 77 78 static driver_t vmbus_et_driver = { 79 VMBUS_ET_NAME, 80 vmbus_et_methods, 81 0 82 }; 83 84 static devclass_t vmbus_et_devclass; 85 86 DRIVER_MODULE(hv_et, vmbus, vmbus_et_driver, vmbus_et_devclass, NULL, NULL); 87 MODULE_VERSION(hv_et, 1); 88 89 static __inline uint64_t 90 hyperv_sbintime2count(sbintime_t time) 91 { 92 struct timespec val; 93 94 val = sbttots(time); 95 return (val.tv_sec * HYPERV_TIMER_FREQ) + 96 (val.tv_nsec / HYPERV_TIMER_NS_FACTOR); 97 } 98 99 static int 100 vmbus_et_start(struct eventtimer *et __unused, sbintime_t first, 101 sbintime_t period __unused) 102 { 103 uint64_t current; 104 105 current = rdmsr(MSR_HV_TIME_REF_COUNT); 106 current += hyperv_sbintime2count(first); 107 wrmsr(MSR_HV_STIMER0_COUNT, current); 108 109 return (0); 110 } 111 112 void 113 vmbus_et_intr(struct trapframe *frame) 114 { 115 struct trapframe *oldframe; 116 struct thread *td; 117 118 if (vmbus_et.et_active) { 119 td = curthread; 120 td->td_intr_nesting_level++; 121 oldframe = td->td_intr_frame; 122 td->td_intr_frame = frame; 123 vmbus_et.et_event_cb(&vmbus_et, vmbus_et.et_arg); 124 td->td_intr_frame = oldframe; 125 td->td_intr_nesting_level--; 126 } 127 } 128 129 static void 130 vmbus_et_identify(driver_t *driver, device_t parent) 131 { 132 if (device_get_unit(parent) != 0 || 133 device_find_child(parent, VMBUS_ET_NAME, -1) != NULL || 134 (hyperv_features & CPUID_HV_ET_MASK) != CPUID_HV_ET_MASK) 135 return; 136 137 device_add_child(parent, VMBUS_ET_NAME, -1); 138 } 139 140 static int 141 vmbus_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 } 150 151 static void 152 vmbus_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 } 175 176 static int 177 vmbus_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 } 199 200 static int 201 vmbus_et_detach(device_t dev) 202 { 203 return (et_deregister(&vmbus_et)); 204 } 205