2 * Copyright (c) 2015,2016 Microsoft Corp.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
35 #include <sys/systm.h>
38 #include <sys/timeet.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>
44 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000LL) /* 100ns period */
45 #define HV_MAX_DELTA_TICKS 0xffffffffLL
46 #define HV_MIN_DELTA_TICKS 1LL
48 #define MSR_HV_STIMER0_CFG_SINT \
49 ((((uint64_t)VMBUS_SINT_TIMER) << MSR_HV_STIMER_CFG_SINT_SHIFT) & \
50 MSR_HV_STIMER_CFG_SINT_MASK)
53 * Two additionally required features:
54 * - SynIC is needed for interrupt generation.
55 * - Time reference counter is needed to set ABS reference count to
58 #define CPUID_HV_ET_MASK (CPUID_HV_MSR_TIME_REFCNT | \
59 CPUID_HV_MSR_SYNIC | \
60 CPUID_HV_MSR_SYNTIMER)
62 static struct eventtimer *et;
64 static __inline uint64_t
65 sbintime2tick(sbintime_t time)
70 return (val.tv_sec * HV_TIMER_FREQUENCY) + (val.tv_nsec / 100);
74 hv_et_start(struct eventtimer *et, sbintime_t firsttime, sbintime_t periodtime)
78 current = rdmsr(MSR_HV_TIME_REF_COUNT);
79 current += sbintime2tick(firsttime);
80 wrmsr(MSR_HV_STIMER0_COUNT, current);
86 vmbus_et_intr(struct trapframe *frame)
88 struct trapframe *oldframe;
93 td->td_intr_nesting_level++;
94 oldframe = td->td_intr_frame;
95 td->td_intr_frame = frame;
96 et->et_event_cb(et, et->et_arg);
97 td->td_intr_frame = oldframe;
98 td->td_intr_nesting_level--;
103 hv_et_identify(driver_t *driver, device_t parent)
105 if (device_find_child(parent, "hv_et", -1) != NULL ||
106 (hyperv_features & CPUID_HV_ET_MASK) != CPUID_HV_ET_MASK)
109 device_add_child(parent, "hv_et", -1);
113 hv_et_probe(device_t dev)
115 device_set_desc(dev, "Hyper-V event timer");
117 return (BUS_PROBE_NOWILDCARD);
121 vmbus_et_config(void *arg __unused)
124 * Make sure that STIMER0 is really disabled before writing
127 * "Writing to the configuration register of a timer that
128 * is already enabled may result in undefined behaviour."
133 /* Stop counting, and this also implies disabling STIMER0 */
134 wrmsr(MSR_HV_STIMER0_COUNT, 0);
136 val = rdmsr(MSR_HV_STIMER0_CONFIG);
137 if ((val & MSR_HV_STIMER_CFG_ENABLE) == 0)
141 wrmsr(MSR_HV_STIMER0_CONFIG,
142 MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT);
146 hv_et_attach(device_t dev)
148 /* XXX: need allocate SINT and remove global et */
149 et = device_get_softc(dev);
151 et->et_name = "Hyper-V";
152 et->et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU;
153 et->et_quality = 1000;
154 et->et_frequency = HV_TIMER_FREQUENCY;
155 et->et_min_period = HV_MIN_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
156 et->et_max_period = HV_MAX_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
157 et->et_start = hv_et_start;
161 * Delay a bit to make sure that MSR_HV_TIME_REF_COUNT will
162 * not return 0, since writing 0 to STIMER0_COUNT will disable
166 smp_rendezvous(NULL, vmbus_et_config, NULL, NULL);
168 return (et_register(et));
172 hv_et_detach(device_t dev)
174 return (et_deregister(et));
177 static device_method_t hv_et_methods[] = {
178 DEVMETHOD(device_identify, hv_et_identify),
179 DEVMETHOD(device_probe, hv_et_probe),
180 DEVMETHOD(device_attach, hv_et_attach),
181 DEVMETHOD(device_detach, hv_et_detach),
186 static driver_t hv_et_driver = {
189 sizeof(struct eventtimer)
192 static devclass_t hv_et_devclass;
193 DRIVER_MODULE(hv_et, vmbus, hv_et_driver, hv_et_devclass, NULL, 0);
194 MODULE_VERSION(hv_et, 1);