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 VMBUS_ET_NAME "hvet"
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)
51 * Two additionally required features:
52 * - SynIC is needed for interrupt generation.
53 * - Time reference counter is needed to set ABS reference count to
56 #define CPUID_HV_ET_MASK (CPUID_HV_MSR_TIME_REFCNT | \
57 CPUID_HV_MSR_SYNIC | \
58 CPUID_HV_MSR_SYNTIMER)
60 static struct eventtimer vmbus_et;
62 static __inline uint64_t
63 hyperv_sbintime2count(sbintime_t time)
68 return (val.tv_sec * HYPERV_TIMER_FREQ) +
69 (val.tv_nsec / HYPERV_TIMER_NS_FACTOR);
73 vmbus_et_start(struct eventtimer *et __unused, sbintime_t first,
74 sbintime_t period __unused)
78 current = rdmsr(MSR_HV_TIME_REF_COUNT);
79 current += hyperv_sbintime2count(first);
80 wrmsr(MSR_HV_STIMER0_COUNT, current);
86 vmbus_et_intr(struct trapframe *frame)
88 struct trapframe *oldframe;
91 if (vmbus_et.et_active) {
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--;
103 vmbus_et_identify(driver_t *driver, device_t parent)
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)
110 device_add_child(parent, VMBUS_ET_NAME, -1);
114 vmbus_et_probe(device_t dev)
116 if (resource_disabled(VMBUS_ET_NAME, 0))
119 device_set_desc(dev, "Hyper-V event timer");
121 return (BUS_PROBE_NOWILDCARD);
125 vmbus_et_config(void *arg __unused)
128 * Make sure that STIMER0 is really disabled before writing
131 * "Writing to the configuration register of a timer that
132 * is already enabled may result in undefined behaviour."
137 /* Stop counting, and this also implies disabling STIMER0 */
138 wrmsr(MSR_HV_STIMER0_COUNT, 0);
140 val = rdmsr(MSR_HV_STIMER0_CONFIG);
141 if ((val & MSR_HV_STIMER_CFG_ENABLE) == 0)
145 wrmsr(MSR_HV_STIMER0_CONFIG,
146 MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT);
150 vmbus_et_attach(device_t dev)
152 /* TODO: use independent IDT vector */
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;
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
168 smp_rendezvous(NULL, vmbus_et_config, NULL, NULL);
170 return (et_register(&vmbus_et));
174 vmbus_et_detach(device_t dev)
176 return (et_deregister(&vmbus_et));
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),
188 static driver_t vmbus_et_driver = {
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);