vmbus_et.c revision 300827 
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: head/sys/dev/hyperv/vmbus/hv_et.c 300827 2016-05-27 06:12:43Z sephe $");
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/hv_vmbus_priv.h>
41#include <dev/hyperv/vmbus/hyperv_reg.h>
42
43#define HV_TIMER_FREQUENCY		(10 * 1000 * 1000LL) /* 100ns period */
44#define HV_MAX_DELTA_TICKS		0xffffffffLL
45#define HV_MIN_DELTA_TICKS		1LL
46
47#define MSR_HV_STIMER0_CFG_SINT		\
48	((((uint64_t)HV_VMBUS_TIMER_SINT) << MSR_HV_STIMER_CFG_SINT_SHIFT) & \
49	 MSR_HV_STIMER_CFG_SINT_MASK)
50
51static struct eventtimer *et;
52
53static inline uint64_t
54sbintime2tick(sbintime_t time)
55{
56	struct timespec val;
57
58	val = sbttots(time);
59	return val.tv_sec * HV_TIMER_FREQUENCY + val.tv_nsec / 100;
60}
61
62static int
63hv_et_start(struct eventtimer *et, sbintime_t firsttime, sbintime_t periodtime)
64{
65	uint64_t current, config;
66
67	config = MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT;
68
69	current = rdmsr(MSR_HV_TIME_REF_COUNT);
70	current += sbintime2tick(firsttime);
71
72	wrmsr(MSR_HV_STIMER0_CONFIG, config);
73	wrmsr(MSR_HV_STIMER0_COUNT, current);
74
75	return (0);
76}
77
78static int
79hv_et_stop(struct eventtimer *et)
80{
81	wrmsr(MSR_HV_STIMER0_CONFIG, 0);
82	wrmsr(MSR_HV_STIMER0_COUNT, 0);
83
84	return (0);
85}
86
87void
88hv_et_intr(struct trapframe *frame)
89{
90	struct trapframe *oldframe;
91	struct thread *td;
92
93	if (et->et_active) {
94		td = curthread;
95		td->td_intr_nesting_level++;
96		oldframe = td->td_intr_frame;
97		td->td_intr_frame = frame;
98		et->et_event_cb(et, et->et_arg);
99		td->td_intr_frame = oldframe;
100		td->td_intr_nesting_level--;
101	}
102}
103
104static void
105hv_et_identify(driver_t *driver, device_t parent)
106{
107	if (device_find_child(parent, "hv_et", -1) != NULL)
108		return;
109
110	device_add_child(parent, "hv_et", -1);
111}
112
113static int
114hv_et_probe(device_t dev)
115{
116	device_set_desc(dev, "Hyper-V event timer");
117
118	return (BUS_PROBE_NOWILDCARD);
119}
120
121static int
122hv_et_attach(device_t dev)
123{
124	/* XXX: need allocate SINT and remove global et */
125	et = device_get_softc(dev);
126
127	et->et_name = "Hyper-V";
128	et->et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU;
129	et->et_quality = 1000;
130	et->et_frequency = HV_TIMER_FREQUENCY;
131	et->et_min_period = HV_MIN_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
132	et->et_max_period = HV_MAX_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
133	et->et_start = hv_et_start;
134	et->et_stop = hv_et_stop;
135	et->et_priv = dev;
136
137	return (et_register(et));
138}
139
140static int
141hv_et_detach(device_t dev)
142{
143	return (et_deregister(et));
144}
145
146static device_method_t hv_et_methods[] = {
147	DEVMETHOD(device_identify,      hv_et_identify),
148	DEVMETHOD(device_probe,         hv_et_probe),
149	DEVMETHOD(device_attach,        hv_et_attach),
150	DEVMETHOD(device_detach,        hv_et_detach),
151
152	DEVMETHOD_END
153};
154
155static driver_t hv_et_driver = {
156	"hv_et",
157	hv_et_methods,
158	sizeof(struct eventtimer)
159};
160
161static devclass_t hv_et_devclass;
162DRIVER_MODULE(hv_et, vmbus, hv_et_driver, hv_et_devclass, NULL, 0);
163MODULE_VERSION(hv_et, 1);
164