vmbus_et.c revision 300834
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 300834 2016-05-27 07:29:31Z 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#include <dev/hyperv/vmbus/hyperv_var.h>
43
44#define HV_TIMER_FREQUENCY		(10 * 1000 * 1000LL) /* 100ns period */
45#define HV_MAX_DELTA_TICKS		0xffffffffLL
46#define HV_MIN_DELTA_TICKS		1LL
47
48#define MSR_HV_STIMER0_CFG_SINT		\
49	((((uint64_t)HV_VMBUS_TIMER_SINT) << MSR_HV_STIMER_CFG_SINT_SHIFT) & \
50	 MSR_HV_STIMER_CFG_SINT_MASK)
51
52/*
53 * Two additionally required features:
54 * - SynIC is needed for interrupt generation.
55 * - Time reference counter is needed to set ABS reference count to
56 *   STIMER0_COUNT.
57 */
58#define CPUID_HV_ET_MASK		(CPUID_HV_MSR_TIME_REFCNT |	\
59					 CPUID_HV_MSR_SYNIC |		\
60					 CPUID_HV_MSR_SYNTIMER)
61
62static struct eventtimer *et;
63
64static inline uint64_t
65sbintime2tick(sbintime_t time)
66{
67	struct timespec val;
68
69	val = sbttots(time);
70	return val.tv_sec * HV_TIMER_FREQUENCY + val.tv_nsec / 100;
71}
72
73static int
74hv_et_start(struct eventtimer *et, sbintime_t firsttime, sbintime_t periodtime)
75{
76	uint64_t current, config;
77
78	config = MSR_HV_STIMER_CFG_AUTOEN | MSR_HV_STIMER0_CFG_SINT;
79
80	current = rdmsr(MSR_HV_TIME_REF_COUNT);
81	current += sbintime2tick(firsttime);
82
83	wrmsr(MSR_HV_STIMER0_CONFIG, config);
84	wrmsr(MSR_HV_STIMER0_COUNT, current);
85
86	return (0);
87}
88
89static int
90hv_et_stop(struct eventtimer *et)
91{
92	wrmsr(MSR_HV_STIMER0_CONFIG, 0);
93	wrmsr(MSR_HV_STIMER0_COUNT, 0);
94
95	return (0);
96}
97
98void
99hv_et_intr(struct trapframe *frame)
100{
101	struct trapframe *oldframe;
102	struct thread *td;
103
104	if (et->et_active) {
105		td = curthread;
106		td->td_intr_nesting_level++;
107		oldframe = td->td_intr_frame;
108		td->td_intr_frame = frame;
109		et->et_event_cb(et, et->et_arg);
110		td->td_intr_frame = oldframe;
111		td->td_intr_nesting_level--;
112	}
113}
114
115static void
116hv_et_identify(driver_t *driver, device_t parent)
117{
118	if (device_find_child(parent, "hv_et", -1) != NULL ||
119	    (hyperv_features & CPUID_HV_ET_MASK) != CPUID_HV_ET_MASK)
120		return;
121
122	device_add_child(parent, "hv_et", -1);
123}
124
125static int
126hv_et_probe(device_t dev)
127{
128	device_set_desc(dev, "Hyper-V event timer");
129
130	return (BUS_PROBE_NOWILDCARD);
131}
132
133static int
134hv_et_attach(device_t dev)
135{
136	/* XXX: need allocate SINT and remove global et */
137	et = device_get_softc(dev);
138
139	et->et_name = "Hyper-V";
140	et->et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU;
141	et->et_quality = 1000;
142	et->et_frequency = HV_TIMER_FREQUENCY;
143	et->et_min_period = HV_MIN_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
144	et->et_max_period = HV_MAX_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
145	et->et_start = hv_et_start;
146	et->et_stop = hv_et_stop;
147	et->et_priv = dev;
148
149	return (et_register(et));
150}
151
152static int
153hv_et_detach(device_t dev)
154{
155	return (et_deregister(et));
156}
157
158static device_method_t hv_et_methods[] = {
159	DEVMETHOD(device_identify,      hv_et_identify),
160	DEVMETHOD(device_probe,         hv_et_probe),
161	DEVMETHOD(device_attach,        hv_et_attach),
162	DEVMETHOD(device_detach,        hv_et_detach),
163
164	DEVMETHOD_END
165};
166
167static driver_t hv_et_driver = {
168	"hv_et",
169	hv_et_methods,
170	sizeof(struct eventtimer)
171};
172
173static devclass_t hv_et_devclass;
174DRIVER_MODULE(hv_et, vmbus, hv_et_driver, hv_et_devclass, NULL, 0);
175MODULE_VERSION(hv_et, 1);
176