vmbus_et.c revision 293873 
1/*-
2 * Copyright (c) 2015 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 293873 2016-01-14 03:05:10Z sephe $");
29
30#include <sys/param.h>
31#include <sys/proc.h>
32#include <sys/systm.h>
33#include <sys/smp.h>
34#include <sys/time.h>
35#include <sys/timeet.h>
36
37#include "hv_vmbus_priv.h"
38
39#define HV_TIMER_FREQUENCY		(10 * 1000 * 1000LL) /* 100ns period */
40#define HV_MAX_DELTA_TICKS		0xffffffffLL
41#define HV_MIN_DELTA_TICKS		1LL
42
43static struct eventtimer et;
44static uint64_t periodticks[MAXCPU];
45
46static inline uint64_t
47sbintime2tick(sbintime_t time)
48{
49	struct timespec val;
50
51	val = sbttots(time);
52	return val.tv_sec * HV_TIMER_FREQUENCY + val.tv_nsec / 100;
53}
54
55static int
56hv_et_start(struct eventtimer *et, sbintime_t firsttime, sbintime_t periodtime)
57{
58	union hv_timer_config timer_cfg;
59	uint64_t current;
60
61	timer_cfg.as_uint64 = 0;
62	timer_cfg.auto_enable = 1;
63	timer_cfg.sintx = HV_VMBUS_MESSAGE_SINT;
64
65	periodticks[curcpu] = sbintime2tick(periodtime);
66	if (firsttime == 0)
67		firsttime = periodtime;
68
69	current = rdmsr(HV_X64_MSR_TIME_REF_COUNT);
70	current += sbintime2tick(firsttime);
71
72	wrmsr(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
73	wrmsr(HV_X64_MSR_STIMER0_COUNT, current);
74
75	return (0);
76}
77
78static int
79hv_et_stop(struct eventtimer *et)
80{
81	wrmsr(HV_X64_MSR_STIMER0_CONFIG, 0);
82	wrmsr(HV_X64_MSR_STIMER0_COUNT, 0);
83
84	return (0);
85}
86
87void
88hv_et_intr(struct trapframe *frame)
89{
90	union hv_timer_config timer_cfg;
91	struct trapframe *oldframe;
92	struct thread *td;
93
94	if (periodticks[curcpu] != 0) {
95		uint64_t tick = sbintime2tick(periodticks[curcpu]);
96		timer_cfg.as_uint64 = rdmsr(HV_X64_MSR_STIMER0_CONFIG);
97		timer_cfg.enable = 0;
98		timer_cfg.auto_enable = 1;
99		timer_cfg.periodic = 1;
100		periodticks[curcpu] = 0;
101
102		wrmsr(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
103		wrmsr(HV_X64_MSR_STIMER0_COUNT, tick);
104	}
105
106	if (et.et_active) {
107		td = curthread;
108		td->td_intr_nesting_level++;
109		oldframe = td->td_intr_frame;
110		td->td_intr_frame = frame;
111		et.et_event_cb(&et, et.et_arg);
112		td->td_intr_frame = oldframe;
113		td->td_intr_nesting_level--;
114	}
115}
116
117void
118hv_et_init(void)
119{
120	et.et_name = "HyperV";
121	et.et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU | ET_FLAGS_PERIODIC;
122	et.et_quality = 1000;
123	et.et_frequency = HV_TIMER_FREQUENCY;
124	et.et_min_period = (1LL << 32) / HV_TIMER_FREQUENCY;
125	et.et_max_period = HV_MAX_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
126	et.et_start = hv_et_start;
127	et.et_stop = hv_et_stop;
128	et.et_priv = &et;
129	et_register(&et);
130}
131
132