1 /*-
2 * Copyright (c) 2009 Adrian Chadd
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 * $FreeBSD: releng/9.1/sys/i386/xen/xen_clock_util.c 193032 2009-05-29 13:36:06Z adrian $
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/9.1/sys/i386/xen/xen_clock_util.c 193032 2009-05-29 13:36:06Z adrian $");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/clock.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 #include <sys/time.h>
41
42 #include <xen/xen_intr.h>
43 #include <vm/vm.h>
44 #include <vm/pmap.h>
45 #include <machine/pmap.h>
46 #include <xen/hypervisor.h>
47 #include <machine/xen/xen-os.h>
48 #include <machine/xen/xenfunc.h>
49 #include <xen/interface/io/xenbus.h>
50 #include <xen/interface/vcpu.h>
51 #include <machine/cpu.h>
52
53 #include <machine/xen/xen_clock_util.h>
54
55 /*
56 * Read the current hypervisor start time (wall clock) from Xen.
57 */
58 void
59 xen_fetch_wallclock(struct timespec *ts)
60 {
61 shared_info_t *s = HYPERVISOR_shared_info;
62 uint32_t ts_version;
63
64 do {
65 ts_version = s->wc_version;
66 rmb();
67 ts->tv_sec = s->wc_sec;
68 ts->tv_nsec = s->wc_nsec;
69 rmb();
70 }
71 while ((s->wc_version & 1) | (ts_version ^ s->wc_version));
72 }
73
74 /*
75 * Read the current hypervisor system uptime value from Xen.
76 */
77 void
78 xen_fetch_uptime(struct timespec *ts)
79 {
80 shared_info_t *s = HYPERVISOR_shared_info;
81 struct vcpu_time_info *src;
82 struct shadow_time_info dst;
83 uint32_t pre_version, post_version;
84
85 src = &s->vcpu_info[smp_processor_id()].time;
86
87 spinlock_enter();
88 do {
89 pre_version = dst.version = src->version;
90 rmb();
91 dst.system_timestamp = src->system_time;
92 rmb();
93 post_version = src->version;
94 }
95 while ((pre_version & 1) | (pre_version ^ post_version));
96
97 spinlock_exit();
98
99 ts->tv_sec = dst.system_timestamp / 1000000000;
100 ts->tv_nsec = dst.system_timestamp % 1000000000;
101 }
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