xref: /openbmc/qemu/hw/s390x/tod-tcg.c (revision b91a0fa7)
1 /*
2  * TOD (Time Of Day) clock - TCG implementation
3  *
4  * Copyright 2018 Red Hat, Inc.
5  * Author(s): David Hildenbrand <david@redhat.com>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or later.
8  * See the COPYING file in the top-level directory.
9  */
10 
11 #include "qemu/osdep.h"
12 #include "qemu-common.h"
13 #include "qapi/error.h"
14 #include "hw/s390x/tod.h"
15 #include "qemu/timer.h"
16 #include "qemu/cutils.h"
17 #include "qemu/module.h"
18 #include "cpu.h"
19 #include "tcg/tcg_s390x.h"
20 
21 static void qemu_s390_tod_get(const S390TODState *td, S390TOD *tod,
22                               Error **errp)
23 {
24     *tod = td->base;
25 
26     tod->low += time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
27     if (tod->low < td->base.low) {
28         tod->high++;
29     }
30 }
31 
32 static void qemu_s390_tod_set(S390TODState *td, const S390TOD *tod,
33                               Error **errp)
34 {
35     CPUState *cpu;
36 
37     td->base = *tod;
38 
39     td->base.low -= time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
40     if (td->base.low > tod->low) {
41         td->base.high--;
42     }
43 
44     /*
45      * The TOD has been changed and we have to recalculate the CKC values
46      * for all CPUs. We do this asynchronously, as "SET CLOCK should be
47      * issued only while all other activity on all CPUs .. has been
48      * suspended".
49      */
50     CPU_FOREACH(cpu) {
51         async_run_on_cpu(cpu, tcg_s390_tod_updated, RUN_ON_CPU_NULL);
52     }
53 }
54 
55 static void qemu_s390_tod_class_init(ObjectClass *oc, void *data)
56 {
57     S390TODClass *tdc = S390_TOD_CLASS(oc);
58 
59     tdc->get = qemu_s390_tod_get;
60     tdc->set = qemu_s390_tod_set;
61 }
62 
63 static void qemu_s390_tod_init(Object *obj)
64 {
65     S390TODState *td = S390_TOD(obj);
66     struct tm tm;
67 
68     qemu_get_timedate(&tm, 0);
69     td->base.high = 0;
70     td->base.low = TOD_UNIX_EPOCH + (time2tod(mktimegm(&tm)) * 1000000000ULL);
71     if (td->base.low < TOD_UNIX_EPOCH) {
72         td->base.high += 1;
73     }
74 }
75 
76 static TypeInfo qemu_s390_tod_info = {
77     .name = TYPE_QEMU_S390_TOD,
78     .parent = TYPE_S390_TOD,
79     .instance_size = sizeof(S390TODState),
80     .instance_init = qemu_s390_tod_init,
81     .class_init = qemu_s390_tod_class_init,
82     .class_size = sizeof(S390TODClass),
83 };
84 
85 static void register_types(void)
86 {
87     type_register_static(&qemu_s390_tod_info);
88 }
89 type_init(register_types);
90