xref: /openbmc/qemu/hw/ppc/spapr_rtc.c (revision 3d9569b8)
1 /*
2  * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
3  *
4  * RTAS Real Time Clock
5  *
6  * Copyright (c) 2010-2011 David Gibson, IBM Corporation.
7  * Copyright 2014 David Gibson, Red Hat.
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a copy
10  * of this software and associated documentation files (the "Software"), to deal
11  * in the Software without restriction, including without limitation the rights
12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13  * copies of the Software, and to permit persons to whom the Software is
14  * furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25  * THE SOFTWARE.
26  */
27 
28 #include "qemu/osdep.h"
29 #include "qemu-common.h"
30 #include "cpu.h"
31 #include "qemu/timer.h"
32 #include "sysemu/sysemu.h"
33 #include "hw/ppc/spapr.h"
34 #include "qapi/error.h"
35 #include "qapi/qapi-events-target.h"
36 #include "qemu/cutils.h"
37 #include "qemu/module.h"
38 
39 void spapr_rtc_read(SpaprRtcState *rtc, struct tm *tm, uint32_t *ns)
40 {
41     int64_t host_ns = qemu_clock_get_ns(rtc_clock);
42     int64_t guest_ns;
43     time_t guest_s;
44 
45     assert(rtc);
46 
47     guest_ns = host_ns + rtc->ns_offset;
48     guest_s = guest_ns / NANOSECONDS_PER_SECOND;
49 
50     if (tm) {
51         gmtime_r(&guest_s, tm);
52     }
53     if (ns) {
54         *ns = guest_ns;
55     }
56 }
57 
58 int spapr_rtc_import_offset(SpaprRtcState *rtc, int64_t legacy_offset)
59 {
60     if (!rtc) {
61         return -ENODEV;
62     }
63 
64     rtc->ns_offset = legacy_offset * NANOSECONDS_PER_SECOND;
65 
66     return 0;
67 }
68 
69 static void rtas_get_time_of_day(PowerPCCPU *cpu, SpaprMachineState *spapr,
70                                  uint32_t token, uint32_t nargs,
71                                  target_ulong args,
72                                  uint32_t nret, target_ulong rets)
73 {
74     struct tm tm;
75     uint32_t ns;
76 
77     if ((nargs != 0) || (nret != 8)) {
78         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
79         return;
80     }
81 
82     spapr_rtc_read(&spapr->rtc, &tm, &ns);
83 
84     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
85     rtas_st(rets, 1, tm.tm_year + 1900);
86     rtas_st(rets, 2, tm.tm_mon + 1);
87     rtas_st(rets, 3, tm.tm_mday);
88     rtas_st(rets, 4, tm.tm_hour);
89     rtas_st(rets, 5, tm.tm_min);
90     rtas_st(rets, 6, tm.tm_sec);
91     rtas_st(rets, 7, ns);
92 }
93 
94 static void rtas_set_time_of_day(PowerPCCPU *cpu, SpaprMachineState *spapr,
95                                  uint32_t token, uint32_t nargs,
96                                  target_ulong args,
97                                  uint32_t nret, target_ulong rets)
98 {
99     SpaprRtcState *rtc = &spapr->rtc;
100     struct tm tm;
101     time_t new_s;
102     int64_t host_ns;
103 
104     if ((nargs != 7) || (nret != 1)) {
105         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
106         return;
107     }
108 
109     tm.tm_year = rtas_ld(args, 0) - 1900;
110     tm.tm_mon = rtas_ld(args, 1) - 1;
111     tm.tm_mday = rtas_ld(args, 2);
112     tm.tm_hour = rtas_ld(args, 3);
113     tm.tm_min = rtas_ld(args, 4);
114     tm.tm_sec = rtas_ld(args, 5);
115 
116     new_s = mktimegm(&tm);
117     if (new_s == -1) {
118         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
119         return;
120     }
121 
122     /* Generate a monitor event for the change */
123     qapi_event_send_rtc_change(qemu_timedate_diff(&tm));
124 
125     host_ns = qemu_clock_get_ns(rtc_clock);
126 
127     rtc->ns_offset = (new_s * NANOSECONDS_PER_SECOND) - host_ns;
128 
129     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
130 }
131 
132 static void spapr_rtc_qom_date(Object *obj, struct tm *current_tm, Error **errp)
133 {
134     spapr_rtc_read(SPAPR_RTC(obj), current_tm, NULL);
135 }
136 
137 static void spapr_rtc_realize(DeviceState *dev, Error **errp)
138 {
139     SpaprRtcState *rtc = SPAPR_RTC(dev);
140     struct tm tm;
141     time_t host_s;
142     int64_t rtc_ns;
143 
144     /* Initialize the RTAS RTC from host time */
145 
146     qemu_get_timedate(&tm, 0);
147     host_s = mktimegm(&tm);
148     rtc_ns = qemu_clock_get_ns(rtc_clock);
149     rtc->ns_offset = host_s * NANOSECONDS_PER_SECOND - rtc_ns;
150 
151     object_property_add_tm(OBJECT(rtc), "date", spapr_rtc_qom_date, NULL);
152 }
153 
154 static const VMStateDescription vmstate_spapr_rtc = {
155     .name = "spapr/rtc",
156     .version_id = 1,
157     .minimum_version_id = 1,
158     .fields = (VMStateField[]) {
159         VMSTATE_INT64(ns_offset, SpaprRtcState),
160         VMSTATE_END_OF_LIST()
161     },
162 };
163 
164 static void spapr_rtc_class_init(ObjectClass *oc, void *data)
165 {
166     DeviceClass *dc = DEVICE_CLASS(oc);
167 
168     dc->realize = spapr_rtc_realize;
169     dc->vmsd = &vmstate_spapr_rtc;
170     /* Reason: This is an internal device only for handling the hypercalls */
171     dc->user_creatable = false;
172 
173     spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
174                         rtas_get_time_of_day);
175     spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
176                         rtas_set_time_of_day);
177 }
178 
179 static const TypeInfo spapr_rtc_info = {
180     .name          = TYPE_SPAPR_RTC,
181     .parent        = TYPE_DEVICE,
182     .instance_size = sizeof(SpaprRtcState),
183     .class_init    = spapr_rtc_class_init,
184 };
185 
186 static void spapr_rtc_register_types(void)
187 {
188     type_register_static(&spapr_rtc_info);
189 }
190 type_init(spapr_rtc_register_types)
191