xref: /openbmc/qemu/hw/ppc/spapr_rtc.c (revision 88c725c7)
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 "cpu.h"
30 #include "qemu/timer.h"
31 #include "sysemu/sysemu.h"
32 #include "hw/ppc/spapr.h"
33 #include "qapi-event.h"
34 #include "qemu/cutils.h"
35 
36 void spapr_rtc_read(sPAPRRTCState *rtc, struct tm *tm, uint32_t *ns)
37 {
38     int64_t host_ns = qemu_clock_get_ns(rtc_clock);
39     int64_t guest_ns;
40     time_t guest_s;
41 
42     assert(rtc);
43 
44     guest_ns = host_ns + rtc->ns_offset;
45     guest_s = guest_ns / NANOSECONDS_PER_SECOND;
46 
47     if (tm) {
48         gmtime_r(&guest_s, tm);
49     }
50     if (ns) {
51         *ns = guest_ns;
52     }
53 }
54 
55 int spapr_rtc_import_offset(sPAPRRTCState *rtc, int64_t legacy_offset)
56 {
57     if (!rtc) {
58         return -ENODEV;
59     }
60 
61     rtc->ns_offset = legacy_offset * NANOSECONDS_PER_SECOND;
62 
63     return 0;
64 }
65 
66 static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPRMachineState *spapr,
67                                  uint32_t token, uint32_t nargs,
68                                  target_ulong args,
69                                  uint32_t nret, target_ulong rets)
70 {
71     struct tm tm;
72     uint32_t ns;
73 
74     if ((nargs != 0) || (nret != 8)) {
75         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
76         return;
77     }
78 
79     spapr_rtc_read(&spapr->rtc, &tm, &ns);
80 
81     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
82     rtas_st(rets, 1, tm.tm_year + 1900);
83     rtas_st(rets, 2, tm.tm_mon + 1);
84     rtas_st(rets, 3, tm.tm_mday);
85     rtas_st(rets, 4, tm.tm_hour);
86     rtas_st(rets, 5, tm.tm_min);
87     rtas_st(rets, 6, tm.tm_sec);
88     rtas_st(rets, 7, ns);
89 }
90 
91 static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPRMachineState *spapr,
92                                  uint32_t token, uint32_t nargs,
93                                  target_ulong args,
94                                  uint32_t nret, target_ulong rets)
95 {
96     sPAPRRTCState *rtc = &spapr->rtc;
97     struct tm tm;
98     time_t new_s;
99     int64_t host_ns;
100 
101     if ((nargs != 7) || (nret != 1)) {
102         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
103         return;
104     }
105 
106     tm.tm_year = rtas_ld(args, 0) - 1900;
107     tm.tm_mon = rtas_ld(args, 1) - 1;
108     tm.tm_mday = rtas_ld(args, 2);
109     tm.tm_hour = rtas_ld(args, 3);
110     tm.tm_min = rtas_ld(args, 4);
111     tm.tm_sec = rtas_ld(args, 5);
112 
113     new_s = mktimegm(&tm);
114     if (new_s == -1) {
115         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
116         return;
117     }
118 
119     /* Generate a monitor event for the change */
120     qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort);
121 
122     host_ns = qemu_clock_get_ns(rtc_clock);
123 
124     rtc->ns_offset = (new_s * NANOSECONDS_PER_SECOND) - host_ns;
125 
126     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
127 }
128 
129 static void spapr_rtc_qom_date(Object *obj, struct tm *current_tm, Error **errp)
130 {
131     spapr_rtc_read(SPAPR_RTC(obj), current_tm, NULL);
132 }
133 
134 static void spapr_rtc_realize(DeviceState *dev, Error **errp)
135 {
136     sPAPRRTCState *rtc = SPAPR_RTC(dev);
137     struct tm tm;
138     time_t host_s;
139     int64_t rtc_ns;
140 
141     /* Initialize the RTAS RTC from host time */
142 
143     qemu_get_timedate(&tm, 0);
144     host_s = mktimegm(&tm);
145     rtc_ns = qemu_clock_get_ns(rtc_clock);
146     rtc->ns_offset = host_s * NANOSECONDS_PER_SECOND - rtc_ns;
147 
148     object_property_add_tm(OBJECT(rtc), "date", spapr_rtc_qom_date, NULL);
149 }
150 
151 static const VMStateDescription vmstate_spapr_rtc = {
152     .name = "spapr/rtc",
153     .version_id = 1,
154     .minimum_version_id = 1,
155     .fields = (VMStateField[]) {
156         VMSTATE_INT64(ns_offset, sPAPRRTCState),
157         VMSTATE_END_OF_LIST()
158     },
159 };
160 
161 static void spapr_rtc_class_init(ObjectClass *oc, void *data)
162 {
163     DeviceClass *dc = DEVICE_CLASS(oc);
164 
165     dc->realize = spapr_rtc_realize;
166     dc->vmsd = &vmstate_spapr_rtc;
167     /* Reason: This is an internal device only for handling the hypercalls */
168     dc->user_creatable = false;
169 
170     spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
171                         rtas_get_time_of_day);
172     spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
173                         rtas_set_time_of_day);
174 }
175 
176 static const TypeInfo spapr_rtc_info = {
177     .name          = TYPE_SPAPR_RTC,
178     .parent        = TYPE_DEVICE,
179     .instance_size = sizeof(sPAPRRTCState),
180     .class_init    = spapr_rtc_class_init,
181 };
182 
183 static void spapr_rtc_register_types(void)
184 {
185     type_register_static(&spapr_rtc_info);
186 }
187 type_init(spapr_rtc_register_types)
188