xref: /openbmc/qemu/hw/ppc/spapr_rtc.c (revision 59a3a1c0)
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 "migration/vmstate.h"
35 #include "qapi/error.h"
36 #include "qapi/qapi-events-misc-target.h"
37 #include "qemu/cutils.h"
38 #include "qemu/module.h"
39 
40 void spapr_rtc_read(SpaprRtcState *rtc, struct tm *tm, uint32_t *ns)
41 {
42     int64_t host_ns = qemu_clock_get_ns(rtc_clock);
43     int64_t guest_ns;
44     time_t guest_s;
45 
46     assert(rtc);
47 
48     guest_ns = host_ns + rtc->ns_offset;
49     guest_s = guest_ns / NANOSECONDS_PER_SECOND;
50 
51     if (tm) {
52         gmtime_r(&guest_s, tm);
53     }
54     if (ns) {
55         *ns = guest_ns;
56     }
57 }
58 
59 int spapr_rtc_import_offset(SpaprRtcState *rtc, int64_t legacy_offset)
60 {
61     if (!rtc) {
62         return -ENODEV;
63     }
64 
65     rtc->ns_offset = legacy_offset * NANOSECONDS_PER_SECOND;
66 
67     return 0;
68 }
69 
70 static void rtas_get_time_of_day(PowerPCCPU *cpu, SpaprMachineState *spapr,
71                                  uint32_t token, uint32_t nargs,
72                                  target_ulong args,
73                                  uint32_t nret, target_ulong rets)
74 {
75     struct tm tm;
76     uint32_t ns;
77 
78     if ((nargs != 0) || (nret != 8)) {
79         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
80         return;
81     }
82 
83     spapr_rtc_read(&spapr->rtc, &tm, &ns);
84 
85     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
86     rtas_st(rets, 1, tm.tm_year + 1900);
87     rtas_st(rets, 2, tm.tm_mon + 1);
88     rtas_st(rets, 3, tm.tm_mday);
89     rtas_st(rets, 4, tm.tm_hour);
90     rtas_st(rets, 5, tm.tm_min);
91     rtas_st(rets, 6, tm.tm_sec);
92     rtas_st(rets, 7, ns);
93 }
94 
95 static void rtas_set_time_of_day(PowerPCCPU *cpu, SpaprMachineState *spapr,
96                                  uint32_t token, uint32_t nargs,
97                                  target_ulong args,
98                                  uint32_t nret, target_ulong rets)
99 {
100     SpaprRtcState *rtc = &spapr->rtc;
101     struct tm tm;
102     time_t new_s;
103     int64_t host_ns;
104 
105     if ((nargs != 7) || (nret != 1)) {
106         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
107         return;
108     }
109 
110     tm.tm_year = rtas_ld(args, 0) - 1900;
111     tm.tm_mon = rtas_ld(args, 1) - 1;
112     tm.tm_mday = rtas_ld(args, 2);
113     tm.tm_hour = rtas_ld(args, 3);
114     tm.tm_min = rtas_ld(args, 4);
115     tm.tm_sec = rtas_ld(args, 5);
116 
117     new_s = mktimegm(&tm);
118     if (new_s == -1) {
119         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
120         return;
121     }
122 
123     /* Generate a monitor event for the change */
124     qapi_event_send_rtc_change(qemu_timedate_diff(&tm));
125 
126     host_ns = qemu_clock_get_ns(rtc_clock);
127 
128     rtc->ns_offset = (new_s * NANOSECONDS_PER_SECOND) - host_ns;
129 
130     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
131 }
132 
133 static void spapr_rtc_qom_date(Object *obj, struct tm *current_tm, Error **errp)
134 {
135     spapr_rtc_read(SPAPR_RTC(obj), current_tm, NULL);
136 }
137 
138 static void spapr_rtc_realize(DeviceState *dev, Error **errp)
139 {
140     SpaprRtcState *rtc = SPAPR_RTC(dev);
141     struct tm tm;
142     time_t host_s;
143     int64_t rtc_ns;
144 
145     /* Initialize the RTAS RTC from host time */
146 
147     qemu_get_timedate(&tm, 0);
148     host_s = mktimegm(&tm);
149     rtc_ns = qemu_clock_get_ns(rtc_clock);
150     rtc->ns_offset = host_s * NANOSECONDS_PER_SECOND - rtc_ns;
151 
152     object_property_add_tm(OBJECT(rtc), "date", spapr_rtc_qom_date, NULL);
153 }
154 
155 static const VMStateDescription vmstate_spapr_rtc = {
156     .name = "spapr/rtc",
157     .version_id = 1,
158     .minimum_version_id = 1,
159     .fields = (VMStateField[]) {
160         VMSTATE_INT64(ns_offset, SpaprRtcState),
161         VMSTATE_END_OF_LIST()
162     },
163 };
164 
165 static void spapr_rtc_class_init(ObjectClass *oc, void *data)
166 {
167     DeviceClass *dc = DEVICE_CLASS(oc);
168 
169     dc->realize = spapr_rtc_realize;
170     dc->vmsd = &vmstate_spapr_rtc;
171     /* Reason: This is an internal device only for handling the hypercalls */
172     dc->user_creatable = false;
173 
174     spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
175                         rtas_get_time_of_day);
176     spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
177                         rtas_set_time_of_day);
178 }
179 
180 static const TypeInfo spapr_rtc_info = {
181     .name          = TYPE_SPAPR_RTC,
182     .parent        = TYPE_DEVICE,
183     .instance_size = sizeof(SpaprRtcState),
184     .class_init    = spapr_rtc_class_init,
185 };
186 
187 static void spapr_rtc_register_types(void)
188 {
189     type_register_static(&spapr_rtc_info);
190 }
191 type_init(spapr_rtc_register_types)
192