xref: /openbmc/qemu/hw/ppc/spapr_rtc.c (revision e7bbc9b1)
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/error.h"
34 #include "qapi/qapi-events-target.h"
35 #include "qemu/cutils.h"
36 
37 void spapr_rtc_read(sPAPRRTCState *rtc, struct tm *tm, uint32_t *ns)
38 {
39     int64_t host_ns = qemu_clock_get_ns(rtc_clock);
40     int64_t guest_ns;
41     time_t guest_s;
42 
43     assert(rtc);
44 
45     guest_ns = host_ns + rtc->ns_offset;
46     guest_s = guest_ns / NANOSECONDS_PER_SECOND;
47 
48     if (tm) {
49         gmtime_r(&guest_s, tm);
50     }
51     if (ns) {
52         *ns = guest_ns;
53     }
54 }
55 
56 int spapr_rtc_import_offset(sPAPRRTCState *rtc, int64_t legacy_offset)
57 {
58     if (!rtc) {
59         return -ENODEV;
60     }
61 
62     rtc->ns_offset = legacy_offset * NANOSECONDS_PER_SECOND;
63 
64     return 0;
65 }
66 
67 static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPRMachineState *spapr,
68                                  uint32_t token, uint32_t nargs,
69                                  target_ulong args,
70                                  uint32_t nret, target_ulong rets)
71 {
72     struct tm tm;
73     uint32_t ns;
74 
75     if ((nargs != 0) || (nret != 8)) {
76         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
77         return;
78     }
79 
80     spapr_rtc_read(&spapr->rtc, &tm, &ns);
81 
82     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
83     rtas_st(rets, 1, tm.tm_year + 1900);
84     rtas_st(rets, 2, tm.tm_mon + 1);
85     rtas_st(rets, 3, tm.tm_mday);
86     rtas_st(rets, 4, tm.tm_hour);
87     rtas_st(rets, 5, tm.tm_min);
88     rtas_st(rets, 6, tm.tm_sec);
89     rtas_st(rets, 7, ns);
90 }
91 
92 static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPRMachineState *spapr,
93                                  uint32_t token, uint32_t nargs,
94                                  target_ulong args,
95                                  uint32_t nret, target_ulong rets)
96 {
97     sPAPRRTCState *rtc = &spapr->rtc;
98     struct tm tm;
99     time_t new_s;
100     int64_t host_ns;
101 
102     if ((nargs != 7) || (nret != 1)) {
103         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
104         return;
105     }
106 
107     tm.tm_year = rtas_ld(args, 0) - 1900;
108     tm.tm_mon = rtas_ld(args, 1) - 1;
109     tm.tm_mday = rtas_ld(args, 2);
110     tm.tm_hour = rtas_ld(args, 3);
111     tm.tm_min = rtas_ld(args, 4);
112     tm.tm_sec = rtas_ld(args, 5);
113 
114     new_s = mktimegm(&tm);
115     if (new_s == -1) {
116         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
117         return;
118     }
119 
120     /* Generate a monitor event for the change */
121     qapi_event_send_rtc_change(qemu_timedate_diff(&tm));
122 
123     host_ns = qemu_clock_get_ns(rtc_clock);
124 
125     rtc->ns_offset = (new_s * NANOSECONDS_PER_SECOND) - host_ns;
126 
127     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
128 }
129 
130 static void spapr_rtc_qom_date(Object *obj, struct tm *current_tm, Error **errp)
131 {
132     spapr_rtc_read(SPAPR_RTC(obj), current_tm, NULL);
133 }
134 
135 static void spapr_rtc_realize(DeviceState *dev, Error **errp)
136 {
137     sPAPRRTCState *rtc = SPAPR_RTC(dev);
138     struct tm tm;
139     time_t host_s;
140     int64_t rtc_ns;
141 
142     /* Initialize the RTAS RTC from host time */
143 
144     qemu_get_timedate(&tm, 0);
145     host_s = mktimegm(&tm);
146     rtc_ns = qemu_clock_get_ns(rtc_clock);
147     rtc->ns_offset = host_s * NANOSECONDS_PER_SECOND - rtc_ns;
148 
149     object_property_add_tm(OBJECT(rtc), "date", spapr_rtc_qom_date, NULL);
150 }
151 
152 static const VMStateDescription vmstate_spapr_rtc = {
153     .name = "spapr/rtc",
154     .version_id = 1,
155     .minimum_version_id = 1,
156     .fields = (VMStateField[]) {
157         VMSTATE_INT64(ns_offset, sPAPRRTCState),
158         VMSTATE_END_OF_LIST()
159     },
160 };
161 
162 static void spapr_rtc_class_init(ObjectClass *oc, void *data)
163 {
164     DeviceClass *dc = DEVICE_CLASS(oc);
165 
166     dc->realize = spapr_rtc_realize;
167     dc->vmsd = &vmstate_spapr_rtc;
168     /* Reason: This is an internal device only for handling the hypercalls */
169     dc->user_creatable = false;
170 
171     spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
172                         rtas_get_time_of_day);
173     spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
174                         rtas_set_time_of_day);
175 }
176 
177 static const TypeInfo spapr_rtc_info = {
178     .name          = TYPE_SPAPR_RTC,
179     .parent        = TYPE_DEVICE,
180     .instance_size = sizeof(sPAPRRTCState),
181     .class_init    = spapr_rtc_class_init,
182 };
183 
184 static void spapr_rtc_register_types(void)
185 {
186     type_register_static(&spapr_rtc_info);
187 }
188 type_init(spapr_rtc_register_types)
189