xref: /openbmc/qemu/hw/s390x/sclpquiesce.c (revision 2e1cacfb)
1 /*
2  * SCLP event type
3  *    Signal Quiesce - trigger system powerdown request
4  *
5  * Copyright IBM, Corp. 2012
6  *
7  * Authors:
8  *  Heinz Graalfs <graalfs@de.ibm.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
11  * option) any later version.  See the COPYING file in the top-level directory.
12  *
13  */
14 
15 #include "qemu/osdep.h"
16 #include "hw/s390x/sclp.h"
17 #include "migration/vmstate.h"
18 #include "qemu/module.h"
19 #include "sysemu/runstate.h"
20 #include "hw/s390x/event-facility.h"
21 
22 typedef struct SignalQuiesce {
23     EventBufferHeader ebh;
24     uint16_t timeout;
25     uint8_t unit;
26 } QEMU_PACKED SignalQuiesce;
27 
28 static bool can_handle_event(uint8_t type)
29 {
30     return type == SCLP_EVENT_SIGNAL_QUIESCE;
31 }
32 
33 static sccb_mask_t send_mask(void)
34 {
35     return SCLP_EVENT_MASK_SIGNAL_QUIESCE;
36 }
37 
38 static sccb_mask_t receive_mask(void)
39 {
40     return 0;
41 }
42 
43 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
44                            int *slen)
45 {
46     SignalQuiesce *sq = (SignalQuiesce *) evt_buf_hdr;
47 
48     if (*slen < sizeof(SignalQuiesce)) {
49         return 0;
50     }
51 
52     if (!event->event_pending) {
53         return 0;
54     }
55     event->event_pending = false;
56 
57     sq->ebh.length = cpu_to_be16(sizeof(SignalQuiesce));
58     sq->ebh.type = SCLP_EVENT_SIGNAL_QUIESCE;
59     sq->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
60     /*
61      * system_powerdown does not have a timeout. Fortunately the
62      * timeout value is currently ignored by Linux, anyway
63      */
64     sq->timeout = cpu_to_be16(0);
65     sq->unit = cpu_to_be16(0);
66     *slen -= sizeof(SignalQuiesce);
67 
68     return 1;
69 }
70 
71 static const VMStateDescription vmstate_sclpquiesce = {
72     .name = TYPE_SCLP_QUIESCE,
73     .version_id = 0,
74     .minimum_version_id = 0,
75     .fields = (const VMStateField[]) {
76         VMSTATE_BOOL(event_pending, SCLPEvent),
77         VMSTATE_END_OF_LIST()
78      }
79 };
80 
81 typedef struct QuiesceNotifier {
82     Notifier notifier;
83     SCLPEvent *event;
84 } QuiesceNotifier;
85 
86 static void quiesce_powerdown_req(Notifier *n, void *opaque)
87 {
88     QuiesceNotifier *qn = container_of(n, QuiesceNotifier, notifier);
89     SCLPEvent *event = qn->event;
90 
91     event->event_pending = true;
92     /* trigger SCLP read operation */
93     sclp_service_interrupt(0);
94 }
95 
96 static int quiesce_init(SCLPEvent *event)
97 {
98     static QuiesceNotifier qn;
99 
100     qn.notifier.notify = quiesce_powerdown_req;
101     qn.event = event;
102 
103     qemu_register_powerdown_notifier(&qn.notifier);
104 
105     return 0;
106 }
107 
108 static void quiesce_reset(DeviceState *dev)
109 {
110    SCLPEvent *event = SCLP_EVENT(dev);
111 
112    event->event_pending = false;
113 }
114 
115 static void quiesce_class_init(ObjectClass *klass, void *data)
116 {
117     DeviceClass *dc = DEVICE_CLASS(klass);
118     SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
119 
120     device_class_set_legacy_reset(dc, quiesce_reset);
121     dc->vmsd = &vmstate_sclpquiesce;
122     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
123     /*
124      * Reason: This is just an internal device - the notifier should
125      * not be registered multiple times in quiesce_init()
126      */
127     dc->user_creatable = false;
128 
129     k->init = quiesce_init;
130     k->get_send_mask = send_mask;
131     k->get_receive_mask = receive_mask;
132     k->can_handle_event = can_handle_event;
133     k->read_event_data = read_event_data;
134     k->write_event_data = NULL;
135 }
136 
137 static const TypeInfo sclp_quiesce_info = {
138     .name          = TYPE_SCLP_QUIESCE,
139     .parent        = TYPE_SCLP_EVENT,
140     .instance_size = sizeof(SCLPEvent),
141     .class_init    = quiesce_class_init,
142     .class_size    = sizeof(SCLPEventClass),
143 };
144 
145 static void register_types(void)
146 {
147     type_register_static(&sclp_quiesce_info);
148 }
149 
150 type_init(register_types)
151