xref: /qemu/hw/s390x/sclpquiesce.c (revision 7271a819)
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 #include "qemu/osdep.h"
15 #include "hw/qdev.h"
16 #include "sysemu/sysemu.h"
17 #include "hw/s390x/sclp.h"
18 #include "hw/s390x/event-facility.h"
19 
20 typedef struct SignalQuiesce {
21     EventBufferHeader ebh;
22     uint16_t timeout;
23     uint8_t unit;
24 } QEMU_PACKED SignalQuiesce;
25 
26 static bool can_handle_event(uint8_t type)
27 {
28     return type == SCLP_EVENT_SIGNAL_QUIESCE;
29 }
30 
31 static unsigned int send_mask(void)
32 {
33     return SCLP_EVENT_MASK_SIGNAL_QUIESCE;
34 }
35 
36 static unsigned int receive_mask(void)
37 {
38     return 0;
39 }
40 
41 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
42                            int *slen)
43 {
44     SignalQuiesce *sq = (SignalQuiesce *) evt_buf_hdr;
45 
46     if (*slen < sizeof(SignalQuiesce)) {
47         return 0;
48     }
49 
50     if (!event->event_pending) {
51         return 0;
52     }
53     event->event_pending = false;
54 
55     sq->ebh.length = cpu_to_be16(sizeof(SignalQuiesce));
56     sq->ebh.type = SCLP_EVENT_SIGNAL_QUIESCE;
57     sq->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
58     /*
59      * system_powerdown does not have a timeout. Fortunately the
60      * timeout value is currently ignored by Linux, anyway
61      */
62     sq->timeout = cpu_to_be16(0);
63     sq->unit = cpu_to_be16(0);
64     *slen -= sizeof(SignalQuiesce);
65 
66     return 1;
67 }
68 
69 static const VMStateDescription vmstate_sclpquiesce = {
70     .name = TYPE_SCLP_QUIESCE,
71     .version_id = 0,
72     .minimum_version_id = 0,
73     .fields = (VMStateField[]) {
74         VMSTATE_BOOL(event_pending, SCLPEvent),
75         VMSTATE_END_OF_LIST()
76      }
77 };
78 
79 typedef struct QuiesceNotifier QuiesceNotifier;
80 
81 static struct QuiesceNotifier {
82     Notifier notifier;
83     SCLPEvent *event;
84 } qn;
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     qn.notifier.notify = quiesce_powerdown_req;
99     qn.event = event;
100 
101     qemu_register_powerdown_notifier(&qn.notifier);
102 
103     return 0;
104 }
105 
106 static void quiesce_reset(DeviceState *dev)
107 {
108    SCLPEvent *event = SCLP_EVENT(dev);
109 
110    event->event_pending = false;
111 }
112 
113 static void quiesce_class_init(ObjectClass *klass, void *data)
114 {
115     DeviceClass *dc = DEVICE_CLASS(klass);
116     SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
117 
118     dc->reset = quiesce_reset;
119     dc->vmsd = &vmstate_sclpquiesce;
120     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
121     /*
122      * Reason: This is just an internal device - the notifier should
123      * not be registered multiple times in quiesce_init()
124      */
125     dc->user_creatable = false;
126 
127     k->init = quiesce_init;
128     k->get_send_mask = send_mask;
129     k->get_receive_mask = receive_mask;
130     k->can_handle_event = can_handle_event;
131     k->read_event_data = read_event_data;
132     k->write_event_data = NULL;
133 }
134 
135 static const TypeInfo sclp_quiesce_info = {
136     .name          = TYPE_SCLP_QUIESCE,
137     .parent        = TYPE_SCLP_EVENT,
138     .instance_size = sizeof(SCLPEvent),
139     .class_init    = quiesce_class_init,
140     .class_size    = sizeof(SCLPEventClass),
141 };
142 
143 static void register_types(void)
144 {
145     type_register_static(&sclp_quiesce_info);
146 }
147 
148 type_init(register_types)
149