xref: /openbmc/qemu/hw/s390x/sclpquiesce.c (revision 650d103d3ea959212f826acb9d3fe80cf30e347b)
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/qdev.h"
17 #include "sysemu/sysemu.h"
18 #include "hw/s390x/sclp.h"
19 #include "migration/vmstate.h"
20 #include "qemu/module.h"
21 #include "hw/s390x/event-facility.h"
22 
23 typedef struct SignalQuiesce {
24     EventBufferHeader ebh;
25     uint16_t timeout;
26     uint8_t unit;
27 } QEMU_PACKED SignalQuiesce;
28 
29 static bool can_handle_event(uint8_t type)
30 {
31     return type == SCLP_EVENT_SIGNAL_QUIESCE;
32 }
33 
34 static sccb_mask_t send_mask(void)
35 {
36     return SCLP_EVENT_MASK_SIGNAL_QUIESCE;
37 }
38 
39 static sccb_mask_t receive_mask(void)
40 {
41     return 0;
42 }
43 
44 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
45                            int *slen)
46 {
47     SignalQuiesce *sq = (SignalQuiesce *) evt_buf_hdr;
48 
49     if (*slen < sizeof(SignalQuiesce)) {
50         return 0;
51     }
52 
53     if (!event->event_pending) {
54         return 0;
55     }
56     event->event_pending = false;
57 
58     sq->ebh.length = cpu_to_be16(sizeof(SignalQuiesce));
59     sq->ebh.type = SCLP_EVENT_SIGNAL_QUIESCE;
60     sq->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
61     /*
62      * system_powerdown does not have a timeout. Fortunately the
63      * timeout value is currently ignored by Linux, anyway
64      */
65     sq->timeout = cpu_to_be16(0);
66     sq->unit = cpu_to_be16(0);
67     *slen -= sizeof(SignalQuiesce);
68 
69     return 1;
70 }
71 
72 static const VMStateDescription vmstate_sclpquiesce = {
73     .name = TYPE_SCLP_QUIESCE,
74     .version_id = 0,
75     .minimum_version_id = 0,
76     .fields = (VMStateField[]) {
77         VMSTATE_BOOL(event_pending, SCLPEvent),
78         VMSTATE_END_OF_LIST()
79      }
80 };
81 
82 typedef struct QuiesceNotifier QuiesceNotifier;
83 
84 static struct QuiesceNotifier {
85     Notifier notifier;
86     SCLPEvent *event;
87 } qn;
88 
89 static void quiesce_powerdown_req(Notifier *n, void *opaque)
90 {
91     QuiesceNotifier *qn = container_of(n, QuiesceNotifier, notifier);
92     SCLPEvent *event = qn->event;
93 
94     event->event_pending = true;
95     /* trigger SCLP read operation */
96     sclp_service_interrupt(0);
97 }
98 
99 static int quiesce_init(SCLPEvent *event)
100 {
101     qn.notifier.notify = quiesce_powerdown_req;
102     qn.event = event;
103 
104     qemu_register_powerdown_notifier(&qn.notifier);
105 
106     return 0;
107 }
108 
109 static void quiesce_reset(DeviceState *dev)
110 {
111    SCLPEvent *event = SCLP_EVENT(dev);
112 
113    event->event_pending = false;
114 }
115 
116 static void quiesce_class_init(ObjectClass *klass, void *data)
117 {
118     DeviceClass *dc = DEVICE_CLASS(klass);
119     SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
120 
121     dc->reset = quiesce_reset;
122     dc->vmsd = &vmstate_sclpquiesce;
123     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
124     /*
125      * Reason: This is just an internal device - the notifier should
126      * not be registered multiple times in quiesce_init()
127      */
128     dc->user_creatable = false;
129 
130     k->init = quiesce_init;
131     k->get_send_mask = send_mask;
132     k->get_receive_mask = receive_mask;
133     k->can_handle_event = can_handle_event;
134     k->read_event_data = read_event_data;
135     k->write_event_data = NULL;
136 }
137 
138 static const TypeInfo sclp_quiesce_info = {
139     .name          = TYPE_SCLP_QUIESCE,
140     .parent        = TYPE_SCLP_EVENT,
141     .instance_size = sizeof(SCLPEvent),
142     .class_init    = quiesce_class_init,
143     .class_size    = sizeof(SCLPEventClass),
144 };
145 
146 static void register_types(void)
147 {
148     type_register_static(&sclp_quiesce_info);
149 }
150 
151 type_init(register_types)
152