hw/s390x/sclpquiesce.c

   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)