hw/watchdog/wdt_diag288.c

   1 /*
   2  * watchdog device diag288 support
   3  *
   4  * Copyright IBM, Corp. 2015
   5  *
   6  * Authors:
   7  *  Xu Wang <gesaint@linux.vnet.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
  10  * option) any later version.  See the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "sysemu/watchdog.h"
  15 #include "hw/sysbus.h"
  16 #include "qemu/timer.h"
  17 #include "hw/watchdog/wdt_diag288.h"
  18
  19 static WatchdogTimerModel model = {
  20     .wdt_name = TYPE_WDT_DIAG288,
  21     .wdt_description = "diag288 device for s390x platform",
  22 };
  23
  24 static const VMStateDescription vmstate_diag288 = {
  25     .name = "vmstate_diag288",
  26     .version_id = 0,
  27     .minimum_version_id = 0,
  28     .fields = (VMStateField[]) {
  29         VMSTATE_TIMER_PTR(timer, DIAG288State),
  30         VMSTATE_BOOL(enabled, DIAG288State),
  31         VMSTATE_END_OF_LIST()
  32     }
  33 };
  34
  35 static void wdt_diag288_reset(DeviceState *dev)
  36 {
  37     DIAG288State *diag288 = DIAG288(dev);
  38
  39     diag288->enabled = false;
  40     timer_del(diag288->timer);
  41 }
  42
  43 static void diag288_reset(void *opaque)
  44 {
  45     DeviceState *diag288 = opaque;
  46
  47     wdt_diag288_reset(diag288);
  48 }
  49
  50 static void diag288_timer_expired(void *dev)
  51 {
  52     qemu_log_mask(CPU_LOG_RESET, "Watchdog timer expired.\n");
  53     watchdog_perform_action();
  54     /* Reset the watchdog only if the guest was notified about expiry. */
  55     switch (get_watchdog_action()) {
  56     case WDT_DEBUG:
  57     case WDT_NONE:
  58     case WDT_PAUSE:
  59          return;
  60     }
  61     wdt_diag288_reset(dev);
  62 }
  63
  64 static int wdt_diag288_handle_timer(DIAG288State *diag288,
  65                                      uint64_t func, uint64_t timeout)
  66 {
  67     switch (func) {
  68     case WDT_DIAG288_INIT:
  69         diag288->enabled = true;
  70         /* fall through */
  71     case WDT_DIAG288_CHANGE:
  72         if (!diag288->enabled) {
  73             return -1;
  74         }
  75         timer_mod(diag288->timer,
  76                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
  77                   timeout * get_ticks_per_sec());
  78         break;
  79     case WDT_DIAG288_CANCEL:
  80         if (!diag288->enabled) {
  81             return -1;
  82         }
  83         diag288->enabled = false;
  84         timer_del(diag288->timer);
  85         break;
  86     default:
  87         return -1;
  88     }
  89
  90     return 0;
  91 }
  92
  93 static void wdt_diag288_realize(DeviceState *dev, Error **errp)
  94 {
  95     DIAG288State *diag288 = DIAG288(dev);
  96
  97     qemu_register_reset(diag288_reset, diag288);
  98     diag288->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, diag288_timer_expired,
  99                                   dev);
 100 }
 101
 102 static void wdt_diag288_unrealize(DeviceState *dev, Error **errp)
 103 {
 104     DIAG288State *diag288 = DIAG288(dev);
 105
 106     timer_del(diag288->timer);
 107     timer_free(diag288->timer);
 108 }
 109
 110 static void wdt_diag288_class_init(ObjectClass *klass, void *data)
 111 {
 112     DeviceClass *dc = DEVICE_CLASS(klass);
 113     DIAG288Class *diag288 = DIAG288_CLASS(klass);
 114
 115     dc->realize = wdt_diag288_realize;
 116     dc->unrealize = wdt_diag288_unrealize;
 117     dc->reset = wdt_diag288_reset;
 118     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 119     dc->vmsd = &vmstate_diag288;
 120     diag288->handle_timer = wdt_diag288_handle_timer;
 121 }
 122
 123 static const TypeInfo wdt_diag288_info = {
 124     .class_init = wdt_diag288_class_init,
 125     .parent = TYPE_DEVICE,
 126     .name  = TYPE_WDT_DIAG288,
 127     .instance_size  = sizeof(DIAG288State),
 128     .class_size = sizeof(DIAG288Class),
 129 };
 130
 131 static void wdt_diag288_register_types(void)
 132 {
 133     watchdog_add_model(&model);
 134     type_register_static(&wdt_diag288_info);
 135 }
 136
 137 type_init(wdt_diag288_register_types)