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 "qemu/osdep.h"
  15 #include "sysemu/reset.h"
  16 #include "sysemu/watchdog.h"
  17 #include "hw/sysbus.h"
  18 #include "qemu/timer.h"
  19 #include "hw/watchdog/wdt_diag288.h"
  20 #include "migration/vmstate.h"
  21 #include "qemu/log.h"
  22 #include "qemu/module.h"
  23
  24 static WatchdogTimerModel model = {
  25     .wdt_name = TYPE_WDT_DIAG288,
  26     .wdt_description = "diag288 device for s390x platform",
  27 };
  28
  29 static const VMStateDescription vmstate_diag288 = {
  30     .name = "vmstate_diag288",
  31     .version_id = 0,
  32     .minimum_version_id = 0,
  33     .fields = (VMStateField[]) {
  34         VMSTATE_TIMER_PTR(timer, DIAG288State),
  35         VMSTATE_BOOL(enabled, DIAG288State),
  36         VMSTATE_END_OF_LIST()
  37     }
  38 };
  39
  40 static void wdt_diag288_reset(DeviceState *dev)
  41 {
  42     DIAG288State *diag288 = DIAG288(dev);
  43
  44     diag288->enabled = false;
  45     timer_del(diag288->timer);
  46 }
  47
  48 static void diag288_reset(void *opaque)
  49 {
  50     DeviceState *diag288 = opaque;
  51
  52     wdt_diag288_reset(diag288);
  53 }
  54
  55 static void diag288_timer_expired(void *dev)
  56 {
  57     qemu_log_mask(CPU_LOG_RESET, "Watchdog timer expired.\n");
  58     /* Reset the watchdog only if the guest gets notified about
  59      * expiry. watchdog_perform_action() may temporarily relinquish
  60      * the BQL; reset before triggering the action to avoid races with
  61      * diag288 instructions. */
  62     switch (get_watchdog_action()) {
  63     case WATCHDOG_ACTION_DEBUG:
  64     case WATCHDOG_ACTION_NONE:
  65     case WATCHDOG_ACTION_PAUSE:
  66         break;
  67     default:
  68         wdt_diag288_reset(dev);
  69     }
  70     watchdog_perform_action();
  71 }
  72
  73 static int wdt_diag288_handle_timer(DIAG288State *diag288,
  74                                      uint64_t func, uint64_t timeout)
  75 {
  76     switch (func) {
  77     case WDT_DIAG288_INIT:
  78         diag288->enabled = true;
  79         /* fall through */
  80     case WDT_DIAG288_CHANGE:
  81         if (!diag288->enabled) {
  82             return -1;
  83         }
  84         timer_mod(diag288->timer,
  85                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
  86                   timeout * NANOSECONDS_PER_SECOND);
  87         break;
  88     case WDT_DIAG288_CANCEL:
  89         if (!diag288->enabled) {
  90             return -1;
  91         }
  92         diag288->enabled = false;
  93         timer_del(diag288->timer);
  94         break;
  95     default:
  96         return -1;
  97     }
  98
  99     return 0;
 100 }
 101
 102 static void wdt_diag288_realize(DeviceState *dev, Error **errp)
 103 {
 104     DIAG288State *diag288 = DIAG288(dev);
 105
 106     qemu_register_reset(diag288_reset, diag288);
 107     diag288->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, diag288_timer_expired,
 108                                   dev);
 109 }
 110
 111 static void wdt_diag288_unrealize(DeviceState *dev)
 112 {
 113     DIAG288State *diag288 = DIAG288(dev);
 114
 115     timer_del(diag288->timer);
 116     timer_free(diag288->timer);
 117 }
 118
 119 static void wdt_diag288_class_init(ObjectClass *klass, void *data)
 120 {
 121     DeviceClass *dc = DEVICE_CLASS(klass);
 122     DIAG288Class *diag288 = DIAG288_CLASS(klass);
 123
 124     dc->realize = wdt_diag288_realize;
 125     dc->unrealize = wdt_diag288_unrealize;
 126     dc->reset = wdt_diag288_reset;
 127     dc->hotpluggable = false;
 128     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 129     dc->vmsd = &vmstate_diag288;
 130     diag288->handle_timer = wdt_diag288_handle_timer;
 131 }
 132
 133 static const TypeInfo wdt_diag288_info = {
 134     .class_init = wdt_diag288_class_init,
 135     .parent = TYPE_DEVICE,
 136     .name  = TYPE_WDT_DIAG288,
 137     .instance_size  = sizeof(DIAG288State),
 138     .class_size = sizeof(DIAG288Class),
 139 };
 140
 141 static void wdt_diag288_register_types(void)
 142 {
 143     watchdog_add_model(&model);
 144     type_register_static(&wdt_diag288_info);
 145 }
 146
 147 type_init(wdt_diag288_register_types)