LXR qemu/hw/watchdog/wdt

   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
  24static WatchdogTimerModel model = {
  25    .wdt_name = TYPE_WDT_DIAG288,
  26    .wdt_description = "diag288 device for s390x platform",
  27};
  28
  29static 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
  40static void wdt_diag288_reset(DeviceState *dev)
  41{
  42    DIAG288State *diag288 = DIAG288(dev);
  43
  44    diag288->enabled = false;
  45    timer_del(diag288->timer);
  46}
  47
  48static void diag288_reset(void *opaque)
  49{
  50    DeviceState *diag288 = opaque;
  51
  52    wdt_diag288_reset(diag288);
  53}
  54
  55static 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
  73static 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
 102static 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
 111static void wdt_diag288_unrealize(DeviceState *dev, Error **errp)
 112{
 113    DIAG288State *diag288 = DIAG288(dev);
 114
 115    timer_del(diag288->timer);
 116    timer_free(diag288->timer);
 117}
 118
 119static 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
 133static 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
 141static void wdt_diag288_register_types(void)
 142{
 143    watchdog_add_model(&model);
 144    type_register_static(&wdt_diag288_info);
 145}
 146
 147type_init(wdt_diag288_register_types)
 148