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