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