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