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