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 24 static WatchdogTimerModel model = { 25 .wdt_name = TYPE_WDT_DIAG288, 26 .wdt_description = "diag288 device for s390x platform", 27 }; 28 29 static 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 40 static void wdt_diag288_reset(DeviceState *dev) 41 { 42 DIAG288State *diag288 = DIAG288(dev); 43 44 diag288->enabled = false; 45 timer_del(diag288->timer); 46 } 47 48 static void diag288_reset(void *opaque) 49 { 50 DeviceState *diag288 = opaque; 51 52 wdt_diag288_reset(diag288); 53 } 54 55 static 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 73 static 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 } 101 102 static 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 } 110 111 static 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 } 118 119 static 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 } 132 133 static 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 }; 140 141 static void wdt_diag288_register_types(void) 142 { 143 watchdog_add_model(&model); 144 type_register_static(&wdt_diag288_info); 145 } 146 147 type_init(wdt_diag288_register_types) 148