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 "qemu/log.h" 21 #include "qemu/module.h" 22 23 static WatchdogTimerModel model = { 24 .wdt_name = TYPE_WDT_DIAG288, 25 .wdt_description = "diag288 device for s390x platform", 26 }; 27 28 static const VMStateDescription vmstate_diag288 = { 29 .name = "vmstate_diag288", 30 .version_id = 0, 31 .minimum_version_id = 0, 32 .fields = (VMStateField[]) { 33 VMSTATE_TIMER_PTR(timer, DIAG288State), 34 VMSTATE_BOOL(enabled, DIAG288State), 35 VMSTATE_END_OF_LIST() 36 } 37 }; 38 39 static void wdt_diag288_reset(DeviceState *dev) 40 { 41 DIAG288State *diag288 = DIAG288(dev); 42 43 diag288->enabled = false; 44 timer_del(diag288->timer); 45 } 46 47 static void diag288_reset(void *opaque) 48 { 49 DeviceState *diag288 = opaque; 50 51 wdt_diag288_reset(diag288); 52 } 53 54 static void diag288_timer_expired(void *dev) 55 { 56 qemu_log_mask(CPU_LOG_RESET, "Watchdog timer expired.\n"); 57 /* Reset the watchdog only if the guest gets notified about 58 * expiry. watchdog_perform_action() may temporarily relinquish 59 * the BQL; reset before triggering the action to avoid races with 60 * diag288 instructions. */ 61 switch (get_watchdog_action()) { 62 case WATCHDOG_ACTION_DEBUG: 63 case WATCHDOG_ACTION_NONE: 64 case WATCHDOG_ACTION_PAUSE: 65 break; 66 default: 67 wdt_diag288_reset(dev); 68 } 69 watchdog_perform_action(); 70 } 71 72 static int wdt_diag288_handle_timer(DIAG288State *diag288, 73 uint64_t func, uint64_t timeout) 74 { 75 switch (func) { 76 case WDT_DIAG288_INIT: 77 diag288->enabled = true; 78 /* fall through */ 79 case WDT_DIAG288_CHANGE: 80 if (!diag288->enabled) { 81 return -1; 82 } 83 timer_mod(diag288->timer, 84 qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 85 timeout * NANOSECONDS_PER_SECOND); 86 break; 87 case WDT_DIAG288_CANCEL: 88 if (!diag288->enabled) { 89 return -1; 90 } 91 diag288->enabled = false; 92 timer_del(diag288->timer); 93 break; 94 default: 95 return -1; 96 } 97 98 return 0; 99 } 100 101 static void wdt_diag288_realize(DeviceState *dev, Error **errp) 102 { 103 DIAG288State *diag288 = DIAG288(dev); 104 105 qemu_register_reset(diag288_reset, diag288); 106 diag288->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, diag288_timer_expired, 107 dev); 108 } 109 110 static void wdt_diag288_unrealize(DeviceState *dev, Error **errp) 111 { 112 DIAG288State *diag288 = DIAG288(dev); 113 114 timer_del(diag288->timer); 115 timer_free(diag288->timer); 116 } 117 118 static void wdt_diag288_class_init(ObjectClass *klass, void *data) 119 { 120 DeviceClass *dc = DEVICE_CLASS(klass); 121 DIAG288Class *diag288 = DIAG288_CLASS(klass); 122 123 dc->realize = wdt_diag288_realize; 124 dc->unrealize = wdt_diag288_unrealize; 125 dc->reset = wdt_diag288_reset; 126 dc->hotpluggable = false; 127 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 128 dc->vmsd = &vmstate_diag288; 129 diag288->handle_timer = wdt_diag288_handle_timer; 130 } 131 132 static const TypeInfo wdt_diag288_info = { 133 .class_init = wdt_diag288_class_init, 134 .parent = TYPE_DEVICE, 135 .name = TYPE_WDT_DIAG288, 136 .instance_size = sizeof(DIAG288State), 137 .class_size = sizeof(DIAG288Class), 138 }; 139 140 static void wdt_diag288_register_types(void) 141 { 142 watchdog_add_model(&model); 143 type_register_static(&wdt_diag288_info); 144 } 145 146 type_init(wdt_diag288_register_types) 147