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 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, 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 dc->reset = 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) 140