1 /* 2 * Reset handlers. 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2016 Red Hat, Inc. 6 * Copyright (c) 2024 Linaro, Ltd. 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a copy 9 * of this software and associated documentation files (the "Software"), to deal 10 * in the Software without restriction, including without limitation the rights 11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 12 * copies of the Software, and to permit persons to whom the Software is 13 * furnished to do so, subject to the following conditions: 14 * 15 * The above copyright notice and this permission notice shall be included in 16 * all copies or substantial portions of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 24 * THE SOFTWARE. 25 */ 26 27 #ifndef QEMU_SYSEMU_RESET_H 28 #define QEMU_SYSEMU_RESET_H 29 30 #include "qapi/qapi-events-run-state.h" 31 32 typedef void QEMUResetHandler(void *opaque); 33 34 /** 35 * qemu_register_resettable: Register an object to be reset 36 * @obj: object to be reset: it must implement the Resettable interface 37 * 38 * Register @obj on the list of objects which will be reset when the 39 * simulation is reset. These objects will be reset in the order 40 * they were added, using the three-phase Resettable protocol, 41 * so first all objects go through the enter phase, then all objects 42 * go through the hold phase, and then finally all go through the 43 * exit phase. 44 * 45 * It is not permitted to register or unregister reset functions or 46 * resettable objects from within any of the reset phase methods of @obj. 47 * 48 * We assume that the caller holds the BQL. 49 */ 50 void qemu_register_resettable(Object *obj); 51 52 /** 53 * qemu_unregister_resettable: Unregister an object to be reset 54 * @obj: object to unregister 55 * 56 * Remove @obj from the list of objects which are reset when the 57 * simulation is reset. It must have been previously added to 58 * the list via qemu_register_resettable(). 59 * 60 * We assume that the caller holds the BQL. 61 */ 62 void qemu_unregister_resettable(Object *obj); 63 64 /** 65 * qemu_register_reset: Register a callback for system reset 66 * @func: function to call 67 * @opaque: opaque data to pass to @func 68 * 69 * Register @func on the list of functions which are called when the 70 * entire system is reset. Functions registered with this API and 71 * Resettable objects registered with qemu_register_resettable() are 72 * handled together, in the order in which they were registered. 73 * Functions registered with this API are called in the 'hold' phase 74 * of the 3-phase reset. 75 * 76 * In general this function should not be used in new code where possible; 77 * for instance, device model reset is better accomplished using the 78 * methods on DeviceState. 79 * 80 * It is not permitted to register or unregister reset functions or 81 * resettable objects from within the @func callback. 82 * 83 * We assume that the caller holds the BQL. 84 */ 85 void qemu_register_reset(QEMUResetHandler *func, void *opaque); 86 87 /** 88 * qemu_register_reset_nosnapshotload: Register a callback for system reset 89 * @func: function to call 90 * @opaque: opaque data to pass to @func 91 * 92 * This is the same as qemu_register_reset(), except that @func is 93 * not called if the reason that the system is being reset is to 94 * put it into a clean state prior to loading a snapshot (i.e. for 95 * SHUTDOWN_CAUSE_SNAPSHOT_LOAD). 96 */ 97 void qemu_register_reset_nosnapshotload(QEMUResetHandler *func, void *opaque); 98 99 /** 100 * qemu_unregister_reset: Unregister a system reset callback 101 * @func: function registered with qemu_register_reset() 102 * @opaque: the same opaque data that was passed to qemu_register_reset() 103 * 104 * Undo the effects of a qemu_register_reset(). The @func and @opaque 105 * must both match the arguments originally used with qemu_register_reset(). 106 * 107 * We assume that the caller holds the BQL. 108 */ 109 void qemu_unregister_reset(QEMUResetHandler *func, void *opaque); 110 111 /** 112 * qemu_devices_reset: Perform a complete system reset 113 * @reason: reason for the reset 114 * 115 * This function performs the low-level work needed to do a complete reset 116 * of the system (calling all the callbacks registered with 117 * qemu_register_reset() and resetting all the Resettable objects registered 118 * with qemu_register_resettable()). It should only be called by the code in a 119 * MachineClass reset method. 120 * 121 * If you want to trigger a system reset from, for instance, a device 122 * model, don't use this function. Use qemu_system_reset_request(). 123 */ 124 void qemu_devices_reset(ShutdownCause reason); 125 126 #endif 127