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diff --git a/include/hw/resettable.h b/include/hw/resettable.h
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+/*
+ * Resettable interface header.
+ *
+ * Copyright (c) 2019 GreenSocs SAS
+ *
+ * Authors:
+ *   Damien Hedde
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_RESETTABLE_H
+#define HW_RESETTABLE_H
+
+#include "qom/object.h"
+
+#define TYPE_RESETTABLE_INTERFACE "resettable"
+
+typedef struct ResettableClass ResettableClass;
+DECLARE_CLASS_CHECKERS(ResettableClass, RESETTABLE,
+                       TYPE_RESETTABLE_INTERFACE)
+
+
+typedef struct ResettableState ResettableState;
+
+/**
+ * ResetType:
+ * Types of reset.
+ *
+ * + Cold: reset resulting from a power cycle of the object.
+ *
+ * TODO: Support has to be added to handle more types. In particular,
+ * ResettableState structure needs to be expanded.
+ */
+typedef enum ResetType {
+    RESET_TYPE_COLD,
+} ResetType;
+
+/*
+ * ResettableClass:
+ * Interface for resettable objects.
+ *
+ * See docs/devel/reset.rst for more detailed information about how QEMU models
+ * reset. This whole API must only be used when holding the iothread mutex.
+ *
+ * All objects which can be reset must implement this interface;
+ * it is usually provided by a base class such as DeviceClass or BusClass.
+ * Every Resettable object must maintain some state tracking the
+ * progress of a reset operation by providing a ResettableState structure.
+ * The functions defined in this module take care of updating the
+ * state of the reset.
+ * The base class implementation of the interface provides this
+ * state and implements the associated method: get_state.
+ *
+ * Concrete object implementations (typically specific devices
+ * such as a UART model) should provide the functions
+ * for the phases.enter, phases.hold and phases.exit methods, which
+ * they can set in their class init function, either directly or
+ * by calling resettable_class_set_parent_phases().
+ * The phase methods are guaranteed to only only ever be called once
+ * for any reset event, in the order 'enter', 'hold', 'exit'.
+ * An object will always move quickly from 'enter' to 'hold'
+ * but might remain in 'hold' for an arbitrary period of time
+ * before eventually reset is deasserted and the 'exit' phase is called.
+ * Object implementations should be prepared for functions handling
+ * inbound connections from other devices (such as qemu_irq handler
+ * functions) to be called at any point during reset after their
+ * 'enter' method has been called.
+ *
+ * Users of a resettable object should not call these methods
+ * directly, but instead use the function resettable_reset().
+ *
+ * @phases.enter: This phase is called when the object enters reset. It
+ * should reset local state of the object, but it must not do anything that
+ * has a side-effect on other objects, such as raising or lowering a qemu_irq
+ * line or reading or writing guest memory. It takes the reset's type as
+ * argument.
+ *
+ * @phases.hold: This phase is called for entry into reset, once every object
+ * in the system which is being reset has had its @phases.enter method called.
+ * At this point devices can do actions that affect other objects.
+ *
+ * @phases.exit: This phase is called when the object leaves the reset state.
+ * Actions affecting other objects are permitted.
+ *
+ * @get_state: Mandatory method which must return a pointer to a
+ * ResettableState.
+ *
+ * @get_transitional_function: transitional method to handle Resettable objects
+ * not yet fully moved to this interface. It will be removed as soon as it is
+ * not needed anymore. This method is optional and may return a pointer to a
+ * function to be used instead of the phases. If the method exists and returns
+ * a non-NULL function pointer then that function is executed as a replacement
+ * of the 'hold' phase method taking the object as argument. The two other phase
+ * methods are not executed.
+ *
+ * @child_foreach: Executes a given callback on every Resettable child. Child
+ * in this context means a child in the qbus tree, so the children of a qbus
+ * are the devices on it, and the children of a device are all the buses it
+ * owns. This is not the same as the QOM object hierarchy. The function takes
+ * additional opaque and ResetType arguments which must be passed unmodified to
+ * the callback.
+ */
+typedef void (*ResettableEnterPhase)(Object *obj, ResetType type);
+typedef void (*ResettableHoldPhase)(Object *obj);
+typedef void (*ResettableExitPhase)(Object *obj);
+typedef ResettableState * (*ResettableGetState)(Object *obj);
+typedef void (*ResettableTrFunction)(Object *obj);
+typedef ResettableTrFunction (*ResettableGetTrFunction)(Object *obj);
+typedef void (*ResettableChildCallback)(Object *, void *opaque,
+                                        ResetType type);
+typedef void (*ResettableChildForeach)(Object *obj,
+                                       ResettableChildCallback cb,
+                                       void *opaque, ResetType type);
+typedef struct ResettablePhases {
+    ResettableEnterPhase enter;
+    ResettableHoldPhase hold;
+    ResettableExitPhase exit;
+} ResettablePhases;
+struct ResettableClass {
+    InterfaceClass parent_class;
+
+    /* Phase methods */
+    ResettablePhases phases;
+
+    /* State access method */
+    ResettableGetState get_state;
+
+    /* Transitional method for legacy reset compatibility */
+    ResettableGetTrFunction get_transitional_function;
+
+    /* Hierarchy handling method */
+    ResettableChildForeach child_foreach;
+};
+
+/**
+ * ResettableState:
+ * Structure holding reset related state. The fields should not be accessed
+ * directly; the definition is here to allow further inclusion into other
+ * objects.
+ *
+ * @count: Number of reset level the object is into. It is incremented when
+ * the reset operation starts and decremented when it finishes.
+ * @hold_phase_pending: flag which indicates that we need to invoke the 'hold'
+ * phase handler for this object.
+ * @exit_phase_in_progress: true if we are currently in the exit phase
+ */
+struct ResettableState {
+    unsigned count;
+    bool hold_phase_pending;
+    bool exit_phase_in_progress;
+};
+
+/**
+ * resettable_state_clear:
+ * Clear the state. It puts the state to the initial (zeroed) state required
+ * to reuse an object. Typically used in realize step of base classes
+ * implementing the interface.
+ */
+static inline void resettable_state_clear(ResettableState *state)
+{
+    memset(state, 0, sizeof(ResettableState));
+}
+
+/**
+ * resettable_reset:
+ * Trigger a reset on an object @obj of type @type. @obj must implement
+ * Resettable interface.
+ *
+ * Calling this function is equivalent to calling @resettable_assert_reset()
+ * then @resettable_release_reset().
+ */
+void resettable_reset(Object *obj, ResetType type);
+
+/**
+ * resettable_assert_reset:
+ * Put an object @obj into reset. @obj must implement Resettable interface.
+ *
+ * @resettable_release_reset() must eventually be called after this call.
+ * There must be one call to @resettable_release_reset() per call of
+ * @resettable_assert_reset(), with the same type argument.
+ *
+ * NOTE: Until support for migration is added, the @resettable_release_reset()
+ * must not be delayed. It must occur just after @resettable_assert_reset() so
+ * that migration cannot be triggered in between. Prefer using
+ * @resettable_reset() for now.
+ */
+void resettable_assert_reset(Object *obj, ResetType type);
+
+/**
+ * resettable_release_reset:
+ * Release the object @obj from reset. @obj must implement Resettable interface.
+ *
+ * See @resettable_assert_reset() description for details.
+ */
+void resettable_release_reset(Object *obj, ResetType type);
+
+/**
+ * resettable_is_in_reset:
+ * Return true if @obj is under reset.
+ *
+ * @obj must implement Resettable interface.
+ */
+bool resettable_is_in_reset(Object *obj);
+
+/**
+ * resettable_change_parent:
+ * Indicate that the parent of Ressettable @obj is changing from @oldp to @newp.
+ * All 3 objects must implement resettable interface. @oldp or @newp may be
+ * NULL.
+ *
+ * This function will adapt the reset state of @obj so that it is coherent
+ * with the reset state of @newp. It may trigger @resettable_assert_reset()
+ * or @resettable_release_reset(). It will do such things only if the reset
+ * state of @newp and @oldp are different.
+ *
+ * When using this function during reset, it must only be called during
+ * a hold phase method. Calling this during enter or exit phase is an error.
+ */
+void resettable_change_parent(Object *obj, Object *newp, Object *oldp);
+
+/**
+ * resettable_cold_reset_fn:
+ * Helper to call resettable_reset((Object *) opaque, RESET_TYPE_COLD).
+ *
+ * This function is typically useful to register a reset handler with
+ * qemu_register_reset.
+ */
+void resettable_cold_reset_fn(void *opaque);
+
+/**
+ * resettable_class_set_parent_phases:
+ *
+ * Save @rc current reset phases into @parent_phases and override @rc phases
+ * by the given new methods (@enter, @hold and @exit).
+ * Each phase is overridden only if the new one is not NULL allowing to
+ * override a subset of phases.
+ */
+void resettable_class_set_parent_phases(ResettableClass *rc,
+                                        ResettableEnterPhase enter,
+                                        ResettableHoldPhase hold,
+                                        ResettableExitPhase exit,
+                                        ResettablePhases *parent_phases);
+
+#endif