qemu/hw/core/reset.c

/*
 *  Reset handlers.
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 * Copyright (c) 2016 Red Hat, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu/osdep.h"
#include "qemu/queue.h"
#include "sysemu/reset.h"
#include "hw/resettable.h"
#include "hw/core/resetcontainer.h"

/*
 * Return a pointer to the singleton container that holds all the Resettable
 * items that will be reset when qemu_devices_reset() is called.
 */
static ResettableContainer *get_root_reset_container(void)
{
    static ResettableContainer *root_reset_container;

    if (!root_reset_container) {
        root_reset_container =
            RESETTABLE_CONTAINER(object_new(TYPE_RESETTABLE_CONTAINER));
    }
    return root_reset_container;
}

typedef struct QEMUResetEntry {
    QTAILQ_ENTRY(QEMUResetEntry) entry;
    QEMUResetHandler *func;
    void *opaque;
    bool skip_on_snapshot_load;
} QEMUResetEntry;

static QTAILQ_HEAD(, QEMUResetEntry) reset_handlers =
    QTAILQ_HEAD_INITIALIZER(reset_handlers);

void qemu_register_reset(QEMUResetHandler *func, void *opaque)
{
    QEMUResetEntry *re = g_new0(QEMUResetEntry, 1);

    re->func = func;
    re->opaque = opaque;
    QTAILQ_INSERT_TAIL(&reset_handlers, re, entry);
}

void qemu_register_reset_nosnapshotload(QEMUResetHandler *func, void *opaque)
{
    QEMUResetEntry *re = g_new0(QEMUResetEntry, 1);

    re->func = func;
    re->opaque = opaque;
    re->skip_on_snapshot_load = true;
    QTAILQ_INSERT_TAIL(&reset_handlers, re, entry);
}

void qemu_unregister_reset(QEMUResetHandler *func, void *opaque)
{
    QEMUResetEntry *re;

    QTAILQ_FOREACH(re, &reset_handlers, entry) {
        if (re->func == func && re->opaque == opaque) {
            QTAILQ_REMOVE(&reset_handlers, re, entry);
            g_free(re);
            return;
        }
    }
}

void qemu_register_resettable(Object *obj)
{
    resettable_container_add(get_root_reset_container(), obj);
}

void qemu_unregister_resettable(Object *obj)
{
    resettable_container_remove(get_root_reset_container(), obj);
}

void qemu_devices_reset(ShutdownCause reason)
{
    QEMUResetEntry *re, *nre;

    /* reset all devices */
    QTAILQ_FOREACH_SAFE(re, &reset_handlers, entry, nre) {
        if (reason == SHUTDOWN_CAUSE_SNAPSHOT_LOAD &&
            re->skip_on_snapshot_load) {
            continue;
        }
        re->func(re->opaque);
    }

    /* Reset the simulation */
    resettable_reset(OBJECT(get_root_reset_container()), RESET_TYPE_COLD);
}