qemu/hw/core/reset.c
Peter Maydell 71b3ea373b hw/core/reset: Implement qemu_register_reset via qemu_register_resettable
Reimplement qemu_register_reset() via qemu_register_resettable().

We define a new LegacyReset object which implements Resettable and
defines its reset hold phase method to call a QEMUResetHandler
function.  When qemu_register_reset() is called, we create a new
LegacyReset object and add it to the simulation_reset
ResettableContainer.  When qemu_unregister_reset() is called, we find
the LegacyReset object in the container and remove it.

This implementation of qemu_unregister_reset() means we'll end up
scanning the ResetContainer's list of child objects twice, once
to find the LegacyReset object, and once in g_ptr_array_remove().
In theory we could avoid this by having the ResettableContainer
interface include a resettable_container_remove_with_equal_func()
that took a callback method so that we could use
g_ptr_array_find_with_equal_func() and g_ptr_array_remove_index().
But we don't expect qemu_unregister_reset() to be called frequently
or in hot paths, and we expect the simulation_reset container to
usually not have many children.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20240220160622.114437-9-peter.maydell@linaro.org
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
2024-02-27 13:01:42 +00:00

188 lines
5.3 KiB
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 "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;
}
/*
* Reason why the currently in-progress qemu_devices_reset() was called.
* If we made at least SHUTDOWN_CAUSE_SNAPSHOT_LOAD have a corresponding
* ResetType we could perhaps avoid the need for this global.
*/
static ShutdownCause device_reset_reason;
/*
* This is an Object which implements Resettable simply to call the
* callback function in the hold phase.
*/
#define TYPE_LEGACY_RESET "legacy-reset"
OBJECT_DECLARE_SIMPLE_TYPE(LegacyReset, LEGACY_RESET)
struct LegacyReset {
Object parent;
ResettableState reset_state;
QEMUResetHandler *func;
void *opaque;
bool skip_on_snapshot_load;
};
OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(LegacyReset, legacy_reset, LEGACY_RESET, OBJECT, { TYPE_RESETTABLE_INTERFACE }, { })
static ResettableState *legacy_reset_get_state(Object *obj)
{
LegacyReset *lr = LEGACY_RESET(obj);
return &lr->reset_state;
}
static void legacy_reset_hold(Object *obj)
{
LegacyReset *lr = LEGACY_RESET(obj);
if (device_reset_reason == SHUTDOWN_CAUSE_SNAPSHOT_LOAD &&
lr->skip_on_snapshot_load) {
return;
}
lr->func(lr->opaque);
}
static void legacy_reset_init(Object *obj)
{
}
static void legacy_reset_finalize(Object *obj)
{
}
static void legacy_reset_class_init(ObjectClass *klass, void *data)
{
ResettableClass *rc = RESETTABLE_CLASS(klass);
rc->get_state = legacy_reset_get_state;
rc->phases.hold = legacy_reset_hold;
}
void qemu_register_reset(QEMUResetHandler *func, void *opaque)
{
Object *obj = object_new(TYPE_LEGACY_RESET);
LegacyReset *lr = LEGACY_RESET(obj);
lr->func = func;
lr->opaque = opaque;
qemu_register_resettable(obj);
}
void qemu_register_reset_nosnapshotload(QEMUResetHandler *func, void *opaque)
{
Object *obj = object_new(TYPE_LEGACY_RESET);
LegacyReset *lr = LEGACY_RESET(obj);
lr->func = func;
lr->opaque = opaque;
lr->skip_on_snapshot_load = true;
qemu_register_resettable(obj);
}
typedef struct FindLegacyInfo {
QEMUResetHandler *func;
void *opaque;
LegacyReset *lr;
} FindLegacyInfo;
static void find_legacy_reset_cb(Object *obj, void *opaque, ResetType type)
{
LegacyReset *lr;
FindLegacyInfo *fli = opaque;
/* Not everything in the ResettableContainer will be a LegacyReset */
lr = LEGACY_RESET(object_dynamic_cast(obj, TYPE_LEGACY_RESET));
if (lr && lr->func == fli->func && lr->opaque == fli->opaque) {
fli->lr = lr;
}
}
static LegacyReset *find_legacy_reset(QEMUResetHandler *func, void *opaque)
{
/*
* Find the LegacyReset with the specified func and opaque,
* by getting the ResettableContainer to call our callback for
* every item in it.
*/
ResettableContainer *rootcon = get_root_reset_container();
ResettableClass *rc = RESETTABLE_GET_CLASS(rootcon);
FindLegacyInfo fli;
fli.func = func;
fli.opaque = opaque;
fli.lr = NULL;
rc->child_foreach(OBJECT(rootcon), find_legacy_reset_cb,
&fli, RESET_TYPE_COLD);
return fli.lr;
}
void qemu_unregister_reset(QEMUResetHandler *func, void *opaque)
{
Object *obj = OBJECT(find_legacy_reset(func, opaque));
if (obj) {
qemu_unregister_resettable(obj);
object_unref(obj);
}
}
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)
{
device_reset_reason = reason;
/* Reset the simulation */
resettable_reset(OBJECT(get_root_reset_container()), RESET_TYPE_COLD);
}