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/*
* QEMU CPU cluster
*
* Copyright (c) 2018 GreenSocs SAS
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see
* <http://www.gnu.org/licenses/gpl-2.0.html>
*/
#ifndef HW_CPU_CLUSTER_H
#define HW_CPU_CLUSTER_H
#include "hw/qdev-core.h"
#include "qom/object.h"
/*
* CPU Cluster type
*
* A cluster is a group of CPUs which are all identical and have the same view
* of the rest of the system. It is mainly an internal QEMU representation and
* does not necessarily match with the notion of clusters on the real hardware.
*
* If CPUs are not identical (for example, Cortex-A53 and Cortex-A57 CPUs in an
* Arm big.LITTLE system) they should be in different clusters. If the CPUs do
* not have the same view of memory (for example the main CPU and a management
* controller processor) they should be in different clusters.
*
* A cluster is created by creating an object of TYPE_CPU_CLUSTER, and then
* adding the CPUs to it as QOM child objects (e.g. using the
* object_initialize_child() or object_property_add_child() functions).
* The CPUs may be either direct children of the cluster object, or indirect
* children (e.g. children of children of the cluster object).
*
* All CPUs must be added as children before the cluster is realized.
* (Regrettably QOM provides no way to prevent adding children to a realized
* object and no way for the parent to be notified when a new child is added
* to it, so this restriction is not checked for, but the system will not
* behave correctly if it is not adhered to. The cluster will assert that
* it contains at least one CPU, which should catch most inadvertent
* violations of this constraint.)
*
* A CPU which is not put into any cluster will be considered implicitly
* to be in a cluster with all the other "loose" CPUs, so all CPUs that are
* not assigned to clusters must be identical.
*/
#define TYPE_CPU_CLUSTER "cpu-cluster"
OBJECT_DECLARE_SIMPLE_TYPE(CPUClusterState, CPU_CLUSTER)
/*
* This limit is imposed by TCG, which puts the cluster ID into an
* 8 bit field (and uses all-1s for the default "not in any cluster").
*/
#define MAX_CLUSTERS 255
/**
* CPUClusterState:
* @cluster_id: The cluster ID. This value is for internal use only and should
* not be exposed directly to the user or to the guest.
*
* State of a CPU cluster.
*/
struct CPUClusterState {
/*< private >*/
DeviceState parent_obj;
/*< public >*/
uint32_t cluster_id;
};
#endif