Fix version for v6.2.0-rc2 release
[qemu.git] / include / hw / cpu / cluster.h
1 /*
2 * QEMU CPU cluster
3 *
4 * Copyright (c) 2018 GreenSocs SAS
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see
18 * <http://www.gnu.org/licenses/gpl-2.0.html>
19 */
20 #ifndef HW_CPU_CLUSTER_H
21 #define HW_CPU_CLUSTER_H
22
23 #include "hw/qdev-core.h"
24 #include "qom/object.h"
25
26 /*
27 * CPU Cluster type
28 *
29 * A cluster is a group of CPUs which are all identical and have the same view
30 * of the rest of the system. It is mainly an internal QEMU representation and
31 * does not necessarily match with the notion of clusters on the real hardware.
32 *
33 * If CPUs are not identical (for example, Cortex-A53 and Cortex-A57 CPUs in an
34 * Arm big.LITTLE system) they should be in different clusters. If the CPUs do
35 * not have the same view of memory (for example the main CPU and a management
36 * controller processor) they should be in different clusters.
37 *
38 * A cluster is created by creating an object of TYPE_CPU_CLUSTER, and then
39 * adding the CPUs to it as QOM child objects (e.g. using the
40 * object_initialize_child() or object_property_add_child() functions).
41 * The CPUs may be either direct children of the cluster object, or indirect
42 * children (e.g. children of children of the cluster object).
43 *
44 * All CPUs must be added as children before the cluster is realized.
45 * (Regrettably QOM provides no way to prevent adding children to a realized
46 * object and no way for the parent to be notified when a new child is added
47 * to it, so this restriction is not checked for, but the system will not
48 * behave correctly if it is not adhered to. The cluster will assert that
49 * it contains at least one CPU, which should catch most inadvertent
50 * violations of this constraint.)
51 *
52 * A CPU which is not put into any cluster will be considered implicitly
53 * to be in a cluster with all the other "loose" CPUs, so all CPUs that are
54 * not assigned to clusters must be identical.
55 */
56
57 #define TYPE_CPU_CLUSTER "cpu-cluster"
58 OBJECT_DECLARE_SIMPLE_TYPE(CPUClusterState, CPU_CLUSTER)
59
60 /*
61 * This limit is imposed by TCG, which puts the cluster ID into an
62 * 8 bit field (and uses all-1s for the default "not in any cluster").
63 */
64 #define MAX_CLUSTERS 255
65
66 /**
67 * CPUClusterState:
68 * @cluster_id: The cluster ID. This value is for internal use only and should
69 * not be exposed directly to the user or to the guest.
70 *
71 * State of a CPU cluster.
72 */
73 struct CPUClusterState {
74 /*< private >*/
75 DeviceState parent_obj;
76
77 /*< public >*/
78 uint32_t cluster_id;
79 };
80
81 #endif