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 25 /* 26 * CPU Cluster type 27 * 28 * A cluster is a group of CPUs which are all identical and have the same view 29 * of the rest of the system. It is mainly an internal QEMU representation and 30 * does not necessarily match with the notion of clusters on the real hardware. 31 * 32 * If CPUs are not identical (for example, Cortex-A53 and Cortex-A57 CPUs in an 33 * Arm big.LITTLE system) they should be in different clusters. If the CPUs do 34 * not have the same view of memory (for example the main CPU and a management 35 * controller processor) they should be in different clusters. 36 * 37 * A cluster is created by creating an object of TYPE_CPU_CLUSTER, and then 38 * adding the CPUs to it as QOM child objects (e.g. using the 39 * object_initialize_child() or object_property_add_child() functions). 40 * The CPUs may be either direct children of the cluster object, or indirect 41 * children (e.g. children of children of the cluster object). 42 * 43 * All CPUs must be added as children before the cluster is realized. 44 * (Regrettably QOM provides no way to prevent adding children to a realized 45 * object and no way for the parent to be notified when a new child is added 46 * to it, so this restriction is not checked for, but the system will not 47 * behave correctly if it is not adhered to. The cluster will assert that 48 * it contains at least one CPU, which should catch most inadvertent 49 * violations of this constraint.) 50 * 51 * A CPU which is not put into any cluster will be considered implicitly 52 * to be in a cluster with all the other "loose" CPUs, so all CPUs that are 53 * not assigned to clusters must be identical. 54 */ 55 56 #define TYPE_CPU_CLUSTER "cpu-cluster" 57 #define CPU_CLUSTER(obj) \ 58 OBJECT_CHECK(CPUClusterState, (obj), TYPE_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 typedef struct CPUClusterState { 74 /*< private >*/ 75 DeviceState parent_obj; 76 77 /*< public >*/ 78 uint32_t cluster_id; 79 } CPUClusterState; 80 81 #endif 82