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 "qemu/osdep.h" 24 #include "hw/qdev.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 #define CPU_CLUSTER(obj) \ 59 OBJECT_CHECK(CPUClusterState, (obj), TYPE_CPU_CLUSTER) 60 61 /* 62 * This limit is imposed by TCG, which puts the cluster ID into an 63 * 8 bit field (and uses all-1s for the default "not in any cluster"). 64 */ 65 #define MAX_CLUSTERS 255 66 67 /** 68 * CPUClusterState: 69 * @cluster_id: The cluster ID. This value is for internal use only and should 70 * not be exposed directly to the user or to the guest. 71 * 72 * State of a CPU cluster. 73 */ 74 typedef struct CPUClusterState { 75 /*< private >*/ 76 DeviceState parent_obj; 77 78 /*< public >*/ 79 uint32_t cluster_id; 80 } CPUClusterState; 81 82 #endif 83