xref: /openbmc/qemu/hw/cpu/cluster.c (revision 542b10bd)
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 
21 #include "qemu/osdep.h"
22 
23 #include "hw/core/cpu.h"
24 #include "hw/cpu/cluster.h"
25 #include "hw/qdev-properties.h"
26 #include "qapi/error.h"
27 
28 static Property cpu_cluster_properties[] = {
29     DEFINE_PROP_UINT32("cluster-id", CPUClusterState, cluster_id, 0),
30     DEFINE_PROP_END_OF_LIST()
31 };
32 
33 typedef struct CallbackData {
34     CPUClusterState *cluster;
35     int cpu_count;
36 } CallbackData;
37 
38 static int add_cpu_to_cluster(Object *obj, void *opaque)
39 {
40     CallbackData *cbdata = opaque;
41     CPUState *cpu = (CPUState *)object_dynamic_cast(obj, TYPE_CPU);
42 
43     if (cpu) {
44         cpu->cluster_index = cbdata->cluster->cluster_id;
45         cbdata->cpu_count++;
46     }
47     return 0;
48 }
49 
50 static void cpu_cluster_realize(DeviceState *dev, Error **errp)
51 {
52     /* Iterate through all our CPU children and set their cluster_index */
53     CPUClusterState *cluster = CPU_CLUSTER(dev);
54     Object *cluster_obj = OBJECT(dev);
55     CallbackData cbdata = {
56         .cluster = cluster,
57         .cpu_count = 0,
58     };
59 
60     if (cluster->cluster_id >= MAX_CLUSTERS) {
61         error_setg(errp, "cluster-id must be less than %d", MAX_CLUSTERS);
62         return;
63     }
64 
65     object_child_foreach_recursive(cluster_obj, add_cpu_to_cluster, &cbdata);
66 
67     /*
68      * A cluster with no CPUs is a bug in the board/SoC code that created it;
69      * if you hit this during development of new code, check that you have
70      * created the CPUs and parented them into the cluster object before
71      * realizing the cluster object.
72      */
73     assert(cbdata.cpu_count > 0);
74 }
75 
76 static void cpu_cluster_class_init(ObjectClass *klass, void *data)
77 {
78     DeviceClass *dc = DEVICE_CLASS(klass);
79 
80     device_class_set_props(dc, cpu_cluster_properties);
81     dc->realize = cpu_cluster_realize;
82 
83     /* This is not directly for users, CPU children must be attached by code */
84     dc->user_creatable = false;
85 }
86 
87 static const TypeInfo cpu_cluster_type_info = {
88     .name = TYPE_CPU_CLUSTER,
89     .parent = TYPE_DEVICE,
90     .instance_size = sizeof(CPUClusterState),
91     .class_init = cpu_cluster_class_init,
92 };
93 
94 static void cpu_cluster_register_types(void)
95 {
96     type_register_static(&cpu_cluster_type_info);
97 }
98 
99 type_init(cpu_cluster_register_types)
100