From: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>

Add support for grouping CPUs into clusters during
FDT machine instantiation.

The clusters are automatically created if CPU parent
is not already an existing cluster.

Signed-off-by: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>
---
 hw/core/fdt_generic.c         | 77 +++++++++++++++++++++++++++++++++++
 include/hw/core/fdt_generic.h | 13 ++++++
 2 files changed, 90 insertions(+)

diff --git a/hw/core/fdt_generic.c b/hw/core/fdt_generic.c
index b3ef0b7d0a..3c28f42491 100644
--- a/hw/core/fdt_generic.c
+++ b/hw/core/fdt_generic.c
@@ -31,6 +31,7 @@
 #include "migration/vmstate.h"
 #include "qemu/coroutine.h"
 #include "qemu/log.h"
+#include "hw/cpu/cluster.h"
 #include "system/reset.h"
 
 #ifndef FDT_GENERIC_ERR_DEBUG
@@ -175,6 +176,75 @@ int fdt_init_has_opaque(FDTMachineInfo *fdti, char *node_path)
     return 0;
 }
 
+static int get_next_cpu_cluster_id(void)
+{
+    static int i;
+
+    return i++;
+}
+
+void fdt_init_register_user_cpu_cluster(FDTMachineInfo *fdti, Object *cluster)
+{
+    int i = get_next_cpu_cluster_id();
+    DeviceState *dev = DEVICE(cluster);
+    FDTCPUCluster *cl;
+
+    qdev_prop_set_uint32(dev, "cluster-id", i);
+
+    cl = g_new0(FDTCPUCluster, 1);
+    cl->cpu_cluster = cluster;
+    cl->next = fdti->clusters;
+    cl->user = true;
+
+    fdti->clusters = cl;
+
+    DB_PRINT(0, "%s: Registered user-defined cpu cluster with id %d\n",
+             object_get_canonical_path(cluster), i);
+}
+
+static void *fdt_init_add_cpu_cluster(FDTMachineInfo *fdti, char *compat)
+{
+    FDTCPUCluster *cl = g_malloc0(sizeof(*cl));
+    int i = get_next_cpu_cluster_id();
+    char *name = g_strdup_printf("cluster%d", i);
+    Object *obj;
+
+    obj = object_new(TYPE_CPU_CLUSTER);
+    object_property_add_child(object_get_root(), name, OBJECT(obj));
+    qdev_prop_set_uint32(DEVICE(obj), "cluster-id", i);
+
+    cl->cpu_type = g_strdup(compat);
+    cl->cpu_cluster = obj;
+    cl->next = fdti->clusters;
+
+    fdti->clusters = cl;
+
+    g_free(name);
+
+    return obj;
+}
+
+void *fdt_init_get_cpu_cluster(FDTMachineInfo *fdti, Object *parent,
+                               char *compat)
+{
+    FDTCPUCluster *cl = fdti->clusters;
+
+    if (object_dynamic_cast(parent, TYPE_CPU_CLUSTER)) {
+        /* The direct parent of this CPU is a CPU cluster. Use it. */
+        return parent;
+    }
+
+    while (cl) {
+        if (!cl->user && !strcmp(compat, cl->cpu_type)) {
+            return cl->cpu_cluster;
+        }
+        cl = cl->next;
+    }
+
+    /* No cluster found so create and return a new one */
+    return fdt_init_add_cpu_cluster(fdti, compat);
+}
+
 void *fdt_init_get_opaque(FDTMachineInfo *fdti, char *node_path)
 {
     FDTDevOpaque *dp;
@@ -199,8 +269,15 @@ FDTMachineInfo *fdt_init_new_fdti(void *fdt)
 
 void fdt_init_destroy_fdti(FDTMachineInfo *fdti)
 {
+    FDTCPUCluster *cl = fdti->clusters;
     FDTDevOpaque *dp;
 
+    while (cl) {
+        FDTCPUCluster *tmp = cl;
+        cl = cl->next;
+        g_free(tmp->cpu_type);
+        g_free(tmp);
+    }
     for (dp = fdti->dev_opaques; dp->node_path; dp++) {
         g_free(dp->node_path);
     }
diff --git a/include/hw/core/fdt_generic.h b/include/hw/core/fdt_generic.h
index a21e3c2440..46b7dc084b 100644
--- a/include/hw/core/fdt_generic.h
+++ b/include/hw/core/fdt_generic.h
@@ -17,6 +17,13 @@ typedef struct FDTDevOpaque {
     void *opaque;
 } FDTDevOpaque;
 
+typedef struct FDTCPUCluster {
+    char *cpu_type;
+    void *cpu_cluster;
+    void *next;
+    bool user;
+} FDTCPUCluster;
+
 typedef struct FDTMachineInfo {
     /* the fdt blob */
     void *fdt;
@@ -26,6 +33,8 @@ typedef struct FDTMachineInfo {
     FDTDevOpaque *dev_opaques;
     /* recheck coroutine queue */
     CoQueue *cq;
+    /* list of all CPU clusters */
+    FDTCPUCluster *clusters;
 } FDTMachineInfo;
 
 /*
@@ -73,6 +82,10 @@ void fdt_init_set_opaque(FDTMachineInfo *fdti, char *node_path, void *opaque);
 int fdt_init_has_opaque(FDTMachineInfo *fdti, char *node_path);
 void *fdt_init_get_opaque(FDTMachineInfo *fdti, char *node_path);
 
+void *fdt_init_get_cpu_cluster(FDTMachineInfo *fdti, Object *parent,
+                               char *compat);
+void fdt_init_register_user_cpu_cluster(FDTMachineInfo *fdti, Object *cluster);
+
 /* statically register a FDTInitFn as being associate with a compatibility */
 
 #define fdt_register_compatibility_opaque(function, compat, n, opaque) \
-- 
2.43.0