hw/intc/loongarch_ipi: Implment cpu hotplug interface

Add logic cpu allocation and cpu mapping with cpu hotplug interface.
When cpu is added, connect ipi gpio irq to CPU IRQ_IPI irq pin.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>

hw/intc/loongarch_ipi.c

@@ -49,6 +49,22 @@ static int loongarch_cpu_by_arch_id(LoongsonIPICommonState *lics,
     return MEMTX_ERROR;
 }
 
+static IPICore *loongarch_ipi_get_cpu(LoongsonIPICommonState *lics,
+                                      DeviceState *dev)
+{
+    CPUClass *k = CPU_GET_CLASS(dev);
+    uint64_t arch_id = k->get_arch_id(CPU(dev));
+    int i;
+
+    for (i = 0; i < lics->num_cpu; i++) {
+        if (lics->cpu[i].arch_id == arch_id) {
+            return &lics->cpu[i];
+        }
+    }
+
+    return NULL;
+}
+
 static void loongarch_ipi_realize(DeviceState *dev, Error **errp)
 {
     LoongsonIPICommonState *lics = LOONGSON_IPI_COMMON(dev);
@@ -80,25 +96,48 @@ static void loongarch_ipi_realize(DeviceState *dev, Error **errp)
 static void loongarch_ipi_cpu_plug(HotplugHandler *hotplug_dev,
                                    DeviceState *dev, Error **errp)
 {
+    LoongsonIPICommonState *lics = LOONGSON_IPI_COMMON(hotplug_dev);
     Object *obj = OBJECT(dev);
+    IPICore *core;
+    int index;
 
     if (!object_dynamic_cast(obj, TYPE_LOONGARCH_CPU)) {
         warn_report("LoongArch extioi: Invalid %s device type",
                                        object_get_typename(obj));
         return;
     }
+
+    core = loongarch_ipi_get_cpu(lics, dev);
+    if (!core) {
+        return;
+    }
+
+    core->cpu = CPU(dev);
+    index = core - lics->cpu;
+
+    /* connect ipi irq to cpu irq */
+    qdev_connect_gpio_out(DEVICE(lics), index, qdev_get_gpio_in(dev, IRQ_IPI));
 }
 
 static void loongarch_ipi_cpu_unplug(HotplugHandler *hotplug_dev,
                                      DeviceState *dev, Error **errp)
 {
+    LoongsonIPICommonState *lics = LOONGSON_IPI_COMMON(hotplug_dev);
     Object *obj = OBJECT(dev);
+    IPICore *core;
 
     if (!object_dynamic_cast(obj, TYPE_LOONGARCH_CPU)) {
         warn_report("LoongArch extioi: Invalid %s device type",
                                        object_get_typename(obj));
         return;
     }
+
+    core = loongarch_ipi_get_cpu(lics, dev);
+    if (!core) {
+        return;
+    }
+
+    core->cpu = NULL;
 }
 
 static void loongarch_ipi_class_init(ObjectClass *klass, void *data)