Constructor support

Allow devices/drivers to register themselves via constructors.
Destructors are not needed (can be registered from a constructor)
and "priority" has been renamed and changed to an enum for clarity.

Signed-off-by: Paul Brook <paul@codesourcery.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

module.c

@@ -0,0 +1,91 @@
+/*
+ * QEMU Module Infrastructure
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include "sys-queue.h"
+#include "module.h"
+
+typedef struct ModuleEntry
+{
+    module_init_type type;
+    void (*init)(void);
+    TAILQ_ENTRY(ModuleEntry) node;
+} ModuleEntry;
+
+typedef struct ModuleTypeList
+{
+    module_init_type type;
+    TAILQ_HEAD(, ModuleEntry) entry_list;
+    TAILQ_ENTRY(ModuleTypeList) node;
+} ModuleTypeList;
+
+static TAILQ_HEAD(, ModuleTypeList) init_type_list;
+
+static ModuleTypeList *find_type_or_alloc(module_init_type type, int alloc)
+{
+    ModuleTypeList *n;
+
+    TAILQ_FOREACH(n, &init_type_list, node) {
+        if (type >= n->type)
+            break;
+    }
+
+    if (!n || n->type != type) {
+        ModuleTypeList *o;
+
+        if (!alloc)
+            return NULL;
+
+        o = qemu_mallocz(sizeof(*o));
+        o->type = type;
+        TAILQ_INIT(&o->entry_list);
+
+        if (n) {
+            TAILQ_INSERT_AFTER(&init_type_list, n, o, node);
+        } else {
+            TAILQ_INSERT_HEAD(&init_type_list, o, node);
+        }
+
+        n = o;
+    }
+
+    return n;
+}
+
+void register_module_init(void (*fn)(void), module_init_type type)
+{
+    ModuleEntry *e;
+    ModuleTypeList *l;
+
+    e = qemu_mallocz(sizeof(*e));
+    e->init = fn;
+
+    l = find_type_or_alloc(type, 1);
+
+    TAILQ_INSERT_TAIL(&l->entry_list, e, node);
+}
+
+void module_call_init(module_init_type type)
+{
+    ModuleTypeList *l;
+    ModuleEntry *e;
+
+    l = find_type_or_alloc(type, 0);
+    if (!l) {
+        return;
+    }
+
+    TAILQ_FOREACH(e, &l->entry_list, node) {
+        e->init();
+    }
+}