Kernel: Extract DeferredCallEntry from Arch/Processor.h

Kernel/Arch/DeferredCallEntry.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2020, Tom <tomut@yahoo.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/BitCast.h>
+#include <AK/Function.h>
+
+namespace Kernel {
+
+struct DeferredCallEntry {
+    using HandlerFunction = Function<void()>;
+
+    DeferredCallEntry* next;
+    alignas(HandlerFunction) u8 handler_storage[sizeof(HandlerFunction)];
+    bool was_allocated;
+
+    HandlerFunction& handler_value()
+    {
+        return *bit_cast<HandlerFunction*>(&handler_storage);
+    }
+
+    void invoke_handler()
+    {
+        handler_value()();
+    }
+};
+
+}