Kernel: Added preliminary support for address arbiters.

AddressArbiter: Added documentation comment, fixed whitespace issue.

AddressArbiter: Fixed incorrect comment, reordered if-statement to be more clear.

SVC: Removed trailing whitespace.

src/core/hle/kernel/address_arbiter.h

@@ -0,0 +1,36 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+
+#include "core/hle/kernel/kernel.h"
+
+// Address arbiters are an underlying kernel synchronization object that can be created/used via
+// supervisor calls (SVCs). They function as sort of a global lock. Typically, games/other CTR
+// applications use them as an underlying mechanism to implement thread-safe barriers, events, and
+// semphores. 
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Kernel namespace
+
+namespace Kernel {
+
+/// Address arbitration types
+enum class ArbitrationType : u32 {
+    Signal,
+    WaitIfLessThan,
+    DecrementAndWaitIfLessThan,
+    WaitIfLessThanWithTimeout,
+    DecrementAndWaitIfLessThanWithTimeout,
+};
+
+/// Arbitrate an address
+Result ArbitrateAddress(Handle handle, ArbitrationType type, u32 address, s32 value);
+
+/// Create an address arbiter
+Handle CreateAddressArbiter(const std::string& name = "Unknown");
+
+} // namespace FileSys