From 9c57b229ea80a99d72aa30615494224547a2b5cc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Gr=C3=A9goire?= <lectem@gmail.com>
Date: Sat, 18 Oct 2025 11:32:12 +0200
Subject: [PATCH] Introduce tracy::TaggedUserlandAddress to pack metadata with
 pointers

---
 public/common/TracyTaggedUserlandAddress.hpp | 47 ++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 public/common/TracyTaggedUserlandAddress.hpp

diff --git a/public/common/TracyTaggedUserlandAddress.hpp b/public/common/TracyTaggedUserlandAddress.hpp
new file mode 100644
index 00000000..505cc0c8
--- /dev/null
+++ b/public/common/TracyTaggedUserlandAddress.hpp
@@ -0,0 +1,47 @@
+#ifndef __TRACYTAGGEDPTR_HPP__
+#define __TRACYTAGGEDPTR_HPP__
+
+#include <stdint.h>
+#include <assert.h>
+
+namespace tracy
+{
+
+class TaggedUserlandAddress
+{
+	uint64_t m_storage;
+	// So far no kernel seems to allow userspace address with more than 56bits userspace VAs since now hardware support it. See https://docs.kernel.org/next/x86/x86_64/mm.html and https://www.kernel.org/doc/html/v5.8/arm64/memory.html#bit-userspace-vas
+	static constexpr uint64_t kUserspaceVABits = 56;
+	static constexpr uint64_t kKernelOnlyBits = 64 - kUserspaceVABits;
+	static constexpr uint64_t kKernelOnlyBitMask = ( ( uint64_t(1) << kKernelOnlyBits ) - uint64_t(1) ) << kUserspaceVABits;
+public:
+	
+	TaggedUserlandAddress() = default;
+	explicit TaggedUserlandAddress( uint64_t address, uint8_t tag = 0 )
+	{
+		assert( ( address & kKernelOnlyBitMask ) == 0 );
+		assert( ( (uint64_t)tag & ~( kKernelOnlyBitMask >> kUserspaceVABits ) ) == 0 );
+		m_storage = address | ( (uint64_t)tag << kUserspaceVABits );
+	}
+
+	void SetPackedValue(uint64_t value) { m_storage = value; }
+	uint64_t GetPackedValue() const { return m_storage; }
+
+	void SetAddress( uint64_t address)
+	{
+		assert( ( address & kKernelOnlyBitMask ) == 0 );
+		m_storage = ( m_storage & kKernelOnlyBitMask ) | address;
+	}
+	uint64_t GetAddress() const { return m_storage & ( ~kKernelOnlyBitMask ); }
+
+	void SetTag( uint8_t tag )
+	{
+		assert( ( (uint64_t)tag & ~( kKernelOnlyBitMask >> kUserspaceVABits ) ) == 0 );
+		m_storage = ( (uint64_t)tag << kUserspaceVABits ) | ( m_storage & ( ~kKernelOnlyBitMask ) );
+	}
+	uint8_t GetTag() const { return (uint8_t)( ( m_storage & kKernelOnlyBitMask ) >> kUserspaceVABits ); }
+};
+
+}
+
+#endif