From a158c214a9521d0fe78adfda23299bc6d907c6fc Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 29 Dec 2022 00:39:13 +0000
Subject: [PATCH] ircd::simt: Add hardware ident access register (AMDGCN).

---
 include/ircd/simt/hwid.h | 59 ++++++++++++++++++++++++++++++++++++++++
 include/ircd/simt/simt.h |  1 +
 2 files changed, 60 insertions(+)
 create mode 100644 include/ircd/simt/hwid.h

diff --git a/include/ircd/simt/hwid.h b/include/ircd/simt/hwid.h
new file mode 100644
index 000000000..1684491b8
--- /dev/null
+++ b/include/ircd/simt/hwid.h
@@ -0,0 +1,59 @@
+// Matrix Construct
+//
+// Copyright (C) Matrix Construct Developers, Authors & Contributors
+// Copyright (C) 2016-2022 Jason Volk <jason@zemos.net>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice is present in all copies. The
+// full license for this software is available in the LICENSE file.
+
+#pragma once
+#define HAVE_IRCD_SIMT_HWID_H
+
+/// HW_ID Register (legacy)
+struct ircd_simt_hwid
+{
+	uint
+	wave,    ///< Wave buffer slot number.
+	simd,    ///< SIMD assigned to within unit.
+	pipl,    ///< Pipeline from which wave dispatched.
+	cu,      ///< Compute Unit ID.
+	sa,      ///< Shader Array within engine.
+	se,      ///< Shader Engine ID.
+	tg,      ///< Thread-group ID.
+	vm,      ///< Virtual Memory ID.
+	queue,   ///< Queue from which wave was dispatched.
+	state,   ///< State ID (graphics only, not compute).
+	me;      ///< Micro-engine ID.
+};
+
+/// Query hardware identification attributes (legacy)
+inline struct ircd_simt_hwid
+__attribute__((always_inline))
+ircd_simt_hwid()
+{
+	uint val = 0;
+	#if defined(__AMDGCN__)
+	asm volatile
+	(
+		"s_getreg_b32 %0, hwreg(HW_REG_HW_ID, 0, 32)"
+		: "=s" (val)
+	);
+	#endif
+
+	return (struct ircd_simt_hwid)
+	{
+		.wave   = (val >> 0)  & 0xf,
+		.simd   = (val >> 4)  & 0x3,
+		.pipl   = (val >> 6)  & 0x3,
+		.cu     = (val >> 8)  & 0xf,
+		.sa     = (val >> 12) & 0x1,
+		.se     = (val >> 13) & 0x3,
+		.tg     = (val >> 16) & 0xf,
+		.vm     = (val >> 20) & 0xf,
+		.queue  = (val >> 24) & 0x7,
+		.state  = (val >> 27) & 0x7,
+		.me     = (val >> 30) & 0x3,
+	};
+}
diff --git a/include/ircd/simt/simt.h b/include/ircd/simt/simt.h
index 7d3c3cba2..70df86fc2 100644
--- a/include/ircd/simt/simt.h
+++ b/include/ircd/simt/simt.h
@@ -13,6 +13,7 @@
 
 #include "portable.h"
 #include "assert.h"
+#include "hwid.h"
 #include "cycles.h"
 #include "mem.h"
 #include "math.h"