1 files changed, 22 insertions, 1 deletions

diff --git a/MdePkg/Include/Register/Amd/Cpuid.h b/MdePkg/Include/Register/Amd/Cpuid.h
index 44394fc7a4..add43c40aa 100644
--- a/MdePkg/Include/Register/Amd/Cpuid.h
+++ b/MdePkg/Include/Register/Amd/Cpuid.h
@@ -6,7 +6,7 @@
   If a register returned is a single 32-bit value, then a data structure is

   not provided for that register.

 

-  Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR>

+  Copyright (c) 2017 - 2024, Advanced Micro Devices. All rights reserved.<BR>

 

   SPDX-License-Identifier: BSD-2-Clause-Patent

 

@@ -43,6 +43,27 @@ CPUID Signature Information
 ///

 

 /**

+  CPUID Extended Topology Enumeration

+

+  @note

+  Reference: AMD64 Architecture Programmer’s Manual Volume 3: General-Purpose and System Instructions,

+             Revision 3.35 Appendix E,

+  E.4.24 Function 8000_0026—Extended CPU Topology:

+    CPUID Fn8000_0026 reports extended topology information for logical processors, including

+    asymmetric and heterogenous topology descriptions. Individual logical processors may report

+    different values in systems with asynchronous and heterogeneous topologies.

+    The topology level is selected by the value passed to the instruction in ECX. To discover the topology

+    of a system, software should execute CPUID Fn8000_0026 with increasing ECX values, starting with

+    a value of zero, until the returned hierarchy level type (CPUID Fn8000_0026_ECX[LevelType]) is

+    equal to zero. It is not guaranteed that all topology level types are present in the system

+

+  @param   EAX  AMD_CPUID_EXTENDED_TOPOLOGY   (0x80000026)

+  @param   ECX  Level number

+

+**/

+#define AMD_CPUID_EXTENDED_TOPOLOGY  0x80000026

+

+/**

   CPUID Extended Processor Signature and Features

 

   @param   EAX  CPUID_EXTENDED_CPU_SIG (0x80000001)