[Patch V3 4/5] UefiCpuPkg: ApWakeupFunction directly use CpuMpData.

["Yuanhao Xie" <yuanhao.xie@intel.com>]

In the original design, once the APs finished executing their assembly
code and switched to executing C code, they would enter a continuous
loop within a function. In this function, they would collect CpuMpData
using the MP_CPU_EXCHANGE_INFO mechanism. However, in the updated
approach, CpuMpData can now be passed directly to the ApWakeUpFunction,
bypassing the need for MP_CPU_EXCHANGE_INFO. This modification is made
in preparation for eliminating the requirement of a second
INIT-SIPI-SIPI sequence in the DXE phase.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
---
 UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm |  4 ++--
 UefiCpuPkg/Library/MpInitLib/MpLib.c           | 12 +++---------
 UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm  |  3 +--
 3 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
index 59db4081d6..d117f09ef5 100644
--- a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
@@ -197,8 +197,8 @@ CProcedureInvoke:
 
     push       ebx               ; Push ApIndex
     mov        eax, esi
-    add        eax, MP_CPU_EXCHANGE_INFO_OFFSET
-    push       eax               ; push address of exchange info data buffer
+    add        eax, MP_CPU_EXCHANGE_INFO_FIELD (CpuMpData)
+    push       dword [eax]       ; push address of CpuMpData
 
     mov        edi, esi
     add        edi, MP_CPU_EXCHANGE_INFO_FIELD (CFunction)
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 1252ee9673..15b24b1805 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -710,17 +710,16 @@ PlaceAPInMwaitLoopOrRunLoop (
 /**
   This function will be called from AP reset code if BSP uses WakeUpAP.
 
-  @param[in] ExchangeInfo     Pointer to the MP exchange info buffer
+  @param[in] CpuMpData        Pointer to CPU MP Data
   @param[in] ApIndex          Number of current executing AP
 **/
 VOID
 EFIAPI
 ApWakeupFunction (
-  IN MP_CPU_EXCHANGE_INFO  *ExchangeInfo,
-  IN UINTN                 ApIndex
+  IN CPU_MP_DATA  *CpuMpData,
+  IN UINTN        ApIndex
   )
 {
-  CPU_MP_DATA       *CpuMpData;
   UINTN             ProcessorNumber;
   EFI_AP_PROCEDURE  Procedure;
   VOID              *Parameter;
@@ -731,11 +730,6 @@ ApWakeupFunction (
   UINTN             CurrentApicMode;
   AP_STACK_DATA     *ApStackData;
 
-  //
-  // AP finished assembly code and begin to execute C code
-  //
-  CpuMpData = ExchangeInfo->CpuMpData;
-
   //
   // AP's local APIC settings will be lost after received INIT IPI
   // We need to re-initialize them at here
diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index 5bcdf7726b..40e80ffab4 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
@@ -259,8 +259,7 @@ CProcedureInvoke:
     add        rsp, 20h
 
     mov        edx, ebx          ; edx is ApIndex
-    mov        ecx, esi
-    add        ecx, MP_CPU_EXCHANGE_INFO_OFFSET ; rcx is address of exchange info data buffer
+    mov        rcx, qword [esi + MP_CPU_EXCHANGE_INFO_FIELD (CpuMpData)]
 
     mov        edi, esi
     add        edi, MP_CPU_EXCHANGE_INFO_FIELD (CFunction)
-- 
2.36.1.windows.1