From 0fdffb71df7c99301c6430a95af207159cbe9655 Mon Sep 17 00:00:00 2001
From: Chao Li <lichao@loongson.cn>
Date: Wed, 18 Dec 2024 10:45:24 +0800
Subject: [PATCH] UefiCpuPkg: Adjust the exception handler logic on LoongArch64

There is a problem with LoongArch64 exception handler, it returns a
unhandled value when we get an exception type, the correct value should
be right shifted 16 bits, so fix it.

Cc: Ray Ni <ray.ni@intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Dun Tan <dun.tan@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Signed-off-by: Chao Li <lichao@loongson.cn>
---
 .../LoongArch/DxeExceptionLib.c                   | 15 +++++++--------
 .../LoongArch/LoongArch64/ArchExceptionHandler.c  |  2 +-
 .../LoongArch/SecPeiExceptionLib.c                |  7 -------
 3 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/DxeExceptionLib.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/DxeExceptionLib.c
index eed5644552..1c60be8312 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/DxeExceptionLib.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/DxeExceptionLib.c
@@ -115,23 +115,22 @@ CommonExceptionHandler (
     // Interrupt
     //
     InterruptType = GetInterruptType (SystemContext);
-    if (InterruptType == 0xFF) {
-      ExceptionType = InterruptType;
-    } else {
+    if (InterruptType != 0xFF) {
       if ((ExternalInterruptHandler != NULL) && (ExternalInterruptHandler[InterruptType] != NULL)) {
         ExternalInterruptHandler[InterruptType](InterruptType, SystemContext);
         return;
       }
     }
-  } else if (ExceptionType == EXCEPT_LOONGARCH_FPD) {
-    EnableFloatingPointUnits ();
-    InitializeFloatingPointUnits ();
-    return;
   } else {
     //
     // Exception
     //
-    ExceptionType >>= CSR_ESTAT_EXC_SHIFT;
+    if (ExceptionType == EXCEPT_LOONGARCH_FPD) {
+      EnableFloatingPointUnits ();
+      InitializeFloatingPointUnits ();
+      return;
+    }
+
     if ((ExceptionHandler != NULL) && (ExceptionHandler[ExceptionType] != NULL)) {
       ExceptionHandler[ExceptionType](ExceptionType, SystemContext);
       return;
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/LoongArch64/ArchExceptionHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/LoongArch64/ArchExceptionHandler.c
index 519fe1e24e..ea299475f5 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/LoongArch64/ArchExceptionHandler.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/LoongArch64/ArchExceptionHandler.c
@@ -27,7 +27,7 @@ GetExceptionType (
 {
   EFI_EXCEPTION_TYPE  ExceptionType;
 
-  ExceptionType = (SystemContext.SystemContextLoongArch64->ESTAT & CSR_ESTAT_EXC);
+  ExceptionType = (SystemContext.SystemContextLoongArch64->ESTAT & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
   return ExceptionType;
 }
 
diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/SecPeiExceptionLib.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/SecPeiExceptionLib.c
index 7588d2050b..dc395c092c 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/SecPeiExceptionLib.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/LoongArch/SecPeiExceptionLib.c
@@ -68,14 +68,7 @@ CommonExceptionHandler (
       //
       IpiInterruptHandler (InterruptType, SystemContext);
       return;
-    } else {
-      ExceptionType = InterruptType;
     }
-  } else {
-    //
-    // Exception
-    //
-    ExceptionType >>= CSR_ESTAT_EXC_SHIFT;
   }
 
   DefaultExceptionHandler (ExceptionType, SystemContext);