UefiCpuPkg: Update CPU MP drivers to support single CPU configuration

[mirror_edk2.git] / UefiCpuPkg / CpuDxe / CpuMp.c

diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index 4ddcca208a36cf7f82ff89764f8f4b22fe034228..da3686e2788e8c50f0652bd743a3a010c42e5a2e 100644 (file)
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -1642,35 +1642,40 @@ InitializeMpSupport (
     return;\r
   }\r
 \r
     return;\r
   }\r
 \r

-  if (gMaxLogicalProcessorNumber == 1) {\r
-    return;\r
-  }\r

 \r
 \r

-  gApStackSize = (UINTN) PcdGet32 (PcdCpuApStackSize);\r
-  ASSERT ((gApStackSize & (SIZE_4KB - 1)) == 0);\r

 \r
 \r

-  mApStackStart = AllocatePages (EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));\r
-  ASSERT (mApStackStart != NULL);\r
+  InitMpSystemData ();\r

 \r
   //\r
 \r
   //\r

-  // the first buffer of stack size used for common stack, when the amount of AP\r
-  // more than 1, we should never free the common stack which maybe used for AP reset.\r
+  // Only perform AP detection if PcdCpuMaxLogicalProcessorNumber is greater than 1\r

   //\r
   //\r

-  mCommonStack = mApStackStart;\r
-  mTopOfApCommonStack = (UINT8*) mApStackStart + gApStackSize;\r
-  mApStackStart = mTopOfApCommonStack;\r
+  if (gMaxLogicalProcessorNumber > 1) {\r

 \r
 \r

-  InitMpSystemData ();\r
+    gApStackSize = (UINTN) PcdGet32 (PcdCpuApStackSize);\r
+    ASSERT ((gApStackSize & (SIZE_4KB - 1)) == 0);\r
+\r
+    mApStackStart = AllocatePages (EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));\r
+    ASSERT (mApStackStart != NULL);\r
+\r
+    //\r
+    // the first buffer of stack size used for common stack, when the amount of AP\r
+    // more than 1, we should never free the common stack which maybe used for AP reset.\r
+    //\r
+    mCommonStack = mApStackStart;\r
+    mTopOfApCommonStack = (UINT8*) mApStackStart + gApStackSize;\r
+    mApStackStart = mTopOfApCommonStack;\r

 \r
 \r

-  PrepareAPStartupCode ();\r
+    PrepareAPStartupCode ();\r

 \r
 \r

-  StartApsStackless ();\r
+    StartApsStackless ();\r
+  }\r

 \r
   DEBUG ((DEBUG_INFO, "Detect CPU count: %d\n", mMpSystemData.NumberOfProcessors));\r
   if (mMpSystemData.NumberOfProcessors == 1) {\r
     FreeApStartupCode ();\r
 \r
   DEBUG ((DEBUG_INFO, "Detect CPU count: %d\n", mMpSystemData.NumberOfProcessors));\r
   if (mMpSystemData.NumberOfProcessors == 1) {\r
     FreeApStartupCode ();\r

-    FreePages (mCommonStack, EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));\r
-    return;\r
+    if (mCommonStack != NULL) {\r
+      FreePages (mCommonStack, EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));\r
+    }\r

   }\r
 \r
   mMpSystemData.CpuDatas = ReallocatePool (\r
   }\r
 \r
   mMpSystemData.CpuDatas = ReallocatePool (\r


@@ -1692,10 +1697,12 @@ InitializeMpSupport (
                   );\r
   ASSERT_EFI_ERROR (Status);\r
 \r
                   );\r
   ASSERT_EFI_ERROR (Status);\r
 \r

-  if (mMpSystemData.NumberOfProcessors < gMaxLogicalProcessorNumber) {\r
-    FreePages (mApStackStart, EFI_SIZE_TO_PAGES (\r
-                                (gMaxLogicalProcessorNumber - mMpSystemData.NumberOfProcessors) *\r
-                                gApStackSize));\r
+  if (mMpSystemData.NumberOfProcessors > 1 && mMpSystemData.NumberOfProcessors < gMaxLogicalProcessorNumber) {\r
+    if (mApStackStart != NULL) {\r
+      FreePages (mApStackStart, EFI_SIZE_TO_PAGES (\r
+                                  (gMaxLogicalProcessorNumber - mMpSystemData.NumberOfProcessors) *\r
+                                  gApStackSize));\r
+    }\r

   }\r
 \r
   Status = gBS->CreateEvent (\r
   }\r
 \r
   Status = gBS->CreateEvent (\r