UefiCpuPkg: Update CPU MP drivers to support single CPU configuration

Only perform AP detection if PcdCpuMaxLogicalProcessorNumber > 1
Only free AP related structures of they were allocated

(Sync patch r18629 from main trunk.)

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/branches/UDK2015@18824 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 48 insertions, 35 deletions

diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index 4ddcca208a..da3686e278 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -1642,35 +1642,40 @@ InitializeMpSupport (
     return;

   }

 

-  if (gMaxLogicalProcessorNumber == 1) {

-    return;

-  }

 

-  gApStackSize = (UINTN) PcdGet32 (PcdCpuApStackSize);

-  ASSERT ((gApStackSize & (SIZE_4KB - 1)) == 0);

 

-  mApStackStart = AllocatePages (EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));

-  ASSERT (mApStackStart != NULL);

+  InitMpSystemData ();

 

   //

-  // the first buffer of stack size used for common stack, when the amount of AP

-  // more than 1, we should never free the common stack which maybe used for AP reset.

+  // Only perform AP detection if PcdCpuMaxLogicalProcessorNumber is greater than 1

   //

-  mCommonStack = mApStackStart;

-  mTopOfApCommonStack = (UINT8*) mApStackStart + gApStackSize;

-  mApStackStart = mTopOfApCommonStack;

+  if (gMaxLogicalProcessorNumber > 1) {

 

-  InitMpSystemData ();

+    gApStackSize = (UINTN) PcdGet32 (PcdCpuApStackSize);

+    ASSERT ((gApStackSize & (SIZE_4KB - 1)) == 0);

+

+    mApStackStart = AllocatePages (EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));

+    ASSERT (mApStackStart != NULL);

+

+    //

+    // the first buffer of stack size used for common stack, when the amount of AP

+    // more than 1, we should never free the common stack which maybe used for AP reset.

+    //

+    mCommonStack = mApStackStart;

+    mTopOfApCommonStack = (UINT8*) mApStackStart + gApStackSize;

+    mApStackStart = mTopOfApCommonStack;

 

-  PrepareAPStartupCode ();

+    PrepareAPStartupCode ();

 

-  StartApsStackless ();

+    StartApsStackless ();

+  }

 

   DEBUG ((DEBUG_INFO, "Detect CPU count: %d\n", mMpSystemData.NumberOfProcessors));

   if (mMpSystemData.NumberOfProcessors == 1) {

     FreeApStartupCode ();

-    FreePages (mCommonStack, EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));

-    return;

+    if (mCommonStack != NULL) {

+      FreePages (mCommonStack, EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));

+    }

   }

 

   mMpSystemData.CpuDatas = ReallocatePool (

@@ -1692,10 +1697,12 @@ InitializeMpSupport (
                   );

   ASSERT_EFI_ERROR (Status);

 

-  if (mMpSystemData.NumberOfProcessors < gMaxLogicalProcessorNumber) {

-    FreePages (mApStackStart, EFI_SIZE_TO_PAGES (

-                                (gMaxLogicalProcessorNumber - mMpSystemData.NumberOfProcessors) *

-                                gApStackSize));

+  if (mMpSystemData.NumberOfProcessors > 1 && mMpSystemData.NumberOfProcessors < gMaxLogicalProcessorNumber) {

+    if (mApStackStart != NULL) {

+      FreePages (mApStackStart, EFI_SIZE_TO_PAGES (

+                                  (gMaxLogicalProcessorNumber - mMpSystemData.NumberOfProcessors) *

+                                  gApStackSize));

+    }

   }

 

   Status = gBS->CreateEvent (

diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
index d5bc0c9b80..8e35f288fe 100644
--- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c
+++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
@@ -357,22 +357,28 @@ CountProcessorNumber (
   // Store BSP's MTRR setting

   //

   MtrrGetAllMtrrs (&PeiCpuMpData->MtrrTable);

+

   //

-  // Send broadcast IPI to APs to wakeup APs

-  //

-  PeiCpuMpData->InitFlag = 1;

-  WakeUpAP (PeiCpuMpData, TRUE, 0, NULL, NULL);

-  //

-  // Wait for AP task to complete and then exit.

-  //

-  MicroSecondDelay (PcdGet32 (PcdCpuApInitTimeOutInMicroSeconds));

-  PeiCpuMpData->InitFlag  = 0;

-  PeiCpuMpData->CpuCount += (UINT32) PeiCpuMpData->MpCpuExchangeInfo->NumApsExecuting;

-  ASSERT (PeiCpuMpData->CpuCount <= PcdGet32(PcdCpuMaxLogicalProcessorNumber));

-  //

-  // Sort BSP/Aps by CPU APIC ID in ascending order

+  // Only perform AP detection if PcdCpuMaxLogicalProcessorNumber is greater than 1

   //

-  SortApicId (PeiCpuMpData);

+  if (PcdGet32 (PcdCpuMaxLogicalProcessorNumber) > 1) {

+    //

+    // Send broadcast IPI to APs to wakeup APs

+    //

+    PeiCpuMpData->InitFlag = 1;

+    WakeUpAP (PeiCpuMpData, TRUE, 0, NULL, NULL);

+    //

+    // Wait for AP task to complete and then exit.

+    //

+    MicroSecondDelay (PcdGet32 (PcdCpuApInitTimeOutInMicroSeconds));

+    PeiCpuMpData->InitFlag = 0;

+    PeiCpuMpData->CpuCount += (UINT32)PeiCpuMpData->MpCpuExchangeInfo->NumApsExecuting;

+    ASSERT (PeiCpuMpData->CpuCount <= PcdGet32 (PcdCpuMaxLogicalProcessorNumber));

+    //

+    // Sort BSP/Aps by CPU APIC ID in ascending order

+    //

+    SortApicId (PeiCpuMpData);

+  }

 

   DEBUG ((EFI_D_INFO, "CpuMpPei: Find %d processors in system.\n", PeiCpuMpData->CpuCount));

   return PeiCpuMpData->CpuCount;