[Patch v5 20/48] UefiCpuPkg/MpInitLib: Add ApWakeupFunction() executed by assembly code

[Jeff Fan <jeff.fan@intel.com>]

ApWakeupFunction() is the first C function executed from AP reset vector. When
APs waken up at the first time, it will sync BSP's MTRR setting and load
microcode on APs and collect APs' BIST information.

When AP tasked finished, it will place APs it one loop specified by ApLoopMode.

v5:
  1. Rename ApCFunction to ApWakeupFunction to meet naming convention.

Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
---
 UefiCpuPkg/Library/MpInitLib/MpLib.c | 198 +++++++++++++++++++++++++++++++++++
 UefiCpuPkg/Library/MpInitLib/MpLib.h |   2 +
 2 files changed, 200 insertions(+)

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 8dfbf57..a4a2c44 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -174,6 +174,59 @@ GetApLoopMode (
 
   return ApLoopMode;
 }
+
+/**
+  Do sync on APs.
+
+  @param[in, out] Buffer  Pointer to private data buffer.
+**/
+VOID
+EFIAPI
+ApInitializeSync (
+  IN OUT VOID  *Buffer
+  )
+{
+  CPU_MP_DATA  *CpuMpData;
+
+  CpuMpData = (CPU_MP_DATA *) Buffer;
+  //
+  // Sync BSP's MTRR table to AP
+  //
+  MtrrSetAllMtrrs (&CpuMpData->MtrrTable);
+  //
+  // Load microcode on AP
+  //
+  MicrocodeDetect (CpuMpData);
+}
+
+/**
+  Find the current Processor number by APIC ID.
+
+  @param[in] CpuMpData         Pointer to PEI CPU MP Data
+  @param[in] ProcessorNumber   Return the pocessor number found
+
+  @retval EFI_SUCCESS          ProcessorNumber is found and returned.
+  @retval EFI_NOT_FOUND        ProcessorNumber is not found.
+**/
+EFI_STATUS
+GetProcessorNumber (
+  IN CPU_MP_DATA               *CpuMpData,
+  OUT UINTN                    *ProcessorNumber
+  )
+{
+  UINTN                   TotalProcessorNumber;
+  UINTN                   Index;
+
+  TotalProcessorNumber = CpuMpData->CpuCount;
+  for (Index = 0; Index < TotalProcessorNumber; Index ++) {
+    if (CpuMpData->CpuData[Index].ApicId == GetApicId ()) {
+      *ProcessorNumber = Index;
+      return EFI_SUCCESS;
+    }
+  }
+  return EFI_NOT_FOUND;
+}
+
 /*
   Initialize CPU AP Data when AP is wakeup at the first time.
 
@@ -209,6 +262,151 @@ InitializeApData (
 }
 
 /**
+  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] NumApsExecuting  Number of current executing AP
+**/
+VOID
+EFIAPI
+ApWakeupFunction (
+  IN MP_CPU_EXCHANGE_INFO      *ExchangeInfo,
+  IN UINTN                     NumApsExecuting
+  )
+{
+  CPU_MP_DATA                *CpuMpData;
+  UINTN                      ProcessorNumber;
+  EFI_AP_PROCEDURE           Procedure;
+  VOID                       *Parameter;
+  UINT32                     BistData;
+  volatile UINT32            *ApStartupSignalBuffer;
+
+  //
+  // AP finished assembly code and begin to execute C code
+  //
+  CpuMpData = ExchangeInfo->CpuMpData;
+
+  ProgramVirtualWireMode (); 
+
+  while (TRUE) {
+    if (CpuMpData->InitFlag == ApInitConfig) {
+      //
+      // Add CPU number
+      //
+      InterlockedIncrement ((UINT32 *) &CpuMpData->CpuCount);
+      ProcessorNumber = NumApsExecuting;
+      //
+      // This is first time AP wakeup, get BIST information from AP stack
+      //
+      BistData = *(UINT32 *) (CpuMpData->Buffer + ProcessorNumber * CpuMpData->CpuApStackSize - sizeof (UINTN));
+      //
+      // Do some AP initialize sync
+      //
+      ApInitializeSync (CpuMpData);
+      //
+      // Sync BSP's Control registers to APs
+      //
+      RestoreVolatileRegisters (&CpuMpData->CpuData[0].VolatileRegisters, FALSE);
+      InitializeApData (CpuMpData, ProcessorNumber, BistData);
+      ApStartupSignalBuffer = CpuMpData->CpuData[ProcessorNumber].StartupApSignal;
+    } else {
+      //
+      // Execute AP function if AP is ready
+      //
+      GetProcessorNumber (CpuMpData, &ProcessorNumber);
+      //
+      // Clear AP start-up signal when AP waken up
+      //
+      ApStartupSignalBuffer = CpuMpData->CpuData[ProcessorNumber].StartupApSignal;
+      InterlockedCompareExchange32 (
+        (UINT32 *) ApStartupSignalBuffer,
+        WAKEUP_AP_SIGNAL,
+        0
+        );
+      if (CpuMpData->ApLoopMode == ApInHltLoop) {
+        //
+        // Restore AP's volatile registers saved
+        //
+        RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters, TRUE);
+      }
+
+      if (GetApState (&CpuMpData->CpuData[ProcessorNumber]) == CpuStateReady) {
+        Procedure = (EFI_AP_PROCEDURE)CpuMpData->CpuData[ProcessorNumber].ApFunction;
+        Parameter = (VOID *) CpuMpData->CpuData[ProcessorNumber].ApFunctionArgument;
+        if (Procedure != NULL) {
+          SetApState (&CpuMpData->CpuData[ProcessorNumber], CpuStateBusy);
+          //
+          // Invoke AP function here
+          //
+          Procedure (Parameter);
+          //
+          // Re-get the CPU APICID and Initial APICID
+          //
+          CpuMpData->CpuData[ProcessorNumber].ApicId        = GetApicId ();
+          CpuMpData->CpuData[ProcessorNumber].InitialApicId = GetInitialApicId ();
+        }
+        SetApState (&CpuMpData->CpuData[ProcessorNumber], CpuStateFinished);
+      }
+    }
+
+    //
+    // AP finished executing C code
+    //
+    InterlockedIncrement ((UINT32 *) &CpuMpData->FinishedCount);
+
+    //
+    // Place AP is specified loop mode
+    //
+    if (CpuMpData->ApLoopMode == ApInHltLoop) {
+      //
+      // Save AP volatile registers
+      //
+      SaveVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters);
+      //
+      // Place AP in HLT-loop
+      //
+      while (TRUE) {
+        DisableInterrupts ();
+        CpuSleep ();
+        CpuPause ();
+      }
+    }
+    while (TRUE) {
+      DisableInterrupts ();
+      if (CpuMpData->ApLoopMode == ApInMwaitLoop) {
+        //
+        // Place AP in MWAIT-loop
+        //
+        AsmMonitor ((UINTN) ApStartupSignalBuffer, 0, 0);
+        if (*ApStartupSignalBuffer != WAKEUP_AP_SIGNAL) {
+          //
+          // Check AP start-up signal again.
+          // If AP start-up signal is not set, place AP into
+          // the specified C-state
+          //
+          AsmMwait (CpuMpData->ApTargetCState << 4, 0);
+        }
+      } else if (CpuMpData->ApLoopMode == ApInRunLoop) {
+        //
+        // Place AP in Run-loop
+        //
+        CpuPause ();
+      } else {
+        ASSERT (FALSE);
+      }
+
+      //
+      // If AP start-up signal is written, AP is waken up
+      // otherwise place AP in loop again
+      //
+      if (*ApStartupSignalBuffer == WAKEUP_AP_SIGNAL) {
+        break;
+      }
+    }
+  }
+}
+
+/**
   MP Initialize Library initialization.
 
   This service will allocate AP reset vector and wakeup all APs to do APs
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index 80ea0b4..72a35ef 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -35,6 +35,8 @@
 #include <Library/MtrrLib.h>
 #include <Library/HobLib.h>
 
+#define WAKEUP_AP_SIGNAL SIGNATURE_32 ('S', 'T', 'A', 'P')
+
 #define CPU_INIT_MP_LIB_HOB_GUID \
   { \
     0x58eb6a19, 0x3699, 0x4c68, { 0xa8, 0x36, 0xda, 0xcd, 0x8e, 0xdc, 0xad, 0x4a } \
-- 
2.7.4.windows.1