UefiCpuPkg/MpInitLib: Implementation of MpInitLibSwitchBSP()

[mirror_edk2.git] / UefiCpuPkg / Library / MpInitLib / MpLib.c

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index d0473fdb37592da32e54d00cc7ce999fccc0cc6e..8ae08f4d5d5f050bf89cda7be0fc614e566f62cc 100644 (file)
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -183,6 +183,26 @@ ExtractProcessorLocation (
   Location->Package = (InitialApicId >> (ThreadBits + CoreBits));\r
 }\r
 \r
+/**\r
+  Worker function for SwitchBSP().\r
+\r
+  Worker function for SwitchBSP(), assigned to the AP which is intended\r
+  to become BSP.\r
+\r
+  @param[in] Buffer   Pointer to CPU MP Data\r
+**/\r
+VOID\r
+EFIAPI\r
+FutureBSPProc (\r
+  IN  VOID            *Buffer\r
+  )\r
+{\r
+  CPU_MP_DATA         *DataInHob;\r
+\r
+  DataInHob = (CPU_MP_DATA *) Buffer;\r
+  AsmExchangeRole (&DataInHob->APInfo, &DataInHob->BSPInfo);\r
+}\r
+\r
 /**\r
   Get the Application Processors state.\r
 \r
@@ -646,11 +666,20 @@ ApWakeupFunction (
           // Invoke AP function here\r
           //\r
           Procedure (Parameter);\r
-          //\r
-          // Re-get the CPU APICID and Initial APICID\r
-          //\r
-          CpuMpData->CpuData[ProcessorNumber].ApicId        = GetApicId ();\r
-          CpuMpData->CpuData[ProcessorNumber].InitialApicId = GetInitialApicId ();\r
+          if (CpuMpData->SwitchBspFlag) {\r
+            //\r
+            // Re-get the processor number due to BSP/AP maybe exchange in AP function\r
+            //\r
+            GetProcessorNumber (CpuMpData, &ProcessorNumber);\r
+            CpuMpData->CpuData[ProcessorNumber].ApFunction = 0;\r
+            CpuMpData->CpuData[ProcessorNumber].ApFunctionArgument = 0;\r
+          } else {\r
+            //\r
+            // Re-get the CPU APICID and Initial APICID\r
+            //\r
+            CpuMpData->CpuData[ProcessorNumber].ApicId        = GetApicId ();\r
+            CpuMpData->CpuData[ProcessorNumber].InitialApicId = GetInitialApicId ();\r
+          }\r
         }\r
         SetApState (&CpuMpData->CpuData[ProcessorNumber], CpuStateFinished);\r
       }\r
@@ -941,6 +970,7 @@ MpInitLibInitialize (
   CpuMpData->CpuCount         = 1;\r
   CpuMpData->BspNumber        = 0;\r
   CpuMpData->WaitEvent        = NULL;\r
+  CpuMpData->SwitchBspFlag    = FALSE;\r
   CpuMpData->CpuData          = (CPU_AP_DATA *) (CpuMpData + 1);\r
   CpuMpData->CpuInfoInHob     = (UINT64) (UINTN) (CpuMpData->CpuData + MaxLogicalProcessorNumber);\r
   InitializeSpinLock(&CpuMpData->MpLock);\r
@@ -1103,6 +1133,110 @@ MpInitLibGetProcessorInfo (
   return EFI_SUCCESS;\r
 }\r
 \r
+/**\r
+  Worker function to switch the requested AP to be the BSP from that point onward.\r
+\r
+  @param[in] ProcessorNumber   The handle number of AP that is to become the new BSP.\r
+  @param[in] EnableOldBSP      If TRUE, then the old BSP will be listed as an\r
+                               enabled AP. Otherwise, it will be disabled.\r
+\r
+  @retval EFI_SUCCESS          BSP successfully switched.\r
+  @retval others               Failed to switch BSP. \r
+\r
+**/\r
+EFI_STATUS\r
+SwitchBSPWorker (\r
+  IN UINTN                     ProcessorNumber,\r
+  IN BOOLEAN                   EnableOldBSP\r
+  )\r
+{\r
+  CPU_MP_DATA                  *CpuMpData;\r
+  UINTN                        CallerNumber;\r
+  CPU_STATE                    State;\r
+  MSR_IA32_APIC_BASE_REGISTER  ApicBaseMsr;\r
+\r
+  CpuMpData = GetCpuMpData ();\r
+\r
+  //\r
+  // Check whether caller processor is BSP\r
+  //\r
+  MpInitLibWhoAmI (&CallerNumber);\r
+  if (CallerNumber != CpuMpData->BspNumber) {\r
+    return EFI_SUCCESS;\r
+  }\r
+\r
+  if (ProcessorNumber >= CpuMpData->CpuCount) {\r
+    return EFI_NOT_FOUND;\r
+  }\r
+\r
+  //\r
+  // Check whether specified AP is disabled\r
+  //\r
+  State = GetApState (&CpuMpData->CpuData[ProcessorNumber]);\r
+  if (State == CpuStateDisabled) {\r
+    return EFI_INVALID_PARAMETER;\r
+  }\r
+\r
+  //\r
+  // Check whether ProcessorNumber specifies the current BSP\r
+  //\r
+  if (ProcessorNumber == CpuMpData->BspNumber) {\r
+    return EFI_INVALID_PARAMETER;\r
+  }\r
+\r
+  //\r
+  // Check whether specified AP is busy\r
+  //\r
+  if (State == CpuStateBusy) {\r
+    return EFI_NOT_READY;\r
+  }\r
+\r
+  CpuMpData->BSPInfo.State = CPU_SWITCH_STATE_IDLE;\r
+  CpuMpData->APInfo.State  = CPU_SWITCH_STATE_IDLE;\r
+  CpuMpData->SwitchBspFlag = TRUE;\r
+\r
+  //\r
+  // Clear the BSP bit of MSR_IA32_APIC_BASE\r
+  //\r
+  ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);\r
+  ApicBaseMsr.Bits.BSP = 0;\r
+  AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);\r
+\r
+  //\r
+  // Need to wakeUp AP (future BSP).\r
+  //\r
+  WakeUpAP (CpuMpData, FALSE, ProcessorNumber, FutureBSPProc, CpuMpData);\r
+\r
+  AsmExchangeRole (&CpuMpData->BSPInfo, &CpuMpData->APInfo);\r
+\r
+  //\r
+  // Set the BSP bit of MSR_IA32_APIC_BASE on new BSP\r
+  //\r
+  ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);\r
+  ApicBaseMsr.Bits.BSP = 1;\r
+  AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);\r
+\r
+  //\r
+  // Wait for old BSP finished AP task\r
+  //\r
+  while (GetApState (&CpuMpData->CpuData[CallerNumber]) != CpuStateFinished) {\r
+    CpuPause ();\r
+  }\r
+\r
+  CpuMpData->SwitchBspFlag = FALSE;\r
+  //\r
+  // Set old BSP enable state\r
+  //\r
+  if (!EnableOldBSP) {\r
+    SetApState (&CpuMpData->CpuData[CallerNumber], CpuStateDisabled);\r
+  }\r
+  //\r
+  // Save new BSP number\r
+  //\r
+  CpuMpData->BspNumber = (UINT32) ProcessorNumber;\r
+\r
+  return EFI_SUCCESS;\r
+}\r
 \r
 /**\r
   This return the handle number for the calling processor.  This service may be\r
@@ -1126,7 +1260,15 @@ MpInitLibWhoAmI (
   OUT UINTN                    *ProcessorNumber\r
   )\r
 {\r
-  return EFI_UNSUPPORTED;\r
+  CPU_MP_DATA           *CpuMpData;\r
+\r
+  if (ProcessorNumber == NULL) {\r
+    return EFI_INVALID_PARAMETER;\r
+  }\r
+\r
+  CpuMpData = GetCpuMpData ();\r
+\r
+  return GetProcessorNumber (CpuMpData, ProcessorNumber);\r
 }\r
 \r
 /**\r