From 41be0da59a6e0366e5e52f9c72ec9228a92a8c01 Mon Sep 17 00:00:00 2001 From: Jeff Fan Date: Thu, 21 Jul 2016 21:20:18 +0800 Subject: [PATCH] UefiCpuPkg/MpInitLib: Implementation of MpInitLibSwitchBSP() v4: 1. Simply the internal function SwitchBSPWorker()'s comment header due to it is duplicated with MpInitLibSwitchBSP(). v3: 1. Rename MpInitLibSwitchBsp to MpInitLibSwitchBSP. Cc: Michael Kinney Cc: Feng Tian Cc: Giri P Mudusuru Cc: Laszlo Ersek Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan Reviewed-by: Michael Kinney Tested-by: Laszlo Ersek Tested-by: Michael Kinney --- UefiCpuPkg/Library/MpInitLib/DxeMpLib.c | 26 ++++- UefiCpuPkg/Library/MpInitLib/MpLib.c | 144 +++++++++++++++++++++++- UefiCpuPkg/Library/MpInitLib/MpLib.h | 53 +++++++++ UefiCpuPkg/Library/MpInitLib/PeiMpLib.c | 2 +- 4 files changed, 218 insertions(+), 7 deletions(-) diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c index 762d76dd7a..785653be8f 100644 --- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c @@ -389,7 +389,31 @@ MpInitLibSwitchBSP ( IN BOOLEAN EnableOldBSP ) { - return EFI_UNSUPPORTED; + EFI_STATUS Status; + BOOLEAN OldInterruptState; + + // + // Before send both BSP and AP to a procedure to exchange their roles, + // interrupt must be disabled. This is because during the exchange role + // process, 2 CPU may use 1 stack. If interrupt happens, the stack will + // be corrupted, since interrupt return address will be pushed to stack + // by hardware. + // + OldInterruptState = SaveAndDisableInterrupts (); + + // + // Mask LINT0 & LINT1 for the old BSP + // + DisableLvtInterrupts (); + + Status = SwitchBSPWorker (ProcessorNumber, EnableOldBSP); + + // + // Restore interrupt state. + // + SetInterruptState (OldInterruptState); + + return Status; } /** diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c index 5fbcb26dda..8ae08f4d5d 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c @@ -183,6 +183,26 @@ ExtractProcessorLocation ( Location->Package = (InitialApicId >> (ThreadBits + CoreBits)); } +/** + Worker function for SwitchBSP(). + + Worker function for SwitchBSP(), assigned to the AP which is intended + to become BSP. + + @param[in] Buffer Pointer to CPU MP Data +**/ +VOID +EFIAPI +FutureBSPProc ( + IN VOID *Buffer + ) +{ + CPU_MP_DATA *DataInHob; + + DataInHob = (CPU_MP_DATA *) Buffer; + AsmExchangeRole (&DataInHob->APInfo, &DataInHob->BSPInfo); +} + /** Get the Application Processors state. @@ -646,11 +666,20 @@ ApWakeupFunction ( // Invoke AP function here // Procedure (Parameter); - // - // Re-get the CPU APICID and Initial APICID - // - CpuMpData->CpuData[ProcessorNumber].ApicId = GetApicId (); - CpuMpData->CpuData[ProcessorNumber].InitialApicId = GetInitialApicId (); + if (CpuMpData->SwitchBspFlag) { + // + // Re-get the processor number due to BSP/AP maybe exchange in AP function + // + GetProcessorNumber (CpuMpData, &ProcessorNumber); + CpuMpData->CpuData[ProcessorNumber].ApFunction = 0; + CpuMpData->CpuData[ProcessorNumber].ApFunctionArgument = 0; + } else { + // + // Re-get the CPU APICID and Initial APICID + // + CpuMpData->CpuData[ProcessorNumber].ApicId = GetApicId (); + CpuMpData->CpuData[ProcessorNumber].InitialApicId = GetInitialApicId (); + } } SetApState (&CpuMpData->CpuData[ProcessorNumber], CpuStateFinished); } @@ -941,6 +970,7 @@ MpInitLibInitialize ( CpuMpData->CpuCount = 1; CpuMpData->BspNumber = 0; CpuMpData->WaitEvent = NULL; + CpuMpData->SwitchBspFlag = FALSE; CpuMpData->CpuData = (CPU_AP_DATA *) (CpuMpData + 1); CpuMpData->CpuInfoInHob = (UINT64) (UINTN) (CpuMpData->CpuData + MaxLogicalProcessorNumber); InitializeSpinLock(&CpuMpData->MpLock); @@ -1103,6 +1133,110 @@ MpInitLibGetProcessorInfo ( return EFI_SUCCESS; } +/** + Worker function to switch the requested AP to be the BSP from that point onward. + + @param[in] ProcessorNumber The handle number of AP that is to become the new BSP. + @param[in] EnableOldBSP If TRUE, then the old BSP will be listed as an + enabled AP. Otherwise, it will be disabled. + + @retval EFI_SUCCESS BSP successfully switched. + @retval others Failed to switch BSP. + +**/ +EFI_STATUS +SwitchBSPWorker ( + IN UINTN ProcessorNumber, + IN BOOLEAN EnableOldBSP + ) +{ + CPU_MP_DATA *CpuMpData; + UINTN CallerNumber; + CPU_STATE State; + MSR_IA32_APIC_BASE_REGISTER ApicBaseMsr; + + CpuMpData = GetCpuMpData (); + + // + // Check whether caller processor is BSP + // + MpInitLibWhoAmI (&CallerNumber); + if (CallerNumber != CpuMpData->BspNumber) { + return EFI_SUCCESS; + } + + if (ProcessorNumber >= CpuMpData->CpuCount) { + return EFI_NOT_FOUND; + } + + // + // Check whether specified AP is disabled + // + State = GetApState (&CpuMpData->CpuData[ProcessorNumber]); + if (State == CpuStateDisabled) { + return EFI_INVALID_PARAMETER; + } + + // + // Check whether ProcessorNumber specifies the current BSP + // + if (ProcessorNumber == CpuMpData->BspNumber) { + return EFI_INVALID_PARAMETER; + } + + // + // Check whether specified AP is busy + // + if (State == CpuStateBusy) { + return EFI_NOT_READY; + } + + CpuMpData->BSPInfo.State = CPU_SWITCH_STATE_IDLE; + CpuMpData->APInfo.State = CPU_SWITCH_STATE_IDLE; + CpuMpData->SwitchBspFlag = TRUE; + + // + // Clear the BSP bit of MSR_IA32_APIC_BASE + // + ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE); + ApicBaseMsr.Bits.BSP = 0; + AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64); + + // + // Need to wakeUp AP (future BSP). + // + WakeUpAP (CpuMpData, FALSE, ProcessorNumber, FutureBSPProc, CpuMpData); + + AsmExchangeRole (&CpuMpData->BSPInfo, &CpuMpData->APInfo); + + // + // Set the BSP bit of MSR_IA32_APIC_BASE on new BSP + // + ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE); + ApicBaseMsr.Bits.BSP = 1; + AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64); + + // + // Wait for old BSP finished AP task + // + while (GetApState (&CpuMpData->CpuData[CallerNumber]) != CpuStateFinished) { + CpuPause (); + } + + CpuMpData->SwitchBspFlag = FALSE; + // + // Set old BSP enable state + // + if (!EnableOldBSP) { + SetApState (&CpuMpData->CpuData[CallerNumber], CpuStateDisabled); + } + // + // Save new BSP number + // + CpuMpData->BspNumber = (UINT32) ProcessorNumber; + + return EFI_SUCCESS; +} /** This return the handle number for the calling processor. This service may be diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h index 84e09702b9..bfc7fb72e0 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.h +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h @@ -42,6 +42,23 @@ 0x58eb6a19, 0x3699, 0x4c68, { 0xa8, 0x36, 0xda, 0xcd, 0x8e, 0xdc, 0xad, 0x4a } \ } +// +// The MP data for switch BSP +// +#define CPU_SWITCH_STATE_IDLE 0 +#define CPU_SWITCH_STATE_STORED 1 +#define CPU_SWITCH_STATE_LOADED 2 + +// +// CPU exchange information for switch BSP +// +typedef struct { + UINT8 State; // offset 0 + UINTN StackPointer; // offset 4 / 8 + IA32_DESCRIPTOR Gdtr; // offset 8 / 16 + IA32_DESCRIPTOR Idtr; // offset 14 / 26 +} CPU_EXCHANGE_ROLE_INFO; + // // AP loop state when APs are in idle state // It's value is the same with PcdCpuApLoopMode @@ -198,6 +215,9 @@ struct _CPU_MP_DATA { AP_INIT_STATE InitFlag; BOOLEAN X2ApicEnable; + BOOLEAN SwitchBspFlag; + CPU_EXCHANGE_ROLE_INFO BSPInfo; + CPU_EXCHANGE_ROLE_INFO APInfo; MTRR_SETTINGS MtrrTable; UINT8 ApLoopMode; UINT8 ApTargetCState; @@ -242,6 +262,22 @@ AsmGetAddressMap ( OUT MP_ASSEMBLY_ADDRESS_MAP *AddressMap ); +/** + This function is called by both the BSP and the AP which is to become the BSP to + Exchange execution context including stack between them. After return from this + function, the BSP becomes AP and the AP becomes the BSP. + + @param[in] MyInfo Pointer to buffer holding the exchanging information for the executing processor. + @param[in] OthersInfo Pointer to buffer holding the exchanging information for the peer. + +**/ +VOID +EFIAPI +AsmExchangeRole ( + IN CPU_EXCHANGE_ROLE_INFO *MyInfo, + IN CPU_EXCHANGE_ROLE_INFO *OthersInfo + ); + /** Get the pointer to CPU MP Data structure. @@ -311,6 +347,23 @@ InitMpGlobalData ( IN CPU_MP_DATA *CpuMpData ); +/** + Worker function to switch the requested AP to be the BSP from that point onward. + + @param[in] ProcessorNumber The handle number of AP that is to become the new BSP. + @param[in] EnableOldBSP If TRUE, then the old BSP will be listed as an + enabled AP. Otherwise, it will be disabled. + + @retval EFI_SUCCESS BSP successfully switched. + @retval others Failed to switch BSP. + +**/ +EFI_STATUS +SwitchBSPWorker ( + IN UINTN ProcessorNumber, + IN BOOLEAN EnableOldBSP + ); + /** Get pointer to CPU MP Data structure from GUIDed HOB. diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c index a7e1cdeac1..cdec0108c5 100644 --- a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c @@ -563,7 +563,7 @@ MpInitLibSwitchBSP ( IN BOOLEAN EnableOldBSP ) { - return EFI_UNSUPPORTED; + return SwitchBSPWorker (ProcessorNumber, EnableOldBSP); } /** -- 2.39.2