Re: [PATCH v4 6/6] UefiCpuPkg/MpInitLib: Remove redundant microcode fields in CPU_MP_DATA

["Dong, Eric" <eric.dong@intel.com>]

Reviewed-by: Eric Dong <eric.dong@intel.com>

> -----Original Message-----
> From: Wu, Hao A
> Sent: Friday, December 27, 2019 3:32 PM
> To: devel@edk2.groups.io
> Cc: Wu, Hao A <hao.a.wu@intel.com>; Dong, Eric <eric.dong@intel.com>; Ni,
> Ray <ray.ni@intel.com>; Laszlo Ersek <lersek@redhat.com>; Zeng, Star
> <star.zeng@intel.com>; Fu, Siyuan <siyuan.fu@intel.com>; Kinney, Michael
> D <michael.d.kinney@intel.com>
> Subject: [PATCH v4 6/6] UefiCpuPkg/MpInitLib: Remove redundant
> microcode fields in CPU_MP_DATA
> 
> Previous commits have introduced below fields in structure CPU_AP_DATA:
> 
>   UINT32                         ProcessorSignature;
>   UINT8                          PlatformId;
>   UINT64                         MicrocodeEntryAddr;
> 
> which store the information of:
> 
> A. CPUID
> B. Platform ID
> C. Detected microcode patch entry address (including the microcode patch
>    header)
> 
> for each processor within system.
> 
> Therefore, the below fields in structure CPU_MP_DATA:
> 
>   UINT32                         ProcessorSignature;
>   UINT32                         ProcessorFlags;
>   UINT64                         MicrocodeDataAddress;
>   UINT32                         MicrocodeRevision;
> 
> which store the BSP's information of:
> 
> A. CPUID
> B. Platform ID
> C. The address and revision of detected microcode patch
> 
> are redundant and can be removed.
> 
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Siyuan Fu <siyuan.fu@intel.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Signed-off-by: Hao A Wu <hao.a.wu@intel.com>
> ---
>  UefiCpuPkg/Library/MpInitLib/MpLib.h     |  5 --
>  UefiCpuPkg/Library/MpInitLib/Microcode.c | 51 ++++++--------------
>  2 files changed, 14 insertions(+), 42 deletions(-)
> 
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h
> b/UefiCpuPkg/Library/MpInitLib/MpLib.h
> index 5f50e79744..6609c958ce 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
> @@ -263,11 +263,6 @@ struct _CPU_MP_DATA {
>    BOOLEAN                        PeriodicMode;
>    BOOLEAN                        TimerInterruptState;
> 
> -  UINT32                         ProcessorSignature;
> -  UINT32                         ProcessorFlags;
> -  UINT64                         MicrocodeDataAddress;
> -  UINT32                         MicrocodeRevision;
> -
>    //
>    // Whether need to use Init-Sipi-Sipi to wake up the APs.
>    // Two cases need to set this value to TRUE. One is in HLT diff --git
> a/UefiCpuPkg/Library/MpInitLib/Microcode.c
> b/UefiCpuPkg/Library/MpInitLib/Microcode.c
> index 74a34c48fa..4ec54b6220 100644
> --- a/UefiCpuPkg/Library/MpInitLib/Microcode.c
> +++ b/UefiCpuPkg/Library/MpInitLib/Microcode.c
> @@ -85,6 +85,7 @@ MicrocodeDetect (
>    UINTN                                   Index;
>    UINT8                                   PlatformId;
>    CPUID_VERSION_INFO_EAX                  Eax;
> +  CPU_AP_DATA                             *CpuData;
>    UINT32                                  CurrentRevision;
>    UINT32                                  LatestRevision;
>    UINTN                                   TotalSize;
> @@ -92,16 +93,9 @@ MicrocodeDetect (
>    UINT32                                  InCompleteCheckSum32;
>    BOOLEAN                                 CorrectMicrocode;
>    VOID                                    *MicrocodeData;
> -  MSR_IA32_PLATFORM_ID_REGISTER           PlatformIdMsr;
> -  UINT32                                  ProcessorFlags;
>    UINT32                                  ThreadId;
>    BOOLEAN                                 IsBspCallIn;
> 
> -  //
> -  // set ProcessorFlags to suppress incorrect compiler/analyzer warnings
> -  //
> -  ProcessorFlags = 0;
> -
>    if (CpuMpData->MicrocodePatchRegionSize == 0) {
>      //
>      // There is no microcode patches
> @@ -127,28 +121,25 @@ MicrocodeDetect (
>    }
> 
>    ExtendedTableLength = 0;
> -  //
> -  // Here data of CPUID leafs have not been collected into context buffer, so
> -  // GetProcessorCpuid() cannot be used here to retrieve CPUID data.
> -  //
> -  AsmCpuid (CPUID_VERSION_INFO, &Eax.Uint32, NULL, NULL, NULL);
> -
> -  //
> -  // The index of platform information resides in bits 50:52 of MSR
> IA32_PLATFORM_ID
> -  //
> -  PlatformIdMsr.Uint64 = AsmReadMsr64 (MSR_IA32_PLATFORM_ID);
> -  PlatformId = (UINT8) PlatformIdMsr.Bits.PlatformId;
> +  Eax.Uint32 = CpuMpData-
> >CpuData[ProcessorNumber].ProcessorSignature;
> +  PlatformId = CpuMpData->CpuData[ProcessorNumber].PlatformId;
> 
>    //
>    // Check whether AP has same processor with BSP.
>    // If yes, direct use microcode info saved by BSP.
>    //
>    if (!IsBspCallIn) {
> -    if ((CpuMpData->ProcessorSignature == Eax.Uint32) &&
> -        (CpuMpData->ProcessorFlags & (1 << PlatformId)) != 0) {
> -        MicrocodeData = (VOID *)(UINTN) CpuMpData-
> >MicrocodeDataAddress;
> -        LatestRevision = CpuMpData->MicrocodeRevision;
> -        goto Done;
> +    //
> +    // Get the CPU data for BSP
> +    //
> +    CpuData = &(CpuMpData->CpuData[CpuMpData->BspNumber]);
> +    if ((CpuData->ProcessorSignature == Eax.Uint32) &&
> +        (CpuData->PlatformId == PlatformId) &&
> +        (CpuData->MicrocodeEntryAddr != 0)) {
> +      MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *)(UINTN) CpuData-
> >MicrocodeEntryAddr;
> +      MicrocodeData       = (VOID *) (MicrocodeEntryPoint + 1);
> +      LatestRevision      = MicrocodeEntryPoint->UpdateRevision;
> +      goto Done;
>      }
>    }
> 
> @@ -216,7 +207,6 @@ MicrocodeDetect (
>          CheckSum32 += MicrocodeEntryPoint->Checksum;
>          if (CheckSum32 == 0) {
>            CorrectMicrocode = TRUE;
> -          ProcessorFlags = MicrocodeEntryPoint->ProcessorFlags;
>          }
>        } else if ((MicrocodeEntryPoint->DataSize != 0) &&
>                   (MicrocodeEntryPoint->UpdateRevision > LatestRevision)) { @@ -
> 260,7 +250,6 @@ MicrocodeDetect (
>                      // Find one
>                      //
>                      CorrectMicrocode = TRUE;
> -                    ProcessorFlags = ExtendedTable->ProcessorFlag;
>                      break;
>                    }
>                  }
> @@ -332,18 +321,6 @@ Done:
>      CpuMpData->CpuData[ProcessorNumber].MicrocodeEntryAddr =
>        (UINTN) MicrocodeData -  sizeof (CPU_MICROCODE_HEADER);
>    }
> -
> -  if (IsBspCallIn && (LatestRevision != 0)) {
> -    //
> -    // Save BSP processor info and microcode info for later AP use.
> -    //
> -    CpuMpData->ProcessorSignature   = Eax.Uint32;
> -    CpuMpData->ProcessorFlags       = ProcessorFlags;
> -    CpuMpData->MicrocodeDataAddress = (UINTN) MicrocodeData;
> -    CpuMpData->MicrocodeRevision    = LatestRevision;
> -    DEBUG ((DEBUG_INFO, "BSP Microcode:: signature [0x%08x],
> ProcessorFlags [0x%08x], \
> -       MicroData [0x%08x], Revision [0x%08x]\n", Eax.Uint32, ProcessorFlags,
> (UINTN) MicrocodeData, LatestRevision));
> -  }
>  }
> 
>  /**
> --
> 2.12.0.windows.1