Re: [Patch] UefiCpuPkg/MpInitLib: Avoid call PcdGe* in Ap & Bsp.

["Ni, Ruiyu" <ruiyu.ni@intel.com>]

With the subject change suggested by Laszlo, Reviewed-by: Ruiyu Ni <Ruiyu.ni@Intel.com>

Thanks/Ray

> -----Original Message-----
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Thursday, October 19, 2017 4:08 PM
> To: Dong, Eric <eric.dong@intel.com>; edk2-devel@lists.01.org
> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Crystal Lee <CrystalLee@ami.com.tw>
> Subject: Re: [edk2] [Patch] UefiCpuPkg/MpInitLib: Avoid call PcdGe* in Ap &
> Bsp.
> 
> On 10/19/17 04:42, Eric Dong wrote:
> > MicrocodeDetect function will run by every threads, and it will use
> > PcdGet to get PcdCpuMicrocodePatchAddress and
> > PcdCpuMicrocodePatchRegionSize, if change both PCD default to dynamic,
> > system will in non-deterministic behavior.
> >
> > By design, UEFI/PI services are single threaded and not re-entrant so
> > Multi processor code should not use UEFI/PI services. Here, Pcd
> > protocol/PPI is used to access dynamic PCDs so it would result in
> > non-deterministic behavior.
> >
> > This code get PCD value in BSP and save them in CPU_MP_DATA for Ap.
> >
> > https://bugzilla.tianocore.org/show_bug.cgi?id=726
> >
> > Cc: Crystal Lee <CrystalLee@ami.com.tw>
> > Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Eric Dong <eric.dong@intel.com>
> > ---
> >  UefiCpuPkg/Library/MpInitLib/Microcode.c | 10 +++-------
> >  UefiCpuPkg/Library/MpInitLib/MpLib.c     |  2 ++
> >  UefiCpuPkg/Library/MpInitLib/MpLib.h     |  2 ++
> >  3 files changed, 7 insertions(+), 7 deletions(-)
> 
> Eric, can you please fix up the subject line after you get an R-b and are about
> to push the patch?
> 
> -UefiCpuPkg/MpInitLib: Avoid call PcdGe* in Ap & Bsp.
> +UefiCpuPkg/MpInitLib: Avoid call PcdGet* in Ap & Bsp.
> 
> Thanks!
> Laszlo
> 
> 
> > diff --git a/UefiCpuPkg/Library/MpInitLib/Microcode.c
> > b/UefiCpuPkg/Library/MpInitLib/Microcode.c
> > index 982995b..35f66f7 100644
> > --- a/UefiCpuPkg/Library/MpInitLib/Microcode.c
> > +++ b/UefiCpuPkg/Library/MpInitLib/Microcode.c
> > @@ -42,8 +42,6 @@ MicrocodeDetect (
> >    IN CPU_MP_DATA             *CpuMpData
> >    )
> >  {
> > -  UINT64                                  MicrocodePatchAddress;
> > -  UINT64                                  MicrocodePatchRegionSize;
> >    UINT32                                  ExtendedTableLength;
> >    UINT32                                  ExtendedTableCount;
> >    CPU_MICROCODE_EXTENDED_TABLE            *ExtendedTable;
> > @@ -61,9 +59,7 @@ MicrocodeDetect (
> >    VOID                                    *MicrocodeData;
> >    MSR_IA32_PLATFORM_ID_REGISTER           PlatformIdMsr;
> >
> > -  MicrocodePatchAddress    = PcdGet64 (PcdCpuMicrocodePatchAddress);
> > -  MicrocodePatchRegionSize = PcdGet64
> > (PcdCpuMicrocodePatchRegionSize);
> > -  if (MicrocodePatchRegionSize == 0) {
> > +  if (CpuMpData->MicrocodePatchRegionSize == 0) {
> >      //
> >      // There is no microcode patches
> >      //
> > @@ -93,8 +89,8 @@ MicrocodeDetect (
> >
> >    LatestRevision = 0;
> >    MicrocodeData  = NULL;
> > -  MicrocodeEnd = (UINTN) (MicrocodePatchAddress +
> > MicrocodePatchRegionSize);
> > -  MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *) (UINTN)
> > MicrocodePatchAddress;
> > +  MicrocodeEnd = (UINTN) (CpuMpData->MicrocodePatchAddress +
> > + CpuMpData->MicrocodePatchRegionSize);
> > +  MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *) (UINTN)
> > + CpuMpData->MicrocodePatchAddress;
> >    do {
> >      //
> >      // Check if the microcode is for the Cpu and the version is newer
> > diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> > b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> > index 924b909..f3ee6d4 100644
> > --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> > +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> > @@ -1458,6 +1458,8 @@ MpInitLibInitialize (
> >    CpuMpData->SwitchBspFlag    = FALSE;
> >    CpuMpData->CpuData          = (CPU_AP_DATA *) (CpuMpData + 1);
> >    CpuMpData->CpuInfoInHob     = (UINT64) (UINTN) (CpuMpData-
> >CpuData + MaxLogicalProcessorNumber);
> > +  CpuMpData->MicrocodePatchAddress    = PcdGet64
> (PcdCpuMicrocodePatchAddress);
> > +  CpuMpData->MicrocodePatchRegionSize = PcdGet64
> > + (PcdCpuMicrocodePatchRegionSize);
> >    InitializeSpinLock(&CpuMpData->MpLock);
> >    //
> >    // Save BSP's Control registers to APs diff --git
> > a/UefiCpuPkg/Library/MpInitLib/MpLib.h
> > b/UefiCpuPkg/Library/MpInitLib/MpLib.h
> > index 19defda..84ae24f 100644
> > --- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
> > +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
> > @@ -233,6 +233,8 @@ struct _CPU_MP_DATA {
> >    UINT8                          Vector;
> >    BOOLEAN                        PeriodicMode;
> >    BOOLEAN                        TimerInterruptState;
> > +  UINT64                         MicrocodePatchAddress;
> > +  UINT64                         MicrocodePatchRegionSize;
> >  };
> >
> >  extern EFI_GUID mCpuInitMpLibHobGuid;
> >