Re: [Patch v3 1/6] UefiCpuPkg/RegisterCpuFeaturesLib: Add "Test Then Write" Macros.

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

Hi Liming & Star,

> -----Original Message-----
> From: Gao, Liming
> Sent: Friday, August 16, 2019 11:44 AM
> To: Dong, Eric <eric.dong@intel.com>; Zeng, Star <star.zeng@intel.com>;
> devel@edk2.groups.io
> Cc: Ni, Ray <ray.ni@intel.com>; Laszlo Ersek <lersek@redhat.com>; Yao,
> Jiewen <jiewen.yao@intel.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>
> Subject: RE: [Patch v3 1/6] UefiCpuPkg/RegisterCpuFeaturesLib: Add "Test
> Then Write" Macros.
> 
> Eric:
> 
> >-----Original Message-----
> >From: Dong, Eric
> >Sent: Friday, August 16, 2019 10:20 AM
> >To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> >Cc: Ni, Ray <ray.ni@intel.com>; Laszlo Ersek <lersek@redhat.com>; Yao,
> >Jiewen <jiewen.yao@intel.com>; Gao, Liming <liming.gao@intel.com>;
> >Kinney, Michael D <michael.d.kinney@intel.com>
> >Subject: RE: [Patch v3 1/6] UefiCpuPkg/RegisterCpuFeaturesLib: Add
> >"Test Then Write" Macros.
> >
> >
> >
> >> -----Original Message-----
> >> From: Zeng, Star
> >> Sent: Friday, August 16, 2019 10:08 AM
> >> To: Dong, Eric <eric.dong@intel.com>; devel@edk2.groups.io
> >> Cc: Ni, Ray <ray.ni@intel.com>; Laszlo Ersek <lersek@redhat.com>;
> >> Yao, Jiewen <jiewen.yao@intel.com>; Gao, Liming
> >> <liming.gao@intel.com>;
> >Kinney,
> >> Michael D <michael.d.kinney@intel.com>; Zeng, Star
> >> <star.zeng@intel.com>
> >> Subject: RE: [Patch v3 1/6] UefiCpuPkg/RegisterCpuFeaturesLib: Add
> >> "Test Then Write" Macros.
> >>
> >>
> >>
> >> > -----Original Message-----
> >> > From: Dong, Eric
> >> > Sent: Friday, August 16, 2019 9:27 AM
> >> > To: Zeng, Star <star.zeng@intel.com>; devel@edk2.groups.io
> >> > Cc: Ni, Ray <ray.ni@intel.com>; Laszlo Ersek <lersek@redhat.com>
> >> > Subject: RE: [Patch v3 1/6] UefiCpuPkg/RegisterCpuFeaturesLib: Add
> >> > "Test Then Write" Macros.
> >> >
> >> > > -----Original Message-----
> >> > > From: Zeng, Star
> >> > > Sent: Friday, August 16, 2019 9:15 AM
> >> > > To: Dong, Eric <eric.dong@intel.com>; devel@edk2.groups.io
> >> > > Cc: Ni, Ray <ray.ni@intel.com>; Laszlo Ersek <lersek@redhat.com>;
> >> > > Zeng, Star <star.zeng@intel.com>
> >> > > Subject: RE: [Patch v3 1/6] UefiCpuPkg/RegisterCpuFeaturesLib:
> >> > > Add "Test Then Write" Macros.
> >> > >
> >> > >
> >> > >
> >> > > > -----Original Message-----
> >> > > > From: Dong, Eric
> >> > > > Sent: Thursday, August 15, 2019 10:51 AM
> >> > > > To: devel@edk2.groups.io
> >> > > > Cc: Ni, Ray <ray.ni@intel.com>; Laszlo Ersek
> >> > > > <lersek@redhat.com>; Zeng, Star <star.zeng@intel.com>
> >> > > > Subject: [Patch v3 1/6] UefiCpuPkg/RegisterCpuFeaturesLib: Add
> >> > > > "Test Then Write" Macros.
> >> > > >
> >> > > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2040
> >> > > >
> >> > > > Add below new micros which test the current value before write
> >> > > > the new value. Only write new value when current value not same
> >> > > > as new
> >> > value.
> >> > > >   CPU_REGISTER_TABLE_TEST_THEN_WRITE32
> >> > > >   CPU_REGISTER_TABLE_TEST_THEN_WRITE64
> >> > > >   CPU_REGISTER_TABLE_TEST_THEN_WRITE_FIELD
> >> > > >
> >> > > > Also add below API:
> >> > > >   CpuRegisterTableTestThenWrite
> >> > > >
> >> > > > Signed-off-by: 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>
> >> > > > ---
> >> > > >  UefiCpuPkg/Include/AcpiCpuData.h              |  1 +
> >> > > >  .../Include/Library/RegisterCpuFeaturesLib.h  | 91
> >> > +++++++++++++++++++
> >> > > >  .../RegisterCpuFeaturesLib.c                  | 45 ++++++++-
> >> > > >  3 files changed, 134 insertions(+), 3 deletions(-)
> >> > > >
> >> > > > diff --git a/UefiCpuPkg/Include/AcpiCpuData.h
> >> > > > b/UefiCpuPkg/Include/AcpiCpuData.h
> >> > > > index b963a2f592..472a1a8070 100644
> >> > > > --- a/UefiCpuPkg/Include/AcpiCpuData.h
> >> > > > +++ b/UefiCpuPkg/Include/AcpiCpuData.h
> >> > > > @@ -81,6 +81,7 @@ typedef struct {
> >> > > >    UINT16         Reserved;              // offset 10 - 11
> >> > > >    UINT32         HighIndex;             // offset 12-15, only valid for
> >> > MemoryMapped
> >> > > >    UINT64         Value;                 // offset 16-23
> >> > > > +  UINT8          TestThenWrite;           // 0ffset 24
> >> > >
> >> > > Could we use one byte of the Reserved field, but not add new field?
> >> > > And use BOOLEAN type for it?
> >> >
> >> > I'm not sure whether use the Reserved field is an correct approach,
> >> > do you have samples which use the reserved fields?
> >> > But I think add new field is a more safe one.
> >>
> >> What "more safe" means here? Adding new field extends the structure,
> >from
> >> the structure layout view of point, it is an incompatible change, the
> >> structure size is not just from 24 to 25 bytes, but to be nature
> >> aligned, the structure
> >size
> >> will be (24 + 8) 32. Since there is Reserved field can be reused,
> >> that size
> >impact
> >> can be removed.
> >
> >Yes, agree the size impact. I'm just not clear whether the Reserved
> >field can be used. Whether it has compatible impact.
> >
> >>
> >> FspGlobalData.h:
> >> SHA-1: a2e61f341d26a78751b2f19b5004c6bbfc8b4fa9
> >> * IntelFsp2Pkg: Support FSP Dispatch mode
> >>
> >> MemoryProfile.h
> >> SHA-1: 072a3ca1d36a42aec97f871c808776ee7038ca06 (related to
> >> 94092aa60341a3e4b1e1ea7c362781b8404ac538)
> >> * MdeModulePkg MemoryProfile.h:two bytes of Reserved[4] as
> >> ActionStringOffset
> >>
> >
> >If so many examples already did it. I think we can also do it.
> >
> >>
> >> If needed, more comments from Ray, Laszlo, Jiewen, Liming and Mike
> >> will
> >be
> >> better.
> >
> >Yes, I think we need get more comments from them.
> 
> I think to reuse the reserved field is a good solution.
> 

Thanks for this valuable input, I will send V4 patch to use Reserved field.

Thanks,
Eric
 

> Thanks
> Liming
> >
> >Thanks,
> >Eric
> >>
> >>
> >> Thanks,
> >> Star
> >>
> >> >
> >> > Thanks,
> >> > Eric
> >> > >
> >> > > Thanks,
> >> > > Star
> >> > >
> >> > > >  } CPU_REGISTER_TABLE_ENTRY;
> >> > > >
> >> > > >  //
> >> > > > diff --git
> >> > > > a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> >> > > > b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> >> > > > index e420e7f075..5bd464b32e 100644
> >> > > > --- a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> >> > > > +++ b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
> >> > > > @@ -348,6 +348,32 @@ CpuRegisterTableWrite (
> >> > > >    IN UINT64              Value
> >> > > >    );
> >> > > >
> >> > > > +/**
> >> > > > +  Adds an entry in specified register table.
> >> > > > +
> >> > > > +  This function adds an entry in specified register table,
> >> > > > + with given register type,  register index, bit section and value.
> >> > > > +
> >> > > > +  Driver will  test the current value before setting new value.
> >> > > > +
> >> > > > +  @param[in]  ProcessorNumber  The index of the CPU to add a
> >> > > > + register
> >> > > > table entry
> >> > > > +  @param[in]  RegisterType     Type of the register to program
> >> > > > +  @param[in]  Index            Index of the register to program
> >> > > > +  @param[in]  ValueMask        Mask of bits in register to write
> >> > > > +  @param[in]  Value            Value to write
> >> > > > +
> >> > > > +  @note This service could be called by BSP only.
> >> > > > +**/
> >> > > > +VOID
> >> > > > +EFIAPI
> >> > > > +CpuRegisterTableTestThenWrite (
> >> > > > +  IN UINTN               ProcessorNumber,
> >> > > > +  IN REGISTER_TYPE       RegisterType,
> >> > > > +  IN UINT64              Index,
> >> > > > +  IN UINT64              ValueMask,
> >> > > > +  IN UINT64              Value
> >> > > > +  );
> >> > > > +
> >> > > >  /**
> >> > > >    Adds an entry in specified Pre-SMM register table.
> >> > > >
> >> > > > @@ -390,6 +416,26 @@ PreSmmCpuRegisterTableWrite (
> >> > > >      CpuRegisterTableWrite (ProcessorNumber, RegisterType,
> >> > > > Index, MAX_UINT32, Value);  \
> >> > > >    } while(FALSE);
> >> > > >
> >> > > > +/**
> >> > > > +  Adds a 32-bit register write entry in specified register table.
> >> > > > +
> >> > > > +  This macro adds an entry in specified register table, with
> >> > > > + given register type,  register index, and value.
> >> > > > +
> >> > > > +  Driver will  test the current value before setting new value.
> >> > > > +
> >> > > > +  @param[in]  ProcessorNumber  The index of the CPU to add a
> >> > > > + register
> >> > > > table entry.
> >> > > > +  @param[in]  RegisterType     Type of the register to program
> >> > > > +  @param[in]  Index            Index of the register to program
> >> > > > +  @param[in]  Value            Value to write
> >> > > > +
> >> > > > +  @note This service could be called by BSP only.
> >> > > > +**/
> >> > > > +#define
> >> > CPU_REGISTER_TABLE_TEST_THEN_WRITE32(ProcessorNumber,
> >> > > > RegisterType, Index, Value)     \
> >> > > > +  do {                                                                                        \
> >> > > > +    CpuRegisterTableTestThenWrite (ProcessorNumber,
> >> > > > +RegisterType, Index, MAX_UINT32, Value);  \
> >> > > > +  } while(FALSE);
> >> > > > +
> >> > > >  /**
> >> > > >    Adds a 64-bit register write entry in specified register table.
> >> > > >
> >> > > > @@ -408,6 +454,26 @@ PreSmmCpuRegisterTableWrite (
> >> > > >      CpuRegisterTableWrite (ProcessorNumber, RegisterType,
> >> > > > Index, MAX_UINT64, Value);  \
> >> > > >    } while(FALSE);
> >> > > >
> >> > > > +/**
> >> > > > +  Adds a 64-bit register write entry in specified register table.
> >> > > > +
> >> > > > +  This macro adds an entry in specified register table, with
> >> > > > + given register type,  register index, and value.
> >> > > > +
> >> > > > +  Driver will  test the current value before setting new value.
> >> > > > +
> >> > > > +  @param[in]  ProcessorNumber  The index of the CPU to add a
> >> > > > + register
> >> > > > table entry.
> >> > > > +  @param[in]  RegisterType     Type of the register to program
> >> > > > +  @param[in]  Index            Index of the register to program
> >> > > > +  @param[in]  Value            Value to write
> >> > > > +
> >> > > > +  @note This service could be called by BSP only.
> >> > > > +**/
> >> > > > +#define
> >> > CPU_REGISTER_TABLE_TEST_THEN_WRITE64(ProcessorNumber,
> >> > > > RegisterType, Index, Value)     \
> >> > > > +  do {                                                                                        \
> >> > > > +    CpuRegisterTableTestThenWrite (ProcessorNumber,
> >> > > > +RegisterType, Index, MAX_UINT64, Value);  \
> >> > > > +  } while(FALSE);
> >> > > > +
> >> > > >  /**
> >> > > >    Adds a bit field write entry in specified register table.
> >> > > >
> >> > > > @@ -431,6 +497,31 @@ PreSmmCpuRegisterTableWrite (
> >> > > >      CpuRegisterTableWrite (ProcessorNumber, RegisterType, Index,
> >> > > > ~ValueMask, Value);             \
> >> > > >    } while(FALSE);
> >> > > >
> >> > > > +/**
> >> > > > +  Adds a bit field write entry in specified register table.
> >> > > > +
> >> > > > +  This macro adds an entry in specified register table, with
> >> > > > + given register type,  register index, bit field section, and value.
> >> > > > +
> >> > > > +  Driver will  test the current value before setting new value.
> >> > > > +
> >> > > > +  @param[in]  ProcessorNumber  The index of the CPU to add a
> >> > > > + register
> >> > > > table entry.
> >> > > > +  @param[in]  RegisterType     Type of the register to program.
> >> > > > +  @param[in]  Index            Index of the register to program.
> >> > > > +  @param[in]  Type             The data type name of a register structure.
> >> > > > +  @param[in]  Field            The bit fiel name in register structure to
> >write.
> >> > > > +  @param[in]  Value            Value to write to the bit field.
> >> > > > +
> >> > > > +  @note This service could be called by BSP only.
> >> > > > +**/
> >> > > > +#define
> >> > > > CPU_REGISTER_TABLE_TEST_THEN_WRITE_FIELD(ProcessorNumber,
> >> > > > RegisterType, Index, Type, Field, Value) \
> >> > > > +  do {                                                                                                     \
> >> > > > +    UINT64  ValueMask;                                                                                     \
> >> > > > +    ValueMask = MAX_UINT64;
> >> \
> >> > > > +    ((Type *)(&ValueMask))->Field = 0;
> >> > \
> >> > > > +    CpuRegisterTableTestThenWrite (ProcessorNumber,
> >> > > > + RegisterType, Index,
> >> > > > ~ValueMask, Value);               \
> >> > > > +  } while(FALSE);
> >> > > > +
> >> > > >  /**
> >> > > >    Adds a 32-bit register write entry in specified register table.
> >> > > >
> >> > > > diff --git
> >> > > >
> >a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib
> >> > > > .c
> >> > > >
> >b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib
> >> > > > .c index 67885bf69b..e9769882b9 100644
> >> > > > ---
> >> > > >
> >a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib
> >> > > > .c
> >> > > > +++
> >> > > >
> >b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/RegisterCpuFeaturesLib
> >> > > > .c @@ -1025,6 +1025,8 @@ EnlargeRegisterTable (
> >> > > >    @param[in]  ValidBitStart    Start of the bit section
> >> > > >    @param[in]  ValidBitLength   Length of the bit section
> >> > > >    @param[in]  Value            Value to write
> >> > > > +  @param[in]  TestThenWrite    Whether need to test current Value
> >> > before
> >> > > > writing.
> >> > > > +
> >> > > >  **/
> >> > > >  VOID
> >> > > >  CpuRegisterTableWriteWorker (
> >> > > > @@ -1034,7 +1036,8 @@ CpuRegisterTableWriteWorker (
> >> > > >    IN UINT64                  Index,
> >> > > >    IN UINT8                   ValidBitStart,
> >> > > >    IN UINT8                   ValidBitLength,
> >> > > > -  IN UINT64                  Value
> >> > > > +  IN UINT64                  Value,
> >> > > > +  IN UINT8                   TestThenWrite
> >> > > >    )
> >> > > >  {
> >> > > >    CPU_FEATURES_DATA        *CpuFeaturesData;
> >> > > > @@ -1070,6 +1073,7 @@ CpuRegisterTableWriteWorker (
> >> > > >    RegisterTableEntry[RegisterTable->TableLength].ValidBitStart
> >> > > > = ValidBitStart;
> >> > > >
> >> > > > RegisterTableEntry[RegisterTable->TableLength].ValidBitLength =
> ValidBitLength;
> >> > > >    RegisterTableEntry[RegisterTable->TableLength].Value          = Value;
> >> > > > +  RegisterTableEntry[RegisterTable->TableLength].TestThenWrite
> >> > > > + = TestThenWrite;
> >> > > >
> >> > > >    RegisterTable->TableLength++;  } @@ -1105,7 +1109,42 @@
> >> > > > CpuRegisterTableWrite (
> >> > > >    Start  = (UINT8)LowBitSet64  (ValueMask);
> >> > > >    End    = (UINT8)HighBitSet64 (ValueMask);
> >> > > >    Length = End - Start + 1;
> >> > > > -  CpuRegisterTableWriteWorker (FALSE, ProcessorNumber,
> >> > > > RegisterType, Index, Start, Length, Value);
> >> > > > +  CpuRegisterTableWriteWorker (FALSE, ProcessorNumber,
> >> > > > +RegisterType, Index, Start, Length, Value, FALSE); }
> >> > > > +
> >> > > > +/**
> >> > > > +  Adds an entry in specified register table.
> >> > > > +
> >> > > > +  This function adds an entry in specified register table,
> >> > > > + with given register type,  register index, bit section and value.
> >> > > > +
> >> > > > +  @param[in]  ProcessorNumber  The index of the CPU to add a
> >> > > > + register
> >> > > > table entry
> >> > > > +  @param[in]  RegisterType     Type of the register to program
> >> > > > +  @param[in]  Index            Index of the register to program
> >> > > > +  @param[in]  ValueMask        Mask of bits in register to write
> >> > > > +  @param[in]  Value            Value to write
> >> > > > +  @param[in]  TestThenWrite    Whether need to test current Value
> >> > before
> >> > > > writing.
> >> > > > +
> >> > > > +  @note This service could be called by BSP only.
> >> > > > +**/
> >> > > > +VOID
> >> > > > +EFIAPI
> >> > > > +CpuRegisterTableTestThenWrite (
> >> > > > +  IN UINTN               ProcessorNumber,
> >> > > > +  IN REGISTER_TYPE       RegisterType,
> >> > > > +  IN UINT64              Index,
> >> > > > +  IN UINT64              ValueMask,
> >> > > > +  IN UINT64              Value
> >> > > > +  )
> >> > > > +{
> >> > > > +  UINT8                   Start;
> >> > > > +  UINT8                   End;
> >> > > > +  UINT8                   Length;
> >> > > > +
> >> > > > +  Start  = (UINT8)LowBitSet64  (ValueMask);
> >> > > > +  End    = (UINT8)HighBitSet64 (ValueMask);
> >> > > > +  Length = End - Start + 1;
> >> > > > +  CpuRegisterTableWriteWorker (FALSE, ProcessorNumber,
> >> > > > + RegisterType, Index, Start, Length, Value, TRUE);
> >> > > >  }
> >> > > >
> >> > > >  /**
> >> > > > @@ -1139,7 +1178,7 @@ PreSmmCpuRegisterTableWrite (
> >> > > >    Start  = (UINT8)LowBitSet64  (ValueMask);
> >> > > >    End    = (UINT8)HighBitSet64 (ValueMask);
> >> > > >    Length = End - Start + 1;
> >> > > > -  CpuRegisterTableWriteWorker (TRUE, ProcessorNumber,
> >> > > > RegisterType, Index, Start, Length, Value);
> >> > > > +  CpuRegisterTableWriteWorker (TRUE, ProcessorNumber,
> >> > > > + RegisterType, Index, Start, Length, Value, FALSE);
> >> > > >  }
> >> > > >
> >> > > >  /**
> >> > > > --
> >> > > > 2.21.0.windows.1