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

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

> -----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.

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