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

["Liming Gao" <liming.gao@intel.com>]

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
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