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

Zeng, Star
 

-----Original Message-----
From: Dong, Eric
Sent: Thursday, August 15, 2019 10:51 AM
To: devel@edk2.groups.io
Cc: Ni, Ray <ray.ni@...>; Laszlo Ersek <lersek@...>; Zeng,
Star <star.zeng@...>
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@...>
Cc: Ray Ni <ray.ni@...>
Cc: Laszlo Ersek <lersek@...>
Cc: Star Zeng <star.zeng@...>
---
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?

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

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