MtrrSetMemoryAttributesInMtrrSettings() is a batch-set API. When setting multiple ranges of memory attributes, the single-set API (MtrrSetMemoryAttributeInMtrrSettings and MtrrSetMemoryAttribute) may fail, but batch-set API may succeed. Add comments to recommend caller to use batch-set API when setting multiple ranges.
Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni <[email protected]> Cc: Ming Shao <[email protected]> --- UefiCpuPkg/Include/Library/MtrrLib.h | 10 ++++++++++ UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 10 ++++++++++ 2 files changed, 20 insertions(+) diff --git a/UefiCpuPkg/Include/Library/MtrrLib.h b/UefiCpuPkg/Include/Library/MtrrLib.h index d56f1057e1..f82c27ea0c 100644 --- a/UefiCpuPkg/Include/Library/MtrrLib.h +++ b/UefiCpuPkg/Include/Library/MtrrLib.h @@ -157,6 +157,11 @@ GetFirmwareVariableMtrrCount ( @retval RETURN_OUT_OF_RESOURCES There are not enough system resources to modify the attributes of the memory resource range. + Multiple memory range attributes setting by calling this API multiple + times may fail with status RETURN_OUT_OF_RESOURCES. It may not mean + the number of CPU MTRRs are too small to set such memory attributes. + Pass the multiple memory range attributes to one call of + MtrrSetMemoryAttributesInMtrrSettings() may succeed. @retval RETURN_BUFFER_TOO_SMALL The fixed internal scratch buffer is too small for MTRR calculation. Caller should use MtrrSetMemoryAttributesInMtrrSettings() to specify external scratch buffer. @@ -354,6 +359,11 @@ MtrrGetDefaultMemoryType ( BaseAddress and Length cannot be modified. @retval RETURN_OUT_OF_RESOURCES There are not enough system resources to modify the attributes of the memory resource range. + Multiple memory range attributes setting by calling this API multiple + times may fail with status RETURN_OUT_OF_RESOURCES. It may not mean + the number of CPU MTRRs are too small to set such memory attributes. + Pass the multiple memory range attributes to one call of + MtrrSetMemoryAttributesInMtrrSettings() may succeed. @retval RETURN_BUFFER_TOO_SMALL The fixed internal scratch buffer is too small for MTRR calculation. Caller should use MtrrSetMemoryAttributesInMtrrSettings() to specify external scratch buffer. diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c index 2496d08ad4..dfce9a996b 100644 --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c @@ -2513,6 +2513,11 @@ Exit: BaseAddress and Length cannot be modified. @retval RETURN_OUT_OF_RESOURCES There are not enough system resources to modify the attributes of the memory resource range. + Multiple memory range attributes setting by calling this API multiple + times may fail with status RETURN_OUT_OF_RESOURCES. It may not mean + the number of CPU MTRRs are too small to set such memory attributes. + Pass the multiple memory range attributes to one call of + MtrrSetMemoryAttributesInMtrrSettings() may succeed. @retval RETURN_BUFFER_TOO_SMALL The fixed internal scratch buffer is too small for MTRR calculation. Caller should use MtrrSetMemoryAttributesInMtrrSettings() to specify external scratch buffer. @@ -2561,6 +2566,11 @@ MtrrSetMemoryAttributeInMtrrSettings ( @retval RETURN_OUT_OF_RESOURCES There are not enough system resources to modify the attributes of the memory resource range. + Multiple memory range attributes setting by calling this API multiple + times may fail with status RETURN_OUT_OF_RESOURCES. It may not mean + the number of CPU MTRRs are too small to set such memory attributes. + Pass the multiple memory range attributes to one call of + MtrrSetMemoryAttributesInMtrrSettings() may succeed. @retval RETURN_BUFFER_TOO_SMALL The fixed internal scratch buffer is too small for MTRR calculation. Caller should use MtrrSetMemoryAttributesInMtrrSettings() to specify external scratch buffer. -- 2.15.1.windows.2 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
