diff options
| author | Ruiyu Ni <ruiyu.ni@intel.com> | 2018-01-18 14:13:32 +0800 |
|---|---|---|
| committer | Ruiyu Ni <ruiyu.ni@intel.com> | 2018-01-24 11:13:17 +0800 |
| commit | bc6a8b78aa77cf63aa896c5dba0d948d4eebfa73 (patch) | |
| tree | 534c8a6d5b2996e018ee545ac256a9a52d9d3fd6 /UefiCpuPkg/Include/Library | |
| parent | 8b2eb7b3f62b1946cdd76e6f7758e106fcf71477 (diff) | |
| download | edk2-bc6a8b78aa77cf63aa896c5dba0d948d4eebfa73.tar.gz edk2-bc6a8b78aa77cf63aa896c5dba0d948d4eebfa73.tar.bz2 edk2-bc6a8b78aa77cf63aa896c5dba0d948d4eebfa73.zip | |
UefiCpuPkg/MtrrLib: Add comments to recommend to use batch-set API
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 <ruiyu.ni@intel.com>
Reviewed-by: Ming Shao <ming.shao@intel.com>
Diffstat (limited to 'UefiCpuPkg/Include/Library')
| -rw-r--r-- | UefiCpuPkg/Include/Library/MtrrLib.h | 10 |
1 files changed, 10 insertions, 0 deletions
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.
|