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| author | Jeff Fan <jeff.fan@intel.com> | 2015-12-18 03:23:53 +0000 |
|---|---|---|
| committer | vanjeff <vanjeff@Edk2> | 2015-12-18 03:23:53 +0000 |
| commit | 9d39ed931bf59b8d5afdccf7e1c30ece817b7a04 (patch) | |
| tree | bf9abc4a763055c679ace5f5e121c1ab68bfdb57 /UefiCpuPkg/UefiCpuPkg.dec | |
| parent | 54a3e8c9f57935ea95b9b255cb1ca59bbc03e6ea (diff) | |
| download | edk2-9d39ed931bf59b8d5afdccf7e1c30ece817b7a04.tar.gz edk2-9d39ed931bf59b8d5afdccf7e1c30ece817b7a04.tar.bz2 edk2-9d39ed931bf59b8d5afdccf7e1c30ece817b7a04.zip | |
UefiCpuPkg: Add PCD PcdCpuApTargetCstate
This new PCD is used to specify the AP C-state value by MWAIT instruction.
More deeper C-state means more longer latency time when APs exiting from MWAIT
state. Platforms need to balance the performance and power saving to find the
proper C-state for APs.
Also, some processor may not ready for the deepest C-state at the beginning.
Platform also could choose the proper chance to place AP into the deeper C-state
by set this PCD before hand-off to OS.
Contributed-under: TianoCore Contribution Agreement 1.0
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19342 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'UefiCpuPkg/UefiCpuPkg.dec')
| -rw-r--r-- | UefiCpuPkg/UefiCpuPkg.dec | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec index 0d42918427..472b38acbc 100644 --- a/UefiCpuPkg/UefiCpuPkg.dec +++ b/UefiCpuPkg/UefiCpuPkg.dec @@ -190,6 +190,11 @@ # @Prompt The AP wait loop state.
# @ValidRange 0x80000001 | 1 - 3
gUefiCpuPkgTokenSpaceGuid.PcdCpuApLoopMode|1|UINT8|0x60008006
+ ## Specifies the AP target C-state for Mwait during POST phase.
+ # The default value 0 means C1 state.
+ # The value is defined as below.<BR><BR>
+ # @Prompt The specified AP target C-state for Mwait.
+ gUefiCpuPkgTokenSpaceGuid.PcdCpuApTargetCstate|0|UINT8|0x00000007
[PcdsDynamic, PcdsDynamicEx]
## Contains the pointer to a CPU S3 data buffer of structure ACPI_CPU_DATA.
|