Revision: 19359
http://sourceforge.net/p/edk2/code/19359
Author: vanjeff
Date: 2015-12-18 05:47:48 +0000 (Fri, 18 Dec 2015)
Log Message:
-----------
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.
(Sync patch r19342 from main trunk.)
Contributed-under: TianoCore Contribution Agreement 1.0
Cc: Feng Tian <[email protected]>
Cc: Michael Kinney <[email protected]>
Cc: Jordan Justen <[email protected]>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <[email protected]>
Reviewed-by: Michael Kinney <[email protected]>
Revision Links:
--------------
http://sourceforge.net/p/edk2/code/19342
Modified Paths:
--------------
branches/UDK2015/UefiCpuPkg/UefiCpuPkg.dec
branches/UDK2015/UefiCpuPkg/UefiCpuPkg.uni
Modified: branches/UDK2015/UefiCpuPkg/UefiCpuPkg.dec
===================================================================
--- branches/UDK2015/UefiCpuPkg/UefiCpuPkg.dec 2015-12-18 05:47:12 UTC (rev
19358)
+++ branches/UDK2015/UefiCpuPkg/UefiCpuPkg.dec 2015-12-18 05:47:48 UTC (rev
19359)
@@ -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.
Modified: branches/UDK2015/UefiCpuPkg/UefiCpuPkg.uni
===================================================================
--- branches/UDK2015/UefiCpuPkg/UefiCpuPkg.uni 2015-12-18 05:47:12 UTC (rev
19358)
+++ branches/UDK2015/UefiCpuPkg/UefiCpuPkg.uni 2015-12-18 05:47:48 UTC (rev
19359)
@@ -288,4 +288,12 @@
++++ \ No newline at end of file
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