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
# @Prompt The AP wait loop state.\r
# @ValidRange 0x80000001 | 1 - 3\r
gUefiCpuPkgTokenSpaceGuid.PcdCpuApLoopMode|1|UINT8|0x60008006\r
# @Prompt The AP wait loop state.\r
# @ValidRange 0x80000001 | 1 - 3\r
gUefiCpuPkgTokenSpaceGuid.PcdCpuApLoopMode|1|UINT8|0x60008006\r
+ ## Specifies the AP target C-state for Mwait during POST phase.\r
+ # The default value 0 means C1 state.\r
+ # The value is defined as below.<BR><BR>\r
+ # @Prompt The specified AP target C-state for Mwait.\r
+ gUefiCpuPkgTokenSpaceGuid.PcdCpuApTargetCstate|0|UINT8|0x00000007\r
\r
[PcdsDynamic, PcdsDynamicEx]\r
## Contains the pointer to a CPU S3 data buffer of structure ACPI_CPU_DATA.\r
\r
[PcdsDynamic, PcdsDynamicEx]\r
## Contains the pointer to a CPU S3 data buffer of structure ACPI_CPU_DATA.\r
\r
#string STR_gUefiCpuPkgTokenSpaceGuid_PcdCpuApLoopMode_HELP #language en-US "Specifies the AP wait loop state during POST phase."\r
\r
\r
#string STR_gUefiCpuPkgTokenSpaceGuid_PcdCpuApLoopMode_HELP #language en-US "Specifies the AP wait loop state during POST phase."\r
\r
+#string STR_gUefiCpuPkgTokenSpaceGuid_PcdCpuApTargetCstate_PROMPT #language en-US "The specified AP target C-state for Mwait"\r
+\r
+#string STR_gUefiCpuPkgTokenSpaceGuid_PcdCpuApTargetCstate_HELP #language en-US "Specifies the AP target C-state for Mwait during POST phase."\r
+\r