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UefiCpuPkg/MpInitLib: Avoid call PcdGet* in Ap & Bsp.

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MicrocodeDetect function will run by every threads, and it will
use PcdGet to get PcdCpuMicrocodePatchAddress and
PcdCpuMicrocodePatchRegionSize, if change both PCD default to dynamic,
system will in non-deterministic behavior.

By design, UEFI/PI services are single threaded and not re-entrant
so Multi processor code should not use UEFI/PI services. Here, Pcd
protocol/PPI is used to access dynamic PCDs so it would result in
non-deterministic behavior.

This code get PCD value in BSP and save them in CPU_MP_DATA for Ap.

https://bugzilla.tianocore.org/show_bug.cgi?id=726

Cc: Crystal Lee <CrystalLee@ami.com.tw>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
This commit is contained in:
Eric Dong
2017-10-19 10:40:16 +08:00
parent 3539e850eb
commit 1e3f7a3782
3 changed files with 8 additions and 8 deletions
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2
UefiCpuPkg/Library/MpInitLib/MpLib.c
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@ -1458,6 +1458,8 @@ MpInitLibInitialize (
CpuMpData->SwitchBspFlag = FALSE;
CpuMpData->CpuData = (CPU_AP_DATA *) (CpuMpData + 1);
CpuMpData->CpuInfoInHob = (UINT64) (UINTN) (CpuMpData->CpuData + MaxLogicalProcessorNumber);
CpuMpData->MicrocodePatchAddress = PcdGet64 (PcdCpuMicrocodePatchAddress);
CpuMpData->MicrocodePatchRegionSize = PcdGet64 (PcdCpuMicrocodePatchRegionSize);
InitializeSpinLock(&CpuMpData->MpLock);
//
// Save BSP's Control registers to APs