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UefiCpuPkg/MpInitLib: Simplify logic in SwitchBsp

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When switch bsp, old bsp and new bsp put CR0/CR4 into stack, and put IDT
and GDT register into a structure. After they exchange their stack, they
restore these registers. This logic is now implemented by assembly code.
This patch aims to reuse (Save/Restore)VolatileRegisters function to
replace such assembly code for better code readability.

Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
This commit is contained in:
Liu, Zhiguang
2022-08-26 15:04:46 +08:00
committed by mergify[bot]
parent 76ec17526b
commit d1abb876f4
4 changed files with 56 additions and 63 deletions
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35
UefiCpuPkg/Library/MpInitLib/MpLib.c
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@ -1,7 +1,7 @@
/** @file
CPU MP Initialize Library common functions.
Copyright (c) 2016 - 2021, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2016 - 2022, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2020, AMD Inc. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@ -15,6 +15,29 @@
EFI_GUID mCpuInitMpLibHobGuid = CPU_INIT_MP_LIB_HOB_GUID;
/**
Save the volatile registers required to be restored following INIT IPI.
@param[out] VolatileRegisters Returns buffer saved the volatile resisters
**/
VOID
SaveVolatileRegisters (
OUT CPU_VOLATILE_REGISTERS *VolatileRegisters
);
/**
Restore the volatile registers following INIT IPI.
@param[in] VolatileRegisters Pointer to volatile resisters
@param[in] IsRestoreDr TRUE: Restore DRx if supported
FALSE: Do not restore DRx
**/
VOID
RestoreVolatileRegisters (
IN CPU_VOLATILE_REGISTERS *VolatileRegisters,
IN BOOLEAN IsRestoreDr
);
/**
The function will check if BSP Execute Disable is enabled.
@ -83,7 +106,12 @@ FutureBSPProc (
CPU_MP_DATA *DataInHob;
DataInHob = (CPU_MP_DATA *)Buffer;
//
// Save and restore volatile registers when switch BSP
//
SaveVolatileRegisters (&DataInHob->APInfo.VolatileRegisters);
AsmExchangeRole (&DataInHob->APInfo, &DataInHob->BSPInfo);
RestoreVolatileRegisters (&DataInHob->APInfo.VolatileRegisters, FALSE);
}
/**
@ -2233,7 +2261,12 @@ SwitchBSPWorker (
//
WakeUpAP (CpuMpData, FALSE, ProcessorNumber, FutureBSPProc, CpuMpData, TRUE);
//
// Save and restore volatile registers when switch BSP
//
SaveVolatileRegisters (&CpuMpData->BSPInfo.VolatileRegisters);
AsmExchangeRole (&CpuMpData->BSPInfo, &CpuMpData->APInfo);
RestoreVolatileRegisters (&CpuMpData->BSPInfo.VolatileRegisters, FALSE);
//
// Set the BSP bit of MSR_IA32_APIC_BASE on new BSP