In the original design, once the APs finished executing their assembly
code and switched to executing C code, they would enter a continuous
loop within a function. In this function, they would collect CpuMpData
using the MP_CPU_EXCHANGE_INFO mechanism. However, in the updated
approach, CpuMpData can now be passed directly to the ApWakeUpFunction,
bypassing the need for MP_CPU_EXCHANGE_INFO. This modification is made
in preparation for eliminating the requirement of a second
INIT-SIPI-SIPI sequence in the DXE phase.
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
---
UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm | 4 ++--
UefiCpuPkg/Library/MpInitLib/MpLib.c | 12 +++---------
UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm | 3 +--
3 files changed, 6 insertions(+), 13 deletions(-)
diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
index 59db4081d6..d117f09ef5 100644
--- a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
@@ -197,8 +197,8 @@ CProcedureInvoke:
push ebx ; Push ApIndex
mov eax, esi
- add eax, MP_CPU_EXCHANGE_INFO_OFFSET
- push eax ; push address of exchange info data buffer
+ add eax, MP_CPU_EXCHANGE_INFO_FIELD (CpuMpData)
+ push dword [eax] ; push address of CpuMpData
mov edi, esi
add edi, MP_CPU_EXCHANGE_INFO_FIELD (CFunction)
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 1252ee9673..15b24b1805 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -710,17 +710,16 @@ PlaceAPInMwaitLoopOrRunLoop (
/**
This function will be called from AP reset code if BSP uses WakeUpAP.
- @param[in] ExchangeInfo Pointer to the MP exchange info buffer
+ @param[in] CpuMpData Pointer to CPU MP Data
@param[in] ApIndex Number of current executing AP
**/
VOID
EFIAPI
ApWakeupFunction (
- IN MP_CPU_EXCHANGE_INFO *ExchangeInfo,
- IN UINTN ApIndex
+ IN CPU_MP_DATA *CpuMpData,
+ IN UINTN ApIndex
)
{
- CPU_MP_DATA *CpuMpData;
UINTN ProcessorNumber;
EFI_AP_PROCEDURE Procedure;
VOID *Parameter;
@@ -731,11 +730,6 @@ ApWakeupFunction (
UINTN CurrentApicMode;
AP_STACK_DATA *ApStackData;
- //
- // AP finished assembly code and begin to execute C code
- //
- CpuMpData = ExchangeInfo->CpuMpData;
-
//
// AP's local APIC settings will be lost after received INIT IPI
// We need to re-initialize them at here
diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index 5bcdf7726b..40e80ffab4 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
@@ -259,8 +259,7 @@ CProcedureInvoke:
add rsp, 20h
mov edx, ebx ; edx is ApIndex
- mov ecx, esi
- add ecx, MP_CPU_EXCHANGE_INFO_OFFSET ; rcx is address of exchange info data buffer
+ mov rcx, qword [esi + MP_CPU_EXCHANGE_INFO_FIELD (CpuMpData)]
mov edi, esi
add edi, MP_CPU_EXCHANGE_INFO_FIELD (CFunction)
--
2.36.1.windows.1
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Reviewed-by: Ray Ni <ray.ni@intel.com>
> -----Original Message-----
> From: Xie, Yuanhao <yuanhao.xie@intel.com>
> Sent: Monday, June 26, 2023 1:57 PM
> To: devel@edk2.groups.io
> Cc: Gerd Hoffmann <kraxel@redhat.com>; Dong, Eric <eric.dong@intel.com>; Ni,
> Ray <ray.ni@intel.com>; Kumar, Rahul R <rahul.r.kumar@intel.com>; Tom
> Lendacky <thomas.lendacky@amd.com>; Xie, Yuanhao
> <yuanhao.xie@intel.com>
> Subject: [Patch V3 4/5] UefiCpuPkg: ApWakeupFunction directly use CpuMpData.
>
> In the original design, once the APs finished executing their assembly
> code and switched to executing C code, they would enter a continuous
> loop within a function. In this function, they would collect CpuMpData
> using the MP_CPU_EXCHANGE_INFO mechanism. However, in the updated
> approach, CpuMpData can now be passed directly to the ApWakeUpFunction,
> bypassing the need for MP_CPU_EXCHANGE_INFO. This modification is made
> in preparation for eliminating the requirement of a second
> INIT-SIPI-SIPI sequence in the DXE phase.
>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Rahul Kumar <rahul1.kumar@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
> ---
> UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm | 4 ++--
> UefiCpuPkg/Library/MpInitLib/MpLib.c | 12 +++---------
> UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm | 3 +--
> 3 files changed, 6 insertions(+), 13 deletions(-)
>
> diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
> b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
> index 59db4081d6..d117f09ef5 100644
> --- a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
> +++ b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
> @@ -197,8 +197,8 @@ CProcedureInvoke:
>
> push ebx ; Push ApIndex
> mov eax, esi
> - add eax, MP_CPU_EXCHANGE_INFO_OFFSET
> - push eax ; push address of exchange info data buffer
> + add eax, MP_CPU_EXCHANGE_INFO_FIELD (CpuMpData)
> + push dword [eax] ; push address of CpuMpData
>
> mov edi, esi
> add edi, MP_CPU_EXCHANGE_INFO_FIELD (CFunction)
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> index 1252ee9673..15b24b1805 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> @@ -710,17 +710,16 @@ PlaceAPInMwaitLoopOrRunLoop (
> /**
> This function will be called from AP reset code if BSP uses WakeUpAP.
>
> - @param[in] ExchangeInfo Pointer to the MP exchange info buffer
> + @param[in] CpuMpData Pointer to CPU MP Data
> @param[in] ApIndex Number of current executing AP
> **/
> VOID
> EFIAPI
> ApWakeupFunction (
> - IN MP_CPU_EXCHANGE_INFO *ExchangeInfo,
> - IN UINTN ApIndex
> + IN CPU_MP_DATA *CpuMpData,
> + IN UINTN ApIndex
> )
> {
> - CPU_MP_DATA *CpuMpData;
> UINTN ProcessorNumber;
> EFI_AP_PROCEDURE Procedure;
> VOID *Parameter;
> @@ -731,11 +730,6 @@ ApWakeupFunction (
> UINTN CurrentApicMode;
> AP_STACK_DATA *ApStackData;
>
> - //
> - // AP finished assembly code and begin to execute C code
> - //
> - CpuMpData = ExchangeInfo->CpuMpData;
> -
> //
> // AP's local APIC settings will be lost after received INIT IPI
> // We need to re-initialize them at here
> diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
> b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
> index 5bcdf7726b..40e80ffab4 100644
> --- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
> +++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
> @@ -259,8 +259,7 @@ CProcedureInvoke:
> add rsp, 20h
>
> mov edx, ebx ; edx is ApIndex
> - mov ecx, esi
> - add ecx, MP_CPU_EXCHANGE_INFO_OFFSET ; rcx is address of exchange
> info data buffer
> + mov rcx, qword [esi + MP_CPU_EXCHANGE_INFO_FIELD (CpuMpData)]
>
> mov edi, esi
> add edi, MP_CPU_EXCHANGE_INFO_FIELD (CFunction)
> --
> 2.36.1.windows.1
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