Cc: Michael Kinney <michael.d.kin...@intel.com>
Cc: Feng Tian <feng.t...@intel.com>
Cc: Giri P Mudusuru <giri.p.mudus...@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff....@intel.com>
---
UefiCpuPkg/Library/MpInitLib/DxeMpLib.c | 26 +++-
UefiCpuPkg/Library/MpInitLib/Ia32/MpEqu.inc | 4 +
UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm | 74 ++++++++++++
UefiCpuPkg/Library/MpInitLib/MpLib.c | 157 ++++++++++++++++++++++++-
UefiCpuPkg/Library/MpInitLib/MpLib.h | 65 ++++++++++
UefiCpuPkg/Library/MpInitLib/PeiMpLib.c | 2 +-
UefiCpuPkg/Library/MpInitLib/X64/MpEqu.inc | 4 +
UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm | 106 +++++++++++++++++
8 files changed, 431 insertions(+), 7 deletions(-)
diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
index f2507eb..ff09fef 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
@@ -387,7 +387,31 @@ MpInitLibSwitchBsp (
IN BOOLEAN EnableOldBSP
)
{
- return EFI_SUCCESS;
+ EFI_STATUS Status;
+ BOOLEAN OldInterruptState;
+
+ //
+ // Before send both BSP and AP to a procedure to exchange their roles,
+ // interrupt must be disabled. This is because during the exchange role
+ // process, 2 CPU may use 1 stack. If interrupt happens, the stack will
+ // be corrupted, since interrupt return address will be pushed to stack
+ // by hardware.
+ //
+ OldInterruptState = SaveAndDisableInterrupts ();
+
+ //
+ // Mask LINT0 & LINT1 for the old BSP
+ //
+ DisableLvtInterrupts ();
+
+ Status = SwitchBspWorker (ProcessorNumber, EnableOldBSP);
+
+ //
+ // Restore interrupt state.
+ //
+ SetInterruptState (OldInterruptState);
+
+ return Status;
}
/**
diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/MpEqu.inc
b/UefiCpuPkg/Library/MpInitLib/Ia32/MpEqu.inc
index f460f7a..5f12079 100644
--- a/UefiCpuPkg/Library/MpInitLib/Ia32/MpEqu.inc
+++ b/UefiCpuPkg/Library/MpInitLib/Ia32/MpEqu.inc
@@ -21,6 +21,10 @@
VacantFlag equ 00h
NotVacantFlag equ 0ffh
+CPU_SWITCH_STATE_IDLE equ 0
+CPU_SWITCH_STATE_STORED equ 1
+CPU_SWITCH_STATE_LOADED equ 2
+
LockLocation equ (RendezvousFunnelProcEnd -
RendezvousFunnelProcStart)
StackStartAddressLocation equ LockLocation + 04h
StackSizeLocation equ LockLocation + 08h
diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
index 29d14e2..a93ba59 100644
--- a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
@@ -209,3 +209,77 @@ ASM_PFX(AsmGetAddressMap):
popad
ret
+
+;-------------------------------------------------------------------------------------
+;AsmExchangeRole procedure follows. This procedure executed by current BSP,
that is
+;about to become an AP. It switches it'stack with the current AP.
+;AsmExchangeRole (IN CPU_EXCHANGE_INFO *MyInfo, IN CPU_EXCHANGE_INFO
*OthersInfo);
+;-------------------------------------------------------------------------------------
+global ASM_PFX(AsmExchangeRole)
+ASM_PFX(AsmExchangeRole):
+ ; DO NOT call other functions in this function, since 2 CPU may use 1 stack
+ ; at the same time. If 1 CPU try to call a function, stack will be
corrupted.
+ pushad
+ mov ebp,esp
+
+ ; esi contains MyInfo pointer
+ mov esi, [ebp + 24h]
+
+ ; edi contains OthersInfo pointer
+ mov edi, [ebp + 28h]
+
+ ;Store EFLAGS, GDTR and IDTR register to stack
+ pushfd
+ mov eax, cr4
+ push eax ; push cr4 firstly
+ mov eax, cr0
+ push eax
+
+ sgdt [esi + 8]
+ sidt [esi + 14]
+
+ ; Store the its StackPointer
+ mov [esi + 4],esp
+
+ ; update its switch state to STORED
+ mov byte [esi], CPU_SWITCH_STATE_STORED
+
+WaitForOtherStored:
+ ; wait until the other CPU finish storing its state
+ cmp byte [edi], CPU_SWITCH_STATE_STORED
+ jz OtherStored
+ pause
+ jmp WaitForOtherStored
+
+OtherStored:
+ ; Since another CPU already stored its state, load them
+ ; load GDTR value
+ lgdt [edi + 8]
+
+ ; load IDTR value
+ lidt [edi + 14]
+
+ ; load its future StackPointer
+ mov esp, [edi + 4]
+
+ ; update the other CPU's switch state to LOADED
+ mov byte [edi], CPU_SWITCH_STATE_LOADED
+
+WaitForOtherLoaded:
+ ; wait until the other CPU finish loading new state,
+ ; otherwise the data in stack may corrupt
+ cmp byte [esi], CPU_SWITCH_STATE_LOADED
+ jz OtherLoaded
+ pause
+ jmp WaitForOtherLoaded
+
+OtherLoaded:
+ ; since the other CPU already get the data it want, leave this procedure
+ pop eax
+ mov cr0, eax
+ pop eax
+ mov cr4, eax
+ popfd
+
+ popad
+ ret
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c
b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 01444d1..6e5a3ac 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -189,6 +189,26 @@ ExtractProcessorLocation (
}
/**
+ Worker function for SwitchBSP().
+
+ Worker function for SwitchBSP(), assigned to the AP which is intended
+ to become BSP.
+
+ @param[in] Buffer Pointer to CPU MP Data
+**/
+VOID
+EFIAPI
+FutureBSPProc (
+ IN VOID *Buffer
+ )
+{
+ CPU_MP_DATA *DataInHob;
+
+ DataInHob = (CPU_MP_DATA *) Buffer;
+ AsmExchangeRole (&DataInHob->APInfo, &DataInHob->BSPInfo);
+}
+
+/**
Get the Application Processors state.
@param[in] CpuData The pointer to CPU_AP_DATA of specified AP
@@ -651,11 +671,20 @@ ApCFunction (
// Invoke AP function here
//
Procedure (Parameter);
- //
- // Re-get the CPU APICID and Initial APICID
- //
- CpuMpData->CpuData[ProcessorNumber].ApicId = GetApicId ();
- CpuMpData->CpuData[ProcessorNumber].InitialApicId = GetInitialApicId
();
+ if (CpuMpData->SwitchBspFlag) {
+ //
+ // Re-get the processor number due to BSP/AP maybe exchange in AP
function
+ //
+ GetProcessorNumber (CpuMpData, &ProcessorNumber);
+ CpuMpData->CpuData[ProcessorNumber].ApFunction = 0;
+ CpuMpData->CpuData[ProcessorNumber].ApFunctionArgument = 0;
+ } else {
+ //
+ // Re-get the CPU APICID and Initial APICID
+ //
+ CpuMpData->CpuData[ProcessorNumber].ApicId = GetApicId ();
+ CpuMpData->CpuData[ProcessorNumber].InitialApicId =
GetInitialApicId ();
+ }
}
SetApState (&CpuMpData->CpuData[ProcessorNumber], CpuStateFinished);
}
@@ -946,6 +975,7 @@ MpInitLibInitialize (
CpuMpData->CpuCount = 1;
CpuMpData->BspNumber = 0;
CpuMpData->WaitEvent = NULL;
+ CpuMpData->SwitchBspFlag = FALSE;
CpuMpData->CpuData = (CPU_AP_DATA *) (CpuMpData + 1);
CpuMpData->CpuInfoInHob = (UINT64) (UINTN) (CpuMpData->CpuData +
MaxLogicalProcessorNumber);
InitializeSpinLock(&CpuMpData->MpLock);
@@ -1107,6 +1137,123 @@ MpInitLibGetProcessorInfo (
return EFI_SUCCESS;
}
+
+/**
+ Worker function to switch the requested AP to be the BSP from that point
onward.
+
+ @param[in] ProcessorNumber The handle number of AP that is to become the
new
+ BSP. The range is from 0 to the total number of
+ logical processors minus 1. The total number of
+ logical processors can be retrieved by
+ MpInitLibGetNumberOfProcessors().
+ @param[in] EnableOldBSP If TRUE, then the old BSP will be listed as an
+ enabled AP. Otherwise, it will be disabled.
+
+ @retval EFI_SUCCESS BSP successfully switched.
+ @retval EFI_UNSUPPORTED Switching the BSP cannot be completed prior
to
+ this service returning.
+ @retval EFI_UNSUPPORTED Switching the BSP is not supported.
+ @retval EFI_SUCCESS The calling processor is an AP.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the current BSP or
+ a disabled AP.
+ @retval EFI_NOT_READY The specified AP is busy.
+
+**/
+EFI_STATUS
+SwitchBspWorker (
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableOldBSP
+ )
+{
+ CPU_MP_DATA *CpuMpData;
+ UINTN CallerNumber;
+ CPU_STATE State;
+ MSR_IA32_APIC_BASE_REGISTER ApicBaseMsr;
+
+ CpuMpData = GetCpuMpData ();
+
+ //
+ // Check whether caller processor is BSP
+ //
+ MpInitLibWhoAmI (&CallerNumber);
+ if (CallerNumber != CpuMpData->BspNumber) {
+ return EFI_SUCCESS;
+ }
+
+ if (ProcessorNumber >= CpuMpData->CpuCount) {
+ return EFI_NOT_FOUND;
+ }
+
+ //
+ // Check whether specified AP is disabled
+ //
+ State = GetApState (&CpuMpData->CpuData[ProcessorNumber]);
+ if (State == CpuStateDisabled) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Check whether ProcessorNumber specifies the current BSP
+ //
+ if (ProcessorNumber == CpuMpData->BspNumber) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Check whether specified AP is busy
+ //
+ if (State == CpuStateBusy) {
+ return EFI_NOT_READY;
+ }
+
+ CpuMpData->BSPInfo.State = CPU_SWITCH_STATE_IDLE;
+ CpuMpData->APInfo.State = CPU_SWITCH_STATE_IDLE;
+ CpuMpData->SwitchBspFlag = TRUE;
+
+ //
+ // Clear the BSP bit of MSR_IA32_APIC_BASE
+ //
+ ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);
+ ApicBaseMsr.Bits.BSP = 0;
+ AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);
+
+ //
+ // Need to wakeUp AP (future BSP).
+ //
+ WakeUpAP (CpuMpData, FALSE, ProcessorNumber, FutureBSPProc, CpuMpData);
+
+ AsmExchangeRole (&CpuMpData->BSPInfo, &CpuMpData->APInfo);
+
+ //
+ // Set the BSP bit of MSR_IA32_APIC_BASE on new BSP
+ //
+ ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE);
+ ApicBaseMsr.Bits.BSP = 1;
+ AsmWriteMsr64 (MSR_IA32_APIC_BASE, ApicBaseMsr.Uint64);
+
+ //
+ // Wait for old BSP finished AP task
+ //
+ while (GetApState (&CpuMpData->CpuData[CallerNumber]) != CpuStateFinished) {
+ CpuPause ();
+ }
+
+ CpuMpData->SwitchBspFlag = FALSE;
+ //
+ // Set old BSP enable state
+ //
+ if (!EnableOldBSP) {
+ SetApState (&CpuMpData->CpuData[CallerNumber], CpuStateDisabled);
+ }
+ //
+ // Save new BSP number
+ //
+ CpuMpData->BspNumber = (UINT32) ProcessorNumber;
+
+ return EFI_SUCCESS;
+}
/**
This return the handle number for the calling processor. This service may be
called from the BSP and APs.
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h
b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index 4d47d66..1abf134 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -37,6 +37,23 @@
#define WAKEUP_AP_SIGNAL SIGNATURE_32 ('S', 'T', 'A', 'P')
+//
+// The MP data for switch BSP
+//
+#define CPU_SWITCH_STATE_IDLE 0
+#define CPU_SWITCH_STATE_STORED 1
+#define CPU_SWITCH_STATE_LOADED 2
+
+//
+// CPU exchange information for switch BSP
+//
+typedef struct {
+ UINT8 State; // offset 0
+ UINTN StackPointer; // offset 4 / 8
+ IA32_DESCRIPTOR Gdtr; // offset 8 / 16
+ IA32_DESCRIPTOR Idtr; // offset 14 / 26
+} CPU_EXCHANGE_ROLE_INFO;
+
typedef enum {
ApInHltLoop = 1,
ApInMwaitLoop = 2,
@@ -173,6 +190,9 @@ struct _CPU_MP_DATA {
AP_INIT_STATE InitFlag;
BOOLEAN X2ApicEnable;
+ BOOLEAN SwitchBspFlag;
+ CPU_EXCHANGE_ROLE_INFO BSPInfo;
+ CPU_EXCHANGE_ROLE_INFO APInfo;
MTRR_SETTINGS MtrrTable;
UINT8 ApLoopMode;
UINT8 ApTargetCState;
@@ -218,6 +238,22 @@ AsmGetAddressMap (
);
/**
+ This function is called by both the BSP and the AP which is to become the
BSP to
+ Exchange execution context including stack between them. After return from
this
+ function, the BSP becomes AP and the AP becomes the BSP.
+
+ @param[in] MyInfo Pointer to buffer holding the exchanging information
for the executing processor.
+ @param[in] OthersInfo Pointer to buffer holding the exchanging information
for the peer.
+
+**/
+VOID
+EFIAPI
+AsmExchangeRole (
+ IN CPU_EXCHANGE_ROLE_INFO *MyInfo,
+ IN CPU_EXCHANGE_ROLE_INFO *OthersInfo
+ );
+
+/**
Get the pointer to CPU MP Data structure.
@return The pointer to CPU MP Data structure.
@@ -287,6 +323,35 @@ InitMpGlobalData (
);
/**
+ Worker function to switch the requested AP to be the BSP from that point
onward.
+
+ @param[in] ProcessorNumber The handle number of AP that is to become the
new
+ BSP. The range is from 0 to the total number of
+ logical processors minus 1. The total number of
+ logical processors can be retrieved by
+ MpInitLibGetNumberOfProcessors().
+ @param[in] EnableOldBSP If TRUE, then the old BSP will be listed as an
+ enabled AP. Otherwise, it will be disabled.
+
+ @retval EFI_SUCCESS BSP successfully switched.
+ @retval EFI_UNSUPPORTED Switching the BSP cannot be completed prior
to
+ this service returning.
+ @retval EFI_UNSUPPORTED Switching the BSP is not supported.
+ @retval EFI_SUCCESS The calling processor is an AP.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the current BSP or
+ a disabled AP.
+ @retval EFI_NOT_READY The specified AP is busy.
+
+**/
+EFI_STATUS
+SwitchBspWorker (
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableOldBSP
+ );
+
+/**
Get pointer to CPU MP Data structure from GUIDed HOB.
@return The pointer to CPU MP Data structure.
diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
index e7a438f..40f5807 100644
--- a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
@@ -603,6 +603,6 @@ MpInitLibSwitchBsp (
IN BOOLEAN EnableOldBSP
)
{
- return EFI_SUCCESS;
+ return SwitchBspWorker (ProcessorNumber, EnableOldBSP);
}
diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpEqu.inc
b/UefiCpuPkg/Library/MpInitLib/X64/MpEqu.inc
index 05847f6..c8a2f1e 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpEqu.inc
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpEqu.inc
@@ -21,6 +21,10 @@
VacantFlag equ 00h
NotVacantFlag equ 0ffh
+CPU_SWITCH_STATE_IDLE equ 0
+CPU_SWITCH_STATE_STORED equ 1
+CPU_SWITCH_STATE_LOADED equ 2
+
LockLocation equ (RendezvousFunnelProcEnd -
RendezvousFunnelProcStart)
StackStartAddressLocation equ LockLocation + 08h
StackSizeLocation equ LockLocation + 10h
diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index 7436705..8ddc453 100644
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
@@ -243,3 +243,109 @@ ASM_PFX(AsmGetAddressMap):
mov qword [rcx + 18h], rax
mov qword [rcx + 20h], AsmRellocateApLoopEnd -
AsmRellocateApLoopStart
ret
+
+;-------------------------------------------------------------------------------------
+;AsmExchangeRole procedure follows. This procedure executed by current BSP,
that is
+;about to become an AP. It switches its stack with the current AP.
+;AsmExchangeRole (IN CPU_EXCHANGE_INFO *MyInfo, IN CPU_EXCHANGE_INFO
*OthersInfo);
+;-------------------------------------------------------------------------------------
+global ASM_PFX(AsmExchangeRole)
+ASM_PFX(AsmExchangeRole):
+ ; DO NOT call other functions in this function, since 2 CPU may use 1 stack
+ ; at the same time. If 1 CPU try to call a function, stack will be
corrupted.
+
+ push rax
+ push rbx
+ push rcx
+ push rdx
+ push rsi
+ push rdi
+ push rbp
+ push r8
+ push r9
+ push r10
+ push r11
+ push r12
+ push r13
+ push r14
+ push r15
+
+ mov rax, cr0
+ push rax
+
+ mov rax, cr4
+ push rax
+
+ ; rsi contains MyInfo pointer
+ mov rsi, rcx
+
+ ; rdi contains OthersInfo pointer
+ mov rdi, rdx
+
+ ;Store EFLAGS, GDTR and IDTR regiter to stack
+ pushfq
+ sgdt [rsi + 16]
+ sidt [rsi + 26]
+
+ ; Store the its StackPointer
+ mov [rsi + 8], rsp
+
+ ; update its switch state to STORED
+ mov byte [rsi], CPU_SWITCH_STATE_STORED
+
+WaitForOtherStored:
+ ; wait until the other CPU finish storing its state
+ cmp byte [rdi], CPU_SWITCH_STATE_STORED
+ jz OtherStored
+ pause
+ jmp WaitForOtherStored
+
+OtherStored:
+ ; Since another CPU already stored its state, load them
+ ; load GDTR value
+ lgdt [rdi + 16]
+
+ ; load IDTR value
+ lidt [rdi + 26]
+
+ ; load its future StackPointer
+ mov rsp, [rdi + 8]
+
+ ; update the other CPU's switch state to LOADED
+ mov byte [rdi], CPU_SWITCH_STATE_LOADED
+
+WaitForOtherLoaded:
+ ; wait until the other CPU finish loading new state,
+ ; otherwise the data in stack may corrupt
+ cmp byte [rsi], CPU_SWITCH_STATE_LOADED
+ jz OtherLoaded
+ pause
+ jmp WaitForOtherLoaded
+
+OtherLoaded:
+ ; since the other CPU already get the data it want, leave this procedure
+ popfq
+
+ pop rax
+ mov cr4, rax
+
+ pop rax
+ mov cr0, rax
+
+ pop r15
+ pop r14
+ pop r13
+ pop r12
+ pop r11
+ pop r10
+ pop r9
+ pop r8
+ pop rbp
+ pop rdi
+ pop rsi
+ pop rdx
+ pop rcx
+ pop rbx
+ pop rax
+
+ ret
--
2.7.4.windows.1
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