[PATCH 2/2] ArmPkg: Add Library/MpInitLib to support EFI_MP_SERVICES_PROTOCOL


Rebecca Cran
 

Add support for EFI_MP_SERVICES_PROTOCOL during the DXE phase under
AArch64.

PSCI_CPU_ON is called to power on the core, the supplied procedure is
executed and PSCI_CPU_OFF is called to power off the core.

Minimal setup is done before calling the supplied procedure: for example
the MMU and caches are not enabled.

Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
---
ArmPkg/ArmPkg.dec | 4 +
ArmPkg/ArmPkg.dsc | 4 +
ArmPkg/Drivers/CpuDxe/AArch64/Arch.c | 22 +
ArmPkg/Drivers/CpuDxe/Arm/Arch.c | 22 +
ArmPkg/Drivers/CpuDxe/CpuDxe.c | 2 +
ArmPkg/Drivers/CpuDxe/CpuDxe.h | 10 +
ArmPkg/Drivers/CpuDxe/CpuDxe.inf | 6 +
ArmPkg/Drivers/CpuDxe/CpuMpInit.c | 604 ++++++++
ArmPkg/Include/Library/MpInitLib.h | 366 +++++
ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S | 61 +
ArmPkg/Library/MpInitLib/DxeMpInitLib.inf | 53 +
ArmPkg/Library/MpInitLib/DxeMpLib.c | 1498 ++++++++++++++++++++
ArmPkg/Library/MpInitLib/InternalMpInitLib.h | 358 +++++
ArmVirtPkg/ArmVirt.dsc.inc | 3 +
14 files changed, 3013 insertions(+)

diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec
index 5935663fa9a3..f8bb4af21749 100644
--- a/ArmPkg/ArmPkg.dec
+++ b/ArmPkg/ArmPkg.dec
@@ -74,6 +74,10 @@
#
DefaultExceptionHandlerLib|Include/Library/DefaultExceptionHandlerLib.h

+ ## @libraryclass Provides a MP Services interface.
+ #
+ MpInitLib|Include/Library/MpInitLib.h
+
## @libraryclass Provides an interface to query miscellaneous OEM
# information.
#
diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
index 8abe3713c829..26fb8bb94c07 100644
--- a/ArmPkg/ArmPkg.dsc
+++ b/ArmPkg/ArmPkg.dsc
@@ -99,6 +99,9 @@
PeiServicesLib|MdePkg/Library/PeiServicesLib/PeiServicesLib.inf
PeiServicesTablePointerLib|MdePkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.inf

+[LibraryClasses.AARCH64]
+ MpInitLib|ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
+
[LibraryClasses.ARM, LibraryClasses.AARCH64]
NULL|ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf

@@ -163,4 +166,5 @@
ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf

[Components.AARCH64, Components.ARM]
+ ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
ArmPkg/Library/StandaloneMmMmuLib/ArmMmuStandaloneMmLib.inf
diff --git a/ArmPkg/Drivers/CpuDxe/AArch64/Arch.c b/ArmPkg/Drivers/CpuDxe/AArch64/Arch.c
new file mode 100644
index 000000000000..a4b9e9037100
--- /dev/null
+++ b/ArmPkg/Drivers/CpuDxe/AArch64/Arch.c
@@ -0,0 +1,22 @@
+/** @file
+ Architecture specific functions.
+
+ Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <CpuDxe.h>
+
+/** Initializes multi-processor support.
+ *
+**/
+VOID
+ArchInitializeMpSupport (
+ VOID
+ )
+{
+ InitializeMpSupport ();
+}
diff --git a/ArmPkg/Drivers/CpuDxe/Arm/Arch.c b/ArmPkg/Drivers/CpuDxe/Arm/Arch.c
new file mode 100644
index 000000000000..0ded264cd06a
--- /dev/null
+++ b/ArmPkg/Drivers/CpuDxe/Arm/Arch.c
@@ -0,0 +1,22 @@
+/** @file
+ Architecture specific functions.
+
+ Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <CpuDxe.h>
+
+/** Initializes multi-processor support.
+ *
+**/
+VOID
+ArchInitializeMpSupport (
+ VOID
+ )
+{
+ /* Nothing to do - ARM doesn't support EFI_MP_SERVICES_PROTOCOL */
+}
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.c b/ArmPkg/Drivers/CpuDxe/CpuDxe.c
index 082ef30fb6c4..db8752f5b54f 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.c
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.c
@@ -279,5 +279,7 @@ CpuDxeInitialize (
);
ASSERT_EFI_ERROR (Status);

+ ArchInitializeMpSupport ();
+
return Status;
}
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.h b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
index 4cf3ab258c24..6e7ceafa4436 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.h
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
@@ -143,4 +143,14 @@ SetGcdMemorySpaceAttributes (
IN UINT64 Attributes
);

+VOID
+InitializeMpSupport (
+ VOID
+ );
+
+VOID
+ArchInitializeMpSupport (
+ VOID
+ );
+
#endif // CPU_DXE_H_
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.inf b/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
index e5549fc71df7..f4cdb8ab5613 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
@@ -26,10 +26,13 @@
Exception.c

[Sources.ARM]
+ Arm/Arch.c
Arm/Mmu.c

[Sources.AARCH64]
+ AArch64/Arch.c
AArch64/Mmu.c
+ CpuMpInit.c

[Packages]
ArmPkg/ArmPkg.dec
@@ -37,6 +40,9 @@
MdePkg/MdePkg.dec
MdeModulePkg/MdeModulePkg.dec

+[LibraryClasses.AARCH64]
+ MpInitLib
+
[LibraryClasses]
ArmLib
ArmMmuLib
diff --git a/ArmPkg/Drivers/CpuDxe/CpuMpInit.c b/ArmPkg/Drivers/CpuDxe/CpuMpInit.c
new file mode 100644
index 000000000000..5bf4ed12b711
--- /dev/null
+++ b/ArmPkg/Drivers/CpuDxe/CpuMpInit.c
@@ -0,0 +1,604 @@
+/** @file
+ Construct MP Services Protocol.
+
+ The MP Services Protocol provides a generalized way of performing following tasks:
+ - Retrieving information of multi-processor environment and MP-related status of
+ specific processors.
+ - Dispatching user-provided function to APs.
+ - Maintain MP-related processor status.
+
+ The MP Services Protocol must be produced on any system with more than one logical
+ processor.
+
+ The Protocol is available only during boot time.
+
+ MP Services Protocol is hardware-independent. Most of the logic of this protocol
+ is architecturally neutral. It abstracts the multi-processor environment and
+ status of processors, and provides interfaces to retrieve information, maintain,
+ and dispatch.
+
+ MP Services Protocol may be consumed by ACPI module. The ACPI module may use this
+ protocol to retrieve data that are needed for an MP platform and report them to OS.
+ MP Services Protocol may also be used to program and configure processors, such
+ as MTRR synchronization for memory space attributes setting in DXE Services.
+ MP Services Protocol may be used by non-CPU DXE drivers to speed up platform boot
+ by taking advantage of the processing capabilities of the APs, for example, using
+ APs to help test system memory in parallel with other device initialization.
+ Diagnostics applications may also use this protocol for multi-processor.
+
+ Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/MpInitLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+/**
+ This service retrieves the number of logical processor in the platform
+ and the number of those logical processors that are enabled on this boot.
+ This service may only be called from the BSP.
+
+ This function is used to retrieve the following information:
+ - The number of logical processors that are present in the system.
+ - The number of enabled logical processors in the system at the instant
+ this call is made.
+
+ Because MP Service Protocol provides services to enable and disable processors
+ dynamically, the number of enabled logical processors may vary during the
+ course of a boot session.
+
+ If this service is called from an AP, then EFI_DEVICE_ERROR is returned.
+ If NumberOfProcessors or NumberOfEnabledProcessors is NULL, then
+ EFI_INVALID_PARAMETER is returned. Otherwise, the total number of processors
+ is returned in NumberOfProcessors, the number of currently enabled processor
+ is returned in NumberOfEnabledProcessors, and EFI_SUCCESS is returned.
+
+ @param[in] This A pointer to the
+ EFI_MP_SERVICES_PROTOCOL instance.
+ @param[out] NumberOfProcessors Pointer to the total number of logical
+ processors in the system, including
+ the BSP and disabled APs.
+ @param[out] NumberOfEnabledProcessors Pointer to the number of enabled
+ logical processors that exist in the
+ system, including the BSP.
+
+ @retval EFI_SUCCESS The number of logical processors and enabled
+ logical processors was retrieved.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_INVALID_PARAMETER NumberOfProcessors is NULL.
+ @retval EFI_INVALID_PARAMETER NumberOfEnabledProcessors is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+GetNumberOfProcessors (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ OUT UINTN *NumberOfProcessors,
+ OUT UINTN *NumberOfEnabledProcessors
+ )
+{
+ return MpInitLibGetNumberOfProcessors (
+ This,
+ NumberOfProcessors,
+ NumberOfEnabledProcessors
+ );
+}
+
+/**
+ Gets detailed MP-related information on the requested processor at the
+ instant this call is made. This service may only be called from the BSP.
+
+ This service retrieves detailed MP-related information about any processor
+ on the platform. Note the following:
+ - The processor information may change during the course of a boot session.
+ - The information presented here is entirely MP related.
+
+ Information regarding the number of caches and their sizes, frequency of
+ operation, slot numbers is all considered platform-related information and is
+ not provided by this service.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] ProcessorNumber The index of the processor.
+ @param[out] ProcessorInfoBuffer A pointer to the buffer where information
+ for the requested processor is deposited.
+
+ @retval EFI_SUCCESS Processor information was returned.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_INVALID_PARAMETER ProcessorInfoBuffer is NULL.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist in the platform.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+GetProcessorInfo (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorNumber,
+ OUT EFI_PROCESSOR_INFORMATION *ProcessorInfoBuffer
+ )
+{
+ return MpInitLibGetProcessorInfo (
+ This,
+ ProcessorNumber,
+ ProcessorInfoBuffer
+ );
+}
+
+/**
+ This service executes a caller provided function on all enabled APs. APs can
+ run either simultaneously or one at a time in sequence. This service supports
+ both blocking and non-blocking requests. The non-blocking requests use EFI
+ events so the BSP can detect when the APs have finished. This service may only
+ be called from the BSP.
+
+ This function is used to dispatch all the enabled APs to the function
+ specified by Procedure. If any enabled AP is busy, then EFI_NOT_READY is
+ returned immediately and Procedure is not started on any AP.
+
+ If SingleThread is TRUE, all the enabled APs execute the function specified by
+ Procedure one by one, in ascending order of processor handle number.
+ Otherwise, all the enabled APs execute the function specified by Procedure
+ simultaneously.
+
+ If WaitEvent is NULL, execution is in blocking mode. The BSP waits until all
+ APs finish or TimeoutInMicroseconds expires. Otherwise, execution is in
+ non-blocking mode, and the BSP returns from this service without waiting for
+ APs. If a non-blocking mode is requested after the UEFI Event
+ EFI_EVENT_GROUP_READY_TO_BOOT is signaled, then EFI_UNSUPPORTED must be
+ returned.
+
+ If the timeout specified by TimeoutInMicroseconds expires before all APs
+ return from Procedure, then Procedure on the failed APs is terminated.
+ All enabled APs are always available for further calls to
+ EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
+ EFI_MP_SERVICES_PROTOCOL.StartupThisAP(). If FailedCpuList is not NULL, its
+ content points to the list of processor handle numbers in which Procedure was
+ terminated.
+
+ Note: It is the responsibility of the consumer of the
+ EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() to make sure that the nature of the
+ code that is executed on the BSP and the dispatched APs is well controlled.
+ The MP Services Protocol does not guarantee that the Procedure function is
+ MP-safe. Hence, the tasks that can be run in parallel are limited to certain
+ independent tasks and well-controlled exclusive code. EFI services and
+ protocols may not be called by APs unless otherwise specified.
+
+ In blocking execution mode, BSP waits until all APs finish or
+ TimeoutInMicroseconds expires.
+
+ In non-blocking execution mode, BSP is freed to return to the caller and then
+ proceed to the next task without having to wait for APs. The following
+ sequence needs to occur in a non-blocking execution mode:
+
+ -# The caller that intends to use this MP Services Protocol in non-blocking
+ mode creates WaitEvent by calling the EFI CreateEvent() service. The
+ caller invokes EFI_MP_SERVICES_PROTOCOL.StartupAllAPs(). If the parameter
+ WaitEvent is not NULL, then StartupAllAPs() executes in non-blocking
+ mode. It requests the function specified by Procedure to be started on
+ all the enabled APs, and releases the BSP to continue with other tasks.
+ -# The caller can use the CheckEvent() and WaitForEvent() services to check
+ the state of the WaitEvent created in step 1.
+ -# When the APs complete their task or TimeoutInMicroSecondss expires, the
+ MP Service signals WaitEvent by calling the EFI SignalEvent() function.
+ If FailedCpuList is not NULL, its content is available when WaitEvent is
+ signaled. If all APs returned from Procedure prior to the timeout, then
+ FailedCpuList is set to NULL. If not all APs return from Procedure before
+ the timeout, then FailedCpuList is filled in with the list of the failed
+ APs. The buffer is allocated by MP Service Protocol using AllocatePool().
+ It is the caller's responsibility to free the buffer with FreePool()
+ service.
+ -# This invocation of SignalEvent() function informs the caller that invoked
+ EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() that either all the APs
+ completed the specified task or a timeout occurred. The contents of
+ FailedCpuList can be examined to determine which APs did not complete the
+ specified task prior to the timeout.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] Procedure A pointer to the function to be run on
+ enabled APs of the system. See type
+ EFI_AP_PROCEDURE.
+ @param[in] SingleThread If TRUE, then all the enabled APs execute
+ the function specified by Procedure one by
+ one, in ascending order of processor
+ handle number. If FALSE, then all the
+ enabled APs execute the function specified
+ by Procedure simultaneously.
+ @param[in] WaitEvent The event created by the caller with
+ CreateEvent() service. If it is NULL,
+ then execute in blocking mode. BSP waits
+ until all APs finish or
+ TimeoutInMicroseconds expires. If it's
+ not NULL, then execute in non-blocking
+ mode. BSP requests the function specified
+ by Procedure to be started on all the
+ enabled APs, and go on executing
+ immediately. If all return from Procedure,
+ or TimeoutInMicroseconds expires, this
+ event is signaled. The BSP can use the
+ CheckEvent() or WaitForEvent()
+ services to check the state of event. Type
+ EFI_EVENT is defined in CreateEvent() in
+ the Unified Extensible Firmware Interface
+ Specification.
+ @param[in] TimeoutInMicroseconds Indicates the time limit in microseconds
+ for APs to return from Procedure, either
+ for blocking or non-blocking mode. Zero
+ means infinity. If the timeout expires
+ before all APs return from Procedure, then
+ Procedure on the failed APs is terminated.
+ All enabled APs are available for next
+ function assigned by
+ EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+ or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+ If the timeout expires in blocking mode,
+ BSP returns EFI_TIMEOUT. If the timeout
+ expires in non-blocking mode, WaitEvent
+ is signaled with SignalEvent().
+ @param[in] ProcedureArgument The parameter passed into Procedure for
+ all APs.
+ @param[out] FailedCpuList If NULL, this parameter is ignored.
+ Otherwise, if all APs finish successfully,
+ then its content is set to NULL. If not
+ all APs finish before timeout expires,
+ then its content is set to address of the
+ buffer holding handle numbers of the
+ failed APs.
+ The buffer is allocated by MP Service
+ Protocol, and it's the caller's
+ responsibility to free the buffer with
+ FreePool() service.
+ In blocking mode, it is ready for
+ consumption when the call returns. In
+ non-blocking mode, it is ready when
+ WaitEvent is signaled. The list of failed
+ CPU is terminated by END_OF_CPU_LIST.
+
+ @retval EFI_SUCCESS In blocking mode, all APs have finished before
+ the timeout expired.
+ @retval EFI_SUCCESS In non-blocking mode, function has been
+ dispatched to all enabled APs.
+ @retval EFI_UNSUPPORTED A non-blocking mode request was made after the
+ UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+ signaled.
+ @retval EFI_DEVICE_ERROR Caller processor is AP.
+ @retval EFI_NOT_STARTED No enabled APs exist in the system.
+ @retval EFI_NOT_READY Any enabled APs are busy.
+ @retval EFI_TIMEOUT In blocking mode, the timeout expired before
+ all enabled APs have finished.
+ @retval EFI_INVALID_PARAMETER Procedure is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+StartupAllAPs (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN BOOLEAN SingleThread,
+ IN EFI_EVENT WaitEvent OPTIONAL,
+ IN UINTN TimeoutInMicroseconds,
+ IN VOID *ProcedureArgument OPTIONAL,
+ OUT UINTN **FailedCpuList OPTIONAL
+ )
+{
+ return MpInitLibStartupAllAPs (
+ This,
+ Procedure,
+ SingleThread,
+ WaitEvent,
+ TimeoutInMicroseconds,
+ ProcedureArgument,
+ FailedCpuList
+ );
+}
+
+/**
+ This service lets the caller get one enabled AP to execute a caller-provided
+ function. The caller can request the BSP to either wait for the completion
+ of the AP or just proceed with the next task by using the EFI event mechanism.
+ See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
+ execution support. This service may only be called from the BSP.
+
+ This function is used to dispatch one enabled AP to the function specified by
+ Procedure passing in the argument specified by ProcedureArgument. If WaitEvent
+ is NULL, execution is in blocking mode. The BSP waits until the AP finishes or
+ TimeoutInMicroSecondss expires. Otherwise, execution is in non-blocking mode.
+ BSP proceeds to the next task without waiting for the AP. If a non-blocking mode
+ is requested after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled,
+ then EFI_UNSUPPORTED must be returned.
+
+ If the timeout specified by TimeoutInMicroseconds expires before the AP returns
+ from Procedure, then execution of Procedure by the AP is terminated. The AP is
+ available for subsequent calls to EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
+ EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] Procedure A pointer to the function to be run on
+ enabled APs of the system. See type
+ EFI_AP_PROCEDURE.
+ @param[in] ProcessorNumber The handle number of the AP. The range is
+ from 0 to the total number of logical
+ processors minus 1. The total number of
+ logical processors can be retrieved by
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @param[in] WaitEvent The event created by the caller with CreateEvent()
+ service. If it is NULL, then execute in
+ blocking mode. BSP waits until all APs finish
+ or TimeoutInMicroseconds expires. If it's
+ not NULL, then execute in non-blocking mode.
+ BSP requests the function specified by
+ Procedure to be started on all the enabled
+ APs, and go on executing immediately. If
+ all return from Procedure or TimeoutInMicroseconds
+ expires, this event is signaled. The BSP
+ can use the CheckEvent() or WaitForEvent()
+ services to check the state of event. Type
+ EFI_EVENT is defined in CreateEvent() in
+ the Unified Extensible Firmware Interface
+ Specification.
+ @param[in] TimeoutInMicroseconds Indicates the time limit in microseconds for
+ APs to return from Procedure, either for
+ blocking or non-blocking mode. Zero means
+ infinity. If the timeout expires before
+ all APs return from Procedure, then Procedure
+ on the failed APs is terminated. All enabled
+ APs are available for next function assigned
+ by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+ or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+ If the timeout expires in blocking mode,
+ BSP returns EFI_TIMEOUT. If the timeout
+ expires in non-blocking mode, WaitEvent
+ is signaled with SignalEvent().
+ @param[in] ProcedureArgument The parameter passed into Procedure for
+ all APs.
+ @param[out] Finished If NULL, this parameter is ignored. In
+ blocking mode, this parameter is ignored.
+ In non-blocking mode, if AP returns from
+ Procedure before the timeout expires, its
+ content is set to TRUE. Otherwise, the
+ value is set to FALSE. The caller can
+ determine if the AP returned from Procedure
+ by evaluating this value.
+
+ @retval EFI_SUCCESS In blocking mode, specified AP finished before
+ the timeout expires.
+ @retval EFI_SUCCESS In non-blocking mode, the function has been
+ dispatched to specified AP.
+ @retval EFI_UNSUPPORTED A non-blocking mode request was made after the
+ UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+ signaled.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_TIMEOUT In blocking mode, the timeout expired before
+ the specified AP has finished.
+ @retval EFI_NOT_READY The specified AP is busy.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the BSP or disabled AP.
+ @retval EFI_INVALID_PARAMETER Procedure is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+StartupThisAP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN UINTN ProcessorNumber,
+ IN EFI_EVENT WaitEvent OPTIONAL,
+ IN UINTN TimeoutInMicroseconds,
+ IN VOID *ProcedureArgument OPTIONAL,
+ OUT BOOLEAN *Finished OPTIONAL
+ )
+{
+ return MpInitLibStartupThisAP (
+ This,
+ Procedure,
+ ProcessorNumber,
+ WaitEvent,
+ TimeoutInMicroseconds,
+ ProcedureArgument,
+ Finished
+ );
+}
+
+/**
+ This service switches the requested AP to be the BSP from that point onward.
+ This service changes the BSP for all purposes. This call can only be
+ performed by the current BSP.
+
+ This service switches the requested AP to be the BSP from that point onward.
+ This service changes the BSP for all purposes. The new BSP can take over the
+ execution of the old BSP and continue seamlessly from where the old one left
+ off. This service may not be supported after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT
+ is signaled.
+
+ If the BSP cannot be switched prior to the return from this service, then
+ EFI_UNSUPPORTED must be returned.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @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.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SwitchBSP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableOldBSP
+ )
+{
+ return MpInitLibSwitchBSP (This, ProcessorNumber, EnableOldBSP);
+}
+
+/**
+ This service lets the caller enable or disable an AP from this point onward.
+ This service may only be called from the BSP.
+
+ This service allows the caller enable or disable an AP from this point onward.
+ The caller can optionally specify the health status of the AP by Health. If
+ an AP is being disabled, then the state of the disabled AP is implementation
+ dependent. If an AP is enabled, then the implementation must guarantee that a
+ complete initialization sequence is performed on the AP, so the AP is in a state
+ that is compatible with an MP operating system. This service may not be supported
+ after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled.
+
+ If the enable or disable AP operation cannot be completed prior to the return
+ from this service, then EFI_UNSUPPORTED must be returned.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @param[in] EnableAP Specifies the new state for the processor for
+ enabled, FALSE for disabled.
+ @param[in] HealthFlag If not NULL, a pointer to a value that specifies
+ the new health status of the AP. This flag
+ corresponds to StatusFlag defined in
+ EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
+ the PROCESSOR_HEALTH_STATUS_BIT is used. All other
+ bits are ignored. If it is NULL, this parameter
+ is ignored.
+
+ @retval EFI_SUCCESS The specified AP was enabled or disabled successfully.
+ @retval EFI_UNSUPPORTED Enabling or disabling an AP cannot be completed
+ prior to this service returning.
+ @retval EFI_UNSUPPORTED Enabling or disabling an AP is not supported.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_NOT_FOUND Processor with the handle specified by ProcessorNumber
+ does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the BSP.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+EnableDisableAP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableAP,
+ IN UINT32 *HealthFlag OPTIONAL
+ )
+{
+ return MpInitLibEnableDisableAP (This, ProcessorNumber, EnableAP, HealthFlag);
+}
+
+/**
+ This return the handle number for the calling processor. This service may be
+ called from the BSP and APs.
+
+ This service returns the processor handle number for the calling processor.
+ The returned value is in the range from 0 to the total number of logical
+ processors minus 1. The total number of logical processors can be retrieved
+ with EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors(). This service may be
+ called from the BSP and APs. If ProcessorNumber is NULL, then EFI_INVALID_PARAMETER
+ is returned. Otherwise, the current processors handle number is returned in
+ ProcessorNumber, and EFI_SUCCESS is returned.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @param[out] 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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+
+ @retval EFI_SUCCESS The current processor handle number was returned
+ in ProcessorNumber.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+WhoAmI (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ OUT UINTN *ProcessorNumber
+ )
+{
+ return MpInitLibWhoAmI (This, ProcessorNumber);
+}
+
+EFI_MP_SERVICES_PROTOCOL mMpServicesTemplate = {
+ GetNumberOfProcessors,
+ GetProcessorInfo,
+ StartupAllAPs,
+ StartupThisAP,
+ SwitchBSP,
+ EnableDisableAP,
+ WhoAmI
+};
+
+/** Initialize multi-processor support.
+
+**/
+VOID
+InitializeMpSupport (
+ VOID
+ )
+{
+ EFI_STATUS Status;
+ EFI_HANDLE Handle;
+ UINTN MaxCpus;
+ EFI_HOB_GENERIC_HEADER *Hob;
+ VOID *HobData;
+ UINTN HobDataSize;
+ ARM_PROCESSOR_TABLE CpuInfo;
+
+ DEBUG ((DEBUG_INFO, "Starting MP services"));
+
+ Hob = GetFirstGuidHob (&gArmMpCoreInfoGuid);
+ if (Hob != NULL) {
+ HobData = GET_GUID_HOB_DATA (Hob);
+ HobDataSize = GET_GUID_HOB_DATA_SIZE (Hob);
+ CpuInfo.ArmCpus = (ARM_CORE_INFO *)HobData;
+ CpuInfo.NumberOfEntries = HobDataSize / sizeof (ARM_CORE_INFO);
+ MaxCpus = CpuInfo.NumberOfEntries;
+ }
+
+ if (MaxCpus == 1) {
+ DEBUG ((DEBUG_WARN, "Trying to use EFI_MP_SERVICES_PROTOCOL on a UP system"));
+ // We are not MP so nothing to do
+ return;
+ }
+
+ MpInitLibInitialize (MaxCpus, &CpuInfo);
+
+ //
+ // Now install the MP services protocol.
+ //
+ Handle = NULL;
+ Status = gBS->InstallMultipleProtocolInterfaces (
+ &Handle,
+ &gEfiMpServiceProtocolGuid,
+ &mMpServicesTemplate,
+ NULL
+ );
+ ASSERT_EFI_ERROR (Status);
+}
diff --git a/ArmPkg/Include/Library/MpInitLib.h b/ArmPkg/Include/Library/MpInitLib.h
new file mode 100644
index 000000000000..a4b80c18a9e8
--- /dev/null
+++ b/ArmPkg/Include/Library/MpInitLib.h
@@ -0,0 +1,366 @@
+/** @file
+
+Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+Portions copyright (c) 2011, Apple Inc. All rights reserved.
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MP_INITLIB_H_
+#define MP_INITLIB_H_
+
+#include <Protocol/Cpu.h>
+#include <Protocol/MpService.h>
+#include <Library/BaseLib.h>
+#include <Library/UefiLib.h>
+#include <Guid/ArmMpCoreInfo.h>
+
+
+/**
+ This service retrieves the number of logical processor in the platform
+ and the number of those logical processors that are enabled on this boot.
+ This service may only be called from the BSP.
+
+ @param[in] This A pointer to the
+ EFI_MP_SERVICES_PROTOCOL instance.
+ @param[out] NumberOfProcessors Pointer to the total number of logical
+ processors in the system, including
+ the BSP and disabled APs.
+ @param[out] NumberOfEnabledProcessors Pointer to the number of enabled
+ logical processors that exist in the
+ system, including the BSP.
+
+ @retval EFI_SUCCESS The number of logical processors and enabled
+ logical processors was retrieved.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_INVALID_PARAMETER NumberOfProcessors is NULL.
+ @retval EFI_INVALID_PARAMETER NumberOfEnabledProcessors is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetNumberOfProcessors (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ OUT UINTN *NumberOfProcessors,
+ OUT UINTN *NumberOfEnabledProcessors
+ );
+
+/**
+ Gets detailed MP-related information on the requested processor at the
+ instant this call is made. This service may only be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] ProcessorIndex The index of the processor.
+ @param[out] ProcessorInfoBuffer A pointer to the buffer where information
+ for the requested processor is deposited.
+
+ @retval EFI_SUCCESS Processor information was returned.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_INVALID_PARAMETER ProcessorInfoBuffer is NULL.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist in the platform.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetProcessorInfo (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorIndex,
+ OUT EFI_PROCESSOR_INFORMATION *ProcessorInfoBuffer
+ );
+
+
+/**
+ This service executes a caller provided function on all enabled APs. APs can
+ run either simultaneously or one at a time in sequence. This service supports
+ both blocking and non-blocking requests. The non-blocking requests use EFI
+ events so the BSP can detect when the APs have finished. This service may only
+ be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] Procedure A pointer to the function to be run on
+ enabled APs of the system. See type
+ EFI_AP_PROCEDURE.
+ @param[in] SingleThread If TRUE, then all the enabled APs execute
+ the function specified by Procedure one by
+ one, in ascending order of processor
+ handle number. If FALSE, then all the
+ enabled APs execute the function specified
+ by Procedure simultaneously.
+ @param[in] WaitEvent The event created by the caller with
+ CreateEvent() service. If it is NULL,
+ then execute in blocking mode. BSP waits
+ until all APs finish or
+ TimeoutInMicroseconds expires. If it's
+ not NULL, then execute in non-blocking
+ mode. BSP requests the function specified
+ by Procedure to be started on all the
+ enabled APs, and go on executing
+ immediately. If all return from Procedure,
+ or TimeoutInMicroseconds expires, this
+ event is signaled. The BSP can use the
+ CheckEvent() or WaitForEvent()
+ services to check the state of event. Type
+ EFI_EVENT is defined in CreateEvent() in
+ the Unified Extensible Firmware Interface
+ Specification.
+ @param[in] TimeoutInMicroseconds Indicates the time limit in microseconds
+ for APs to return from Procedure, either
+ for blocking or non-blocking mode. Zero
+ means infinity. If the timeout expires
+ before all APs return from Procedure, then
+ Procedure on the failed APs is terminated.
+ All enabled APs are available for next
+ function assigned by
+ EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+ or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+ If the timeout expires in blocking mode,
+ BSP returns EFI_TIMEOUT. If the timeout
+ expires in non-blocking mode, WaitEvent
+ is signaled with SignalEvent().
+ @param[in] ProcedureArgument The parameter passed into Procedure for
+ all APs.
+ @param[out] FailedCpuList If NULL, this parameter is ignored.
+ Otherwise, if all APs finish successfully,
+ then its content is set to NULL. If not
+ all APs finish before timeout expires,
+ then its content is set to address of the
+ buffer holding handle numbers of the
+ failed APs.
+ The buffer is allocated by MP Service
+ Protocol, and it's the caller's
+ responsibility to free the buffer with
+ FreePool() service.
+ In blocking mode, it is ready for
+ consumption when the call returns. In
+ non-blocking mode, it is ready when
+ WaitEvent is signaled. The list of failed
+ CPU is terminated by END_OF_CPU_LIST.
+
+ @retval EFI_SUCCESS In blocking mode, all APs have finished before
+ the timeout expired.
+ @retval EFI_SUCCESS In non-blocking mode, function has been
+ dispatched to all enabled APs.
+ @retval EFI_UNSUPPORTED A non-blocking mode request was made after the
+ UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+ signaled.
+ @retval EFI_DEVICE_ERROR Caller processor is AP.
+ @retval EFI_NOT_STARTED No enabled APs exist in the system.
+ @retval EFI_NOT_READY Any enabled APs are busy.
+ @retval EFI_TIMEOUT In blocking mode, the timeout expired before
+ all enabled APs have finished.
+ @retval EFI_INVALID_PARAMETER Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupAllAPs (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN BOOLEAN SingleThread,
+ IN EFI_EVENT WaitEvent OPTIONAL,
+ IN UINTN TimeoutInMicroseconds,
+ IN VOID *ProcedureArgument OPTIONAL,
+ OUT UINTN **FailedCpuList OPTIONAL
+ );
+
+/**
+ This service lets the caller get one enabled AP to execute a caller-provided
+ function. The caller can request the BSP to either wait for the completion
+ of the AP or just proceed with the next task by using the EFI event mechanism.
+ See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
+ execution support. This service may only be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] Procedure A pointer to the function to be run on
+ enabled APs of the system. See type
+ EFI_AP_PROCEDURE.
+ @param[in] ProcessorNumber The handle number of the AP. The range is
+ from 0 to the total number of logical
+ processors minus 1. The total number of
+ logical processors can be retrieved by
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @param[in] WaitEvent The event created by the caller with CreateEvent()
+ service. If it is NULL, then execute in
+ blocking mode. BSP waits until all APs finish
+ or TimeoutInMicroseconds expires. If it's
+ not NULL, then execute in non-blocking mode.
+ BSP requests the function specified by
+ Procedure to be started on all the enabled
+ APs, and go on executing immediately. If
+ all return from Procedure or TimeoutInMicroseconds
+ expires, this event is signaled. The BSP
+ can use the CheckEvent() or WaitForEvent()
+ services to check the state of event. Type
+ EFI_EVENT is defined in CreateEvent() in
+ the Unified Extensible Firmware Interface
+ Specification.
+ @param[in] TimeoutInMicroseconds Indicates the time limit in microseconds for
+ APs to return from Procedure, either for
+ blocking or non-blocking mode. Zero means
+ infinity. If the timeout expires before
+ all APs return from Procedure, then Procedure
+ on the failed APs is terminated. All enabled
+ APs are available for next function assigned
+ by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+ or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+ If the timeout expires in blocking mode,
+ BSP returns EFI_TIMEOUT. If the timeout
+ expires in non-blocking mode, WaitEvent
+ is signaled with SignalEvent().
+ @param[in] ProcedureArgument The parameter passed into Procedure for
+ all APs.
+ @param[out] Finished If NULL, this parameter is ignored. In
+ blocking mode, this parameter is ignored.
+ In non-blocking mode, if AP returns from
+ Procedure before the timeout expires, its
+ content is set to TRUE. Otherwise, the
+ value is set to FALSE. The caller can
+ determine if the AP returned from Procedure
+ by evaluating this value.
+
+ @retval EFI_SUCCESS In blocking mode, specified AP finished before
+ the timeout expires.
+ @retval EFI_SUCCESS In non-blocking mode, the function has been
+ dispatched to specified AP.
+ @retval EFI_UNSUPPORTED A non-blocking mode request was made after the
+ UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+ signaled.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_TIMEOUT In blocking mode, the timeout expired before
+ the specified AP has finished.
+ @retval EFI_NOT_READY The specified AP is busy.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the BSP or disabled AP.
+ @retval EFI_INVALID_PARAMETER Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupThisAP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN UINTN ProcessorNumber,
+ IN EFI_EVENT WaitEvent OPTIONAL,
+ IN UINTN TimeoutInMicroseconds,
+ IN VOID *ProcedureArgument OPTIONAL,
+ OUT BOOLEAN *Finished OPTIONAL
+ );
+
+/**
+ This service switches the requested AP to be the BSP from that point onward.
+ This service changes the BSP for all purposes. This call can only be
+ performed by the current BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @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
+EFIAPI
+MpInitLibSwitchBSP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableOldBSP
+ );
+
+/**
+ This service lets the caller enable or disable an AP from this point onward.
+ This service may only be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @param[in] EnableAP Specifies the new state for the processor for
+ enabled, FALSE for disabled.
+ @param[in] HealthFlag If not NULL, a pointer to a value that specifies
+ the new health status of the AP. This flag
+ corresponds to StatusFlag defined in
+ EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
+ the PROCESSOR_HEALTH_STATUS_BIT is used. All other
+ bits are ignored. If it is NULL, this parameter
+ is ignored.
+
+ @retval EFI_SUCCESS The specified AP was enabled or disabled successfully.
+ @retval EFI_UNSUPPORTED Enabling or disabling an AP cannot be completed
+ prior to this service returning.
+ @retval EFI_UNSUPPORTED Enabling or disabling an AP is not supported.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_NOT_FOUND Processor with the handle specified by ProcessorNumber
+ does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the BSP.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibEnableDisableAP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableAP,
+ IN UINT32 *HealthFlag OPTIONAL
+ );
+
+/**
+ This return the handle number for the calling processor. This service may be
+ called from the BSP and APs.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @param[out] 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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+
+ @retval EFI_SUCCESS The current processor handle number was returned
+ in ProcessorNumber.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibWhoAmI (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ OUT UINTN *ProcessorNumber
+ );
+
+/** Initializes the MP Services system data
+
+ @param NumberOfProcessors The number of processors, both BSP and AP.
+ @param CpuInfo CPU information gathered earlier during boot.
+
+**/
+VOID
+MpInitLibInitialize (
+ IN UINTN NumberOfProcessors,
+ IN ARM_PROCESSOR_TABLE *CpuInfo
+ );
+
+
+
+#endif /* MP_INITLIB_H_ */
diff --git a/ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S b/ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S
new file mode 100644
index 000000000000..287db060e594
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S
@@ -0,0 +1,61 @@
+#===============================================================================
+# Copyright (c) 2021 NUVIA Inc. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#===============================================================================
+
+.text
+.align 3
+
+#include <AsmMacroIoLibV8.h>
+#include <IndustryStandard/ArmStdSmc.h>
+
+#include "InternalMpInitLib.h"
+
+GCC_ASM_IMPORT (gApStacksBase)
+GCC_ASM_IMPORT (gProcessorIDs)
+GCC_ASM_IMPORT (ApProcedure)
+GCC_ASM_IMPORT (gApStackSize)
+
+GCC_ASM_EXPORT (ApEntryPoint)
+
+StartupAddr: .8byte ASM_PFX(ApProcedure)
+
+// Entry-point for the AP
+// VOID
+// ApEntryPoint (
+// VOID
+// );
+ASM_PFX(ApEntryPoint):
+ mrs x0, mpidr_el1
+ ldr x1, gProcessorIDs
+ mov x2, 0 // x2 = processor index
+ mov x3, 0 // x3 = address offset
+
+// Find index in gProcessorIDs for current processor
+1:
+ ldr x4, [x1, x3] // x4 = gProcessorIDs + x3
+ cmp x4, 0 // check if we've reached the end of gProcessorIDs
+ beq ProcessorNotFound
+ add x3, x3, 8 // x3 += sizeof (*gProcessorIDs)
+ add x2, x2, 1 // x2++
+ cmp x0, x4 // if mpidr_el1 != *(gProcessorIDs + x3) then loop
+ bne 1b
+ sub x2, x2, 1
+
+// Calculate stack address
+ // x2 contains the index for the current processor
+ ldr x0, gApStacksBase
+ ldr x1, gApStackSize
+ mul x3, x2, x1 // x3 = ProcessorIndex * gApStackSize
+ add x4, x0, x3 // x4 = gApStacksBase + x3
+ add sp, x4, x1 // sp = x4 + gApStackSize
+
+ ldr x0, StartupAddr // ASM_PFX(ApProcedure)
+ blr x0 // doesn't return
+
+ProcessorNotFound:
+// Turn off the processor
+ MOV32 (w0, ARM_SMC_ID_PSCI_CPU_OFF)
+ smc #0
+ b .
diff --git a/ArmPkg/Library/MpInitLib/DxeMpInitLib.inf b/ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
new file mode 100644
index 000000000000..2275b6cca33a
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
@@ -0,0 +1,53 @@
+#/** @file
+#
+# Component description file for the DxeMpInitLib module.
+#
+# Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#**/
+
+[Defines]
+ INF_VERSION = 1.29
+ BASE_NAME = DxeMpInitLib
+ FILE_GUID = c9ca773c-8ae4-4b74-82fd-f7345503294e
+ MODULE_TYPE = DXE_DRIVER
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = MpInitLib|DXE_DRIVER
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+# VALID_ARCHITECTURES = AARCH64
+#
+
+[Sources.AARCH64]
+ AArch64/MpFuncs.S
+
+[Sources]
+ DxeMpLib.c
+ InternalMpInitLib.h
+
+[Packages]
+ ArmPkg/ArmPkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+ MdePkg/MdePkg.dec
+
+[LibraryClasses]
+ ArmLib
+ ArmSmcLib
+ BaseLib
+ BaseMemoryLib
+ DebugLib
+ HobLib
+ MemoryAllocationLib
+ UefiBootServicesTableLib
+ UefiDriverEntryPoint
+ UefiLib
+
+[Protocols]
+ gEfiMpServiceProtocolGuid
+
+[Guids]
+ gArmMpCoreInfoGuid
diff --git a/ArmPkg/Library/MpInitLib/DxeMpLib.c b/ArmPkg/Library/MpInitLib/DxeMpLib.c
new file mode 100644
index 000000000000..6053db740624
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/DxeMpLib.c
@@ -0,0 +1,1498 @@
+/** @file
+ Construct MP Services Protocol.
+
+ Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+ Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
+ Portions Copyright (c) 2011, Apple Inc. All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Ppi/ArmMpCoreInfo.h>
+#include <Library/ArmLib.h>
+#include <Library/ArmSmcLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/MpInitLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <IndustryStandard/ArmStdSmc.h>
+
+#include "InternalMpInitLib.h"
+
+#define POLL_INTERVAL_US 50000
+
+STATIC CPU_MP_DATA mCpuMpData;
+STATIC BOOLEAN mNonBlockingModeAllowed;
+UINT64 *gApStacksBase;
+UINT64 *gProcessorIDs;
+CONST UINT64 gApStackSize = AP_STACK_SIZE;
+
+/** C entry-point for the AP.
+ This function gets called from the assembly function ApEntryPoint.
+
+**/
+VOID
+ApProcedure (
+ VOID
+ )
+{
+ ARM_SMC_ARGS Args;
+ EFI_AP_PROCEDURE ApProcedure;
+ VOID *ApParameter;
+ UINTN ProcessorIndex;
+
+ MpInitLibWhoAmI (&mMpServicesTemplate, &ProcessorIndex);
+
+ /* Fetch the user-supplied procedure and parameter to execute */
+ ApProcedure = mCpuMpData.CpuData[ProcessorIndex].Procedure;
+ ApParameter = mCpuMpData.CpuData[ProcessorIndex].Parameter;
+
+ ApProcedure (ApParameter);
+
+ mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
+
+ /* Since we're finished with this AP, turn it off */
+ Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
+ ArmCallSmc (&Args);
+
+ /* Should never be reached */
+ ASSERT (FALSE);
+ CpuDeadLoop ();
+}
+
+/** Turns on the specified core using PSCI and executes the user-supplied
+ function that's been configured via a previous call to SetApProcedure.
+
+ @param ProcessorIndex The index of the core to turn on.
+
+ @retval EFI_SUCCESS Success.
+ @retval EFI_DEVICE_ERROR The processor could not be turned on.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+DispatchCpu (
+ IN UINTN ProcessorIndex
+ )
+{
+ ARM_SMC_ARGS Args;
+ EFI_STATUS Status;
+
+ Status = EFI_SUCCESS;
+
+ mCpuMpData.CpuData[ProcessorIndex].State = CpuStateBusy;
+
+ /* Turn the AP on */
+ if (sizeof (Args.Arg0) == sizeof (UINT32)) {
+ Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH32;
+ } else {
+ Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH64;
+ }
+ Args.Arg1 = gProcessorIDs[ProcessorIndex];
+ Args.Arg2 = (UINTN)ApEntryPoint;
+
+ ArmCallSmc (&Args);
+
+ if (Args.Arg0 != ARM_SMC_PSCI_RET_SUCCESS) {
+ DEBUG ((DEBUG_ERROR, "PSCI_CPU_ON call failed: %d", Args.Arg0));
+ Status = EFI_DEVICE_ERROR;
+ }
+
+ return Status;
+}
+
+/** Returns whether the specified processor is the BSP.
+
+ @param[in] ProcessorIndex The index the processor to check.
+
+ @return TRUE if the processor is the BSP, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorBSP (
+ UINTN ProcessorIndex
+ )
+{
+ EFI_PROCESSOR_INFORMATION *CpuInfo;
+
+ CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+ return (CpuInfo->StatusFlag & PROCESSOR_AS_BSP_BIT) != 0;
+}
+
+/** Returns whether the processor executing this function is the BSP.
+
+ @return Whether the current processor is the BSP.
+**/
+STATIC
+BOOLEAN
+IsCurrentProcessorBSP (
+ VOID
+ )
+{
+ EFI_STATUS Status;
+ UINTN ProcessorIndex;
+
+ Status = MpInitLibWhoAmI (&mMpServicesTemplate, &ProcessorIndex);
+ ASSERT_EFI_ERROR (Status);
+ if (EFI_ERROR (Status)) {
+ return FALSE;
+ }
+
+ return IsProcessorBSP (ProcessorIndex);
+}
+
+/** Get the Application Processors state.
+
+ @param[in] CpuData The pointer to CPU_AP_DATA of specified AP.
+
+ @return The AP status.
+**/
+CPU_STATE
+GetApState (
+ IN CPU_AP_DATA *CpuData
+ )
+{
+ return CpuData->State;
+}
+
+/** Configures the processor context with the user-supplied procedure and
+ argument.
+
+ @param CpuData The processor context.
+ @param Procedure The user-supplied procedure.
+ @param ProcedureArgument The user-supplied procedure argument.
+
+**/
+STATIC
+VOID
+SetApProcedure (
+ IN CPU_AP_DATA *CpuData,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN VOID *ProcedureArgument
+ )
+{
+ ASSERT (CpuData != NULL);
+ ASSERT (Procedure != NULL);
+
+ CpuData->Parameter = ProcedureArgument;
+ CpuData->Procedure = Procedure;
+}
+
+/** Returns the index of the next processor that is blocked.
+
+ @param[out] NextNumber The index of the next blocked processor.
+
+ @retval EFI_SUCCESS Successfully found the next blocked processor.
+ @retval EFI_NOT_FOUND There are no blocked processors.
+
+**/
+STATIC
+EFI_STATUS
+GetNextBlockedNumber (
+ OUT UINTN *NextNumber
+ )
+{
+ UINTN Index;
+ CPU_STATE State;
+ CPU_AP_DATA *CpuData;
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ CpuData = &mCpuMpData.CpuData[Index];
+ if (IsProcessorBSP (Index)) {
+ // Skip BSP
+ continue;
+ }
+
+ State = CpuData->State;
+
+ if (State == CpuStateBlocked) {
+ *NextNumber = Index;
+ return EFI_SUCCESS;
+ }
+ }
+
+ return EFI_NOT_FOUND;
+}
+
+/** Stalls the BSP for the minimum of POLL_INTERVAL_US and Timeout.
+
+ @param[in] Timeout The time limit in microseconds remaining for
+ APs to return from Procedure.
+
+ @retval StallTime Time of execution stall.
+**/
+STATIC
+UINTN
+CalculateAndStallInterval (
+ IN UINTN Timeout
+ )
+{
+ UINTN StallTime;
+
+ if (Timeout < POLL_INTERVAL_US && Timeout != 0) {
+ StallTime = Timeout;
+ } else {
+ StallTime = POLL_INTERVAL_US;
+ }
+
+ gBS->Stall (StallTime);
+
+ return StallTime;
+}
+
+/**
+ This service retrieves the number of logical processor in the platform
+ and the number of those logical processors that are enabled on this boot.
+ This service may only be called from the BSP.
+
+ @param[in] This A pointer to the
+ EFI_MP_SERVICES_PROTOCOL instance.
+ @param[out] NumberOfProcessors Pointer to the total number of logical
+ processors in the system, including
+ the BSP and disabled APs.
+ @param[out] NumberOfEnabledProcessors Pointer to the number of enabled
+ logical processors that exist in the
+ system, including the BSP.
+
+ @retval EFI_SUCCESS The number of logical processors and enabled
+ logical processors was retrieved.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_INVALID_PARAMETER NumberOfProcessors is NULL.
+ @retval EFI_INVALID_PARAMETER NumberOfEnabledProcessors is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetNumberOfProcessors (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ OUT UINTN *NumberOfProcessors,
+ OUT UINTN *NumberOfEnabledProcessors
+ )
+{
+ if ((NumberOfProcessors == NULL) || (NumberOfEnabledProcessors == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (!IsCurrentProcessorBSP ()) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ *NumberOfProcessors = mCpuMpData.NumberOfProcessors;
+ *NumberOfEnabledProcessors = mCpuMpData.NumberOfEnabledProcessors;
+ return EFI_SUCCESS;
+}
+
+/**
+ Gets detailed MP-related information on the requested processor at the
+ instant this call is made. This service may only be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] ProcessorIndex The index of the processor.
+ @param[out] ProcessorInfoBuffer A pointer to the buffer where information
+ for the requested processor is deposited.
+
+ @retval EFI_SUCCESS Processor information was returned.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_INVALID_PARAMETER ProcessorInfoBuffer is NULL.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist in the platform.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetProcessorInfo (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorIndex,
+ OUT EFI_PROCESSOR_INFORMATION *ProcessorInfoBuffer
+ )
+{
+ if (ProcessorInfoBuffer == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (!IsCurrentProcessorBSP ()) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ ProcessorIndex &= ~CPU_V2_EXTENDED_TOPOLOGY;
+
+ if (ProcessorIndex >= mCpuMpData.NumberOfProcessors) {
+ return EFI_NOT_FOUND;
+ }
+
+ CopyMem (
+ ProcessorInfoBuffer,
+ &mCpuMpData.CpuData[ProcessorIndex],
+ sizeof (EFI_PROCESSOR_INFORMATION)
+ );
+ return EFI_SUCCESS;
+}
+
+/** Returns whether the specified processor is enabled.
+
+ @param[in] ProcessorIndex The index of the processor to check.
+
+ @return TRUE if the processor is enabled, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorEnabled (
+ UINTN ProcessorIndex
+ )
+{
+ EFI_PROCESSOR_INFORMATION *CpuInfo;
+
+ CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+ return (CpuInfo->StatusFlag & PROCESSOR_ENABLED_BIT) != 0;
+}
+
+/** Returns whether all processors are in the idle state.
+
+ @return Whether all the processors are idle.
+
+**/
+STATIC
+BOOLEAN
+CheckAllCpusReady (
+ VOID
+ )
+{
+ UINTN Index;
+ CPU_AP_DATA *CpuData;
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ CpuData = &mCpuMpData.CpuData[Index];
+ if (IsProcessorBSP (Index)) {
+ // Skip BSP
+ continue;
+ }
+
+ if (!IsProcessorEnabled (Index)) {
+ // Skip Disabled processors
+ continue;
+ }
+
+ if (GetApState (CpuData) != CpuStateIdle) {
+ return FALSE;
+ }
+ }
+
+ return TRUE;
+}
+
+/** Sets up the state for the StartupAllAPs function.
+
+ @param SingleThread Whether the APs will execute sequentially.
+
+**/
+STATIC
+VOID
+StartupAllAPsPrepareState (
+ IN BOOLEAN SingleThread
+ )
+{
+ UINTN Index;
+ CPU_STATE APInitialState;
+ CPU_AP_DATA *CpuData;
+
+ mCpuMpData.FinishCount = 0;
+ mCpuMpData.StartCount = 0;
+ mCpuMpData.SingleThread = SingleThread;
+
+ APInitialState = CpuStateReady;
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ CpuData = &mCpuMpData.CpuData[Index];
+
+ //
+ // Get APs prepared, and put failing APs into FailedCpuList.
+ // If "SingleThread", only 1 AP will put into ready state, other AP will be
+ // put into ready state 1 by 1, until the previous 1 finished its task.
+ // If not "SingleThread", all APs are put into ready state from the
+ // beginning
+ //
+
+ if (IsProcessorBSP (Index)) {
+ // Skip BSP
+ continue;
+ }
+
+ if (!IsProcessorEnabled (Index)) {
+ // Skip Disabled processors
+ if (mCpuMpData.FailedList != NULL) {
+ mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
+ }
+
+ continue;
+ }
+
+ ASSERT (GetApState (CpuData) == CpuStateIdle);
+ CpuData->State = APInitialState;
+
+ mCpuMpData.StartCount++;
+ if (SingleThread) {
+ APInitialState = CpuStateBlocked;
+ }
+ }
+}
+
+/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
+
+ @param Procedure The user-supplied procedure.
+ @param ProcedureArgument The user-supplied procedure argument.
+ @param WaitEvent The wait event to be signaled when the work is
+ complete or a timeout has occurred.
+ @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+ indicates an infinite timeout.
+
+ @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsWithWaitEvent (
+ IN EFI_AP_PROCEDURE Procedure,
+ IN VOID *ProcedureArgument,
+ IN EFI_EVENT WaitEvent,
+ IN UINTN TimeoutInMicroseconds
+ )
+{
+ EFI_STATUS Status;
+ UINTN Index;
+ CPU_AP_DATA *CpuData;
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ CpuData = &mCpuMpData.CpuData[Index];
+ if (IsProcessorBSP (Index)) {
+ // Skip BSP
+ continue;
+ }
+
+ if (!IsProcessorEnabled (Index)) {
+ // Skip Disabled processors
+ continue;
+ }
+
+ if (GetApState (CpuData) == CpuStateReady) {
+ SetApProcedure (CpuData, Procedure, ProcedureArgument);
+ }
+ }
+
+ //
+ // Save data into private data structure, and create timer to poll AP state
+ // before exiting
+ //
+ mCpuMpData.Procedure = Procedure;
+ mCpuMpData.ProcedureArgument = ProcedureArgument;
+ mCpuMpData.WaitEvent = WaitEvent;
+ mCpuMpData.Timeout = TimeoutInMicroseconds;
+ mCpuMpData.TimeoutActive = (BOOLEAN)(TimeoutInMicroseconds != 0);
+ Status = gBS->SetTimer (
+ mCpuMpData.CheckAllAPsEvent,
+ TimerPeriodic,
+ POLL_INTERVAL_US
+ );
+ return Status;
+}
+
+/** Handles execution of StartupAllAPs when no wait event has been specified.
+
+ @param Procedure The user-supplied procedure.
+ @param ProcedureArgument The user-supplied procedure argument.
+ @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+ indicates an infinite timeout.
+ @param SingleThread Whether the APs will execute sequentially.
+ @param FailedCpuList User-supplied pointer for list of failed CPUs.
+
+ @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsNoWaitEvent (
+ IN EFI_AP_PROCEDURE Procedure,
+ IN VOID *ProcedureArgument,
+ IN UINTN TimeoutInMicroseconds,
+ IN BOOLEAN SingleThread,
+ IN UINTN **FailedCpuList
+ )
+{
+ EFI_STATUS Status;
+ UINTN Index;
+ UINTN NextIndex;
+ UINTN Timeout;
+ CPU_AP_DATA *CpuData;
+
+ Timeout = TimeoutInMicroseconds;
+
+ while (TRUE) {
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ CpuData = &mCpuMpData.CpuData[Index];
+ if (IsProcessorBSP (Index)) {
+ // Skip BSP
+ continue;
+ }
+
+ if (!IsProcessorEnabled (Index)) {
+ // Skip Disabled processors
+ continue;
+ }
+
+ switch (GetApState (CpuData)) {
+ case CpuStateReady:
+ SetApProcedure (CpuData, Procedure, ProcedureArgument);
+ Status = DispatchCpu (Index);
+ if (EFI_ERROR (Status)) {
+ CpuData->State = CpuStateIdle;
+ Status = EFI_NOT_READY;
+ goto Done;
+ }
+
+ break;
+
+ case CpuStateFinished:
+ mCpuMpData.FinishCount++;
+ if (SingleThread) {
+ Status = GetNextBlockedNumber (&NextIndex);
+ if (!EFI_ERROR (Status)) {
+ mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
+ }
+ }
+
+ CpuData->State = CpuStateIdle;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ if (mCpuMpData.FinishCount == mCpuMpData.StartCount) {
+ Status = EFI_SUCCESS;
+ goto Done;
+ }
+
+ if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
+ Status = EFI_TIMEOUT;
+ goto Done;
+ }
+
+ Timeout -= CalculateAndStallInterval (Timeout);
+ }
+
+Done:
+ if (FailedCpuList != NULL) {
+ if (mCpuMpData.FailedListIndex == 0) {
+ FreePool (*FailedCpuList);
+ *FailedCpuList = NULL;
+ }
+ }
+
+ return Status;
+}
+
+/**
+ This service executes a caller provided function on all enabled APs. APs can
+ run either simultaneously or one at a time in sequence. This service supports
+ both blocking and non-blocking requests. The non-blocking requests use EFI
+ events so the BSP can detect when the APs have finished. This service may only
+ be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] Procedure A pointer to the function to be run on
+ enabled APs of the system. See type
+ EFI_AP_PROCEDURE.
+ @param[in] SingleThread If TRUE, then all the enabled APs execute
+ the function specified by Procedure one by
+ one, in ascending order of processor
+ handle number. If FALSE, then all the
+ enabled APs execute the function specified
+ by Procedure simultaneously.
+ @param[in] WaitEvent The event created by the caller with
+ CreateEvent() service. If it is NULL,
+ then execute in blocking mode. BSP waits
+ until all APs finish or
+ TimeoutInMicroseconds expires. If it's
+ not NULL, then execute in non-blocking
+ mode. BSP requests the function specified
+ by Procedure to be started on all the
+ enabled APs, and go on executing
+ immediately. If all return from Procedure,
+ or TimeoutInMicroseconds expires, this
+ event is signaled. The BSP can use the
+ CheckEvent() or WaitForEvent()
+ services to check the state of event. Type
+ EFI_EVENT is defined in CreateEvent() in
+ the Unified Extensible Firmware Interface
+ Specification.
+ @param[in] TimeoutInMicroseconds Indicates the time limit in microseconds
+ for APs to return from Procedure, either
+ for blocking or non-blocking mode. Zero
+ means infinity. If the timeout expires
+ before all APs return from Procedure, then
+ Procedure on the failed APs is terminated.
+ All enabled APs are available for next
+ function assigned by
+ EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+ or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+ If the timeout expires in blocking mode,
+ BSP returns EFI_TIMEOUT. If the timeout
+ expires in non-blocking mode, WaitEvent
+ is signaled with SignalEvent().
+ @param[in] ProcedureArgument The parameter passed into Procedure for
+ all APs.
+ @param[out] FailedCpuList If NULL, this parameter is ignored.
+ Otherwise, if all APs finish successfully,
+ then its content is set to NULL. If not
+ all APs finish before timeout expires,
+ then its content is set to address of the
+ buffer holding handle numbers of the
+ failed APs.
+ The buffer is allocated by MP Service
+ Protocol, and it's the caller's
+ responsibility to free the buffer with
+ FreePool() service.
+ In blocking mode, it is ready for
+ consumption when the call returns. In
+ non-blocking mode, it is ready when
+ WaitEvent is signaled. The list of failed
+ CPU is terminated by END_OF_CPU_LIST.
+
+ @retval EFI_SUCCESS In blocking mode, all APs have finished before
+ the timeout expired.
+ @retval EFI_SUCCESS In non-blocking mode, function has been
+ dispatched to all enabled APs.
+ @retval EFI_UNSUPPORTED A non-blocking mode request was made after the
+ UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+ signaled.
+ @retval EFI_DEVICE_ERROR Caller processor is AP.
+ @retval EFI_NOT_STARTED No enabled APs exist in the system.
+ @retval EFI_NOT_READY Any enabled APs are busy.
+ @retval EFI_TIMEOUT In blocking mode, the timeout expired before
+ all enabled APs have finished.
+ @retval EFI_INVALID_PARAMETER Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupAllAPs (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN BOOLEAN SingleThread,
+ IN EFI_EVENT WaitEvent OPTIONAL,
+ IN UINTN TimeoutInMicroseconds,
+ IN VOID *ProcedureArgument OPTIONAL,
+ OUT UINTN **FailedCpuList OPTIONAL
+ )
+{
+ EFI_STATUS Status;
+
+ if (!IsCurrentProcessorBSP ()) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ if (mCpuMpData.NumberOfProcessors == 1) {
+ return EFI_NOT_STARTED;
+ }
+
+ if (Procedure == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
+ return EFI_UNSUPPORTED;
+ }
+
+ if (!CheckAllCpusReady ()) {
+ return EFI_NOT_READY;
+ }
+
+ if (FailedCpuList != NULL) {
+ mCpuMpData.FailedList = AllocatePool (
+ (mCpuMpData.NumberOfProcessors + 1) *
+ sizeof (UINTN)
+ );
+ if (mCpuMpData.FailedList == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ SetMemN (
+ mCpuMpData.FailedList,
+ (mCpuMpData.NumberOfProcessors + 1) *
+ sizeof (UINTN),
+ END_OF_CPU_LIST
+ );
+ mCpuMpData.FailedListIndex = 0;
+ *FailedCpuList = mCpuMpData.FailedList;
+ }
+
+ StartupAllAPsPrepareState (SingleThread);
+
+ if (WaitEvent != NULL) {
+ Status = StartupAllAPsWithWaitEvent (
+ Procedure,
+ ProcedureArgument,
+ WaitEvent,
+ TimeoutInMicroseconds
+ );
+ } else {
+ Status = StartupAllAPsNoWaitEvent (
+ Procedure,
+ ProcedureArgument,
+ TimeoutInMicroseconds,
+ SingleThread,
+ FailedCpuList
+ );
+ }
+
+ return Status;
+}
+
+/**
+ This service lets the caller get one enabled AP to execute a caller-provided
+ function. The caller can request the BSP to either wait for the completion
+ of the AP or just proceed with the next task by using the EFI event mechanism.
+ See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
+ execution support. This service may only be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL
+ instance.
+ @param[in] Procedure A pointer to the function to be run on
+ enabled APs of the system. See type
+ EFI_AP_PROCEDURE.
+ @param[in] ProcessorNumber The handle number of the AP. The range is
+ from 0 to the total number of logical
+ processors minus 1. The total number of
+ logical processors can be retrieved by
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @param[in] WaitEvent The event created by the caller with CreateEvent()
+ service. If it is NULL, then execute in
+ blocking mode. BSP waits until all APs finish
+ or TimeoutInMicroseconds expires. If it's
+ not NULL, then execute in non-blocking mode.
+ BSP requests the function specified by
+ Procedure to be started on all the enabled
+ APs, and go on executing immediately. If
+ all return from Procedure or TimeoutInMicroseconds
+ expires, this event is signaled. The BSP
+ can use the CheckEvent() or WaitForEvent()
+ services to check the state of event. Type
+ EFI_EVENT is defined in CreateEvent() in
+ the Unified Extensible Firmware Interface
+ Specification.
+ @param[in] TimeoutInMicroseconds Indicates the time limit in microseconds for
+ APs to return from Procedure, either for
+ blocking or non-blocking mode. Zero means
+ infinity. If the timeout expires before
+ all APs return from Procedure, then Procedure
+ on the failed APs is terminated. All enabled
+ APs are available for next function assigned
+ by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+ or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+ If the timeout expires in blocking mode,
+ BSP returns EFI_TIMEOUT. If the timeout
+ expires in non-blocking mode, WaitEvent
+ is signaled with SignalEvent().
+ @param[in] ProcedureArgument The parameter passed into Procedure for
+ all APs.
+ @param[out] Finished If NULL, this parameter is ignored. In
+ blocking mode, this parameter is ignored.
+ In non-blocking mode, if AP returns from
+ Procedure before the timeout expires, its
+ content is set to TRUE. Otherwise, the
+ value is set to FALSE. The caller can
+ determine if the AP returned from Procedure
+ by evaluating this value.
+
+ @retval EFI_SUCCESS In blocking mode, specified AP finished before
+ the timeout expires.
+ @retval EFI_SUCCESS In non-blocking mode, the function has been
+ dispatched to specified AP.
+ @retval EFI_UNSUPPORTED A non-blocking mode request was made after the
+ UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+ signaled.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_TIMEOUT In blocking mode, the timeout expired before
+ the specified AP has finished.
+ @retval EFI_NOT_READY The specified AP is busy.
+ @retval EFI_NOT_FOUND The processor with the handle specified by
+ ProcessorNumber does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the BSP or disabled AP.
+ @retval EFI_INVALID_PARAMETER Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupThisAP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN UINTN ProcessorNumber,
+ IN EFI_EVENT WaitEvent OPTIONAL,
+ IN UINTN TimeoutInMicroseconds,
+ IN VOID *ProcedureArgument OPTIONAL,
+ OUT BOOLEAN *Finished OPTIONAL
+ )
+{
+ EFI_STATUS Status;
+ UINTN Timeout;
+ CPU_AP_DATA *CpuData;
+
+ if (!IsCurrentProcessorBSP ()) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ if (Procedure == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+ return EFI_NOT_FOUND;
+ }
+
+ CpuData = &mCpuMpData.CpuData[ProcessorNumber];
+
+ if (IsProcessorBSP (ProcessorNumber)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (!IsProcessorEnabled (ProcessorNumber)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (GetApState (CpuData) != CpuStateIdle) {
+ return EFI_NOT_READY;
+ }
+
+ if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
+ return EFI_UNSUPPORTED;
+ }
+
+ Timeout = TimeoutInMicroseconds;
+
+ mCpuMpData.StartCount = 1;
+ mCpuMpData.FinishCount = 0;
+
+ SetApProcedure (
+ CpuData,
+ Procedure,
+ ProcedureArgument
+ );
+
+ Status = DispatchCpu (ProcessorNumber);
+ if (EFI_ERROR (Status)) {
+ CpuData->State = CpuStateIdle;
+ return EFI_NOT_READY;
+ }
+
+ if (WaitEvent != NULL) {
+ // Non Blocking
+ mCpuMpData.WaitEvent = WaitEvent;
+ gBS->SetTimer (
+ CpuData->CheckThisAPEvent,
+ TimerPeriodic,
+ POLL_INTERVAL_US
+ );
+ return EFI_SUCCESS;
+ }
+
+ // Blocking
+ while (TRUE) {
+ if (GetApState (CpuData) == CpuStateFinished) {
+ CpuData->State = CpuStateIdle;
+ break;
+ }
+
+ if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
+ return EFI_TIMEOUT;
+ }
+
+ Timeout -= CalculateAndStallInterval (Timeout);
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ This service switches the requested AP to be the BSP from that point onward.
+ This service changes the BSP for all purposes. This call can only be
+ performed by the current BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @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
+EFIAPI
+MpInitLibSwitchBSP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableOldBSP
+ )
+{
+ UINTN Index;
+ CPU_AP_DATA *CpuData;
+
+ CpuData = &mCpuMpData.CpuData[ProcessorNumber];
+
+ if (!IsCurrentProcessorBSP ()) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+ return EFI_NOT_FOUND;
+ }
+
+ if (!IsProcessorEnabled (ProcessorNumber)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (IsProcessorBSP (ProcessorNumber)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ if (IsProcessorBSP (Index)) {
+ break;
+ }
+ }
+
+ ASSERT (Index != mCpuMpData.NumberOfProcessors);
+
+ if (GetApState (CpuData) != CpuStateIdle) {
+ return EFI_NOT_READY;
+ }
+
+ // Skip for now as we need switch a bunch of stack stuff around and it's
+ // complex. May not be worth it?
+ return EFI_NOT_READY;
+}
+
+/**
+ This service lets the caller enable or disable an AP from this point onward.
+ This service may only be called from the BSP.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+ @param[in] EnableAP Specifies the new state for the processor for
+ enabled, FALSE for disabled.
+ @param[in] HealthFlag If not NULL, a pointer to a value that specifies
+ the new health status of the AP. This flag
+ corresponds to StatusFlag defined in
+ EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
+ the PROCESSOR_HEALTH_STATUS_BIT is used. All other
+ bits are ignored. If it is NULL, this parameter
+ is ignored.
+
+ @retval EFI_SUCCESS The specified AP was enabled or disabled successfully.
+ @retval EFI_UNSUPPORTED Enabling or disabling an AP cannot be completed
+ prior to this service returning.
+ @retval EFI_UNSUPPORTED Enabling or disabling an AP is not supported.
+ @retval EFI_DEVICE_ERROR The calling processor is an AP.
+ @retval EFI_NOT_FOUND Processor with the handle specified by ProcessorNumber
+ does not exist.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber specifies the BSP.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibEnableDisableAP (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ IN UINTN ProcessorNumber,
+ IN BOOLEAN EnableAP,
+ IN UINT32 *HealthFlag OPTIONAL
+ )
+{
+ UINTN StatusFlag;
+ CPU_AP_DATA *CpuData;
+
+ StatusFlag = mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag;
+ CpuData = &mCpuMpData.CpuData[ProcessorNumber];
+
+ if (!IsCurrentProcessorBSP ()) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+ return EFI_NOT_FOUND;
+ }
+
+ if (IsProcessorBSP (ProcessorNumber)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (GetApState (CpuData) != CpuStateIdle) {
+ return EFI_UNSUPPORTED;
+ }
+
+ if (EnableAP) {
+ if (!IsProcessorEnabled (ProcessorNumber)) {
+ mCpuMpData.NumberOfEnabledProcessors++;
+ }
+
+ StatusFlag |= PROCESSOR_ENABLED_BIT;
+ } else {
+ if (IsProcessorEnabled (ProcessorNumber)) {
+ mCpuMpData.NumberOfEnabledProcessors--;
+ }
+
+ StatusFlag &= ~PROCESSOR_ENABLED_BIT;
+ }
+
+ if (HealthFlag != NULL) {
+ StatusFlag &= ~PROCESSOR_HEALTH_STATUS_BIT;
+ StatusFlag |= (*HealthFlag & PROCESSOR_HEALTH_STATUS_BIT);
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ This return the handle number for the calling processor. This service may be
+ called from the BSP and APs.
+
+ @param[in] This A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+ @param[out] 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
+ EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+
+ @retval EFI_SUCCESS The current processor handle number was returned
+ in ProcessorNumber.
+ @retval EFI_INVALID_PARAMETER ProcessorNumber is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibWhoAmI (
+ IN EFI_MP_SERVICES_PROTOCOL *This,
+ OUT UINTN *ProcessorNumber
+ )
+{
+ UINTN Index;
+ UINT64 ProcessorId;
+ CPU_AP_DATA *CpuData;
+
+ if (ProcessorNumber == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ ProcessorId = ArmReadMpidr ();
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ CpuData = &mCpuMpData.CpuData[Index];
+ if (CpuData->Info.ProcessorId == ProcessorId) {
+ break;
+ }
+ }
+
+ *ProcessorNumber = Index;
+ return EFI_SUCCESS;
+}
+
+/** Adds the specified processor the list of failed processors.
+
+ @param ProcessorIndex The processor index to add.
+ @param ApState Processor state.
+
+**/
+STATIC
+VOID
+AddProcessorToFailedList (
+ UINTN ProcessorIndex,
+ CPU_STATE ApState
+ )
+{
+ UINTN Index;
+ BOOLEAN Found;
+
+ Found = FALSE;
+
+ if (ApState == CpuStateIdle) {
+ return;
+ }
+
+ // If we are retrying make sure we don't double count
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ if (mCpuMpData.FailedList[Index] == END_OF_CPU_LIST) {
+ break;
+ }
+
+ if (mCpuMpData.FailedList[ProcessorIndex] == Index) {
+ Found = TRUE;
+ break;
+ }
+ }
+
+ /* If the CPU isn't already in the FailedList, add it */
+ if (!Found) {
+ mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
+ }
+}
+
+/** Handles the StartupAllAPs case where the timeout has occurred.
+
+**/
+STATIC
+VOID
+ProcessStartupAllAPsTimeout (
+ VOID
+ )
+{
+ CPU_AP_DATA *CpuData;
+ UINTN Index;
+
+ if (mCpuMpData.FailedList == NULL) {
+ return;
+ }
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ CpuData = &mCpuMpData.CpuData[Index];
+ if (IsProcessorBSP (Index)) {
+ // Skip BSP
+ continue;
+ }
+
+ if (!IsProcessorEnabled (Index)) {
+ // Skip Disabled processors
+ continue;
+ }
+
+ AddProcessorToFailedList (Index, GetApState (CpuData));
+ }
+}
+
+/** Updates the status of the APs.
+
+ @param[in] ProcessorIndex The index of the AP to update.
+**/
+STATIC
+VOID
+UpdateApStatus (
+ IN UINTN ProcessorIndex
+ )
+{
+ EFI_STATUS Status;
+ CPU_AP_DATA *CpuData;
+ CPU_AP_DATA *NextCpuData;
+ CPU_STATE State;
+ UINTN NextNumber;
+
+ CpuData = &mCpuMpData.CpuData[ProcessorIndex];
+
+ if (IsProcessorBSP (ProcessorIndex)) {
+ // Skip BSP
+ return;
+ }
+
+ if (!IsProcessorEnabled (ProcessorIndex)) {
+ // Skip Disabled processors
+ return;
+ }
+
+ State = GetApState (CpuData);
+
+ switch (State) {
+ case CpuStateFinished:
+ if (mCpuMpData.SingleThread) {
+ Status = GetNextBlockedNumber (&NextNumber);
+ if (!EFI_ERROR (Status)) {
+ NextCpuData = &mCpuMpData.CpuData[NextNumber];
+
+ NextCpuData->State = CpuStateReady;
+
+ SetApProcedure (
+ NextCpuData,
+ mCpuMpData.Procedure,
+ mCpuMpData.ProcedureArgument
+ );
+ }
+ }
+
+ CpuData->State = CpuStateIdle;
+ mCpuMpData.FinishCount++;
+ break;
+
+ default:
+ break;
+ }
+}
+
+/**
+ If a timeout is specified in StartupAllAps(), a timer is set, which invokes
+ this procedure periodically to check whether all APs have finished.
+
+ @param[in] Event The WaitEvent the user supplied.
+ @param[in] Context The event context.
+**/
+STATIC
+VOID
+EFIAPI
+CheckAllAPsStatus (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ UINTN Index;
+
+ if (mCpuMpData.TimeoutActive) {
+ mCpuMpData.Timeout -= CalculateAndStallInterval (mCpuMpData.Timeout);
+ }
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ UpdateApStatus (Index);
+ }
+
+ if (mCpuMpData.TimeoutActive && mCpuMpData.Timeout == 0) {
+ ProcessStartupAllAPsTimeout ();
+
+ // Force terminal exit
+ mCpuMpData.FinishCount = mCpuMpData.StartCount;
+ }
+
+ if (mCpuMpData.FinishCount != mCpuMpData.StartCount) {
+ return;
+ }
+
+ gBS->SetTimer (
+ mCpuMpData.CheckAllAPsEvent,
+ TimerCancel,
+ 0
+ );
+
+ if (mCpuMpData.FailedListIndex == 0) {
+ if (mCpuMpData.FailedList != NULL) {
+ FreePool (mCpuMpData.FailedList);
+ mCpuMpData.FailedList = NULL;
+ }
+ }
+
+ gBS->SignalEvent (mCpuMpData.WaitEvent);
+}
+
+/** Invoked periodically via a timer to check the state of the processor.
+
+ @param Event The event supplied by the timer expiration.
+ @param Context The processor context.
+
+**/
+STATIC
+VOID
+EFIAPI
+CheckThisAPStatus (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ EFI_STATUS Status;
+ CPU_AP_DATA *CpuData;
+ CPU_STATE State;
+
+ CpuData = Context;
+ CpuData->TimeTaken += POLL_INTERVAL_US;
+
+ State = GetApState (CpuData);
+
+ if (State == CpuStateFinished) {
+ Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
+ ASSERT_EFI_ERROR (Status);
+
+ if (mCpuMpData.WaitEvent != NULL) {
+ Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
+ ASSERT_EFI_ERROR (Status);
+ }
+
+ CpuData->State = CpuStateIdle;
+ }
+
+ if (CpuData->TimeTaken > CpuData->Timeout) {
+ if (mCpuMpData.WaitEvent != NULL) {
+ Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
+ ASSERT_EFI_ERROR (Status);
+ }
+ }
+}
+
+/**
+ This function is called by all processors (both BSP and AP) once and collects
+ MP related data.
+
+ @param BSP TRUE if the processor is the BSP.
+ @param Mpidr The MPIDR for the specified processor.
+ @param ProcessorIndex The index of the processor.
+
+ @return EFI_SUCCESS if the data for the processor collected and filled in.
+
+**/
+STATIC
+EFI_STATUS
+FillInProcessorInformation (
+ IN BOOLEAN BSP,
+ IN UINTN Mpidr,
+ IN UINTN ProcessorIndex
+ )
+{
+ EFI_PROCESSOR_INFORMATION *CpuInfo;
+
+ CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+ /* The MPIDR passed in may be a pseudo-MPIDR that's missing the bit 31 RES1.
+ * Fix it so it's a proper MPIDR.
+ */
+ CpuInfo->ProcessorId = BIT31 | Mpidr;
+ CpuInfo->StatusFlag = PROCESSOR_ENABLED_BIT | PROCESSOR_HEALTH_STATUS_BIT;
+
+ if (BSP) {
+ CpuInfo->StatusFlag |= PROCESSOR_AS_BSP_BIT;
+ }
+
+ CpuInfo->Location.Package = GET_CLUSTER_ID (Mpidr);
+ CpuInfo->Location.Core = GET_CORE_ID (Mpidr);
+ CpuInfo->Location.Thread = 0;
+
+ CpuInfo->ExtendedInformation.Location2.Package = 0;
+ CpuInfo->ExtendedInformation.Location2.Module = 0;
+ CpuInfo->ExtendedInformation.Location2.Tile = 0;
+ CpuInfo->ExtendedInformation.Location2.Die = GET_CLUSTER_ID (Mpidr);
+ CpuInfo->ExtendedInformation.Location2.Core = GET_CORE_ID (Mpidr);
+ CpuInfo->ExtendedInformation.Location2.Thread = 0;
+
+ mCpuMpData.CpuData[ProcessorIndex].State = BSP ? CpuStateBusy : CpuStateIdle;
+
+ mCpuMpData.CpuData[ProcessorIndex].Procedure = NULL;
+ mCpuMpData.CpuData[ProcessorIndex].Parameter = NULL;
+
+ return EFI_SUCCESS;
+}
+
+/** Initializes the MP Services system data
+
+ @param NumberOfProcessors The number of processors, both BSP and AP.
+ @param CpuInfo CPU information gathered earlier during boot.
+
+**/
+VOID
+MpInitLibInitialize (
+ IN UINTN NumberOfProcessors,
+ IN ARM_PROCESSOR_TABLE *CpuInfo
+ )
+{
+ EFI_STATUS Status;
+ UINTN Index;
+ EFI_EVENT ReadyToBootEvent;
+
+ //
+ // Clear the data structure area first.
+ //
+ ZeroMem (&mCpuMpData, sizeof (CPU_MP_DATA));
+ //
+ // First BSP fills and inits all known values, including its own records.
+ //
+ mCpuMpData.NumberOfProcessors = NumberOfProcessors;
+ mCpuMpData.NumberOfEnabledProcessors = NumberOfProcessors;
+
+ mCpuMpData.CpuData = AllocateZeroPool (
+ mCpuMpData.NumberOfProcessors *
+ sizeof (CPU_AP_DATA)
+ );
+ ASSERT (mCpuMpData.CpuData != NULL);
+
+ /* Allocate one extra for the NULL entry at the end */
+ gProcessorIDs = AllocatePool ((mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64));
+ ASSERT (gProcessorIDs != NULL);
+
+ FillInProcessorInformation (TRUE, CpuInfo->ArmCpus[0].Mpidr, 0);
+ gProcessorIDs[0] = mCpuMpData.CpuData[0].Info.ProcessorId;
+
+ Status = gBS->CreateEvent (
+ EVT_TIMER | EVT_NOTIFY_SIGNAL,
+ TPL_CALLBACK,
+ CheckAllAPsStatus,
+ NULL,
+ &mCpuMpData.CheckAllAPsEvent
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ gApStacksBase = AllocatePool (
+ mCpuMpData.NumberOfProcessors *
+ gApStackSize
+ );
+ ASSERT (gApStacksBase != NULL);
+
+ for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+ if (IsProcessorBSP (Index)) {
+ /* Skip BSP */
+ continue;
+ }
+
+ FillInProcessorInformation (FALSE, CpuInfo->ArmCpus[Index].Mpidr, Index);
+
+ gProcessorIDs[Index] = mCpuMpData.CpuData[Index].Info.ProcessorId;
+
+ Status = gBS->CreateEvent (
+ EVT_TIMER | EVT_NOTIFY_SIGNAL,
+ TPL_CALLBACK,
+ CheckThisAPStatus,
+ (VOID *)&mCpuMpData.CpuData[Index],
+ &mCpuMpData.CpuData[Index].CheckThisAPEvent
+ );
+ ASSERT (Status == EFI_SUCCESS);
+ }
+
+ Status = EfiCreateEventReadyToBootEx (
+ TPL_CALLBACK,
+ ReadyToBootSignaled,
+ NULL,
+ &ReadyToBootEvent
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ gProcessorIDs[Index] = 0;
+}
+
+/**
+ Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
+ signaled. After this point, non-blocking mode is no longer allowed.
+
+ @param Event Event whose notification function is being invoked.
+ @param Context The pointer to the notification function's context,
+ which is implementation-dependent.
+
+**/
+STATIC
+VOID
+EFIAPI
+ReadyToBootSignaled (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ mNonBlockingModeAllowed = FALSE;
+}
+
diff --git a/ArmPkg/Library/MpInitLib/InternalMpInitLib.h b/ArmPkg/Library/MpInitLib/InternalMpInitLib.h
new file mode 100644
index 000000000000..d08bb76246d7
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/InternalMpInitLib.h
@@ -0,0 +1,358 @@
+/** @file
+
+Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+Portions copyright (c) 2011, Apple Inc. All rights reserved.
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MP_INTERNAL_INIT_LIB_H_
+#define MP_INTERNAL_INIT_LIB_H_
+
+#include <Protocol/Cpu.h>
+#include <Protocol/MpService.h>
+
+#include <Library/BaseLib.h>
+#include <Library/UefiLib.h>
+
+
+#define AP_STACK_SIZE 0x1000
+
+//
+// Internal Data Structures
+//
+
+//
+// AP state
+//
+// The state transitions for an AP when it process a procedure are:
+// Idle ----> Ready ----> Busy ----> Idle
+// [BSP] [AP] [AP]
+//
+typedef enum {
+ CpuStateIdle,
+ CpuStateReady,
+ CpuStateBlocked,
+ CpuStateBusy,
+ CpuStateFinished,
+ CpuStateDisabled
+} CPU_STATE;
+
+//
+// Define Individual Processor Data block.
+//
+typedef struct {
+ EFI_PROCESSOR_INFORMATION Info;
+ EFI_AP_PROCEDURE Procedure;
+ VOID *Parameter;
+ CPU_STATE State;
+ EFI_EVENT CheckThisAPEvent;
+ UINTN Timeout;
+ UINTN TimeTaken;
+} CPU_AP_DATA;
+
+//
+// Define MP data block which consumes individual processor block.
+//
+typedef struct {
+ UINTN NumberOfProcessors;
+ UINTN NumberOfEnabledProcessors;
+ EFI_EVENT CheckAllAPsEvent;
+ EFI_EVENT WaitEvent;
+ UINTN FinishCount;
+ UINTN StartCount;
+ EFI_AP_PROCEDURE Procedure;
+ VOID *ProcedureArgument;
+ BOOLEAN SingleThread;
+ UINTN StartedNumber;
+ CPU_AP_DATA *CpuData;
+ UINTN Timeout;
+ UINTN *FailedList;
+ UINTN FailedListIndex;
+ BOOLEAN TimeoutActive;
+} CPU_MP_DATA;
+
+EFI_STATUS
+EFIAPI
+CpuMpServicesInit (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ );
+
+extern EFI_MP_SERVICES_PROTOCOL mMpServicesTemplate;
+
+/** Secondary core entry point.
+
+**/
+VOID ApEntryPoint (
+ VOID
+ );
+
+/** C entry-point for the AP.
+ This function gets called from the assembly function ApEntryPoint.
+**/
+VOID
+ApProcedure (
+ VOID
+ );
+
+/** Turns on the specified core using PSCI and executes the user-supplied
+ function that's been configured via a previous call to SetApProcedure.
+
+ @param ProcessorIndex The index of the core to turn on.
+
+ @retval EFI_SUCCESS The processor was successfully turned on.
+ @retval EFI_DEVICE_ERROR An error occurred turning the processor on.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+DispatchCpu (
+ IN UINTN ProcessorIndex
+ );
+
+/** Returns whether the specified processor is the BSP.
+
+ @param[in] ProcessorIndex The index the processor to check.
+
+ @return TRUE if the processor is the BSP, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorBSP (
+ UINTN ProcessorIndex
+ );
+
+/** Returns whether the processor executing this function is the BSP.
+
+ @return Whether the current processor is the BSP.
+**/
+STATIC
+BOOLEAN
+IsCurrentProcessorBSP (
+ VOID
+ );
+
+/** Returns whether the specified processor is enabled.
+
+ @param[in] ProcessorIndex The index of the processor to check.
+
+ @return TRUE if the processor is enabled, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorEnabled (
+ UINTN ProcessorIndex
+ );
+
+/** Configures the processor context with the user-supplied procedure and
+ argument.
+
+ @param CpuData The processor context.
+ @param Procedure The user-supplied procedure.
+ @param ProcedureArgument The user-supplied procedure argument.
+
+**/
+STATIC
+VOID
+SetApProcedure (
+ IN CPU_AP_DATA *CpuData,
+ IN EFI_AP_PROCEDURE Procedure,
+ IN VOID *ProcedureArgument
+ );
+
+/**
+ Get the Application Processors state.
+
+ @param[in] CpuData The pointer to CPU_AP_DATA of specified AP
+
+ @return The AP status
+**/
+CPU_STATE
+GetApState (
+ IN CPU_AP_DATA *CpuData
+ );
+
+/** Returns the index of the next processor that is blocked.
+
+ @param[out] NextNumber The index of the next blocked processor.
+
+ @retval EFI_SUCCESS Successfully found the next blocked processor.
+ @retval EFI_NOT_FOUND There are no blocked processors.
+
+**/
+STATIC
+EFI_STATUS
+GetNextBlockedNumber (
+ OUT UINTN *NextNumber
+ );
+
+/** Stalls the BSP for the minimum of gPollInterval and Timeout.
+
+ @param[in] Timeout The time limit in microseconds remaining for
+ APs to return from Procedure.
+
+ @retval StallTime Time of execution stall.
+**/
+STATIC
+UINTN
+CalculateAndStallInterval (
+ IN UINTN Timeout
+ );
+
+/** Returns whether all processors are in the idle state.
+
+ @return Whether all the processors are idle.
+
+**/
+STATIC
+BOOLEAN
+CheckAllCpusReady (
+ VOID
+ );
+
+/** Sets up the state for the StartupAllAPs function.
+
+ @param SingleThread Whether the APs will execute sequentially.
+
+**/
+STATIC
+VOID
+StartupAllAPsPrepareState (
+ IN BOOLEAN SingleThread
+ );
+
+/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
+
+ @param Procedure The user-supplied procedure.
+ @param ProcedureArgument The user-supplied procedure argument.
+ @param WaitEvent The wait event to be signaled when the work is
+ complete or a timeout has occurred.
+ @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+ indicates an infinite timeout.
+
+ @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsWithWaitEvent (
+ IN EFI_AP_PROCEDURE Procedure,
+ IN VOID *ProcedureArgument,
+ IN EFI_EVENT WaitEvent,
+ IN UINTN TimeoutInMicroseconds
+ );
+
+/** Handles execution of StartupAllAPs when no wait event has been specified.
+
+ @param Procedure The user-supplied procedure.
+ @param ProcedureArgument The user-supplied procedure argument.
+ @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+ indicates an infinite timeout.
+ @param SingleThread Whether the APs will execute sequentially.
+ @param FailedCpuList User-supplied pointer for list of failed CPUs.
+
+ @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsNoWaitEvent (
+ IN EFI_AP_PROCEDURE Procedure,
+ IN VOID *ProcedureArgument,
+ IN UINTN TimeoutInMicroseconds,
+ IN BOOLEAN SingleThread,
+ IN UINTN **FailedCpuList
+ );
+
+
+/** Adds the specified processor the list of failed processors.
+
+ @param ProcessorIndex The processor index to add.
+ @param ApState Processor state.
+
+**/
+STATIC
+VOID
+AddProcessorToFailedList (
+ UINTN ProcessorIndex,
+ CPU_STATE ApState
+ );
+
+/** Handles the StartupAllAPs case where the timeout has occurred.
+
+**/
+STATIC
+VOID
+ProcessStartupAllAPsTimeout (
+ VOID
+ );
+
+/**
+ If a timeout is specified in StartupAllAps(), a timer is set, which invokes
+ this procedure periodically to check whether all APs have finished.
+
+ @param[in] Event The WaitEvent the user supplied.
+ @param[in] Context The event context.
+**/
+STATIC
+VOID
+EFIAPI
+CheckAllAPsStatus (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ );
+
+/** Invoked periodically via a timer to check the state of the processor.
+
+ @param Event The event supplied by the timer expiration.
+ @param Context The processor context.
+
+**/
+STATIC
+VOID
+EFIAPI
+CheckThisAPStatus (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ );
+
+/**
+ This function is called by all processors (both BSP and AP) once and collects
+ MP related data.
+
+ @param BSP TRUE if the processor is the BSP.
+ @param Mpidr The MPIDR for the specified processor.
+ @param ProcessorIndex The index of the processor.
+
+ @return EFI_SUCCESS if the data for the processor collected and filled in.
+
+**/
+STATIC
+EFI_STATUS
+FillInProcessorInformation (
+ IN BOOLEAN BSP,
+ IN UINTN Mpidr,
+ IN UINTN ProcessorIndex
+ );
+
+/**
+ Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
+ signaled. After this point, non-blocking mode is no longer allowed.
+
+ @param Event Event whose notification function is being invoked.
+ @param Context The pointer to the notification function's context,
+ which is implementation-dependent.
+
+**/
+STATIC
+VOID
+EFIAPI
+ReadyToBootSignaled (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ );
+
+
+#endif /* MP_INTERNAL_INIT_LIB_H_ */
diff --git a/ArmVirtPkg/ArmVirt.dsc.inc b/ArmVirtPkg/ArmVirt.dsc.inc
index 5a1598d90ca7..af6e48fd6cfc 100644
--- a/ArmVirtPkg/ArmVirt.dsc.inc
+++ b/ArmVirtPkg/ArmVirt.dsc.inc
@@ -261,6 +261,9 @@
[LibraryClasses.ARM]
ArmSoftFloatLib|ArmPkg/Library/ArmSoftFloatLib/ArmSoftFloatLib.inf

+[LibraryClasses.AARCH64]
+ MpInitLib|ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
+
[BuildOptions]
RVCT:RELEASE_*_*_CC_FLAGS = -DMDEPKG_NDEBUG

--
2.31.1


Sami Mujawar
 

Hi Rebecca,

Thanks you for this patch.

I think this patch could be split in 2 - 3 patches (CpuDxe  & MpInitLib and the ArmVirtPkg change should be a separate patch).

Please find my feedback inline marked [SAMI].

I think the usage of MPIDR and CpuInfo->ProcessorId needs to be revisited in this patch series. I have kept my feedback on usage of MPIDR and the MT bit [24] to give the context. But, it will be good to only retain the affinity bits and mask all other bits of the MPIDR.

Please let me know if you have any queries.

Regards,

Sami Mujawar


On 18/10/2021 04:39 PM, Rebecca Cran wrote:
Add support for EFI_MP_SERVICES_PROTOCOL during the DXE phase under
AArch64.

PSCI_CPU_ON is called to power on the core, the supplied procedure is
executed and PSCI_CPU_OFF is called to power off the core.

Minimal setup is done before calling the supplied procedure: for example
the MMU and caches are not enabled.

Signed-off-by: Rebecca Cran <rebecca@...>
---
 ArmPkg/ArmPkg.dec                            |    4 +
 ArmPkg/ArmPkg.dsc                            |    4 +
 ArmPkg/Drivers/CpuDxe/AArch64/Arch.c         |   22 +
 ArmPkg/Drivers/CpuDxe/Arm/Arch.c             |   22 +
 ArmPkg/Drivers/CpuDxe/CpuDxe.c               |    2 +
 ArmPkg/Drivers/CpuDxe/CpuDxe.h               |   10 +
 ArmPkg/Drivers/CpuDxe/CpuDxe.inf             |    6 +
 ArmPkg/Drivers/CpuDxe/CpuMpInit.c            |  604 ++++++++
 ArmPkg/Include/Library/MpInitLib.h           |  366 +++++
 ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S   |   61 +
 ArmPkg/Library/MpInitLib/DxeMpInitLib.inf    |   53 +
 ArmPkg/Library/MpInitLib/DxeMpLib.c          | 1498 ++++++++++++++++++++
 ArmPkg/Library/MpInitLib/InternalMpInitLib.h |  358 +++++
 ArmVirtPkg/ArmVirt.dsc.inc                   |    3 +
 14 files changed, 3013 insertions(+)

diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec
index 5935663fa9a3..f8bb4af21749 100644
--- a/ArmPkg/ArmPkg.dec
+++ b/ArmPkg/ArmPkg.dec
@@ -74,6 +74,10 @@
   #
   DefaultExceptionHandlerLib|Include/Library/DefaultExceptionHandlerLib.h
 
+  ##  @libraryclass  Provides a MP Services interface.
+  #
+  MpInitLib|Include/Library/MpInitLib.h
+
   ##  @libraryclass  Provides an interface to query miscellaneous OEM
   #   information.
   #
diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
index 8abe3713c829..26fb8bb94c07 100644
--- a/ArmPkg/ArmPkg.dsc
+++ b/ArmPkg/ArmPkg.dsc
@@ -99,6 +99,9 @@
   PeiServicesLib|MdePkg/Library/PeiServicesLib/PeiServicesLib.inf
   PeiServicesTablePointerLib|MdePkg/Library/PeiServicesTablePointerLib/PeiServicesTablePointerLib.inf
 
+[LibraryClasses.AARCH64]
+  MpInitLib|ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
+
 [LibraryClasses.ARM, LibraryClasses.AARCH64]
   NULL|ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
 
@@ -163,4 +166,5 @@
   ArmPkg/Library/ArmMmuLib/ArmMmuPeiLib.inf
 
 [Components.AARCH64, Components.ARM]
+  ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
[SAMI] Should this be in the [Components.AARCH64] section, as DxeMpInitLib.inf currently supports AARCH64 only?
   ArmPkg/Library/StandaloneMmMmuLib/ArmMmuStandaloneMmLib.inf
diff --git a/ArmPkg/Drivers/CpuDxe/AArch64/Arch.c b/ArmPkg/Drivers/CpuDxe/AArch64/Arch.c
new file mode 100644
index 000000000000..a4b9e9037100
--- /dev/null
+++ b/ArmPkg/Drivers/CpuDxe/AArch64/Arch.c
@@ -0,0 +1,22 @@
+/** @file
+  Architecture specific functions.
+
+  Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <CpuDxe.h>
+
+/** Initializes multi-processor support.
+ *
+**/
+VOID
+ArchInitializeMpSupport (
+  VOID
+  )
+{
+  InitializeMpSupport ();
+}
diff --git a/ArmPkg/Drivers/CpuDxe/Arm/Arch.c b/ArmPkg/Drivers/CpuDxe/Arm/Arch.c
new file mode 100644
index 000000000000..0ded264cd06a
--- /dev/null
+++ b/ArmPkg/Drivers/CpuDxe/Arm/Arch.c
@@ -0,0 +1,22 @@
+/** @file
+  Architecture specific functions.
+
+  Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <CpuDxe.h>
+
+/** Initializes multi-processor support.
+ *
+**/
+VOID
+ArchInitializeMpSupport (
+  VOID
+  )
+{
+  /* Nothing to do - ARM doesn't support EFI_MP_SERVICES_PROTOCOL */
+}
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.c b/ArmPkg/Drivers/CpuDxe/CpuDxe.c
index 082ef30fb6c4..db8752f5b54f 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.c
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.c
@@ -279,5 +279,7 @@ CpuDxeInitialize (
                   );
   ASSERT_EFI_ERROR (Status);
 
+  ArchInitializeMpSupport ();
+
   return Status;
 }
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.h b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
index 4cf3ab258c24..6e7ceafa4436 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.h
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.h
@@ -143,4 +143,14 @@ SetGcdMemorySpaceAttributes (
   IN UINT64                              Attributes
   );
 
+VOID
+InitializeMpSupport (
+  VOID
+  );
+
+VOID
+ArchInitializeMpSupport (
+  VOID
+  );
+
 #endif // CPU_DXE_H_
diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.inf b/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
index e5549fc71df7..f4cdb8ab5613 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.inf
@@ -26,10 +26,13 @@
   Exception.c
 
 [Sources.ARM]
+  Arm/Arch.c
   Arm/Mmu.c
 
 [Sources.AARCH64]
+  AArch64/Arch.c
   AArch64/Mmu.c
+  CpuMpInit.c
 
 [Packages]
   ArmPkg/ArmPkg.dec
@@ -37,6 +40,9 @@
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec
 
+[LibraryClasses.AARCH64]
+  MpInitLib
+
 [LibraryClasses]
   ArmLib
   ArmMmuLib
diff --git a/ArmPkg/Drivers/CpuDxe/CpuMpInit.c b/ArmPkg/Drivers/CpuDxe/CpuMpInit.c
new file mode 100644
index 000000000000..5bf4ed12b711
--- /dev/null
+++ b/ArmPkg/Drivers/CpuDxe/CpuMpInit.c
@@ -0,0 +1,604 @@
+/** @file
+  Construct MP Services Protocol.
+
+  The MP Services Protocol provides a generalized way of performing following tasks:
+    - Retrieving information of multi-processor environment and MP-related status of
+      specific processors.
+    - Dispatching user-provided function to APs.
+    - Maintain MP-related processor status.
+
+  The MP Services Protocol must be produced on any system with more than one logical
+  processor.
+
+  The Protocol is available only during boot time.
+
+  MP Services Protocol is hardware-independent. Most of the logic of this protocol
+  is architecturally neutral. It abstracts the multi-processor environment and
+  status of processors, and provides interfaces to retrieve information, maintain,
+  and dispatch.
+
+  MP Services Protocol may be consumed by ACPI module. The ACPI module may use this
+  protocol to retrieve data that are needed for an MP platform and report them to OS.
+  MP Services Protocol may also be used to program and configure processors, such
+  as MTRR synchronization for memory space attributes setting in DXE Services.
+  MP Services Protocol may be used by non-CPU DXE drivers to speed up platform boot
+  by taking advantage of the processing capabilities of the APs, for example, using
+  APs to help test system memory in parallel with other device initialization.
+  Diagnostics applications may also use this protocol for multi-processor.
+
+  Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/MpInitLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+/**
+  This service retrieves the number of logical processor in the platform
+  and the number of those logical processors that are enabled on this boot.
+  This service may only be called from the BSP.
+
+  This function is used to retrieve the following information:
+    - The number of logical processors that are present in the system.
+    - The number of enabled logical processors in the system at the instant
+      this call is made.
+
+  Because MP Service Protocol provides services to enable and disable processors
+  dynamically, the number of enabled logical processors may vary during the
+  course of a boot session.
+
+  If this service is called from an AP, then EFI_DEVICE_ERROR is returned.
+  If NumberOfProcessors or NumberOfEnabledProcessors is NULL, then
+  EFI_INVALID_PARAMETER is returned. Otherwise, the total number of processors
+  is returned in NumberOfProcessors, the number of currently enabled processor
+  is returned in NumberOfEnabledProcessors, and EFI_SUCCESS is returned.
+
+  @param[in]  This                        A pointer to the
+                                          EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] NumberOfProcessors          Pointer to the total number of logical
+                                          processors in the system, including
+                                          the BSP and disabled APs.
+  @param[out] NumberOfEnabledProcessors   Pointer to the number of enabled
+                                          logical processors that exist in the
+                                          system, including the BSP.
+
+  @retval EFI_SUCCESS             The number of logical processors and enabled
+                                  logical processors was retrieved.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   NumberOfProcessors is NULL.
+  @retval EFI_INVALID_PARAMETER   NumberOfEnabledProcessors is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+GetNumberOfProcessors (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                     *NumberOfProcessors,
+  OUT UINTN                     *NumberOfEnabledProcessors
+  )
+{
+  return MpInitLibGetNumberOfProcessors (
+    This,
+    NumberOfProcessors,
+    NumberOfEnabledProcessors
+    );
[SAMI] Please adjust the code alignment.
+}
+
+/**
+  Gets detailed MP-related information on the requested processor at the
+  instant this call is made. This service may only be called from the BSP.
+
+  This service retrieves detailed MP-related information about any processor
+  on the platform. Note the following:
+    - The processor information may change during the course of a boot session.
+    - The information presented here is entirely MP related.
+
+  Information regarding the number of caches and their sizes, frequency of
+  operation, slot numbers is all considered platform-related information and is
+  not provided by this service.
+
+  @param[in]  This                  A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                    instance.
+  @param[in]  ProcessorNumber       The index of the processor.
+  @param[out] ProcessorInfoBuffer   A pointer to the buffer where information
+                                    for the requested processor is deposited.
+
+  @retval EFI_SUCCESS             Processor information was returned.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   ProcessorInfoBuffer is NULL.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist in the platform.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+GetProcessorInfo (
+  IN  EFI_MP_SERVICES_PROTOCOL   *This,
+  IN  UINTN                      ProcessorNumber,
+  OUT EFI_PROCESSOR_INFORMATION  *ProcessorInfoBuffer
+  )
+{
+  return MpInitLibGetProcessorInfo (
+           This,
+           ProcessorNumber,
+           ProcessorInfoBuffer
+           );
+}
+
+/**
+  This service executes a caller provided function on all enabled APs. APs can
+  run either simultaneously or one at a time in sequence. This service supports
+  both blocking and non-blocking requests. The non-blocking requests use EFI
+  events so the BSP can detect when the APs have finished. This service may only
+  be called from the BSP.
+
+  This function is used to dispatch all the enabled APs to the function
+  specified by Procedure.  If any enabled AP is busy, then EFI_NOT_READY is
+  returned immediately and Procedure is not started on any AP.
+
+  If SingleThread is TRUE, all the enabled APs execute the function specified by
+  Procedure one by one, in ascending order of processor handle number.
+  Otherwise, all the enabled APs execute the function specified by Procedure
+  simultaneously.
+
+  If WaitEvent is NULL, execution is in blocking mode. The BSP waits until all
+  APs finish or TimeoutInMicroseconds expires. Otherwise, execution is in
+  non-blocking mode, and the BSP returns from this service without waiting for
+  APs. If a non-blocking mode is requested after the UEFI Event
+  EFI_EVENT_GROUP_READY_TO_BOOT is signaled, then EFI_UNSUPPORTED must be
+  returned.
+
+  If the timeout specified by TimeoutInMicroseconds expires before all APs
+  return from Procedure, then Procedure on the failed APs is terminated.
+  All enabled APs are always available for further calls to
+  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
+  EFI_MP_SERVICES_PROTOCOL.StartupThisAP(). If FailedCpuList is not NULL, its
+  content points to the list of processor handle numbers in which Procedure was
+  terminated.
+
+  Note: It is the responsibility of the consumer of the
+  EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() to make sure that the nature of the
+  code that is executed on the BSP and the dispatched APs is well controlled.
+  The MP Services Protocol does not guarantee that the Procedure function is
+  MP-safe. Hence, the tasks that can be run in parallel are limited to certain
+  independent tasks and well-controlled exclusive code. EFI services and
+  protocols may not be called by APs unless otherwise specified.
+
+  In blocking execution mode, BSP waits until all APs finish or
+  TimeoutInMicroseconds expires.
+
+  In non-blocking execution mode, BSP is freed to return to the caller and then
+  proceed to the next task without having to wait for APs. The following
+  sequence needs to occur in a non-blocking execution mode:
+
+    -# The caller that intends to use this MP Services Protocol in non-blocking
+       mode creates WaitEvent by calling the EFI CreateEvent() service.  The
+       caller invokes EFI_MP_SERVICES_PROTOCOL.StartupAllAPs(). If the parameter
+       WaitEvent is not NULL, then StartupAllAPs() executes in non-blocking
+       mode. It requests the function specified by Procedure to be started on
+       all the enabled APs, and releases the BSP to continue with other tasks.
+    -# The caller can use the CheckEvent() and WaitForEvent() services to check
+       the state of the WaitEvent created in step 1.
+    -# When the APs complete their task or TimeoutInMicroSecondss expires, the
+       MP Service signals WaitEvent by calling the EFI SignalEvent() function.
+       If FailedCpuList is not NULL, its content is available when WaitEvent is
+       signaled. If all APs returned from Procedure prior to the timeout, then
+       FailedCpuList is set to NULL. If not all APs return from Procedure before
+       the timeout, then FailedCpuList is filled in with the list of the failed
+       APs. The buffer is allocated by MP Service Protocol using AllocatePool().
+       It is the caller's responsibility to free the buffer with FreePool()
+       service.
+    -# This invocation of SignalEvent() function informs the caller that invoked
+       EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() that either all the APs
+       completed the specified task or a timeout occurred. The contents of
+       FailedCpuList can be examined to determine which APs did not complete the
+       specified task prior to the timeout.
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  SingleThread            If TRUE, then all the enabled APs execute
+                                      the function specified by Procedure one by
+                                      one, in ascending order of processor
+                                      handle number.  If FALSE, then all the
+                                      enabled APs execute the function specified
+                                      by Procedure simultaneously.
+  @param[in]  WaitEvent               The event created by the caller with
+                                      CreateEvent() service.  If it is NULL,
+                                      then execute in blocking mode. BSP waits
+                                      until all APs finish or
+                                      TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking
+                                      mode. BSP requests the function specified
+                                      by Procedure to be started on all the
+                                      enabled APs, and go on executing
+                                      immediately. If all return from Procedure,
+                                      or TimeoutInMicroseconds expires, this
+                                      event is signaled. The BSP can use the
+                                      CheckEvent() or WaitForEvent()
+                                      services to check the state of event. Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds
+                                      for APs to return from Procedure, either
+                                      for blocking or non-blocking mode. Zero
+                                      means infinity.  If the timeout expires
+                                      before all APs return from Procedure, then
+                                      Procedure on the failed APs is terminated.
+                                      All enabled APs are available for next
+                                      function assigned by
+                                      EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] FailedCpuList           If NULL, this parameter is ignored.
+                                      Otherwise, if all APs finish successfully,
+                                      then its content is set to NULL. If not
+                                      all APs finish before timeout expires,
+                                      then its content is set to address of the
+                                      buffer holding handle numbers of the
+                                      failed APs.
+                                      The buffer is allocated by MP Service
+                                      Protocol, and it's the caller's
+                                      responsibility to free the buffer with
+                                      FreePool() service.
+                                      In blocking mode, it is ready for
+                                      consumption when the call returns. In
+                                      non-blocking mode, it is ready when
+                                      WaitEvent is signaled. The list of failed
+                                      CPU is terminated by  END_OF_CPU_LIST.
+
+  @retval EFI_SUCCESS             In blocking mode, all APs have finished before
+                                  the timeout expired.
+  @retval EFI_SUCCESS             In non-blocking mode, function has been
+                                  dispatched to all enabled APs.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        Caller processor is AP.
+  @retval EFI_NOT_STARTED         No enabled APs exist in the system.
+  @retval EFI_NOT_READY           Any enabled APs are busy.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  all enabled APs have finished.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+StartupAllAPs (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  BOOLEAN                   SingleThread,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT UINTN                     **FailedCpuList         OPTIONAL
+  )
+{
+  return MpInitLibStartupAllAPs (
+           This,
+           Procedure,
+           SingleThread,
+           WaitEvent,
+           TimeoutInMicroseconds,
+           ProcedureArgument,
+           FailedCpuList
+           );
+}
+
+/**
+  This service lets the caller get one enabled AP to execute a caller-provided
+  function. The caller can request the BSP to either wait for the completion
+  of the AP or just proceed with the next task by using the EFI event mechanism.
+  See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
+  execution support.  This service may only be called from the BSP.
+
+  This function is used to dispatch one enabled AP to the function specified by
+  Procedure passing in the argument specified by ProcedureArgument.  If WaitEvent
+  is NULL, execution is in blocking mode. The BSP waits until the AP finishes or
+  TimeoutInMicroSecondss expires. Otherwise, execution is in non-blocking mode.
+  BSP proceeds to the next task without waiting for the AP. If a non-blocking mode
+  is requested after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled,
+  then EFI_UNSUPPORTED must be returned.
+
+  If the timeout specified by TimeoutInMicroseconds expires before the AP returns
+  from Procedure, then execution of Procedure by the AP is terminated. The AP is
+  available for subsequent calls to EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() and
+  EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  ProcessorNumber         The handle number of the AP. The range is
+                                      from 0 to the total number of logical
+                                      processors minus 1. The total number of
+                                      logical processors can be retrieved by
+                                      EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in]  WaitEvent               The event created by the caller with CreateEvent()
+                                      service.  If it is NULL, then execute in
+                                      blocking mode. BSP waits until all APs finish
+                                      or TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking mode.
+                                      BSP requests the function specified by
+                                      Procedure to be started on all the enabled
+                                      APs, and go on executing immediately. If
+                                      all return from Procedure or TimeoutInMicroseconds
+                                      expires, this event is signaled. The BSP
+                                      can use the CheckEvent() or WaitForEvent()
+                                      services to check the state of event.  Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds for
+                                      APs to return from Procedure, either for
+                                      blocking or non-blocking mode. Zero means
+                                      infinity.  If the timeout expires before
+                                      all APs return from Procedure, then Procedure
+                                      on the failed APs is terminated. All enabled
+                                      APs are available for next function assigned
+                                      by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] Finished                If NULL, this parameter is ignored.  In
+                                      blocking mode, this parameter is ignored.
+                                      In non-blocking mode, if AP returns from
+                                      Procedure before the timeout expires, its
+                                      content is set to TRUE. Otherwise, the
+                                      value is set to FALSE. The caller can
+                                      determine if the AP returned from Procedure
+                                      by evaluating this value.
+
+  @retval EFI_SUCCESS             In blocking mode, specified AP finished before
+                                  the timeout expires.
+  @retval EFI_SUCCESS             In non-blocking mode, the function has been
+                                  dispatched to specified AP.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  the specified AP has finished.
+  @retval EFI_NOT_READY           The specified AP is busy.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP or disabled AP.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+StartupThisAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  UINTN                     ProcessorNumber,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT BOOLEAN                   *Finished               OPTIONAL
+  )
+{
+  return MpInitLibStartupThisAP (
+           This,
+           Procedure,
+           ProcessorNumber,
+           WaitEvent,
+           TimeoutInMicroseconds,
+           ProcedureArgument,
+           Finished
+           );
+}
+
+/**
+  This service switches the requested AP to be the BSP from that point onward.
+  This service changes the BSP for all purposes.   This call can only be
+  performed by the current BSP.
+
+  This service switches the requested AP to be the BSP from that point onward.
+  This service changes the BSP for all purposes. The new BSP can take over the
+  execution of the old BSP and continue seamlessly from where the old one left
+  off. This service may not be supported after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT
+  is signaled.
+
+  If the BSP cannot be switched prior to the return from this service, then
+  EFI_UNSUPPORTED must be returned.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @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.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SwitchBSP (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                    ProcessorNumber,
+  IN  BOOLEAN                  EnableOldBSP
+  )
+{
+  return MpInitLibSwitchBSP (This, ProcessorNumber, EnableOldBSP);
+}
+
+/**
+  This service lets the caller enable or disable an AP from this point onward.
+  This service may only be called from the BSP.
+
+  This service allows the caller enable or disable an AP from this point onward.
+  The caller can optionally specify the health status of the AP by Health. If
+  an AP is being disabled, then the state of the disabled AP is implementation
+  dependent. If an AP is enabled, then the implementation must guarantee that a
+  complete initialization sequence is performed on the AP, so the AP is in a state
+  that is compatible with an MP operating system. This service may not be supported
+  after the UEFI Event EFI_EVENT_GROUP_READY_TO_BOOT is signaled.
+
+  If the enable or disable AP operation cannot be completed prior to the return
+  from this service, then EFI_UNSUPPORTED must be returned.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in] EnableAP          Specifies the new state for the processor for
+                               enabled, FALSE for disabled.
+  @param[in] HealthFlag        If not NULL, a pointer to a value that specifies
+                               the new health status of the AP. This flag
+                               corresponds to StatusFlag defined in
+                               EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
+                               the PROCESSOR_HEALTH_STATUS_BIT is used. All other
+                               bits are ignored.  If it is NULL, this parameter
+                               is ignored.
+
+  @retval EFI_SUCCESS             The specified AP was enabled or disabled successfully.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP cannot be completed
+                                  prior to this service returning.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP is not supported.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_NOT_FOUND           Processor with the handle specified by ProcessorNumber
+                                  does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+EnableDisableAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                     ProcessorNumber,
+  IN  BOOLEAN                   EnableAP,
+  IN  UINT32                    *HealthFlag OPTIONAL
+  )
+{
+  return MpInitLibEnableDisableAP (This, ProcessorNumber, EnableAP, HealthFlag);
+}
+
+/**
+  This return the handle number for the calling processor.  This service may be
+  called from the BSP and APs.
+
+  This service returns the processor handle number for the calling processor.
+  The returned value is in the range from 0 to the total number of logical
+  processors minus 1. The total number of logical processors can be retrieved
+  with EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors(). This service may be
+  called from the BSP and APs. If ProcessorNumber is NULL, then EFI_INVALID_PARAMETER
+  is returned. Otherwise, the current processors handle number is returned in
+  ProcessorNumber, and EFI_SUCCESS is returned.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] 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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+
+  @retval EFI_SUCCESS             The current processor handle number was returned
+                                  in ProcessorNumber.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber is NULL.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+WhoAmI (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                    *ProcessorNumber
+  )
+{
+  return MpInitLibWhoAmI (This, ProcessorNumber);
+}
+
+EFI_MP_SERVICES_PROTOCOL  mMpServicesTemplate = {
+  GetNumberOfProcessors,
+  GetProcessorInfo,
+  StartupAllAPs,
+  StartupThisAP,
+  SwitchBSP,
+  EnableDisableAP,
+  WhoAmI
+};
+
+/** Initialize multi-processor support.
+
+**/
+VOID
+InitializeMpSupport (
+  VOID
+  )
+{
+  EFI_STATUS              Status;
+  EFI_HANDLE              Handle;
+  UINTN                   MaxCpus;
+  EFI_HOB_GENERIC_HEADER  *Hob;
+  VOID                    *HobData;
+  UINTN                   HobDataSize;
+  ARM_PROCESSOR_TABLE     CpuInfo;
+
+  DEBUG ((DEBUG_INFO, "Starting MP services"));
+
+  Hob = GetFirstGuidHob (&gArmMpCoreInfoGuid);
+  if (Hob != NULL) {
+    HobData         = GET_GUID_HOB_DATA (Hob);
+    HobDataSize     = GET_GUID_HOB_DATA_SIZE (Hob);
+    CpuInfo.ArmCpus = (ARM_CORE_INFO *)HobData;
+    CpuInfo.NumberOfEntries = HobDataSize / sizeof (ARM_CORE_INFO);
+    MaxCpus = CpuInfo.NumberOfEntries;
+  }
+
+  if (MaxCpus == 1) {
+    DEBUG ((DEBUG_WARN, "Trying to use EFI_MP_SERVICES_PROTOCOL on a UP system"));
+    // We are not MP so nothing to do
+    return;
+  }
+
+  MpInitLibInitialize (MaxCpus, &CpuInfo);
[SAMI] There is a chance that MaxCpus will be uninitialised if the Hob is NULL. I think MaxCpus must be initialised to zero at the start of this function.
I also think CpuInfo.Header should be initialised (or at least zeroed) before use, to prevent CpuInf.Header from containing random data.
[/SAMI]
+
+  //
+  // Now install the MP services protocol.
+  //
+  Handle = NULL;
+  Status = gBS->InstallMultipleProtocolInterfaces (
+                  &Handle,
+                  &gEfiMpServiceProtocolGuid,
+                  &mMpServicesTemplate,
+                  NULL
+                  );
+  ASSERT_EFI_ERROR (Status);
+}
diff --git a/ArmPkg/Include/Library/MpInitLib.h b/ArmPkg/Include/Library/MpInitLib.h
new file mode 100644
index 000000000000..a4b80c18a9e8
--- /dev/null
+++ b/ArmPkg/Include/Library/MpInitLib.h
@@ -0,0 +1,366 @@
+/** @file
+
+Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+Portions copyright (c) 2011, Apple Inc. All rights reserved.
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MP_INITLIB_H_
+#define MP_INITLIB_H_
+
+#include <Protocol/Cpu.h>
+#include <Protocol/MpService.h>
+#include <Library/BaseLib.h>
+#include <Library/UefiLib.h>
+#include <Guid/ArmMpCoreInfo.h>
+
+
+/**
+  This service retrieves the number of logical processor in the platform
+  and the number of those logical processors that are enabled on this boot.
+  This service may only be called from the BSP.
+
+  @param[in]  This                        A pointer to the
+                                          EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] NumberOfProcessors          Pointer to the total number of logical
+                                          processors in the system, including
+                                          the BSP and disabled APs.
+  @param[out] NumberOfEnabledProcessors   Pointer to the number of enabled
+                                          logical processors that exist in the
+                                          system, including the BSP.
+
+  @retval EFI_SUCCESS             The number of logical processors and enabled
+                                  logical processors was retrieved.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   NumberOfProcessors is NULL.
+  @retval EFI_INVALID_PARAMETER   NumberOfEnabledProcessors is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetNumberOfProcessors (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                     *NumberOfProcessors,
+  OUT UINTN                     *NumberOfEnabledProcessors
+  );
+
+/**
+  Gets detailed MP-related information on the requested processor at the
+  instant this call is made. This service may only be called from the BSP.
+
+  @param[in]  This                  A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                    instance.
+  @param[in]  ProcessorIndex        The index of the processor.
+  @param[out] ProcessorInfoBuffer   A pointer to the buffer where information
+                                    for the requested processor is deposited.
+
+  @retval EFI_SUCCESS             Processor information was returned.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   ProcessorInfoBuffer is NULL.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist in the platform.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetProcessorInfo (
+  IN  EFI_MP_SERVICES_PROTOCOL   *This,
+  IN  UINTN                      ProcessorIndex,
+  OUT EFI_PROCESSOR_INFORMATION  *ProcessorInfoBuffer
+  );
+
+
+/**
+  This service executes a caller provided function on all enabled APs. APs can
+  run either simultaneously or one at a time in sequence. This service supports
+  both blocking and non-blocking requests. The non-blocking requests use EFI
+  events so the BSP can detect when the APs have finished. This service may only
+  be called from the BSP.
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  SingleThread            If TRUE, then all the enabled APs execute
+                                      the function specified by Procedure one by
+                                      one, in ascending order of processor
+                                      handle number.  If FALSE, then all the
+                                      enabled APs execute the function specified
+                                      by Procedure simultaneously.
+  @param[in]  WaitEvent               The event created by the caller with
+                                      CreateEvent() service.  If it is NULL,
+                                      then execute in blocking mode. BSP waits
+                                      until all APs finish or
+                                      TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking
+                                      mode. BSP requests the function specified
+                                      by Procedure to be started on all the
+                                      enabled APs, and go on executing
+                                      immediately. If all return from Procedure,
+                                      or TimeoutInMicroseconds expires, this
+                                      event is signaled. The BSP can use the
+                                      CheckEvent() or WaitForEvent()
+                                      services to check the state of event. Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds
+                                      for APs to return from Procedure, either
+                                      for blocking or non-blocking mode. Zero
+                                      means infinity.  If the timeout expires
+                                      before all APs return from Procedure, then
+                                      Procedure on the failed APs is terminated.
+                                      All enabled APs are available for next
+                                      function assigned by
+                                      EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] FailedCpuList           If NULL, this parameter is ignored.
+                                      Otherwise, if all APs finish successfully,
+                                      then its content is set to NULL. If not
+                                      all APs finish before timeout expires,
+                                      then its content is set to address of the
+                                      buffer holding handle numbers of the
+                                      failed APs.
+                                      The buffer is allocated by MP Service
+                                      Protocol, and it's the caller's
+                                      responsibility to free the buffer with
+                                      FreePool() service.
+                                      In blocking mode, it is ready for
+                                      consumption when the call returns. In
+                                      non-blocking mode, it is ready when
+                                      WaitEvent is signaled. The list of failed
+                                      CPU is terminated by  END_OF_CPU_LIST.
+
+  @retval EFI_SUCCESS             In blocking mode, all APs have finished before
+                                  the timeout expired.
+  @retval EFI_SUCCESS             In non-blocking mode, function has been
+                                  dispatched to all enabled APs.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        Caller processor is AP.
+  @retval EFI_NOT_STARTED         No enabled APs exist in the system.
+  @retval EFI_NOT_READY           Any enabled APs are busy.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  all enabled APs have finished.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupAllAPs (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  BOOLEAN                   SingleThread,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT UINTN                     **FailedCpuList         OPTIONAL
+  );
+
+/**
+  This service lets the caller get one enabled AP to execute a caller-provided
+  function. The caller can request the BSP to either wait for the completion
+  of the AP or just proceed with the next task by using the EFI event mechanism.
+  See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
+  execution support.  This service may only be called from the BSP.
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  ProcessorNumber         The handle number of the AP. The range is
+                                      from 0 to the total number of logical
+                                      processors minus 1. The total number of
+                                      logical processors can be retrieved by
+                                      EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in]  WaitEvent               The event created by the caller with CreateEvent()
+                                      service.  If it is NULL, then execute in
+                                      blocking mode. BSP waits until all APs finish
+                                      or TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking mode.
+                                      BSP requests the function specified by
+                                      Procedure to be started on all the enabled
+                                      APs, and go on executing immediately. If
+                                      all return from Procedure or TimeoutInMicroseconds
+                                      expires, this event is signaled. The BSP
+                                      can use the CheckEvent() or WaitForEvent()
+                                      services to check the state of event.  Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds for
+                                      APs to return from Procedure, either for
+                                      blocking or non-blocking mode. Zero means
+                                      infinity.  If the timeout expires before
+                                      all APs return from Procedure, then Procedure
+                                      on the failed APs is terminated. All enabled
+                                      APs are available for next function assigned
+                                      by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] Finished                If NULL, this parameter is ignored.  In
+                                      blocking mode, this parameter is ignored.
+                                      In non-blocking mode, if AP returns from
+                                      Procedure before the timeout expires, its
+                                      content is set to TRUE. Otherwise, the
+                                      value is set to FALSE. The caller can
+                                      determine if the AP returned from Procedure
+                                      by evaluating this value.
+
+  @retval EFI_SUCCESS             In blocking mode, specified AP finished before
+                                  the timeout expires.
+  @retval EFI_SUCCESS             In non-blocking mode, the function has been
+                                  dispatched to specified AP.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  the specified AP has finished.
+  @retval EFI_NOT_READY           The specified AP is busy.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP or disabled AP.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupThisAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  UINTN                     ProcessorNumber,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT BOOLEAN                   *Finished               OPTIONAL
+  );
+
+/**
+  This service switches the requested AP to be the BSP from that point onward.
+  This service changes the BSP for all purposes.   This call can only be
+  performed by the current BSP.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @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
+EFIAPI
+MpInitLibSwitchBSP (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                    ProcessorNumber,
+  IN  BOOLEAN                  EnableOldBSP
+  );
+
+/**
+  This service lets the caller enable or disable an AP from this point onward.
+  This service may only be called from the BSP.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in] EnableAP          Specifies the new state for the processor for
+                               enabled, FALSE for disabled.
+  @param[in] HealthFlag        If not NULL, a pointer to a value that specifies
+                               the new health status of the AP. This flag
+                               corresponds to StatusFlag defined in
+                               EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
+                               the PROCESSOR_HEALTH_STATUS_BIT is used. All other
+                               bits are ignored.  If it is NULL, this parameter
+                               is ignored.
+
+  @retval EFI_SUCCESS             The specified AP was enabled or disabled successfully.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP cannot be completed
+                                  prior to this service returning.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP is not supported.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_NOT_FOUND           Processor with the handle specified by ProcessorNumber
+                                  does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibEnableDisableAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                     ProcessorNumber,
+  IN  BOOLEAN                   EnableAP,
+  IN  UINT32                    *HealthFlag OPTIONAL
+  );
+
+/**
+  This return the handle number for the calling processor.  This service may be
+  called from the BSP and APs.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] 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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+
+  @retval EFI_SUCCESS             The current processor handle number was returned
+                                  in ProcessorNumber.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibWhoAmI (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                    *ProcessorNumber
+  );
+
+/** Initializes the MP Services system data
+
+   @param NumberOfProcessors The number of processors, both BSP and AP.
+   @param CpuInfo            CPU information gathered earlier during boot.
+
+**/
+VOID
+MpInitLibInitialize (
+  IN   UINTN     NumberOfProcessors,
+  IN   ARM_PROCESSOR_TABLE *CpuInfo
+  );
+
+
+
+#endif /* MP_INITLIB_H_ */
diff --git a/ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S b/ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S
new file mode 100644
index 000000000000..287db060e594
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/AArch64/MpFuncs.S
@@ -0,0 +1,61 @@
+#===============================================================================
+#  Copyright (c) 2021 NUVIA Inc. All rights reserved.
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#===============================================================================
+
+.text
+.align 3
+
+#include <AsmMacroIoLibV8.h>
+#include <IndustryStandard/ArmStdSmc.h>
+
+#include "InternalMpInitLib.h"
+
+GCC_ASM_IMPORT (gApStacksBase)
+GCC_ASM_IMPORT (gProcessorIDs)
+GCC_ASM_IMPORT (ApProcedure)
+GCC_ASM_IMPORT (gApStackSize)
+
+GCC_ASM_EXPORT (ApEntryPoint)
+
+StartupAddr:        .8byte ASM_PFX(ApProcedure)
+
+// Entry-point for the AP
+// VOID
+// ApEntryPoint (
+//   VOID
+//   );
+ASM_PFX(ApEntryPoint):
+  mrs x0, mpidr_el1
+  ldr x1, gProcessorIDs
+  mov x2, 0                   // x2 = processor index
+  mov x3, 0                   // x3 = address offset
+
+// Find index in gProcessorIDs for current processor
+1:
+  ldr x4, [x1, x3]            // x4 = gProcessorIDs + x3
+  cmp x4, 0                   // check if we've reached the end of gProcessorIDs
+  beq ProcessorNotFound
+  add x3, x3, 8               // x3 += sizeof (*gProcessorIDs)
+  add x2, x2, 1               // x2++
+  cmp x0, x4                  // if mpidr_el1 != *(gProcessorIDs + x3) then loop
[SAMI] I think this may not work for PEs with the MT bit[24] set. Please see my comment further ahead in FillInProcessorInformation().
+  bne 1b
+  sub x2, x2, 1
+
+// Calculate stack address
+  // x2 contains the index for the current processor
+  ldr x0, gApStacksBase
+  ldr x1, gApStackSize
+  mul x3, x2, x1              // x3 = ProcessorIndex * gApStackSize
+  add x4, x0, x3              // x4 = gApStacksBase + x3
+  add sp, x4, x1              // sp = x4 + gApStackSize
+
+  ldr x0, StartupAddr         // ASM_PFX(ApProcedure)
+  blr x0                      // doesn't return
+
+ProcessorNotFound:
+// Turn off the processor
+  MOV32 (w0, ARM_SMC_ID_PSCI_CPU_OFF)
+  smc #0
+  b .
diff --git a/ArmPkg/Library/MpInitLib/DxeMpInitLib.inf b/ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
new file mode 100644
index 000000000000..2275b6cca33a
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
@@ -0,0 +1,53 @@
+#/** @file
+#
+# Component description file for the DxeMpInitLib module.
+#
+# Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 1.29
+  BASE_NAME                      = DxeMpInitLib
+  FILE_GUID                      = c9ca773c-8ae4-4b74-82fd-f7345503294e
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = MpInitLib|DXE_DRIVER
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = AARCH64
+#
+
+[Sources.AARCH64]
+  AArch64/MpFuncs.S
+
+[Sources]
+  DxeMpLib.c
+  InternalMpInitLib.h
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  ArmLib
+  ArmSmcLib
+  BaseLib
+  BaseMemoryLib
+  DebugLib
+  HobLib
+  MemoryAllocationLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  UefiLib
+
+[Protocols]
+  gEfiMpServiceProtocolGuid
+
+[Guids]
+  gArmMpCoreInfoGuid
diff --git a/ArmPkg/Library/MpInitLib/DxeMpLib.c b/ArmPkg/Library/MpInitLib/DxeMpLib.c
new file mode 100644
index 000000000000..6053db740624
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/DxeMpLib.c
@@ -0,0 +1,1498 @@
+/** @file
+  Construct MP Services Protocol.
+
+  Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+  Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
+  Portions Copyright (c) 2011, Apple Inc. All rights reserved.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Ppi/ArmMpCoreInfo.h>
+#include <Library/ArmLib.h>
+#include <Library/ArmSmcLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/MpInitLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <IndustryStandard/ArmStdSmc.h>
+
+#include "InternalMpInitLib.h"
+
+#define POLL_INTERVAL_US  50000
+
+STATIC CPU_MP_DATA  mCpuMpData;
+STATIC BOOLEAN      mNonBlockingModeAllowed;
+UINT64              *gApStacksBase;
+UINT64              *gProcessorIDs;
+CONST UINT64        gApStackSize = AP_STACK_SIZE;
+
+/** C entry-point for the AP.
+    This function gets called from the assembly function ApEntryPoint.
+
+**/
+VOID
+ApProcedure (
+  VOID
+  )
+{
+  ARM_SMC_ARGS      Args;
+  EFI_AP_PROCEDURE  ApProcedure;
+  VOID              *ApParameter;
+  UINTN             ProcessorIndex;
+
+  MpInitLibWhoAmI (&mMpServicesTemplate, &ProcessorIndex);
+
+  /* Fetch the user-supplied procedure and parameter to execute */
+  ApProcedure = mCpuMpData.CpuData[ProcessorIndex].Procedure;
+  ApParameter = mCpuMpData.CpuData[ProcessorIndex].Parameter;
+
[SAMI] Is it possible to change the name of the local function pointer variable ApProcedure, please?
+  ApProcedure (ApParameter);
+
+  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateFinished;
+
+  /* Since we're finished with this AP, turn it off */
+  Args.Arg0 = ARM_SMC_ID_PSCI_CPU_OFF;
+  ArmCallSmc (&Args);
+
+  /* Should never be reached */
+  ASSERT (FALSE);
+  CpuDeadLoop ();
+}
+
+/** Turns on the specified core using PSCI and executes the user-supplied
+    function that's been configured via a previous call to SetApProcedure.
+
+    @param ProcessorIndex The index of the core to turn on.
+
+    @retval EFI_SUCCESS      Success.
+    @retval EFI_DEVICE_ERROR The processor could not be turned on.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+DispatchCpu (
+  IN UINTN ProcessorIndex
+  )
+{
+  ARM_SMC_ARGS  Args;
+  EFI_STATUS    Status;
+
+  Status = EFI_SUCCESS;
+
+  mCpuMpData.CpuData[ProcessorIndex].State = CpuStateBusy;
+
+  /* Turn the AP on */
+  if (sizeof (Args.Arg0) == sizeof (UINT32)) {
+    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH32;
+  } else {
+    Args.Arg0 = ARM_SMC_ID_PSCI_CPU_ON_AARCH64;
+  }
+  Args.Arg1 = gProcessorIDs[ProcessorIndex];
+  Args.Arg2 = (UINTN)ApEntryPoint;
+
+  ArmCallSmc (&Args);
+
+  if (Args.Arg0 != ARM_SMC_PSCI_RET_SUCCESS) {
+    DEBUG ((DEBUG_ERROR, "PSCI_CPU_ON call failed: %d", Args.Arg0));
+    Status = EFI_DEVICE_ERROR;
+  }
+
+  return Status;
+}
+
+/** Returns whether the specified processor is the BSP.
+
+  @param[in] ProcessorIndex The index the processor to check.
+
+  @return TRUE if the processor is the BSP, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorBSP (
+  UINTN ProcessorIndex
+  )
+{
+  EFI_PROCESSOR_INFORMATION  *CpuInfo;
+
+  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+  return (CpuInfo->StatusFlag & PROCESSOR_AS_BSP_BIT) != 0;
+}
+
+/** Returns whether the processor executing this function is the BSP.
+
+    @return Whether the current processor is the BSP.
+**/
+STATIC
+BOOLEAN
+IsCurrentProcessorBSP (
+  VOID
+  )
+{
+  EFI_STATUS  Status;
+  UINTN       ProcessorIndex;
+
+  Status = MpInitLibWhoAmI (&mMpServicesTemplate, &ProcessorIndex);
+  ASSERT_EFI_ERROR (Status);
[SAMI] I think this assert can be changed to ASSERT (0) and moved inside the if condition below.
+  if (EFI_ERROR (Status)) {
+    return FALSE;
+  }
+
+  return IsProcessorBSP (ProcessorIndex);
+}
+
+/** Get the Application Processors state.
+
+  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP.
+
+  @return The AP status.
+**/
+CPU_STATE
+GetApState (
+  IN  CPU_AP_DATA     *CpuData
+  )
+{
+  return CpuData->State;
+}
+
+/** Configures the processor context with the user-supplied procedure and
+    argument.
+
+   @param CpuData           The processor context.
+   @param Procedure         The user-supplied procedure.
+   @param ProcedureArgument The user-supplied procedure argument.
+
+**/
+STATIC
+VOID
+SetApProcedure (
+  IN   CPU_AP_DATA        *CpuData,
+  IN   EFI_AP_PROCEDURE   Procedure,
+  IN   VOID               *ProcedureArgument
+  )
+{
+  ASSERT (CpuData != NULL);
+  ASSERT (Procedure != NULL);
+
+  CpuData->Parameter = ProcedureArgument;
+  CpuData->Procedure = Procedure;
+}
+
+/** Returns the index of the next processor that is blocked.
+
+   @param[out] NextNumber The index of the next blocked processor.
+
+   @retval EFI_SUCCESS   Successfully found the next blocked processor.
+   @retval EFI_NOT_FOUND There are no blocked processors.
+
+**/
+STATIC
+EFI_STATUS
+GetNextBlockedNumber (
+  OUT UINTN *NextNumber
+  )
+{
+  UINTN        Index;
+  CPU_STATE    State;
+  CPU_AP_DATA  *CpuData;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    State = CpuData->State;
+
+    if (State == CpuStateBlocked) {
+      *NextNumber = Index;
+      return EFI_SUCCESS;
+    }
+  }
+
+  return EFI_NOT_FOUND;
+}
+
+/** Stalls the BSP for the minimum of POLL_INTERVAL_US and Timeout.
+
+   @param[in]  Timeout    The time limit in microseconds remaining for
+                          APs to return from Procedure.
+
+   @retval     StallTime  Time of execution stall.
+**/
+STATIC
+UINTN
+CalculateAndStallInterval (
+  IN UINTN Timeout
+  )
+{
+  UINTN  StallTime;
+
+  if (Timeout < POLL_INTERVAL_US && Timeout != 0) {
[SAMI] Please use extra parentheses. see https://edk2-docs.gitbook.io/edk-ii-c-coding-standards-specification/5_source_files/52_spacing#5.2.2.10-use-extra-parentheses-rather-than-depending-on-in-depth-knowledge-of-the-order-of-precedenc
Same at other places in this series.
[/SAMI]
+    StallTime = Timeout;
+  } else {
+    StallTime = POLL_INTERVAL_US;
+  }
+
+  gBS->Stall (StallTime);
+
+  return StallTime;
+}
+
+/**
+  This service retrieves the number of logical processor in the platform
+  and the number of those logical processors that are enabled on this boot.
+  This service may only be called from the BSP.
+
+  @param[in]  This                        A pointer to the
+                                          EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] NumberOfProcessors          Pointer to the total number of logical
+                                          processors in the system, including
+                                          the BSP and disabled APs.
+  @param[out] NumberOfEnabledProcessors   Pointer to the number of enabled
+                                          logical processors that exist in the
+                                          system, including the BSP.
+
+  @retval EFI_SUCCESS             The number of logical processors and enabled
+                                  logical processors was retrieved.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   NumberOfProcessors is NULL.
+  @retval EFI_INVALID_PARAMETER   NumberOfEnabledProcessors is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetNumberOfProcessors (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                     *NumberOfProcessors,
+  OUT UINTN                     *NumberOfEnabledProcessors
+  )
+{
+  if ((NumberOfProcessors == NULL) || (NumberOfEnabledProcessors == NULL)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  *NumberOfProcessors = mCpuMpData.NumberOfProcessors;
+  *NumberOfEnabledProcessors = mCpuMpData.NumberOfEnabledProcessors;
+  return EFI_SUCCESS;
+}
+
+/**
+  Gets detailed MP-related information on the requested processor at the
+  instant this call is made. This service may only be called from the BSP.
+
+  @param[in]  This                  A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                    instance.
+  @param[in]  ProcessorIndex        The index of the processor.
+  @param[out] ProcessorInfoBuffer   A pointer to the buffer where information
+                                    for the requested processor is deposited.
+
+  @retval EFI_SUCCESS             Processor information was returned.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_INVALID_PARAMETER   ProcessorInfoBuffer is NULL.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist in the platform.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibGetProcessorInfo (
+  IN  EFI_MP_SERVICES_PROTOCOL   *This,
+  IN  UINTN                      ProcessorIndex,
+  OUT EFI_PROCESSOR_INFORMATION  *ProcessorInfoBuffer
+  )
+{
+  if (ProcessorInfoBuffer == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  ProcessorIndex &= ~CPU_V2_EXTENDED_TOPOLOGY;
[SAMI] I don't see this set anywhere in the code. Also the other functions do not clear this bit before processing. Can you help me to understand this, please?
+
+  if (ProcessorIndex >= mCpuMpData.NumberOfProcessors) {
+    return EFI_NOT_FOUND;
+  }
+
+  CopyMem (
+    ProcessorInfoBuffer,
+    &mCpuMpData.CpuData[ProcessorIndex],
+    sizeof (EFI_PROCESSOR_INFORMATION)
+    );
+  return EFI_SUCCESS;
+}
+
+/** Returns whether the specified processor is enabled.
+
+   @param[in] ProcessorIndex The index of the processor to check.
+
+   @return TRUE if the processor is enabled, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorEnabled (
+  UINTN ProcessorIndex
+  )
+{
+  EFI_PROCESSOR_INFORMATION  *CpuInfo;
+
+  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+  return (CpuInfo->StatusFlag & PROCESSOR_ENABLED_BIT) != 0;
+}
+
+/** Returns whether all processors are in the idle state.
+
+   @return Whether all the processors are idle.
+
+**/
+STATIC
+BOOLEAN
+CheckAllCpusReady (
+  VOID
+  )
+{
+  UINTN        Index;
+  CPU_AP_DATA  *CpuData;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    if (!IsProcessorEnabled (Index)) {
+      // Skip Disabled processors
+      continue;
+    }
+
+    if (GetApState (CpuData) != CpuStateIdle) {
+      return FALSE;
+    }
+  }
+
+  return TRUE;
+}
+
+/** Sets up the state for the StartupAllAPs function.
+
+   @param SingleThread Whether the APs will execute sequentially.
+
+**/
+STATIC
+VOID
+StartupAllAPsPrepareState (
+  IN BOOLEAN SingleThread
+  )
+{
+  UINTN        Index;
+  CPU_STATE    APInitialState;
+  CPU_AP_DATA  *CpuData;
+
+  mCpuMpData.FinishCount  = 0;
+  mCpuMpData.StartCount   = 0;
+  mCpuMpData.SingleThread = SingleThread;
+
+  APInitialState = CpuStateReady;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+
+    //
+    // Get APs prepared, and put failing APs into FailedCpuList.
+    // If "SingleThread", only 1 AP will put into ready state, other AP will be
+    // put into ready state 1 by 1, until the previous 1 finished its task.
+    // If not "SingleThread", all APs are put into ready state from the
+    // beginning
+    //
+
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    if (!IsProcessorEnabled (Index)) {
+      // Skip Disabled processors
+      if (mCpuMpData.FailedList != NULL) {
+        mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
+      }
+
+      continue;
+    }
+
+    ASSERT (GetApState (CpuData) == CpuStateIdle);
+    CpuData->State = APInitialState;
+
+    mCpuMpData.StartCount++;
+    if (SingleThread) {
+      APInitialState = CpuStateBlocked;
+    }
+  }
+}
+
+/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
+
+   @param Procedure         The user-supplied procedure.
+   @param ProcedureArgument The user-supplied procedure argument.
+   @param WaitEvent         The wait event to be signaled when the work is
+                            complete or a timeout has occurred.
+   @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                                indicates an infinite timeout.
+
+   @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsWithWaitEvent (
+  IN EFI_AP_PROCEDURE Procedure,
+  IN VOID             *ProcedureArgument,
+  IN EFI_EVENT        WaitEvent,
+  IN UINTN            TimeoutInMicroseconds
+  )
+{
+  EFI_STATUS   Status;
+  UINTN        Index;
+  CPU_AP_DATA  *CpuData;
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    if (!IsProcessorEnabled (Index)) {
+      // Skip Disabled processors
+      continue;
+    }
+
+    if (GetApState (CpuData) == CpuStateReady) {
+      SetApProcedure (CpuData, Procedure, ProcedureArgument);
+    }
+  }
+
+  //
+  // Save data into private data structure, and create timer to poll AP state
+  // before exiting
+  //
+  mCpuMpData.Procedure = Procedure;
+  mCpuMpData.ProcedureArgument = ProcedureArgument;
+  mCpuMpData.WaitEvent     = WaitEvent;
+  mCpuMpData.Timeout       = TimeoutInMicroseconds;
+  mCpuMpData.TimeoutActive = (BOOLEAN)(TimeoutInMicroseconds != 0);
+  Status = gBS->SetTimer (
+                  mCpuMpData.CheckAllAPsEvent,
+                  TimerPeriodic,
+                  POLL_INTERVAL_US
+                  );
+  return Status;
+}
+
+/** Handles execution of StartupAllAPs when no wait event has been specified.
+
+   @param Procedure             The user-supplied procedure.
+   @param ProcedureArgument     The user-supplied procedure argument.
+   @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                                indicates an infinite timeout.
+   @param SingleThread          Whether the APs will execute sequentially.
+   @param FailedCpuList         User-supplied pointer for list of failed CPUs.
+
+   @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsNoWaitEvent (
+  IN EFI_AP_PROCEDURE Procedure,
+  IN VOID             *ProcedureArgument,
+  IN UINTN            TimeoutInMicroseconds,
+  IN BOOLEAN          SingleThread,
+  IN UINTN            **FailedCpuList
+  )
+{
+  EFI_STATUS   Status;
+  UINTN        Index;
+  UINTN        NextIndex;
+  UINTN        Timeout;
+  CPU_AP_DATA  *CpuData;
+
+  Timeout = TimeoutInMicroseconds;
+
+  while (TRUE) {
+    for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+      CpuData = &mCpuMpData.CpuData[Index];
+      if (IsProcessorBSP (Index)) {
+        // Skip BSP
+        continue;
+      }
+
+      if (!IsProcessorEnabled (Index)) {
+        // Skip Disabled processors
+        continue;
+      }
+
+      switch (GetApState (CpuData)) {
+        case CpuStateReady:
+          SetApProcedure (CpuData, Procedure, ProcedureArgument);
+          Status = DispatchCpu (Index);
+          if (EFI_ERROR (Status)) {
+            CpuData->State = CpuStateIdle;
+            Status = EFI_NOT_READY;
+            goto Done;
+          }
+
+          break;
+
+        case CpuStateFinished:
+          mCpuMpData.FinishCount++;
+          if (SingleThread) {
+            Status = GetNextBlockedNumber (&NextIndex);
+            if (!EFI_ERROR (Status)) {
+              mCpuMpData.CpuData[NextIndex].State = CpuStateReady;
+            }
+          }
+
+          CpuData->State = CpuStateIdle;
+          break;
+
+        default:
+          break;
+      }
+    }
+
+    if (mCpuMpData.FinishCount == mCpuMpData.StartCount) {
+      Status = EFI_SUCCESS;
+      goto Done;
+    }
+
+    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
+      Status = EFI_TIMEOUT;
+      goto Done;
+    }
+
+    Timeout -= CalculateAndStallInterval (Timeout);
+  }
+
+Done:
+  if (FailedCpuList != NULL) {
+    if (mCpuMpData.FailedListIndex == 0) {
+      FreePool (*FailedCpuList);
+      *FailedCpuList = NULL;
+    }
+  }
+
+  return Status;
+}
+
+/**
+  This service executes a caller provided function on all enabled APs. APs can
+  run either simultaneously or one at a time in sequence. This service supports
+  both blocking and non-blocking requests. The non-blocking requests use EFI
+  events so the BSP can detect when the APs have finished. This service may only
+  be called from the BSP.
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  SingleThread            If TRUE, then all the enabled APs execute
+                                      the function specified by Procedure one by
+                                      one, in ascending order of processor
+                                      handle number.  If FALSE, then all the
+                                      enabled APs execute the function specified
+                                      by Procedure simultaneously.
+  @param[in]  WaitEvent               The event created by the caller with
+                                      CreateEvent() service.  If it is NULL,
+                                      then execute in blocking mode. BSP waits
+                                      until all APs finish or
+                                      TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking
+                                      mode. BSP requests the function specified
+                                      by Procedure to be started on all the
+                                      enabled APs, and go on executing
+                                      immediately. If all return from Procedure,
+                                      or TimeoutInMicroseconds expires, this
+                                      event is signaled. The BSP can use the
+                                      CheckEvent() or WaitForEvent()
+                                      services to check the state of event. Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds
+                                      for APs to return from Procedure, either
+                                      for blocking or non-blocking mode. Zero
+                                      means infinity.  If the timeout expires
+                                      before all APs return from Procedure, then
+                                      Procedure on the failed APs is terminated.
+                                      All enabled APs are available for next
+                                      function assigned by
+                                      EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] FailedCpuList           If NULL, this parameter is ignored.
+                                      Otherwise, if all APs finish successfully,
+                                      then its content is set to NULL. If not
+                                      all APs finish before timeout expires,
+                                      then its content is set to address of the
+                                      buffer holding handle numbers of the
+                                      failed APs.
+                                      The buffer is allocated by MP Service
+                                      Protocol, and it's the caller's
+                                      responsibility to free the buffer with
+                                      FreePool() service.
+                                      In blocking mode, it is ready for
+                                      consumption when the call returns. In
+                                      non-blocking mode, it is ready when
+                                      WaitEvent is signaled. The list of failed
+                                      CPU is terminated by  END_OF_CPU_LIST.
+
+  @retval EFI_SUCCESS             In blocking mode, all APs have finished before
+                                  the timeout expired.
+  @retval EFI_SUCCESS             In non-blocking mode, function has been
+                                  dispatched to all enabled APs.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        Caller processor is AP.
+  @retval EFI_NOT_STARTED         No enabled APs exist in the system.
+  @retval EFI_NOT_READY           Any enabled APs are busy.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  all enabled APs have finished.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupAllAPs (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  BOOLEAN                   SingleThread,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT UINTN                     **FailedCpuList         OPTIONAL
+  )
+{
+  EFI_STATUS  Status;
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  if (mCpuMpData.NumberOfProcessors == 1) {
+    return EFI_NOT_STARTED;
+  }
+
+  if (Procedure == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
+    return EFI_UNSUPPORTED;
+  }
+
+  if (!CheckAllCpusReady ()) {
+    return EFI_NOT_READY;
+  }
+
+  if (FailedCpuList != NULL) {
+    mCpuMpData.FailedList = AllocatePool (
+                              (mCpuMpData.NumberOfProcessors + 1) *
+                              sizeof (UINTN)
+                              );
+    if (mCpuMpData.FailedList == NULL) {
+      return EFI_OUT_OF_RESOURCES;
+    }
+
+    SetMemN (
+      mCpuMpData.FailedList,
+      (mCpuMpData.NumberOfProcessors + 1) *
+      sizeof (UINTN),
+      END_OF_CPU_LIST
+      );
+    mCpuMpData.FailedListIndex = 0;
+    *FailedCpuList = mCpuMpData.FailedList;
+  }
+
+  StartupAllAPsPrepareState (SingleThread);
+
+  if (WaitEvent != NULL) {
+    Status = StartupAllAPsWithWaitEvent (
+               Procedure,
+               ProcedureArgument,
+               WaitEvent,
+               TimeoutInMicroseconds
+               );
+  } else {
+    Status = StartupAllAPsNoWaitEvent (
+               Procedure,
+               ProcedureArgument,
+               TimeoutInMicroseconds,
+               SingleThread,
+               FailedCpuList
+               );
+  }
+
+  return Status;
+}
+
+/**
+  This service lets the caller get one enabled AP to execute a caller-provided
+  function. The caller can request the BSP to either wait for the completion
+  of the AP or just proceed with the next task by using the EFI event mechanism.
+  See EFI_MP_SERVICES_PROTOCOL.StartupAllAPs() for more details on non-blocking
+  execution support.  This service may only be called from the BSP.
+
+  @param[in]  This                    A pointer to the EFI_MP_SERVICES_PROTOCOL
+                                      instance.
+  @param[in]  Procedure               A pointer to the function to be run on
+                                      enabled APs of the system. See type
+                                      EFI_AP_PROCEDURE.
+  @param[in]  ProcessorNumber         The handle number of the AP. The range is
+                                      from 0 to the total number of logical
+                                      processors minus 1. The total number of
+                                      logical processors can be retrieved by
+                                      EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in]  WaitEvent               The event created by the caller with CreateEvent()
+                                      service.  If it is NULL, then execute in
+                                      blocking mode. BSP waits until all APs finish
+                                      or TimeoutInMicroseconds expires.  If it's
+                                      not NULL, then execute in non-blocking mode.
+                                      BSP requests the function specified by
+                                      Procedure to be started on all the enabled
+                                      APs, and go on executing immediately. If
+                                      all return from Procedure or TimeoutInMicroseconds
+                                      expires, this event is signaled. The BSP
+                                      can use the CheckEvent() or WaitForEvent()
+                                      services to check the state of event.  Type
+                                      EFI_EVENT is defined in CreateEvent() in
+                                      the Unified Extensible Firmware Interface
+                                      Specification.
+  @param[in]  TimeoutInMicroseconds   Indicates the time limit in microseconds for
+                                      APs to return from Procedure, either for
+                                      blocking or non-blocking mode. Zero means
+                                      infinity.  If the timeout expires before
+                                      all APs return from Procedure, then Procedure
+                                      on the failed APs is terminated. All enabled
+                                      APs are available for next function assigned
+                                      by EFI_MP_SERVICES_PROTOCOL.StartupAllAPs()
+                                      or EFI_MP_SERVICES_PROTOCOL.StartupThisAP().
+                                      If the timeout expires in blocking mode,
+                                      BSP returns EFI_TIMEOUT.  If the timeout
+                                      expires in non-blocking mode, WaitEvent
+                                      is signaled with SignalEvent().
+  @param[in]  ProcedureArgument       The parameter passed into Procedure for
+                                      all APs.
+  @param[out] Finished                If NULL, this parameter is ignored.  In
+                                      blocking mode, this parameter is ignored.
+                                      In non-blocking mode, if AP returns from
+                                      Procedure before the timeout expires, its
+                                      content is set to TRUE. Otherwise, the
+                                      value is set to FALSE. The caller can
+                                      determine if the AP returned from Procedure
+                                      by evaluating this value.
+
+  @retval EFI_SUCCESS             In blocking mode, specified AP finished before
+                                  the timeout expires.
+  @retval EFI_SUCCESS             In non-blocking mode, the function has been
+                                  dispatched to specified AP.
+  @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
+                                  UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
+                                  signaled.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
+                                  the specified AP has finished.
+  @retval EFI_NOT_READY           The specified AP is busy.
+  @retval EFI_NOT_FOUND           The processor with the handle specified by
+                                  ProcessorNumber does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP or disabled AP.
+  @retval EFI_INVALID_PARAMETER   Procedure is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibStartupThisAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  EFI_AP_PROCEDURE          Procedure,
+  IN  UINTN                     ProcessorNumber,
+  IN  EFI_EVENT                 WaitEvent               OPTIONAL,
+  IN  UINTN                     TimeoutInMicroseconds,
+  IN  VOID                      *ProcedureArgument      OPTIONAL,
+  OUT BOOLEAN                   *Finished               OPTIONAL
+  )
+{
+  EFI_STATUS   Status;
+  UINTN        Timeout;
+  CPU_AP_DATA  *CpuData;
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  if (Procedure == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+    return EFI_NOT_FOUND;
+  }
+
+  CpuData = &mCpuMpData.CpuData[ProcessorNumber];
+
+  if (IsProcessorBSP (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (!IsProcessorEnabled (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (GetApState (CpuData) != CpuStateIdle) {
+    return EFI_NOT_READY;
+  }
+
+  if ((WaitEvent != NULL) && !mNonBlockingModeAllowed) {
+    return EFI_UNSUPPORTED;
+  }
+
+  Timeout = TimeoutInMicroseconds;
+
+  mCpuMpData.StartCount  = 1;
+  mCpuMpData.FinishCount = 0;
+
+  SetApProcedure (
+    CpuData,
+    Procedure,
+    ProcedureArgument
+    );
+
+  Status = DispatchCpu (ProcessorNumber);
+  if (EFI_ERROR (Status)) {
+    CpuData->State = CpuStateIdle;
+    return EFI_NOT_READY;
+  }
+
+  if (WaitEvent != NULL) {
+    // Non Blocking
+    mCpuMpData.WaitEvent = WaitEvent;
+    gBS->SetTimer (
+           CpuData->CheckThisAPEvent,
+           TimerPeriodic,
+           POLL_INTERVAL_US
+           );
+    return EFI_SUCCESS;
+  }
+
+  // Blocking
+  while (TRUE) {
+    if (GetApState (CpuData) == CpuStateFinished) {
+      CpuData->State = CpuStateIdle;
+      break;
+    }
+
+    if ((TimeoutInMicroseconds != 0) && (Timeout == 0)) {
+      return EFI_TIMEOUT;
+    }
+
+    Timeout -= CalculateAndStallInterval (Timeout);
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  This service switches the requested AP to be the BSP from that point onward.
+  This service changes the BSP for all purposes.   This call can only be
+  performed by the current BSP.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @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
+EFIAPI
+MpInitLibSwitchBSP (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                    ProcessorNumber,
+  IN  BOOLEAN                  EnableOldBSP
+  )
+{
+  UINTN        Index;
+  CPU_AP_DATA  *CpuData;
+
+  CpuData = &mCpuMpData.CpuData[ProcessorNumber];
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+    return EFI_NOT_FOUND;
+  }
+
+  if (!IsProcessorEnabled (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (IsProcessorBSP (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    if (IsProcessorBSP (Index)) {
+      break;
+    }
+  }
+
+  ASSERT (Index != mCpuMpData.NumberOfProcessors);
+
+  if (GetApState (CpuData) != CpuStateIdle) {
+    return EFI_NOT_READY;
+  }
+
+  // Skip for now as we need switch a bunch of stack stuff around and it's
+  // complex. May not be worth it?
+  return EFI_NOT_READY;
[SAMI] Should this function just return EFI_UNSUPPORTED? I don't think any other processing is needed in this function.
+}
+
+/**
+  This service lets the caller enable or disable an AP from this point onward.
+  This service may only be called from the BSP.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+  @param[in] EnableAP          Specifies the new state for the processor for
+                               enabled, FALSE for disabled.
+  @param[in] HealthFlag        If not NULL, a pointer to a value that specifies
+                               the new health status of the AP. This flag
+                               corresponds to StatusFlag defined in
+                               EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
+                               the PROCESSOR_HEALTH_STATUS_BIT is used. All other
+                               bits are ignored.  If it is NULL, this parameter
+                               is ignored.
+
+  @retval EFI_SUCCESS             The specified AP was enabled or disabled successfully.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP cannot be completed
+                                  prior to this service returning.
+  @retval EFI_UNSUPPORTED         Enabling or disabling an AP is not supported.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
+  @retval EFI_NOT_FOUND           Processor with the handle specified by ProcessorNumber
+                                  does not exist.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibEnableDisableAP (
+  IN  EFI_MP_SERVICES_PROTOCOL  *This,
+  IN  UINTN                     ProcessorNumber,
+  IN  BOOLEAN                   EnableAP,
+  IN  UINT32                    *HealthFlag OPTIONAL
+  )
+{
+  UINTN        StatusFlag;
+  CPU_AP_DATA  *CpuData;
+
+  StatusFlag = mCpuMpData.CpuData[ProcessorNumber].Info.StatusFlag;
+  CpuData    = &mCpuMpData.CpuData[ProcessorNumber];
+
+  if (!IsCurrentProcessorBSP ()) {
+    return EFI_DEVICE_ERROR;
+  }
+
+  if (ProcessorNumber >= mCpuMpData.NumberOfProcessors) {
+    return EFI_NOT_FOUND;
+  }
+
+  if (IsProcessorBSP (ProcessorNumber)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (GetApState (CpuData) != CpuStateIdle) {
+    return EFI_UNSUPPORTED;
+  }
+
+  if (EnableAP) {
+    if (!IsProcessorEnabled (ProcessorNumber)) {
+      mCpuMpData.NumberOfEnabledProcessors++;
+    }
+
+    StatusFlag |= PROCESSOR_ENABLED_BIT;
+  } else {
+    if (IsProcessorEnabled (ProcessorNumber)) {
+      mCpuMpData.NumberOfEnabledProcessors--;
+    }
+
+    StatusFlag &= ~PROCESSOR_ENABLED_BIT;
+  }
+
+  if (HealthFlag != NULL) {
+    StatusFlag &= ~PROCESSOR_HEALTH_STATUS_BIT;
+    StatusFlag |= (*HealthFlag & PROCESSOR_HEALTH_STATUS_BIT);
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  This return the handle number for the calling processor.  This service may be
+  called from the BSP and APs.
+
+  @param[in] This              A pointer to the EFI_MP_SERVICES_PROTOCOL instance.
+  @param[out] 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
+                               EFI_MP_SERVICES_PROTOCOL.GetNumberOfProcessors().
+
+  @retval EFI_SUCCESS             The current processor handle number was returned
+                                  in ProcessorNumber.
+  @retval EFI_INVALID_PARAMETER   ProcessorNumber is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+MpInitLibWhoAmI (
+  IN EFI_MP_SERVICES_PROTOCOL  *This,
+  OUT UINTN                    *ProcessorNumber
+  )
+{
+  UINTN        Index;
+  UINT64       ProcessorId;
+  CPU_AP_DATA  *CpuData;
+
+  if (ProcessorNumber == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  ProcessorId = ArmReadMpidr ();
[SAMI] Here again, I think it will not work on PEs with the MT bit[24] set. I think it would be better to mask of all other bits of MPIDR and only keep use the affinity bits.  CpuData->Info.ProcessorId should only store the affinity bits.
This would also match the requirement by the PSCI specification version D.b (https://developer.arm.com/documentation/den0022/latest/). See section 5.1.4 CPU_ON
    If the calling Exception level is using AArch64, the format is:
        • Bits[40:63]: Must be zero
        • Bits[32:39] Aff3: Match Aff3 of target core MPIDR
        • Bits[24:31] Must be zero
        • Bits[16:23] Aff2: Match Aff2 of target core MPIDR
        • Bits[8:15] Aff1: Match Aff1 of target core MPIDR
        • Bits[0:7] Aff0: Match Aff0 of target core MPIDR
[/SAMI]
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
+    if (CpuData->Info.ProcessorId == ProcessorId) {
+      break;
+    }
+  }
+
+  *ProcessorNumber = Index;
+  return EFI_SUCCESS;
+}
+
+/** Adds the specified processor the list of failed processors.
+
+   @param ProcessorIndex The processor index to add.
+   @param ApState        Processor state.
+
+**/
+STATIC
+VOID
+AddProcessorToFailedList (
+  UINTN           ProcessorIndex,
+  CPU_STATE       ApState
+  )
+{
+  UINTN    Index;
+  BOOLEAN  Found;
+
+  Found = FALSE;
+
+  if (ApState == CpuStateIdle) {
+    return;
+  }
+
+  // If we are retrying make sure we don't double count
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
[SAMI] Can the for loop run from 0 to mCpuMpData.FailedListIndex? In that case we would not need to check against END_OF_CPU_LIST right?
+    if (mCpuMpData.FailedList[Index] == END_OF_CPU_LIST) {
+      break;
+    }
+
+    if (mCpuMpData.FailedList[ProcessorIndex] == Index) {
[SAMI] Should this check be (mCpuMpData.FailedList[Index] == ProcessorIndex) ?
+      Found = TRUE;
+      break;
+    }
+  }
+
+  /* If the CPU isn't already in the FailedList, add it */
+  if (!Found) {
+    mCpuMpData.FailedList[mCpuMpData.FailedListIndex++] = Index;
+  }
+}
+
+/** Handles the StartupAllAPs case where the timeout has occurred.
+
+**/
+STATIC
+VOID
+ProcessStartupAllAPsTimeout (
+  VOID
+  )
+{
+  CPU_AP_DATA  *CpuData;
+  UINTN        Index;
+
+  if (mCpuMpData.FailedList == NULL) {
+    return;
+  }
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    CpuData = &mCpuMpData.CpuData[Index];
[SAMI] Minor optimisation could be achieved if CpuData initialisation is done just before calling AddProcessorToFailedList().
+    if (IsProcessorBSP (Index)) {
+      // Skip BSP
+      continue;
+    }
+
+    if (!IsProcessorEnabled (Index)) {
+      // Skip Disabled processors
+      continue;
+    }
+
+    AddProcessorToFailedList (Index, GetApState (CpuData));
+  }
+}
+
+/** Updates the status of the APs.
+
+   @param[in] ProcessorIndex The index of the AP to update.
+**/
+STATIC
+VOID
+UpdateApStatus (
+  IN UINTN ProcessorIndex
+  )
+{
+  EFI_STATUS   Status;
+  CPU_AP_DATA  *CpuData;
+  CPU_AP_DATA  *NextCpuData;
+  CPU_STATE    State;
+  UINTN        NextNumber;
+
+  CpuData = &mCpuMpData.CpuData[ProcessorIndex];
+
+  if (IsProcessorBSP (ProcessorIndex)) {
+    // Skip BSP
+    return;
+  }
+
+  if (!IsProcessorEnabled (ProcessorIndex)) {
+    // Skip Disabled processors
+    return;
+  }
+
+  State = GetApState (CpuData);
+
+  switch (State) {
+    case CpuStateFinished:
+      if (mCpuMpData.SingleThread) {
+        Status = GetNextBlockedNumber (&NextNumber);
+        if (!EFI_ERROR (Status)) {
+          NextCpuData = &mCpuMpData.CpuData[NextNumber];
+
+          NextCpuData->State = CpuStateReady;
+
+          SetApProcedure (
+            NextCpuData,
+            mCpuMpData.Procedure,
+            mCpuMpData.ProcedureArgument
+            );
+        }
+      }
+
+      CpuData->State = CpuStateIdle;
+      mCpuMpData.FinishCount++;
+      break;
+
+    default:
+      break;
+  }
+}
+
+/**
+  If a timeout is specified in StartupAllAps(), a timer is set, which invokes
+  this procedure periodically to check whether all APs have finished.
+
+  @param[in] Event   The WaitEvent the user supplied.
+  @param[in] Context The event context.
+**/
+STATIC
+VOID
+EFIAPI
+CheckAllAPsStatus (
+  IN  EFI_EVENT   Event,
+  IN  VOID        *Context
+  )
+{
+  UINTN  Index;
+
+  if (mCpuMpData.TimeoutActive) {
+    mCpuMpData.Timeout -= CalculateAndStallInterval (mCpuMpData.Timeout);
+  }
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    UpdateApStatus (Index);
+  }
+
+  if (mCpuMpData.TimeoutActive && mCpuMpData.Timeout == 0) {
+    ProcessStartupAllAPsTimeout ();
+
+    // Force terminal exit
+    mCpuMpData.FinishCount = mCpuMpData.StartCount;
+  }
+
+  if (mCpuMpData.FinishCount != mCpuMpData.StartCount) {
+    return;
+  }
+
+  gBS->SetTimer (
+         mCpuMpData.CheckAllAPsEvent,
+         TimerCancel,
+         0
+         );
+
+  if (mCpuMpData.FailedListIndex == 0) {
+    if (mCpuMpData.FailedList != NULL) {
+      FreePool (mCpuMpData.FailedList);
+      mCpuMpData.FailedList = NULL;
+    }
+  }
+
+  gBS->SignalEvent (mCpuMpData.WaitEvent);
+}
+
+/** Invoked periodically via a timer to check the state of the processor.
+
+   @param Event   The event supplied by the timer expiration.
+   @param Context The processor context.
+
+**/
+STATIC
+VOID
+EFIAPI
+CheckThisAPStatus (
+  IN  EFI_EVENT   Event,
+  IN  VOID        *Context
+  )
+{
+  EFI_STATUS   Status;
+  CPU_AP_DATA  *CpuData;
+  CPU_STATE    State;
+
+  CpuData = Context;
+  CpuData->TimeTaken += POLL_INTERVAL_US;
+
+  State = GetApState (CpuData);
+
+  if (State == CpuStateFinished) {
+    Status = gBS->SetTimer (CpuData->CheckThisAPEvent, TimerCancel, 0);
+    ASSERT_EFI_ERROR (Status);
+
+    if (mCpuMpData.WaitEvent != NULL) {
+      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
+      ASSERT_EFI_ERROR (Status);
+    }
+
+    CpuData->State = CpuStateIdle;
+  }
+
+  if (CpuData->TimeTaken > CpuData->Timeout) {
+    if (mCpuMpData.WaitEvent != NULL) {
+      Status = gBS->SignalEvent (mCpuMpData.WaitEvent);
+      ASSERT_EFI_ERROR (Status);
+    }
+  }
+}
+
+/**
+  This function is called by all processors (both BSP and AP) once and collects
+  MP related data.
+
+  @param BSP            TRUE if the processor is the BSP.
+  @param Mpidr          The MPIDR for the specified processor.
+  @param ProcessorIndex The index of the processor.
+
+  @return EFI_SUCCESS if the data for the processor collected and filled in.
+
+**/
+STATIC
+EFI_STATUS
+FillInProcessorInformation (
+  IN BOOLEAN      BSP,
+  IN UINTN        Mpidr,
+  IN UINTN        ProcessorIndex
+  )
+{
+  EFI_PROCESSOR_INFORMATION  *CpuInfo;
+
+  CpuInfo = &mCpuMpData.CpuData[ProcessorIndex].Info;
+
+  /* The MPIDR passed in may be a pseudo-MPIDR that's missing the bit 31 RES1.
+   * Fix it so it's a proper MPIDR.
+   */
+  CpuInfo->ProcessorId = BIT31 | Mpidr;
[SAMI] I believe the MT, bit [24] may need to be set as well. Otherwise, the checks in MpInitLibWhoAm() would fail as ArmReadMpidr() would return this bit as set if the PE is implemented using a multithreading type approach.
+  CpuInfo->StatusFlag  = PROCESSOR_ENABLED_BIT | PROCESSOR_HEALTH_STATUS_BIT;
+
+  if (BSP) {
+    CpuInfo->StatusFlag |= PROCESSOR_AS_BSP_BIT;
+  }
+
+  CpuInfo->Location.Package = GET_CLUSTER_ID (Mpidr);
+  CpuInfo->Location.Core    = GET_CORE_ID (Mpidr);
+  CpuInfo->Location.Thread  = 0;
[SAMI] I think the MPIDR_EL1.MT bit should be used to decide if Multi Threading is supported and value for CpuInfo->Location.Thread should be set appropriately.
+
+  CpuInfo->ExtendedInformation.Location2.Package = 0;
+  CpuInfo->ExtendedInformation.Location2.Module  = 0;
+  CpuInfo->ExtendedInformation.Location2.Tile    = 0;
+  CpuInfo->ExtendedInformation.Location2.Die     = GET_CLUSTER_ID (Mpidr);
+  CpuInfo->ExtendedInformation.Location2.Core    = GET_CORE_ID (Mpidr);
+  CpuInfo->ExtendedInformation.Location2.Thread  = 0;
+
+  mCpuMpData.CpuData[ProcessorIndex].State = BSP ? CpuStateBusy : CpuStateIdle;
+
+  mCpuMpData.CpuData[ProcessorIndex].Procedure = NULL;
+  mCpuMpData.CpuData[ProcessorIndex].Parameter = NULL;
+
+  return EFI_SUCCESS;
+}
+
+/** Initializes the MP Services system data
+
+   @param NumberOfProcessors The number of processors, both BSP and AP.
+   @param CpuInfo            CPU information gathered earlier during boot.
+
+**/
+VOID
+MpInitLibInitialize (
+  IN   UINTN     NumberOfProcessors,
+  IN   ARM_PROCESSOR_TABLE *CpuInfo
+  )
+{
+  EFI_STATUS  Status;
+  UINTN       Index;
+  EFI_EVENT   ReadyToBootEvent;
+
+  //
+  // Clear the data structure area first.
+  //
+  ZeroMem (&mCpuMpData, sizeof (CPU_MP_DATA));
+  //
+  // First BSP fills and inits all known values, including its own records.
+  //
+  mCpuMpData.NumberOfProcessors = NumberOfProcessors;
+  mCpuMpData.NumberOfEnabledProcessors = NumberOfProcessors;
+
+  mCpuMpData.CpuData = AllocateZeroPool (
+                         mCpuMpData.NumberOfProcessors *
+                         sizeof (CPU_AP_DATA)
+                         );
+  ASSERT (mCpuMpData.CpuData != NULL);
+
+  /* Allocate one extra for the NULL entry at the end */
+  gProcessorIDs = AllocatePool ((mCpuMpData.NumberOfProcessors + 1) * sizeof (UINT64));
+  ASSERT (gProcessorIDs != NULL);
+
+  FillInProcessorInformation (TRUE, CpuInfo->ArmCpus[0].Mpidr, 0);
+  gProcessorIDs[0] = mCpuMpData.CpuData[0].Info.ProcessorId;
+
+  Status = gBS->CreateEvent (
+                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  CheckAllAPsStatus,
+                  NULL,
+                  &mCpuMpData.CheckAllAPsEvent
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  gApStacksBase = AllocatePool (
+                    mCpuMpData.NumberOfProcessors *
+                    gApStackSize
+                    );
+  ASSERT (gApStacksBase != NULL);
+
+  for (Index = 0; Index < mCpuMpData.NumberOfProcessors; Index++) {
+    if (IsProcessorBSP (Index)) {
+      /* Skip BSP */
+      continue;
+    }
+
+    FillInProcessorInformation (FALSE, CpuInfo->ArmCpus[Index].Mpidr, Index);
+
+    gProcessorIDs[Index] = mCpuMpData.CpuData[Index].Info.ProcessorId;
+
+    Status = gBS->CreateEvent (
+                    EVT_TIMER | EVT_NOTIFY_SIGNAL,
+                    TPL_CALLBACK,
+                    CheckThisAPStatus,
+                    (VOID *)&mCpuMpData.CpuData[Index],
+                    &mCpuMpData.CpuData[Index].CheckThisAPEvent
+                    );
+    ASSERT (Status == EFI_SUCCESS);
+  }
+
+  Status = EfiCreateEventReadyToBootEx (
+             TPL_CALLBACK,
+             ReadyToBootSignaled,
+             NULL,
+             &ReadyToBootEvent
+             );
+  ASSERT_EFI_ERROR (Status);
+
+  gProcessorIDs[Index] = 0;
+}
+
+/**
+  Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
+  signaled. After this point, non-blocking mode is no longer allowed.
+
+  @param  Event     Event whose notification function is being invoked.
+  @param  Context   The pointer to the notification function's context,
+                    which is implementation-dependent.
+
+**/
+STATIC
+VOID
+EFIAPI
+ReadyToBootSignaled (
+  IN  EFI_EVENT                Event,
+  IN  VOID                     *Context
+  )
+{
+  mNonBlockingModeAllowed = FALSE;
+}
+
diff --git a/ArmPkg/Library/MpInitLib/InternalMpInitLib.h b/ArmPkg/Library/MpInitLib/InternalMpInitLib.h
new file mode 100644
index 000000000000..d08bb76246d7
--- /dev/null
+++ b/ArmPkg/Library/MpInitLib/InternalMpInitLib.h
@@ -0,0 +1,358 @@
+/** @file
+
+Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+Portions copyright (c) 2011, Apple Inc. All rights reserved.
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef MP_INTERNAL_INIT_LIB_H_
+#define MP_INTERNAL_INIT_LIB_H_
+
+#include <Protocol/Cpu.h>
+#include <Protocol/MpService.h>
+
+#include <Library/BaseLib.h>
+#include <Library/UefiLib.h>
+
+
+#define AP_STACK_SIZE 0x1000
+
+//
+// Internal Data Structures
+//
+
+//
+// AP state
+//
+// The state transitions for an AP when it process a procedure are:
+//  Idle ----> Ready ----> Busy ----> Idle
+//       [BSP]       [AP]       [AP]
+//
+typedef enum {
+  CpuStateIdle,
+  CpuStateReady,
+  CpuStateBlocked,
+  CpuStateBusy,
+  CpuStateFinished,
+  CpuStateDisabled
+} CPU_STATE;
+
+//
+// Define Individual Processor Data block.
+//
+typedef struct {
+  EFI_PROCESSOR_INFORMATION    Info;
+  EFI_AP_PROCEDURE             Procedure;
+  VOID                         *Parameter;
+  CPU_STATE                    State;
+  EFI_EVENT                    CheckThisAPEvent;
+  UINTN                        Timeout;
+  UINTN                        TimeTaken;
+} CPU_AP_DATA;
+
+//
+// Define MP data block which consumes individual processor block.
+//
+typedef struct {
+  UINTN                   NumberOfProcessors;
+  UINTN                   NumberOfEnabledProcessors;
+  EFI_EVENT               CheckAllAPsEvent;
+  EFI_EVENT               WaitEvent;
+  UINTN                   FinishCount;
+  UINTN                   StartCount;
+  EFI_AP_PROCEDURE        Procedure;
+  VOID                    *ProcedureArgument;
+  BOOLEAN                 SingleThread;
+  UINTN                   StartedNumber;
+  CPU_AP_DATA             *CpuData;
+  UINTN                   Timeout;
+  UINTN                   *FailedList;
+  UINTN                   FailedListIndex;
+  BOOLEAN                 TimeoutActive;
+} CPU_MP_DATA;
+
+EFI_STATUS
+EFIAPI
+CpuMpServicesInit (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  );
+
+extern EFI_MP_SERVICES_PROTOCOL  mMpServicesTemplate;
+
+/** Secondary core entry point.
+
+**/
+VOID  ApEntryPoint (
+  VOID
+  );
+
+/** C entry-point for the AP.
+    This function gets called from the assembly function ApEntryPoint.
+**/
+VOID
+ApProcedure (
+  VOID
+  );
+
+/** Turns on the specified core using PSCI and executes the user-supplied
+    function that's been configured via a previous call to SetApProcedure.
+
+   @param ProcessorIndex The index of the core to turn on.
+
+   @retval EFI_SUCCESS       The processor was successfully turned on.
+   @retval EFI_DEVICE_ERROR  An error occurred turning the processor on.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+DispatchCpu (
+  IN UINTN ProcessorIndex
+  );
+
+/** Returns whether the specified processor is the BSP.
+
+   @param[in] ProcessorIndex The index the processor to check.
+
+   @return TRUE if the processor is the BSP, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorBSP (
+  UINTN ProcessorIndex
+  );
+
+/** Returns whether the processor executing this function is the BSP.
+
+   @return Whether the current processor is the BSP.
+**/
+STATIC
+BOOLEAN
+IsCurrentProcessorBSP (
+  VOID
+  );
+
+/** Returns whether the specified processor is enabled.
+
+   @param[in] ProcessorIndex The index of the processor to check.
+
+   @return TRUE if the processor is enabled, FALSE otherwise.
+**/
+STATIC
+BOOLEAN
+IsProcessorEnabled (
+  UINTN ProcessorIndex
+  );
+
+/** Configures the processor context with the user-supplied procedure and
+    argument.
+
+   @param CpuData           The processor context.
+   @param Procedure         The user-supplied procedure.
+   @param ProcedureArgument The user-supplied procedure argument.
+
+**/
+STATIC
+VOID
+SetApProcedure (
+  IN   CPU_AP_DATA         *CpuData,
+  IN   EFI_AP_PROCEDURE    Procedure,
+  IN   VOID                *ProcedureArgument
+  );
+
+/**
+  Get the Application Processors state.
+
+  @param[in]  CpuData    The pointer to CPU_AP_DATA of specified AP
+
+  @return  The AP status
+**/
+CPU_STATE
+GetApState (
+  IN  CPU_AP_DATA     *CpuData
+  );
+
+/** Returns the index of the next processor that is blocked.
+
+   @param[out] NextNumber The index of the next blocked processor.
+
+   @retval EFI_SUCCESS   Successfully found the next blocked processor.
+   @retval EFI_NOT_FOUND There are no blocked processors.
+
+**/
+STATIC
+EFI_STATUS
+GetNextBlockedNumber (
+  OUT UINTN *NextNumber
+  );
+
+/** Stalls the BSP for the minimum of gPollInterval and Timeout.
+
+   @param[in]  Timeout    The time limit in microseconds remaining for
+                          APs to return from Procedure.
+
+   @retval     StallTime  Time of execution stall.
+**/
+STATIC
+UINTN
+CalculateAndStallInterval (
+  IN UINTN Timeout
+  );
+
+/** Returns whether all processors are in the idle state.
+
+   @return Whether all the processors are idle.
+
+**/
+STATIC
+BOOLEAN
+CheckAllCpusReady (
+  VOID
+  );
+
+/** Sets up the state for the StartupAllAPs function.
+
+   @param SingleThread Whether the APs will execute sequentially.
+
+**/
+STATIC
+VOID
+StartupAllAPsPrepareState (
+  IN BOOLEAN SingleThread
+  );
+
+/** Handles execution of StartupAllAPs when a WaitEvent has been specified.
+
+   @param Procedure         The user-supplied procedure.
+   @param ProcedureArgument The user-supplied procedure argument.
+   @param WaitEvent         The wait event to be signaled when the work is
+                            complete or a timeout has occurred.
+   @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                                indicates an infinite timeout.
+
+   @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsWithWaitEvent (
+  IN EFI_AP_PROCEDURE Procedure,
+  IN VOID             *ProcedureArgument,
+  IN EFI_EVENT        WaitEvent,
+  IN UINTN            TimeoutInMicroseconds
+  );
+
+/** Handles execution of StartupAllAPs when no wait event has been specified.
+
+   @param Procedure             The user-supplied procedure.
+   @param ProcedureArgument     The user-supplied procedure argument.
+   @param TimeoutInMicroseconds The timeout for the work to be completed. Zero
+                                indicates an infinite timeout.
+   @param SingleThread          Whether the APs will execute sequentially.
+   @param FailedCpuList         User-supplied pointer for list of failed CPUs.
+
+   @return EFI_SUCCESS on success.
+**/
+STATIC
+EFI_STATUS
+StartupAllAPsNoWaitEvent (
+  IN EFI_AP_PROCEDURE Procedure,
+  IN VOID             *ProcedureArgument,
+  IN UINTN            TimeoutInMicroseconds,
+  IN BOOLEAN          SingleThread,
+  IN UINTN            **FailedCpuList
+  );
+
+
+/** Adds the specified processor the list of failed processors.
+
+   @param ProcessorIndex The processor index to add.
+   @param ApState         Processor state.
+
+**/
+STATIC
+VOID
+AddProcessorToFailedList (
+  UINTN           ProcessorIndex,
+  CPU_STATE       ApState
+  );
+
+/** Handles the StartupAllAPs case where the timeout has occurred.
+
+**/
+STATIC
+VOID
+ProcessStartupAllAPsTimeout (
+  VOID
+  );
+
+/**
+  If a timeout is specified in StartupAllAps(), a timer is set, which invokes
+  this procedure periodically to check whether all APs have finished.
+
+  @param[in] Event   The WaitEvent the user supplied.
+  @param[in] Context The event context.
+**/
+STATIC
+VOID
+EFIAPI
+CheckAllAPsStatus (
+  IN  EFI_EVENT   Event,
+  IN  VOID        *Context
+  );
+
+/** Invoked periodically via a timer to check the state of the processor.
+
+   @param Event   The event supplied by the timer expiration.
+   @param Context The processor context.
+
+**/
+STATIC
+VOID
+EFIAPI
+CheckThisAPStatus (
+  IN  EFI_EVENT   Event,
+  IN  VOID        *Context
+  );
+
+/**
+  This function is called by all processors (both BSP and AP) once and collects
+  MP related data.
+
+  @param BSP            TRUE if the processor is the BSP.
+  @param Mpidr          The MPIDR for the specified processor.
+  @param ProcessorIndex The index of the processor.
+
+  @return EFI_SUCCESS if the data for the processor collected and filled in.
+
+**/
+STATIC
+EFI_STATUS
+FillInProcessorInformation (
+  IN BOOLEAN      BSP,
+  IN UINTN        Mpidr,
+  IN UINTN        ProcessorIndex
+  );
+
+/**
+  Event notification function called when the EFI_EVENT_GROUP_READY_TO_BOOT is
+  signaled. After this point, non-blocking mode is no longer allowed.
+
+  @param  Event     Event whose notification function is being invoked.
+  @param  Context   The pointer to the notification function's context,
+                    which is implementation-dependent.
+
+**/
+STATIC
+VOID
+EFIAPI
+ReadyToBootSignaled (
+  IN  EFI_EVENT                Event,
+  IN  VOID                     *Context
+  );
+
+
+#endif /* MP_INTERNAL_INIT_LIB_H_ */
diff --git a/ArmVirtPkg/ArmVirt.dsc.inc b/ArmVirtPkg/ArmVirt.dsc.inc
index 5a1598d90ca7..af6e48fd6cfc 100644
--- a/ArmVirtPkg/ArmVirt.dsc.inc
+++ b/ArmVirtPkg/ArmVirt.dsc.inc
@@ -261,6 +261,9 @@
 [LibraryClasses.ARM]
   ArmSoftFloatLib|ArmPkg/Library/ArmSoftFloatLib/ArmSoftFloatLib.inf
 
+[LibraryClasses.AARCH64]
+  MpInitLib|ArmPkg/Library/MpInitLib/DxeMpInitLib.inf
+
 [BuildOptions]
   RVCT:RELEASE_*_*_CC_FLAGS  = -DMDEPKG_NDEBUG
 

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