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/** @file
Copyright (c) 2016 HP Development Company, L.P.
Copyright (c) 2016 - 2021, Arm Limited. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Base.h>
#include <Pi/PiMmCis.h>
#include <Library/ArmSvcLib.h>
#include <Library/ArmLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/HobLib.h>
#include <Protocol/DebugSupport.h> // for EFI_SYSTEM_CONTEXT
#include <Guid/ZeroGuid.h>
#include <Guid/MmramMemoryReserve.h>
#include <IndustryStandard/ArmStdSmc.h>
#include "StandaloneMmCpu.h"
EFI_STATUS
EFIAPI
MmFoundationEntryRegister (
IN CONST EFI_MM_CONFIGURATION_PROTOCOL *This,
IN EFI_MM_ENTRY_POINT MmEntryPoint
);
//
// On ARM platforms every event is expected to have a GUID associated with
// it. It will be used by the MM Entry point to find the handler for the
// event. It will either be populated in a EFI_MM_COMMUNICATE_HEADER by the
// caller of the event (e.g. MM_COMMUNICATE SMC) or by the CPU driver
// (e.g. during an asynchronous event). In either case, this context is
// maintained in an array which has an entry for each CPU. The pointer to this
// array is held in PerCpuGuidedEventContext. Memory is allocated once the
// number of CPUs in the system are made known through the
// MP_INFORMATION_HOB_DATA.
//
EFI_MM_COMMUNICATE_HEADER **PerCpuGuidedEventContext = NULL;
// Descriptor with whereabouts of memory used for communication with the normal world
EFI_MMRAM_DESCRIPTOR mNsCommBuffer;
MP_INFORMATION_HOB_DATA *mMpInformationHobData;
EFI_MM_CONFIGURATION_PROTOCOL mMmConfig = {
0,
MmFoundationEntryRegister
};
STATIC EFI_MM_ENTRY_POINT mMmEntryPoint = NULL;
EFI_STATUS
PiMmStandaloneArmTfCpuDriverEntry (
IN UINTN EventId,
IN UINTN CpuNumber,
IN UINTN NsCommBufferAddr
)
{
EFI_MM_COMMUNICATE_HEADER *GuidedEventContext;
EFI_MM_ENTRY_CONTEXT MmEntryPointContext;
EFI_STATUS Status;
UINTN NsCommBufferSize;
DEBUG ((DEBUG_INFO, "Received event - 0x%x on cpu %d\n", EventId, CpuNumber));
Status = EFI_SUCCESS;
//
// ARM TF passes SMC FID of the MM_COMMUNICATE interface as the Event ID upon
// receipt of a synchronous MM request. Use the Event ID to distinguish
// between synchronous and asynchronous events.
//
if (ARM_SMC_ID_MM_COMMUNICATE_AARCH64 != EventId) {
DEBUG ((DEBUG_INFO, "UnRecognized Event - 0x%x\n", EventId));
return EFI_INVALID_PARAMETER;
}
// Perform parameter validation of NsCommBufferAddr
if (NsCommBufferAddr == (UINTN)NULL) {
return EFI_INVALID_PARAMETER;
}
if (NsCommBufferAddr < mNsCommBuffer.PhysicalStart) {
return EFI_ACCESS_DENIED;
}
if ((NsCommBufferAddr + sizeof (EFI_MM_COMMUNICATE_HEADER)) >=
(mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize)) {
return EFI_INVALID_PARAMETER;
}
// Find out the size of the buffer passed
NsCommBufferSize = ((EFI_MM_COMMUNICATE_HEADER *) NsCommBufferAddr)->MessageLength +
sizeof (EFI_MM_COMMUNICATE_HEADER);
// perform bounds check.
if (NsCommBufferAddr + NsCommBufferSize >=
mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize) {
return EFI_ACCESS_DENIED;
}
GuidedEventContext = NULL;
// Now that the secure world can see the normal world buffer, allocate
// memory to copy the communication buffer to the secure world.
Status = mMmst->MmAllocatePool (
EfiRuntimeServicesData,
NsCommBufferSize,
(VOID **) &GuidedEventContext
);
if (Status != EFI_SUCCESS) {
DEBUG ((DEBUG_INFO, "Mem alloc failed - 0x%x\n", EventId));
return EFI_OUT_OF_RESOURCES;
}
// X1 contains the VA of the normal world memory accessible from
// S-EL0
CopyMem (GuidedEventContext, (CONST VOID *) NsCommBufferAddr, NsCommBufferSize);
// Stash the pointer to the allocated Event Context for this CPU
PerCpuGuidedEventContext[CpuNumber] = GuidedEventContext;
ZeroMem (&MmEntryPointContext, sizeof (EFI_MM_ENTRY_CONTEXT));
MmEntryPointContext.CurrentlyExecutingCpu = CpuNumber;
MmEntryPointContext.NumberOfCpus = mMpInformationHobData->NumberOfProcessors;
// Populate the MM system table with MP and state information
mMmst->CurrentlyExecutingCpu = CpuNumber;
mMmst->NumberOfCpus = mMpInformationHobData->NumberOfProcessors;
mMmst->CpuSaveStateSize = 0;
mMmst->CpuSaveState = NULL;
if (mMmEntryPoint == NULL) {
DEBUG ((DEBUG_INFO, "Mm Entry point Not Found\n"));
return EFI_UNSUPPORTED;
}
mMmEntryPoint (&MmEntryPointContext);
// Free the memory allocation done earlier and reset the per-cpu context
ASSERT (GuidedEventContext);
CopyMem ((VOID *)NsCommBufferAddr, (CONST VOID *) GuidedEventContext, NsCommBufferSize);
Status = mMmst->MmFreePool ((VOID *) GuidedEventContext);
if (Status != EFI_SUCCESS) {
return EFI_OUT_OF_RESOURCES;
}
PerCpuGuidedEventContext[CpuNumber] = NULL;
return Status;
}
EFI_STATUS
EFIAPI
MmFoundationEntryRegister (
IN CONST EFI_MM_CONFIGURATION_PROTOCOL *This,
IN EFI_MM_ENTRY_POINT MmEntryPoint
)
{
// store the entry point in a global
mMmEntryPoint = MmEntryPoint;
return EFI_SUCCESS;
}
/**
This function is the main entry point for an MM handler dispatch
or communicate-based callback.
@param DispatchHandle The unique handle assigned to this handler by MmiHandlerRegister().
@param Context Points to an optional handler context which was specified when the handler was registered.
@param CommBuffer A pointer to a collection of data in memory that will
be conveyed from a non-MM environment into an MM environment.
@param CommBufferSize The size of the CommBuffer.
@return Status Code
**/
EFI_STATUS
EFIAPI
PiMmCpuTpFwRootMmiHandler (
IN EFI_HANDLE DispatchHandle,
IN CONST VOID *Context, OPTIONAL
IN OUT VOID *CommBuffer, OPTIONAL
IN OUT UINTN *CommBufferSize OPTIONAL
)
{
EFI_STATUS Status;
UINTN CpuNumber;
ASSERT (Context == NULL);
ASSERT (CommBuffer == NULL);
ASSERT (CommBufferSize == NULL);
CpuNumber = mMmst->CurrentlyExecutingCpu;
if (PerCpuGuidedEventContext[CpuNumber] == NULL) {
return EFI_NOT_FOUND;
}
DEBUG ((DEBUG_INFO, "CommBuffer - 0x%x, CommBufferSize - 0x%x\n",
PerCpuGuidedEventContext[CpuNumber],
PerCpuGuidedEventContext[CpuNumber]->MessageLength));
Status = mMmst->MmiManage (
&PerCpuGuidedEventContext[CpuNumber]->HeaderGuid,
NULL,
PerCpuGuidedEventContext[CpuNumber]->Data,
&PerCpuGuidedEventContext[CpuNumber]->MessageLength
);
if (Status != EFI_SUCCESS) {
DEBUG ((DEBUG_WARN, "Unable to manage Guided Event - %d\n", Status));
}
return Status;
}
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