/** @file Copyright (c) 2016-2021, Arm Limited. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent **/ #include #include #include #include #include #include #include #include #include #include #include #include "MmCommunicate.h" // // Address, Length of the pre-allocated buffer for communication with the secure // world. // STATIC ARM_MEMORY_REGION_DESCRIPTOR mNsCommBuffMemRegion; // Notification event when virtual address map is set. STATIC EFI_EVENT mSetVirtualAddressMapEvent; // // Handle to install the MM Communication Protocol // STATIC EFI_HANDLE mMmCommunicateHandle; /** Communicates with a registered handler. This function provides a service to send and receive messages from a registered UEFI service. @param[in] This The EFI_MM_COMMUNICATION_PROTOCOL instance. @param[in, out] CommBufferPhysical Physical address of the MM communication buffer @param[in, out] CommBufferVirtual Virtual address of the MM communication buffer @param[in, out] CommSize The size of the data buffer being passed in. On input, when not omitted, the buffer should cover EFI_MM_COMMUNICATE_HEADER and the value of MessageLength field. On exit, the size of data being returned. Zero if the handler does not wish to reply with any data. This parameter is optional and may be NULL. @retval EFI_SUCCESS The message was successfully posted. @retval EFI_INVALID_PARAMETER CommBufferPhysical or CommBufferVirtual was NULL, or integer value pointed by CommSize does not cover EFI_MM_COMMUNICATE_HEADER and the value of MessageLength field. @retval EFI_BAD_BUFFER_SIZE The buffer is too large for the MM implementation. If this error is returned, the MessageLength field in the CommBuffer header or the integer pointed by CommSize, are updated to reflect the maximum payload size the implementation can accommodate. @retval EFI_ACCESS_DENIED The CommunicateBuffer parameter or CommSize parameter, if not omitted, are in address range that cannot be accessed by the MM environment. **/ EFI_STATUS EFIAPI MmCommunication2Communicate ( IN CONST EFI_MM_COMMUNICATION2_PROTOCOL *This, IN OUT VOID *CommBufferPhysical, IN OUT VOID *CommBufferVirtual, IN OUT UINTN *CommSize OPTIONAL ) { EFI_MM_COMMUNICATE_HEADER *CommunicateHeader; ARM_SMC_ARGS CommunicateSmcArgs; EFI_STATUS Status; UINTN BufferSize; Status = EFI_ACCESS_DENIED; BufferSize = 0; ZeroMem (&CommunicateSmcArgs, sizeof (ARM_SMC_ARGS)); // // Check parameters // if ((CommBufferVirtual == NULL) || (CommBufferPhysical == NULL)) { return EFI_INVALID_PARAMETER; } Status = EFI_SUCCESS; CommunicateHeader = CommBufferVirtual; // CommBuffer is a mandatory parameter. Hence, Rely on // MessageLength + Header to ascertain the // total size of the communication payload rather than // rely on optional CommSize parameter BufferSize = CommunicateHeader->MessageLength + sizeof (CommunicateHeader->HeaderGuid) + sizeof (CommunicateHeader->MessageLength); // If CommSize is not omitted, perform size inspection before proceeding. if (CommSize != NULL) { // This case can be used by the consumer of this driver to find out the // max size that can be used for allocating CommBuffer. if ((*CommSize == 0) || (*CommSize > mNsCommBuffMemRegion.Length)) { *CommSize = mNsCommBuffMemRegion.Length; Status = EFI_BAD_BUFFER_SIZE; } // // CommSize should cover at least MessageLength + sizeof (EFI_MM_COMMUNICATE_HEADER); // if (*CommSize < BufferSize) { Status = EFI_INVALID_PARAMETER; } } // // If the message length is 0 or greater than what can be tolerated by the MM // environment then return the expected size. // if ((CommunicateHeader->MessageLength == 0) || (BufferSize > mNsCommBuffMemRegion.Length)) { CommunicateHeader->MessageLength = mNsCommBuffMemRegion.Length - sizeof (CommunicateHeader->HeaderGuid) - sizeof (CommunicateHeader->MessageLength); Status = EFI_BAD_BUFFER_SIZE; } // MessageLength or CommSize check has failed, return here. if (EFI_ERROR (Status)) { return Status; } // SMC Function ID CommunicateSmcArgs.Arg0 = ARM_SMC_ID_MM_COMMUNICATE_AARCH64; // Cookie CommunicateSmcArgs.Arg1 = 0; // Copy Communication Payload CopyMem ((VOID *)mNsCommBuffMemRegion.VirtualBase, CommBufferVirtual, BufferSize); // comm_buffer_address (64-bit physical address) CommunicateSmcArgs.Arg2 = (UINTN)mNsCommBuffMemRegion.PhysicalBase; // comm_size_address (not used, indicated by setting to zero) CommunicateSmcArgs.Arg3 = 0; // Call the Standalone MM environment. ArmCallSmc (&CommunicateSmcArgs); switch (CommunicateSmcArgs.Arg0) { case ARM_SMC_MM_RET_SUCCESS: ZeroMem (CommBufferVirtual, BufferSize); // On successful return, the size of data being returned is inferred from // MessageLength + Header. CommunicateHeader = (EFI_MM_COMMUNICATE_HEADER *)mNsCommBuffMemRegion.VirtualBase; BufferSize = CommunicateHeader->MessageLength + sizeof (CommunicateHeader->HeaderGuid) + sizeof (CommunicateHeader->MessageLength); CopyMem ( CommBufferVirtual, (VOID *)mNsCommBuffMemRegion.VirtualBase, BufferSize ); Status = EFI_SUCCESS; break; case ARM_SMC_MM_RET_INVALID_PARAMS: Status = EFI_INVALID_PARAMETER; break; case ARM_SMC_MM_RET_DENIED: Status = EFI_ACCESS_DENIED; break; case ARM_SMC_MM_RET_NO_MEMORY: // Unexpected error since the CommSize was checked for zero length // prior to issuing the SMC Status = EFI_OUT_OF_RESOURCES; ASSERT (0); break; default: Status = EFI_ACCESS_DENIED; ASSERT (0); } return Status; } // // MM Communication Protocol instance // STATIC EFI_MM_COMMUNICATION2_PROTOCOL mMmCommunication2 = { MmCommunication2Communicate }; /** Notification callback on SetVirtualAddressMap event. This function notifies the MM communication protocol interface on SetVirtualAddressMap event and converts pointers used in this driver from physical to virtual address. @param Event SetVirtualAddressMap event. @param Context A context when the SetVirtualAddressMap triggered. @retval EFI_SUCCESS The function executed successfully. @retval Other Some error occurred when executing this function. **/ STATIC VOID EFIAPI NotifySetVirtualAddressMap ( IN EFI_EVENT Event, IN VOID *Context ) { EFI_STATUS Status; Status = gRT->ConvertPointer ( EFI_OPTIONAL_PTR, (VOID **)&mNsCommBuffMemRegion.VirtualBase ); if (EFI_ERROR (Status)) { DEBUG (( DEBUG_ERROR, "NotifySetVirtualAddressMap():" " Unable to convert MM runtime pointer. Status:0x%r\n", Status )); } } STATIC EFI_STATUS GetMmCompatibility ( ) { EFI_STATUS Status; UINT32 MmVersion; ARM_SMC_ARGS MmVersionArgs; // MM_VERSION uses SMC32 calling conventions MmVersionArgs.Arg0 = ARM_SMC_ID_MM_VERSION_AARCH32; ArmCallSmc (&MmVersionArgs); MmVersion = MmVersionArgs.Arg0; if ((MM_MAJOR_VER (MmVersion) == MM_CALLER_MAJOR_VER) && (MM_MINOR_VER (MmVersion) >= MM_CALLER_MINOR_VER)) { DEBUG (( DEBUG_INFO, "MM Version: Major=0x%x, Minor=0x%x\n", MM_MAJOR_VER (MmVersion), MM_MINOR_VER (MmVersion) )); Status = EFI_SUCCESS; } else { DEBUG (( DEBUG_ERROR, "Incompatible MM Versions.\n Current Version: Major=0x%x, Minor=0x%x.\n Expected: Major=0x%x, Minor>=0x%x.\n", MM_MAJOR_VER (MmVersion), MM_MINOR_VER (MmVersion), MM_CALLER_MAJOR_VER, MM_CALLER_MINOR_VER )); Status = EFI_UNSUPPORTED; } return Status; } STATIC EFI_GUID *CONST mGuidedEventGuid[] = { &gEfiEndOfDxeEventGroupGuid, &gEfiEventExitBootServicesGuid, &gEfiEventReadyToBootGuid, }; STATIC EFI_EVENT mGuidedEvent[ARRAY_SIZE (mGuidedEventGuid)]; /** Event notification that is fired when GUIDed Event Group is signaled. @param Event The Event that is being processed, not used. @param Context Event Context, not used. **/ STATIC VOID EFIAPI MmGuidedEventNotify ( IN EFI_EVENT Event, IN VOID *Context ) { EFI_MM_COMMUNICATE_HEADER Header; UINTN Size; // // Use Guid to initialize EFI_SMM_COMMUNICATE_HEADER structure // CopyGuid (&Header.HeaderGuid, Context); Header.MessageLength = 1; Header.Data[0] = 0; Size = sizeof (Header); MmCommunication2Communicate (&mMmCommunication2, &Header, &Header, &Size); } /** The Entry Point for MM Communication This function installs the MM communication protocol interface and finds out what type of buffer management will be required prior to invoking the communication SMC. @param ImageHandle The firmware allocated handle for the EFI image. @param SystemTable A pointer to the EFI System Table. @retval EFI_SUCCESS The entry point is executed successfully. @retval Other Some error occurred when executing this entry point. **/ EFI_STATUS EFIAPI MmCommunication2Initialize ( IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable ) { EFI_STATUS Status; UINTN Index; // Check if we can make the MM call Status = GetMmCompatibility (); if (EFI_ERROR (Status)) { goto ReturnErrorStatus; } mNsCommBuffMemRegion.PhysicalBase = PcdGet64 (PcdMmBufferBase); // During boot , Virtual and Physical are same mNsCommBuffMemRegion.VirtualBase = mNsCommBuffMemRegion.PhysicalBase; mNsCommBuffMemRegion.Length = PcdGet64 (PcdMmBufferSize); ASSERT (mNsCommBuffMemRegion.PhysicalBase != 0); ASSERT (mNsCommBuffMemRegion.Length != 0); Status = gDS->AddMemorySpace ( EfiGcdMemoryTypeReserved, mNsCommBuffMemRegion.PhysicalBase, mNsCommBuffMemRegion.Length, EFI_MEMORY_WB | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME ); if (EFI_ERROR (Status)) { DEBUG (( DEBUG_ERROR, "MmCommunicateInitialize: " "Failed to add MM-NS Buffer Memory Space\n" )); goto ReturnErrorStatus; } Status = gDS->SetMemorySpaceAttributes ( mNsCommBuffMemRegion.PhysicalBase, mNsCommBuffMemRegion.Length, EFI_MEMORY_WB | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME ); if (EFI_ERROR (Status)) { DEBUG (( DEBUG_ERROR, "MmCommunicateInitialize: " "Failed to set MM-NS Buffer Memory attributes\n" )); goto CleanAddedMemorySpace; } // Install the communication protocol Status = gBS->InstallProtocolInterface ( &mMmCommunicateHandle, &gEfiMmCommunication2ProtocolGuid, EFI_NATIVE_INTERFACE, &mMmCommunication2 ); if (EFI_ERROR (Status)) { DEBUG (( DEBUG_ERROR, "MmCommunicationInitialize: " "Failed to install MM communication protocol\n" )); goto CleanAddedMemorySpace; } // Register notification callback when virtual address is associated // with the physical address. // Create a Set Virtual Address Map event. Status = gBS->CreateEvent ( EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE, TPL_NOTIFY, NotifySetVirtualAddressMap, NULL, &mSetVirtualAddressMapEvent ); ASSERT_EFI_ERROR (Status); for (Index = 0; Index < ARRAY_SIZE (mGuidedEventGuid); Index++) { Status = gBS->CreateEventEx ( EVT_NOTIFY_SIGNAL, TPL_CALLBACK, MmGuidedEventNotify, mGuidedEventGuid[Index], mGuidedEventGuid[Index], &mGuidedEvent[Index] ); ASSERT_EFI_ERROR (Status); if (EFI_ERROR (Status)) { while (Index-- > 0) { gBS->CloseEvent (mGuidedEvent[Index]); } goto UninstallProtocol; } } return EFI_SUCCESS; UninstallProtocol: gBS->UninstallProtocolInterface ( mMmCommunicateHandle, &gEfiMmCommunication2ProtocolGuid, &mMmCommunication2 ); CleanAddedMemorySpace: gDS->RemoveMemorySpace ( mNsCommBuffMemRegion.PhysicalBase, mNsCommBuffMemRegion.Length ); ReturnErrorStatus: return EFI_INVALID_PARAMETER; }