Re: [edk2 PATCH v3 2/2] ArmPkg/Drivers: Add EFI_MM_COMMUNICATION_PROTOCOL DXE driver.

[Supreeth Venkatesh <supreeth.venkatesh@arm.com>]

On Wed, 2017-12-13 at 11:26 +0000, Meenakshi Aggarwal wrote:
> Hi Supreeth,
> 
> Few comments inline.
Thank you for your comments.
> 
> 
> > 
> > -----Original Message-----
> > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf
> > Of
> > Supreeth Venkatesh
> > Sent: Friday, November 17, 2017 10:18 PM
> > To: edk2-devel@lists.01.org
> > Cc: leif.lindholm@linaro.org; ard.biesheuvel@linaro.org
> > Subject: [edk2] [edk2 PATCH v3 2/2] ArmPkg/Drivers: Add
> > EFI_MM_COMMUNICATION_PROTOCOL DXE driver.
> > 
> > PI v1.5 Specification Volume 4 defines Management Mode Core
> > Interface
> > and defines EFI_MM_COMMUNICATION_PROTOCOL. This protocol provides
> > a
> > means of communicating between drivers outside of MM and MMI
> > handlers inside of MM.
> > 
> > This patch implements the EFI_MM_COMMUNICATION_PROTOCOL DXE
> > runtime
> > driver for AARCH64 platforms. It uses SMCs allocated from the
> > standard
> > SMC range defined in
> > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fi
> > nfo
> > center.arm.com%2Fhelp%2Ftopic%2Fcom.arm.doc.den0060a%2FDEN0060A_
> > ARM_MM_Interface_Specification.pdf&data=02%7C01%7Cmeenakshi.aggar
> > wal%40nxp.com%7C27ae12fc41414e501f8208d52ddb09f3%7C686ea1d3bc2b4
> > c6fa92cd99c5c301635%7C0%7C1%7C636465341155830632&sdata=pYKl2uUUF
> > VCS4M87y%2BRK8TE852QqcusN0Fm208IkjtU%3D&reserved=0
> > to communicate with the standalone MM environment in the secure
> > world.
> > 
> > This patch also adds the MM Communication driver (.inf) file to
> > define entry
> > point for this driver and other compile related information the
> > driver
> > needs.
> > 
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Achin Gupta <achin.gupta@arm.com>
> > Signed-off-by: Supreeth Venkatesh <supreeth.venkatesh@arm.com>
> > ---
> >  .../Drivers/MmCommunicationDxe/MmCommunication.c   | 339
> > +++++++++++++++++++++
> >  .../Drivers/MmCommunicationDxe/MmCommunication.inf |  50 +++
> >  2 files changed, 389 insertions(+)
> >  create mode 100644
> > ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
> >  create mode 100644
> > ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> > 
> > diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
> > b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
> > new file mode 100644
> > index 0000000000..e801c1c601
> > --- /dev/null
> > +++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
> > @@ -0,0 +1,339 @@
> > +/** @file
> > +
> > +  Copyright (c) 2016-2017, ARM Limited. All rights reserved.
> > +
> > +  This program and the accompanying materials
> > +  are licensed and made available under the terms and conditions
> > of the BSD
> > License
> > +  which accompanies this distribution.  The full text of the
> > license may be
> > found at
> > +
> > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fo
> > pe
> > nsource.org%2Flicenses%2Fbsd-
> > license.php&data=02%7C01%7Cmeenakshi.aggarwal%40nxp.com%7C27ae12
> > fc41414e501f8208d52ddb09f3%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0
> > %7C0%7C636465341155830632&sdata=GPd9o7ovyTU10etIxP%2BBYNsYUKq
> > m37tPcc%2BQDKtext4%3D&reserved=0
> > +
> > +  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
> > BASIS,
> > +  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
> > EXPRESS OR IMPLIED.
> > +
> > +**/
> > +
> > +#include <Library/ArmLib.h>
> > +#include <Library/ArmSmcLib.h>
> > +#include <Library/BaseMemoryLib.h>
> > +#include <Library/DebugLib.h>
> > +#include <Library/DxeServicesTableLib.h>
> > +#include <Library/HobLib.h>
> > +#include <Library/PcdLib.h>
> > +#include <Library/UefiBootServicesTableLib.h>
> > +#include <Library/UefiRuntimeServicesTableLib.h>
> > +
> > +#include <Protocol/MmCommunication.h>
> > +
> > +#include <IndustryStandard/ArmStdSmc.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 an interface to send and receive messages
> > to the
> > +  Standalone MM environment on behalf of UEFI services.  This
> > function is
> > part
> > +  of the MM Communication Protocol that may be called in physical
> > mode
> > prior to
> > +  SetVirtualAddressMap() and in virtual mode after
> > SetVirtualAddressMap().
> > +
> > +  @param[in]      This                The
> > EFI_MM_COMMUNICATION_PROTOCOL
> > +                                      instance.
> > +  @param[in, out] CommBuffer          A pointer to the buffer to
> > convey
> > +                                      into MMRAM.
> > +  @param[in, out] CommSize            The size of the data buffer
> > being
> > +                                      passed in. This is optional.
> > +
> > +  @retval EFI_SUCCESS                 The message was successfully
> > posted.
> > +  @retval EFI_INVALID_PARAMETER       The CommBuffer was NULL.
> > +  @retval EFI_BAD_BUFFER_SIZE         The buffer size is incorrect
> > 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
> > +**/
> > +STATIC
> > +EFI_STATUS
> > +EFIAPI
> > +MmCommunicationCommunicate (
> > +  IN CONST EFI_MM_COMMUNICATION_PROTOCOL  *This,
> > +  IN OUT VOID                             *CommBuffer,
> > +  IN OUT UINTN                            *CommSize OPTIONAL
> > +  )
> > +{
> > +  EFI_MM_COMMUNICATE_HEADER   *CommunicateHeader;
> > +  ARM_SMC_ARGS                CommunicateSmcArgs;
> > +  EFI_STATUS                  Status;
> > +  UINTN                       BufferSize;
> > +
> > +  CommunicateHeader = CommBuffer;
> > +  Status = EFI_ACCESS_DENIED;
> > +  BufferSize = 0;
> > +
> > +  ZeroMem (&CommunicateSmcArgs, sizeof (ARM_SMC_ARGS));
> > +
> > +  //
> > +  // Check parameters
> > +  //
> > +  if (CommBuffer == NULL) {
> > +    return EFI_INVALID_PARAMETER;
> > +  }
> > +
> > +  // If the length of the CommBuffer is 0 then return the expected
> > length.
> > +  if (CommSize) {
> > +    if (*CommSize == 0) {
> > +      *CommSize = mNsCommBuffMemRegion.Length;
> > +      return EFI_BAD_BUFFER_SIZE;
> > +    }
> > +    //
> > +    // CommSize must hold HeaderGuid and MessageLength
> > +    //
> > +    if (*CommSize < sizeof (EFI_MM_COMMUNICATE_HEADER)) {
> > +        return EFI_INVALID_PARAMETER;
> > +    }
> > +    BufferSize = *CommSize;
> > +  } else {
> > +    BufferSize = CommunicateHeader->MessageLength +
> > +                 sizeof (CommunicateHeader->HeaderGuid) +
> > +                 sizeof (CommunicateHeader->MessageLength);
> > +  }
> > +
> > +  //
> > +  // If the buffer size is 0 or greater than what can be tolerated
> > by the MM
> > +  // environment then return the expected size.
> > +  //
> > +  if ((BufferSize == 0) ||
> > +      (BufferSize > mNsCommBuffMemRegion.Length)) {
> > +    CommunicateHeader->MessageLength =
> > mNsCommBuffMemRegion.Length -
> > +                                       sizeof (CommunicateHeader-
> > >HeaderGuid) -
> > +                                       sizeof (CommunicateHeader-
> > >MessageLength);
> > +    return EFI_BAD_BUFFER_SIZE;
> > +  }
> > +
> > +  // SMC Function ID
> > +  CommunicateSmcArgs.Arg0 =
> > ARM_SMC_ID_MM_COMMUNICATE_AARCH64;
> > +
> > +  // Reserved for Future. Must be Zero.
> > +  CommunicateSmcArgs.Arg1 = 0;
> > +
> > +  if (mNsCommBuffMemRegion.VirtualBase) {
> > +    CopyMem ((VOID *)mNsCommBuffMemRegion.VirtualBase,
> > CommBuffer, BufferSize);
> > +  } else {
> > +    return EFI_ACCESS_DENIED;
> > +  }
> > +
> > +  // For the SMC64 version, this parameter is a 64-bit Physical
> > Address (PA)
> > +  // or Intermediate Physical Address (IPA).
> > +  // For the SMC32 version, this parameter is a 32-bit PA or IPA.
> > +  CommunicateSmcArgs.Arg2 =
> > (UINTN)mNsCommBuffMemRegion.PhysicalBase;
> > +
> > +  // comm_size_address is a PA or an IPA that holds the size of
> > the
> > +  // communication buffer being passed in. This parameter is
> > optional
> > +  // and can be omitted by passing a zero.
> > +  // ARM does not recommend using it since this might require the
> > +  // implementation to create a separate memory mapping for the
> > parameter.
> > +  // ARM recommends storing the buffer size in the buffer itself.
> > +  CommunicateSmcArgs.Arg3 = 0;
> > +
> > +  // Call the Standalone MM environment.
> > +  ArmCallSmc (&CommunicateSmcArgs);
> > +
> > +  switch (CommunicateSmcArgs.Arg0) {
> > +  case ARM_SMC_MM_RET_SUCCESS:
> > +    // On exit, the size of data being returned is inferred from
> > +    // CommSize or MessageLength + Header.
> > +    CopyMem (CommBuffer,
> > +             (const VOID *)mNsCommBuffMemRegion.VirtualBase,
> > +             BufferSize);
> > +    Status = EFI_SUCCESS;
> > +    break;
> > +
> > +  case ARM_SMC_MM_RET_NOT_SUPPORTED:
> > +  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
> > +  default:
> > +    Status = EFI_ACCESS_DENIED;
> > +    ASSERT (0);
> > +  }
> > +
> > +  return Status;
> > +}
> > +
> > +//
> > +// MM Communication Protocol instance
> > +//
> > +EFI_MM_COMMUNICATION_PROTOCOL  mMmCommunication = {
> > +  MmCommunicationCommunicate
> > +};
> > +
> > +/**
> > +  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));
> > +  }
> > +
> > +}
> > +
> > +/**
> > +  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
> > +MmCommunicationInitialize (
> > +  IN EFI_HANDLE         ImageHandle,
> > +  IN EFI_SYSTEM_TABLE  *SystemTable
> > +  )
> > +{
> > +  EFI_STATUS                 Status;
> > +
> > +  mNsCommBuffMemRegion.PhysicalBase = PcdGet64 (PcdMmBufferBase);
> > +  // During boot , Virtual and Physical are same
> > +  mNsCommBuffMemRegion.VirtualBase =
> > mNsCommBuffMemRegion.PhysicalBase;
> > +  mNsCommBuffMemRegion.Length = PcdGet64 (PcdMmBufferSize);
> > +
> > +  if (mNsCommBuffMemRegion.PhysicalBase == 0) {
> > +    DEBUG ((DEBUG_ERROR, "MmCommunicateInitialize: "
> > +            "Invalid MM Buffer Base Address.\n"));
> > +    goto ReturnErrorStatus;
> > +  }
> > +
> [Meenakshi Aggarwal] VirtualBase address assignment should be done
> after checking PhysicalBase.
If you prefer it that way. However, there is no major optimization, if
it is before. If this is not merged yet, I will incorporate this into
the next version.
> 
> > 
> > +  if (mNsCommBuffMemRegion.Length == 0) {
> > +    DEBUG ((DEBUG_ERROR, "MmCommunicateInitialize: "
> > +            "Maximum Buffer Size is zero.\n"));
> > +    goto ReturnErrorStatus;
> > +  }
> > +
> > +  Status = gDS->AddMemorySpace (EfiGcdMemoryTypeSystemMemory,
> > +                                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;
> [Meenakshi Aggarwal] no need of goto statement here, we can directly
> return error as no cleanup is being performed  under goto statement.
Use of goto here is to have more readable and easier to understand
code. Even though its a "goto", its being used in a structured manner
to have a only one return point for success and failure cases.
> > 
> > +  }
> > +
> > +  Status = gDS-
> > > 
> > > SetMemorySpaceAttributes(mNsCommBuffMemRegion.PhysicalBase,
> [Meenakshi Aggarwal] space before opening bracket please
Thanks. Ok.
> > 
> > +                                         mNsCommBuffMemRegion.Leng
> > th,
> > +                                         EFI_MEMORY_WB |
> > EFI_MEMORY_XP);
> > +  if (EFI_ERROR (Status)) {
> > +    DEBUG ((DEBUG_ERROR, "MmCommunicateInitialize: "
> > +            "Failed to set MM-NS Buffer Memory attributes\n"));
> > +    goto CleanAddedMemorySpace;
> > +  }
> > +
> > +  Status = gBS->AllocatePages (AllocateAddress,
> > +                               EfiRuntimeServicesData,
> > +                               EFI_SIZE_TO_PAGES
> > (mNsCommBuffMemRegion.Length),
> > +                               &mNsCommBuffMemRegion.PhysicalBase)
> > ;
> > +  if (EFI_ERROR (Status)) {
> > +    DEBUG ((DEBUG_ERROR, "MmCommunicateInitialize: "
> > +            "Failed to allocate MM-NS Buffer Memory Space\n"));
> > +    goto CleanAddedMemorySpace;
> > +  }
> > +
> > +  // Install the communication protocol
> > +  Status = gBS->InstallProtocolInterface (&mMmCommunicateHandle,
> > +                                          &gEfiMmCommunicationProt
> > ocolGuid,
> > +                                          EFI_NATIVE_INTERFACE,
> > +                                          &mMmCommunication);
> > +  if (EFI_ERROR(Status)) {
> [Meenakshi Aggarwal] Space after EFI_ERROR please
Thanks. Ok.
> 
> > 
> > +    DEBUG ((DEBUG_ERROR, "MmCommunicationInitialize: "
> > +            "Failed to install MM communication protocol\n"));
> > +    goto CleanAllocatedPages;
> > +  }
> > +
> > +  // 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,  //
> > Type
> > +                             TPL_NOTIFY,                         /
> > / NotifyTpl
> > +                             NotifySetVirtualAddressMap,         /
> > / NotifyFunction
> > +                             NULL,                               /
> > / NotifyContext
> > +                             &mSetVirtualAddressMapEvent         /
> > / Event
> > +                            );
> > +  if (Status == EFI_SUCCESS) {
> > +    return Status;
> > +  }
> > +
> > +  gBS->UninstallProtocolInterface(mMmCommunicateHandle,
> > +                                  &gEfiMmCommunicationProtocolGuid
> > ,
> > +                                  &mMmCommunication);
> > +
> > +CleanAllocatedPages:
> > +  gBS->FreePages (mNsCommBuffMemRegion.PhysicalBase,
> > +                  EFI_SIZE_TO_PAGES
> > (mNsCommBuffMemRegion.Length));
> > +
> > +CleanAddedMemorySpace:
> > +  gDS->RemoveMemorySpace (mNsCommBuffMemRegion.PhysicalBase,
> > +                          mNsCommBuffMemRegion.Length);
> > +
> > +ReturnErrorStatus:
> > +  return EFI_INVALID_PARAMETER;
> > +}
> > diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> > b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> > new file mode 100644
> > index 0000000000..d39ee5fdd7
> > --- /dev/null
> > +++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> > @@ -0,0 +1,50 @@
> > +#/** @file
> > +#
> > +#  DXE MM Communicate driver
> > +#
> > +#  Copyright (c) 2016 - 2017, ARM Limited. All rights reserved.
> > +#
> > +#  This program and the accompanying materials
> > +#  are licensed and made available under the terms and conditions
> > of the
> > BSD License
> > +#  which accompanies this distribution.  The full text of the
> > license may be
> > found at
> > +#
> > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fo
> > pe
> > nsource.org%2Flicenses%2Fbsd-
> > license.php&data=02%7C01%7Cmeenakshi.aggarwal%40nxp.com%7C27ae12
> > fc41414e501f8208d52ddb09f3%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0
> > %7C0%7C636465341155830632&sdata=GPd9o7ovyTU10etIxP%2BBYNsYUKq
> > m37tPcc%2BQDKtext4%3D&reserved=0
> > +#
> > +#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
> > BASIS,
> > +#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
> > EXPRESS OR IMPLIED.
> > +#
> > +#**/
> > +
> > +[Defines]
> > +  INF_VERSION                    = 0x0001001A
> > +  BASE_NAME                      = ArmMmCommunication
> > +  FILE_GUID                      = 09EE81D3-F15E-43F4-85B4-
> > CB9873DA5D6B
> > +  MODULE_TYPE                    = DXE_RUNTIME_DRIVER
> > +  VERSION_STRING                 = 1.0
> > +
> > +  ENTRY_POINT                    = MmCommunicationInitialize
> > +
> > +[Sources.Common]
> > +  MmCommunication.c
> > +
> > +[Packages]
> > +  ArmPkg/ArmPkg.dec
> > +  MdePkg/MdePkg.dec
> > +
> > +[LibraryClasses]
> > +  ArmLib
> > +  ArmSmcLib
> > +  BaseMemoryLib
> > +  DebugLib
> > +  DxeServicesTableLib
> > +  HobLib
> > +  UefiDriverEntryPoint
> > +
> > +[Protocols]
> > +  gEfiMmCommunicationProtocolGuid              ## PRODUCES
> > +
> > +[Pcd.common]
> > +  gArmTokenSpaceGuid.PcdMmBufferBase
> > +  gArmTokenSpaceGuid.PcdMmBufferSize
> > +
> > +[Depex]
> > +  TRUE
> > --
> > 2.14.1
> > 
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