[PATCH resend 3/7] ArmPkg/MmCommunicationDxe: expose MM Communicate 2 protocol

["Ard Biesheuvel" <ard.biesheuvel@arm.com>]

Implement the new MmCommunication2 protocol which supports the use
of standalone MM at runtime inside an address space that has been
virtually remapped by the OS.

Note that the implementation of the old MM Communicate protocol is
removed: it never worked correctly so there is no point in keeping it.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
---
 ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c   | 81 +++++++++-----------
 ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf |  6 +-
 2 files changed, 41 insertions(+), 46 deletions(-)

diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
index a9e06be1adc2..9457eaf1d809 100644
--- a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
+++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2016-2018, ARM Limited. All rights reserved.
+  Copyright (c) 2016-2020, ARM Limited. All rights reserved.
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -16,7 +16,7 @@
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiRuntimeServicesTableLib.h>
 
-#include <Protocol/MmCommunication.h>
+#include <Protocol/MmCommunication2.h>
 
 #include <IndustryStandard/ArmStdSmc.h>
 
@@ -39,39 +39,34 @@ 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().
+  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] 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.
+  @param[in] This                The EFI_MM_COMMUNICATION_PROTOCOL instance.
+  @param[in] CommBufferPhysical  Physical address of the MM communication buffer
+  @param[in] CommBufferVirtual   Virtual address of the MM communication buffer
+  @param[in] CommSize            The size of the data buffer being passed in. 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 was NULL or CommBufferVirtual was NULL.
+  @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.
 
-  @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
+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;
@@ -87,11 +82,11 @@ MmCommunicationCommunicate (
   //
   // Check parameters
   //
-  if (CommBuffer == NULL) {
+  if (CommBufferVirtual == NULL) {
     return EFI_INVALID_PARAMETER;
   }
 
-  CommunicateHeader = CommBuffer;
+  CommunicateHeader = CommBufferVirtual;
   // CommBuffer is a mandatory parameter. Hence, Rely on
   // MessageLength + Header to ascertain the
   // total size of the communication payload rather than
@@ -136,7 +131,7 @@ MmCommunicationCommunicate (
   CommunicateSmcArgs.Arg1 = 0;
 
   // Copy Communication Payload
-  CopyMem ((VOID *)mNsCommBuffMemRegion.VirtualBase, CommBuffer, BufferSize);
+  CopyMem ((VOID *)mNsCommBuffMemRegion.VirtualBase, CommBufferVirtual, BufferSize);
 
   // comm_buffer_address (64-bit physical address)
   CommunicateSmcArgs.Arg2 = (UINTN)mNsCommBuffMemRegion.PhysicalBase;
@@ -149,7 +144,7 @@ MmCommunicationCommunicate (
 
   switch (CommunicateSmcArgs.Arg0) {
   case ARM_SMC_MM_RET_SUCCESS:
-    ZeroMem (CommBuffer, BufferSize);
+    ZeroMem (CommBufferVirtual, BufferSize);
     // On successful return, the size of data being returned is inferred from
     // MessageLength + Header.
     CommunicateHeader = (EFI_MM_COMMUNICATE_HEADER *)mNsCommBuffMemRegion.VirtualBase;
@@ -158,7 +153,7 @@ MmCommunicationCommunicate (
                  sizeof (CommunicateHeader->MessageLength);
 
     CopyMem (
-      CommBuffer,
+      CommBufferVirtual,
       (VOID *)mNsCommBuffMemRegion.VirtualBase,
       BufferSize
       );
@@ -191,8 +186,8 @@ MmCommunicationCommunicate (
 //
 // MM Communication Protocol instance
 //
-EFI_MM_COMMUNICATION_PROTOCOL  mMmCommunication = {
-  MmCommunicationCommunicate
+STATIC EFI_MM_COMMUNICATION2_PROTOCOL  mMmCommunication2 = {
+  MmCommunication2Communicate
 };
 
 /**
@@ -293,7 +288,7 @@ MmGuidedEventNotify (
   Header.Data[0] = 0;
 
   Size = sizeof (Header);
-  MmCommunicationCommunicate (&mMmCommunication, &Header, &Size);
+  MmCommunication2Communicate (&mMmCommunication2, &Header, &Header, &Size);
 }
 
 /**
@@ -312,7 +307,7 @@ MmGuidedEventNotify (
 **/
 EFI_STATUS
 EFIAPI
-MmCommunicationInitialize (
+MmCommunication2Initialize (
   IN EFI_HANDLE         ImageHandle,
   IN EFI_SYSTEM_TABLE  *SystemTable
   )
@@ -363,9 +358,9 @@ MmCommunicationInitialize (
   // Install the communication protocol
   Status = gBS->InstallProtocolInterface (
                   &mMmCommunicateHandle,
-                  &gEfiMmCommunicationProtocolGuid,
+                  &gEfiMmCommunication2ProtocolGuid,
                   EFI_NATIVE_INTERFACE,
-                  &mMmCommunication
+                  &mMmCommunication2
                   );
   if (EFI_ERROR(Status)) {
     DEBUG ((DEBUG_ERROR, "MmCommunicationInitialize: "
@@ -402,8 +397,8 @@ MmCommunicationInitialize (
 UninstallProtocol:
   gBS->UninstallProtocolInterface (
          mMmCommunicateHandle,
-         &gEfiMmCommunicationProtocolGuid,
-         &mMmCommunication
+         &gEfiMmCommunication2ProtocolGuid,
+         &mMmCommunication2
          );
 
 CleanAddedMemorySpace:
diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
index 505228704ea5..2465fb77c58e 100644
--- a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
+++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
@@ -2,7 +2,7 @@
 #
 #  DXE MM Communicate driver
 #
-#  Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.
+#  Copyright (c) 2016 - 2020, ARM Limited. All rights reserved.
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -14,7 +14,7 @@ [Defines]
   FILE_GUID                      = 09EE81D3-F15E-43F4-85B4-CB9873DA5D6B
   MODULE_TYPE                    = DXE_RUNTIME_DRIVER
   VERSION_STRING                 = 1.0
-  ENTRY_POINT                    = MmCommunicationInitialize
+  ENTRY_POINT                    = MmCommunication2Initialize
 
 #
 # The following is for reference only and not required by
@@ -40,7 +40,7 @@ [LibraryClasses]
   UefiDriverEntryPoint
 
 [Protocols]
-  gEfiMmCommunicationProtocolGuid              ## PRODUCES
+  gEfiMmCommunication2ProtocolGuid              ## PRODUCES
 
 [Guids]
   gEfiEndOfDxeEventGroupGuid
-- 
2.17.1