[PATCH 2/7] MdeModulePkg/SmmIpl: expose MM communicate 2 protocol

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

From: Ard Biesheuvel <ard.biesheuvel@linaro.org>

The MM communicate 2 protocol was introduced to factor out the mismatch
between traditional MM, which requires the physical address of the MM
buffer to be passed, and standalone MM, which copies the MM communicate
buffer data into a separate buffer, requiring the virtual address. For
this reason, MM communicate 2 carries both addresses, allowing the
implementation to decide which address it needs.

This hides this implementation detail from the callers of the protocol,
which simply passes both addresses without having to reason about what the
implementation of the protocol actually needs.

Note that the old version of the protocol is retained, in order to support
existing implementations that don't require this flexibility.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c   | 79 ++++++++++++++++++++
 MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf |  1 +
 2 files changed, 80 insertions(+)

diff --git a/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c b/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c
index 1cf8c93227a3..d86b8b4a6a29 100644
--- a/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c
+++ b/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c
@@ -10,6 +10,7 @@
 
 #include <Protocol/SmmBase2.h>
 #include <Protocol/SmmCommunication.h>
+#include <Protocol/MmCommunication2.h>
 #include <Protocol/SmmAccess2.h>
 #include <Protocol/SmmConfiguration.h>
 #include <Protocol/SmmControl2.h>
@@ -118,6 +119,39 @@ SmmCommunicationCommunicate (
   IN OUT UINTN                             *CommSize OPTIONAL
   );
 
+/**
+  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] 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  The CommBuffer 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.
+
+**/
+EFI_STATUS
+EFIAPI
+SmmCommunicationMmCommunicate2 (
+  IN CONST EFI_MM_COMMUNICATION2_PROTOCOL   *This,
+  IN OUT VOID                               *CommBufferPhysical,
+  IN OUT VOID                               *CommBufferVirtual,
+  IN OUT UINTN                              *CommSize OPTIONAL
+  );
+
 /**
   Event notification that is fired every time a gEfiSmmConfigurationProtocol installs.
 
@@ -240,6 +274,13 @@ EFI_SMM_COMMUNICATION_PROTOCOL  mSmmCommunication = {
   SmmCommunicationCommunicate
 };
 
+//
+// PI 1.7 MM Communication Protocol 2 instance
+//
+EFI_MM_COMMUNICATION2_PROTOCOL  mMmCommunication2 = {
+  SmmCommunicationMmCommunicate2
+};
+
 //
 // SMM Core Private Data structure that contains the data shared between
 // the SMM IPL and the SMM Core.
@@ -576,6 +617,44 @@ SmmCommunicationCommunicate (
   return (Status == EFI_SUCCESS) ? EFI_SUCCESS : EFI_NOT_FOUND;
 }
 
+/**
+  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] 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  The CommBuffer 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.
+
+**/
+EFI_STATUS
+EFIAPI
+SmmCommunicationMmCommunicate2 (
+  IN CONST EFI_MM_COMMUNICATION2_PROTOCOL   *This,
+  IN OUT VOID                               *CommBufferPhysical,
+  IN OUT VOID                               *CommBufferVirtual,
+  IN OUT UINTN                              *CommSize OPTIONAL
+  )
+{
+  return SmmCommunicationCommunicate (&mSmmCommunication,
+                                      CommBufferPhysical,
+                                      CommSize);
+}
+
 /**
   Event notification that is fired when GUIDed Event Group is signaled.
 
diff --git a/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf b/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf
index b6b1bbcdac51..0a05d593522e 100644
--- a/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf
+++ b/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf
@@ -50,6 +50,7 @@ [LibraryClasses]
 [Protocols]
   gEfiSmmBase2ProtocolGuid                      ## PRODUCES
   gEfiSmmCommunicationProtocolGuid              ## PRODUCES
+  gEfiMmCommunication2ProtocolGuid              ## PRODUCES
   gEfiSmmAccess2ProtocolGuid                    ## CONSUMES
   ## NOTIFY
   ## CONSUMES
-- 
2.17.1