[edk2][PATCH V1 1/1] ArmPkg: introduce FF-A interface support in MM_COMMUNICATE

["Sayanta Pattanayak" <sayanta.pattanayak@arm.com>]

From: Aditya Angadi <aditya.angadi@arm.com>

With the introduction of Firmware Framework for Arm platforms (FF-A),
normal world and secure world endpoints can use FF-A interface for
communication with each other. In this patch, FFA_MSG_SEND_DIRECT_REQ
and FFA_VERSION interfaces are introduced. This change adds an option
to either use the existing SMC interface or the introduced FF-A
interface based on the value of PcdFfaEnable.

Signed-off-by: Aditya Angadi <aditya.angadi@arm.com>
Signed-off-by: Sayanta Pattanayak <sayanta.pattanayak@arm.com>
---
 ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf |  3 +
 ArmPkg/Include/IndustryStandard/ArmFfaSvc.h           |  2 +
 ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c   | 73 ++++++++++++++++----
 3 files changed, 63 insertions(+), 15 deletions(-)

diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
index 05b6de73ff34..da8462755a6f 100644
--- a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
+++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
@@ -52,5 +52,8 @@
   gArmTokenSpaceGuid.PcdMmBufferBase
   gArmTokenSpaceGuid.PcdMmBufferSize
 
+[FeaturePcd.AARCH64]
+  gArmTokenSpaceGuid.PcdFfaEnable
+
 [Depex]
   gEfiCpuArchProtocolGuid
diff --git a/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h b/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h
index 65b8343ade61..5a300a7295db 100644
--- a/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h
+++ b/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h
@@ -19,6 +19,8 @@
 #define ARM_SVC_ID_FFA_VERSION_AARCH32                  0x84000063
 #define ARM_SVC_ID_FFA_MSG_SEND_DIRECT_REQ_AARCH64      0xC400006F
 #define ARM_SVC_ID_FFA_MSG_SEND_DIRECT_RESP_AARCH64     0xC4000070
+#define ARM_SVC_ID_FFA_SUCCESS_AARCH64                  0xC4000061
+#define ARM_SVC_ID_FFA_SUCCESS_AARCH32                  0x84000060
 
 #define SPM_MAJOR_VERSION_FFA                           1
 #define SPM_MINOR_VERSION_FFA                           0
diff --git a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
index b1e309580988..ff15903473ad 100644
--- a/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
+++ b/ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c
@@ -18,6 +18,7 @@
 
 #include <Protocol/MmCommunication2.h>
 
+#include <IndustryStandard/ArmFfaSvc.h>
 #include <IndustryStandard/ArmStdSmc.h>
 
 #include "MmCommunicate.h"
@@ -73,6 +74,7 @@ MmCommunication2Communicate (
   ARM_SMC_ARGS                CommunicateSmcArgs;
   EFI_STATUS                  Status;
   UINTN                       BufferSize;
+  UINTN                       Ret;
 
   Status = EFI_ACCESS_DENIED;
   BufferSize = 0;
@@ -124,26 +126,55 @@ MmCommunication2Communicate (
     return EFI_BAD_BUFFER_SIZE;
   }
 
-  // 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;
+  // Use the FF-A interface if enabled.
+  if (FeaturePcdGet (PcdFfaEnable)) {
+    // FF-A Interface ID for direct message communication
+    CommunicateSmcArgs.Arg0 = ARM_SVC_ID_FFA_MSG_SEND_DIRECT_REQ_AARCH64;
 
-  // comm_size_address (not used, indicated by setting to zero)
-  CommunicateSmcArgs.Arg3 = 0;
+    // FF-A Destination EndPoint ID, not used as of now
+    CommunicateSmcArgs.Arg1 = 0x0;
+
+    // Reserved for future use(MBZ)
+    CommunicateSmcArgs.Arg2 = 0x0;
+
+    // Arg3 onwards are the IMPLEMENTATION DEFINED FF-A parameters
+    // SMC Function ID
+    CommunicateSmcArgs.Arg3 = ARM_SMC_ID_MM_COMMUNICATE_AARCH64;
+
+    // Cookie
+    CommunicateSmcArgs.Arg4 = 0x0;
+
+    // comm_buffer_address (64-bit physical address)
+    CommunicateSmcArgs.Arg5 = (UINTN)mNsCommBuffMemRegion.PhysicalBase;
+
+    // comm_size_address (not used, indicated by setting to zero)
+    CommunicateSmcArgs.Arg6 = 0;
+  } else {
+    // SMC Function ID
+    CommunicateSmcArgs.Arg0 = ARM_SMC_ID_MM_COMMUNICATE_AARCH64;
+
+    // Cookie
+    CommunicateSmcArgs.Arg1 = 0;
+
+    // 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:
+  Ret = CommunicateSmcArgs.Arg0;
+
+  if ((FeaturePcdGet (PcdFfaEnable) &&
+      (Ret == ARM_SVC_ID_FFA_SUCCESS_AARCH64)) ||
+      (Ret == ARM_SMC_MM_RET_SUCCESS))
+  {
     ZeroMem (CommBufferVirtual, BufferSize);
     // On successful return, the size of data being returned is inferred from
     // MessageLength + Header.
@@ -158,8 +189,14 @@ MmCommunication2Communicate (
       BufferSize
       );
     Status = EFI_SUCCESS;
-    break;
+    return Status;
+  }
 
+  if (FeaturePcdGet (PcdFfaEnable))
+    Ret = CommunicateSmcArgs.Arg2;
+
+  // Error Codes are same for FF-A and SMC interface
+  switch (Ret) {
   case ARM_SMC_MM_RET_INVALID_PARAMS:
     Status = EFI_INVALID_PARAMETER;
     break;
@@ -233,8 +270,14 @@ GetMmCompatibility ()
   UINT32       MmVersion;
   ARM_SMC_ARGS MmVersionArgs;
 
-  // MM_VERSION uses SMC32 calling conventions
-  MmVersionArgs.Arg0 = ARM_SMC_ID_MM_VERSION_AARCH32;
+  if (FeaturePcdGet (PcdFfaEnable)) {
+    MmVersionArgs.Arg0 = ARM_SVC_ID_FFA_VERSION_AARCH32;
+    MmVersionArgs.Arg1 = MM_CALLER_MAJOR_VER << MM_MAJOR_VER_SHIFT;
+    MmVersionArgs.Arg1 |= MM_CALLER_MINOR_VER;
+  } else {
+    // MM_VERSION uses SMC32 calling conventions
+    MmVersionArgs.Arg0 = ARM_SMC_ID_MM_VERSION_AARCH32;
+  }
 
   ArmCallSmc (&MmVersionArgs);
 
-- 
2.17.1