[PATCH v2 10/13] StandaloneMmMmuLib: Add option to use FF-A calls to get memory region's permissions

["Sughosh Ganu" <sughosh.ganu@linaro.org>]

From: Achin Gupta <achin.gupta@arm.com>

Allow getting memory region's permissions using either of the Firmware
Framework(FF-A) ABI transport or through the earlier used SVC calls.

Signed-off-by: Achin Gupta <achin.gupta@arm.com>
Co-developed-by: Sughosh Ganu <sughosh.ganu@linaro.org>
---
 ArmPkg/Library/StandaloneMmMmuLib/ArmMmuStandaloneMmLib.inf       |  3 +
 ArmPkg/Include/IndustryStandard/ArmFfaSvc.h                       | 18 ++++++
 ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c | 66 +++++++++++++++++---
 3 files changed, 78 insertions(+), 9 deletions(-)

diff --git a/ArmPkg/Library/StandaloneMmMmuLib/ArmMmuStandaloneMmLib.inf b/ArmPkg/Library/StandaloneMmMmuLib/ArmMmuStandaloneMmLib.inf
index 85973687f5..a29dd800b5 100644
--- a/ArmPkg/Library/StandaloneMmMmuLib/ArmMmuStandaloneMmLib.inf
+++ b/ArmPkg/Library/StandaloneMmMmuLib/ArmMmuStandaloneMmLib.inf
@@ -23,6 +23,9 @@
   ArmPkg/ArmPkg.dec
   MdePkg/MdePkg.dec
 
+[Pcd]
+  gArmTokenSpaceGuid.PcdFfaEnable
+
 [LibraryClasses]
   ArmLib
   CacheMaintenanceLib
diff --git a/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h b/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h
index bdf6ce4676..65b8343ade 100644
--- a/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h
+++ b/ArmPkg/Include/IndustryStandard/ArmFfaSvc.h
@@ -23,4 +23,22 @@
 #define SPM_MAJOR_VERSION_FFA                           1
 #define SPM_MINOR_VERSION_FFA                           0
 
+#define ARM_FFA_SPM_RET_SUCCESS                          0
+#define ARM_FFA_SPM_RET_NOT_SUPPORTED                   -1
+#define ARM_FFA_SPM_RET_INVALID_PARAMETERS              -2
+#define ARM_FFA_SPM_RET_NO_MEMORY                       -3
+#define ARM_FFA_SPM_RET_BUSY                            -4
+#define ARM_FFA_SPM_RET_INTERRUPTED                     -5
+#define ARM_FFA_SPM_RET_DENIED                          -6
+#define ARM_FFA_SPM_RET_RETRY                           -7
+#define ARM_FFA_SPM_RET_ABORTED                         -8
+
+// For now, the destination id to be used in the FF-A calls
+// is being hard-coded. Subsequently, support will be added
+// to get the endpoint id's dynamically
+// This is the endpoint id used by the optee os's implementation
+// of the spmc.
+// https://github.com/OP-TEE/optee_os/blob/master/core/arch/arm/kernel/stmm_sp.c#L66
+#define ARM_FFA_DESTINATION_ENDPOINT_ID                  3
+
 #endif // ARM_FFA_SVC_H_
diff --git a/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c b/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c
index 362b1a0f8a..893e291907 100644
--- a/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c
+++ b/ArmPkg/Library/StandaloneMmMmuLib/AArch64/ArmMmuStandaloneMmLib.c
@@ -16,6 +16,7 @@
 #include <Library/ArmSvcLib.h>
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
 
 STATIC
 EFI_STATUS
@@ -24,20 +25,67 @@ GetMemoryPermissions (
   OUT UINT32                    *MemoryAttributes
   )
 {
+  INT32         Ret;
   ARM_SVC_ARGS  GetMemoryPermissionsSvcArgs = {0};
-
-  GetMemoryPermissionsSvcArgs.Arg0 = ARM_SVC_ID_SP_GET_MEM_ATTRIBUTES_AARCH64;
-  GetMemoryPermissionsSvcArgs.Arg1 = BaseAddress;
-  GetMemoryPermissionsSvcArgs.Arg2 = 0;
-  GetMemoryPermissionsSvcArgs.Arg3 = 0;
+  BOOLEAN       FfaEnabled;
+
+  FfaEnabled = FeaturePcdGet (PcdFfaEnable);
+  if (FfaEnabled) {
+    GetMemoryPermissionsSvcArgs.Arg0 = ARM_SVC_ID_FFA_MSG_SEND_DIRECT_REQ_AARCH64;
+    GetMemoryPermissionsSvcArgs.Arg1 = ARM_FFA_DESTINATION_ENDPOINT_ID;
+    GetMemoryPermissionsSvcArgs.Arg2 = 0;
+    GetMemoryPermissionsSvcArgs.Arg3 = ARM_SVC_ID_SP_GET_MEM_ATTRIBUTES_AARCH64;
+    GetMemoryPermissionsSvcArgs.Arg4 = BaseAddress;
+  } else {
+    GetMemoryPermissionsSvcArgs.Arg0 = ARM_SVC_ID_SP_GET_MEM_ATTRIBUTES_AARCH64;
+    GetMemoryPermissionsSvcArgs.Arg1 = BaseAddress;
+    GetMemoryPermissionsSvcArgs.Arg2 = 0;
+    GetMemoryPermissionsSvcArgs.Arg3 = 0;
+  }
 
   ArmCallSvc (&GetMemoryPermissionsSvcArgs);
-  if (GetMemoryPermissionsSvcArgs.Arg0 == ARM_SVC_SPM_RET_INVALID_PARAMS) {
-    *MemoryAttributes = 0;
-    return EFI_INVALID_PARAMETER;
+  if (FfaEnabled) {
+    Ret = GetMemoryPermissionsSvcArgs.Arg3;
+
+    switch (Ret) {
+    case ARM_FFA_SPM_RET_INVALID_PARAMETERS:
+      *MemoryAttributes = 0;
+      return EFI_INVALID_PARAMETER;
+
+    case ARM_FFA_SPM_RET_DENIED:
+      *MemoryAttributes = 0;
+      return EFI_NOT_READY;
+
+    case ARM_FFA_SPM_RET_NOT_SUPPORTED:
+      *MemoryAttributes = 0;
+      return EFI_UNSUPPORTED;
+
+    case ARM_FFA_SPM_RET_BUSY:
+      *MemoryAttributes = 0;
+      return EFI_NOT_READY;
+
+    case ARM_FFA_SPM_RET_ABORTED:
+      *MemoryAttributes = 0;
+      return EFI_ABORTED;
+    }
+
+    *MemoryAttributes = GetMemoryPermissionsSvcArgs.Arg3;
+  } else {
+    Ret = GetMemoryPermissionsSvcArgs.Arg0;
+
+    switch (Ret) {
+    case ARM_SVC_SPM_RET_INVALID_PARAMS:
+      *MemoryAttributes = 0;
+      return EFI_INVALID_PARAMETER;
+
+    case ARM_SVC_SPM_RET_NOT_SUPPORTED:
+      *MemoryAttributes = 0;
+      return EFI_UNSUPPORTED;
+    }
+
+    *MemoryAttributes = GetMemoryPermissionsSvcArgs.Arg0;
   }
 
-  *MemoryAttributes = GetMemoryPermissionsSvcArgs.Arg0;
   return EFI_SUCCESS;
 }
 
-- 
2.17.1