feat(spm): add FFA_MSG_SEND2 forwarding in SPMD

Add FF-A v1.1 indirect messaging ABI FFA_MSG_SEND2 to SPMD to allow
message forwarding across normal/secure worlds.

Change-Id: I074fbd2e4d13893925f987cee271d49da3aaf64b
Signed-off-by: Federico Recanati <federico.recanati@arm.com>

include/services/ffa_svc.h

@@ -116,6 +116,7 @@
 #define FFA_MSG_YIELD		FFA_FID(SMC_32, FFA_FNUM_MSG_YIELD)
 #define FFA_MSG_RUN		FFA_FID(SMC_32, FFA_FNUM_MSG_RUN)
 #define FFA_MSG_SEND		FFA_FID(SMC_32, FFA_FNUM_MSG_SEND)
+#define FFA_MSG_SEND2		FFA_FID(SMC_32, FFA_FNUM_MSG_SEND2)
 #define FFA_MSG_SEND_DIRECT_REQ_SMC32 \
 	FFA_FID(SMC_32, FFA_FNUM_MSG_SEND_DIRECT_REQ)
 #define FFA_MSG_SEND_DIRECT_RESP_SMC32	\

services/std_svc/spmd/spmd_main.c

@@ -688,16 +688,13 @@ uint64_t spmd_smc_handler(uint32_t smc_fid,
 	case FFA_NOTIFICATION_GET:
 	case FFA_NOTIFICATION_INFO_GET:
 	case FFA_NOTIFICATION_INFO_GET_SMC64:
+	case FFA_MSG_SEND2:
 #endif
+	case FFA_MSG_RUN:
 		/*
-		 * Above calls should not be forwarded from Secure world to
-		 * Normal world.
-		 *
-		 * Fall through to forward the call to the other world
+		 * Above calls should be invoked only by the Normal world and
+		 * must not be forwarded from Secure world to Normal world.
 		 */
-	case FFA_MSG_RUN:
-		/* This interface must be invoked only by the Normal world */
-
 		if (secure_origin) {
 			return spmd_ffa_error_return(handle,
 						     FFA_ERROR_NOT_SUPPORTED);