feat(spmc): enable parsing of messaging methods from manifest

Ensure that the `messaging-methods` entry is populated in
an SP's manifest. Currently only direct messaging is supported
so alert if this does not match the manifest entry.

Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Change-Id: I67f1fad71a3507627993a004e0f8579388faf178

services/std_svc/spm/el3_spmc/spmc_main.c

@@ -544,6 +544,23 @@ static int sp_manifest_parse(void *sp_manifest, int offset,
 
 	sp->execution_state = config_32;
 
+	ret = fdt_read_uint32(sp_manifest, node,
+			      "messaging-method", &config_32);
+	if (ret != 0) {
+		ERROR("Missing Secure Partition messaging method.\n");
+		return ret;
+	}
+
+	/* Validate this entry, we currently only support direct messaging. */
+	if ((config_32 & ~(FFA_PARTITION_DIRECT_REQ_RECV |
+			  FFA_PARTITION_DIRECT_REQ_SEND)) != 0U) {
+		WARN("Invalid Secure Partition messaging method (0x%x)\n",
+		     config_32);
+		return -EINVAL;
+	}
+
+	sp->properties = config_32;
+
 	ret = fdt_read_uint32(sp_manifest, node,
 			      "execution-ctx-count", &config_32);