+/* 4 bytes */
+struct fdb_index_tbl_entry_t {
+	/* Bucket Table index of first Bucket with this MAC address */
+	u16 bucket_idx;
+	u16 bucket_entries; /* Number of entries in this bucket */
+};

Please drop the _t. That is normally used to indicate a type, but this
is actually a struct

+void icssm_prueth_sw_fdb_tbl_init(struct prueth *prueth)
+{
+	struct fdb_tbl *t = prueth->fdb_tbl;
+
+	t->index_a = (struct fdb_index_array_t *)((__force const void *)
+			prueth->mem[V2_1_FDB_TBL_LOC].va +
+			V2_1_FDB_TBL_OFFSET);

You cast it to a const void * and then a non-const fdb_index_array_t *?