diff --git a/include/sbi/sbi_domain.h b/include/sbi/sbi_domain.h
index 3360e090..c8a6da99 100644
--- a/include/sbi/sbi_domain.h
+++ b/include/sbi/sbi_domain.h
@@ -164,6 +164,25 @@ struct sbi_domain_memregion {
 	unsigned long flags;
 };
 
+/** Check if regionA is sub-region of regionB */
+static inline bool sbi_domain_memregion_is_subset(
+				const struct sbi_domain_memregion *regA,
+				const struct sbi_domain_memregion *regB)
+{
+	ulong regA_start = regA->base;
+	ulong regA_end = regA->base + (BIT(regA->order) - 1);
+	ulong regB_start = regB->base;
+	ulong regB_end = regB->base + (BIT(regB->order) - 1);
+
+	if ((regB_start <= regA_start) &&
+	    (regA_start < regB_end) &&
+	    (regB_start < regA_end) &&
+	    (regA_end <= regB_end))
+		return true;
+
+	return false;
+}
+
 /** Representation of OpenSBI domain */
 struct sbi_domain {
 	/** Node in linked list of domains */
@@ -222,6 +241,9 @@ extern struct sbi_dlist domain_list;
 #define sbi_domain_for_each_memregion(__d, __r) \
 	for ((__r) = (__d)->regions; (__r)->order; (__r)++)
 
+#define sbi_domain_for_each_memregion_idx(__d, __r, __i) \
+	for ((__r) = (__d)->regions, (__i) = 0; (__r)->order; (__r)++, (__i)++)
+
 /**
  * Check whether given HART is assigned to specified domain
  * @param dom pointer to domain
diff --git a/lib/sbi/sbi_domain.c b/lib/sbi/sbi_domain.c
index 74cc1e3f..a19bf25b 100644
--- a/lib/sbi/sbi_domain.c
+++ b/lib/sbi/sbi_domain.c
@@ -285,29 +285,12 @@ static bool is_region_valid(const struct sbi_domain_memregion *reg)
 	return true;
 }
 
-/** Check if regionA is sub-region of regionB */
-static bool is_region_subset(const struct sbi_domain_memregion *regA,
-			     const struct sbi_domain_memregion *regB)
-{
-	ulong regA_start = regA->base;
-	ulong regA_end = regA->base + (BIT(regA->order) - 1);
-	ulong regB_start = regB->base;
-	ulong regB_end = regB->base + (BIT(regB->order) - 1);
-
-	if ((regB_start <= regA_start) &&
-	    (regA_start < regB_end) &&
-	    (regB_start < regA_end) &&
-	    (regA_end <= regB_end))
-		return true;
-
-	return false;
-}
-
 /** Check if regionA can be replaced by regionB */
 static bool is_region_compatible(const struct sbi_domain_memregion *regA,
 				 const struct sbi_domain_memregion *regB)
 {
-	if (is_region_subset(regA, regB) && regA->flags == regB->flags)
+	if (sbi_domain_memregion_is_subset(regA, regB) &&
+	    regA->flags == regB->flags)
 		return true;
 
 	return false;
@@ -367,7 +350,7 @@ static const struct sbi_domain_memregion *find_next_subset_region(
 
 	sbi_domain_for_each_memregion(dom, sreg) {
 		if (sreg == reg || (sreg->base <= addr) ||
-		    !is_region_subset(sreg, reg))
+		    !sbi_domain_memregion_is_subset(sreg, reg))
 			continue;
 
 		if (!ret || (sreg->base < ret->base) ||