diff --git a/target/arm/helper.c b/target/arm/helper.c
index 252651a8d1..47afaec6b4 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -10352,7 +10352,7 @@ int aa64_va_parameter_tbi(uint64_t tcr, ARMMMUIdx mmu_idx)
 {
     if (regime_has_2_ranges(mmu_idx)) {
         return extract64(tcr, 37, 2);
-    } else if (mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S) {
+    } else if (regime_is_stage2(mmu_idx)) {
         return 0; /* VTCR_EL2 */
     } else {
         /* Replicate the single TBI bit so we always have 2 bits.  */
@@ -10364,7 +10364,7 @@ int aa64_va_parameter_tbid(uint64_t tcr, ARMMMUIdx mmu_idx)
 {
     if (regime_has_2_ranges(mmu_idx)) {
         return extract64(tcr, 51, 2);
-    } else if (mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S) {
+    } else if (regime_is_stage2(mmu_idx)) {
         return 0; /* VTCR_EL2 */
     } else {
         /* Replicate the single TBID bit so we always have 2 bits.  */
@@ -10474,7 +10474,7 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, uint64_t va,
     int select, tsz, tbi, max_tsz, min_tsz, ps, sh;
     ARMGranuleSize gran;
     ARMCPU *cpu = env_archcpu(env);
-    bool stage2 = mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S;
+    bool stage2 = regime_is_stage2(mmu_idx);
 
     if (!regime_has_2_ranges(mmu_idx)) {
         select = 0;
@@ -10541,22 +10541,18 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, uint64_t va,
         }
         ds = false;
     } else if (ds) {
-        switch (mmu_idx) {
-        case ARMMMUIdx_Stage2:
-        case ARMMMUIdx_Stage2_S:
+        if (regime_is_stage2(mmu_idx)) {
             if (gran == Gran16K) {
                 ds = cpu_isar_feature(aa64_tgran16_2_lpa2, cpu);
             } else {
                 ds = cpu_isar_feature(aa64_tgran4_2_lpa2, cpu);
             }
-            break;
-        default:
+        } else {
             if (gran == Gran16K) {
                 ds = cpu_isar_feature(aa64_tgran16_lpa2, cpu);
             } else {
                 ds = cpu_isar_feature(aa64_tgran4_lpa2, cpu);
             }
-            break;
         }
         if (ds) {
             min_tsz = 12;
diff --git a/target/arm/internals.h b/target/arm/internals.h
index 1926f3679c..2c4768dd05 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -673,6 +673,11 @@ static inline bool regime_is_pan(CPUARMState *env, ARMMMUIdx mmu_idx)
     }
 }
 
+static inline bool regime_is_stage2(ARMMMUIdx mmu_idx)
+{
+    return mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S;
+}
+
 /* Return the exception level which controls this address translation regime */
 static inline uint32_t regime_el(CPUARMState *env, ARMMMUIdx mmu_idx)
 {
diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index aed6f92d6f..32d6412586 100644
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -823,8 +823,7 @@ static int get_S1prot(CPUARMState *env, ARMMMUIdx mmu_idx, bool is_aa64,
     bool have_wxn;
     int wxn = 0;
 
-    assert(mmu_idx != ARMMMUIdx_Stage2);
-    assert(mmu_idx != ARMMMUIdx_Stage2_S);
+    assert(!regime_is_stage2(mmu_idx));
 
     user_rw = simple_ap_to_rw_prot_is_user(ap, true);
     if (is_user) {
@@ -1152,7 +1151,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
         goto do_fault;
     }
 
-    if (mmu_idx != ARMMMUIdx_Stage2 && mmu_idx != ARMMMUIdx_Stage2_S) {
+    if (!regime_is_stage2(mmu_idx)) {
         /*
          * The starting level depends on the virtual address size (which can
          * be up to 48 bits) and the translation granule size. It indicates
@@ -1323,7 +1322,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
         attrs = extract64(descriptor, 2, 10)
             | (extract64(descriptor, 52, 12) << 10);
 
-        if (mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S) {
+        if (regime_is_stage2(mmu_idx)) {
             /* Stage 2 table descriptors do not include any attribute fields */
             break;
         }
@@ -1355,7 +1354,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
 
     ap = extract32(attrs, 4, 2);
 
-    if (mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S) {
+    if (regime_is_stage2(mmu_idx)) {
         ns = mmu_idx == ARMMMUIdx_Stage2;
         xn = extract32(attrs, 11, 2);
         result->f.prot = get_S2prot(env, ap, xn, s1_is_el0);
@@ -1385,7 +1384,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
         result->f.guarded = guarded;
     }
 
-    if (mmu_idx == ARMMMUIdx_Stage2 || mmu_idx == ARMMMUIdx_Stage2_S) {
+    if (regime_is_stage2(mmu_idx)) {
         result->cacheattrs.is_s2_format = true;
         result->cacheattrs.attrs = extract32(attrs, 0, 4);
     } else {
@@ -1416,8 +1415,7 @@ do_fault:
     fi->type = fault_type;
     fi->level = level;
     /* Tag the error as S2 for failed S1 PTW at S2 or ordinary S2.  */
-    fi->stage2 = fi->s1ptw || (mmu_idx == ARMMMUIdx_Stage2 ||
-                               mmu_idx == ARMMMUIdx_Stage2_S);
+    fi->stage2 = fi->s1ptw || regime_is_stage2(mmu_idx);
     fi->s1ns = mmu_idx == ARMMMUIdx_Stage2;
     return true;
 }