[PATCH 2/3] target/arm: ARMv8.4-TTST extension

[remi.denis.courmont@huawei.com]

From: Rémi Denis-Courmont <remi.denis.courmont@huawei.com>

This adds for the Small Translation tables extension in AArch64 state.

Signed-off-by: Rémi Denis-Courmont <remi.denis.courmont@huawei.com>
---
 target/arm/cpu.h    |  5 +++++
 target/arm/helper.c | 13 ++++++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 39abb2a36b..604b9cdd0e 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3991,6 +3991,11 @@ static inline bool isar_feature_aa64_uao(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, UAO) != 0;
 }
 
+static inline bool isar_feature_aa64_st(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, ST) != 0;
+}
+
 static inline bool isar_feature_aa64_bti(const ARMISARegisters *id)
 {
     return FIELD_EX64(id->id_aa64pfr1, ID_AA64PFR1, BT) != 0;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index b927e53ab0..c3a186db35 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -10851,7 +10851,7 @@ static bool check_s2_mmu_setup(ARMCPU *cpu, bool is_aa64, uint32_t level,
             if (level == 0 && pamax <= 42) {
                 return false;
             }
-            if (level == 3) {
+            if (level == 3 && !cpu_isar_feature(aa64_st, cpu)) {
                 return false;
             }
             break;
@@ -10946,7 +10946,7 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, uint64_t va,
 {
     uint64_t tcr = regime_tcr(env, mmu_idx)->raw_tcr;
     bool epd, hpd, using16k, using64k;
-    int select, tsz, tbi;
+    int select, tsz, tbi, max_tsz;
 
     if (!regime_has_2_ranges(mmu_idx)) {
         select = 0;
@@ -10981,7 +10981,14 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, uint64_t va,
             hpd = extract64(tcr, 42, 1);
         }
     }
-    tsz = MIN(tsz, 39);  /* TODO: ARMv8.4-TTST */
+
+    if (cpu_isar_feature(aa64_st, env_archcpu(env))) {
+        max_tsz = 48 - using64k;
+    } else {
+        max_tsz = 39;
+    }
+
+    tsz = MIN(tsz, max_tsz);
     tsz = MAX(tsz, 16);  /* TODO: ARMv8.2-LVA  */
 
     /* Present TBI as a composite with TBID.  */
-- 
2.29.2