target/arm: Implement TPIDR2_EL0

This register is part of SME, but isn't closely related to the
rest of the extension.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220620175235.60881-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 33 insertions, 0 deletions

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index df677b2..05d1e2e 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -474,6 +474,7 @@ typedef struct CPUArchState {
             };
             uint64_t tpidr_el[4];
         };
+        uint64_t tpidr2_el0;
         /* The secure banks of these registers don't map anywhere */
         uint64_t tpidrurw_s;
         uint64_t tpidrprw_s;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 6457e63..d21ba7a 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6279,6 +6279,35 @@ static const ARMCPRegInfo zcr_reginfo[] = {
       .writefn = zcr_write, .raw_writefn = raw_write },
 };
 
+#ifdef TARGET_AARCH64
+static CPAccessResult access_tpidr2(CPUARMState *env, const ARMCPRegInfo *ri,
+                                    bool isread)
+{
+    int el = arm_current_el(env);
+
+    if (el == 0) {
+        uint64_t sctlr = arm_sctlr(env, el);
+        if (!(sctlr & SCTLR_EnTP2)) {
+            return CP_ACCESS_TRAP;
+        }
+    }
+    /* TODO: FEAT_FGT */
+    if (el < 3
+        && arm_feature(env, ARM_FEATURE_EL3)
+        && !(env->cp15.scr_el3 & SCR_ENTP2)) {
+        return CP_ACCESS_TRAP_EL3;
+    }
+    return CP_ACCESS_OK;
+}
+
+static const ARMCPRegInfo sme_reginfo[] = {
+    { .name = "TPIDR2_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 13, .crm = 0, .opc2 = 5,
+      .access = PL0_RW, .accessfn = access_tpidr2,
+      .fieldoffset = offsetof(CPUARMState, cp15.tpidr2_el0) },
+};
+#endif /* TARGET_AARCH64 */
+
 void hw_watchpoint_update(ARMCPU *cpu, int n)
 {
     CPUARMState *env = &cpu->env;
@@ -8440,6 +8469,9 @@ void register_cp_regs_for_features(ARMCPU *cpu)
     }
 
 #ifdef TARGET_AARCH64
+    if (cpu_isar_feature(aa64_sme, cpu)) {
+        define_arm_cp_regs(cpu, sme_reginfo);
+    }
     if (cpu_isar_feature(aa64_pauth, cpu)) {
         define_arm_cp_regs(cpu, pauth_reginfo);
     }