target/arm: Implement FEAT_TIDCP1

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230831232441.66020-5-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

docs/system/arm/emulation.rst

@@ -92,6 +92,7 @@ the following architecture extensions:
 - FEAT_SME_I16I64 (16-bit to 64-bit integer widening outer product instructions)
 - FEAT_SPECRES (Speculation restriction instructions)
 - FEAT_SSBS (Speculative Store Bypass Safe)
+- FEAT_TIDCP1 (EL0 use of IMPLEMENTATION DEFINED functionality)
 - FEAT_TLBIOS (TLB invalidate instructions in Outer Shareable domain)
 - FEAT_TLBIRANGE (TLB invalidate range instructions)
 - FEAT_TTCNP (Translation table Common not private translations)

target/arm/cpu.h

@@ -3980,6 +3980,11 @@ static inline bool isar_feature_aa64_hcx(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, HCX) != 0;
 }
 
+static inline bool isar_feature_aa64_tidcp1(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR1, TIDCP1) != 0;
+}
+
 static inline bool isar_feature_aa64_uao(const ARMISARegisters *id)
 {
     return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, UAO) != 0;

target/arm/helper.h

@@ -81,6 +81,7 @@ DEF_HELPER_FLAGS_2(check_bxj_trap, TCG_CALL_NO_WG, void, env, i32)
 
 DEF_HELPER_4(access_check_cp_reg, cptr, env, i32, i32, i32)
 DEF_HELPER_FLAGS_2(lookup_cp_reg, TCG_CALL_NO_RWG_SE, cptr, env, i32)
+DEF_HELPER_FLAGS_2(tidcp_el0, TCG_CALL_NO_WG, void, env, i32)
 DEF_HELPER_FLAGS_2(tidcp_el1, TCG_CALL_NO_WG, void, env, i32)
 DEF_HELPER_3(set_cp_reg, void, env, cptr, i32)
 DEF_HELPER_2(get_cp_reg, i32, env, cptr)

target/arm/tcg/cpu64.c

@@ -1071,6 +1071,7 @@ void aarch64_max_tcg_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64MMFR1, XNX, 1);      /* FEAT_XNX */
     t = FIELD_DP64(t, ID_AA64MMFR1, ETS, 1);      /* FEAT_ETS */
     t = FIELD_DP64(t, ID_AA64MMFR1, HCX, 1);      /* FEAT_HCX */
+    t = FIELD_DP64(t, ID_AA64MMFR1, TIDCP1, 1);   /* FEAT_TIDCP1 */
     cpu->isar.id_aa64mmfr1 = t;
 
     t = cpu->isar.id_aa64mmfr2;

target/arm/tcg/op_helper.c

@@ -777,6 +777,26 @@ void HELPER(tidcp_el1)(CPUARMState *env, uint32_t syndrome)
     }
 }
 
+/*
+ * Similarly, for FEAT_TIDCP1 at EL0.
+ * We have already checked for the presence of the feature.
+ */
+void HELPER(tidcp_el0)(CPUARMState *env, uint32_t syndrome)
+{
+    /* See arm_sctlr(), but we also need the sctlr el. */
+    ARMMMUIdx mmu_idx = arm_mmu_idx_el(env, 0);
+    int target_el = mmu_idx == ARMMMUIdx_E20_0 ? 2 : 1;
+
+    /*
+     * The bit is not valid unless the target el is aa64, but since the
+     * bit test is simpler perform that first and check validity after.
+     */
+    if ((env->cp15.sctlr_el[target_el] & SCTLR_TIDCP)
+        && arm_el_is_aa64(env, target_el)) {
+        raise_exception_ra(env, EXCP_UDEF, syndrome, target_el, GETPC());
+    }
+}
+
 void HELPER(set_cp_reg)(CPUARMState *env, const void *rip, uint32_t value)
 {
     const ARMCPRegInfo *ri = rip;

target/arm/tcg/translate-a64.c

@@ -2163,6 +2163,11 @@ static void handle_sys(DisasContext *s, bool isread,
          */
         syndrome = syn_aa64_sysregtrap(op0, op1, op2, crn, crm, rt, isread);
         switch (s->current_el) {
+        case 0:
+            if (dc_isar_feature(aa64_tidcp1, s)) {
+                gen_helper_tidcp_el0(cpu_env, tcg_constant_i32(syndrome));
+            }
+            break;
         case 1:
             gen_helper_tidcp_el1(cpu_env, tcg_constant_i32(syndrome));
             break;

target/arm/tcg/translate.c

@@ -4640,6 +4640,12 @@ static void do_coproc_insn(DisasContext *s, int cpnum, int is64,
          * but raises the same exception, so order doesn't matter.
          */
         switch (s->current_el) {
+        case 0:
+            if (arm_dc_feature(s, ARM_FEATURE_AARCH64)
+                && dc_isar_feature(aa64_tidcp1, s)) {
+                gen_helper_tidcp_el0(cpu_env, tcg_constant_i32(syndrome));
+            }
+            break;
         case 1:
             gen_helper_tidcp_el1(cpu_env, tcg_constant_i32(syndrome));
             break;