target/arm: Add new_pc argument to helper_exception_return

Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190108223129.5570-12-richard.henderson@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target/arm/helper-a64.c

@@ -925,7 +925,7 @@ static int el_from_spsr(uint32_t spsr)
     }
 }
 
-void HELPER(exception_return)(CPUARMState *env)
+void HELPER(exception_return)(CPUARMState *env, uint64_t new_pc)
 {
     int cur_el = arm_current_el(env);
     unsigned int spsr_idx = aarch64_banked_spsr_index(cur_el);
@@ -991,9 +991,9 @@ void HELPER(exception_return)(CPUARMState *env)
         aarch64_sync_64_to_32(env);
 
         if (spsr & CPSR_T) {
-            env->regs[15] = env->elr_el[cur_el] & ~0x1;
+            env->regs[15] = new_pc & ~0x1;
         } else {
-            env->regs[15] = env->elr_el[cur_el] & ~0x3;
+            env->regs[15] = new_pc & ~0x3;
         }
         qemu_log_mask(CPU_LOG_INT, "Exception return from AArch64 EL%d to "
                       "AArch32 EL%d PC 0x%" PRIx32 "\n",
@@ -1005,7 +1005,7 @@ void HELPER(exception_return)(CPUARMState *env)
             env->pstate &= ~PSTATE_SS;
         }
         aarch64_restore_sp(env, new_el);
-        env->pc = env->elr_el[cur_el];
+        env->pc = new_pc;
         qemu_log_mask(CPU_LOG_INT, "Exception return from AArch64 EL%d to "
                       "AArch64 EL%d PC 0x%" PRIx64 "\n",
                       cur_el, new_el, env->pc);
@@ -1031,7 +1031,7 @@ illegal_return:
      * no change to exception level, execution state or stack pointer
      */
     env->pstate |= PSTATE_IL;
-    env->pc = env->elr_el[cur_el];
+    env->pc = new_pc;
     spsr &= PSTATE_NZCV | PSTATE_DAIF;
     spsr |= pstate_read(env) & ~(PSTATE_NZCV | PSTATE_DAIF);
     pstate_write(env, spsr);

target/arm/helper-a64.h

@@ -86,7 +86,7 @@ DEF_HELPER_2(advsimd_f16tosinth, i32, f16, ptr)
 DEF_HELPER_2(advsimd_f16touinth, i32, f16, ptr)
 DEF_HELPER_2(sqrt_f16, f16, f16, ptr)
 
-DEF_HELPER_1(exception_return, void, env)
+DEF_HELPER_2(exception_return, void, env, i64)
 
 DEF_HELPER_FLAGS_3(pacia, TCG_CALL_NO_WG, i64, env, i64, i64)
 DEF_HELPER_FLAGS_3(pacib, TCG_CALL_NO_WG, i64, env, i64, i64)

target/arm/translate-a64.c

@@ -1981,6 +1981,7 @@ static void disas_exc(DisasContext *s, uint32_t insn)
 static void disas_uncond_b_reg(DisasContext *s, uint32_t insn)
 {
     unsigned int opc, op2, op3, rn, op4;
+    TCGv_i64 dst;
 
     opc = extract32(insn, 21, 4);
     op2 = extract32(insn, 16, 5);
@@ -2011,7 +2012,11 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn)
         if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
             gen_io_start();
         }
-        gen_helper_exception_return(cpu_env);
+        dst = tcg_temp_new_i64();
+        tcg_gen_ld_i64(dst, cpu_env,
+                       offsetof(CPUARMState, elr_el[s->current_el]));
+        gen_helper_exception_return(cpu_env, dst);
+        tcg_temp_free_i64(dst);
         if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
             gen_io_end();
         }