[PATCH v3 09/19] target/microblaze: Force rtid, rted, rtbd to exit

[Richard Henderson]

These return-from-exception type instructions have modified
MSR to re-enable various forms of interrupt.  Force a return
to the main loop.

Consolidate the cleanup of tb_flags into mb_tr_translate_insn.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/microblaze/translate.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index 608d413c83..da84fdb20b 100644
--- a/target/microblaze/translate.c
+++ b/target/microblaze/translate.c
@@ -1518,7 +1518,6 @@ static void do_rti(DisasContext *dc)
     tcg_gen_or_i32(cpu_msr, cpu_msr, tmp);
 
     tcg_temp_free_i32(tmp);
-    dc->tb_flags &= ~DRTI_FLAG;
 }
 
 static void do_rtb(DisasContext *dc)
@@ -1531,7 +1530,6 @@ static void do_rtb(DisasContext *dc)
     tcg_gen_or_i32(cpu_msr, cpu_msr, tmp);
 
     tcg_temp_free_i32(tmp);
-    dc->tb_flags &= ~DRTB_FLAG;
 }
 
 static void do_rte(DisasContext *dc)
@@ -1545,7 +1543,6 @@ static void do_rte(DisasContext *dc)
     tcg_gen_or_i32(cpu_msr, cpu_msr, tmp);
 
     tcg_temp_free_i32(tmp);
-    dc->tb_flags &= ~DRTE_FLAG;
 }
 
 /* Insns connected to FSL or AXI stream attached devices.  */
@@ -1700,12 +1697,16 @@ static void mb_tr_translate_insn(DisasContextBase *dcb, 
CPUState *cs)
          * Finish any return-from branch.
          * TODO: Diagnose rtXd in delay slot of rtYd earlier.
          */
-        if (dc->tb_flags & DRTI_FLAG) {
-            do_rti(dc);
-        } else if (dc->tb_flags & DRTB_FLAG) {
-            do_rtb(dc);
-        } else if (dc->tb_flags & DRTE_FLAG) {
-            do_rte(dc);
+        uint32_t rt_ibe = dc->tb_flags & (DRTI_FLAG | DRTB_FLAG | DRTE_FLAG);
+        if (unlikely(rt_ibe != 0)) {
+            dc->tb_flags &= ~(DRTI_FLAG | DRTB_FLAG | DRTE_FLAG);
+            if (rt_ibe & DRTI_FLAG) {
+                do_rti(dc);
+            } else if (rt_ibe & DRTB_FLAG) {
+                do_rtb(dc);
+            } else {
+                do_rte(dc);
+            }
         }
 
         /* Complete the branch, ending the TB. */
@@ -1723,8 +1724,12 @@ static void mb_tr_translate_insn(DisasContextBase *dcb, 
CPUState *cs)
              */
             break;
         case DISAS_NEXT:
-            /* Normal insn a delay slot.  */
-            dc->base.is_jmp = DISAS_JUMP;
+            /*
+             * Normal insn a delay slot.
+             * However, the return-from-exception type insns should
+             * return to the main loop, as they have adjusted MSR.
+             */
+            dc->base.is_jmp = (rt_ibe ? DISAS_EXIT_JUMP : DISAS_JUMP);
             break;
         case DISAS_EXIT_NEXT:
             /*
-- 
2.25.1