From: Richard Henderson <richard.henderson@linaro.org>
Date: Mon, 31 Aug 2020 17:35:15 +0000 (-0700)
Subject: target/microblaze: Force rtid, rted, rtbd to exit
X-Git-Tag: v5.2.0-rc0~128^2~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3c745866ed8169638accecd81e61dcfafa3cb3fb;p=thirdparty%2Fqemu.git

target/microblaze: Force rtid, rted, rtbd to exit

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>
---

diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index 608d413c83d..da84fdb20b9 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:
             /*