target-mips: generate fences

Make use of memory barrier TCG opcode in MIPS front end.

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>

target-mips/translate.c

@@ -13109,6 +13109,34 @@ static void gen_ldst_pair (DisasContext *ctx, uint32_t opc, int rd,
     tcg_temp_free(t1);
 }
 
+static void gen_sync(int stype)
+{
+    TCGBar tcg_mo = TCG_BAR_SC;
+
+    switch (stype) {
+    case 0x4: /* SYNC_WMB */
+        tcg_mo |= TCG_MO_ST_ST;
+        break;
+    case 0x10: /* SYNC_MB */
+        tcg_mo |= TCG_MO_ALL;
+        break;
+    case 0x11: /* SYNC_ACQUIRE */
+        tcg_mo |= TCG_MO_LD_LD | TCG_MO_LD_ST;
+        break;
+    case 0x12: /* SYNC_RELEASE */
+        tcg_mo |= TCG_MO_ST_ST | TCG_MO_LD_ST;
+        break;
+    case 0x13: /* SYNC_RMB */
+        tcg_mo |= TCG_MO_LD_LD;
+        break;
+    default:
+        tcg_mo |= TCG_MO_ALL;
+        break;
+    }
+
+    tcg_gen_mb(tcg_mo);
+}
+
 static void gen_pool32axf (CPUMIPSState *env, DisasContext *ctx, int rt, int rs)
 {
     int extension = (ctx->opcode >> 6) & 0x3f;
@@ -13384,7 +13412,7 @@ static void gen_pool32axf (CPUMIPSState *env, DisasContext *ctx, int rt, int rs)
     case 0x2d:
         switch (minor) {
         case SYNC:
-            /* NOP */
+            gen_sync(extract32(ctx->opcode, 16, 5));
             break;
         case SYSCALL:
             generate_exception_end(ctx, EXCP_SYSCALL);
@@ -17201,7 +17229,7 @@ static void decode_opc_special(CPUMIPSState *env, DisasContext *ctx)
         break;
     case OPC_SYNC:
         check_insn(ctx, ISA_MIPS2);
-        /* Treat as NOP. */
+        gen_sync(extract32(ctx->opcode, 6, 5));
         break;
 
 #if defined(TARGET_MIPS64)