From bdd9cad15c329ca1f79a9185c98844f1c6b4d96c Mon Sep 17 00:00:00 2001
From: Pranith Kumar <bobby.prani@gmail.com>
Date: Mon, 26 Feb 2018 03:18:40 -0500
Subject: [PATCH] tcg/ppc: Add support for fence

Backports commit 7b4af5ee8a1336bc39714b6de47924ee71fba761 from qemu
---
 qemu/tcg/ppc/tcg-target.inc.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/qemu/tcg/ppc/tcg-target.inc.c b/qemu/tcg/ppc/tcg-target.inc.c
index 2b0a5bbf..ca1bdae0 100644
--- a/qemu/tcg/ppc/tcg-target.inc.c
+++ b/qemu/tcg/ppc/tcg-target.inc.c
@@ -475,6 +475,10 @@ static int tcg_target_const_match(tcg_target_long val, TCGType type,
 #define STHX   XO31(407)
 #define STWX   XO31(151)
 
+#define EIEIO  XO31(854)
+#define HWSYNC XO31(598)
+#define LWSYNC (HWSYNC | (1u << 21))
+
 #define SPR(a, b) ((((a)<<5)|(b))<<11)
 #define LR     SPR(8, 0)
 #define CTR    SPR(9, 0)
@@ -1249,6 +1253,18 @@ static void tcg_out_brcond2 (TCGContext *s, const TCGArg *args,
     tcg_out_bc(s, BC | BI(7, CR_EQ) | BO_COND_TRUE, arg_label(s, args[5]));
 }
 
+static void tcg_out_mb(TCGContext *s, TCGArg a0)
+{
+    uint32_t insn = HWSYNC;
+    a0 &= TCG_MO_ALL;
+    if (a0 == TCG_MO_LD_LD) {
+        insn = LWSYNC;
+    } else if (a0 == TCG_MO_ST_ST) {
+        insn = EIEIO;
+    }
+    tcg_out32(s, insn);
+}
+
 void ppc_tb_set_jmp_target(uintptr_t jmp_addr, uintptr_t addr)
 {
     tcg_insn_unit i1, i2;
@@ -2444,6 +2460,10 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args,
         tcg_out32(s, MULHD | TAB(args[0], args[1], args[2]));
         break;
 
+    case INDEX_op_mb:
+        tcg_out_mb(s, args[0]);
+        break;
+
     case INDEX_op_mov_i32:   /* Always emitted via tcg_out_mov.  */
     case INDEX_op_mov_i64:
     case INDEX_op_movi_i32:  /* Always emitted via tcg_out_movi.  */
@@ -2591,6 +2611,7 @@ static const TCGTargetOpDef ppc_op_defs[] = {
     { INDEX_op_qemu_st_i64, { "S", "S", "S", "S" } },
 #endif
 
+    { INDEX_op_mb, { } },
     { -1 },
 };