[PATCH 03/20] target/arm: Convert barrier insns to decodetree

[Peter Maydell <peter.maydell@linaro.org>]

Convert the insns in the "Barriers" instruction class to
decodetree: CLREX, DSB, DMB, ISB and SB.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/tcg/a64.decode      |  7 +++
 target/arm/tcg/translate-a64.c | 92 ++++++++++++++--------------------
 2 files changed, 46 insertions(+), 53 deletions(-)

diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode
index 1efd436e175..553f6904d9c 100644
--- a/target/arm/tcg/a64.decode
+++ b/target/arm/tcg/a64.decode
@@ -181,3 +181,10 @@ ERETA           1101011 0100 11111 00001 m:1 11111 11111 &reta  # ERETAA, ERETAB
   # that isn't specifically allocated to an instruction must NOP
   NOP           1101 0101 0000 0011 0010 ---- --- 11111
 }
+
+# Barriers
+
+CLREX           1101 0101 0000 0011 0011 imm:4 010 11111
+DSB_DMB         1101 0101 0000 0011 0011 domain:2 types:2 10- 11111
+ISB             1101 0101 0000 0011 0011 imm:4 110 11111
+SB              1101 0101 0000 0011 0011 0000 111 11111
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index ecc4b9c1bd3..09258a9854f 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -1757,67 +1757,56 @@ static bool trans_AUTIBSP(DisasContext *s, arg_AUTIBSP *a)
     return true;
 }
 
-static void gen_clrex(DisasContext *s, uint32_t insn)
+static bool trans_CLREX(DisasContext *s, arg_CLREX *a)
 {
     tcg_gen_movi_i64(cpu_exclusive_addr, -1);
+    return true;
 }
 
-/* CLREX, DSB, DMB, ISB */
-static void handle_sync(DisasContext *s, uint32_t insn,
-                        unsigned int op1, unsigned int op2, unsigned int crm)
+static bool trans_DSB_DMB(DisasContext *s, arg_DSB_DMB *a)
 {
+    /* We handle DSB and DMB the same way */
     TCGBar bar;
 
-    if (op1 != 3) {
-        unallocated_encoding(s);
-        return;
+    switch (a->types) {
+    case 1: /* MBReqTypes_Reads */
+        bar = TCG_BAR_SC | TCG_MO_LD_LD | TCG_MO_LD_ST;
+        break;
+    case 2: /* MBReqTypes_Writes */
+        bar = TCG_BAR_SC | TCG_MO_ST_ST;
+        break;
+    default: /* MBReqTypes_All */
+        bar = TCG_BAR_SC | TCG_MO_ALL;
+        break;
     }
+    tcg_gen_mb(bar);
+    return true;
+}
 
-    switch (op2) {
-    case 2: /* CLREX */
-        gen_clrex(s, insn);
-        return;
-    case 4: /* DSB */
-    case 5: /* DMB */
-        switch (crm & 3) {
-        case 1: /* MBReqTypes_Reads */
-            bar = TCG_BAR_SC | TCG_MO_LD_LD | TCG_MO_LD_ST;
-            break;
-        case 2: /* MBReqTypes_Writes */
-            bar = TCG_BAR_SC | TCG_MO_ST_ST;
-            break;
-        default: /* MBReqTypes_All */
-            bar = TCG_BAR_SC | TCG_MO_ALL;
-            break;
-        }
-        tcg_gen_mb(bar);
-        return;
-    case 6: /* ISB */
-        /* We need to break the TB after this insn to execute
-         * a self-modified code correctly and also to take
-         * any pending interrupts immediately.
-         */
-        reset_btype(s);
-        gen_goto_tb(s, 0, 4);
-        return;
+static bool trans_ISB(DisasContext *s, arg_ISB *a)
+{
+    /*
+     * We need to break the TB after this insn to execute
+     * self-modifying code correctly and also to take
+     * any pending interrupts immediately.
+     */
+    reset_btype(s);
+    gen_goto_tb(s, 0, 4);
+    return true;
+}
 
-    case 7: /* SB */
-        if (crm != 0 || !dc_isar_feature(aa64_sb, s)) {
-            goto do_unallocated;
-        }
-        /*
-         * TODO: There is no speculation barrier opcode for TCG;
-         * MB and end the TB instead.
-         */
-        tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
-        gen_goto_tb(s, 0, 4);
-        return;
-
-    default:
-    do_unallocated:
-        unallocated_encoding(s);
-        return;
+static bool trans_SB(DisasContext *s, arg_SB *a)
+{
+    if (!dc_isar_feature(aa64_sb, s)) {
+        return false;
     }
+    /*
+     * TODO: There is no speculation barrier opcode for TCG;
+     * MB and end the TB instead.
+     */
+    tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
+    gen_goto_tb(s, 0, 4);
+    return true;
 }
 
 static void gen_xaflag(void)
@@ -2280,9 +2269,6 @@ static void disas_system(DisasContext *s, uint32_t insn)
             return;
         }
         switch (crn) {
-        case 3: /* CLREX, DSB, DMB, ISB */
-            handle_sync(s, insn, op1, op2, crm);
-            break;
         case 4: /* MSR (immediate) */
             handle_msr_i(s, insn, op1, op2, crm);
             break;
-- 
2.34.1