target/arm: Introduce finalize_memop_{atom,pair}

Let finalize_memop_atom be the new basic function, with
finalize_memop and finalize_memop_pair testing FEAT_LSE2
to apply the appropriate atomicity.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230530191438.411344-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/tcg/translate-a64.c

@@ -14098,6 +14098,8 @@ static void aarch64_tr_init_disas_context(DisasContextBase *dcbase,
     tcg_debug_assert(dc->tbid & 1);
 #endif
 
+    dc->lse2 = dc_isar_feature(aa64_lse2, dc);
+
     /* Single step state. The code-generation logic here is:
      *  SS_ACTIVE == 0:
      *   generate code with no special handling for single-stepping (except

target/arm/tcg/translate.c

@@ -9168,6 +9168,7 @@ static void arm_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
         dc->sme_trap_nonstreaming =
             EX_TBFLAG_A32(tb_flags, SME_TRAP_NONSTREAMING);
     }
+    dc->lse2 = false; /* applies only to aarch64 */
     dc->cp_regs = cpu->cp_regs;
     dc->features = env->features;
 

target/arm/tcg/translate.h

@@ -90,6 +90,7 @@ typedef struct DisasContext {
     uint64_t features; /* CPU features bits */
     bool aarch64;
     bool thumb;
+    bool lse2;
     /* Because unallocated encodings generate different exception syndrome
      * information from traps due to FP being disabled, we can't do a single
      * "is fp access disabled" check at a high level in the decode tree.
@@ -557,12 +558,13 @@ static inline TCGv_ptr fpstatus_ptr(ARMFPStatusFlavour flavour)
 }
 
 /**
- * finalize_memop:
+ * finalize_memop_atom:
  * @s: DisasContext
  * @opc: size+sign+align of the memory operation
+ * @atom: atomicity of the memory operation
  *
- * Build the complete MemOp for a memory operation, including alignment
- * and endianness.
+ * Build the complete MemOp for a memory operation, including alignment,
+ * endianness, and atomicity.
  *
  * If (op & MO_AMASK) then the operation already contains the required
  * alignment, e.g. for AccType_ATOMIC.  Otherwise, this an optionally
@@ -572,12 +574,39 @@ static inline TCGv_ptr fpstatus_ptr(ARMFPStatusFlavour flavour)
  * and this is applied here.  Note that there is no way to indicate that
  * no alignment should ever be enforced; this must be handled manually.
  */
-static inline MemOp finalize_memop(DisasContext *s, MemOp opc)
+static inline MemOp finalize_memop_atom(DisasContext *s, MemOp opc, MemOp atom)
 {
     if (s->align_mem && !(opc & MO_AMASK)) {
         opc |= MO_ALIGN;
     }
-    return opc | s->be_data;
+    return opc | atom | s->be_data;
+}
+
+/**
+ * finalize_memop:
+ * @s: DisasContext
+ * @opc: size+sign+align of the memory operation
+ *
+ * Like finalize_memop_atom, but with default atomicity.
+ */
+static inline MemOp finalize_memop(DisasContext *s, MemOp opc)
+{
+    MemOp atom = s->lse2 ? MO_ATOM_WITHIN16 : MO_ATOM_IFALIGN;
+    return finalize_memop_atom(s, opc, atom);
+}
+
+/**
+ * finalize_memop_pair:
+ * @s: DisasContext
+ * @opc: size+sign+align of the memory operation
+ *
+ * Like finalize_memop_atom, but with atomicity for a pair.
+ * C.f. Pseudocode for Mem[], operand ispair.
+ */
+static inline MemOp finalize_memop_pair(DisasContext *s, MemOp opc)
+{
+    MemOp atom = s->lse2 ? MO_ATOM_WITHIN16_PAIR : MO_ATOM_IFALIGN_PAIR;
+    return finalize_memop_atom(s, opc, atom);
 }
 
 /**