target-arm: A64: Implement DC ZVA

Implement the DC ZVA instruction, which clears a block of memory.
The fast path obtains a pointer to the underlying RAM via the TCG TLB
data structure so we can do a direct memset(), with fallback to a
simple byte-store loop in the slow path.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 0ec2f65586..4c5402a0f7 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -1335,6 +1335,11 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread,
         tcg_rt = cpu_reg(s, rt);
         tcg_gen_movi_i64(tcg_rt, s->current_pl << 2);
         return;
+    case ARM_CP_DC_ZVA:
+        /* Writes clear the aligned block of memory which rt points into. */
+        tcg_rt = cpu_reg(s, rt);
+        gen_helper_dc_zva(cpu_env, tcg_rt);
+        return;
     default:
         break;
     }