From 3a5d095277cf004da81fce0c1b9a4427bfe65df9 Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Tue, 3 Jul 2018 02:42:02 -0400
Subject: [PATCH] target/arm: Implement SVE prefetches

Backports commit dec6cf6b43a1e3b18626852064d1e6e863c9b681 from qemu
---
 qemu/target/arm/sve.decode      | 23 +++++++++++++++++++++++
 qemu/target/arm/translate-sve.c | 21 +++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/qemu/target/arm/sve.decode b/qemu/target/arm/sve.decode
index 1cf61fc4..9d57e67b 100644
--- a/qemu/target/arm/sve.decode
+++ b/qemu/target/arm/sve.decode
@@ -794,6 +794,29 @@ LD1RQ_zprr      1010010 .. 00 ..... 000 ... ..... ..... \
 LD1RQ_zpri      1010010 .. 00 0.... 001 ... ..... ..... \
                 @rpri_load_msz nreg=0
 
+# SVE 32-bit gather prefetch (scalar plus 32-bit scaled offsets)
+PRF             1000010 00 -1 ----- 0-- --- ----- 0 ----
+
+# SVE 32-bit gather prefetch (vector plus immediate)
+PRF             1000010 -- 00 ----- 111 --- ----- 0 ----
+
+# SVE contiguous prefetch (scalar plus immediate)
+PRF             1000010 11 1- ----- 0-- --- ----- 0 ----
+
+# SVE contiguous prefetch (scalar plus scalar)
+PRF_rr          1000010 -- 00 rm:5 110 --- ----- 0 ----
+
+### SVE Memory 64-bit Gather Group
+
+# SVE 64-bit gather prefetch (scalar plus 64-bit scaled offsets)
+PRF             1100010 00 11 ----- 1-- --- ----- 0 ----
+
+# SVE 64-bit gather prefetch (scalar plus unpacked 32-bit scaled offsets)
+PRF             1100010 00 -1 ----- 0-- --- ----- 0 ----
+
+# SVE 64-bit gather prefetch (vector plus immediate)
+PRF             1100010 -- 00 ----- 111 --- ----- 0 ----
+
 ### SVE Memory Store Group
 
 # SVE contiguous store (scalar plus immediate)
diff --git a/qemu/target/arm/translate-sve.c b/qemu/target/arm/translate-sve.c
index 0a665add..579e7eda 100644
--- a/qemu/target/arm/translate-sve.c
+++ b/qemu/target/arm/translate-sve.c
@@ -4465,3 +4465,24 @@ static bool trans_ST1_zprz(DisasContext *s, arg_ST1_zprz *a, uint32_t insn)
                cpu_reg_sp(s, a->rn), fn);
     return true;
 }
+
+/*
+ * Prefetches
+ */
+
+static bool trans_PRF(DisasContext *s, arg_PRF *a, uint32_t insn)
+{
+    /* Prefetch is a nop within QEMU.  */
+    sve_access_check(s);
+    return true;
+}
+
+static bool trans_PRF_rr(DisasContext *s, arg_PRF_rr *a, uint32_t insn)
+{
+    if (a->rm == 31) {
+        return false;
+    }
+    /* Prefetch is a nop within QEMU.  */
+    sve_access_check(s);
+    return true;
+}