From e15aa7c5a76e2f731aed8b107ed742529f1b647d Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Thu, 25 Feb 2021 15:10:36 -0500
Subject: [PATCH] target/arm: Implement the STGP instruction

Backports commit 6439d67fc944cf29de94a160e9450a2063c7b515 from qemu
---
 qemu/target/arm/translate-a64.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/qemu/target/arm/translate-a64.c b/qemu/target/arm/translate-a64.c
index 33cb474c..62222bdc 100644
--- a/qemu/target/arm/translate-a64.c
+++ b/qemu/target/arm/translate-a64.c
@@ -2877,7 +2877,7 @@ static void disas_ld_lit(DisasContext *s, uint32_t insn)
  * +-----+-------+---+---+-------+---+-------+-------+------+------+
  *
  * opc: LDP/STP/LDNP/STNP        00 -> 32 bit, 10 -> 64 bit
- *      LDPSW                    01
+ *      LDPSW/STGP               01
  *      LDP/STP/LDNP/STNP (SIMD) 00 -> 32 bit, 01 -> 64 bit, 10 -> 128 bit
  *   V: 0 -> GPR, 1 -> Vector
  * idx: 00 -> signed offset with non-temporal hint, 01 -> post-index,
@@ -2903,6 +2903,7 @@ static void disas_ldst_pair(DisasContext *s, uint32_t insn)
     bool is_signed = false;
     bool postindex = false;
     bool wback = false;
+    bool set_tag = false;
 
     TCGv_i64 clean_addr, dirty_addr;
     int size;
@@ -2914,6 +2915,14 @@ static void disas_ldst_pair(DisasContext *s, uint32_t insn)
 
     if (is_vector) {
         size = 2 + opc;
+    } else if (opc == 1 && !is_load) {
+        /* STGP */
+        if (!dc_isar_feature(aa64_mte_insn_reg, s) || index == 0) {
+            unallocated_encoding(s);
+            return;
+        }
+        size = 3;
+        set_tag = true;
     } else {
         size = 2 + extract32(opc, 1, 1);
         is_signed = extract32(opc, 0, 1);
@@ -2954,7 +2963,7 @@ static void disas_ldst_pair(DisasContext *s, uint32_t insn)
         return;
     }
 
-    offset <<= size;
+    offset <<= (set_tag ? LOG2_TAG_GRANULE : size);
 
     if (rn == 31) {
         gen_check_sp_alignment(s);
@@ -2964,8 +2973,22 @@ static void disas_ldst_pair(DisasContext *s, uint32_t insn)
     if (!postindex) {
         tcg_gen_addi_i64(tcg_ctx, dirty_addr, dirty_addr, offset);
     }
-    clean_addr = clean_data_tbi(s, dirty_addr);
 
+    if (set_tag) {
+        if (!s->ata) {
+            /*
+             * TODO: We could rely on the stores below, at least for
+             * system mode, if we arrange to add MO_ALIGN_16.
+             */
+            gen_helper_stg_stub(tcg_ctx, tcg_ctx->cpu_env, dirty_addr);
+        } else if (tb_cflags(s->base.tb) & CF_PARALLEL) {
+            gen_helper_stg_parallel(tcg_ctx, tcg_ctx->cpu_env, dirty_addr, dirty_addr);
+        } else {
+            gen_helper_stg(tcg_ctx, tcg_ctx->cpu_env, dirty_addr, dirty_addr);
+        }
+    }
+
+    clean_addr = clean_data_tbi(s, dirty_addr);
     if (is_vector) {
         if (is_load) {
             do_fp_ld(s, rt, clean_addr, size);