[RFC PATCH 01/13] target/riscv: Add UXL to tb flags

[LIU Zhiwei]

For 32-bit applications run on 64-bit cpu, it may share some code
with other 64-bit applictions. Thus we should distinguish the translated
cache of the share code with a tb flag.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
---
 target/riscv/cpu.h       | 15 +++++++++++++++
 target/riscv/translate.c |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index bf1c899c00..2b3ba21a78 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -394,9 +394,20 @@ FIELD(TB_FLAGS, SEW, 5, 3)
 FIELD(TB_FLAGS, VILL, 8, 1)
 /* Is a Hypervisor instruction load/store allowed? */
 FIELD(TB_FLAGS, HLSX, 9, 1)
+FIELD(TB_FLAGS, UXL, 10, 2)
 
 bool riscv_cpu_is_32bit(CPURISCVState *env);
 
+static inline bool riscv_cpu_is_uxl32(CPURISCVState *env)
+{
+#ifndef CONFIG_USER_ONLY
+    return (get_field(env->mstatus, MSTATUS64_UXL) == 1) &&
+           !riscv_cpu_is_32bit(env) &&
+           (env->priv == PRV_U);
+#endif
+    return false;
+}
+
 /*
  * A simplification for VLMAX
  * = (1 << LMUL) * VLEN / (8 * (1 << SEW))
@@ -451,6 +462,10 @@ static inline void cpu_get_tb_cpu_state(CPURISCVState 
*env, target_ulong *pc,
             flags = FIELD_DP32(flags, TB_FLAGS, HLSX, 1);
         }
     }
+    if (riscv_cpu_is_uxl32(env)) {
+        flags = FIELD_DP32(flags, TB_FLAGS, UXL,
+                           get_field(env->mstatus, MSTATUS64_UXL));
+    }
 #endif
 
     *pflags = flags;
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 076f28b9c1..ac4a545da8 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -67,6 +67,8 @@ typedef struct DisasContext {
     CPUState *cs;
     TCGv zero;
     TCGv sink;
+    /* UXLEN is 32 bit for 64-bit CPU */
+    bool uxl32;
 } DisasContext;
 
 static inline bool has_ext(DisasContext *ctx, uint32_t ext)
@@ -912,6 +914,7 @@ static void riscv_tr_init_disas_context(DisasContextBase 
*dcbase, CPUState *cs)
     ctx->mlen = 1 << (ctx->sew  + 3 - ctx->lmul);
     ctx->vl_eq_vlmax = FIELD_EX32(tb_flags, TB_FLAGS, VL_EQ_VLMAX);
     ctx->cs = cs;
+    ctx->uxl32 = FIELD_EX32(tb_flags, TB_FLAGS, UXL) == 1;
 }
 
 static void riscv_tr_tb_start(DisasContextBase *dcbase, CPUState *cpu)
-- 
2.17.1