Write mask is representing the bits we care about.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/insn_trans/trans_rvi.c.inc | 4 ++--
 target/riscv/op_helper.c                | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc
index e51dbc41c5..40c81421f2 100644
--- a/target/riscv/insn_trans/trans_rvi.c.inc
+++ b/target/riscv/insn_trans/trans_rvi.c.inc
@@ -486,7 +486,7 @@ static bool trans_csrrw(DisasContext *ctx, arg_csrrw *a)
         return do_csrw(ctx, a->csr, src);
     }
 
-    TCGv mask = tcg_constant_tl(-1);
+    TCGv mask = tcg_constant_tl(get_xl(ctx) == MXL_RV32 ? UINT32_MAX : -1);
     return do_csrrw(ctx, a->rd, a->csr, src, mask);
 }
 
@@ -537,7 +537,7 @@ static bool trans_csrrwi(DisasContext *ctx, arg_csrrwi *a)
         return do_csrw(ctx, a->csr, src);
     }
 
-    TCGv mask = tcg_constant_tl(-1);
+    TCGv mask = tcg_constant_tl(get_xl(ctx) == MXL_RV32 ? UINT32_MAX : -1);
     return do_csrrw(ctx, a->rd, a->csr, src, mask);
 }
 
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index 095d39671b..acfad598e1 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -50,7 +50,8 @@ target_ulong helper_csrr(CPURISCVState *env, int csr)
 
 void helper_csrw(CPURISCVState *env, int csr, target_ulong src)
 {
-    RISCVException ret = riscv_csrrw(env, csr, NULL, src, -1);
+    target_ulong mask = env->xl == MXL_RV32 ? UINT32_MAX : -1;
+    RISCVException ret = riscv_csrrw(env, csr, NULL, src, mask);
 
     if (ret != RISCV_EXCP_NONE) {
         riscv_raise_exception(env, ret, GETPC());
-- 
2.25.1