[PATCH v5 5/7] target/riscv: Correct mcause/scause bit width for RV32 in RV64 QEMU

[LIU Zhiwei <zhiwei_liu@linux.alibaba.com>]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

Ensure mcause high bit is correctly set by using 32-bit width for RV32
mode and 64-bit width for RV64 mode.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_helper.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 4f0ab90ac7..3eedb26cd9 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -1673,6 +1673,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     target_ulong tinst = 0;
     target_ulong htval = 0;
     target_ulong mtval2 = 0;
+    int sxlen = 0;
+    int mxlen = 0;
 
     if (!async) {
         /* set tval to badaddr for traps with address information */
@@ -1799,7 +1801,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         s = set_field(s, MSTATUS_SPP, env->priv);
         s = set_field(s, MSTATUS_SIE, 0);
         env->mstatus = s;
-        env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
+        sxlen = 16 << riscv_cpu_sxl(env);
+        env->scause = cause | ((target_ulong)async << (sxlen - 1));
         env->sepc = env->pc;
         env->stval = tval;
         env->htval = htval;
@@ -1830,7 +1833,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         s = set_field(s, MSTATUS_MPP, env->priv);
         s = set_field(s, MSTATUS_MIE, 0);
         env->mstatus = s;
-        env->mcause = cause | ~(((target_ulong)-1) >> async);
+        mxlen = 16 << riscv_cpu_mxl(env);
+        env->mcause = cause | ((target_ulong)async << (mxlen - 1));
         env->mepc = env->pc;
         env->mtval = tval;
         env->mtval2 = mtval2;
-- 
2.25.1