It works!!!
user@starfive:~$ sudo hdparm --direct -t /dev/mmcblk1
/dev/mmcblk1:
Timing O_DIRECT disk reads: 218 MB in 3.00 seconds = 72.64 MB/sec
Btw seems JH7110’s GPIO cannot handle faster io speed. If I set dts to HS400 mode, speed would be extremely slow.