Hi, I read this:

• https://community.st.com/t5/stm32-mpus-products/solved-how-to-use-hardware-ciphers-with-cryptsetup-on/td-p/106582

• search based on https://gitlab.com/cryptsetup/cryptsetup/-/wikis/DMCrypt and https://wiki.archlinux.org/title/Dm-crypt/Device_encryption#Encryption_options_for_plain_mode

Basically, one needs

CONFIG_MD=y, CONFIG_BLK_DEV_DM=y, CONFIG_DM_CRYPT=y, CONFIG_CRYPTO_CRYPTD=m

when building the kernel. Hopefully, this makes en- and decryption faster.