> +/* ki_hint changed from enum to u16, make sure rw_hint fits into u16 */
I don't think this comment is very useful.
> +static inline u16 ki_hint_valid(enum rw_hint hint)
I'd call this ki_hint_validate.
> +{
> + if (hint > MAX_KI_HINT)
> + return 0;
> +
> + return hint;
Nit: kill the empty line.
