On Sat, Feb 27, 2021 at 02:01:26PM -0800, Jacob Pan wrote: > +/* -------- IOCTLs for IOASID file descriptor (/dev/ioasid) -------- */ > + > +/** > + * IOASID_GET_API_VERSION - _IO(IOASID_TYPE, IOASID_BASE + 0) > + * > + * Report the version of the IOASID API. This allows us to bump the entire > + * API version should we later need to add or change features in incompatible > + * ways. > + * Return: IOASID_API_VERSION > + * Availability: Always > + */ > +#define IOASID_GET_API_VERSION _IO(IOASID_TYPE, IOASID_BASE + 0) I think this is generally a bad idea, if you change the API later then also change the ioctl numbers and everything should work out eg use the 4th argument to IOC to specify something about the ABI Jason
