Alan Coopersmith <[EMAIL PROTECTED]> wrote:
> Garrett D'Amore wrote:
> > 1) The macros themselves that make use of _IOCPARM_MASK (_IOR, _IOW,
> > _IORW) are "private" to ON. That is, external code shouldn't be
> > directly using them.
>
> Are they? I've been working to get our DRI/DRM (graphics direct
> rendering, not media rights/restrictions) changes upstream - currently
> the drm.h header exports the ioctl defintions as:
>
> #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
In SunOS-4.x, these definitions were needed and SunOS-4.x indeed is unable
to deal with ioctl parameters > 255 as copy in/out was donee by the kernel.
With SunOS-5.x, the numbers in the IOCTL function number are only something
like a "hint". Copy in/out is done by the driver and the driver knows the real
sizes of the structures. Unless there is a clash, I see no need to extend
_IOC_NRMASK.
Jörg
--
EMail:[EMAIL PROTECTED] (home) Jörg Schilling D-13353 Berlin
[EMAIL PROTECTED] (uni)
[EMAIL PROTECTED] (work) Blog: http://schily.blogspot.com/
URL: http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily
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