Subject: Re: IPL_* and IST_* constants
To: Charles M. Hannum <>
From: Chris G Demetriou <Chris_G_Demetriou@UX2.SP.CS.CMU.EDU>
List: tech-kern
Date: 03/19/1996 07:09:58
>    > The following constants must be defined in <machine/psl.h>, if _KERNEL
>    > is defined:
>    How are they brought into scope by drivers?
> Based on current practice, it seems that including either of
> <machine/psl.h> or <machine/cpu.h> should do it.  Whether or not
> including both should be allowed is outside the scope of my message.
> I find it bad form to gratuitously #include extra files, so I'd
> recommend not making psl.h idempotent unless there is a pressing need
> to.

So, is the answer to include them via <machine/cpu.h>?

And, if so, is it still mandatory to put them in <machine/psl.h>?

Unfortunately, saying "implementors must put them here, but i'm not
going to nail down how you correctly use them" doesn't particularly
help driver developers.