Date: Thu, 26 May 2005 09:33:47 +0100 From: Doug Rabson <dfr@nlsystems.com> To: freebsd-arch@freebsd.org Cc: arch@freebsd.org, nyan@jp.FreeBSD.org, Marcel Moolenaar <marcel@xcllnt.net> Subject: Re: [RFC] remove bus_memio.h and bus_pio.h Message-ID: <200505260933.49013.dfr@nlsystems.com> In-Reply-To: <c980ee30aebf003752cce2498c1a6516@xcllnt.net> References: <20050525.212009.71136852.nyan@jp.FreeBSD.org> <20050525.111945.41668351.imp@bsdimp.com> <c980ee30aebf003752cce2498c1a6516@xcllnt.net>
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On Wednesday 25 May 2005 18:40, Marcel Moolenaar wrote: > On May 25, 2005, at 10:19 AM, M. Warner Losh wrote: > > Short answer: > > > > Great idea. > > Seconded. Thirded. > > > Longer, more detailed answer. > > > > The original idea was to provide a hint to busspace that this > > driver only ever used a certain subset of the available mappings so > > it should assume that subset and agressively optimize the code. > > It has also worked against, well, me in the past in that I couldn't > figure out why a driver simply didn't want to work with memio while > it worked perfectly with pio. Then I spotted the bus_pio.h header at > the top and cursed, cursed, cursed. > > I'm all for performance tuning, but the newbus optimization is just > too weird for its own good this way. Hey, don't blame this on newbus - it predates newbus by quite a bit. I seem to remember that this came in with the first import of CAM so you can blame Justin :-)
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