From owner-freebsd-hackers Mon Jan 20 03:27:55 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.4/8.8.4) id DAA25158 for hackers-outgoing; Mon, 20 Jan 1997 03:27:55 -0800 (PST) Received: from hda.hda.com (ip65-max1-fitch.ziplink.net [199.232.245.65]) by freefall.freebsd.org (8.8.4/8.8.4) with SMTP id DAA25152; Mon, 20 Jan 1997 03:27:50 -0800 (PST) Received: (from dufault@localhost) by hda.hda.com (8.6.12/8.6.12) id GAA20525; Mon, 20 Jan 1997 06:23:29 -0500 From: Peter Dufault Message-Id: <199701201123.GAA20525@hda.hda.com> Subject: Re: Would like to us a BIT in buf.h In-Reply-To: <199701200414.UAA09566@freefall.freebsd.org> from Julian Elischer at "Jan 19, 97 08:14:20 pm" To: julian@freefall.freebsd.org (Julian Elischer) Date: Mon, 20 Jan 1997 06:23:29 -0500 (EST) Cc: hackers@freefall.freebsd.org X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > I would like to get a bit in the buf b_flags lword. > > however it's full :( > > If I could get it I would like to call this bit B_UIO. > > the setting of this bit would indicate to some drivers > that the (initially b_driver2 field but eventually b_addr) field > points to a UIO struct that details the physical > scatter/gather (page) segments of the io requested, rather than > a kv mapping of said space. Isn't this a bus mapping issue? Based on the device being talked to you have a different bus resource you have to set up in physio. You could be allocating mapping registers, or setting up bounce buffers, etc., and you can't have a bit for each flavor. You also have to free this resource when done. I don't see why anyone outside of bus setup / driver entry / bus free should poke around in the raw transfers buffers. Peter -- Peter Dufault (dufault@hda.com) Realtime Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936