From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by oss.sgi.com (8.11.2/8.11.3) id g01KYYv26332 for linux-mips-outgoing; Tue, 1 Jan 2002 12:34:34 -0800 Received: from ns1.ltc.com (vsat-148-63-243-254.c3.sb4.mrt.starband.net [148.63.243.254]) by oss.sgi.com (8.11.2/8.11.3) with SMTP id g01KYLg26328 for ; Tue, 1 Jan 2002 12:34:24 -0800 Received: from prefect (unknown [10.1.1.86]) by ns1.ltc.com (Postfix) with SMTP id EFFD5590A9; Tue, 1 Jan 2002 14:30:11 -0500 (EST) Message-ID: <016d01c192fb$518a9dd0$5601010a@prefect> From: "Bradley D. LaRonde" To: "Jun Sun" , "Jim Paris" Cc: "Alan Cox" , "Geert Uytterhoeven" , "Maciej W. Rozycki" , "Linux/MIPS Development" References: <20011221134452.A21586@neurosis.mit.edu> <20020101112223.A14847@mvista.com> Subject: Re: ISA Date: Tue, 1 Jan 2002 14:34:24 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Sender: owner-linux-mips@oss.sgi.com Precedence: bulk ----- Original Message ----- From: "Jun Sun" To: "Jim Paris" Cc: "Alan Cox" ; "Geert Uytterhoeven" ; "Maciej W. Rozycki" ; "Linux/MIPS Development" Sent: Tuesday, January 01, 2002 2:22 PM Subject: Re: ISA > 1. each address space has an id. > 2. kernel pre-defines a couple of well-known ones, 0 for CPU physical, > 1 for virtual, etc. > 3. When drivers discover the devices, they get the address and also > the address space id where the address resides. > 4. there are a set of macro's that converts/maps an address or an > address region from one space to another. The first thing that jumps out at me is that now every bus access has an added switch in it. Either that or drivers would get back access function pointers, but that eliminates the chance to inline trivial bus accesses. Regards, Brad