From owner-cvs-all Tue Jul 18 13:29:43 2000 Delivered-To: cvs-all@freebsd.org Received: from feral.com (feral.com [192.67.166.1]) by hub.freebsd.org (Postfix) with ESMTP id 104CD37B510; Tue, 18 Jul 2000 13:29:34 -0700 (PDT) (envelope-from mjacob@feral.com) Received: from semuta.feral.com (semuta [192.67.166.70]) by feral.com (8.9.3/8.9.3) with ESMTP id NAA32610; Tue, 18 Jul 2000 13:29:31 -0700 Date: Tue, 18 Jul 2000 13:29:23 -0700 (PDT) From: Matthew Jacob Reply-To: mjacob@feral.com To: "Justin T. Gibbs" Cc: "Justin T. Gibbs" , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/cam cam_ccb.h cam_xpt.c src/sys/cam/scsi scsi_all.c scsi_message.h src/sys/dev/aic7xxx aicasm_insformat.h 93cx6.c 93cx6.h ahc_eisa.c ahc_pci.c aic7xxx.c aic7xxx.h aic7xxx.reg aic7xxx.seq aicasm.c aicasm.h aicasm_gram.y ... In-Reply-To: <200007182025.OAA53788@pluto.plutotech.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > > >What's the '39 bit addressing'? > > In the past, the S/G format looked like: > > uint8_t address[4]; > uint8_t datalen[3]; > uint8_t spare; > > Through some firmware manipulation, that last byte, other than a flag > bit, can be used as the 5th byte of the address. Oh, okay- this is an adaptec specific thingie. With 39 bits, you'll be able to cover what I believe is the current entire physical address space for all shipping Alpha platforms (they're all, I believe, 40 bit address space implementations- the top bit is an I/O vs. Memory space selector- remember p0 && p1 spaces for VAXen?). > >Also- maybe it's time to start considering 64 bit PCI > > I'm hoping that being able to address 512GB will be enough > for a while. I'd rather not expand the size of the S/G list > members for address space no-one will be touching for the > foreseeable future. Oh, I think I'm thinking more about the general PCI and bus_dma implementation where we might consider starting to have 64 bit versions RSN..... To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message