From owner-freebsd-arch Tue Dec 12 23:20:52 2000 From owner-freebsd-arch@FreeBSD.ORG Tue Dec 12 23:20:50 2000 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mass.osd.bsdi.com (adsl-63-202-176-64.dsl.snfc21.pacbell.net [63.202.176.64]) by hub.freebsd.org (Postfix) with ESMTP id 175D037B400 for ; Tue, 12 Dec 2000 23:20:50 -0800 (PST) Received: from mass.osd.bsdi.com (localhost [127.0.0.1]) by mass.osd.bsdi.com (8.11.1/8.11.1) with ESMTP id eBD7UV307046 for ; Tue, 12 Dec 2000 23:30:35 -0800 (PST) (envelope-from msmith@mass.osd.bsdi.com) Message-Id: <200012130730.eBD7UV307046@mass.osd.bsdi.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: arch@freebsd.org Subject: Proposed bus address typedef. Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 12 Dec 2000 23:30:31 -0800 From: Mike Smith Sender: msmith@mass.osd.bsdi.com Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I'd like to propose some changes to the way we represent bus addresses, to deal with situations where u_long (IMO not a good choice to begin with) is too small. Specifically, I'd like to be able to deal with x86 systems in PAE mode, where physical addresses are 36 bits in size. To achieve this, I would like to introduce a typedef, bus_addr_t, which is defined on a given platform as being large enough to contain any bus-addressable location. This type would then be used in the following applications (initially): - The resource manager - The resource list code (helpers for bus implementations) - The busspace and busdma subsystems Note that this will break binary compatibility with loadable modules, but should not cause significant problems at the source level with code currently assuming that u_long or u_int32_t is big enough (except when it isn't, of course). Comments? -- ... every activity meets with opposition, everyone who acts has his rivals and unfortunately opponents also. But not because people want to be opponents, rather because the tasks and relationships force people to take different points of view. [Dr. Fritz Todt] V I C T O R Y N O T V E N G E A N C E To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message