From owner-svn-src-projects@FreeBSD.ORG Sun Jun 6 04:05:13 2010 Return-Path: Delivered-To: svn-src-projects@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F2E8F106566B for ; Sun, 6 Jun 2010 04:05:13 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id 88AB88FC0A for ; Sun, 6 Jun 2010 04:05:13 +0000 (UTC) Received: from [127.0.0.1] (pooker.samsco.org [168.103.85.57]) (authenticated bits=0) by pooker.samsco.org (8.14.3/8.14.3) with ESMTP id o563cUgT034821; Sat, 5 Jun 2010 21:38:30 -0600 (MDT) (envelope-from scottl@samsco.org) Mime-Version: 1.0 (Apple Message framework v1078) Content-Type: text/plain; charset=us-ascii From: Scott Long In-Reply-To: <20100605.203348.651115405925906974.imp@bsdimp.com> Date: Sat, 5 Jun 2010 21:38:30 -0600 Content-Transfer-Encoding: quoted-printable Message-Id: <516EEDC6-069A-4780-84DF-BBFF43ABCDE5@samsco.org> References: <201006052041.o55KfMF6032155@svn.freebsd.org> <184A275D-B98A-4DBF-9F4D-22F27B9319DD@mac.com> <20100605.203348.651115405925906974.imp@bsdimp.com> To: "M. Warner Losh" X-Mailer: Apple Mail (2.1078) X-Spam-Status: No, score=-50.0 required=3.8 tests=ALL_TRUSTED, T_RP_MATCHES_RCVD autolearn=unavailable version=3.3.0 X-Spam-Checker-Version: SpamAssassin 3.3.0 (2010-01-18) on pooker.samsco.org Cc: svn-src-projects@FreeBSD.org, xcllnt@mac.com, nwhitehorn@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r208850 - projects/ppc64/sys/powerpc/include X-BeenThere: svn-src-projects@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the src " projects" tree" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Jun 2010 04:05:14 -0000 On Jun 5, 2010, at 8:33 PM, M. Warner Losh wrote: > In message: <184A275D-B98A-4DBF-9F4D-22F27B9319DD@mac.com> > Marcel Moolenaar writes: > :=20 > : On Jun 5, 2010, at 1:41 PM, Nathan Whitehorn wrote: > :=20 > : > Author: nwhitehorn > : > Date: Sat Jun 5 20:41:22 2010 > : > New Revision: 208850 > : > URL: http://svn.freebsd.org/changeset/base/208850 > : >=20 > : > Log: > : > BUS_SPACE_UNRESTRICTED is a flag, not an address, so it should be = an int, > : > not a long. > :=20 > : This probably isn't right. How would you distinguish between a = 32-bit > : maximum of and unlimited if both can have the value 0xFFFFFFFF. > : Making BUS_SPACE_UNRESTRICTED a long prevents zero-extension to = 64-bit > : and thus prevents this ambiguity. >=20 > But this define is used for busdma's number of segments. It isn't > used for an address at all... >=20 > from the busdma man page for bus_dma_tag_create: > nsegments Number of discontinuities (scatter/gather = segments) > allowed in a DMA mapped region. If there is = no > restriction, BUS_SPACE_UNRESTRICTED may be = speci- > fied. >=20 > so an argument consistent with the definition of nsegments is what is > needed. The man page doesn't specify a type for nsegments, but > sys/bus_dma.h defines it as: >=20 > int bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, > bus_size_t boundary, bus_addr_t lowaddr, > bus_addr_t highaddr, bus_dma_filter_t *filtfunc, > void *filtfuncarg, bus_size_t maxsize, int = nsegments, > bus_size_t maxsegsz, int flags, bus_dma_lock_t = *lockfunc, > void *lockfuncarg, bus_dma_tag_t *dmat); >=20 > so it is more proper to have it be an int than a long. >=20 > I got tripped up on this stupid name too when I was adding it for > MIPS. Any why it is in a MD file instead of an MI file is beyond me. > I think it should be defined in sys/bus_dma.h, but maybe I'm just = nuts... >=20 No, you're not nuts. I've had a grand unification of MI/MD parts of = busdma on my mind for years, and probably at least 2 or 3 aborted = attempts lying around in old defunct trees. Any unification is going to = risk API/ABI changes, so I ultimately don't want to do it simply for = cleanliness sake. =20 Scott