Date: Wed, 26 Oct 2005 13:24:02 -0400 From: John Baldwin <jhb@freebsd.org> To: Scott Long <scottl@samsco.org> Cc: freebsd-hackers@freebsd.org Subject: Re: [Fwd: Re: use of bus_dmamap_sync] Message-ID: <200510261324.03790.jhb@freebsd.org> In-Reply-To: <435FA6A9.4000600@samsco.org> References: <435EEC56.9080708@samsco.org> <200510261130.45506.jhb@freebsd.org> <435FA6A9.4000600@samsco.org>
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On Wednesday 26 October 2005 11:54 am, Scott Long wrote: > > Perhaps on i386. Each arch implements sync(). Argh, it does look like > > the memory barriers needed on e.g., Alpha aren't used with static buffers > > because of the map != NULL check in sys/busdma.h. *sigh* I guess archs > > that need membars even without bounce buffers need to always allocate and > > setup a bus_dmamap. None of that matters for i386 though. > > Feel free to fix alpha. Again, long ago, I thought that alpha pretended > to be coherent in the 2GB DMA window that we use so that it could be > more like i386. If that's not true then that's fine. If you need to > make structural changes to the MI code on order to fix alpha, please let > me know. No, I'm just a moron. Alpha uses the nobounce_map for static buffers, so bus_dmamap_sync will use the appropriate membars. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
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