[Xen-devel] Re: [ofa-general] mthca use of dma_sync_single is bo

To:	mst@xxxxxxxxxxxxxx
Subject:	[Xen-devel] Re: [ofa-general] mthca use of dma_sync_single is bogus
From:	Roland Dreier <rdreier@xxxxxxxxx>
Date:	Mon, 09 Jul 2007 14:29:40 -0700
Authentication-results:	sj-dkim-3; header.From=rdreier@xxxxxxxxx; dkim=pass ( sig from cisco.com/sjdkim3002 verified; );
Cc:	Lukas Hejtmanek <xhejtman@xxxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx, Keir Fraser <keir@xxxxxxxxxxxxx>, general@xxxxxxxxxxxxxxxxxxxxx
Delivery-date:	Tue, 10 Jul 2007 10:12:08 -0700
Dkim-signature:	v=0.5; a=rsa-sha256; q=dns/txt; l=746; t=1184016581; x=1184880581; c=relaxed/simple; s=sjdkim3002; h=Content-Type:From:Subject:Content-Transfer-Encoding:MIME-Version; d=cisco.com; i=rdreier@xxxxxxxxx; z=From:=20Roland=20Dreier=20<rdreier@xxxxxxxxx> \|Subject:=20Re=3A=20[ofa-general]=20mthca=20use=20of=20dma_sync_single=20 is=20bogus \|Sender:=20; bh=gVR7AxDiryROmJhnYpWjADJHWihtiWekadr2t7KYfXc=; b=dofTWYM/+EwTxuPKrgGa1wt/SX74l0QWhuFEof+LLJplyz+DaPey1WbGKFcpviISq/1L8TCe 0Hk2gGBxj2mww2d0YKG3Hi0JqwgyV0hKskDKhjmTJRGimd22vH/m2jN+;
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxx
In-reply-to:	<adalkdpxopo.fsf@xxxxxxxxx> (Roland Dreier's message of "Mon, 09 Jul 2007 14:16:19 -0700")
List-help:	<mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id:	Xen developer discussion <xen-devel.lists.xensource.com>
List-post:	<mailto:xen-devel@lists.xensource.com>
List-subscribe:	<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe:	<http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References:	<adalkdpxopo.fsf@xxxxxxxxx>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent:	Gnus/5.1007 (Gnus v5.10.7) XEmacs/21.4.20 (linux)

 >     void
 >     dma_sync_single_range(struct device *dev, dma_addr_t dma_handle,
 >                    unsigned long offset, size_t size,
 >                    enum dma_data_direction direction)

It seems the document has bitrotted a little, since
dma_sync_single_range() doesn't actually exist for most architectures;
what is really implemented is dma_sync_single_range_for_cpu() and
dma_sync_single_range_for_device().  But assuming those are usable in
our situation, they seem to be exactly what we want.  I'll try to get
clarification from the DMA API experts (and also fix the documentation
in the kernel).

Unfortunately it seems like the kernel's swiotlb does not implement
the full DMA API so this won't actually fix Xen :(.

 - R.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

WARNING - OLD ARCHIVES

xen-devel

[Xen-devel] Re: [ofa-general] mthca use of dma_sync_single is bogus