From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030456Ab0B0SPW (ORCPT ); Sat, 27 Feb 2010 13:15:22 -0500 Received: from mail-iw0-f182.google.com ([209.85.223.182]:35854 "EHLO mail-iw0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030293Ab0B0SPU (ORCPT ); Sat, 27 Feb 2010 13:15:20 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=NdFGgAtKJakg+5DAewhP5JiolWlsmMuVZk2/OfKSSPU1dTqJJ0Tz13XXWftXzlyboI PY1wA3zD0ichuAlpc9SdIC7ttpDY58n2ZlDJocHu1SJF1znL6SawycEq+yvJARqIqyhH Cu0meC00T+9sAUmLFkP/m4VDmxj/sHLt1tfls= MIME-Version: 1.0 In-Reply-To: <20100227.040502.182574085.davem@davemloft.net> References: <51f3faa71002261908y7cfa62eeicb3e56d5c920887a@mail.gmail.com> <20100227.015350.71138134.davem@davemloft.net> <201002271259.31596.bzolnier@gmail.com> <20100227.040502.182574085.davem@davemloft.net> Date: Sat, 27 Feb 2010 12:15:19 -0600 Message-ID: <51f3faa71002271015i7c9ec45j18381b1269bfd799@mail.gmail.com> Subject: Re: [RFC PATCH] fix problems with NETIF_F_HIGHDMA in networking drivers From: Robert Hancock To: David Miller Cc: bzolnier@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 27, 2010 at 6:05 AM, David Miller wrote: > From: Bartlomiej Zolnierkiewicz > Date: Sat, 27 Feb 2010 12:59:31 +0100 > >> Having IOMMU (even if it is only a software one, i.e. this would >> mean swiotlb for x86-32/highmem) always in place would simplify >> things greatly.. > > I agree, things would be a lot simpler. Yeah, the situation kind of sucks on the platforms that don't have any IOMMU support, since it means that the DMA API can't handle anything over 4GB properly and you need all these hacks in the block layer, networking layer, etc. It would be nice if some kind of IOMMU support could be relied upon always. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Hancock Subject: Re: [RFC PATCH] fix problems with NETIF_F_HIGHDMA in networking drivers Date: Sat, 27 Feb 2010 12:15:19 -0600 Message-ID: <51f3faa71002271015i7c9ec45j18381b1269bfd799@mail.gmail.com> References: <51f3faa71002261908y7cfa62eeicb3e56d5c920887a@mail.gmail.com> <20100227.015350.71138134.davem@davemloft.net> <201002271259.31596.bzolnier@gmail.com> <20100227.040502.182574085.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: bzolnier@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org To: David Miller Return-path: In-Reply-To: <20100227.040502.182574085.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sat, Feb 27, 2010 at 6:05 AM, David Miller wrote: > From: Bartlomiej Zolnierkiewicz > Date: Sat, 27 Feb 2010 12:59:31 +0100 > >> Having IOMMU (even if it is only a software one, i.e. this would >> mean swiotlb for x86-32/highmem) always in place would simplify >> things greatly.. > > I agree, things would be a lot simpler. Yeah, the situation kind of sucks on the platforms that don't have any IOMMU support, since it means that the DMA API can't handle anything over 4GB properly and you need all these hacks in the block layer, networking layer, etc. It would be nice if some kind of IOMMU support could be relied upon always.