Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764401AbZDBPIg (ORCPT ); Thu, 2 Apr 2009 11:08:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758667AbZDBPIY (ORCPT ); Thu, 2 Apr 2009 11:08:24 -0400 Received: from mail.vyatta.com ([76.74.103.46]:57909 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760133AbZDBPIX (ORCPT ); Thu, 2 Apr 2009 11:08:23 -0400 Date: Thu, 2 Apr 2009 08:08:06 -0700 From: Stephen Hemminger To: Joerg Roedel Cc: FUJITA Tomonori , davej@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [Bug 487894] New: sky2 0000:06:00.0: DMA-API: device driver frees DMA memory with different size Message-ID: <20090402080806.047e2716@nehalam> In-Reply-To: <20090402143142.GA4776@amd.com> References: <20090402105415.GD21083@amd.com> <20090402200634I.fujita.tomonori@lab.ntt.co.jp> <20090402111839.GE21083@amd.com> <20090402230346B.fujita.tomonori@lab.ntt.co.jp> <20090402143142.GA4776@amd.com> Organization: Vyatta X-Mailer: Claws Mail 3.6.1 (GTK+ 2.16.0; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2680 Lines: 67 On Thu, 2 Apr 2009 16:31:42 +0200 Joerg Roedel wrote: > On Thu, Apr 02, 2009 at 11:03:58PM +0900, FUJITA Tomonori wrote: > > On Thu, 2 Apr 2009 13:18:39 +0200 > > Joerg Roedel wrote: > > > > > On Thu, Apr 02, 2009 at 08:06:26PM +0900, FUJITA Tomonori wrote: > > > > On Thu, 2 Apr 2009 12:54:15 +0200 > > > > Joerg Roedel wrote: > > > > > > > > > On Wed, Apr 01, 2009 at 11:02:45AM -0700, Stephen Hemminger wrote: > > > > > > > > > > > > The sky2 driver uses pci_unmap_len and pci_unmap_len_set which on 32 bit > > > > > > platforms are meaningless so they are stubbed out. > > > > > > Basically, DMA-API checks are wrong/bogus to enforce on 32bit x86 as is. > > > > > > > > > > As far as I know the VT-d driver is available on 32 bit x86 too. So this should > > > > > not always be a nop. > > > > > > > > VT-d is available on only x86_64. > > > > > > At least there was a patch to enable it on 32 bit too. See > > > > > > https://lists.linux-foundation.org/pipermail/iommu/2009-February/001080.html > > > > > > It seems not to be upstream yet. > > > > It's not in upstream. > > > > > > Anyway, about the original problem, I think that the best fix is not > > to stub out the dma API; using the dma API properly is always a good > > thing. > > True. > > For the real fix I prepared this fix. We still should find a better #ifdef > condition but that should not be a seperate patch. Does that look ok to > everyone? If yes, I send it to Ingo. > > commit e8cdd3b8d2fc3ec2a1dd337cba94feb7a7442751 > Author: Joerg Roedel > Date: Thu Apr 2 15:55:55 2009 +0200 > > x86/dma: unify definition of pci_unmap_addr* and pci_unmap_len macros > > Impact: unification of pci-dma macros and pci_32h removal > > This patch unifies the definition of the pci_unmap_addr*, pci_unmap_len* > and DECLARE_PCI_UNMAP* macros. This makes sense because the pci_unmap > functions are no longer no-ops anymore when the kernel runs with > CONFIG_DMA_API_DEBUG. This also simplifies the port of x86_64 iommu > drivers to 32 bit x86 and let us get rid of pci_32.h. > > Signed-off-by: Joerg Roedel Would also like some more comments to explain to the kernel neophytes why the 32 bit version is no-op. Do other arch have same issue? Acked-by: Stephen Hemminger -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/