From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73190C433B4 for ; Wed, 28 Apr 2021 10:25:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 31B4561107 for ; Wed, 28 Apr 2021 10:25:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239396AbhD1K0Y (ORCPT ); Wed, 28 Apr 2021 06:26:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238295AbhD1K0X (ORCPT ); Wed, 28 Apr 2021 06:26:23 -0400 Received: from mail-wr1-x42d.google.com (mail-wr1-x42d.google.com [IPv6:2a00:1450:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDB26C061574 for ; Wed, 28 Apr 2021 03:25:38 -0700 (PDT) Received: by mail-wr1-x42d.google.com with SMTP id a4so62468522wrr.2 for ; Wed, 28 Apr 2021 03:25:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=Bwu2rvkvN7gIZgfFitfEHTzbFUX5cjTsDc1ntVZl3eQ=; b=PHZeQvSpD9gY/jZeF+Zw2eXX30t8tvzRaZFemI+co9ssuQJ5VmkKic+in5tGy1voiI +JbG2h+dGoZ/G7jodqkrWRnDvqMHa+gVEgnr4zHczTntfWyOoWVoXaxQcHqXpiK2yXjl bkhPD5asbliuzx3DkFvnuveaTuLwFkNVRijOUe8uTOsvWAizVeIoXmThi2TrC3YVMc7p 20iUBDZKOaklWfdjYQI1TquVFSrnj8YFJvZwGlQPSh3rmsqoU0DQGOYUCqKey8oVkujI zDpM/DGNrIlmm0i4MBPcsp16t4/kmCEMcJMHglWv4NzCh/y3+uPg0kqcwq6iidzS3XZ5 Yc7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=Bwu2rvkvN7gIZgfFitfEHTzbFUX5cjTsDc1ntVZl3eQ=; b=ksNSkWbDF3kFoffloBEOTzHLbvkPMlkRpr71m0xjp5Lf0wReYHfv9tLw1ILAOu7FHq 7CSCAcKMvqBAZuxjpZaponWYGziak+AcBgSgbX1s1V7ntBDst349yi4/qGRAqYKULn68 DnyPhA+aN0rL+jQ6r4g/HY9Zmd7eWxvTBME62SZmMGLkgYt4n1LGyR0IJaxBrkEpp7MK oRlGzKn8Y94g7Ql9cW5xPt1Nbob0d/JyaoMpVJlu9990R7xVzs0P90GwKiILsCKUXN1Z yfLH2XQzlYsRlxw2eoqa61xuFX29wTJpfugTvN6du87axYuFFfd9GuvawDUekM4ZenaM lrYw== X-Gm-Message-State: AOAM533dy6MCe81wWmFhlymimO9hAOqqWBmIzEGfiEJP2ZvL/RFl8y5K WvqU5BtCj+HB1Zy6Tma9UFU= X-Google-Smtp-Source: ABdhPJyg7JPa6ZNYGm2DugdINct82FO1jCIP+1ZhYmTKZMahiNC6lNjGXCn7YoYbQE30oSy2QINbiA== X-Received: by 2002:a5d:53c9:: with SMTP id a9mr20283167wrw.108.1619605537794; Wed, 28 Apr 2021 03:25:37 -0700 (PDT) Received: from Red ([2a01:cb1d:3d5:a100:264b:feff:fe03:2806]) by smtp.googlemail.com with ESMTPSA id a9sm3381689wmj.1.2021.04.28.03.25.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Apr 2021 03:25:37 -0700 (PDT) Date: Wed, 28 Apr 2021 12:25:35 +0200 From: Corentin Labbe To: Robin Murphy Cc: hch@lst.de, m.szyprowski@samsung.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: DMA mapping fill dma_address to 0 Message-ID: References: <6ce3614e-af79-2a36-de83-6cbb4d9fe9a4@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6ce3614e-af79-2a36-de83-6cbb4d9fe9a4@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le Wed, Apr 28, 2021 at 11:06:10AM +0100, Robin Murphy a écrit : > On 2021-04-28 09:42, Corentin Labbe wrote: > > Hello > > > > I work on the crypto offloader driver of cortina/gemini SL3516 SoC. > > I test it by filling a LUKS2 partition. > > I got a reproductible problem when handling skcipher requests. > > I use dma_map_sg() and when iterating other the result, sg_dma_address(sg) return 0. > > But sg_dma_len(sg) is still correct (4096 in my case). > > > > Below is a simplified view of my code: > > nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src), DMA_TO_DEVICE); > > (nr_sgs = 1 in my case) > > sg = areq->src; > > if (!sg_dma_address(sg)) > > FAIL > > What is this check supposed to be for in the first place? 0 is a valid > DMA address, because it's also a valid physical address, and I recall > RAM at PA 0 on Hikey 960 flushing out some bugs in the past when we > tried to use 0 for DMA_MAPPING_ERROR. All the Gemini DTs appear to show > RAM starting at PA 0 too, so I'd have to guess that it's simply the case > that your DMA buffer happened to end up using that particular page. > > Robin. > Yes, 0 is a valid DMA address. I just find it by going further and printing mem_map value and testing it against sg_page() return. So my original problem was not related to this. Sorry for the noise. Thanks