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=-6.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLACK 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 0636EC433ED for ; Tue, 20 Apr 2021 05:29:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEDF16109E for ; Tue, 20 Apr 2021 05:29:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229835AbhDTFaP (ORCPT ); Tue, 20 Apr 2021 01:30:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229504AbhDTFaN (ORCPT ); Tue, 20 Apr 2021 01:30:13 -0400 Received: from mail-qk1-x730.google.com (mail-qk1-x730.google.com [IPv6:2607:f8b0:4864:20::730]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB714C06174A for ; Mon, 19 Apr 2021 22:29:42 -0700 (PDT) Received: by mail-qk1-x730.google.com with SMTP id v7so10192790qkj.13 for ; Mon, 19 Apr 2021 22:29:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:cc:date:in-reply-to:references :organization:user-agent:mime-version:content-transfer-encoding; bh=CD5KgC7jtIRxFp9L5EX0XqWGl1RUghQJwWPnq/cGmzA=; b=JCafrJcSXX4Mn66ZWw8U8ND0HHkGqhAmFRiw8OMyTHMosRl8XNVwao/iHwNS7jMLX1 /N7bbezhvWpt+Iqas9/VOpTAJrx4FkJp16RYUuY7uI6+ufT58hn2Lkk2gei8Or6L8eOS pPm3UWa12JX9fTiXDsRAF82Qrq92UEv3Qi6zkHFgExT0gNh+CmoNr3fpsvKM5pCD8REE xmVPf2zAPQetho4L8Gz6N/1cXKukAoxpvXHCTPuBnDDst5T8fNKgPTTbQTasdckAOFur lfTbDyKvTK+fqPslxjcFuGjRG7OC8RIU6BlXRrkQ99635WyW5KLZYWjN4b9OGUCv1KJf raWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:organization:user-agent:mime-version :content-transfer-encoding; bh=CD5KgC7jtIRxFp9L5EX0XqWGl1RUghQJwWPnq/cGmzA=; b=o8pmbkmKPLAxm9i4z/COO39ZNyoJl3r1i7CunF9GKozNw4z2NjuNVOLw+DeoybK7uq EoCnjp1w1TLAANxMCNFbrReBB3YniHus8RLErCrB/1xGH1ySE1zfDUFNdEmuPtepP1Ep ltI4HfHEpvtv+a0kOXfhiCEc4v9W3I1qwCu75pTkvTt8Lvpc8IsATQScpaQZK2IAB3oy C98CtKDFfZBysyaeGmMUR1W81PVkBGC0BOpunGfQ7TJWsFH4J8L1vSSZnxNksgA5C+UT NPbehQeYWCy0cw+fRhGKEUhfuW1IvOarQS8L5LkXvp0QWF7PiKLNcUIC61b2zPsFlb6o mTqQ== X-Gm-Message-State: AOAM531YIWRlIq1Pyr9icuh1ZwzOVNo0tKZzef7FbVA8ygQ7dgtRZAq3 xZgX/UmHJfqF5ykjmGxH+H8= X-Google-Smtp-Source: ABdhPJwZS2BpuCSdCWdDvSF5KnO6hp7JbxTakxD8Xsi7lNH9Uo+5o2UZGcERr3xdBBoefGdvXPZw9w== X-Received: by 2002:a37:a206:: with SMTP id l6mr15817573qke.5.1618896581783; Mon, 19 Apr 2021 22:29:41 -0700 (PDT) Received: from li-908e0a4c-2250-11b2-a85c-f027e903211b.ibm.com ([177.35.200.187]) by smtp.gmail.com with ESMTPSA id v3sm5539052qkb.124.2021.04.19.22.29.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Apr 2021 22:29:41 -0700 (PDT) Message-ID: <2977fdf112bce230ca6739c0a7f9f1f55bd2f693.camel@gmail.com> Subject: Re: [PATCH 1/1] powerpc/pseries/iommu: Fix window size for direct mapping with pmem From: Leonardo Bras To: Alexey Kardashevskiy , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Date: Tue, 20 Apr 2021 02:29:38 -0300 In-Reply-To: <58b28a98-37aa-055f-5dec-d8c0005c9519@ozlabs.ru> References: <20210420045404.438735-1-leobras.c@gmail.com> <58b28a98-37aa-055f-5dec-d8c0005c9519@ozlabs.ru> Organization: IBM Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2021-04-20 at 15:18 +1000, Alexey Kardashevskiy wrote: > > On 20/04/2021 14:54, Leonardo Bras wrote: > > As of today, if the DDW is big enough to fit (1 << MAX_PHYSMEM_BITS) it's > > possible to use direct DMA mapping even with pmem region. > > > > But, if that happens, the window size (len) is set to > > (MAX_PHYSMEM_BITS - page_shift) instead of MAX_PHYSMEM_BITS, causing a > > pagesize times smaller DDW to be created, being insufficient for correct > > usage. > > > > Fix this so the correct window size is used in this case. > > Good find indeed. > > afaict this does not create a huge problem though as > query.largest_available_block is always smaller than (MAX_PHYSMEM_BITS - > page_shift) where it matters (phyp). > > > Reviewed-by: Alexey Kardashevskiy > Thanks for reviewing! Leonardo Bras