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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 3CE8BC1975A for ; Mon, 23 Mar 2020 01:58:21 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F167420722 for ; Mon, 23 Mar 2020 01:58:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ozlabs-ru.20150623.gappssmtp.com header.i=@ozlabs-ru.20150623.gappssmtp.com header.b="DEnNwepo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F167420722 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 9251585F18; Mon, 23 Mar 2020 01:58:20 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vaBjuMjPDddU; Mon, 23 Mar 2020 01:58:18 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 5BD5D85F11; Mon, 23 Mar 2020 01:58:18 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3FCC0C089F; Mon, 23 Mar 2020 01:58:18 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 04E5BC0177 for ; Mon, 23 Mar 2020 01:58:16 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id F0B68885D1 for ; Mon, 23 Mar 2020 01:58:15 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mGQqETR-O77s for ; Mon, 23 Mar 2020 01:58:13 +0000 (UTC) X-Greylist: delayed 00:24:04 by SQLgrey-1.7.6 Received: from mail-oi1-f193.google.com (mail-oi1-f193.google.com [209.85.167.193]) by hemlock.osuosl.org (Postfix) with ESMTPS id AF96D885B5 for ; Mon, 23 Mar 2020 01:58:13 +0000 (UTC) Received: by mail-oi1-f193.google.com with SMTP id r7so13291468oij.0 for ; Sun, 22 Mar 2020 18:58:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ozlabs-ru.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=EwgK0L4cl4l7KkAyMjH+XgiGhnPNrrjuTsf1/mFdSlo=; b=DEnNwepotofFPsQsfkVxITWQCCmjGMPImFzDVLYc4Wh80aZRKJ7aI4+kmxWJojzVDX JLg95aG59YVRNKv5xtrhKMgpjFPQYzgw8bPvsDfPFVTYCG/bE+r4ebG6L9jOcCor90qj Rz0+L5InG1tvI5loK0n7Z8wjhU7PGe3zTvWbm0T18dW3qOdhabuN6hz8yICxo8m7ZpO0 Rotrolk2OiQ0PyEiSOOPl2wuxzjqc0kHQG4CbwZrzzmuEuQ0spTGTPtaYJ/QdjcOzh4y rYZTaZNwm4IKGOVKFWxCKgWWyeovW91suP8Fklx8EQcoHTi3Or+o0LFPVGsFURRvjhuQ Hoig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=EwgK0L4cl4l7KkAyMjH+XgiGhnPNrrjuTsf1/mFdSlo=; b=ZeICCe6t6xQRR3pniqCD0UiiaY/utkb/1ygfwyshLHAmp9CqRSxWkK89M9Z6Xtf5k2 Zh81GOpkgr9jwDbDot7yaZspbMnrsg7FWBTypbHse7XCyNGhdZJQfiuaeb0GlfB28ICl Wpiw+45NKj2lhpu4avY2V0Chb2MweNlliZbR6pWil5hmi9kmmMgsvw+TC0fWqlv7SV+7 eRlNgI7ETO+C4qfLAHH3RZ+IyccxSLV9qL2a/a9uypTFbSOQfrUEZqqmqySA0uUKuqWo 37alt/hRvamga6ndlh3F5RNAGVvv4d/nhEFUX+NADDKe2ykI+nOHmBuuT4B5mnSTZPdT kgyQ== X-Gm-Message-State: ANhLgQ1ebz9JaXF3tPlzbNdEsfuXhmsA2airhvs0HsMvGJcYV9Yo5Tx/ IG3/xgVW19uH08glDvZB40rziBqCh+M= X-Google-Smtp-Source: ADFU+vvQBuyMFVVSR8lgO3arpSDAHWxHIGE+sB9I+yMkE5KJA7fOLD036sEBGgQ0IqPba1QeRQUxnA== X-Received: by 2002:a17:90a:1784:: with SMTP id q4mr22453558pja.111.1584926921610; Sun, 22 Mar 2020 18:28:41 -0700 (PDT) Received: from [192.168.10.21] (ppp121-45-221-81.bras1.cbr2.internode.on.net. [121.45.221.81]) by smtp.gmail.com with ESMTPSA id o5sm1319722pgm.70.2020.03.22.18.28.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 22 Mar 2020 18:28:40 -0700 (PDT) Subject: Re: [PATCH 1/2] dma-mapping: add a dma_ops_bypass flag to struct device To: Christoph Hellwig , iommu@lists.linux-foundation.org References: <20200320141640.366360-1-hch@lst.de> <20200320141640.366360-2-hch@lst.de> From: Alexey Kardashevskiy Autocrypt: addr=aik@ozlabs.ru; keydata= mQINBE+rT0sBEADFEI2UtPRsLLvnRf+tI9nA8T91+jDK3NLkqV+2DKHkTGPP5qzDZpRSH6mD EePO1JqpVuIow/wGud9xaPA5uvuVgRS1q7RU8otD+7VLDFzPRiRE4Jfr2CW89Ox6BF+q5ZPV /pS4v4G9eOrw1v09lEKHB9WtiBVhhxKK1LnUjPEH3ifkOkgW7jFfoYgTdtB3XaXVgYnNPDFo PTBYsJy+wr89XfyHr2Ev7BB3Xaf7qICXdBF8MEVY8t/UFsesg4wFWOuzCfqxFmKEaPDZlTuR tfLAeVpslNfWCi5ybPlowLx6KJqOsI9R2a9o4qRXWGP7IwiMRAC3iiPyk9cknt8ee6EUIxI6 t847eFaVKI/6WcxhszI0R6Cj+N4y+1rHfkGWYWupCiHwj9DjILW9iEAncVgQmkNPpUsZECLT WQzMuVSxjuXW4nJ6f4OFHqL2dU//qR+BM/eJ0TT3OnfLcPqfucGxubhT7n/CXUxEy+mvWwnm s9p4uqVpTfEuzQ0/bE6t7dZdPBua7eYox1AQnk8JQDwC3Rn9kZq2O7u5KuJP5MfludMmQevm pHYEMF4vZuIpWcOrrSctJfIIEyhDoDmR34bCXAZfNJ4p4H6TPqPh671uMQV82CfTxTrMhGFq 8WYU2AH86FrVQfWoH09z1WqhlOm/KZhAV5FndwVjQJs1MRXD8QARAQABtCRBbGV4ZXkgS2Fy ZGFzaGV2c2tpeSA8YWlrQG96bGFicy5ydT6JAjgEEwECACIFAk+rT0sCGwMGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAAAoJEIYTPdgrwSC5fAIP/0wf/oSYaCq9PhO0UP9zLSEz66SSZUf7 AM9O1rau1lJpT8RoNa0hXFXIVbqPPKPZgorQV8SVmYRLr0oSmPnTiZC82x2dJGOR8x4E01gK TanY53J/Z6+CpYykqcIpOlGsytUTBA+AFOpdaFxnJ9a8p2wA586fhCZHVpV7W6EtUPH1SFTQ q5xvBmr3KkWGjz1FSLH4FeB70zP6uyuf/B2KPmdlPkyuoafl2UrU8LBADi/efc53PZUAREih sm3ch4AxaL4QIWOmlE93S+9nHZSRo9jgGXB1LzAiMRII3/2Leg7O4hBHZ9Nki8/fbDo5///+ kD4L7UNbSUM/ACWHhd4m1zkzTbyRzvL8NAVQ3rckLOmju7Eu9whiPueGMi5sihy9VQKHmEOx OMEhxLRQbzj4ypRLS9a+oxk1BMMu9cd/TccNy0uwx2UUjDQw/cXw2rRWTRCxoKmUsQ+eNWEd iYLW6TCfl9CfHlT6A7Zmeqx2DCeFafqEd69DqR9A8W5rx6LQcl0iOlkNqJxxbbW3ddDsLU/Y r4cY20++WwOhSNghhtrroP+gouTOIrNE/tvG16jHs8nrYBZuc02nfX1/gd8eguNfVX/ZTHiR gHBWe40xBKwBEK2UeqSpeVTohYWGBkcd64naGtK9qHdo1zY1P55lHEc5Uhlk743PgAnOi27Q ns5zuQINBE+rT0sBEACnV6GBSm+25ACT+XAE0t6HHAwDy+UKfPNaQBNTTt31GIk5aXb2Kl/p AgwZhQFEjZwDbl9D/f2GtmUHWKcCmWsYd5M/6Ljnbp0Ti5/xi6FyfqnO+G/wD2VhGcKBId1X Em/B5y1kZVbzcGVjgD3HiRTqE63UPld45bgK2XVbi2+x8lFvzuFq56E3ZsJZ+WrXpArQXib2 hzNFwQleq/KLBDOqTT7H+NpjPFR09Qzfa7wIU6pMNF2uFg5ihb+KatxgRDHg70+BzQfa6PPA o1xioKXW1eHeRGMmULM0Eweuvpc7/STD3K7EJ5bBq8svoXKuRxoWRkAp9Ll65KTUXgfS+c0x gkzJAn8aTG0z/oEJCKPJ08CtYQ5j7AgWJBIqG+PpYrEkhjzSn+DZ5Yl8r+JnZ2cJlYsUHAB9 jwBnWmLCR3gfop65q84zLXRQKWkASRhBp4JK3IS2Zz7Nd/Sqsowwh8x+3/IUxVEIMaVoUaxk Wt8kx40h3VrnLTFRQwQChm/TBtXqVFIuv7/Mhvvcq11xnzKjm2FCnTvCh6T2wJw3de6kYjCO 7wsaQ2y3i1Gkad45S0hzag/AuhQJbieowKecuI7WSeV8AOFVHmgfhKti8t4Ff758Z0tw5Fpc BFDngh6Lty9yR/fKrbkkp6ux1gJ2QncwK1v5kFks82Cgj+DSXK6GUQARAQABiQIfBBgBAgAJ BQJPq09LAhsMAAoJEIYTPdgrwSC5NYEP/2DmcEa7K9A+BT2+G5GXaaiFa098DeDrnjmRvumJ BhA1UdZRdfqICBADmKHlJjj2xYo387sZpS6ABbhrFxM6s37g/pGPvFUFn49C47SqkoGcbeDz Ha7JHyYUC+Tz1dpB8EQDh5xHMXj7t59mRDgsZ2uVBKtXj2ZkbizSHlyoeCfs1gZKQgQE8Ffc F8eWKoqAQtn3j4nE3RXbxzTJJfExjFB53vy2wV48fUBdyoXKwE85fiPglQ8bU++0XdOr9oyy j1llZlB9t3tKVv401JAdX8EN0++ETiOovQdzE1m+6ioDCtKEx84ObZJM0yGSEGEanrWjiwsa nzeK0pJQM9EwoEYi8TBGhHC9ksaAAQipSH7F2OHSYIlYtd91QoiemgclZcSgrxKSJhyFhmLr QEiEILTKn/pqJfhHU/7R7UtlDAmFMUp7ByywB4JLcyD10lTmrEJ0iyRRTVfDrfVP82aMBXgF tKQaCxcmLCaEtrSrYGzd1sSPwJne9ssfq0SE/LM1J7VdCjm6OWV33SwKrfd6rOtvOzgadrG6 3bgUVBw+bsXhWDd8tvuCXmdY4bnUblxF2B6GOwSY43v6suugBttIyW5Bl2tXSTwP+zQisOJo +dpVG2pRr39h+buHB3NY83NEPXm1kUOhduJUA17XUY6QQCAaN4sdwPqHq938S3EmtVhsuQIN BFq54uIBEACtPWrRdrvqfwQF+KMieDAMGdWKGSYSfoEGGJ+iNR8v255IyCMkty+yaHafvzpl PFtBQ/D7Fjv+PoHdFq1BnNTk8u2ngfbre9wd9MvTDsyP/TmpF0wyyTXhhtYvE267Av4X/BQT lT9IXKyAf1fP4BGYdTNgQZmAjrRsVUW0j6gFDrN0rq2J9emkGIPvt9rQt6xGzrd6aXonbg5V j6Uac1F42ESOZkIh5cN6cgnGdqAQb8CgLK92Yc8eiCVCH3cGowtzQ2m6U32qf30cBWmzfSH0 HeYmTP9+5L8qSTA9s3z0228vlaY0cFGcXjdodBeVbhqQYseMF9FXiEyRs28uHAJEyvVZwI49 CnAgVV/n1eZa5qOBpBL+ZSURm8Ii0vgfvGSijPGbvc32UAeAmBWISm7QOmc6sWa1tobCiVmY SNzj5MCNk8z4cddoKIc7Wt197+X/X5JPUF5nQRvg3SEHvfjkS4uEst9GwQBpsbQYH9MYWq2P PdxZ+xQE6v7cNB/pGGyXqKjYCm6v70JOzJFmheuUq0Ljnfhfs15DmZaLCGSMC0Amr+rtefpA y9FO5KaARgdhVjP2svc1F9KmTUGinSfuFm3quadGcQbJw+lJNYIfM7PMS9fftq6vCUBoGu3L j4xlgA/uQl/LPneu9mcvit8JqcWGS3fO+YeagUOon1TRqQARAQABiQRsBBgBCAAgFiEEZSrP ibrORRTHQ99dhhM92CvBILkFAlq54uICGwICQAkQhhM92CvBILnBdCAEGQEIAB0WIQQIhvWx rCU+BGX+nH3N7sq0YorTbQUCWrni4gAKCRDN7sq0YorTbVVSD/9V1xkVFyUCZfWlRuryBRZm S4GVaNtiV2nfUfcThQBfF0sSW/aFkLP6y+35wlOGJE65Riw1C2Ca9WQYk0xKvcZrmuYkK3DZ 0M9/Ikkj5/2v0vxz5Z5w/9+IaCrnk7pTnHZuZqOh23NeVZGBls/IDIvvLEjpD5UYicH0wxv+ X6cl1RoP2Kiyvenf0cS73O22qSEw0Qb9SId8wh0+ClWet2E7hkjWFkQfgJ3hujR/JtwDT/8h 3oCZFR0KuMPHRDsCepaqb/k7VSGTLBjVDOmr6/C9FHSjq0WrVB9LGOkdnr/xcISDZcMIpbRm EkIQ91LkT/HYIImL33ynPB0SmA+1TyMgOMZ4bakFCEn1vxB8Ir8qx5O0lHMOiWMJAp/PAZB2 r4XSSHNlXUaWUg1w3SG2CQKMFX7vzA31ZeEiWO8tj/c2ZjQmYjTLlfDK04WpOy1vTeP45LG2 wwtMA1pKvQ9UdbYbovz92oyZXHq81+k5Fj/YA1y2PI4MdHO4QobzgREoPGDkn6QlbJUBf4To pEbIGgW5LRPLuFlOPWHmIS/sdXDrllPc29aX2P7zdD/ivHABslHmt7vN3QY+hG0xgsCO1JG5 pLORF2N5XpM95zxkZqvYfC5tS/qhKyMcn1kC0fcRySVVeR3tUkU8/caCqxOqeMe2B6yTiU1P aNDq25qYFLeYxg67D/4w/P6BvNxNxk8hx6oQ10TOlnmeWp1q0cuutccblU3ryRFLDJSngTEu ZgnOt5dUFuOZxmMkqXGPHP1iOb+YDznHmC0FYZFG2KAc9pO0WuO7uT70lL6larTQrEneTDxQ CMQLP3qAJ/2aBH6SzHIQ7sfbsxy/63jAiHiT3cOaxAKsWkoV2HQpnmPOJ9u02TPjYmdpeIfa X2tXyeBixa3i/6dWJ4nIp3vGQicQkut1YBwR7dJq67/FCV3Mlj94jI0myHT5PIrCS2S8LtWX ikTJSxWUKmh7OP5mrqhwNe0ezgGiWxxvyNwThOHc5JvpzJLd32VDFilbxgu4Hhnf6LcgZJ2c Zd44XWqUu7FzVOYaSgIvTP0hNrBYm/E6M7yrLbs3JY74fGzPWGRbBUHTZXQEqQnZglXaVB5V ZhSFtHopZnBSCUSNDbB+QGy4B/E++Bb02IBTGl/JxmOwG+kZUnymsPvTtnNIeTLHxN/H/ae0 c7E5M+/NpslPCmYnDjs5qg0/3ihh6XuOGggZQOqrYPC3PnsNs3NxirwOkVPQgO6mXxpuifvJ DG9EMkK8IBXnLulqVk54kf7fE0jT/d8RTtJIA92GzsgdK2rpT1MBKKVffjRFGwN7nQVOzi4T XrB5p+6ML7Bd84xOEGsj/vdaXmz1esuH7BOZAGEZfLRCHJ0GVCSssg== Message-ID: <2f31d0dd-aa7e-8b76-c8a1-5759fda5afc9@ozlabs.ru> Date: Mon, 23 Mar 2020 12:28:34 +1100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200320141640.366360-2-hch@lst.de> Content-Language: en-US Cc: Greg Kroah-Hartman , Robin Murphy , linux-kernel@vger.kernel.org, "Aneesh Kumar K.V" , linuxppc-dev@lists.ozlabs.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 21/03/2020 01:16, Christoph Hellwig wrote: > Several IOMMU drivers have a bypass mode where they can use a direct > mapping if the devices DMA mask is large enough. Add generic support > to the core dma-mapping code to do that to switch those drivers to > a common solution. > > Signed-off-by: Christoph Hellwig > --- > include/linux/device.h | 6 ++++++ > include/linux/dma-mapping.h | 30 ++++++++++++++++++------------ > kernel/dma/mapping.c | 36 +++++++++++++++++++++++++++--------- > 3 files changed, 51 insertions(+), 21 deletions(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 0cd7c647c16c..09be8bb2c4a6 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -525,6 +525,11 @@ struct dev_links_info { > * sync_state() callback. > * @dma_coherent: this particular device is dma coherent, even if the > * architecture supports non-coherent devices. > + * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the > + * streaming DMA operations (->map_* / ->unmap_* / ->sync_*), > + * and optionall (if the coherent mask is large enough) also > + * for dma allocations. This flag is managed by the dma ops > + * instance from ->dma_supported. > * > * At the lowest level, every device in a Linux system is represented by an > * instance of struct device. The device structure contains the information > @@ -625,6 +630,7 @@ struct device { > defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) > bool dma_coherent:1; > #endif > + bool dma_ops_bypass : 1; > }; > > static inline struct device *kobj_to_dev(struct kobject *kobj) > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 330ad58fbf4d..c3af0cf5e435 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -188,9 +188,15 @@ static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma, > } > #endif /* CONFIG_DMA_DECLARE_COHERENT */ > > -static inline bool dma_is_direct(const struct dma_map_ops *ops) > +/* > + * Check if the devices uses a direct mapping for streaming DMA operations. > + * This allows IOMMU drivers to set a bypass mode if the DMA mask is large > + * enough. > + */ > +static inline bool dma_map_direct(struct device *dev, > + const struct dma_map_ops *ops) > { > - return likely(!ops); > + return likely(!ops) || dev->dma_ops_bypass; > } > > /* > @@ -279,7 +285,7 @@ static inline dma_addr_t dma_map_page_attrs(struct device *dev, > dma_addr_t addr; > > BUG_ON(!valid_dma_direction(dir)); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); > else > addr = ops->map_page(dev, page, offset, size, dir, attrs); > @@ -294,7 +300,7 @@ static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > dma_direct_unmap_page(dev, addr, size, dir, attrs); > else if (ops->unmap_page) > ops->unmap_page(dev, addr, size, dir, attrs); > @@ -313,7 +319,7 @@ static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, > int ents; > > BUG_ON(!valid_dma_direction(dir)); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); > else > ents = ops->map_sg(dev, sg, nents, dir, attrs); > @@ -331,7 +337,7 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg > > BUG_ON(!valid_dma_direction(dir)); > debug_dma_unmap_sg(dev, sg, nents, dir); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > dma_direct_unmap_sg(dev, sg, nents, dir, attrs); > else if (ops->unmap_sg) > ops->unmap_sg(dev, sg, nents, dir, attrs); > @@ -352,7 +358,7 @@ static inline dma_addr_t dma_map_resource(struct device *dev, > if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr)))) > return DMA_MAPPING_ERROR; > > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs); > else if (ops->map_resource) > addr = ops->map_resource(dev, phys_addr, size, dir, attrs); > @@ -368,7 +374,7 @@ static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (!dma_is_direct(ops) && ops->unmap_resource) > + if (!dma_map_direct(dev, ops) && ops->unmap_resource) > ops->unmap_resource(dev, addr, size, dir, attrs); > debug_dma_unmap_resource(dev, addr, size, dir); > } > @@ -380,7 +386,7 @@ static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > dma_direct_sync_single_for_cpu(dev, addr, size, dir); > else if (ops->sync_single_for_cpu) > ops->sync_single_for_cpu(dev, addr, size, dir); > @@ -394,7 +400,7 @@ static inline void dma_sync_single_for_device(struct device *dev, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > dma_direct_sync_single_for_device(dev, addr, size, dir); > else if (ops->sync_single_for_device) > ops->sync_single_for_device(dev, addr, size, dir); > @@ -408,7 +414,7 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > dma_direct_sync_sg_for_cpu(dev, sg, nelems, dir); > else if (ops->sync_sg_for_cpu) > ops->sync_sg_for_cpu(dev, sg, nelems, dir); > @@ -422,7 +428,7 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, > const struct dma_map_ops *ops = get_dma_ops(dev); > > BUG_ON(!valid_dma_direction(dir)); > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > dma_direct_sync_sg_for_device(dev, sg, nelems, dir); > else if (ops->sync_sg_for_device) > ops->sync_sg_for_device(dev, sg, nelems, dir); > diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c > index 12ff766ec1fa..fdea45574345 100644 > --- a/kernel/dma/mapping.c > +++ b/kernel/dma/mapping.c > @@ -105,6 +105,24 @@ void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, > } > EXPORT_SYMBOL(dmam_alloc_attrs); > > +static bool dma_alloc_direct(struct device *dev, const struct dma_map_ops *ops) > +{ > + if (!ops) > + return true; > + > + /* > + * Allows IOMMU drivers to bypass dynamic translations if the DMA mask > + * is large enough. > + */ > + if (dev->dma_ops_bypass) { > + if (min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit) >= > + dma_direct_get_required_mask(dev)) > + return true; > + } Why not do this in dma_map_direct() as well? Or simply have just one dma_map_direct()? And one more general question - we need a way to use non-direct IOMMU for RAM above certain limit. Let's say we have a system with: 0 .. 0x1.0000.0000 0x100.0000.0000 .. 0x101.0000.0000 2x4G, each is 1TB aligned. And we can map directly only the first 4GB (because of the maximum IOMMU table size) but not the other. And 1:1 on that "pseries" is done with offset=0x0800.0000.0000.0000. So we want to check every bus address against dev->bus_dma_limit, not dev->coherent_dma_mask. In the example above I'd set bus_dma_limit to 0x0800.0001.0000.0000 and 1:1 mapping for the second 4GB would not be tried. Does this sound reasonable? Thanks, > + > + return false; > +} > + > /* > * Create scatter-list for the already allocated DMA buffer. > */ > @@ -138,7 +156,7 @@ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > - if (dma_is_direct(ops)) > + if (dma_alloc_direct(dev, ops)) > return dma_direct_get_sgtable(dev, sgt, cpu_addr, dma_addr, > size, attrs); > if (!ops->get_sgtable) > @@ -206,7 +224,7 @@ bool dma_can_mmap(struct device *dev) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > - if (dma_is_direct(ops)) > + if (dma_alloc_direct(dev, ops)) > return dma_direct_can_mmap(dev); > return ops->mmap != NULL; > } > @@ -231,7 +249,7 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > - if (dma_is_direct(ops)) > + if (dma_alloc_direct(dev, ops)) > return dma_direct_mmap(dev, vma, cpu_addr, dma_addr, size, > attrs); > if (!ops->mmap) > @@ -244,7 +262,7 @@ u64 dma_get_required_mask(struct device *dev) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > return dma_direct_get_required_mask(dev); > if (ops->get_required_mask) > return ops->get_required_mask(dev); > @@ -275,7 +293,7 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, > /* let the implementation decide on the zone to allocate from: */ > flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM); > > - if (dma_is_direct(ops)) > + if (dma_alloc_direct(dev, ops)) > cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs); > else if (ops->alloc) > cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs); > @@ -307,7 +325,7 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, > return; > > debug_dma_free_coherent(dev, size, cpu_addr, dma_handle); > - if (dma_is_direct(ops)) > + if (dma_alloc_direct(dev, ops)) > dma_direct_free(dev, size, cpu_addr, dma_handle, attrs); > else if (ops->free) > ops->free(dev, size, cpu_addr, dma_handle, attrs); > @@ -318,7 +336,7 @@ int dma_supported(struct device *dev, u64 mask) > { > const struct dma_map_ops *ops = get_dma_ops(dev); > > - if (dma_is_direct(ops)) > + if (!ops) > return dma_direct_supported(dev, mask); > if (!ops->dma_supported) > return 1; > @@ -374,7 +392,7 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, > > BUG_ON(!valid_dma_direction(dir)); > > - if (dma_is_direct(ops)) > + if (dma_alloc_direct(dev, ops)) > arch_dma_cache_sync(dev, vaddr, size, dir); > else if (ops->cache_sync) > ops->cache_sync(dev, vaddr, size, dir); > @@ -386,7 +404,7 @@ size_t dma_max_mapping_size(struct device *dev) > const struct dma_map_ops *ops = get_dma_ops(dev); > size_t size = SIZE_MAX; > > - if (dma_is_direct(ops)) > + if (dma_map_direct(dev, ops)) > size = dma_direct_max_mapping_size(dev); > else if (ops && ops->max_mapping_size) > size = ops->max_mapping_size(dev); > -- Alexey _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu