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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 0D339C433E0 for ; Mon, 1 Feb 2021 16:37:35 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 A457460235 for ; Mon, 1 Feb 2021 16:37:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A457460235 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 7C1F2858AF; Mon, 1 Feb 2021 16:37:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id y-DOOOHGjegK; Mon, 1 Feb 2021 16:37:33 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 8B8188527F; Mon, 1 Feb 2021 16:37:33 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 800BFC0174; Mon, 1 Feb 2021 16:37:33 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id B79ADC013A for ; Mon, 1 Feb 2021 16:37:32 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id A6A958499A for ; Mon, 1 Feb 2021 16:37:32 +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 l7FfoV3mLcEr for ; Mon, 1 Feb 2021 16:37:31 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 5297584948 for ; Mon, 1 Feb 2021 16:37:31 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id C42486736F; Mon, 1 Feb 2021 17:37:26 +0100 (CET) Date: Mon, 1 Feb 2021 17:37:26 +0100 From: Christoph Hellwig To: Ricardo Ribalda Subject: Re: [PATCH 6/6] media: uvcvideo: Use dma_alloc_noncontiguos API Message-ID: <20210201163726.GA8279@lst.de> References: <20210128145837.2250561-1-hch@lst.de> <20210128145837.2250561-7-hch@lst.de> <20210128150955.GA30563@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Sergey Senozhatsky , Linux Doc Mailing List , Linux Kernel Mailing List , Linux Media Mailing List , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Mauro Carvalho Chehab , Robin Murphy , Christoph Hellwig 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 Thu, Jan 28, 2021 at 06:00:57PM +0100, Ricardo Ribalda wrote: > > Given that we vmap the addresses this also needs > > flush_kernel_vmap_range / invalidate_kernel_vmap_range calls for > > VIVT architectures. > > We only read from the device to the cpu. Then can we run only > invalidate_kernel_vmap_range() ? > > something like ? > else { > dma_sync_sgtable_for_cpu(dma_dev, uvc_urb->sgt, DMA_FROM_DEVICE); > invalidate_kernel_vmap_range(uvc_urb->buffer, > uvc_urb->stream->urb_size ); > } Yes. Right now we don't have a proper state machine for the *_kernel_vmap_range, but we should probably add one once usage of this grows. Until then I need to respin my API patch to document how callers need to use *_kernel_vmap_range, as well as adding the so far missing dma-debug support. As we're getting toward the end of the merge window I'll try to get this done ASAP. How should we plan to merge this code? Do you have a tree you'd like to pick up the whole thing for? Or should I create a dma-mapping tree branch that can be pulled in? _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu