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=-2.2 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 7FC38C433F4 for ; Fri, 31 Aug 2018 05:50:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1E8D2083A for ; Fri, 31 Aug 2018 05:50:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="dDkJEwzd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F1E8D2083A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727309AbeHaJ4h (ORCPT ); Fri, 31 Aug 2018 05:56:37 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:34686 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727202AbeHaJ4g (ORCPT ); Fri, 31 Aug 2018 05:56:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=q811eMT5lda/oXK2icQo0XxLX74T529LrzCbrH/4PC4=; b=dDkJEwzdqMCj2YUoHyqYPcLhe CrH5EgWmDYAHifrAMbrXE6Kf/AkRhjtC+cHxsZFRsx3QevEjx1ivY662Lr0gPifMpcAnskkeMa1CP 8c63T6spuSxki/WsxARZ9yv4PcTz8zmoY3/0bBoaeTDkI1HX+wW/LxdfmxgVp/PBuczl1Z36XZxrU tMClLt+4JFI9Rw+LBkW1cIlzVQqy4L589CoJO7AaHwBFkWOyQ76soSodF8Fje9/1gWdTZ66QR3UZk 656iE3WvX0heatHJjUceinpRyW8MDVx2CovGPxc5CGKKBwRB/fQGUOH6XO09yaZg3ZKQjuvLlkubk 5C/yQXHIg==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1fvcKV-0004DY-SV; Fri, 31 Aug 2018 05:50:47 +0000 Date: Thu, 30 Aug 2018 22:50:47 -0700 From: Christoph Hellwig To: Ezequiel Garcia Cc: Christoph Hellwig , linux-media@vger.kernel.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Laurent Pinchart , Tomasz Figa , "Matwey V . Kornilov" , Alan Stern , kernel@collabora.com, Keiichi Watanabe Subject: Re: [RFC 2/3] USB: core: Add non-coherent buffer allocation helpers Message-ID: <20180831055047.GA9140@infradead.org> References: <20180830172030.23344-1-ezequiel@collabora.com> <20180830172030.23344-3-ezequiel@collabora.com> <20180830175850.GA11521@infradead.org> <4fc5107f93871599ead017af7ad50f22535a7683.camel@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4fc5107f93871599ead017af7ad50f22535a7683.camel@collabora.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 30, 2018 at 07:11:35PM -0300, Ezequiel Garcia wrote: > On Thu, 2018-08-30 at 10:58 -0700, Christoph Hellwig wrote: > > Please don't introduce new DMA_ATTR_NON_CONSISTENT users, it is > > a rather horrible interface, and I plan to kill it off rather sooner > > than later. I plan to post some patches for a better interface > > that can reuse the normal dma_sync_single_* interfaces for ownership > > transfers. I can happily include usb in that initial patch set based > > on your work here if that helps. > > Please do. Until we have proper allocators that go thru the DMA API, > drivers will have to kmalloc the USB transfer buffers, and have > streaming mappings. Which in turns mean not using IOMMU or CMA. dma_map_page will of course use the iommu. From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [RFC,2/3] USB: core: Add non-coherent buffer allocation helpers From: Christoph Hellwig Message-Id: <20180831055047.GA9140@infradead.org> Date: Thu, 30 Aug 2018 22:50:47 -0700 To: Ezequiel Garcia Cc: Christoph Hellwig , linux-media@vger.kernel.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Laurent Pinchart , Tomasz Figa , "Matwey V . Kornilov" , Alan Stern , kernel@collabora.com, Keiichi Watanabe List-ID: T24gVGh1LCBBdWcgMzAsIDIwMTggYXQgMDc6MTE6MzVQTSAtMDMwMCwgRXplcXVpZWwgR2FyY2lh IHdyb3RlOgo+IE9uIFRodSwgMjAxOC0wOC0zMCBhdCAxMDo1OCAtMDcwMCwgQ2hyaXN0b3BoIEhl bGx3aWcgd3JvdGU6Cj4gPiBQbGVhc2UgZG9uJ3QgaW50cm9kdWNlIG5ldyBETUFfQVRUUl9OT05f Q09OU0lTVEVOVCB1c2VycywgaXQgaXMKPiA+IGEgcmF0aGVyIGhvcnJpYmxlIGludGVyZmFjZSwg YW5kIEkgcGxhbiB0byBraWxsIGl0IG9mZiByYXRoZXIgc29vbmVyCj4gPiB0aGFuIGxhdGVyLiAg SSBwbGFuIHRvIHBvc3Qgc29tZSBwYXRjaGVzIGZvciBhIGJldHRlciBpbnRlcmZhY2UKPiA+IHRo YXQgY2FuIHJldXNlIHRoZSBub3JtYWwgZG1hX3N5bmNfc2luZ2xlXyogaW50ZXJmYWNlcyBmb3Ig b3duZXJzaGlwCj4gPiB0cmFuc2ZlcnMuICBJIGNhbiBoYXBwaWx5IGluY2x1ZGUgdXNiIGluIHRo YXQgaW5pdGlhbCBwYXRjaCBzZXQgYmFzZWQKPiA+IG9uIHlvdXIgd29yayBoZXJlIGlmIHRoYXQg aGVscHMuCj4gCj4gUGxlYXNlIGRvLiBVbnRpbCB3ZSBoYXZlIHByb3BlciBhbGxvY2F0b3JzIHRo YXQgZ28gdGhydSB0aGUgRE1BIEFQSSwKPiBkcml2ZXJzIHdpbGwgaGF2ZSB0byBrbWFsbG9jIHRo ZSBVU0IgdHJhbnNmZXIgYnVmZmVycywgYW5kIGhhdmUKPiBzdHJlYW1pbmcgbWFwcGluZ3MuIFdo aWNoIGluIHR1cm5zIG1lYW4gbm90IHVzaW5nIElPTU1VIG9yIENNQS4KCmRtYV9tYXBfcGFnZSB3 aWxsIG9mIGNvdXJzZSB1c2UgdGhlIGlvbW11Lgo= From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@infradead.org (Christoph Hellwig) Date: Thu, 30 Aug 2018 22:50:47 -0700 Subject: [RFC 2/3] USB: core: Add non-coherent buffer allocation helpers In-Reply-To: <4fc5107f93871599ead017af7ad50f22535a7683.camel@collabora.com> References: <20180830172030.23344-1-ezequiel@collabora.com> <20180830172030.23344-3-ezequiel@collabora.com> <20180830175850.GA11521@infradead.org> <4fc5107f93871599ead017af7ad50f22535a7683.camel@collabora.com> Message-ID: <20180831055047.GA9140@infradead.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Aug 30, 2018 at 07:11:35PM -0300, Ezequiel Garcia wrote: > On Thu, 2018-08-30 at 10:58 -0700, Christoph Hellwig wrote: > > Please don't introduce new DMA_ATTR_NON_CONSISTENT users, it is > > a rather horrible interface, and I plan to kill it off rather sooner > > than later. I plan to post some patches for a better interface > > that can reuse the normal dma_sync_single_* interfaces for ownership > > transfers. I can happily include usb in that initial patch set based > > on your work here if that helps. > > Please do. Until we have proper allocators that go thru the DMA API, > drivers will have to kmalloc the USB transfer buffers, and have > streaming mappings. Which in turns mean not using IOMMU or CMA. dma_map_page will of course use the iommu.