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, 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 DC537C43461 for ; Fri, 11 Sep 2020 07:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A413A221EF for ; Fri, 11 Sep 2020 07:09:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725648AbgIKHJz (ORCPT ); Fri, 11 Sep 2020 03:09:55 -0400 Received: from verein.lst.de ([213.95.11.211]:35756 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725468AbgIKHJy (ORCPT ); Fri, 11 Sep 2020 03:09:54 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id DFED868B02; Fri, 11 Sep 2020 09:09:50 +0200 (CEST) Date: Fri, 11 Sep 2020 09:09:50 +0200 From: Christoph Hellwig To: Robin Murphy Cc: Christoph Hellwig , Tony Luck , Fenghua Yu , Thomas Bogendoerfer , iommu@lists.linux-foundation.org, Tomasz Figa , Joerg Roedel , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org Subject: Re: [PATCH 04/12] dma-mapping: fix DMA_OPS dependencies Message-ID: <20200911070950.GB22394@lst.de> References: <20200908164758.3177341-1-hch@lst.de> <20200908164758.3177341-5-hch@lst.de> <1e3c7094-62da-6e8c-0a41-0bc63dd3db68@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1e3c7094-62da-6e8c-0a41-0bc63dd3db68@arm.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Thu, Sep 10, 2020 at 01:55:37PM +0100, Robin Murphy wrote: > AFAICS all three of these bus drivers are only proxying a struct > dma_map_ops * pointer around, so if they used the set_dma_ops() helper they > shouldn't even need these selects at all. Only INTEL_MIC_HOST appears to > have a logical dependency on DMA_OPS for actual functionality. > > However, I have a vague feeling you might not be fond of those dma_ops > helpers, and I have no great objection to this one-liner as-is, so (modulo > the couple of commit message typos), The problem with these inherÑ–tances is that they don't actually work for the general case. You'd also need to inherity things like the dma ranges, the bus limits, etc, etc. So we need to kill them instead. That whole mic/vop case is even worse than that with it's weird set of chained dma ops that seems to implement some kind of device side iommu that isn't in scope for the DMA API at all. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Fri, 11 Sep 2020 07:09:50 +0000 Subject: Re: [PATCH 04/12] dma-mapping: fix DMA_OPS dependencies Message-Id: <20200911070950.GB22394@lst.de> List-Id: References: <20200908164758.3177341-1-hch@lst.de> <20200908164758.3177341-5-hch@lst.de> <1e3c7094-62da-6e8c-0a41-0bc63dd3db68@arm.com> In-Reply-To: <1e3c7094-62da-6e8c-0a41-0bc63dd3db68@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="macroman" Content-Transfer-Encoding: base64 To: Robin Murphy Cc: Christoph Hellwig , Tony Luck , Fenghua Yu , Thomas Bogendoerfer , iommu@lists.linux-foundation.org, Tomasz Figa , Joerg Roedel , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org T24gVGh1LCBTZXAgMTAsIDIwMjAgYXQgMDE6NTU6MzdQTSArMDEwMCwgUm9iaW4gTXVycGh5IHdy b3RlOgo+IEFGQUlDUyBhbGwgdGhyZWUgb2YgdGhlc2UgYnVzIGRyaXZlcnMgYXJlIG9ubHkgcHJv eHlpbmcgYSBzdHJ1Y3QgCj4gZG1hX21hcF9vcHMgKiBwb2ludGVyIGFyb3VuZCwgc28gaWYgdGhl eSB1c2VkIHRoZSBzZXRfZG1hX29wcygpIGhlbHBlciB0aGV5IAo+IHNob3VsZG4ndCBldmVuIG5l ZWQgdGhlc2Ugc2VsZWN0cyBhdCBhbGwuIE9ubHkgSU5URUxfTUlDX0hPU1QgYXBwZWFycyB0byAK PiBoYXZlIGEgbG9naWNhbCBkZXBlbmRlbmN5IG9uIERNQV9PUFMgZm9yIGFjdHVhbCBmdW5jdGlv bmFsaXR5Lgo+Cj4gSG93ZXZlciwgSSBoYXZlIGEgdmFndWUgZmVlbGluZyB5b3UgbWlnaHQgbm90 IGJlIGZvbmQgb2YgdGhvc2UgZG1hX29wcyAKPiBoZWxwZXJzLCBhbmQgSSBoYXZlIG5vIGdyZWF0 IG9iamVjdGlvbiB0byB0aGlzIG9uZS1saW5lciBhcy1pcywgc28gKG1vZHVsbyAKPiB0aGUgY291 cGxlIG9mIGNvbW1pdCBtZXNzYWdlIHR5cG9zKSwKClRoZSBwcm9ibGVtIHdpdGggdGhlc2UgaW5o ZXLRlnRhbmNlcyBpcyB0aGF0IHRoZXkgZG9uJ3QgYWN0dWFsbHkgd29yawpmb3IgdGhlIGdlbmVy YWwgY2FzZS4gIFlvdSdkIGFsc28gbmVlZCB0byBpbmhlcml0eSB0aGluZ3MgbGlrZSB0aGUKZG1h IHJhbmdlcywgdGhlIGJ1cyBsaW1pdHMsIGV0YywgZXRjLiAgU28gd2UgbmVlZCB0byBraWxsIHRo ZW0gaW5zdGVhZC4KVGhhdCB3aG9sZSBtaWMvdm9wIGNhc2UgaXMgZXZlbiB3b3JzZSB0aGFuIHRo YXQgd2l0aCBpdCdzIHdlaXJkIHNldApvZiBjaGFpbmVkIGRtYSBvcHMgdGhhdCBzZWVtcyB0byBp bXBsZW1lbnQgc29tZSBraW5kIG9mIGRldmljZSBzaWRlCmlvbW11IHRoYXQgaXNuJ3QgaW4gc2Nv cGUgZm9yIHRoZSBETUEgQVBJIGF0IGFsbC4= 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 BC4AEC43461 for ; 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Fri, 11 Sep 2020 09:09:50 +0200 (CEST) Date: Fri, 11 Sep 2020 09:09:50 +0200 From: Christoph Hellwig To: Robin Murphy Subject: Re: [PATCH 04/12] dma-mapping: fix DMA_OPS dependencies Message-ID: <20200911070950.GB22394@lst.de> References: <20200908164758.3177341-1-hch@lst.de> <20200908164758.3177341-5-hch@lst.de> <1e3c7094-62da-6e8c-0a41-0bc63dd3db68@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1e3c7094-62da-6e8c-0a41-0bc63dd3db68@arm.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Fenghua Yu , Tony Luck , linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, 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="utf-8" Content-Transfer-Encoding: base64 Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" T24gVGh1LCBTZXAgMTAsIDIwMjAgYXQgMDE6NTU6MzdQTSArMDEwMCwgUm9iaW4gTXVycGh5IHdy b3RlOgo+IEFGQUlDUyBhbGwgdGhyZWUgb2YgdGhlc2UgYnVzIGRyaXZlcnMgYXJlIG9ubHkgcHJv eHlpbmcgYSBzdHJ1Y3QgCj4gZG1hX21hcF9vcHMgKiBwb2ludGVyIGFyb3VuZCwgc28gaWYgdGhl eSB1c2VkIHRoZSBzZXRfZG1hX29wcygpIGhlbHBlciB0aGV5IAo+IHNob3VsZG4ndCBldmVuIG5l ZWQgdGhlc2Ugc2VsZWN0cyBhdCBhbGwuIE9ubHkgSU5URUxfTUlDX0hPU1QgYXBwZWFycyB0byAK PiBoYXZlIGEgbG9naWNhbCBkZXBlbmRlbmN5IG9uIERNQV9PUFMgZm9yIGFjdHVhbCBmdW5jdGlv bmFsaXR5Lgo+Cj4gSG93ZXZlciwgSSBoYXZlIGEgdmFndWUgZmVlbGluZyB5b3UgbWlnaHQgbm90 IGJlIGZvbmQgb2YgdGhvc2UgZG1hX29wcyAKPiBoZWxwZXJzLCBhbmQgSSBoYXZlIG5vIGdyZWF0 IG9iamVjdGlvbiB0byB0aGlzIG9uZS1saW5lciBhcy1pcywgc28gKG1vZHVsbyAKPiB0aGUgY291 cGxlIG9mIGNvbW1pdCBtZXNzYWdlIHR5cG9zKSwKClRoZSBwcm9ibGVtIHdpdGggdGhlc2UgaW5o ZXLRlnRhbmNlcyBpcyB0aGF0IHRoZXkgZG9uJ3QgYWN0dWFsbHkgd29yawpmb3IgdGhlIGdlbmVy YWwgY2FzZS4gIFlvdSdkIGFsc28gbmVlZCB0byBpbmhlcml0eSB0aGluZ3MgbGlrZSB0aGUKZG1h IHJhbmdlcywgdGhlIGJ1cyBsaW1pdHMsIGV0YywgZXRjLiAgU28gd2UgbmVlZCB0byBraWxsIHRo ZW0gaW5zdGVhZC4KVGhhdCB3aG9sZSBtaWMvdm9wIGNhc2UgaXMgZXZlbiB3b3JzZSB0aGFuIHRo YXQgd2l0aCBpdCdzIHdlaXJkIHNldApvZiBjaGFpbmVkIGRtYSBvcHMgdGhhdCBzZWVtcyB0byBp bXBsZW1lbnQgc29tZSBraW5kIG9mIGRldmljZSBzaWRlCmlvbW11IHRoYXQgaXNuJ3QgaW4gc2Nv cGUgZm9yIHRoZSBETUEgQVBJIGF0IGFsbC4KX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX18KaW9tbXUgbWFpbGluZyBsaXN0CmlvbW11QGxpc3RzLmxpbnV4LWZv dW5kYXRpb24ub3JnCmh0dHBzOi8vbGlzdHMubGludXhmb3VuZGF0aW9uLm9yZy9tYWlsbWFuL2xp c3RpbmZvL2lvbW11