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=-5.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 22D5FC47096 for ; Thu, 3 Jun 2021 10:54:32 +0000 (UTC) Received: from smtp4.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 BC21760FE7 for ; Thu, 3 Jun 2021 10:54:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BC21760FE7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 6B54940564; Thu, 3 Jun 2021 10:54:31 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6bczGN7DSAs8; Thu, 3 Jun 2021 10:54:30 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTP id DB0F140529; Thu, 3 Jun 2021 10:54:29 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id AC63FC000D; Thu, 3 Jun 2021 10:54:29 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 99EA7C0001 for ; Thu, 3 Jun 2021 10:54:28 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 809CE400E7 for ; Thu, 3 Jun 2021 10:54:28 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RB6EBuqSSFkh for ; Thu, 3 Jun 2021 10:54:27 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp2.osuosl.org (Postfix) with ESMTP id 77765400C8 for ; Thu, 3 Jun 2021 10:54:27 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3DB131063; Thu, 3 Jun 2021 03:54:26 -0700 (PDT) Received: from [10.57.73.64] (unknown [10.57.73.64]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EE9B53F774; Thu, 3 Jun 2021 03:54:24 -0700 (PDT) Subject: Re: [Intel-gfx] i915 and swiotlb_max_segment To: Tvrtko Ursulin , Joonas Lahtinen , Christoph Hellwig , Konrad Rzeszutek Wilk , Tvrtko Ursulin References: <20210510152525.GA30093@lst.de> <162270961054.11739.9148402963893484386@jlahtine-mobl.ger.corp.intel.com> From: Robin Murphy Message-ID: <4ac86429-9289-12b5-f4cd-b23ce020bbd6@arm.com> Date: Thu, 3 Jun 2021 11:54:19 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB Cc: intel-gfx@lists.freedesktop.org, iommu@lists.linux-foundation.org, dri-devel@lists.freedesktop.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-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" T24gMjAyMS0wNi0wMyAxMDoxNywgVHZydGtvIFVyc3VsaW4gd3JvdGU6Cj4gCj4gSGksCj4gCj4g T24gMDMvMDYvMjAyMSAwOTo0MCwgSm9vbmFzIExhaHRpbmVuIHdyb3RlOgo+PiArIFR2cnRrbyB0 byB0YWtlIGEgbG9vawo+Pgo+PiBRdW90aW5nIEtvbnJhZCBSemVzenV0ZWsgV2lsayAoMjAyMS0w NS0yMCAxODoxMjo1OCkKPj4+IE9uIE1vbiwgTWF5IDEwLCAyMDIxIGF0IDA1OjI1OjI1UE0gKzAy MDAsIENocmlzdG9waCBIZWxsd2lnIHdyb3RlOgo+Pj4+IEhpIGFsbCwKPj4+Pgo+Pj4+IHN3aW90 bGJfbWF4X3NlZ21lbnQgaXMgYSByYXRoZXIgc3RyYW5nZSAiQVBJIiBleHBvcnQgYnkgc3dpb3Rs Yi5jLAo+Pj4+IGFuZCBpOTE1IGlzIHRoZSBvbmx5IChyZW1haW5pbmcpIHVzZXIuCj4+Pj4KPj4+ PiBzd2lvdGxiX21heF9zZWdtZW50IHJldHVybnMgMCBpZiBzd2lvdGxiIGlzIG5vdCBpbiB1c2Us IDEgaWYKPj4+PiBTV0lPVExCX0ZPUkNFIGlzIHNldCBvciBzd2lvdGxiLXplbiBpcyBzZXQsIGFu ZCB0aGUgc3dpb3RsYiBzZWdtZW50Cj4+Pj4gc2l6ZSB3aGVuIHN3aW90bGIgaXMgb3RoZXJ3aXNl IGVuYWJsZWQuCj4+Pj4KPj4+PiBpOTE1IHRoZW4gdXNlcyBpdCB0bzoKPj4+Pgo+Pj4+IMKgIGEp IGRlY2lkZWQgb24gdGhlIG1heCBvcmRlciBpbiBpOTE1X2dlbV9vYmplY3RfZ2V0X3BhZ2VzX2lu dGVybmFsCj4+Pj4gwqAgYikgZGVjaWRlIG9uIGEgbWF4IHNlZ21lbnQgc2l6ZSBpbiBpOTE1X3Nn X3NlZ21lbnRfc2l6ZQo+Pj4+Cj4+Pj4gZm9yIGEpIGl0IHJlYWxseSBzZWVtcyBpOTE1IHNob3Vs ZCBzd2l0Y2ggdG8gZG1hX2FsbG9jX25vbmNvaGVyZW50Cj4+Pj4gb3IgZG1hX2FsbG9jX25vbmNv bnRpZ291cyBBU0FQIGluc3RlYWQgb2YgdXNpbmcgYWxsb2NfcGFnZSBhbmQKPj4+PiBzdHJlYW1p bmcgRE1BIG1hcHBpbmdzLsKgIEFueSBjaGFuY2UgSSBjb3VsZCB0cmljayBvbmUgb2YgdGhlIGk5 MTUKPj4+PiBtYWludGFpbmVzIGludG8gZG9pbmcganVzdCB0aGF0IGdpdmVuIHRoYXQgdGhlIGNh bGxjaGFpbiBpcyBub3QKPj4+PiBleGFjdGx5IHRyaXZpYWw/Cj4+Pj4KPj4+PiBGb3IgYikgSSdt IG5vdCBzdXJlIHN3aW90bGIgYW5kIGk5MTUgcmVhbGx5IGFncmVlIG9uIHRoZSBtZWFuaW5nCj4+ Pj4gb2YgdGhlIHZhbHVlLsKgIHN3aW90bGJfc2V0X21heF9zZWdtZW50IGJhc2ljYWxseSByZXR1 cm5zIHRoZSBlbnRpcmUKPj4+PiBzaXplIG9mIHRoZSBzd2lvdGxiIGJ1ZmZlciwgd2hpbGUgaTkx NSBzZWVtcyB0byB1c2UgaXQgdG8gbGltaXQKPj4+PiB0aGUgc2l6ZSBlYWNoIHNjYXR0ZXJsaXN0 IGVudHJ5LsKgIEl0IHNlZW1zIGxpa2UgZG1hX21heF9tYXBwaW5nX3NpemUKPj4+PiBtaWdodCBi ZSB0aGUgYmVzdCB2YWx1ZSB0byB1c2UgaGVyZS4KPj4+Cj4+PiBZZXMuIFRoZSBiYWNrZ3JvdW5k IGJlaGluZCB0aGF0IHdhcyBTV0lPVExCIHdvdWxkIGZhaWwgYmVjYXVzZSB3ZWxsLCB0aGUKPj4+ IHNpemUgb2YgdGhlIHNnIHdhcyB0b28gbGFyZ2UuIEFuZCBzb21lIHdheSB0byBsaW1pdCBpdCB0 byBtYXggc2l6ZQo+Pj4gd2FzIG5lZWRlZCAtIHRoZSBkbWFfbWF4X21hcHBpbmdfc2l6ZSAic2hv dWxkIiBiZSBqdXN0IGZpbmUuCj4gCj4gQ2FuJ3Qgc2F5IEkgYW0gMTAwJSBhdCBob21lIGhlcmUg YnV0IHdoYXQgSSByZW1lbWJlciBpcyB0aGF0IHRoZSAKPiBsaW1pdGluZyBmYWN0b3Igd2FzIG1h eGltdW0gc2l6ZSBvZiBhIHNnIHNlZ21lbnQgYW5kIG5vdCB0b3RhbCBzaXplIG9mIAo+IHRoZSBt YXBwaW5nLgo+IAo+IExvb2tpbmcgYXQgdGhlIGNvZGUgdG9kYXksIGlmIHdlIHdvdWxkIHJlcGxh Y2UgdXNhZ2UgCj4gc3dpb3RsYl9tYXhfc2VnbWVudCgpIHdpdGggZG1hX21heF9tYXBwaW5nX3Np emUoKSwgSSBkb24ndCBzZWUgdGhhdCAKPiB3b3VsZCB3b3JrIHdoZW4gd2UgY2FsbCBkbWFfbWFw X3NnX2F0dHJzKCkuCj4gCj4gQmVjYXVzZSBBRkFJQ1QgY29kZSBjYW4gZW5kIHVwIGluIGRtYV9k aXJlY3RfbWF4X21hcHBpbmdfc2l6ZSgpIChub3QgCj4gc3VyZSB3aGVuIHRoZSBvcHMtPm1hcF9z ZyBwYXRoIGlzIGFjdGl2ZSBhbmQgd2hlcmUgdG8gdHJhY2UgdGhhdCkgd2hlcmUgCj4gd2UgaGF2 ZToKPiAKPiBzaXplX3QgZG1hX2RpcmVjdF9tYXhfbWFwcGluZ19zaXplKHN0cnVjdCBkZXZpY2Ug KmRldikKPiB7Cj4gIMKgwqDCoMKgLyogSWYgU1dJT1RMQiBpcyBhY3RpdmUsIHVzZSBpdHMgbWF4 aW11bSBtYXBwaW5nIHNpemUgKi8KPiAgwqDCoMKgwqBpZiAoaXNfc3dpb3RsYl9hY3RpdmUoKSAm Jgo+ICDCoMKgwqDCoMKgwqDCoCAoZG1hX2FkZHJlc3NpbmdfbGltaXRlZChkZXYpIHx8IHN3aW90 bGJfZm9yY2UgPT0gU1dJT1RMQl9GT1JDRSkpCj4gIMKgwqDCoMKgwqDCoMKgIHJldHVybiBzd2lv dGxiX21heF9tYXBwaW5nX3NpemUoZGV2KTsKPiAgwqDCoMKgwqByZXR1cm4gU0laRV9NQVg7Cj4g fQo+IAo+IFNvIGZvciBhbGwgc3dpb3RsYiBjYXNlcywgaW5jbHVkaW5nIGZvcmNlLCB3ZSBnZXQ6 Cj4gCj4gc2l6ZV90IHN3aW90bGJfbWF4X21hcHBpbmdfc2l6ZShzdHJ1Y3QgZGV2aWNlICpkZXYp Cj4gewo+ICDCoMKgwqDCoHJldHVybiAoKHNpemVfdClJT19UTEJfU0laRSkgKiBJT19UTEJfU0VH U0laRTsKPiB9Cj4gCj4gV2hpY2ggaXMgZml4ZWQgYW5kIGRvZXNuJ3QgYWxpZ24gd2l0aCBzd2lv dGxiX21heF9zZWdtZW50KCkuIEJ1dCB5b3UgCj4gZ3V5cyBhcmUgdGhlIGV4cGVydHMgaGVyZSBz byBwbGVhc2UgZmVlbCB0byBjb3JyZWN0IG1lLgoKQnV0IHN3aW90bGJfbWF4X3NlZ21lbnQgaXMg YWxzbyBlZmZlY3RpdmVseSBmaXhlZCBmb3IgYSBnaXZlbiBzeXN0ZW0gCmNvaW5maWdyYXRpb24s IGF0IGVpdGhlciBhIHBhZ2UgKHVuZGVyIGNlcnRhaW4gY2lyY3Vtc3RhbmNlcyksIG9yIGEgCnZh bHVlIGNvbnNpZGVyYWJseSBsYXJnZXIgdGhhbiB3aGF0IHRoZSBsb25nZXN0IG1hcHBhYmxlIFNH IHNlZ21lbnQgCmFjdHVhbGx5IGlzLiBOZWl0aGVyIHNlZW1zIHBhcnRpY3VsYXJseSB1c2VmdWws IGFuZCB0byBiZSBob25lc3QgSSAKc3VzcGVjdCB0aGUgZm9yY2VkLWJvdW5jZSBjYXNlcyBvbmx5 IHNldCBpdCB0byBhIHBhZ2UgYXMgYSBzbGVkZ2VoYW1tZXIgCnRvIG1ha2UgdGhpbmdzIHdvcmsg KmJlY2F1c2UqIHRoZSAibm9ybWFsIiB2YWx1ZSBpcyBub25zZW5zZS4KClJvYmluLgpfX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwppb21tdSBtYWlsaW5nIGxp c3QKaW9tbXVAbGlzdHMubGludXgtZm91bmRhdGlvbi5vcmcKaHR0cHM6Ly9saXN0cy5saW51eGZv dW5kYXRpb24ub3JnL21haWxtYW4vbGlzdGluZm8vaW9tbXU= 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=-5.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 D1EA4C47082 for ; Thu, 3 Jun 2021 10:54:28 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 8E66E60FE7 for ; Thu, 3 Jun 2021 10:54:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E66E60FE7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0215489EAC; Thu, 3 Jun 2021 10:54:28 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 8913589EAC; Thu, 3 Jun 2021 10:54:27 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3DB131063; Thu, 3 Jun 2021 03:54:26 -0700 (PDT) Received: from [10.57.73.64] (unknown [10.57.73.64]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EE9B53F774; Thu, 3 Jun 2021 03:54:24 -0700 (PDT) Subject: Re: [Intel-gfx] i915 and swiotlb_max_segment To: Tvrtko Ursulin , Joonas Lahtinen , Christoph Hellwig , Konrad Rzeszutek Wilk , Tvrtko Ursulin References: <20210510152525.GA30093@lst.de> <162270961054.11739.9148402963893484386@jlahtine-mobl.ger.corp.intel.com> From: Robin Murphy Message-ID: <4ac86429-9289-12b5-f4cd-b23ce020bbd6@arm.com> Date: Thu, 3 Jun 2021 11:54:19 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, iommu@lists.linux-foundation.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 2021-06-03 10:17, Tvrtko Ursulin wrote: > > Hi, > > On 03/06/2021 09:40, Joonas Lahtinen wrote: >> + Tvrtko to take a look >> >> Quoting Konrad Rzeszutek Wilk (2021-05-20 18:12:58) >>> On Mon, May 10, 2021 at 05:25:25PM +0200, Christoph Hellwig wrote: >>>> Hi all, >>>> >>>> swiotlb_max_segment is a rather strange "API" export by swiotlb.c, >>>> and i915 is the only (remaining) user. >>>> >>>> swiotlb_max_segment returns 0 if swiotlb is not in use, 1 if >>>> SWIOTLB_FORCE is set or swiotlb-zen is set, and the swiotlb segment >>>> size when swiotlb is otherwise enabled. >>>> >>>> i915 then uses it to: >>>> >>>>   a) decided on the max order in i915_gem_object_get_pages_internal >>>>   b) decide on a max segment size in i915_sg_segment_size >>>> >>>> for a) it really seems i915 should switch to dma_alloc_noncoherent >>>> or dma_alloc_noncontigous ASAP instead of using alloc_page and >>>> streaming DMA mappings.  Any chance I could trick one of the i915 >>>> maintaines into doing just that given that the callchain is not >>>> exactly trivial? >>>> >>>> For b) I'm not sure swiotlb and i915 really agree on the meaning >>>> of the value.  swiotlb_set_max_segment basically returns the entire >>>> size of the swiotlb buffer, while i915 seems to use it to limit >>>> the size each scatterlist entry.  It seems like dma_max_mapping_size >>>> might be the best value to use here. >>> >>> Yes. The background behind that was SWIOTLB would fail because well, the >>> size of the sg was too large. And some way to limit it to max size >>> was needed - the dma_max_mapping_size "should" be just fine. > > Can't say I am 100% at home here but what I remember is that the > limiting factor was maximum size of a sg segment and not total size of > the mapping. > > Looking at the code today, if we would replace usage > swiotlb_max_segment() with dma_max_mapping_size(), I don't see that > would work when we call dma_map_sg_attrs(). > > Because AFAICT code can end up in dma_direct_max_mapping_size() (not > sure when the ops->map_sg path is active and where to trace that) where > we have: > > size_t dma_direct_max_mapping_size(struct device *dev) > { >     /* If SWIOTLB is active, use its maximum mapping size */ >     if (is_swiotlb_active() && >         (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE)) >         return swiotlb_max_mapping_size(dev); >     return SIZE_MAX; > } > > So for all swiotlb cases, including force, we get: > > size_t swiotlb_max_mapping_size(struct device *dev) > { >     return ((size_t)IO_TLB_SIZE) * IO_TLB_SEGSIZE; > } > > Which is fixed and doesn't align with swiotlb_max_segment(). But you > guys are the experts here so please feel to correct me. But swiotlb_max_segment is also effectively fixed for a given system coinfigration, at either a page (under certain circumstances), or a value considerably larger than what the longest mappable SG segment actually is. Neither seems particularly useful, and to be honest I suspect the forced-bounce cases only set it to a page as a sledgehammer to make things work *because* the "normal" value is nonsense. Robin. 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=-5.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 630EAC47096 for ; Thu, 3 Jun 2021 13:32:37 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 1E14A613DE for ; Thu, 3 Jun 2021 13:32:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E14A613DE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F2ED36E17D; Thu, 3 Jun 2021 13:32:33 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 8913589EAC; Thu, 3 Jun 2021 10:54:27 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3DB131063; Thu, 3 Jun 2021 03:54:26 -0700 (PDT) Received: from [10.57.73.64] (unknown [10.57.73.64]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EE9B53F774; Thu, 3 Jun 2021 03:54:24 -0700 (PDT) To: Tvrtko Ursulin , Joonas Lahtinen , Christoph Hellwig , Konrad Rzeszutek Wilk , Tvrtko Ursulin References: <20210510152525.GA30093@lst.de> <162270961054.11739.9148402963893484386@jlahtine-mobl.ger.corp.intel.com> From: Robin Murphy Message-ID: <4ac86429-9289-12b5-f4cd-b23ce020bbd6@arm.com> Date: Thu, 3 Jun 2021 11:54:19 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB X-Mailman-Approved-At: Thu, 03 Jun 2021 13:32:32 +0000 Subject: Re: [Intel-gfx] i915 and swiotlb_max_segment X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, iommu@lists.linux-foundation.org, dri-devel@lists.freedesktop.org Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" T24gMjAyMS0wNi0wMyAxMDoxNywgVHZydGtvIFVyc3VsaW4gd3JvdGU6Cj4gCj4gSGksCj4gCj4g T24gMDMvMDYvMjAyMSAwOTo0MCwgSm9vbmFzIExhaHRpbmVuIHdyb3RlOgo+PiArIFR2cnRrbyB0 byB0YWtlIGEgbG9vawo+Pgo+PiBRdW90aW5nIEtvbnJhZCBSemVzenV0ZWsgV2lsayAoMjAyMS0w NS0yMCAxODoxMjo1OCkKPj4+IE9uIE1vbiwgTWF5IDEwLCAyMDIxIGF0IDA1OjI1OjI1UE0gKzAy MDAsIENocmlzdG9waCBIZWxsd2lnIHdyb3RlOgo+Pj4+IEhpIGFsbCwKPj4+Pgo+Pj4+IHN3aW90 bGJfbWF4X3NlZ21lbnQgaXMgYSByYXRoZXIgc3RyYW5nZSAiQVBJIiBleHBvcnQgYnkgc3dpb3Rs Yi5jLAo+Pj4+IGFuZCBpOTE1IGlzIHRoZSBvbmx5IChyZW1haW5pbmcpIHVzZXIuCj4+Pj4KPj4+ PiBzd2lvdGxiX21heF9zZWdtZW50IHJldHVybnMgMCBpZiBzd2lvdGxiIGlzIG5vdCBpbiB1c2Us IDEgaWYKPj4+PiBTV0lPVExCX0ZPUkNFIGlzIHNldCBvciBzd2lvdGxiLXplbiBpcyBzZXQsIGFu ZCB0aGUgc3dpb3RsYiBzZWdtZW50Cj4+Pj4gc2l6ZSB3aGVuIHN3aW90bGIgaXMgb3RoZXJ3aXNl IGVuYWJsZWQuCj4+Pj4KPj4+PiBpOTE1IHRoZW4gdXNlcyBpdCB0bzoKPj4+Pgo+Pj4+IMKgIGEp IGRlY2lkZWQgb24gdGhlIG1heCBvcmRlciBpbiBpOTE1X2dlbV9vYmplY3RfZ2V0X3BhZ2VzX2lu dGVybmFsCj4+Pj4gwqAgYikgZGVjaWRlIG9uIGEgbWF4IHNlZ21lbnQgc2l6ZSBpbiBpOTE1X3Nn X3NlZ21lbnRfc2l6ZQo+Pj4+Cj4+Pj4gZm9yIGEpIGl0IHJlYWxseSBzZWVtcyBpOTE1IHNob3Vs ZCBzd2l0Y2ggdG8gZG1hX2FsbG9jX25vbmNvaGVyZW50Cj4+Pj4gb3IgZG1hX2FsbG9jX25vbmNv bnRpZ291cyBBU0FQIGluc3RlYWQgb2YgdXNpbmcgYWxsb2NfcGFnZSBhbmQKPj4+PiBzdHJlYW1p bmcgRE1BIG1hcHBpbmdzLsKgIEFueSBjaGFuY2UgSSBjb3VsZCB0cmljayBvbmUgb2YgdGhlIGk5 MTUKPj4+PiBtYWludGFpbmVzIGludG8gZG9pbmcganVzdCB0aGF0IGdpdmVuIHRoYXQgdGhlIGNh bGxjaGFpbiBpcyBub3QKPj4+PiBleGFjdGx5IHRyaXZpYWw/Cj4+Pj4KPj4+PiBGb3IgYikgSSdt IG5vdCBzdXJlIHN3aW90bGIgYW5kIGk5MTUgcmVhbGx5IGFncmVlIG9uIHRoZSBtZWFuaW5nCj4+ Pj4gb2YgdGhlIHZhbHVlLsKgIHN3aW90bGJfc2V0X21heF9zZWdtZW50IGJhc2ljYWxseSByZXR1 cm5zIHRoZSBlbnRpcmUKPj4+PiBzaXplIG9mIHRoZSBzd2lvdGxiIGJ1ZmZlciwgd2hpbGUgaTkx NSBzZWVtcyB0byB1c2UgaXQgdG8gbGltaXQKPj4+PiB0aGUgc2l6ZSBlYWNoIHNjYXR0ZXJsaXN0 IGVudHJ5LsKgIEl0IHNlZW1zIGxpa2UgZG1hX21heF9tYXBwaW5nX3NpemUKPj4+PiBtaWdodCBi ZSB0aGUgYmVzdCB2YWx1ZSB0byB1c2UgaGVyZS4KPj4+Cj4+PiBZZXMuIFRoZSBiYWNrZ3JvdW5k IGJlaGluZCB0aGF0IHdhcyBTV0lPVExCIHdvdWxkIGZhaWwgYmVjYXVzZSB3ZWxsLCB0aGUKPj4+ IHNpemUgb2YgdGhlIHNnIHdhcyB0b28gbGFyZ2UuIEFuZCBzb21lIHdheSB0byBsaW1pdCBpdCB0 byBtYXggc2l6ZQo+Pj4gd2FzIG5lZWRlZCAtIHRoZSBkbWFfbWF4X21hcHBpbmdfc2l6ZSAic2hv dWxkIiBiZSBqdXN0IGZpbmUuCj4gCj4gQ2FuJ3Qgc2F5IEkgYW0gMTAwJSBhdCBob21lIGhlcmUg YnV0IHdoYXQgSSByZW1lbWJlciBpcyB0aGF0IHRoZSAKPiBsaW1pdGluZyBmYWN0b3Igd2FzIG1h eGltdW0gc2l6ZSBvZiBhIHNnIHNlZ21lbnQgYW5kIG5vdCB0b3RhbCBzaXplIG9mIAo+IHRoZSBt YXBwaW5nLgo+IAo+IExvb2tpbmcgYXQgdGhlIGNvZGUgdG9kYXksIGlmIHdlIHdvdWxkIHJlcGxh Y2UgdXNhZ2UgCj4gc3dpb3RsYl9tYXhfc2VnbWVudCgpIHdpdGggZG1hX21heF9tYXBwaW5nX3Np emUoKSwgSSBkb24ndCBzZWUgdGhhdCAKPiB3b3VsZCB3b3JrIHdoZW4gd2UgY2FsbCBkbWFfbWFw X3NnX2F0dHJzKCkuCj4gCj4gQmVjYXVzZSBBRkFJQ1QgY29kZSBjYW4gZW5kIHVwIGluIGRtYV9k aXJlY3RfbWF4X21hcHBpbmdfc2l6ZSgpIChub3QgCj4gc3VyZSB3aGVuIHRoZSBvcHMtPm1hcF9z ZyBwYXRoIGlzIGFjdGl2ZSBhbmQgd2hlcmUgdG8gdHJhY2UgdGhhdCkgd2hlcmUgCj4gd2UgaGF2 ZToKPiAKPiBzaXplX3QgZG1hX2RpcmVjdF9tYXhfbWFwcGluZ19zaXplKHN0cnVjdCBkZXZpY2Ug KmRldikKPiB7Cj4gIMKgwqDCoMKgLyogSWYgU1dJT1RMQiBpcyBhY3RpdmUsIHVzZSBpdHMgbWF4 aW11bSBtYXBwaW5nIHNpemUgKi8KPiAgwqDCoMKgwqBpZiAoaXNfc3dpb3RsYl9hY3RpdmUoKSAm Jgo+ICDCoMKgwqDCoMKgwqDCoCAoZG1hX2FkZHJlc3NpbmdfbGltaXRlZChkZXYpIHx8IHN3aW90 bGJfZm9yY2UgPT0gU1dJT1RMQl9GT1JDRSkpCj4gIMKgwqDCoMKgwqDCoMKgIHJldHVybiBzd2lv dGxiX21heF9tYXBwaW5nX3NpemUoZGV2KTsKPiAgwqDCoMKgwqByZXR1cm4gU0laRV9NQVg7Cj4g fQo+IAo+IFNvIGZvciBhbGwgc3dpb3RsYiBjYXNlcywgaW5jbHVkaW5nIGZvcmNlLCB3ZSBnZXQ6 Cj4gCj4gc2l6ZV90IHN3aW90bGJfbWF4X21hcHBpbmdfc2l6ZShzdHJ1Y3QgZGV2aWNlICpkZXYp Cj4gewo+ICDCoMKgwqDCoHJldHVybiAoKHNpemVfdClJT19UTEJfU0laRSkgKiBJT19UTEJfU0VH U0laRTsKPiB9Cj4gCj4gV2hpY2ggaXMgZml4ZWQgYW5kIGRvZXNuJ3QgYWxpZ24gd2l0aCBzd2lv dGxiX21heF9zZWdtZW50KCkuIEJ1dCB5b3UgCj4gZ3V5cyBhcmUgdGhlIGV4cGVydHMgaGVyZSBz byBwbGVhc2UgZmVlbCB0byBjb3JyZWN0IG1lLgoKQnV0IHN3aW90bGJfbWF4X3NlZ21lbnQgaXMg YWxzbyBlZmZlY3RpdmVseSBmaXhlZCBmb3IgYSBnaXZlbiBzeXN0ZW0gCmNvaW5maWdyYXRpb24s IGF0IGVpdGhlciBhIHBhZ2UgKHVuZGVyIGNlcnRhaW4gY2lyY3Vtc3RhbmNlcyksIG9yIGEgCnZh bHVlIGNvbnNpZGVyYWJseSBsYXJnZXIgdGhhbiB3aGF0IHRoZSBsb25nZXN0IG1hcHBhYmxlIFNH IHNlZ21lbnQgCmFjdHVhbGx5IGlzLiBOZWl0aGVyIHNlZW1zIHBhcnRpY3VsYXJseSB1c2VmdWws IGFuZCB0byBiZSBob25lc3QgSSAKc3VzcGVjdCB0aGUgZm9yY2VkLWJvdW5jZSBjYXNlcyBvbmx5 IHNldCBpdCB0byBhIHBhZ2UgYXMgYSBzbGVkZ2VoYW1tZXIgCnRvIG1ha2UgdGhpbmdzIHdvcmsg KmJlY2F1c2UqIHRoZSAibm9ybWFsIiB2YWx1ZSBpcyBub25zZW5zZS4KClJvYmluLgpfX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpJbnRlbC1nZnggbWFpbGlu ZyBsaXN0CkludGVsLWdmeEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVl ZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9pbnRlbC1nZngK