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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 BE2C1C7618B for ; Thu, 25 Jul 2019 14:52:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9318121734 for ; Thu, 25 Jul 2019 14:52:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="Z5lSewpC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388497AbfGYOw2 (ORCPT ); Thu, 25 Jul 2019 10:52:28 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:35766 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387646AbfGYOw2 (ORCPT ); Thu, 25 Jul 2019 10:52:28 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x6PEpwLH089026; Thu, 25 Jul 2019 09:51:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1564066318; bh=6eVBtz7pC5rPsO60ddc64kp9iSy+XJZAc+HuTFyJ08s=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=Z5lSewpCrBq60eVRn9ewoGY9sYcen7BfsGC5Ryho9b2zDeuf6W4TBq4LtUXOClE7A 2oZ8CbyMXq+O9xHqPrGY9XK0VwlRgc3O8IvVZyPvOEUpCVodA9wMfpkYqkM/dhpr+2 kRdTvW4xMnTvzmLV1QF/PUFQ+0el5ryqp5Nfs74Q= Received: from DFLE100.ent.ti.com (dfle100.ent.ti.com [10.64.6.21]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x6PEpwex070194 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 25 Jul 2019 09:51:58 -0500 Received: from DFLE114.ent.ti.com (10.64.6.35) by DFLE100.ent.ti.com (10.64.6.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Thu, 25 Jul 2019 09:51:58 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Thu, 25 Jul 2019 09:51:58 -0500 Received: from [10.250.86.29] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x6PEpucs096397; Thu, 25 Jul 2019 09:51:57 -0500 Subject: Re: [PATCH v6 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps To: Christoph Hellwig CC: John Stultz , lkml , Laura Abbott , Benjamin Gaignard , Sumit Semwal , Liam Mark , Pratik Patel , Brian Starkey , Vincent Donnefort , Sudipto Paul , Xu YiPing , "Chenfeng (puck)" , butao , "Xiaqing (A)" , Yudongbin , Chenbo Feng , Alistair Strachan , dri-devel References: <20190718100840.GB19666@infradead.org> <20190724065958.GC16225@infradead.org> <8e6f8e4f-20fc-1f1f-2228-f4fd7c7c5c1f@ti.com> <20190725125014.GD20286@infradead.org> <0eae0024-1fdf-bd06-a8ff-1a41f0af3c69@ti.com> <20190725140448.GA25010@infradead.org> <8e2ec315-5d18-68b2-8cb5-2bfb8a116d1b@ti.com> <20190725141144.GA14609@infradead.org> <20190725143040.GA21894@infradead.org> From: "Andrew F. Davis" Message-ID: Date: Thu, 25 Jul 2019 10:51:56 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190725143040.GA21894@infradead.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/25/19 10:30 AM, Christoph Hellwig wrote: > On Thu, Jul 25, 2019 at 10:25:50AM -0400, Andrew F. Davis wrote: >> On 7/25/19 10:11 AM, Christoph Hellwig wrote: >>> On Thu, Jul 25, 2019 at 10:10:08AM -0400, Andrew F. Davis wrote: >>>> Pages yes, but not "normal" pages from the kernel managed area. >>>> page_to_pfn() will return bad values on the pages returned by this >>>> allocator and so will any of the kernel sync/map functions. Therefor >>>> those operations cannot be common and need special per-heap handling. >>> >>> Well, that means this thing is buggy and abuses the scatterlist API >>> and we can't merge it anyway, so it is irrelevant. >>> >> >> Since when do scatterlists need to only have kernel virtual backed >> memory pages? Device memory is stored in scatterlists and >> dma_sync_sg_for_* would fail just the same when the cache ops were >> attempted. > > I'm not sure what you mean with virtual backed memory pages, as we > don't really have that concept. > > But a page in the scatterlist needs to be able to be used everywhere > we'd normally use a page, e.g. page_to_phys, page_to_pfn, kmap, > page_address (if !highmem) as consumers including the dma mapping > interface do all that. > > If you want to dma map memory that does not have page backing you > need to use dma_map_resource. > I probably should have worded that better. It does have page backing, what I meant by "page_to_pfn() will return bad values" is not that it won't give you the correct pfn, it will, but that then that pfn is not part of the normal memory space (lowmem/highmem) it's device memory, so cache ops won't work. But you should not be doing that on device memory anyway. That is a problem with Ion I want to avoid, it assumed all buffers were in DDR and so would do cache operations on them unconditionally, too many assumptions were made as too much was moved into the common core code and not enough was left for the heaps themselves to decide. From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Andrew F. Davis" Subject: Re: [PATCH v6 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps Date: Thu, 25 Jul 2019 10:51:56 -0400 Message-ID: References: <20190718100840.GB19666@infradead.org> <20190724065958.GC16225@infradead.org> <8e6f8e4f-20fc-1f1f-2228-f4fd7c7c5c1f@ti.com> <20190725125014.GD20286@infradead.org> <0eae0024-1fdf-bd06-a8ff-1a41f0af3c69@ti.com> <20190725140448.GA25010@infradead.org> <8e2ec315-5d18-68b2-8cb5-2bfb8a116d1b@ti.com> <20190725141144.GA14609@infradead.org> <20190725143040.GA21894@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from lelv0143.ext.ti.com (lelv0143.ext.ti.com [198.47.23.248]) by gabe.freedesktop.org (Postfix) with ESMTPS id 203F26E768 for ; Thu, 25 Jul 2019 14:52:23 +0000 (UTC) In-Reply-To: <20190725143040.GA21894@infradead.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Christoph Hellwig Cc: Yudongbin , Sudipto Paul , Xu YiPing , Alistair Strachan , Vincent Donnefort , "Chenfeng (puck)" , dri-devel , Chenbo Feng , lkml , Liam Mark , "Xiaqing (A)" , Pratik Patel , butao List-Id: dri-devel@lists.freedesktop.org T24gNy8yNS8xOSAxMDozMCBBTSwgQ2hyaXN0b3BoIEhlbGx3aWcgd3JvdGU6Cj4gT24gVGh1LCBK dWwgMjUsIDIwMTkgYXQgMTA6MjU6NTBBTSAtMDQwMCwgQW5kcmV3IEYuIERhdmlzIHdyb3RlOgo+ PiBPbiA3LzI1LzE5IDEwOjExIEFNLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90ZToKPj4+IE9uIFRo dSwgSnVsIDI1LCAyMDE5IGF0IDEwOjEwOjA4QU0gLTA0MDAsIEFuZHJldyBGLiBEYXZpcyB3cm90 ZToKPj4+PiBQYWdlcyB5ZXMsIGJ1dCBub3QgIm5vcm1hbCIgcGFnZXMgZnJvbSB0aGUga2VybmVs IG1hbmFnZWQgYXJlYS4KPj4+PiBwYWdlX3RvX3BmbigpIHdpbGwgcmV0dXJuIGJhZCB2YWx1ZXMg b24gdGhlIHBhZ2VzIHJldHVybmVkIGJ5IHRoaXMKPj4+PiBhbGxvY2F0b3IgYW5kIHNvIHdpbGwg YW55IG9mIHRoZSBrZXJuZWwgc3luYy9tYXAgZnVuY3Rpb25zLiBUaGVyZWZvcgo+Pj4+IHRob3Nl IG9wZXJhdGlvbnMgY2Fubm90IGJlIGNvbW1vbiBhbmQgbmVlZCBzcGVjaWFsIHBlci1oZWFwIGhh bmRsaW5nLgo+Pj4KPj4+IFdlbGwsIHRoYXQgbWVhbnMgdGhpcyB0aGluZyBpcyBidWdneSBhbmQg YWJ1c2VzIHRoZSBzY2F0dGVybGlzdCBBUEkKPj4+IGFuZCB3ZSBjYW4ndCBtZXJnZSBpdCBhbnl3 YXksIHNvIGl0IGlzIGlycmVsZXZhbnQuCj4+Pgo+Pgo+PiBTaW5jZSB3aGVuIGRvIHNjYXR0ZXJs aXN0cyBuZWVkIHRvIG9ubHkgaGF2ZSBrZXJuZWwgdmlydHVhbCBiYWNrZWQKPj4gbWVtb3J5IHBh Z2VzPyBEZXZpY2UgbWVtb3J5IGlzIHN0b3JlZCBpbiBzY2F0dGVybGlzdHMgYW5kCj4+IGRtYV9z eW5jX3NnX2Zvcl8qIHdvdWxkIGZhaWwganVzdCB0aGUgc2FtZSB3aGVuIHRoZSBjYWNoZSBvcHMg d2VyZQo+PiBhdHRlbXB0ZWQuCj4gCj4gSSdtIG5vdCBzdXJlIHdoYXQgeW91IG1lYW4gd2l0aCB2 aXJ0dWFsIGJhY2tlZCBtZW1vcnkgcGFnZXMsIGFzIHdlCj4gZG9uJ3QgcmVhbGx5IGhhdmUgdGhh dCBjb25jZXB0Lgo+IAo+IEJ1dCBhIHBhZ2UgaW4gdGhlIHNjYXR0ZXJsaXN0IG5lZWRzIHRvIGJl IGFibGUgdG8gYmUgdXNlZCBldmVyeXdoZXJlCj4gd2UnZCBub3JtYWxseSB1c2UgYSBwYWdlLCBl LmcuIHBhZ2VfdG9fcGh5cywgcGFnZV90b19wZm4sIGttYXAsCj4gcGFnZV9hZGRyZXNzIChpZiAh aGlnaG1lbSkgYXMgY29uc3VtZXJzIGluY2x1ZGluZyB0aGUgZG1hIG1hcHBpbmcKPiBpbnRlcmZh Y2UgZG8gYWxsIHRoYXQuCj4gCj4gSWYgeW91IHdhbnQgdG8gZG1hIG1hcCBtZW1vcnkgdGhhdCBk b2VzIG5vdCBoYXZlIHBhZ2UgYmFja2luZyB5b3UKPiBuZWVkIHRvIHVzZSBkbWFfbWFwX3Jlc291 cmNlLgo+IAoKSSBwcm9iYWJseSBzaG91bGQgaGF2ZSB3b3JkZWQgdGhhdCBiZXR0ZXIuCgpJdCBk b2VzIGhhdmUgcGFnZSBiYWNraW5nLCB3aGF0IEkgbWVhbnQgYnkgInBhZ2VfdG9fcGZuKCkgd2ls bCByZXR1cm4KYmFkIHZhbHVlcyIgaXMgbm90IHRoYXQgaXQgd29uJ3QgZ2l2ZSB5b3UgdGhlIGNv cnJlY3QgcGZuLCBpdCB3aWxsLCBidXQKdGhhdCB0aGVuIHRoYXQgcGZuIGlzIG5vdCBwYXJ0IG9m IHRoZSBub3JtYWwgbWVtb3J5IHNwYWNlCihsb3dtZW0vaGlnaG1lbSkgaXQncyBkZXZpY2UgbWVt b3J5LCBzbyBjYWNoZSBvcHMgd29uJ3Qgd29yay4gQnV0IHlvdQpzaG91bGQgbm90IGJlIGRvaW5n IHRoYXQgb24gZGV2aWNlIG1lbW9yeSBhbnl3YXkuCgpUaGF0IGlzIGEgcHJvYmxlbSB3aXRoIElv biBJIHdhbnQgdG8gYXZvaWQsIGl0IGFzc3VtZWQgYWxsIGJ1ZmZlcnMgd2VyZQppbiBERFIgYW5k IHNvIHdvdWxkIGRvIGNhY2hlIG9wZXJhdGlvbnMgb24gdGhlbSB1bmNvbmRpdGlvbmFsbHksIHRv bwptYW55IGFzc3VtcHRpb25zIHdlcmUgbWFkZSBhcyB0b28gbXVjaCB3YXMgbW92ZWQgaW50byB0 aGUgY29tbW9uIGNvcmUKY29kZSBhbmQgbm90IGVub3VnaCB3YXMgbGVmdCBmb3IgdGhlIGhlYXBz IHRoZW1zZWx2ZXMgdG8gZGVjaWRlLgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1kZXZlbEBsaXN0cy5mcmVl ZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5m by9kcmktZGV2ZWw=