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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 742CEC7618B for ; Thu, 25 Jul 2019 14:11:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 47BFD22BF5 for ; Thu, 25 Jul 2019 14:11:47 +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="ag0sWRS2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387905AbfGYOLq (ORCPT ); Thu, 25 Jul 2019 10:11:46 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:34912 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725867AbfGYOLp (ORCPT ); Thu, 25 Jul 2019 10:11:45 -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=rVU3OdYVB/xxhc+Jxe+Jl0rvuIWAAmVPWnVC1lgwyac=; b=ag0sWRS2Qau6/riWg3p8KEakN 879W/vBUC7KhSFSuRmVrddLtdB+ukxtpMcsgoDdTk3iHr0s+Xw6ewyntMvp4Eerrw5vUjV2JrKI5+ BRjfvW0r7QfVyp4L8LfjZMW3yS+muIPpdCptG0YM8vfE7w7c9aPH0JHWs2QzvzBPt9loTWP1nyZ4T 58pi6b0FzZdPCa8JKojNGEy+/57NctfhMHMuztnzLcUMBqmfvwgUKmcGmX35Dsdb+f980RoRtTDht H3JKkAp4EfelUoFFPn6BU18hLE2pz3Igtrej1ytLc6NVvgVgF5Y5yPGrJWBGTUr8c6pWpy1YdaLm2 LHbtTAczg==; Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hqeTA-0004Hq-RH; Thu, 25 Jul 2019 14:11:44 +0000 Date: Thu, 25 Jul 2019 07:11:44 -0700 From: Christoph Hellwig To: "Andrew F. Davis" Cc: Christoph Hellwig , 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 Subject: Re: [PATCH v6 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps Message-ID: <20190725141144.GA14609@infradead.org> References: <20190624194908.121273-1-john.stultz@linaro.org> <20190624194908.121273-5-john.stultz@linaro.org> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8e2ec315-5d18-68b2-8cb5-2bfb8a116d1b@ti.com> User-Agent: Mutt/1.11.4 (2019-03-13) 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, 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.