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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 09E8BC433E0 for ; Thu, 11 Mar 2021 12:33:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3BED64FDF for ; Thu, 11 Mar 2021 12:33:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233241AbhCKMdQ convert rfc822-to-8bit (ORCPT ); Thu, 11 Mar 2021 07:33:16 -0500 Received: from aposti.net ([89.234.176.197]:47038 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233243AbhCKMcp (ORCPT ); Thu, 11 Mar 2021 07:32:45 -0500 Date: Thu, 11 Mar 2021 12:32:27 +0000 From: Paul Cercueil Subject: Re: [PATCH v2 3/5] drm: Add and export function drm_gem_cma_mmap_noncoherent To: Christoph Hellwig Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Sam Ravnborg , od@zcrc.me, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org Message-Id: <3I1TPQ.E55GRWWDYVRG@crapouillou.net> In-Reply-To: <20210311122642.GB1739082@infradead.org> References: <20210307202835.253907-1-paul@crapouillou.net> <20210307202835.253907-4-paul@crapouillou.net> <20210311122642.GB1739082@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, Le jeu. 11 mars 2021 à 12:26, Christoph Hellwig a écrit : >> +int drm_gem_cma_mmap_noncoherent(struct drm_gem_object *obj, >> + struct vm_area_struct *vma) >> +{ >> + struct drm_gem_cma_object *cma_obj; >> + unsigned long pfn; >> + int ret; >> + >> + /* >> + * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and >> set the >> + * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want >> to map >> + * the whole buffer. >> + */ >> + vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node); >> + vma->vm_flags &= ~VM_PFNMAP; >> + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); >> + >> + cma_obj = to_drm_gem_cma_obj(obj); >> + >> + pfn = PHYS_PFN(dma_to_phys(cma_obj->base.dev->dev, >> cma_obj->paddr)); >> + >> + ret = remap_pfn_range(vma, vma->vm_start, pfn, >> + vma->vm_end - vma->vm_start, >> + vma->vm_page_prot); > > dma_to_phys must not be used by drivers. > > I have a proper helper for this waiting for users: > > http://git.infradead.org/users/hch/misc.git/commitdiff/96a546e7229ec53aadbdb7936d1e5e6cb5958952 > > If you can confirm the helpers works for you I can try to still sneak > it to Linus for 5.12 to ease the merge pain. I can try. How do I get a page pointer from a dma_addr_t? -Paul