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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 51D3EC32771 for ; Fri, 24 Jan 2020 11:08:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A8B42077C for ; Fri, 24 Jan 2020 11:08:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864091; bh=1GskCnw+liBqG1ez3LCZngD9cZHudWsp/1IJW8+1NJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AZrQonhiahU/LYx8/y2Q2t8jWyhCiyTJvXYU9EjDT3lrn9xg9tbCU/TGc4o2VuHER iTWVGedXGxXDnldZaObUiZN+u4UhujGxlmHz6lLq6wAOXW4k0Ymo+MvZCZlLy59Y1k HYy8MsV9QMiNnBnablFkMnfEZSI8RgT38ZZlpfXg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732285AbgAXLIK (ORCPT ); Fri, 24 Jan 2020 06:08:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:43510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389598AbgAXLIG (ORCPT ); Fri, 24 Jan 2020 06:08:06 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4DE652071A; Fri, 24 Jan 2020 11:08:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864085; bh=1GskCnw+liBqG1ez3LCZngD9cZHudWsp/1IJW8+1NJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fouFs6KO2Al3uc7zqIPtslWJluVFoRfiRhHKCE0UebKEjaXLXE2my4DWPjjuP2con 7epo2LlCQ6zwa1YVxCO2NY62/zXneg9eR29o6sAu5mz4NgV0kVCNV87s7E4OxQvFgq M6rms4bxNI3GhLR4Dyg9rmFEDxsiZyiYkx+L6xUo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleksandr Andrushchenko , Julien Grall , Sasha Levin Subject: [PATCH 4.19 168/639] drm/xen-front: Fix mmap attributes for display buffers Date: Fri, 24 Jan 2020 10:25:38 +0100 Message-Id: <20200124093108.206814201@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleksandr Andrushchenko [ Upstream commit 24ded292a5c2ed476f01c77fee65f8320552cd27 ] When GEM backing storage is allocated those are normal pages, so there is no point using pgprot_writecombine while mmaping. This fixes mismatch of buffer pages' memory attributes between the frontend and backend which may cause screen artifacts. Fixes: c575b7eeb89f ("drm/xen-front: Add support for Xen PV display frontend") Signed-off-by: Oleksandr Andrushchenko Suggested-by: Julien Grall Acked-by: Julien Grall Link: https://patchwork.freedesktop.org/patch/msgid/20190129150422.19867-1-andr2000@gmail.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/xen/xen_drm_front_gem.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c index c85bfe7571cbf..802662839e7ed 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c @@ -236,8 +236,14 @@ static int gem_mmap_obj(struct xen_gem_object *xen_obj, vma->vm_flags &= ~VM_PFNMAP; vma->vm_flags |= VM_MIXEDMAP; vma->vm_pgoff = 0; - vma->vm_page_prot = - pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + /* + * According to Xen on ARM ABI (xen/include/public/arch-arm.h): + * all memory which is shared with other entities in the system + * (including the hypervisor and other guests) must reside in memory + * which is mapped as Normal Inner Write-Back Outer Write-Back + * Inner-Shareable. + */ + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); /* * vm_operations_struct.fault handler will be called if CPU access @@ -283,8 +289,9 @@ void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj) if (!xen_obj->pages) return NULL; + /* Please see comment in gem_mmap_obj on mapping and attributes. */ return vmap(xen_obj->pages, xen_obj->num_pages, - VM_MAP, pgprot_writecombine(PAGE_KERNEL)); + VM_MAP, PAGE_KERNEL); } void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj, -- 2.20.1