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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 384E0C33CB6 for ; Thu, 16 Jan 2020 17:00:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0CAE32081E for ; Thu, 16 Jan 2020 17:00:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194043; bh=f/u8zFAjCNc6rmpGCQzhfg7rSXfsqqu01yrugzFPqnU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=y0lHgcwJIcq1wpAvVpZdKmf+IT/v8DntoBKTatZYKnQ8OqWzyKkB1r70bAT/gWs9n Kdmbp7GZQyxDkgCO7Zi+Vh+WVRFxzj8KFBD/ms9RuyIvHukQF8dtium8i//ZIDNgEf SdMj5b99PxGzVm1UGWcctZXVZDhnr1soBEcKlSgk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387529AbgAPRAm (ORCPT ); Thu, 16 Jan 2020 12:00:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:50346 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387850AbgAPRAd (ORCPT ); Thu, 16 Jan 2020 12:00:33 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5E9DB22525; Thu, 16 Jan 2020 17:00:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194033; bh=f/u8zFAjCNc6rmpGCQzhfg7rSXfsqqu01yrugzFPqnU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mhAK8F9zNRfWD3lqS9+U//x/26on7daYc7kU3/vfSUu6fqkOawI1gmiZZ+akS4Fzd F0Fjcio953FuUZi5Vw0yQ2zYhVLN05UL3egu2swPm7z3EBeGS+cUCVJAe2rl24T/XA R0pSOIn4/KHwHn3Nnrg/xZsKUPVP1zcDE/lnuI94= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oleksandr Andrushchenko , Julien Grall , Sasha Levin , dri-devel@lists.freedesktop.org, xen-devel@lists.xenproject.org Subject: [PATCH AUTOSEL 4.19 152/671] drm/xen-front: Fix mmap attributes for display buffers Date: Thu, 16 Jan 2020 11:51:01 -0500 Message-Id: <20200116165940.10720-35-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116165940.10720-1-sashal@kernel.org> References: <20200116165940.10720-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 c85bfe7571cb..802662839e7e 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