From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: [PATCH] drm/bochs: fix bochs_gem_prime_mmap Date: Mon, 4 Feb 2019 19:38:58 +0100 Message-ID: <20190204183858.8976-1-kraxel@redhat.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: dri-devel@lists.freedesktop.org Cc: Gerd Hoffmann , David Airlie , Daniel Vetter , "open list:DRM DRIVER FOR BOCHS VIRTUAL GPU" , open list List-Id: dri-devel@lists.freedesktop.org ttm_fbdev_mmap() just doesn't work. It appears to work fine, mmap() returns success, but any attempt to actually access the mapping causes a SIGBUS. We can just use drm_gem_prime_mmap() instead. Almost. We have to copy over the start offset from the ttm_buffer_object vm_node to the drm_gem_object vm_node so the offset math in drm_gem_prime_mmap() works correctly for us even though we use ttm to manage our objects. Signed-off-by: Gerd Hoffmann --- drivers/gpu/drm/bochs/bochs_mm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bochs/bochs_mm.c b/drivers/gpu/drm/bochs/bochs_mm.c index 641a33f134..49463348a0 100644 --- a/drivers/gpu/drm/bochs/bochs_mm.c +++ b/drivers/gpu/drm/bochs/bochs_mm.c @@ -442,5 +442,6 @@ int bochs_gem_prime_mmap(struct drm_gem_object *obj, { struct bochs_bo *bo = gem_to_bochs_bo(obj); - return ttm_fbdev_mmap(vma, &bo->bo); + bo->gem.vma_node.vm_node.start = bo->bo.vma_node.vm_node.start; + return drm_gem_prime_mmap(obj, vma); } -- 2.9.3 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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 96C44C282C4 for ; Mon, 4 Feb 2019 18:39:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62B042176F for ; Mon, 4 Feb 2019 18:39:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729323AbfBDSjF (ORCPT ); Mon, 4 Feb 2019 13:39:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33936 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727917AbfBDSjF (ORCPT ); Mon, 4 Feb 2019 13:39:05 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9BEFF58E40; Mon, 4 Feb 2019 18:39:04 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-249.ams2.redhat.com [10.36.116.249]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9E872100191D; Mon, 4 Feb 2019 18:38:59 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 9C061A1E3; Mon, 4 Feb 2019 19:38:58 +0100 (CET) From: Gerd Hoffmann To: dri-devel@lists.freedesktop.org Cc: Gerd Hoffmann , David Airlie , Daniel Vetter , virtualization@lists.linux-foundation.org (open list:DRM DRIVER FOR BOCHS VIRTUAL GPU), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] drm/bochs: fix bochs_gem_prime_mmap Date: Mon, 4 Feb 2019 19:38:58 +0100 Message-Id: <20190204183858.8976-1-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 04 Feb 2019 18:39:04 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ttm_fbdev_mmap() just doesn't work. It appears to work fine, mmap() returns success, but any attempt to actually access the mapping causes a SIGBUS. We can just use drm_gem_prime_mmap() instead. Almost. We have to copy over the start offset from the ttm_buffer_object vm_node to the drm_gem_object vm_node so the offset math in drm_gem_prime_mmap() works correctly for us even though we use ttm to manage our objects. Signed-off-by: Gerd Hoffmann --- drivers/gpu/drm/bochs/bochs_mm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bochs/bochs_mm.c b/drivers/gpu/drm/bochs/bochs_mm.c index 641a33f134..49463348a0 100644 --- a/drivers/gpu/drm/bochs/bochs_mm.c +++ b/drivers/gpu/drm/bochs/bochs_mm.c @@ -442,5 +442,6 @@ int bochs_gem_prime_mmap(struct drm_gem_object *obj, { struct bochs_bo *bo = gem_to_bochs_bo(obj); - return ttm_fbdev_mmap(vma, &bo->bo); + bo->gem.vma_node.vm_node.start = bo->bo.vma_node.vm_node.start; + return drm_gem_prime_mmap(obj, vma); } -- 2.9.3