Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753732AbdCTJq4 (ORCPT ); Mon, 20 Mar 2017 05:46:56 -0400 Received: from mout.kundenserver.de ([212.227.126.134]:53549 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753435AbdCTJp7 (ORCPT ); Mon, 20 Mar 2017 05:45:59 -0400 From: Arnd Bergmann To: Daniel Vetter , Jani Nikula , David Airlie Cc: Arnd Bergmann , Chris Wilson , Tvrtko Ursulin , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] drm/i915: split out check for noncontiguous pfn range Date: Mon, 20 Mar 2017 10:40:28 +0100 Message-Id: <20170320094335.1266306-2-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20170320094335.1266306-1-arnd@arndb.de> References: <20170320094335.1266306-1-arnd@arndb.de> X-Provags-ID: V03:K0:wsoikxTm87AF/C8rVdtvESX5vSn/8xiE1+M8UQMCT1p78fE7GGA 5mkqbeA13eFlD3wA47gBnnsxBUhqI8GTtrW2SxR00jMyRE2hsH/EQNuD62L8DDu4umFQqUm nHX8oLPEw1GLHr5KanTAYY/Dsz7T3vGIkVp7TyegWqI3oxKxDt93PPh134TzUc4zrNlb3+K 8bcRFC5LLVu2S65RIB4eQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:dcCinznIWnA=:SYoQiVnCH/iZ9ErJZxmBMW CwJhvs54NkG1V1NhI8YKDoRM+4b3KHxOABeo/dk7cygICdvQBvPTtpYgKlh9c5dNuJBLnALcy SFmxTGgtspX4pQrtTv7DZbLfS/Unf9qMf/rSfZ63KDOOmRbyrOeBFCET0V9EmGg457PhfAnDV eiRwD2mdugLVTH/kUH8E2AtwDrHT9bu1DRSo6JM6PjWSFtXfZ/OUgAP+BpTdDxKWFzMBbKr1i 8sSuXrwV7utN6FTSiJxDq0+tfkL1wkxfVSwIr6OugslfRwZqtlVeCtKPpOy9osw1kIpEDErSS mWlTkbqr9t2TYJrBlvnJYJ0TbH5v61Au8bfUbYDRDGF4bug4bLM6H20JnOPL/4QWqGLNj3qtL /KAZ/gjRzGvDpQe7C0U4S4z0H/Mdf/X2+B3EanVCMH6KjdLOKF7PLs8V4+8Rack1QZi7kQb8h QqPovjCziAqaI+gYzZEeT9aaGYK5c7TEib6YAjlNw5pnm6E0c2AKs/1Hmmht6QbrHC/qckE6u SoNIilSA809iNummwKzP4hxRRy8wjL9q41PCfdr7PP3FBmj6g03q4FvZz+wOHlgU/o9Ood3Li ARHLFOImgVVQd4Iw7YF5bXgXa/w2Ksz3Mc0q7Rbrj/PkrYz6IJO5JnD/DhfuI5laVGDlEnAz5 Fpc7BgA3jBssuYv4HInAGiO3xoD057ZtpRqzZdJW3f6YyvFCZ/xqJ8zqkDpSIvAY5/DQ= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1663 Lines: 43 We get a warning with gcc-7 about a pointless comparison when using a linear memmap: drivers/gpu/drm/i915/selftests/scatterlist.c: In function 'alloc_table': drivers/gpu/drm/i915/selftests/scatterlist.c:219:66: error: self-comparison always evaluates to false [-Werror=tautological-compare] Splitting out the comparison into a separate function avoids the warning and makes it slightly more obvious what happens. Fixes: 935a2f776aa5 ("drm/i915: Add some selftests for sg_table manipulation") Signed-off-by: Arnd Bergmann --- drivers/gpu/drm/i915/selftests/scatterlist.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/selftests/scatterlist.c b/drivers/gpu/drm/i915/selftests/scatterlist.c index eb2cda8e2b9f..c072b0f9180b 100644 --- a/drivers/gpu/drm/i915/selftests/scatterlist.c +++ b/drivers/gpu/drm/i915/selftests/scatterlist.c @@ -189,6 +189,11 @@ static unsigned int random(unsigned long n, return 1 + (prandom_u32_state(rnd) % 1024); } +static inline bool page_contiguous(struct page *first, struct page *last, unsigned long npages) +{ + return first + npages == last; +} + static int alloc_table(struct pfn_table *pt, unsigned long count, unsigned long max, npages_fn_t npages_fn, @@ -216,7 +221,8 @@ static int alloc_table(struct pfn_table *pt, unsigned long npages = npages_fn(n, count, rnd); /* Nobody expects the Sparse Memmap! */ - if (pfn_to_page(pfn + npages) != pfn_to_page(pfn) + npages) { + if (!page_contiguous(pfn_to_page(pfn), + pfn_to_page(pfn + npages), npages)) { sg_free_table(&pt->st); return -ENOSPC; } -- 2.9.0