From patchwork Tue Nov 3 09:27:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 11876827 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B9276A2 for ; Tue, 3 Nov 2020 10:35:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0602922447 for ; Tue, 3 Nov 2020 10:35:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="BWJY7YL9"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="W6vWFt0H" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728688AbgKCKfD (ORCPT ); Tue, 3 Nov 2020 05:35:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728543AbgKCKeI (ORCPT ); Tue, 3 Nov 2020 05:34:08 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CF58C0613D1; Tue, 3 Nov 2020 02:34:08 -0800 (PST) Message-Id: <20201103095859.726187546@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1604399641; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=r3bRNSPyDxqBB2q1RmPpZiq/s1h+pWiITk0Gb+X4YiE=; b=BWJY7YL9koWIqQGO6oJX8GMg2970+m6CUIohd/XJevMmQ80PB19bJDJ6iS8RO72tFyrU5a zermc/VLuhpDSGwb6AlQ+XUnPAk/ooP0r2CdnCXy7SbeJDAVykp+GhIB7O+PeOHtxIB/kQ kGAzLI/8Albxroia7VjhmBhPwLPYvYm7buHcNBklvKblOslUE8GFJQxCNSKNTUzn67UA6c dCL9UHwiUeuSbb9mKfvGa5CyJx9FEPWWAQv536xf3Kv7je840+HegrNr76dqY6DZp1xmcI hfpxU76xevyfk1dRUoZcIUQ3vKAJLr6y/fVXGv/9UWFE20X3bXjqdNO7IqY7sQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1604399641; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=r3bRNSPyDxqBB2q1RmPpZiq/s1h+pWiITk0Gb+X4YiE=; b=W6vWFt0HyJmTC8mcOcU1LotSVA5E0cTby+uitrXhlUWJjwzfnwYugo9E0ZaVshQFT42zsP ckJmRhJkQSF0aCCw== Date: Tue, 03 Nov 2020 10:27:43 +0100 From: Thomas Gleixner To: LKML Cc: Linus Torvalds , Peter Zijlstra , Paul McKenney , Christoph Hellwig , Sebastian Andrzej Siewior , Christian Koenig , Huang Rui , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, Andrew Morton , linux-mm@kvack.org, Alexander Viro , Benjamin LaHaise , linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, x86@kernel.org, Vineet Gupta , linux-snps-arc@lists.infradead.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, Michal Simek , Thomas Bogendoerfer , linux-mips@vger.kernel.org, Nick Hu , Greentime Hu , Vincent Chen , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, "David S. Miller" , sparclinux@vger.kernel.org, Chris Zankel , Max Filippov , linux-xtensa@linux-xtensa.org, Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , VMware Graphics , Roland Scheidegger , Dave Airlie , Gerd Hoffmann , virtualization@lists.linux-foundation.org, spice-devel@lists.freedesktop.org, Ben Skeggs , nouveau@lists.freedesktop.org, Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , intel-gfx@lists.freedesktop.org Subject: [patch V3 31/37] drm/ttm: Replace kmap_atomic() usage References: <20201103092712.714480842@linutronix.de> MIME-Version: 1.0 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org There is no reason to disable pagefaults and preemption as a side effect of kmap_atomic_prot(). Use kmap_local_page_prot() instead and document the reasoning for the mapping usage with the given pgprot. Remove the NULL pointer check for the map. These functions return a valid address for valid pages and the return was bogus anyway as it would have left preemption and pagefaults disabled. Signed-off-by: Thomas Gleixner Cc: Christian Koenig Cc: Huang Rui Cc: David Airlie Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org --- V3: New patch --- drivers/gpu/drm/ttm/ttm_bo_util.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -181,13 +181,15 @@ static int ttm_copy_io_ttm_page(struct t return -ENOMEM; src = (void *)((unsigned long)src + (page << PAGE_SHIFT)); - dst = kmap_atomic_prot(d, prot); - if (!dst) - return -ENOMEM; + /* + * Ensure that a highmem page is mapped with the correct + * pgprot. For non highmem the mapping is already there. + */ + dst = kmap_local_page_prot(d, prot); memcpy_fromio(dst, src, PAGE_SIZE); - kunmap_atomic(dst); + kunmap_local(dst); return 0; } @@ -203,13 +205,15 @@ static int ttm_copy_ttm_io_page(struct t return -ENOMEM; dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT)); - src = kmap_atomic_prot(s, prot); - if (!src) - return -ENOMEM; + /* + * Ensure that a highmem page is mapped with the correct + * pgprot. For non highmem the mapping is already there. + */ + src = kmap_local_page_prot(s, prot); memcpy_toio(dst, src, PAGE_SIZE); - kunmap_atomic(src); + kunmap_local(src); return 0; }