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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02CA5C77B6E for ; Thu, 6 Apr 2023 11:33:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237770AbjDFLdz (ORCPT ); Thu, 6 Apr 2023 07:33:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237373AbjDFLdH (ORCPT ); Thu, 6 Apr 2023 07:33:07 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94D6693EB; Thu, 6 Apr 2023 04:32:35 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E04AD6446A; Thu, 6 Apr 2023 11:32:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25E1AC433D2; Thu, 6 Apr 2023 11:32:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680780754; bh=VWeaSIihX1UD1HpAC36qM6ZP2rDBKHTw1ESYWCVeS1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z2Q23ggOGmLSunqlW9N5zb9/xfrkhhT6tgdL686YtskoeXtsxwRyrSK/h6BLXSnPn Jovz3CUQjwXJa12AYgRzcNyfAkv5/uJNkXGMwth1X0UIWk7Kab2PiiIgx9Ir5WQBGF E5IfWth/QfBqYc8g2SaXtU32J47XE6OKmRT9/9c1xTMtONrMYFlNDwW1v6gRqsf68I lrTrAr4Unt+N7CjyltAEQPtUnt5dSxQT+39MC6sIropfWt+cYiOCj/BhzGsKP0dejd TMhjBokR/q2VZPVMeen5Dfm8SxqBwSPVPaLpRfqn5YWR5q4CnBHzUMaiKJGG2K8alP DIZPncAKq8mfA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Gow , =?UTF-8?q?Lu=C3=ADs=20Mendes?= , =?UTF-8?q?Christian=20K=C3=B6nig?= , Arunpravin Paneer Selvam , Sasha Levin , maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.1 11/17] drm: buddy_allocator: Fix buddy allocator init on 32-bit systems Date: Thu, 6 Apr 2023 07:32:05 -0400 Message-Id: <20230406113211.648424-11-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230406113211.648424-1-sashal@kernel.org> References: <20230406113211.648424-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Gow [ Upstream commit 4453545b5b4c3eff941f69a5530f916d899db025 ] The drm buddy allocator tests were broken on 32-bit systems, as rounddown_pow_of_two() takes a long, and the buddy allocator handles 64-bit sizes even on 32-bit systems. This can be reproduced with the drm_buddy_allocator KUnit tests on i386: ./tools/testing/kunit/kunit.py run --arch i386 \ --kunitconfig ./drivers/gpu/drm/tests drm_buddy (It results in kernel BUG_ON() when too many blocks are created, due to the block size being too small.) This was independently uncovered (and fixed) by Luís Mendes, whose patch added a new u64 variant of rounddown_pow_of_two(). This version instead recalculates the size based on the order. Reported-by: Luís Mendes Link: https://lore.kernel.org/lkml/CAEzXK1oghXAB_KpKpm=-CviDQbNaH0qfgYTSSjZgvvyj4U78AA@mail.gmail.com/T/ Signed-off-by: David Gow Acked-by: Christian König Reviewed-by: Arunpravin Paneer Selvam Link: https://patchwork.freedesktop.org/patch/msgid/20230329065532.2122295-1-davidgow@google.com Signed-off-by: Christian König Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_buddy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index 3d1f50f481cfd..7098f125b54a9 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -146,8 +146,8 @@ int drm_buddy_init(struct drm_buddy *mm, u64 size, u64 chunk_size) unsigned int order; u64 root_size; - root_size = rounddown_pow_of_two(size); - order = ilog2(root_size) - ilog2(chunk_size); + order = ilog2(size) - ilog2(chunk_size); + root_size = chunk_size << order; root = drm_block_alloc(mm, NULL, order, offset); if (!root) -- 2.39.2