From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH] iommu/io-pgtable-arm: fix self-test WARNs on i386 Date: Wed, 25 Feb 2015 13:38:46 +0100 Message-ID: <20150225123845.GA5362@8bytes.org> References: <1424111900-23887-1-git-send-email-will.deacon@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1424111900-23887-1-git-send-email-will.deacon-5wv7dgnIgG8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Will Deacon Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Mon, Feb 16, 2015 at 06:38:20PM +0000, Will Deacon wrote: > Various build/boot bots have reported WARNs being triggered by the ARM > iopgtable LPAE self-tests on i386 machines. > > This boils down to two instances of right-shifting a 32-bit unsigned > long (i.e. an iova) by more than the size of the type. On 32-bit ARM, > this happens to give us zero, hence my testing didn't catch this > earlier. > > This patch fixes the issue by using DIV_ROUND_UP and explicit case to > to avoid the erroneous shifts. > > Reported-by: Fengguang Wu > Reported-by: Huang Ying > Signed-off-by: Will Deacon > --- > > Joerg -- please can you apply this as a fix for 3.20? Applied to my fixes branch, thanks Will.