From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH v3 3/3] iommu/io-pgtable: Avoid redundant TLB syncs Date: Wed, 10 Feb 2016 14:21:13 +0000 Message-ID: <20160210142112.GK1052@arm.com> References: <81a5e784494a04713e152659c95b34e92d944f32.1453723096.git.robin.murphy@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: <81a5e784494a04713e152659c95b34e92d944f32.1453723096.git.robin.murphy-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: Robin Murphy Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Tue, Jan 26, 2016 at 05:13:15PM +0000, Robin Murphy wrote: > In certain unmapping situations it is quite possible to end up issuing > back-to-back TLB synchronisations, which at best is a waste of time and > effort, and at worst causes some hardware to get rather confused. Whilst > the pagetable implementations, or the IOMMU drivers, or both, could keep > track of things to avoid this happening, it seems to make the most sense > to prevent code duplication and add some simple state tracking in the > common interface between the two. > > Reviewed-by: Laurent Pinchart > Signed-off-by: Robin Murphy > --- > drivers/iommu/io-pgtable.h | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) Acked-by: Will Deacon Will From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 10 Feb 2016 14:21:13 +0000 Subject: [PATCH v3 3/3] iommu/io-pgtable: Avoid redundant TLB syncs In-Reply-To: <81a5e784494a04713e152659c95b34e92d944f32.1453723096.git.robin.murphy@arm.com> References: <81a5e784494a04713e152659c95b34e92d944f32.1453723096.git.robin.murphy@arm.com> Message-ID: <20160210142112.GK1052@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jan 26, 2016 at 05:13:15PM +0000, Robin Murphy wrote: > In certain unmapping situations it is quite possible to end up issuing > back-to-back TLB synchronisations, which at best is a waste of time and > effort, and at worst causes some hardware to get rather confused. Whilst > the pagetable implementations, or the IOMMU drivers, or both, could keep > track of things to avoid this happening, it seems to make the most sense > to prevent code duplication and add some simple state tracking in the > common interface between the two. > > Reviewed-by: Laurent Pinchart > Signed-off-by: Robin Murphy > --- > drivers/iommu/io-pgtable.h | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) Acked-by: Will Deacon Will