From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH] iommu/arm-smmu-v2: Add support for 16 bit VMID Date: Fri, 19 Feb 2016 17:13:30 +0000 Message-ID: <20160219171329.GO27062@arm.com> References: <1455819817-8432-1-git-send-email-tchalamarla@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1455819817-8432-1-git-send-email-tchalamarla-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@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: tchalamarla-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org Cc: Geethasowjanya.Akula-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Thu, Feb 18, 2016 at 10:23:37AM -0800, tchalamarla-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org wrote: > From: Tirumalesh Chalamarla > > ARM-SMMUv2 supports upto 16 bit VMID. This patch enables > 16 bit VMID when requested from device-tree. > > Signed-off-by: Tirumalesh Chalamarla > --- > .../devicetree/bindings/iommu/arm,smmu.txt | 2 ++ > drivers/iommu/arm-smmu.c | 21 ++++++++++++++++++++- > 2 files changed, 22 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt > index 7180745..bb7e569 100644 > --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt > +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt > @@ -55,6 +55,8 @@ conditions. > aliases of secure registers have to be used during > SMMU configuration. > > +- smmu-enable-vmid16 : Enable 16 bit VMID, if allowed. Why do we need a new property for this, given that we can detect it from the ID registers? I can't think of a reason why we wouldn't use 16-bit VMIDs if they were available to us. Will