From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 3/6] iommu/amd: Introduce amd_iommu_get_num_iommus() Date: Mon, 28 Dec 2015 16:43:00 +0100 Message-ID: <20151228154300.GK18805@8bytes.org> References: <1450811957-1511-1-git-send-email-Suravee.Suthikulpanit@amd.com> <1450811957-1511-4-git-send-email-Suravee.Suthikulpanit@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1450811957-1511-4-git-send-email-Suravee.Suthikulpanit-5C7GfCeVMHo@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: Suravee Suthikulpanit Cc: peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, acme-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Tue, Dec 22, 2015 at 01:19:14PM -0600, Suthikulpanit, Suravee wrote: > This patch introduces amd_iommu_get_num_iommus(). Initially, this is > intended to be used by Perf AMD IOMMU driver. > > Signed-off-by: Suravee Suthikulpanit > --- > drivers/iommu/amd_iommu_init.c | 16 ++++++++++++++++ > include/linux/perf/perf_event_amd_iommu.h | 2 ++ > 2 files changed, 18 insertions(+) > > diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c > index 275c0f5..9c62613 100644 > --- a/drivers/iommu/amd_iommu_init.c > +++ b/drivers/iommu/amd_iommu_init.c > @@ -2244,6 +2244,22 @@ bool amd_iommu_v2_supported(void) > } > EXPORT_SYMBOL(amd_iommu_v2_supported); > > +static int amd_iommu_cnt; > + > +int amd_iommu_get_num_iommus(void) > +{ > + struct amd_iommu *iommu; > + > + if (amd_iommu_cnt) > + return amd_iommu_cnt; > + > + for_each_iommu(iommu) > + amd_iommu_cnt++; It is better to set amd_iommu_cnt during IOMMU initialization. You can just increment this value after an IOMMU has been set up. Joerg