From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Dutile Subject: Re: [PATCH] iommu: add a function to find an iommu group by id Date: Mon, 25 Mar 2013 11:07:26 -0400 Message-ID: <5150682E.6040900@redhat.com> References: <1364167429-6432-1-git-send-email-aik@ozlabs.ru> <1364221712.24132.632.camel@bling.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1364221712.24132.632.camel-xdHQ/5r00wBBDLzU/O5InQ@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: Alex Williamson Cc: Alexey Kardashevskiy , Benjamin Herrenschmidt , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, David Gibson List-Id: iommu@lists.linux-foundation.org On 03/25/2013 10:28 AM, Alex Williamson wrote: > On Mon, 2013-03-25 at 10:23 +1100, Alexey Kardashevskiy wrote: >> As IOMMU groups are exposed to the user space by their numbers, >> the user space can use them in various kernel APIs so the kernel >> might need an API to find a group by its ID. >> >> As an example, QEMU VFIO on PPC64 platform needs it to associate >> a logical bus number (LIOBN) with a specific IOMMU group in order >> to support in-kernel handling of DMA map/unmap requests. >> >> The patch adds the iommu_group_get_by_id(id) function which performs >> such search. > > Subject: [PATCH v3].... > > v2 was the last one, where's the changelog for v3? >> v2: fixed reference counting. >> and changed function name... >> Signed-off-by: Alexey Kardashevskiy >> --- > > Acked-by: Alex Williamson > >> drivers/iommu/iommu.c | 29 +++++++++++++++++++++++++++++ >> include/linux/iommu.h | 1 + >> 2 files changed, 30 insertions(+) >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index 1065a1a..0de83eb 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -204,6 +204,35 @@ again: >> } >> EXPORT_SYMBOL_GPL(iommu_group_alloc); >> >> +struct iommu_group *iommu_group_get_by_id(int id) >> +{ >> + struct kobject *group_kobj; >> + struct iommu_group *group; >> + const char *name; >> + >> + if (!iommu_group_kset) >> + return NULL; >> + >> + name = kasprintf(GFP_KERNEL, "%d", id); >> + if (!name) >> + return NULL; >> + >> + group_kobj = kset_find_obj(iommu_group_kset, name); >> + kfree(name); >> + >> + if (!group_kobj) >> + return NULL; >> + >> + group = container_of(group_kobj, struct iommu_group, kobj); >> + BUG_ON(group->id != id); >> + >> + kobject_get(group->devices_kobj); >> + kobject_put(&group->kobj); >> + >> + return group; >> +} >> +EXPORT_SYMBOL_GPL(iommu_group_get_by_id); >> + >> /** >> * iommu_group_get_iommudata - retrieve iommu_data registered for a group >> * @group: the group >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index f3b99e1..00e5d7d 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -113,6 +113,7 @@ struct iommu_ops { >> extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops); >> extern bool iommu_present(struct bus_type *bus); >> extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus); >> +extern struct iommu_group *iommu_group_get_by_id(int id); >> extern void iommu_domain_free(struct iommu_domain *domain); >> extern int iommu_attach_device(struct iommu_domain *domain, >> struct device *dev); > > > > _______________________________________________ > iommu mailing list > iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu