From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yh0-x229.google.com (mail-yh0-x229.google.com [IPv6:2607:f8b0:4002:c01::229]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 8F1202C0A4B for ; Mon, 6 May 2013 17:26:33 +1000 (EST) Received: by mail-yh0-f41.google.com with SMTP id i72so667558yha.28 for ; Mon, 06 May 2013 00:26:30 -0700 (PDT) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 4/6] iommu: Add a function to find an iommu group by id Date: Mon, 6 May 2013 17:25:55 +1000 Message-Id: <1367825157-27231-5-git-send-email-aik@ozlabs.ru> In-Reply-To: <1367825157-27231-1-git-send-email-aik@ozlabs.ru> References: <1367825157-27231-1-git-send-email-aik@ozlabs.ru> Cc: kvm@vger.kernel.org, Alexey Kardashevskiy , Alexander Graf , kvm-ppc@vger.kernel.org, Alex Williamson , Paul Mackerras , Joerg Roedel , David Gibson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. This adds the iommu_group_get_by_id(id) function which performs this search. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Paul Mackerras --- 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 ddbdaca..5514dfa 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); -- 1.7.10.4