From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757634AbbA0AKZ (ORCPT ); Mon, 26 Jan 2015 19:10:25 -0500 Received: from 8bytes.org ([81.169.241.247]:51332 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757411AbbA0AJR (ORCPT ); Mon, 26 Jan 2015 19:09:17 -0500 From: Joerg Roedel To: iommu@lists.linux-foundation.org Cc: Will Deacon , Kukjin Kim , David Woodhouse , Heiko Stuebner , Hiroshi Doyu , Thierry Reding , Alex Williamson , Arnd Bergmann , linux-kernel@vger.kernel.org, Robin Murphy , Laurent Pinchart , Joerg Roedel , jroedel@suse.de Subject: [PATCH 3/5] iommu: Limit iommu_attach/detach_device to devices with their own group Date: Tue, 27 Jan 2015 01:08:57 +0100 Message-Id: <1422317339-22620-4-git-send-email-joro@8bytes.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422317339-22620-1-git-send-email-joro@8bytes.org> References: <1422317339-22620-1-git-send-email-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel This patch changes the behavior of the iommu_attach_device and iommu_detach_device functions. With this change these functions only work on devices that have their own group. For all other devices the iommu_group_attach/detach functions must be used. Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 59 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 8f33ddd3..b63a550 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -51,6 +51,7 @@ struct iommu_group { void (*iommu_data_release)(void *iommu_data); char *name; int id; + unsigned dev_cnt; struct iommu_domain *default_domain; }; @@ -380,6 +381,7 @@ rename: mutex_lock(&group->mutex); list_add_tail(&device->list, &group->devices); + group->dev_cnt += 1; mutex_unlock(&group->mutex); /* Notify any listeners about change to group. */ @@ -408,6 +410,7 @@ void iommu_group_remove_device(struct device *dev) IOMMU_GROUP_NOTIFY_DEL_DEVICE, dev); mutex_lock(&group->mutex); + group->dev_cnt -= 1; list_for_each_entry(tmp_device, &group->devices, list) { if (tmp_device->dev == dev) { device = tmp_device; @@ -943,7 +946,8 @@ void iommu_domain_free(struct iommu_domain *domain) } EXPORT_SYMBOL_GPL(iommu_domain_free); -int iommu_attach_device(struct iommu_domain *domain, struct device *dev) +static int __iommu_attach_device(struct iommu_domain *domain, + struct device *dev) { int ret; if (unlikely(domain->ops->attach_dev == NULL)) @@ -954,9 +958,38 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) trace_attach_device_to_domain(dev); return ret; } + +int iommu_attach_device(struct iommu_domain *domain, struct device *dev) +{ + struct iommu_group *group; + int ret; + + group = iommu_group_get(dev); + /* FIXME: Remove this when groups a mandatory for iommu drivers */ + if (group == NULL) + return __iommu_attach_device(domain, dev); + + /* + * We have a group - lock it to make sure the device-count doesn't + * change while we are attaching + */ + mutex_lock(&group->mutex); + ret = -EINVAL; + if (group->dev_cnt != 1) + goto out_unlock; + + ret = iommu_attach_group(domain, group); + +out_unlock: + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return ret; +} EXPORT_SYMBOL_GPL(iommu_attach_device); -void iommu_detach_device(struct iommu_domain *domain, struct device *dev) +static void __iommu_detach_device(struct iommu_domain *domain, + struct device *dev) { if (unlikely(domain->ops->detach_dev == NULL)) return; @@ -964,6 +997,28 @@ void iommu_detach_device(struct iommu_domain *domain, struct device *dev) domain->ops->detach_dev(domain, dev); trace_detach_device_from_domain(dev); } + +void iommu_detach_device(struct iommu_domain *domain, struct device *dev) +{ + struct iommu_group *group; + + group = iommu_group_get(dev); + /* FIXME: Remove this when groups a mandatory for iommu drivers */ + if (group == NULL) + return __iommu_detach_device(domain, dev); + + mutex_lock(&group->mutex); + if (group->dev_cnt != 1) { + WARN_ON(1); + goto out_unlock; + } + + iommu_detach_group(domain, group); + +out_unlock: + mutex_unlock(&group->mutex); + iommu_group_put(group); +} EXPORT_SYMBOL_GPL(iommu_detach_device); /* @@ -980,7 +1035,7 @@ static int iommu_group_do_attach_device(struct device *dev, void *data) { struct iommu_domain *domain = data; - return iommu_attach_device(domain, dev); + return __iommu_attach_device(domain, dev); } int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) @@ -994,7 +1049,7 @@ static int iommu_group_do_detach_device(struct device *dev, void *data) { struct iommu_domain *domain = data; - iommu_detach_device(domain, dev); + __iommu_detach_device(domain, dev); return 0; } -- 1.9.1