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From: Joerg Roedel <joro@8bytes.org>
To: iommu@lists.linux-foundation.org
Cc: Will Deacon <will.deacon@arm.com>, Kukjin Kim <kgene@kernel.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Heiko Stuebner <heiko@sntech.de>, Hiroshi Doyu <hdoyu@nvidia.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-kernel@vger.kernel.org, Robin Murphy <robin.murphy@arm.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Joerg Roedel <joro@8bytes.org>,
	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	[thread overview]
Message-ID: <1422317339-22620-4-git-send-email-joro@8bytes.org> (raw)
In-Reply-To: <1422317339-22620-1-git-send-email-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

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 <jroedel@suse.de>
---
 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


  parent reply	other threads:[~2015-01-27  0:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-27  0:08 [RFC PATCH 0/5] iommu: Introduce default domains for iommu groups Joerg Roedel
2015-01-27  0:08 ` [PATCH 1/5] iommu: Add default domain to iommu-groups Joerg Roedel
2015-01-27  0:08 ` [PATCH 2/5] iommu: Allocate a default domain for iommu groups Joerg Roedel
2015-01-28 14:30   ` Will Deacon
2015-01-28 15:11     ` Robin Murphy
2015-01-30 12:25     ` Joerg Roedel
2015-01-27  0:08 ` Joerg Roedel [this message]
2015-01-28 14:35   ` [PATCH 3/5] iommu: Limit iommu_attach/detach_device to devices with their own group Will Deacon
2015-01-30 12:28     ` Joerg Roedel
2015-02-02 16:45       ` Will Deacon
2015-02-03 12:25   ` Thierry Reding
2015-02-03 12:59     ` Joerg Roedel
2015-01-27  0:08 ` [PATCH 4/5] iommu: Make sure a device is always attached to a domain Joerg Roedel
2015-01-28 14:38   ` Will Deacon
2015-01-30 12:29     ` Joerg Roedel
2015-01-27  0:08 ` [PATCH 5/5] iommu: Add iommu_get_domain_for_dev function Joerg Roedel

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