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Commit e39cb8a3 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu: Make sure a device is always attached to a domain 



Make use of the default domain and re-attach a device to it
when it is detached from another domain. Also enforce that a
device has to be in the default domain before it can be
attached to a different domain.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 426a2738

drivers/iommu/iommu.c

+76 −8
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ struct iommu_group { 
	char *name;

	int id;

	struct iommu_domain *default_domain;

	struct iommu_domain *domain;

};



struct iommu_device {
@@ -78,6 +79,12 @@ struct iommu_group_attribute iommu_group_attr_##_name = \ 


static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,

						 unsigned type);

static int __iommu_attach_device(struct iommu_domain *domain,

				 struct device *dev);

static int __iommu_attach_group(struct iommu_domain *domain,

				struct iommu_group *group);

static void __iommu_detach_group(struct iommu_domain *domain,

				 struct iommu_group *group);



static ssize_t iommu_group_attr_show(struct kobject *kobj,

				     struct attribute *__attr, char *buf)
@@ -376,6 +383,8 @@ rename: 


	mutex_lock(&group->mutex);

	list_add_tail(&device->list, &group->devices);

	if (group->domain)

		__iommu_attach_device(group->domain, dev);

	mutex_unlock(&group->mutex);



	/* Notify any listeners about change to group. */
@@ -455,19 +464,30 @@ static int iommu_group_device_count(struct iommu_group *group) 
 * The group->mutex is held across callbacks, which will block calls to

 * iommu_group_add/remove_device.

 */

int iommu_group_for_each_dev(struct iommu_group *group, void *data,

static int __iommu_group_for_each_dev(struct iommu_group *group, void *data,

				      int (*fn)(struct device *, void *))

{

	struct iommu_device *device;

	int ret = 0;



	mutex_lock(&group->mutex);

	list_for_each_entry(device, &group->devices, list) {

		ret = fn(device->dev, data);

		if (ret)

			break;

	}

	return ret;

}





int iommu_group_for_each_dev(struct iommu_group *group, void *data,

			     int (*fn)(struct device *, void *))

{

	int ret;



	mutex_lock(&group->mutex);

	ret = __iommu_group_for_each_dev(group, data, fn);

	mutex_unlock(&group->mutex);



	return ret;

}

EXPORT_SYMBOL_GPL(iommu_group_for_each_dev);
@@ -727,6 +747,7 @@ static struct iommu_group *iommu_group_get_for_pci_dev(struct pci_dev *pdev) 
		 */

		group->default_domain = __iommu_domain_alloc(pdev->dev.bus,

							     IOMMU_DOMAIN_DMA);

		group->domain = group->default_domain;

	}



	return group;
@@ -1012,7 +1033,7 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) 
	if (iommu_group_device_count(group) != 1)

		goto out_unlock;



	ret = __iommu_attach_device(domain, dev);

	ret = __iommu_attach_group(domain, group);



out_unlock:

	mutex_unlock(&group->mutex);
@@ -1047,7 +1068,7 @@ void iommu_detach_device(struct iommu_domain *domain, struct device *dev) 
		goto out_unlock;

	}



	__iommu_detach_device(domain, dev);

	__iommu_detach_group(domain, group);



out_unlock:

	mutex_unlock(&group->mutex);
@@ -1072,10 +1093,31 @@ static int iommu_group_do_attach_device(struct device *dev, void *data) 
	return __iommu_attach_device(domain, dev);

}



int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)

static int __iommu_attach_group(struct iommu_domain *domain,

				struct iommu_group *group)

{

	return iommu_group_for_each_dev(group, domain,

	int ret;



	if (group->default_domain && group->domain != group->default_domain)

		return -EBUSY;



	ret = __iommu_group_for_each_dev(group, domain,

					 iommu_group_do_attach_device);

	if (ret == 0)

		group->domain = domain;



	return ret;

}



int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)

{

	int ret;



	mutex_lock(&group->mutex);

	ret = __iommu_attach_group(domain, group);

	mutex_unlock(&group->mutex);



	return ret;

}

EXPORT_SYMBOL_GPL(iommu_attach_group);
@@ -1088,9 +1130,35 @@ static int iommu_group_do_detach_device(struct device *dev, void *data) 
	return 0;

}



static void __iommu_detach_group(struct iommu_domain *domain,

				 struct iommu_group *group)

{

	int ret;



	if (!group->default_domain) {

		__iommu_group_for_each_dev(group, domain,

					   iommu_group_do_detach_device);

		group->domain = NULL;

		return;

	}



	if (group->domain == group->default_domain)

		return;



	/* Detach by re-attaching to the default domain */

	ret = __iommu_group_for_each_dev(group, group->default_domain,

					 iommu_group_do_attach_device);

	if (ret != 0)

		WARN_ON(1);

	else

		group->domain = group->default_domain;

}



void iommu_detach_group(struct iommu_domain *domain, struct iommu_group *group)

{

	iommu_group_for_each_dev(group, domain, iommu_group_do_detach_device);

	mutex_lock(&group->mutex);

	__iommu_detach_group(domain, group);

	mutex_unlock(&group->mutex);

}

EXPORT_SYMBOL_GPL(iommu_detach_group);