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iommu: Move lock from iommu_change_dev_def_domain() to its caller

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The intention is to make it possible to put group ownership check and
default domain change in a same critical region protected by the group's
mutex lock. No intentional functional change.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230322064956.263419-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Lu Baolu 2023-03-22 14:49:54 +08:00 committed by Joerg Roedel
parent dba9ca9d41
commit 33793748de
1 changed files with 14 additions and 15 deletions
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29
drivers/iommu/iommu.c
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@ -2889,7 +2889,7 @@ static int iommu_change_dev_def_domain(struct iommu_group *group,
int ret, dev_def_dom;
struct device *dev;
mutex_lock(&group->mutex);
lockdep_assert_held(&group->mutex);
if (group->default_domain != group->domain) {
dev_err_ratelimited(prev_dev, "Group not assigned to default domain\n");
@ -2978,28 +2978,15 @@ static int iommu_change_dev_def_domain(struct iommu_group *group,
goto free_new_domain;
group->domain = group->default_domain;
/*
* Release the mutex here because ops->probe_finalize() call-back of
* some vendor IOMMU drivers calls arm_iommu_attach_device() which
* in-turn might call back into IOMMU core code, where it tries to take
* group->mutex, resulting in a deadlock.
*/
mutex_unlock(&group->mutex);
/* Make sure dma_ops is appropriatley set */
iommu_group_do_probe_finalize(dev, group->default_domain);
iommu_domain_free(prev_dom);
return 0;
free_new_domain:
iommu_domain_free(group->default_domain);
group->default_domain = prev_dom;
group->domain = prev_dom;
out:
mutex_unlock(&group->mutex);
return ret;
}
@ -3089,7 +3076,19 @@ static ssize_t iommu_group_store_type(struct iommu_group *group,
goto out;
}
mutex_lock(&group->mutex);
ret = iommu_change_dev_def_domain(group, dev, req_type);
/*
* Release the mutex here because ops->probe_finalize() call-back of
* some vendor IOMMU drivers calls arm_iommu_attach_device() which
* in-turn might call back into IOMMU core code, where it tries to take
* group->mutex, resulting in a deadlock.
*/
mutex_unlock(&group->mutex);
/* Make sure dma_ops is appropriatley set */
if (!ret)
iommu_group_do_probe_finalize(dev, group->default_domain);
ret = ret ?: count;
out: