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authorLu Baolu <baolu.lu@linux.intel.com>2023-03-22 07:49:54 +0100
committerJoerg Roedel <jroedel@suse.de>2023-03-22 15:45:17 +0100
commit33793748de8fde338c11277d3d16dadc79ba65bf (patch)
tree1affdcc3371b33aaa2238fbfcb9c4eee88d93904 /drivers/iommu
parentiommu: Same critical region for device release and removal (diff)
downloadlinux-33793748de8fde338c11277d3d16dadc79ba65bf.tar.xz
linux-33793748de8fde338c11277d3d16dadc79ba65bf.zip
iommu: Move lock from iommu_change_dev_def_domain() to its caller
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>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/iommu.c29
1 files changed, 14 insertions, 15 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 419d5655ce61..32c51e6a3491 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -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: