[PATCH v6 07/33] iommu: Avoid reallocate default domain for a group

[Yong Wu]

If group->default_domain exists, avoid reallocate it.

In some iommu drivers, there may be several devices share a group. Avoid
realloc the default domain for this case.

Signed-off-by: Yong Wu <yong...@mediatek.com>
---
 drivers/iommu/iommu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3d099a31ddca..f4b87e6abe80 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -266,7 +266,8 @@ int iommu_probe_device(struct device *dev)
         * support default domains, so the return value is not yet
         * checked.
         */
-       iommu_alloc_default_domain(group, dev);
+       if (!group->default_domain)
+               iommu_alloc_default_domain(group, dev);
 
        if (group->default_domain) {
                ret = __iommu_attach_device(group->default_domain, dev);
-- 
2.18.0