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authorRobin Murphy <robin.murphy@arm.com>2016-11-11 17:59:24 +0000
committerJoerg Roedel <jroedel@suse.de>2016-11-15 12:25:33 +0100
commit3a8d40b6ce8c3f682d3b00a568d406b2f8726701 (patch)
tree9843119a9ff7556b4ed1ccbedc0837e225e4b658 /drivers/iommu
parentf2f101f6bcb3c47a432543dd309056e58192550f (diff)
downloadlinux-3a8d40b6ce8c3f682d3b00a568d406b2f8726701.tar.gz
iommu/mediatek: Fix M4Uv2 group refcounting
For each subsequent device assigned to the m4u_group after its initial
allocation, we need to take an additional reference. Otherwise, the
caller of iommu_group_get_for_dev() will inadvertently remove the
reference taken by iommu_group_add_device(), and the group will be
freed prematurely if any device is removed.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/mtk_iommu.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index b12c12d74c33..9799daeaacde 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -410,6 +410,8 @@ static struct iommu_group *mtk_iommu_device_group(struct device *dev)
 		data->m4u_group = iommu_group_alloc();
 		if (IS_ERR(data->m4u_group))
 			dev_err(dev, "Failed to allocate M4U IOMMU group\n");
+	} else {
+		iommu_group_ref_get(data->m4u_group);
 	}
 	return data->m4u_group;
 }