From: Thierry Reding <treding@xxxxxxxxxx>
In order to share groups between multiple devices we keep track of them
in a per-SMMU list. When an IOMMU group is released, a dangling pointer
to it stays around in that list. Fix this by implementing an IOMMU data
release callback for groups where the dangling pointer can be removed.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/iommu/tegra-smmu.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index c439c0929ef8..2574e716086b 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -19,6 +19,7 @@
struct tegra_smmu_group {
struct list_head list;
+ struct tegra_smmu *smmu;
const struct tegra_smmu_group_soc *soc;
struct iommu_group *group;
};
@@ -813,6 +814,16 @@ tegra_smmu_find_group(struct tegra_smmu *smmu, unsigned int swgroup)
return NULL;
}
+static void tegra_smmu_group_release(void *iommu_data)
+{
+ struct tegra_smmu_group *group = iommu_data;
+ struct tegra_smmu *smmu = group->smmu;
+
+ mutex_lock(&smmu->lock);
+ list_del(&group->list);
+ mutex_unlock(&smmu->lock);
+}
+
static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
unsigned int swgroup)
{
@@ -840,6 +851,7 @@ static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
}
INIT_LIST_HEAD(&group->list);
+ group->smmu = smmu;
group->soc = soc;
group->group = iommu_group_alloc();
@@ -849,6 +861,7 @@ static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
return NULL;
}
+ iommu_group_set_iommudata(group->group, group, tegra_smmu_group_release);
iommu_group_set_name(group->group, soc->name);
list_add_tail(&group->list, &smmu->groups);
mutex_unlock(&smmu->lock);
--
2.27.0
