iommu/qcom: fix device leak on of_xlate()

Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().

Note that commit e2eae09939a8 ("iommu/qcom: add missing put_device()
call in qcom_iommu_of_xlate()") fixed the leak in a couple of error
paths, but the reference is still leaking on success and late failures.

Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu")
Cc: stable@vger.kernel.org	# 4.14: e2eae09939a8
Cc: Rob Clark <robin.clark@oss.qualcomm.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index 9222a4a48bb3343586ebd2e2579a0722038ba8e4..f69d9276dc55c75a82a353f8f7fbb7a9fbd071d7 100644 (file)
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -566,14 +566,14 @@ static int qcom_iommu_of_xlate(struct device *dev,
 
        qcom_iommu = platform_get_drvdata(iommu_pdev);
 
+       put_device(&iommu_pdev->dev);
+
        /* make sure the asid specified in dt is valid, so we don't have
         * to sanity check this elsewhere:
         */
        if (WARN_ON(asid > qcom_iommu->max_asid) ||
-           WARN_ON(qcom_iommu->ctxs[asid] == NULL)) {
-               put_device(&iommu_pdev->dev);
+           WARN_ON(qcom_iommu->ctxs[asid] == NULL))
                return -EINVAL;
-       }
 
        if (!dev_iommu_priv_get(dev)) {
                dev_iommu_priv_set(dev, qcom_iommu);
@@ -582,10 +582,8 @@ static int qcom_iommu_of_xlate(struct device *dev,
                 * multiple different iommu devices.  Multiple context
                 * banks are ok, but multiple devices are not:
                 */
-               if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev))) {
-                       put_device(&iommu_pdev->dev);
+               if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev)))
                        return -EINVAL;
-               }
        }
 
        return iommu_fwspec_add_ids(dev, &asid, 1);