iommu/mediatek: Add error path for loop of mm_dts_parse

The mtk_iommu_mm_dts_parse will parse the smi larbs nodes. if the i+1
larb is parsed fail, we should put_device for the i..0 larbs.

There are two places need to comment:
1) The larbid may be not linear mapping, we should loop whole
   the array in the error path.
2) I move this line position: "data->larb_imu[id].dev = &plarbdev->dev;"
   before "if (!plarbdev->dev.driver)", That means set
   data->larb_imu[id].dev before the error path. then we don't need
   "platform_device_put(plarbdev)" again in probe_defer case. All depend
   on "put_device" of the error path in error cases.

Fixes: d2e9a11 ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
Signed-off-by: Yong Wu <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Reviewed-by: Matthias Brugger <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>

Author: YongWu-HF

drivers/iommu/mtk_iommu.c

@@ -1067,8 +1067,10 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 		u32 id;
 
 		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
-		if (!larbnode)
-			return -EINVAL;
+		if (!larbnode) {
+			ret = -EINVAL;
+			goto err_larbdev_put;
+		}
 
 		if (!of_device_is_available(larbnode)) {
 			of_node_put(larbnode);
@@ -1081,14 +1083,16 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 
 		plarbdev = of_find_device_by_node(larbnode);
 		of_node_put(larbnode);
-		if (!plarbdev)
-			return -ENODEV;
+		if (!plarbdev) {
+			ret = -ENODEV;
+			goto err_larbdev_put;
+		}
+		data->larb_imu[id].dev = &plarbdev->dev;
 
 		if (!plarbdev->dev.driver) {
-			platform_device_put(plarbdev);
-			return -EPROBE_DEFER;
+			ret = -EPROBE_DEFER;
+			goto err_larbdev_put;
 		}
-		data->larb_imu[id].dev = &plarbdev->dev;
 
 		component_match_add(dev, match, component_compare_dev, &plarbdev->dev);
 		platform_device_put(plarbdev);
@@ -1123,6 +1127,15 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 		return -EINVAL;
 	}
 	return 0;
+
+err_larbdev_put:
+	/* id may be not linear mapping, loop whole the array */
+	for (i = MTK_LARB_NR_MAX - 1; i >= 0; i++) {
+		if (!data->larb_imu[i].dev)
+			continue;
+		put_device(data->larb_imu[i].dev);
+	}
+	return ret;
 }
 
 static int mtk_iommu_probe(struct platform_device *pdev)