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: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20221018024258.19073-4-yong.wu@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index df490236e1fb57e16c79f8507ad82433e11791af..e0c669b75271d8c346f48730382d6cdfce058125 100644 (file)
--- a/drivers/iommu/mtk_iommu.c
+++ b/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)