[PATCH v4 4/5] iommu/arm-smmu: to backward compatible with probe non-deferral

[Zhen Lei]

This patch eliminate the strong dependence on Laurent's series(to support
probe deferral). That means, no matter whether Laurent's series upstreamed
or not, the smmu-v3 driver will always work well.

Signed-off-by: Zhen Lei <thunder.leizhen at huawei.com>
---
 drivers/iommu/arm-smmu-v3.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 021a846..66052e9 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1857,6 +1857,12 @@ static int arm_smmu_add_device(struct device *dev)
 	struct pci_dev *pdev;
 	struct device *root;

+	if (dev->archdata.iommu == ERR_PTR(-EPROBE_DEFER)) {
+		dev->archdata.iommu = NULL;
+
+		return of_iommu_configure(dev, dev->of_node) ? 0 : -ENODEV;
+	}
+
 	/* only support pci devices hotplug */
 	if (!dev_is_pci(dev))
 		return -ENODEV;
@@ -1930,6 +1936,11 @@ static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
 		return -EINVAL;

 	smmu = platform_get_drvdata(pdev);
+	if (!smmu) {
+		dev->archdata.iommu = ERR_PTR(-EPROBE_DEFER);
+
+		return -EPROBE_DEFER;
+	}

 	if (!dev->archdata.iommu)
 		dev->archdata.iommu = smmu;
@@ -2768,7 +2779,6 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)

 	/* Record our private device structure */
 	platform_set_drvdata(pdev, smmu);
-	of_iommu_set_ops(smmu->dev->of_node, &arm_smmu_ops);

 	/* Reset the device */
 	ret = arm_smmu_device_reset(smmu);
@@ -2840,7 +2850,13 @@ static void __exit arm_smmu_exit(void)
 subsys_initcall(arm_smmu_init);
 module_exit(arm_smmu_exit);

-IOMMU_OF_DECLARE(arm_smmu_v3, "arm,smmu-v3", NULL);
+static int arm_smmu_of_iommu_init(struct device_node *np)
+{
+	of_iommu_set_ops(np, &arm_smmu_ops);
+
+	return 0;
+}
+IOMMU_OF_DECLARE(arm_smmu_v3, "arm,smmu-v3", arm_smmu_of_iommu_init);

 MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
 MODULE_AUTHOR("Will Deacon <will.deacon at arm.com>");
--
2.5.0