iommu/exynos: Fix driver initialization sequence

Registering a SYSMMU platform driver might directly trigger initializing
IOMMU domains and performing the initial mappings. Also the IOMMU core
might use the IOMMU hardware once it has been registered with
iommu_device_register() function. Ensure that all driver resources are
allocated and initialized before the driver advertise its presence to the
platform bus and the IOMMU subsystem.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20221110154407.26531-1-m.szyprowski@samsung.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 45fd485..b0cde22 100644 (file)
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -708,10 +708,6 @@ static int exynos_sysmmu_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
-       ret = iommu_device_register(&data->iommu, &exynos_iommu_ops, dev);
-       if (ret)
-               goto err_iommu_register;
-
        platform_set_drvdata(pdev, data);
 
        if (PG_ENT_SHIFT < 0) {
@@ -743,11 +739,13 @@ static int exynos_sysmmu_probe(struct platform_device *pdev)
 
        pm_runtime_enable(dev);
 
+       ret = iommu_device_register(&data->iommu, &exynos_iommu_ops, dev);
+       if (ret)
+               goto err_dma_set_mask;
+
        return 0;
 
 err_dma_set_mask:
-       iommu_device_unregister(&data->iommu);
-err_iommu_register:
        iommu_device_sysfs_remove(&data->iommu);
        return ret;
 }
@@ -1432,12 +1430,6 @@ static int __init exynos_iommu_init(void)
                return -ENOMEM;
        }
 
-       ret = platform_driver_register(&exynos_sysmmu_driver);
-       if (ret) {
-               pr_err("%s: Failed to register driver\n", __func__);
-               goto err_reg_driver;
-       }
-
        zero_lv2_table = kmem_cache_zalloc(lv2table_kmem_cache, GFP_KERNEL);
        if (zero_lv2_table == NULL) {
                pr_err("%s: Failed to allocate zero level2 page table\n",
@@ -1446,10 +1438,16 @@ static int __init exynos_iommu_init(void)
                goto err_zero_lv2;
        }
 
+       ret = platform_driver_register(&exynos_sysmmu_driver);
+       if (ret) {
+               pr_err("%s: Failed to register driver\n", __func__);
+               goto err_reg_driver;
+       }
+
        return 0;
-err_zero_lv2:
-       platform_driver_unregister(&exynos_sysmmu_driver);
 err_reg_driver:
+       platform_driver_unregister(&exynos_sysmmu_driver);
+err_zero_lv2:
        kmem_cache_destroy(lv2table_kmem_cache);
        return ret;
 }