projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 1ca55d50 OT |
1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* | |
| 3 | * Stub IOMMU driver which does nothing. | |
| 4 | * The main purpose of it being present is to reuse generic IOMMU device tree | |
| 5 | * bindings by Xen grant DMA-mapping layer. | |
| 6 | * | |
| 7 | * Copyright (C) 2022 EPAM Systems Inc. | |
| 8 | */ | |
| 9 | ||
| 10 | #include <linux/iommu.h> | |
| 11 | #include <linux/of.h> | |
| 12 | #include <linux/platform_device.h> | |
| 13 | ||
| 14 | struct grant_dma_iommu_device { | |
| 15 | struct device *dev; | |
| 16 | struct iommu_device iommu; | |
| 17 | }; | |
| 18 | ||
| 19 | /* Nothing is really needed here */ | |
| 20 | static const struct iommu_ops grant_dma_iommu_ops; | |
| 21 | ||
| 22 | static const struct of_device_id grant_dma_iommu_of_match[] = { | |
| 23 | { .compatible = "xen,grant-dma" }, | |
| 24 | { }, | |
| 25 | }; | |
| 26 | ||
| 27 | static int grant_dma_iommu_probe(struct platform_device *pdev) | |
| 28 | { | |
| 29 | struct grant_dma_iommu_device *mmu; | |
| 30 | int ret; | |
| 31 | ||
| 32 | mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL); | |
| 33 | if (!mmu) | |
| 34 | return -ENOMEM; | |
| 35 | ||
| 36 | mmu->dev = &pdev->dev; | |
| 37 | ||
| 38 | ret = iommu_device_register(&mmu->iommu, &grant_dma_iommu_ops, &pdev->dev); | |
| 39 | if (ret) | |
| 40 | return ret; | |
| 41 | ||
| 42 | platform_set_drvdata(pdev, mmu); | |
| 43 | ||
| 44 | return 0; | |
| 45 | } | |
| 46 | ||
| 47 | static int grant_dma_iommu_remove(struct platform_device *pdev) | |
| 48 | { | |
| 49 | struct grant_dma_iommu_device *mmu = platform_get_drvdata(pdev); | |
| 50 | ||
| 51 | platform_set_drvdata(pdev, NULL); | |
| 52 | iommu_device_unregister(&mmu->iommu); | |
| 53 | ||
| 54 | return 0; | |
| 55 | } | |
| 56 | ||
| 57 | static struct platform_driver grant_dma_iommu_driver = { | |
| 58 | .driver = { | |
| 59 | .name = "grant-dma-iommu", | |
| 60 | .of_match_table = grant_dma_iommu_of_match, | |
| 61 | }, | |
| 62 | .probe = grant_dma_iommu_probe, | |
| 63 | .remove = grant_dma_iommu_remove, | |
| 64 | }; | |
| 65 | ||
| 66 | static int __init grant_dma_iommu_init(void) | |
| 67 | { | |
| 68 | struct device_node *iommu_np; | |
| 69 | ||
| 70 | iommu_np = of_find_matching_node(NULL, grant_dma_iommu_of_match); | |
| 71 | if (!iommu_np) | |
| 72 | return 0; | |
| 73 | ||
| 74 | of_node_put(iommu_np); | |
| 75 | ||
| 76 | return platform_driver_register(&grant_dma_iommu_driver); | |
| 77 | } | |
| 78 | subsys_initcall(grant_dma_iommu_init); |