xref: /linux/drivers/vfio/platform/vfio_amba.c (revision 55a42f78ffd386e01a5404419f8c5ded7db70a21)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2013 - Virtual Open Systems
4  * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
5  */
6 
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/vfio.h>
10 #include <linux/pm_runtime.h>
11 #include <linux/amba/bus.h>
12 
13 #include "vfio_platform_private.h"
14 
15 #define DRIVER_VERSION  "0.10"
16 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
17 #define DRIVER_DESC     "VFIO for AMBA devices - User Level meta-driver"
18 
19 /* probing devices from the AMBA bus */
20 
21 static struct resource *get_amba_resource(struct vfio_platform_device *vdev,
22 					  int i)
23 {
24 	struct amba_device *adev = (struct amba_device *) vdev->opaque;
25 
26 	if (i == 0)
27 		return &adev->res;
28 
29 	return NULL;
30 }
31 
32 static int get_amba_irq(struct vfio_platform_device *vdev, int i)
33 {
34 	struct amba_device *adev = (struct amba_device *) vdev->opaque;
35 	int ret = 0;
36 
37 	if (i < AMBA_NR_IRQS)
38 		ret = adev->irq[i];
39 
40 	/* zero is an unset IRQ for AMBA devices */
41 	return ret ? ret : -ENXIO;
42 }
43 
44 static int vfio_amba_init_dev(struct vfio_device *core_vdev)
45 {
46 	struct vfio_platform_device *vdev =
47 		container_of(core_vdev, struct vfio_platform_device, vdev);
48 	struct amba_device *adev = to_amba_device(core_vdev->dev);
49 	int ret;
50 
51 	vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
52 	if (!vdev->name)
53 		return -ENOMEM;
54 
55 	vdev->opaque = (void *) adev;
56 	vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
57 	vdev->get_resource = get_amba_resource;
58 	vdev->get_irq = get_amba_irq;
59 	vdev->reset_required = false;
60 
61 	ret = vfio_platform_init_common(vdev);
62 	if (ret)
63 		kfree(vdev->name);
64 	return ret;
65 }
66 
67 static const struct vfio_device_ops vfio_amba_ops;
68 static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
69 {
70 	struct vfio_platform_device *vdev;
71 	int ret;
72 
73 	dev_err_once(&adev->dev, "DEPRECATION: vfio-amba is deprecated and will be removed in a future kernel release\n");
74 
75 	vdev = vfio_alloc_device(vfio_platform_device, vdev, &adev->dev,
76 				 &vfio_amba_ops);
77 	if (IS_ERR(vdev))
78 		return PTR_ERR(vdev);
79 
80 	ret = vfio_register_group_dev(&vdev->vdev);
81 	if (ret)
82 		goto out_put_vdev;
83 
84 	pm_runtime_enable(&adev->dev);
85 	dev_set_drvdata(&adev->dev, vdev);
86 	return 0;
87 
88 out_put_vdev:
89 	vfio_put_device(&vdev->vdev);
90 	return ret;
91 }
92 
93 static void vfio_amba_release_dev(struct vfio_device *core_vdev)
94 {
95 	struct vfio_platform_device *vdev =
96 		container_of(core_vdev, struct vfio_platform_device, vdev);
97 
98 	vfio_platform_release_common(vdev);
99 	kfree(vdev->name);
100 }
101 
102 static void vfio_amba_remove(struct amba_device *adev)
103 {
104 	struct vfio_platform_device *vdev = dev_get_drvdata(&adev->dev);
105 
106 	vfio_unregister_group_dev(&vdev->vdev);
107 	pm_runtime_disable(vdev->device);
108 	vfio_put_device(&vdev->vdev);
109 }
110 
111 static const struct vfio_device_ops vfio_amba_ops = {
112 	.name		= "vfio-amba",
113 	.init		= vfio_amba_init_dev,
114 	.release	= vfio_amba_release_dev,
115 	.open_device	= vfio_platform_open_device,
116 	.close_device	= vfio_platform_close_device,
117 	.ioctl		= vfio_platform_ioctl,
118 	.read		= vfio_platform_read,
119 	.write		= vfio_platform_write,
120 	.mmap		= vfio_platform_mmap,
121 	.bind_iommufd	= vfio_iommufd_physical_bind,
122 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
123 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
124 	.detach_ioas	= vfio_iommufd_physical_detach_ioas,
125 };
126 
127 static const struct amba_id vfio_amba_ids[] = {
128 	{ 0, 0 },
129 };
130 
131 MODULE_DEVICE_TABLE(amba, vfio_amba_ids);
132 
133 static struct amba_driver vfio_amba_driver = {
134 	.probe = vfio_amba_probe,
135 	.remove = vfio_amba_remove,
136 	.id_table = vfio_amba_ids,
137 	.drv = {
138 		.name = "vfio-amba",
139 	},
140 	.driver_managed_dma = true,
141 };
142 
143 module_amba_driver(vfio_amba_driver);
144 
145 MODULE_VERSION(DRIVER_VERSION);
146 MODULE_LICENSE("GPL v2");
147 MODULE_AUTHOR(DRIVER_AUTHOR);
148 MODULE_DESCRIPTION(DRIVER_DESC);
149