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 	vdev = vfio_alloc_device(vfio_platform_device, vdev, &adev->dev,
74 				 &vfio_amba_ops);
75 	if (IS_ERR(vdev))
76 		return PTR_ERR(vdev);
77 
78 	ret = vfio_register_group_dev(&vdev->vdev);
79 	if (ret)
80 		goto out_put_vdev;
81 
82 	pm_runtime_enable(&adev->dev);
83 	dev_set_drvdata(&adev->dev, vdev);
84 	return 0;
85 
86 out_put_vdev:
87 	vfio_put_device(&vdev->vdev);
88 	return ret;
89 }
90 
91 static void vfio_amba_release_dev(struct vfio_device *core_vdev)
92 {
93 	struct vfio_platform_device *vdev =
94 		container_of(core_vdev, struct vfio_platform_device, vdev);
95 
96 	vfio_platform_release_common(vdev);
97 	kfree(vdev->name);
98 	vfio_free_device(core_vdev);
99 }
100 
101 static void vfio_amba_remove(struct amba_device *adev)
102 {
103 	struct vfio_platform_device *vdev = dev_get_drvdata(&adev->dev);
104 
105 	vfio_unregister_group_dev(&vdev->vdev);
106 	pm_runtime_disable(vdev->device);
107 	vfio_put_device(&vdev->vdev);
108 }
109 
110 static const struct vfio_device_ops vfio_amba_ops = {
111 	.name		= "vfio-amba",
112 	.init		= vfio_amba_init_dev,
113 	.release	= vfio_amba_release_dev,
114 	.open_device	= vfio_platform_open_device,
115 	.close_device	= vfio_platform_close_device,
116 	.ioctl		= vfio_platform_ioctl,
117 	.read		= vfio_platform_read,
118 	.write		= vfio_platform_write,
119 	.mmap		= vfio_platform_mmap,
120 };
121 
122 static const struct amba_id pl330_ids[] = {
123 	{ 0, 0 },
124 };
125 
126 MODULE_DEVICE_TABLE(amba, pl330_ids);
127 
128 static struct amba_driver vfio_amba_driver = {
129 	.probe = vfio_amba_probe,
130 	.remove = vfio_amba_remove,
131 	.id_table = pl330_ids,
132 	.drv = {
133 		.name = "vfio-amba",
134 		.owner = THIS_MODULE,
135 	},
136 	.driver_managed_dma = true,
137 };
138 
139 module_amba_driver(vfio_amba_driver);
140 
141 MODULE_VERSION(DRIVER_VERSION);
142 MODULE_LICENSE("GPL v2");
143 MODULE_AUTHOR(DRIVER_AUTHOR);
144 MODULE_DESCRIPTION(DRIVER_DESC);
145