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/amba/bus.h>
11 
12 #include "vfio_platform_private.h"
13 
14 #define DRIVER_VERSION  "0.10"
15 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
16 #define DRIVER_DESC     "VFIO for AMBA devices - User Level meta-driver"
17 
18 /* probing devices from the AMBA bus */
19 
20 static struct resource *get_amba_resource(struct vfio_platform_device *vdev,
21 					  int i)
22 {
23 	struct amba_device *adev = (struct amba_device *) vdev->opaque;
24 
25 	if (i == 0)
26 		return &adev->res;
27 
28 	return NULL;
29 }
30 
31 static int get_amba_irq(struct vfio_platform_device *vdev, int i)
32 {
33 	struct amba_device *adev = (struct amba_device *) vdev->opaque;
34 	int ret = 0;
35 
36 	if (i < AMBA_NR_IRQS)
37 		ret = adev->irq[i];
38 
39 	/* zero is an unset IRQ for AMBA devices */
40 	return ret ? ret : -ENXIO;
41 }
42 
43 static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
44 {
45 	struct vfio_platform_device *vdev;
46 	int ret;
47 
48 	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
49 	if (!vdev)
50 		return -ENOMEM;
51 
52 	vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
53 	if (!vdev->name) {
54 		kfree(vdev);
55 		return -ENOMEM;
56 	}
57 
58 	vdev->opaque = (void *) adev;
59 	vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
60 	vdev->get_resource = get_amba_resource;
61 	vdev->get_irq = get_amba_irq;
62 	vdev->reset_required = false;
63 
64 	ret = vfio_platform_probe_common(vdev, &adev->dev);
65 	if (ret) {
66 		kfree(vdev->name);
67 		kfree(vdev);
68 		return ret;
69 	}
70 
71 	dev_set_drvdata(&adev->dev, vdev);
72 	return 0;
73 }
74 
75 static void vfio_amba_remove(struct amba_device *adev)
76 {
77 	struct vfio_platform_device *vdev = dev_get_drvdata(&adev->dev);
78 
79 	vfio_platform_remove_common(vdev);
80 	kfree(vdev->name);
81 	kfree(vdev);
82 }
83 
84 static const struct amba_id pl330_ids[] = {
85 	{ 0, 0 },
86 };
87 
88 MODULE_DEVICE_TABLE(amba, pl330_ids);
89 
90 static struct amba_driver vfio_amba_driver = {
91 	.probe = vfio_amba_probe,
92 	.remove = vfio_amba_remove,
93 	.id_table = pl330_ids,
94 	.drv = {
95 		.name = "vfio-amba",
96 		.owner = THIS_MODULE,
97 	},
98 	.driver_managed_dma = true,
99 };
100 
101 module_amba_driver(vfio_amba_driver);
102 
103 MODULE_VERSION(DRIVER_VERSION);
104 MODULE_LICENSE("GPL v2");
105 MODULE_AUTHOR(DRIVER_AUTHOR);
106 MODULE_DESCRIPTION(DRIVER_DESC);
107