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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * IOMMU sysfs class support
4 *
5 * Copyright (C) 2014 Red Hat, Inc. All rights reserved.
6 * Author: Alex Williamson <alex.williamson@redhat.com>
7 */
8
9#include <linux/device.h>
10#include <linux/iommu.h>
11#include <linux/init.h>
12#include <linux/slab.h>
13
14/*
15 * We provide a common class "devices" group which initially has no attributes.
16 * As devices are added to the IOMMU, we'll add links to the group.
17 */
18static struct attribute *devices_attr[] = {
19 NULL,
20};
21
22static const struct attribute_group devices_attr_group = {
23 .name = "devices",
24 .attrs = devices_attr,
25};
26
27static const struct attribute_group *dev_groups[] = {
28 &devices_attr_group,
29 NULL,
30};
31
32static void release_device(struct device *dev)
33{
34 kfree(dev);
35}
36
37static struct class iommu_class = {
38 .name = "iommu",
39 .dev_release = release_device,
40 .dev_groups = dev_groups,
41};
42
43static int __init iommu_dev_init(void)
44{
45 return class_register(&iommu_class);
46}
47postcore_initcall(iommu_dev_init);
48
49/*
50 * Init the struct device for the IOMMU. IOMMU specific attributes can
51 * be provided as an attribute group, allowing a unique namespace per
52 * IOMMU type.
53 */
54int iommu_device_sysfs_add(struct iommu_device *iommu,
55 struct device *parent,
56 const struct attribute_group **groups,
57 const char *fmt, ...)
58{
59 va_list vargs;
60 int ret;
61
62 iommu->dev = kzalloc(sizeof(*iommu->dev), GFP_KERNEL);
63 if (!iommu->dev)
64 return -ENOMEM;
65
66 device_initialize(iommu->dev);
67
68 iommu->dev->class = &iommu_class;
69 iommu->dev->parent = parent;
70 iommu->dev->groups = groups;
71
72 va_start(vargs, fmt);
73 ret = kobject_set_name_vargs(&iommu->dev->kobj, fmt, vargs);
74 va_end(vargs);
75 if (ret)
76 goto error;
77
78 ret = device_add(iommu->dev);
79 if (ret)
80 goto error;
81
82 dev_set_drvdata(iommu->dev, iommu);
83
84 return 0;
85
86error:
87 put_device(iommu->dev);
88 return ret;
89}
90EXPORT_SYMBOL_GPL(iommu_device_sysfs_add);
91
92void iommu_device_sysfs_remove(struct iommu_device *iommu)
93{
94 dev_set_drvdata(iommu->dev, NULL);
95 device_unregister(iommu->dev);
96 iommu->dev = NULL;
97}
98EXPORT_SYMBOL_GPL(iommu_device_sysfs_remove);
99
100/*
101 * IOMMU drivers can indicate a device is managed by a given IOMMU using
102 * this interface. A link to the device will be created in the "devices"
103 * directory of the IOMMU device in sysfs and an "iommu" link will be
104 * created under the linked device, pointing back at the IOMMU device.
105 */
106int iommu_device_link(struct iommu_device *iommu, struct device *link)
107{
108 int ret;
109
110 if (!iommu || IS_ERR(iommu))
111 return -ENODEV;
112
113 ret = sysfs_add_link_to_group(&iommu->dev->kobj, "devices",
114 &link->kobj, dev_name(link));
115 if (ret)
116 return ret;
117
118 ret = sysfs_create_link_nowarn(&link->kobj, &iommu->dev->kobj, "iommu");
119 if (ret)
120 sysfs_remove_link_from_group(&iommu->dev->kobj, "devices",
121 dev_name(link));
122
123 return ret;
124}
125EXPORT_SYMBOL_GPL(iommu_device_link);
126
127void iommu_device_unlink(struct iommu_device *iommu, struct device *link)
128{
129 if (!iommu || IS_ERR(iommu))
130 return;
131
132 sysfs_remove_link(&link->kobj, "iommu");
133 sysfs_remove_link_from_group(&iommu->dev->kobj, "devices", dev_name(link));
134}
135EXPORT_SYMBOL_GPL(iommu_device_unlink);
1/*
2 * IOMMU sysfs class support
3 *
4 * Copyright (C) 2014 Red Hat, Inc. All rights reserved.
5 * Author: Alex Williamson <alex.williamson@redhat.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/device.h>
13#include <linux/iommu.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16
17/*
18 * We provide a common class "devices" group which initially has no attributes.
19 * As devices are added to the IOMMU, we'll add links to the group.
20 */
21static struct attribute *devices_attr[] = {
22 NULL,
23};
24
25static const struct attribute_group iommu_devices_attr_group = {
26 .name = "devices",
27 .attrs = devices_attr,
28};
29
30static const struct attribute_group *iommu_dev_groups[] = {
31 &iommu_devices_attr_group,
32 NULL,
33};
34
35static void iommu_release_device(struct device *dev)
36{
37 kfree(dev);
38}
39
40static struct class iommu_class = {
41 .name = "iommu",
42 .dev_release = iommu_release_device,
43 .dev_groups = iommu_dev_groups,
44};
45
46static int __init iommu_dev_init(void)
47{
48 return class_register(&iommu_class);
49}
50postcore_initcall(iommu_dev_init);
51
52/*
53 * Create an IOMMU device and return a pointer to it. IOMMU specific
54 * attributes can be provided as an attribute group, allowing a unique
55 * namespace per IOMMU type.
56 */
57struct device *iommu_device_create(struct device *parent, void *drvdata,
58 const struct attribute_group **groups,
59 const char *fmt, ...)
60{
61 struct device *dev;
62 va_list vargs;
63 int ret;
64
65 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
66 if (!dev)
67 return ERR_PTR(-ENOMEM);
68
69 device_initialize(dev);
70
71 dev->class = &iommu_class;
72 dev->parent = parent;
73 dev->groups = groups;
74 dev_set_drvdata(dev, drvdata);
75
76 va_start(vargs, fmt);
77 ret = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
78 va_end(vargs);
79 if (ret)
80 goto error;
81
82 ret = device_add(dev);
83 if (ret)
84 goto error;
85
86 return dev;
87
88error:
89 put_device(dev);
90 return ERR_PTR(ret);
91}
92
93void iommu_device_destroy(struct device *dev)
94{
95 if (!dev || IS_ERR(dev))
96 return;
97
98 device_unregister(dev);
99}
100
101/*
102 * IOMMU drivers can indicate a device is managed by a given IOMMU using
103 * this interface. A link to the device will be created in the "devices"
104 * directory of the IOMMU device in sysfs and an "iommu" link will be
105 * created under the linked device, pointing back at the IOMMU device.
106 */
107int iommu_device_link(struct device *dev, struct device *link)
108{
109 int ret;
110
111 if (!dev || IS_ERR(dev))
112 return -ENODEV;
113
114 ret = sysfs_add_link_to_group(&dev->kobj, "devices",
115 &link->kobj, dev_name(link));
116 if (ret)
117 return ret;
118
119 ret = sysfs_create_link_nowarn(&link->kobj, &dev->kobj, "iommu");
120 if (ret)
121 sysfs_remove_link_from_group(&dev->kobj, "devices",
122 dev_name(link));
123
124 return ret;
125}
126
127void iommu_device_unlink(struct device *dev, struct device *link)
128{
129 if (!dev || IS_ERR(dev))
130 return;
131
132 sysfs_remove_link(&link->kobj, "iommu");
133 sysfs_remove_link_from_group(&dev->kobj, "devices", dev_name(link));
134}