1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * File attributes for Mediated devices
4 *
5 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
6 * Author: Neo Jia <cjia@nvidia.com>
7 * Kirti Wankhede <kwankhede@nvidia.com>
8 */
9
10 #include <linux/sysfs.h>
11 #include <linux/ctype.h>
12 #include <linux/device.h>
13 #include <linux/slab.h>
14 #include <linux/uuid.h>
15 #include <linux/mdev.h>
16
17 #include "mdev_private.h"
18
19 /* Static functions */
20
mdev_type_attr_show(struct kobject * kobj,struct attribute * __attr,char * buf)21 static ssize_t mdev_type_attr_show(struct kobject *kobj,
22 struct attribute *__attr, char *buf)
23 {
24 struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
25 struct mdev_type *type = to_mdev_type(kobj);
26 ssize_t ret = -EIO;
27
28 if (attr->show)
29 ret = attr->show(type, attr, buf);
30 return ret;
31 }
32
mdev_type_attr_store(struct kobject * kobj,struct attribute * __attr,const char * buf,size_t count)33 static ssize_t mdev_type_attr_store(struct kobject *kobj,
34 struct attribute *__attr,
35 const char *buf, size_t count)
36 {
37 struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
38 struct mdev_type *type = to_mdev_type(kobj);
39 ssize_t ret = -EIO;
40
41 if (attr->store)
42 ret = attr->store(type, attr, buf, count);
43 return ret;
44 }
45
46 static const struct sysfs_ops mdev_type_sysfs_ops = {
47 .show = mdev_type_attr_show,
48 .store = mdev_type_attr_store,
49 };
50
create_store(struct mdev_type * mtype,struct mdev_type_attribute * attr,const char * buf,size_t count)51 static ssize_t create_store(struct mdev_type *mtype,
52 struct mdev_type_attribute *attr, const char *buf,
53 size_t count)
54 {
55 char *str;
56 guid_t uuid;
57 int ret;
58
59 if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
60 return -EINVAL;
61
62 str = kstrndup(buf, count, GFP_KERNEL);
63 if (!str)
64 return -ENOMEM;
65
66 ret = guid_parse(str, &uuid);
67 kfree(str);
68 if (ret)
69 return ret;
70
71 ret = mdev_device_create(mtype, &uuid);
72 if (ret)
73 return ret;
74
75 return count;
76 }
77
78 static MDEV_TYPE_ATTR_WO(create);
79
mdev_type_release(struct kobject * kobj)80 static void mdev_type_release(struct kobject *kobj)
81 {
82 struct mdev_type *type = to_mdev_type(kobj);
83
84 pr_debug("Releasing group %s\n", kobj->name);
85 /* Pairs with the get in add_mdev_supported_type() */
86 mdev_put_parent(type->parent);
87 kfree(type);
88 }
89
90 static struct kobj_type mdev_type_ktype = {
91 .sysfs_ops = &mdev_type_sysfs_ops,
92 .release = mdev_type_release,
93 };
94
add_mdev_supported_type(struct mdev_parent * parent,unsigned int type_group_id)95 static struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
96 unsigned int type_group_id)
97 {
98 struct mdev_type *type;
99 struct attribute_group *group =
100 parent->mdev_driver->supported_type_groups[type_group_id];
101 int ret;
102
103 if (!group->name) {
104 pr_err("%s: Type name empty!\n", __func__);
105 return ERR_PTR(-EINVAL);
106 }
107
108 type = kzalloc(sizeof(*type), GFP_KERNEL);
109 if (!type)
110 return ERR_PTR(-ENOMEM);
111
112 type->kobj.kset = parent->mdev_types_kset;
113 type->parent = parent;
114 /* Pairs with the put in mdev_type_release() */
115 mdev_get_parent(parent);
116 type->type_group_id = type_group_id;
117
118 ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
119 "%s-%s", dev_driver_string(parent->dev),
120 group->name);
121 if (ret) {
122 kobject_put(&type->kobj);
123 return ERR_PTR(ret);
124 }
125
126 ret = sysfs_create_file(&type->kobj, &mdev_type_attr_create.attr);
127 if (ret)
128 goto attr_create_failed;
129
130 type->devices_kobj = kobject_create_and_add("devices", &type->kobj);
131 if (!type->devices_kobj) {
132 ret = -ENOMEM;
133 goto attr_devices_failed;
134 }
135
136 ret = sysfs_create_files(&type->kobj,
137 (const struct attribute **)group->attrs);
138 if (ret) {
139 ret = -ENOMEM;
140 goto attrs_failed;
141 }
142 return type;
143
144 attrs_failed:
145 kobject_put(type->devices_kobj);
146 attr_devices_failed:
147 sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
148 attr_create_failed:
149 kobject_del(&type->kobj);
150 kobject_put(&type->kobj);
151 return ERR_PTR(ret);
152 }
153
remove_mdev_supported_type(struct mdev_type * type)154 static void remove_mdev_supported_type(struct mdev_type *type)
155 {
156 struct attribute_group *group =
157 type->parent->mdev_driver->supported_type_groups[type->type_group_id];
158
159 sysfs_remove_files(&type->kobj,
160 (const struct attribute **)group->attrs);
161 kobject_put(type->devices_kobj);
162 sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
163 kobject_del(&type->kobj);
164 kobject_put(&type->kobj);
165 }
166
add_mdev_supported_type_groups(struct mdev_parent * parent)167 static int add_mdev_supported_type_groups(struct mdev_parent *parent)
168 {
169 int i;
170
171 for (i = 0; parent->mdev_driver->supported_type_groups[i]; i++) {
172 struct mdev_type *type;
173
174 type = add_mdev_supported_type(parent, i);
175 if (IS_ERR(type)) {
176 struct mdev_type *ltype, *tmp;
177
178 list_for_each_entry_safe(ltype, tmp, &parent->type_list,
179 next) {
180 list_del(<ype->next);
181 remove_mdev_supported_type(ltype);
182 }
183 return PTR_ERR(type);
184 }
185 list_add(&type->next, &parent->type_list);
186 }
187 return 0;
188 }
189
190 /* mdev sysfs functions */
parent_remove_sysfs_files(struct mdev_parent * parent)191 void parent_remove_sysfs_files(struct mdev_parent *parent)
192 {
193 struct mdev_type *type, *tmp;
194
195 list_for_each_entry_safe(type, tmp, &parent->type_list, next) {
196 list_del(&type->next);
197 remove_mdev_supported_type(type);
198 }
199
200 kset_unregister(parent->mdev_types_kset);
201 }
202
parent_create_sysfs_files(struct mdev_parent * parent)203 int parent_create_sysfs_files(struct mdev_parent *parent)
204 {
205 int ret;
206
207 parent->mdev_types_kset = kset_create_and_add("mdev_supported_types",
208 NULL, &parent->dev->kobj);
209
210 if (!parent->mdev_types_kset)
211 return -ENOMEM;
212
213 INIT_LIST_HEAD(&parent->type_list);
214
215 ret = add_mdev_supported_type_groups(parent);
216 if (ret)
217 goto create_err;
218 return 0;
219
220 create_err:
221 kset_unregister(parent->mdev_types_kset);
222 return ret;
223 }
224
remove_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)225 static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
226 const char *buf, size_t count)
227 {
228 struct mdev_device *mdev = to_mdev_device(dev);
229 unsigned long val;
230
231 if (kstrtoul(buf, 0, &val) < 0)
232 return -EINVAL;
233
234 if (val && device_remove_file_self(dev, attr)) {
235 int ret;
236
237 ret = mdev_device_remove(mdev);
238 if (ret)
239 return ret;
240 }
241
242 return count;
243 }
244
245 static DEVICE_ATTR_WO(remove);
246
247 static struct attribute *mdev_device_attrs[] = {
248 &dev_attr_remove.attr,
249 NULL,
250 };
251
252 static const struct attribute_group mdev_device_group = {
253 .attrs = mdev_device_attrs,
254 };
255
256 const struct attribute_group *mdev_device_groups[] = {
257 &mdev_device_group,
258 NULL
259 };
260
mdev_create_sysfs_files(struct mdev_device * mdev)261 int mdev_create_sysfs_files(struct mdev_device *mdev)
262 {
263 struct mdev_type *type = mdev->type;
264 struct kobject *kobj = &mdev->dev.kobj;
265 int ret;
266
267 ret = sysfs_create_link(type->devices_kobj, kobj, dev_name(&mdev->dev));
268 if (ret)
269 return ret;
270
271 ret = sysfs_create_link(kobj, &type->kobj, "mdev_type");
272 if (ret)
273 goto type_link_failed;
274 return ret;
275
276 type_link_failed:
277 sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
278 return ret;
279 }
280
mdev_remove_sysfs_files(struct mdev_device * mdev)281 void mdev_remove_sysfs_files(struct mdev_device *mdev)
282 {
283 struct kobject *kobj = &mdev->dev.kobj;
284
285 sysfs_remove_link(kobj, "mdev_type");
286 sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
287 }
288