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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 <[email protected]>
7 * Kirti Wankhede <[email protected]>
8 */
9
10#include <linux/sysfs.h>
11#include <linux/ctype.h>
12#include <linux/slab.h>
13#include <linux/mdev.h>
14
15#include "mdev_private.h"
16
17struct mdev_type_attribute {
18 struct attribute attr;
19 ssize_t (*show)(struct mdev_type *mtype,
20 struct mdev_type_attribute *attr, char *buf);
21 ssize_t (*store)(struct mdev_type *mtype,
22 struct mdev_type_attribute *attr, const char *buf,
23 size_t count);
24};
25
26#define MDEV_TYPE_ATTR_RO(_name) \
27 struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
28#define MDEV_TYPE_ATTR_WO(_name) \
29 struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
30
31static ssize_t mdev_type_attr_show(struct kobject *kobj,
32 struct attribute *__attr, char *buf)
33{
34 struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
35 struct mdev_type *type = to_mdev_type(kobj);
36 ssize_t ret = -EIO;
37
38 if (attr->show)
39 ret = attr->show(type, attr, buf);
40 return ret;
41}
42
43static ssize_t mdev_type_attr_store(struct kobject *kobj,
44 struct attribute *__attr,
45 const char *buf, size_t count)
46{
47 struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
48 struct mdev_type *type = to_mdev_type(kobj);
49 ssize_t ret = -EIO;
50
51 if (attr->store)
52 ret = attr->store(type, attr, buf, count);
53 return ret;
54}
55
56static const struct sysfs_ops mdev_type_sysfs_ops = {
57 .show = mdev_type_attr_show,
58 .store = mdev_type_attr_store,
59};
60
61static ssize_t create_store(struct mdev_type *mtype,
62 struct mdev_type_attribute *attr, const char *buf,
63 size_t count)
64{
65 char *str;
66 guid_t uuid;
67 int ret;
68
69 if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
70 return -EINVAL;
71
72 str = kstrndup(buf, count, GFP_KERNEL);
73 if (!str)
74 return -ENOMEM;
75
76 ret = guid_parse(str, &uuid);
77 kfree(str);
78 if (ret)
79 return ret;
80
81 ret = mdev_device_create(mtype, &uuid);
82 if (ret)
83 return ret;
84
85 return count;
86}
87static MDEV_TYPE_ATTR_WO(create);
88
89static ssize_t device_api_show(struct mdev_type *mtype,
90 struct mdev_type_attribute *attr, char *buf)
91{
92 return sysfs_emit(buf, "%s\n", mtype->parent->mdev_driver->device_api);
93}
94static MDEV_TYPE_ATTR_RO(device_api);
95
96static ssize_t name_show(struct mdev_type *mtype,
97 struct mdev_type_attribute *attr, char *buf)
98{
99 return sysfs_emit(buf, "%s\n",
100 mtype->pretty_name ? mtype->pretty_name : mtype->sysfs_name);
101}
102
103static MDEV_TYPE_ATTR_RO(name);
104
105static ssize_t available_instances_show(struct mdev_type *mtype,
106 struct mdev_type_attribute *attr,
107 char *buf)
108{
109 struct mdev_driver *drv = mtype->parent->mdev_driver;
110
111 if (drv->get_available)
112 return sysfs_emit(buf, "%u\n", drv->get_available(mtype));
113 return sysfs_emit(buf, "%u\n",
114 atomic_read(&mtype->parent->available_instances));
115}
116static MDEV_TYPE_ATTR_RO(available_instances);
117
118static ssize_t description_show(struct mdev_type *mtype,
119 struct mdev_type_attribute *attr,
120 char *buf)
121{
122 return mtype->parent->mdev_driver->show_description(mtype, buf);
123}
124static MDEV_TYPE_ATTR_RO(description);
125
126static struct attribute *mdev_types_core_attrs[] = {
127 &mdev_type_attr_create.attr,
128 &mdev_type_attr_device_api.attr,
129 &mdev_type_attr_name.attr,
130 &mdev_type_attr_available_instances.attr,
131 &mdev_type_attr_description.attr,
132 NULL,
133};
134
135static umode_t mdev_types_core_is_visible(struct kobject *kobj,
136 struct attribute *attr, int n)
137{
138 if (attr == &mdev_type_attr_description.attr &&
139 !to_mdev_type(kobj)->parent->mdev_driver->show_description)
140 return 0;
141 return attr->mode;
142}
143
144static struct attribute_group mdev_type_core_group = {
145 .attrs = mdev_types_core_attrs,
146 .is_visible = mdev_types_core_is_visible,
147};
148
149static const struct attribute_group *mdev_type_groups[] = {
150 &mdev_type_core_group,
151 NULL,
152};
153
154static void mdev_type_release(struct kobject *kobj)
155{
156 struct mdev_type *type = to_mdev_type(kobj);
157
158 pr_debug("Releasing group %s\n", kobj->name);
159 /* Pairs with the get in mdev_type_add() */
160 put_device(type->parent->dev);
161}
162
163static const struct kobj_type mdev_type_ktype = {
164 .sysfs_ops = &mdev_type_sysfs_ops,
165 .release = mdev_type_release,
166 .default_groups = mdev_type_groups,
167};
168
169static int mdev_type_add(struct mdev_parent *parent, struct mdev_type *type)
170{
171 int ret;
172
173 type->kobj.kset = parent->mdev_types_kset;
174 type->parent = parent;
175 /* Pairs with the put in mdev_type_release() */
176 get_device(parent->dev);
177
178 ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
179 "%s-%s", dev_driver_string(parent->dev),
180 type->sysfs_name);
181 if (ret) {
182 kobject_put(&type->kobj);
183 return ret;
184 }
185
186 type->devices_kobj = kobject_create_and_add("devices", &type->kobj);
187 if (!type->devices_kobj) {
188 ret = -ENOMEM;
189 goto attr_devices_failed;
190 }
191
192 return 0;
193
194attr_devices_failed:
195 kobject_del(&type->kobj);
196 kobject_put(&type->kobj);
197 return ret;
198}
199
200static void mdev_type_remove(struct mdev_type *type)
201{
202 kobject_put(type->devices_kobj);
203 kobject_del(&type->kobj);
204 kobject_put(&type->kobj);
205}
206
207/* mdev sysfs functions */
208void parent_remove_sysfs_files(struct mdev_parent *parent)
209{
210 int i;
211
212 for (i = 0; i < parent->nr_types; i++)
213 mdev_type_remove(parent->types[i]);
214 kset_unregister(parent->mdev_types_kset);
215}
216
217int parent_create_sysfs_files(struct mdev_parent *parent)
218{
219 int ret, i;
220
221 parent->mdev_types_kset = kset_create_and_add("mdev_supported_types",
222 NULL, &parent->dev->kobj);
223 if (!parent->mdev_types_kset)
224 return -ENOMEM;
225
226 for (i = 0; i < parent->nr_types; i++) {
227 ret = mdev_type_add(parent, parent->types[i]);
228 if (ret)
229 goto out_err;
230 }
231 return 0;
232
233out_err:
234 while (--i >= 0)
235 mdev_type_remove(parent->types[i]);
236 kset_unregister(parent->mdev_types_kset);
237 return ret;
238}
239
240static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
241 const char *buf, size_t count)
242{
243 struct mdev_device *mdev = to_mdev_device(dev);
244 unsigned long val;
245
246 if (kstrtoul(buf, 0, &val) < 0)
247 return -EINVAL;
248
249 if (val && device_remove_file_self(dev, attr)) {
250 int ret;
251
252 ret = mdev_device_remove(mdev);
253 if (ret)
254 return ret;
255 }
256
257 return count;
258}
259
260static DEVICE_ATTR_WO(remove);
261
262static struct attribute *mdev_device_attrs[] = {
263 &dev_attr_remove.attr,
264 NULL,
265};
266
267static const struct attribute_group mdev_device_group = {
268 .attrs = mdev_device_attrs,
269};
270
271const struct attribute_group *mdev_device_groups[] = {
272 &mdev_device_group,
273 NULL
274};
275
276int mdev_create_sysfs_files(struct mdev_device *mdev)
277{
278 struct mdev_type *type = mdev->type;
279 struct kobject *kobj = &mdev->dev.kobj;
280 int ret;
281
282 ret = sysfs_create_link(type->devices_kobj, kobj, dev_name(&mdev->dev));
283 if (ret)
284 return ret;
285
286 ret = sysfs_create_link(kobj, &type->kobj, "mdev_type");
287 if (ret)
288 goto type_link_failed;
289 return ret;
290
291type_link_failed:
292 sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
293 return ret;
294}
295
296void mdev_remove_sysfs_files(struct mdev_device *mdev)
297{
298 struct kobject *kobj = &mdev->dev.kobj;
299
300 sysfs_remove_link(kobj, "mdev_type");
301 sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
302}