summaryrefslogtreecommitdiff
path: root/drivers/vfio/mdev/mdev_core.c
blob: ed86087631344b2eb6d6ac2d55210cd8eb020fc6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Mediated device Core Driver
 *
 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
 *     Author: Neo Jia <cjia@nvidia.com>
 *             Kirti Wankhede <kwankhede@nvidia.com>
 */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/sysfs.h>
#include <linux/mdev.h>

#include "mdev_private.h"

#define DRIVER_VERSION		"0.1"
#define DRIVER_AUTHOR		"NVIDIA Corporation"
#define DRIVER_DESC		"Mediated device Core Driver"

static LIST_HEAD(parent_list);
static DEFINE_MUTEX(parent_list_lock);
static struct class_compat *mdev_bus_compat_class;

static LIST_HEAD(mdev_list);
static DEFINE_MUTEX(mdev_list_lock);

struct device *mdev_parent_dev(struct mdev_device *mdev)
{
	return mdev->parent->dev;
}
EXPORT_SYMBOL(mdev_parent_dev);

void *mdev_get_drvdata(struct mdev_device *mdev)
{
	return mdev->driver_data;
}
EXPORT_SYMBOL(mdev_get_drvdata);

void mdev_set_drvdata(struct mdev_device *mdev, void *data)
{
	mdev->driver_data = data;
}
EXPORT_SYMBOL(mdev_set_drvdata);

struct device *mdev_dev(struct mdev_device *mdev)
{
	return &mdev->dev;
}
EXPORT_SYMBOL(mdev_dev);

struct mdev_device *mdev_from_dev(struct device *dev)
{
	return dev_is_mdev(dev) ? to_mdev_device(dev) : NULL;
}
EXPORT_SYMBOL(mdev_from_dev);

const guid_t *mdev_uuid(struct mdev_device *mdev)
{
	return &mdev->uuid;
}
EXPORT_SYMBOL(mdev_uuid);

/* Should be called holding parent_list_lock */
static struct mdev_parent *__find_parent_device(struct device *dev)
{
	struct mdev_parent *parent;

	list_for_each_entry(parent, &parent_list, next) {
		if (parent->dev == dev)
			return parent;
	}
	return NULL;
}

static void mdev_release_parent(struct kref *kref)
{
	struct mdev_parent *parent = container_of(kref, struct mdev_parent,
						  ref);
	struct device *dev = parent->dev;

	kfree(parent);
	put_device(dev);
}

static struct mdev_parent *mdev_get_parent(struct mdev_parent *parent)
{
	if (parent)
		kref_get(&parent->ref);

	return parent;
}

static void mdev_put_parent(struct mdev_parent *parent)
{
	if (parent)
		kref_put(&parent->ref, mdev_release_parent);
}

/* Caller must hold parent unreg_sem read or write lock */
static void mdev_device_remove_common(struct mdev_device *mdev)
{
	struct mdev_parent *parent;
	struct mdev_type *type;
	int ret;

	type = to_mdev_type(mdev->type_kobj);
	mdev_remove_sysfs_files(&mdev->dev, type);
	device_del(&mdev->dev);
	parent = mdev->parent;
	lockdep_assert_held(&parent->unreg_sem);
	ret = parent->ops->remove(mdev);
	if (ret)
		dev_err(&mdev->dev, "Remove failed: err=%d\n", ret);

	/* Balances with device_initialize() */
	put_device(&mdev->dev);
	mdev_put_parent(parent);
}

static int mdev_device_remove_cb(struct device *dev, void *data)
{
	if (dev_is_mdev(dev)) {
		struct mdev_device *mdev;

		mdev = to_mdev_device(dev);
		mdev_device_remove_common(mdev);
	}
	return 0;
}

/*
 * mdev_register_device : Register a device
 * @dev: device structure representing parent device.
 * @ops: Parent device operation structure to be registered.
 *
 * Add device to list of registered parent devices.
 * Returns a negative value on error, otherwise 0.
 */
int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
{
	int ret;
	struct mdev_parent *parent;

	/* check for mandatory ops */
	if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups)
		return -EINVAL;

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

	mutex_lock(&parent_list_lock);

	/* Check for duplicate */
	parent = __find_parent_device(dev);
	if (parent) {
		parent = NULL;
		ret = -EEXIST;
		goto add_dev_err;
	}

	parent = kzalloc(sizeof(*parent), GFP_KERNEL);
	if (!parent) {
		ret = -ENOMEM;
		goto add_dev_err;
	}

	kref_init(&parent->ref);
	init_rwsem(&parent->unreg_sem);

	parent->dev = dev;
	parent->ops = ops;

	if (!mdev_bus_compat_class) {
		mdev_bus_compat_class = class_compat_register("mdev_bus");
		if (!mdev_bus_compat_class) {
			ret = -ENOMEM;
			goto add_dev_err;
		}
	}

	ret = parent_create_sysfs_files(parent);
	if (ret)
		goto add_dev_err;

	ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
	if (ret)
		dev_warn(dev, "Failed to create compatibility class link\n");

	list_add(&parent->next, &parent_list);
	mutex_unlock(&parent_list_lock);

	dev_info(dev, "MDEV: Registered\n");
	return 0;

add_dev_err:
	mutex_unlock(&parent_list_lock);
	if (parent)
		mdev_put_parent(parent);
	else
		put_device(dev);
	return ret;
}
EXPORT_SYMBOL(mdev_register_device);

/*
 * mdev_unregister_device : Unregister a parent device
 * @dev: device structure representing parent device.
 *
 * Remove device from list of registered parent devices. Give a chance to free
 * existing mediated devices for given device.
 */

void mdev_unregister_device(struct device *dev)
{
	struct mdev_parent *parent;

	mutex_lock(&parent_list_lock);
	parent = __find_parent_device(dev);

	if (!parent) {
		mutex_unlock(&parent_list_lock);
		return;
	}
	dev_info(dev, "MDEV: Unregistering\n");

	list_del(&parent->next);
	mutex_unlock(&parent_list_lock);

	down_write(&parent->unreg_sem);

	class_compat_remove_link(mdev_bus_compat_class, dev, NULL);

	device_for_each_child(dev, NULL, mdev_device_remove_cb);

	parent_remove_sysfs_files(parent);
	up_write(&parent->unreg_sem);

	mdev_put_parent(parent);
}
EXPORT_SYMBOL(mdev_unregister_device);

static void mdev_device_free(struct mdev_device *mdev)
{
	mutex_lock(&mdev_list_lock);
	list_del(&mdev->next);
	mutex_unlock(&mdev_list_lock);

	dev_dbg(&mdev->dev, "MDEV: destroying\n");
	kfree(mdev);
}

static void mdev_device_release(struct device *dev)
{
	struct mdev_device *mdev = to_mdev_device(dev);

	mdev_device_free(mdev);
}

int mdev_device_create(struct kobject *kobj,
		       struct device *dev, const guid_t *uuid)
{
	int ret;
	struct mdev_device *mdev, *tmp;
	struct mdev_parent *parent;
	struct mdev_type *type = to_mdev_type(kobj);

	parent = mdev_get_parent(type->parent);
	if (!parent)
		return -EINVAL;

	mutex_lock(&mdev_list_lock);

	/* Check for duplicate */
	list_for_each_entry(tmp, &mdev_list, next) {
		if (guid_equal(&tmp->uuid, uuid)) {
			mutex_unlock(&mdev_list_lock);
			ret = -EEXIST;
			goto mdev_fail;
		}
	}

	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
	if (!mdev) {
		mutex_unlock(&mdev_list_lock);
		ret = -ENOMEM;
		goto mdev_fail;
	}

	guid_copy(&mdev->uuid, uuid);
	list_add(&mdev->next, &mdev_list);
	mutex_unlock(&mdev_list_lock);

	mdev->parent = parent;

	/* Check if parent unregistration has started */
	if (!down_read_trylock(&parent->unreg_sem)) {
		mdev_device_free(mdev);
		ret = -ENODEV;
		goto mdev_fail;
	}

	device_initialize(&mdev->dev);
	mdev->dev.parent  = dev;
	mdev->dev.bus     = &mdev_bus_type;
	mdev->dev.release = mdev_device_release;
	dev_set_name(&mdev->dev, "%pUl", uuid);
	mdev->dev.groups = parent->ops->mdev_attr_groups;
	mdev->type_kobj = kobj;

	ret = parent->ops->create(kobj, mdev);
	if (ret)
		goto ops_create_fail;

	ret = device_add(&mdev->dev);
	if (ret)
		goto add_fail;

	ret = mdev_create_sysfs_files(&mdev->dev, type);
	if (ret)
		goto sysfs_fail;

	mdev->active = true;
	dev_dbg(&mdev->dev, "MDEV: created\n");
	up_read(&parent->unreg_sem);

	return 0;

sysfs_fail:
	device_del(&mdev->dev);
add_fail:
	parent->ops->remove(mdev);
ops_create_fail:
	up_read(&parent->unreg_sem);
	put_device(&mdev->dev);
mdev_fail:
	mdev_put_parent(parent);
	return ret;
}

int mdev_device_remove(struct device *dev)
{
	struct mdev_device *mdev, *tmp;
	struct mdev_parent *parent;

	mdev = to_mdev_device(dev);

	mutex_lock(&mdev_list_lock);
	list_for_each_entry(tmp, &mdev_list, next) {
		if (tmp == mdev)
			break;
	}

	if (tmp != mdev) {
		mutex_unlock(&mdev_list_lock);
		return -ENODEV;
	}

	if (!mdev->active) {
		mutex_unlock(&mdev_list_lock);
		return -EAGAIN;
	}

	mdev->active = false;
	mutex_unlock(&mdev_list_lock);

	parent = mdev->parent;
	/* Check if parent unregistration has started */
	if (!down_read_trylock(&parent->unreg_sem))
		return -ENODEV;

	mdev_device_remove_common(mdev);
	up_read(&parent->unreg_sem);
	return 0;
}

int mdev_set_iommu_device(struct device *dev, struct device *iommu_device)
{
	struct mdev_device *mdev = to_mdev_device(dev);

	mdev->iommu_device = iommu_device;

	return 0;
}
EXPORT_SYMBOL(mdev_set_iommu_device);

struct device *mdev_get_iommu_device(struct device *dev)
{
	struct mdev_device *mdev = to_mdev_device(dev);

	return mdev->iommu_device;
}
EXPORT_SYMBOL(mdev_get_iommu_device);

static int __init mdev_init(void)
{
	return mdev_bus_register();
}

static void __exit mdev_exit(void)
{
	if (mdev_bus_compat_class)
		class_compat_unregister(mdev_bus_compat_class);

	mdev_bus_unregister();
}

module_init(mdev_init)
module_exit(mdev_exit)

MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_SOFTDEP("post: vfio_mdev");