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1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/virtio.h>
3#include <linux/spinlock.h>
4#include <linux/virtio_config.h>
5#include <linux/module.h>
6#include <linux/idr.h>
7#include <uapi/linux/virtio_ids.h>
8
9/* Unique numbering for virtio devices. */
10static DEFINE_IDA(virtio_index_ida);
11
12static ssize_t device_show(struct device *_d,
13 struct device_attribute *attr, char *buf)
14{
15 struct virtio_device *dev = dev_to_virtio(_d);
16 return sprintf(buf, "0x%04x\n", dev->id.device);
17}
18static DEVICE_ATTR_RO(device);
19
20static ssize_t vendor_show(struct device *_d,
21 struct device_attribute *attr, char *buf)
22{
23 struct virtio_device *dev = dev_to_virtio(_d);
24 return sprintf(buf, "0x%04x\n", dev->id.vendor);
25}
26static DEVICE_ATTR_RO(vendor);
27
28static ssize_t status_show(struct device *_d,
29 struct device_attribute *attr, char *buf)
30{
31 struct virtio_device *dev = dev_to_virtio(_d);
32 return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
33}
34static DEVICE_ATTR_RO(status);
35
36static ssize_t modalias_show(struct device *_d,
37 struct device_attribute *attr, char *buf)
38{
39 struct virtio_device *dev = dev_to_virtio(_d);
40 return sprintf(buf, "virtio:d%08Xv%08X\n",
41 dev->id.device, dev->id.vendor);
42}
43static DEVICE_ATTR_RO(modalias);
44
45static ssize_t features_show(struct device *_d,
46 struct device_attribute *attr, char *buf)
47{
48 struct virtio_device *dev = dev_to_virtio(_d);
49 unsigned int i;
50 ssize_t len = 0;
51
52 /* We actually represent this as a bitstring, as it could be
53 * arbitrary length in future. */
54 for (i = 0; i < sizeof(dev->features)*8; i++)
55 len += sprintf(buf+len, "%c",
56 __virtio_test_bit(dev, i) ? '1' : '0');
57 len += sprintf(buf+len, "\n");
58 return len;
59}
60static DEVICE_ATTR_RO(features);
61
62static struct attribute *virtio_dev_attrs[] = {
63 &dev_attr_device.attr,
64 &dev_attr_vendor.attr,
65 &dev_attr_status.attr,
66 &dev_attr_modalias.attr,
67 &dev_attr_features.attr,
68 NULL,
69};
70ATTRIBUTE_GROUPS(virtio_dev);
71
72static inline int virtio_id_match(const struct virtio_device *dev,
73 const struct virtio_device_id *id)
74{
75 if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
76 return 0;
77
78 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
79}
80
81/* This looks through all the IDs a driver claims to support. If any of them
82 * match, we return 1 and the kernel will call virtio_dev_probe(). */
83static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
84{
85 unsigned int i;
86 struct virtio_device *dev = dev_to_virtio(_dv);
87 const struct virtio_device_id *ids;
88
89 ids = drv_to_virtio(_dr)->id_table;
90 for (i = 0; ids[i].device; i++)
91 if (virtio_id_match(dev, &ids[i]))
92 return 1;
93 return 0;
94}
95
96static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
97{
98 struct virtio_device *dev = dev_to_virtio(_dv);
99
100 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
101 dev->id.device, dev->id.vendor);
102}
103
104void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
105 unsigned int fbit)
106{
107 unsigned int i;
108 struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
109
110 for (i = 0; i < drv->feature_table_size; i++)
111 if (drv->feature_table[i] == fbit)
112 return;
113
114 if (drv->feature_table_legacy) {
115 for (i = 0; i < drv->feature_table_size_legacy; i++)
116 if (drv->feature_table_legacy[i] == fbit)
117 return;
118 }
119
120 BUG();
121}
122EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
123
124static void __virtio_config_changed(struct virtio_device *dev)
125{
126 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
127
128 if (!dev->config_enabled)
129 dev->config_change_pending = true;
130 else if (drv && drv->config_changed)
131 drv->config_changed(dev);
132}
133
134void virtio_config_changed(struct virtio_device *dev)
135{
136 unsigned long flags;
137
138 spin_lock_irqsave(&dev->config_lock, flags);
139 __virtio_config_changed(dev);
140 spin_unlock_irqrestore(&dev->config_lock, flags);
141}
142EXPORT_SYMBOL_GPL(virtio_config_changed);
143
144void virtio_config_disable(struct virtio_device *dev)
145{
146 spin_lock_irq(&dev->config_lock);
147 dev->config_enabled = false;
148 spin_unlock_irq(&dev->config_lock);
149}
150EXPORT_SYMBOL_GPL(virtio_config_disable);
151
152void virtio_config_enable(struct virtio_device *dev)
153{
154 spin_lock_irq(&dev->config_lock);
155 dev->config_enabled = true;
156 if (dev->config_change_pending)
157 __virtio_config_changed(dev);
158 dev->config_change_pending = false;
159 spin_unlock_irq(&dev->config_lock);
160}
161EXPORT_SYMBOL_GPL(virtio_config_enable);
162
163void virtio_add_status(struct virtio_device *dev, unsigned int status)
164{
165 might_sleep();
166 dev->config->set_status(dev, dev->config->get_status(dev) | status);
167}
168EXPORT_SYMBOL_GPL(virtio_add_status);
169
170int virtio_finalize_features(struct virtio_device *dev)
171{
172 int ret = dev->config->finalize_features(dev);
173 unsigned status;
174
175 might_sleep();
176 if (ret)
177 return ret;
178
179 if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
180 return 0;
181
182 virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
183 status = dev->config->get_status(dev);
184 if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
185 dev_err(&dev->dev, "virtio: device refuses features: %x\n",
186 status);
187 return -ENODEV;
188 }
189 return 0;
190}
191EXPORT_SYMBOL_GPL(virtio_finalize_features);
192
193static int virtio_dev_probe(struct device *_d)
194{
195 int err, i;
196 struct virtio_device *dev = dev_to_virtio(_d);
197 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
198 u64 device_features;
199 u64 driver_features;
200 u64 driver_features_legacy;
201
202 /* We have a driver! */
203 virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);
204
205 /* Figure out what features the device supports. */
206 device_features = dev->config->get_features(dev);
207
208 /* Figure out what features the driver supports. */
209 driver_features = 0;
210 for (i = 0; i < drv->feature_table_size; i++) {
211 unsigned int f = drv->feature_table[i];
212 BUG_ON(f >= 64);
213 driver_features |= (1ULL << f);
214 }
215
216 /* Some drivers have a separate feature table for virtio v1.0 */
217 if (drv->feature_table_legacy) {
218 driver_features_legacy = 0;
219 for (i = 0; i < drv->feature_table_size_legacy; i++) {
220 unsigned int f = drv->feature_table_legacy[i];
221 BUG_ON(f >= 64);
222 driver_features_legacy |= (1ULL << f);
223 }
224 } else {
225 driver_features_legacy = driver_features;
226 }
227
228 if (device_features & (1ULL << VIRTIO_F_VERSION_1))
229 dev->features = driver_features & device_features;
230 else
231 dev->features = driver_features_legacy & device_features;
232
233 /* Transport features always preserved to pass to finalize_features. */
234 for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
235 if (device_features & (1ULL << i))
236 __virtio_set_bit(dev, i);
237
238 if (drv->validate) {
239 err = drv->validate(dev);
240 if (err)
241 goto err;
242 }
243
244 err = virtio_finalize_features(dev);
245 if (err)
246 goto err;
247
248 err = drv->probe(dev);
249 if (err)
250 goto err;
251
252 /* If probe didn't do it, mark device DRIVER_OK ourselves. */
253 if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK))
254 virtio_device_ready(dev);
255
256 if (drv->scan)
257 drv->scan(dev);
258
259 virtio_config_enable(dev);
260
261 return 0;
262err:
263 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
264 return err;
265
266}
267
268static int virtio_dev_remove(struct device *_d)
269{
270 struct virtio_device *dev = dev_to_virtio(_d);
271 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
272
273 virtio_config_disable(dev);
274
275 drv->remove(dev);
276
277 /* Driver should have reset device. */
278 WARN_ON_ONCE(dev->config->get_status(dev));
279
280 /* Acknowledge the device's existence again. */
281 virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
282 return 0;
283}
284
285static struct bus_type virtio_bus = {
286 .name = "virtio",
287 .match = virtio_dev_match,
288 .dev_groups = virtio_dev_groups,
289 .uevent = virtio_uevent,
290 .probe = virtio_dev_probe,
291 .remove = virtio_dev_remove,
292};
293
294int register_virtio_driver(struct virtio_driver *driver)
295{
296 /* Catch this early. */
297 BUG_ON(driver->feature_table_size && !driver->feature_table);
298 driver->driver.bus = &virtio_bus;
299 return driver_register(&driver->driver);
300}
301EXPORT_SYMBOL_GPL(register_virtio_driver);
302
303void unregister_virtio_driver(struct virtio_driver *driver)
304{
305 driver_unregister(&driver->driver);
306}
307EXPORT_SYMBOL_GPL(unregister_virtio_driver);
308
309/**
310 * register_virtio_device - register virtio device
311 * @dev : virtio device to be registered
312 *
313 * On error, the caller must call put_device on &@dev->dev (and not kfree),
314 * as another code path may have obtained a reference to @dev.
315 *
316 * Returns: 0 on suceess, -error on failure
317 */
318int register_virtio_device(struct virtio_device *dev)
319{
320 int err;
321
322 dev->dev.bus = &virtio_bus;
323 device_initialize(&dev->dev);
324
325 /* Assign a unique device index and hence name. */
326 err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
327 if (err < 0)
328 goto out;
329
330 dev->index = err;
331 dev_set_name(&dev->dev, "virtio%u", dev->index);
332
333 spin_lock_init(&dev->config_lock);
334 dev->config_enabled = false;
335 dev->config_change_pending = false;
336
337 /* We always start by resetting the device, in case a previous
338 * driver messed it up. This also tests that code path a little. */
339 dev->config->reset(dev);
340
341 /* Acknowledge that we've seen the device. */
342 virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
343
344 INIT_LIST_HEAD(&dev->vqs);
345
346 /*
347 * device_add() causes the bus infrastructure to look for a matching
348 * driver.
349 */
350 err = device_add(&dev->dev);
351 if (err)
352 ida_simple_remove(&virtio_index_ida, dev->index);
353out:
354 if (err)
355 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
356 return err;
357}
358EXPORT_SYMBOL_GPL(register_virtio_device);
359
360void unregister_virtio_device(struct virtio_device *dev)
361{
362 int index = dev->index; /* save for after device release */
363
364 device_unregister(&dev->dev);
365 ida_simple_remove(&virtio_index_ida, index);
366}
367EXPORT_SYMBOL_GPL(unregister_virtio_device);
368
369#ifdef CONFIG_PM_SLEEP
370int virtio_device_freeze(struct virtio_device *dev)
371{
372 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
373
374 virtio_config_disable(dev);
375
376 dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
377
378 if (drv && drv->freeze)
379 return drv->freeze(dev);
380
381 return 0;
382}
383EXPORT_SYMBOL_GPL(virtio_device_freeze);
384
385int virtio_device_restore(struct virtio_device *dev)
386{
387 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
388 int ret;
389
390 /* We always start by resetting the device, in case a previous
391 * driver messed it up. */
392 dev->config->reset(dev);
393
394 /* Acknowledge that we've seen the device. */
395 virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
396
397 /* Maybe driver failed before freeze.
398 * Restore the failed status, for debugging. */
399 if (dev->failed)
400 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
401
402 if (!drv)
403 return 0;
404
405 /* We have a driver! */
406 virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);
407
408 ret = virtio_finalize_features(dev);
409 if (ret)
410 goto err;
411
412 if (drv->restore) {
413 ret = drv->restore(dev);
414 if (ret)
415 goto err;
416 }
417
418 /* Finally, tell the device we're all set */
419 virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
420
421 virtio_config_enable(dev);
422
423 return 0;
424
425err:
426 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
427 return ret;
428}
429EXPORT_SYMBOL_GPL(virtio_device_restore);
430#endif
431
432static int virtio_init(void)
433{
434 if (bus_register(&virtio_bus) != 0)
435 panic("virtio bus registration failed");
436 return 0;
437}
438
439static void __exit virtio_exit(void)
440{
441 bus_unregister(&virtio_bus);
442 ida_destroy(&virtio_index_ida);
443}
444core_initcall(virtio_init);
445module_exit(virtio_exit);
446
447MODULE_LICENSE("GPL");
1#include <linux/virtio.h>
2#include <linux/spinlock.h>
3#include <linux/virtio_config.h>
4#include <linux/module.h>
5#include <linux/idr.h>
6#include <uapi/linux/virtio_ids.h>
7
8/* Unique numbering for virtio devices. */
9static DEFINE_IDA(virtio_index_ida);
10
11static ssize_t device_show(struct device *_d,
12 struct device_attribute *attr, char *buf)
13{
14 struct virtio_device *dev = dev_to_virtio(_d);
15 return sprintf(buf, "0x%04x\n", dev->id.device);
16}
17static DEVICE_ATTR_RO(device);
18
19static ssize_t vendor_show(struct device *_d,
20 struct device_attribute *attr, char *buf)
21{
22 struct virtio_device *dev = dev_to_virtio(_d);
23 return sprintf(buf, "0x%04x\n", dev->id.vendor);
24}
25static DEVICE_ATTR_RO(vendor);
26
27static ssize_t status_show(struct device *_d,
28 struct device_attribute *attr, char *buf)
29{
30 struct virtio_device *dev = dev_to_virtio(_d);
31 return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
32}
33static DEVICE_ATTR_RO(status);
34
35static ssize_t modalias_show(struct device *_d,
36 struct device_attribute *attr, char *buf)
37{
38 struct virtio_device *dev = dev_to_virtio(_d);
39 return sprintf(buf, "virtio:d%08Xv%08X\n",
40 dev->id.device, dev->id.vendor);
41}
42static DEVICE_ATTR_RO(modalias);
43
44static ssize_t features_show(struct device *_d,
45 struct device_attribute *attr, char *buf)
46{
47 struct virtio_device *dev = dev_to_virtio(_d);
48 unsigned int i;
49 ssize_t len = 0;
50
51 /* We actually represent this as a bitstring, as it could be
52 * arbitrary length in future. */
53 for (i = 0; i < sizeof(dev->features)*8; i++)
54 len += sprintf(buf+len, "%c",
55 __virtio_test_bit(dev, i) ? '1' : '0');
56 len += sprintf(buf+len, "\n");
57 return len;
58}
59static DEVICE_ATTR_RO(features);
60
61static struct attribute *virtio_dev_attrs[] = {
62 &dev_attr_device.attr,
63 &dev_attr_vendor.attr,
64 &dev_attr_status.attr,
65 &dev_attr_modalias.attr,
66 &dev_attr_features.attr,
67 NULL,
68};
69ATTRIBUTE_GROUPS(virtio_dev);
70
71static inline int virtio_id_match(const struct virtio_device *dev,
72 const struct virtio_device_id *id)
73{
74 if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
75 return 0;
76
77 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
78}
79
80/* This looks through all the IDs a driver claims to support. If any of them
81 * match, we return 1 and the kernel will call virtio_dev_probe(). */
82static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
83{
84 unsigned int i;
85 struct virtio_device *dev = dev_to_virtio(_dv);
86 const struct virtio_device_id *ids;
87
88 ids = drv_to_virtio(_dr)->id_table;
89 for (i = 0; ids[i].device; i++)
90 if (virtio_id_match(dev, &ids[i]))
91 return 1;
92 return 0;
93}
94
95static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
96{
97 struct virtio_device *dev = dev_to_virtio(_dv);
98
99 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
100 dev->id.device, dev->id.vendor);
101}
102
103void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
104 unsigned int fbit)
105{
106 unsigned int i;
107 struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
108
109 for (i = 0; i < drv->feature_table_size; i++)
110 if (drv->feature_table[i] == fbit)
111 return;
112
113 if (drv->feature_table_legacy) {
114 for (i = 0; i < drv->feature_table_size_legacy; i++)
115 if (drv->feature_table_legacy[i] == fbit)
116 return;
117 }
118
119 BUG();
120}
121EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
122
123static void __virtio_config_changed(struct virtio_device *dev)
124{
125 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
126
127 if (!dev->config_enabled)
128 dev->config_change_pending = true;
129 else if (drv && drv->config_changed)
130 drv->config_changed(dev);
131}
132
133void virtio_config_changed(struct virtio_device *dev)
134{
135 unsigned long flags;
136
137 spin_lock_irqsave(&dev->config_lock, flags);
138 __virtio_config_changed(dev);
139 spin_unlock_irqrestore(&dev->config_lock, flags);
140}
141EXPORT_SYMBOL_GPL(virtio_config_changed);
142
143void virtio_config_disable(struct virtio_device *dev)
144{
145 spin_lock_irq(&dev->config_lock);
146 dev->config_enabled = false;
147 spin_unlock_irq(&dev->config_lock);
148}
149EXPORT_SYMBOL_GPL(virtio_config_disable);
150
151void virtio_config_enable(struct virtio_device *dev)
152{
153 spin_lock_irq(&dev->config_lock);
154 dev->config_enabled = true;
155 if (dev->config_change_pending)
156 __virtio_config_changed(dev);
157 dev->config_change_pending = false;
158 spin_unlock_irq(&dev->config_lock);
159}
160EXPORT_SYMBOL_GPL(virtio_config_enable);
161
162void virtio_add_status(struct virtio_device *dev, unsigned int status)
163{
164 dev->config->set_status(dev, dev->config->get_status(dev) | status);
165}
166EXPORT_SYMBOL_GPL(virtio_add_status);
167
168int virtio_finalize_features(struct virtio_device *dev)
169{
170 int ret = dev->config->finalize_features(dev);
171 unsigned status;
172
173 if (ret)
174 return ret;
175
176 if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
177 return 0;
178
179 virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
180 status = dev->config->get_status(dev);
181 if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
182 dev_err(&dev->dev, "virtio: device refuses features: %x\n",
183 status);
184 return -ENODEV;
185 }
186 return 0;
187}
188EXPORT_SYMBOL_GPL(virtio_finalize_features);
189
190static int virtio_dev_probe(struct device *_d)
191{
192 int err, i;
193 struct virtio_device *dev = dev_to_virtio(_d);
194 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
195 u64 device_features;
196 u64 driver_features;
197 u64 driver_features_legacy;
198
199 /* We have a driver! */
200 virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);
201
202 /* Figure out what features the device supports. */
203 device_features = dev->config->get_features(dev);
204
205 /* Figure out what features the driver supports. */
206 driver_features = 0;
207 for (i = 0; i < drv->feature_table_size; i++) {
208 unsigned int f = drv->feature_table[i];
209 BUG_ON(f >= 64);
210 driver_features |= (1ULL << f);
211 }
212
213 /* Some drivers have a separate feature table for virtio v1.0 */
214 if (drv->feature_table_legacy) {
215 driver_features_legacy = 0;
216 for (i = 0; i < drv->feature_table_size_legacy; i++) {
217 unsigned int f = drv->feature_table_legacy[i];
218 BUG_ON(f >= 64);
219 driver_features_legacy |= (1ULL << f);
220 }
221 } else {
222 driver_features_legacy = driver_features;
223 }
224
225 if (device_features & (1ULL << VIRTIO_F_VERSION_1))
226 dev->features = driver_features & device_features;
227 else
228 dev->features = driver_features_legacy & device_features;
229
230 /* Transport features always preserved to pass to finalize_features. */
231 for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
232 if (device_features & (1ULL << i))
233 __virtio_set_bit(dev, i);
234
235 if (drv->validate) {
236 err = drv->validate(dev);
237 if (err)
238 goto err;
239 }
240
241 err = virtio_finalize_features(dev);
242 if (err)
243 goto err;
244
245 err = drv->probe(dev);
246 if (err)
247 goto err;
248
249 /* If probe didn't do it, mark device DRIVER_OK ourselves. */
250 if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK))
251 virtio_device_ready(dev);
252
253 if (drv->scan)
254 drv->scan(dev);
255
256 virtio_config_enable(dev);
257
258 return 0;
259err:
260 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
261 return err;
262
263}
264
265static int virtio_dev_remove(struct device *_d)
266{
267 struct virtio_device *dev = dev_to_virtio(_d);
268 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
269
270 virtio_config_disable(dev);
271
272 drv->remove(dev);
273
274 /* Driver should have reset device. */
275 WARN_ON_ONCE(dev->config->get_status(dev));
276
277 /* Acknowledge the device's existence again. */
278 virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
279 return 0;
280}
281
282static struct bus_type virtio_bus = {
283 .name = "virtio",
284 .match = virtio_dev_match,
285 .dev_groups = virtio_dev_groups,
286 .uevent = virtio_uevent,
287 .probe = virtio_dev_probe,
288 .remove = virtio_dev_remove,
289};
290
291int register_virtio_driver(struct virtio_driver *driver)
292{
293 /* Catch this early. */
294 BUG_ON(driver->feature_table_size && !driver->feature_table);
295 driver->driver.bus = &virtio_bus;
296 return driver_register(&driver->driver);
297}
298EXPORT_SYMBOL_GPL(register_virtio_driver);
299
300void unregister_virtio_driver(struct virtio_driver *driver)
301{
302 driver_unregister(&driver->driver);
303}
304EXPORT_SYMBOL_GPL(unregister_virtio_driver);
305
306/**
307 * register_virtio_device - register virtio device
308 * @dev : virtio device to be registered
309 *
310 * On error, the caller must call put_device on &@dev->dev (and not kfree),
311 * as another code path may have obtained a reference to @dev.
312 *
313 * Returns: 0 on suceess, -error on failure
314 */
315int register_virtio_device(struct virtio_device *dev)
316{
317 int err;
318
319 dev->dev.bus = &virtio_bus;
320 device_initialize(&dev->dev);
321
322 /* Assign a unique device index and hence name. */
323 err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
324 if (err < 0)
325 goto out;
326
327 dev->index = err;
328 dev_set_name(&dev->dev, "virtio%u", dev->index);
329
330 spin_lock_init(&dev->config_lock);
331 dev->config_enabled = false;
332 dev->config_change_pending = false;
333
334 /* We always start by resetting the device, in case a previous
335 * driver messed it up. This also tests that code path a little. */
336 dev->config->reset(dev);
337
338 /* Acknowledge that we've seen the device. */
339 virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
340
341 INIT_LIST_HEAD(&dev->vqs);
342
343 /*
344 * device_add() causes the bus infrastructure to look for a matching
345 * driver.
346 */
347 err = device_add(&dev->dev);
348 if (err)
349 ida_simple_remove(&virtio_index_ida, dev->index);
350out:
351 if (err)
352 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
353 return err;
354}
355EXPORT_SYMBOL_GPL(register_virtio_device);
356
357void unregister_virtio_device(struct virtio_device *dev)
358{
359 int index = dev->index; /* save for after device release */
360
361 device_unregister(&dev->dev);
362 ida_simple_remove(&virtio_index_ida, index);
363}
364EXPORT_SYMBOL_GPL(unregister_virtio_device);
365
366#ifdef CONFIG_PM_SLEEP
367int virtio_device_freeze(struct virtio_device *dev)
368{
369 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
370
371 virtio_config_disable(dev);
372
373 dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
374
375 if (drv && drv->freeze)
376 return drv->freeze(dev);
377
378 return 0;
379}
380EXPORT_SYMBOL_GPL(virtio_device_freeze);
381
382int virtio_device_restore(struct virtio_device *dev)
383{
384 struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
385 int ret;
386
387 /* We always start by resetting the device, in case a previous
388 * driver messed it up. */
389 dev->config->reset(dev);
390
391 /* Acknowledge that we've seen the device. */
392 virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
393
394 /* Maybe driver failed before freeze.
395 * Restore the failed status, for debugging. */
396 if (dev->failed)
397 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
398
399 if (!drv)
400 return 0;
401
402 /* We have a driver! */
403 virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);
404
405 ret = virtio_finalize_features(dev);
406 if (ret)
407 goto err;
408
409 if (drv->restore) {
410 ret = drv->restore(dev);
411 if (ret)
412 goto err;
413 }
414
415 /* Finally, tell the device we're all set */
416 virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
417
418 virtio_config_enable(dev);
419
420 return 0;
421
422err:
423 virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
424 return ret;
425}
426EXPORT_SYMBOL_GPL(virtio_device_restore);
427#endif
428
429static int virtio_init(void)
430{
431 if (bus_register(&virtio_bus) != 0)
432 panic("virtio bus registration failed");
433 return 0;
434}
435
436static void __exit virtio_exit(void)
437{
438 bus_unregister(&virtio_bus);
439 ida_destroy(&virtio_index_ida);
440}
441core_initcall(virtio_init);
442module_exit(virtio_exit);
443
444MODULE_LICENSE("GPL");