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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ec3d41c4 RR |
2 | #include <linux/virtio.h> |
3 | #include <linux/spinlock.h> | |
4 | #include <linux/virtio_config.h> | |
b5a2c4f1 | 5 | #include <linux/module.h> |
90e03207 | 6 | #include <linux/idr.h> |
b6098c30 | 7 | #include <uapi/linux/virtio_ids.h> |
ec3d41c4 | 8 | |
b769f579 | 9 | /* Unique numbering for virtio devices. */ |
90e03207 | 10 | static DEFINE_IDA(virtio_index_ida); |
b769f579 | 11 | |
ec3d41c4 RR |
12 | static ssize_t device_show(struct device *_d, |
13 | struct device_attribute *attr, char *buf) | |
14 | { | |
9bffdca8 | 15 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 16 | return sprintf(buf, "0x%04x\n", dev->id.device); |
ec3d41c4 | 17 | } |
3736dab6 GKH |
18 | static DEVICE_ATTR_RO(device); |
19 | ||
ec3d41c4 RR |
20 | static ssize_t vendor_show(struct device *_d, |
21 | struct device_attribute *attr, char *buf) | |
22 | { | |
9bffdca8 | 23 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 24 | return sprintf(buf, "0x%04x\n", dev->id.vendor); |
ec3d41c4 | 25 | } |
3736dab6 GKH |
26 | static DEVICE_ATTR_RO(vendor); |
27 | ||
ec3d41c4 RR |
28 | static ssize_t status_show(struct device *_d, |
29 | struct device_attribute *attr, char *buf) | |
30 | { | |
9bffdca8 | 31 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 32 | return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); |
ec3d41c4 | 33 | } |
3736dab6 GKH |
34 | static DEVICE_ATTR_RO(status); |
35 | ||
b01d9f28 RR |
36 | static ssize_t modalias_show(struct device *_d, |
37 | struct device_attribute *attr, char *buf) | |
38 | { | |
9bffdca8 | 39 | struct virtio_device *dev = dev_to_virtio(_d); |
b01d9f28 RR |
40 | return sprintf(buf, "virtio:d%08Xv%08X\n", |
41 | dev->id.device, dev->id.vendor); | |
42 | } | |
3736dab6 GKH |
43 | static DEVICE_ATTR_RO(modalias); |
44 | ||
a9289282 RR |
45 | static ssize_t features_show(struct device *_d, |
46 | struct device_attribute *attr, char *buf) | |
47 | { | |
9bffdca8 | 48 | struct virtio_device *dev = dev_to_virtio(_d); |
a9289282 RR |
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. */ | |
e16e12be | 54 | for (i = 0; i < sizeof(dev->features)*8; i++) |
a9289282 | 55 | len += sprintf(buf+len, "%c", |
e16e12be | 56 | __virtio_test_bit(dev, i) ? '1' : '0'); |
a9289282 RR |
57 | len += sprintf(buf+len, "\n"); |
58 | return len; | |
59 | } | |
3736dab6 GKH |
60 | static DEVICE_ATTR_RO(features); |
61 | ||
62 | static 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, | |
ec3d41c4 | 69 | }; |
3736dab6 | 70 | ATTRIBUTE_GROUPS(virtio_dev); |
ec3d41c4 RR |
71 | |
72 | static inline int virtio_id_match(const struct virtio_device *dev, | |
73 | const struct virtio_device_id *id) | |
74 | { | |
e3353853 | 75 | if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID) |
ec3d41c4 RR |
76 | return 0; |
77 | ||
c89e8016 | 78 | return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor; |
ec3d41c4 RR |
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(). */ | |
83 | static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) | |
84 | { | |
85 | unsigned int i; | |
9bffdca8 | 86 | struct virtio_device *dev = dev_to_virtio(_dv); |
ec3d41c4 RR |
87 | const struct virtio_device_id *ids; |
88 | ||
9a2bdcc8 | 89 | ids = drv_to_virtio(_dr)->id_table; |
ec3d41c4 RR |
90 | for (i = 0; ids[i].device; i++) |
91 | if (virtio_id_match(dev, &ids[i])) | |
92 | return 1; | |
93 | return 0; | |
94 | } | |
95 | ||
b01d9f28 RR |
96 | static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) |
97 | { | |
9bffdca8 | 98 | struct virtio_device *dev = dev_to_virtio(_dv); |
b01d9f28 RR |
99 | |
100 | return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", | |
101 | dev->id.device, dev->id.vendor); | |
102 | } | |
103 | ||
c45a6816 RR |
104 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
105 | unsigned int fbit) | |
106 | { | |
107 | unsigned int i; | |
9a2bdcc8 | 108 | struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); |
c45a6816 RR |
109 | |
110 | for (i = 0; i < drv->feature_table_size; i++) | |
111 | if (drv->feature_table[i] == fbit) | |
112 | return; | |
b3bb62d1 MT |
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 | ||
c45a6816 RR |
120 | BUG(); |
121 | } | |
122 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
123 | ||
22b7050a MT |
124 | static 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 | ||
134 | void 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 | } | |
142 | EXPORT_SYMBOL_GPL(virtio_config_changed); | |
143 | ||
9fe7bfce | 144 | void virtio_config_disable(struct virtio_device *dev) |
22b7050a MT |
145 | { |
146 | spin_lock_irq(&dev->config_lock); | |
147 | dev->config_enabled = false; | |
148 | spin_unlock_irq(&dev->config_lock); | |
149 | } | |
9fe7bfce | 150 | EXPORT_SYMBOL_GPL(virtio_config_disable); |
22b7050a | 151 | |
9fe7bfce | 152 | void virtio_config_enable(struct virtio_device *dev) |
22b7050a MT |
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 | } | |
9fe7bfce JF |
161 | EXPORT_SYMBOL_GPL(virtio_config_enable); |
162 | ||
163 | void virtio_add_status(struct virtio_device *dev, unsigned int status) | |
164 | { | |
ab7a2375 | 165 | might_sleep(); |
9fe7bfce JF |
166 | dev->config->set_status(dev, dev->config->get_status(dev) | status); |
167 | } | |
168 | EXPORT_SYMBOL_GPL(virtio_add_status); | |
22b7050a | 169 | |
9fe7bfce | 170 | int virtio_finalize_features(struct virtio_device *dev) |
30683a8c MT |
171 | { |
172 | int ret = dev->config->finalize_features(dev); | |
173 | unsigned status; | |
174 | ||
ab7a2375 | 175 | might_sleep(); |
30683a8c MT |
176 | if (ret) |
177 | return ret; | |
178 | ||
179 | if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) | |
180 | return 0; | |
181 | ||
9fe7bfce | 182 | virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); |
30683a8c MT |
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 | } | |
9fe7bfce | 191 | EXPORT_SYMBOL_GPL(virtio_finalize_features); |
30683a8c | 192 | |
ec3d41c4 RR |
193 | static int virtio_dev_probe(struct device *_d) |
194 | { | |
c45a6816 | 195 | int err, i; |
9bffdca8 | 196 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 197 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
d0254773 | 198 | u64 device_features; |
c102659d | 199 | u64 driver_features; |
b3bb62d1 | 200 | u64 driver_features_legacy; |
ec3d41c4 | 201 | |
c45a6816 | 202 | /* We have a driver! */ |
9fe7bfce | 203 | virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
204 | |
205 | /* Figure out what features the device supports. */ | |
206 | device_features = dev->config->get_features(dev); | |
207 | ||
c102659d MT |
208 | /* Figure out what features the driver supports. */ |
209 | driver_features = 0; | |
c45a6816 RR |
210 | for (i = 0; i < drv->feature_table_size; i++) { |
211 | unsigned int f = drv->feature_table[i]; | |
d0254773 | 212 | BUG_ON(f >= 64); |
c102659d | 213 | driver_features |= (1ULL << f); |
c45a6816 RR |
214 | } |
215 | ||
b3bb62d1 MT |
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 | ||
747ae34a | 228 | if (device_features & (1ULL << VIRTIO_F_VERSION_1)) |
b3bb62d1 MT |
229 | dev->features = driver_features & device_features; |
230 | else | |
231 | dev->features = driver_features_legacy & device_features; | |
c102659d | 232 | |
c624896e | 233 | /* Transport features always preserved to pass to finalize_features. */ |
dd7c7bc4 | 234 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) |
d0254773 | 235 | if (device_features & (1ULL << i)) |
e16e12be | 236 | __virtio_set_bit(dev, i); |
dd7c7bc4 | 237 | |
404123c2 MT |
238 | if (drv->validate) { |
239 | err = drv->validate(dev); | |
240 | if (err) | |
241 | goto err; | |
242 | } | |
243 | ||
30683a8c | 244 | err = virtio_finalize_features(dev); |
5c609a5e MT |
245 | if (err) |
246 | goto err; | |
ef688e15 | 247 | |
ec3d41c4 RR |
248 | err = drv->probe(dev); |
249 | if (err) | |
cb3f6d9d | 250 | goto err; |
22b7050a | 251 | |
5b40a7da RR |
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 | ||
cb3f6d9d MT |
256 | if (drv->scan) |
257 | drv->scan(dev); | |
ef688e15 | 258 | |
cb3f6d9d MT |
259 | virtio_config_enable(dev); |
260 | ||
261 | return 0; | |
262 | err: | |
9fe7bfce | 263 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
ec3d41c4 | 264 | return err; |
cb3f6d9d | 265 | |
ec3d41c4 RR |
266 | } |
267 | ||
74b2553f RR |
268 | static int virtio_dev_remove(struct device *_d) |
269 | { | |
9bffdca8 | 270 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 271 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
74b2553f | 272 | |
22b7050a MT |
273 | virtio_config_disable(dev); |
274 | ||
74b2553f | 275 | drv->remove(dev); |
6e5aa7ef RR |
276 | |
277 | /* Driver should have reset device. */ | |
5543a6ac | 278 | WARN_ON_ONCE(dev->config->get_status(dev)); |
6e5aa7ef RR |
279 | |
280 | /* Acknowledge the device's existence again. */ | |
9fe7bfce | 281 | virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); |
74b2553f RR |
282 | return 0; |
283 | } | |
284 | ||
e962fa66 MM |
285 | static struct bus_type virtio_bus = { |
286 | .name = "virtio", | |
287 | .match = virtio_dev_match, | |
3736dab6 | 288 | .dev_groups = virtio_dev_groups, |
e962fa66 MM |
289 | .uevent = virtio_uevent, |
290 | .probe = virtio_dev_probe, | |
291 | .remove = virtio_dev_remove, | |
292 | }; | |
293 | ||
ec3d41c4 RR |
294 | int register_virtio_driver(struct virtio_driver *driver) |
295 | { | |
c45a6816 RR |
296 | /* Catch this early. */ |
297 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 298 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
299 | return driver_register(&driver->driver); |
300 | } | |
301 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
302 | ||
303 | void unregister_virtio_driver(struct virtio_driver *driver) | |
304 | { | |
305 | driver_unregister(&driver->driver); | |
306 | } | |
307 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
308 | ||
f2b44cde | 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 | */ | |
ec3d41c4 RR |
318 | int register_virtio_device(struct virtio_device *dev) |
319 | { | |
320 | int err; | |
321 | ||
322 | dev->dev.bus = &virtio_bus; | |
f2b44cde | 323 | device_initialize(&dev->dev); |
b769f579 RR |
324 | |
325 | /* Assign a unique device index and hence name. */ | |
90e03207 AH |
326 | err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); |
327 | if (err < 0) | |
328 | goto out; | |
329 | ||
330 | dev->index = err; | |
99e0b6c8 | 331 | dev_set_name(&dev->dev, "virtio%u", dev->index); |
ec3d41c4 | 332 | |
22b7050a MT |
333 | spin_lock_init(&dev->config_lock); |
334 | dev->config_enabled = false; | |
335 | dev->config_change_pending = false; | |
336 | ||
6e5aa7ef RR |
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 | ||
ec3d41c4 | 341 | /* Acknowledge that we've seen the device. */ |
9fe7bfce | 342 | virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); |
ec3d41c4 | 343 | |
9499f5e7 RR |
344 | INIT_LIST_HEAD(&dev->vqs); |
345 | ||
f2b44cde | 346 | /* |
347 | * device_add() causes the bus infrastructure to look for a matching | |
348 | * driver. | |
349 | */ | |
350 | err = device_add(&dev->dev); | |
e60ea67b | 351 | if (err) |
352 | ida_simple_remove(&virtio_index_ida, dev->index); | |
90e03207 | 353 | out: |
ec3d41c4 | 354 | if (err) |
9fe7bfce | 355 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
ec3d41c4 RR |
356 | return err; |
357 | } | |
358 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
359 | ||
360 | void unregister_virtio_device(struct virtio_device *dev) | |
361 | { | |
237242bd CH |
362 | int index = dev->index; /* save for after device release */ |
363 | ||
ec3d41c4 | 364 | device_unregister(&dev->dev); |
237242bd | 365 | ida_simple_remove(&virtio_index_ida, index); |
ec3d41c4 RR |
366 | } |
367 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
368 | ||
c6716bae MT |
369 | #ifdef CONFIG_PM_SLEEP |
370 | int virtio_device_freeze(struct virtio_device *dev) | |
371 | { | |
372 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); | |
373 | ||
22b7050a MT |
374 | virtio_config_disable(dev); |
375 | ||
c6716bae MT |
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 | } | |
383 | EXPORT_SYMBOL_GPL(virtio_device_freeze); | |
384 | ||
385 | int virtio_device_restore(struct virtio_device *dev) | |
386 | { | |
387 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); | |
5c609a5e | 388 | int ret; |
c6716bae MT |
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. */ | |
9fe7bfce | 395 | virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); |
c6716bae MT |
396 | |
397 | /* Maybe driver failed before freeze. | |
398 | * Restore the failed status, for debugging. */ | |
399 | if (dev->failed) | |
9fe7bfce | 400 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
c6716bae MT |
401 | |
402 | if (!drv) | |
403 | return 0; | |
404 | ||
405 | /* We have a driver! */ | |
9fe7bfce | 406 | virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c6716bae | 407 | |
30683a8c | 408 | ret = virtio_finalize_features(dev); |
5c609a5e MT |
409 | if (ret) |
410 | goto err; | |
c6716bae MT |
411 | |
412 | if (drv->restore) { | |
5c609a5e MT |
413 | ret = drv->restore(dev); |
414 | if (ret) | |
415 | goto err; | |
c6716bae MT |
416 | } |
417 | ||
418 | /* Finally, tell the device we're all set */ | |
9fe7bfce | 419 | virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
c6716bae | 420 | |
22b7050a MT |
421 | virtio_config_enable(dev); |
422 | ||
c6716bae | 423 | return 0; |
5c609a5e MT |
424 | |
425 | err: | |
9fe7bfce | 426 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
5c609a5e | 427 | return ret; |
c6716bae MT |
428 | } |
429 | EXPORT_SYMBOL_GPL(virtio_device_restore); | |
430 | #endif | |
431 | ||
ec3d41c4 RR |
432 | static int virtio_init(void) |
433 | { | |
434 | if (bus_register(&virtio_bus) != 0) | |
435 | panic("virtio bus registration failed"); | |
436 | return 0; | |
437 | } | |
c6fd4701 RR |
438 | |
439 | static void __exit virtio_exit(void) | |
440 | { | |
441 | bus_unregister(&virtio_bus); | |
c13f99b7 | 442 | ida_destroy(&virtio_index_ida); |
c6fd4701 | 443 | } |
ec3d41c4 | 444 | core_initcall(virtio_init); |
c6fd4701 RR |
445 | module_exit(virtio_exit); |
446 | ||
447 | MODULE_LICENSE("GPL"); |