Commit | Line | Data |
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ec3d41c4 RR |
1 | #include <linux/virtio.h> |
2 | #include <linux/spinlock.h> | |
3 | #include <linux/virtio_config.h> | |
b5a2c4f1 | 4 | #include <linux/module.h> |
90e03207 | 5 | #include <linux/idr.h> |
b6098c30 | 6 | #include <uapi/linux/virtio_ids.h> |
ec3d41c4 | 7 | |
b769f579 | 8 | /* Unique numbering for virtio devices. */ |
90e03207 | 9 | static DEFINE_IDA(virtio_index_ida); |
b769f579 | 10 | |
ec3d41c4 RR |
11 | static ssize_t device_show(struct device *_d, |
12 | struct device_attribute *attr, char *buf) | |
13 | { | |
9bffdca8 | 14 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 15 | return sprintf(buf, "0x%04x\n", dev->id.device); |
ec3d41c4 | 16 | } |
3736dab6 GKH |
17 | static DEVICE_ATTR_RO(device); |
18 | ||
ec3d41c4 RR |
19 | static ssize_t vendor_show(struct device *_d, |
20 | struct device_attribute *attr, char *buf) | |
21 | { | |
9bffdca8 | 22 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 23 | return sprintf(buf, "0x%04x\n", dev->id.vendor); |
ec3d41c4 | 24 | } |
3736dab6 GKH |
25 | static DEVICE_ATTR_RO(vendor); |
26 | ||
ec3d41c4 RR |
27 | static ssize_t status_show(struct device *_d, |
28 | struct device_attribute *attr, char *buf) | |
29 | { | |
9bffdca8 | 30 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 31 | return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); |
ec3d41c4 | 32 | } |
3736dab6 GKH |
33 | static DEVICE_ATTR_RO(status); |
34 | ||
b01d9f28 RR |
35 | static ssize_t modalias_show(struct device *_d, |
36 | struct device_attribute *attr, char *buf) | |
37 | { | |
9bffdca8 | 38 | struct virtio_device *dev = dev_to_virtio(_d); |
b01d9f28 RR |
39 | return sprintf(buf, "virtio:d%08Xv%08X\n", |
40 | dev->id.device, dev->id.vendor); | |
41 | } | |
3736dab6 GKH |
42 | static DEVICE_ATTR_RO(modalias); |
43 | ||
a9289282 RR |
44 | static ssize_t features_show(struct device *_d, |
45 | struct device_attribute *attr, char *buf) | |
46 | { | |
9bffdca8 | 47 | struct virtio_device *dev = dev_to_virtio(_d); |
a9289282 RR |
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. */ | |
e16e12be | 53 | for (i = 0; i < sizeof(dev->features)*8; i++) |
a9289282 | 54 | len += sprintf(buf+len, "%c", |
e16e12be | 55 | __virtio_test_bit(dev, i) ? '1' : '0'); |
a9289282 RR |
56 | len += sprintf(buf+len, "\n"); |
57 | return len; | |
58 | } | |
3736dab6 GKH |
59 | static DEVICE_ATTR_RO(features); |
60 | ||
61 | static 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, | |
ec3d41c4 | 68 | }; |
3736dab6 | 69 | ATTRIBUTE_GROUPS(virtio_dev); |
ec3d41c4 RR |
70 | |
71 | static inline int virtio_id_match(const struct virtio_device *dev, | |
72 | const struct virtio_device_id *id) | |
73 | { | |
e3353853 | 74 | if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID) |
ec3d41c4 RR |
75 | return 0; |
76 | ||
c89e8016 | 77 | return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor; |
ec3d41c4 RR |
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(). */ | |
82 | static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) | |
83 | { | |
84 | unsigned int i; | |
9bffdca8 | 85 | struct virtio_device *dev = dev_to_virtio(_dv); |
ec3d41c4 RR |
86 | const struct virtio_device_id *ids; |
87 | ||
9a2bdcc8 | 88 | ids = drv_to_virtio(_dr)->id_table; |
ec3d41c4 RR |
89 | for (i = 0; ids[i].device; i++) |
90 | if (virtio_id_match(dev, &ids[i])) | |
91 | return 1; | |
92 | return 0; | |
93 | } | |
94 | ||
b01d9f28 RR |
95 | static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) |
96 | { | |
9bffdca8 | 97 | struct virtio_device *dev = dev_to_virtio(_dv); |
b01d9f28 RR |
98 | |
99 | return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", | |
100 | dev->id.device, dev->id.vendor); | |
101 | } | |
102 | ||
c45a6816 RR |
103 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
104 | unsigned int fbit) | |
105 | { | |
106 | unsigned int i; | |
9a2bdcc8 | 107 | struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); |
c45a6816 RR |
108 | |
109 | for (i = 0; i < drv->feature_table_size; i++) | |
110 | if (drv->feature_table[i] == fbit) | |
111 | return; | |
b3bb62d1 MT |
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 | ||
c45a6816 RR |
119 | BUG(); |
120 | } | |
121 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
122 | ||
22b7050a MT |
123 | static 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 | ||
133 | void 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 | } | |
141 | EXPORT_SYMBOL_GPL(virtio_config_changed); | |
142 | ||
9fe7bfce | 143 | void virtio_config_disable(struct virtio_device *dev) |
22b7050a MT |
144 | { |
145 | spin_lock_irq(&dev->config_lock); | |
146 | dev->config_enabled = false; | |
147 | spin_unlock_irq(&dev->config_lock); | |
148 | } | |
9fe7bfce | 149 | EXPORT_SYMBOL_GPL(virtio_config_disable); |
22b7050a | 150 | |
9fe7bfce | 151 | void virtio_config_enable(struct virtio_device *dev) |
22b7050a MT |
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 | } | |
9fe7bfce JF |
160 | EXPORT_SYMBOL_GPL(virtio_config_enable); |
161 | ||
162 | void virtio_add_status(struct virtio_device *dev, unsigned int status) | |
163 | { | |
164 | dev->config->set_status(dev, dev->config->get_status(dev) | status); | |
165 | } | |
166 | EXPORT_SYMBOL_GPL(virtio_add_status); | |
22b7050a | 167 | |
9fe7bfce | 168 | int virtio_finalize_features(struct virtio_device *dev) |
30683a8c MT |
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 | ||
9fe7bfce | 179 | virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); |
30683a8c MT |
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 | } | |
9fe7bfce | 188 | EXPORT_SYMBOL_GPL(virtio_finalize_features); |
30683a8c | 189 | |
ec3d41c4 RR |
190 | static int virtio_dev_probe(struct device *_d) |
191 | { | |
c45a6816 | 192 | int err, i; |
9bffdca8 | 193 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 194 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
d0254773 | 195 | u64 device_features; |
c102659d | 196 | u64 driver_features; |
b3bb62d1 | 197 | u64 driver_features_legacy; |
ec3d41c4 | 198 | |
c45a6816 | 199 | /* We have a driver! */ |
9fe7bfce | 200 | virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
201 | |
202 | /* Figure out what features the device supports. */ | |
203 | device_features = dev->config->get_features(dev); | |
204 | ||
c102659d MT |
205 | /* Figure out what features the driver supports. */ |
206 | driver_features = 0; | |
c45a6816 RR |
207 | for (i = 0; i < drv->feature_table_size; i++) { |
208 | unsigned int f = drv->feature_table[i]; | |
d0254773 | 209 | BUG_ON(f >= 64); |
c102659d | 210 | driver_features |= (1ULL << f); |
c45a6816 RR |
211 | } |
212 | ||
b3bb62d1 MT |
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 | ||
747ae34a | 225 | if (device_features & (1ULL << VIRTIO_F_VERSION_1)) |
b3bb62d1 MT |
226 | dev->features = driver_features & device_features; |
227 | else | |
228 | dev->features = driver_features_legacy & device_features; | |
c102659d | 229 | |
c624896e | 230 | /* Transport features always preserved to pass to finalize_features. */ |
dd7c7bc4 | 231 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) |
d0254773 | 232 | if (device_features & (1ULL << i)) |
e16e12be | 233 | __virtio_set_bit(dev, i); |
dd7c7bc4 | 234 | |
404123c2 MT |
235 | if (drv->validate) { |
236 | err = drv->validate(dev); | |
237 | if (err) | |
238 | goto err; | |
239 | } | |
240 | ||
30683a8c | 241 | err = virtio_finalize_features(dev); |
5c609a5e MT |
242 | if (err) |
243 | goto err; | |
ef688e15 | 244 | |
ec3d41c4 RR |
245 | err = drv->probe(dev); |
246 | if (err) | |
cb3f6d9d | 247 | goto err; |
22b7050a | 248 | |
5b40a7da RR |
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 | ||
cb3f6d9d MT |
253 | if (drv->scan) |
254 | drv->scan(dev); | |
ef688e15 | 255 | |
cb3f6d9d MT |
256 | virtio_config_enable(dev); |
257 | ||
258 | return 0; | |
259 | err: | |
9fe7bfce | 260 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
ec3d41c4 | 261 | return err; |
cb3f6d9d | 262 | |
ec3d41c4 RR |
263 | } |
264 | ||
74b2553f RR |
265 | static int virtio_dev_remove(struct device *_d) |
266 | { | |
9bffdca8 | 267 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 268 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
74b2553f | 269 | |
22b7050a MT |
270 | virtio_config_disable(dev); |
271 | ||
74b2553f | 272 | drv->remove(dev); |
6e5aa7ef RR |
273 | |
274 | /* Driver should have reset device. */ | |
5543a6ac | 275 | WARN_ON_ONCE(dev->config->get_status(dev)); |
6e5aa7ef RR |
276 | |
277 | /* Acknowledge the device's existence again. */ | |
9fe7bfce | 278 | virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); |
74b2553f RR |
279 | return 0; |
280 | } | |
281 | ||
e962fa66 MM |
282 | static struct bus_type virtio_bus = { |
283 | .name = "virtio", | |
284 | .match = virtio_dev_match, | |
3736dab6 | 285 | .dev_groups = virtio_dev_groups, |
e962fa66 MM |
286 | .uevent = virtio_uevent, |
287 | .probe = virtio_dev_probe, | |
288 | .remove = virtio_dev_remove, | |
289 | }; | |
290 | ||
ec3d41c4 RR |
291 | int register_virtio_driver(struct virtio_driver *driver) |
292 | { | |
c45a6816 RR |
293 | /* Catch this early. */ |
294 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 295 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
296 | return driver_register(&driver->driver); |
297 | } | |
298 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
299 | ||
300 | void unregister_virtio_driver(struct virtio_driver *driver) | |
301 | { | |
302 | driver_unregister(&driver->driver); | |
303 | } | |
304 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
305 | ||
306 | int register_virtio_device(struct virtio_device *dev) | |
307 | { | |
308 | int err; | |
309 | ||
310 | dev->dev.bus = &virtio_bus; | |
b769f579 RR |
311 | |
312 | /* Assign a unique device index and hence name. */ | |
90e03207 AH |
313 | err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); |
314 | if (err < 0) | |
315 | goto out; | |
316 | ||
317 | dev->index = err; | |
99e0b6c8 | 318 | dev_set_name(&dev->dev, "virtio%u", dev->index); |
ec3d41c4 | 319 | |
22b7050a MT |
320 | spin_lock_init(&dev->config_lock); |
321 | dev->config_enabled = false; | |
322 | dev->config_change_pending = false; | |
323 | ||
6e5aa7ef RR |
324 | /* We always start by resetting the device, in case a previous |
325 | * driver messed it up. This also tests that code path a little. */ | |
326 | dev->config->reset(dev); | |
327 | ||
ec3d41c4 | 328 | /* Acknowledge that we've seen the device. */ |
9fe7bfce | 329 | virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); |
ec3d41c4 | 330 | |
9499f5e7 RR |
331 | INIT_LIST_HEAD(&dev->vqs); |
332 | ||
ec3d41c4 RR |
333 | /* device_register() causes the bus infrastructure to look for a |
334 | * matching driver. */ | |
335 | err = device_register(&dev->dev); | |
90e03207 | 336 | out: |
ec3d41c4 | 337 | if (err) |
9fe7bfce | 338 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
ec3d41c4 RR |
339 | return err; |
340 | } | |
341 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
342 | ||
343 | void unregister_virtio_device(struct virtio_device *dev) | |
344 | { | |
237242bd CH |
345 | int index = dev->index; /* save for after device release */ |
346 | ||
ec3d41c4 | 347 | device_unregister(&dev->dev); |
237242bd | 348 | ida_simple_remove(&virtio_index_ida, index); |
ec3d41c4 RR |
349 | } |
350 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
351 | ||
c6716bae MT |
352 | #ifdef CONFIG_PM_SLEEP |
353 | int virtio_device_freeze(struct virtio_device *dev) | |
354 | { | |
355 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); | |
356 | ||
22b7050a MT |
357 | virtio_config_disable(dev); |
358 | ||
c6716bae MT |
359 | dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED; |
360 | ||
361 | if (drv && drv->freeze) | |
362 | return drv->freeze(dev); | |
363 | ||
364 | return 0; | |
365 | } | |
366 | EXPORT_SYMBOL_GPL(virtio_device_freeze); | |
367 | ||
368 | int virtio_device_restore(struct virtio_device *dev) | |
369 | { | |
370 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); | |
5c609a5e | 371 | int ret; |
c6716bae MT |
372 | |
373 | /* We always start by resetting the device, in case a previous | |
374 | * driver messed it up. */ | |
375 | dev->config->reset(dev); | |
376 | ||
377 | /* Acknowledge that we've seen the device. */ | |
9fe7bfce | 378 | virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); |
c6716bae MT |
379 | |
380 | /* Maybe driver failed before freeze. | |
381 | * Restore the failed status, for debugging. */ | |
382 | if (dev->failed) | |
9fe7bfce | 383 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
c6716bae MT |
384 | |
385 | if (!drv) | |
386 | return 0; | |
387 | ||
388 | /* We have a driver! */ | |
9fe7bfce | 389 | virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c6716bae | 390 | |
30683a8c | 391 | ret = virtio_finalize_features(dev); |
5c609a5e MT |
392 | if (ret) |
393 | goto err; | |
c6716bae MT |
394 | |
395 | if (drv->restore) { | |
5c609a5e MT |
396 | ret = drv->restore(dev); |
397 | if (ret) | |
398 | goto err; | |
c6716bae MT |
399 | } |
400 | ||
401 | /* Finally, tell the device we're all set */ | |
9fe7bfce | 402 | virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
c6716bae | 403 | |
22b7050a MT |
404 | virtio_config_enable(dev); |
405 | ||
c6716bae | 406 | return 0; |
5c609a5e MT |
407 | |
408 | err: | |
9fe7bfce | 409 | virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); |
5c609a5e | 410 | return ret; |
c6716bae MT |
411 | } |
412 | EXPORT_SYMBOL_GPL(virtio_device_restore); | |
413 | #endif | |
414 | ||
ec3d41c4 RR |
415 | static int virtio_init(void) |
416 | { | |
417 | if (bus_register(&virtio_bus) != 0) | |
418 | panic("virtio bus registration failed"); | |
419 | return 0; | |
420 | } | |
c6fd4701 RR |
421 | |
422 | static void __exit virtio_exit(void) | |
423 | { | |
424 | bus_unregister(&virtio_bus); | |
c13f99b7 | 425 | ida_destroy(&virtio_index_ida); |
c6fd4701 | 426 | } |
ec3d41c4 | 427 | core_initcall(virtio_init); |
c6fd4701 RR |
428 | module_exit(virtio_exit); |
429 | ||
430 | MODULE_LICENSE("GPL"); |