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> |
ec3d41c4 | 6 | |
b769f579 | 7 | /* Unique numbering for virtio devices. */ |
90e03207 | 8 | static DEFINE_IDA(virtio_index_ida); |
b769f579 | 9 | |
ec3d41c4 RR |
10 | static ssize_t device_show(struct device *_d, |
11 | struct device_attribute *attr, char *buf) | |
12 | { | |
9bffdca8 | 13 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 14 | return sprintf(buf, "0x%04x\n", dev->id.device); |
ec3d41c4 | 15 | } |
3736dab6 GKH |
16 | static DEVICE_ATTR_RO(device); |
17 | ||
ec3d41c4 RR |
18 | static ssize_t vendor_show(struct device *_d, |
19 | struct device_attribute *attr, char *buf) | |
20 | { | |
9bffdca8 | 21 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 22 | return sprintf(buf, "0x%04x\n", dev->id.vendor); |
ec3d41c4 | 23 | } |
3736dab6 GKH |
24 | static DEVICE_ATTR_RO(vendor); |
25 | ||
ec3d41c4 RR |
26 | static ssize_t status_show(struct device *_d, |
27 | struct device_attribute *attr, char *buf) | |
28 | { | |
9bffdca8 | 29 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 30 | return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); |
ec3d41c4 | 31 | } |
3736dab6 GKH |
32 | static DEVICE_ATTR_RO(status); |
33 | ||
b01d9f28 RR |
34 | static ssize_t modalias_show(struct device *_d, |
35 | struct device_attribute *attr, char *buf) | |
36 | { | |
9bffdca8 | 37 | struct virtio_device *dev = dev_to_virtio(_d); |
b01d9f28 RR |
38 | return sprintf(buf, "virtio:d%08Xv%08X\n", |
39 | dev->id.device, dev->id.vendor); | |
40 | } | |
3736dab6 GKH |
41 | static DEVICE_ATTR_RO(modalias); |
42 | ||
a9289282 RR |
43 | static ssize_t features_show(struct device *_d, |
44 | struct device_attribute *attr, char *buf) | |
45 | { | |
9bffdca8 | 46 | struct virtio_device *dev = dev_to_virtio(_d); |
a9289282 RR |
47 | unsigned int i; |
48 | ssize_t len = 0; | |
49 | ||
50 | /* We actually represent this as a bitstring, as it could be | |
51 | * arbitrary length in future. */ | |
e16e12be | 52 | for (i = 0; i < sizeof(dev->features)*8; i++) |
a9289282 | 53 | len += sprintf(buf+len, "%c", |
e16e12be | 54 | __virtio_test_bit(dev, i) ? '1' : '0'); |
a9289282 RR |
55 | len += sprintf(buf+len, "\n"); |
56 | return len; | |
57 | } | |
3736dab6 GKH |
58 | static DEVICE_ATTR_RO(features); |
59 | ||
60 | static struct attribute *virtio_dev_attrs[] = { | |
61 | &dev_attr_device.attr, | |
62 | &dev_attr_vendor.attr, | |
63 | &dev_attr_status.attr, | |
64 | &dev_attr_modalias.attr, | |
65 | &dev_attr_features.attr, | |
66 | NULL, | |
ec3d41c4 | 67 | }; |
3736dab6 | 68 | ATTRIBUTE_GROUPS(virtio_dev); |
ec3d41c4 RR |
69 | |
70 | static inline int virtio_id_match(const struct virtio_device *dev, | |
71 | const struct virtio_device_id *id) | |
72 | { | |
e3353853 | 73 | if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID) |
ec3d41c4 RR |
74 | return 0; |
75 | ||
c89e8016 | 76 | return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor; |
ec3d41c4 RR |
77 | } |
78 | ||
79 | /* This looks through all the IDs a driver claims to support. If any of them | |
80 | * match, we return 1 and the kernel will call virtio_dev_probe(). */ | |
81 | static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) | |
82 | { | |
83 | unsigned int i; | |
9bffdca8 | 84 | struct virtio_device *dev = dev_to_virtio(_dv); |
ec3d41c4 RR |
85 | const struct virtio_device_id *ids; |
86 | ||
9a2bdcc8 | 87 | ids = drv_to_virtio(_dr)->id_table; |
ec3d41c4 RR |
88 | for (i = 0; ids[i].device; i++) |
89 | if (virtio_id_match(dev, &ids[i])) | |
90 | return 1; | |
91 | return 0; | |
92 | } | |
93 | ||
b01d9f28 RR |
94 | static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) |
95 | { | |
9bffdca8 | 96 | struct virtio_device *dev = dev_to_virtio(_dv); |
b01d9f28 RR |
97 | |
98 | return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", | |
99 | dev->id.device, dev->id.vendor); | |
100 | } | |
101 | ||
ec3d41c4 RR |
102 | static void add_status(struct virtio_device *dev, unsigned status) |
103 | { | |
104 | dev->config->set_status(dev, dev->config->get_status(dev) | status); | |
105 | } | |
106 | ||
c45a6816 RR |
107 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
108 | unsigned int fbit) | |
109 | { | |
110 | unsigned int i; | |
9a2bdcc8 | 111 | struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); |
c45a6816 RR |
112 | |
113 | for (i = 0; i < drv->feature_table_size; i++) | |
114 | if (drv->feature_table[i] == fbit) | |
115 | return; | |
b3bb62d1 MT |
116 | |
117 | if (drv->feature_table_legacy) { | |
118 | for (i = 0; i < drv->feature_table_size_legacy; i++) | |
119 | if (drv->feature_table_legacy[i] == fbit) | |
120 | return; | |
121 | } | |
122 | ||
c45a6816 RR |
123 | BUG(); |
124 | } | |
125 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
126 | ||
22b7050a MT |
127 | static void __virtio_config_changed(struct virtio_device *dev) |
128 | { | |
129 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); | |
130 | ||
131 | if (!dev->config_enabled) | |
132 | dev->config_change_pending = true; | |
133 | else if (drv && drv->config_changed) | |
134 | drv->config_changed(dev); | |
135 | } | |
136 | ||
137 | void virtio_config_changed(struct virtio_device *dev) | |
138 | { | |
139 | unsigned long flags; | |
140 | ||
141 | spin_lock_irqsave(&dev->config_lock, flags); | |
142 | __virtio_config_changed(dev); | |
143 | spin_unlock_irqrestore(&dev->config_lock, flags); | |
144 | } | |
145 | EXPORT_SYMBOL_GPL(virtio_config_changed); | |
146 | ||
147 | static void virtio_config_disable(struct virtio_device *dev) | |
148 | { | |
149 | spin_lock_irq(&dev->config_lock); | |
150 | dev->config_enabled = false; | |
151 | spin_unlock_irq(&dev->config_lock); | |
152 | } | |
153 | ||
154 | static void virtio_config_enable(struct virtio_device *dev) | |
155 | { | |
156 | spin_lock_irq(&dev->config_lock); | |
157 | dev->config_enabled = true; | |
158 | if (dev->config_change_pending) | |
159 | __virtio_config_changed(dev); | |
160 | dev->config_change_pending = false; | |
161 | spin_unlock_irq(&dev->config_lock); | |
162 | } | |
163 | ||
ec3d41c4 RR |
164 | static int virtio_dev_probe(struct device *_d) |
165 | { | |
c45a6816 | 166 | int err, i; |
9bffdca8 | 167 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 168 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
d0254773 | 169 | u64 device_features; |
c102659d | 170 | u64 driver_features; |
b3bb62d1 | 171 | u64 driver_features_legacy; |
cb3f6d9d | 172 | unsigned status; |
ec3d41c4 | 173 | |
c45a6816 | 174 | /* We have a driver! */ |
ec3d41c4 | 175 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
176 | |
177 | /* Figure out what features the device supports. */ | |
178 | device_features = dev->config->get_features(dev); | |
179 | ||
c102659d MT |
180 | /* Figure out what features the driver supports. */ |
181 | driver_features = 0; | |
c45a6816 RR |
182 | for (i = 0; i < drv->feature_table_size; i++) { |
183 | unsigned int f = drv->feature_table[i]; | |
d0254773 | 184 | BUG_ON(f >= 64); |
c102659d | 185 | driver_features |= (1ULL << f); |
c45a6816 RR |
186 | } |
187 | ||
b3bb62d1 MT |
188 | /* Some drivers have a separate feature table for virtio v1.0 */ |
189 | if (drv->feature_table_legacy) { | |
190 | driver_features_legacy = 0; | |
191 | for (i = 0; i < drv->feature_table_size_legacy; i++) { | |
192 | unsigned int f = drv->feature_table_legacy[i]; | |
193 | BUG_ON(f >= 64); | |
194 | driver_features_legacy |= (1ULL << f); | |
195 | } | |
196 | } else { | |
197 | driver_features_legacy = driver_features; | |
198 | } | |
199 | ||
747ae34a MT |
200 | /* Detect legacy-only drivers and disable VIRTIO_F_VERSION_1. */ |
201 | if (drv->legacy_only) | |
202 | device_features &= ~(1ULL << VIRTIO_F_VERSION_1); | |
203 | ||
204 | if (device_features & (1ULL << VIRTIO_F_VERSION_1)) | |
b3bb62d1 MT |
205 | dev->features = driver_features & device_features; |
206 | else | |
207 | dev->features = driver_features_legacy & device_features; | |
c102659d | 208 | |
c624896e | 209 | /* Transport features always preserved to pass to finalize_features. */ |
dd7c7bc4 | 210 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) |
d0254773 | 211 | if (device_features & (1ULL << i)) |
e16e12be | 212 | __virtio_set_bit(dev, i); |
dd7c7bc4 | 213 | |
ef688e15 RR |
214 | dev->config->finalize_features(dev); |
215 | ||
cb3f6d9d MT |
216 | if (virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { |
217 | add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); | |
218 | status = dev->config->get_status(dev); | |
219 | if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) { | |
220 | dev_err(_d, "virtio: device refuses features: %x\n", | |
221 | status); | |
222 | err = -ENODEV; | |
223 | goto err; | |
224 | } | |
225 | } | |
226 | ||
ec3d41c4 RR |
227 | err = drv->probe(dev); |
228 | if (err) | |
cb3f6d9d | 229 | goto err; |
22b7050a | 230 | |
cb3f6d9d MT |
231 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
232 | if (drv->scan) | |
233 | drv->scan(dev); | |
ef688e15 | 234 | |
cb3f6d9d MT |
235 | virtio_config_enable(dev); |
236 | ||
237 | return 0; | |
238 | err: | |
239 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
ec3d41c4 | 240 | return err; |
cb3f6d9d | 241 | |
ec3d41c4 RR |
242 | } |
243 | ||
74b2553f RR |
244 | static int virtio_dev_remove(struct device *_d) |
245 | { | |
9bffdca8 | 246 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 247 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
74b2553f | 248 | |
22b7050a MT |
249 | virtio_config_disable(dev); |
250 | ||
74b2553f | 251 | drv->remove(dev); |
6e5aa7ef RR |
252 | |
253 | /* Driver should have reset device. */ | |
5543a6ac | 254 | WARN_ON_ONCE(dev->config->get_status(dev)); |
6e5aa7ef RR |
255 | |
256 | /* Acknowledge the device's existence again. */ | |
257 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
74b2553f RR |
258 | return 0; |
259 | } | |
260 | ||
e962fa66 MM |
261 | static struct bus_type virtio_bus = { |
262 | .name = "virtio", | |
263 | .match = virtio_dev_match, | |
3736dab6 | 264 | .dev_groups = virtio_dev_groups, |
e962fa66 MM |
265 | .uevent = virtio_uevent, |
266 | .probe = virtio_dev_probe, | |
267 | .remove = virtio_dev_remove, | |
268 | }; | |
269 | ||
ec3d41c4 RR |
270 | int register_virtio_driver(struct virtio_driver *driver) |
271 | { | |
c45a6816 RR |
272 | /* Catch this early. */ |
273 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 274 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
275 | return driver_register(&driver->driver); |
276 | } | |
277 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
278 | ||
279 | void unregister_virtio_driver(struct virtio_driver *driver) | |
280 | { | |
281 | driver_unregister(&driver->driver); | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
284 | ||
285 | int register_virtio_device(struct virtio_device *dev) | |
286 | { | |
287 | int err; | |
288 | ||
289 | dev->dev.bus = &virtio_bus; | |
b769f579 RR |
290 | |
291 | /* Assign a unique device index and hence name. */ | |
90e03207 AH |
292 | err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); |
293 | if (err < 0) | |
294 | goto out; | |
295 | ||
296 | dev->index = err; | |
99e0b6c8 | 297 | dev_set_name(&dev->dev, "virtio%u", dev->index); |
ec3d41c4 | 298 | |
22b7050a MT |
299 | spin_lock_init(&dev->config_lock); |
300 | dev->config_enabled = false; | |
301 | dev->config_change_pending = false; | |
302 | ||
6e5aa7ef RR |
303 | /* We always start by resetting the device, in case a previous |
304 | * driver messed it up. This also tests that code path a little. */ | |
305 | dev->config->reset(dev); | |
306 | ||
ec3d41c4 RR |
307 | /* Acknowledge that we've seen the device. */ |
308 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
309 | ||
9499f5e7 RR |
310 | INIT_LIST_HEAD(&dev->vqs); |
311 | ||
ec3d41c4 RR |
312 | /* device_register() causes the bus infrastructure to look for a |
313 | * matching driver. */ | |
314 | err = device_register(&dev->dev); | |
90e03207 | 315 | out: |
ec3d41c4 RR |
316 | if (err) |
317 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
318 | return err; | |
319 | } | |
320 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
321 | ||
322 | void unregister_virtio_device(struct virtio_device *dev) | |
323 | { | |
237242bd CH |
324 | int index = dev->index; /* save for after device release */ |
325 | ||
ec3d41c4 | 326 | device_unregister(&dev->dev); |
237242bd | 327 | ida_simple_remove(&virtio_index_ida, index); |
ec3d41c4 RR |
328 | } |
329 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
330 | ||
c6716bae MT |
331 | #ifdef CONFIG_PM_SLEEP |
332 | int virtio_device_freeze(struct virtio_device *dev) | |
333 | { | |
334 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); | |
335 | ||
22b7050a MT |
336 | virtio_config_disable(dev); |
337 | ||
c6716bae MT |
338 | dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED; |
339 | ||
340 | if (drv && drv->freeze) | |
341 | return drv->freeze(dev); | |
342 | ||
343 | return 0; | |
344 | } | |
345 | EXPORT_SYMBOL_GPL(virtio_device_freeze); | |
346 | ||
347 | int virtio_device_restore(struct virtio_device *dev) | |
348 | { | |
349 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); | |
350 | ||
351 | /* We always start by resetting the device, in case a previous | |
352 | * driver messed it up. */ | |
353 | dev->config->reset(dev); | |
354 | ||
355 | /* Acknowledge that we've seen the device. */ | |
356 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
357 | ||
358 | /* Maybe driver failed before freeze. | |
359 | * Restore the failed status, for debugging. */ | |
360 | if (dev->failed) | |
361 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
362 | ||
363 | if (!drv) | |
364 | return 0; | |
365 | ||
366 | /* We have a driver! */ | |
367 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); | |
368 | ||
369 | dev->config->finalize_features(dev); | |
370 | ||
371 | if (drv->restore) { | |
372 | int ret = drv->restore(dev); | |
373 | if (ret) { | |
374 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
375 | return ret; | |
376 | } | |
377 | } | |
378 | ||
379 | /* Finally, tell the device we're all set */ | |
380 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); | |
381 | ||
22b7050a MT |
382 | virtio_config_enable(dev); |
383 | ||
c6716bae MT |
384 | return 0; |
385 | } | |
386 | EXPORT_SYMBOL_GPL(virtio_device_restore); | |
387 | #endif | |
388 | ||
ec3d41c4 RR |
389 | static int virtio_init(void) |
390 | { | |
391 | if (bus_register(&virtio_bus) != 0) | |
392 | panic("virtio bus registration failed"); | |
393 | return 0; | |
394 | } | |
c6fd4701 RR |
395 | |
396 | static void __exit virtio_exit(void) | |
397 | { | |
398 | bus_unregister(&virtio_bus); | |
399 | } | |
ec3d41c4 | 400 | core_initcall(virtio_init); |
c6fd4701 RR |
401 | module_exit(virtio_exit); |
402 | ||
403 | MODULE_LICENSE("GPL"); |