blob: 3a43ebf83a49d6b869339e8f94da1f097141cb07 [file] [log] [blame]
Rusty Russellec3d41c2007-10-22 11:03:36 +10001#include <linux/virtio.h>
2#include <linux/spinlock.h>
3#include <linux/virtio_config.h>
4
Rusty Russellb769f572008-05-30 15:09:42 -05005/* Unique numbering for virtio devices. */
6static unsigned int dev_index;
7
Rusty Russellec3d41c2007-10-22 11:03:36 +10008static ssize_t device_show(struct device *_d,
9 struct device_attribute *attr, char *buf)
10{
11 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
12 return sprintf(buf, "%hu", dev->id.device);
13}
14static ssize_t vendor_show(struct device *_d,
15 struct device_attribute *attr, char *buf)
16{
17 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
18 return sprintf(buf, "%hu", dev->id.vendor);
19}
20static ssize_t status_show(struct device *_d,
21 struct device_attribute *attr, char *buf)
22{
23 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
24 return sprintf(buf, "0x%08x", dev->config->get_status(dev));
25}
Rusty Russellb01d9f22007-10-22 11:03:39 +100026static ssize_t modalias_show(struct device *_d,
27 struct device_attribute *attr, char *buf)
28{
29 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
30
31 return sprintf(buf, "virtio:d%08Xv%08X\n",
32 dev->id.device, dev->id.vendor);
33}
Rusty Russella9289282009-06-12 22:16:37 -060034static ssize_t features_show(struct device *_d,
35 struct device_attribute *attr, char *buf)
36{
37 struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
38 unsigned int i;
39 ssize_t len = 0;
40
41 /* We actually represent this as a bitstring, as it could be
42 * arbitrary length in future. */
43 for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
44 len += sprintf(buf+len, "%c",
45 test_bit(i, dev->features) ? '1' : '0');
46 len += sprintf(buf+len, "\n");
47 return len;
48}
Rusty Russellec3d41c2007-10-22 11:03:36 +100049static struct device_attribute virtio_dev_attrs[] = {
50 __ATTR_RO(device),
51 __ATTR_RO(vendor),
52 __ATTR_RO(status),
Rusty Russellb01d9f22007-10-22 11:03:39 +100053 __ATTR_RO(modalias),
Rusty Russella9289282009-06-12 22:16:37 -060054 __ATTR_RO(features),
Rusty Russellec3d41c2007-10-22 11:03:36 +100055 __ATTR_NULL
56};
57
58static inline int virtio_id_match(const struct virtio_device *dev,
59 const struct virtio_device_id *id)
60{
Christian Borntraegere3353852009-05-26 15:46:10 +020061 if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
Rusty Russellec3d41c2007-10-22 11:03:36 +100062 return 0;
63
Christian Borntraegerc89e8012009-05-26 15:46:09 +020064 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
Rusty Russellec3d41c2007-10-22 11:03:36 +100065}
66
67/* This looks through all the IDs a driver claims to support. If any of them
68 * match, we return 1 and the kernel will call virtio_dev_probe(). */
69static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
70{
71 unsigned int i;
72 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
73 const struct virtio_device_id *ids;
74
75 ids = container_of(_dr, struct virtio_driver, driver)->id_table;
76 for (i = 0; ids[i].device; i++)
77 if (virtio_id_match(dev, &ids[i]))
78 return 1;
79 return 0;
80}
81
Rusty Russellb01d9f22007-10-22 11:03:39 +100082static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
83{
84 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
85
86 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
87 dev->id.device, dev->id.vendor);
88}
89
Rusty Russellec3d41c2007-10-22 11:03:36 +100090static void add_status(struct virtio_device *dev, unsigned status)
91{
92 dev->config->set_status(dev, dev->config->get_status(dev) | status);
93}
94
Rusty Russellc45a6812008-05-02 21:50:50 -050095void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
96 unsigned int fbit)
97{
98 unsigned int i;
99 struct virtio_driver *drv = container_of(vdev->dev.driver,
100 struct virtio_driver, driver);
101
102 for (i = 0; i < drv->feature_table_size; i++)
103 if (drv->feature_table[i] == fbit)
104 return;
105 BUG();
106}
107EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
108
Rusty Russellec3d41c2007-10-22 11:03:36 +1000109static int virtio_dev_probe(struct device *_d)
110{
Rusty Russellc45a6812008-05-02 21:50:50 -0500111 int err, i;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000112 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
113 struct virtio_driver *drv = container_of(dev->dev.driver,
114 struct virtio_driver, driver);
Rusty Russellc45a6812008-05-02 21:50:50 -0500115 u32 device_features;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000116
Rusty Russellc45a6812008-05-02 21:50:50 -0500117 /* We have a driver! */
Rusty Russellec3d41c2007-10-22 11:03:36 +1000118 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
Rusty Russellc45a6812008-05-02 21:50:50 -0500119
120 /* Figure out what features the device supports. */
121 device_features = dev->config->get_features(dev);
122
123 /* Features supported by both device and driver into dev->features. */
124 memset(dev->features, 0, sizeof(dev->features));
125 for (i = 0; i < drv->feature_table_size; i++) {
126 unsigned int f = drv->feature_table[i];
127 BUG_ON(f >= 32);
128 if (device_features & (1 << f))
129 set_bit(f, dev->features);
130 }
131
Rusty Russellc6248962008-07-25 12:06:07 -0500132 /* Transport features always preserved to pass to finalize_features. */
Rusty Russelldd7c7bc2008-07-25 12:06:07 -0500133 for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
134 if (device_features & (1 << i))
135 set_bit(i, dev->features);
136
Rusty Russellef688e12009-06-12 22:16:35 -0600137 dev->config->finalize_features(dev);
138
Rusty Russellec3d41c2007-10-22 11:03:36 +1000139 err = drv->probe(dev);
140 if (err)
141 add_status(dev, VIRTIO_CONFIG_S_FAILED);
Rusty Russellef688e12009-06-12 22:16:35 -0600142 else
Mark McLoughlinb92dea62008-06-15 23:20:50 +1000143 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
Rusty Russellef688e12009-06-12 22:16:35 -0600144
Rusty Russellec3d41c2007-10-22 11:03:36 +1000145 return err;
146}
147
Rusty Russell74b25532007-11-19 11:20:42 -0500148static int virtio_dev_remove(struct device *_d)
149{
150 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
151 struct virtio_driver *drv = container_of(dev->dev.driver,
152 struct virtio_driver, driver);
153
Rusty Russell74b25532007-11-19 11:20:42 -0500154 drv->remove(dev);
Rusty Russell6e5aa7e2008-02-04 23:50:03 -0500155
156 /* Driver should have reset device. */
157 BUG_ON(dev->config->get_status(dev));
158
159 /* Acknowledge the device's existence again. */
160 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
Rusty Russell74b25532007-11-19 11:20:42 -0500161 return 0;
162}
163
Mark McLoughline962fa62008-06-13 13:46:40 +0100164static struct bus_type virtio_bus = {
165 .name = "virtio",
166 .match = virtio_dev_match,
167 .dev_attrs = virtio_dev_attrs,
168 .uevent = virtio_uevent,
169 .probe = virtio_dev_probe,
170 .remove = virtio_dev_remove,
171};
172
Rusty Russellec3d41c2007-10-22 11:03:36 +1000173int register_virtio_driver(struct virtio_driver *driver)
174{
Rusty Russellc45a6812008-05-02 21:50:50 -0500175 /* Catch this early. */
176 BUG_ON(driver->feature_table_size && !driver->feature_table);
Rusty Russellec3d41c2007-10-22 11:03:36 +1000177 driver->driver.bus = &virtio_bus;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000178 return driver_register(&driver->driver);
179}
180EXPORT_SYMBOL_GPL(register_virtio_driver);
181
182void unregister_virtio_driver(struct virtio_driver *driver)
183{
184 driver_unregister(&driver->driver);
185}
186EXPORT_SYMBOL_GPL(unregister_virtio_driver);
187
188int register_virtio_device(struct virtio_device *dev)
189{
190 int err;
191
192 dev->dev.bus = &virtio_bus;
Rusty Russellb769f572008-05-30 15:09:42 -0500193
194 /* Assign a unique device index and hence name. */
195 dev->index = dev_index++;
Kay Sievers99e0b6c2008-12-30 09:25:56 -0600196 dev_set_name(&dev->dev, "virtio%u", dev->index);
Rusty Russellec3d41c2007-10-22 11:03:36 +1000197
Rusty Russell6e5aa7e2008-02-04 23:50:03 -0500198 /* We always start by resetting the device, in case a previous
199 * driver messed it up. This also tests that code path a little. */
200 dev->config->reset(dev);
201
Rusty Russellec3d41c2007-10-22 11:03:36 +1000202 /* Acknowledge that we've seen the device. */
203 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
204
Rusty Russell9499f5e2009-06-12 22:16:35 -0600205 INIT_LIST_HEAD(&dev->vqs);
206
Rusty Russellec3d41c2007-10-22 11:03:36 +1000207 /* device_register() causes the bus infrastructure to look for a
208 * matching driver. */
209 err = device_register(&dev->dev);
210 if (err)
211 add_status(dev, VIRTIO_CONFIG_S_FAILED);
212 return err;
213}
214EXPORT_SYMBOL_GPL(register_virtio_device);
215
216void unregister_virtio_device(struct virtio_device *dev)
217{
218 device_unregister(&dev->dev);
219}
220EXPORT_SYMBOL_GPL(unregister_virtio_device);
221
Rusty Russellec3d41c2007-10-22 11:03:36 +1000222static int virtio_init(void)
223{
224 if (bus_register(&virtio_bus) != 0)
225 panic("virtio bus registration failed");
226 return 0;
227}
Rusty Russellc6fd4702008-02-04 23:50:05 -0500228
229static void __exit virtio_exit(void)
230{
231 bus_unregister(&virtio_bus);
232}
Rusty Russellec3d41c2007-10-22 11:03:36 +1000233core_initcall(virtio_init);
Rusty Russellc6fd4702008-02-04 23:50:05 -0500234module_exit(virtio_exit);
235
236MODULE_LICENSE("GPL");