blob: c3b3f7f0d9d197ec0fd6e56aa99cd8b50e616cfa [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>
Paul Gortmakerb5a2c4f2011-07-03 16:20:30 -04004#include <linux/module.h>
Asias He90e03202012-05-03 10:20:51 +08005#include <linux/idr.h>
Rusty Russellec3d41c2007-10-22 11:03:36 +10006
Rusty Russellb769f572008-05-30 15:09:42 -05007/* Unique numbering for virtio devices. */
Asias He90e03202012-05-03 10:20:51 +08008static DEFINE_IDA(virtio_index_ida);
Rusty Russellb769f572008-05-30 15:09:42 -05009
Rusty Russellec3d41c2007-10-22 11:03:36 +100010static ssize_t device_show(struct device *_d,
11 struct device_attribute *attr, char *buf)
12{
13 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
Stephen Hemmingerbe6528b2010-11-09 22:20:29 -080014 return sprintf(buf, "0x%04x\n", dev->id.device);
Rusty Russellec3d41c2007-10-22 11:03:36 +100015}
16static ssize_t vendor_show(struct device *_d,
17 struct device_attribute *attr, char *buf)
18{
19 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
Stephen Hemmingerbe6528b2010-11-09 22:20:29 -080020 return sprintf(buf, "0x%04x\n", dev->id.vendor);
Rusty Russellec3d41c2007-10-22 11:03:36 +100021}
22static ssize_t status_show(struct device *_d,
23 struct device_attribute *attr, char *buf)
24{
25 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
Stephen Hemmingerbe6528b2010-11-09 22:20:29 -080026 return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
Rusty Russellec3d41c2007-10-22 11:03:36 +100027}
Rusty Russellb01d9f22007-10-22 11:03:39 +100028static ssize_t modalias_show(struct device *_d,
29 struct device_attribute *attr, char *buf)
30{
31 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
32
33 return sprintf(buf, "virtio:d%08Xv%08X\n",
34 dev->id.device, dev->id.vendor);
35}
Rusty Russella9289282009-06-12 22:16:37 -060036static ssize_t features_show(struct device *_d,
37 struct device_attribute *attr, char *buf)
38{
39 struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
40 unsigned int i;
41 ssize_t len = 0;
42
43 /* We actually represent this as a bitstring, as it could be
44 * arbitrary length in future. */
45 for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
46 len += sprintf(buf+len, "%c",
47 test_bit(i, dev->features) ? '1' : '0');
48 len += sprintf(buf+len, "\n");
49 return len;
50}
Rusty Russellec3d41c2007-10-22 11:03:36 +100051static struct device_attribute virtio_dev_attrs[] = {
52 __ATTR_RO(device),
53 __ATTR_RO(vendor),
54 __ATTR_RO(status),
Rusty Russellb01d9f22007-10-22 11:03:39 +100055 __ATTR_RO(modalias),
Rusty Russella9289282009-06-12 22:16:37 -060056 __ATTR_RO(features),
Rusty Russellec3d41c2007-10-22 11:03:36 +100057 __ATTR_NULL
58};
59
60static inline int virtio_id_match(const struct virtio_device *dev,
61 const struct virtio_device_id *id)
62{
Christian Borntraegere3353852009-05-26 15:46:10 +020063 if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
Rusty Russellec3d41c2007-10-22 11:03:36 +100064 return 0;
65
Christian Borntraegerc89e8012009-05-26 15:46:09 +020066 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
Rusty Russellec3d41c2007-10-22 11:03:36 +100067}
68
69/* This looks through all the IDs a driver claims to support. If any of them
70 * match, we return 1 and the kernel will call virtio_dev_probe(). */
71static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
72{
73 unsigned int i;
74 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
75 const struct virtio_device_id *ids;
76
77 ids = container_of(_dr, struct virtio_driver, driver)->id_table;
78 for (i = 0; ids[i].device; i++)
79 if (virtio_id_match(dev, &ids[i]))
80 return 1;
81 return 0;
82}
83
Rusty Russellb01d9f22007-10-22 11:03:39 +100084static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
85{
86 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
87
88 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
89 dev->id.device, dev->id.vendor);
90}
91
Rusty Russellec3d41c2007-10-22 11:03:36 +100092static void add_status(struct virtio_device *dev, unsigned status)
93{
94 dev->config->set_status(dev, dev->config->get_status(dev) | status);
95}
96
Rusty Russellc45a6812008-05-02 21:50:50 -050097void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
98 unsigned int fbit)
99{
100 unsigned int i;
101 struct virtio_driver *drv = container_of(vdev->dev.driver,
102 struct virtio_driver, driver);
103
104 for (i = 0; i < drv->feature_table_size; i++)
105 if (drv->feature_table[i] == fbit)
106 return;
107 BUG();
108}
109EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
110
Rusty Russellec3d41c2007-10-22 11:03:36 +1000111static int virtio_dev_probe(struct device *_d)
112{
Rusty Russellc45a6812008-05-02 21:50:50 -0500113 int err, i;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000114 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
115 struct virtio_driver *drv = container_of(dev->dev.driver,
116 struct virtio_driver, driver);
Rusty Russellc45a6812008-05-02 21:50:50 -0500117 u32 device_features;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000118
Rusty Russellc45a6812008-05-02 21:50:50 -0500119 /* We have a driver! */
Rusty Russellec3d41c2007-10-22 11:03:36 +1000120 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
Rusty Russellc45a6812008-05-02 21:50:50 -0500121
122 /* Figure out what features the device supports. */
123 device_features = dev->config->get_features(dev);
124
125 /* Features supported by both device and driver into dev->features. */
126 memset(dev->features, 0, sizeof(dev->features));
127 for (i = 0; i < drv->feature_table_size; i++) {
128 unsigned int f = drv->feature_table[i];
129 BUG_ON(f >= 32);
130 if (device_features & (1 << f))
131 set_bit(f, dev->features);
132 }
133
Rusty Russellc6248962008-07-25 12:06:07 -0500134 /* Transport features always preserved to pass to finalize_features. */
Rusty Russelldd7c7bc2008-07-25 12:06:07 -0500135 for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
136 if (device_features & (1 << i))
137 set_bit(i, dev->features);
138
Rusty Russellef688e12009-06-12 22:16:35 -0600139 dev->config->finalize_features(dev);
140
Rusty Russellec3d41c2007-10-22 11:03:36 +1000141 err = drv->probe(dev);
142 if (err)
143 add_status(dev, VIRTIO_CONFIG_S_FAILED);
Nicholas Bellinger59057fb2012-07-11 21:22:16 +0000144 else {
Mark McLoughlinb92dea62008-06-15 23:20:50 +1000145 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
Nicholas Bellinger59057fb2012-07-11 21:22:16 +0000146 if (drv->scan)
147 drv->scan(dev);
148 }
Rusty Russellef688e12009-06-12 22:16:35 -0600149
Rusty Russellec3d41c2007-10-22 11:03:36 +1000150 return err;
151}
152
Rusty Russell74b25532007-11-19 11:20:42 -0500153static int virtio_dev_remove(struct device *_d)
154{
155 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
156 struct virtio_driver *drv = container_of(dev->dev.driver,
157 struct virtio_driver, driver);
158
Rusty Russell74b25532007-11-19 11:20:42 -0500159 drv->remove(dev);
Rusty Russell6e5aa7e2008-02-04 23:50:03 -0500160
161 /* Driver should have reset device. */
162 BUG_ON(dev->config->get_status(dev));
163
164 /* Acknowledge the device's existence again. */
165 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
Rusty Russell74b25532007-11-19 11:20:42 -0500166 return 0;
167}
168
Mark McLoughline962fa662008-06-13 13:46:40 +0100169static struct bus_type virtio_bus = {
170 .name = "virtio",
171 .match = virtio_dev_match,
172 .dev_attrs = virtio_dev_attrs,
173 .uevent = virtio_uevent,
174 .probe = virtio_dev_probe,
175 .remove = virtio_dev_remove,
176};
177
Rusty Russellec3d41c2007-10-22 11:03:36 +1000178int register_virtio_driver(struct virtio_driver *driver)
179{
Rusty Russellc45a6812008-05-02 21:50:50 -0500180 /* Catch this early. */
181 BUG_ON(driver->feature_table_size && !driver->feature_table);
Rusty Russellec3d41c2007-10-22 11:03:36 +1000182 driver->driver.bus = &virtio_bus;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000183 return driver_register(&driver->driver);
184}
185EXPORT_SYMBOL_GPL(register_virtio_driver);
186
187void unregister_virtio_driver(struct virtio_driver *driver)
188{
189 driver_unregister(&driver->driver);
190}
191EXPORT_SYMBOL_GPL(unregister_virtio_driver);
192
193int register_virtio_device(struct virtio_device *dev)
194{
195 int err;
196
197 dev->dev.bus = &virtio_bus;
Rusty Russellb769f572008-05-30 15:09:42 -0500198
199 /* Assign a unique device index and hence name. */
Asias He90e03202012-05-03 10:20:51 +0800200 err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
201 if (err < 0)
202 goto out;
203
204 dev->index = err;
Kay Sievers99e0b6c2008-12-30 09:25:56 -0600205 dev_set_name(&dev->dev, "virtio%u", dev->index);
Rusty Russellec3d41c2007-10-22 11:03:36 +1000206
Rusty Russell6e5aa7e2008-02-04 23:50:03 -0500207 /* We always start by resetting the device, in case a previous
208 * driver messed it up. This also tests that code path a little. */
209 dev->config->reset(dev);
210
Rusty Russellec3d41c2007-10-22 11:03:36 +1000211 /* Acknowledge that we've seen the device. */
212 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
213
Rusty Russell9499f5e2009-06-12 22:16:35 -0600214 INIT_LIST_HEAD(&dev->vqs);
215
Rusty Russellec3d41c2007-10-22 11:03:36 +1000216 /* device_register() causes the bus infrastructure to look for a
217 * matching driver. */
218 err = device_register(&dev->dev);
Asias He90e03202012-05-03 10:20:51 +0800219out:
Rusty Russellec3d41c2007-10-22 11:03:36 +1000220 if (err)
221 add_status(dev, VIRTIO_CONFIG_S_FAILED);
222 return err;
223}
224EXPORT_SYMBOL_GPL(register_virtio_device);
225
226void unregister_virtio_device(struct virtio_device *dev)
227{
228 device_unregister(&dev->dev);
Asias He90e03202012-05-03 10:20:51 +0800229 ida_simple_remove(&virtio_index_ida, dev->index);
Rusty Russellec3d41c2007-10-22 11:03:36 +1000230}
231EXPORT_SYMBOL_GPL(unregister_virtio_device);
232
Rusty Russellec3d41c2007-10-22 11:03:36 +1000233static int virtio_init(void)
234{
235 if (bus_register(&virtio_bus) != 0)
236 panic("virtio bus registration failed");
237 return 0;
238}
Rusty Russellc6fd4702008-02-04 23:50:05 -0500239
240static void __exit virtio_exit(void)
241{
242 bus_unregister(&virtio_bus);
243}
Rusty Russellec3d41c2007-10-22 11:03:36 +1000244core_initcall(virtio_init);
Rusty Russellc6fd4702008-02-04 23:50:05 -0500245module_exit(virtio_exit);
246
247MODULE_LICENSE("GPL");