blob: 984c501c258ffa8bc6f7ad1ad14be741494ba5ee [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>
Rusty Russellec3d41c2007-10-22 11:03:36 +10005
Rusty Russellb769f572008-05-30 15:09:42 -05006/* Unique numbering for virtio devices. */
7static unsigned int dev_index;
8
Rusty Russellec3d41c2007-10-22 11:03:36 +10009static ssize_t device_show(struct device *_d,
10 struct device_attribute *attr, char *buf)
11{
12 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
Stephen Hemmingerbe6528b2010-11-09 22:20:29 -080013 return sprintf(buf, "0x%04x\n", dev->id.device);
Rusty Russellec3d41c2007-10-22 11:03:36 +100014}
15static ssize_t vendor_show(struct device *_d,
16 struct device_attribute *attr, char *buf)
17{
18 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
Stephen Hemmingerbe6528b2010-11-09 22:20:29 -080019 return sprintf(buf, "0x%04x\n", dev->id.vendor);
Rusty Russellec3d41c2007-10-22 11:03:36 +100020}
21static ssize_t status_show(struct device *_d,
22 struct device_attribute *attr, char *buf)
23{
24 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
Stephen Hemmingerbe6528b2010-11-09 22:20:29 -080025 return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
Rusty Russellec3d41c2007-10-22 11:03:36 +100026}
Rusty Russellb01d9f22007-10-22 11:03:39 +100027static ssize_t modalias_show(struct device *_d,
28 struct device_attribute *attr, char *buf)
29{
30 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
31
32 return sprintf(buf, "virtio:d%08Xv%08X\n",
33 dev->id.device, dev->id.vendor);
34}
Rusty Russella9289282009-06-12 22:16:37 -060035static ssize_t features_show(struct device *_d,
36 struct device_attribute *attr, char *buf)
37{
38 struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
39 unsigned int i;
40 ssize_t len = 0;
41
42 /* We actually represent this as a bitstring, as it could be
43 * arbitrary length in future. */
44 for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
45 len += sprintf(buf+len, "%c",
46 test_bit(i, dev->features) ? '1' : '0');
47 len += sprintf(buf+len, "\n");
48 return len;
49}
Rusty Russellec3d41c2007-10-22 11:03:36 +100050static struct device_attribute virtio_dev_attrs[] = {
51 __ATTR_RO(device),
52 __ATTR_RO(vendor),
53 __ATTR_RO(status),
Rusty Russellb01d9f22007-10-22 11:03:39 +100054 __ATTR_RO(modalias),
Rusty Russella9289282009-06-12 22:16:37 -060055 __ATTR_RO(features),
Rusty Russellec3d41c2007-10-22 11:03:36 +100056 __ATTR_NULL
57};
58
59static inline int virtio_id_match(const struct virtio_device *dev,
60 const struct virtio_device_id *id)
61{
Christian Borntraegere3353852009-05-26 15:46:10 +020062 if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
Rusty Russellec3d41c2007-10-22 11:03:36 +100063 return 0;
64
Christian Borntraegerc89e8012009-05-26 15:46:09 +020065 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
Rusty Russellec3d41c2007-10-22 11:03:36 +100066}
67
68/* This looks through all the IDs a driver claims to support. If any of them
69 * match, we return 1 and the kernel will call virtio_dev_probe(). */
70static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
71{
72 unsigned int i;
73 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
74 const struct virtio_device_id *ids;
75
76 ids = container_of(_dr, struct virtio_driver, driver)->id_table;
77 for (i = 0; ids[i].device; i++)
78 if (virtio_id_match(dev, &ids[i]))
79 return 1;
80 return 0;
81}
82
Rusty Russellb01d9f22007-10-22 11:03:39 +100083static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
84{
85 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
86
87 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
88 dev->id.device, dev->id.vendor);
89}
90
Rusty Russellec3d41c2007-10-22 11:03:36 +100091static void add_status(struct virtio_device *dev, unsigned status)
92{
93 dev->config->set_status(dev, dev->config->get_status(dev) | status);
94}
95
Rusty Russellc45a6812008-05-02 21:50:50 -050096void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
97 unsigned int fbit)
98{
99 unsigned int i;
100 struct virtio_driver *drv = container_of(vdev->dev.driver,
101 struct virtio_driver, driver);
102
103 for (i = 0; i < drv->feature_table_size; i++)
104 if (drv->feature_table[i] == fbit)
105 return;
106 BUG();
107}
108EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
109
Rusty Russellec3d41c2007-10-22 11:03:36 +1000110static int virtio_dev_probe(struct device *_d)
111{
Rusty Russellc45a6812008-05-02 21:50:50 -0500112 int err, i;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000113 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
114 struct virtio_driver *drv = container_of(dev->dev.driver,
115 struct virtio_driver, driver);
Rusty Russellc45a6812008-05-02 21:50:50 -0500116 u32 device_features;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000117
Rusty Russellc45a6812008-05-02 21:50:50 -0500118 /* We have a driver! */
Rusty Russellec3d41c2007-10-22 11:03:36 +1000119 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
Rusty Russellc45a6812008-05-02 21:50:50 -0500120
121 /* Figure out what features the device supports. */
122 device_features = dev->config->get_features(dev);
123
124 /* Features supported by both device and driver into dev->features. */
125 memset(dev->features, 0, sizeof(dev->features));
126 for (i = 0; i < drv->feature_table_size; i++) {
127 unsigned int f = drv->feature_table[i];
128 BUG_ON(f >= 32);
129 if (device_features & (1 << f))
130 set_bit(f, dev->features);
131 }
132
Rusty Russellc6248962008-07-25 12:06:07 -0500133 /* Transport features always preserved to pass to finalize_features. */
Rusty Russelldd7c7bc2008-07-25 12:06:07 -0500134 for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
135 if (device_features & (1 << i))
136 set_bit(i, dev->features);
137
Rusty Russellef688e12009-06-12 22:16:35 -0600138 dev->config->finalize_features(dev);
139
Rusty Russellec3d41c2007-10-22 11:03:36 +1000140 err = drv->probe(dev);
141 if (err)
142 add_status(dev, VIRTIO_CONFIG_S_FAILED);
Rusty Russellef688e12009-06-12 22:16:35 -0600143 else
Mark McLoughlinb92dea62008-06-15 23:20:50 +1000144 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
Rusty Russellef688e12009-06-12 22:16:35 -0600145
Rusty Russellec3d41c2007-10-22 11:03:36 +1000146 return err;
147}
148
Rusty Russell74b25532007-11-19 11:20:42 -0500149static int virtio_dev_remove(struct device *_d)
150{
151 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
152 struct virtio_driver *drv = container_of(dev->dev.driver,
153 struct virtio_driver, driver);
154
Rusty Russell74b25532007-11-19 11:20:42 -0500155 drv->remove(dev);
Rusty Russell6e5aa7e2008-02-04 23:50:03 -0500156
157 /* Driver should have reset device. */
158 BUG_ON(dev->config->get_status(dev));
159
160 /* Acknowledge the device's existence again. */
161 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
Rusty Russell74b25532007-11-19 11:20:42 -0500162 return 0;
163}
164
Mark McLoughline962fa62008-06-13 13:46:40 +0100165static struct bus_type virtio_bus = {
166 .name = "virtio",
167 .match = virtio_dev_match,
168 .dev_attrs = virtio_dev_attrs,
169 .uevent = virtio_uevent,
170 .probe = virtio_dev_probe,
171 .remove = virtio_dev_remove,
172};
173
Rusty Russellec3d41c2007-10-22 11:03:36 +1000174int register_virtio_driver(struct virtio_driver *driver)
175{
Rusty Russellc45a6812008-05-02 21:50:50 -0500176 /* Catch this early. */
177 BUG_ON(driver->feature_table_size && !driver->feature_table);
Rusty Russellec3d41c2007-10-22 11:03:36 +1000178 driver->driver.bus = &virtio_bus;
Rusty Russellec3d41c2007-10-22 11:03:36 +1000179 return driver_register(&driver->driver);
180}
181EXPORT_SYMBOL_GPL(register_virtio_driver);
182
183void unregister_virtio_driver(struct virtio_driver *driver)
184{
185 driver_unregister(&driver->driver);
186}
187EXPORT_SYMBOL_GPL(unregister_virtio_driver);
188
189int register_virtio_device(struct virtio_device *dev)
190{
191 int err;
192
193 dev->dev.bus = &virtio_bus;
Rusty Russellb769f572008-05-30 15:09:42 -0500194
195 /* Assign a unique device index and hence name. */
196 dev->index = dev_index++;
Kay Sievers99e0b6c2008-12-30 09:25:56 -0600197 dev_set_name(&dev->dev, "virtio%u", dev->index);
Rusty Russellec3d41c2007-10-22 11:03:36 +1000198
Rusty Russell6e5aa7e2008-02-04 23:50:03 -0500199 /* We always start by resetting the device, in case a previous
200 * driver messed it up. This also tests that code path a little. */
201 dev->config->reset(dev);
202
Rusty Russellec3d41c2007-10-22 11:03:36 +1000203 /* Acknowledge that we've seen the device. */
204 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
205
Rusty Russell9499f5e2009-06-12 22:16:35 -0600206 INIT_LIST_HEAD(&dev->vqs);
207
Rusty Russellec3d41c2007-10-22 11:03:36 +1000208 /* device_register() causes the bus infrastructure to look for a
209 * matching driver. */
210 err = device_register(&dev->dev);
211 if (err)
212 add_status(dev, VIRTIO_CONFIG_S_FAILED);
213 return err;
214}
215EXPORT_SYMBOL_GPL(register_virtio_device);
216
217void unregister_virtio_device(struct virtio_device *dev)
218{
219 device_unregister(&dev->dev);
220}
221EXPORT_SYMBOL_GPL(unregister_virtio_device);
222
Rusty Russellec3d41c2007-10-22 11:03:36 +1000223static int virtio_init(void)
224{
225 if (bus_register(&virtio_bus) != 0)
226 panic("virtio bus registration failed");
227 return 0;
228}
Rusty Russellc6fd4702008-02-04 23:50:05 -0500229
230static void __exit virtio_exit(void)
231{
232 bus_unregister(&virtio_bus);
233}
Rusty Russellec3d41c2007-10-22 11:03:36 +1000234core_initcall(virtio_init);
Rusty Russellc6fd4702008-02-04 23:50:05 -0500235module_exit(virtio_exit);
236
237MODULE_LICENSE("GPL");