kmemtrace: SLOB hooks.
[linux-2.6/kmemtrace.git] / drivers / virtio / virtio.c
blob7084e7e146c0b6fbc319bb9ceefcf419b7111a13
1 #include <linux/virtio.h>
2 #include <linux/spinlock.h>
3 #include <linux/virtio_config.h>
5 /* Unique numbering for virtio devices. */
6 static unsigned int dev_index;
8 static ssize_t device_show(struct device *_d,
9 struct device_attribute *attr, char *buf)
11 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
12 return sprintf(buf, "%hu", dev->id.device);
14 static ssize_t vendor_show(struct device *_d,
15 struct device_attribute *attr, char *buf)
17 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
18 return sprintf(buf, "%hu", dev->id.vendor);
20 static ssize_t status_show(struct device *_d,
21 struct device_attribute *attr, char *buf)
23 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
24 return sprintf(buf, "0x%08x", dev->config->get_status(dev));
26 static ssize_t modalias_show(struct device *_d,
27 struct device_attribute *attr, char *buf)
29 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
31 return sprintf(buf, "virtio:d%08Xv%08X\n",
32 dev->id.device, dev->id.vendor);
34 static struct device_attribute virtio_dev_attrs[] = {
35 __ATTR_RO(device),
36 __ATTR_RO(vendor),
37 __ATTR_RO(status),
38 __ATTR_RO(modalias),
39 __ATTR_NULL
42 static inline int virtio_id_match(const struct virtio_device *dev,
43 const struct virtio_device_id *id)
45 if (id->device != dev->id.device)
46 return 0;
48 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
51 /* This looks through all the IDs a driver claims to support. If any of them
52 * match, we return 1 and the kernel will call virtio_dev_probe(). */
53 static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
55 unsigned int i;
56 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
57 const struct virtio_device_id *ids;
59 ids = container_of(_dr, struct virtio_driver, driver)->id_table;
60 for (i = 0; ids[i].device; i++)
61 if (virtio_id_match(dev, &ids[i]))
62 return 1;
63 return 0;
66 static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
68 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
70 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
71 dev->id.device, dev->id.vendor);
74 static struct bus_type virtio_bus = {
75 .name = "virtio",
76 .match = virtio_dev_match,
77 .dev_attrs = virtio_dev_attrs,
78 .uevent = virtio_uevent,
81 static void add_status(struct virtio_device *dev, unsigned status)
83 dev->config->set_status(dev, dev->config->get_status(dev) | status);
86 void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
87 unsigned int fbit)
89 unsigned int i;
90 struct virtio_driver *drv = container_of(vdev->dev.driver,
91 struct virtio_driver, driver);
93 for (i = 0; i < drv->feature_table_size; i++)
94 if (drv->feature_table[i] == fbit)
95 return;
96 BUG();
98 EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
100 static int virtio_dev_probe(struct device *_d)
102 int err, i;
103 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
104 struct virtio_driver *drv = container_of(dev->dev.driver,
105 struct virtio_driver, driver);
106 u32 device_features;
108 /* We have a driver! */
109 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
111 /* Figure out what features the device supports. */
112 device_features = dev->config->get_features(dev);
114 /* Features supported by both device and driver into dev->features. */
115 memset(dev->features, 0, sizeof(dev->features));
116 for (i = 0; i < drv->feature_table_size; i++) {
117 unsigned int f = drv->feature_table[i];
118 BUG_ON(f >= 32);
119 if (device_features & (1 << f))
120 set_bit(f, dev->features);
123 err = drv->probe(dev);
124 if (err)
125 add_status(dev, VIRTIO_CONFIG_S_FAILED);
126 else {
127 /* They should never have set feature bits beyond 32 */
128 dev->config->set_features(dev, dev->features[0]);
129 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
131 return err;
134 static int virtio_dev_remove(struct device *_d)
136 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
137 struct virtio_driver *drv = container_of(dev->dev.driver,
138 struct virtio_driver, driver);
140 drv->remove(dev);
142 /* Driver should have reset device. */
143 BUG_ON(dev->config->get_status(dev));
145 /* Acknowledge the device's existence again. */
146 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
147 return 0;
150 int register_virtio_driver(struct virtio_driver *driver)
152 /* Catch this early. */
153 BUG_ON(driver->feature_table_size && !driver->feature_table);
154 driver->driver.bus = &virtio_bus;
155 driver->driver.probe = virtio_dev_probe;
156 driver->driver.remove = virtio_dev_remove;
157 return driver_register(&driver->driver);
159 EXPORT_SYMBOL_GPL(register_virtio_driver);
161 void unregister_virtio_driver(struct virtio_driver *driver)
163 driver_unregister(&driver->driver);
165 EXPORT_SYMBOL_GPL(unregister_virtio_driver);
167 int register_virtio_device(struct virtio_device *dev)
169 int err;
171 dev->dev.bus = &virtio_bus;
173 /* Assign a unique device index and hence name. */
174 dev->index = dev_index++;
175 sprintf(dev->dev.bus_id, "virtio%u", dev->index);
177 /* We always start by resetting the device, in case a previous
178 * driver messed it up. This also tests that code path a little. */
179 dev->config->reset(dev);
181 /* Acknowledge that we've seen the device. */
182 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
184 /* device_register() causes the bus infrastructure to look for a
185 * matching driver. */
186 err = device_register(&dev->dev);
187 if (err)
188 add_status(dev, VIRTIO_CONFIG_S_FAILED);
189 return err;
191 EXPORT_SYMBOL_GPL(register_virtio_device);
193 void unregister_virtio_device(struct virtio_device *dev)
195 device_unregister(&dev->dev);
197 EXPORT_SYMBOL_GPL(unregister_virtio_device);
199 static int virtio_init(void)
201 if (bus_register(&virtio_bus) != 0)
202 panic("virtio bus registration failed");
203 return 0;
206 static void __exit virtio_exit(void)
208 bus_unregister(&virtio_bus);
210 core_initcall(virtio_init);
211 module_exit(virtio_exit);
213 MODULE_LICENSE("GPL");