tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <linux/virtio.h>
2#include <linux/spinlock.h>
3#include <linux/virtio_config.h>
4
5static ssize_t device_show(struct device *_d,
6 struct device_attribute *attr, char *buf)
7{
8 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
9 return sprintf(buf, "%hu", dev->id.device);
10}
11static ssize_t vendor_show(struct device *_d,
12 struct device_attribute *attr, char *buf)
13{
14 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
15 return sprintf(buf, "%hu", dev->id.vendor);
16}
17static ssize_t status_show(struct device *_d,
18 struct device_attribute *attr, char *buf)
19{
20 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
21 return sprintf(buf, "0x%08x", dev->config->get_status(dev));
22}
23static ssize_t modalias_show(struct device *_d,
24 struct device_attribute *attr, char *buf)
25{
26 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
27
28 return sprintf(buf, "virtio:d%08Xv%08X\n",
29 dev->id.device, dev->id.vendor);
30}
31static struct device_attribute virtio_dev_attrs[] = {
32 __ATTR_RO(device),
33 __ATTR_RO(vendor),
34 __ATTR_RO(status),
35 __ATTR_RO(modalias),
36 __ATTR_NULL
37};
38
39static inline int virtio_id_match(const struct virtio_device *dev,
40 const struct virtio_device_id *id)
41{
42 if (id->device != dev->id.device)
43 return 0;
44
45 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
46}
47
48/* This looks through all the IDs a driver claims to support. If any of them
49 * match, we return 1 and the kernel will call virtio_dev_probe(). */
50static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
51{
52 unsigned int i;
53 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
54 const struct virtio_device_id *ids;
55
56 ids = container_of(_dr, struct virtio_driver, driver)->id_table;
57 for (i = 0; ids[i].device; i++)
58 if (virtio_id_match(dev, &ids[i]))
59 return 1;
60 return 0;
61}
62
63static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
64{
65 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
66
67 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
68 dev->id.device, dev->id.vendor);
69}
70
71static struct bus_type virtio_bus = {
72 .name = "virtio",
73 .match = virtio_dev_match,
74 .dev_attrs = virtio_dev_attrs,
75 .uevent = virtio_uevent,
76};
77
78static void add_status(struct virtio_device *dev, unsigned status)
79{
80 dev->config->set_status(dev, dev->config->get_status(dev) | status);
81}
82
83static int virtio_dev_probe(struct device *_d)
84{
85 int err;
86 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
87 struct virtio_driver *drv = container_of(dev->dev.driver,
88 struct virtio_driver, driver);
89
90 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
91 err = drv->probe(dev);
92 if (err)
93 add_status(dev, VIRTIO_CONFIG_S_FAILED);
94 else
95 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
96 return err;
97}
98
99static int virtio_dev_remove(struct device *_d)
100{
101 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
102 struct virtio_driver *drv = container_of(dev->dev.driver,
103 struct virtio_driver, driver);
104
105 drv->remove(dev);
106
107 /* Driver should have reset device. */
108 BUG_ON(dev->config->get_status(dev));
109
110 /* Acknowledge the device's existence again. */
111 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
112 return 0;
113}
114
115int register_virtio_driver(struct virtio_driver *driver)
116{
117 driver->driver.bus = &virtio_bus;
118 driver->driver.probe = virtio_dev_probe;
119 driver->driver.remove = virtio_dev_remove;
120 return driver_register(&driver->driver);
121}
122EXPORT_SYMBOL_GPL(register_virtio_driver);
123
124void unregister_virtio_driver(struct virtio_driver *driver)
125{
126 driver_unregister(&driver->driver);
127}
128EXPORT_SYMBOL_GPL(unregister_virtio_driver);
129
130int register_virtio_device(struct virtio_device *dev)
131{
132 int err;
133
134 dev->dev.bus = &virtio_bus;
135 sprintf(dev->dev.bus_id, "%u", dev->index);
136
137 /* We always start by resetting the device, in case a previous
138 * driver messed it up. This also tests that code path a little. */
139 dev->config->reset(dev);
140
141 /* Acknowledge that we've seen the device. */
142 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
143
144 /* device_register() causes the bus infrastructure to look for a
145 * matching driver. */
146 err = device_register(&dev->dev);
147 if (err)
148 add_status(dev, VIRTIO_CONFIG_S_FAILED);
149 return err;
150}
151EXPORT_SYMBOL_GPL(register_virtio_device);
152
153void unregister_virtio_device(struct virtio_device *dev)
154{
155 device_unregister(&dev->dev);
156}
157EXPORT_SYMBOL_GPL(unregister_virtio_device);
158
159static int virtio_init(void)
160{
161 if (bus_register(&virtio_bus) != 0)
162 panic("virtio bus registration failed");
163 return 0;
164}
165
166static void __exit virtio_exit(void)
167{
168 bus_unregister(&virtio_bus);
169}
170core_initcall(virtio_init);
171module_exit(virtio_exit);
172
173MODULE_LICENSE("GPL");