1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
#include <linux/virtio.h>
#include <linux/spinlock.h>
#include <linux/virtio_config.h>
/* Unique numbering for virtio devices. */
static unsigned int dev_index;
static ssize_t device_show(struct device *_d,
struct device_attribute *attr, char *buf)
{
struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
return sprintf(buf, "%hu", dev->id.device);
}
static ssize_t vendor_show(struct device *_d,
struct device_attribute *attr, char *buf)
{
struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
return sprintf(buf, "%hu", dev->id.vendor);
}
static ssize_t status_show(struct device *_d,
struct device_attribute *attr, char *buf)
{
struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
return sprintf(buf, "0x%08x", dev->config->get_status(dev));
}
static ssize_t modalias_show(struct device *_d,
struct device_attribute *attr, char *buf)
{
struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
return sprintf(buf, "virtio:d%08Xv%08X\n",
dev->id.device, dev->id.vendor);
}
static struct device_attribute virtio_dev_attrs[] = {
__ATTR_RO(device),
__ATTR_RO(vendor),
__ATTR_RO(status),
__ATTR_RO(modalias),
__ATTR_NULL
};
static inline int virtio_id_match(const struct virtio_device *dev,
const struct virtio_device_id *id)
{
if (id->device != dev->id.device)
return 0;
return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
}
/* This looks through all the IDs a driver claims to support. If any of them
* match, we return 1 and the kernel will call virtio_dev_probe(). */
static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
{
unsigned int i;
struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
const struct virtio_device_id *ids;
ids = container_of(_dr, struct virtio_driver, driver)->id_table;
for (i = 0; ids[i].device; i++)
if (virtio_id_match(dev, &ids[i]))
return 1;
return 0;
}
static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
{
struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
dev->id.device, dev->id.vendor);
}
static void add_status(struct virtio_device *dev, unsigned status)
{
dev->config->set_status(dev, dev->config->get_status(dev) | status);
}
void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
unsigned int fbit)
{
unsigned int i;
struct virtio_driver *drv = container_of(vdev->dev.driver,
struct virtio_driver, driver);
for (i = 0; i < drv->feature_table_size; i++)
if (drv->feature_table[i] == fbit)
return;
BUG();
}
EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
static int virtio_dev_probe(struct device *_d)
{
int err, i;
struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
struct virtio_driver *drv = container_of(dev->dev.driver,
struct virtio_driver, driver);
u32 device_features;
/* We have a driver! */
add_status(dev, VIRTIO_CONFIG_S_DRIVER);
/* Figure out what features the device supports. */
device_features = dev->config->get_features(dev);
/* Features supported by both device and driver into dev->features. */
memset(dev->features, 0, sizeof(dev->features));
for (i = 0; i < drv->feature_table_size; i++) {
unsigned int f = drv->feature_table[i];
BUG_ON(f >= 32);
if (device_features & (1 << f))
set_bit(f, dev->features);
}
/* Transport features always preserved to pass to finalize_features. */
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
if (device_features & (1 << i))
set_bit(i, dev->features);
dev->config->finalize_features(dev);
err = drv->probe(dev);
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
else
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
return err;
}
static int virtio_dev_remove(struct device *_d)
{
struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
struct virtio_driver *drv = container_of(dev->dev.driver,
struct virtio_driver, driver);
drv->remove(dev);
/* Driver should have reset device. */
BUG_ON(dev->config->get_status(dev));
/* Acknowledge the device's existence again. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
return 0;
}
static struct bus_type virtio_bus = {
.name = "virtio",
.match = virtio_dev_match,
.dev_attrs = virtio_dev_attrs,
.uevent = virtio_uevent,
.probe = virtio_dev_probe,
.remove = virtio_dev_remove,
};
int register_virtio_driver(struct virtio_driver *driver)
{
/* Catch this early. */
BUG_ON(driver->feature_table_size && !driver->feature_table);
driver->driver.bus = &virtio_bus;
return driver_register(&driver->driver);
}
EXPORT_SYMBOL_GPL(register_virtio_driver);
void unregister_virtio_driver(struct virtio_driver *driver)
{
driver_unregister(&driver->driver);
}
EXPORT_SYMBOL_GPL(unregister_virtio_driver);
int register_virtio_device(struct virtio_device *dev)
{
int err;
dev->dev.bus = &virtio_bus;
/* Assign a unique device index and hence name. */
dev->index = dev_index++;
dev_set_name(&dev->dev, "virtio%u", dev->index);
/* We always start by resetting the device, in case a previous
* driver messed it up. This also tests that code path a little. */
dev->config->reset(dev);
/* Acknowledge that we've seen the device. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
/* device_register() causes the bus infrastructure to look for a
* matching driver. */
err = device_register(&dev->dev);
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
return err;
}
EXPORT_SYMBOL_GPL(register_virtio_device);
void unregister_virtio_device(struct virtio_device *dev)
{
device_unregister(&dev->dev);
}
EXPORT_SYMBOL_GPL(unregister_virtio_device);
static int virtio_init(void)
{
if (bus_register(&virtio_bus) != 0)
panic("virtio bus registration failed");
return 0;
}
static void __exit virtio_exit(void)
{
bus_unregister(&virtio_bus);
}
core_initcall(virtio_init);
module_exit(virtio_exit);
MODULE_LICENSE("GPL");
|
