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ec3d41c4 RR |
1 | #include <linux/virtio.h> |
2 | #include <linux/spinlock.h> | |
3 | #include <linux/virtio_config.h> | |
4 | ||
5 | static 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 | } | |
11 | static 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 | } | |
17 | static 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 | } | |
b01d9f28 RR |
23 | static 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 | } | |
ec3d41c4 RR |
31 | static struct device_attribute virtio_dev_attrs[] = { |
32 | __ATTR_RO(device), | |
33 | __ATTR_RO(vendor), | |
34 | __ATTR_RO(status), | |
b01d9f28 | 35 | __ATTR_RO(modalias), |
ec3d41c4 RR |
36 | __ATTR_NULL |
37 | }; | |
38 | ||
39 | static 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(). */ | |
50 | static 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 | ||
b01d9f28 RR |
63 | static 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 | ||
ec3d41c4 RR |
71 | static struct bus_type virtio_bus = { |
72 | .name = "virtio", | |
73 | .match = virtio_dev_match, | |
74 | .dev_attrs = virtio_dev_attrs, | |
b01d9f28 | 75 | .uevent = virtio_uevent, |
ec3d41c4 RR |
76 | }; |
77 | ||
78 | static void add_status(struct virtio_device *dev, unsigned status) | |
79 | { | |
80 | dev->config->set_status(dev, dev->config->get_status(dev) | status); | |
81 | } | |
82 | ||
c45a6816 RR |
83 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
84 | unsigned int fbit) | |
85 | { | |
86 | unsigned int i; | |
87 | struct virtio_driver *drv = container_of(vdev->dev.driver, | |
88 | struct virtio_driver, driver); | |
89 | ||
90 | for (i = 0; i < drv->feature_table_size; i++) | |
91 | if (drv->feature_table[i] == fbit) | |
92 | return; | |
93 | BUG(); | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
96 | ||
ec3d41c4 RR |
97 | static int virtio_dev_probe(struct device *_d) |
98 | { | |
c45a6816 | 99 | int err, i; |
ec3d41c4 RR |
100 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); |
101 | struct virtio_driver *drv = container_of(dev->dev.driver, | |
102 | struct virtio_driver, driver); | |
c45a6816 | 103 | u32 device_features; |
ec3d41c4 | 104 | |
c45a6816 | 105 | /* We have a driver! */ |
ec3d41c4 | 106 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
107 | |
108 | /* Figure out what features the device supports. */ | |
109 | device_features = dev->config->get_features(dev); | |
110 | ||
111 | /* Features supported by both device and driver into dev->features. */ | |
112 | memset(dev->features, 0, sizeof(dev->features)); | |
113 | for (i = 0; i < drv->feature_table_size; i++) { | |
114 | unsigned int f = drv->feature_table[i]; | |
115 | BUG_ON(f >= 32); | |
116 | if (device_features & (1 << f)) | |
117 | set_bit(f, dev->features); | |
118 | } | |
119 | ||
ec3d41c4 RR |
120 | err = drv->probe(dev); |
121 | if (err) | |
122 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
c45a6816 | 123 | else { |
ec3d41c4 | 124 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
c45a6816 RR |
125 | /* They should never have set feature bits beyond 32 */ |
126 | dev->config->set_features(dev, dev->features[0]); | |
127 | } | |
ec3d41c4 RR |
128 | return err; |
129 | } | |
130 | ||
74b2553f RR |
131 | static int virtio_dev_remove(struct device *_d) |
132 | { | |
133 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); | |
134 | struct virtio_driver *drv = container_of(dev->dev.driver, | |
135 | struct virtio_driver, driver); | |
136 | ||
74b2553f | 137 | drv->remove(dev); |
6e5aa7ef RR |
138 | |
139 | /* Driver should have reset device. */ | |
140 | BUG_ON(dev->config->get_status(dev)); | |
141 | ||
142 | /* Acknowledge the device's existence again. */ | |
143 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
74b2553f RR |
144 | return 0; |
145 | } | |
146 | ||
ec3d41c4 RR |
147 | int register_virtio_driver(struct virtio_driver *driver) |
148 | { | |
c45a6816 RR |
149 | /* Catch this early. */ |
150 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 RR |
151 | driver->driver.bus = &virtio_bus; |
152 | driver->driver.probe = virtio_dev_probe; | |
74b2553f | 153 | driver->driver.remove = virtio_dev_remove; |
ec3d41c4 RR |
154 | return driver_register(&driver->driver); |
155 | } | |
156 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
157 | ||
158 | void unregister_virtio_driver(struct virtio_driver *driver) | |
159 | { | |
160 | driver_unregister(&driver->driver); | |
161 | } | |
162 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
163 | ||
164 | int register_virtio_device(struct virtio_device *dev) | |
165 | { | |
166 | int err; | |
167 | ||
168 | dev->dev.bus = &virtio_bus; | |
2ad3cfba | 169 | sprintf(dev->dev.bus_id, "virtio%u", dev->index); |
ec3d41c4 | 170 | |
6e5aa7ef RR |
171 | /* We always start by resetting the device, in case a previous |
172 | * driver messed it up. This also tests that code path a little. */ | |
173 | dev->config->reset(dev); | |
174 | ||
ec3d41c4 RR |
175 | /* Acknowledge that we've seen the device. */ |
176 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
177 | ||
178 | /* device_register() causes the bus infrastructure to look for a | |
179 | * matching driver. */ | |
180 | err = device_register(&dev->dev); | |
181 | if (err) | |
182 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
183 | return err; | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
186 | ||
187 | void unregister_virtio_device(struct virtio_device *dev) | |
188 | { | |
189 | device_unregister(&dev->dev); | |
190 | } | |
191 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
192 | ||
ec3d41c4 RR |
193 | static int virtio_init(void) |
194 | { | |
195 | if (bus_register(&virtio_bus) != 0) | |
196 | panic("virtio bus registration failed"); | |
197 | return 0; | |
198 | } | |
c6fd4701 RR |
199 | |
200 | static void __exit virtio_exit(void) | |
201 | { | |
202 | bus_unregister(&virtio_bus); | |
203 | } | |
ec3d41c4 | 204 | core_initcall(virtio_init); |
c6fd4701 RR |
205 | module_exit(virtio_exit); |
206 | ||
207 | MODULE_LICENSE("GPL"); |