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ec3d41c4 RR |
1 | #include <linux/virtio.h> |
2 | #include <linux/spinlock.h> | |
3 | #include <linux/virtio_config.h> | |
4 | ||
b769f579 RR |
5 | /* Unique numbering for virtio devices. */ |
6 | static unsigned int dev_index; | |
7 | ||
ec3d41c4 RR |
8 | static ssize_t device_show(struct device *_d, |
9 | struct device_attribute *attr, char *buf) | |
10 | { | |
11 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); | |
12 | return sprintf(buf, "%hu", dev->id.device); | |
13 | } | |
14 | static ssize_t vendor_show(struct device *_d, | |
15 | struct device_attribute *attr, char *buf) | |
16 | { | |
17 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); | |
18 | return sprintf(buf, "%hu", dev->id.vendor); | |
19 | } | |
20 | static ssize_t status_show(struct device *_d, | |
21 | struct device_attribute *attr, char *buf) | |
22 | { | |
23 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); | |
24 | return sprintf(buf, "0x%08x", dev->config->get_status(dev)); | |
25 | } | |
b01d9f28 RR |
26 | static ssize_t modalias_show(struct device *_d, |
27 | struct device_attribute *attr, char *buf) | |
28 | { | |
29 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); | |
30 | ||
31 | return sprintf(buf, "virtio:d%08Xv%08X\n", | |
32 | dev->id.device, dev->id.vendor); | |
33 | } | |
ec3d41c4 RR |
34 | static struct device_attribute virtio_dev_attrs[] = { |
35 | __ATTR_RO(device), | |
36 | __ATTR_RO(vendor), | |
37 | __ATTR_RO(status), | |
b01d9f28 | 38 | __ATTR_RO(modalias), |
ec3d41c4 RR |
39 | __ATTR_NULL |
40 | }; | |
41 | ||
42 | static inline int virtio_id_match(const struct virtio_device *dev, | |
43 | const struct virtio_device_id *id) | |
44 | { | |
45 | if (id->device != dev->id.device) | |
46 | return 0; | |
47 | ||
48 | return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor; | |
49 | } | |
50 | ||
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) | |
54 | { | |
55 | unsigned int i; | |
56 | struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); | |
57 | const struct virtio_device_id *ids; | |
58 | ||
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; | |
64 | } | |
65 | ||
b01d9f28 RR |
66 | static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) |
67 | { | |
68 | struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); | |
69 | ||
70 | return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", | |
71 | dev->id.device, dev->id.vendor); | |
72 | } | |
73 | ||
ec3d41c4 RR |
74 | static void add_status(struct virtio_device *dev, unsigned status) |
75 | { | |
76 | dev->config->set_status(dev, dev->config->get_status(dev) | status); | |
77 | } | |
78 | ||
c45a6816 RR |
79 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
80 | unsigned int fbit) | |
81 | { | |
82 | unsigned int i; | |
83 | struct virtio_driver *drv = container_of(vdev->dev.driver, | |
84 | struct virtio_driver, driver); | |
85 | ||
86 | for (i = 0; i < drv->feature_table_size; i++) | |
87 | if (drv->feature_table[i] == fbit) | |
88 | return; | |
89 | BUG(); | |
90 | } | |
91 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
92 | ||
ec3d41c4 RR |
93 | static int virtio_dev_probe(struct device *_d) |
94 | { | |
c45a6816 | 95 | int err, i; |
ec3d41c4 RR |
96 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); |
97 | struct virtio_driver *drv = container_of(dev->dev.driver, | |
98 | struct virtio_driver, driver); | |
c45a6816 | 99 | u32 device_features; |
ec3d41c4 | 100 | |
c45a6816 | 101 | /* We have a driver! */ |
ec3d41c4 | 102 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
103 | |
104 | /* Figure out what features the device supports. */ | |
105 | device_features = dev->config->get_features(dev); | |
106 | ||
107 | /* Features supported by both device and driver into dev->features. */ | |
108 | memset(dev->features, 0, sizeof(dev->features)); | |
109 | for (i = 0; i < drv->feature_table_size; i++) { | |
110 | unsigned int f = drv->feature_table[i]; | |
111 | BUG_ON(f >= 32); | |
112 | if (device_features & (1 << f)) | |
113 | set_bit(f, dev->features); | |
114 | } | |
115 | ||
ec3d41c4 RR |
116 | err = drv->probe(dev); |
117 | if (err) | |
118 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
c45a6816 | 119 | else { |
c45a6816 RR |
120 | /* They should never have set feature bits beyond 32 */ |
121 | dev->config->set_features(dev, dev->features[0]); | |
b92dea67 | 122 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
c45a6816 | 123 | } |
ec3d41c4 RR |
124 | return err; |
125 | } | |
126 | ||
74b2553f RR |
127 | static int virtio_dev_remove(struct device *_d) |
128 | { | |
129 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); | |
130 | struct virtio_driver *drv = container_of(dev->dev.driver, | |
131 | struct virtio_driver, driver); | |
132 | ||
74b2553f | 133 | drv->remove(dev); |
6e5aa7ef RR |
134 | |
135 | /* Driver should have reset device. */ | |
136 | BUG_ON(dev->config->get_status(dev)); | |
137 | ||
138 | /* Acknowledge the device's existence again. */ | |
139 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
74b2553f RR |
140 | return 0; |
141 | } | |
142 | ||
e962fa66 MM |
143 | static struct bus_type virtio_bus = { |
144 | .name = "virtio", | |
145 | .match = virtio_dev_match, | |
146 | .dev_attrs = virtio_dev_attrs, | |
147 | .uevent = virtio_uevent, | |
148 | .probe = virtio_dev_probe, | |
149 | .remove = virtio_dev_remove, | |
150 | }; | |
151 | ||
ec3d41c4 RR |
152 | int register_virtio_driver(struct virtio_driver *driver) |
153 | { | |
c45a6816 RR |
154 | /* Catch this early. */ |
155 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 156 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
157 | return driver_register(&driver->driver); |
158 | } | |
159 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
160 | ||
161 | void unregister_virtio_driver(struct virtio_driver *driver) | |
162 | { | |
163 | driver_unregister(&driver->driver); | |
164 | } | |
165 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
166 | ||
167 | int register_virtio_device(struct virtio_device *dev) | |
168 | { | |
169 | int err; | |
170 | ||
171 | dev->dev.bus = &virtio_bus; | |
b769f579 RR |
172 | |
173 | /* Assign a unique device index and hence name. */ | |
174 | dev->index = dev_index++; | |
2ad3cfba | 175 | sprintf(dev->dev.bus_id, "virtio%u", dev->index); |
ec3d41c4 | 176 | |
6e5aa7ef RR |
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); | |
180 | ||
ec3d41c4 RR |
181 | /* Acknowledge that we've seen the device. */ |
182 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
183 | ||
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; | |
190 | } | |
191 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
192 | ||
193 | void unregister_virtio_device(struct virtio_device *dev) | |
194 | { | |
195 | device_unregister(&dev->dev); | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
198 | ||
ec3d41c4 RR |
199 | static int virtio_init(void) |
200 | { | |
201 | if (bus_register(&virtio_bus) != 0) | |
202 | panic("virtio bus registration failed"); | |
203 | return 0; | |
204 | } | |
c6fd4701 RR |
205 | |
206 | static void __exit virtio_exit(void) | |
207 | { | |
208 | bus_unregister(&virtio_bus); | |
209 | } | |
ec3d41c4 | 210 | core_initcall(virtio_init); |
c6fd4701 RR |
211 | module_exit(virtio_exit); |
212 | ||
213 | MODULE_LICENSE("GPL"); |