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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 | } | |
a9289282 RR |
34 | static ssize_t features_show(struct device *_d, |
35 | struct device_attribute *attr, char *buf) | |
36 | { | |
37 | struct virtio_device *dev = container_of(_d, struct virtio_device, dev); | |
38 | unsigned int i; | |
39 | ssize_t len = 0; | |
40 | ||
41 | /* We actually represent this as a bitstring, as it could be | |
42 | * arbitrary length in future. */ | |
43 | for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++) | |
44 | len += sprintf(buf+len, "%c", | |
45 | test_bit(i, dev->features) ? '1' : '0'); | |
46 | len += sprintf(buf+len, "\n"); | |
47 | return len; | |
48 | } | |
ec3d41c4 RR |
49 | static struct device_attribute virtio_dev_attrs[] = { |
50 | __ATTR_RO(device), | |
51 | __ATTR_RO(vendor), | |
52 | __ATTR_RO(status), | |
b01d9f28 | 53 | __ATTR_RO(modalias), |
a9289282 | 54 | __ATTR_RO(features), |
ec3d41c4 RR |
55 | __ATTR_NULL |
56 | }; | |
57 | ||
58 | static inline int virtio_id_match(const struct virtio_device *dev, | |
59 | const struct virtio_device_id *id) | |
60 | { | |
e3353853 | 61 | if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID) |
ec3d41c4 RR |
62 | return 0; |
63 | ||
c89e8016 | 64 | return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor; |
ec3d41c4 RR |
65 | } |
66 | ||
67 | /* This looks through all the IDs a driver claims to support. If any of them | |
68 | * match, we return 1 and the kernel will call virtio_dev_probe(). */ | |
69 | static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) | |
70 | { | |
71 | unsigned int i; | |
72 | struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); | |
73 | const struct virtio_device_id *ids; | |
74 | ||
75 | ids = container_of(_dr, struct virtio_driver, driver)->id_table; | |
76 | for (i = 0; ids[i].device; i++) | |
77 | if (virtio_id_match(dev, &ids[i])) | |
78 | return 1; | |
79 | return 0; | |
80 | } | |
81 | ||
b01d9f28 RR |
82 | static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) |
83 | { | |
84 | struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); | |
85 | ||
86 | return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", | |
87 | dev->id.device, dev->id.vendor); | |
88 | } | |
89 | ||
ec3d41c4 RR |
90 | static void add_status(struct virtio_device *dev, unsigned status) |
91 | { | |
92 | dev->config->set_status(dev, dev->config->get_status(dev) | status); | |
93 | } | |
94 | ||
c45a6816 RR |
95 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
96 | unsigned int fbit) | |
97 | { | |
98 | unsigned int i; | |
99 | struct virtio_driver *drv = container_of(vdev->dev.driver, | |
100 | struct virtio_driver, driver); | |
101 | ||
102 | for (i = 0; i < drv->feature_table_size; i++) | |
103 | if (drv->feature_table[i] == fbit) | |
104 | return; | |
105 | BUG(); | |
106 | } | |
107 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
108 | ||
ec3d41c4 RR |
109 | static int virtio_dev_probe(struct device *_d) |
110 | { | |
c45a6816 | 111 | int err, i; |
ec3d41c4 RR |
112 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); |
113 | struct virtio_driver *drv = container_of(dev->dev.driver, | |
114 | struct virtio_driver, driver); | |
c45a6816 | 115 | u32 device_features; |
ec3d41c4 | 116 | |
c45a6816 | 117 | /* We have a driver! */ |
ec3d41c4 | 118 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
119 | |
120 | /* Figure out what features the device supports. */ | |
121 | device_features = dev->config->get_features(dev); | |
122 | ||
123 | /* Features supported by both device and driver into dev->features. */ | |
124 | memset(dev->features, 0, sizeof(dev->features)); | |
125 | for (i = 0; i < drv->feature_table_size; i++) { | |
126 | unsigned int f = drv->feature_table[i]; | |
127 | BUG_ON(f >= 32); | |
128 | if (device_features & (1 << f)) | |
129 | set_bit(f, dev->features); | |
130 | } | |
131 | ||
c624896e | 132 | /* Transport features always preserved to pass to finalize_features. */ |
dd7c7bc4 RR |
133 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) |
134 | if (device_features & (1 << i)) | |
135 | set_bit(i, dev->features); | |
136 | ||
ef688e15 RR |
137 | dev->config->finalize_features(dev); |
138 | ||
ec3d41c4 RR |
139 | err = drv->probe(dev); |
140 | if (err) | |
141 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
ef688e15 | 142 | else |
b92dea67 | 143 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
ef688e15 | 144 | |
ec3d41c4 RR |
145 | return err; |
146 | } | |
147 | ||
74b2553f RR |
148 | static int virtio_dev_remove(struct device *_d) |
149 | { | |
150 | struct virtio_device *dev = container_of(_d,struct virtio_device,dev); | |
151 | struct virtio_driver *drv = container_of(dev->dev.driver, | |
152 | struct virtio_driver, driver); | |
153 | ||
74b2553f | 154 | drv->remove(dev); |
6e5aa7ef RR |
155 | |
156 | /* Driver should have reset device. */ | |
157 | BUG_ON(dev->config->get_status(dev)); | |
158 | ||
159 | /* Acknowledge the device's existence again. */ | |
160 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
74b2553f RR |
161 | return 0; |
162 | } | |
163 | ||
e962fa66 MM |
164 | static struct bus_type virtio_bus = { |
165 | .name = "virtio", | |
166 | .match = virtio_dev_match, | |
167 | .dev_attrs = virtio_dev_attrs, | |
168 | .uevent = virtio_uevent, | |
169 | .probe = virtio_dev_probe, | |
170 | .remove = virtio_dev_remove, | |
171 | }; | |
172 | ||
ec3d41c4 RR |
173 | int register_virtio_driver(struct virtio_driver *driver) |
174 | { | |
c45a6816 RR |
175 | /* Catch this early. */ |
176 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 177 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
178 | return driver_register(&driver->driver); |
179 | } | |
180 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
181 | ||
182 | void unregister_virtio_driver(struct virtio_driver *driver) | |
183 | { | |
184 | driver_unregister(&driver->driver); | |
185 | } | |
186 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
187 | ||
188 | int register_virtio_device(struct virtio_device *dev) | |
189 | { | |
190 | int err; | |
191 | ||
192 | dev->dev.bus = &virtio_bus; | |
b769f579 RR |
193 | |
194 | /* Assign a unique device index and hence name. */ | |
195 | dev->index = dev_index++; | |
99e0b6c8 | 196 | dev_set_name(&dev->dev, "virtio%u", dev->index); |
ec3d41c4 | 197 | |
6e5aa7ef RR |
198 | /* We always start by resetting the device, in case a previous |
199 | * driver messed it up. This also tests that code path a little. */ | |
200 | dev->config->reset(dev); | |
201 | ||
ec3d41c4 RR |
202 | /* Acknowledge that we've seen the device. */ |
203 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
204 | ||
9499f5e7 RR |
205 | INIT_LIST_HEAD(&dev->vqs); |
206 | ||
ec3d41c4 RR |
207 | /* device_register() causes the bus infrastructure to look for a |
208 | * matching driver. */ | |
209 | err = device_register(&dev->dev); | |
210 | if (err) | |
211 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
212 | return err; | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
215 | ||
216 | void unregister_virtio_device(struct virtio_device *dev) | |
217 | { | |
218 | device_unregister(&dev->dev); | |
219 | } | |
220 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
221 | ||
ec3d41c4 RR |
222 | static int virtio_init(void) |
223 | { | |
224 | if (bus_register(&virtio_bus) != 0) | |
225 | panic("virtio bus registration failed"); | |
226 | return 0; | |
227 | } | |
c6fd4701 RR |
228 | |
229 | static void __exit virtio_exit(void) | |
230 | { | |
231 | bus_unregister(&virtio_bus); | |
232 | } | |
ec3d41c4 | 233 | core_initcall(virtio_init); |
c6fd4701 RR |
234 | module_exit(virtio_exit); |
235 | ||
236 | MODULE_LICENSE("GPL"); |