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ec3d41c4 RR |
1 | #include <linux/virtio.h> |
2 | #include <linux/spinlock.h> | |
3 | #include <linux/virtio_config.h> | |
b5a2c4f1 | 4 | #include <linux/module.h> |
90e03207 | 5 | #include <linux/idr.h> |
ec3d41c4 | 6 | |
b769f579 | 7 | /* Unique numbering for virtio devices. */ |
90e03207 | 8 | static DEFINE_IDA(virtio_index_ida); |
b769f579 | 9 | |
ec3d41c4 RR |
10 | static ssize_t device_show(struct device *_d, |
11 | struct device_attribute *attr, char *buf) | |
12 | { | |
9bffdca8 | 13 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 14 | return sprintf(buf, "0x%04x\n", dev->id.device); |
ec3d41c4 RR |
15 | } |
16 | static ssize_t vendor_show(struct device *_d, | |
17 | struct device_attribute *attr, char *buf) | |
18 | { | |
9bffdca8 | 19 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 20 | return sprintf(buf, "0x%04x\n", dev->id.vendor); |
ec3d41c4 RR |
21 | } |
22 | static ssize_t status_show(struct device *_d, | |
23 | struct device_attribute *attr, char *buf) | |
24 | { | |
9bffdca8 | 25 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 26 | return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); |
ec3d41c4 | 27 | } |
b01d9f28 RR |
28 | static ssize_t modalias_show(struct device *_d, |
29 | struct device_attribute *attr, char *buf) | |
30 | { | |
9bffdca8 | 31 | struct virtio_device *dev = dev_to_virtio(_d); |
b01d9f28 RR |
32 | return sprintf(buf, "virtio:d%08Xv%08X\n", |
33 | dev->id.device, dev->id.vendor); | |
34 | } | |
a9289282 RR |
35 | static ssize_t features_show(struct device *_d, |
36 | struct device_attribute *attr, char *buf) | |
37 | { | |
9bffdca8 | 38 | struct virtio_device *dev = dev_to_virtio(_d); |
a9289282 RR |
39 | unsigned int i; |
40 | ssize_t len = 0; | |
41 | ||
42 | /* We actually represent this as a bitstring, as it could be | |
43 | * arbitrary length in future. */ | |
44 | for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++) | |
45 | len += sprintf(buf+len, "%c", | |
46 | test_bit(i, dev->features) ? '1' : '0'); | |
47 | len += sprintf(buf+len, "\n"); | |
48 | return len; | |
49 | } | |
ec3d41c4 RR |
50 | static struct device_attribute virtio_dev_attrs[] = { |
51 | __ATTR_RO(device), | |
52 | __ATTR_RO(vendor), | |
53 | __ATTR_RO(status), | |
b01d9f28 | 54 | __ATTR_RO(modalias), |
a9289282 | 55 | __ATTR_RO(features), |
ec3d41c4 RR |
56 | __ATTR_NULL |
57 | }; | |
58 | ||
59 | static inline int virtio_id_match(const struct virtio_device *dev, | |
60 | const struct virtio_device_id *id) | |
61 | { | |
e3353853 | 62 | if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID) |
ec3d41c4 RR |
63 | return 0; |
64 | ||
c89e8016 | 65 | return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor; |
ec3d41c4 RR |
66 | } |
67 | ||
68 | /* This looks through all the IDs a driver claims to support. If any of them | |
69 | * match, we return 1 and the kernel will call virtio_dev_probe(). */ | |
70 | static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) | |
71 | { | |
72 | unsigned int i; | |
9bffdca8 | 73 | struct virtio_device *dev = dev_to_virtio(_dv); |
ec3d41c4 RR |
74 | const struct virtio_device_id *ids; |
75 | ||
76 | ids = container_of(_dr, struct virtio_driver, driver)->id_table; | |
77 | for (i = 0; ids[i].device; i++) | |
78 | if (virtio_id_match(dev, &ids[i])) | |
79 | return 1; | |
80 | return 0; | |
81 | } | |
82 | ||
b01d9f28 RR |
83 | static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) |
84 | { | |
9bffdca8 | 85 | struct virtio_device *dev = dev_to_virtio(_dv); |
b01d9f28 RR |
86 | |
87 | return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", | |
88 | dev->id.device, dev->id.vendor); | |
89 | } | |
90 | ||
ec3d41c4 RR |
91 | static void add_status(struct virtio_device *dev, unsigned status) |
92 | { | |
93 | dev->config->set_status(dev, dev->config->get_status(dev) | status); | |
94 | } | |
95 | ||
c45a6816 RR |
96 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
97 | unsigned int fbit) | |
98 | { | |
99 | unsigned int i; | |
100 | struct virtio_driver *drv = container_of(vdev->dev.driver, | |
101 | struct virtio_driver, driver); | |
102 | ||
103 | for (i = 0; i < drv->feature_table_size; i++) | |
104 | if (drv->feature_table[i] == fbit) | |
105 | return; | |
106 | BUG(); | |
107 | } | |
108 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
109 | ||
ec3d41c4 RR |
110 | static int virtio_dev_probe(struct device *_d) |
111 | { | |
c45a6816 | 112 | int err, i; |
9bffdca8 | 113 | struct virtio_device *dev = dev_to_virtio(_d); |
ec3d41c4 RR |
114 | struct virtio_driver *drv = container_of(dev->dev.driver, |
115 | struct virtio_driver, driver); | |
c45a6816 | 116 | u32 device_features; |
ec3d41c4 | 117 | |
c45a6816 | 118 | /* We have a driver! */ |
ec3d41c4 | 119 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
120 | |
121 | /* Figure out what features the device supports. */ | |
122 | device_features = dev->config->get_features(dev); | |
123 | ||
124 | /* Features supported by both device and driver into dev->features. */ | |
125 | memset(dev->features, 0, sizeof(dev->features)); | |
126 | for (i = 0; i < drv->feature_table_size; i++) { | |
127 | unsigned int f = drv->feature_table[i]; | |
128 | BUG_ON(f >= 32); | |
129 | if (device_features & (1 << f)) | |
130 | set_bit(f, dev->features); | |
131 | } | |
132 | ||
c624896e | 133 | /* Transport features always preserved to pass to finalize_features. */ |
dd7c7bc4 RR |
134 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) |
135 | if (device_features & (1 << i)) | |
136 | set_bit(i, dev->features); | |
137 | ||
ef688e15 RR |
138 | dev->config->finalize_features(dev); |
139 | ||
ec3d41c4 RR |
140 | err = drv->probe(dev); |
141 | if (err) | |
142 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
59057fbc | 143 | else { |
b92dea67 | 144 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
59057fbc NB |
145 | if (drv->scan) |
146 | drv->scan(dev); | |
147 | } | |
ef688e15 | 148 | |
ec3d41c4 RR |
149 | return err; |
150 | } | |
151 | ||
74b2553f RR |
152 | static int virtio_dev_remove(struct device *_d) |
153 | { | |
9bffdca8 | 154 | struct virtio_device *dev = dev_to_virtio(_d); |
74b2553f RR |
155 | struct virtio_driver *drv = container_of(dev->dev.driver, |
156 | struct virtio_driver, driver); | |
157 | ||
74b2553f | 158 | drv->remove(dev); |
6e5aa7ef RR |
159 | |
160 | /* Driver should have reset device. */ | |
5543a6ac | 161 | WARN_ON_ONCE(dev->config->get_status(dev)); |
6e5aa7ef RR |
162 | |
163 | /* Acknowledge the device's existence again. */ | |
164 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
74b2553f RR |
165 | return 0; |
166 | } | |
167 | ||
e962fa66 MM |
168 | static struct bus_type virtio_bus = { |
169 | .name = "virtio", | |
170 | .match = virtio_dev_match, | |
171 | .dev_attrs = virtio_dev_attrs, | |
172 | .uevent = virtio_uevent, | |
173 | .probe = virtio_dev_probe, | |
174 | .remove = virtio_dev_remove, | |
175 | }; | |
176 | ||
ec3d41c4 RR |
177 | int register_virtio_driver(struct virtio_driver *driver) |
178 | { | |
c45a6816 RR |
179 | /* Catch this early. */ |
180 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 181 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
182 | return driver_register(&driver->driver); |
183 | } | |
184 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
185 | ||
186 | void unregister_virtio_driver(struct virtio_driver *driver) | |
187 | { | |
188 | driver_unregister(&driver->driver); | |
189 | } | |
190 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
191 | ||
192 | int register_virtio_device(struct virtio_device *dev) | |
193 | { | |
194 | int err; | |
195 | ||
196 | dev->dev.bus = &virtio_bus; | |
b769f579 RR |
197 | |
198 | /* Assign a unique device index and hence name. */ | |
90e03207 AH |
199 | err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); |
200 | if (err < 0) | |
201 | goto out; | |
202 | ||
203 | dev->index = err; | |
99e0b6c8 | 204 | dev_set_name(&dev->dev, "virtio%u", dev->index); |
ec3d41c4 | 205 | |
6e5aa7ef RR |
206 | /* We always start by resetting the device, in case a previous |
207 | * driver messed it up. This also tests that code path a little. */ | |
208 | dev->config->reset(dev); | |
209 | ||
ec3d41c4 RR |
210 | /* Acknowledge that we've seen the device. */ |
211 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
212 | ||
9499f5e7 RR |
213 | INIT_LIST_HEAD(&dev->vqs); |
214 | ||
ec3d41c4 RR |
215 | /* device_register() causes the bus infrastructure to look for a |
216 | * matching driver. */ | |
217 | err = device_register(&dev->dev); | |
90e03207 | 218 | out: |
ec3d41c4 RR |
219 | if (err) |
220 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
221 | return err; | |
222 | } | |
223 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
224 | ||
225 | void unregister_virtio_device(struct virtio_device *dev) | |
226 | { | |
227 | device_unregister(&dev->dev); | |
90e03207 | 228 | ida_simple_remove(&virtio_index_ida, dev->index); |
ec3d41c4 RR |
229 | } |
230 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
231 | ||
ec3d41c4 RR |
232 | static int virtio_init(void) |
233 | { | |
234 | if (bus_register(&virtio_bus) != 0) | |
235 | panic("virtio bus registration failed"); | |
236 | return 0; | |
237 | } | |
c6fd4701 RR |
238 | |
239 | static void __exit virtio_exit(void) | |
240 | { | |
241 | bus_unregister(&virtio_bus); | |
242 | } | |
ec3d41c4 | 243 | core_initcall(virtio_init); |
c6fd4701 RR |
244 | module_exit(virtio_exit); |
245 | ||
246 | MODULE_LICENSE("GPL"); |