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