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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 | ||
9a2bdcc8 | 76 | ids = drv_to_virtio(_dr)->id_table; |
ec3d41c4 RR |
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; | |
9a2bdcc8 | 100 | struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); |
c45a6816 RR |
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; |
9bffdca8 | 112 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 113 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
c45a6816 | 114 | u32 device_features; |
ec3d41c4 | 115 | |
c45a6816 | 116 | /* We have a driver! */ |
ec3d41c4 | 117 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
118 | |
119 | /* Figure out what features the device supports. */ | |
120 | device_features = dev->config->get_features(dev); | |
121 | ||
122 | /* Features supported by both device and driver into dev->features. */ | |
123 | memset(dev->features, 0, sizeof(dev->features)); | |
124 | for (i = 0; i < drv->feature_table_size; i++) { | |
125 | unsigned int f = drv->feature_table[i]; | |
126 | BUG_ON(f >= 32); | |
127 | if (device_features & (1 << f)) | |
128 | set_bit(f, dev->features); | |
129 | } | |
130 | ||
c624896e | 131 | /* Transport features always preserved to pass to finalize_features. */ |
dd7c7bc4 RR |
132 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) |
133 | if (device_features & (1 << i)) | |
134 | set_bit(i, dev->features); | |
135 | ||
ef688e15 RR |
136 | dev->config->finalize_features(dev); |
137 | ||
ec3d41c4 RR |
138 | err = drv->probe(dev); |
139 | if (err) | |
140 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
59057fbc | 141 | else { |
b92dea67 | 142 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
59057fbc NB |
143 | if (drv->scan) |
144 | drv->scan(dev); | |
145 | } | |
ef688e15 | 146 | |
ec3d41c4 RR |
147 | return err; |
148 | } | |
149 | ||
74b2553f RR |
150 | static int virtio_dev_remove(struct device *_d) |
151 | { | |
9bffdca8 | 152 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 153 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
74b2553f | 154 | |
74b2553f | 155 | drv->remove(dev); |
6e5aa7ef RR |
156 | |
157 | /* Driver should have reset device. */ | |
5543a6ac | 158 | WARN_ON_ONCE(dev->config->get_status(dev)); |
6e5aa7ef RR |
159 | |
160 | /* Acknowledge the device's existence again. */ | |
161 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
74b2553f RR |
162 | return 0; |
163 | } | |
164 | ||
e962fa66 MM |
165 | static struct bus_type virtio_bus = { |
166 | .name = "virtio", | |
167 | .match = virtio_dev_match, | |
168 | .dev_attrs = virtio_dev_attrs, | |
169 | .uevent = virtio_uevent, | |
170 | .probe = virtio_dev_probe, | |
171 | .remove = virtio_dev_remove, | |
172 | }; | |
173 | ||
ec3d41c4 RR |
174 | int register_virtio_driver(struct virtio_driver *driver) |
175 | { | |
c45a6816 RR |
176 | /* Catch this early. */ |
177 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 178 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
179 | return driver_register(&driver->driver); |
180 | } | |
181 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
182 | ||
183 | void unregister_virtio_driver(struct virtio_driver *driver) | |
184 | { | |
185 | driver_unregister(&driver->driver); | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
188 | ||
189 | int register_virtio_device(struct virtio_device *dev) | |
190 | { | |
191 | int err; | |
192 | ||
193 | dev->dev.bus = &virtio_bus; | |
b769f579 RR |
194 | |
195 | /* Assign a unique device index and hence name. */ | |
90e03207 AH |
196 | err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); |
197 | if (err < 0) | |
198 | goto out; | |
199 | ||
200 | dev->index = err; | |
99e0b6c8 | 201 | dev_set_name(&dev->dev, "virtio%u", dev->index); |
ec3d41c4 | 202 | |
6e5aa7ef RR |
203 | /* We always start by resetting the device, in case a previous |
204 | * driver messed it up. This also tests that code path a little. */ | |
205 | dev->config->reset(dev); | |
206 | ||
ec3d41c4 RR |
207 | /* Acknowledge that we've seen the device. */ |
208 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
209 | ||
9499f5e7 RR |
210 | INIT_LIST_HEAD(&dev->vqs); |
211 | ||
ec3d41c4 RR |
212 | /* device_register() causes the bus infrastructure to look for a |
213 | * matching driver. */ | |
214 | err = device_register(&dev->dev); | |
90e03207 | 215 | out: |
ec3d41c4 RR |
216 | if (err) |
217 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
218 | return err; | |
219 | } | |
220 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
221 | ||
222 | void unregister_virtio_device(struct virtio_device *dev) | |
223 | { | |
237242bd CH |
224 | int index = dev->index; /* save for after device release */ |
225 | ||
ec3d41c4 | 226 | device_unregister(&dev->dev); |
237242bd | 227 | ida_simple_remove(&virtio_index_ida, index); |
ec3d41c4 RR |
228 | } |
229 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
230 | ||
ec3d41c4 RR |
231 | static int virtio_init(void) |
232 | { | |
233 | if (bus_register(&virtio_bus) != 0) | |
234 | panic("virtio bus registration failed"); | |
235 | return 0; | |
236 | } | |
c6fd4701 RR |
237 | |
238 | static void __exit virtio_exit(void) | |
239 | { | |
240 | bus_unregister(&virtio_bus); | |
241 | } | |
ec3d41c4 | 242 | core_initcall(virtio_init); |
c6fd4701 RR |
243 | module_exit(virtio_exit); |
244 | ||
245 | MODULE_LICENSE("GPL"); |