Commit | Line | Data |
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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 | 15 | } |
3736dab6 GKH |
16 | static DEVICE_ATTR_RO(device); |
17 | ||
ec3d41c4 RR |
18 | static ssize_t vendor_show(struct device *_d, |
19 | struct device_attribute *attr, char *buf) | |
20 | { | |
9bffdca8 | 21 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 22 | return sprintf(buf, "0x%04x\n", dev->id.vendor); |
ec3d41c4 | 23 | } |
3736dab6 GKH |
24 | static DEVICE_ATTR_RO(vendor); |
25 | ||
ec3d41c4 RR |
26 | static ssize_t status_show(struct device *_d, |
27 | struct device_attribute *attr, char *buf) | |
28 | { | |
9bffdca8 | 29 | struct virtio_device *dev = dev_to_virtio(_d); |
be6528b2 | 30 | return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); |
ec3d41c4 | 31 | } |
3736dab6 GKH |
32 | static DEVICE_ATTR_RO(status); |
33 | ||
b01d9f28 RR |
34 | static ssize_t modalias_show(struct device *_d, |
35 | struct device_attribute *attr, char *buf) | |
36 | { | |
9bffdca8 | 37 | struct virtio_device *dev = dev_to_virtio(_d); |
b01d9f28 RR |
38 | return sprintf(buf, "virtio:d%08Xv%08X\n", |
39 | dev->id.device, dev->id.vendor); | |
40 | } | |
3736dab6 GKH |
41 | static DEVICE_ATTR_RO(modalias); |
42 | ||
a9289282 RR |
43 | static ssize_t features_show(struct device *_d, |
44 | struct device_attribute *attr, char *buf) | |
45 | { | |
9bffdca8 | 46 | struct virtio_device *dev = dev_to_virtio(_d); |
a9289282 RR |
47 | unsigned int i; |
48 | ssize_t len = 0; | |
49 | ||
50 | /* We actually represent this as a bitstring, as it could be | |
51 | * arbitrary length in future. */ | |
52 | for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++) | |
53 | len += sprintf(buf+len, "%c", | |
54 | test_bit(i, dev->features) ? '1' : '0'); | |
55 | len += sprintf(buf+len, "\n"); | |
56 | return len; | |
57 | } | |
3736dab6 GKH |
58 | static DEVICE_ATTR_RO(features); |
59 | ||
60 | static struct attribute *virtio_dev_attrs[] = { | |
61 | &dev_attr_device.attr, | |
62 | &dev_attr_vendor.attr, | |
63 | &dev_attr_status.attr, | |
64 | &dev_attr_modalias.attr, | |
65 | &dev_attr_features.attr, | |
66 | NULL, | |
ec3d41c4 | 67 | }; |
3736dab6 | 68 | ATTRIBUTE_GROUPS(virtio_dev); |
ec3d41c4 RR |
69 | |
70 | static inline int virtio_id_match(const struct virtio_device *dev, | |
71 | const struct virtio_device_id *id) | |
72 | { | |
e3353853 | 73 | if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID) |
ec3d41c4 RR |
74 | return 0; |
75 | ||
c89e8016 | 76 | return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor; |
ec3d41c4 RR |
77 | } |
78 | ||
79 | /* This looks through all the IDs a driver claims to support. If any of them | |
80 | * match, we return 1 and the kernel will call virtio_dev_probe(). */ | |
81 | static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) | |
82 | { | |
83 | unsigned int i; | |
9bffdca8 | 84 | struct virtio_device *dev = dev_to_virtio(_dv); |
ec3d41c4 RR |
85 | const struct virtio_device_id *ids; |
86 | ||
9a2bdcc8 | 87 | ids = drv_to_virtio(_dr)->id_table; |
ec3d41c4 RR |
88 | for (i = 0; ids[i].device; i++) |
89 | if (virtio_id_match(dev, &ids[i])) | |
90 | return 1; | |
91 | return 0; | |
92 | } | |
93 | ||
b01d9f28 RR |
94 | static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) |
95 | { | |
9bffdca8 | 96 | struct virtio_device *dev = dev_to_virtio(_dv); |
b01d9f28 RR |
97 | |
98 | return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", | |
99 | dev->id.device, dev->id.vendor); | |
100 | } | |
101 | ||
ec3d41c4 RR |
102 | static void add_status(struct virtio_device *dev, unsigned status) |
103 | { | |
104 | dev->config->set_status(dev, dev->config->get_status(dev) | status); | |
105 | } | |
106 | ||
c45a6816 RR |
107 | void virtio_check_driver_offered_feature(const struct virtio_device *vdev, |
108 | unsigned int fbit) | |
109 | { | |
110 | unsigned int i; | |
9a2bdcc8 | 111 | struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); |
c45a6816 RR |
112 | |
113 | for (i = 0; i < drv->feature_table_size; i++) | |
114 | if (drv->feature_table[i] == fbit) | |
115 | return; | |
116 | BUG(); | |
117 | } | |
118 | EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); | |
119 | ||
ec3d41c4 RR |
120 | static int virtio_dev_probe(struct device *_d) |
121 | { | |
c45a6816 | 122 | int err, i; |
9bffdca8 | 123 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 124 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
c45a6816 | 125 | u32 device_features; |
ec3d41c4 | 126 | |
c45a6816 | 127 | /* We have a driver! */ |
ec3d41c4 | 128 | add_status(dev, VIRTIO_CONFIG_S_DRIVER); |
c45a6816 RR |
129 | |
130 | /* Figure out what features the device supports. */ | |
131 | device_features = dev->config->get_features(dev); | |
132 | ||
133 | /* Features supported by both device and driver into dev->features. */ | |
134 | memset(dev->features, 0, sizeof(dev->features)); | |
135 | for (i = 0; i < drv->feature_table_size; i++) { | |
136 | unsigned int f = drv->feature_table[i]; | |
137 | BUG_ON(f >= 32); | |
138 | if (device_features & (1 << f)) | |
139 | set_bit(f, dev->features); | |
140 | } | |
141 | ||
c624896e | 142 | /* Transport features always preserved to pass to finalize_features. */ |
dd7c7bc4 RR |
143 | for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) |
144 | if (device_features & (1 << i)) | |
145 | set_bit(i, dev->features); | |
146 | ||
ef688e15 RR |
147 | dev->config->finalize_features(dev); |
148 | ||
ec3d41c4 RR |
149 | err = drv->probe(dev); |
150 | if (err) | |
151 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
59057fbc | 152 | else { |
b92dea67 | 153 | add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); |
59057fbc NB |
154 | if (drv->scan) |
155 | drv->scan(dev); | |
156 | } | |
ef688e15 | 157 | |
ec3d41c4 RR |
158 | return err; |
159 | } | |
160 | ||
74b2553f RR |
161 | static int virtio_dev_remove(struct device *_d) |
162 | { | |
9bffdca8 | 163 | struct virtio_device *dev = dev_to_virtio(_d); |
9a2bdcc8 | 164 | struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); |
74b2553f | 165 | |
74b2553f | 166 | drv->remove(dev); |
6e5aa7ef RR |
167 | |
168 | /* Driver should have reset device. */ | |
5543a6ac | 169 | WARN_ON_ONCE(dev->config->get_status(dev)); |
6e5aa7ef RR |
170 | |
171 | /* Acknowledge the device's existence again. */ | |
172 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
74b2553f RR |
173 | return 0; |
174 | } | |
175 | ||
e962fa66 MM |
176 | static struct bus_type virtio_bus = { |
177 | .name = "virtio", | |
178 | .match = virtio_dev_match, | |
3736dab6 | 179 | .dev_groups = virtio_dev_groups, |
e962fa66 MM |
180 | .uevent = virtio_uevent, |
181 | .probe = virtio_dev_probe, | |
182 | .remove = virtio_dev_remove, | |
183 | }; | |
184 | ||
ec3d41c4 RR |
185 | int register_virtio_driver(struct virtio_driver *driver) |
186 | { | |
c45a6816 RR |
187 | /* Catch this early. */ |
188 | BUG_ON(driver->feature_table_size && !driver->feature_table); | |
ec3d41c4 | 189 | driver->driver.bus = &virtio_bus; |
ec3d41c4 RR |
190 | return driver_register(&driver->driver); |
191 | } | |
192 | EXPORT_SYMBOL_GPL(register_virtio_driver); | |
193 | ||
194 | void unregister_virtio_driver(struct virtio_driver *driver) | |
195 | { | |
196 | driver_unregister(&driver->driver); | |
197 | } | |
198 | EXPORT_SYMBOL_GPL(unregister_virtio_driver); | |
199 | ||
200 | int register_virtio_device(struct virtio_device *dev) | |
201 | { | |
202 | int err; | |
203 | ||
204 | dev->dev.bus = &virtio_bus; | |
b769f579 RR |
205 | |
206 | /* Assign a unique device index and hence name. */ | |
90e03207 AH |
207 | err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); |
208 | if (err < 0) | |
209 | goto out; | |
210 | ||
211 | dev->index = err; | |
99e0b6c8 | 212 | dev_set_name(&dev->dev, "virtio%u", dev->index); |
ec3d41c4 | 213 | |
6e5aa7ef RR |
214 | /* We always start by resetting the device, in case a previous |
215 | * driver messed it up. This also tests that code path a little. */ | |
216 | dev->config->reset(dev); | |
217 | ||
ec3d41c4 RR |
218 | /* Acknowledge that we've seen the device. */ |
219 | add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); | |
220 | ||
9499f5e7 RR |
221 | INIT_LIST_HEAD(&dev->vqs); |
222 | ||
ec3d41c4 RR |
223 | /* device_register() causes the bus infrastructure to look for a |
224 | * matching driver. */ | |
225 | err = device_register(&dev->dev); | |
90e03207 | 226 | out: |
ec3d41c4 RR |
227 | if (err) |
228 | add_status(dev, VIRTIO_CONFIG_S_FAILED); | |
229 | return err; | |
230 | } | |
231 | EXPORT_SYMBOL_GPL(register_virtio_device); | |
232 | ||
233 | void unregister_virtio_device(struct virtio_device *dev) | |
234 | { | |
237242bd CH |
235 | int index = dev->index; /* save for after device release */ |
236 | ||
ec3d41c4 | 237 | device_unregister(&dev->dev); |
237242bd | 238 | ida_simple_remove(&virtio_index_ida, index); |
ec3d41c4 RR |
239 | } |
240 | EXPORT_SYMBOL_GPL(unregister_virtio_device); | |
241 | ||
ec3d41c4 RR |
242 | static int virtio_init(void) |
243 | { | |
244 | if (bus_register(&virtio_bus) != 0) | |
245 | panic("virtio bus registration failed"); | |
246 | return 0; | |
247 | } | |
c6fd4701 RR |
248 | |
249 | static void __exit virtio_exit(void) | |
250 | { | |
251 | bus_unregister(&virtio_bus); | |
252 | } | |
ec3d41c4 | 253 | core_initcall(virtio_init); |
c6fd4701 RR |
254 | module_exit(virtio_exit); |
255 | ||
256 | MODULE_LICENSE("GPL"); |