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1#include <linux/virtio.h>
2#include <linux/spinlock.h>
3#include <linux/virtio_config.h>
4
5/* Unique numbering for virtio devices. */
6static unsigned int dev_index;
7
8static 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, "0x%04x\n", dev->id.device);
13}
14static 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, "0x%04x\n", dev->id.vendor);
19}
20static 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\n", dev->config->get_status(dev));
25}
26static 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}
34static 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}
49static struct device_attribute virtio_dev_attrs[] = {
50 __ATTR_RO(device),
51 __ATTR_RO(vendor),
52 __ATTR_RO(status),
53 __ATTR_RO(modalias),
54 __ATTR_RO(features),
55 __ATTR_NULL
56};
57
58static inline int virtio_id_match(const struct virtio_device *dev,
59 const struct virtio_device_id *id)
60{
61 if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
62 return 0;
63
64 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
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(). */
69static 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
82static 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
90static void add_status(struct virtio_device *dev, unsigned status)
91{
92 dev->config->set_status(dev, dev->config->get_status(dev) | status);
93}
94
95void 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}
107EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
108
109static int virtio_dev_probe(struct device *_d)
110{
111 int err, i;
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);
115 u32 device_features;
116
117 /* We have a driver! */
118 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
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
132 /* Transport features always preserved to pass to finalize_features. */
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
137 dev->config->finalize_features(dev);
138
139 err = drv->probe(dev);
140 if (err)
141 add_status(dev, VIRTIO_CONFIG_S_FAILED);
142 else
143 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
144
145 return err;
146}
147
148static 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
154 drv->remove(dev);
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);
161 return 0;
162}
163
164static 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
173int register_virtio_driver(struct virtio_driver *driver)
174{
175 /* Catch this early. */
176 BUG_ON(driver->feature_table_size && !driver->feature_table);
177 driver->driver.bus = &virtio_bus;
178 return driver_register(&driver->driver);
179}
180EXPORT_SYMBOL_GPL(register_virtio_driver);
181
182void unregister_virtio_driver(struct virtio_driver *driver)
183{
184 driver_unregister(&driver->driver);
185}
186EXPORT_SYMBOL_GPL(unregister_virtio_driver);
187
188int register_virtio_device(struct virtio_device *dev)
189{
190 int err;
191
192 dev->dev.bus = &virtio_bus;
193
194 /* Assign a unique device index and hence name. */
195 dev->index = dev_index++;
196 dev_set_name(&dev->dev, "virtio%u", dev->index);
197
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
202 /* Acknowledge that we've seen the device. */
203 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
204
205 INIT_LIST_HEAD(&dev->vqs);
206
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}
214EXPORT_SYMBOL_GPL(register_virtio_device);
215
216void unregister_virtio_device(struct virtio_device *dev)
217{
218 device_unregister(&dev->dev);
219}
220EXPORT_SYMBOL_GPL(unregister_virtio_device);
221
222static int virtio_init(void)
223{
224 if (bus_register(&virtio_bus) != 0)
225 panic("virtio bus registration failed");
226 return 0;
227}
228
229static void __exit virtio_exit(void)
230{
231 bus_unregister(&virtio_bus);
232}
233core_initcall(virtio_init);
234module_exit(virtio_exit);
235
236MODULE_LICENSE("GPL");
1#include <linux/virtio.h>
2#include <linux/spinlock.h>
3#include <linux/virtio_config.h>
4#include <linux/module.h>
5#include <linux/idr.h>
6
7/* Unique numbering for virtio devices. */
8static DEFINE_IDA(virtio_index_ida);
9
10static 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);
14 return sprintf(buf, "0x%04x\n", dev->id.device);
15}
16static 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);
20 return sprintf(buf, "0x%04x\n", dev->id.vendor);
21}
22static 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);
26 return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
27}
28static 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}
36static 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}
51static struct device_attribute virtio_dev_attrs[] = {
52 __ATTR_RO(device),
53 __ATTR_RO(vendor),
54 __ATTR_RO(status),
55 __ATTR_RO(modalias),
56 __ATTR_RO(features),
57 __ATTR_NULL
58};
59
60static inline int virtio_id_match(const struct virtio_device *dev,
61 const struct virtio_device_id *id)
62{
63 if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
64 return 0;
65
66 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
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(). */
71static 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
84static 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
92static void add_status(struct virtio_device *dev, unsigned status)
93{
94 dev->config->set_status(dev, dev->config->get_status(dev) | status);
95}
96
97void 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}
109EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
110
111static int virtio_dev_probe(struct device *_d)
112{
113 int err, i;
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);
117 u32 device_features;
118
119 /* We have a driver! */
120 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
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
134 /* Transport features always preserved to pass to finalize_features. */
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
139 dev->config->finalize_features(dev);
140
141 err = drv->probe(dev);
142 if (err)
143 add_status(dev, VIRTIO_CONFIG_S_FAILED);
144 else
145 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
146
147 return err;
148}
149
150static int virtio_dev_remove(struct device *_d)
151{
152 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
153 struct virtio_driver *drv = container_of(dev->dev.driver,
154 struct virtio_driver, driver);
155
156 drv->remove(dev);
157
158 /* Driver should have reset device. */
159 BUG_ON(dev->config->get_status(dev));
160
161 /* Acknowledge the device's existence again. */
162 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
163 return 0;
164}
165
166static struct bus_type virtio_bus = {
167 .name = "virtio",
168 .match = virtio_dev_match,
169 .dev_attrs = virtio_dev_attrs,
170 .uevent = virtio_uevent,
171 .probe = virtio_dev_probe,
172 .remove = virtio_dev_remove,
173};
174
175int register_virtio_driver(struct virtio_driver *driver)
176{
177 /* Catch this early. */
178 BUG_ON(driver->feature_table_size && !driver->feature_table);
179 driver->driver.bus = &virtio_bus;
180 return driver_register(&driver->driver);
181}
182EXPORT_SYMBOL_GPL(register_virtio_driver);
183
184void unregister_virtio_driver(struct virtio_driver *driver)
185{
186 driver_unregister(&driver->driver);
187}
188EXPORT_SYMBOL_GPL(unregister_virtio_driver);
189
190int register_virtio_device(struct virtio_device *dev)
191{
192 int err;
193
194 dev->dev.bus = &virtio_bus;
195
196 /* Assign a unique device index and hence name. */
197 err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
198 if (err < 0)
199 goto out;
200
201 dev->index = err;
202 dev_set_name(&dev->dev, "virtio%u", dev->index);
203
204 /* We always start by resetting the device, in case a previous
205 * driver messed it up. This also tests that code path a little. */
206 dev->config->reset(dev);
207
208 /* Acknowledge that we've seen the device. */
209 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
210
211 INIT_LIST_HEAD(&dev->vqs);
212
213 /* device_register() causes the bus infrastructure to look for a
214 * matching driver. */
215 err = device_register(&dev->dev);
216out:
217 if (err)
218 add_status(dev, VIRTIO_CONFIG_S_FAILED);
219 return err;
220}
221EXPORT_SYMBOL_GPL(register_virtio_device);
222
223void unregister_virtio_device(struct virtio_device *dev)
224{
225 device_unregister(&dev->dev);
226 ida_simple_remove(&virtio_index_ida, dev->index);
227}
228EXPORT_SYMBOL_GPL(unregister_virtio_device);
229
230static int virtio_init(void)
231{
232 if (bus_register(&virtio_bus) != 0)
233 panic("virtio bus registration failed");
234 return 0;
235}
236
237static void __exit virtio_exit(void)
238{
239 bus_unregister(&virtio_bus);
240}
241core_initcall(virtio_init);
242module_exit(virtio_exit);
243
244MODULE_LICENSE("GPL");