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Diffstat (limited to 'drivers/virtio/virtio.c')
-rw-r--r--drivers/virtio/virtio.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
new file mode 100644
index 000000000000..15d7787dea87
--- /dev/null
+++ b/drivers/virtio/virtio.c
@@ -0,0 +1,189 @@
1#include <linux/virtio.h>
2#include <linux/spinlock.h>
3#include <linux/virtio_config.h>
4
5static ssize_t device_show(struct device *_d,
6 struct device_attribute *attr, char *buf)
7{
8 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
9 return sprintf(buf, "%hu", dev->id.device);
10}
11static ssize_t vendor_show(struct device *_d,
12 struct device_attribute *attr, char *buf)
13{
14 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
15 return sprintf(buf, "%hu", dev->id.vendor);
16}
17static ssize_t status_show(struct device *_d,
18 struct device_attribute *attr, char *buf)
19{
20 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
21 return sprintf(buf, "0x%08x", dev->config->get_status(dev));
22}
23static ssize_t modalias_show(struct device *_d,
24 struct device_attribute *attr, char *buf)
25{
26 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
27
28 return sprintf(buf, "virtio:d%08Xv%08X\n",
29 dev->id.device, dev->id.vendor);
30}
31static struct device_attribute virtio_dev_attrs[] = {
32 __ATTR_RO(device),
33 __ATTR_RO(vendor),
34 __ATTR_RO(status),
35 __ATTR_RO(modalias),
36 __ATTR_NULL
37};
38
39static inline int virtio_id_match(const struct virtio_device *dev,
40 const struct virtio_device_id *id)
41{
42 if (id->device != dev->id.device)
43 return 0;
44
45 return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
46}
47
48/* This looks through all the IDs a driver claims to support. If any of them
49 * match, we return 1 and the kernel will call virtio_dev_probe(). */
50static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
51{
52 unsigned int i;
53 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
54 const struct virtio_device_id *ids;
55
56 ids = container_of(_dr, struct virtio_driver, driver)->id_table;
57 for (i = 0; ids[i].device; i++)
58 if (virtio_id_match(dev, &ids[i]))
59 return 1;
60 return 0;
61}
62
63static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
64{
65 struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
66
67 return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
68 dev->id.device, dev->id.vendor);
69}
70
71static struct bus_type virtio_bus = {
72 .name = "virtio",
73 .match = virtio_dev_match,
74 .dev_attrs = virtio_dev_attrs,
75 .uevent = virtio_uevent,
76};
77
78static void add_status(struct virtio_device *dev, unsigned status)
79{
80 dev->config->set_status(dev, dev->config->get_status(dev) | status);
81}
82
83static int virtio_dev_probe(struct device *_d)
84{
85 int err;
86 struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
87 struct virtio_driver *drv = container_of(dev->dev.driver,
88 struct virtio_driver, driver);
89
90 add_status(dev, VIRTIO_CONFIG_S_DRIVER);
91 err = drv->probe(dev);
92 if (err)
93 add_status(dev, VIRTIO_CONFIG_S_FAILED);
94 else
95 add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
96 return err;
97}
98
99int register_virtio_driver(struct virtio_driver *driver)
100{
101 driver->driver.bus = &virtio_bus;
102 driver->driver.probe = virtio_dev_probe;
103 return driver_register(&driver->driver);
104}
105EXPORT_SYMBOL_GPL(register_virtio_driver);
106
107void unregister_virtio_driver(struct virtio_driver *driver)
108{
109 driver_unregister(&driver->driver);
110}
111EXPORT_SYMBOL_GPL(unregister_virtio_driver);
112
113int register_virtio_device(struct virtio_device *dev)
114{
115 int err;
116
117 dev->dev.bus = &virtio_bus;
118 sprintf(dev->dev.bus_id, "%u", dev->index);
119
120 /* Acknowledge that we've seen the device. */
121 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
122
123 /* device_register() causes the bus infrastructure to look for a
124 * matching driver. */
125 err = device_register(&dev->dev);
126 if (err)
127 add_status(dev, VIRTIO_CONFIG_S_FAILED);
128 return err;
129}
130EXPORT_SYMBOL_GPL(register_virtio_device);
131
132void unregister_virtio_device(struct virtio_device *dev)
133{
134 device_unregister(&dev->dev);
135}
136EXPORT_SYMBOL_GPL(unregister_virtio_device);
137
138int __virtio_config_val(struct virtio_device *vdev,
139 u8 type, void *val, size_t size)
140{
141 void *token;
142 unsigned int len;
143
144 token = vdev->config->find(vdev, type, &len);
145 if (!token)
146 return -ENOENT;
147
148 if (len != size)
149 return -EIO;
150
151 vdev->config->get(vdev, token, val, size);
152 return 0;
153}
154EXPORT_SYMBOL_GPL(__virtio_config_val);
155
156int virtio_use_bit(struct virtio_device *vdev,
157 void *token, unsigned int len, unsigned int bitnum)
158{
159 unsigned long bits[16];
160
161 /* This makes it convenient to pass-through find() results. */
162 if (!token)
163 return 0;
164
165 /* bit not in range of this bitfield? */
166 if (bitnum * 8 >= len / 2)
167 return 0;
168
169 /* Giant feature bitfields are silly. */
170 BUG_ON(len > sizeof(bits));
171 vdev->config->get(vdev, token, bits, len);
172
173 if (!test_bit(bitnum, bits))
174 return 0;
175
176 /* Set acknowledge bit, and write it back. */
177 set_bit(bitnum + len * 8 / 2, bits);
178 vdev->config->set(vdev, token, bits, len);
179 return 1;
180}
181EXPORT_SYMBOL_GPL(virtio_use_bit);
182
183static int virtio_init(void)
184{
185 if (bus_register(&virtio_bus) != 0)
186 panic("virtio bus registration failed");
187 return 0;
188}
189core_initcall(virtio_init);
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-12 12:50:23 -0500