1 #include <linux/virtio.h> 2 #include <linux/spinlock.h> 3 #include <linux/virtio_config.h> 4 5 static 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 } 11 static 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 } 17 static 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 } 23 static 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 } 31 static 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 39 static 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(). */ 50 static 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 63 static 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 71 static 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 78 static void add_status(struct virtio_device *dev, unsigned status) 79 { 80 dev->config->set_status(dev, dev->config->get_status(dev) | status); 81 } 82 83 static 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 99 static int virtio_dev_remove(struct device *_d) 100 { 101 struct virtio_device *dev = container_of(_d,struct virtio_device,dev); 102 struct virtio_driver *drv = container_of(dev->dev.driver, 103 struct virtio_driver, driver); 104 105 dev->config->set_status(dev, dev->config->get_status(dev) 106 & ~VIRTIO_CONFIG_S_DRIVER); 107 drv->remove(dev); 108 return 0; 109 } 110 111 int register_virtio_driver(struct virtio_driver *driver) 112 { 113 driver->driver.bus = &virtio_bus; 114 driver->driver.probe = virtio_dev_probe; 115 driver->driver.remove = virtio_dev_remove; 116 return driver_register(&driver->driver); 117 } 118 EXPORT_SYMBOL_GPL(register_virtio_driver); 119 120 void unregister_virtio_driver(struct virtio_driver *driver) 121 { 122 driver_unregister(&driver->driver); 123 } 124 EXPORT_SYMBOL_GPL(unregister_virtio_driver); 125 126 int register_virtio_device(struct virtio_device *dev) 127 { 128 int err; 129 130 dev->dev.bus = &virtio_bus; 131 sprintf(dev->dev.bus_id, "%u", dev->index); 132 133 /* Acknowledge that we've seen the device. */ 134 add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); 135 136 /* device_register() causes the bus infrastructure to look for a 137 * matching driver. */ 138 err = device_register(&dev->dev); 139 if (err) 140 add_status(dev, VIRTIO_CONFIG_S_FAILED); 141 return err; 142 } 143 EXPORT_SYMBOL_GPL(register_virtio_device); 144 145 void unregister_virtio_device(struct virtio_device *dev) 146 { 147 device_unregister(&dev->dev); 148 } 149 EXPORT_SYMBOL_GPL(unregister_virtio_device); 150 151 int __virtio_config_val(struct virtio_device *vdev, 152 u8 type, void *val, size_t size) 153 { 154 void *token; 155 unsigned int len; 156 157 token = vdev->config->find(vdev, type, &len); 158 if (!token) 159 return -ENOENT; 160 161 if (len != size) 162 return -EIO; 163 164 vdev->config->get(vdev, token, val, size); 165 return 0; 166 } 167 EXPORT_SYMBOL_GPL(__virtio_config_val); 168 169 int virtio_use_bit(struct virtio_device *vdev, 170 void *token, unsigned int len, unsigned int bitnum) 171 { 172 unsigned long bits[16]; 173 174 /* This makes it convenient to pass-through find() results. */ 175 if (!token) 176 return 0; 177 178 /* bit not in range of this bitfield? */ 179 if (bitnum * 8 >= len / 2) 180 return 0; 181 182 /* Giant feature bitfields are silly. */ 183 BUG_ON(len > sizeof(bits)); 184 vdev->config->get(vdev, token, bits, len); 185 186 if (!test_bit(bitnum, bits)) 187 return 0; 188 189 /* Set acknowledge bit, and write it back. */ 190 set_bit(bitnum + len * 8 / 2, bits); 191 vdev->config->set(vdev, token, bits, len); 192 return 1; 193 } 194 EXPORT_SYMBOL_GPL(virtio_use_bit); 195 196 static int virtio_init(void) 197 { 198 if (bus_register(&virtio_bus) != 0) 199 panic("virtio bus registration failed"); 200 return 0; 201 } 202 core_initcall(virtio_init); 203