diff options
Diffstat (limited to 'drivers/virtio/virtio.c')
| -rw-r--r-- | drivers/virtio/virtio.c | 159 |
1 files changed, 121 insertions, 38 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index b535483bc55..fed0ce198ae 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -1,48 +1,79 @@ #include <linux/virtio.h> #include <linux/spinlock.h> #include <linux/virtio_config.h> +#include <linux/module.h> +#include <linux/idr.h> + +/* Unique numbering for virtio devices. */ +static DEFINE_IDA(virtio_index_ida); static ssize_t device_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - return sprintf(buf, "%hu", dev->id.device); + struct virtio_device *dev = dev_to_virtio(_d); + return sprintf(buf, "0x%04x\n", dev->id.device); } +static DEVICE_ATTR_RO(device); + static ssize_t vendor_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - return sprintf(buf, "%hu", dev->id.vendor); + struct virtio_device *dev = dev_to_virtio(_d); + return sprintf(buf, "0x%04x\n", dev->id.vendor); } +static DEVICE_ATTR_RO(vendor); + static ssize_t status_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - return sprintf(buf, "0x%08x", dev->config->get_status(dev)); + struct virtio_device *dev = dev_to_virtio(_d); + return sprintf(buf, "0x%08x\n", dev->config->get_status(dev)); } +static DEVICE_ATTR_RO(status); + static ssize_t modalias_show(struct device *_d, struct device_attribute *attr, char *buf) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - + struct virtio_device *dev = dev_to_virtio(_d); return sprintf(buf, "virtio:d%08Xv%08X\n", dev->id.device, dev->id.vendor); } -static struct device_attribute virtio_dev_attrs[] = { - __ATTR_RO(device), - __ATTR_RO(vendor), - __ATTR_RO(status), - __ATTR_RO(modalias), - __ATTR_NULL +static DEVICE_ATTR_RO(modalias); + +static ssize_t features_show(struct device *_d, + struct device_attribute *attr, char *buf) +{ + struct virtio_device *dev = dev_to_virtio(_d); + unsigned int i; + ssize_t len = 0; + + /* We actually represent this as a bitstring, as it could be + * arbitrary length in future. */ + for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++) + len += sprintf(buf+len, "%c", + test_bit(i, dev->features) ? '1' : '0'); + len += sprintf(buf+len, "\n"); + return len; +} +static DEVICE_ATTR_RO(features); + +static struct attribute *virtio_dev_attrs[] = { + &dev_attr_device.attr, + &dev_attr_vendor.attr, + &dev_attr_status.attr, + &dev_attr_modalias.attr, + &dev_attr_features.attr, + NULL, }; +ATTRIBUTE_GROUPS(virtio_dev); static inline int virtio_id_match(const struct virtio_device *dev, const struct virtio_device_id *id) { - if (id->device != dev->id.device) + if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID) return 0; - return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor; + return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor; } /* This looks through all the IDs a driver claims to support. If any of them @@ -50,10 +81,10 @@ static inline int virtio_id_match(const struct virtio_device *dev, static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) { unsigned int i; - struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); + struct virtio_device *dev = dev_to_virtio(_dv); const struct virtio_device_id *ids; - ids = container_of(_dr, struct virtio_driver, driver)->id_table; + ids = drv_to_virtio(_dr)->id_table; for (i = 0; ids[i].device; i++) if (virtio_id_match(dev, &ids[i])) return 1; @@ -62,61 +93,100 @@ static int virtio_dev_match(struct device *_dv, struct device_driver *_dr) static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env) { - struct virtio_device *dev = container_of(_dv,struct virtio_device,dev); + struct virtio_device *dev = dev_to_virtio(_dv); return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", dev->id.device, dev->id.vendor); } -static struct bus_type virtio_bus = { - .name = "virtio", - .match = virtio_dev_match, - .dev_attrs = virtio_dev_attrs, - .uevent = virtio_uevent, -}; - static void add_status(struct virtio_device *dev, unsigned status) { dev->config->set_status(dev, dev->config->get_status(dev) | status); } +void virtio_check_driver_offered_feature(const struct virtio_device *vdev, + unsigned int fbit) +{ + unsigned int i; + struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver); + + for (i = 0; i < drv->feature_table_size; i++) + if (drv->feature_table[i] == fbit) + return; + BUG(); +} +EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); + static int virtio_dev_probe(struct device *_d) { - int err; - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - struct virtio_driver *drv = container_of(dev->dev.driver, - struct virtio_driver, driver); + int err, i; + struct virtio_device *dev = dev_to_virtio(_d); + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); + u32 device_features; + /* We have a driver! */ add_status(dev, VIRTIO_CONFIG_S_DRIVER); + + /* Figure out what features the device supports. */ + device_features = dev->config->get_features(dev); + + /* Features supported by both device and driver into dev->features. */ + memset(dev->features, 0, sizeof(dev->features)); + for (i = 0; i < drv->feature_table_size; i++) { + unsigned int f = drv->feature_table[i]; + BUG_ON(f >= 32); + if (device_features & (1 << f)) + set_bit(f, dev->features); + } + + /* Transport features always preserved to pass to finalize_features. */ + for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) + if (device_features & (1 << i)) + set_bit(i, dev->features); + + dev->config->finalize_features(dev); + err = drv->probe(dev); if (err) add_status(dev, VIRTIO_CONFIG_S_FAILED); - else + else { add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); + if (drv->scan) + drv->scan(dev); + } + return err; } static int virtio_dev_remove(struct device *_d) { - struct virtio_device *dev = container_of(_d,struct virtio_device,dev); - struct virtio_driver *drv = container_of(dev->dev.driver, - struct virtio_driver, driver); + struct virtio_device *dev = dev_to_virtio(_d); + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); drv->remove(dev); /* Driver should have reset device. */ - BUG_ON(dev->config->get_status(dev)); + WARN_ON_ONCE(dev->config->get_status(dev)); /* Acknowledge the device's existence again. */ add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); return 0; } +static struct bus_type virtio_bus = { + .name = "virtio", + .match = virtio_dev_match, + .dev_groups = virtio_dev_groups, + .uevent = virtio_uevent, + .probe = virtio_dev_probe, + .remove = virtio_dev_remove, +}; + int register_virtio_driver(struct virtio_driver *driver) { + /* Catch this early. */ + BUG_ON(driver->feature_table_size && !driver->feature_table); driver->driver.bus = &virtio_bus; - driver->driver.probe = virtio_dev_probe; - driver->driver.remove = virtio_dev_remove; return driver_register(&driver->driver); } EXPORT_SYMBOL_GPL(register_virtio_driver); @@ -132,7 +202,14 @@ int register_virtio_device(struct virtio_device *dev) int err; dev->dev.bus = &virtio_bus; - sprintf(dev->dev.bus_id, "%u", dev->index); + + /* Assign a unique device index and hence name. */ + err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL); + if (err < 0) + goto out; + + dev->index = err; + dev_set_name(&dev->dev, "virtio%u", dev->index); /* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ @@ -141,9 +218,12 @@ int register_virtio_device(struct virtio_device *dev) /* Acknowledge that we've seen the device. */ add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); + INIT_LIST_HEAD(&dev->vqs); + /* device_register() causes the bus infrastructure to look for a * matching driver. */ err = device_register(&dev->dev); +out: if (err) add_status(dev, VIRTIO_CONFIG_S_FAILED); return err; @@ -152,7 +232,10 @@ EXPORT_SYMBOL_GPL(register_virtio_device); void unregister_virtio_device(struct virtio_device *dev) { + int index = dev->index; /* save for after device release */ + device_unregister(&dev->dev); + ida_simple_remove(&virtio_index_ida, index); } EXPORT_SYMBOL_GPL(unregister_virtio_device); |