360 lines
9 KiB
C
360 lines
9 KiB
C
|
#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 = 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 = 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 = 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 = dev_to_virtio(_d);
|
||
|
|
return sprintf(buf, "virtio:d%08Xv%08X\n",
|
||
|
|
dev->id.device, dev->id.vendor);
|
||
|
|
}
|
||
|
|
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 && id->device != VIRTIO_DEV_ANY_ID)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
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
|
||
|
|
* match, we return 1 and the kernel will call virtio_dev_probe(). */
|
||
|
|
static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
|
||
|
|
{
|
||
|
|
unsigned int i;
|
||
|
|
struct virtio_device *dev = dev_to_virtio(_dv);
|
||
|
|
const struct virtio_device_id *ids;
|
||
|
|
|
||
|
|
ids = drv_to_virtio(_dr)->id_table;
|
||
|
|
for (i = 0; ids[i].device; i++)
|
||
|
|
if (virtio_id_match(dev, &ids[i]))
|
||
|
|
return 1;
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
|
||
|
|
{
|
||
|
|
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 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 void __virtio_config_changed(struct virtio_device *dev)
|
||
|
|
{
|
||
|
|
struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
|
||
|
|
|
||
|
|
if (!dev->config_enabled)
|
||
|
|
dev->config_change_pending = true;
|
||
|
|
else if (drv && drv->config_changed)
|
||
|
|
drv->config_changed(dev);
|
||
|
|
}
|
||
|
|
|
||
|
|
void virtio_config_changed(struct virtio_device *dev)
|
||
|
|
{
|
||
|
|
unsigned long flags;
|
||
|
|
|
||
|
|
spin_lock_irqsave(&dev->config_lock, flags);
|
||
|
|
__virtio_config_changed(dev);
|
||
|
|
spin_unlock_irqrestore(&dev->config_lock, flags);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(virtio_config_changed);
|
||
|
|
|
||
|
|
static void virtio_config_disable(struct virtio_device *dev)
|
||
|
|
{
|
||
|
|
spin_lock_irq(&dev->config_lock);
|
||
|
|
dev->config_enabled = false;
|
||
|
|
spin_unlock_irq(&dev->config_lock);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void virtio_config_enable(struct virtio_device *dev)
|
||
|
|
{
|
||
|
|
spin_lock_irq(&dev->config_lock);
|
||
|
|
dev->config_enabled = true;
|
||
|
|
if (dev->config_change_pending)
|
||
|
|
__virtio_config_changed(dev);
|
||
|
|
dev->config_change_pending = false;
|
||
|
|
spin_unlock_irq(&dev->config_lock);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int virtio_dev_probe(struct device *_d)
|
||
|
|
{
|
||
|
|
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 {
|
||
|
|
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
|
||
|
|
if (drv->scan)
|
||
|
|
drv->scan(dev);
|
||
|
|
|
||
|
|
virtio_config_enable(dev);
|
||
|
|
}
|
||
|
|
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int virtio_dev_remove(struct device *_d)
|
||
|
|
{
|
||
|
|
struct virtio_device *dev = dev_to_virtio(_d);
|
||
|
|
struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
|
||
|
|
|
||
|
|
virtio_config_disable(dev);
|
||
|
|
|
||
|
|
drv->remove(dev);
|
||
|
|
|
||
|
|
/* Driver should have reset device. */
|
||
|
|
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;
|
||
|
|
return driver_register(&driver->driver);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(register_virtio_driver);
|
||
|
|
|
||
|
|
void unregister_virtio_driver(struct virtio_driver *driver)
|
||
|
|
{
|
||
|
|
driver_unregister(&driver->driver);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(unregister_virtio_driver);
|
||
|
|
|
||
|
|
int register_virtio_device(struct virtio_device *dev)
|
||
|
|
{
|
||
|
|
int err;
|
||
|
|
|
||
|
|
dev->dev.bus = &virtio_bus;
|
||
|
|
|
||
|
|
/* 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);
|
||
|
|
|
||
|
|
spin_lock_init(&dev->config_lock);
|
||
|
|
dev->config_enabled = false;
|
||
|
|
dev->config_change_pending = false;
|
||
|
|
|
||
|
|
/* We always start by resetting the device, in case a previous
|
||
|
|
* driver messed it up. This also tests that code path a little. */
|
||
|
|
dev->config->reset(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;
|
||
|
|
}
|
||
|
|
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);
|
||
|
|
|
||
|
|
#ifdef CONFIG_PM_SLEEP
|
||
|
|
int virtio_device_freeze(struct virtio_device *dev)
|
||
|
|
{
|
||
|
|
struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
|
||
|
|
|
||
|
|
virtio_config_disable(dev);
|
||
|
|
|
||
|
|
dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
|
||
|
|
|
||
|
|
if (drv && drv->freeze)
|
||
|
|
return drv->freeze(dev);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(virtio_device_freeze);
|
||
|
|
|
||
|
|
int virtio_device_restore(struct virtio_device *dev)
|
||
|
|
{
|
||
|
|
struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
|
||
|
|
|
||
|
|
/* We always start by resetting the device, in case a previous
|
||
|
|
* driver messed it up. */
|
||
|
|
dev->config->reset(dev);
|
||
|
|
|
||
|
|
/* Acknowledge that we've seen the device. */
|
||
|
|
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
|
||
|
|
|
||
|
|
/* Maybe driver failed before freeze.
|
||
|
|
* Restore the failed status, for debugging. */
|
||
|
|
if (dev->failed)
|
||
|
|
add_status(dev, VIRTIO_CONFIG_S_FAILED);
|
||
|
|
|
||
|
|
if (!drv)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
/* We have a driver! */
|
||
|
|
add_status(dev, VIRTIO_CONFIG_S_DRIVER);
|
||
|
|
|
||
|
|
dev->config->finalize_features(dev);
|
||
|
|
|
||
|
|
if (drv->restore) {
|
||
|
|
int ret = drv->restore(dev);
|
||
|
|
if (ret) {
|
||
|
|
add_status(dev, VIRTIO_CONFIG_S_FAILED);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Finally, tell the device we're all set */
|
||
|
|
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
|
||
|
|
|
||
|
|
virtio_config_enable(dev);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(virtio_device_restore);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static int virtio_init(void)
|
||
|
|
{
|
||
|
|
if (bus_register(&virtio_bus) != 0)
|
||
|
|
panic("virtio bus registration failed");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void __exit virtio_exit(void)
|
||
|
|
{
|
||
|
|
bus_unregister(&virtio_bus);
|
||
|
|
}
|
||
|
|
core_initcall(virtio_init);
|
||
|
|
module_exit(virtio_exit);
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL");
|