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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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/* 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 sysfs_emit(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 sysfs_emit(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 sysfs_emit(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 sysfs_emit(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 < VIRTIO_FEATURES_BITS; i++) len += sysfs_emit_at(buf, len, "%c", __virtio_test_bit(dev, i) ? '1' : '0'); len += sysfs_emit_at(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, const 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(const struct device *_dv, struct kobj_uevent_env *env){ const struct virtio_device *dev = dev_to_virtio(_dv);
return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X", dev->id.device, dev->id.vendor);}
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;
if (drv->feature_table_legacy) { for (i = 0; i < drv->feature_table_size_legacy; i++) if (drv->feature_table_legacy[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_core_enabled || dev->config_driver_disabled) dev->config_change_pending = true; else if (drv && drv->config_changed) { drv->config_changed(dev); dev->config_change_pending = false; }}
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);
/** * virtio_config_driver_disable - disable config change reporting by drivers * @dev: the device to disable * * This is only allowed to be called by a driver and disabling can't * be nested. */void virtio_config_driver_disable(struct virtio_device *dev){ spin_lock_irq(&dev->config_lock); dev->config_driver_disabled = true; spin_unlock_irq(&dev->config_lock);}EXPORT_SYMBOL_GPL(virtio_config_driver_disable);
/** * virtio_config_driver_enable - enable config change reporting by drivers * @dev: the device to enable * * This is only allowed to be called by a driver and enabling can't * be nested. */void virtio_config_driver_enable(struct virtio_device *dev){ spin_lock_irq(&dev->config_lock); dev->config_driver_disabled = false; if (dev->config_change_pending) __virtio_config_changed(dev); spin_unlock_irq(&dev->config_lock);}EXPORT_SYMBOL_GPL(virtio_config_driver_enable);
static void virtio_config_core_disable(struct virtio_device *dev){ spin_lock_irq(&dev->config_lock); dev->config_core_enabled = false; spin_unlock_irq(&dev->config_lock);}
static void virtio_config_core_enable(struct virtio_device *dev){ spin_lock_irq(&dev->config_lock); dev->config_core_enabled = true; if (dev->config_change_pending) __virtio_config_changed(dev); spin_unlock_irq(&dev->config_lock);}
void virtio_add_status(struct virtio_device *dev, unsigned int status){ might_sleep(); dev->config->set_status(dev, dev->config->get_status(dev) | status);}EXPORT_SYMBOL_GPL(virtio_add_status);
/* Do some validation, then set FEATURES_OK */static int virtio_features_ok(struct virtio_device *dev){ unsigned int status;
might_sleep();
if (virtio_check_mem_acc_cb(dev)) { if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n"); return -ENODEV; }
if (!virtio_has_feature(dev, VIRTIO_F_ACCESS_PLATFORM)) { dev_warn(&dev->dev, "device must provide VIRTIO_F_ACCESS_PLATFORM\n"); return -ENODEV; } }
if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) return 0;
virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); status = dev->config->get_status(dev); if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) { dev_err(&dev->dev, "virtio: device refuses features: %x\n", status); return -ENODEV; } return 0;}
/** * virtio_reset_device - quiesce device for removal * @dev: the device to reset * * Prevents device from sending interrupts and accessing memory. * * Generally used for cleanup during driver / device removal. * * Once this has been invoked, caller must ensure that * virtqueue_notify / virtqueue_kick are not in progress. * * Note: this guarantees that vq callbacks are not in progress, however caller * is responsible for preventing access from other contexts, such as a system * call/workqueue/bh. Invoking virtio_break_device then flushing any such * contexts is one way to handle that. * */void virtio_reset_device(struct virtio_device *dev){#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION /* * The below virtio_synchronize_cbs() guarantees that any * interrupt for this line arriving after * virtio_synchronize_vqs() has completed is guaranteed to see * vq->broken as true. */ virtio_break_device(dev); virtio_synchronize_cbs(dev);#endif
dev->config->reset(dev); /* Flush pending VQ/configuration callbacks. */ virtio_synchronize_cbs(dev);}EXPORT_SYMBOL_GPL(virtio_reset_device);
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); u64 device_features[VIRTIO_FEATURES_U64S]; u64 driver_features[VIRTIO_FEATURES_U64S]; u64 driver_features_legacy;
/* We have a driver! */ virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);
/* Figure out what features the device supports. */ virtio_get_features(dev, device_features);
/* Figure out what features the driver supports. */ virtio_features_zero(driver_features); for (i = 0; i < drv->feature_table_size; i++) { unsigned int f = drv->feature_table[i]; if (!WARN_ON_ONCE(f >= VIRTIO_FEATURES_BITS)) virtio_features_set_bit(driver_features, f); }
/* Some drivers have a separate feature table for virtio v1.0 */ if (drv->feature_table_legacy) { driver_features_legacy = 0; for (i = 0; i < drv->feature_table_size_legacy; i++) { unsigned int f = drv->feature_table_legacy[i]; if (!WARN_ON_ONCE(f >= 64)) driver_features_legacy |= (1ULL << f); } } else { driver_features_legacy = driver_features[0]; }
if (virtio_features_test_bit(device_features, VIRTIO_F_VERSION_1)) { for (i = 0; i < VIRTIO_FEATURES_U64S; ++i) dev->features_array[i] = driver_features[i] & device_features[i]; } else { virtio_features_from_u64(dev->features_array, driver_features_legacy & device_features[0]); }
/* When debugging, user may filter some features by hand. */ virtio_debug_device_filter_features(dev);
/* Transport features always preserved to pass to finalize_features. */ for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) if (virtio_features_test_bit(device_features, i)) __virtio_set_bit(dev, i);
err = dev->config->finalize_features(dev); if (err) goto err;
if (drv->validate) { u64 features[VIRTIO_FEATURES_U64S];
virtio_features_copy(features, dev->features_array); err = drv->validate(dev); if (err) goto err;
/* Did validation change any features? Then write them again. */ if (!virtio_features_equal(features, dev->features_array)) { err = dev->config->finalize_features(dev); if (err) goto err; } }
err = virtio_features_ok(dev); if (err) goto err;
err = drv->probe(dev); if (err) goto err;
/* If probe didn't do it, mark device DRIVER_OK ourselves. */ if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK)) virtio_device_ready(dev);
if (drv->scan) drv->scan(dev);
virtio_config_core_enable(dev);
return 0;
err: virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); return err;
}
static void 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_core_disable(dev);
drv->remove(dev);
/* Driver should have reset device. */ WARN_ON_ONCE(dev->config->get_status(dev));
/* Acknowledge the device's existence again. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
of_node_put(dev->dev.of_node);}
/* * virtio_irq_get_affinity - get IRQ affinity mask for device * @_d: ptr to dev structure * @irq_vec: interrupt vector number * * Return the CPU affinity mask for @_d and @irq_vec. */static const struct cpumask *virtio_irq_get_affinity(struct device *_d, unsigned int irq_vec){ struct virtio_device *dev = dev_to_virtio(_d);
if (!dev->config->get_vq_affinity) return NULL;
return dev->config->get_vq_affinity(dev, irq_vec);}
/** * virtio_device_shutdown - break and reset a device on shutdown * @dev: the device * * Drivers with their own .shutdown method should quiesce their activity and * then call this to stop the device the way the generic shutdown path does. */void virtio_device_shutdown(struct virtio_device *dev){ /* * Some devices get wedged if you kick them after they are * reset. Mark all vqs as broken to make sure we don't. */ virtio_break_device(dev); /* * Guarantee that any callback will see vq->broken as true. */ virtio_synchronize_cbs(dev); /* * As IOMMUs are reset on shutdown, this will block device access to memory. * Some devices get wedged if this happens, so reset to make sure it does not. */ dev->config->reset(dev);}EXPORT_SYMBOL_GPL(virtio_device_shutdown);
static void virtio_dev_shutdown(struct device *_d){ struct virtio_device *dev = dev_to_virtio(_d); struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
/* * Stop accesses to or from the device. * We only need to do it if there's a driver - no accesses otherwise. */ if (!drv) return;
/* If the driver has its own shutdown method, use that. */ if (drv->shutdown) { drv->shutdown(dev); return; }
virtio_device_shutdown(dev);}
static int virtio_dev_num_vf(struct device *dev){ struct virtio_device *vdev = dev_to_virtio(dev);
return dev_num_vf(vdev->dev.parent);}
static const 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, .irq_get_affinity = virtio_irq_get_affinity, .shutdown = virtio_dev_shutdown, .num_vf = virtio_dev_num_vf,};
int __register_virtio_driver(struct virtio_driver *driver, struct module *owner){ /* Catch this early. */ BUG_ON(driver->feature_table_size && !driver->feature_table); driver->driver.bus = &virtio_bus; driver->driver.owner = owner;
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);
static int virtio_device_of_init(struct virtio_device *dev){ struct device_node *np, *pnode = dev_of_node(dev->dev.parent); char compat[] = "virtio,deviceXXXXXXXX"; int ret, count;
if (!pnode) return 0;
count = of_get_available_child_count(pnode); if (!count) return 0;
/* There can be only 1 child node */ if (WARN_ON(count > 1)) return -EINVAL;
np = of_get_next_available_child(pnode, NULL); if (WARN_ON(!np)) return -ENODEV;
ret = snprintf(compat, sizeof(compat), "virtio,device%x", dev->id.device); BUG_ON(ret >= sizeof(compat));
/* * On powerpc/pseries virtio devices are PCI devices so PCI * vendor/device ids play the role of the "compatible" property. * Simply don't init of_node in this case. */ if (!of_device_is_compatible(np, compat)) { ret = 0; goto out; }
dev->dev.of_node = np; return 0;
out: of_node_put(np); return ret;}
/** * register_virtio_device - register virtio device * @dev : virtio device to be registered * * On error, the caller must call put_device on &@dev->dev (and not kfree), * as another code path may have obtained a reference to @dev. * * Returns: 0 on success, -error on failure */int register_virtio_device(struct virtio_device *dev){ int err;
dev->dev.bus = &virtio_bus; device_initialize(&dev->dev);
/* Assign a unique device index and hence name. */ err = ida_alloc(&virtio_index_ida, GFP_KERNEL); if (err < 0) goto out;
dev->index = err; err = dev_set_name(&dev->dev, "virtio%u", dev->index); if (err) goto out_ida_remove;
err = virtio_device_of_init(dev); if (err) goto out_ida_remove;
spin_lock_init(&dev->config_lock); dev->config_driver_disabled = false; dev->config_core_enabled = false; dev->config_change_pending = false;
INIT_LIST_HEAD(&dev->vqs); spin_lock_init(&dev->vqs_list_lock);
/* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ virtio_reset_device(dev);
/* Acknowledge that we've seen the device. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
virtio_debug_device_init(dev);
/* * device_add() causes the bus infrastructure to look for a matching * driver. */ err = device_add(&dev->dev); if (err) goto out_of_node_put;
return 0;
out_of_node_put: of_node_put(dev->dev.of_node);out_ida_remove: ida_free(&virtio_index_ida, dev->index);out: virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); return err;}EXPORT_SYMBOL_GPL(register_virtio_device);
bool is_virtio_device(struct device *dev){ return dev->bus == &virtio_bus;}EXPORT_SYMBOL_GPL(is_virtio_device);
void unregister_virtio_device(struct virtio_device *dev){ int index = dev->index; /* save for after device release */
virtio_debug_device_exit(dev); device_unregister(&dev->dev); ida_free(&virtio_index_ida, index);}EXPORT_SYMBOL_GPL(unregister_virtio_device);
static int virtio_device_restore_priv(struct virtio_device *dev, bool restore){ struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); int ret;
/* We always start by resetting the device, in case a previous * driver messed it up. */ virtio_reset_device(dev);
/* Acknowledge that we've seen the device. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
/* Maybe driver failed before freeze. * Restore the failed status, for debugging. */ if (dev->failed) virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
if (!drv) return 0;
/* We have a driver! */ virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);
ret = dev->config->finalize_features(dev); if (ret) goto err;
ret = virtio_features_ok(dev); if (ret) goto err;
if (restore) { if (drv->restore) { ret = drv->restore(dev); if (ret) goto err; } } else { ret = drv->reset_done(dev); if (ret) goto err; }
/* If restore didn't do it, mark device DRIVER_OK ourselves. */ if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK)) virtio_device_ready(dev);
virtio_config_core_enable(dev);
return 0;
err: virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); return ret;}
#ifdef CONFIG_PM_SLEEPint virtio_device_freeze(struct virtio_device *dev){ struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); int ret;
virtio_config_core_disable(dev);
dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
if (drv && drv->freeze) { ret = drv->freeze(dev); if (ret) { virtio_config_core_enable(dev); return ret; } }
return 0;}EXPORT_SYMBOL_GPL(virtio_device_freeze);
int virtio_device_restore(struct virtio_device *dev){ return virtio_device_restore_priv(dev, true);}EXPORT_SYMBOL_GPL(virtio_device_restore);#endif
int virtio_device_reset_prepare(struct virtio_device *dev){ struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); int ret;
if (!drv || !drv->reset_prepare) return -EOPNOTSUPP;
virtio_config_core_disable(dev);
dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
ret = drv->reset_prepare(dev); if (ret) { virtio_config_core_enable(dev); return ret; }
return 0;}EXPORT_SYMBOL_GPL(virtio_device_reset_prepare);
int virtio_device_reset_done(struct virtio_device *dev){ struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
if (!drv || !drv->reset_done) return -EOPNOTSUPP;
return virtio_device_restore_priv(dev, false);}EXPORT_SYMBOL_GPL(virtio_device_reset_done);
static int virtio_init(void){ BUILD_BUG_ON(offsetof(struct virtio_device, features) != offsetof(struct virtio_device, features_array[0]));
if (bus_register(&virtio_bus) != 0) panic("virtio bus registration failed"); virtio_debug_init(); return 0;}
static void __exit virtio_exit(void){ virtio_debug_exit(); bus_unregister(&virtio_bus); ida_destroy(&virtio_index_ida);}core_initcall(virtio_init);module_exit(virtio_exit);
MODULE_DESCRIPTION("Virtio core interface");MODULE_LICENSE("GPL");