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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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#include <linux/module.h>#include <linux/slab.h>#include <linux/sysfs.h>#include <linux/mdev.h>
#include "mdev_private.h"
#define DRIVER_VERSION "0.1"#define DRIVER_AUTHOR "NVIDIA Corporation"#define DRIVER_DESC "Mediated device Core Driver"
static struct class_compat *mdev_bus_compat_class;
static LIST_HEAD(mdev_list);static DEFINE_MUTEX(mdev_list_lock);
/* Caller must hold parent unreg_sem read or write lock */static void mdev_device_remove_common(struct mdev_device *mdev){ struct mdev_parent *parent = mdev->type->parent;
mdev_remove_sysfs_files(mdev); device_del(&mdev->dev); lockdep_assert_held(&parent->unreg_sem); /* Balances with device_initialize() */ put_device(&mdev->dev);}
static int mdev_device_remove_cb(struct device *dev, void *data){ if (dev->bus == &mdev_bus_type) mdev_device_remove_common(to_mdev_device(dev)); return 0;}
/* * mdev_register_parent: Register a device as parent for mdevs * @parent: parent structure registered * @dev: device structure representing parent device. * @mdev_driver: Device driver to bind to the newly created mdev * @types: Array of supported mdev types * @nr_types: Number of entries in @types * * Registers the @parent structure as a parent for mdev types and thus mdev * devices. The caller needs to hold a reference on @dev that must not be * released until after the call to mdev_unregister_parent(). * * Returns a negative value on error, otherwise 0. */int mdev_register_parent(struct mdev_parent *parent, struct device *dev, struct mdev_driver *mdev_driver, struct mdev_type **types, unsigned int nr_types){ char *env_string = "MDEV_STATE=registered"; char *envp[] = { env_string, NULL }; int ret;
memset(parent, 0, sizeof(*parent)); init_rwsem(&parent->unreg_sem); parent->dev = dev; parent->mdev_driver = mdev_driver; parent->types = types; parent->nr_types = nr_types; atomic_set(&parent->available_instances, mdev_driver->max_instances);
ret = parent_create_sysfs_files(parent); if (ret) return ret;
ret = class_compat_create_link(mdev_bus_compat_class, dev); if (ret) dev_warn(dev, "Failed to create compatibility class link\n");
dev_info(dev, "MDEV: Registered\n"); kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp); return 0;}EXPORT_SYMBOL(mdev_register_parent);
/* * mdev_unregister_parent : Unregister a parent device * @parent: parent structure to unregister */void mdev_unregister_parent(struct mdev_parent *parent){ char *env_string = "MDEV_STATE=unregistered"; char *envp[] = { env_string, NULL };
dev_info(parent->dev, "MDEV: Unregistering\n");
down_write(&parent->unreg_sem); class_compat_remove_link(mdev_bus_compat_class, parent->dev); device_for_each_child(parent->dev, NULL, mdev_device_remove_cb); parent_remove_sysfs_files(parent); up_write(&parent->unreg_sem);
kobject_uevent_env(&parent->dev->kobj, KOBJ_CHANGE, envp);}EXPORT_SYMBOL(mdev_unregister_parent);
static void mdev_device_release(struct device *dev){ struct mdev_device *mdev = to_mdev_device(dev); struct mdev_parent *parent = mdev->type->parent;
mutex_lock(&mdev_list_lock); list_del(&mdev->next); if (!parent->mdev_driver->get_available) atomic_inc(&parent->available_instances); mutex_unlock(&mdev_list_lock);
/* Pairs with the get in mdev_device_create() */ kobject_put(&mdev->type->kobj);
dev_dbg(&mdev->dev, "MDEV: destroying\n"); kfree(mdev);}
int mdev_device_create(struct mdev_type *type, const guid_t *uuid){ int ret; struct mdev_device *mdev, *tmp; struct mdev_parent *parent = type->parent; struct mdev_driver *drv = parent->mdev_driver;
mutex_lock(&mdev_list_lock);
/* Check for duplicate */ list_for_each_entry(tmp, &mdev_list, next) { if (guid_equal(&tmp->uuid, uuid)) { mutex_unlock(&mdev_list_lock); return -EEXIST; } }
if (!drv->get_available) { /* * Note: that non-atomic read and dec is fine here because * all modifications are under mdev_list_lock. */ if (!atomic_read(&parent->available_instances)) { mutex_unlock(&mdev_list_lock); return -EUSERS; } atomic_dec(&parent->available_instances); }
mdev = kzalloc_obj(*mdev); if (!mdev) { mutex_unlock(&mdev_list_lock); return -ENOMEM; }
device_initialize(&mdev->dev); mdev->dev.parent = parent->dev; mdev->dev.bus = &mdev_bus_type; mdev->dev.release = mdev_device_release; mdev->dev.groups = mdev_device_groups; mdev->type = type; /* Pairs with the put in mdev_device_release() */ kobject_get(&type->kobj);
guid_copy(&mdev->uuid, uuid); list_add(&mdev->next, &mdev_list); mutex_unlock(&mdev_list_lock);
ret = dev_set_name(&mdev->dev, "%pUl", uuid); if (ret) goto out_put_device;
/* Check if parent unregistration has started */ if (!down_read_trylock(&parent->unreg_sem)) { ret = -ENODEV; goto out_put_device; }
ret = device_add(&mdev->dev); if (ret) goto out_unlock;
ret = device_driver_attach(&drv->driver, &mdev->dev); if (ret) goto out_del;
ret = mdev_create_sysfs_files(mdev); if (ret) goto out_del;
mdev->active = true; dev_dbg(&mdev->dev, "MDEV: created\n"); up_read(&parent->unreg_sem);
return 0;
out_del: device_del(&mdev->dev);out_unlock: up_read(&parent->unreg_sem);out_put_device: put_device(&mdev->dev); return ret;}
int mdev_device_remove(struct mdev_device *mdev){ struct mdev_device *tmp; struct mdev_parent *parent = mdev->type->parent;
mutex_lock(&mdev_list_lock); list_for_each_entry(tmp, &mdev_list, next) { if (tmp == mdev) break; }
if (tmp != mdev) { mutex_unlock(&mdev_list_lock); return -ENODEV; }
if (!mdev->active) { mutex_unlock(&mdev_list_lock); return -EAGAIN; }
mdev->active = false; mutex_unlock(&mdev_list_lock);
/* Check if parent unregistration has started */ if (!down_read_trylock(&parent->unreg_sem)) return -ENODEV;
mdev_device_remove_common(mdev); up_read(&parent->unreg_sem); return 0;}
static int __init mdev_init(void){ int ret;
ret = bus_register(&mdev_bus_type); if (ret) return ret;
mdev_bus_compat_class = class_compat_register("mdev_bus"); if (!mdev_bus_compat_class) { bus_unregister(&mdev_bus_type); return -ENOMEM; }
return 0;}
static void __exit mdev_exit(void){ class_compat_unregister(mdev_bus_compat_class); bus_unregister(&mdev_bus_type);}
subsys_initcall(mdev_init)module_exit(mdev_exit)
MODULE_VERSION(DRIVER_VERSION);MODULE_LICENSE("GPL v2");MODULE_AUTHOR(DRIVER_AUTHOR);MODULE_DESCRIPTION(DRIVER_DESC);