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authorChristoph Hellwig <hch@lst.de>2022-09-23 12:26:42 +0300
committerAlex Williamson <alex.williamson@redhat.com>2022-10-04 21:06:58 +0300
commit89345d5177aa0f6d678251e1e0870b0eeb1ab510 (patch)
tree8e29a3f83f05c8aa5a64b6b66c522c18d763c2b4 /drivers/vfio/mdev
parentbdef2b7896df293736330eb6eb0f43947049b828 (diff)
downloadlinux-89345d5177aa0f6d678251e1e0870b0eeb1ab510.tar.xz
vfio/mdev: embedd struct mdev_parent in the parent data structure
Simplify mdev_{un}register_device by requiring the caller to pass in a structure allocate as part of the parent device structure. This removes the need for a list of parents and the separate mdev_parent refcount as we can simplify rely on the reference to the parent device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/mdev')
-rw-r--r--drivers/vfio/mdev/mdev_core.c120
-rw-r--r--drivers/vfio/mdev/mdev_private.h23
-rw-r--r--drivers/vfio/mdev/mdev_sysfs.c4
3 files changed, 24 insertions, 123 deletions
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 2c32923fbad2..fa05ac339695 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -18,8 +18,6 @@
#define DRIVER_AUTHOR "NVIDIA Corporation"
#define DRIVER_DESC "Mediated device Core Driver"
-static LIST_HEAD(parent_list);
-static DEFINE_MUTEX(parent_list_lock);
static struct class_compat *mdev_bus_compat_class;
static LIST_HEAD(mdev_list);
@@ -61,28 +59,6 @@ struct device *mtype_get_parent_dev(struct mdev_type *mtype)
}
EXPORT_SYMBOL(mtype_get_parent_dev);
-/* Should be called holding parent_list_lock */
-static struct mdev_parent *__find_parent_device(struct device *dev)
-{
- struct mdev_parent *parent;
-
- list_for_each_entry(parent, &parent_list, next) {
- if (parent->dev == dev)
- return parent;
- }
- return NULL;
-}
-
-void mdev_release_parent(struct kref *kref)
-{
- struct mdev_parent *parent = container_of(kref, struct mdev_parent,
- ref);
- struct device *dev = parent->dev;
-
- kfree(parent);
- put_device(dev);
-}
-
/* Caller must hold parent unreg_sem read or write lock */
static void mdev_device_remove_common(struct mdev_device *mdev)
{
@@ -105,125 +81,73 @@ static int mdev_device_remove_cb(struct device *dev, void *data)
}
/*
- * mdev_register_device : Register a device
+ * 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
*
- * Add device to list of registered parent devices.
+ * Registers the @parent stucture 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_device(struct device *dev, struct mdev_driver *mdev_driver)
+int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
+ struct mdev_driver *mdev_driver)
{
- int ret;
- struct mdev_parent *parent;
char *env_string = "MDEV_STATE=registered";
char *envp[] = { env_string, NULL };
+ int ret;
/* check for mandatory ops */
if (!mdev_driver->supported_type_groups)
return -EINVAL;
- dev = get_device(dev);
- if (!dev)
- return -EINVAL;
-
- mutex_lock(&parent_list_lock);
-
- /* Check for duplicate */
- parent = __find_parent_device(dev);
- if (parent) {
- parent = NULL;
- ret = -EEXIST;
- goto add_dev_err;
- }
-
- parent = kzalloc(sizeof(*parent), GFP_KERNEL);
- if (!parent) {
- ret = -ENOMEM;
- goto add_dev_err;
- }
-
- kref_init(&parent->ref);
+ memset(parent, 0, sizeof(*parent));
init_rwsem(&parent->unreg_sem);
-
parent->dev = dev;
parent->mdev_driver = mdev_driver;
if (!mdev_bus_compat_class) {
mdev_bus_compat_class = class_compat_register("mdev_bus");
- if (!mdev_bus_compat_class) {
- ret = -ENOMEM;
- goto add_dev_err;
- }
+ if (!mdev_bus_compat_class)
+ return -ENOMEM;
}
ret = parent_create_sysfs_files(parent);
if (ret)
- goto add_dev_err;
+ return ret;
ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
if (ret)
dev_warn(dev, "Failed to create compatibility class link\n");
- list_add(&parent->next, &parent_list);
- mutex_unlock(&parent_list_lock);
-
dev_info(dev, "MDEV: Registered\n");
kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
-
return 0;
-
-add_dev_err:
- mutex_unlock(&parent_list_lock);
- if (parent)
- mdev_put_parent(parent);
- else
- put_device(dev);
- return ret;
}
-EXPORT_SYMBOL(mdev_register_device);
+EXPORT_SYMBOL(mdev_register_parent);
/*
- * mdev_unregister_device : Unregister a parent device
- * @dev: device structure representing parent device.
- *
- * Remove device from list of registered parent devices. Give a chance to free
- * existing mediated devices for given device.
+ * mdev_unregister_parent : Unregister a parent device
+ * @parent: parent structure to unregister
*/
-
-void mdev_unregister_device(struct device *dev)
+void mdev_unregister_parent(struct mdev_parent *parent)
{
- struct mdev_parent *parent;
char *env_string = "MDEV_STATE=unregistered";
char *envp[] = { env_string, NULL };
- mutex_lock(&parent_list_lock);
- parent = __find_parent_device(dev);
-
- if (!parent) {
- mutex_unlock(&parent_list_lock);
- return;
- }
- dev_info(dev, "MDEV: Unregistering\n");
-
- list_del(&parent->next);
- mutex_unlock(&parent_list_lock);
+ dev_info(parent->dev, "MDEV: Unregistering\n");
down_write(&parent->unreg_sem);
-
- class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
-
- device_for_each_child(dev, NULL, mdev_device_remove_cb);
-
+ class_compat_remove_link(mdev_bus_compat_class, parent->dev, NULL);
+ device_for_each_child(parent->dev, NULL, mdev_device_remove_cb);
parent_remove_sysfs_files(parent);
up_write(&parent->unreg_sem);
- mdev_put_parent(parent);
-
- /* We still have the caller's reference to use for the uevent */
- kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
+ kobject_uevent_env(&parent->dev->kobj, KOBJ_CHANGE, envp);
}
-EXPORT_SYMBOL(mdev_unregister_device);
+EXPORT_SYMBOL(mdev_unregister_parent);
static void mdev_device_release(struct device *dev)
{
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index 7c9fc79f3d83..297f911fdc89 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -13,17 +13,6 @@
int mdev_bus_register(void);
void mdev_bus_unregister(void);
-struct mdev_parent {
- struct device *dev;
- struct mdev_driver *mdev_driver;
- struct kref ref;
- struct list_head next;
- struct kset *mdev_types_kset;
- struct list_head type_list;
- /* Synchronize device creation/removal with parent unregistration */
- struct rw_semaphore unreg_sem;
-};
-
struct mdev_type {
struct kobject kobj;
struct kobject *devices_kobj;
@@ -48,16 +37,4 @@ void mdev_remove_sysfs_files(struct mdev_device *mdev);
int mdev_device_create(struct mdev_type *kobj, const guid_t *uuid);
int mdev_device_remove(struct mdev_device *dev);
-void mdev_release_parent(struct kref *kref);
-
-static inline void mdev_get_parent(struct mdev_parent *parent)
-{
- kref_get(&parent->ref);
-}
-
-static inline void mdev_put_parent(struct mdev_parent *parent)
-{
- kref_put(&parent->ref, mdev_release_parent);
-}
-
#endif /* MDEV_PRIVATE_H */
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 4bfbf49aaa66..b71ffc559487 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -81,7 +81,7 @@ static void mdev_type_release(struct kobject *kobj)
pr_debug("Releasing group %s\n", kobj->name);
/* Pairs with the get in add_mdev_supported_type() */
- mdev_put_parent(type->parent);
+ put_device(type->parent->dev);
kfree(type);
}
@@ -110,7 +110,7 @@ static struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
type->kobj.kset = parent->mdev_types_kset;
type->parent = parent;
/* Pairs with the put in mdev_type_release() */
- mdev_get_parent(parent);
+ get_device(parent->dev);
type->type_group_id = type_group_id;
ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,