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// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */ #include <linux/module.h>#include <linux/slab.h>#include <linux/rhashtable.h>#include <linux/list.h>#include <linux/sort.h>#include <linux/objagg.h> #define CREATE_TRACE_POINTS#include <trace/events/objagg.h> struct objagg {	const struct objagg_ops *ops;	void *priv;	struct rhashtable obj_ht;	struct rhashtable_params ht_params;	struct list_head obj_list;	unsigned int obj_count;}; struct objagg_obj {	struct rhash_head ht_node; /* member of objagg->obj_ht */	struct list_head list; /* member of objagg->obj_list */	struct objagg_obj *parent; /* if the object is nested, this				    * holds pointer to parent, otherwise NULL				    */	union {		void *delta_priv; /* user delta private */		void *root_priv; /* user root private */	};	unsigned int refcount; /* counts number of users of this object				* including nested objects				*/	struct objagg_obj_stats stats;	unsigned long obj[0];}; static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj){	return ++objagg_obj->refcount;} static unsigned int objagg_obj_ref_dec(struct objagg_obj *objagg_obj){	return --objagg_obj->refcount;} static void objagg_obj_stats_inc(struct objagg_obj *objagg_obj){	objagg_obj->stats.user_count++;	objagg_obj->stats.delta_user_count++;	if (objagg_obj->parent)		objagg_obj->parent->stats.delta_user_count++;} static void objagg_obj_stats_dec(struct objagg_obj *objagg_obj){	objagg_obj->stats.user_count--;	objagg_obj->stats.delta_user_count--;	if (objagg_obj->parent)		objagg_obj->parent->stats.delta_user_count--;} static bool objagg_obj_is_root(const struct objagg_obj *objagg_obj){	/* Nesting is not supported, so we can use ->parent	 * to figure out if the object is root.	 */	return !objagg_obj->parent;} /** * objagg_obj_root_priv - obtains root private for an object * @objagg_obj:	objagg object instance * * Note: all locking must be provided by the caller. * * Either the object is root itself when the private is returned * directly, or the parent is root and its private is returned * instead. * * Returns a user private root pointer. */const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj){	if (objagg_obj_is_root(objagg_obj))		return objagg_obj->root_priv;	WARN_ON(!objagg_obj_is_root(objagg_obj->parent));	return objagg_obj->parent->root_priv;}EXPORT_SYMBOL(objagg_obj_root_priv); /** * objagg_obj_delta_priv - obtains delta private for an object * @objagg_obj:	objagg object instance * * Note: all locking must be provided by the caller. * * Returns user private delta pointer or NULL in case the passed * object is root. */const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj){	if (objagg_obj_is_root(objagg_obj))		return NULL;	return objagg_obj->delta_priv;}EXPORT_SYMBOL(objagg_obj_delta_priv); /** * objagg_obj_raw - obtains object user private pointer * @objagg_obj:	objagg object instance * * Note: all locking must be provided by the caller. * * Returns user private pointer as was passed to objagg_obj_get() by "obj" arg. */const void *objagg_obj_raw(const struct objagg_obj *objagg_obj){	return objagg_obj->obj;}EXPORT_SYMBOL(objagg_obj_raw); static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj){	return rhashtable_lookup_fast(&objagg->obj_ht, obj, objagg->ht_params);} static int objagg_obj_parent_assign(struct objagg *objagg,				    struct objagg_obj *objagg_obj,				    struct objagg_obj *parent){	void *delta_priv; 	delta_priv = objagg->ops->delta_create(objagg->priv, parent->obj,					       objagg_obj->obj);	if (IS_ERR(delta_priv))		return PTR_ERR(delta_priv); 	/* User returned a delta private, that means that	 * our object can be aggregated into the parent.	 */	objagg_obj->parent = parent;	objagg_obj->delta_priv = delta_priv;	objagg_obj_ref_inc(objagg_obj->parent);	trace_objagg_obj_parent_assign(objagg, objagg_obj,				       parent,				       parent->refcount);	return 0;} static int objagg_obj_parent_lookup_assign(struct objagg *objagg,					   struct objagg_obj *objagg_obj){	struct objagg_obj *objagg_obj_cur;	int err; 	list_for_each_entry(objagg_obj_cur, &objagg->obj_list, list) {		/* Nesting is not supported. In case the object		 * is not root, it cannot be assigned as parent.		 */		if (!objagg_obj_is_root(objagg_obj_cur))			continue;		err = objagg_obj_parent_assign(objagg, objagg_obj,					       objagg_obj_cur);		if (!err)			return 0;	}	return -ENOENT;} static void __objagg_obj_put(struct objagg *objagg,			     struct objagg_obj *objagg_obj); static void objagg_obj_parent_unassign(struct objagg *objagg,				       struct objagg_obj *objagg_obj){	trace_objagg_obj_parent_unassign(objagg, objagg_obj,					 objagg_obj->parent,					 objagg_obj->parent->refcount);	objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv);	__objagg_obj_put(objagg, objagg_obj->parent);} static int objagg_obj_root_create(struct objagg *objagg,				  struct objagg_obj *objagg_obj){	objagg_obj->root_priv = objagg->ops->root_create(objagg->priv,							 objagg_obj->obj);	if (IS_ERR(objagg_obj->root_priv))		return PTR_ERR(objagg_obj->root_priv); 	trace_objagg_obj_root_create(objagg, objagg_obj);	return 0;} static void objagg_obj_root_destroy(struct objagg *objagg,				    struct objagg_obj *objagg_obj){	trace_objagg_obj_root_destroy(objagg, objagg_obj);	objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv);} static int objagg_obj_init(struct objagg *objagg,			   struct objagg_obj *objagg_obj){	int err; 	/* Try to find if the object can be aggregated under an existing one. */	err = objagg_obj_parent_lookup_assign(objagg, objagg_obj);	if (!err)		return 0;	/* If aggregation is not possible, make the object a root. */	return objagg_obj_root_create(objagg, objagg_obj);} static void objagg_obj_fini(struct objagg *objagg,			    struct objagg_obj *objagg_obj){	if (!objagg_obj_is_root(objagg_obj))		objagg_obj_parent_unassign(objagg, objagg_obj);	else		objagg_obj_root_destroy(objagg, objagg_obj);} static struct objagg_obj *objagg_obj_create(struct objagg *objagg, void *obj){	struct objagg_obj *objagg_obj;	int err; 	objagg_obj = kzalloc(sizeof(*objagg_obj) + objagg->ops->obj_size,			     GFP_KERNEL);	if (!objagg_obj)		return ERR_PTR(-ENOMEM);	objagg_obj_ref_inc(objagg_obj);	memcpy(objagg_obj->obj, obj, objagg->ops->obj_size); 	err = objagg_obj_init(objagg, objagg_obj);	if (err)		goto err_obj_init; 	err = rhashtable_insert_fast(&objagg->obj_ht, &objagg_obj->ht_node,				     objagg->ht_params);	if (err)		goto err_ht_insert;	list_add(&objagg_obj->list, &objagg->obj_list);	objagg->obj_count++;	trace_objagg_obj_create(objagg, objagg_obj); 	return objagg_obj; err_ht_insert:	objagg_obj_fini(objagg, objagg_obj);err_obj_init:	kfree(objagg_obj);	return ERR_PTR(err);} static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj){	struct objagg_obj *objagg_obj; 	/* First, try to find the object exactly as user passed it,	 * perhaps it is already in use.	 */	objagg_obj = objagg_obj_lookup(objagg, obj);	if (objagg_obj) {		objagg_obj_ref_inc(objagg_obj);		return objagg_obj;	} 	return objagg_obj_create(objagg, obj);} /** * objagg_obj_get - gets an object within objagg instance * @objagg:	objagg instance * @obj:	user-specific private object pointer * * Note: all locking must be provided by the caller. * * Size of the "obj" memory is specified in "objagg->ops". * * There are 3 main options this function wraps: * 1) The object according to "obj" already exist. In that case *    the reference counter is incrementes and the object is returned. * 2) The object does not exist, but it can be aggregated within *    another object. In that case, user ops->delta_create() is called *    to obtain delta data and a new object is created with returned *    user-delta private pointer. * 3) The object does not exist and cannot be aggregated into *    any of the existing objects. In that case, user ops->root_create() *    is called to create the root and a new object is created with *    returned user-root private pointer. * * Returns a pointer to objagg object instance in case of success, * otherwise it returns pointer error using ERR_PTR macro. */struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj){	struct objagg_obj *objagg_obj; 	objagg_obj = __objagg_obj_get(objagg, obj);	if (IS_ERR(objagg_obj))		return objagg_obj;	objagg_obj_stats_inc(objagg_obj);	trace_objagg_obj_get(objagg, objagg_obj, objagg_obj->refcount);	return objagg_obj;}EXPORT_SYMBOL(objagg_obj_get); static void objagg_obj_destroy(struct objagg *objagg,			       struct objagg_obj *objagg_obj){	trace_objagg_obj_destroy(objagg, objagg_obj);	--objagg->obj_count;	list_del(&objagg_obj->list);	rhashtable_remove_fast(&objagg->obj_ht, &objagg_obj->ht_node,			       objagg->ht_params);	objagg_obj_fini(objagg, objagg_obj);	kfree(objagg_obj);} static void __objagg_obj_put(struct objagg *objagg,			     struct objagg_obj *objagg_obj){	if (!objagg_obj_ref_dec(objagg_obj))		objagg_obj_destroy(objagg, objagg_obj);} /** * objagg_obj_put - puts an object within objagg instance * @objagg:	objagg instance * @objagg_obj:	objagg object instance * * Note: all locking must be provided by the caller. * * Symmetric to objagg_obj_get(). */void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj){	trace_objagg_obj_put(objagg, objagg_obj, objagg_obj->refcount);	objagg_obj_stats_dec(objagg_obj);	__objagg_obj_put(objagg, objagg_obj);}EXPORT_SYMBOL(objagg_obj_put); /** * objagg_create - creates a new objagg instance * @ops:	user-specific callbacks * @priv:	pointer to a private data passed to the ops * * Note: all locking must be provided by the caller. * * The purpose of the library is to provide an infrastructure to * aggregate user-specified objects. Library does not care about the type * of the object. User fills-up ops which take care of the specific * user object manipulation. * * As a very stupid example, consider integer numbers. For example * number 8 as a root object. That can aggregate number 9 with delta 1, * number 10 with delta 2, etc. This example is implemented as * a part of a testing module in test_objagg.c file. * * Each objagg instance contains multiple trees. Each tree node is * represented by "an object". In the current implementation there can be * only roots and leafs nodes. Leaf nodes are called deltas. * But in general, this can be easily extended for intermediate nodes. * In that extension, a delta would be associated with all non-root * nodes. * * Returns a pointer to newly created objagg instance in case of success, * otherwise it returns pointer error using ERR_PTR macro. */struct objagg *objagg_create(const struct objagg_ops *ops, void *priv){	struct objagg *objagg;	int err; 	if (WARN_ON(!ops || !ops->root_create || !ops->root_destroy ||		    !ops->delta_create || !ops->delta_destroy))		return ERR_PTR(-EINVAL);	objagg = kzalloc(sizeof(*objagg), GFP_KERNEL);	if (!objagg)		return ERR_PTR(-ENOMEM);	objagg->ops = ops;	objagg->priv = priv;	INIT_LIST_HEAD(&objagg->obj_list); 	objagg->ht_params.key_len = ops->obj_size;	objagg->ht_params.key_offset = offsetof(struct objagg_obj, obj);	objagg->ht_params.head_offset = offsetof(struct objagg_obj, ht_node); 	err = rhashtable_init(&objagg->obj_ht, &objagg->ht_params);	if (err)		goto err_rhashtable_init; 	trace_objagg_create(objagg);	return objagg; err_rhashtable_init:	kfree(objagg);	return ERR_PTR(err);}EXPORT_SYMBOL(objagg_create); /** * objagg_destroy - destroys a new objagg instance * @objagg:	objagg instance * * Note: all locking must be provided by the caller. */void objagg_destroy(struct objagg *objagg){	trace_objagg_destroy(objagg);	WARN_ON(!list_empty(&objagg->obj_list));	rhashtable_destroy(&objagg->obj_ht);	kfree(objagg);}EXPORT_SYMBOL(objagg_destroy); static int objagg_stats_info_sort_cmp_func(const void *a, const void *b){	const struct objagg_obj_stats_info *stats_info1 = a;	const struct objagg_obj_stats_info *stats_info2 = b; 	if (stats_info1->is_root != stats_info2->is_root)		return stats_info2->is_root - stats_info1->is_root;	if (stats_info1->stats.delta_user_count !=	    stats_info2->stats.delta_user_count)		return stats_info2->stats.delta_user_count -		       stats_info1->stats.delta_user_count;	return stats_info2->stats.user_count - stats_info1->stats.user_count;} /** * objagg_stats_get - obtains stats of the objagg instance * @objagg:	objagg instance * * Note: all locking must be provided by the caller. * * The returned structure contains statistics of all object * currently in use, ordered by following rules: * 1) Root objects are always on lower indexes than the rest. * 2) Objects with higher delta user count are always on lower *    indexes. * 3) In case more objects have the same delta user count, *    the objects are ordered by user count. * * Returns a pointer to stats instance in case of success, * otherwise it returns pointer error using ERR_PTR macro. */const struct objagg_stats *objagg_stats_get(struct objagg *objagg){	struct objagg_stats *objagg_stats;	struct objagg_obj *objagg_obj;	size_t alloc_size;	int i; 	alloc_size = sizeof(*objagg_stats) +		     sizeof(objagg_stats->stats_info[0]) * objagg->obj_count;	objagg_stats = kzalloc(alloc_size, GFP_KERNEL);	if (!objagg_stats)		return ERR_PTR(-ENOMEM); 	i = 0;	list_for_each_entry(objagg_obj, &objagg->obj_list, list) {		memcpy(&objagg_stats->stats_info[i].stats, &objagg_obj->stats,		       sizeof(objagg_stats->stats_info[0].stats));		objagg_stats->stats_info[i].objagg_obj = objagg_obj;		objagg_stats->stats_info[i].is_root =					objagg_obj_is_root(objagg_obj);		i++;	}	objagg_stats->stats_info_count = i; 	sort(objagg_stats->stats_info, objagg_stats->stats_info_count,	     sizeof(struct objagg_obj_stats_info),	     objagg_stats_info_sort_cmp_func, NULL); 	return objagg_stats;}EXPORT_SYMBOL(objagg_stats_get); /** * objagg_stats_puts - puts stats of the objagg instance * @objagg_stats:	objagg instance stats * * Note: all locking must be provided by the caller. */void objagg_stats_put(const struct objagg_stats *objagg_stats){	kfree(objagg_stats);}EXPORT_SYMBOL(objagg_stats_put); MODULE_LICENSE("Dual BSD/GPL");MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");

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