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https://github.com/edk2-porting/linux-next.git
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0a020d416d
This lib tracks objects which could be of two types: 1) root object 2) nested object - with a "delta" which differentiates it from the associated root object The objects are tracked by a hashtable and reference-counted. User is responsible of implementing callbacks to create/destroy root entity related to each root object and callback to create/destroy nested object delta. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
502 lines
14 KiB
C
502 lines
14 KiB
C
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
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/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/rhashtable.h>
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#include <linux/list.h>
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#include <linux/sort.h>
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#include <linux/objagg.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/objagg.h>
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struct objagg {
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const struct objagg_ops *ops;
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void *priv;
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struct rhashtable obj_ht;
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struct rhashtable_params ht_params;
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struct list_head obj_list;
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unsigned int obj_count;
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};
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struct objagg_obj {
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struct rhash_head ht_node; /* member of objagg->obj_ht */
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struct list_head list; /* member of objagg->obj_list */
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struct objagg_obj *parent; /* if the object is nested, this
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* holds pointer to parent, otherwise NULL
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*/
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union {
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void *delta_priv; /* user delta private */
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void *root_priv; /* user root private */
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};
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unsigned int refcount; /* counts number of users of this object
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* including nested objects
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*/
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struct objagg_obj_stats stats;
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unsigned long obj[0];
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};
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static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj)
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{
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return ++objagg_obj->refcount;
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}
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static unsigned int objagg_obj_ref_dec(struct objagg_obj *objagg_obj)
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{
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return --objagg_obj->refcount;
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}
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static void objagg_obj_stats_inc(struct objagg_obj *objagg_obj)
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{
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objagg_obj->stats.user_count++;
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objagg_obj->stats.delta_user_count++;
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if (objagg_obj->parent)
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objagg_obj->parent->stats.delta_user_count++;
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}
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static void objagg_obj_stats_dec(struct objagg_obj *objagg_obj)
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{
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objagg_obj->stats.user_count--;
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objagg_obj->stats.delta_user_count--;
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if (objagg_obj->parent)
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objagg_obj->parent->stats.delta_user_count--;
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}
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static bool objagg_obj_is_root(const struct objagg_obj *objagg_obj)
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{
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/* Nesting is not supported, so we can use ->parent
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* to figure out if the object is root.
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*/
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return !objagg_obj->parent;
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}
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/**
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* objagg_obj_root_priv - obtains root private for an object
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* @objagg_obj: objagg object instance
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*
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* Note: all locking must be provided by the caller.
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*
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* Either the object is root itself when the private is returned
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* directly, or the parent is root and its private is returned
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* instead.
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*
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* Returns a user private root pointer.
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*/
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const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj)
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{
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if (objagg_obj_is_root(objagg_obj))
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return objagg_obj->root_priv;
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WARN_ON(!objagg_obj_is_root(objagg_obj->parent));
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return objagg_obj->parent->root_priv;
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}
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EXPORT_SYMBOL(objagg_obj_root_priv);
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/**
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* objagg_obj_delta_priv - obtains delta private for an object
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* @objagg_obj: objagg object instance
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*
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* Note: all locking must be provided by the caller.
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*
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* Returns user private delta pointer or NULL in case the passed
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* object is root.
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*/
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const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj)
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{
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if (objagg_obj_is_root(objagg_obj))
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return NULL;
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return objagg_obj->delta_priv;
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}
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EXPORT_SYMBOL(objagg_obj_delta_priv);
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/**
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* objagg_obj_raw - obtains object user private pointer
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* @objagg_obj: objagg object instance
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*
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* Note: all locking must be provided by the caller.
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*
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* Returns user private pointer as was passed to objagg_obj_get() by "obj" arg.
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*/
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const void *objagg_obj_raw(const struct objagg_obj *objagg_obj)
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{
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return objagg_obj->obj;
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}
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EXPORT_SYMBOL(objagg_obj_raw);
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static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj)
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{
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return rhashtable_lookup_fast(&objagg->obj_ht, obj, objagg->ht_params);
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}
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static int objagg_obj_parent_assign(struct objagg *objagg,
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struct objagg_obj *objagg_obj,
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struct objagg_obj *parent)
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{
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void *delta_priv;
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delta_priv = objagg->ops->delta_create(objagg->priv, parent->obj,
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objagg_obj->obj);
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if (IS_ERR(delta_priv))
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return PTR_ERR(delta_priv);
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/* User returned a delta private, that means that
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* our object can be aggregated into the parent.
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*/
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objagg_obj->parent = parent;
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objagg_obj->delta_priv = delta_priv;
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objagg_obj_ref_inc(objagg_obj->parent);
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trace_objagg_obj_parent_assign(objagg, objagg_obj,
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parent,
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parent->refcount);
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return 0;
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}
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static int objagg_obj_parent_lookup_assign(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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struct objagg_obj *objagg_obj_cur;
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int err;
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list_for_each_entry(objagg_obj_cur, &objagg->obj_list, list) {
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/* Nesting is not supported. In case the object
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* is not root, it cannot be assigned as parent.
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*/
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if (!objagg_obj_is_root(objagg_obj_cur))
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continue;
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err = objagg_obj_parent_assign(objagg, objagg_obj,
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objagg_obj_cur);
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if (!err)
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return 0;
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}
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return -ENOENT;
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}
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static void __objagg_obj_put(struct objagg *objagg,
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struct objagg_obj *objagg_obj);
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static void objagg_obj_parent_unassign(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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trace_objagg_obj_parent_unassign(objagg, objagg_obj,
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objagg_obj->parent,
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objagg_obj->parent->refcount);
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objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv);
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__objagg_obj_put(objagg, objagg_obj->parent);
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}
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static int objagg_obj_root_create(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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objagg_obj->root_priv = objagg->ops->root_create(objagg->priv,
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objagg_obj->obj);
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if (IS_ERR(objagg_obj->root_priv))
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return PTR_ERR(objagg_obj->root_priv);
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trace_objagg_obj_root_create(objagg, objagg_obj);
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return 0;
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}
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static void objagg_obj_root_destroy(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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trace_objagg_obj_root_destroy(objagg, objagg_obj);
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objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv);
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}
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static int objagg_obj_init(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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int err;
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/* Try to find if the object can be aggregated under an existing one. */
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err = objagg_obj_parent_lookup_assign(objagg, objagg_obj);
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if (!err)
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return 0;
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/* If aggregation is not possible, make the object a root. */
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return objagg_obj_root_create(objagg, objagg_obj);
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}
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static void objagg_obj_fini(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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if (!objagg_obj_is_root(objagg_obj))
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objagg_obj_parent_unassign(objagg, objagg_obj);
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else
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objagg_obj_root_destroy(objagg, objagg_obj);
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}
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static struct objagg_obj *objagg_obj_create(struct objagg *objagg, void *obj)
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{
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struct objagg_obj *objagg_obj;
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int err;
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objagg_obj = kzalloc(sizeof(*objagg_obj) + objagg->ops->obj_size,
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GFP_KERNEL);
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if (!objagg_obj)
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return ERR_PTR(-ENOMEM);
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objagg_obj_ref_inc(objagg_obj);
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memcpy(objagg_obj->obj, obj, objagg->ops->obj_size);
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err = objagg_obj_init(objagg, objagg_obj);
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if (err)
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goto err_obj_init;
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err = rhashtable_insert_fast(&objagg->obj_ht, &objagg_obj->ht_node,
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objagg->ht_params);
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if (err)
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goto err_ht_insert;
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list_add(&objagg_obj->list, &objagg->obj_list);
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objagg->obj_count++;
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trace_objagg_obj_create(objagg, objagg_obj);
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return objagg_obj;
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err_ht_insert:
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objagg_obj_fini(objagg, objagg_obj);
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err_obj_init:
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kfree(objagg_obj);
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return ERR_PTR(err);
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}
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static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj)
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{
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struct objagg_obj *objagg_obj;
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/* First, try to find the object exactly as user passed it,
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* perhaps it is already in use.
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*/
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objagg_obj = objagg_obj_lookup(objagg, obj);
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if (objagg_obj) {
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objagg_obj_ref_inc(objagg_obj);
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return objagg_obj;
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}
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return objagg_obj_create(objagg, obj);
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}
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/**
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* objagg_obj_get - gets an object within objagg instance
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* @objagg: objagg instance
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* @obj: user-specific private object pointer
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*
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* Note: all locking must be provided by the caller.
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*
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* Size of the "obj" memory is specified in "objagg->ops".
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*
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* There are 3 main options this function wraps:
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* 1) The object according to "obj" already exist. In that case
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* the reference counter is incrementes and the object is returned.
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* 2) The object does not exist, but it can be aggregated within
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* another object. In that case, user ops->delta_create() is called
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* to obtain delta data and a new object is created with returned
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* user-delta private pointer.
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* 3) The object does not exist and cannot be aggregated into
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* any of the existing objects. In that case, user ops->root_create()
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* is called to create the root and a new object is created with
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* returned user-root private pointer.
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*
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* Returns a pointer to objagg object instance in case of success,
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* otherwise it returns pointer error using ERR_PTR macro.
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*/
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struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj)
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{
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struct objagg_obj *objagg_obj;
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objagg_obj = __objagg_obj_get(objagg, obj);
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if (IS_ERR(objagg_obj))
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return objagg_obj;
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objagg_obj_stats_inc(objagg_obj);
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trace_objagg_obj_get(objagg, objagg_obj, objagg_obj->refcount);
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return objagg_obj;
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}
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EXPORT_SYMBOL(objagg_obj_get);
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static void objagg_obj_destroy(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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trace_objagg_obj_destroy(objagg, objagg_obj);
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--objagg->obj_count;
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list_del(&objagg_obj->list);
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rhashtable_remove_fast(&objagg->obj_ht, &objagg_obj->ht_node,
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objagg->ht_params);
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objagg_obj_fini(objagg, objagg_obj);
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kfree(objagg_obj);
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}
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static void __objagg_obj_put(struct objagg *objagg,
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struct objagg_obj *objagg_obj)
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{
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if (!objagg_obj_ref_dec(objagg_obj))
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objagg_obj_destroy(objagg, objagg_obj);
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}
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/**
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* objagg_obj_put - puts an object within objagg instance
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* @objagg: objagg instance
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* @objagg_obj: objagg object instance
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*
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* Note: all locking must be provided by the caller.
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*
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* Symmetric to objagg_obj_get().
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*/
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void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj)
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{
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trace_objagg_obj_put(objagg, objagg_obj, objagg_obj->refcount);
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objagg_obj_stats_dec(objagg_obj);
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__objagg_obj_put(objagg, objagg_obj);
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}
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EXPORT_SYMBOL(objagg_obj_put);
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/**
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* objagg_create - creates a new objagg instance
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* @ops: user-specific callbacks
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* @priv: pointer to a private data passed to the ops
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*
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* Note: all locking must be provided by the caller.
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*
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* The purpose of the library is to provide an infrastructure to
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* aggregate user-specified objects. Library does not care about the type
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* of the object. User fills-up ops which take care of the specific
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* user object manipulation.
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*
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* As a very stupid example, consider integer numbers. For example
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* number 8 as a root object. That can aggregate number 9 with delta 1,
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* number 10 with delta 2, etc. This example is implemented as
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* a part of a testing module in test_objagg.c file.
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*
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* Each objagg instance contains multiple trees. Each tree node is
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* represented by "an object". In the current implementation there can be
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* only roots and leafs nodes. Leaf nodes are called deltas.
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* But in general, this can be easily extended for intermediate nodes.
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* In that extension, a delta would be associated with all non-root
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* nodes.
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*
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* Returns a pointer to newly created objagg instance in case of success,
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* otherwise it returns pointer error using ERR_PTR macro.
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*/
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struct objagg *objagg_create(const struct objagg_ops *ops, void *priv)
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{
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struct objagg *objagg;
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int err;
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if (WARN_ON(!ops || !ops->root_create || !ops->root_destroy ||
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!ops->delta_create || !ops->delta_destroy))
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return ERR_PTR(-EINVAL);
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objagg = kzalloc(sizeof(*objagg), GFP_KERNEL);
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if (!objagg)
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return ERR_PTR(-ENOMEM);
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objagg->ops = ops;
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objagg->priv = priv;
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INIT_LIST_HEAD(&objagg->obj_list);
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objagg->ht_params.key_len = ops->obj_size;
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objagg->ht_params.key_offset = offsetof(struct objagg_obj, obj);
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objagg->ht_params.head_offset = offsetof(struct objagg_obj, ht_node);
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err = rhashtable_init(&objagg->obj_ht, &objagg->ht_params);
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if (err)
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goto err_rhashtable_init;
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trace_objagg_create(objagg);
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return objagg;
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err_rhashtable_init:
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kfree(objagg);
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return ERR_PTR(err);
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}
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EXPORT_SYMBOL(objagg_create);
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/**
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* objagg_destroy - destroys a new objagg instance
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* @objagg: objagg instance
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*
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* Note: all locking must be provided by the caller.
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*/
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void objagg_destroy(struct objagg *objagg)
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{
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trace_objagg_destroy(objagg);
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WARN_ON(!list_empty(&objagg->obj_list));
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rhashtable_destroy(&objagg->obj_ht);
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kfree(objagg);
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}
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EXPORT_SYMBOL(objagg_destroy);
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static int objagg_stats_info_sort_cmp_func(const void *a, const void *b)
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{
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const struct objagg_obj_stats_info *stats_info1 = a;
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const struct objagg_obj_stats_info *stats_info2 = b;
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if (stats_info1->is_root != stats_info2->is_root)
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return stats_info2->is_root - stats_info1->is_root;
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if (stats_info1->stats.delta_user_count !=
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stats_info2->stats.delta_user_count)
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return stats_info2->stats.delta_user_count -
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stats_info1->stats.delta_user_count;
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return stats_info2->stats.user_count - stats_info1->stats.user_count;
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}
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/**
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* objagg_stats_get - obtains stats of the objagg instance
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* @objagg: objagg instance
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*
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* Note: all locking must be provided by the caller.
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*
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* The returned structure contains statistics of all object
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* currently in use, ordered by following rules:
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* 1) Root objects are always on lower indexes than the rest.
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* 2) Objects with higher delta user count are always on lower
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* indexes.
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* 3) In case more objects have the same delta user count,
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* the objects are ordered by user count.
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*
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* Returns a pointer to stats instance in case of success,
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* otherwise it returns pointer error using ERR_PTR macro.
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*/
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const struct objagg_stats *objagg_stats_get(struct objagg *objagg)
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{
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struct objagg_stats *objagg_stats;
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struct objagg_obj *objagg_obj;
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size_t alloc_size;
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int i;
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alloc_size = sizeof(*objagg_stats) +
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sizeof(objagg_stats->stats_info[0]) * objagg->obj_count;
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objagg_stats = kzalloc(alloc_size, GFP_KERNEL);
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if (!objagg_stats)
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return ERR_PTR(-ENOMEM);
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i = 0;
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list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
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memcpy(&objagg_stats->stats_info[i].stats, &objagg_obj->stats,
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sizeof(objagg_stats->stats_info[0].stats));
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objagg_stats->stats_info[i].objagg_obj = objagg_obj;
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objagg_stats->stats_info[i].is_root =
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objagg_obj_is_root(objagg_obj);
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i++;
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}
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objagg_stats->stats_info_count = i;
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sort(objagg_stats->stats_info, objagg_stats->stats_info_count,
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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>");
|
|
MODULE_DESCRIPTION("Object aggregation manager");
|