// 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/idr.h>
#include <linux/list.h>
#include <linux/sort.h>
#include <linux/objagg.h>
#define CREATE_TRACE_POINTS
#include <trace/events/objagg.h>
struct objagg_hints {
struct rhashtable node_ht;
struct rhashtable_params ht_params;
struct list_head node_list;
unsigned int node_count;
unsigned int root_count;
unsigned int refcount;
const struct objagg_ops *ops;
};
struct objagg_hints_node {
struct rhash_head ht_node; /* member of objagg_hints->node_ht */
struct list_head list; /* member of objagg_hints->node_list */
struct objagg_hints_node *parent;
unsigned int root_id;
struct objagg_obj_stats_info stats_info;
unsigned long obj[];
};
static struct objagg_hints_node *
objagg_hints_lookup(struct objagg_hints *objagg_hints, void *obj)
{
if (!objagg_hints)
return NULL;
return rhashtable_lookup_fast(&objagg_hints->node_ht, obj,
objagg_hints->ht_params);
}
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 ida root_ida;
struct objagg_hints *hints;
};
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 root_id;
unsigned int refcount; /* counts number of users of this object
* including nested objects
*/
struct objagg_obj_stats stats;
unsigned long obj[];
};
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,
bool take_parent_ref)
{
void *delta_priv;
if (WARN_ON(!objagg_obj_is_root(parent)))
return -EINVAL;
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;
if (take_parent_ref)
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, true);
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_id_alloc(struct objagg *objagg,
struct objagg_obj *objagg_obj,
struct objagg_hints_node *hnode)
{
unsigned int min, max;
int root_id;
/* In case there are no hints available, the root id is invalid. */
if (!objagg->hints) {
objagg_obj->root_id = OBJAGG_OBJ_ROOT_ID_INVALID;
return 0;
}
if (hnode) {
min = hnode->root_id;
max = hnode->root_id;
} else {
/* For objects with no hint, start after the last
* hinted root_id.
*/
min = objagg->hints->root_count;
max = ~0;
}
root_id = ida_alloc_range(&objagg->root_ida, min, max, GFP_KERNEL);
if (root_id < 0)
return root_id;
objagg_obj->root_id = root_id;
return 0;
}
static void objagg_obj_root_id_free(struct objagg *objagg,
struct objagg_obj *objagg_obj)
{
if (!objagg->hints)
return;
ida_free(&objagg->root_ida, objagg_obj->root_id);
}
static int objagg_obj_root_create(struct objagg *objagg,
struct objagg_obj *objagg_obj,
struct objagg_hints_node *hnode)
{
int err;
err = objagg_obj_root_id_alloc(objagg, objagg_obj, hnode);
if (err)
return err;
objagg_obj->root_priv = objagg->ops->root_create(objagg->priv,
objagg_obj->obj,
objagg_obj->root_id);
if (IS_ERR(objagg_obj->root_priv)) {
err = PTR_ERR(objagg_obj->root_priv);
goto err_root_create;
}
trace_objagg_obj_root_create(objagg, objagg_obj);
return 0;
err_root_create:
objagg_obj_root_id_free(objagg, objagg_obj);
return err;
}
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);
objagg_obj_root_id_free(objagg, objagg_obj);
}
static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj);
static int objagg_obj_init_with_hints(struct objagg *objagg,
struct objagg_obj *objagg_obj,
bool *hint_found)
{
struct objagg_hints_node *hnode;
struct objagg_obj *parent;
int err;
hnode = objagg_hints_lookup(objagg->hints, objagg_obj->obj);
if (!hnode) {
*hint_found = false;
return 0;
}
*hint_found = true;
if (!hnode->parent)
return objagg_obj_root_create(objagg, objagg_obj, hnode);
parent = __objagg_obj_get(objagg, hnode->parent->obj);
if (IS_ERR(parent))
return PTR_ERR(parent);
err = objagg_obj_parent_assign(objagg, objagg_obj, parent, false);
if (err) {
*hint_found = false;
err = 0;
goto err_parent_assign;
}
return 0;
err_parent_assign:
objagg_obj_put(objagg, parent);
return err;
}
static int objagg_obj_init(struct objagg *objagg,
struct objagg_obj *objagg_obj)
{
bool hint_found;
int err;
/* First, try to use hints if they are available and
* if they provide result.
*/
err = objagg_obj_init_with_hints(objagg, objagg_obj, &hint_found);
if (err)
return err;
if (hint_found)
return 0;
/* 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, NULL);
}
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 incremented 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
* @objagg_hints: hints, can be NULL
* @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,
struct objagg_hints *objagg_hints, void *priv)
{
struct objagg *objagg;
int err;
if (WARN_ON(!ops || !ops->root_create || !ops->root_destroy ||
!ops->delta_check || !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;
if (objagg_hints) {
objagg->hints = objagg_hints;
objagg_hints->refcount++;
}
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;
ida_init(&objagg->root_ida);
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);
ida_destroy(&objagg->root_ida);
WARN_ON(!list_empty(&objagg->obj_list));
rhashtable_destroy(&objagg->obj_ht);
if (objagg->hints)
objagg_hints_put(objagg->hints);
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;
int i;
objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
objagg->obj_count), 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);
if (objagg_stats->stats_info[i].is_root)
objagg_stats->root_count++;
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_put - 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);
static struct objagg_hints_node *
objagg_hints_node_create(struct objagg_hints *objagg_hints,
struct objagg_obj *objagg_obj, size_t obj_size,
struct objagg_hints_node *parent_hnode)
{
unsigned int user_count = objagg_obj->stats.user_count;
struct objagg_hints_node *hnode;
int err;
hnode = kzalloc(sizeof(*hnode) + obj_size, GFP_KERNEL);
if (!hnode)
return ERR_PTR(-ENOMEM);
memcpy(hnode->obj, &objagg_obj->obj, obj_size);
hnode->stats_info.stats.user_count = user_count;
hnode->stats_info.stats.delta_user_count = user_count;
if (parent_hnode) {
parent_hnode->stats_info.stats.delta_user_count += user_count;
} else {
hnode->root_id = objagg_hints->root_count++;
hnode->stats_info.is_root = true;
}
hnode->stats_info.objagg_obj = objagg_obj;
err = rhashtable_insert_fast(&objagg_hints->node_ht, &hnode->ht_node,
objagg_hints->ht_params);
if (err)
goto err_ht_insert;
list_add(&hnode->list, &objagg_hints->node_list);
hnode->parent = parent_hnode;
objagg_hints->node_count++;
return hnode;
err_ht_insert:
kfree(hnode);
return ERR_PTR(err);
}
static void objagg_hints_flush(struct objagg_hints *objagg_hints)
{
struct objagg_hints_node *hnode, *tmp;
list_for_each_entry_safe(hnode, tmp, &objagg_hints->node_list, list) {
list_del(&hnode->list);
rhashtable_remove_fast(&objagg_hints->node_ht, &hnode->ht_node,
objagg_hints->ht_params);
kfree(hnode);
}
}
struct objagg_tmp_node {
struct objagg_obj *objagg_obj;
bool crossed_out;
};
struct objagg_tmp_graph {
struct objagg_tmp_node *nodes;
unsigned long nodes_count;
unsigned long *edges;
};
static int objagg_tmp_graph_edge_index(struct objagg_tmp_graph *graph,
int parent_index, int index)
{
return index * graph->nodes_count + parent_index;
}
static void objagg_tmp_graph_edge_set(struct objagg_tmp_graph *graph,
int parent_index, int index)
{
int edge_index = objagg_tmp_graph_edge_index(graph, index,
parent_index);
__set_bit(edge_index, graph->edges);
}
static bool objagg_tmp_graph_is_edge(struct objagg_tmp_graph *graph,
int parent_index, int index)
{
int edge_index = objagg_tmp_graph_edge_index(graph, index,
parent_index);
return test_bit(edge_index, graph->edges);
}
static unsigned int objagg_tmp_graph_node_weight(struct objagg_tmp_graph *graph,
unsigned int index)
{
struct objagg_tmp_node *node = &graph->nodes[index];
unsigned int weight = node->objagg_obj->stats.user_count;
int j;
/* Node weight is sum of node users and all other nodes users
* that this node can represent with delta.
*/
for (j = 0; j < graph->nodes_count; j++) {
if (!objagg_tmp_graph_is_edge(graph, index, j))
continue;
node = &graph->nodes[j];
if (node->crossed_out)
continue;
weight += node->objagg_obj->stats.user_count;
}
return weight;
}
static int objagg_tmp_graph_node_max_weight(struct objagg_tmp_graph *graph)
{
struct objagg_tmp_node *node;
unsigned int max_weight = 0;
unsigned int weight;
int max_index = -1;
int i;
for (i = 0; i < graph->nodes_count; i++) {
node = &graph->nodes[i];
if (node->crossed_out)
continue;
weight = objagg_tmp_graph_node_weight(graph, i);
if (weight >= max_weight) {
max_weight = weight;
max_index = i;
}
}
return max_index;
}
static struct objagg_tmp_graph *objagg_tmp_graph_create(struct objagg *objagg)
{
unsigned int nodes_count = objagg->obj_count;
struct objagg_tmp_graph *graph;
struct objagg_tmp_node *node;
struct objagg_tmp_node *pnode;
struct objagg_obj *objagg_obj;
int i, j;
graph = kzalloc(sizeof(*graph), GFP_KERNEL);
if (!graph)
return NULL;
graph->nodes = kcalloc(nodes_count, sizeof(*graph->nodes), GFP_KERNEL);
if (!graph->nodes)
goto err_nodes_alloc;
graph->nodes_count = nodes_count;
graph->edges = bitmap_zalloc(nodes_count * nodes_count, GFP_KERNEL);
if (!graph->edges)
goto err_edges_alloc;
i = 0;
list_for_each_entry(objagg_obj, &objagg->obj_list, list) {
node = &graph->nodes[i++];
node->objagg_obj = objagg_obj;
}
/* Assemble a temporary graph. Insert edge X->Y in case Y can be
* in delta of X.
*/
for (i = 0; i < nodes_count; i++) {
for (j = 0; j < nodes_count; j++) {
if (i == j)
continue;
pnode = &graph->nodes[i];
node = &graph->nodes[j];
if (objagg->ops->delta_check(objagg->priv,
pnode->objagg_obj->obj,
node->objagg_obj->obj)) {
objagg_tmp_graph_edge_set(graph, i, j);
}
}
}
return graph;
err_edges_alloc:
kfree(graph->nodes);
err_nodes_alloc:
kfree(graph);
return NULL;
}
static void objagg_tmp_graph_destroy(struct objagg_tmp_graph *graph)
{
bitmap_free(graph->edges);
kfree(graph->nodes);
kfree(graph);
}
static int
objagg_opt_simple_greedy_fillup_hints(struct objagg_hints *objagg_hints,
struct objagg *objagg)
{
struct objagg_hints_node *hnode, *parent_hnode;
struct objagg_tmp_graph *graph;
struct objagg_tmp_node *node;
int index;
int j;
int err;
graph = objagg_tmp_graph_create(objagg);
if (!graph)
return -ENOMEM;
/* Find the nodes from the ones that can accommodate most users
* and cross them out of the graph. Save them to the hint list.
*/
while ((index = objagg_tmp_graph_node_max_weight(graph)) != -1) {
node = &graph->nodes[index];
node->crossed_out = true;
hnode = objagg_hints_node_create(objagg_hints,
node->objagg_obj,
objagg->ops->obj_size,
NULL);
if (IS_ERR(hnode)) {
err = PTR_ERR(hnode);
goto out;
}
parent_hnode = hnode;
for (j = 0; j < graph->nodes_count; j++) {
if (!objagg_tmp_graph_is_edge(graph, index, j))
continue;
node = &graph->nodes[j];
if (node->crossed_out)
continue;
node->crossed_out = true;
hnode = objagg_hints_node_create(objagg_hints,
node->objagg_obj,
objagg->ops->obj_size,
parent_hnode);
if (IS_ERR(hnode)) {
err = PTR_ERR(hnode);
goto out;
}
}
}
err = 0;
out:
objagg_tmp_graph_destroy(graph);
return err;
}
struct objagg_opt_algo {
int (*fillup_hints)(struct objagg_hints *objagg_hints,
struct objagg *objagg);
};
static const struct objagg_opt_algo objagg_opt_simple_greedy = {
.fillup_hints = objagg_opt_simple_greedy_fillup_hints,
};
static const struct objagg_opt_algo *objagg_opt_algos[] = {
[OBJAGG_OPT_ALGO_SIMPLE_GREEDY] = &objagg_opt_simple_greedy,
};
/**
* objagg_hints_get - obtains hints instance
* @objagg: objagg instance
* @opt_algo_type: type of hints finding algorithm
*
* Note: all locking must be provided by the caller.
*
* According to the algo type, the existing objects of objagg instance
* are going to be went-through to assemble an optimal tree. We call this
* tree hints. These hints can be later on used for creation of
* a new objagg instance. There, the future object creations are going
* to be consulted with these hints in order to find out, where exactly
* the new object should be put as a root or delta.
*
* Returns a pointer to hints instance in case of success,
* otherwise it returns pointer error using ERR_PTR macro.
*/
struct objagg_hints *objagg_hints_get(struct objagg *objagg,
enum objagg_opt_algo_type opt_algo_type)
{
const struct objagg_opt_algo *algo = objagg_opt_algos[opt_algo_type];
struct objagg_hints *objagg_hints;
int err;
objagg_hints = kzalloc(sizeof(*objagg_hints), GFP_KERNEL);
if (!objagg_hints)
return ERR_PTR(-ENOMEM);
objagg_hints->ops = objagg->ops;
objagg_hints->refcount = 1;
INIT_LIST_HEAD(&objagg_hints->node_list);
objagg_hints->ht_params.key_len = objagg->ops->obj_size;
objagg_hints->ht_params.key_offset =
offsetof(struct objagg_hints_node, obj);
objagg_hints->ht_params.head_offset =
offsetof(struct objagg_hints_node, ht_node);
err = rhashtable_init(&objagg_hints->node_ht, &objagg_hints->ht_params);
if (err)
goto err_rhashtable_init;
err = algo->fillup_hints(objagg_hints, objagg);
if (err)
goto err_fillup_hints;
if (WARN_ON(objagg_hints->node_count != objagg->obj_count)) {
err = -EINVAL;
goto err_node_count_check;
}
return objagg_hints;
err_node_count_check:
err_fillup_hints:
objagg_hints_flush(objagg_hints);
rhashtable_destroy(&objagg_hints->node_ht);
err_rhashtable_init:
kfree(objagg_hints);
return ERR_PTR(err);
}
EXPORT_SYMBOL(objagg_hints_get);
/**
* objagg_hints_put - puts hints instance
* @objagg_hints: objagg hints instance
*
* Note: all locking must be provided by the caller.
*/
void objagg_hints_put(struct objagg_hints *objagg_hints)
{
if (--objagg_hints->refcount)
return;
objagg_hints_flush(objagg_hints);
rhashtable_destroy(&objagg_hints->node_ht);
kfree(objagg_hints);
}
EXPORT_SYMBOL(objagg_hints_put);
/**
* objagg_hints_stats_get - obtains stats of the hints instance
* @objagg_hints: hints instance
*
* Note: all locking must be provided by the caller.
*
* The returned structure contains statistics of all objects
* 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 multiple 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_hints_stats_get(struct objagg_hints *objagg_hints)
{
struct objagg_stats *objagg_stats;
struct objagg_hints_node *hnode;
int i;
objagg_stats = kzalloc(struct_size(objagg_stats, stats_info,
objagg_hints->node_count),
GFP_KERNEL);
if (!objagg_stats)
return ERR_PTR(-ENOMEM);
i = 0;
list_for_each_entry(hnode, &objagg_hints->node_list, list) {
memcpy(&objagg_stats->stats_info[i], &hnode->stats_info,
sizeof(objagg_stats->stats_info[0]));
if (objagg_stats->stats_info[i].is_root)
objagg_stats->root_count++;
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_hints_stats_get);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Jiri Pirko <[email protected]>");
MODULE_DESCRIPTION("Object aggregation manager");
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