/* SPDX-License-Identifier: GPL-2.0 *//* * Statically sized hash table implementation * (C) 2012  Sasha Levin <levinsasha928@gmail.com> */ #ifndef _LINUX_HASHTABLE_H#define _LINUX_HASHTABLE_H #include <linux/list.h>#include <linux/types.h>#include <linux/kernel.h>#include <linux/bitops.h>#include <linux/hash.h>#include <linux/log2.h> #define DEFINE_HASHTABLE(name, bits)						\	struct hlist_head name[1 << (bits)] =					\			{ [0 ... ((1 << (bits)) - 1)] = HLIST_HEAD_INIT } #define DECLARE_HASHTABLE(name, bits)                                   	\	struct hlist_head name[1 << (bits)] #define HASH_SIZE(name) (ARRAY_SIZE(name))#define HASH_BITS(name) ilog2(HASH_SIZE(name)) /* Use hash_32 when possible to allow for fast 32bit hashing in 64bit kernels. */#define hash_min(val, bits)							\	(sizeof(val) <= 4 ? hash_32(val, bits) : hash_long(val, bits)) static inline void __hash_init(struct hlist_head *ht, unsigned int sz){	unsigned int i; 	for (i = 0; i < sz; i++)		INIT_HLIST_HEAD(&ht[i]);} /** * hash_init - initialize a hash table * @hashtable: hashtable to be initialized * * Calculates the size of the hashtable from the given parameter, otherwise * same as hash_init_size. * * This has to be a macro since HASH_BITS() will not work on pointers since * it calculates the size during preprocessing. */#define hash_init(hashtable) __hash_init(hashtable, HASH_SIZE(hashtable)) /** * hash_add - add an object to a hashtable * @hashtable: hashtable to add to * @node: the &struct hlist_node of the object to be added * @key: the key of the object to be added */#define hash_add(hashtable, node, key)						\	hlist_add_head(node, &hashtable[hash_min(key, HASH_BITS(hashtable))]) /** * hash_hashed - check whether an object is in any hashtable * @node: the &struct hlist_node of the object to be checked */static inline bool hash_hashed(struct hlist_node *node){	return !hlist_unhashed(node);} static inline bool __hash_empty(struct hlist_head *ht, unsigned int sz){	unsigned int i; 	for (i = 0; i < sz; i++)		if (!hlist_empty(&ht[i]))			return false; 	return true;} /** * hash_empty - check whether a hashtable is empty * @hashtable: hashtable to check * * This has to be a macro since HASH_BITS() will not work on pointers since * it calculates the size during preprocessing. */#define hash_empty(hashtable) __hash_empty(hashtable, HASH_SIZE(hashtable)) /** * hash_del - remove an object from a hashtable * @node: &struct hlist_node of the object to remove */static inline void hash_del(struct hlist_node *node){	hlist_del_init(node);} /** * hash_for_each - iterate over a hashtable * @name: hashtable to iterate * @bkt: integer to use as bucket loop cursor * @obj: the type * to use as a loop cursor for each entry * @member: the name of the hlist_node within the struct */#define hash_for_each(name, bkt, obj, member)				\	for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\			(bkt)++)\		hlist_for_each_entry(obj, &name[bkt], member) /** * hash_for_each_safe - iterate over a hashtable safe against removal of * hash entry * @name: hashtable to iterate * @bkt: integer to use as bucket loop cursor * @tmp: a &struct used for temporary storage * @obj: the type * to use as a loop cursor for each entry * @member: the name of the hlist_node within the struct */#define hash_for_each_safe(name, bkt, tmp, obj, member)			\	for ((bkt) = 0, obj = NULL; obj == NULL && (bkt) < HASH_SIZE(name);\			(bkt)++)\		hlist_for_each_entry_safe(obj, tmp, &name[bkt], member) /** * hash_for_each_possible - iterate over all possible objects hashing to the * same bucket * @name: hashtable to iterate * @obj: the type * to use as a loop cursor for each entry * @member: the name of the hlist_node within the struct * @key: the key of the objects to iterate over */#define hash_for_each_possible(name, obj, member, key)			\	hlist_for_each_entry(obj, &name[hash_min(key, HASH_BITS(name))], member) /** * hash_for_each_possible_safe - iterate over all possible objects hashing to the * same bucket safe against removals * @name: hashtable to iterate * @obj: the type * to use as a loop cursor for each entry * @tmp: a &struct used for temporary storage * @member: the name of the hlist_node within the struct * @key: the key of the objects to iterate over */#define hash_for_each_possible_safe(name, obj, tmp, member, key)	\	hlist_for_each_entry_safe(obj, tmp,\		&name[hash_min(key, HASH_BITS(name))], member)  #endif