| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Resizable, Scalable, Concurrent Hash Table |
| * |
| * Simple structures that might be needed in include |
| * files. |
| */ |
| |
| #ifndef _LINUX_RHASHTABLE_TYPES_H |
| #define _LINUX_RHASHTABLE_TYPES_H |
| |
| #include <linux/atomic.h> |
| #include <linux/compiler.h> |
| #include <linux/mutex.h> |
| #include <linux/workqueue.h> |
| |
| struct rhash_head { |
| struct rhash_head __rcu *next; |
| }; |
| |
| struct rhlist_head { |
| struct rhash_head rhead; |
| struct rhlist_head __rcu *next; |
| }; |
| |
| struct bucket_table; |
| |
| /** |
| * struct rhashtable_compare_arg - Key for the function rhashtable_compare |
| * @ht: Hash table |
| * @key: Key to compare against |
| */ |
| struct rhashtable_compare_arg { |
| struct rhashtable *ht; |
| const void *key; |
| }; |
| |
| typedef u32 (*rht_hashfn_t)(const void *data, u32 len, u32 seed); |
| typedef u32 (*rht_obj_hashfn_t)(const void *data, u32 len, u32 seed); |
| typedef int (*rht_obj_cmpfn_t)(struct rhashtable_compare_arg *arg, |
| const void *obj); |
| |
| /** |
| * struct rhashtable_params - Hash table construction parameters |
| * @nelem_hint: Hint on number of elements, should be 75% of desired size |
| * @key_len: Length of key |
| * @key_offset: Offset of key in struct to be hashed |
| * @head_offset: Offset of rhash_head in struct to be hashed |
| * @max_size: Maximum size while expanding |
| * @min_size: Minimum size while shrinking |
| * @automatic_shrinking: Enable automatic shrinking of tables |
| * @hashfn: Hash function (default: jhash2 if !(key_len % 4), or jhash) |
| * @obj_hashfn: Function to hash object |
| * @obj_cmpfn: Function to compare key with object |
| */ |
| struct rhashtable_params { |
| u16 nelem_hint; |
| u16 key_len; |
| u16 key_offset; |
| u16 head_offset; |
| unsigned int max_size; |
| u16 min_size; |
| bool automatic_shrinking; |
| rht_hashfn_t hashfn; |
| rht_obj_hashfn_t obj_hashfn; |
| rht_obj_cmpfn_t obj_cmpfn; |
| }; |
| |
| /** |
| * struct rhashtable - Hash table handle |
| * @tbl: Bucket table |
| * @key_len: Key length for hashfn |
| * @max_elems: Maximum number of elements in table |
| * @p: Configuration parameters |
| * @rhlist: True if this is an rhltable |
| * @run_work: Deferred worker to expand/shrink asynchronously |
| * @mutex: Mutex to protect current/future table swapping |
| * @lock: Spin lock to protect walker list |
| * @nelems: Number of elements in table |
| */ |
| struct rhashtable { |
| struct bucket_table __rcu *tbl; |
| unsigned int key_len; |
| unsigned int max_elems; |
| struct rhashtable_params p; |
| bool rhlist; |
| struct work_struct run_work; |
| struct mutex mutex; |
| spinlock_t lock; |
| atomic_t nelems; |
| }; |
| |
| /** |
| * struct rhltable - Hash table with duplicate objects in a list |
| * @ht: Underlying rhtable |
| */ |
| struct rhltable { |
| struct rhashtable ht; |
| }; |
| |
| /** |
| * struct rhashtable_walker - Hash table walker |
| * @list: List entry on list of walkers |
| * @tbl: The table that we were walking over |
| */ |
| struct rhashtable_walker { |
| struct list_head list; |
| struct bucket_table *tbl; |
| }; |
| |
| /** |
| * struct rhashtable_iter - Hash table iterator |
| * @ht: Table to iterate through |
| * @p: Current pointer |
| * @list: Current hash list pointer |
| * @walker: Associated rhashtable walker |
| * @slot: Current slot |
| * @skip: Number of entries to skip in slot |
| */ |
| struct rhashtable_iter { |
| struct rhashtable *ht; |
| struct rhash_head *p; |
| struct rhlist_head *list; |
| struct rhashtable_walker walker; |
| unsigned int slot; |
| unsigned int skip; |
| bool end_of_table; |
| }; |
| |
| int rhashtable_init(struct rhashtable *ht, |
| const struct rhashtable_params *params); |
| int rhltable_init(struct rhltable *hlt, |
| const struct rhashtable_params *params); |
| |
| #endif /* _LINUX_RHASHTABLE_TYPES_H */ |