diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/list_nulls.h | 3 | ||||
| -rw-r--r-- | include/linux/rhashtable.h | 57 |
2 files changed, 49 insertions, 11 deletions
diff --git a/include/linux/list_nulls.h b/include/linux/list_nulls.h index 5d10ae364b5e..e8c300e06438 100644 --- a/include/linux/list_nulls.h +++ b/include/linux/list_nulls.h @@ -21,8 +21,9 @@ struct hlist_nulls_head { struct hlist_nulls_node { struct hlist_nulls_node *next, **pprev; }; +#define NULLS_MARKER(value) (1UL | (((long)value) << 1)) #define INIT_HLIST_NULLS_HEAD(ptr, nulls) \ - ((ptr)->first = (struct hlist_nulls_node *) (1UL | (((long)nulls) << 1))) + ((ptr)->first = (struct hlist_nulls_node *) NULLS_MARKER(nulls)) #define hlist_nulls_entry(ptr, type, member) container_of(ptr,type,member) /** diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index a1688f0a6193..de7cac753b09 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -18,15 +18,32 @@ #ifndef _LINUX_RHASHTABLE_H #define _LINUX_RHASHTABLE_H -#include <linux/rculist.h> +#include <linux/list_nulls.h> #include <linux/workqueue.h> +/* + * The end of the chain is marked with a special nulls marks which has + * the following format: + * + * +-------+-----------------------------------------------------+-+ + * | Base | Hash |1| + * +-------+-----------------------------------------------------+-+ + * + * Base (4 bits) : Reserved to distinguish between multiple tables. + * Specified via &struct rhashtable_params.nulls_base. + * Hash (27 bits): Full hash (unmasked) of first element added to bucket + * 1 (1 bit) : Nulls marker (always set) + * + * The remaining bits of the next pointer remain unused for now. + */ +#define RHT_BASE_BITS 4 +#define RHT_HASH_BITS 27 +#define RHT_BASE_SHIFT RHT_HASH_BITS + struct rhash_head { struct rhash_head __rcu *next; }; -#define INIT_HASH_HEAD(ptr) ((ptr)->next = NULL) - /** * struct bucket_table - Table of hash buckets * @size: Number of hash buckets @@ -55,6 +72,7 @@ struct rhashtable; * @hash_rnd: Seed to use while hashing * @max_shift: Maximum number of shifts while expanding * @min_shift: Minimum number of shifts while shrinking + * @nulls_base: Base value to generate nulls marker * @locks_mul: Number of bucket locks to allocate per cpu (default: 128) * @hashfn: Function to hash key * @obj_hashfn: Function to hash object @@ -69,6 +87,7 @@ struct rhashtable_params { u32 hash_rnd; size_t max_shift; size_t min_shift; + u32 nulls_base; size_t locks_mul; rht_hashfn_t hashfn; rht_obj_hashfn_t obj_hashfn; @@ -100,6 +119,24 @@ struct rhashtable { bool being_destroyed; }; +static inline unsigned long rht_marker(const struct rhashtable *ht, u32 hash) +{ + return NULLS_MARKER(ht->p.nulls_base + hash); +} + +#define INIT_RHT_NULLS_HEAD(ptr, ht, hash) \ + ((ptr) = (typeof(ptr)) rht_marker(ht, hash)) + +static inline bool rht_is_a_nulls(const struct rhash_head *ptr) +{ + return ((unsigned long) ptr & 1); +} + +static inline unsigned long rht_get_nulls_value(const struct rhash_head *ptr) +{ + return ((unsigned long) ptr) >> 1; +} + #ifdef CONFIG_PROVE_LOCKING int lockdep_rht_mutex_is_held(struct rhashtable *ht); int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, u32 hash); @@ -157,7 +194,7 @@ void rhashtable_destroy(struct rhashtable *ht); */ #define rht_for_each_continue(pos, head, tbl, hash) \ for (pos = rht_dereference_bucket(head, tbl, hash); \ - pos; \ + !rht_is_a_nulls(pos); \ pos = rht_dereference_bucket((pos)->next, tbl, hash)) /** @@ -180,7 +217,7 @@ void rhashtable_destroy(struct rhashtable *ht); */ #define rht_for_each_entry_continue(tpos, pos, head, tbl, hash, member) \ for (pos = rht_dereference_bucket(head, tbl, hash); \ - pos && rht_entry(tpos, pos, member); \ + (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \ pos = rht_dereference_bucket((pos)->next, tbl, hash)) /** @@ -209,9 +246,9 @@ void rhashtable_destroy(struct rhashtable *ht); */ #define rht_for_each_entry_safe(tpos, pos, next, tbl, hash, member) \ for (pos = rht_dereference_bucket((tbl)->buckets[hash], tbl, hash), \ - next = pos ? rht_dereference_bucket(pos->next, tbl, hash) \ - : NULL; \ - pos && rht_entry(tpos, pos, member); \ + next = !rht_is_a_nulls(pos) ? \ + rht_dereference_bucket(pos->next, tbl, hash) : NULL; \ + (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \ pos = next) /** @@ -228,7 +265,7 @@ void rhashtable_destroy(struct rhashtable *ht); #define rht_for_each_rcu_continue(pos, head, tbl, hash) \ for (({barrier(); }), \ pos = rht_dereference_bucket_rcu(head, tbl, hash); \ - pos; \ + !rht_is_a_nulls(pos); \ pos = rcu_dereference_raw(pos->next)) /** @@ -260,7 +297,7 @@ void rhashtable_destroy(struct rhashtable *ht); #define rht_for_each_entry_rcu_continue(tpos, pos, head, tbl, hash, member) \ for (({barrier(); }), \ pos = rht_dereference_bucket_rcu(head, tbl, hash); \ - pos && rht_entry(tpos, pos, member); \ + (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \ pos = rht_dereference_bucket_rcu(pos->next, tbl, hash)) /** |