Add more macros used for removing hash table entries. Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- A potential user is gendwarfksyms scripts/include/hashtable.h | 50 +++++++++++++++++++++++++++ scripts/include/list.h | 69 +++++++++++++++++++++++++++++++++++++ 2 files changed, 119 insertions(+) diff --git a/scripts/include/hashtable.h b/scripts/include/hashtable.h index a0a2c8f5f639..45abcb12bfce 100644 --- a/scripts/include/hashtable.h +++ b/scripts/include/hashtable.h @@ -15,6 +15,23 @@ #define hash_head(table, key) (&(table)[(key) % HASH_SIZE(table)]) +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 + * @table: hashtable to be initialized + * + * This has to be a macro since HASH_SIZE() will not work on pointers since + * it calculates the size during preprocessing. + */ +#define hash_init(table) __hash_init(table, HASH_SIZE(table)) + /** * hash_add - add an object to a hashtable * @table: hashtable to add to @@ -24,6 +41,15 @@ #define hash_add(table, node, key) \ hlist_add_head(node, hash_head(table, key)) +/** + * 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 * @table: hashtable to iterate @@ -34,6 +60,18 @@ for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ hlist_for_each_entry(obj, &table[_bkt], member) +/** + * hash_for_each_safe - iterate over a hashtable safe against removal of + * hash entry + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @tmp: a &struct hlist_node used for temporary storage + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_safe(table, obj, tmp, member) \ + for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ + hlist_for_each_entry_safe(obj, tmp, &table[_bkt], member) + /** * hash_for_each_possible - iterate over all possible objects hashing to the * same bucket @@ -45,4 +83,16 @@ #define hash_for_each_possible(table, obj, member, key) \ hlist_for_each_entry(obj, hash_head(table, key), member) +/** + * hash_for_each_possible_safe - iterate over all possible objects hashing to the + * same bucket safe against removals + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @tmp: a &struct hlist_node 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(table, obj, tmp, member, key) \ + hlist_for_each_entry_safe(obj, tmp, hash_head(table, key), member) + #endif /* HASHTABLE_H */ diff --git a/scripts/include/list.h b/scripts/include/list.h index 409201cd495b..fea1e2b79063 100644 --- a/scripts/include/list.h +++ b/scripts/include/list.h @@ -268,6 +268,63 @@ static inline int list_empty(const struct list_head *head) */ #define HLIST_HEAD_INIT { .first = NULL } +#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) +static inline void INIT_HLIST_NODE(struct hlist_node *h) +{ + h->next = NULL; + h->pprev = NULL; +} + +/** + * hlist_unhashed - Has node been removed from list and reinitialized? + * @h: Node to be checked + * + * Not that not all removal functions will leave a node in unhashed + * state. For example, hlist_nulls_del_init_rcu() does leave the + * node in unhashed state, but hlist_nulls_del() does not. + */ +static inline int hlist_unhashed(const struct hlist_node *h) +{ + return !h->pprev; +} + +static inline void __hlist_del(struct hlist_node *n) +{ + struct hlist_node *next = n->next; + struct hlist_node **pprev = n->pprev; + + *pprev = next; + if (next) + next->pprev = pprev; +} + +/** + * hlist_del - Delete the specified hlist_node from its list + * @n: Node to delete. + * + * Note that this function leaves the node in hashed state. Use + * hlist_del_init() or similar instead to unhash @n. + */ +static inline void hlist_del(struct hlist_node *n) +{ + __hlist_del(n); + n->next = LIST_POISON1; + n->pprev = LIST_POISON2; +} + +/** + * hlist_del_init - Delete the specified hlist_node from its list and initialize + * @n: Node to delete. + * + * Note that this function leaves the node in unhashed state. + */ +static inline void hlist_del_init(struct hlist_node *n) +{ + if (!hlist_unhashed(n)) { + __hlist_del(n); + INIT_HLIST_NODE(n); + } +} /** * hlist_add_head - add a new entry at the beginning of the hlist @@ -306,4 +363,16 @@ static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) pos; \ pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) +/** + * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry + * @pos: the type * to use as a loop cursor. + * @n: a &struct hlist_node to use as temporary storage + * @head: the head for your list. + * @member: the name of the hlist_node within the struct. + */ +#define hlist_for_each_entry_safe(pos, n, head, member) \ + for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\ + pos && ({ n = pos->member.next; 1; }); \ + pos = hlist_entry_safe(n, typeof(*pos), member)) + #endif /* LIST_H */ -- 2.43.0