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Diffstat (limited to 'c_src/include/linux/list_nulls.h')
-rw-r--r-- | c_src/include/linux/list_nulls.h | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/c_src/include/linux/list_nulls.h b/c_src/include/linux/list_nulls.h deleted file mode 100644 index fa6e8471..00000000 --- a/c_src/include/linux/list_nulls.h +++ /dev/null @@ -1,145 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _LINUX_LIST_NULLS_H -#define _LINUX_LIST_NULLS_H - -#include <linux/poison.h> -#include <linux/const.h> - -/* - * Special version of lists, where end of list is not a NULL pointer, - * but a 'nulls' marker, which can have many different values. - * (up to 2^31 different values guaranteed on all platforms) - * - * In the standard hlist, termination of a list is the NULL pointer. - * In this special 'nulls' variant, we use the fact that objects stored in - * a list are aligned on a word (4 or 8 bytes alignment). - * We therefore use the last significant bit of 'ptr' : - * Set to 1 : This is a 'nulls' end-of-list marker (ptr >> 1) - * Set to 0 : This is a pointer to some object (ptr) - */ - -struct hlist_nulls_head { - struct hlist_nulls_node *first; -}; - -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 *) NULLS_MARKER(nulls)) - -#define hlist_nulls_entry(ptr, type, member) container_of(ptr,type,member) - -#define hlist_nulls_entry_safe(ptr, type, member) \ - ({ typeof(ptr) ____ptr = (ptr); \ - !is_a_nulls(____ptr) ? hlist_nulls_entry(____ptr, type, member) : NULL; \ - }) -/** - * ptr_is_a_nulls - Test if a ptr is a nulls - * @ptr: ptr to be tested - * - */ -static inline int is_a_nulls(const struct hlist_nulls_node *ptr) -{ - return ((unsigned long)ptr & 1); -} - -/** - * get_nulls_value - Get the 'nulls' value of the end of chain - * @ptr: end of chain - * - * Should be called only if is_a_nulls(ptr); - */ -static inline unsigned long get_nulls_value(const struct hlist_nulls_node *ptr) -{ - return ((unsigned long)ptr) >> 1; -} - -/** - * hlist_nulls_unhashed - Has node been removed and reinitialized? - * @h: Node to be checked - * - * Not that not all removal functions will leave a node in unhashed state. - * For example, hlist_del_init_rcu() leaves the node in unhashed state, - * but hlist_nulls_del() does not. - */ -static inline int hlist_nulls_unhashed(const struct hlist_nulls_node *h) -{ - return !h->pprev; -} - -/** - * hlist_nulls_unhashed_lockless - Has node been removed and reinitialized? - * @h: Node to be checked - * - * Not that not all removal functions will leave a node in unhashed state. - * For example, hlist_del_init_rcu() leaves the node in unhashed state, - * but hlist_nulls_del() does not. Unlike hlist_nulls_unhashed(), this - * function may be used locklessly. - */ -static inline int hlist_nulls_unhashed_lockless(const struct hlist_nulls_node *h) -{ - return !READ_ONCE(h->pprev); -} - -static inline int hlist_nulls_empty(const struct hlist_nulls_head *h) -{ - return is_a_nulls(READ_ONCE(h->first)); -} - -static inline void hlist_nulls_add_head(struct hlist_nulls_node *n, - struct hlist_nulls_head *h) -{ - struct hlist_nulls_node *first = h->first; - - n->next = first; - WRITE_ONCE(n->pprev, &h->first); - h->first = n; - if (!is_a_nulls(first)) - WRITE_ONCE(first->pprev, &n->next); -} - -static inline void __hlist_nulls_del(struct hlist_nulls_node *n) -{ - struct hlist_nulls_node *next = n->next; - struct hlist_nulls_node **pprev = n->pprev; - - WRITE_ONCE(*pprev, next); - if (!is_a_nulls(next)) - WRITE_ONCE(next->pprev, pprev); -} - -static inline void hlist_nulls_del(struct hlist_nulls_node *n) -{ - __hlist_nulls_del(n); - WRITE_ONCE(n->pprev, LIST_POISON2); -} - -/** - * hlist_nulls_for_each_entry - iterate over list of given type - * @tpos: the type * to use as a loop cursor. - * @pos: the &struct hlist_node to use as a loop cursor. - * @head: the head for your list. - * @member: the name of the hlist_node within the struct. - * - */ -#define hlist_nulls_for_each_entry(tpos, pos, head, member) \ - for (pos = (head)->first; \ - (!is_a_nulls(pos)) && \ - ({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member); 1;}); \ - pos = pos->next) - -/** - * hlist_nulls_for_each_entry_from - iterate over a hlist continuing from current point - * @tpos: the type * to use as a loop cursor. - * @pos: the &struct hlist_node to use as a loop cursor. - * @member: the name of the hlist_node within the struct. - * - */ -#define hlist_nulls_for_each_entry_from(tpos, pos, member) \ - for (; (!is_a_nulls(pos)) && \ - ({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member); 1;}); \ - pos = pos->next) - -#endif |