1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef LIST_H 3 #define LIST_H 4 5 /* 6 * Copied from include/linux/... 7 */ 8 9 #undef offsetof 10 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) 11 12 /** 13 * container_of - cast a member of a structure out to the containing structure 14 * @ptr: the pointer to the member. 15 * @type: the type of the container struct this is embedded in. 16 * @member: the name of the member within the struct. 17 * 18 */ 19 #define container_of(ptr, type, member) ({ \ 20 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 21 (type *)( (char *)__mptr - offsetof(type,member) );}) 22 23 24 struct list_head { 25 struct list_head *next, *prev; 26 }; 27 28 29 #define LIST_HEAD_INIT(name) { &(name), &(name) } 30 31 #define LIST_HEAD(name) \ 32 struct list_head name = LIST_HEAD_INIT(name) 33 34 /** 35 * list_entry - get the struct for this entry 36 * @ptr: the &struct list_head pointer. 37 * @type: the type of the struct this is embedded in. 38 * @member: the name of the list_head within the struct. 39 */ 40 #define list_entry(ptr, type, member) \ 41 container_of(ptr, type, member) 42 43 /** 44 * list_for_each_entry - iterate over list of given type 45 * @pos: the type * to use as a loop cursor. 46 * @head: the head for your list. 47 * @member: the name of the list_head within the struct. 48 */ 49 #define list_for_each_entry(pos, head, member) \ 50 for (pos = list_entry((head)->next, typeof(*pos), member); \ 51 &pos->member != (head); \ 52 pos = list_entry(pos->member.next, typeof(*pos), member)) 53 54 /** 55 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry 56 * @pos: the type * to use as a loop cursor. 57 * @n: another type * to use as temporary storage 58 * @head: the head for your list. 59 * @member: the name of the list_head within the struct. 60 */ 61 #define list_for_each_entry_safe(pos, n, head, member) \ 62 for (pos = list_entry((head)->next, typeof(*pos), member), \ 63 n = list_entry(pos->member.next, typeof(*pos), member); \ 64 &pos->member != (head); \ 65 pos = n, n = list_entry(n->member.next, typeof(*n), member)) 66 67 /** 68 * list_empty - tests whether a list is empty 69 * @head: the list to test. 70 */ 71 static inline int list_empty(const struct list_head *head) 72 { 73 return head->next == head; 74 } 75 76 /* 77 * Insert a new entry between two known consecutive entries. 78 * 79 * This is only for internal list manipulation where we know 80 * the prev/next entries already! 81 */ 82 static inline void __list_add(struct list_head *_new, 83 struct list_head *prev, 84 struct list_head *next) 85 { 86 next->prev = _new; 87 _new->next = next; 88 _new->prev = prev; 89 prev->next = _new; 90 } 91 92 /** 93 * list_add_tail - add a new entry 94 * @new: new entry to be added 95 * @head: list head to add it before 96 * 97 * Insert a new entry before the specified head. 98 * This is useful for implementing queues. 99 */ 100 static inline void list_add_tail(struct list_head *_new, struct list_head *head) 101 { 102 __list_add(_new, head->prev, head); 103 } 104 105 /* 106 * Delete a list entry by making the prev/next entries 107 * point to each other. 108 * 109 * This is only for internal list manipulation where we know 110 * the prev/next entries already! 111 */ 112 static inline void __list_del(struct list_head *prev, struct list_head *next) 113 { 114 next->prev = prev; 115 prev->next = next; 116 } 117 118 #define LIST_POISON1 ((void *) 0x00100100) 119 #define LIST_POISON2 ((void *) 0x00200200) 120 /** 121 * list_del - deletes entry from list. 122 * @entry: the element to delete from the list. 123 * Note: list_empty() on entry does not return true after this, the entry is 124 * in an undefined state. 125 */ 126 static inline void list_del(struct list_head *entry) 127 { 128 __list_del(entry->prev, entry->next); 129 entry->next = (struct list_head*)LIST_POISON1; 130 entry->prev = (struct list_head*)LIST_POISON2; 131 } 132 #endif 133
