xref: /linux/io_uring/slist.h (revision 0abcfd8983e3d3d27b8f5f7d01fed4354eb422c4)
1 #ifndef INTERNAL_IO_SLIST_H
2 #define INTERNAL_IO_SLIST_H
3 
4 #include <linux/io_uring_types.h>
5 
6 #define __wq_list_for_each(pos, head)				\
7 	for (pos = (head)->first; pos; pos = (pos)->next)
8 
9 #define wq_list_for_each(pos, prv, head)			\
10 	for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
11 
12 #define wq_list_for_each_resume(pos, prv)			\
13 	for (; pos; prv = pos, pos = (pos)->next)
14 
15 #define wq_list_empty(list)	(READ_ONCE((list)->first) == NULL)
16 
17 #define INIT_WQ_LIST(list)	do {				\
18 	(list)->first = NULL;					\
19 } while (0)
20 
21 static inline void wq_list_add_after(struct io_wq_work_node *node,
22 				     struct io_wq_work_node *pos,
23 				     struct io_wq_work_list *list)
24 {
25 	struct io_wq_work_node *next = pos->next;
26 
27 	pos->next = node;
28 	node->next = next;
29 	if (!next)
30 		list->last = node;
31 }
32 
33 static inline void wq_list_add_tail(struct io_wq_work_node *node,
34 				    struct io_wq_work_list *list)
35 {
36 	node->next = NULL;
37 	if (!list->first) {
38 		list->last = node;
39 		WRITE_ONCE(list->first, node);
40 	} else {
41 		list->last->next = node;
42 		list->last = node;
43 	}
44 }
45 
46 static inline void wq_list_add_head(struct io_wq_work_node *node,
47 				    struct io_wq_work_list *list)
48 {
49 	node->next = list->first;
50 	if (!node->next)
51 		list->last = node;
52 	WRITE_ONCE(list->first, node);
53 }
54 
55 static inline void wq_list_cut(struct io_wq_work_list *list,
56 			       struct io_wq_work_node *last,
57 			       struct io_wq_work_node *prev)
58 {
59 	/* first in the list, if prev==NULL */
60 	if (!prev)
61 		WRITE_ONCE(list->first, last->next);
62 	else
63 		prev->next = last->next;
64 
65 	if (last == list->last)
66 		list->last = prev;
67 	last->next = NULL;
68 }
69 
70 static inline void wq_stack_add_head(struct io_wq_work_node *node,
71 				     struct io_wq_work_node *stack)
72 {
73 	node->next = stack->next;
74 	stack->next = node;
75 }
76 
77 static inline void wq_list_del(struct io_wq_work_list *list,
78 			       struct io_wq_work_node *node,
79 			       struct io_wq_work_node *prev)
80 {
81 	wq_list_cut(list, node, prev);
82 }
83 
84 static inline
85 struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack)
86 {
87 	struct io_wq_work_node *node = stack->next;
88 
89 	stack->next = node->next;
90 	return node;
91 }
92 
93 static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
94 {
95 	if (!work->list.next)
96 		return NULL;
97 
98 	return container_of(work->list.next, struct io_wq_work, list);
99 }
100 
101 #endif // INTERNAL_IO_SLIST_H
102