1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3 * Copyright (c) 2015, Linaro Limited
4 */
5 #ifndef __KERNEL_WAIT_QUEUE_H
6 #define __KERNEL_WAIT_QUEUE_H
7
8 #include <tee_api_types.h>
9 #include <types_ext.h>
10 #include <sys/queue.h>
11
12 struct wait_queue_elem;
13 SLIST_HEAD(wait_queue, wait_queue_elem);
14
15 #define WAIT_QUEUE_INITIALIZER { .slh_first = NULL }
16
17 struct condvar;
18 struct wait_queue_elem {
19 short handle;
20 bool done;
21 bool wait_read;
22 struct condvar *cv;
23 SLIST_ENTRY(wait_queue_elem) link;
24 };
25
26 /*
27 * Initializes a wait queue
28 */
29 void wq_init(struct wait_queue *wq);
30
31 /*
32 * Initializes a wait queue element and adds it to the wait queue. This
33 * function is supposed to be called before the lock that protects the
34 * resource we need to wait for is released.
35 *
36 * One call to this function must be followed by one call to wq_wait_final()
37 * on the same wait queue element.
38 */
39 void wq_wait_init_condvar(struct wait_queue *wq, struct wait_queue_elem *wqe,
40 struct condvar *cv, bool wait_read);
41
wq_wait_init(struct wait_queue * wq,struct wait_queue_elem * wqe,bool wait_read)42 static inline void wq_wait_init(struct wait_queue *wq,
43 struct wait_queue_elem *wqe, bool wait_read)
44 {
45 wq_wait_init_condvar(wq, wqe, NULL, wait_read);
46 }
47
48 /* Waits for the wait queue element to be awakened or timed out */
49 TEE_Result wq_wait_final(struct wait_queue *wq, struct wait_queue_elem *wqe,
50 uint32_t timeout_ms, const void *sync_obj,
51 const char *fname, int lineno);
52
53 /* Wakes up the first wait queue element in the wait queue, if there is one */
54 void wq_wake_next(struct wait_queue *wq, const void *sync_obj,
55 const char *fname, int lineno);
56
57 /* Returns true if the wait queue doesn't contain any elements */
58 bool wq_is_empty(struct wait_queue *wq);
59
60 void wq_promote_condvar(struct wait_queue *wq, struct condvar *cv,
61 bool only_one, const void *sync_obj, const char *fname,
62 int lineno);
63 bool wq_have_condvar(struct wait_queue *wq, struct condvar *cv);
64
65 #endif /*__KERNEL_WAIT_QUEUE_H*/
66
67