1 /*
2 * Copyright (c) 2019 Intel corporation
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include <zephyr/kernel.h>
8 #include <zephyr/kernel_structs.h>
9 #include <zephyr/spinlock.h>
10 #include <kswap.h>
11 #include <zephyr/internal/syscall_handler.h>
12 #include <zephyr/init.h>
13 #include <ksched.h>
14
k_futex_find_data(struct k_futex * futex)15 static struct z_futex_data *k_futex_find_data(struct k_futex *futex)
16 {
17 struct k_object *obj;
18
19 obj = k_object_find(futex);
20 if ((obj == NULL) || (obj->type != K_OBJ_FUTEX)) {
21 return NULL;
22 }
23
24 return obj->data.futex_data;
25 }
26
z_impl_k_futex_wake(struct k_futex * futex,bool wake_all)27 int z_impl_k_futex_wake(struct k_futex *futex, bool wake_all)
28 {
29 k_spinlock_key_t key;
30 unsigned int woken = 0U;
31 struct k_thread *thread;
32 struct z_futex_data *futex_data;
33
34 futex_data = k_futex_find_data(futex);
35 if (futex_data == NULL) {
36 return -EINVAL;
37 }
38
39 key = k_spin_lock(&futex_data->lock);
40
41 do {
42 thread = z_unpend_first_thread(&futex_data->wait_q);
43 if (thread != NULL) {
44 woken++;
45 arch_thread_return_value_set(thread, 0);
46 z_ready_thread(thread);
47 }
48 } while (thread && wake_all);
49
50 if (woken == 0) {
51 k_spin_unlock(&futex_data->lock, key);
52 } else {
53 z_reschedule(&futex_data->lock, key);
54 }
55
56 return woken;
57 }
58
z_vrfy_k_futex_wake(struct k_futex * futex,bool wake_all)59 static inline int z_vrfy_k_futex_wake(struct k_futex *futex, bool wake_all)
60 {
61 if (K_SYSCALL_MEMORY_WRITE(futex, sizeof(struct k_futex)) != 0) {
62 return -EACCES;
63 }
64
65 return z_impl_k_futex_wake(futex, wake_all);
66 }
67 #include <zephyr/syscalls/k_futex_wake_mrsh.c>
68
z_impl_k_futex_wait(struct k_futex * futex,int expected,k_timeout_t timeout)69 int z_impl_k_futex_wait(struct k_futex *futex, int expected,
70 k_timeout_t timeout)
71 {
72 int ret;
73 k_spinlock_key_t key;
74 struct z_futex_data *futex_data;
75
76 futex_data = k_futex_find_data(futex);
77 if (futex_data == NULL) {
78 return -EINVAL;
79 }
80
81 if (atomic_get(&futex->val) != (atomic_val_t)expected) {
82 return -EAGAIN;
83 }
84
85 key = k_spin_lock(&futex_data->lock);
86
87 ret = z_pend_curr(&futex_data->lock,
88 key, &futex_data->wait_q, timeout);
89 if (ret == -EAGAIN) {
90 ret = -ETIMEDOUT;
91 }
92
93 return ret;
94 }
95
z_vrfy_k_futex_wait(struct k_futex * futex,int expected,k_timeout_t timeout)96 static inline int z_vrfy_k_futex_wait(struct k_futex *futex, int expected,
97 k_timeout_t timeout)
98 {
99 if (K_SYSCALL_MEMORY_WRITE(futex, sizeof(struct k_futex)) != 0) {
100 return -EACCES;
101 }
102
103 return z_impl_k_futex_wait(futex, expected, timeout);
104 }
105 #include <zephyr/syscalls/k_futex_wait_mrsh.c>
106
