1 // SPDX-License-Identifier: GPL-2.0+
3  * Helper functions to sync execution between parent and child processes.
29 #define CHILD_FAIL_IF(x, sync)						\  argument
34 			(sync)->child_gave_up = true;			\
35 			prod_parent(sync);				\
36 			return 1;					\
40 #define PARENT_FAIL_IF(x, sync)						\  argument
45 			(sync)->parent_gave_up = true;			\
46 			prod_child(sync);				\
47 			return 1;					\
51 #define PARENT_SKIP_IF_UNSUPPORTED(x, sync, msg)			\  argument
53 		if ((x) == -1 && (errno == ENODEV || errno == EINVAL)) { \
54 			(sync)->parent_gave_up = true;			\
55 			prod_child(sync);				\
56 			SKIP_IF_MSG(1, msg);				\
60 int init_child_sync(struct child_sync *sync)  in init_child_sync()  argument
64 	ret = sem_init(&sync->sem_parent, 1, 0);  in init_child_sync()
67 		return 1;  in init_child_sync()
70 	ret = sem_init(&sync->sem_child, 1, 0);  in init_child_sync()
73 		return 1;  in init_child_sync()
79 void destroy_child_sync(struct child_sync *sync)  in destroy_child_sync()  argument
81 	sem_destroy(&sync->sem_parent);  in destroy_child_sync()
82 	sem_destroy(&sync->sem_child);  in destroy_child_sync()
85 int wait_child(struct child_sync *sync)  in wait_child()  argument
90 	ret = sem_wait(&sync->sem_parent);  in wait_child()
93 		return 1;  in wait_child()
96 	return sync->child_gave_up;  in wait_child()
99 int prod_child(struct child_sync *sync)  in prod_child()  argument
104 	ret = sem_post(&sync->sem_child);  in prod_child()
107 		return 1;  in prod_child()
113 int wait_parent(struct child_sync *sync)  in wait_parent()  argument
118 	ret = sem_wait(&sync->sem_child);  in wait_parent()
121 		return 1;  in wait_parent()
124 	return sync->parent_gave_up;  in wait_parent()
127 int prod_parent(struct child_sync *sync)  in prod_parent()  argument
132 	ret = sem_post(&sync->sem_parent);  in prod_parent()
135 		return 1;  in prod_parent()