xref: /freebsd/sys/compat/linuxkpi/common/include/linux/sched.h (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 #ifndef	_LINUX_SCHED_H_
32 #define	_LINUX_SCHED_H_
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/proc.h>
37 #include <sys/sched.h>
38 #include <sys/sleepqueue.h>
39 
40 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
41 
42 #define	TASK_RUNNING		0
43 #define	TASK_INTERRUPTIBLE	1
44 #define	TASK_UNINTERRUPTIBLE	2
45 #define	TASK_DEAD		64
46 #define	TASK_WAKEKILL		128
47 #define	TASK_WAKING		256
48 
49 #define	TASK_SHOULD_STOP	1
50 #define	TASK_STOPPED		2
51 
52 /*
53  * A task_struct is only provided for those tasks created with kthread.
54  * Using these routines with threads not started via kthread will cause
55  * panics because no task_struct is allocated and td_retval[1] is
56  * overwritten by syscalls which kernel threads will not make use of.
57  */
58 struct task_struct {
59 	struct	thread *task_thread;
60 	int	(*task_fn)(void *data);
61 	void	*task_data;
62 	int	task_ret;
63 	int	state;
64 	int	should_stop;
65 };
66 
67 #define	current			task_struct_get(curthread)
68 #define	task_struct_get(x)	((struct task_struct *)(uintptr_t)(x)->td_retval[1])
69 #define	task_struct_set(x, y)	(x)->td_retval[1] = (uintptr_t)(y)
70 
71 /* ensure the task_struct pointer fits into the td_retval[1] field */
72 CTASSERT(sizeof(((struct thread *)0)->td_retval[1]) >= sizeof(uintptr_t));
73 
74 #define	set_current_state(x)						\
75 	atomic_store_rel_int((volatile int *)&current->state, (x))
76 #define	__set_current_state(x)	current->state = (x)
77 
78 
79 #define	schedule()							\
80 do {									\
81 	void *c;							\
82 									\
83 	if (cold)							\
84 		break;							\
85 	c = curthread;							\
86 	sleepq_lock(c);							\
87 	if (current->state == TASK_INTERRUPTIBLE ||			\
88 	    current->state == TASK_UNINTERRUPTIBLE) {			\
89 		sleepq_add(c, NULL, "task", SLEEPQ_SLEEP, 0);		\
90 		sleepq_wait(c, 0);					\
91 	} else {							\
92 		sleepq_release(c);					\
93 		sched_relinquish(curthread);				\
94 	}								\
95 } while (0)
96 
97 #define	wake_up_process(x)						\
98 do {									\
99 	int wakeup_swapper;						\
100 	void *c;							\
101 									\
102 	c = (x)->task_thread;						\
103 	sleepq_lock(c);							\
104 	(x)->state = TASK_RUNNING;					\
105 	wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);		\
106 	sleepq_release(c);						\
107 	if (wakeup_swapper)						\
108 		kick_proc0();						\
109 } while (0)
110 
111 #define	cond_resched()	if (!cold)	sched_relinquish(curthread)
112 
113 #define	sched_yield()	sched_relinquish(curthread)
114 
115 static inline long
116 schedule_timeout(signed long timeout)
117 {
118 	if (timeout < 0)
119 		return 0;
120 
121 	pause("lstim", timeout);
122 
123 	return 0;
124 }
125 
126 #endif	/* _LINUX_SCHED_H_ */
127