xref: /freebsd/sys/compat/linuxkpi/common/include/linux/sched.h (revision 8ef24a0d4b28fe230e20637f56869cc4148cd2ca)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2016 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 threads created by kthread() and
54  * file operation callbacks.
55  *
56  * Using these routines outside the above mentioned contexts will
57  * cause panics because no task_struct is assigned and td_retval[1] is
58  * overwritten by syscalls.
59  */
60 struct task_struct {
61 	struct	thread *task_thread;
62 	int	(*task_fn)(void *data);
63 	void	*task_data;
64 	int	task_ret;
65 	int	state;
66 	int	should_stop;
67 	pid_t	pid;
68 	const char    *comm;
69 	void	*bsd_ioctl_data;
70 	unsigned	bsd_ioctl_len;
71 };
72 
73 #define	current			task_struct_get(curthread)
74 #define	task_struct_get(x)	((struct task_struct *)(uintptr_t)(x)->td_retval[1])
75 #define	task_struct_fill(x, y) do {		\
76   	(y)->task_thread = (x);			\
77 	(y)->comm = (x)->td_name;		\
78 	(y)->pid = (x)->td_tid;			\
79 } while (0)
80 #define	task_struct_set(x, y)	(x)->td_retval[1] = (uintptr_t)(y)
81 
82 /* ensure the task_struct pointer fits into the td_retval[1] field */
83 CTASSERT(sizeof(((struct thread *)0)->td_retval[1]) >= sizeof(uintptr_t));
84 
85 #define	set_current_state(x)						\
86 	atomic_store_rel_int((volatile int *)&current->state, (x))
87 #define	__set_current_state(x)	current->state = (x)
88 
89 
90 #define	schedule()							\
91 do {									\
92 	void *c;							\
93 									\
94 	if (cold)							\
95 		break;							\
96 	c = curthread;							\
97 	sleepq_lock(c);							\
98 	if (current->state == TASK_INTERRUPTIBLE ||			\
99 	    current->state == TASK_UNINTERRUPTIBLE) {			\
100 		sleepq_add(c, NULL, "task", SLEEPQ_SLEEP, 0);		\
101 		sleepq_wait(c, 0);					\
102 	} else {							\
103 		sleepq_release(c);					\
104 		sched_relinquish(curthread);				\
105 	}								\
106 } while (0)
107 
108 #define	wake_up_process(x)						\
109 do {									\
110 	int wakeup_swapper;						\
111 	void *c;							\
112 									\
113 	c = (x)->task_thread;						\
114 	sleepq_lock(c);							\
115 	(x)->state = TASK_RUNNING;					\
116 	wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);		\
117 	sleepq_release(c);						\
118 	if (wakeup_swapper)						\
119 		kick_proc0();						\
120 } while (0)
121 
122 #define	cond_resched()	if (!cold)	sched_relinquish(curthread)
123 
124 #define	sched_yield()	sched_relinquish(curthread)
125 
126 static inline long
127 schedule_timeout(signed long timeout)
128 {
129 	if (timeout < 0)
130 		return 0;
131 
132 	pause("lstim", timeout);
133 
134 	return 0;
135 }
136 
137 #endif	/* _LINUX_SCHED_H_ */
138