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 *)¤t->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
schedule_timeout(signed long timeout)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