1 /* $NetBSD: sched.h,v 1.23 2021/12/27 13:28:41 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #ifndef _LINUX_SCHED_H_
33 #define _LINUX_SCHED_H_
34
35 #include <sys/param.h>
36
37 #include <sys/cdefs.h>
38 #include <sys/kernel.h>
39 #include <sys/lwp.h>
40 #include <sys/proc.h>
41 #include <sys/sched.h>
42
43 #include <asm/barrier.h>
44 #include <asm/param.h>
45 #include <asm/processor.h>
46
47 #include <linux/device.h>
48 #include <linux/errno.h>
49
50 struct seq_file;
51
52 #define TASK_COMM_LEN MAXCOMLEN
53
54 #define MAX_SCHEDULE_TIMEOUT (INT_MAX/2) /* paranoia */
55
56 #define TASK_UNINTERRUPTIBLE __BIT(0)
57 #define TASK_INTERRUPTIBLE __BIT(1)
58
59 #define current curproc
60
61 static inline pid_t
task_pid_nr(struct proc * p)62 task_pid_nr(struct proc *p)
63 {
64 return p->p_pid;
65 }
66
67 static inline long
schedule_timeout_uninterruptible(long timeout)68 schedule_timeout_uninterruptible(long timeout)
69 {
70 unsigned start, end;
71
72 KASSERT(timeout >= 0);
73 KASSERT(timeout < MAX_SCHEDULE_TIMEOUT);
74
75 if (cold) {
76 unsigned us;
77 if (hz <= 1000) {
78 unsigned ms = hztoms(MIN((unsigned long)timeout,
79 mstohz(INT_MAX/2)));
80 us = MIN(ms, INT_MAX/1000)*1000;
81 } else if (hz <= 1000000) {
82 us = MIN(timeout, (INT_MAX/1000000)/hz)*hz*1000000;
83 } else {
84 us = timeout/(1000000/hz);
85 }
86 DELAY(us);
87 return 0;
88 }
89
90 start = getticks();
91 /* Caller is expected to loop anyway, so no harm in truncating. */
92 (void)kpause("loonix", /*intr*/false, MIN(timeout, INT_MAX/2), NULL);
93 end = getticks();
94
95 return timeout - MIN(timeout, (end - start));
96 }
97
98 static inline bool
need_resched(void)99 need_resched(void)
100 {
101
102 return preempt_needed();
103 }
104
105 static inline void
cond_resched(void)106 cond_resched(void)
107 {
108
109 preempt_point();
110 }
111
112 static inline bool
signal_pending_state(int state,struct proc * p)113 signal_pending_state(int state, struct proc *p)
114 {
115
116 KASSERT(p == current);
117 KASSERT(state & (TASK_INTERRUPTIBLE|TASK_UNINTERRUPTIBLE));
118 if (state & TASK_UNINTERRUPTIBLE)
119 return false;
120 return sigispending(curlwp, 0);
121 }
122
123 static inline void
sched_setscheduler(struct proc * p,int class,struct sched_param * param)124 sched_setscheduler(struct proc *p, int class, struct sched_param *param)
125 {
126
127 KASSERT(p == curproc);
128 KASSERT(class == SCHED_FIFO);
129 KASSERT(param->sched_priority == 1);
130
131 lwp_lock(curlwp);
132 curlwp->l_class = class;
133 lwp_changepri(curlwp, PRI_KERNEL_RT);
134 lwp_unlock(curlwp);
135 }
136
137 #endif /* _LINUX_SCHED_H_ */
138