sched.h revision 1.23 
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
50struct 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
61static inline pid_t
62task_pid_nr(struct proc *p)
63{
64	return p->p_pid;
65}
66
67static inline long
68schedule_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
98static inline bool
99need_resched(void)
100{
101
102	return preempt_needed();
103}
104
105static inline void
106cond_resched(void)
107{
108
109	preempt_point();
110}
111
112static inline bool
113signal_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
123static inline void
124sched_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