sched.h revision 1.22 
1/*	$NetBSD: sched.h,v 1.22 2021/12/19 12:45:50 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
58#define	current	curproc
59
60static inline pid_t
61task_pid_nr(struct proc *p)
62{
63	return p->p_pid;
64}
65
66static inline long
67schedule_timeout_uninterruptible(long timeout)
68{
69	unsigned start, end;
70
71	KASSERT(timeout >= 0);
72	KASSERT(timeout < MAX_SCHEDULE_TIMEOUT);
73
74	if (cold) {
75		unsigned us;
76		if (hz <= 1000) {
77			unsigned ms = hztoms(MIN((unsigned long)timeout,
78			    mstohz(INT_MAX/2)));
79			us = MIN(ms, INT_MAX/1000)*1000;
80		} else if (hz <= 1000000) {
81			us = MIN(timeout, (INT_MAX/1000000)/hz)*hz*1000000;
82		} else {
83			us = timeout/(1000000/hz);
84		}
85		DELAY(us);
86		return 0;
87	}
88
89	start = getticks();
90	/* Caller is expected to loop anyway, so no harm in truncating.  */
91	(void)kpause("loonix", /*intr*/false, MIN(timeout, INT_MAX/2), NULL);
92	end = getticks();
93
94	return timeout - MIN(timeout, (end - start));
95}
96
97static inline bool
98need_resched(void)
99{
100
101	return preempt_needed();
102}
103
104static inline void
105cond_resched(void)
106{
107
108	preempt_point();
109}
110
111static inline bool
112signal_pending_state(int state, struct proc *p)
113{
114
115	KASSERT(p == current);
116	if (state & TASK_UNINTERRUPTIBLE)
117		return false;
118	return sigispending(curlwp, 0);
119}
120
121static inline void
122sched_setscheduler(struct proc *p, int class, struct sched_param *param)
123{
124
125	KASSERT(p == curproc);
126	KASSERT(class == SCHED_FIFO);
127	KASSERT(param->sched_priority == 1);
128
129	lwp_lock(curlwp);
130	curlwp->l_class = class;
131	lwp_changepri(curlwp, PRI_KERNEL_RT);
132	lwp_unlock(curlwp);
133}
134
135#endif  /* _LINUX_SCHED_H_ */
136