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sched.h revision 1.18 
      1 /*	$NetBSD: sched.h,v 1.18 2021/12/19 10:38:05 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 #include <sys/cdefs.h>
     37 #include <sys/kernel.h>
     38 #include <sys/proc.h>
     39 
     40 #include <asm/param.h>
     41 #include <asm/barrier.h>
     42 #include <asm/processor.h>
     43 #include <linux/device.h>
     44 #include <linux/errno.h>
     45 
     46 struct seq_file;
     47 
     48 #define	TASK_COMM_LEN	MAXCOMLEN
     49 
     50 #define	MAX_SCHEDULE_TIMEOUT	(INT_MAX/2)	/* paranoia */
     51 
     52 #define	TASK_UNINTERRUPTIBLE	__BIT(0)
     53 
     54 #define	current	curproc
     55 
     56 static inline pid_t
     57 task_pid_nr(struct proc *p)
     58 {
     59 	return p->p_pid;
     60 }
     61 
     62 static inline long
     63 schedule_timeout_uninterruptible(long timeout)
     64 {
     65 	long remain;
     66 	int start, end;
     67 
     68 	if (cold) {
     69 		unsigned us;
     70 		if (hz <= 1000) {
     71 			unsigned ms = hztoms(MIN((unsigned long)timeout,
     72 			    mstohz(INT_MAX)));
     73 			us = MIN(ms, INT_MAX/1000)*1000;
     74 		} else if (hz <= 1000000) {
     75 			us = MIN(timeout, (INT_MAX/1000000)/hz)*hz*1000000;
     76 		} else {
     77 			us = timeout/(1000000/hz);
     78 		}
     79 		DELAY(us);
     80 		return 0;
     81 	}
     82 
     83 	start = getticks();
     84 	/* Caller is expected to loop anyway, so no harm in truncating.  */
     85 	(void)kpause("loonix", false /*!intr*/, MIN(timeout, INT_MAX), NULL);
     86 	end = getticks();
     87 
     88 	remain = timeout - (end - start);
     89 	return remain > 0 ? remain : 0;
     90 }
     91 
     92 static inline bool
     93 need_resched(void)
     94 {
     95 	/* XXX kpreempt_disable */
     96 	/* XXX ci_want_resched */
     97 	return (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD);
     98 }
     99 
    100 static inline void
    101 cond_resched(void)
    102 {
    103 
    104 	preempt_point();
    105 }
    106 
    107 static inline bool
    108 signal_pending_state(int state, struct proc *p)
    109 {
    110 
    111 	KASSERT(p == current);
    112 	if (state & TASK_UNINTERRUPTIBLE)
    113 		return false;
    114 	return sigispending(curlwp, 0);
    115 }
    116 
    117 #endif  /* _LINUX_SCHED_H_ */
    118