/* This file contains some utility routines for SCHED.
 *
 * The entry points are:
 *   no_sys:		called for invalid system call numbers
 *   sched_isokendpt:	check the validity of an endpoint
 *   sched_isemtyendpt  check for validity and availability of endpoint slot
 *   is_from_pm		check whether message is originated from PM
 *   nice_to_priority	convert nice level to priority queue
 */

#include "sched.h"
#include <machine/archtypes.h>
#include <sys/resource.h> /* for PRIO_MAX & PRIO_MIN */
#include "kernel/proc.h" /* for queue constants */
#include "schedproc.h"

/*===========================================================================*
 *				no_sys					     *
 *===========================================================================*/
PUBLIC int no_sys(int who_e, int call_nr)
{
/* A system call number not implemented by PM has been requested. */
  printf("SCHED: in no_sys, call nr %d from %d\n", call_nr, who_e);
  return(ENOSYS);
}


/*===========================================================================*
 *				sched_isokendpt			 	     *
 *===========================================================================*/
PUBLIC int sched_isokendpt(int endpoint, int *proc)
{
	*proc = _ENDPOINT_P(endpoint);
	if (*proc < 0)
		return (EBADSRCDST); /* Don't schedule tasks */
	if(*proc >= NR_PROCS)
		return (EINVAL);
	if(endpoint != schedproc[*proc].endpoint)
		return (EDEADSRCDST);
	if(!(schedproc[*proc].flags & IN_USE))
		return (EDEADSRCDST);
	return (OK);
}

/*===========================================================================*
 *				sched_isemtyendpt		 	     *
 *===========================================================================*/
PUBLIC int sched_isemtyendpt(int endpoint, int *proc)
{
	*proc = _ENDPOINT_P(endpoint);
	if (*proc < 0)
		return (EBADSRCDST); /* Don't schedule tasks */
	if(*proc >= NR_PROCS)
		return (EINVAL);
	if(schedproc[*proc].flags & IN_USE)
		return (EDEADSRCDST);
	return (OK);
}

/*===========================================================================*
 *				is_from_pm				     *
 *===========================================================================*/
PUBLIC int is_from_pm(message *m_ptr)
{
	if (m_ptr->m_source == PM_PROC_NR) {
		return 1;
	}
	return 0;
}

/*===========================================================================*
 *				nice_to_priority			     *
 *===========================================================================*/
PUBLIC int nice_to_priority(int nice, unsigned* new_q)
{
	if (nice < PRIO_MIN || nice > PRIO_MAX) return(EINVAL);

	*new_q = MAX_USER_Q + (nice-PRIO_MIN) * (MIN_USER_Q-MAX_USER_Q+1) /
	    (PRIO_MAX-PRIO_MIN+1);
	if (*new_q < MAX_USER_Q) *new_q = MAX_USER_Q;	/* shouldn't happen */
	if (*new_q > MIN_USER_Q) *new_q = MIN_USER_Q;	/* shouldn't happen */

	return (OK);
}