BBN-Vax-TCP/sys/calloc.c

/*	calloc.c	4.2	81/04/28	*/

#include "../h/param.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/vm.h"
#include "../h/pte.h"
#include "../h/cmap.h"

extern	cabase, calimit;
extern	struct pte camap[];

caddr_t	cacur = (caddr_t)&cabase;
caddr_t	camax = (caddr_t)&cabase;
int	cax = 0;
/*
 * This is a kernel-mode storage allocator.
 * It is very primitive, currently, in that
 * there is no way to give space back.
 * It serves, for the time being, the needs of
 * auto-configuration code and the like which
 * need to allocate some stuff at boot time.
 */
caddr_t
calloc(size)
	int size;
{
	register caddr_t res;
	register int i;

	if (cacur+size >= (caddr_t)&calimit)
		panic("calloc");
	while (cacur+size > camax) {
		(void) vmemall(&camap[cax], CLSIZE, &proc[0], CSYS);
		vmaccess(&camap[cax], camax, CLSIZE);
		for (i = 0; i < CLSIZE; i++)
			clearseg(camap[cax++].pg_pfnum);
		camax += NBPG * CLSIZE;
	}
	res = cacur;
	cacur += size;
	return (res);
}