/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)vm_machdep.c	7.10 (Berkeley) 12/16/90
 */

#include "sys/param.h"
#include "sys/systm.h"
#include "sys/user.h"
#include "sys/proc.h"
#include "sys/cmap.h"
#include "sys/vm.h"
#include "sys/text.h"

#include "../include/pte.h"
#include "../include/mtpr.h"

/*
 * Set a red zone in the kernel stack after the u. area.
 */
setredzone(pte, vaddr)
	register struct pte *pte;
	caddr_t vaddr;
{

	pte += (sizeof (struct user) + NBPG - 1) / NBPG;
	*(int *)pte &= ~PG_PROT;
	*(int *)pte |= PG_URKR;
	if (vaddr)
		mtpr(TBIS, vaddr + sizeof (struct user));
}

/*
 * Check for valid program size
 * NB - Check data and data growth separately as they may overflow 
 * when summed together.
 */
chksize(ts, ids, uds, ss)
	unsigned ts, ids, uds, ss;
{
	extern unsigned maxtsize;

	if (ctob(ts) > maxtsize ||
	    ctob(ids) > u.u_rlimit[RLIMIT_DATA].rlim_cur ||
	    ctob(uds) > u.u_rlimit[RLIMIT_DATA].rlim_cur ||
	    ctob(ids + uds) > u.u_rlimit[RLIMIT_DATA].rlim_cur ||
	    ctob(ss) > u.u_rlimit[RLIMIT_STACK].rlim_cur) {
		return (ENOMEM);
	}
	return (0);
}

/*ARGSUSED*/
newptes(pte, v, size)
	register struct pte *pte;
	u_int v;
	register int size;
{
	register caddr_t a = ptob(v);

#ifdef lint
	pte = pte;
#endif
	if (size >= 8) {
		mtpr(TBIA, 0);
		return;
	}
	while (size > 0) {
		mtpr(TBIS, a);
		a += NBPG;
		size--;
	}
}

/*
 * Change protection codes of text segment.
 * Have to flush translation buffer since this
 * affect virtual memory mapping of current process.
 */
chgprot(addr, tprot)
	caddr_t addr;
	long tprot;
{
	unsigned v;
	int tp;
	register struct pte *pte;
	register struct cmap *c;

	v = clbase(btop(addr));
	if (!isatsv(u.u_procp, v))
		return (EFAULT);
	tp = vtotp(u.u_procp, v);
	pte = tptopte(u.u_procp, tp);
	if (pte->pg_fod == 0 && pte->pg_pfnum) {
		c = &cmap[pgtocm(pte->pg_pfnum)];
		if (c->c_blkno)
			munhash(c->c_vp, (daddr_t)(u_long)c->c_blkno);
	}
	*(int *)pte &= ~PG_PROT;
	*(int *)pte |= tprot;
	distcl(pte);
	tbiscl(v);
	return (0);
}

settprot(tprot)
	long tprot;
{
	register int *ptaddr, i;

	ptaddr = (int *)mfpr(P0BR);
	for (i = 0; i < u.u_tsize; i++) {
		ptaddr[i] &= ~PG_PROT;
		ptaddr[i] |= tprot;
	}
	mtpr(TBIA, 0);
}

/*
 * Rest are machine-dependent
 */

getmemc(addr)
	caddr_t addr;
{
	register int c;
	struct pte savemap;

	savemap = mmap[0];
	*(int *)mmap = PG_V | PG_KR | btop(addr);
	mtpr(TBIS, vmmap);
	c = *(char *)&vmmap[(int)addr & PGOFSET];
	mmap[0] = savemap;
	mtpr(TBIS, vmmap);
	return (c & 0377);
}

putmemc(addr, val)
	caddr_t addr;
{
	struct pte savemap;

	savemap = mmap[0];
	*(int *)mmap = PG_V | PG_KW | btop(addr);
	mtpr(TBIS, vmmap);
	*(char *)&vmmap[(int)addr & PGOFSET] = val;
	mmap[0] = savemap;
	mtpr(TBIS, vmmap);
}

/*
 * Move pages from one kernel virtual address to another.
 * Both addresses are assumed to reside in the Sysmap,
 * and size must be a multiple of CLSIZE.
 */
pagemove(from, to, size)
	register caddr_t from, to;
	int size;
{
	register struct pte *fpte, *tpte;

	if (size % CLBYTES)
		panic("pagemove");
	fpte = kvtopte(from);
	tpte = kvtopte(to);
	while (size > 0) {
		*tpte++ = *fpte;
		*(int *)fpte++ = 0;
		mtpr(TBIS, from);
		mtpr(TBIS, to);
		from += NBPG;
		to += NBPG;
		size -= NBPG;
	}
}