/*-
 * Copyright (c) 1989, 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software developed by the Computer Systems
 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
 * BG 91-66 and contributed to Berkeley.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
/* from: static char sccsid[] = "@(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93"; */
static char *rcsid = "$Id: kvm_om68k.c,v 1.1 1994/05/16 05:31:31 chopps Exp $";
#endif /* LIBC_SCCS and not lint */

/*
 * m68k machine dependent routines for kvm.  Hopefully, the forthcoming 
 * vm code will one day obsolete this module.
 */

#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <unistd.h>
#include <nlist.h>
#include <kvm.h>

#include <vm/vm.h>
#include <vm/vm_param.h>

#include <limits.h>
#include <db.h>

#include "kvm_private.h"

#include <machine/pte.h>

#ifndef btop
#define	btop(x)		(((unsigned)(x)) >> PGSHIFT)	/* XXX */
#define	ptob(x)		((caddr_t)((x) << PGSHIFT))	/* XXX */
#endif

struct vmstate {
	u_long lowram;
	int mmutype;
	struct ste *Sysseg;
};

#define KREAD(kd, addr, p)\
	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))

void
_kvm_freevtop(kd)
	kvm_t *kd;
{
	if (kd->vmst != 0)
		free(kd->vmst);
}

int
_kvm_initvtop(kd)
	kvm_t *kd;
{
	struct vmstate *vm;
	struct nlist nlist[4];

	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
	if (vm == 0)
		return (-1);
	kd->vmst = vm;

	nlist[0].n_name = "_lowram";
#if defined(amiga) || defined(mac68k)
	nlist[1].n_name = "_cpu040";
#else
	nlist[1].n_name = "_mmutype";
#endif
	nlist[2].n_name = "_Sysseg";
	nlist[3].n_name = 0;

	if (kvm_nlist(kd, nlist) != 0) {
		_kvm_err(kd, kd->program, "bad namelist");
		return (-1);
	}
	vm->Sysseg = 0;
	if (KREAD(kd, (u_long)nlist[0].n_value, &vm->lowram)) {
		_kvm_err(kd, kd->program, "cannot read lowram");
		return (-1);
	}
	if (KREAD(kd, (u_long)nlist[1].n_value, &vm->mmutype)) {
		_kvm_err(kd, kd->program, "cannot read mmutype");
		return (-1);
	}
	if (KREAD(kd, (u_long)nlist[2].n_value, &vm->Sysseg)) {
		_kvm_err(kd, kd->program, "cannot read segment table");
		return (-1);
	}
	return (0);
}

static int
_kvm_vatop(kd, sta, va, pa)
	kvm_t *kd;
	struct ste *sta;
	u_long va;
	u_long *pa;
{
	register struct vmstate *vm;
	register u_long lowram;
	register u_long addr;
	int p, ste, pte;
	int offset;

	if (ISALIVE(kd)) {
		_kvm_err(kd, 0, "vatop called in live kernel!");
		return((off_t)0);
	}
	vm = kd->vmst;
	offset = va & PGOFSET;
	/*
	 * If we are initializing (kernel segment table pointer not yet set)
	 * then return pa == va to avoid infinite recursion.
	 */
	if (vm->Sysseg == 0) {
		*pa = va;
		return (NBPG - offset);
	}
	lowram = vm->lowram;
#if defined(amiga) || defined(mac68k)
	{ int cpu040 = vm->mmutype;
#else
	{
#endif
		addr = (u_long)&sta[va >> SEGSHIFT];
		/*
		 * Can't use KREAD to read kernel segment table entries.
		 * Fortunately it is 1-to-1 mapped so we don't have to. 
		 */
		if (sta == vm->Sysseg) {
			if (lseek(kd->pmfd, (off_t)addr, 0) == -1 ||
			    read(kd->pmfd, (char *)&ste, sizeof(ste)) < 0)
				goto invalid;
		} else if (KREAD(kd, addr, &ste))
			goto invalid;
		if ((ste & SG_V) == 0) {
			_kvm_err(kd, 0, "invalid segment (%x)", ste);
			return((off_t)0);
		}
		p = btop(va & SG_PMASK);
		addr = (ste & SG_FRAME) + (p * sizeof(struct pte));
	}
	/*
	 * Address from STE is a physical address so don't use kvm_read.
	 */
	if (lseek(kd->pmfd, (off_t)(addr - lowram), 0) == -1 || 
	    read(kd->pmfd, (char *)&pte, sizeof(pte)) < 0)
		goto invalid;
	addr = pte & PG_FRAME;
	if (pte == PG_NV) {
		_kvm_err(kd, 0, "page not valid");
		return (0);
	}
	*pa = addr - lowram + offset;
	
	return (NBPG - offset);
invalid:
	_kvm_err(kd, 0, "invalid address (%x)", va);
	return (0);
}

int
_kvm_kvatop(kd, va, pa)
	kvm_t *kd;
	u_long va;
	u_long *pa;
{
	return (_kvm_vatop(kd, (u_long)kd->vmst->Sysseg, va, pa));
}

/*
 * Translate a user virtual address to a physical address.
 */
int
_kvm_uvatop(kd, p, va, pa)
	kvm_t *kd;
	const struct proc *p;
	u_long va;
	u_long *pa;
{
	register struct vmspace *vms = p->p_vmspace;
	int kva;

	/*
	 * If this is a live kernel we just look it up in the kernel
	 * virtually allocated flat 4mb page table (i.e. let the kernel
	 * do the table walk).  In this way, we avoid needing to know
	 * the MMU type.
	 */
	if (ISALIVE(kd)) {
		struct pte *ptab;
		int pte, offset;

		kva = (int)&vms->vm_pmap.pm_ptab;
		if (KREAD(kd, kva, &ptab)) {
			_kvm_err(kd, 0, "invalid address (%x)", va);
			return (0);
		}
		kva = (int)&ptab[btop(va)];
		if (KREAD(kd, kva, &pte) || (pte & PG_V) == 0) {
			_kvm_err(kd, 0, "invalid address (%x)", va);
			return (0);
		}
		offset = va & PGOFSET;
		*pa = (pte & PG_FRAME) | offset;
		return (NBPG - offset);
	}
	/*
	 * Otherwise, we just walk the table ourself.
	 */
	kva = (int)&vms->vm_pmap.pm_stab;
	if (KREAD(kd, kva, &kva)) {
		_kvm_err(kd, 0, "invalid address (%x)", va);
		return (0);
	}
	return (_kvm_vatop(kd, kva, va, pa));
}