VAX/vax_mmu.c

/* vax_mm.c - VAX memory management simulator

   Copyright (c) 1998-2002, Robert M Supnik

   Permission is hereby granted, free of charge, to any person obtaining a
   copy of this software and associated documentation files (the "Software"),
   to deal in the Software without restriction, including without limitation
   the rights to use, copy, modify, merge, publish, distribute, sublicense,
   and/or sell copies of the Software, and to permit persons to whom the
   Software is furnished to do so, subject to the following conditions:

   The above copyright notice and this permission notice shall be included in
   all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   ROBERT M SUPNIK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

   Except as contained in this notice, the name of Robert M Supnik shall not
   be used in advertising or otherwise to promote the sale, use or other dealings
   in this Software without prior written authorization from Robert M Supnik.

   This module contains the instruction simulators for

	Read		-	read virtual
	Write		-	write virtual
	ReadL(P)	-	read aligned physical longword (physical context)
	WriteL(P)	-	write aligned physical longword (physical context)
	ReadB(W)	-	read aligned physical byte (word)
	WriteB(W)	-	write aligned physical byte (word)
	Test		-	test acccess

	zap_tb		-	clear TB
	zap_tb_ent	-	clear TB entry
	chk_tb_ent	-	check TB entry
	set_map_reg	-	set up working map registers
*/

#include "vax_defs.h"
#include <setjmp.h>

struct tlbent {
	int32 tag;					/* tag */
	int32 pte;					/* pte */
};

typedef struct tlbent TLBENT;

extern uint32 *M;
extern uint32 align[4];
extern int32 PSL;
extern int32 mapen;
extern int32 p1, p2;
extern int32 P0BR, P0LR;
extern int32 P1BR, P1LR;
extern int32 SBR, SLR;
extern int32 SISR;
extern jmp_buf save_env;
extern UNIT cpu_unit;

int32 p0br, p0lr;					/* dynamic copies */
int32 p1br, p1lr;					/* altered per ucode */
int32 sbr, slr;
extern int32 mchk_va, mchk_ref;				/* for mcheck */
TLBENT stlb[VA_TBSIZE], ptlb[VA_TBSIZE];
static const int32 insert[4] = {
 0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF };
static const int32 cvtacc[16] = { 0, 0,
	TLB_ACCW (KERN)+TLB_ACCR (KERN),
	TLB_ACCR (KERN),
	TLB_ACCW (KERN)+TLB_ACCW (EXEC)+TLB_ACCW (SUPV)+TLB_ACCW (USER)+
		TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV)+TLB_ACCR (USER),
	TLB_ACCW (KERN)+TLB_ACCW (EXEC)+TLB_ACCR (KERN)+TLB_ACCR (EXEC),
	TLB_ACCW (KERN)+TLB_ACCR (KERN)+TLB_ACCR (EXEC),
	TLB_ACCR (KERN)+TLB_ACCR (EXEC),
	TLB_ACCW (KERN)+TLB_ACCW (EXEC)+TLB_ACCW (SUPV)+
		TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV),
	TLB_ACCW (KERN)+TLB_ACCW (EXEC)+
		TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV),
	TLB_ACCW (KERN)+TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV),
	TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV),
	TLB_ACCW (KERN)+TLB_ACCW (EXEC)+TLB_ACCW (SUPV)+
		TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV)+TLB_ACCR (USER),
	TLB_ACCW (KERN)+TLB_ACCW (EXEC)+
		TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV)+TLB_ACCR (USER),
	TLB_ACCW (KERN)+
		TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV)+TLB_ACCR (USER),
	TLB_ACCR (KERN)+TLB_ACCR (EXEC)+TLB_ACCR (SUPV)+TLB_ACCR (USER)
};

t_stat tlb_ex (t_value *vptr, t_addr addr, UNIT *uptr, int32 sw);
t_stat tlb_dep (t_value val, t_addr addr, UNIT *uptr, int32 sw);
t_stat tlb_reset (DEVICE *dptr);

TLBENT fill (t_addr va, int32 lnt, int32 acc, int32 *stat);
int32 ReadB (t_addr pa);
void WriteB (t_addr pa, int32 val);
int32 ReadW (t_addr pa);
void WriteW (t_addr pa, int32 val);
int32 ReadL (t_addr pa);
void WriteL (t_addr pa, int32 val);
int32 ReadLP (t_addr pa);
void WriteLP (t_addr pa, int32 val);
extern int32 ReadIO (t_addr pa, int32 lnt);
extern void WriteIO (t_addr pa, int32 val, int32 lnt);
extern int32 ReadReg (t_addr pa, int32 lnt);
extern void WriteReg (t_addr pa, int32 val, int32 lnt);

/* TLB data structures

   tlb_dev	pager device descriptor
   tlb_unit	pager units
   pager_reg	pager register list
*/

UNIT tlb_unit[] = {
	{ UDATA (NULL, UNIT_FIX, VA_TBSIZE * 2) },
	{ UDATA (NULL, UNIT_FIX, VA_TBSIZE * 2) }  };

REG tlb_reg[] = {
	{ NULL }  };

DEVICE tlb_dev = {
	"TLB", tlb_unit, tlb_reg, NULL,
	2, 16, VA_N_TBI * 2, 1, 16, 32,
	&tlb_ex, &tlb_dep, &tlb_reset,
	NULL, NULL, NULL };

/* Read and write virtual

   These routines logically fall into three phases:

   1.	Look up the virtual address in the translation buffer, calling
	the fill routine on a tag mismatch or access mismatch (invalid
	tlb entries have access = 0 and thus always mismatch).  The
	fill routine handles all errors.  If the resulting physical
	address is aligned, do an aligned physical read or write.
   2.	Test for unaligned across page boundaries.  If cross page, look
	up the physical address of the second page.  If not cross page,
	the second physical address is the same as the first.
   3.	Using the two physical addresses, do an unaligned read or
	write, with three cases: unaligned long, unaligned word within
	a longword, unaligned word crossing a longword boundary.
*/

/* Read virtual

   Inputs:
	va	=	virtual address
	lnt	=	length code (BWLQ)
	acc	=	access code (KESU)
   Output:
	returned data, right justified in 32b longword
*/

int32 Read (t_addr va, int32 lnt, int32 acc)
{
int32 vpn, off, tbi, pa;
int32 pa1, bo, sc, wl, wh;
TLBENT xpte;

mchk_va = va;
if (mapen) {						/* mapping on? */
	vpn = VA_GETVPN (va);				/* get vpn, offset */
	off = VA_GETOFF (va);
	tbi = VA_GETTBI (vpn);
	xpte = (va & VA_S0)? stlb[tbi]: ptlb[tbi];	/* access tlb */
	if (((xpte.pte & acc) == 0) || (xpte.tag != vpn) ||
	    ((acc & TLB_WACC) && ((xpte.pte & TLB_M) == 0)))
	    xpte = fill (va, lnt, acc, NULL);		/* fill if needed */
	pa = (xpte.pte & TLB_PFN) | off;  }		/* get phys addr */
else pa = va & PAMASK;
if ((pa & (lnt - 1)) == 0) {				/* aligned? */
	if (lnt >= L_LONG) return ReadL (pa);		/* long, quad? */
	if (lnt == L_WORD) return ReadW (pa);		/* word? */
	return ReadB (pa);  }				/* byte */
if (mapen && ((off + lnt) > VA_PAGSIZE)) {		/* cross page? */
	vpn = VA_GETVPN (va + lnt);			/* vpn 2nd page */
	tbi = VA_GETTBI (vpn);
	xpte = (va & VA_S0)? stlb[tbi]: ptlb[tbi];	/* access tlb */
	if (((xpte.pte & acc) == 0) || (xpte.tag != vpn) ||
	    ((acc & TLB_WACC) && ((xpte.pte & TLB_M) == 0)))
	    xpte = fill (va + lnt, lnt, acc, NULL);	/* fill if needed */
	pa1 = (xpte.pte & TLB_PFN) | VA_GETOFF (va + 4);  }
else pa1 = (pa + 4) & PAMASK;				/* not cross page */
bo = pa & 3;
if (lnt >= L_LONG) {					/* lw unaligned? */
	sc = bo << 3;
	wl = ReadL (pa);				/* read both lw */
	wh = ReadL (pa1);				/* extract */
	return (((wl >> sc) & align[bo]) | (wh << (32 - sc)));  }
else if (bo == 1) return ((ReadL (pa) >> 8) & WMASK);
else {	wl = ReadL (pa);				/* word cross lw */
	wh = ReadL (pa1);				/* read, extract */
	return (((wl >> 24) & 0xFF) | ((wh & 0xFF) << 8));  }
}

/* Write virtual

   Inputs:
	va	=	virtual address
	val	=	data to be written, right justified in 32b lw
	lnt	=	length code (BWLQ)
	acc	=	access code (KESU)
   Output:
	none
*/

void Write (t_addr va, int32 val, int32 lnt, int32 acc)
{
int32 vpn, off, tbi, pa;
int32 pa1, bo, sc, wl, wh;
TLBENT xpte;

mchk_va = va;
if (mapen) {
	vpn = VA_GETVPN (va);
	off = VA_GETOFF (va);
	tbi = VA_GETTBI (vpn);
	xpte = (va & VA_S0)? stlb[tbi]: ptlb[tbi];	/* access tlb */
	if (((xpte.pte & acc) == 0) || (xpte.tag != vpn) ||
	    ((xpte.pte & TLB_M) == 0))
	    xpte = fill (va, lnt, acc, NULL);
	pa = (xpte.pte & TLB_PFN) | off;  }
else pa = va & PAMASK;
if ((pa & (lnt - 1)) == 0) {				/* aligned? */
	if (lnt >= L_LONG) WriteL (pa, val);		/* long, quad? */
	else if (lnt == L_WORD) WriteW (pa, val);	/* word? */
	else WriteB (pa, val);				/* byte */
	return;  }
if (mapen && ((off + lnt) > VA_PAGSIZE)) {
	vpn = VA_GETVPN (va + 4);
	tbi = VA_GETTBI (vpn);
	xpte = (va & VA_S0)? stlb[tbi]: ptlb[tbi];	/* access tlb */
	if (((xpte.pte & acc) == 0) || (xpte.tag != vpn) ||
	    ((xpte.pte & TLB_M) == 0))
	    xpte = fill (va + lnt, lnt, acc, NULL);
	pa1 = (xpte.pte & TLB_PFN) | VA_GETOFF (va + 4);  }
else pa1 = (pa + 4) & PAMASK;
bo = pa & 3;
wl = ReadL (pa);
if (lnt >= L_LONG) {
	sc = bo << 3;
	wh = ReadL (pa1);
	wl = (wl & insert[bo]) | (val << sc);
	wh = (wh & ~insert[bo]) | ((val >> (32 - sc)) & insert[bo]);
	WriteL (pa, wl);
	WriteL (pa1, wh);  }
else if (bo == 1) {
	wl = (wl & 0xFF0000FF) | (val << 8);
	WriteL (pa, wl);  }
else {	wh = ReadL (pa1);
	wl = (wl & 0x00FFFFFF) | (val << 24);
	wh = (wh & 0xFFFFFF00) | ((val >> 8) & 0xFF);
	WriteL (pa, wl);
	WriteL (pa1, wh);  }
return;
}

/* Test access to a byte (VAX PROBEx) */

int32 Test (int32 va, int32 acc, int32 *status)
{
int32 vpn, off, tbi;
TLBENT xpte;

*status = PR_OK;					/* assume ok */
if (mapen) {						/* mapping on? */
	vpn = VA_GETVPN (va);				/* get vpn, off */
	off = VA_GETOFF (va);
	tbi = VA_GETTBI (vpn);
	xpte = (va & VA_S0)? stlb[tbi]: ptlb[tbi];	/* access tlb */
	if ((xpte.pte & acc) && (xpte.tag == vpn))	/* TB hit, acc ok? */ 
	    return (xpte.pte & TLB_PFN) | off;
	xpte = fill (va, L_BYTE, acc, status);		/* fill TB */
	if (*status == PR_OK) return (xpte.pte & TLB_PFN) | off;
	else return -1;  }
return va & PAMASK;					/* ret phys addr */
}

/* Read aligned physical (in virtual context, unless indicated)

   Inputs:
	pa	=	physical address, naturally aligned
   Output:
	returned data, right justified in 32b longword
*/

int32 ReadB (t_addr pa)
{
int32 dat;

if (ADDR_IS_MEM (pa)) dat = M[pa >> 2];
else {	mchk_ref = REF_V;
	if (ADDR_IS_IO (pa)) dat = ReadIO (pa, L_BYTE);
	else dat = ReadReg (pa, L_BYTE);  }
return ((dat >> ((pa & 3) << 3)) & BMASK);
}

int32 ReadW (t_addr pa)
{
int32 dat;

if (ADDR_IS_MEM (pa)) dat = M[pa >> 2];
else {	mchk_ref = REF_V;
	if (ADDR_IS_IO (pa)) dat = ReadIO (pa, L_WORD);
	else dat = ReadReg (pa, L_WORD);  }
return ((dat >> ((pa & 2)? 16: 0)) & WMASK);
}

int32 ReadL (t_addr pa)
{
if (ADDR_IS_MEM (pa)) return M[pa >> 2];
mchk_ref = REF_V;
if (ADDR_IS_IO (pa)) return ReadIO (pa, L_LONG);
return ReadReg (pa, L_LONG);
}

int32 ReadLP (t_addr pa)
{
if (ADDR_IS_MEM (pa)) return M[pa >> 2];
mchk_va = pa;
mchk_ref = REF_P;
if (ADDR_IS_IO (pa)) return ReadIO (pa, L_LONG);
return ReadReg (pa, L_LONG);
}

/* Write aligned physical (in virtual context, unless indicated)

   Inputs:
	pa	=	physical address, naturally aligned
	val	=	data to be written, right justified in 32b longword
   Output:
	none
*/

void WriteB (t_addr pa, int32 val)
{
if (ADDR_IS_MEM (pa)) {
	int32 id = pa >> 2;
	int32 sc = (pa & 3) << 3;
	int32 mask = 0xFF << sc;
	M[id] = (M[id] & ~mask) | (val << sc);  }
else {	mchk_ref = REF_V;
	if (ADDR_IS_IO (pa)) WriteIO (pa, val, L_BYTE);
	else WriteReg (pa, val, L_BYTE);  }
return;
}

void WriteW (t_addr pa, int32 val)
{
if (ADDR_IS_MEM (pa)) {
	int32 id = pa >> 2;
	M[id] = (pa & 2)? (M[id] & 0xFFFF) | (val << 16):
	    (M[id] & ~0xFFFF) | val;  }
else {	mchk_ref = REF_V;
	if (ADDR_IS_IO (pa)) WriteIO (pa, val, L_WORD);
	else WriteReg (pa, val, L_WORD);  }
return;
}

void WriteL (t_addr pa, int32 val)
{
if (ADDR_IS_MEM (pa)) M[pa >> 2] = val;
else {	mchk_ref = REF_V;
	if (ADDR_IS_IO (pa)) WriteIO (pa, val, L_LONG);
	else WriteReg (pa, val, L_LONG);  }
return;
}

void WriteLP (t_addr pa, int32 val)
{
if (ADDR_IS_MEM (pa)) M[pa >> 2] = val;
else {	mchk_va = pa;
	mchk_ref = REF_P;
	if (ADDR_IS_IO (pa)) WriteIO (pa, val, L_LONG);
	else WriteReg (pa, val, L_LONG);  }
return;
}

/* TLB fill

   This routine fills the TLB after a tag or access mismatch, or
   on a write if pte<m> = 0.  It fills the TLB and returns the
   pte to the caller.  On an error, it aborts directly to the
   fault handler in the CPU.

   If called from map (VAX PROBEx), the error status is returned
   to the caller, and no fault occurs.
*/

#define MM_ERR(param) { \
	if (stat) { *stat = param; return zero_pte;  } \
	p1 = MM_PARAM (acc & TLB_WACC, param); \
	p2 = va; \
	ABORT ((param & PR_TNV)? ABORT_TNV: ABORT_ACV); }

TLBENT fill (t_addr va, int32 lnt, int32 acc, int32 *stat)
{
int32 ptidx = (((uint32) va) >> 7) & ~03;
int32 tlbpte, ptead, pte, tbi, vpn;
static TLBENT zero_pte = { 0, 0 };

if (va & VA_S0) {					/* system space? */
	if (ptidx >= slr) MM_ERR (PR_LNV);		/* system */
	ptead = sbr + ptidx;  }
else {	if (va & VA_P1) {				/* P1? */
	    if (ptidx < p1lr) MM_ERR (PR_LNV);
	    ptead = p1br + ptidx;  }
	else {						/* P0 */
	    if (ptidx >= p0lr)
	    MM_ERR (PR_LNV);
	    ptead = p0br + ptidx;  }
	if ((ptead & VA_S0) == 0)
	    ABORT (STOP_PPTE);				/* ppte must be sys */
	vpn = VA_GETVPN (ptead);			/* get vpn, tbi */
	tbi = VA_GETTBI (vpn);
	if (stlb[tbi].tag != vpn) {			/* in sys tlb? */
	    ptidx = ((uint32) ptead) >> 7;		/* xlate like sys */
	    if (ptidx >= slr) MM_ERR (PR_PLNV);
	    pte = ReadLP (sbr + ptidx);			/* get system pte */
	    if ((pte & PTE_V) == 0) MM_ERR (PR_PTNV);	/* spte TNV? */
	    stlb[tbi].tag = vpn;			/* set stlb tag */
	    stlb[tbi].pte = cvtacc[PTE_GETACC (pte)] |
		((pte << VA_N_OFF) & TLB_PFN);  }	/* set stlb data */
	ptead = (stlb[tbi].pte & TLB_PFN) | VA_GETOFF (ptead);  }
pte = ReadL (ptead);					/* read pte */
tlbpte = cvtacc[PTE_GETACC (pte)] |			/* cvt access */
	((pte << VA_N_OFF) & TLB_PFN);			/* set addr */
if ((tlbpte & acc) == 0) MM_ERR (PR_ACV);		/* chk access */
if ((pte & PTE_V) == 0) MM_ERR (PR_TNV);		/* check valid */
if (acc & TLB_WACC) {					/* write? */
	if ((pte & PTE_M) == 0) WriteL (ptead, pte | PTE_M);
	tlbpte = tlbpte | TLB_M;  }			/* set M */
vpn = VA_GETVPN (va);
tbi = VA_GETTBI (vpn);
if ((va & VA_S0) == 0) {				/* process space? */
	ptlb[tbi].tag = vpn;				/* store tlb ent */
	ptlb[tbi].pte = tlbpte;
	return ptlb[tbi];  }
stlb[tbi].tag = vpn;					/* system space */
stlb[tbi].pte = tlbpte;					/* store tlb ent */
return stlb[tbi];
}

/* Utility routines */

extern void set_map_reg (void)
{
p0br = P0BR & ~03;
p1br = (P1BR - 0x800000) & ~03;				/* VA<30> >> 7 */
sbr = (SBR - 0x1000000) & ~03;				/* VA<31> >> 7 */
p0lr = (P0LR << 2);
p1lr = (P1LR << 2) + 0x800000;				/* VA<30> >> 7 */
slr = (SLR << 2) + 0x1000000;				/* VA<31> >> 7 */
return;
}

/* Zap process (0) or whole (1) tb */

void zap_tb (int stb)
{
int32 i;

for (i = 0; i < VA_TBSIZE; i++) {
	ptlb[i].tag = ptlb[i].pte = -1;
	if (stb) stlb[i].tag = stlb[i].pte = -1;  }
return;
}

/* Zap single tb entry corresponding to va */

void zap_tb_ent (int32 va)
{
int32 tbi = VA_GETTBI (VA_GETVPN (va));

if (va & VA_S0) stlb[tbi].tag = stlb[tbi].pte = -1;
else ptlb[tbi].tag = ptlb[tbi].pte = -1;
return;
}

/* Check for tlb entry corresponding to va */

t_bool chk_tb_ent (int32 va)
{
int32 vpn = VA_GETVPN (va);
int32 tbi = VA_GETTBI (vpn);
TLBENT xpte;

xpte = (va & VA_S0)? stlb[tbi]: ptlb[tbi];
if (xpte.tag == vpn) return TRUE;
return FALSE;
}

/* TLB examine */

t_stat tlb_ex (t_value *vptr, t_addr addr, UNIT *uptr, int32 sw)
{
int32 tlbn = uptr - tlb_unit;
int32 idx = addr >> 1;

if (idx >= VA_TBSIZE) return SCPE_NXM;
if (addr & 1) *vptr = ((uint32) (tlbn? stlb[idx].pte: ptlb[idx].pte));
else *vptr = ((uint32) (tlbn? stlb[idx].tag: ptlb[idx].tag));
return SCPE_OK;
}

/* TLB deposit */

t_stat tlb_dep (t_value val, t_addr addr, UNIT *uptr, int32 sw)
{
int32 tlbn = uptr - tlb_unit;
int32 idx = addr >> 1;

if (idx >= VA_TBSIZE) return SCPE_NXM;
if (addr & 1) {
	if (tlbn) stlb[idx].pte = (int32) val;
	else ptlb[idx].pte = (int32) val;  }
else {	if (tlbn) stlb[idx].tag = (int32) val;
	else ptlb[idx].tag = (int32) val;  }
return SCPE_OK;
}

/* TLB reset */

t_stat tlb_reset (DEVICE *dptr)
{
int32 i;

for (i = 0; i < VA_TBSIZE; i++)
	stlb[i].tag = ptlb[i].tag = stlb[i].pte = ptlb[i].pte = -1;
return SCPE_OK;
}