diff --git a/sys/arch/mips/include/locore.h b/sys/arch/mips/include/locore.h
index 5ab5a8535a33..f407318644b6 100644
--- a/sys/arch/mips/include/locore.h
+++ b/sys/arch/mips/include/locore.h
@@ -1,4 +1,4 @@
-/* $NetBSD: locore.h,v 1.38 2000/06/29 06:00:43 cgd Exp $ */
+/* $NetBSD: locore.h,v 1.39 2000/07/20 18:33:40 jeffs Exp $ */
 
 /*
  * Copyright 1996 The Board of Trustees of The Leland Stanford
@@ -223,6 +223,7 @@ extern u_int	mips_L1ICacheLSize;
 extern int	mips_L2CachePresent;
 extern u_int	mips_L2CacheLSize;
 extern u_int	mips_CacheAliasMask;
+extern u_int	mips_CachePreferMask;
 
 #ifdef MIPS3
 extern int	mips3_L1TwoWayCache;
diff --git a/sys/arch/mips/mips/locore.S b/sys/arch/mips/mips/locore.S
index bf1bed8e3f4c..b51c58005f46 100644
--- a/sys/arch/mips/mips/locore.S
+++ b/sys/arch/mips/mips/locore.S
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.S,v 1.109 2000/07/19 22:05:02 jeffs Exp $	*/
+/*	$NetBSD: locore.S,v 1.110 2000/07/20 18:33:42 jeffs Exp $	*/
 
 /*
  * Copyright (c) 1992, 1993
@@ -1297,6 +1297,7 @@ _C_LABEL(cpu_arch):
 	.globl	_C_LABEL(mips_L1DCacheLSize)
 	.globl	_C_LABEL(mips_L1ICacheLSize)
 	.globl	_C_LABEL(mips_CacheAliasMask)
+	.globl	_C_LABEL(mips_CachePreferMask)
 	.globl	_C_LABEL(mips_L2CacheSize)
 	.globl	_C_LABEL(mips_L2CacheLSize)
 	.globl	_C_LABEL(mips_L2CachePresent)
@@ -1310,6 +1311,8 @@ _C_LABEL(mips_L1ICacheLSize):
 	.word	0
 _C_LABEL(mips_CacheAliasMask):
 	.word 0
+_C_LABEL(mips_CachePreferMask):
+	.word 0
 _C_LABEL(mips_L2CacheSize):
 	.word	0
 _C_LABEL(mips_L2CacheLSize):
diff --git a/sys/arch/mips/mips/mips_machdep.c b/sys/arch/mips/mips/mips_machdep.c
index a09319f80aae..88949d54163f 100644
--- a/sys/arch/mips/mips/mips_machdep.c
+++ b/sys/arch/mips/mips/mips_machdep.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: mips_machdep.c,v 1.94 2000/07/10 23:21:16 jeffs Exp $	*/
+/*	$NetBSD: mips_machdep.c,v 1.95 2000/07/20 18:33:42 jeffs Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -52,7 +52,7 @@
 
 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
 
-__KERNEL_RCSID(0, "$NetBSD: mips_machdep.c,v 1.94 2000/07/10 23:21:16 jeffs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mips_machdep.c,v 1.95 2000/07/20 18:33:42 jeffs Exp $");
 
 #include "opt_compat_netbsd.h"
 #include "opt_compat_ultrix.h"
@@ -224,6 +224,7 @@ mips3_ConfigCache()
 	    MIPS3_CONFIG_DB);
 
 	mips_CacheAliasMask = (mips_L1DCacheSize - 1) & ~(NBPG - 1);
+	mips_CachePreferMask = max(mips_L1DCacheSize,mips_L1ICacheSize) - 1;
 
 	/*
 	 * Clear out the I and D caches.
@@ -582,6 +583,7 @@ cpu_identify()
 			/* One less alias bit with 2 way cache. */
 			mips_CacheAliasMask =
 				((mips_L1DCacheSize/2) - 1) & ~(NBPG - 1);
+			mips_CachePreferMask >>= 1;
 		}
 		else
 			printf(", direct mapped");
diff --git a/sys/arch/mips/mips/pmap.c b/sys/arch/mips/mips/pmap.c
index 485bf3793e5a..c4cd04e493c7 100644
--- a/sys/arch/mips/mips/pmap.c
+++ b/sys/arch/mips/mips/pmap.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: pmap.c,v 1.103 2000/06/29 08:11:27 mrg Exp $	*/
+/*	$NetBSD: pmap.c,v 1.104 2000/07/20 18:33:43 jeffs Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -78,7 +78,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.103 2000/06/29 08:11:27 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.104 2000/07/20 18:33:43 jeffs Exp $");
 
 /*
  *	Manages physical address maps.
@@ -2153,13 +2153,14 @@ pmap_prefer(foff, vap)
 	vaddr_t foff;
 	vaddr_t *vap;
 {
-	vaddr_t	va = *vap;
+	vaddr_t	va;
 	vsize_t d;
 
 	if (CPUISMIPS3) {
+		va = *vap;
+
 		d = foff - va;
-		/* Use 64K to prevent virtual coherency exceptions */
-		d &= (0x10000 - 1);
+		d &= mips_CachePreferMask;
 		*vap = va + d;
 	}
 }