From 63f2f1279759f48f29dc5b6cc95d89699edf5a11 Mon Sep 17 00:00:00 2001
From: mhitch <mhitch@NetBSD.org>
Date: Wed, 25 Jun 1997 05:06:01 +0000
Subject: [PATCH] Someday I'll learn how the MIPS cpu works;  add some delay
 after the tlbp when switching to a new process.  This was causing a ktlbmiss
 and stack overflow panic on R3000 machines.

---
 sys/arch/mips/mips/locore_r2000.S | 6 +++---
 sys/arch/mips/mips/locore_r4000.S | 6 +++++-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/sys/arch/mips/mips/locore_r2000.S b/sys/arch/mips/mips/locore_r2000.S
index 154907edda2f..2a611bad10e5 100644
--- a/sys/arch/mips/mips/locore_r2000.S
+++ b/sys/arch/mips/mips/locore_r2000.S
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore_r2000.S,v 1.36 1997/06/23 21:45:05 mhitch Exp $	*/
+/*	$NetBSD: locore_r2000.S,v 1.37 1997/06/25 05:06:01 mhitch Exp $	*/
 
 /*
  * Copyright (c) 1992, 1993
@@ -1671,8 +1671,8 @@ LEAF(mips1_cpu_switch_resume)
 	mtc0	v0, MIPS_COP_0_TLB_HI
 	nop
 	tlbp					# probe for entry
-	nop
 	mfc0	s1, MIPS_COP_0_TLB_INDEX	# see if we found it
+	nop
 	bltz	s1, 1f				# not found
 	li	s1, MIPS_KSEG0_START
 	mtc0	s1, MIPS_COP_0_TLB_HI
@@ -1691,8 +1691,8 @@ LEAF(mips1_cpu_switch_resume)
 	mtc0	v0, MIPS_COP_0_TLB_HI
 	nop
 	tlbp					# probe for entry
-	nop
 	mfc0	s1, MIPS_COP_0_TLB_INDEX	# see if we found it
+	nop
 	bltz	s1, 1f				# not found
 	li	s1, MIPS_KSEG0_START
 	mtc0	s1, MIPS_COP_0_TLB_HI
diff --git a/sys/arch/mips/mips/locore_r4000.S b/sys/arch/mips/mips/locore_r4000.S
index 0210287b84fc..25fd3009b6ad 100644
--- a/sys/arch/mips/mips/locore_r4000.S
+++ b/sys/arch/mips/mips/locore_r4000.S
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore_r4000.S,v 1.37 1997/06/23 21:45:11 mhitch Exp $	*/
+/*	$NetBSD: locore_r4000.S,v 1.38 1997/06/25 05:06:05 mhitch Exp $	*/
 
 /*
  * Copyright (c) 1997 Jonathan Stone (hereinafter referred to as the author)
@@ -2177,7 +2177,9 @@ LEAF(mips3_cpu_switch_resume)
 	nop
 	tlbp					# probe for existing entry
 	nop
+	nop
 	mfc0	s1, MIPS_COP_0_TLB_INDEX
+	nop
 	slti	s1, s1, 8			# if found in random entry
 	bnez	s1, 2f
 	mtc0	zero, MIPS_COP_0_TLB_LO0	# flush it
@@ -2206,7 +2208,9 @@ LEAF(mips3_cpu_switch_resume)
 	nop
 	tlbp					# probe for existing entry
 	nop
+	nop
 	mfc0	s1, MIPS_COP_0_TLB_INDEX
+	nop
 	slti	s1, s1, 8			# if found in random entry
 	bnez	s1, 2f
 	mtc0	zero, MIPS_COP_0_TLB_LO0	# flush it