From 092e3c8b7a21b4de6aba97538fab2be99b71f246 Mon Sep 17 00:00:00 2001
From: martin <martin@NetBSD.org>
Date: Fri, 15 Sep 2006 07:42:38 +0000
Subject: [PATCH] Do not bother to save fpu state when we are about to get rid
 of it.

---
 sys/arch/sparc64/include/cpu.h        |  3 ++-
 sys/arch/sparc64/sparc64/locore.s     | 13 ++++++++++++-
 sys/arch/sparc64/sparc64/vm_machdep.c |  6 +++---
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/sys/arch/sparc64/include/cpu.h b/sys/arch/sparc64/include/cpu.h
index f79f8db9600d..ab48b37a77b6 100644
--- a/sys/arch/sparc64/include/cpu.h
+++ b/sys/arch/sparc64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: cpu.h,v 1.55 2006/09/13 11:35:53 mrg Exp $ */
+/*	$NetBSD: cpu.h,v 1.56 2006/09/15 07:42:38 martin Exp $ */
 
 /*
  * Copyright (c) 1992, 1993
@@ -307,6 +307,7 @@ int	statintr(void *);	/* level 14 (statclock) interrupt code */
 struct fpstate64;
 void	savefpstate(struct fpstate64 *);
 void	loadfpstate(struct fpstate64 *);
+void	clearfpstate(void);
 uint64_t	probeget(paddr_t, int, int);
 int	probeset(paddr_t, int, int, uint64_t);
 
diff --git a/sys/arch/sparc64/sparc64/locore.s b/sys/arch/sparc64/sparc64/locore.s
index 37086983eba6..0aed3a181ca0 100644
--- a/sys/arch/sparc64/sparc64/locore.s
+++ b/sys/arch/sparc64/sparc64/locore.s
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.s,v 1.215 2006/09/13 11:35:53 mrg Exp $	*/
+/*	$NetBSD: locore.s,v 1.216 2006/09/15 07:42:38 martin Exp $	*/
 
 /*
  * Copyright (c) 1996-2002 Eduardo Horvath
@@ -10232,6 +10232,17 @@ Lkcerr:
 	 mov	EFAULT, %o0
 	NOTREACHED
 
+/*
+ * clearfpstate()
+ *
+ * Drops the current fpu state, without saving it.
+ */
+ENTRY(clearfpstate)
+	rdpr	%pstate, %o1		! enable FPU
+	wr	%g0, FPRS_FEF, %fprs
+	or	%o1, PSTATE_PEF, %o1
+	retl
+	 wrpr	%o1, 0, %pstate
 
 /*
  * savefpstate(f) struct fpstate *f;
diff --git a/sys/arch/sparc64/sparc64/vm_machdep.c b/sys/arch/sparc64/sparc64/vm_machdep.c
index 346236328447..6cad47e63e23 100644
--- a/sys/arch/sparc64/sparc64/vm_machdep.c
+++ b/sys/arch/sparc64/sparc64/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: vm_machdep.c,v 1.64 2006/08/31 16:49:21 matt Exp $ */
+/*	$NetBSD: vm_machdep.c,v 1.65 2006/09/15 07:42:38 martin Exp $ */
 
 /*
  * Copyright (c) 1996-2002 Eduardo Horvath.  All rights reserved.
@@ -50,7 +50,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.64 2006/08/31 16:49:21 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.65 2006/09/15 07:42:38 martin Exp $");
 
 #include "opt_coredump.h"
 
@@ -325,7 +325,7 @@ cpu_lwp_free(l, proc)
 
 	if ((fs = l->l_md.md_fpstate) != NULL) {
 		if (l == fplwp) {
-			savefpstate(fs);
+			clearfpstate();
 			fplwp = NULL;
 		}
 		free((void *)fs, M_SUBPROC);