From c39ae7f5d7ba8d3d2767a68d39209720a2a504ac Mon Sep 17 00:00:00 2001
From: uwe <uwe@NetBSD.org>
Date: Sun, 1 Jun 2008 23:07:20 +0000
Subject: [PATCH] Recycle unused _REG_EXPEVT slot in mcontext for _REG_GBR.

As the size of mcontext is not changed, we avoid the hassle of
versioning all the calls that use it.

_REG_EXPEVT was never used by any code in the tree.  Reporting EXPEVT
makes sense only for signals and in that case we pass it to userland
in ksi_trap already which is official MI way to get this (MD) information.

Old binaries running on new kernels will now have their GBR set from
new mcontext, but that's ok too, as GBR was not properly supported by
old kernels (not saved in trapframe), so old binaries couldn't have
possibly used it anyway.
---
 lib/libpthread/arch/sh3/_context_u.S | 8 +++++++-
 lib/libpthread/arch/sh3/genassym.cf  | 4 ++--
 sys/arch/sh3/include/mcontext.h      | 4 ++--
 sys/arch/sh3/sh3/sh3_machdep.c       | 8 ++++----
 4 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/lib/libpthread/arch/sh3/_context_u.S b/lib/libpthread/arch/sh3/_context_u.S
index ba2295931049..b765035d8f63 100644
--- a/lib/libpthread/arch/sh3/_context_u.S
+++ b/lib/libpthread/arch/sh3/_context_u.S
@@ -1,4 +1,4 @@
-/*	$NetBSD: _context_u.S,v 1.5 2006/01/04 17:44:53 uwe Exp $ */
+/*	$NetBSD: _context_u.S,v 1.6 2008/06/01 23:07:20 uwe Exp $ */
 
 /*
  * Copyright (c) 2003 Christian P. Groessler
@@ -58,6 +58,9 @@
 	mov.l	r14, @((_REG_R14 * 4), r1)				; \
 	/* _REG_R15 is too far to use @(disp, Rn) */			  \
 									  \
+	stc	gbr, r0							; \
+	mov.l	r0,  @((_REG_GBR * 4), r1)				; \
+									  \
 	/* in Hitachi calling convention mac regs are callee saved */	  \
 	sts	mach, r0						; \
 	mov.l	r0, @((_REG_MACH * 4), r1)				; \
@@ -93,6 +96,9 @@
 	mov.l	@((_REG_R14 * 4), r1), r14				; \
 	/* _REG_R15 is too far to use @(disp, Rn) */			  \
 									  \
+	mov.l	@((_REG_GBR * 4), r1), r0				; \
+	ldc	r0, gbr							; \
+									  \
 	/* in Hitachi calling convention mac regs are callee saved */	  \
 	mov.l	@((_REG_MACH * 4), r1), r0				; \
 	mov.l	@((_REG_MACL * 4), r1), r2				; \
diff --git a/lib/libpthread/arch/sh3/genassym.cf b/lib/libpthread/arch/sh3/genassym.cf
index c6c11e680153..4970b0693202 100644
--- a/lib/libpthread/arch/sh3/genassym.cf
+++ b/lib/libpthread/arch/sh3/genassym.cf
@@ -1,4 +1,4 @@
-#	$NetBSD: genassym.cf,v 1.7 2008/04/28 20:23:02 martin Exp $
+#	$NetBSD: genassym.cf,v 1.8 2008/06/01 23:07:20 uwe Exp $
 
 # Copyright (c) 2001 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -49,7 +49,7 @@ define _UC_FPU				_UC_FPU
 define _UC_USER				_UC_USER
 define _UC_USER_BIT			_UC_USER_BIT
 
-define	_REG_EXPEVT	_REG_EXPEVT
+define	_REG_GBR	_REG_GBR
 define	_REG_PC		_REG_PC
 define	_REG_SR		_REG_SR
 define	_REG_MACL	_REG_MACL
diff --git a/sys/arch/sh3/include/mcontext.h b/sys/arch/sh3/include/mcontext.h
index 9e15fd1f44fe..539efb53efc5 100644
--- a/sys/arch/sh3/include/mcontext.h
+++ b/sys/arch/sh3/include/mcontext.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: mcontext.h,v 1.6 2008/04/28 20:23:35 martin Exp $	*/
+/*	$NetBSD: mcontext.h,v 1.7 2008/06/01 23:07:20 uwe Exp $	*/
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -40,7 +40,7 @@
 typedef int		__greg_t;
 typedef __greg_t	__gregset_t[_NGREG];
 
-#define	_REG_EXPEVT	0
+#define	_REG_GBR	0
 #define	_REG_PC		1
 #define	_REG_SR		2
 #define	_REG_MACL	3
diff --git a/sys/arch/sh3/sh3/sh3_machdep.c b/sys/arch/sh3/sh3/sh3_machdep.c
index f791b2992d24..eab71f96bd7c 100644
--- a/sys/arch/sh3/sh3/sh3_machdep.c
+++ b/sys/arch/sh3/sh3/sh3_machdep.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: sh3_machdep.c,v 1.73 2008/06/01 00:46:01 uwe Exp $	*/
+/*	$NetBSD: sh3_machdep.c,v 1.74 2008/06/01 23:07:20 uwe Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2002 The NetBSD Foundation, Inc.
@@ -65,7 +65,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sh3_machdep.c,v 1.73 2008/06/01 00:46:01 uwe Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sh3_machdep.c,v 1.74 2008/06/01 23:07:20 uwe Exp $");
 
 #include "opt_kgdb.h"
 #include "opt_memsize.h"
@@ -583,7 +583,7 @@ cpu_getmcontext(l, mcp, flags)
 	__greg_t ras_pc;
 
 	/* Save register context. */
-	gr[_REG_EXPEVT] = tf->tf_expevt;
+	gr[_REG_GBR]    = tf->tf_gbr;
 	gr[_REG_PC]     = tf->tf_spc;
 	gr[_REG_SR]     = tf->tf_ssr;
 	gr[_REG_MACL]   = tf->tf_macl;
@@ -632,7 +632,7 @@ cpu_setmcontext(l, mcp, flags)
 		if (((tf->tf_ssr ^ gr[_REG_SR]) & PSL_USERSTATIC) != 0)
 			return (EINVAL);
 
-		/* _REG_EXPEVT not restored */
+		tf->tf_gbr    = gr[_REG_GBR];
 		tf->tf_spc    = gr[_REG_PC];
 		tf->tf_ssr    = gr[_REG_SR];
 		tf->tf_macl   = gr[_REG_MACL];