From 6d2170be4561293a6aa821c773687bd3f18e8206 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Thu, 18 Dec 2008 19:13:22 +0000
Subject: powerpc/4xx: Extended DCR support v2

This adds supports to the "extended" DCR addressing via the indirect
mfdcrx/mtdcrx instructions supported by some 4xx cores (440H6 and
later).

I enabled the feature for now only on AMCC 460 chips.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/sysdev/dcr-low.S | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'arch/powerpc/sysdev')

diff --git a/arch/powerpc/sysdev/dcr-low.S b/arch/powerpc/sysdev/dcr-low.S
index 2078f39..d3098ef 100644
--- a/arch/powerpc/sysdev/dcr-low.S
+++ b/arch/powerpc/sysdev/dcr-low.S
@@ -11,14 +11,20 @@
 
 #include <asm/ppc_asm.h>
 #include <asm/processor.h>
+#include <asm/bug.h>
 
 #define DCR_ACCESS_PROLOG(table) \
+	cmpli	cr0,r3,1024;	 \
 	rlwinm  r3,r3,4,18,27;   \
 	lis     r5,table@h;      \
 	ori     r5,r5,table@l;   \
 	add     r3,r3,r5;        \
+	bge-	1f;		 \
 	mtctr   r3;              \
-	bctr
+	bctr;			 \
+1:	trap;			 \
+	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0;	\
+	blr
 
 _GLOBAL(__mfdcr)
 	DCR_ACCESS_PROLOG(__mfdcr_table)
-- 
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