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>
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)