[SPARC64]: Do not assume sun4v chips have load-twin/store-init support.

Check the cpu type in the OBP device tree before committing to
using the optimized Niagara memcpy and memset implementation.

If we don't recognize the cpu type, use a completely generic
version.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/lib/GENcopy_to_user.S

@@ -0,0 +1,38 @@
+/* GENcopy_to_user.S: Generic sparc64 copy to userspace.
+ *
+ * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
+ */
+
+#define EX_ST(x)		\
+98:	x;			\
+	.section .fixup;	\
+	.align 4;		\
+99:	retl;			\
+	 mov	1, %o0;		\
+	.section __ex_table,"a";\
+	.align 4;		\
+	.word 98b, 99b;		\
+	.text;			\
+	.align 4;
+
+#ifndef ASI_AIUS
+#define ASI_AIUS	0x11
+#endif
+
+#define FUNC_NAME		GENcopy_to_user
+#define STORE(type,src,addr)	type##a src, [addr] ASI_AIUS
+#define EX_RETVAL(x)		0
+
+#ifdef __KERNEL__
+	/* Writing to %asi is _expensive_ so we hardcode it.
+	 * Reading %asi to check for KERNEL_DS is comparatively
+	 * cheap.
+	 */
+#define PREAMBLE					\
+	rd		%asi, %g1;			\
+	cmp		%g1, ASI_AIUS;			\
+	bne,pn		%icc, memcpy_user_stub;		\
+	 nop
+#endif
+
+#include "GENmemcpy.S"