[SPARC64]: Detect sun4v early in boot process.

We look for "SUNW,sun4v" in the 'compatible' property
of the root OBP device tree node.

Protect every %ver register access, to make sure it is
not touched on sun4v, as %ver is hyperprivileged there.

Lock kernel TLB entries using hypervisor calls instead of
calls into OBP.

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

include/asm-sparc64/head.h

@@ -24,6 +24,12 @@
 #define PANTHER_IMPL		0x0019 /* Ultra-IV+   */
 #define SERRANO_IMPL		0x0022 /* Ultra-IIIi+ */
 
+#define BRANCH_IF_SUN4V(tmp1,label)		\
+	sethi	%hi(is_sun4v), %tmp1;		\
+	lduw	[%tmp1 + %lo(is_sun4v)], %tmp1; \
+	brnz,pn	%tmp1, label;			\
+	 nop
+
 #define BRANCH_IF_CHEETAH_BASE(tmp1,tmp2,label)	\
 	rdpr	%ver, %tmp1;			\
 	sethi	%hi(__CHEETAH_ID), %tmp2;	\