[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>

arch/sparc64/kernel/us2e_cpufreq.c

@@ -346,6 +346,9 @@ static int __init us2e_freq_init(void)
 	unsigned long manuf, impl, ver;
 	int ret;
 
+	if (tlb_type != spitfire)
+		return -ENODEV;
+
 	__asm__("rdpr %%ver, %0" : "=r" (ver));
 	manuf = ((ver >> 48) & 0xffff);
 	impl  = ((ver >> 32) & 0xffff);