x86: uv: introduce a means to translate from gpa -> socket_paddr

The UV BIOS has been updated to implement some of our interface
functionality differently than originally expected.  These patches update
the kernel to the bios implementation and include a few minor bug fixes
which prevent us from doing significant testing on real hardware.

This patch:

For SGI UV systems, translate from a global physical address back to a
socket physical address.  This does nothing to ensure the socket physical
address is actually addressable by the kernel.  That is the responsibility
of the user of the function.
Signed-off-by: NRobin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86/include/asm/uv/uv_hub.h

@@ -232,6 +232,19 @@ static inline unsigned long uv_gpa(void *v)
 	return uv_soc_phys_ram_to_gpa(__pa(v));
 }
 
+/* UV global physical address --> socket phys RAM */
+static inline unsigned long uv_gpa_to_soc_phys_ram(unsigned long gpa)
+{
+	unsigned long paddr = gpa & uv_hub_info->gpa_mask;
+	unsigned long remap_base = uv_hub_info->lowmem_remap_base;
+	unsigned long remap_top =  uv_hub_info->lowmem_remap_top;
+
+	if (paddr >= remap_base && paddr < remap_base + remap_top)
+		paddr -= remap_base;
+	return paddr;
+}
+
+
 /* gnode -> pnode */
 static inline unsigned long uv_gpa_to_gnode(unsigned long gpa)
 {