X86: uv: implement a gru_read_gpa kernel function

The BIOS has decided to store a pointer to the partition reserved page in
a scratch MMR.  The GRU is only able to read an MMR using a vload
instruction.  The gru_read_gpa() function will implemented.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h
index 46990bc..f7b553a 100644
--- a/drivers/misc/sgi-gru/grutables.h
+++ b/drivers/misc/sgi-gru/grutables.h
@@ -224,6 +224,7 @@
 	atomic_long_t flush_tlb_gru_zero_asid;
 
 	atomic_long_t copy_gpa;
+	atomic_long_t read_gpa;
 
 	atomic_long_t mesq_receive;
 	atomic_long_t mesq_receive_none;