sparc64: Fix page table walk for PUD hugepages

[ Upstream commit 70f3c8b ]

For a PUD hugepage entry, we need to propagate bits [32:22]
from virtual address to resolve at 4M granularity. However,
the current code was incorrectly propagating bits [29:19].
This bug can cause incorrect data to be returned for pages
backed with 16G hugepages.

Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/sparc/include/asm/tsb.h

@@ -217,7 +217,7 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
 	sllx		REG2, 32, REG2;			\
 	andcc		REG1, REG2, %g0;		\
 	be,pt		%xcc, 700f;			\
-	 sethi		%hi(0x1ffc0000), REG2;		\
+	 sethi		%hi(0xffe00000), REG2;		\
 	sllx		REG2, 1, REG2;			\
 	brgez,pn	REG1, FAIL_LABEL;		\
 	 andn		REG1, REG2, REG1;		\