powerpc/mm: Add SMP support to no-hash TLB handling

This commit moves the whole no-hash TLB handling out of line into a
new tlb_nohash.c file, and implements some basic SMP support using
IPIs and/or broadcast tlbivax instructions.

Note that I'm using local invalidations for D->I cache coherency.

At worst, if another processor is trying to execute the same and
has the old entry in its TLB, it will just take a fault and re-do
the TLB flush locally (it won't re-do the cache flush in any case).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index b9e1a1d..8fee696f 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -488,7 +488,7 @@
 		 * we invalidate the TLB here, thus avoiding dcbst
 		 * misbehaviour.
 		 */
-		_tlbie(address, 0 /* 8xx doesn't care about PID */);
+		_tlbil_va(address, 0 /* 8xx doesn't care about PID */);
 #endif
 		/* The _PAGE_USER test should really be _PAGE_EXEC, but
 		 * older glibc versions execute some code from no-exec