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/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index 7dc52ec..fd97e50 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -85,7 +85,7 @@
 	BUG_ON(!pte_none(*(kmap_pte-idx)));
 #endif
 	__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
-	local_flush_tlb_page(vaddr);
+	local_flush_tlb_page(NULL, vaddr);
 
 	return (void*) vaddr;
 }
@@ -113,7 +113,7 @@
 	 * this pte without first remap it
 	 */
 	pte_clear(&init_mm, vaddr, kmap_pte-idx);
-	local_flush_tlb_page(vaddr);
+	local_flush_tlb_page(NULL, vaddr);
 #endif
 	pagefault_enable();
 }