sparc: tsb must be flushed before tlb

This fixes a race where a cpu may re-load a tlb from a stale tsb right
after it has been flushed by a remote function call.

I still see some instability when stressing the system with parallel
kernel builds while creating memory pressure by writing to
/proc/sys/vm/nr_hugepages, but this patch improves the stability
significantly.

Signed-off-by: Dave Kleikamp <[e-mail]>
Acked-by: Bob Picco <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

arch/sparc/mm/tlb.c

···
 	}
 
 	if (!tb->active) {
-		global_flush_tlb_page(mm, vaddr);
 		flush_tsb_user_page(mm, vaddr);
+		global_flush_tlb_page(mm, vaddr);
 		goto out;
 	}