x86/mm: Unify remote INVLPG code

There are currently three paths through the remote flush code:

1. full invalidation
2. single page invalidation using invlpg
3. ranged invalidation using invlpg

This takes 2 and 3 and combines them in to a single path by
making the single-page one just be the start and end be start
plus a single page.  This makes placement of our tracepoint easier.

Signed-off-by: Dave Hansen <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Cc: Rik van Riel <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>

Author: hansendc

arch/x86/mm/tlb.c

@@ -102,13 +102,13 @@ static void flush_tlb_func(void *info)
 
 	if (f->flush_mm != this_cpu_read(cpu_tlbstate.active_mm))
 		return;
+	if (!f->flush_end)
+		f->flush_end = f->flush_start + PAGE_SIZE;
 
 	count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED);
 	if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
 		if (f->flush_end == TLB_FLUSH_ALL)
 			local_flush_tlb();
-		else if (!f->flush_end)
-			__flush_tlb_single(f->flush_start);
 		else {
 			unsigned long addr;
 			addr = f->flush_start;