[PATCH 3/2] mm/remap_pfn_range: restore missing flush

[Jeremy Fitzhardinge <jeremy@goop.org>]

Restore the cache flush and BUG_ON removed in the conversion to using
apply_to_page_range().

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citix.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
 mm/memory.c |    4 ++++
 1 file changed, 4 insertions(+)

===================================================================
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1484,6 +1484,8 @@
 	struct remap_data *rmd = data;
 	pte_t pte = pte_mkspecial(pfn_pte(rmd->pfn++, rmd->prot));
 
+	BUG_ON(!pte_none(*ptep));
+
 	set_pte_at(rmd->mm, addr, ptep, pte);
 
 	return 0;
@@ -1535,6 +1537,8 @@
 
 	BUG_ON(addr >= end);
 
+	flush_cache_range(vma, addr, end);
+
 	rmd.mm = mm;
 	rmd.pfn = pfn;
 	rmd.prot = prot;