ARM: 7923/1: mm: fix dcache flush logic for compound high pages

When given a compound high page, __flush_dcache_page will only flush
the first page of the compound page repeatedly rather than the entire
set of constituent pages.

This error was introduced by:
   0b19f933 ARM: mm: Add support for flushing HugeTLB pages.

This patch corrects the logic such that all constituent pages are now
flushed.

Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/flush.c

@@ -175,16 +175,16 @@ void __flush_dcache_page(struct address_space *mapping, struct page *page)
 		unsigned long i;
 		if (cache_is_vipt_nonaliasing()) {
 			for (i = 0; i < (1 << compound_order(page)); i++) {
-				void *addr = kmap_atomic(page);
+				void *addr = kmap_atomic(page + i);
 				__cpuc_flush_dcache_area(addr, PAGE_SIZE);
 				kunmap_atomic(addr);
 			}
 		} else {
 			for (i = 0; i < (1 << compound_order(page)); i++) {
-				void *addr = kmap_high_get(page);
+				void *addr = kmap_high_get(page + i);
 				if (addr) {
 					__cpuc_flush_dcache_area(addr, PAGE_SIZE);
-					kunmap_high(page);
+					kunmap_high(page + i);
 				}
 			}
 		}