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:
   0b19f93 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: Steve Capper <steve.capper@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 6d5ba9a..3387e60 100644 (file)
--- a/arch/arm/mm/flush.c
+++ b/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);
                                }
                        }
                }