sh: Ensure all PG_dcache_dirty pages are written back.

With some of the cache rework an address aliasing optimization was added,
but this managed to fail on certain mappings resulting in pages with
PG_dcache_dirty set never writing back their dcache lines. This patch
reverts to the earlier behaviour of simply always writing back when the
dirty bit is set.

Signed-off-by: Markus Pietrek <Markus.Pietrek@emtrion.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 2 insertions, 6 deletions

diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index e9415d3ea94a..b8607fa7ae12 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -133,12 +133,8 @@ void __update_cache(struct vm_area_struct *vma,
         page = pfn_to_page(pfn);
         if (pfn_valid(pfn)) {
                 int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags);
-                if (dirty) {
-                        unsigned long addr = (unsigned long)page_address(page);
-
-                        if (pages_do_alias(addr, address & PAGE_MASK))
-                                __flush_purge_region((void *)addr, PAGE_SIZE);
-                }
+                if (dirty)
+                        __flush_purge_region(page_address(page), PAGE_SIZE);
         }
 }