sh: Optimise flush_dcache_page() on SH4
If the page is not mapped into any process's address space then aliases
cannot exist in the cache. So reduce the amount of flushing we perform.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index 560ddb6..a2301da 100644
--- a/arch/sh/mm/cache-sh4.c
+++ b/arch/sh/mm/cache-sh4.c
@@ -109,6 +109,7 @@
static void sh4_flush_dcache_page(void *arg)
{
struct page *page = arg;
+ unsigned long addr = (unsigned long)page_address(page);
#ifndef CONFIG_SMP
struct address_space *mapping = page_mapping(page);
@@ -116,16 +117,8 @@
set_bit(PG_dcache_dirty, &page->flags);
else
#endif
- {
- unsigned long phys = page_to_phys(page);
- unsigned long addr = CACHE_OC_ADDRESS_ARRAY;
- int i, n;
-
- /* Loop all the D-cache */
- n = boot_cpu_data.dcache.n_aliases;
- for (i = 0; i < n; i++, addr += PAGE_SIZE)
- flush_cache_one(addr, phys);
- }
+ flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
+ (addr & shm_align_mask), page_to_phys(page));
wmb();
}