Commit b4c89276 authored by Matt Fleming's avatar Matt Fleming
Browse files

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: default avatarMatt Fleming <matt@console-pimps.org>
parent 3f5ab768

arch/sh/mm/cache-sh4.c

+3 −10
Original line number Diff line number Diff line
@@ -109,6 +109,7 @@ static inline void flush_cache_one(unsigned long start, unsigned long phys) 
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 @@ static void sh4_flush_dcache_page(void *arg) 
		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();

}