From 2d4dc890b5c8fabd818a8586607e6843c4375e62 Mon Sep 17 00:00:00 2001 From: Ilya Loginov Date: Thu, 26 Nov 2009 09:16:19 +0100 Subject: block: add helpers to run flush_dcache_page() against a bio and a request's pages Mtdblock driver doesn't call flush_dcache_page for pages in request. So, this causes problems on architectures where the icache doesn't fill from the dcache or with dcache aliases. The patch fixes this. The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid pointless empty cache-thrashing loops on architectures for which flush_dcache_page() is a no-op. Every architecture was provided with this flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is equal 1 or do nothing otherwise. See "fix mtd_blkdevs problem with caches on some architectures" discussion on LKML for more information. Signed-off-by: Ilya Loginov Cc: Ingo Molnar Cc: David Woodhouse Cc: Peter Horton Cc: "Ed L. Cashin" Signed-off-by: Jens Axboe --- include/asm-generic/cacheflush.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/asm-generic') diff --git a/include/asm-generic/cacheflush.h b/include/asm-generic/cacheflush.h index ba4ec39a113..57b5c3c82e8 100644 --- a/include/asm-generic/cacheflush.h +++ b/include/asm-generic/cacheflush.h @@ -13,6 +13,7 @@ #define flush_cache_dup_mm(mm) do { } while (0) #define flush_cache_range(vma, start, end) do { } while (0) #define flush_cache_page(vma, vmaddr, pfn) do { } while (0) +#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0 #define flush_dcache_page(page) do { } while (0) #define flush_dcache_mmap_lock(mapping) do { } while (0) #define flush_dcache_mmap_unlock(mapping) do { } while (0) -- cgit v1.2.3