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authorIlya Loginov <isloginov@gmail.com>2009-11-26 09:16:19 +0100
committerJens Axboe <jens.axboe@oracle.com>2009-11-26 09:16:19 +0100
commit2d4dc890b5c8fabd818a8586607e6843c4375e62 (patch)
tree9976ed7b0eed0056f8289aeb6a2b0abf8c940454 /arch/x86/include
parentcfq: Make use of service count to estimate the rb_key offset (diff)
downloadlinux-2d4dc890b5c8fabd818a8586607e6843c4375e62.tar.xz
linux-2d4dc890b5c8fabd818a8586607e6843c4375e62.zip
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 <isloginov@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Peter Horton <phorton@bitbox.co.uk> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/cacheflush.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h
index b54f6afe7ec4..9076add593a8 100644
--- a/arch/x86/include/asm/cacheflush.h
+++ b/arch/x86/include/asm/cacheflush.h
@@ -12,6 +12,7 @@ static inline void flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end) { }
static inline void flush_cache_page(struct vm_area_struct *vma,
unsigned long vmaddr, unsigned long pfn) { }
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
static inline void flush_dcache_page(struct page *page) { }
static inline void flush_dcache_mmap_lock(struct address_space *mapping) { }
static inline void flush_dcache_mmap_unlock(struct address_space *mapping) { }