There is a magic ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE cpp symbol that guards non-stub availability of flush_dcache_pagge. Use that to check if flush_dcache_pagg is implemented. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- include/asm-generic/cacheflush.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/cacheflush.h b/include/asm-generic/cacheflush.h index bf9bb83e9fc8d..bbbb4d4ef6516 100644 --- a/include/asm-generic/cacheflush.h +++ b/include/asm-generic/cacheflush.h @@ -2,8 +2,6 @@ #ifndef _ASM_GENERIC_CACHEFLUSH_H #define _ASM_GENERIC_CACHEFLUSH_H -#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0 - /* * The cache doesn't need to be flushed when TLB entries change when * the cache is mapped to physical memory, not virtual memory @@ -42,12 +40,14 @@ static inline void flush_cache_page(struct vm_area_struct *vma, } #endif -#ifndef flush_dcache_page +#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE static inline void flush_dcache_page(struct page *page) { } +#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0 #endif + #ifndef flush_dcache_mmap_lock static inline void flush_dcache_mmap_lock(struct address_space *mapping) { -- 2.26.2