[PATCH 07/29] asm-generic: improve the flush_dcache_page stub

From: Christoph Hellwig
Date: Fri May 15 2020 - 10:37:41 EST


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