[PATCH] LoongArch: Remove superfluous flush_dcache_page() definition

[Huacai Chen]

LoongArch doesn't have cache aliases, so flush_dcache_page() is a no-op.
There is a generic implementation for this case in include/asm-generic/
cacheflush.h. So remove the superfluous flush_dcache_page() definition,
which also silences such build warnings:

   In file included from crypto/scompress.c:12:
   include/crypto/scatterwalk.h: In function 'scatterwalk_pagedone':
   include/crypto/scatterwalk.h:76:30: warning: variable 'page' set but not used [-Wunused-but-set-variable]
      76 |                 struct page *page;
         |                              ^~~~
   crypto/scompress.c: In function 'scomp_acomp_comp_decomp':
>> crypto/scompress.c:174:38: warning: unused variable 'dst_page' [-Wunused-variable]
     174 |                         struct page *dst_page = sg_page(req->dst);
         |

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202403091614.NeUw5zcv-lkp@xxxxxxxxx/
Suggested-by: Barry Song <21cnbao@xxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
 arch/loongarch/include/asm/cacheflush.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/loongarch/include/asm/cacheflush.h b/arch/loongarch/include/asm/cacheflush.h
index 80bd74106985..f8754d08a31a 100644
--- a/arch/loongarch/include/asm/cacheflush.h
+++ b/arch/loongarch/include/asm/cacheflush.h
@@ -37,8 +37,6 @@ void local_flush_icache_range(unsigned long start, unsigned long end);
 #define flush_icache_range	local_flush_icache_range
 #define flush_icache_user_range	local_flush_icache_range
 
-#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
-
 #define flush_cache_all()				do { } while (0)
 #define flush_cache_mm(mm)				do { } while (0)
 #define flush_cache_dup_mm(mm)				do { } while (0)
@@ -47,7 +45,6 @@ void local_flush_icache_range(unsigned long start, unsigned long end);
 #define flush_cache_vmap(start, end)			do { } while (0)
 #define flush_cache_vunmap(start, end)			do { } while (0)
 #define flush_icache_user_page(vma, page, addr, len)	do { } while (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)
 
-- 
2.43.0