[PATCH] m68k: make __pfn_to_phys() and __phys_to_pfn() available for !MMU

[Mike Rapoport]

Recent changes that obsoleted DISCONTIGMEM on m68k switched the MMU variant
to use generic definitions of __pfn_to_phys() and __phys_to_pfn(), but
missed the !MMU variant which caused a build failure:

All errors (new ones prefixed by >>):

   drivers/media/common/videobuf2/videobuf2-dma-contig.c: In function 'vb2_dc_get_userptr':
>> drivers/media/common/videobuf2/videobuf2-dma-contig.c:509:5: error: implicit declaration of function '__pfn_to_phys' [-Werror=implicit-function-declaration]
     509 |     __pfn_to_phys(nums[0]), size, buf->dma_dir, 0);
         |     ^~~~~~~~~~~~~
   cc1: some warnings being treated as errors

Enable __pfn_to_phys() and __phys_to_pfn() on !MMU builds.

Fixes: 4bfc848e0981 ("m68k/mm: enable use of generic memory_model.h for !DISCONTIGMEM")
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
---
 arch/m68k/include/asm/page.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/m68k/include/asm/page.h b/arch/m68k/include/asm/page.h
index 6116d7094292..97087dd3ca6d 100644
--- a/arch/m68k/include/asm/page.h
+++ b/arch/m68k/include/asm/page.h
@@ -62,7 +62,7 @@ extern unsigned long _ramend;
 #include <asm/page_no.h>
 #endif
 
-#ifdef CONFIG_DISCONTIGMEM
+#if !defined(CONFIG_MMU) || defined(CONFIG_DISCONTIGMEM)
 #define __phys_to_pfn(paddr)	((unsigned long)((paddr) >> PAGE_SHIFT))
 #define __pfn_to_phys(pfn)	PFN_PHYS(pfn)
 #endif
-- 
2.28.0