On Wed, 25 Jan 2023 21:07:57 +0200 Mike Rapoport <rppt@xxxxxxxxxx> wrote: > Every architecture that supports FLATMEM memory model defines its own > version of pfn_valid() that essentially compares a pfn to max_mapnr. > > Use mips/powerpc version implemented as static inline as a generic > implementation of pfn_valid() and drop its per-architecture definitions arm allnoconfig: ./include/asm-generic/memory_model.h:23:19: error: static declaration of 'pfn_valid' follows non-static declaration 23 | static inline int pfn_valid(unsigned long pfn) | ^~~~~~~~~ ./arch/arm/include/asm/page.h:160:12: note: previous declaration of 'pfn_valid' with type 'int(long unsigned int)' 160 | extern int pfn_valid(unsigned long); | ^~~~~~~~~ I thought of doing --- a/arch/arm/include/asm/page.h~mm-arch-add-generic-implementation-of-pfn_valid-for-flatmem-fix +++ a/arch/arm/include/asm/page.h @@ -156,10 +156,6 @@ extern void copy_page(void *to, const vo typedef struct page *pgtable_t; -#ifdef CONFIG_HAVE_ARCH_PFN_VALID -extern int pfn_valid(unsigned long); -#endif - #include <asm/memory.h> #endif /* !__ASSEMBLY__ */ _ but I'm seeing a pfn_valid declaration in arch/arc/include/asm/page.h which might be a problem. v2, please ;)