mm, arch: add generic implementation of pfn_valid() for FLATMEM

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.

[[email protected]: fix the generic pfn_valid()]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Acked-by: Guo Ren <[email protected]>		[csky]
Acked-by: Huacai Chen <[email protected]>	[LoongArch]
Acked-by: Stafford Horne <[email protected]>	[OpenRISC]
Acked-by: Michael Ellerman <[email protected]>	[powerpc]
Reviewed-by: David Hildenbrand <[email protected]>
Tested-by: Conor Dooley <[email protected]>
Cc: Brian Cain <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions