mm/memblock: introduce PHYS_ADDR_MAX

So far code was using ULLONG_MAX and type casting to obtain a
phys_addr_t with all bits set.  The typecast is necessary to silence
compiler warnings on 32-bit platforms.

Use the simpler but still type safe approach "~(phys_addr_t)0" to create a
preprocessor define for all bits set.

Link: http://lkml.kernel.org/r/20180406213809.566-1-stefan@agner.ch
Signed-off-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 7aed92624531..7c4e8f1f72d8 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -29,6 +29,7 @@
 #define LLONG_MIN       (-LLONG_MAX - 1)
 #define ULLONG_MAX      (~0ULL)
 #define SIZE_MAX        (~(size_t)0)
+#define PHYS_ADDR_MAX   (~(phys_addr_t)0)
 
 #define U8_MAX          ((u8)~0U)
 #define S8_MAX          ((s8)(U8_MAX>>1))