From 603b892200e653dd7e86a0e4a315561534d97441 Mon Sep 17 00:00:00 2001 From: Mathieu Malaterre Date: Wed, 7 Mar 2018 21:34:35 +0100 Subject: [PATCH] powerpc: Avoid comparison of unsigned long >= 0 in pfn_valid() Rewrite comparison since all values compared are of type `unsigned long`. Instead of using unsigned properties and rewriting the original code as: (originally suggested by Segher Boessenkool ) #define pfn_valid(pfn) \ (((pfn) - ARCH_PFN_OFFSET) < (max_mapnr - ARCH_PFN_OFFSET)) Prefer a static inline function to make code as readable as possible. Fix a warning (treated as error in W=1): arch/powerpc/include/asm/page.h:129:32: error: comparison of unsigned expression >= 0 is always true [-Werror=type-limits] #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) ^ Suggested-by: Christophe Leroy Signed-off-by: Mathieu Malaterre Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/page.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index d5f1c41b7dba..dec9ce5ba8af 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -126,7 +126,15 @@ extern long long virt_phys_offset; #ifdef CONFIG_FLATMEM #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) -#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) +#ifndef __ASSEMBLY__ +extern unsigned long max_mapnr; +static inline bool pfn_valid(unsigned long pfn) +{ + unsigned long min_pfn = ARCH_PFN_OFFSET; + + return pfn >= min_pfn && pfn < max_mapnr; +} +#endif #endif #define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT) -- 2.30.2