From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-x243.google.com (mail-wr0-x243.google.com [IPv6:2a00:1450:400c:c0c::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zxQPJ6DyWzF1kx for ; Thu, 8 Mar 2018 07:35:00 +1100 (AEDT) Received: by mail-wr0-x243.google.com with SMTP id w77so3506753wrc.6 for ; Wed, 07 Mar 2018 12:35:00 -0800 (PST) Sender: Mathieu Malaterre From: Mathieu Malaterre To: Michael Ellerman Cc: Mathieu Malaterre , Benjamin Herrenschmidt , Paul Mackerras , Balbir Singh , linuxppc-dev@lists.ozlabs.org (open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 05/21] powerpc: Avoid comparison of unsigned long >= 0 in pfn_valid Date: Wed, 7 Mar 2018 21:34:35 +0100 Message-Id: <20180307203436.23696-1-malat@debian.org> In-Reply-To: <20180225172236.29650-6-malat@debian.org> References: <20180225172236.29650-6-malat@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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): CC arch/powerpc/kernel/irq.o In file included from ./include/linux/bug.h:5:0, from ./include/linux/cpumask.h:13, from ./include/linux/smp.h:13, from ./include/linux/kernel_stat.h:5, from arch/powerpc/kernel/irq.c:35: ./include/linux/dma-mapping.h: In function ‘dma_map_resource’: ./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 --- 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 8da5d4c1cab2..6f74938483b7 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) -- 2.11.0