From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC2FBC432C0 for ; Wed, 20 Nov 2019 15:45:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AF5520714 for ; Wed, 20 Nov 2019 15:45:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732372AbfKTPpG (ORCPT ); Wed, 20 Nov 2019 10:45:06 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52620 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729743AbfKTPkR (ORCPT ); Wed, 20 Nov 2019 10:40:17 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iXS5U-0004ag-7y; Wed, 20 Nov 2019 15:40:12 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iXS5T-0004HB-BG; Wed, 20 Nov 2019 15:40:11 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Nick Desaulniers" , "James Y Knight" , "Nathan Chancellor" , "Arnd Bergmann" , "Bill Wendling" , "Linus Torvalds" , "Jakub Jelinek" , "David Howells" , "Qian Cai" , "David S. Miller" Date: Wed, 20 Nov 2019 15:37:32 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 22/83] asm-generic: fix -Wtype-limits compiler warnings In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.78-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Qian Cai commit cbedfe11347fe418621bd188d58a206beb676218 upstream. Commit d66acc39c7ce ("bitops: Optimise get_order()") introduced a compilation warning because "rx_frag_size" is an "ushort" while PAGE_SHIFT here is 16. The commit changed the get_order() to be a multi-line macro where compilers insist to check all statements in the macro even when __builtin_constant_p(rx_frag_size) will return false as "rx_frag_size" is a module parameter. In file included from ./arch/powerpc/include/asm/page_64.h:107, from ./arch/powerpc/include/asm/page.h:242, from ./arch/powerpc/include/asm/mmu.h:132, from ./arch/powerpc/include/asm/lppaca.h:47, from ./arch/powerpc/include/asm/paca.h:17, from ./arch/powerpc/include/asm/current.h:13, from ./include/linux/thread_info.h:21, from ./arch/powerpc/include/asm/processor.h:39, from ./include/linux/prefetch.h:15, from drivers/net/ethernet/emulex/benet/be_main.c:14: drivers/net/ethernet/emulex/benet/be_main.c: In function 'be_rx_cqs_create': ./include/asm-generic/getorder.h:54:9: warning: comparison is always true due to limited range of data type [-Wtype-limits] (((n) < (1UL << PAGE_SHIFT)) ? 0 : \ ^ drivers/net/ethernet/emulex/benet/be_main.c:3138:33: note: in expansion of macro 'get_order' adapter->big_page_size = (1 << get_order(rx_frag_size)) * PAGE_SIZE; ^~~~~~~~~ Fix it by moving all of this multi-line macro into a proper function, and killing __get_order() off. [akpm@linux-foundation.org: remove __get_order() altogether] [cai@lca.pw: v2] Link: http://lkml.kernel.org/r/1564000166-31428-1-git-send-email-cai@lca.pw Link: http://lkml.kernel.org/r/1563914986-26502-1-git-send-email-cai@lca.pw Fixes: d66acc39c7ce ("bitops: Optimise get_order()") Signed-off-by: Qian Cai Reviewed-by: Nathan Chancellor Cc: David S. Miller Cc: Arnd Bergmann Cc: David Howells Cc: Jakub Jelinek Cc: Nick Desaulniers Cc: Bill Wendling Cc: James Y Knight Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- include/asm-generic/getorder.h | 50 ++++++++++++++-------------------- 1 file changed, 20 insertions(+), 30 deletions(-) --- a/include/asm-generic/getorder.h +++ b/include/asm-generic/getorder.h @@ -6,24 +6,6 @@ #include #include -/* - * Runtime evaluation of get_order() - */ -static inline __attribute_const__ -int __get_order(unsigned long size) -{ - int order; - - size--; - size >>= PAGE_SHIFT; -#if BITS_PER_LONG == 32 - order = fls(size); -#else - order = fls64(size); -#endif - return order; -} - /** * get_order - Determine the allocation order of a memory size * @size: The size for which to get the order @@ -42,19 +24,27 @@ int __get_order(unsigned long size) * to hold an object of the specified size. * * The result is undefined if the size is 0. - * - * This function may be used to initialise variables with compile time - * evaluations of constants. */ -#define get_order(n) \ -( \ - __builtin_constant_p(n) ? ( \ - ((n) == 0UL) ? BITS_PER_LONG - PAGE_SHIFT : \ - (((n) < (1UL << PAGE_SHIFT)) ? 0 : \ - ilog2((n) - 1) - PAGE_SHIFT + 1) \ - ) : \ - __get_order(n) \ -) +static inline __attribute_const__ int get_order(unsigned long size) +{ + if (__builtin_constant_p(size)) { + if (!size) + return BITS_PER_LONG - PAGE_SHIFT; + + if (size < (1UL << PAGE_SHIFT)) + return 0; + + return ilog2((size) - 1) - PAGE_SHIFT + 1; + } + + size--; + size >>= PAGE_SHIFT; +#if BITS_PER_LONG == 32 + return fls(size); +#else + return fls64(size); +#endif +} #endif /* __ASSEMBLY__ */