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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 46986C76186 for ; Wed, 24 Jul 2019 02:29:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1718020665 for ; Wed, 24 Jul 2019 02:29:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="eDOr7PQI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727197AbfGXC3n (ORCPT ); Tue, 23 Jul 2019 22:29:43 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:46579 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387566AbfGXC3l (ORCPT ); Tue, 23 Jul 2019 22:29:41 -0400 Received: by mail-wr1-f65.google.com with SMTP id z1so45108799wru.13; Tue, 23 Jul 2019 19:29:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=TLtx0N0iTDt+TcQGK6XUkJYJ0+fHixleXGl8p31XVfo=; b=eDOr7PQIbMwNaNWyIQeyHtYiT3PKoptD3mkASWB4ZLU3CFxrEdigBWsSZ0DDJkrsfn kSH+HmOYLdxHBx+MjSB4cyqGVjt8s5oaKjQKMxro/szqtGiwEM5YkEwirejbFsHZGhGW NiBGOOS3m8KKvMJYEIbBg6j8nHeWg86FR60Ecds00gikp9ANCQgbhxnWyGh1nT4MW+YO RyLe30sjKXyhLRvgrbYnKnRWbjI650SmFes+psMidJUMmCTAoYOFvK0v8/ovEJ4CThy/ JrXGHCzFy8ZlqLcEmdsukJNJMxahDxImt8cl/YaUsxsVb2GyAcTDInd5xjU3y3D4qcbn cJkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=TLtx0N0iTDt+TcQGK6XUkJYJ0+fHixleXGl8p31XVfo=; b=P3pO5AwfWQgdFou+tUo9vszZ5kiB/BxsF4s/293YaDr5wE380bZpTlvPiF1zB0xQlG Up6/dCciv57YAqVhgdtjUu5ViZrbDbJ/r2amNyzPZ5GlCSqJm87yzOwcEuJcy6jaOqe/ EhEIPyg34DbDq0uO/kWbKJ3IUMsagCM2N94xtgI+YD2LfHZb73O75zHehmPPcnt75beJ 4P2BwGOkdz5V+Y6OSZxwlitoDNOJu35+wh4uDw+6uQ51GY+F/6UoNCk8TipPI+yIHNAO BZr91JyVtUXm3vMDK62GpzkaM3PO8YZZa+MNm9V/4oVTXuleR8UuYd7qBqd+aexPm5Q7 5hzg== X-Gm-Message-State: APjAAAX4IciYyk77EKWxOakL1vX8rHtSGyd7z6P9SCerAPClu9EYGbGY SU5vICrvtRZ4v4dsDdsgtYI= X-Google-Smtp-Source: APXvYqxP82OlR+xwzksHk3Bqw3NSV0ilSAxJ/JRHknHnb7OTFiah0RTA+6+ucX6uPJv/uDNiZAdhZg== X-Received: by 2002:adf:f348:: with SMTP id e8mr87051410wrp.76.1563935379043; Tue, 23 Jul 2019 19:29:39 -0700 (PDT) Received: from archlinux-threadripper ([2a01:4f8:222:2f1b::2]) by smtp.gmail.com with ESMTPSA id w14sm34548442wrk.44.2019.07.23.19.29.38 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 23 Jul 2019 19:29:38 -0700 (PDT) Date: Tue, 23 Jul 2019 19:29:36 -0700 From: Nathan Chancellor To: Qian Cai Cc: akpm@linux-foundation.org, davem@davemloft.net, arnd@arndb.de, dhowells@redhat.com, jakub@redhat.com, ndesaulniers@google.com, morbo@google.com, jyknight@google.com, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] asm-generic: fix -Wtype-limits compiler warnings Message-ID: <20190724022936.GA73305@archlinux-threadripper> References: <1563914986-26502-1-git-send-email-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1563914986-26502-1-git-send-email-cai@lca.pw> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 23, 2019 at 04:49:46PM -0400, Qian Cai wrote: > The 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 almost all of this multi-line macro into a proper > function __get_order(), and leave get_order() as a single-line macro in > order to avoid compilation errors. Wouldn't it just be better to rename __get_order to get_order? > Fixes: d66acc39c7ce ("bitops: Optimise get_order()") > Signed-off-by: Qian Cai Other than that, LGTM. Reviewed-by: Nathan Chancellor