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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 6BD3BC64EB8 for ; Tue, 9 Oct 2018 17:14:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31A48214DA for ; Tue, 9 Oct 2018 17:14:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="L3y9/iks" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 31A48214DA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726979AbeJJAcY (ORCPT ); Tue, 9 Oct 2018 20:32:24 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:38913 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726434AbeJJAcY (ORCPT ); Tue, 9 Oct 2018 20:32:24 -0400 Received: by mail-wr1-f68.google.com with SMTP id 61-v6so2672020wrb.6 for ; Tue, 09 Oct 2018 10:14:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ixmq0eTdX6XQdK50jLnhNrpgIWjhAAnM3DDCvlSc1f0=; b=L3y9/iksAIKE2JGWKiRt9NRvPE7HaQmoxOvhJlD05571FUQq3Z8nz1iNeZt7LdH1fR hrACy4j/8cA51P2eQMa11slap3S/VxYg3EieuSSx4TCDlW53zwirKRy9q5p7h0SQwS5l /2qpaFv5ENThILHgO2jdRkDwHNXlHUjO/74ZI5KKTt5QsT2r0R+F99YaSem353IkjqoZ LYYSwrb4/dx0L4cZ8u4bLy9wyUjJrVw1WhRYaAr6TILLtNcpUxJOJBdDTXOtiz8YDOvP 76L3iDIdj/PFyeo2VI7sjBa8kQqR3IFy35qz0n6o2F5lUV3yVrxNa+G/WQcqN52MS0FB kkuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ixmq0eTdX6XQdK50jLnhNrpgIWjhAAnM3DDCvlSc1f0=; b=VCITDtvqgkN7HqCQ1QNgr2DKA6iIBxw3eSAd+ShNbVoMt3/NsJ6h8YnF1JOF2gqOZl nfWL57c9eZrM6JwGCWKkzwy9FP/4QaRQgUxqw0cL8cMm8CoFzz4UdY/CEIvOlEpWarOx xy58htn7XYkfLSlHkyCrtQLwTfsyrNldhiy6EMctTQACP6bmYTkYdsZDISqQ1gItlMvM wZ1z95ajBQi29hslNP8epzzdWKP3Gp+Js1FiYVw8oHu2mDSEqxC0PTezcDrrO+/hiEVG wEsI1aDENnz6/BZbdXrj0xcL2dsD/2XCSjLzAl7s+M56RhGqXXmChvN/cra+G8mU6Uyq 5F7w== X-Gm-Message-State: ABuFfoiQ2kCKJSnXX461EaG/STw9yjwha+s7xjiwK2aFwmkw4tH0aC5w oRs8oiHualmujA04/PdQjjs= X-Google-Smtp-Source: ACcGV62t6G5rgbTtWcsN9KvMI9e1kauB2U2o+0sIhHRW//wXRAiGSF9vrYzOAQ73unsh5H4alVbArw== X-Received: by 2002:a5d:680b:: with SMTP id w11-v6mr19087047wru.186.1539105265109; Tue, 09 Oct 2018 10:14:25 -0700 (PDT) Received: from localhost.localdomain ([2a01:4f8:10b:24a5::2]) by smtp.gmail.com with ESMTPSA id f1-v6sm13467468wme.23.2018.10.09.10.14.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Oct 2018 10:14:24 -0700 (PDT) From: Nathan Chancellor To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Lukas Bulwahn , Nick Desaulniers , Nathan Chancellor Subject: [PATCH] drm/i915: Convert _print_param to a macro Date: Tue, 9 Oct 2018 10:14:01 -0700 Message-Id: <20181009171401.14980-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.19.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When building the kernel with Clang with defconfig and CONFIG_64BIT disabled, vmlinux fails to link because of the BUILD_BUG in _print_param. ld: drivers/gpu/drm/i915/i915_params.o: in function `i915_params_dump': i915_params.c:(.text+0x56): undefined reference to `__compiletime_assert_191' This function is semantically invalid unless the code is first inlined then constant folded, which doesn't work for Clang because semantic analysis happens before optimization/inlining. Converting this function to a macro avoids this problem and allows Clang to properly remove the BUILD_BUG during optimization. The output of 'objdump -D' is identically before and after this change for GCC regardless of if CONFIG_64BIT is set and allows Clang to link the kernel successfully with or without CONFIG_64BIT set. Link: https://github.com/ClangBuiltLinux/linux/issues/191 Suggested-by: Nick Desaulniers Signed-off-by: Nathan Chancellor --- drivers/gpu/drm/i915/i915_params.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 295e981e4a39..a0f20b9b6f2d 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -174,22 +174,19 @@ i915_param_named(enable_dpcd_backlight, bool, 0600, i915_param_named(enable_gvt, bool, 0400, "Enable support for Intel GVT-g graphics virtualization host support(default:false)"); -static __always_inline void _print_param(struct drm_printer *p, - const char *name, - const char *type, - const void *x) -{ - if (!__builtin_strcmp(type, "bool")) - drm_printf(p, "i915.%s=%s\n", name, yesno(*(const bool *)x)); - else if (!__builtin_strcmp(type, "int")) - drm_printf(p, "i915.%s=%d\n", name, *(const int *)x); - else if (!__builtin_strcmp(type, "unsigned int")) - drm_printf(p, "i915.%s=%u\n", name, *(const unsigned int *)x); - else if (!__builtin_strcmp(type, "char *")) - drm_printf(p, "i915.%s=%s\n", name, *(const char **)x); - else - BUILD_BUG(); -} +#define _print_param(p, name, type, x) \ +do { \ + if (!__builtin_strcmp(type, "bool")) \ + drm_printf(p, "i915.%s=%s\n", name, yesno(*(const bool *)x)); \ + else if (!__builtin_strcmp(type, "int")) \ + drm_printf(p, "i915.%s=%d\n", name, *(const int *)x); \ + else if (!__builtin_strcmp(type, "unsigned int")) \ + drm_printf(p, "i915.%s=%u\n", name, *(const unsigned int *)x); \ + else if (!__builtin_strcmp(type, "char *")) \ + drm_printf(p, "i915.%s=%s\n", name, *(const char **)x); \ + else \ + BUILD_BUG(); \ +} while (0) /** * i915_params_dump - dump i915 modparams -- 2.19.0