From nobody Wed Dec 17 21:14:20 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39BE8C04FE0 for ; Wed, 16 Aug 2023 09:50:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243590AbjHPJua (ORCPT ); Wed, 16 Aug 2023 05:50:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243619AbjHPJuM (ORCPT ); Wed, 16 Aug 2023 05:50:12 -0400 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EC41AD1 for ; Wed, 16 Aug 2023 02:50:10 -0700 (PDT) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8Cxh+jRm9xkxhQZAA--.15873S3; Wed, 16 Aug 2023 17:50:09 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxPCPQm9xkOeZbAA--.10301S2; Wed, 16 Aug 2023 17:50:08 +0800 (CST) From: Tiezhu Yang To: Huacai Chen Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn Subject: [PATCH] LoongArch: Put the body of play_dead() into arch_cpu_idle_dead() Date: Wed, 16 Aug 2023 17:50:08 +0800 Message-Id: <1692179408-32740-1-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 X-CM-TRANSID: AQAAf8DxPCPQm9xkOeZbAA--.10301S2 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoWxZw1xCw4xGF43tFy7CFy3trc_yoW5Gr15pF yUAryDJr4Fgrn7Z34DJ3yrWr98Jr9rGw1a9a17AFWrAa17XF1DXrZYyas0qFnYqayF9a40 qayrW3yFvF4UuabCm3ZEXasCq-sJn29KB7ZKAUJUUUUr529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9Yb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUXVWUAwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU AVWUtwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMxCIbckI1I0E14v2 6r1Y6r17MI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17 CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF 0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIx AIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnIWIev Ja73UjIFyTuYvjxUc0eHDUUUU Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The initial aim is to silence the following objtool warning: arch/loongarch/kernel/process.o: warning: objtool: arch_cpu_idle_dead() fal= ls through to next function start_thread() According to tools/objtool/Documentation/objtool.txt, this is because the last instruction of arch_cpu_idle_dead() is a call to a noreturn function play_dead(). In order to silence the warning, one simple way is to add the noreturn function play_dead() to objtool's hard-coded global_noreturns array, that is to say, just put "NORETURN(play_dead)" into tools/objtool/noreturns.h, it works well. But I noticed that play_dead() is only defined once and only called by arch_cpu_idle_dead(), so put the body of play_dead() into the caller arch_cpu_idle_dead(), then remove the noreturn function play_dead() is an alternative way which can reduce the overhead of the function call at the same time. Signed-off-by: Tiezhu Yang --- arch/loongarch/include/asm/smp.h | 2 -- arch/loongarch/kernel/process.c | 7 ------- arch/loongarch/kernel/smp.c | 2 +- 3 files changed, 1 insertion(+), 10 deletions(-) diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/= smp.h index 416b653..66ecb48 100644 --- a/arch/loongarch/include/asm/smp.h +++ b/arch/loongarch/include/asm/smp.h @@ -98,8 +98,6 @@ static inline void __cpu_die(unsigned int cpu) { loongson_cpu_die(cpu); } - -extern void __noreturn play_dead(void); #endif =20 #endif /* __ASM_SMP_H */ diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/proces= s.c index 2e04eb0..4ee1e9d 100644 --- a/arch/loongarch/kernel/process.c +++ b/arch/loongarch/kernel/process.c @@ -61,13 +61,6 @@ EXPORT_SYMBOL(__stack_chk_guard); unsigned long boot_option_idle_override =3D IDLE_NO_OVERRIDE; EXPORT_SYMBOL(boot_option_idle_override); =20 -#ifdef CONFIG_HOTPLUG_CPU -void __noreturn arch_cpu_idle_dead(void) -{ - play_dead(); -} -#endif - asmlinkage void ret_from_fork(void); asmlinkage void ret_from_kernel_thread(void); =20 diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c index 8ea1bbc..6667b0a 100644 --- a/arch/loongarch/kernel/smp.c +++ b/arch/loongarch/kernel/smp.c @@ -317,7 +317,7 @@ void loongson_cpu_die(unsigned int cpu) mb(); } =20 -void play_dead(void) +void __noreturn arch_cpu_idle_dead(void) { register uint64_t addr; register void (*init_fn)(void); --=20 2.1.0