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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 DDF61C282D7 for ; Wed, 13 Feb 2019 20:18:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF92F222AC for ; Wed, 13 Feb 2019 20:18:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="bRPJ2lW1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394572AbfBMUSW (ORCPT ); Wed, 13 Feb 2019 15:18:22 -0500 Received: from esa1.hgst.iphmx.com ([68.232.141.245]:63574 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394556AbfBMUSV (ORCPT ); Wed, 13 Feb 2019 15:18:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1550089101; x=1581625101; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=YZUqK4Qfap9iJXTgeai1JroJ8SUKDUcCMd3sVPqcbE8=; b=bRPJ2lW1XnJAt6Kq3deax77XKlKElGX9xJ6cBWQp53i5gkyTExoTE56b HBpQuxSzB+9vuOoJ+CGep7cDxT2Xo8bP6SccHLITku3hh5Q1TUOt8/eVM piFbrFiIEG83oao0ra0ygszH8dxJNRhQjAEz+TsInulaaf95sj/TzBa32 mGb5XAetsRw8feKM+dgUmNPkZwFPE5Q4QgWFDXcIvSe6G8lUlTseEXYKn YOU7GzDXN5ErzUpxXV5qFJYBlIWakm7psJ0b9UzEOM6nVLONqT/W202FG qe/cPGLzAoNkLx7bQpfxCSmoZafYPltH0Ziop7ATdkBCmHImrbXLMSz/I w==; X-IronPort-AV: E=Sophos;i="5.58,366,1544457600"; d="scan'208";a="206321181" Received: from h199-255-45-15.hgst.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 14 Feb 2019 04:18:20 +0800 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP; 13 Feb 2019 11:58:54 -0800 Received: from jedi-01.sdcorp.global.sandisk.com (HELO jedi-01.int.fusionio.com) ([10.11.143.218]) by uls-op-cesaip02.wdc.com with ESMTP; 13 Feb 2019 12:18:20 -0800 From: Atish Patra To: linux-riscv@lists.infradead.org Cc: Atish Patra , Alan Kao , Albert Ou , Andreas Schwab , Anup Patel , Daniel Lezcano , Dmitriy Cherkasov , Guenter Roeck , Jason Cooper , Johan Hovold , linux-kernel@vger.kernel.org, Marc Zyngier , Palmer Dabbelt , Paul Walmsley , Thomas Gleixner Subject: [v5 PATCH 1/8] RISC-V: Do not wait indefinitely in __cpu_up Date: Wed, 13 Feb 2019 12:18:05 -0800 Message-Id: <1550089092-28783-2-git-send-email-atish.patra@wdc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1550089092-28783-1-git-send-email-atish.patra@wdc.com> References: <1550089092-28783-1-git-send-email-atish.patra@wdc.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In SMP path, __cpu_up waits for other CPU to come online indefinitely. This is wrong as other CPU might be disabled in machine mode and possible CPU is set to the cpus present in DT. Introduce a completion variable and waits only for a second. Signed-off-by: Atish Patra Reviewed-by: Anup Patel Reviewed-by: Christoph Hellwig --- arch/riscv/kernel/smpboot.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 6e281325..d369b669 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -39,6 +39,7 @@ void *__cpu_up_stack_pointer[NR_CPUS]; void *__cpu_up_task_pointer[NR_CPUS]; +static DECLARE_COMPLETION(cpu_running); void __init smp_prepare_boot_cpu(void) { @@ -77,6 +78,7 @@ void __init setup_smp(void) int __cpu_up(unsigned int cpu, struct task_struct *tidle) { + int ret = 0; int hartid = cpuid_to_hartid_map(cpu); tidle->thread_info.cpu = cpu; @@ -92,10 +94,16 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) task_stack_page(tidle) + THREAD_SIZE); WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle); - while (!cpu_online(cpu)) - cpu_relax(); + lockdep_assert_held(&cpu_running); + wait_for_completion_timeout(&cpu_running, + msecs_to_jiffies(1000)); - return 0; + if (!cpu_online(cpu)) { + pr_crit("CPU%u: failed to come online\n", cpu); + ret = -EIO; + } + + return ret; } void __init smp_cpus_done(unsigned int max_cpus) @@ -121,6 +129,7 @@ asmlinkage void __init smp_callin(void) * a local TLB flush right now just in case. */ local_flush_tlb_all(); + complete(&cpu_running); /* * Disable preemption before enabling interrupts, so we don't try to * schedule a CPU that hasn't actually started yet. -- 2.7.4