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 D1737C43381 for ; Fri, 22 Feb 2019 19:41:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 978DB2070B for ; Fri, 22 Feb 2019 19:41:48 +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="WS4zA5C3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726844AbfBVTlq (ORCPT ); Fri, 22 Feb 2019 14:41:46 -0500 Received: from esa6.hgst.iphmx.com ([216.71.154.45]:9380 "EHLO esa6.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725937AbfBVTlo (ORCPT ); Fri, 22 Feb 2019 14:41:44 -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=1550864505; x=1582400505; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=YZUqK4Qfap9iJXTgeai1JroJ8SUKDUcCMd3sVPqcbE8=; b=WS4zA5C39gGry6XAjOpX9s0ohah72q/VlQruFLNvjsY9ObTvBaW/N+Z8 E2wN5B67HZl/WvYF5+c2qJ1cjPxQPFwGlXOyXisGsyYobxGQZgQMKPECD WxTfWJ61xb9lhWR+4VPHazln5kozJgG88RbSxRxzL5TPIrIOxdPEhpxEF SGC8lOELiBvHMhfFJKwBXIliKvgdQIzEDsg2O9kF0osrS5K9i2RCfhYWX P+CGTmJT/G8sx61DY2xuaC3lR8SszM8H6SDpUolo7rfJs8npQakQxwAD9 yhFamJvLihCpvmdDh2+N6BA+xqyKsPmpzte3O9/6T24SzXu0JHZRzi9gy w==; X-IronPort-AV: E=Sophos;i="5.58,400,1544457600"; d="scan'208";a="103727134" 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; 23 Feb 2019 03:41:44 +0800 Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep02.wdc.com with ESMTP; 22 Feb 2019 11:22:03 -0800 Received: from jedi-01.sdcorp.global.sandisk.com (HELO jedi-01.int.fusionio.com) ([10.11.143.218]) by uls-op-cesaip01.wdc.com with ESMTP; 22 Feb 2019 11:41:44 -0800 From: Atish Patra To: linux-riscv@lists.infradead.org Cc: Atish Patra , Alan Kao , Albert Ou , Andreas Schwab , Anup Patel , Dmitriy Cherkasov , Johan Hovold , linux-kernel@vger.kernel.org, Palmer Dabbelt , Paul Walmsley , Thomas Gleixner Subject: [v6 PATCH 1/6] RISC-V: Do not wait indefinitely in __cpu_up Date: Fri, 22 Feb 2019 11:41:35 -0800 Message-Id: <1550864500-13652-2-git-send-email-atish.patra@wdc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1550864500-13652-1-git-send-email-atish.patra@wdc.com> References: <1550864500-13652-1-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