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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C803C77B7A for ; Sat, 3 Jun 2023 20:08:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229487AbjFCUI4 (ORCPT ); Sat, 3 Jun 2023 16:08:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231874AbjFCUIq (ORCPT ); Sat, 3 Jun 2023 16:08:46 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 147BC1B1 for ; Sat, 3 Jun 2023 13:07:55 -0700 (PDT) Message-ID: <20230603200459.889612295@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1685822823; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=Y46eTbENCwKeEacqCP+RntAtFJd0WeB3KmTST49uhjE=; b=uzaFJoAicXXB1OMPQ6488zyFUrKvJ+MPs3GtqQZR8wA3AR9I/3Bpk6mhRkDLuzKTs0S4Mq HgrPcsOBgoErTzLeUSC/+IpopPE7KNuzZCR8kUEoUnRMIcNCZOrA+kJnl3wahqoDoXP5bv DrZ/THD2rPTj1pIBOL0YG+eKuE8anGCStrObe7EVv8TL4WvGnMjIcp3agjPnvm31M6qXjd WRNpJPqUo1CCMo+OmYXl4HAD4OnMS44D5N6COtOgUAzOw3uKdGQAYcO7GZ3JMvTMCMzFPb IkkWRnekR6wHvnZnLUbMJT7qPoMcPsjFGh89ILg8vcX7AzMWH13sAmDaid2HbA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1685822823; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=Y46eTbENCwKeEacqCP+RntAtFJd0WeB3KmTST49uhjE=; b=8FveJwVoVmiP1lJU+Lhh3x5CU6ewAbCz36APqoBREfMpFa74nq/tEGtvLd+8xDNEsCSGe+ MJtScKp7oSMZFqBw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Ashok Raj , Dave Hansen , Tony Luck , Arjan van de Veen , Peter Zijlstra , Eric Biederman Subject: [patch 5/6] x86/smp: Split sending INIT IPI out into a helper function References: <20230603193439.502645149@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Sat, 3 Jun 2023 22:07:03 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Putting CPUs into INIT is a safer place during kexec() to park CPUs. Split the INIT assert/deassert sequence out so it can be reused. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/smpboot.c | 51 +++++++++++++++++++--------------------------- 1 file changed, 22 insertions(+), 29 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -853,47 +853,40 @@ wakeup_secondary_cpu_via_nmi(int apicid, return (send_status | accept_status); } -static int -wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) +static void send_init_sequence(int phys_apicid) { - unsigned long send_status = 0, accept_status = 0; - int maxlvt, num_starts, j; - - maxlvt = lapic_get_maxlvt(); + int maxlvt = lapic_get_maxlvt(); - /* - * Be paranoid about clearing APIC errors. - */ + /* Be paranoid about clearing APIC errors. */ if (APIC_INTEGRATED(boot_cpu_apic_version)) { - if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ + /* Due to the Pentium erratum 3AP. */ + if (maxlvt > 3) apic_write(APIC_ESR, 0); apic_read(APIC_ESR); } - pr_debug("Asserting INIT\n"); - - /* - * Turn INIT on target chip - */ - /* - * Send IPI - */ - apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT, - phys_apicid); - - pr_debug("Waiting for send to finish...\n"); - send_status = safe_apic_wait_icr_idle(); + /* Assert INIT on the target CPU */ + apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT, phys_apicid); + safe_apic_wait_icr_idle(); udelay(init_udelay); - pr_debug("Deasserting INIT\n"); - - /* Target chip */ - /* Send IPI */ + /* Deassert INIT on the target CPU */ apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid); + safe_apic_wait_icr_idle(); +} + +/* + * Wake up AP by INIT, INIT, STARTUP sequence. + */ +static int wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) +{ + unsigned long send_status = 0, accept_status = 0; + int maxlvt, num_starts, j; + + preempt_disable(); - pr_debug("Waiting for send to finish...\n"); - send_status = safe_apic_wait_icr_idle(); + send_init_sequence(phys_apicid); mb();