From patchwork Fri Jul 28 12:13:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 13331802 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 38A9EC001E0 for ; Fri, 28 Jul 2023 12:13:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235412AbjG1MNf (ORCPT ); Fri, 28 Jul 2023 08:13:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236025AbjG1MNX (ORCPT ); Fri, 28 Jul 2023 08:13:23 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4F523C31; Fri, 28 Jul 2023 05:13:06 -0700 (PDT) Message-ID: <20230728120930.672330175@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1690546385; 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=LotaVQs4RlrtT3Fsb/omzWTh9eCCKi/NbM3QS9xGwX0=; b=yNqXWhzplelPEC6EqufzV+PoVxUllAeo/Wi+p1hFo5vurLPMbYblXp4jGlR+9otM3JuTtM +viqKycR0ud2Z6znI05wUqOWt04KOT7tsUi4dJOl2lSxrZAMpL3uPBkBr0TGce0RXYhxqE dKWkAES7ZFTztoI33OonKhlt3QUZdgdBl3g1OyipOdBa5TrCCX0Vd7mDwFYvQEzck8N8Y1 68KZSE5vB3RAPQwCjf+G3FkMB0lRTdyDAwMrMyla4RBp6/xMzDaOxEFA3OjogF6NApMA7O 3nG+FCaeEg+iLV2GGB6qLt/548OkVmdrTJFrcXEk0oA1Q1sUoQ+KuH+Ri3/bQg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1690546385; 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=LotaVQs4RlrtT3Fsb/omzWTh9eCCKi/NbM3QS9xGwX0=; b=wQFyFMOjMztzLvHuRRL8abQLdZo6Iawb1LV3/u9l0jn7S5GkkfyF2TuM8sNXVifAIuRJhj 7k0sg+o64YADRaCQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Tom Lendacky , Andrew Cooper , Arjan van de Ven , "James E.J. Bottomley" , Dick Kennedy , James Smart , "Martin K. Petersen" , linux-scsi@vger.kernel.org, Guenter Roeck , linux-hwmon@vger.kernel.org, Jean Delvare , Huang Rui , Juergen Gross , Steve Wahl , Mike Travis , Dimitri Sivanich , Russ Anderson Subject: [patch v2 18/38] x86/cpu/topology: Cure the abuse of cpuinfo for persisting logical ids References: <20230728105650.565799744@linutronix.de> MIME-Version: 1.0 Date: Fri, 28 Jul 2023 14:13:05 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Per CPU cpuinfo is used to persist the logical package and die IDs. That's really not the right place simply because cpuinfo is subject to be reinitialized when a CPU goes through an offline/online cycle. This works by chance today, but that's far from correct and neither obvious nor documented. Add a per cpu datastructure which persists those logical IDs, which allows to cleanup the CPUID evaluation code. This is a temporary workaround until the larger topology management is in place, which makes all of this logical management mechanics obsolete. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/smpboot.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -124,7 +124,20 @@ struct mwait_cpu_dead { */ static DEFINE_PER_CPU_ALIGNED(struct mwait_cpu_dead, mwait_cpu_dead); -/* Logical package management. We might want to allocate that dynamically */ +/* Logical package management. */ +struct logical_maps { + u32 phys_pkg_id; + u32 phys_die_id; + u32 logical_pkg_id; + u32 logical_die_id; +}; + +/* Temporary workaround until the full topology mechanics is in place */ +static DEFINE_PER_CPU_READ_MOSTLY(struct logical_maps, logical_maps) = { + .phys_pkg_id = U32_MAX, + .phys_die_id = U32_MAX, +}; + unsigned int __max_logical_packages __read_mostly; EXPORT_SYMBOL(__max_logical_packages); static unsigned int logical_packages __read_mostly; @@ -345,10 +358,8 @@ int topology_phys_to_logical_pkg(unsigne int cpu; for_each_possible_cpu(cpu) { - struct cpuinfo_x86 *c = &cpu_data(cpu); - - if (c->initialized && c->topo.pkg_id == phys_pkg) - return c->topo.logical_pkg_id; + if (per_cpu(logical_maps.phys_pkg_id, cpu) == phys_pkg) + return per_cpu(logical_maps.logical_pkg_id, cpu); } return -1; } @@ -366,11 +377,9 @@ static int topology_phys_to_logical_die( int cpu, proc_id = cpu_data(cur_cpu).topo.pkg_id; for_each_possible_cpu(cpu) { - struct cpuinfo_x86 *c = &cpu_data(cpu); - - if (c->initialized && c->topo.die_id == die_id && - c->topo.pkg_id == proc_id) - return c->topo.logical_die_id; + if (per_cpu(logical_maps.phys_pkg_id, cpu) == proc_id && + per_cpu(logical_maps.phys_die_id, cpu) == die_id) + return per_cpu(logical_maps.logical_die_id, cpu); } return -1; } @@ -395,6 +404,8 @@ int topology_update_package_map(unsigned cpu, pkg, new); } found: + per_cpu(logical_maps.phys_pkg_id, cpu) = pkg; + per_cpu(logical_maps.logical_pkg_id, cpu) = new; cpu_data(cpu).topo.logical_pkg_id = new; return 0; } @@ -418,6 +429,8 @@ int topology_update_die_map(unsigned int cpu, die, new); } found: + per_cpu(logical_maps.phys_die_id, cpu) = die; + per_cpu(logical_maps.logical_die_id, cpu) = new; cpu_data(cpu).topo.logical_die_id = new; return 0; }