From patchwork Fri Jul 28 12:13:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 13331807 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 470A9C001DE for ; Fri, 28 Jul 2023 12:14:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235938AbjG1MOZ (ORCPT ); Fri, 28 Jul 2023 08:14:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235646AbjG1MNe (ORCPT ); Fri, 28 Jul 2023 08:13:34 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDE524219; Fri, 28 Jul 2023 05:13:11 -0700 (PDT) Message-ID: <20230728120930.895466874@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1690546390; 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=UqiiOrV6qFVmLayEKJExgkdA2s95N7jm4m59y0h1Wug=; b=fgQReNQdRn9/yvbqP/CdlFu5LxypeGGTwddlcC0s2G4u4MHGhhmMqNYZv7BFy91KwwEA0k bSRfOJloS28zA4wkd/8zyrawfF3UwJjhX/bEVbcYRI4u+JL8urA4X2WgJAEG69/NB8AD+1 RG3xnrU98QmiXPR/m/3n8zmtF8FuOzGZZgTuUHPv5pDPovgODKVqPw+tLbarNZgkhxA/JR +9tTAIF7TKAs1nGuald5SFQdQcbI1MQCufZwoXIXudZQXh2dduR0mSnt3HgmxIE7QxqFKP hV8mZgmeqDTrdyf9VrN1C+26dFuz2qbJIbePoIoQ6/TMGacFEhs0bGVNUuPEeA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1690546390; 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=UqiiOrV6qFVmLayEKJExgkdA2s95N7jm4m59y0h1Wug=; b=yCt1+DeZ/St5T5qYw7lNG+ybbKk1llaPu80y6NgiEy+tqc+ASby7vzN4wQVwyFcdeT4YCe CS0ai21ctKzAMbAQ== 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 22/38] x86/cpu: Add legacy topology parser References: <20230728105650.565799744@linutronix.de> MIME-Version: 1.0 Date: Fri, 28 Jul 2023 14:13:10 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org The legacy topology detection via CPUID leaf 4, which provides the number of cores in the package and CPUID leaf 1 which provides the number of logical CPUs in case that FEATURE_HT is enabled and the CMP_LEGACY feature is not set, is shared for Intel, Centaur amd Zhaoxin CPUs. Lift the code from common.c without the early detection hack and provide it as common fallback mechanism. Will be utilized in later changes. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/common.c | 3 ++ arch/x86/kernel/cpu/topology.h | 2 + arch/x86/kernel/cpu/topology_common.c | 37 ++++++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -883,6 +883,9 @@ void detect_ht(struct cpuinfo_x86 *c) #ifdef CONFIG_SMP int index_msb, core_bits; + if (topo_is_converted(c)) + return; + if (detect_ht_early(c) < 0) return; --- a/arch/x86/kernel/cpu/topology.h +++ b/arch/x86/kernel/cpu/topology.h @@ -7,6 +7,8 @@ struct topo_scan { unsigned int dom_shifts[TOPO_MAX_DOMAIN]; unsigned int dom_ncpus[TOPO_MAX_DOMAIN]; + // Legacy CPUID[1]:EBX[23:16] number of logical processors + unsigned int ebx1_nproc_shift; }; bool topo_is_converted(struct cpuinfo_x86 *c); --- a/arch/x86/kernel/cpu/topology_common.c +++ b/arch/x86/kernel/cpu/topology_common.c @@ -24,6 +24,41 @@ void topology_set_dom(struct topo_scan * } } +static unsigned int parse_num_cores(struct cpuinfo_x86 *c) +{ + struct { + u32 cache_type : 5, + unused : 21, + ncores : 6; + } eax; + + if (c->cpuid_level < 4) + return 1; + + cpuid_subleaf_reg(4, 0, CPUID_EAX, &eax); + if (!eax.cache_type) + return 1; + + return eax.ncores + 1; +} + +static void __maybe_unused parse_legacy(struct topo_scan *tscan) +{ + unsigned int cores, core_shift, smt_shift = 0; + struct cpuinfo_x86 *c = tscan->c; + + cores = parse_num_cores(c); + core_shift = get_count_order(cores); + + if (cpu_has(c, X86_FEATURE_HT)) { + if (!WARN_ON_ONCE(tscan->ebx1_nproc_shift < core_shift)) + smt_shift = tscan->ebx1_nproc_shift - core_shift; + } + + topology_set_dom(tscan, TOPO_SMT_DOMAIN, smt_shift, 1U << smt_shift); + topology_set_dom(tscan, TOPO_CORE_DOMAIN, core_shift, cores >> smt_shift); +} + bool topo_is_converted(struct cpuinfo_x86 *c) { /* Temporary until everything is converted over. */ @@ -88,6 +123,8 @@ static void parse_topology(struct topo_s /* The above is sufficient for UP */ if (!IS_ENABLED(CONFIG_SMP)) return; + + tscan->ebx1_nproc_shift = get_count_order(ebx.nproc); } static void topo_set_ids(struct topo_scan *tscan)