From nobody Mon Feb 9 04:16:11 2026 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 A2644C001B0 for ; Mon, 7 Aug 2023 13:56:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232217AbjHGN4g (ORCPT ); Mon, 7 Aug 2023 09:56:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234574AbjHGN4N (ORCPT ); Mon, 7 Aug 2023 09:56:13 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D48C230E6 for ; Mon, 7 Aug 2023 06:54:03 -0700 (PDT) Message-ID: <20230807135028.957980935@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1691416429; 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=ph7RYPSGUyMuFVs2yJ045YytT8AyPZYMy0+K0KiHV3c=; b=lpaO6/ZmrKCyJgmJ2rFvtDsqnC+QbF2AxqmmgLpn15UrjOcbXwkSxXYQVL5t7Cy5Gfhvse R3VVz+SXGZWHcJ4A/TJ+X+qaGnfkP3d8key5eJ54lqx2fveumR3I4RrFFGYIuubBEH+QGw PMcFrcxnMRYmbXXR6kuY0q7ljtGq1MomJA/0bCc0jm6lXasZXgYjFfqIoLlnVldbxZ2Phh +7oELvK/Ke1j7/LEzmEmQbao+aD9xfxYxfCLI1e1Pv1ISa9ygiJnukOZhtpYVXgZe7QO0N l6SWnLkJVFMENO0RdaKYOAdyEpBLcrKBDQjoIm40yAiCm/gLTbvZ6vSW4m3njQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1691416429; 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=ph7RYPSGUyMuFVs2yJ045YytT8AyPZYMy0+K0KiHV3c=; b=sFnIZqwJYWUDUa5fF6yrsi+9p88PE8KFWxoTA0yzJBIp0OBhwuhlhCJ0Klz3NwuaWALTYj VTrpkk/0b3mQt+DQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Tom Lendacky , Andrew Cooper , Arjan van de Ven , Huang Rui , Juergen Gross , Dimitri Sivanich , Michael Kelley , Sohil Mehta , K Prateek Nayak , Kan Liang , Zhang Rui , "Paul E. McKenney" , Feng Tang , Andy Shevchenko Subject: [patch 48/53] x86/cpu/topology: Retrieve cores per package from topology bitmaps References: <20230807130108.853357011@linutronix.de> MIME-Version: 1.0 Date: Mon, 7 Aug 2023 15:53:48 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Similar to other sizing information the number of cores per package can be established from the topology bitmap. Provide a function for retrieving that information and replace the buggy hack in the CPUID evaluation with it. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/topology.c | 43 +++++++++++++++++++++++++++++= +++++ arch/x86/kernel/cpu/topology.h | 3 ++ arch/x86/kernel/cpu/topology_common.c | 18 ++------------ 3 files changed, 49 insertions(+), 15 deletions(-) --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -227,6 +227,49 @@ int topology_get_logical_id(u32 apicid, } EXPORT_SYMBOL_GPL(topology_get_logical_id); =20 +/** + * topology_unit_count - Retrieve the count of specified units at a given = topology domain level + * @apicid: The APIC ID which specifies the search range + * @which_units: The domain level specifying the units to count + * @at_level: The domain level at which @which_units have to be counted + * + * This returns the number of possible units according to the enumerated + * information. + * + * E.g. topology_count_units(apicid, TOPO_CORE_DOMAIN, TOPO_PKG_DOMAIN) + * counts the number of possible cores in the package to which @apicid + * belongs. + * + * @at_level must obviously be greater than @which_level to produce useful + * results. If @at_level is equal to @which_units the result is + * unsurprisingly 1. If @at_level is less than @which_units the results + * is by definition undefined and the function returns 0. + */ +unsigned int topology_unit_count(u32 apicid, enum x86_topology_domains whi= ch_units, + enum x86_topology_domains at_level) +{ + /* Remove the bits below @at_level to get the proper level ID of @apicid = */ + unsigned int lvlid =3D topo_apicid(apicid, at_level); + unsigned int id, end, cnt =3D 0; + + if (lvlid >=3D MAX_LOCAL_APIC) + return 0; + if (!test_bit(lvlid, apic_maps[at_level].map)) + return 0; + if (which_units > at_level) + return 0; + if (which_units =3D=3D at_level) + return 1; + + /* Calculate the exclusive end */ + end =3D lvlid + (1U << x86_topo_system.dom_shifts[at_level]); + /* Unfortunately there is no bitmap_weight_range() */ + for (id =3D find_next_bit(apic_maps[which_units].map, end, lvlid); + id < end; id =3D find_next_bit(apic_maps[which_units].map, end, ++id= )) + cnt++; + return cnt; +} + #ifdef CONFIG_ACPI_HOTPLUG_CPU /** * topology_hotplug_apic - Handle a physical hotplugged APIC after boot --- a/arch/x86/kernel/cpu/topology.h +++ b/arch/x86/kernel/cpu/topology.h @@ -50,4 +50,7 @@ static inline void topology_update_dom(s =20 extern const char *domain_names[TOPO_MAX_DOMAIN]; =20 +unsigned int topology_unit_count(u32 apicid, enum x86_topology_domains whi= ch_units, + enum x86_topology_domains at_level); + #endif /* ARCH_X86_TOPOLOGY_H */ --- a/arch/x86/kernel/cpu/topology_common.c +++ b/arch/x86/kernel/cpu/topology_common.c @@ -154,25 +154,15 @@ static void topo_set_ids(struct topo_sca /* Relative core ID */ c->topo.core_id =3D topo_relative_domain_id(apicid, TOPO_CORE_DOMAIN); =20 + /* Maximum number of cores on this package */ + c->x86_max_cores =3D topology_unit_count(apicid, TOPO_CORE_DOMAIN, TOPO_P= KG_DOMAIN); + c->topo.amd_node_id =3D tscan->amd_node_id; =20 if (c->x86_vendor =3D=3D X86_VENDOR_AMD) cpu_topology_fixup_amd(tscan); } =20 -static void topo_set_max_cores(struct topo_scan *tscan) -{ - /* - * Bug compatible for now. This is broken on hybrid systems: - * 8 cores SMT + 8 cores w/o SMT - * tscan.dom_ncpus[TOPO_CORE_DOMAIN] =3D 24; 24 / 2 =3D 12 !! - * - * Cannot be fixed without further topology enumeration changes. - */ - tscan->c->x86_max_cores =3D tscan->dom_ncpus[TOPO_CORE_DOMAIN] >> - x86_topo_system.dom_shifts[TOPO_SMT_DOMAIN]; -} - void cpu_parse_topology(struct cpuinfo_x86 *c) { unsigned int dom, cpu =3D smp_processor_id(); @@ -198,7 +188,6 @@ void cpu_parse_topology(struct cpuinfo_x } =20 topo_set_ids(&tscan); - topo_set_max_cores(&tscan); } =20 void __init cpu_init_topology(struct cpuinfo_x86 *c) @@ -220,7 +209,6 @@ void __init cpu_init_topology(struct cpu } =20 topo_set_ids(&tscan); - topo_set_max_cores(&tscan); =20 /* * AMD systems have Nodes per package which cannot be mapped to