From nobody Sun Feb 8 05:47:58 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4BCDB134CCB; Fri, 16 Feb 2024 15:17:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708096625; cv=none; b=iP+Md1p9FB6Q4Yuln22I80GcQCP7qCEDNAMBVwnF8eWWLYqtveVuYoKr8LI8pJ+NeaPNJ8oM9f4q7XHApWLii0mb7HJrCuG+HRVTm+yjec0zd+gow0wGFwC3dhfdmUy2Vg87sRXdXM5/x8fJksOzsy02yPoXXtmOMwF0Oao0dt8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708096625; c=relaxed/simple; bh=RTx+H+vBhQMbKg6b2qhlPjHWtSlweeJGFro/wRY4EZM=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=Kmdhb9Ob0saKyxL6+YiiW1RJ3mmaZgb5sdeBOQNoxLjAxZmTIaCXBWFhi+PYLTDqHTLEYdAMQxWqKoibTP3gq1cyvALYj51wu50ABMOCl0qzMsV7Qq1Pslvj7+S1xs/h+rHLqtPmob35v4/rZJIg4GKktW8qOoBOETWv7tKkTWQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=wr8PRE0V; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=srvYKC5B; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="wr8PRE0V"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="srvYKC5B" Date: Fri, 16 Feb 2024 15:17:01 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1708096621; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iIkNn5y9RDjsmq+FKmQznWLW0Cv0Je6Y9XSM3DuE1Qk=; b=wr8PRE0V6SFHQnW2wnaeVd/+UjAKMoBpfIRzl2Rp6fJcawS5zIBth50nJ5eyFuER7Xxpn1 ts1lNzziAuiQg0XyljYqyV5tPC2pfRCotBvVUIgsyB78uzYGNUi1ff/83iuFJtp2C68++E m85vh86AFnYymo/nhkE6Ngf8z4Telygzvai244YdBH1qnxyI38bQPjlyjkgIQf9bqnHqXM GjLYsADtPBYy4AdNOh+tPBocuOCGqFXZV7/imUAWr9tK8lgNLYCt+8BgKAnkJzN0tdjR5a KENQR+8ylDloAvsyfUEu63JWP+Xc8spXRcY5nPkH9Rhz7daMbLRNiZ4XhOfyuA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1708096621; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iIkNn5y9RDjsmq+FKmQznWLW0Cv0Je6Y9XSM3DuE1Qk=; b=srvYKC5B2mFRTX7WuBpBR9hI4nxk4tlkNMGH/f90uH9k7woSCbLfK5RERS0JfBZ6B5a+3/ Riuwd2BhNOERm5Cw== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/apic] x86/cpu/topology: Use a data structure for topology info Cc: Thomas Gleixner , Michael Kelley , Sohil Mehta , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240213210252.111451909@linutronix.de> References: <20240213210252.111451909@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <170809662109.398.3557889395932667096.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/apic branch of tip: Commit-ID: 72530464ed609bcdd49a760e9d0bc3b16717ff2b Gitweb: https://git.kernel.org/tip/72530464ed609bcdd49a760e9d0bc3b16= 717ff2b Author: Thomas Gleixner AuthorDate: Tue, 13 Feb 2024 22:05:49 +01:00 Committer: Thomas Gleixner CommitterDate: Thu, 15 Feb 2024 22:07:43 +01:00 x86/cpu/topology: Use a data structure for topology info Put the processor accounting into a data structure, which will gain more topology related information in the next steps, and sanitize the accounting. Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley Tested-by: Sohil Mehta Link: https://lore.kernel.org/r/20240213210252.111451909@linutronix.de --- arch/x86/kernel/cpu/topology.c | 59 ++++++++++++++++----------------- 1 file changed, 29 insertions(+), 30 deletions(-) diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index 8b42918..815e3ee 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -23,25 +23,24 @@ DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC) __= read_mostly; u32 cpuid_to_apicid[] __read_mostly =3D { [0 ... NR_CPUS - 1] =3D BAD_APIC= ID, }; =20 /* + * Keep track of assigned, disabled and rejected CPUs. Present assigned + * with 1 as CPU #0 is reserved for the boot CPU. + */ +static struct { + unsigned int nr_assigned_cpus; + unsigned int nr_disabled_cpus; + unsigned int nr_rejected_cpus; +} topo_info __read_mostly =3D { + .nr_assigned_cpus =3D 1, +}; + +/* * Processor to be disabled specified by kernel parameter * disable_cpu_apicid=3D, mostly used for the kdump 2nd kernel to * avoid undefined behaviour caused by sending INIT from AP to BSP. */ static u32 disabled_cpu_apicid __ro_after_init =3D BAD_APICID; =20 -static unsigned int num_processors; -static unsigned int disabled_cpus; - -/* - * The number of allocated logical CPU IDs. Since logical CPU IDs are allo= cated - * contiguously, it equals to current allocated max logical CPU ID plus 1. - * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range, - * so the maximum of nr_logical_cpuids is nr_cpu_ids. - * - * NOTE: Reserve 0 for BSP. - */ -static int nr_logical_cpuids =3D 1; - bool arch_match_cpu_phys_id(int cpu, u64 phys_id) { return phys_id =3D=3D (u64)cpuid_to_apicid[cpu]; @@ -75,7 +74,7 @@ static int __init smp_init_primary_thread_mask(void) return 0; } =20 - for (cpu =3D 0; cpu < nr_logical_cpuids; cpu++) + for (cpu =3D 0; cpu < topo_info.nr_assigned_cpus; cpu++) cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]); return 0; } @@ -89,7 +88,7 @@ static int topo_lookup_cpuid(u32 apic_id) int i; =20 /* CPU# to APICID mapping is persistent once it is established */ - for (i =3D 0; i < nr_logical_cpuids; i++) { + for (i =3D 0; i < topo_info.nr_assigned_cpus; i++) { if (cpuid_to_apicid[i] =3D=3D apic_id) return i; } @@ -107,22 +106,21 @@ static int allocate_logical_cpuid(u32 apic_id) if (cpu >=3D 0) return cpu; =20 - cpuid_to_apicid[nr_logical_cpuids] =3D apic_id; - return nr_logical_cpuids++; + return topo_info.nr_assigned_cpus++; } =20 -static void cpu_update_apic(int cpu, u32 apicid) +static void cpu_update_apic(unsigned int cpu, u32 apic_id) { #if defined(CONFIG_SMP) || defined(CONFIG_X86_64) - early_per_cpu(x86_cpu_to_apicid, cpu) =3D apicid; + early_per_cpu(x86_cpu_to_apicid, cpu) =3D apic_id; #endif + cpuid_to_apicid[cpu] =3D apic_id; set_cpu_possible(cpu, true); - set_bit(apicid, phys_cpu_present_map); + set_bit(apic_id, phys_cpu_present_map); set_cpu_present(cpu, true); - num_processors++; =20 if (system_state !=3D SYSTEM_BOOTING) - cpu_mark_primary_thread(cpu, apicid); + cpu_mark_primary_thread(cpu, apic_id); } =20 static int generic_processor_info(int apicid) @@ -137,18 +135,18 @@ static int generic_processor_info(int apicid) return 0; =20 if (disabled_cpu_apicid =3D=3D apicid) { - int thiscpu =3D num_processors + disabled_cpus; + int thiscpu =3D topo_info.nr_assigned_cpus + topo_info.nr_disabled_cpus; =20 pr_warn("APIC: Disabling requested cpu. Processor %d/0x%x ignored.\n", thiscpu, apicid); =20 - disabled_cpus++; + topo_info.nr_rejected_cpus++; return -ENODEV; } =20 - if (num_processors >=3D nr_cpu_ids) { + if (topo_info.nr_assigned_cpus >=3D nr_cpu_ids) { pr_warn_once("APIC: CPU limit of %d reached. Ignoring further CPUs\n", n= r_cpu_ids); - disabled_cpus++; + topo_info.nr_rejected_cpus++; return -ENOSPC; } =20 @@ -178,14 +176,16 @@ static int __initdata setup_possible_cpus =3D -1; */ __init void prefill_possible_map(void) { + unsigned int num_processors =3D topo_info.nr_assigned_cpus; + unsigned int disabled_cpus =3D topo_info.nr_disabled_cpus; int i, possible; =20 i =3D setup_max_cpus ?: 1; if (setup_possible_cpus =3D=3D -1) { - possible =3D num_processors; + possible =3D topo_info.nr_assigned_cpus; #ifdef CONFIG_HOTPLUG_CPU if (setup_max_cpus) - possible +=3D disabled_cpus; + possible +=3D num_processors; #else if (possible > i) possible =3D i; @@ -238,7 +238,7 @@ void __init topology_register_apic(u32 apic_id, u32 acp= i_id, bool present) } =20 if (!present) { - disabled_cpus++; + topo_info.nr_disabled_cpus++; return; } =20 @@ -295,7 +295,6 @@ void topology_hotunplug_apic(unsigned int cpu) per_cpu(x86_cpu_to_apicid, cpu) =3D BAD_APICID; clear_bit(apic_id, phys_cpu_present_map); set_cpu_present(cpu, false); - num_processors--; } #endif