From nobody Sat Feb 7 09:46:42 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 4F9BE1350D8; Fri, 16 Feb 2024 15:17:05 +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=1708096627; cv=none; b=DMUjVxmMxdoRxkv2TUgP4K699hGpaJB0O2LBnzHwVA7wY/tYTBbQkcbwzQlr4AKYGyfkqOkCKOtL7QcL38OpvfcN5IRCwyba3NB52QNQQSCDv30ymqC/SvCgzNIPdRNDvG9A+ZcDSnKhv9UKAToOr4hPYEKqABebkU88hEyy+a4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708096627; c=relaxed/simple; bh=IitY8G8n/RkqvgQ9VELSid8s+aPi1eVKxKbGDUtu/2M=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=k6j9CaF8/0bjf6uleh3W+XvA/QYfy6pAz/cwoc/cT0w08970wmYvuES7cNUGz4CoKXI8B8BA9waYi0YaoTNg/ytL6fBJOMorJYhy2gTOzo8fXqigRXSFcQ8snqeRoYMXMnIVkvbBFlJ4SkBAqfMcXC/ONbfiGo96kAN3UaTyyo4= 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=CnyTXgo3; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Euuk8fxL; 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="CnyTXgo3"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Euuk8fxL" Date: Fri, 16 Feb 2024 15:17:02 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1708096623; 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=CkdZ5F8LC9ZFkpl1eya+O5soyvlsiTF9897MrUm11vA=; b=CnyTXgo3CHmJ1ls8WZIgBCDOPTdUnlfs1noSJ5bI8+cn3TBf/QaSQJ5h7WAGEYeElSgSSh 1+XBSJsIejs9+X2Hdl28HaeJqi4phHntBjLdwvkJwpoQFW5CYCrCbqhq3Csj3FjdtslvRc oLUXQpRLO8uTOwiMihmvrROg/9izZ7T972WmM/L2+iDTnAnAzKCSjLbcR6XPmTmalU7fTT RbdbfQtxHZo5Gem/aK2+SiVXo/Y4Q/5CSWBdEbtlU7kC+wdd9lICdT9QEh5mBGiG1IlKZo Q1+NUuSFw9ielPaBfXZkSFYMKtlrBAtWcWPIqTiwSGfLePOoqbGLJ8+Ut55/tQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1708096623; 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=CkdZ5F8LC9ZFkpl1eya+O5soyvlsiTF9897MrUm11vA=; b=Euuk8fxLR2xULGX0Cxf2V7QoTgWE+ktZ9mRbPNRcWZ2tr/Df/rq9YVL9PlY3l3uAUHs92s liURtkyTN8hO6IDA== 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: Confine topology information Cc: Thomas Gleixner , Michael Kelley , Sohil Mehta , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240213210251.994756960@linutronix.de> References: <20240213210251.994756960@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <170809662288.398.16525230259695602703.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: 58aa34abe9954cd5dfbf322fc612146c5f45e52b Gitweb: https://git.kernel.org/tip/58aa34abe9954cd5dfbf322fc612146c5= f45e52b Author: Thomas Gleixner AuthorDate: Tue, 13 Feb 2024 22:05:46 +01:00 Committer: Thomas Gleixner CommitterDate: Thu, 15 Feb 2024 22:07:42 +01:00 x86/cpu/topology: Confine topology information Now that all external fiddling with num_processors and disabled_cpus is gone, move the last user prefill_possible_map() into the topology code too and remove the global visibility of these variables. Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley Tested-by: Sohil Mehta Link: https://lore.kernel.org/r/20240213210251.994756960@linutronix.de --- arch/x86/include/asm/smp.h | 3 +- arch/x86/kernel/apic/apic.c | 1 +- arch/x86/kernel/cpu/topology.c | 76 ++++++++++++++++++++++++++++++++- arch/x86/kernel/smpboot.c | 72 +------------------------------- 4 files changed, 74 insertions(+), 78 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 4fab2ed..f1510d6 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -9,7 +9,6 @@ #include =20 extern int smp_num_siblings; -extern unsigned int num_processors; =20 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map); DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map); @@ -174,8 +173,6 @@ static inline struct cpumask *cpu_llc_shared_mask(int c= pu) } #endif /* CONFIG_SMP */ =20 -extern unsigned disabled_cpus; - #ifdef CONFIG_DEBUG_NMI_SELFTEST extern void nmi_selftest(void); #else diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 5814b80..a42d8a6 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2054,7 +2054,6 @@ void __init init_apic_mappings(void) pr_info("APIC: disable apic facility\n"); apic_disable(); } - num_processors =3D 1; } } =20 diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index 669e258..a6c9314 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -29,8 +29,8 @@ u32 cpuid_to_apicid[] __read_mostly =3D { [0 ... NR_CPUS = - 1] =3D BAD_APICID, }; */ static u32 disabled_cpu_apicid __ro_after_init =3D BAD_APICID; =20 -unsigned int num_processors; -unsigned disabled_cpus; +static unsigned int num_processors; +static unsigned int disabled_cpus; =20 /* * The number of allocated logical CPU IDs. Since logical CPU IDs are allo= cated @@ -174,6 +174,71 @@ static int generic_processor_info(int apicid) return cpu; } =20 +static int __initdata setup_possible_cpus =3D -1; + +/* + * cpu_possible_mask should be static, it cannot change as cpu's + * are onlined, or offlined. The reason is per-cpu data-structures + * are allocated by some modules at init time, and don't expect to + * do this dynamically on cpu arrival/departure. + * cpu_present_mask on the other hand can change dynamically. + * In case when cpu_hotplug is not compiled, then we resort to current + * behaviour, which is cpu_possible =3D=3D cpu_present. + * - Ashok Raj + * + * Three ways to find out the number of additional hotplug CPUs: + * - If the BIOS specified disabled CPUs in ACPI/mptables use that. + * - The user can overwrite it with possible_cpus=3DNUM + * - Otherwise don't reserve additional CPUs. + * We do this because additional CPUs waste a lot of memory. + * -AK + */ +__init void prefill_possible_map(void) +{ + int i, possible; + + i =3D setup_max_cpus ?: 1; + if (setup_possible_cpus =3D=3D -1) { + possible =3D num_processors; +#ifdef CONFIG_HOTPLUG_CPU + if (setup_max_cpus) + possible +=3D disabled_cpus; +#else + if (possible > i) + possible =3D i; +#endif + } else + possible =3D setup_possible_cpus; + + total_cpus =3D max_t(int, possible, num_processors + disabled_cpus); + + /* nr_cpu_ids could be reduced via nr_cpus=3D */ + if (possible > nr_cpu_ids) { + pr_warn("%d Processors exceeds NR_CPUS limit of %u\n", + possible, nr_cpu_ids); + possible =3D nr_cpu_ids; + } + +#ifdef CONFIG_HOTPLUG_CPU + if (!setup_max_cpus) +#endif + if (possible > i) { + pr_warn("%d Processors exceeds max_cpus limit of %u\n", + possible, setup_max_cpus); + possible =3D i; + } + + set_nr_cpu_ids(possible); + + pr_info("Allowing %d CPUs, %d hotplug CPUs\n", + possible, max_t(int, possible - num_processors, 0)); + + reset_cpu_possible_mask(); + + for (i =3D 0; i < possible; i++) + set_cpu_possible(i, true); +} + /** * topology_register_apic - Register an APIC in early topology maps * @apic_id: The APIC ID to set up @@ -251,6 +316,13 @@ void topology_hotunplug_apic(unsigned int cpu) } #endif =20 +static int __init _setup_possible_cpus(char *str) +{ + get_option(&str, &setup_possible_cpus); + return 0; +} +early_param("possible_cpus", _setup_possible_cpus); + static int __init apic_set_disabled_cpu_apicid(char *arg) { if (!arg || !get_option(&arg, &disabled_cpu_apicid)) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 000b856..bfb99b5 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1291,78 +1291,6 @@ void __init native_smp_cpus_done(unsigned int max_cp= us) cache_aps_init(); } =20 -static int __initdata setup_possible_cpus =3D -1; -static int __init _setup_possible_cpus(char *str) -{ - get_option(&str, &setup_possible_cpus); - return 0; -} -early_param("possible_cpus", _setup_possible_cpus); - - -/* - * cpu_possible_mask should be static, it cannot change as cpu's - * are onlined, or offlined. The reason is per-cpu data-structures - * are allocated by some modules at init time, and don't expect to - * do this dynamically on cpu arrival/departure. - * cpu_present_mask on the other hand can change dynamically. - * In case when cpu_hotplug is not compiled, then we resort to current - * behaviour, which is cpu_possible =3D=3D cpu_present. - * - Ashok Raj - * - * Three ways to find out the number of additional hotplug CPUs: - * - If the BIOS specified disabled CPUs in ACPI/mptables use that. - * - The user can overwrite it with possible_cpus=3DNUM - * - Otherwise don't reserve additional CPUs. - * We do this because additional CPUs waste a lot of memory. - * -AK - */ -__init void prefill_possible_map(void) -{ - int i, possible; - - i =3D setup_max_cpus ?: 1; - if (setup_possible_cpus =3D=3D -1) { - possible =3D num_processors; -#ifdef CONFIG_HOTPLUG_CPU - if (setup_max_cpus) - possible +=3D disabled_cpus; -#else - if (possible > i) - possible =3D i; -#endif - } else - possible =3D setup_possible_cpus; - - total_cpus =3D max_t(int, possible, num_processors + disabled_cpus); - - /* nr_cpu_ids could be reduced via nr_cpus=3D */ - if (possible > nr_cpu_ids) { - pr_warn("%d Processors exceeds NR_CPUS limit of %u\n", - possible, nr_cpu_ids); - possible =3D nr_cpu_ids; - } - -#ifdef CONFIG_HOTPLUG_CPU - if (!setup_max_cpus) -#endif - if (possible > i) { - pr_warn("%d Processors exceeds max_cpus limit of %u\n", - possible, setup_max_cpus); - possible =3D i; - } - - set_nr_cpu_ids(possible); - - pr_info("Allowing %d CPUs, %d hotplug CPUs\n", - possible, max_t(int, possible - num_processors, 0)); - - reset_cpu_possible_mask(); - - for (i =3D 0; i < possible; i++) - set_cpu_possible(i, true); -} - /* correctly size the local cpu masks */ void __init setup_cpu_local_masks(void) {