From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515889; cv=none; d=zohomail.com; s=zohoarc; b=ZU/xfJekMzqq12bqy/P48iPmLL6OGU5ITwhnZ7Q8e+7/NROAXY5YIHZcBVDLDr7bA5pNFoA1l/unxw7JolMTqoYlzhzFLcAQbQ6olQP02jpzj92FFe9/RwK2Cu/Gp732qBHBCrliV6l240k/NLjn6gpT2nkwx/iq5VPOs4npPFE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1681515889; h=Content-Type:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=IlHV62TWgKh1cdgK7stl2AzD5yScRMLzrcA90zGNlOQ=; b=J7QYBFa90Y9+bbm7IDqBi45NgahJFeusID+S5LanjcrrAUYDlI+2O5oi8h3gi+xbPrpu1pns9UJEWsNuf6Hd+CgF6m46QHYIDLQi6jwv3ThE3TycEb5yGFpKj1yRwo9nM+p3AFlKGsk4PHNOx1M2zAm5VEoqju6eTxRqmkjZIh8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1681515889404310.18833967529304; Fri, 14 Apr 2023 16:44:49 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.521261.809725 (Exim 4.92) (envelope-from ) id 1pnT5X-0000zx-KT; Fri, 14 Apr 2023 23:44:19 +0000 Received: by outflank-mailman (output) from mailman id 521261.809725; Fri, 14 Apr 2023 23:44:19 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5X-0000zq-GR; Fri, 14 Apr 2023 23:44:19 +0000 Received: by outflank-mailman (input) for mailman id 521261; Fri, 14 Apr 2023 23:44:18 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5W-0000zb-I8 for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:18 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 440ecfed-db1e-11ed-8611-37d641c3527e; Sat, 15 Apr 2023 01:44:15 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 440ecfed-db1e-11ed-8611-37d641c3527e Message-ID: <20230414232309.261127575@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515855; 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=IlHV62TWgKh1cdgK7stl2AzD5yScRMLzrcA90zGNlOQ=; b=ZSJ2jYDTvrOcSfB+q9NW+WGp94J7gVM5nWU/8DuwnoZDMu+XBZCbSUvTxL+DR4BvKxavFN jhuRONKx7L6r94CMMXtiIONzHNo1K+Igs8Z0LLNxD99J31QKLzvq4MDfPqPJUdJy0who+d mKrkRcfXkOBt5Idh86wWBXAvBPESGtEj994l0Sk8+em2iAJUZAhObLDXX+j3oXrngnpCuw zyRT6xozBWS7ZDWw8BWKkQqW6Qlj1eCTnFv9dCNIQazSMGDnTo3mcHwD/wv9ccqLmI3o2G GJGLBHoc9N7XmTNB1GAm0gwQkaNsttkeRSqEESmeoHEEgOdQdWWA8b6V/dbDuQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515855; 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=IlHV62TWgKh1cdgK7stl2AzD5yScRMLzrcA90zGNlOQ=; b=5y7iOO6UN0/F9Na7fC7zsih/Bs+dHvWN4EhYECYw/BugXKR0lZggZtmRr+wdRcc8V09+nR evNcawtvhTVqcwDg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 01/37] x86/smpboot: Cleanup topology_phys_to_logical_pkg()/die() References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:14 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515891470100007 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Make topology_phys_to_logical_pkg_die() static as it's only used in smpboot.c and fixup the kernel-doc warnings for both functions. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/topology.h | 3 --- arch/x86/kernel/smpboot.c | 10 ++++++---- 2 files changed, 6 insertions(+), 7 deletions(-) --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -139,7 +139,6 @@ static inline int topology_max_smt_threa int topology_update_package_map(unsigned int apicid, unsigned int cpu); int topology_update_die_map(unsigned int dieid, unsigned int cpu); int topology_phys_to_logical_pkg(unsigned int pkg); -int topology_phys_to_logical_die(unsigned int die, unsigned int cpu); bool topology_is_primary_thread(unsigned int cpu); bool topology_smt_supported(void); #else @@ -149,8 +148,6 @@ topology_update_package_map(unsigned int static inline int topology_update_die_map(unsigned int dieid, unsigned int cpu) { return 0; } static inline int topology_phys_to_logical_pkg(unsigned int pkg) { return = 0; } -static inline int topology_phys_to_logical_die(unsigned int die, - unsigned int cpu) { return 0; } static inline int topology_max_die_per_package(void) { return 1; } static inline int topology_max_smt_threads(void) { return 1; } static inline bool topology_is_primary_thread(unsigned int cpu) { return t= rue; } --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -288,6 +288,7 @@ bool topology_smt_supported(void) =20 /** * topology_phys_to_logical_pkg - Map a physical package id to a logical + * @phys_pkg: The physical package id to map * * Returns logical package id or -1 if not found */ @@ -304,15 +305,17 @@ int topology_phys_to_logical_pkg(unsigne return -1; } EXPORT_SYMBOL(topology_phys_to_logical_pkg); + /** * topology_phys_to_logical_die - Map a physical die id to logical + * @die_id: The physical die id to map + * @cur_cpu: The CPU for which the mapping is done * * Returns logical die id or -1 if not found */ -int topology_phys_to_logical_die(unsigned int die_id, unsigned int cur_cpu) +static int topology_phys_to_logical_die(unsigned int die_id, unsigned int = cur_cpu) { - int cpu; - int proc_id =3D cpu_data(cur_cpu).phys_proc_id; + int cpu, proc_id =3D cpu_data(cur_cpu).phys_proc_id; =20 for_each_possible_cpu(cpu) { struct cpuinfo_x86 *c =3D &cpu_data(cpu); @@ -323,7 +326,6 @@ int topology_phys_to_logical_die(unsigne } return -1; } -EXPORT_SYMBOL(topology_phys_to_logical_die); =20 /** * topology_update_package_map - Update the physical to logical package map From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515892; cv=none; d=zohomail.com; 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Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 02/37] cpu/hotplug: Mark arch_disable_smp_support() and bringup_nonboot_cpus() __init References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:16 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515893226100015 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" No point in keeping them around. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/smpboot.c | 4 ++-- kernel/cpu.c | 2 +- kernel/smp.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1269,9 +1269,9 @@ int native_cpu_up(unsigned int cpu, stru } =20 /** - * arch_disable_smp_support() - disables SMP support for x86 at runtime + * arch_disable_smp_support() - Disables SMP support for x86 at boottime */ -void arch_disable_smp_support(void) +void __init arch_disable_smp_support(void) { disable_ioapic_support(); } --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1502,7 +1502,7 @@ int bringup_hibernate_cpu(unsigned int s return 0; } =20 -void bringup_nonboot_cpus(unsigned int setup_max_cpus) +void __init bringup_nonboot_cpus(unsigned int setup_max_cpus) { unsigned int cpu; =20 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -1051,7 +1051,7 @@ EXPORT_SYMBOL(setup_max_cpus); * SMP mode to . */ =20 -void __weak arch_disable_smp_support(void) { } +void __weak __init arch_disable_smp_support(void) { } =20 static int __init nosmp(char *str) { From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; 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Fri, 14 Apr 2023 23:44:21 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 45f0e738-db1e-11ed-b21e-6b7b168915f2; Sat, 15 Apr 2023 01:44:19 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 45f0e738-db1e-11ed-b21e-6b7b168915f2 Message-ID: <20230414232309.385574446@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515858; 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=IHNUiYT/aa+9U/QrFpO4u8KQro95rDNTw6iEEK5ze9o=; b=1GGWgmKl+Z16YESLBwfkaJ8pYvl0ibRrRLZ//qbrV6Rn4ejq8Bvi6vo9cC/d06/jSPEXR4 hvZPrEqwgB1nXc44jqzGpA3g8UhwvIHA09SMd8L91BmwlYgaP2m77BjOpifPA2Jp8FR9F+ c0G0jy+fXRMuNBDQtZn5Uv5VCIUDjwdIxXIzMKcFSmEiflIS9qbg0CEGaA9Azgv3qTSjMh 2Q6Nmfsfu+SPkBhJwKselmJZVd9FCtpTg9fyXFZ6j2n8kUoisHbXRgCmcH48m/s4qcThpJ o2FriQZJckk/vdgmu5g5vmRYvkI+K74QUFnLD6JN3zpP58uh1nfGpXn5o7XkuA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515858; 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=IHNUiYT/aa+9U/QrFpO4u8KQro95rDNTw6iEEK5ze9o=; b=cHgI8T+6dl0c5QvmY+jPTGI3Fml5ooLABkADGz2XWt8RyEwXHfElCQYbWkrIndZHTvvRK5 Onzbq0bjdDoTP8Dg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 03/37] x86/smpboot: Avoid pointless delay calibration is TSC is synchronized References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:18 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515891385100005 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When TSC is synchronized across sockets then there is no reason in calibrating the delay for the first CPU which comes up on a socket. Just reuse the existing calibration value. This removes 100ms pointlessly wasted time from CPU hotplug. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/smpboot.c | 38 ++++++++++++++++++++++++-------------- arch/x86/kernel/tsc.c | 20 ++++++++++++++++---- 2 files changed, 40 insertions(+), 18 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -178,10 +178,7 @@ static void smp_callin(void) */ apic_ap_setup(); =20 - /* - * Save our processor parameters. Note: this information - * is needed for clock calibration. - */ + /* Save our processor parameters. */ smp_store_cpu_info(cpuid); =20 /* @@ -192,14 +189,6 @@ static void smp_callin(void) =20 ap_init_aperfmperf(); =20 - /* - * Get our bogomips. - * Update loops_per_jiffy in cpu_data. Previous call to - * smp_store_cpu_info() stored a value that is close but not as - * accurate as the value just calculated. - */ - calibrate_delay(); - cpu_data(cpuid).loops_per_jiffy =3D loops_per_jiffy; pr_debug("Stack at about %p\n", &cpuid); =20 wmb(); @@ -212,8 +201,24 @@ static void smp_callin(void) cpumask_set_cpu(cpuid, cpu_callin_mask); } =20 +static void ap_calibrate_delay(void) +{ + /* + * Calibrate the delay loop and update loops_per_jiffy in cpu_data. + * smp_store_cpu_info() stored a value that is close but not as + * accurate as the value just calculated. + * + * As this is invoked after the TSC synchronization check, + * calibrate_delay_is_known() will skip the calibration routine + * when TSC is synchronized across sockets. + */ + calibrate_delay(); + cpu_data(smp_processor_id()).loops_per_jiffy =3D loops_per_jiffy; +} + static int cpu0_logical_apicid; static int enable_start_cpu0; + /* * Activate a secondary processor. */ @@ -240,10 +245,15 @@ static void notrace start_secondary(void =20 /* otherwise gcc will move up smp_processor_id before the cpu_init */ barrier(); + /* Check TSC synchronization with the control CPU: */ + check_tsc_sync_target(); + /* - * Check TSC synchronization with the boot CPU: + * Calibrate the delay loop after the TSC synchronization check. + * This allows to skip the calibration when TSC is synchronized + * across sockets. */ - check_tsc_sync_target(); + ap_calibrate_delay(); =20 speculative_store_bypass_ht_init(); =20 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1598,10 +1598,7 @@ void __init tsc_init(void) =20 #ifdef CONFIG_SMP /* - * If we have a constant TSC and are using the TSC for the delay loop, - * we can skip clock calibration if another cpu in the same socket has alr= eady - * been calibrated. This assumes that CONSTANT_TSC applies to all - * cpus in the socket - this should be a safe assumption. + * Check whether existing calibration data can be reused. */ unsigned long calibrate_delay_is_known(void) { @@ -1609,6 +1606,21 @@ unsigned long calibrate_delay_is_known(v int constant_tsc =3D cpu_has(&cpu_data(cpu), X86_FEATURE_CONSTANT_TSC); const struct cpumask *mask =3D topology_core_cpumask(cpu); =20 + /* + * If TSC has constant frequency and TSC is synchronized across + * sockets then reuse CPU0 calibration. + */ + if (constant_tsc && !tsc_unstable) + return cpu_data(0).loops_per_jiffy; + + /* + * If TSC has constant frequency and TSC is not synchronized across + * sockets and this is not the first CPU in the socket, then reuse + * the calibration value of an already online CPU on that socket. + * + * This assumes that CONSTANT_TSC is consistent for all CPUs in a + * socket. + */ if (!constant_tsc || !mask) return 0; From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; 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Fri, 14 Apr 2023 23:44:21 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 46f44033-db1e-11ed-b21e-6b7b168915f2; Sat, 15 Apr 2023 01:44:20 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 46f44033-db1e-11ed-b21e-6b7b168915f2 Message-ID: <20230414232309.448345494@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515860; 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=SRk3RrJ8+RSaiZTRwxMk0fG1NuTGaGpFKdBZXu8mJKE=; b=TenZelvKdY6Tx+OsImAHk36b4tbQIR+z0M1WnFpjy8y+51j9W5eVFc7Of6Sf8s0X5uq+xc 6SLC+/lL+CpUg+kTVvDAN1gjqSax0V+tVQNmmxi4coTX5o01NqKtoGfLSsdE0lb320KW1r QEHnIVRUnqLfhZgK+7fQTY+n7WOGwL6ll+eunwu5W5z5A2qnT1aRW5PuasQXgjsBUf/jBU 7xOQ39cpNhzE0/XOurXN0gDhM1Ox280g/R6YyoZtAiatQnNAao3G3M3vKjSts9mlj9G6qX S7eGW9eMYE6lWwqIwp+CRBO4mI9eSSdxCdQI74WXa5fo3DgjCo/bZ5Uwga1FYg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515860; 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=SRk3RrJ8+RSaiZTRwxMk0fG1NuTGaGpFKdBZXu8mJKE=; b=GpdL477IqUbVLYXts40m+nkntEs4l/SFSgjl8WTxVs9fG2Y4NeqfbJbNj3fY+ekDTnUTf2 CVV1j8YeN8LpbeAA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 04/37] x86/smpboot: Rename start_cpu0() to soft_restart_cpu() References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:19 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515892533100013 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This is used in the SEV play_dead() implementation to re-online CPUs. But that has nothing to do with CPU0. Signed-off-by: Thomas Gleixner Cc: Tom Lendacky Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/cpu.h | 2 +- arch/x86/kernel/callthunks.c | 2 +- arch/x86/kernel/head_32.S | 10 +++++----- arch/x86/kernel/head_64.S | 10 +++++----- arch/x86/kernel/sev.c | 2 +- 5 files changed, 13 insertions(+), 13 deletions(-) --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -30,7 +30,7 @@ struct x86_cpu { #ifdef CONFIG_HOTPLUG_CPU extern int arch_register_cpu(int num); extern void arch_unregister_cpu(int); -extern void start_cpu0(void); +extern void soft_restart_cpu(void); #ifdef CONFIG_DEBUG_HOTPLUG_CPU0 extern int _debug_hotplug_cpu(int cpu, int action); #endif --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -134,7 +134,7 @@ static bool skip_addr(void *dest) if (dest =3D=3D ret_from_fork) return true; #ifdef CONFIG_HOTPLUG_CPU - if (dest =3D=3D start_cpu0) + if (dest =3D=3D soft_restart_cpu) return true; #endif #ifdef CONFIG_FUNCTION_TRACER --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -140,16 +140,16 @@ SYM_CODE_END(startup_32) =20 #ifdef CONFIG_HOTPLUG_CPU /* - * Boot CPU0 entry point. It's called from play_dead(). Everything has bee= n set - * up already except stack. We just set up stack here. Then call - * start_secondary(). + * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for + * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot + * unplug. Everything is set up already except the stack. */ -SYM_FUNC_START(start_cpu0) +SYM_FUNC_START(soft_restart_cpu) movl initial_stack, %ecx movl %ecx, %esp call *(initial_code) 1: jmp 1b -SYM_FUNC_END(start_cpu0) +SYM_FUNC_END(soft_restart_cpu) #endif =20 /* --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -377,11 +377,11 @@ SYM_CODE_END(secondary_startup_64) =20 #ifdef CONFIG_HOTPLUG_CPU /* - * Boot CPU0 entry point. It's called from play_dead(). Everything has bee= n set - * up already except stack. We just set up stack here. Then call - * start_secondary() via .Ljump_to_C_code. + * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for + * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot + * unplug. Everything is set up already except the stack. */ -SYM_CODE_START(start_cpu0) +SYM_CODE_START(soft_restart_cpu) ANNOTATE_NOENDBR UNWIND_HINT_EMPTY =20 @@ -390,7 +390,7 @@ SYM_CODE_START(start_cpu0) movq TASK_threadsp(%rcx), %rsp =20 jmp .Ljump_to_C_code -SYM_CODE_END(start_cpu0) +SYM_CODE_END(soft_restart_cpu) #endif =20 #ifdef CONFIG_AMD_MEM_ENCRYPT --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -1326,7 +1326,7 @@ static void sev_es_play_dead(void) * If we get here, the VCPU was woken up again. Jump to CPU * startup code to get it back online. */ - start_cpu0(); + soft_restart_cpu(); } #else /* CONFIG_HOTPLUG_CPU */ #define sev_es_play_dead native_play_dead From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515892; cv=none; d=zohomail.com; s=zohoarc; b=NYfffry+L4f7y2MmXouHMtbMlYWd2kzFJfWXwLS8JTGahOvehoLW9Nge9beiernJQ+6Af8+w2K43xvy3nyjpkYntwsna4wB7MYEsbEovoukxYKm3cEK+EEdjUQXNqPU7z3SToIj+CR7TWLyp0fC7aSPQ6J4UTKxjprg/7dlNdvY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1681515892; h=Content-Type:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=d2aa8PgTtRDs84GbzPYsg9/c/UFZj39RiJ/AAhETCGQ=; b=QEIAVO4HiUtpUtgpw+ERFyF7YuSJGkeKSkiwoLycFpE1RY6zGblXZ5EqIOcTXVsSs6K0R+T4b7A2P0ShIyBEj15RaO2NtIj4RvdhspqAirgtXc8i/PigHxBQdZuy+wuPpwmlAASUUvcXMi+refNmpfj2A88hZ2JeM2yHb85iOyI= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1681515892339579.5999215788338; Fri, 14 Apr 2023 16:44:52 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.521266.809774 (Exim 4.92) (envelope-from ) id 1pnT5c-0002Dz-SX; Fri, 14 Apr 2023 23:44:24 +0000 Received: by outflank-mailman (output) from mailman id 521266.809774; Fri, 14 Apr 2023 23:44:24 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5c-0002C8-Oh; Fri, 14 Apr 2023 23:44:24 +0000 Received: by outflank-mailman (input) for mailman id 521266; Fri, 14 Apr 2023 23:44:24 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5c-0000zb-4c for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:24 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 47f825ef-db1e-11ed-8611-37d641c3527e; Sat, 15 Apr 2023 01:44:22 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 47f825ef-db1e-11ed-8611-37d641c3527e Message-ID: <20230414232309.510911744@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515862; 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=d2aa8PgTtRDs84GbzPYsg9/c/UFZj39RiJ/AAhETCGQ=; b=g4jq/m8sUm3dCRnIPA0dwXXquH1L4TZDkHABiQoYlnjqLC+rJPpJqxy/IaoXl2Ast0od+p CiKL7+fD0P/yOnSTmRwtqCgs50Gux2IhjOKxTWrY/yQZpbQgUKprRZgoR48vA7MalN2Ein wjm/JhwASW4BdRf1odYjAAQ//Da46eXuhGP3fTvTUqPqi1SEsWGcT8cUSKBsEaxJpxMwri t4TDP+VrP0GoyskBjuHSwyAZxkBjwuKAJeiqvUmsCCKQWGebsQbQ/dYW0PwkMnMEHx/+UQ Dk3BAh9FNSoDZhz5JHGwg35NvV4HQZFZp3Q2oCe3rsQbsck8yVtweC9RSpalJg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515862; 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=d2aa8PgTtRDs84GbzPYsg9/c/UFZj39RiJ/AAhETCGQ=; b=6YjZFgK/aGr78TaRzK8UpHBzLtU3o1jB0TrBSGUihSUOr+Hyfc039ben0Zk8EZVKRloViH We4cnTEgROLKpkAw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 05/37] x86/topology: Remove CPU0 hotplug option References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:21 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515894264100019 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This was introduced together with commit e1c467e69040 ("x86, hotplug: Wake up CPU0 via NMI instead of INIT, SIPI, SIPI") to eventually support physical hotplug of CPU0: "We'll change this code in the future to wake up hard offlined CPU0 if real platform and request are available." 11 years later this has not happened and physical hotplug is not officially supported. Remove the cruft. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- Documentation/admin-guide/kernel-parameters.txt | 14 --- Documentation/core-api/cpu_hotplug.rst | 13 --- arch/x86/Kconfig | 43 ---------- arch/x86/include/asm/cpu.h | 3=20 arch/x86/kernel/topology.c | 98 -------------------= ----- arch/x86/power/cpu.c | 37 --------- 6 files changed, 6 insertions(+), 202 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -795,20 +795,6 @@ Format: ,,,[,] =20 - cpu0_hotplug [X86] Turn on CPU0 hotplug feature when - CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off. - Some features depend on CPU0. Known dependencies are: - 1. Resume from suspend/hibernate depends on CPU0. - Suspend/hibernate will fail if CPU0 is offline and you - need to online CPU0 before suspend/hibernate. - 2. PIC interrupts also depend on CPU0. CPU0 can't be - removed if a PIC interrupt is detected. - It's said poweroff/reboot may depend on CPU0 on some - machines although I haven't seen such issues so far - after CPU0 is offline on a few tested machines. - If the dependencies are under your control, you can - turn on cpu0_hotplug. - cpuidle.off=3D1 [CPU_IDLE] disable the cpuidle sub-system =20 --- a/Documentation/core-api/cpu_hotplug.rst +++ b/Documentation/core-api/cpu_hotplug.rst @@ -127,17 +127,8 @@ Once the CPU is shutdown, it will be rem $ echo 1 > /sys/devices/system/cpu/cpu4/online smpboot: Booting Node 0 Processor 4 APIC 0x1 =20 -The CPU is usable again. This should work on all CPUs. CPU0 is often speci= al -and excluded from CPU hotplug. On X86 the kernel option -*CONFIG_BOOTPARAM_HOTPLUG_CPU0* has to be enabled in order to be able to -shutdown CPU0. Alternatively the kernel command option *cpu0_hotplug* can = be -used. Some known dependencies of CPU0: - -* Resume from hibernate/suspend. Hibernate/suspend will fail if CPU0 is of= fline. -* PIC interrupts. CPU0 can't be removed if a PIC interrupt is detected. - -Please let Fenghua Yu know if you find any dependen= cies -on CPU0. +The CPU is usable again. This should work on all CPUs, but CPU0 is often s= pecial +and excluded from CPU hotplug. =20 The CPU hotplug coordination =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2294,49 +2294,6 @@ config HOTPLUG_CPU def_bool y depends on SMP =20 -config BOOTPARAM_HOTPLUG_CPU0 - bool "Set default setting of cpu0_hotpluggable" - depends on HOTPLUG_CPU - help - Set whether default state of cpu0_hotpluggable is on or off. - - Say Y here to enable CPU0 hotplug by default. If this switch - is turned on, there is no need to give cpu0_hotplug kernel - parameter and the CPU0 hotplug feature is enabled by default. - - Please note: there are two known CPU0 dependencies if you want - to enable the CPU0 hotplug feature either by this switch or by - cpu0_hotplug kernel parameter. - - First, resume from hibernate or suspend always starts from CPU0. - So hibernate and suspend are prevented if CPU0 is offline. - - Second dependency is PIC interrupts always go to CPU0. CPU0 can not - offline if any interrupt can not migrate out of CPU0. There may - be other CPU0 dependencies. - - Please make sure the dependencies are under your control before - you enable this feature. - - Say N if you don't want to enable CPU0 hotplug feature by default. - You still can enable the CPU0 hotplug feature at boot by kernel - parameter cpu0_hotplug. - -config DEBUG_HOTPLUG_CPU0 - def_bool n - prompt "Debug CPU0 hotplug" - depends on HOTPLUG_CPU - help - Enabling this option offlines CPU0 (if CPU0 can be offlined) as - soon as possible and boots up userspace with CPU0 offlined. User - can online CPU0 back after boot time. - - To debug CPU0 hotplug, you need to enable CPU0 offline/online - feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during - compilation or giving cpu0_hotplug kernel parameter at boot. - - If unsure, say N. - config COMPAT_VDSO def_bool n prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -31,9 +31,6 @@ struct x86_cpu { extern int arch_register_cpu(int num); extern void arch_unregister_cpu(int); extern void soft_restart_cpu(void); -#ifdef CONFIG_DEBUG_HOTPLUG_CPU0 -extern int _debug_hotplug_cpu(int cpu, int action); -#endif #endif =20 extern void ap_init_aperfmperf(void); --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -38,102 +38,12 @@ static DEFINE_PER_CPU(struct x86_cpu, cpu_devices); =20 #ifdef CONFIG_HOTPLUG_CPU - -#ifdef CONFIG_BOOTPARAM_HOTPLUG_CPU0 -static int cpu0_hotpluggable =3D 1; -#else -static int cpu0_hotpluggable; -static int __init enable_cpu0_hotplug(char *str) -{ - cpu0_hotpluggable =3D 1; - return 1; -} - -__setup("cpu0_hotplug", enable_cpu0_hotplug); -#endif - -#ifdef CONFIG_DEBUG_HOTPLUG_CPU0 -/* - * This function offlines a CPU as early as possible and allows userspace = to - * boot up without the CPU. The CPU can be onlined back by user after boot. - * - * This is only called for debugging CPU offline/online feature. - */ -int _debug_hotplug_cpu(int cpu, int action) -{ - int ret; - - if (!cpu_is_hotpluggable(cpu)) - return -EINVAL; - - switch (action) { - case 0: - ret =3D remove_cpu(cpu); - if (!ret) - pr_info("DEBUG_HOTPLUG_CPU0: CPU %u is now offline\n", cpu); - else - pr_debug("Can't offline CPU%d.\n", cpu); - break; - case 1: - ret =3D add_cpu(cpu); - if (ret) - pr_debug("Can't online CPU%d.\n", cpu); - - break; - default: - ret =3D -EINVAL; - } - - return ret; -} - -static int __init debug_hotplug_cpu(void) +int arch_register_cpu(int cpu) { - _debug_hotplug_cpu(0, 0); - return 0; -} - -late_initcall_sync(debug_hotplug_cpu); -#endif /* CONFIG_DEBUG_HOTPLUG_CPU0 */ - -int arch_register_cpu(int num) -{ - struct cpuinfo_x86 *c =3D &cpu_data(num); - - /* - * Currently CPU0 is only hotpluggable on Intel platforms. Other - * vendors can add hotplug support later. - * Xen PV guests don't support CPU0 hotplug at all. - */ - if (c->x86_vendor !=3D X86_VENDOR_INTEL || - cpu_feature_enabled(X86_FEATURE_XENPV)) - cpu0_hotpluggable =3D 0; - - /* - * Two known BSP/CPU0 dependencies: Resume from suspend/hibernate - * depends on BSP. PIC interrupts depend on BSP. - * - * If the BSP dependencies are under control, one can tell kernel to - * enable BSP hotplug. This basically adds a control file and - * one can attempt to offline BSP. - */ - if (num =3D=3D 0 && cpu0_hotpluggable) { - unsigned int irq; - /* - * We won't take down the boot processor on i386 if some - * interrupts only are able to be serviced by the BSP in PIC. - */ - for_each_active_irq(irq) { - if (!IO_APIC_IRQ(irq) && irq_has_action(irq)) { - cpu0_hotpluggable =3D 0; - break; - } - } - } - if (num || cpu0_hotpluggable) - per_cpu(cpu_devices, num).cpu.hotpluggable =3D 1; + struct x86_cpu *xc =3D per_cpu_ptr(&cpu_devices, cpu); =20 - return register_cpu(&per_cpu(cpu_devices, num).cpu, num); + xc->cpu.hotpluggable =3D cpu > 0; + return register_cpu(&xc->cpu, cpu); } EXPORT_SYMBOL(arch_register_cpu); =20 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -351,43 +351,6 @@ static int bsp_pm_callback(struct notifi case PM_HIBERNATION_PREPARE: ret =3D bsp_check(); break; -#ifdef CONFIG_DEBUG_HOTPLUG_CPU0 - case PM_RESTORE_PREPARE: - /* - * When system resumes from hibernation, online CPU0 because - * 1. it's required for resume and - * 2. the CPU was online before hibernation - */ - if (!cpu_online(0)) - _debug_hotplug_cpu(0, 1); - break; - case PM_POST_RESTORE: - /* - * When a resume really happens, this code won't be called. - * - * This code is called only when user space hibernation software - * prepares for snapshot device during boot time. So we just - * call _debug_hotplug_cpu() to restore to CPU0's state prior to - * preparing the snapshot device. - * - * This works for normal boot case in our CPU0 hotplug debug - * mode, i.e. CPU0 is offline and user mode hibernation - * software initializes during boot time. - * - * If CPU0 is online and user application accesses snapshot - * device after boot time, this will offline CPU0 and user may - * see different CPU0 state before and after accessing - * the snapshot device. But hopefully this is not a case when - * user debugging CPU0 hotplug. Even if users hit this case, - * they can easily online CPU0 back. - * - * To simplify this debug code, we only consider normal boot - * case. Otherwise we need to remember CPU0's state and restore - * to that state and resolve racy conditions etc. - */ - _debug_hotplug_cpu(0, 0); - break; -#endif default: break; } From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515889; cv=none; d=zohomail.com; s=zohoarc; b=dVCupiZEUc1QpPGCwT7f1vlEcKNaOUYZOpTVteYfm+munXTD3GQ85bQZXtFIt8WrZiMUUUOTMCD39dfF4TZXK5HPJ/xPsGPEVkNhTwIQyX3NDWYhwfAEb2Y9WXFRBv3m4XQyTT4nH78aWXsB+KPX9yoeDUWDE2KxDUPvxBqmkeI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1681515889; h=Content-Type:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=YH9enl+MJMA7M+jHkGDtbicNr+Ixljj01H/xHz4Qh68=; b=lC7WMUhqVziEmd7sQFah+624ZjlUyD1xO+r1ToI6oL3S3BWf8ps5XLpf+zcmHvqVZyjVSNGDchykVQyBLBoYCAkc/+OEvhFdyP29N7bzaoDPJEmjwRhMpOrp7DgupTlQSHF9Xhd+kvLz68IVL+uQfgbVzs3RQdLlNrkDRQSfzcg= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1681515889277363.08424999765816; Fri, 14 Apr 2023 16:44:49 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.521267.809778 (Exim 4.92) (envelope-from ) id 1pnT5d-0002It-9h; Fri, 14 Apr 2023 23:44:25 +0000 Received: by outflank-mailman (output) from mailman id 521267.809778; Fri, 14 Apr 2023 23:44:25 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5d-0002Ht-2x; Fri, 14 Apr 2023 23:44:25 +0000 Received: by outflank-mailman (input) for mailman id 521267; Fri, 14 Apr 2023 23:44:24 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5c-0001Th-G1 for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:24 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 48e4ba5e-db1e-11ed-b21e-6b7b168915f2; Sat, 15 Apr 2023 01:44:23 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 48e4ba5e-db1e-11ed-b21e-6b7b168915f2 Message-ID: <20230414232309.573146108@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515863; 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=YH9enl+MJMA7M+jHkGDtbicNr+Ixljj01H/xHz4Qh68=; b=lpyjAm63G6/b32sEy2uepr/mwtvLxNaVZIUgygQvLzALETE8fY9zKOsUJn47ur21f6W14A V2tnHnJYBZ1CJN22W1lTtZ/rc6uajRww1SwLf8shpZdCOhX0eOSE//5WpUk6MbTpvqnR5X qZU37iLHk5J6vEkA5V5T/+OF3dsRu/6COL0XsoQ/S7QyrnGbtOZ10i5838omOG817CfU4Q wnB32letUr83o/0uqFoR5Pi8jZWinNlL6rig7eZUjtVjm5/rd8LWR2a5RVvkxhhNsMfni8 tZJwVT1nbrbuO6Pt7yiZlgUrGKoZmXqt+t1/7rlqYhGz6DIacVWHGb0RmWJU3A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515863; 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=YH9enl+MJMA7M+jHkGDtbicNr+Ixljj01H/xHz4Qh68=; b=aRdJRfhum/Hx0Do87bftDWbAr15dWCqnPq1ID3UStY4wRkpCpotZQGfhlALDv9i+4/sicD Li5ESueuDU/IBvAg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 06/37] x86/smpboot: Remove the CPU0 hotplug kludge References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:22 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515890913100003 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This was introduced with commit e1c467e69040 ("x86, hotplug: Wake up CPU0 via NMI instead of INIT, SIPI, SIPI") to eventually support physical hotplug of CPU0: "We'll change this code in the future to wake up hard offlined CPU0 if real platform and request are available." 11 years later this has not happened and physical hotplug is not officially supported. Remove the cruft. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/apic.h | 1=20 arch/x86/include/asm/smp.h | 1=20 arch/x86/kernel/smpboot.c | 170 +++----------------------------------= ----- drivers/acpi/processor_idle.c | 4=20 4 files changed, 14 insertions(+), 162 deletions(-) --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -377,7 +377,6 @@ extern struct apic *__apicdrivers[], *__ * APIC functionality to boot other CPUs - only used on SMP: */ #ifdef CONFIG_SMP -extern int wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_ei= p); extern int lapic_can_unplug_cpu(void); #endif =20 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -129,7 +129,6 @@ void native_play_dead(void); void play_dead_common(void); void wbinvd_on_cpu(int cpu); int wbinvd_on_all_cpus(void); -void cond_wakeup_cpu0(void); =20 void native_smp_send_reschedule(int cpu); void native_send_call_func_ipi(const struct cpumask *mask); --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -216,9 +216,6 @@ static void ap_calibrate_delay(void) cpu_data(smp_processor_id()).loops_per_jiffy =3D loops_per_jiffy; } =20 -static int cpu0_logical_apicid; -static int enable_start_cpu0; - /* * Activate a secondary processor. */ @@ -241,8 +238,6 @@ static void notrace start_secondary(void x86_cpuinit.early_percpu_clock_init(); smp_callin(); =20 - enable_start_cpu0 =3D 0; - /* otherwise gcc will move up smp_processor_id before the cpu_init */ barrier(); /* Check TSC synchronization with the control CPU: */ @@ -410,7 +405,7 @@ void smp_store_cpu_info(int id) c->cpu_index =3D id; /* * During boot time, CPU0 has this setup already. Save the info when - * bringing up AP or offlined CPU0. + * bringing up an AP. */ identify_secondary_cpu(c); c->initialized =3D true; @@ -807,51 +802,14 @@ static void __init smp_quirk_init_udelay } =20 /* - * Poke the other CPU in the eye via NMI to wake it up. Remember that the = normal - * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this - * won't ... remember to clear down the APIC, etc later. - */ -int -wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip) -{ - u32 dm =3D apic->dest_mode_logical ? APIC_DEST_LOGICAL : APIC_DEST_PHYSIC= AL; - unsigned long send_status, accept_status =3D 0; - int maxlvt; - - /* Target chip */ - /* Boot on the stack */ - /* Kick the second */ - apic_icr_write(APIC_DM_NMI | dm, apicid); - - pr_debug("Waiting for send to finish...\n"); - send_status =3D safe_apic_wait_icr_idle(); - - /* - * Give the other CPU some time to accept the IPI. - */ - udelay(200); - if (APIC_INTEGRATED(boot_cpu_apic_version)) { - maxlvt =3D lapic_get_maxlvt(); - if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ - apic_write(APIC_ESR, 0); - accept_status =3D (apic_read(APIC_ESR) & 0xEF); - } - pr_debug("NMI sent\n"); - - if (send_status) - pr_err("APIC never delivered???\n"); - if (accept_status) - pr_err("APIC delivery error (%lx)\n", accept_status); - - return (send_status | accept_status); -} - -static int -wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) + * Wake up AP by INIT, INIT, STARTUP sequence. + */ +static int wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long st= art_eip) { unsigned long send_status =3D 0, accept_status =3D 0; int maxlvt, num_starts, j; =20 + preempt_disable(); maxlvt =3D lapic_get_maxlvt(); =20 /* @@ -957,6 +915,7 @@ wakeup_secondary_cpu_via_init(int phys_a if (accept_status) pr_err("APIC delivery error (%lx)\n", accept_status); =20 + preempt_enable(); return (send_status | accept_status); } =20 @@ -997,67 +956,6 @@ static void announce_cpu(int cpu, int ap node, cpu, apicid); } =20 -static int wakeup_cpu0_nmi(unsigned int cmd, struct pt_regs *regs) -{ - int cpu; - - cpu =3D smp_processor_id(); - if (cpu =3D=3D 0 && !cpu_online(cpu) && enable_start_cpu0) - return NMI_HANDLED; - - return NMI_DONE; -} - -/* - * Wake up AP by INIT, INIT, STARTUP sequence. - * - * Instead of waiting for STARTUP after INITs, BSP will execute the BIOS - * boot-strap code which is not a desired behavior for waking up BSP. To - * void the boot-strap code, wake up CPU0 by NMI instead. - * - * This works to wake up soft offlined CPU0 only. If CPU0 is hard offlined - * (i.e. physically hot removed and then hot added), NMI won't wake it up. - * We'll change this code in the future to wake up hard offlined CPU0 if - * real platform and request are available. - */ -static int -wakeup_cpu_via_init_nmi(int cpu, unsigned long start_ip, int apicid, - int *cpu0_nmi_registered) -{ - int id; - int boot_error; - - preempt_disable(); - - /* - * Wake up AP by INIT, INIT, STARTUP sequence. - */ - if (cpu) { - boot_error =3D wakeup_secondary_cpu_via_init(apicid, start_ip); - goto out; - } - - /* - * Wake up BSP by nmi. - * - * Register a NMI handler to help wake up CPU0. - */ - boot_error =3D register_nmi_handler(NMI_LOCAL, - wakeup_cpu0_nmi, 0, "wake_cpu0"); - - if (!boot_error) { - enable_start_cpu0 =3D 1; - *cpu0_nmi_registered =3D 1; - id =3D apic->dest_mode_logical ? cpu0_logical_apicid : apicid; - boot_error =3D wakeup_secondary_cpu_via_nmi(id, start_ip); - } - -out: - preempt_enable(); - - return boot_error; -} - int common_cpu_up(unsigned int cpu, struct task_struct *idle) { int ret; @@ -1086,8 +984,7 @@ int common_cpu_up(unsigned int cpu, stru * Returns zero if CPU booted OK, else error code from * ->wakeup_secondary_cpu. */ -static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle, - int *cpu0_nmi_registered) +static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle) { /* start_ip had better be page-aligned! */ unsigned long start_ip =3D real_mode_header->trampoline_start; @@ -1120,7 +1017,6 @@ static int do_boot_cpu(int apicid, int c * This grunge runs the startup process for * the targeted processor. */ - if (x86_platform.legacy.warm_reset) { =20 pr_debug("Setting warm reset code and vector.\n"); @@ -1149,15 +1045,14 @@ static int do_boot_cpu(int apicid, int c * - Use a method from the APIC driver if one defined, with wakeup * straight to 64-bit mode preferred over wakeup to RM. * Otherwise, - * - Use an INIT boot APIC message for APs or NMI for BSP. + * - Use an INIT boot APIC message */ if (apic->wakeup_secondary_cpu_64) boot_error =3D apic->wakeup_secondary_cpu_64(apicid, start_ip); else if (apic->wakeup_secondary_cpu) boot_error =3D apic->wakeup_secondary_cpu(apicid, start_ip); else - boot_error =3D wakeup_cpu_via_init_nmi(cpu, start_ip, apicid, - cpu0_nmi_registered); + boot_error =3D wakeup_secondary_cpu_via_init(apicid, start_ip); =20 if (!boot_error) { /* @@ -1206,9 +1101,8 @@ static int do_boot_cpu(int apicid, int c int native_cpu_up(unsigned int cpu, struct task_struct *tidle) { int apicid =3D apic->cpu_present_to_apicid(cpu); - int cpu0_nmi_registered =3D 0; unsigned long flags; - int err, ret =3D 0; + int err; =20 lockdep_assert_irqs_enabled(); =20 @@ -1247,11 +1141,10 @@ int native_cpu_up(unsigned int cpu, stru if (err) return err; =20 - err =3D do_boot_cpu(apicid, cpu, tidle, &cpu0_nmi_registered); + err =3D do_boot_cpu(apicid, cpu, tidle); if (err) { pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu); - ret =3D -EIO; - goto unreg_nmi; + return err; } =20 /* @@ -1267,15 +1160,7 @@ int native_cpu_up(unsigned int cpu, stru touch_nmi_watchdog(); } =20 -unreg_nmi: - /* - * Clean up the nmi handler. Do this after the callin and callout sync - * to avoid impact of possible long unregister time. - */ - if (cpu0_nmi_registered) - unregister_nmi_handler(NMI_LOCAL, "wake_cpu0"); - - return ret; + return 0; } =20 /** @@ -1373,14 +1258,6 @@ static void __init smp_cpu_index_default } } =20 -static void __init smp_get_logical_apicid(void) -{ - if (x2apic_mode) - cpu0_logical_apicid =3D apic_read(APIC_LDR); - else - cpu0_logical_apicid =3D GET_APIC_LOGICAL_ID(apic_read(APIC_LDR)); -} - void __init smp_prepare_cpus_common(void) { unsigned int i; @@ -1443,8 +1320,6 @@ void __init native_smp_prepare_cpus(unsi /* Setup local timer */ x86_init.timers.setup_percpu_clockev(); =20 - smp_get_logical_apicid(); - pr_info("CPU0: "); print_cpu_info(&cpu_data(0)); =20 @@ -1752,18 +1627,6 @@ void play_dead_common(void) local_irq_disable(); } =20 -/** - * cond_wakeup_cpu0 - Wake up CPU0 if needed. - * - * If NMI wants to wake up CPU0, start CPU0. - */ -void cond_wakeup_cpu0(void) -{ - if (smp_processor_id() =3D=3D 0 && enable_start_cpu0) - start_cpu0(); -} -EXPORT_SYMBOL_GPL(cond_wakeup_cpu0); - /* * We need to flush the caches before going to sleep, lest we have * dirty data in our caches when we come back up. @@ -1831,8 +1694,6 @@ static inline void mwait_play_dead(void) __monitor(mwait_ptr, 0, 0); mb(); __mwait(eax, 0); - - cond_wakeup_cpu0(); } } =20 @@ -1841,11 +1702,8 @@ void hlt_play_dead(void) if (__this_cpu_read(cpu_info.x86) >=3D 4) wbinvd(); =20 - while (1) { + while (1) native_halt(); - - cond_wakeup_cpu0(); - } } =20 void native_play_dead(void) --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -597,10 +597,6 @@ static int acpi_idle_play_dead(struct cp io_idle(cx->address); } else return -ENODEV; - -#if defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU) - cond_wakeup_cpu0(); -#endif } =20 /* Never reached */ From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; 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a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515865; 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=yXU88DPM4+gDgwwKQLancKUxDjIhod/zoYFzhLlkywE=; b=MdNuozlhNGUku1R1Tw5i7+TfSWnt88h5jzNnGTOji+filOi1PFWkM9UpldmpxTl1Bs6qoB RP/SXlqo2sMOuJDA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 07/37] x86/smpboot: Restrict soft_restart_cpu() to SEV References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:24 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515892183100009 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Now that the CPU0 hotplug cruft is gone, the only user is AMD SEV. Signed-off-by: Thomas Gleixner Cc: Tom Lendacky Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/callthunks.c | 2 +- arch/x86/kernel/head_32.S | 14 -------------- arch/x86/kernel/head_64.S | 2 +- 3 files changed, 2 insertions(+), 16 deletions(-) --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -133,7 +133,7 @@ static bool skip_addr(void *dest) /* Accounts directly */ if (dest =3D=3D ret_from_fork) return true; -#ifdef CONFIG_HOTPLUG_CPU +#if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_AMD_MEM_ENCRYPT) if (dest =3D=3D soft_restart_cpu) return true; #endif --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -138,20 +138,6 @@ SYM_CODE_START(startup_32) jmp .Ldefault_entry SYM_CODE_END(startup_32) =20 -#ifdef CONFIG_HOTPLUG_CPU -/* - * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for - * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot - * unplug. Everything is set up already except the stack. - */ -SYM_FUNC_START(soft_restart_cpu) - movl initial_stack, %ecx - movl %ecx, %esp - call *(initial_code) -1: jmp 1b -SYM_FUNC_END(soft_restart_cpu) -#endif - /* * Non-boot CPU entry point; entered from trampoline.S * We can't lgdt here, because lgdt itself uses a data segment, but --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -375,7 +375,7 @@ SYM_CODE_END(secondary_startup_64) #include "verify_cpu.S" #include "sev_verify_cbit.S" =20 -#ifdef CONFIG_HOTPLUG_CPU +#if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_AMD_MEM_ENCRYPT) /* * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515889; cv=none; d=zohomail.com; s=zohoarc; b=ajeJkT27WXktG/N7dfe/ef/nmoWanD7coPeLYez0595RQi4KjTTn9JDN5Ox+twfg2WBeZfYunQ2EYzchaoprMG/AhzOv62ttU71/+ewA5CxMidM1GtEwxlh/1GjYtwhsCO7c4F7OHnsVsP2DpqmGomTx8p4VDEVEzy0sywBDzbY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1681515889; h=Content-Type:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=1Wi+qwoi+evP9/DCOV2cSOOVm8Cmr+iaowZLI6jmphg=; b=FrHrXqa7id0SmT+XRHVV2CBehvHQJNhz0XwqtAXKUyeTsxBVuOUjL6rQpxnIFUwIrevd6RUrx184eAkeFL6O2J0uW8CZ6tFguWimQkUIKK2SIZsXTyBQbhpSC1H+Ee76cuJkZDMNDgU7MJy4ppUqd1h0dZJt/K3xQrGY5P3kPd4= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1681515889414695.9016529733432; Fri, 14 Apr 2023 16:44:49 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.521269.809805 (Exim 4.92) (envelope-from ) id 1pnT5i-0003Bo-9h; Fri, 14 Apr 2023 23:44:30 +0000 Received: by outflank-mailman (output) from mailman id 521269.809805; Fri, 14 Apr 2023 23:44:30 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5i-0003BR-1Z; Fri, 14 Apr 2023 23:44:30 +0000 Received: by outflank-mailman (input) for mailman id 521269; Fri, 14 Apr 2023 23:44:29 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5h-0000zb-4r for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:29 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 4b01e6b6-db1e-11ed-8611-37d641c3527e; Sat, 15 Apr 2023 01:44:27 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4b01e6b6-db1e-11ed-8611-37d641c3527e Message-ID: <20230414232309.697634212@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515867; 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=1Wi+qwoi+evP9/DCOV2cSOOVm8Cmr+iaowZLI6jmphg=; b=AtRfJAw/8dYgxzfcjPmLpOmGdUx0vCx8DqJiiMUmA3Cx+ZLSfVD8knv2kLNlnnW0M6wLbC T2QMHllGrZw7clK5/9Izh2AsnDdOvwLy0I4V80idxIhDm2+ZbZDLAikAULtI4e2AXQKPJr hBN5Y+KDw8n4D6Q1OvfiiBRG0iaAfEdsTfZ4cQweomKAopqUvixONL5zoVls1tMNAxyOEc sq7MkdcHTAZO6XblFcZcs66KyhWSvsJm9iqyZTxzUjsNnLQXic0xapY2RzQ/O/jDEPsPId R7R0FelILdrBFPupQz1xDszAcoMcHcibu8KNFeW7JRloBkiOApBN6zt3RCxP6g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515867; 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=1Wi+qwoi+evP9/DCOV2cSOOVm8Cmr+iaowZLI6jmphg=; b=erfBajWkK4A2wOU949cIjl3VUhIAl2v89iiOuXqsNlKDnlt3hip7OcUwwjvwGRE24kiwsr gNkbbyv7cvDgLNDA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 08/37] x86/smpboot: Split up native_cpu_up() into separate phases and document them References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:26 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515890495100001 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: David Woodhouse There are four logical parts to what native_cpu_up() does on the BSP (or on the controlling CPU for a later hotplug): 1) Wake the AP by sending the INIT/SIPI/SIPI sequence. 2) Wait for the AP to make it as far as wait_for_master_cpu() which sets that CPU's bit in cpu_initialized_mask, then sets the bit in cpu_callout_mask to let the AP proceed through cpu_init(). 3) Wait for the AP to finish cpu_init() and get as far as the smp_callin() call, which sets that CPU's bit in cpu_callin_mask. 4) Perform the TSC synchronization and wait for the AP to actually mark itself online in cpu_online_mask. In preparation to allow these phases to operate in parallel on multiple APs, split them out into separate functions and document the interactions a little more clearly in both the BP and AP code paths. No functional change intended. Signed-off-by: David Woodhouse Signed-off-by: Usama Arif Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/smpboot.c | 187 +++++++++++++++++++++++++++++------------= ----- 1 file changed, 121 insertions(+), 66 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -193,6 +193,10 @@ static void smp_callin(void) =20 wmb(); =20 + /* + * This runs the AP through all the cpuhp states to its target + * state (CPUHP_ONLINE in the case of serial bringup). + */ notify_cpu_starting(cpuid); =20 /* @@ -233,14 +237,31 @@ static void notrace start_secondary(void load_cr3(swapper_pg_dir); __flush_tlb_all(); #endif + /* + * Sync point with wait_cpu_initialized(). Before proceeding through + * cpu_init(), the AP will call wait_for_master_cpu() which sets its + * own bit in cpu_initialized_mask and then waits for the BSP to set + * its bit in cpu_callout_mask to release it. + */ cpu_init_secondary(); rcu_cpu_starting(raw_smp_processor_id()); x86_cpuinit.early_percpu_clock_init(); + + /* + * Sync point with wait_cpu_callin(). The AP doesn't wait here + * but just sets the bit to let the controlling CPU (BSP) know that + * it's got this far. + */ smp_callin(); =20 - /* otherwise gcc will move up smp_processor_id before the cpu_init */ + /* Otherwise gcc will move up smp_processor_id() before cpu_init() */ barrier(); - /* Check TSC synchronization with the control CPU: */ + + /* + * Check TSC synchronization with the control CPU, which will do + * its part of this from wait_cpu_online(), making it an implicit + * synchronization point. + */ check_tsc_sync_target(); =20 /* @@ -259,6 +280,7 @@ static void notrace start_secondary(void * half valid vector space. */ lock_vector_lock(); + /* Sync point with do_wait_cpu_online() */ set_cpu_online(smp_processor_id(), true); lapic_online(); unlock_vector_lock(); @@ -981,17 +1003,13 @@ int common_cpu_up(unsigned int cpu, stru /* * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad * (ie clustered apic addressing mode), this is a LOGICAL apic ID. - * Returns zero if CPU booted OK, else error code from + * Returns zero if startup was successfully sent, else error code from * ->wakeup_secondary_cpu. */ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle) { - /* start_ip had better be page-aligned! */ unsigned long start_ip =3D real_mode_header->trampoline_start; =20 - unsigned long boot_error =3D 0; - unsigned long timeout; - #ifdef CONFIG_X86_64 /* If 64-bit wakeup method exists, use the 64-bit mode trampoline IP */ if (apic->wakeup_secondary_cpu_64) @@ -1048,60 +1066,89 @@ static int do_boot_cpu(int apicid, int c * - Use an INIT boot APIC message */ if (apic->wakeup_secondary_cpu_64) - boot_error =3D apic->wakeup_secondary_cpu_64(apicid, start_ip); + return apic->wakeup_secondary_cpu_64(apicid, start_ip); else if (apic->wakeup_secondary_cpu) - boot_error =3D apic->wakeup_secondary_cpu(apicid, start_ip); - else - boot_error =3D wakeup_secondary_cpu_via_init(apicid, start_ip); + return apic->wakeup_secondary_cpu(apicid, start_ip); =20 - if (!boot_error) { - /* - * Wait 10s total for first sign of life from AP - */ - boot_error =3D -1; - timeout =3D jiffies + 10*HZ; - while (time_before(jiffies, timeout)) { - if (cpumask_test_cpu(cpu, cpu_initialized_mask)) { - /* - * Tell AP to proceed with initialization - */ - cpumask_set_cpu(cpu, cpu_callout_mask); - boot_error =3D 0; - break; - } - schedule(); - } - } + return wakeup_secondary_cpu_via_init(apicid, start_ip); +} =20 - if (!boot_error) { - /* - * Wait till AP completes initial initialization - */ - while (!cpumask_test_cpu(cpu, cpu_callin_mask)) { - /* - * Allow other tasks to run while we wait for the - * AP to come online. This also gives a chance - * for the MTRR work(triggered by the AP coming online) - * to be completed in the stop machine context. - */ - schedule(); - } - } +static int wait_cpu_cpumask(unsigned int cpu, const struct cpumask *mask) +{ + unsigned long timeout; =20 - if (x86_platform.legacy.warm_reset) { - /* - * Cleanup possible dangling ends... - */ - smpboot_restore_warm_reset_vector(); + /* + * Wait up to 10s for the CPU to report in. + */ + timeout =3D jiffies + 10*HZ; + while (time_before(jiffies, timeout)) { + if (cpumask_test_cpu(cpu, mask)) + return 0; + + schedule(); } + return -1; +} =20 - return boot_error; +/* + * Bringup step two: Wait for the target AP to reach cpu_init_secondary() + * and thus wait_for_master_cpu(), then set cpu_callout_mask to allow it + * to proceed. The AP will then proceed past setting its 'callin' bit + * and end up waiting in check_tsc_sync_target() until we reach + * do_wait_cpu_online() to tend to it. + */ +static int wait_cpu_initialized(unsigned int cpu) +{ + /* + * Wait for first sign of life from AP. + */ + if (wait_cpu_cpumask(cpu, cpu_initialized_mask)) + return -1; + + cpumask_set_cpu(cpu, cpu_callout_mask); + return 0; } =20 -int native_cpu_up(unsigned int cpu, struct task_struct *tidle) +/* + * Bringup step three: Wait for the target AP to reach smp_callin(). + * The AP is not waiting for us here so we don't need to parallelise + * this step. Not entirely clear why we care about this, since we just + * proceed directly to TSC synchronization which is the next sync + * point with the AP anyway. + */ +static void wait_cpu_callin(unsigned int cpu) +{ + while (!cpumask_test_cpu(cpu, cpu_callin_mask)) + schedule(); +} + +/* + * Bringup step four: Synchronize the TSC and wait for the target AP + * to reach set_cpu_online() in start_secondary(). + */ +static void wait_cpu_online(unsigned int cpu) { - int apicid =3D apic->cpu_present_to_apicid(cpu); unsigned long flags; + + /* + * Check TSC synchronization with the AP (keep irqs disabled + * while doing so): + */ + local_irq_save(flags); + check_tsc_sync_source(cpu); + local_irq_restore(flags); + + /* + * Wait for the AP to mark itself online, so the core caller + * can drop sparse_irq_lock. + */ + while (!cpu_online(cpu)) + schedule(); +} + +static int native_kick_ap(unsigned int cpu, struct task_struct *tidle) +{ + int apicid =3D apic->cpu_present_to_apicid(cpu); int err; =20 lockdep_assert_irqs_enabled(); @@ -1142,25 +1189,33 @@ int native_cpu_up(unsigned int cpu, stru return err; =20 err =3D do_boot_cpu(apicid, cpu, tidle); - if (err) { + if (err) pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu); - return err; - } =20 - /* - * Check TSC synchronization with the AP (keep irqs disabled - * while doing so): - */ - local_irq_save(flags); - check_tsc_sync_source(cpu); - local_irq_restore(flags); + return err; +} =20 - while (!cpu_online(cpu)) { - cpu_relax(); - touch_nmi_watchdog(); - } +int native_cpu_up(unsigned int cpu, struct task_struct *tidle) +{ + int ret; =20 - return 0; + ret =3D native_kick_ap(cpu, tidle); + if (ret) + goto out; + + ret =3D wait_cpu_initialized(cpu); + if (ret) + goto out; + + wait_cpu_callin(cpu); + wait_cpu_online(cpu); + +out: + /* Cleanup possible dangling ends... */ + if (x86_platform.legacy.warm_reset) + smpboot_restore_warm_reset_vector(); + + return ret; } =20 /** From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; 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a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515868; 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=38vdbwHqBLIqPwRw5MqT+R7Ll28v39Ia/30h9IRZRBU=; b=MftkEADdginftZmZ+/cCkpBXX8KUjRl1mx3aoGgqqGTOVFHczgdVkY20eVN/Z+ePOHG5TU YFmw4iY8ytDodjDg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 09/37] x86/smpboot: Get rid of cpu_init_secondary() References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:28 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515893264100016 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The synchronization of the AP with the control CPU is a SMP boot problem and has nothing to do with cpu_init(). Open code cpu_init_secondary() in start_secondary() and move wait_for_master_cpu() into the SMP boot code. No functional change. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/processor.h | 1 - arch/x86/kernel/cpu/common.c | 27 --------------------------- arch/x86/kernel/smpboot.c | 24 +++++++++++++++++++----- 3 files changed, 19 insertions(+), 33 deletions(-) --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -551,7 +551,6 @@ extern void switch_gdt_and_percpu_base(i extern void load_direct_gdt(int); extern void load_fixmap_gdt(int); extern void cpu_init(void); -extern void cpu_init_secondary(void); extern void cpu_init_exception_handling(void); extern void cr4_init(void); =20 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2122,19 +2122,6 @@ static void dbg_restore_debug_regs(void) #define dbg_restore_debug_regs() #endif /* ! CONFIG_KGDB */ =20 -static void wait_for_master_cpu(int cpu) -{ -#ifdef CONFIG_SMP - /* - * wait for ACK from master CPU before continuing - * with AP initialization - */ - WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)); - while (!cpumask_test_cpu(cpu, cpu_callout_mask)) - cpu_relax(); -#endif -} - static inline void setup_getcpu(int cpu) { unsigned long cpudata =3D vdso_encode_cpunode(cpu, early_cpu_to_node(cpu)= ); @@ -2238,8 +2225,6 @@ void cpu_init(void) struct task_struct *cur =3D current; int cpu =3D raw_smp_processor_id(); =20 - wait_for_master_cpu(cpu); - ucode_cpu_init(cpu); =20 #ifdef CONFIG_NUMA @@ -2292,18 +2277,6 @@ void cpu_init(void) load_fixmap_gdt(cpu); } =20 -#ifdef CONFIG_SMP -void cpu_init_secondary(void) -{ - /* - * Relies on the BP having set-up the IDT tables, which are loaded - * on this CPU in cpu_init_exception_handling(). - */ - cpu_init_exception_handling(); - cpu_init(); -} -#endif - #ifdef CONFIG_MICROCODE_LATE_LOADING /** * store_cpu_caps() - Store a snapshot of CPU capabilities --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -220,6 +220,17 @@ static void ap_calibrate_delay(void) cpu_data(smp_processor_id()).loops_per_jiffy =3D loops_per_jiffy; } =20 +static void wait_for_master_cpu(int cpu) +{ + /* + * Wait for release by control CPU before continuing with AP + * initialization. + */ + WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)); + while (!cpumask_test_cpu(cpu, cpu_callout_mask)) + cpu_relax(); +} + /* * Activate a secondary processor. */ @@ -237,13 +248,16 @@ static void notrace start_secondary(void load_cr3(swapper_pg_dir); __flush_tlb_all(); #endif + cpu_init_exception_handling(); + /* - * Sync point with wait_cpu_initialized(). Before proceeding through - * cpu_init(), the AP will call wait_for_master_cpu() which sets its - * own bit in cpu_initialized_mask and then waits for the BSP to set - * its bit in cpu_callout_mask to release it. + * Sync point with wait_cpu_initialized(). Sets AP in + * cpu_initialized_mask and then waits for the control CPU + * to release it. */ - cpu_init_secondary(); + wait_for_master_cpu(raw_smp_processor_id()); + + cpu_init(); rcu_cpu_starting(raw_smp_processor_id()); x86_cpuinit.early_percpu_clock_init(); From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515892; cv=none; d=zohomail.com; s=zohoarc; b=QKdbbp36ptqsM9pOKZdd6b8gpome1oil0fkncH/+3LSP5qxr8du/IFry+7XmRCLvY30+6XffVoZRr/mVBma1G3i90Yz77DNxy72T4w3H3g/w3ukarSCIYqWJTyvR26/zJForsAYn4YsLwWGdPR+WTdo/HyYK4NZs0U8A+A+VgOs= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1681515892; h=Content-Type:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=u2pIwytrv1vZgLx+4s6Zqq6fs8EHbK9BS70kDc1o//Q=; b=RIKIAIOy+NsYW1tXL78KAwSIc3xf6nyz433BkGpICLprOBAMVuegemBUwdXZXXRbWTT44f1XsJomQYo4xjpEqA//lQUecteH2QM2LAODZTdrQ1CtgmEItx3OLG9rK80BaMRatUXlyXzY4tDD8VP/JP/x/titIq9O0Pz1M3DZuZw= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1681515892388848.766846062518; Fri, 14 Apr 2023 16:44:52 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.521271.809824 (Exim 4.92) (envelope-from ) id 1pnT5l-0003pD-H5; Fri, 14 Apr 2023 23:44:33 +0000 Received: by outflank-mailman (output) from mailman id 521271.809824; Fri, 14 Apr 2023 23:44:33 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5l-0003od-81; Fri, 14 Apr 2023 23:44:33 +0000 Received: by outflank-mailman (input) for mailman id 521271; Fri, 14 Apr 2023 23:44:32 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5k-0000zb-40 for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:32 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 4cea9c1a-db1e-11ed-8611-37d641c3527e; Sat, 15 Apr 2023 01:44:30 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4cea9c1a-db1e-11ed-8611-37d641c3527e Message-ID: <20230414232309.823800249@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515870; 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=u2pIwytrv1vZgLx+4s6Zqq6fs8EHbK9BS70kDc1o//Q=; b=tj9xEvgya1srEI62cuunab7v24wBazw6wpcxMtpv79720yev1kGcsEOxNFRId8qJ8lqNgr q1f11vM+Nc4aB4NgnBxR6tIQfQU2iMcMUeRzBxRZmT8RWJKM3p19eh3Ukgff4IpPXHAAmQ OLzNAKEJS2vpJEbsoOLlJHaRdWtjNT4f1mD1+bDAcp/oan26jOAxfnbm6Tpuvt1St80R8P dPrGNEb4Zg6w49Q/eELNuFnnuSnEIQhX8h7OuWa4y9Uk6de034h6Q46GBDo6gmOK33DmEP YQXfDKPvV28Xy5XOo7nZYu9OBqWv20e7LFSwhwcY173bD1coDcsMG/2Q9JSTZg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515870; 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=u2pIwytrv1vZgLx+4s6Zqq6fs8EHbK9BS70kDc1o//Q=; b=YNu0rancrP7gWuufcUKxrEH7bo8bWOmpZPxm7N3EMgjD1anaBUmHq23Qv/x7FzdBfUPs2b nJi2pgQCB1pCr2DA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 10/37] x86/cpu/cacheinfo: Remove cpu_callout_mask dependency References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:29 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515894532100021 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" cpu_callout_mask is used for the stop machine based MTRR/PAT init. In preparation of moving the BP/AP synchronization to the core hotplug code, use a private CPU mask for cacheinfo and manage it in the starting/dying hotplug state. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/cpu/cacheinfo.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/cpu/cacheinfo.c +++ b/arch/x86/kernel/cpu/cacheinfo.c @@ -39,6 +39,8 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t /* Shared L2 cache maps */ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_l2c_shared_map); =20 +static cpumask_var_t cpu_cacheinfo_mask; + /* Kernel controls MTRR and/or PAT MSRs. */ unsigned int memory_caching_control __ro_after_init; =20 @@ -1172,8 +1174,10 @@ void cache_bp_restore(void) cache_cpu_init(); } =20 -static int cache_ap_init(unsigned int cpu) +static int cache_ap_online(unsigned int cpu) { + cpumask_set_cpu(cpu, cpu_cacheinfo_mask); + if (!memory_caching_control || get_cache_aps_delayed_init()) return 0; =20 @@ -1191,11 +1195,17 @@ static int cache_ap_init(unsigned int cp * lock to prevent MTRR entry changes */ stop_machine_from_inactive_cpu(cache_rendezvous_handler, NULL, - cpu_callout_mask); + cpu_cacheinfo_mask); =20 return 0; } =20 +static int cache_ap_offline(unsigned int cpu) +{ + cpumask_clear_cpu(cpu, cpu_cacheinfo_mask); + return 0; +} + /* * Delayed cache initialization for all AP's */ @@ -1210,9 +1220,12 @@ void cache_aps_init(void) =20 static int __init cache_ap_register(void) { + zalloc_cpumask_var(&cpu_cacheinfo_mask, GFP_KERNEL); + cpumask_set_cpu(smp_processor_id(), cpu_cacheinfo_mask); + cpuhp_setup_state_nocalls(CPUHP_AP_CACHECTRL_STARTING, "x86/cachectrl:starting", - cache_ap_init, NULL); + cache_ap_online, cache_ap_offline); return 0; } -core_initcall(cache_ap_register); +early_initcall(cache_ap_register); From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; 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a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515871; 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=/ZK0+aYTDprGh+TLZnlXwtj4Vfn8D4d3BT+xMJ2O4BY=; b=vjkoNmrHuvgLnadmWDBQsaj4074jsURhSMcG/y+SAv5U7Hjl873Sfi0Y38vZ0CiBW30lkc YSRug6WOf+XkPtW/Ok7DfLfUey146jL84NdowhhogdHAP/UKxbH2eo4JQjN009SbEVnvNW 1zv9NUb4vEW1lio3uk0/iDb4xih4TRxA+1g65l9y4CxPj9/vIKfhtqspZBp17LHEOMwTUs uqFNHzjdehaY7LPLRMdLZxqYkTGv4zrW/lRcOci3KT4V49tXaioV61gsRoQXocuqUqCvtS KqU2xIzYJQYvtQyq2IG1EFa3XvWD9GUEZsifVyZD2YZ/wz91ynh5mZJDMN6fTQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515871; 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=/ZK0+aYTDprGh+TLZnlXwtj4Vfn8D4d3BT+xMJ2O4BY=; b=5l86SHxSNU5XjxfrY2KYmiaNiv7XnFBAOMn0HfeVzwcXghypKkHnPtf+Boxw8mjzqZQmUJ Sn14SMUAF/D/3pAQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 11/37] x86/smpboot: Move synchronization masks to SMP boot code References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:31 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515895282100023 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The usage is in smpboot.c and not in the CPU initialization code. The XEN_PV usage of cpu_callout_mask is obsolete as cpu_init() not longer waits and cacheinfo has its own CPU mask now, so cpu_callout_mask can be made static too. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/cpumask.h | 5 ----- arch/x86/kernel/cpu/common.c | 17 ----------------- arch/x86/kernel/smpboot.c | 16 ++++++++++++++++ arch/x86/xen/smp_pv.c | 3 --- 4 files changed, 16 insertions(+), 25 deletions(-) --- a/arch/x86/include/asm/cpumask.h +++ b/arch/x86/include/asm/cpumask.h @@ -4,11 +4,6 @@ #ifndef __ASSEMBLY__ #include =20 -extern cpumask_var_t cpu_callin_mask; -extern cpumask_var_t cpu_callout_mask; -extern cpumask_var_t cpu_initialized_mask; -extern cpumask_var_t cpu_sibling_setup_mask; - extern void setup_cpu_local_masks(void); =20 /* --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -67,14 +67,6 @@ =20 u32 elf_hwcap2 __read_mostly; =20 -/* all of these masks are initialized in setup_cpu_local_masks() */ -cpumask_var_t cpu_initialized_mask; -cpumask_var_t cpu_callout_mask; -cpumask_var_t cpu_callin_mask; - -/* representing cpus for which sibling maps can be computed */ -cpumask_var_t cpu_sibling_setup_mask; - /* Number of siblings per CPU package */ int smp_num_siblings =3D 1; EXPORT_SYMBOL(smp_num_siblings); @@ -168,15 +160,6 @@ static void ppin_init(struct cpuinfo_x86 clear_cpu_cap(c, info->feature); } =20 -/* correctly size the local cpu masks */ -void __init setup_cpu_local_masks(void) -{ - alloc_bootmem_cpumask_var(&cpu_initialized_mask); - alloc_bootmem_cpumask_var(&cpu_callin_mask); - alloc_bootmem_cpumask_var(&cpu_callout_mask); - alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask); -} - static void default_init(struct cpuinfo_x86 *c) { #ifdef CONFIG_X86_64 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -101,6 +101,13 @@ EXPORT_PER_CPU_SYMBOL(cpu_die_map); DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); =20 +/* All of these masks are initialized in setup_cpu_local_masks() */ +static cpumask_var_t cpu_initialized_mask; +static cpumask_var_t cpu_callout_mask; +static cpumask_var_t cpu_callin_mask; +/* Representing CPUs for which sibling maps can be computed */ +static cpumask_var_t cpu_sibling_setup_mask; + /* Logical package management. We might want to allocate that dynamically = */ unsigned int __max_logical_packages __read_mostly; EXPORT_SYMBOL(__max_logical_packages); @@ -1548,6 +1555,15 @@ early_param("possible_cpus", _setup_poss set_cpu_possible(i, true); } =20 +/* correctly size the local cpu masks */ +void __init setup_cpu_local_masks(void) +{ + alloc_bootmem_cpumask_var(&cpu_initialized_mask); + alloc_bootmem_cpumask_var(&cpu_callin_mask); + alloc_bootmem_cpumask_var(&cpu_callout_mask); + alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask); +} + #ifdef CONFIG_HOTPLUG_CPU =20 /* Recompute SMT state for all CPUs on offline */ --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -254,15 +254,12 @@ cpu_initialize_context(unsigned int cpu, struct desc_struct *gdt; unsigned long gdt_mfn; =20 - /* used to tell cpu_init() that it can proceed with initialization */ - cpumask_set_cpu(cpu, cpu_callout_mask); if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map)) return 0; =20 ctxt =3D kzalloc(sizeof(*ctxt), GFP_KERNEL); if (ctxt =3D=3D NULL) { cpumask_clear_cpu(cpu, xen_cpu_initialized_map); - cpumask_clear_cpu(cpu, cpu_callout_mask); return -ENOMEM; } From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515897; cv=none; d=zohomail.com; s=zohoarc; b=ZyxWfSaFAwWfaHxHvcVF4p3IYW5y+5YjCUvfLK75ELlhsvJjf2Mn0IB1LUUcU5noywafY2vW7LkiZJ4EXdrbRIXIPsHJkDkfPJ2ShvG72EJsvzvTJu3Iy8Yrp+FpS9lLOwXdTu+/B0s9ocBOzYo2ekLIN7hsfABZ2Op3S3pCAlg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; 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Fri, 14 Apr 2023 23:44:35 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5n-0004HW-GB; Fri, 14 Apr 2023 23:44:35 +0000 Received: by outflank-mailman (input) for mailman id 521273; Fri, 14 Apr 2023 23:44:34 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5m-0001Th-CM for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:34 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 4edf5eb0-db1e-11ed-b21e-6b7b168915f2; Sat, 15 Apr 2023 01:44:33 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4edf5eb0-db1e-11ed-b21e-6b7b168915f2 Message-ID: <20230414232309.948211096@linutronix.de> DKIM-Signature: v=1; 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Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 12/37] x86/smpboot: Make TSC synchronization function call based References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:32 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515899287100001 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Spin-waiting on the control CPU until the AP reaches the TSC synchronization is just a waste especially in the case that there is no synchronization required. As the synchronization has to run with interrupts disabled the control CPU part can just be done from a SMP function call. The upcoming AP issues that call async only in the case that synchronization is required. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/tsc.h | 2 -- arch/x86/kernel/smpboot.c | 20 +++----------------- arch/x86/kernel/tsc_sync.c | 36 +++++++++++------------------------- 3 files changed, 14 insertions(+), 44 deletions(-) --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -55,12 +55,10 @@ extern bool tsc_async_resets; #ifdef CONFIG_X86_TSC extern bool tsc_store_and_check_tsc_adjust(bool bootcpu); extern void tsc_verify_tsc_adjust(bool resume); -extern void check_tsc_sync_source(int cpu); extern void check_tsc_sync_target(void); #else static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return f= alse; } static inline void tsc_verify_tsc_adjust(bool resume) { } -static inline void check_tsc_sync_source(int cpu) { } static inline void check_tsc_sync_target(void) { } #endif =20 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -278,11 +278,7 @@ static void notrace start_secondary(void /* Otherwise gcc will move up smp_processor_id() before cpu_init() */ barrier(); =20 - /* - * Check TSC synchronization with the control CPU, which will do - * its part of this from wait_cpu_online(), making it an implicit - * synchronization point. - */ + /* Check TSC synchronization with the control CPU. */ check_tsc_sync_target(); =20 /* @@ -1144,21 +1140,11 @@ static void wait_cpu_callin(unsigned int } =20 /* - * Bringup step four: Synchronize the TSC and wait for the target AP - * to reach set_cpu_online() in start_secondary(). + * Bringup step four: Wait for the target AP to reach set_cpu_online() in + * start_secondary(). */ static void wait_cpu_online(unsigned int cpu) { - unsigned long flags; - - /* - * Check TSC synchronization with the AP (keep irqs disabled - * while doing so): - */ - local_irq_save(flags); - check_tsc_sync_source(cpu); - local_irq_restore(flags); - /* * Wait for the AP to mark itself online, so the core caller * can drop sparse_irq_lock. --- a/arch/x86/kernel/tsc_sync.c +++ b/arch/x86/kernel/tsc_sync.c @@ -245,7 +245,6 @@ bool tsc_store_and_check_tsc_adjust(bool */ static atomic_t start_count; static atomic_t stop_count; -static atomic_t skip_test; static atomic_t test_runs; =20 /* @@ -344,21 +343,14 @@ static inline unsigned int loop_timeout( } =20 /* - * Source CPU calls into this - it waits for the freshly booted - * target CPU to arrive and then starts the measurement: + * The freshly booted CPU initiates this via an async SMP function call. */ -void check_tsc_sync_source(int cpu) +static void check_tsc_sync_source(void *__cpu) { + unsigned int cpu =3D (unsigned long)__cpu; int cpus =3D 2; =20 /* - * No need to check if we already know that the TSC is not - * synchronized or if we have no TSC. - */ - if (unsynchronized_tsc()) - return; - - /* * Set the maximum number of test runs to * 1 if the CPU does not provide the TSC_ADJUST MSR * 3 if the MSR is available, so the target can try to adjust @@ -368,16 +360,9 @@ void check_tsc_sync_source(int cpu) else atomic_set(&test_runs, 3); retry: - /* - * Wait for the target to start or to skip the test: - */ - while (atomic_read(&start_count) !=3D cpus - 1) { - if (atomic_read(&skip_test) > 0) { - atomic_set(&skip_test, 0); - return; - } + /* Wait for the target to start. */ + while (atomic_read(&start_count) !=3D cpus - 1) cpu_relax(); - } =20 /* * Trigger the target to continue into the measurement too: @@ -397,14 +382,14 @@ void check_tsc_sync_source(int cpu) if (!nr_warps) { atomic_set(&test_runs, 0); =20 - pr_debug("TSC synchronization [CPU#%d -> CPU#%d]: passed\n", + pr_debug("TSC synchronization [CPU#%d -> CPU#%u]: passed\n", smp_processor_id(), cpu); =20 } else if (atomic_dec_and_test(&test_runs) || random_warps) { /* Force it to 0 if random warps brought us here */ atomic_set(&test_runs, 0); =20 - pr_warn("TSC synchronization [CPU#%d -> CPU#%d]:\n", + pr_warn("TSC synchronization [CPU#%d -> CPU#%u]:\n", smp_processor_id(), cpu); pr_warn("Measured %Ld cycles TSC warp between CPUs, " "turning off TSC clock.\n", max_warp); @@ -457,11 +442,12 @@ void check_tsc_sync_target(void) * SoCs the TSC is frequency synchronized, but still the TSC ADJUST * register might have been wreckaged by the BIOS.. */ - if (tsc_store_and_check_tsc_adjust(false) || tsc_clocksource_reliable) { - atomic_inc(&skip_test); + if (tsc_store_and_check_tsc_adjust(false) || tsc_clocksource_reliable) return; - } =20 + /* Kick the control CPU into the TSC synchronization function */ + smp_call_function_single(cpumask_first(cpu_online_mask), check_tsc_sync_s= ource, + (unsigned long *)(unsigned long)cpu, 0); retry: /* * Register this CPU's participation and wait for the From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515901; cv=none; d=zohomail.com; s=zohoarc; b=J2Weo1VXmLk7cd6grgSM4eKLB4EVKbl2F6h+9T+ZHOQChc5Ba5SH8EOTOlbNL2P/daagL84Z0fpr04oaZw7aLdVxch+9XniBXjBXl4MkAgQ7YpICwoPWJ2tXM2r5OC8OoxrN37R8EJycz9TvirsX3q1znGzV8fqwVo43aIHVCyQ= ARC-Message-Signature: i=1; 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a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515875; 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=o+IIZolWdFzFoKPnCYeSD1bdkqJKKR73ExqiLPCERDI=; b=YtXMog5VLahh+j7fmWogAvr6ObdCeMs2/pQmIXREKblleGoCtvJL4rCNiqdvWzbyjDcTRQ uiN2/aQVEAqhEyWPSPIkKx0AVkXmtnjjoHfjwT3/yh44khK5MSa6L7h2bJz7b22ZDlJ6sh 00pAwnPCUJWCsn2Ejc57QMUUvq4xsRjx3LwBphTuReLzL6PmYvBpWBQh7nPpyk6UmRKfhO 2Eee0WLf6JgST16c76h3RPniWFIj95CGMwloYJMAwCCsO+gfqOq1rnGnjyKNvGqHT1gYGv P1F3HkYh07cMCdG7gc3D1VPgXDTVfI3a8otMhGht4nwU8AdufkquSsBkf+sOZA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515875; 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=o+IIZolWdFzFoKPnCYeSD1bdkqJKKR73ExqiLPCERDI=; b=/GA3IGAqyXeZ0ie5H89dtUrqgSL/9oSjEmZXWUtsSX1UpgcGxjRjqmWWhXVPw2ws/g8YlI DVurnNfTpyXvJvDg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 13/37] x86/smpboot: Remove cpu_callin_mask References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:34 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515903294100007 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Now that TSC synchronization is SMP function call based there is no reason to wait for the AP to be set in smp_callin_mask. The control CPU waits for the AP to set itself in the online mask anyway. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/smpboot.c | 61 +++++++----------------------------------= ----- 1 file changed, 10 insertions(+), 51 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -104,7 +104,6 @@ EXPORT_PER_CPU_SYMBOL(cpu_info); /* All of these masks are initialized in setup_cpu_local_masks() */ static cpumask_var_t cpu_initialized_mask; static cpumask_var_t cpu_callout_mask; -static cpumask_var_t cpu_callin_mask; /* Representing CPUs for which sibling maps can be computed */ static cpumask_var_t cpu_sibling_setup_mask; =20 @@ -167,21 +166,16 @@ static inline void smpboot_restore_warm_ */ static void smp_callin(void) { - int cpuid; + int cpuid =3D smp_processor_id(); =20 /* * If waken up by an INIT in an 82489DX configuration - * cpu_callout_mask guarantees we don't get here before - * an INIT_deassert IPI reaches our local APIC, so it is - * now safe to touch our local APIC. - */ - cpuid =3D smp_processor_id(); - - /* - * the boot CPU has finished the init stage and is spinning - * on callin_map until we finish. We are free to set up this - * CPU, first the APIC. (this is probably redundant on most - * boards) + * cpu_callout_mask guarantees we don't get here before an + * INIT_deassert IPI reaches our local APIC, so it is now safe to + * touch our local APIC. + * + * Set up this CPU, first the APIC, which is probably redundant on + * most boards. */ apic_ap_setup(); =20 @@ -192,7 +186,7 @@ static void smp_callin(void) * The topology information must be up to date before * calibrate_delay() and notify_cpu_starting(). */ - set_cpu_sibling_map(raw_smp_processor_id()); + set_cpu_sibling_map(cpuid); =20 ap_init_aperfmperf(); =20 @@ -205,11 +199,6 @@ static void smp_callin(void) * state (CPUHP_ONLINE in the case of serial bringup). */ notify_cpu_starting(cpuid); - - /* - * Allow the master to continue. - */ - cpumask_set_cpu(cpuid, cpu_callin_mask); } =20 static void ap_calibrate_delay(void) @@ -268,11 +257,6 @@ static void notrace start_secondary(void rcu_cpu_starting(raw_smp_processor_id()); x86_cpuinit.early_percpu_clock_init(); =20 - /* - * Sync point with wait_cpu_callin(). The AP doesn't wait here - * but just sets the bit to let the controlling CPU (BSP) know that - * it's got this far. - */ smp_callin(); =20 /* Otherwise gcc will move up smp_processor_id() before cpu_init() */ @@ -1112,7 +1096,7 @@ static int wait_cpu_cpumask(unsigned int * and thus wait_for_master_cpu(), then set cpu_callout_mask to allow it * to proceed. The AP will then proceed past setting its 'callin' bit * and end up waiting in check_tsc_sync_target() until we reach - * do_wait_cpu_online() to tend to it. + * wait_cpu_online() to tend to it. */ static int wait_cpu_initialized(unsigned int cpu) { @@ -1127,20 +1111,7 @@ static int wait_cpu_initialized(unsigned } =20 /* - * Bringup step three: Wait for the target AP to reach smp_callin(). - * The AP is not waiting for us here so we don't need to parallelise - * this step. Not entirely clear why we care about this, since we just - * proceed directly to TSC synchronization which is the next sync - * point with the AP anyway. - */ -static void wait_cpu_callin(unsigned int cpu) -{ - while (!cpumask_test_cpu(cpu, cpu_callin_mask)) - schedule(); -} - -/* - * Bringup step four: Wait for the target AP to reach set_cpu_online() in + * Bringup step three: Wait for the target AP to reach set_cpu_online() in * start_secondary(). */ static void wait_cpu_online(unsigned int cpu) @@ -1170,14 +1141,6 @@ static int native_kick_ap(unsigned int c } =20 /* - * Already booted CPU? - */ - if (cpumask_test_cpu(cpu, cpu_callin_mask)) { - pr_debug("do_boot_cpu %d Already started\n", cpu); - return -ENOSYS; - } - - /* * Save current MTRR state in case it was changed since early boot * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync: */ @@ -1214,7 +1177,6 @@ int native_cpu_up(unsigned int cpu, stru if (ret) goto out; =20 - wait_cpu_callin(cpu); wait_cpu_online(cpu); =20 out: @@ -1330,7 +1292,6 @@ void __init smp_prepare_cpus_common(void * Setup boot CPU information */ smp_store_boot_cpu_info(); /* Final full version of the data */ - cpumask_copy(cpu_callin_mask, cpumask_of(0)); mb(); =20 for_each_possible_cpu(i) { @@ -1545,7 +1506,6 @@ early_param("possible_cpus", _setup_poss void __init setup_cpu_local_masks(void) { alloc_bootmem_cpumask_var(&cpu_initialized_mask); - alloc_bootmem_cpumask_var(&cpu_callin_mask); alloc_bootmem_cpumask_var(&cpu_callout_mask); alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask); } @@ -1609,7 +1569,6 @@ static void remove_cpu_from_maps(int cpu { set_cpu_online(cpu, false); cpumask_clear_cpu(cpu, cpu_callout_mask); - cpumask_clear_cpu(cpu, cpu_callin_mask); /* was set by cpu_init() */ cpumask_clear_cpu(cpu, cpu_initialized_mask); numa_remove_cpu(cpu); From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; 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Fri, 14 Apr 2023 23:44:37 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 50c924e4-db1e-11ed-b21e-6b7b168915f2; Sat, 15 Apr 2023 01:44:37 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 50c924e4-db1e-11ed-b21e-6b7b168915f2 Message-ID: <20230414232310.073038650@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515876; 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=GyywxqWp8oXO9/e7syapChEN4EQiJFDwV+0SUoqcKJk=; b=JUqSST6sUfcIWAgxhbacXjpEmmObS6IQmZ8ClrGYKz6doTL5ISmvBQwKyUHTzWuCMn0jQ2 kxURDWFhZo9th4otAi+IQxUNu4L5D+QqiOZWbyNzW73qnBtuAg4kKtwBnKA13ZEyQuUA3X 24NTR55n5XqMxhu41NV27bpjHdQ+JlbVY0oF+P/tIz60xJTXSar+rkM76hsA2KCV9DFE63 6moUS8v6t62b1FyFg672g0WX5bUvfVeqnGzGFuSCL/S0/rzXi15l7IZ4fLWeFV2skFwkBv DN49AN17nBshRWNeN2Y+3WWvPRAiTBVV4LsFXW/N5eBDDmUXpiGL65/32uCbZA== DKIM-Signature: v=1; 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Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 14/37] cpu/hotplug: Rework sparse_irq locking in bringup_cpu() References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:36 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515902643100005 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" There is no harm to hold sparse_irq lock until the upcoming CPU completes in cpuhp_online_idle(). This allows to remove cpu_online() synchronization from architecture code. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- kernel/cpu.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -558,7 +558,7 @@ static int cpuhp_kick_ap(int cpu, struct return ret; } =20 -static int bringup_wait_for_ap(unsigned int cpu) +static int bringup_wait_for_ap_online(unsigned int cpu) { struct cpuhp_cpu_state *st =3D per_cpu_ptr(&cpuhp_state, cpu); =20 @@ -579,15 +579,12 @@ static int bringup_wait_for_ap(unsigned */ if (!cpu_smt_allowed(cpu)) return -ECANCELED; - - if (st->target <=3D CPUHP_AP_ONLINE_IDLE) - return 0; - - return cpuhp_kick_ap(cpu, st, st->target); + return 0; } =20 static int bringup_cpu(unsigned int cpu) { + struct cpuhp_cpu_state *st =3D per_cpu_ptr(&cpuhp_state, cpu); struct task_struct *idle =3D idle_thread_get(cpu); int ret; =20 @@ -606,10 +603,23 @@ static int bringup_cpu(unsigned int cpu) =20 /* Arch-specific enabling code. */ ret =3D __cpu_up(cpu, idle); - irq_unlock_sparse(); if (ret) - return ret; - return bringup_wait_for_ap(cpu); + goto out_unlock; + + ret =3D bringup_wait_for_ap_online(cpu); + if (ret) + goto out_unlock; + + irq_unlock_sparse(); + + if (st->target <=3D CPUHP_AP_ONLINE_IDLE) + return 0; + + return cpuhp_kick_ap(cpu, st, st->target); + +out_unlock: + irq_unlock_sparse(); + return ret; } =20 static int finish_cpu(unsigned int cpu) From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515900; 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Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 15/37] x86/smpboot: Remove wait for cpu_online() References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:37 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515901267100003 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Now that the core code drops sparse_irq_lock after the idle thread synchronized, it's pointless to wait for the AP to mark itself online. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/smpboot.c | 25 ++----------------------- 1 file changed, 2 insertions(+), 23 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1110,20 +1110,6 @@ static int wait_cpu_initialized(unsigned return 0; } =20 -/* - * Bringup step three: Wait for the target AP to reach set_cpu_online() in - * start_secondary(). - */ -static void wait_cpu_online(unsigned int cpu) -{ - /* - * Wait for the AP to mark itself online, so the core caller - * can drop sparse_irq_lock. - */ - while (!cpu_online(cpu)) - schedule(); -} - static int native_kick_ap(unsigned int cpu, struct task_struct *tidle) { int apicid =3D apic->cpu_present_to_apicid(cpu); @@ -1170,16 +1156,9 @@ int native_cpu_up(unsigned int cpu, stru int ret; =20 ret =3D native_kick_ap(cpu, tidle); - if (ret) - goto out; - - ret =3D wait_cpu_initialized(cpu); - if (ret) - goto out; - - wait_cpu_online(cpu); + if (!ret) + ret =3D wait_cpu_initialized(cpu); =20 -out: /* Cleanup possible dangling ends... */ if (x86_platform.legacy.warm_reset) smpboot_restore_warm_reset_vector(); From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515903; cv=none; d=zohomail.com; s=zohoarc; b=iFMbt+uR4GBrY0VI9QKp6B3WYd1nwqzr7jnKVpUDDsEsYijnO8Cyi0QE+neeQB935G6C2h4YSXsyk75eIyVqJZdjLHRUoxRsH6Ln94nR1foX7tILzpcoUaj002ahZCgEO++X82hBGFyPXdb7TYr9dKjvc/JOBuB3q3W5QvuyotM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; 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Fri, 14 Apr 2023 23:44:44 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5w-0006Zl-Ap; Fri, 14 Apr 2023 23:44:44 +0000 Received: by outflank-mailman (input) for mailman id 521282; Fri, 14 Apr 2023 23:44:42 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5t-0000zb-Ls for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:41 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 52adff75-db1e-11ed-8611-37d641c3527e; Sat, 15 Apr 2023 01:44:40 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 52adff75-db1e-11ed-8611-37d641c3527e Message-ID: <20230414232310.194293270@linutronix.de> DKIM-Signature: v=1; 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Piccoli" , Piotr Gorski , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, David Woodhouse , Usama Arif , Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 16/37] x86/xen/smp_pv: Remove wait for CPU online References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:39 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515905310100011 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Now that the core code drops sparse_irq_lock after the idle thread synchronized, it's pointless to wait for the AP to mark itself online. Whether the control CPU runs in a wait loop or sleeps in the core code waiting for the online operation to complete makes no difference. Signed-off-by: Thomas Gleixner Cc: Juergen Gross Cc: Boris Ostrovsky Cc: xen-devel@lists.xenproject.org Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/xen/smp_pv.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -340,11 +340,11 @@ static int xen_pv_cpu_up(unsigned int cp =20 xen_pmu_init(cpu); =20 - rc =3D HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL); - BUG_ON(rc); - - while (cpu_report_state(cpu) !=3D CPU_ONLINE) - HYPERVISOR_sched_op(SCHEDOP_yield, NULL); + /* + * Why is this a BUG? If the hypercall fails then everything can be + * rolled back, no? + */ + BUG_ON(HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL)); =20 return 0; } From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681515903; cv=none; d=zohomail.com; s=zohoarc; b=Di2s9ZYrqlgGx7g7kfrlH25xPvLohWm4KHcKOrYPrV4r5D6k3VEPO99LNaa+r22kMkPgaWf749I5ByONDs4/yIe1jqo6MNk6DUVFKU9ptKfywGVNefLT+uFNoGaheWs8qs9XjXwetzOnbC6Nxv7Bcey8ayUoKiX4bcAAl++WMw8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1681515903; h=Content-Type:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=e1FMo66EmKhD6c9vNMbCMEr10b7nb30z1HTBJhSwsws=; b=IIrH5voam1T6ZncKSJeElN2oX4Mi0IOtv0wTvtf0mE4TxMTSVELqVN33Vmr3cNwwdL4fditU8k6xZnq5omwCRTtx51RTQzFrCDJkoi9OHWD2t6b+3oJHjhPRlyJyeHanMnxd0lIJOPz4GG64+xskWMVwfhyHalWG4pwlkeiOGic= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1681515903926705.8216559383525; Fri, 14 Apr 2023 16:45:03 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.521285.809885 (Exim 4.92) (envelope-from ) id 1pnT5x-0006kf-Gk; Fri, 14 Apr 2023 23:44:45 +0000 Received: by outflank-mailman (output) from mailman id 521285.809885; Fri, 14 Apr 2023 23:44:45 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5w-0006jJ-Sf; Fri, 14 Apr 2023 23:44:44 +0000 Received: by outflank-mailman (input) for mailman id 521285; Fri, 14 Apr 2023 23:44:43 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT5v-0000zb-Cg for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:44:43 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 53a62147-db1e-11ed-8611-37d641c3527e; Sat, 15 Apr 2023 01:44:41 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 53a62147-db1e-11ed-8611-37d641c3527e Message-ID: <20230414232310.256412375@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515881; 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=e1FMo66EmKhD6c9vNMbCMEr10b7nb30z1HTBJhSwsws=; b=gZ0HEhv3acCl5QBYyuBxsWswUfiT2pTSEiPx8KAuYf607AwMRXvsLBlYW5dljp8oWs/ntm Rl62blc06B+wdYag6mxiaHF4d6UazbaaiGafHMeetJ/A7Hs5RVhUzMngs/dEe59idC0O2F aA4jOVKszqOh4s2mn+PKplYpnPle5vYAOnMKw27lKXhJvIh/kbhLy4lRj7cXXA/G581Bej PsarGBYF6AEmBjKJMVj8L9q7SGw5rle2qMtTuVh6V6kezaC/bwaovVLX9d1Zsm+GX8ANmu PhMCi/IYxY/Oqm30JTDcZDBgs/Y7EGdHwcz8miDR/Arr0Wrr//IGKwmjd5YAMQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515881; 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=e1FMo66EmKhD6c9vNMbCMEr10b7nb30z1HTBJhSwsws=; b=4fNwIQeLJaYUXs5/LQAEGEGLbWkObI//eYOHt1swXrTx799wwKeZFlTzry5MJCiAr70s7q ypFOiCNeSLElyzBg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, David Woodhouse , Usama Arif , Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 17/37] x86/xen/hvm: Get rid of DEAD_FROZEN handling References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:41 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681515904251100009 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" No point in this conditional voodoo. Un-initializing the lock mechanism is safe to be called unconditionally even if it was already invoked when the CPU died. Remove the invocation of xen_smp_intr_free() as that has been already cleaned up in xen_cpu_dead_hvm(). Signed-off-by: Thomas Gleixner Cc: Juergen Gross Cc: Boris Ostrovsky Cc: xen-devel@lists.xenproject.org Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/xen/enlighten_hvm.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -161,13 +161,12 @@ static int xen_cpu_up_prepare_hvm(unsign int rc =3D 0; =20 /* - * This can happen if CPU was offlined earlier and - * offlining timed out in common_cpu_die(). + * If a CPU was offlined earlier and offlining timed out then the + * lock mechanism is still initialized. Uninit it unconditionally + * as it's safe to call even if already uninited. Interrupts and + * timer have already been handled in xen_cpu_dead_hvm(). */ - if (cpu_report_state(cpu) =3D=3D CPU_DEAD_FROZEN) { - xen_smp_intr_free(cpu); - xen_uninit_lock_cpu(cpu); - } + xen_uninit_lock_cpu(cpu); =20 if (cpu_acpi_id(cpu) !=3D U32_MAX) per_cpu(xen_vcpu_id, cpu) =3D cpu_acpi_id(cpu); From nobody Fri Nov 1 00:09:59 2024 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 01A10C77B7D for ; Fri, 14 Apr 2023 23:46:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230156AbjDNXq0 (ORCPT ); Fri, 14 Apr 2023 19:46:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230184AbjDNXpo (ORCPT ); Fri, 14 Apr 2023 19:45:44 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D6969EFA; Fri, 14 Apr 2023 16:44:59 -0700 (PDT) Message-ID: <20230414232310.319386819@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515883; 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=7hAm6I9MiGtPmIXfa24B9PQ6b2IikPrY0L+IvEnJvPI=; b=jK/GS8nzEcoNMYUK0AKSW91HahqfcKmgmQ+JtmtDnur9HSlYdew/SITlGW5QELStSGh6Q/ V57WOhEWSVSxWZWhG3SaBczDcMaraK+itB6zsiGdpLQtzoC7yxxSloqDZW6B4Njz8MWDbR miMPGsiCOdTRydFFdFmiS70GYeAIK8oBwYAUlay9JYTfVbSXJ63AXiImeMdnSL+M470Et5 VfCBSEigMVHivkoKuqa+6Tu/41+RxN+9jOUZtcMtyT4RoQND7Pp1xwtWviW33NcuD2Qa/G AC+ABgPHvS+/XtBUfn+u5LoukNQ3JpVGWaLmycJWPrCSc7LATrT2CKreEiN1ng== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515883; 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=7hAm6I9MiGtPmIXfa24B9PQ6b2IikPrY0L+IvEnJvPI=; b=IpKwz96GwSWUZ2KDbHlOo0nFprwPP3s9jahoNB/qpcC8qkXn9/Q9MaoBQo6UsIzMi7+Hea LODiZVcbnARULPAg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 18/37] cpu/hotplug: Add CPU state tracking and synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:42 +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" The CPU state tracking and synchronization mechanism in smpboot.c is completely independent of the hotplug code and all logic around it is implemented in architecture specific code. Except for the state reporting of the AP there is absolutely nothing architecture specific and the sychronization and decision functions can be moved into the generic hotplug core code. Provide an integrated variant and add the core synchronization and decision points. This comes in two flavours: 1) DEAD state synchronization Updated by the architecture code once the AP reaches the point where it is ready to be torn down by the control CPU, e.g. by removing power or clocks or tear down via the hypervisor. The control CPU waits for this state to be reached with a timeout. If the state is reached an architecture specific cleanup function is invoked. 2) Full state synchronization This extends #1 with AP alive synchronization. This is new functionality, which allows to replace architecture specific wait mechanims, e.g. cpumasks, completely. It also prevents that an AP which is in a limbo state can be brought up again. This can happen when an AP failed to report dead state during a previous off-line operation. The dead synchronization is what most architectures use. Only x86 makes a bringup decision based on that state at the moment. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/Kconfig | 15 +++ include/linux/cpuhotplug.h | 12 ++ kernel/cpu.c | 193 ++++++++++++++++++++++++++++++++++++++++= ++++- kernel/smpboot.c | 2=20 4 files changed, 221 insertions(+), 1 deletion(-) --- a/arch/Kconfig +++ b/arch/Kconfig @@ -34,6 +34,21 @@ config ARCH_HAS_SUBPAGE_FAULTS config HOTPLUG_SMT bool =20 +# Selected by HOTPLUG_CORE_SYNC_DEAD or HOTPLUG_CORE_SYNC_FULL +config HOTPLUG_CORE_SYNC + bool + +# Basic CPU dead synchronization selected by architecture +config HOTPLUG_CORE_SYNC_DEAD + bool + select HOTPLUG_CORE_SYNC + +# Full CPU synchronization with alive state selected by architecture +config HOTPLUG_CORE_SYNC_FULL + bool + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU + select HOTPLUG_CORE_SYNC + config GENERIC_ENTRY bool =20 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -519,4 +519,16 @@ void cpuhp_online_idle(enum cpuhp_state static inline void cpuhp_online_idle(enum cpuhp_state state) { } #endif =20 +void cpuhp_ap_sync_alive(void); +void arch_cpuhp_sync_state_poll(void); +void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu); + +#ifdef CONFIG_HOTPLUG_CORE_SYNC_DEAD +void cpuhp_ap_report_dead(void); +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu); +#else +static inline void cpuhp_ap_report_dead(void) { } +static inline void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { } +#endif + #endif --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -59,6 +60,7 @@ * @last: For multi-instance rollback, remember how far we got * @cb_state: The state for a single callback (install/uninstall) * @result: Result of the operation + * @ap_sync_state: State for AP synchronization * @done_up: Signal completion to the issuer of the task for cpu-up * @done_down: Signal completion to the issuer of the task for cpu-down */ @@ -76,6 +78,7 @@ struct cpuhp_cpu_state { struct hlist_node *last; enum cpuhp_state cb_state; int result; + atomic_t ap_sync_state; struct completion done_up; struct completion done_down; #endif @@ -276,6 +279,182 @@ static bool cpuhp_is_atomic_state(enum c return CPUHP_AP_IDLE_DEAD <=3D state && state < CPUHP_AP_ONLINE; } =20 +/* Synchronization state management */ +enum cpuhp_sync_state { + SYNC_STATE_DEAD, + SYNC_STATE_KICKED, + SYNC_STATE_SHOULD_DIE, + SYNC_STATE_ALIVE, + SYNC_STATE_SHOULD_ONLINE, + SYNC_STATE_ONLINE, +}; + +#ifdef CONFIG_HOTPLUG_CORE_SYNC +/** + * cpuhp_ap_update_sync_state - Update synchronization state during bringu= p/teardown + * @state: The synchronization state to set + * + * No synchronization point. Just update of the synchronization state. + */ +static inline void cpuhp_ap_update_sync_state(enum cpuhp_sync_state state) +{ + atomic_t *st =3D this_cpu_ptr(&cpuhp_state.ap_sync_state); + int sync =3D atomic_read(st); + + while (!atomic_try_cmpxchg(st, &sync, state)); +} + +void __weak arch_cpuhp_sync_state_poll(void) { cpu_relax(); } + +static bool cpuhp_wait_for_sync_state(unsigned int cpu, enum cpuhp_sync_st= ate state, + enum cpuhp_sync_state next_state) +{ + atomic_t *st =3D per_cpu_ptr(&cpuhp_state.ap_sync_state, cpu); + ktime_t now, end, start =3D ktime_get(); + int sync; + + end =3D start + 10ULL * NSEC_PER_SEC; + + sync =3D atomic_read(st); + while (1) { + if (sync =3D=3D state) { + if (!atomic_try_cmpxchg(st, &sync, next_state)) + continue; + return true; + } + + now =3D ktime_get(); + if (now > end) { + /* Timeout. Leave the state unchanged */ + return false; + } else if (now - start < NSEC_PER_MSEC) { + /* Poll for one millisecond */ + arch_cpuhp_sync_state_poll(); + } else { + usleep_range_state(USEC_PER_MSEC, 2 * USEC_PER_MSEC, TASK_UNINTERRUPTIB= LE); + } + sync =3D atomic_read(st); + } + return true; +} +#else /* CONFIG_HOTPLUG_CORE_SYNC */ +static inline void cpuhp_ap_update_sync_state(enum cpuhp_sync_state state)= { } +#endif /* !CONFIG_HOTPLUG_CORE_SYNC */ + +#ifdef CONFIG_HOTPLUG_CORE_SYNC_DEAD +/** + * cpuhp_ap_report_dead - Update synchronization state to DEAD + * + * No synchronization point. Just update of the synchronization state. + */ +void cpuhp_ap_report_dead(void) +{ + cpuhp_ap_update_sync_state(SYNC_STATE_DEAD); +} + +void __weak arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { } + +/* + * Late CPU shutdown synchronization point. Cannot use cpuhp_state::done_d= own + * because the AP cannot issue complete() at this stage. + */ +static void cpuhp_bp_sync_dead(unsigned int cpu) +{ + atomic_t *st =3D per_cpu_ptr(&cpuhp_state.ap_sync_state, cpu); + int sync =3D atomic_read(st); + + do { + /* CPU can have reported dead already. Don't overwrite that! */ + if (sync =3D=3D SYNC_STATE_DEAD) + break; + } while (!atomic_try_cmpxchg(st, &sync, SYNC_STATE_SHOULD_DIE)); + + if (cpuhp_wait_for_sync_state(cpu, SYNC_STATE_DEAD, SYNC_STATE_DEAD)) { + /* CPU reached dead state. Invoke the cleanup function */ + arch_cpuhp_cleanup_dead_cpu(cpu); + return; + } + + /* No further action possible. Emit message and give up. */ + pr_err("CPU%u failed to report dead state\n", cpu); +} +#else /* CONFIG_HOTPLUG_CORE_SYNC_DEAD */ +static inline void cpuhp_bp_sync_dead(unsigned int cpu) { } +#endif /* !CONFIG_HOTPLUG_CORE_SYNC_DEAD */ + +#ifdef CONFIG_HOTPLUG_CORE_SYNC_FULL +/** + * cpuhp_ap_sync_alive - Synchronize AP with the control CPU once it is al= ive + * + * Updates the AP synchronization state to SYNC_STATE_ALIVE and waits + * for the BP to release it. + */ +void cpuhp_ap_sync_alive(void) +{ + atomic_t *st =3D this_cpu_ptr(&cpuhp_state.ap_sync_state); + + cpuhp_ap_update_sync_state(SYNC_STATE_ALIVE); + + /* Wait for the control CPU to release it. */ + while (atomic_read(st) !=3D SYNC_STATE_SHOULD_ONLINE) + cpu_relax(); +} + +static bool cpuhp_can_boot_ap(unsigned int cpu) +{ + atomic_t *st =3D per_cpu_ptr(&cpuhp_state.ap_sync_state, cpu); + int sync =3D atomic_read(st); + +again: + switch (sync) { + case SYNC_STATE_DEAD: + /* CPU is properly dead */ + break; + case SYNC_STATE_KICKED: + /* CPU did not come up in previous attempt */ + break; + case SYNC_STATE_ALIVE: + /* CPU is stuck cpuhp_ap_sync_alive(). */ + break; + default: + /* CPU failed to report online or dead and is in limbo state. */ + return false; + } + + /* Prepare for booting */ + if (!atomic_try_cmpxchg(st, &sync, SYNC_STATE_KICKED)) + goto again; + + return true; +} + +void __weak arch_cpuhp_cleanup_kick_cpu(unsigned int cpu) { } + +/* + * Early CPU bringup synchronization point. Cannot use cpuhp_state::done_up + * because the AP cannot issue complete() so early in the bringup. + */ +static int cpuhp_bp_sync_alive(unsigned int cpu) +{ + int ret =3D 0; + + if (!IS_ENABLED(CONFIG_HOTPLUG_CORE_SYNC_FULL)) + return 0; + + if (!cpuhp_wait_for_sync_state(cpu, SYNC_STATE_ALIVE, SYNC_STATE_SHOULD_O= NLINE)) { + pr_err("CPU%u failed to report alive state\n", cpu); + ret =3D -EIO; + } + + /* Let the architecture cleanup the kick alive mechanics. */ + arch_cpuhp_cleanup_kick_cpu(cpu); + return ret; +} +#else /* CONFIG_HOTPLUG_CORE_SYNC_FULL */ +static inline int cpuhp_bp_sync_alive(unsigned int cpu) { return 0; } +static inline bool cpuhp_can_boot_ap(unsigned int cpu) { return true; } +#endif /* !CONFIG_HOTPLUG_CORE_SYNC_FULL */ + /* Serializes the updates to cpu_online_mask, cpu_present_mask */ static DEFINE_MUTEX(cpu_add_remove_lock); bool cpuhp_tasks_frozen; @@ -588,6 +767,9 @@ static int bringup_cpu(unsigned int cpu) struct task_struct *idle =3D idle_thread_get(cpu); int ret; =20 + if (!cpuhp_can_boot_ap(cpu)) + return -EAGAIN; + /* * Reset stale stack state from the last time this CPU was online. */ @@ -606,6 +788,10 @@ static int bringup_cpu(unsigned int cpu) if (ret) goto out_unlock; =20 + ret =3D cpuhp_bp_sync_alive(cpu); + if (ret) + goto out_unlock; + ret =3D bringup_wait_for_ap_online(cpu); if (ret) goto out_unlock; @@ -1109,6 +1295,8 @@ static int takedown_cpu(unsigned int cpu /* This actually kills the CPU. */ __cpu_die(cpu); =20 + cpuhp_bp_sync_dead(cpu); + tick_cleanup_dead_cpu(cpu); rcutree_migrate_callbacks(cpu); return 0; @@ -1355,8 +1543,10 @@ void cpuhp_online_idle(enum cpuhp_state if (state !=3D CPUHP_AP_ONLINE_IDLE) return; =20 + cpuhp_ap_update_sync_state(SYNC_STATE_ONLINE); + /* - * Unpart the stopper thread before we start the idle loop (and start + * Unpark the stopper thread before we start the idle loop (and start * scheduling); this ensures the stopper task is always available. */ stop_machine_unpark(smp_processor_id()); @@ -2722,6 +2912,7 @@ void __init boot_cpu_hotplug_init(void) { #ifdef CONFIG_SMP cpumask_set_cpu(smp_processor_id(), &cpus_booted_once_mask); + atomic_set(this_cpu_ptr(&cpuhp_state.ap_sync_state), SYNC_STATE_ONLINE); #endif this_cpu_write(cpuhp_state.state, CPUHP_ONLINE); this_cpu_write(cpuhp_state.target, CPUHP_ONLINE); --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -326,6 +326,7 @@ void smpboot_unregister_percpu_thread(st } EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread); =20 +#ifndef CONFIG_HOTPLUG_CORE_SYNC static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) =3D ATOMIC_INIT(CPU_POS= T_DEAD); =20 /* @@ -488,3 +489,4 @@ bool cpu_report_death(void) } =20 #endif /* #ifdef CONFIG_HOTPLUG_CPU */ +#endif /* !CONFIG_HOTPLUG_CORE_SYNC */ From nobody Fri Nov 1 00:09:59 2024 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 E64A4C77B7A for ; Fri, 14 Apr 2023 23:46:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230380AbjDNXqI (ORCPT ); Fri, 14 Apr 2023 19:46:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230129AbjDNXpb (ORCPT ); Fri, 14 Apr 2023 19:45:31 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59F7F59EA; Fri, 14 Apr 2023 16:44:48 -0700 (PDT) Message-ID: <20230414232310.382005483@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515885; 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=3+qlITNV53BaRfy3keVD52aWouI/gE/YQxgQoDSFHFQ=; b=d/JnboK/jkYT0GCssjVJ90Y/WenuKe1jZIeYgv20OJ8XmoGVYLF1ZTVBI388KIvGG81BdO s78WecNm45vveuEvwyWBqpgE+vTtwDzERMCqW1Wa+4ETTvB/cX6F944F3VGLD5QdOboktX oYzSxcLkz1ApMjeWZS/WTENuQtTLSkNhnQRy9RzQFKh/XLNn3yGYZts1NNhtJC5HjIGI5o GW7Dy1zD4MwOm3khrT+nIHASKJLyysL3C4C/JHrrPJSnMuLIm7wmYPRipyZTKCP/Pk5TvQ t4mSIMmTLfqg4c1OUMFcIfZVIVmu4xkWF38NJIgv/C8Mj3XL31D/6X50h3AvSA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515885; 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=3+qlITNV53BaRfy3keVD52aWouI/gE/YQxgQoDSFHFQ=; b=yCWdMiSVNqst3Q7S9gg95ghiR9su0xx9UWqm5RPQMRYbxRMm2BYagQWZ6uYhvAgJKN0wb7 iDVKrki61JxGxVBA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, David Woodhouse , Usama Arif , Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 19/37] x86/smpboot: Switch to hotplug core state synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:44 +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" The new AP state tracking and synchronization mechanism in the CPU hotplug core code allows to remove quite some x86 specific code: 1) The AP alive synchronization based on cpumasks 2) The decision whether an AP can be brought up again Signed-off-by: Thomas Gleixner Cc: Juergen Gross Cc: Boris Ostrovsky Cc: xen-devel@lists.xenproject.org Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/Kconfig | 1=20 arch/x86/include/asm/smp.h | 7 + arch/x86/kernel/smp.c | 1=20 arch/x86/kernel/smpboot.c | 159 ++++++++++------------------------------= ----- arch/x86/xen/smp_hvm.c | 16 +--- arch/x86/xen/smp_pv.c | 39 ++++++----- 6 files changed, 72 insertions(+), 151 deletions(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -272,6 +272,7 @@ config X86 select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER select HAVE_GENERIC_VDSO + select HOTPLUG_CORE_SYNC_FULL if SMP select HOTPLUG_SMT if SMP select IRQ_FORCED_THREADING select NEED_PER_CPU_EMBED_FIRST_CHUNK --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -38,6 +38,8 @@ struct smp_ops { void (*crash_stop_other_cpus)(void); void (*smp_send_reschedule)(int cpu); =20 + void (*cleanup_dead_cpu)(unsigned cpu); + void (*poll_sync_state)(void); int (*cpu_up)(unsigned cpu, struct task_struct *tidle); int (*cpu_disable)(void); void (*cpu_die)(unsigned int cpu); @@ -90,7 +92,8 @@ static inline int __cpu_disable(void) =20 static inline void __cpu_die(unsigned int cpu) { - smp_ops.cpu_die(cpu); + if (smp_ops.cpu_die) + smp_ops.cpu_die(cpu); } =20 static inline void play_dead(void) @@ -122,8 +125,6 @@ void native_smp_cpus_done(unsigned int m int common_cpu_up(unsigned int cpunum, struct task_struct *tidle); int native_cpu_up(unsigned int cpunum, struct task_struct *tidle); int native_cpu_disable(void); -int common_cpu_die(unsigned int cpu); -void native_cpu_die(unsigned int cpu); void hlt_play_dead(void); void native_play_dead(void); void play_dead_common(void); --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -269,7 +269,6 @@ struct smp_ops smp_ops =3D { .smp_send_reschedule =3D native_smp_send_reschedule, =20 .cpu_up =3D native_cpu_up, - .cpu_die =3D native_cpu_die, .cpu_disable =3D native_cpu_disable, .play_dead =3D native_play_dead, =20 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -57,6 +57,7 @@ #include #include #include +#include =20 #include #include @@ -101,9 +102,6 @@ EXPORT_PER_CPU_SYMBOL(cpu_die_map); DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); =20 -/* All of these masks are initialized in setup_cpu_local_masks() */ -static cpumask_var_t cpu_initialized_mask; -static cpumask_var_t cpu_callout_mask; /* Representing CPUs for which sibling maps can be computed */ static cpumask_var_t cpu_sibling_setup_mask; =20 @@ -169,8 +167,8 @@ static void smp_callin(void) int cpuid =3D smp_processor_id(); =20 /* - * If waken up by an INIT in an 82489DX configuration - * cpu_callout_mask guarantees we don't get here before an + * If waken up by an INIT in an 82489DX configuration the alive + * synchronization guarantees we don't get here before an * INIT_deassert IPI reaches our local APIC, so it is now safe to * touch our local APIC. * @@ -216,17 +214,6 @@ static void ap_calibrate_delay(void) cpu_data(smp_processor_id()).loops_per_jiffy =3D loops_per_jiffy; } =20 -static void wait_for_master_cpu(int cpu) -{ - /* - * Wait for release by control CPU before continuing with AP - * initialization. - */ - WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)); - while (!cpumask_test_cpu(cpu, cpu_callout_mask)) - cpu_relax(); -} - /* * Activate a secondary processor. */ @@ -247,11 +234,10 @@ static void notrace start_secondary(void cpu_init_exception_handling(); =20 /* - * Sync point with wait_cpu_initialized(). Sets AP in - * cpu_initialized_mask and then waits for the control CPU - * to release it. + * Sync point with the hotplug core. Sets the sync state to ALIVE + * and waits for the control CPU to release it. */ - wait_for_master_cpu(raw_smp_processor_id()); + cpuhp_ap_sync_alive(); =20 cpu_init(); rcu_cpu_starting(raw_smp_processor_id()); @@ -285,7 +271,6 @@ static void notrace start_secondary(void set_cpu_online(smp_processor_id(), true); lapic_online(); unlock_vector_lock(); - cpu_set_state_online(smp_processor_id()); x86_platform.nmi_init(); =20 /* enable local interrupts */ @@ -736,9 +721,10 @@ static void impress_friends(void) * Allow the user to impress friends. */ pr_debug("Before bogomips\n"); - for_each_possible_cpu(cpu) - if (cpumask_test_cpu(cpu, cpu_callout_mask)) + for_each_possible_cpu(cpu) { + if (cpumask_test_cpu(cpu, cpu_online_mask)) bogosum +=3D cpu_data(cpu).loops_per_jiffy; + } pr_info("Total of %d processors activated (%lu.%02lu BogoMIPS)\n", num_online_cpus(), bogosum/(500000/HZ), @@ -1010,6 +996,7 @@ int common_cpu_up(unsigned int cpu, stru static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle) { unsigned long start_ip =3D real_mode_header->trampoline_start; + int ret; =20 #ifdef CONFIG_X86_64 /* If 64-bit wakeup method exists, use the 64-bit mode trampoline IP */ @@ -1050,13 +1037,6 @@ static int do_boot_cpu(int apicid, int c } } =20 - /* - * AP might wait on cpu_callout_mask in cpu_init() with - * cpu_initialized_mask set if previous attempt to online - * it timed-out. Clear cpu_initialized_mask so that after - * INIT/SIPI it could start with a clean state. - */ - cpumask_clear_cpu(cpu, cpu_initialized_mask); smp_mb(); =20 /* @@ -1067,47 +1047,16 @@ static int do_boot_cpu(int apicid, int c * - Use an INIT boot APIC message */ if (apic->wakeup_secondary_cpu_64) - return apic->wakeup_secondary_cpu_64(apicid, start_ip); + ret =3D apic->wakeup_secondary_cpu_64(apicid, start_ip); else if (apic->wakeup_secondary_cpu) - return apic->wakeup_secondary_cpu(apicid, start_ip); - - return wakeup_secondary_cpu_via_init(apicid, start_ip); -} - -static int wait_cpu_cpumask(unsigned int cpu, const struct cpumask *mask) -{ - unsigned long timeout; - - /* - * Wait up to 10s for the CPU to report in. - */ - timeout =3D jiffies + 10*HZ; - while (time_before(jiffies, timeout)) { - if (cpumask_test_cpu(cpu, mask)) - return 0; - - schedule(); - } - return -1; -} - -/* - * Bringup step two: Wait for the target AP to reach cpu_init_secondary() - * and thus wait_for_master_cpu(), then set cpu_callout_mask to allow it - * to proceed. The AP will then proceed past setting its 'callin' bit - * and end up waiting in check_tsc_sync_target() until we reach - * wait_cpu_online() to tend to it. - */ -static int wait_cpu_initialized(unsigned int cpu) -{ - /* - * Wait for first sign of life from AP. - */ - if (wait_cpu_cpumask(cpu, cpu_initialized_mask)) - return -1; + ret =3D apic->wakeup_secondary_cpu(apicid, start_ip); + else + ret =3D wakeup_secondary_cpu_via_init(apicid, start_ip); =20 - cpumask_set_cpu(cpu, cpu_callout_mask); - return 0; + /* If the wakeup mechanism failed, cleanup the warm reset vector */ + if (ret) + arch_cpuhp_cleanup_kick_cpu(cpu); + return ret; } =20 static int native_kick_ap(unsigned int cpu, struct task_struct *tidle) @@ -1132,11 +1081,6 @@ static int native_kick_ap(unsigned int c */ mtrr_save_state(); =20 - /* x86 CPUs take themselves offline, so delayed offline is OK. */ - err =3D cpu_check_up_prepare(cpu); - if (err && err !=3D -EBUSY) - return err; - /* the FPU context is blank, nobody can own it */ per_cpu(fpu_fpregs_owner_ctx, cpu) =3D NULL; =20 @@ -1153,17 +1097,29 @@ static int native_kick_ap(unsigned int c =20 int native_cpu_up(unsigned int cpu, struct task_struct *tidle) { - int ret; - - ret =3D native_kick_ap(cpu, tidle); - if (!ret) - ret =3D wait_cpu_initialized(cpu); + return native_kick_ap(cpu, tidle); +} =20 +void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu) +{ /* Cleanup possible dangling ends... */ - if (x86_platform.legacy.warm_reset) + if (smp_ops.cpu_up =3D=3D native_cpu_up && x86_platform.legacy.warm_reset) smpboot_restore_warm_reset_vector(); +} =20 - return ret; +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) +{ + if (smp_ops.cleanup_dead_cpu) + smp_ops.cleanup_dead_cpu(cpu); + + if (system_state =3D=3D SYSTEM_RUNNING) + pr_info("CPU %u is now offline\n", cpu); +} + +void arch_cpuhp_sync_state_poll(void) +{ + if (smp_ops.poll_sync_state) + smp_ops.poll_sync_state(); } =20 /** @@ -1355,9 +1311,6 @@ void __init native_smp_prepare_boot_cpu( if (!IS_ENABLED(CONFIG_SMP)) switch_gdt_and_percpu_base(me); =20 - /* already set me in cpu_online_mask in boot_cpu_init() */ - cpumask_set_cpu(me, cpu_callout_mask); - cpu_set_state_online(me); native_pv_lock_init(); } =20 @@ -1484,8 +1437,6 @@ early_param("possible_cpus", _setup_poss /* correctly size the local cpu masks */ void __init setup_cpu_local_masks(void) { - alloc_bootmem_cpumask_var(&cpu_initialized_mask); - alloc_bootmem_cpumask_var(&cpu_callout_mask); alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask); } =20 @@ -1547,9 +1498,6 @@ static void remove_siblinginfo(int cpu) static void remove_cpu_from_maps(int cpu) { set_cpu_online(cpu, false); - cpumask_clear_cpu(cpu, cpu_callout_mask); - /* was set by cpu_init() */ - cpumask_clear_cpu(cpu, cpu_initialized_mask); numa_remove_cpu(cpu); } =20 @@ -1600,36 +1548,11 @@ int native_cpu_disable(void) return 0; } =20 -int common_cpu_die(unsigned int cpu) -{ - int ret =3D 0; - - /* We don't do anything here: idle task is faking death itself. */ - - /* They ack this in play_dead() by setting CPU_DEAD */ - if (cpu_wait_death(cpu, 5)) { - if (system_state =3D=3D SYSTEM_RUNNING) - pr_info("CPU %u is now offline\n", cpu); - } else { - pr_err("CPU %u didn't die...\n", cpu); - ret =3D -1; - } - - return ret; -} - -void native_cpu_die(unsigned int cpu) -{ - common_cpu_die(cpu); -} - void play_dead_common(void) { idle_task_exit(); =20 - /* Ack it */ - (void)cpu_report_death(); - + cpuhp_ap_report_dead(); /* * With physical CPU hotplug, we should halt the cpu */ @@ -1731,12 +1654,6 @@ int native_cpu_disable(void) return -ENOSYS; } =20 -void native_cpu_die(unsigned int cpu) -{ - /* We said "no" in __cpu_disable */ - BUG(); -} - void native_play_dead(void) { BUG(); --- a/arch/x86/xen/smp_hvm.c +++ b/arch/x86/xen/smp_hvm.c @@ -55,18 +55,16 @@ static void __init xen_hvm_smp_prepare_c } =20 #ifdef CONFIG_HOTPLUG_CPU -static void xen_hvm_cpu_die(unsigned int cpu) +static void xen_hvm_cleanup_dead_cpu(unsigned int cpu) { - if (common_cpu_die(cpu) =3D=3D 0) { - if (xen_have_vector_callback) { - xen_smp_intr_free(cpu); - xen_uninit_lock_cpu(cpu); - xen_teardown_timer(cpu); - } + if (xen_have_vector_callback) { + xen_smp_intr_free(cpu); + xen_uninit_lock_cpu(cpu); + xen_teardown_timer(cpu); } } #else -static void xen_hvm_cpu_die(unsigned int cpu) +static void xen_hvm_cleanup_dead_cpu(unsigned int cpu) { BUG(); } @@ -77,7 +75,7 @@ void __init xen_hvm_smp_init(void) smp_ops.smp_prepare_boot_cpu =3D xen_hvm_smp_prepare_boot_cpu; smp_ops.smp_prepare_cpus =3D xen_hvm_smp_prepare_cpus; smp_ops.smp_cpus_done =3D xen_smp_cpus_done; - smp_ops.cpu_die =3D xen_hvm_cpu_die; + smp_ops.cleanup_dead_cpu =3D xen_hvm_cleanup_dead_cpu; =20 if (!xen_have_vector_callback) { #ifdef CONFIG_PARAVIRT_SPINLOCKS --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -62,6 +62,7 @@ static void cpu_bringup(void) int cpu; =20 cr4_init(); + cpuhp_ap_sync_alive(); cpu_init(); touch_softlockup_watchdog(); =20 @@ -83,7 +84,7 @@ static void cpu_bringup(void) =20 set_cpu_online(cpu, true); =20 - cpu_set_state_online(cpu); /* Implies full memory barrier. */ + smp_mb(); =20 /* We can take interrupts now: we're officially "up". */ local_irq_enable(); @@ -323,14 +324,6 @@ static int xen_pv_cpu_up(unsigned int cp =20 xen_setup_runstate_info(cpu); =20 - /* - * PV VCPUs are always successfully taken down (see 'while' loop - * in xen_cpu_die()), so -EBUSY is an error. - */ - rc =3D cpu_check_up_prepare(cpu); - if (rc) - return rc; - /* make sure interrupts start blocked */ per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask =3D 1; =20 @@ -349,6 +342,11 @@ static int xen_pv_cpu_up(unsigned int cp return 0; } =20 +static void xen_pv_poll_sync_state(void) +{ + HYPERVISOR_sched_op(SCHEDOP_yield, NULL); +} + #ifdef CONFIG_HOTPLUG_CPU static int xen_pv_cpu_disable(void) { @@ -364,18 +362,18 @@ static int xen_pv_cpu_disable(void) =20 static void xen_pv_cpu_die(unsigned int cpu) { - while (HYPERVISOR_vcpu_op(VCPUOP_is_up, - xen_vcpu_nr(cpu), NULL)) { + while (HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu), NULL)) { __set_current_state(TASK_UNINTERRUPTIBLE); schedule_timeout(HZ/10); } +} =20 - if (common_cpu_die(cpu) =3D=3D 0) { - xen_smp_intr_free(cpu); - xen_uninit_lock_cpu(cpu); - xen_teardown_timer(cpu); - xen_pmu_finish(cpu); - } +static void xen_pv_cleanup_dead_cpu(unsigned int cpu) +{ + xen_smp_intr_free(cpu); + xen_uninit_lock_cpu(cpu); + xen_teardown_timer(cpu); + xen_pmu_finish(cpu); } =20 static void __noreturn xen_pv_play_dead(void) /* used only with HOTPLUG_CP= U */ @@ -397,6 +395,11 @@ static void xen_pv_cpu_die(unsigned int BUG(); } =20 +static void xen_pv_cleanup_dead_cpu(unsigned int cpu) +{ + BUG(); +} + static void __noreturn xen_pv_play_dead(void) { BUG(); @@ -437,6 +440,8 @@ static const struct smp_ops xen_smp_ops =20 .cpu_up =3D xen_pv_cpu_up, .cpu_die =3D xen_pv_cpu_die, + .cleanup_dead_cpu =3D xen_pv_cleanup_dead_cpu, + .poll_sync_state =3D xen_pv_poll_sync_state, .cpu_disable =3D xen_pv_cpu_disable, .play_dead =3D xen_pv_play_dead, From nobody Fri Nov 1 00:09:59 2024 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 714FDC77B77 for ; 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Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 20/37] cpu/hotplug: Remove cpu_report_state() and related unused cruft References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:46 +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" No more users. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- include/linux/cpu.h | 2 - kernel/smpboot.c | 90 -----------------------------------------------= ----- 2 files changed, 92 deletions(-) --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -184,8 +184,6 @@ void arch_cpu_idle_enter(void); void arch_cpu_idle_exit(void); void arch_cpu_idle_dead(void); =20 -int cpu_report_state(int cpu); -int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); void play_idle_precise(u64 duration_ns, u64 latency_ns); =20 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -329,97 +329,7 @@ EXPORT_SYMBOL_GPL(smpboot_unregister_per #ifndef CONFIG_HOTPLUG_CORE_SYNC static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) =3D ATOMIC_INIT(CPU_POS= T_DEAD); =20 -/* - * Called to poll specified CPU's state, for example, when waiting for - * a CPU to come online. - */ -int cpu_report_state(int cpu) -{ - return atomic_read(&per_cpu(cpu_hotplug_state, cpu)); -} - -/* - * If CPU has died properly, set its state to CPU_UP_PREPARE and - * return success. Otherwise, return -EBUSY if the CPU died after - * cpu_wait_death() timed out. And yet otherwise again, return -EAGAIN - * if cpu_wait_death() timed out and the CPU still hasn't gotten around - * to dying. In the latter two cases, the CPU might not be set up - * properly, but it is up to the arch-specific code to decide. - * Finally, -EIO indicates an unanticipated problem. - * - * Note that it is permissible to omit this call entirely, as is - * done in architectures that do no CPU-hotplug error checking. - */ -int cpu_check_up_prepare(int cpu) -{ - if (!IS_ENABLED(CONFIG_HOTPLUG_CPU)) { - atomic_set(&per_cpu(cpu_hotplug_state, cpu), CPU_UP_PREPARE); - return 0; - } - - switch (atomic_read(&per_cpu(cpu_hotplug_state, cpu))) { - - case CPU_POST_DEAD: - - /* The CPU died properly, so just start it up again. */ - atomic_set(&per_cpu(cpu_hotplug_state, cpu), CPU_UP_PREPARE); - return 0; - - case CPU_DEAD_FROZEN: - - /* - * Timeout during CPU death, so let caller know. - * The outgoing CPU completed its processing, but after - * cpu_wait_death() timed out and reported the error. The - * caller is free to proceed, in which case the state - * will be reset properly by cpu_set_state_online(). - * Proceeding despite this -EBUSY return makes sense - * for systems where the outgoing CPUs take themselves - * offline, with no post-death manipulation required from - * a surviving CPU. - */ - return -EBUSY; - - case CPU_BROKEN: - - /* - * The most likely reason we got here is that there was - * a timeout during CPU death, and the outgoing CPU never - * did complete its processing. This could happen on - * a virtualized system if the outgoing VCPU gets preempted - * for more than five seconds, and the user attempts to - * immediately online that same CPU. Trying again later - * might return -EBUSY above, hence -EAGAIN. - */ - return -EAGAIN; - - case CPU_UP_PREPARE: - /* - * Timeout while waiting for the CPU to show up. Allow to try - * again later. - */ - return 0; - - default: - - /* Should not happen. Famous last words. */ - return -EIO; - } -} - -/* - * Mark the specified CPU online. - * - * Note that it is permissible to omit this call entirely, as is - * done in architectures that do no CPU-hotplug error checking. - */ -void cpu_set_state_online(int cpu) -{ - (void)atomic_xchg(&per_cpu(cpu_hotplug_state, cpu), CPU_ONLINE); -} - #ifdef CONFIG_HOTPLUG_CPU - /* * Wait for the specified CPU to exit the idle loop and die. */ From nobody Fri Nov 1 00:09:59 2024 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 28141C77B71 for ; Fri, 14 Apr 2023 23:46:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230404AbjDNXqL (ORCPT ); Fri, 14 Apr 2023 19:46:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230311AbjDNXpc (ORCPT ); Fri, 14 Apr 2023 19:45:32 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3B74AD12; Fri, 14 Apr 2023 16:44:51 -0700 (PDT) Message-ID: <20230414232310.506665258@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515888; 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=BWuCF2CiZKIQbbVy6vgpgYODjXTXdK2iLGuwNDfmq40=; b=f+z8dnbF0VfVZ2drfvyKG7CFHH0pFiyt/pWm7ehfcpt37yeWoaaqrXqvZgx9e/X+XvrZce gt4gtyv6t++LGb/9kB1kGkXRTvx7bPDMmlE2YCfC4bhE+s0E3cJidnKxtsU1uFW28KmFrm Eh1JSahdrCC66cB1rpXpEnDQUWYAaCehtBdvR4JcyEbKg1e1N2/wIL2n3XDGfkKj7+6Kc2 i/dgOOZylb3sazc82Iv1WIdzwGBFxWc2QRD+sOwDm8QUeivjB4vTaM4N2GaxbzQoD4goZa 9mik80mRNDqag2mcRqOovhsRU7cr3S59unOU29PAZedSzmpwu0Vl+6WwRIUstA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515888; 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=BWuCF2CiZKIQbbVy6vgpgYODjXTXdK2iLGuwNDfmq40=; b=HrYkhb/PC8lVyjiszH07tO75RvI9fVkc6wkdtUyyzhBuNuOW308LHInmD5FALuyFMFj8ZV PF23VUQhymsOP5DA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 21/37] ARM: smp: Switch to hotplug core state synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:47 +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" Switch to the CPU hotplug core state tracking and synchronization mechanim. No functional change intended. Signed-off-by: Thomas Gleixner Cc: Russell King Cc: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/arm/Kconfig | 1 + arch/arm/include/asm/smp.h | 2 +- arch/arm/kernel/smp.c | 18 +++++++----------- 3 files changed, 9 insertions(+), 12 deletions(-) --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -124,6 +124,7 @@ config ARM select HAVE_SYSCALL_TRACEPOINTS select HAVE_UID16 select HAVE_VIRT_CPU_ACCOUNTING_GEN + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select IRQ_FORCED_THREADING select MODULES_USE_ELF_REL select NEED_DMA_MAP_STATE --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -64,7 +64,7 @@ extern void secondary_startup_arm(void); =20 extern int __cpu_disable(void); =20 -extern void __cpu_die(unsigned int cpu); +static inline void __cpu_die(unsigned int cpu) { } =20 extern void arch_send_call_function_single_ipi(int cpu); extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -289,15 +289,11 @@ int __cpu_disable(void) } =20 /* - * called on the thread which is asking for a CPU to be shutdown - - * waits until shutdown has completed, or it is timed out. + * called on the thread which is asking for a CPU to be shutdown after the + * shutdown completed. */ -void __cpu_die(unsigned int cpu) +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { - if (!cpu_wait_death(cpu, 5)) { - pr_err("CPU%u: cpu didn't die\n", cpu); - return; - } pr_debug("CPU%u: shutdown\n", cpu); =20 clear_tasks_mm_cpumask(cpu); @@ -337,11 +333,11 @@ void arch_cpu_idle_dead(void) flush_cache_louis(); =20 /* - * Tell __cpu_die() that this CPU is now safe to dispose of. Once - * this returns, power and/or clocks can be removed at any point - * from this CPU and its cache by platform_cpu_kill(). + * Tell cpuhp_bp_sync_dead() that this CPU is now safe to dispose + * of. Once this returns, power and/or clocks can be removed at + * any point from this CPU and its cache by platform_cpu_kill(). */ - (void)cpu_report_death(); + cpuhp_ap_report_dead(); =20 /* * Ensure that the cache lines associated with that completion are From nobody Fri Nov 1 00:09:59 2024 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 C6F46C77B71 for ; Fri, 14 Apr 2023 23:47:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230293AbjDNXrG (ORCPT ); Fri, 14 Apr 2023 19:47:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230230AbjDNXql (ORCPT ); Fri, 14 Apr 2023 19:46:41 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FE70B464; Fri, 14 Apr 2023 16:45:41 -0700 (PDT) Message-ID: <20230414232310.569498144@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515889; 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=dAqk1yNFRcZF7qilzpcfVR/70NZ8+F/SNrVuS7Hd0dk=; b=AU6aWn3llfgN87vGRPuEWQIrjtTFwK3yn2f2vw94yybrTzt5H4LRbc91tm1Xw3BwSnq5hP rQmL01eHYwGuD/tJ0f+L2+Oe406bYjAoY3D+heXxkuTKO7KuUfo+Vs6B1IlkwX6ZMSgfKv MeC7l/ITcGbKIYw5eRyObkCJegLxrMXZzPk/rNGf+zutst2sEf6AX47fGrPZphUN9CnuIP 6Hqq0/37hmlZ5Bbfm3XWsFI3yH4n+lXK8uvrCVgYW4m/9hcfQmz9XLNpsQ2ZNbshSo8dWB 0ORFcD1Xi54QY+d+vfpgXIdhI1e6dB7Jux3a2oBfTKMsXcUuUQI04NVVQTd0zA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515889; 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=dAqk1yNFRcZF7qilzpcfVR/70NZ8+F/SNrVuS7Hd0dk=; b=9EnFpcJNs8EwCrNKZip93QB/LFNFkvbQArfrS6NvwMyIg/IEdfp5AE2HOIUr5Sp+QKyDnB /vmf1BkRatgvPdDA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 22/37] arm64: smp: Switch to hotplug core state synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:49 +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" Switch to the CPU hotplug core state tracking and synchronization mechanim. No functional change intended. Signed-off-by: Thomas Gleixner Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Tested-by: Juergen Gross Tested-by: Mark Rutland Tested-by: Michael Kelley --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/smp.h | 2 +- arch/arm64/kernel/smp.c | 14 +++++--------- 3 files changed, 7 insertions(+), 10 deletions(-) --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -216,6 +216,7 @@ config ARM64 select HAVE_KPROBES select HAVE_KRETPROBES select HAVE_GENERIC_VDSO + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select IRQ_DOMAIN select IRQ_FORCED_THREADING select KASAN_VMALLOC if KASAN --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -99,7 +99,7 @@ static inline void arch_send_wakeup_ipi_ =20 extern int __cpu_disable(void); =20 -extern void __cpu_die(unsigned int cpu); +static inline void __cpu_die(unsigned int cpu) { } extern void cpu_die(void); extern void cpu_die_early(void); =20 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -333,17 +333,13 @@ static int op_cpu_kill(unsigned int cpu) } =20 /* - * called on the thread which is asking for a CPU to be shutdown - - * waits until shutdown has completed, or it is timed out. + * Called on the thread which is asking for a CPU to be shutdown after the + * shutdown completed. */ -void __cpu_die(unsigned int cpu) +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { int err; =20 - if (!cpu_wait_death(cpu, 5)) { - pr_crit("CPU%u: cpu didn't die\n", cpu); - return; - } pr_debug("CPU%u: shutdown\n", cpu); =20 /* @@ -370,8 +366,8 @@ void cpu_die(void) =20 local_daif_mask(); =20 - /* Tell __cpu_die() that this CPU is now safe to dispose of */ - (void)cpu_report_death(); + /* Tell cpuhp_bp_sync_dead() that this CPU is now safe to dispose of */ + cpuhp_ap_report_dead(); =20 /* * Actually shutdown the CPU. This must never fail. The specific hotplug From nobody Fri Nov 1 00:09:59 2024 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 73D30C77B72 for ; Fri, 14 Apr 2023 23:46:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230150AbjDNXqQ (ORCPT ); Fri, 14 Apr 2023 19:46:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230323AbjDNXpe (ORCPT ); Fri, 14 Apr 2023 19:45:34 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E685B771; Fri, 14 Apr 2023 16:44:55 -0700 (PDT) Message-ID: <20230414232310.631170657@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515891; 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=y6SldvuVXq/pw8ptav6ZzZhZk50vNE0+ALorGdATBvE=; b=j7ir4M38uyCqNd0WpGFhlMbHqqP22sIUkP6lTXCI4ZoMelPAhB0ZW3jUKq/qNg7dgtIPyr wAgHvssp340UT3vn/QZsaFN0BbxJz/50Bk2j/ViCY7pmbdjJltpv6UUhTwyesp5uV/hH5R rn30yImLh2MbCenzGtlPdqYodmJQsWXgthmyh3VDgg8IsWfSP8TgZqODKQUJwz+InU8in3 FyxZW7Fp+CUcayGzDXYKM02cvf34xnDKNWTxsXl+QFRwELU5xV0mCQa2KjOMor4Q501Rct 0HVatbGD4qEO2xAAV9X3ZovODF8RAMi5ZzvUu9hOjJPsLeNkmpDExwTMMJ6FBg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515891; 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=y6SldvuVXq/pw8ptav6ZzZhZk50vNE0+ALorGdATBvE=; b=Qg+tSuukciCk/31JBTMbNipFvroQgicaNOn31ON18qthuCRxjFkOmjqqsu/6PGW7nvHreJ GQLRpem8ebEejbCw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Guo Ren , linux-csky@vger.kernel.org, David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 23/37] csky/smp: Switch to hotplug core state synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:50 +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" Switch to the CPU hotplug core state tracking and synchronization mechanim. No functional change intended. Signed-off-by: Thomas Gleixner Cc: Guo Ren Cc: linux-csky@vger.kernel.org Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/csky/Kconfig | 1 + arch/csky/include/asm/smp.h | 2 +- arch/csky/kernel/smp.c | 8 ++------ 3 files changed, 4 insertions(+), 7 deletions(-) --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -96,6 +96,7 @@ config CSKY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select MAY_HAVE_SPARSE_IRQ select MODULES_USE_ELF_RELA if MODULES select OF --- a/arch/csky/include/asm/smp.h +++ b/arch/csky/include/asm/smp.h @@ -23,7 +23,7 @@ void __init set_send_ipi(void (*func)(co =20 int __cpu_disable(void); =20 -void __cpu_die(unsigned int cpu); +static inline void __cpu_die(unsigned int cpu) { } =20 #endif /* CONFIG_SMP */ =20 --- a/arch/csky/kernel/smp.c +++ b/arch/csky/kernel/smp.c @@ -291,12 +291,8 @@ int __cpu_disable(void) return 0; } =20 -void __cpu_die(unsigned int cpu) +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { - if (!cpu_wait_death(cpu, 5)) { - pr_crit("CPU%u: shutdown failed\n", cpu); - return; - } pr_notice("CPU%u: shutdown\n", cpu); } =20 @@ -304,7 +300,7 @@ void arch_cpu_idle_dead(void) { idle_task_exit(); =20 - cpu_report_death(); + cpuhp_ap_report_dead(); =20 while (!secondary_stack) arch_cpu_idle(); From nobody Fri Nov 1 00:09:59 2024 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 CC187C77B72 for ; Fri, 14 Apr 2023 23:46:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230420AbjDNXqU (ORCPT ); Fri, 14 Apr 2023 19:46:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230250AbjDNXpf (ORCPT ); Fri, 14 Apr 2023 19:45:35 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A121FB775; Fri, 14 Apr 2023 16:44:55 -0700 (PDT) Message-ID: <20230414232310.693105830@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515893; 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=mLdwoL7i0j/gvs95W7juPrPE5guQlLpBTCOH6DWIfHg=; b=y1vQpfJDA9JbXkT4n2QDDyergrLrjhNoIcOXwKPLBgXGWR69MsWEbhct6B2Q0Beq9IabGw 8AdipYQcGyGv10JjhcWmTMA6nb+uKbsSx/MN8HdunT5YcA8SzmppaMBbV7cQ+4LIlc+rZg M4S3YtNPEpFxh9BpQS/uuKImmvSvY9SOjP7kEGHRSjocKuW8Hkd+wsQRNAhaJSu1q3Ji84 SfmMJL8bUIWPuJwGfQ1vQpsLmkVhRAcjnaf3HglDZNmuBZv36ILD3UsCeX4NSzkNQbUFEr jFiHQ+uYjIIWiDdw9m0lRurk39p0R7S/zFpzTGvsKaBrVSf8BTbzIWNSs/wA3w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515893; 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=mLdwoL7i0j/gvs95W7juPrPE5guQlLpBTCOH6DWIfHg=; b=M7xQ1hL+35efJyLWe/r6UMXIs4XiyYXK60NpoJQ4tJZIRf0mH7XTaz2kcmwMNEzpQl+EWC m32CcBw/MSN+BxAg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Thomas Bogendoerfer , linux-mips@vger.kernel.org, David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 24/37] MIPS: SMP_CPS: Switch to hotplug core state synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:52 +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" Switch to the CPU hotplug core state tracking and synchronization mechanim. This unfortunately requires to add dead reporting to the non CPS platforms as CPS is the only user, but it allows an overall consolidation of this functionality. No functional change intended. Signed-off-by: Thomas Gleixner Cc: Thomas Bogendoerfer Cc: linux-mips@vger.kernel.org Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/mips/Kconfig | 1 + arch/mips/cavium-octeon/smp.c | 1 + arch/mips/include/asm/smp-ops.h | 1 + arch/mips/kernel/smp-bmips.c | 1 + arch/mips/kernel/smp-cps.c | 14 +++++--------- arch/mips/kernel/smp.c | 8 ++++++++ arch/mips/loongson64/smp.c | 1 + 7 files changed, 18 insertions(+), 9 deletions(-) --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2356,6 +2356,7 @@ config MIPS_CPS select MIPS_CM select MIPS_CPS_PM if HOTPLUG_CPU select SMP + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select SYNC_R4K if (CEVT_R4K || CSRC_R4K) select SYS_SUPPORTS_HOTPLUG_CPU select SYS_SUPPORTS_SCHED_SMT if CPU_MIPSR6 --- a/arch/mips/cavium-octeon/smp.c +++ b/arch/mips/cavium-octeon/smp.c @@ -344,6 +344,7 @@ void play_dead(void) int cpu =3D cpu_number_map(cvmx_get_core_num()); =20 idle_task_exit(); + cpuhp_ap_report_dead(); octeon_processor_boot =3D 0xff; per_cpu(cpu_state, cpu) =3D CPU_DEAD; =20 --- a/arch/mips/include/asm/smp-ops.h +++ b/arch/mips/include/asm/smp-ops.h @@ -33,6 +33,7 @@ struct plat_smp_ops { #ifdef CONFIG_HOTPLUG_CPU int (*cpu_disable)(void); void (*cpu_die)(unsigned int cpu); + void (*cleanup_dead_cpu)(unsigned cpu); #endif #ifdef CONFIG_KEXEC void (*kexec_nonboot_cpu)(void); --- a/arch/mips/kernel/smp-bmips.c +++ b/arch/mips/kernel/smp-bmips.c @@ -390,6 +390,7 @@ static void bmips_cpu_die(unsigned int c void __ref play_dead(void) { idle_task_exit(); + cpuhp_ap_report_dead(); =20 /* flush data cache */ _dma_cache_wback_inv(0, ~0); --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -497,8 +497,7 @@ void play_dead(void) } } =20 - /* This CPU has chosen its way out */ - (void)cpu_report_death(); + cpuhp_ap_report_dead(); =20 cps_shutdown_this_cpu(cpu_death); =20 @@ -521,7 +520,9 @@ static void wait_for_sibling_halt(void * } while (!(halted & TCHALT_H)); } =20 -static void cps_cpu_die(unsigned int cpu) +static void cps_cpu_die(unsigned int cpu) { } + +static void cps_cleanup_dead_cpu(unsigned cpu) { unsigned core =3D cpu_core(&cpu_data[cpu]); unsigned int vpe_id =3D cpu_vpe_id(&cpu_data[cpu]); @@ -529,12 +530,6 @@ static void cps_cpu_die(unsigned int cpu unsigned stat; int err; =20 - /* Wait for the cpu to choose its way out */ - if (!cpu_wait_death(cpu, 5)) { - pr_err("CPU%u: didn't offline\n", cpu); - return; - } - /* * Now wait for the CPU to actually offline. Without doing this that * offlining may race with one or more of: @@ -618,6 +613,7 @@ static const struct plat_smp_ops cps_smp #ifdef CONFIG_HOTPLUG_CPU .cpu_disable =3D cps_cpu_disable, .cpu_die =3D cps_cpu_die, + .cleanup_dead_cpu =3D cps_cleanup_dead_cpu, #endif #ifdef CONFIG_KEXEC .kexec_nonboot_cpu =3D cps_kexec_nonboot_cpu, --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -690,6 +690,14 @@ void flush_tlb_one(unsigned long vaddr) EXPORT_SYMBOL(flush_tlb_page); EXPORT_SYMBOL(flush_tlb_one); =20 +#ifdef CONFIG_HOTPLUG_CPU +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) +{ + if (mp_ops->cleanup_dead_cpu) + mp_ops->cleanup_dead_cpu(cpu); +} +#endif + #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST =20 static void tick_broadcast_callee(void *info) --- a/arch/mips/loongson64/smp.c +++ b/arch/mips/loongson64/smp.c @@ -788,6 +788,7 @@ void play_dead(void) void (*play_dead_at_ckseg1)(int *); =20 idle_task_exit(); + cpuhp_ap_report_dead(); =20 prid_imp =3D read_c0_prid() & PRID_IMP_MASK; prid_rev =3D read_c0_prid() & PRID_REV_MASK; From nobody Fri Nov 1 00:09:59 2024 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 67D20C77B72 for ; Fri, 14 Apr 2023 23:46:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229992AbjDNXqW (ORCPT ); Fri, 14 Apr 2023 19:46:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230325AbjDNXpf (ORCPT ); Fri, 14 Apr 2023 19:45:35 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89D979754; Fri, 14 Apr 2023 16:44:56 -0700 (PDT) Message-ID: <20230414232310.754812729@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515894; 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=R05iW7fNVcum8Q+mjf2E3yOsCRNZdrRM4MkZfsXKqKc=; b=aUiik8SryxpjaeRHuGDH1CVCPJrHdz4ToboDiBvyrgybp5D/pPkGbz7paiwVK8VODAE0fl SgTT+QXtuBbN0fpZxUWKztpQGU0bjPZSUW3fxyRe9IQVkvcbXWq/0x43vpjbVvOarJH7HV uIjYrrAOYGCrtSVeXL3Klmw/1hn994FxUZywCAJZ5ETy96ETN4uYpOv1uP93+BscjKqka+ yexDk6oAjmOIdMrSOugyHKVHXN1255/Us+8JjFFS+8Qfs8u4ygXpDFKFDNp8KDDwtuiQU3 N8RPw7aSRn8YI2NswkTZsr81vwh3F5+iNvqvFAUv07ki8YW+7xmZPHzCBoIC9w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515894; 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=R05iW7fNVcum8Q+mjf2E3yOsCRNZdrRM4MkZfsXKqKc=; b=caenbNdiUoGPpEuAuhFVb0nh5RPBSUL+B8V0qrD3LKpWvQp6oNtGy6pLTh0H4xLk3s7H+h 2RFNt+MohEqWQ1CQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 25/37] parisc: Switch to hotplug core state synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:54 +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" Switch to the CPU hotplug core state tracking and synchronization mechanim. No functional change intended. Signed-off-by: Thomas Gleixner Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/parisc/Kconfig | 1 + arch/parisc/kernel/process.c | 4 ++-- arch/parisc/kernel/smp.c | 7 +++---- 3 files changed, 6 insertions(+), 6 deletions(-) --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -56,6 +56,7 @@ config PARISC select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_REGS_AND_STACK_ACCESS_API + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select GENERIC_SCHED_CLOCK select GENERIC_IRQ_MIGRATION if SMP select HAVE_UNSTABLE_SCHED_CLOCK if SMP --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -166,8 +166,8 @@ void arch_cpu_idle_dead(void) =20 local_irq_disable(); =20 - /* Tell __cpu_die() that this CPU is now safe to dispose of. */ - (void)cpu_report_death(); + /* Tell the core that this CPU is now safe to dispose of. */ + cpuhp_ap_report_dead(); =20 /* Ensure that the cache lines are written out. */ flush_cache_all_local(); --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -500,11 +500,10 @@ int __cpu_disable(void) void __cpu_die(unsigned int cpu) { pdc_cpu_rendezvous_lock(); +} =20 - if (!cpu_wait_death(cpu, 5)) { - pr_crit("CPU%u: cpu didn't die\n", cpu); - return; - } +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) +{ pr_info("CPU%u: is shutting down\n", cpu); =20 /* set task's state to interruptible sleep */ From nobody Fri Nov 1 00:09:59 2024 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 24843C77B71 for ; Fri, 14 Apr 2023 23:48:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230325AbjDNXsr (ORCPT ); Fri, 14 Apr 2023 19:48:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231150AbjDNXsX (ORCPT ); Fri, 14 Apr 2023 19:48:23 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D85C86AA; Fri, 14 Apr 2023 16:47:05 -0700 (PDT) Message-ID: <20230414232310.817955867@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515896; 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=ayzVJgXuvflj3xjg1mGXZolHpFmSekkZ0AyhKY70H0Q=; b=GY2K7k5oePF4smJsnVlCWc197Gnvm2xpV+H4Y4U8e+jaRt3VB8iE9Bg1axBb2bpO+/I7XE wTG8GN8vNucA/g3rxDLFU6mc1SvUhxpbP0wveuvbhDGNZd++q35ihkBqOmSICTjhquJjYJ gQ/8Bkd6FpRUM+MX/SRhgi0pwhuLuSCrUZwmZ1fPuiU+CEObkKTMFIVqx8V0B6LfZdF2Zy vTSM8z3vPt6+fF/Bmw0aE9UGx+RqDICSvY+n8F5aACJ8IZ8FOG+IfKxylVEweXpqRrNp+K c5k4vI/XDc1rGZAhq8CumldbXaaUQJlgNjb18yycd/3lTwMlhsF9uxtK+pKsOQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515896; 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=ayzVJgXuvflj3xjg1mGXZolHpFmSekkZ0AyhKY70H0Q=; b=K/mg+lwQlwHWac81k54xHqleQCPzjnE1varYnMwenALS/XLp9IX7NBh95fkmdnzkG0JM9N NgO+APSKFCAt65CA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Mark Rutland , Sabin Rapan Subject: [patch 26/37] riscv: Switch to hotplug core state synchronization References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:55 +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" Switch to the CPU hotplug core state tracking and synchronization mechanim. No functional change intended. Signed-off-by: Thomas Gleixner Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: linux-riscv@lists.infradead.org Acked-by: Palmer Dabbelt Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/smp.h | 2 +- arch/riscv/kernel/cpu-hotplug.c | 14 +++++++------- 3 files changed, 9 insertions(+), 8 deletions(-) --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -116,6 +116,7 @@ config RISCV select HAVE_RSEQ select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select IRQ_DOMAIN select IRQ_FORCED_THREADING select MODULES_USE_ELF_RELA if MODULES --- a/arch/riscv/include/asm/smp.h +++ b/arch/riscv/include/asm/smp.h @@ -64,7 +64,7 @@ asmlinkage void smp_callin(void); =20 #if defined CONFIG_HOTPLUG_CPU int __cpu_disable(void); -void __cpu_die(unsigned int cpu); +static inline void __cpu_die(unsigned int cpu) { } #endif /* CONFIG_HOTPLUG_CPU */ =20 #else --- a/arch/riscv/kernel/cpu-hotplug.c +++ b/arch/riscv/kernel/cpu-hotplug.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -48,17 +49,15 @@ int __cpu_disable(void) return ret; } =20 +#ifdef CONFIG_HOTPLUG_CPU /* - * Called on the thread which is asking for a CPU to be shutdown. + * Called on the thread which is asking for a CPU to be shutdown, if the + * CPU reported dead to the hotplug core. */ -void __cpu_die(unsigned int cpu) +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { int ret =3D 0; =20 - if (!cpu_wait_death(cpu, 5)) { - pr_err("CPU %u: didn't die\n", cpu); - return; - } pr_notice("CPU%u: off\n", cpu); =20 /* Verify from the firmware if the cpu is really stopped*/ @@ -75,9 +74,10 @@ void arch_cpu_idle_dead(void) { idle_task_exit(); =20 - (void)cpu_report_death(); + cpuhp_ap_report_dead(); =20 cpu_ops[smp_processor_id()]->cpu_stop(); /* It should never reach here */ BUG(); } +#endif From nobody Fri Nov 1 00:09:59 2024 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 7D4BDC77B72 for ; Fri, 14 Apr 2023 23:46:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230467AbjDNXqd (ORCPT ); Fri, 14 Apr 2023 19:46:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230033AbjDNXpq (ORCPT ); Fri, 14 Apr 2023 19:45:46 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C185FB764; Fri, 14 Apr 2023 16:45:04 -0700 (PDT) Message-ID: <20230414232310.880220709@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515898; 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=auQqEwsU9PrP6dmLhZ2HNf+yKNnP8AcVm6NVRhQvyDs=; b=UQ9zo5ANA3bXro6uBe1FOBxXvcfoSQEiD24Xrn7vh8KjSNUhNMcqLW1wljHJEJ+e8j4GDJ N1EWMYIroPUN4YgTfbVjru09sBWEDKR5SQth1/0kGQgcTNZpj5XjpFfxTvJhJa1qZtvmXw wJMkqQYqdVRSHK1GBFiS97ApX5A77MdAt+hpRt1LADSzZH/uFNSbjXsbu3HZBSvh8G0y2P EK0CnndcvpELSRQBHbYZKRgcaUhr6Z8TtUOgSj+l3dKGuu0eZBB3TQY8X7TLCDbAdL4JaV dJXPejZzrfw0jpwXNhC/giE+cyNnTnS/yF70lli9Oe14OjMbSX5LRocaBNalvA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515898; 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=auQqEwsU9PrP6dmLhZ2HNf+yKNnP8AcVm6NVRhQvyDs=; b=3UjUp0tk+qEdheiIONrPumzFg6y/RDymanoMKy3WCuwS6WRIh+kUkt2pm7bfL23mY4jSCI ishR5iLfVIQKiiCw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 27/37] cpu/hotplug: Remove unused state functions References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:57 +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" All users converted to the hotplug core mechanism. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- include/linux/cpu.h | 2 - kernel/smpboot.c | 75 -----------------------------------------------= ----- 2 files changed, 77 deletions(-) --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -193,8 +193,6 @@ static inline void play_idle(unsigned lo } =20 #ifdef CONFIG_HOTPLUG_CPU -bool cpu_wait_death(unsigned int cpu, int seconds); -bool cpu_report_death(void); void cpuhp_report_idle_dead(void); #else static inline void cpuhp_report_idle_dead(void) { } --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -325,78 +325,3 @@ void smpboot_unregister_percpu_thread(st cpus_read_unlock(); } EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread); - -#ifndef CONFIG_HOTPLUG_CORE_SYNC -static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) =3D ATOMIC_INIT(CPU_POS= T_DEAD); - -#ifdef CONFIG_HOTPLUG_CPU -/* - * Wait for the specified CPU to exit the idle loop and die. - */ -bool cpu_wait_death(unsigned int cpu, int seconds) -{ - int jf_left =3D seconds * HZ; - int oldstate; - bool ret =3D true; - int sleep_jf =3D 1; - - might_sleep(); - - /* The outgoing CPU will normally get done quite quickly. */ - if (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) =3D=3D CPU_DEAD) - goto update_state_early; - udelay(5); - - /* But if the outgoing CPU dawdles, wait increasingly long times. */ - while (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) !=3D CPU_DEAD) { - schedule_timeout_uninterruptible(sleep_jf); - jf_left -=3D sleep_jf; - if (jf_left <=3D 0) - break; - sleep_jf =3D DIV_ROUND_UP(sleep_jf * 11, 10); - } -update_state_early: - oldstate =3D atomic_read(&per_cpu(cpu_hotplug_state, cpu)); -update_state: - if (oldstate =3D=3D CPU_DEAD) { - /* Outgoing CPU died normally, update state. */ - smp_mb(); /* atomic_read() before update. */ - atomic_set(&per_cpu(cpu_hotplug_state, cpu), CPU_POST_DEAD); - } else { - /* Outgoing CPU still hasn't died, set state accordingly. */ - if (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - &oldstate, CPU_BROKEN)) - goto update_state; - ret =3D false; - } - return ret; -} - -/* - * Called by the outgoing CPU to report its successful death. Return - * false if this report follows the surviving CPU's timing out. - * - * A separate "CPU_DEAD_FROZEN" is used when the surviving CPU - * timed out. This approach allows architectures to omit calls to - * cpu_check_up_prepare() and cpu_set_state_online() without defeating - * the next cpu_wait_death()'s polling loop. - */ -bool cpu_report_death(void) -{ - int oldstate; - int newstate; - int cpu =3D smp_processor_id(); - - oldstate =3D atomic_read(&per_cpu(cpu_hotplug_state, cpu)); - do { - if (oldstate !=3D CPU_BROKEN) - newstate =3D CPU_DEAD; - else - newstate =3D CPU_DEAD_FROZEN; - } while (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - &oldstate, newstate)); - return newstate =3D=3D CPU_DEAD; -} - -#endif /* #ifdef CONFIG_HOTPLUG_CPU */ -#endif /* !CONFIG_HOTPLUG_CORE_SYNC */ From nobody Fri Nov 1 00:09:59 2024 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 4A815C77B76 for ; Fri, 14 Apr 2023 23:46:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230462AbjDNXq3 (ORCPT ); Fri, 14 Apr 2023 19:46:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230339AbjDNXpq (ORCPT ); Fri, 14 Apr 2023 19:45:46 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C218CB766; Fri, 14 Apr 2023 16:45:04 -0700 (PDT) Message-ID: <20230414232310.941680232@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515899; 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=PwaT1nVbkmNxpYn2jntunVyX300rI6JOSPoxKblUFxc=; b=J4d36wqGXDsa4D15fuC6bgECzfAAInQki6KA3SUyC98aD0yQW6gcNLFjQOCHcXv2J+orZG 5Qmhd0e6dbHL514sP/COcIuWz15soNEsWHzEh1yBv2+hd5B8wqzYOidLR2BE5cayvWqW8Z HTkU8Nrl6+H70MJnTBAZDmHlfDfKJpBLY0P7kmzee0usDqsCKruEINfZUsjihRGa5dTOub nsf1V7hsU0pvXa2Ve2ehvBeS9w4NMv0lT4Qar9j26QhzX8zbcfe2cv28EW7JmGjaOXAvGg fSx2t8XhhVFut65VN9kClCBXCqftJpibwk/DAZDt6leoEUA5kSkPTRcDM8b5qA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515899; 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=PwaT1nVbkmNxpYn2jntunVyX300rI6JOSPoxKblUFxc=; b=GT9ybsNnlf8a2CqrpgJaThMxA4ODF78eIoN2mtLu9TxUz4hUltbB6uZ6jFavUSEgOGT604 TxVe7hxr4awf6HAw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Mark Rutland , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Sabin Rapan Subject: [patch 28/37] cpu/hotplug: Reset task stack state in _cpu_up() References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:44:59 +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" From: David Woodhouse Commit dce1ca0525bf ("sched/scs: Reset task stack state in bringup_cpu()") ensured that the shadow call stack and KASAN poisoning were removed from a CPU's stack each time that CPU is brought up, not just once. This is not incorrect. However, with parallel bringup the idle thread setup will happen at a different step. As a consequence the cleanup in bringup_cpu() would be too late. Move the SCS/KASAN cleanup to the generic _cpu_up() function instead, which already ensures that the new CPU's stack is available, purely to allow for early failure. This occurs when the CPU to be brought up is in the CPUHP_OFFLINE state, which should correctly do the cleanup any time the CPU has been taken down to the point where such is needed. Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Tested-by: Mark Rutland Reviewed-by: Mark Rutland Tested-by: Juergen Gross Tested-by: Michael Kelley --- kernel/cpu.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -769,12 +769,6 @@ static int bringup_cpu(unsigned int cpu) return -EAGAIN; =20 /* - * Reset stale stack state from the last time this CPU was online. - */ - scs_task_reset(idle); - kasan_unpoison_task_stack(idle); - - /* * Some architectures have to walk the irq descriptors to * setup the vector space for the cpu which comes online. * Prevent irq alloc/free across the bringup. @@ -1581,6 +1575,12 @@ static int _cpu_up(unsigned int cpu, int ret =3D PTR_ERR(idle); goto out; } + + /* + * Reset stale stack state from the last time this CPU was online. + */ + scs_task_reset(idle); + kasan_unpoison_task_stack(idle); } =20 cpuhp_tasks_frozen =3D tasks_frozen; From nobody Fri Nov 1 00:09:59 2024 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 5AF9FC77B71 for ; Fri, 14 Apr 2023 23:47:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231148AbjDNXrx (ORCPT ); Fri, 14 Apr 2023 19:47:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231126AbjDNXrF (ORCPT ); Fri, 14 Apr 2023 19:47:05 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79C929742; Fri, 14 Apr 2023 16:46:07 -0700 (PDT) Message-ID: <20230414232311.004104404@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515901; 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=ocDa9/b5b649kz9ODCiS7Obhl2xff0PGySrVJUnu/1Q=; b=Md1KUi0t4p5246hEM+Qbsg81XiYR2jMjuw8Cw1D96u97R/Z2vnRzvzyGsvg5/thdzlhagw VxVAyRxzHuR0yoObilNCNxEii10xKHOuzvMmMpympXYYlB2U8gUH+sjsIvQSBudSOTSmdM UnCqcdLP+SdXgts22XiNkil1Ao3IAY8flV5MA9J+wt6a2jzpqf6qFRYX/asyt9IKYGJESJ xr1bFKQEJqtc2y44yr2+c326EAG2BPB0FHdGHcRgBqiJBXhDU2UyMAE2uzcyA4utOsub3q p754cUuO5uG6++I5nPeZhand8mstexdu0PM3TYbIMB2kMernSkCdSX7RIPkZfA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515901; 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=ocDa9/b5b649kz9ODCiS7Obhl2xff0PGySrVJUnu/1Q=; b=BXd39doKKTpBx8WPmaV0PtWPunRukkpmlrtLhowy8wImwT3Zn16BG6OqXrJtidsxX/8Ej+ driBsAHHd5CWSWBA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 29/37] cpu/hotplug: Provide a split up CPUHP_BRINGUP mechanism References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:00 +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" The bring up logic of a to be onlined CPU consists of several parts, which are considered to be a single hotplug state: 1) Control CPU issues the wake-up 2) To be onlined CPU starts up, does the minimal initialization, reports to be alive and waits for release into the complete bring-up. 3) Control CPU waits for the alive report and releases the upcoming CPU for the complete bring-up. Allow to split this into two states: 1) Control CPU issues the wake-up After that the to be onlined CPU starts up, does the minimal initialization, reports to be alive and waits for release into the full bring-up. As this can run after the control CPU dropped the hotplug locks the code which is executed on the AP before it reports alive has to be carefully audited to not violate any of the hotplug constraints, especially not modifying any of the various cpumasks. This is really only meant to avoid waiting for the AP to react on the wake-up. Of course an architecture can move strict CPU related setup functionality, e.g. microcode loading, with care before the synchronization point to save further pointless waiting time. 2) Control CPU waits for the alive report and releases the upcoming CPU for the complete bring-up. This allows that the two states can be split up to run all to be onlined CPUs up to state #1 on the control CPU and then at a later point run state #2. This spares some of the latencies of the full serialized per CPU bringup by avoiding the per CPU wakeup/wait serialization. The assumption is that the first AP already waits when the last AP has been woken up. This obvioulsy depends on the hardware latencies and depending on the timings this might still not completely eliminate all wait scenarios. This split is just a preparatory step for enabling the parallel bringup later. The boot time bringup is still fully serialized. It has a separate config switch so that architectures which want to support parallel bringup can test the split of the CPUHP_BRINGUG step separately. To enable this the architecture must support the CPU hotplug core sync mechanism and has to be audited that there are no implicit hotplug state dependencies which require a fully serialized bringup. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/Kconfig | 4 ++ include/linux/cpuhotplug.h | 4 ++ kernel/cpu.c | 70 ++++++++++++++++++++++++++++++++++++++++= +++-- 3 files changed, 76 insertions(+), 2 deletions(-) --- a/arch/Kconfig +++ b/arch/Kconfig @@ -49,6 +49,10 @@ config HOTPLUG_CORE_SYNC_FULL select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select HOTPLUG_CORE_SYNC =20 +config HOTPLUG_SPLIT_STARTUP + bool + select HOTPLUG_CORE_SYNC_FULL + config GENERIC_ENTRY bool =20 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -133,6 +133,7 @@ enum cpuhp_state { CPUHP_MIPS_SOC_PREPARE, CPUHP_BP_PREPARE_DYN, CPUHP_BP_PREPARE_DYN_END =3D CPUHP_BP_PREPARE_DYN + 20, + CPUHP_BP_KICK_AP, CPUHP_BRINGUP_CPU, =20 /* @@ -519,9 +520,12 @@ void cpuhp_online_idle(enum cpuhp_state static inline void cpuhp_online_idle(enum cpuhp_state state) { } #endif =20 +struct task_struct; + void cpuhp_ap_sync_alive(void); void arch_cpuhp_sync_state_poll(void); void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu); +int arch_cpuhp_kick_ap_alive(unsigned int cpu, struct task_struct *tidle); =20 #ifdef CONFIG_HOTPLUG_CORE_SYNC_DEAD void cpuhp_ap_report_dead(void); --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -759,6 +759,47 @@ static int bringup_wait_for_ap_online(un return 0; } =20 +#ifdef CONFIG_HOTPLUG_SPLIT_STARTUP +static int cpuhp_kick_ap_alive(unsigned int cpu) +{ + if (!cpuhp_can_boot_ap(cpu)) + return -EAGAIN; + + return arch_cpuhp_kick_ap_alive(cpu, idle_thread_get(cpu)); +} + +static int cpuhp_bringup_ap(unsigned int cpu) +{ + struct cpuhp_cpu_state *st =3D per_cpu_ptr(&cpuhp_state, cpu); + int ret; + + /* + * Some architectures have to walk the irq descriptors to + * setup the vector space for the cpu which comes online. + * Prevent irq alloc/free across the bringup. + */ + irq_lock_sparse(); + + ret =3D cpuhp_bp_sync_alive(cpu); + if (ret) + goto out_unlock; + + ret =3D bringup_wait_for_ap_online(cpu); + if (ret) + goto out_unlock; + + irq_unlock_sparse(); + + if (st->target <=3D CPUHP_AP_ONLINE_IDLE) + return 0; + + return cpuhp_kick_ap(cpu, st, st->target); + +out_unlock: + irq_unlock_sparse(); + return ret; +} +#else static int bringup_cpu(unsigned int cpu) { struct cpuhp_cpu_state *st =3D per_cpu_ptr(&cpuhp_state, cpu); @@ -775,7 +816,6 @@ static int bringup_cpu(unsigned int cpu) */ irq_lock_sparse(); =20 - /* Arch-specific enabling code. */ ret =3D __cpu_up(cpu, idle); if (ret) goto out_unlock; @@ -799,6 +839,7 @@ static int bringup_cpu(unsigned int cpu) irq_unlock_sparse(); return ret; } +#endif =20 static int finish_cpu(unsigned int cpu) { @@ -1938,13 +1979,38 @@ static struct cpuhp_step cpuhp_hp_states .startup.single =3D timers_prepare_cpu, .teardown.single =3D timers_dead_cpu, }, - /* Kicks the plugged cpu into life */ + +#ifdef CONFIG_HOTPLUG_SPLIT_STARTUP + /* + * Kicks the AP alive. AP will wait in cpuhp_ap_sync_alive() until + * the next step will release it. + */ + [CPUHP_BP_KICK_AP] =3D { + .name =3D "cpu:kick_ap", + .startup.single =3D cpuhp_kick_ap_alive, + }, + + /* + * Waits for the AP to reach cpuhp_ap_sync_alive() and then + * releases it for the complete bringup. + */ + [CPUHP_BRINGUP_CPU] =3D { + .name =3D "cpu:bringup", + .startup.single =3D cpuhp_bringup_ap, + .teardown.single =3D finish_cpu, + .cant_stop =3D true, + }, +#else + /* + * All-in-one CPU bringup state which includes the kick alive. + */ [CPUHP_BRINGUP_CPU] =3D { .name =3D "cpu:bringup", .startup.single =3D bringup_cpu, .teardown.single =3D finish_cpu, .cant_stop =3D true, }, +#endif /* Final state before CPU kills itself */ [CPUHP_AP_IDLE_DEAD] =3D { .name =3D "idle:dead", From nobody Fri Nov 1 00:09:59 2024 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 E8F81C77B71 for ; Fri, 14 Apr 2023 23:47:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230324AbjDNXre (ORCPT ); Fri, 14 Apr 2023 19:47:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230449AbjDNXrA (ORCPT ); Fri, 14 Apr 2023 19:47:00 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02009C140; Fri, 14 Apr 2023 16:46:00 -0700 (PDT) Message-ID: <20230414232311.066246849@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515902; 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=cY/Vb0k8l53HgnPO915OdGCDzaj2v7X/LK/0bhlR+ZM=; b=Rl28BYLRw1xoqBY2XVna4334ensDR9FZzUXIXCLNtZ0ZnRftdKxlp0PMWMq1HaFMs/Nvoh XqGn6TtnTp761vrtUa5+ABOqgv49/+dDRkb1k96bmalthN4bjNP4h3EacgIX7TIRoFoQ1L UV+FOsaKzNfqWlzPpun3ecs+zhYGqo6qHGZzsNZ57SQvznqryxMS+L3SqK9W/dGy+VDKv9 YxTV8knnunEjK8aSQH5isteVb77I0eCsLEqmlSmZcWsTyG9EdV1bj0iMexF7biZ5gNOCfj ROw3zMy677VniDryW+1xRSofiRytmHDazA6lDPsXJmr7uXM+XbDSfwEveQWQlQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515902; 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=cY/Vb0k8l53HgnPO915OdGCDzaj2v7X/LK/0bhlR+ZM=; b=D1VjUKIFe77+cdNW6ebx9l5dhZNCMlm+6Ti8d+rxHqlUBIfv17CftGyUs1Xi5cbqbTIHp+ wg0OL2V4Mj/Lh/Bw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 30/37] x86/smpboot: Enable split CPU startup References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:02 +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" The x86 CPU bringup state currently does AP wake-up, wait for AP to respond and then release it for full bringup. It is safe to be split into a wake-up and and a separate wait+release state. Provide the required functions and enable the split CPU bringup, which prepares for parallel bringup, where the bringup of the non-boot CPUs takes two iterations: One to prepare and wake all APs and the second to wait and release them. Depending on timing this can eliminate the wait time completely. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/Kconfig | 2 +- arch/x86/include/asm/smp.h | 9 ++------- arch/x86/kernel/smp.c | 2 +- arch/x86/kernel/smpboot.c | 8 ++++---- arch/x86/xen/smp_pv.c | 4 ++-- 5 files changed, 10 insertions(+), 15 deletions(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -272,8 +272,8 @@ config X86 select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER select HAVE_GENERIC_VDSO - select HOTPLUG_CORE_SYNC_FULL if SMP select HOTPLUG_SMT if SMP + select HOTPLUG_SPLIT_STARTUP if SMP select IRQ_FORCED_THREADING select NEED_PER_CPU_EMBED_FIRST_CHUNK select NEED_PER_CPU_PAGE_FIRST_CHUNK --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -40,7 +40,7 @@ struct smp_ops { =20 void (*cleanup_dead_cpu)(unsigned cpu); void (*poll_sync_state)(void); - int (*cpu_up)(unsigned cpu, struct task_struct *tidle); + int (*kick_ap_alive)(unsigned cpu, struct task_struct *tidle); int (*cpu_disable)(void); void (*cpu_die)(unsigned int cpu); void (*play_dead)(void); @@ -80,11 +80,6 @@ static inline void smp_cpus_done(unsigne smp_ops.smp_cpus_done(max_cpus); } =20 -static inline int __cpu_up(unsigned int cpu, struct task_struct *tidle) -{ - return smp_ops.cpu_up(cpu, tidle); -} - static inline int __cpu_disable(void) { return smp_ops.cpu_disable(); @@ -123,7 +118,7 @@ void native_smp_prepare_cpus(unsigned in void calculate_max_logical_packages(void); void native_smp_cpus_done(unsigned int max_cpus); int common_cpu_up(unsigned int cpunum, struct task_struct *tidle); -int native_cpu_up(unsigned int cpunum, struct task_struct *tidle); +int native_kick_ap(unsigned int cpu, struct task_struct *tidle); int native_cpu_disable(void); void hlt_play_dead(void); void native_play_dead(void); --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -268,7 +268,7 @@ struct smp_ops smp_ops =3D { #endif .smp_send_reschedule =3D native_smp_send_reschedule, =20 - .cpu_up =3D native_cpu_up, + .kick_ap_alive =3D native_kick_ap, .cpu_disable =3D native_cpu_disable, .play_dead =3D native_play_dead, =20 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1070,7 +1070,7 @@ static int do_boot_cpu(int apicid, int c return ret; } =20 -static int native_kick_ap(unsigned int cpu, struct task_struct *tidle) +int native_kick_ap(unsigned int cpu, struct task_struct *tidle) { int apicid =3D apic->cpu_present_to_apicid(cpu); int err; @@ -1106,15 +1106,15 @@ static int native_kick_ap(unsigned int c return err; } =20 -int native_cpu_up(unsigned int cpu, struct task_struct *tidle) +int arch_cpuhp_kick_ap_alive(unsigned int cpu, struct task_struct *tidle) { - return native_kick_ap(cpu, tidle); + return smp_ops.kick_ap_alive(cpu, tidle); } =20 void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu) { /* Cleanup possible dangling ends... */ - if (smp_ops.cpu_up =3D=3D native_cpu_up && x86_platform.legacy.warm_reset) + if (smp_ops.kick_ap_alive =3D=3D native_kick_ap && x86_platform.legacy.wa= rm_reset) smpboot_restore_warm_reset_vector(); } =20 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -314,7 +314,7 @@ cpu_initialize_context(unsigned int cpu, return 0; } =20 -static int xen_pv_cpu_up(unsigned int cpu, struct task_struct *idle) +static int xen_pv_kick_ap(unsigned int cpu, struct task_struct *idle) { int rc; =20 @@ -438,7 +438,7 @@ static const struct smp_ops xen_smp_ops .smp_prepare_cpus =3D xen_pv_smp_prepare_cpus, .smp_cpus_done =3D xen_smp_cpus_done, =20 - .cpu_up =3D xen_pv_cpu_up, + .kick_ap_alive =3D xen_pv_kick_ap, .cpu_die =3D xen_pv_cpu_die, .cleanup_dead_cpu =3D xen_pv_cleanup_dead_cpu, .poll_sync_state =3D xen_pv_poll_sync_state, From nobody Fri Nov 1 00:09:59 2024 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 C62C7C77B71 for ; Fri, 14 Apr 2023 23:47:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231145AbjDNXrk (ORCPT ); Fri, 14 Apr 2023 19:47:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230451AbjDNXrA (ORCPT ); Fri, 14 Apr 2023 19:47:00 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F7BEA5CD; Fri, 14 Apr 2023 16:46:00 -0700 (PDT) Message-ID: <20230414232311.128590508@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515904; 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=1po2rJ4fVgJP8Lz7zlVuql3iIT5xp2VpR+B+sueZaiQ=; b=j2f464LqemKF5EyymLaTszAtW5FGztj8vmPcDPj1wK7YU7fOHNTdZk2/K8gAJFZq9pfDGY 5swh08e6d90aHqmMGF6WkIyj8axPVjUxuJuAViwZJ1cdvU6xcoF9zb87nqcct5XNmsoX0o Y0cHSVhAJwX30WEOO0lshPZ8xsXVjRD0fZRGdhHxX3DVdfFiIehL5+rfIQAY4cxNaAwRps 53guQBH31H4F+J1+vPDF/UwhFysy5n0UHaveg6UXzsIamQzkfs0Z0QqIZPRxbWQld5Mev3 7k6omsH4VccEFnKEdLPC9J1LIDlQw0AxGEp7j6OfTQ3DxOTM+UbH+I/cU+I8Bw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515904; 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=1po2rJ4fVgJP8Lz7zlVuql3iIT5xp2VpR+B+sueZaiQ=; b=H0vP+GAKFQrHzIZje+HAambScu8P4RD3X0xBakqALypG7Ph1OaLTUgdSgEHGbKo8mVzf0A CNqZe/l3Ol72rcBw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 31/37] x86/apic: Provide cpu_primary_thread mask References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:03 +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" Make the primary thread tracking CPU mask based in preparation for simpler handling of parallel bootup. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/apic.h | 2 -- arch/x86/include/asm/topology.h | 19 +++++++++++++++---- arch/x86/kernel/apic/apic.c | 20 +++++++++----------- arch/x86/kernel/smpboot.c | 12 +++--------- 4 files changed, 27 insertions(+), 26 deletions(-) --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -506,10 +506,8 @@ extern int default_check_phys_apicid_pre #endif /* CONFIG_X86_LOCAL_APIC */ =20 #ifdef CONFIG_SMP -bool apic_id_is_primary_thread(unsigned int id); void apic_smt_update(void); #else -static inline bool apic_id_is_primary_thread(unsigned int id) { return fal= se; } static inline void apic_smt_update(void) { } #endif =20 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -31,9 +31,9 @@ * CONFIG_NUMA. */ #include +#include =20 #ifdef CONFIG_NUMA -#include =20 #include #include @@ -139,9 +139,20 @@ static inline int topology_max_smt_threa int topology_update_package_map(unsigned int apicid, unsigned int cpu); int topology_update_die_map(unsigned int dieid, unsigned int cpu); int topology_phys_to_logical_pkg(unsigned int pkg); -bool topology_is_primary_thread(unsigned int cpu); bool topology_smt_supported(void); -#else + +extern struct cpumask __cpu_primary_thread_mask; +#define cpu_primary_thread_mask ((const struct cpumask *)&__cpu_primary_th= read_mask) + +/** + * topology_is_primary_thread - Check whether CPU is the primary SMT thread + * @cpu: CPU to check + */ +static inline bool topology_is_primary_thread(unsigned int cpu) +{ + return cpumask_test_cpu(cpu, cpu_primary_thread_mask); +} +#else /* CONFIG_SMP */ #define topology_max_packages() (1) static inline int topology_update_package_map(unsigned int apicid, unsigned int cpu) { retur= n 0; } @@ -152,7 +163,7 @@ static inline int topology_max_die_per_p static inline int topology_max_smt_threads(void) { return 1; } static inline bool topology_is_primary_thread(unsigned int cpu) { return t= rue; } static inline bool topology_smt_supported(void) { return false; } -#endif +#endif /* !CONFIG_SMP */ =20 static inline void arch_fix_phys_package_id(int num, u32 slot) { --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2387,20 +2387,16 @@ bool arch_match_cpu_phys_id(int cpu, u64 } =20 #ifdef CONFIG_SMP -/** - * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary = thread - * @apicid: APIC ID to check - */ -bool apic_id_is_primary_thread(unsigned int apicid) +static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { - u32 mask; - - if (smp_num_siblings =3D=3D 1) - return true; /* Isolate the SMT bit(s) in the APICID and check for 0 */ - mask =3D (1U << (fls(smp_num_siblings) - 1)) - 1; - return !(apicid & mask); + u32 mask =3D (1U << (fls(smp_num_siblings) - 1)) - 1; + + if (smp_num_siblings =3D=3D 1 || !(apicid & mask)) + cpumask_set_cpu(cpu, &__cpu_primary_thread_mask); } +#else +static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int = apicid) { } #endif =20 /* @@ -2545,6 +2541,8 @@ int generic_processor_info(int apicid, i set_cpu_present(cpu, true); num_processors++; =20 + cpu_mark_primary_thread(cpu, apicid); + return cpu; } =20 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -102,6 +102,9 @@ EXPORT_PER_CPU_SYMBOL(cpu_die_map); DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); =20 +/* CPUs which are the primary SMT threads */ +struct cpumask __cpu_primary_thread_mask __read_mostly; + /* Representing CPUs for which sibling maps can be computed */ static cpumask_var_t cpu_sibling_setup_mask; =20 @@ -294,15 +297,6 @@ static void notrace start_secondary(void } =20 /** - * topology_is_primary_thread - Check whether CPU is the primary SMT thread - * @cpu: CPU to check - */ -bool topology_is_primary_thread(unsigned int cpu) -{ - return apic_id_is_primary_thread(per_cpu(x86_cpu_to_apicid, cpu)); -} - -/** * topology_smt_supported - Check whether SMT is supported by the CPUs */ bool topology_smt_supported(void) From nobody Fri Nov 1 00:09:59 2024 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 EF5D7C77B72 for ; Fri, 14 Apr 2023 23:48:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231163AbjDNXsM (ORCPT ); Fri, 14 Apr 2023 19:48:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230469AbjDNXro (ORCPT ); Fri, 14 Apr 2023 19:47:44 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62B60C165; Fri, 14 Apr 2023 16:46:28 -0700 (PDT) Message-ID: <20230414232311.192114505@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515906; 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=OOycMYPFVi5YhixhBoVMbIx7KiHrtAXAV72ZpNnWZL8=; b=hJ/cJ/LsDaASOUqASLPPkSC6Ps6RxfdsA7gQYRBMpPaZEuge6FBpr2f6vVc+8HZFkB/rmb RJy5f49D9C3GZ5iAOC7Zko7KcGkJJr2aVQq4d0I8MHxwSrgTL3A0ePu6a/KfQsXuVA4Xbu ajazkAeZDlEyf5WTyO4+9yNz86aTWvAhKkL+wFnm59Pu29bb/grFar2EnhIA3IYkZTtEDm 0zbDi0Vg6WqjBsnDoMhcNfUK9CtbuR2h5QYljCFrrrsyKUW96SL8J44WHxTF6P75LRzQZI y5u0fp80f4IGejFZO38GlIfCPV4fIBaOEn1NXHQkG/2n87JafGV7laJAQBArhQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515906; 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=OOycMYPFVi5YhixhBoVMbIx7KiHrtAXAV72ZpNnWZL8=; b=3elqLNqpb58Nl0QV7Y5mpEmw+yXYy7Jx8aSLhWQ4/jwrJTvN020KSkN4jR6yL3KGS/kbNN oIimmB7TZWnYdBDQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 32/37] cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:05 +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" There is often significant latency in the early stages of CPU bringup, and time is wasted by waking each CPU (e.g. with SIPI/INIT/INIT on x86) and then waiting for it to respond before moving on to the next. Allow a platform to enable parallel setup which brings all to be onlined CPUs up to the CPUHP_BP_KICK_AP state. While this state advancement on the control CPU (BP) is single-threaded the important part is the last state CPUHP_BP_KICK_AP which wakes the to be onlined CPUs up. This allows the CPUs to run up to the first sychronization point cpuhp_ap_sync_alive() where they wait for the control CPU to release them one by one for the full onlining procedure. This parallelism depends on the CPU hotplug core sync mechanism which ensures that the parallel brought up CPUs wait for release before touching any state which would make the CPU visible to anything outside the hotplug control mechanism. To handle the SMT constraints of X86 correctly the bringup happens in two iterations when CONFIG_HOTPLUG_SMT is enabled. The control CPU brings up the primary SMT threads of each core first, which can load the microcode without the need to rendevouz with the thread siblings. Once that's completed it brings up the secondary SMT threads. Co-developed-by: David Woodhouse Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- Documentation/admin-guide/kernel-parameters.txt | 6 + arch/Kconfig | 4=20 include/linux/cpuhotplug.h | 1=20 kernel/cpu.c | 103 +++++++++++++++++++= +++-- 4 files changed, 109 insertions(+), 5 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -815,6 +815,12 @@ on every CPU online, such as boot, and resume from suspend. Default: 10000 =20 + cpuhp.parallel=3D + [SMP] Enable/disable parallel bringup of secondary CPUs + Format: + Default is enabled if CONFIG_HOTPLUG_PARALLEL=3Dy. Otherwise + the parameter has no effect. + crash_kexec_post_notifiers Run kdump after running panic-notifiers and dumping kmsg. This only for the users who doubt kdump always --- a/arch/Kconfig +++ b/arch/Kconfig @@ -53,6 +53,10 @@ config HOTPLUG_SPLIT_STARTUP bool select HOTPLUG_CORE_SYNC_FULL =20 +config HOTPLUG_PARALLEL + bool + select HOTPLUG_SPLIT_STARTUP + config GENERIC_ENTRY bool =20 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -526,6 +526,7 @@ void cpuhp_ap_sync_alive(void); void arch_cpuhp_sync_state_poll(void); void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu); int arch_cpuhp_kick_ap_alive(unsigned int cpu, struct task_struct *tidle); +bool arch_cpuhp_init_parallel_bringup(void); =20 #ifdef CONFIG_HOTPLUG_CORE_SYNC_DEAD void cpuhp_ap_report_dead(void); --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -649,8 +649,23 @@ bool cpu_smt_possible(void) cpu_smt_control !=3D CPU_SMT_NOT_SUPPORTED; } EXPORT_SYMBOL_GPL(cpu_smt_possible); + +static inline bool cpuhp_smt_aware(void) +{ + return topology_smt_supported(); +} + +static inline const struct cpumask *cpuhp_get_primary_thread_mask(void) +{ + return cpu_primary_thread_mask; +} #else static inline bool cpu_smt_allowed(unsigned int cpu) { return true; } +static inline bool cpuhp_smt_aware(void) { return false; } +static inline const struct cpumask *cpuhp_get_primary_thread_mask(void) +{ + return cpu_present_mask; +} #endif =20 static inline enum cpuhp_state @@ -1743,16 +1758,94 @@ int bringup_hibernate_cpu(unsigned int s return 0; } =20 -void __init bringup_nonboot_cpus(unsigned int setup_max_cpus) +static void __init cpuhp_bringup_mask(const struct cpumask *mask, unsigned= int ncpus, + enum cpuhp_state target) { unsigned int cpu; =20 - for_each_present_cpu(cpu) { - if (num_online_cpus() >=3D setup_max_cpus) + for_each_cpu(cpu, mask) { + struct cpuhp_cpu_state *st =3D per_cpu_ptr(&cpuhp_state, cpu); + + if (!--ncpus) break; - if (!cpu_online(cpu)) - cpu_up(cpu, CPUHP_ONLINE); + + if (cpu_up(cpu, target) && can_rollback_cpu(st)) { + /* + * If this failed then cpu_up() might have only + * rolled back to CPUHP_BP_KICK_AP for the final + * online. Clean it up. NOOP if already rolled back. + */ + WARN_ON(cpuhp_invoke_callback_range(false, cpu, st, CPUHP_OFFLINE)); + } + } +} + +#ifdef CONFIG_HOTPLUG_PARALLEL +static bool __cpuhp_parallel_bringup __ro_after_init =3D true; + +static int __init parallel_bringup_parse_param(char *arg) +{ + return kstrtobool(arg, &__cpuhp_parallel_bringup); +} +early_param("cpuhp.parallel", parallel_bringup_parse_param); + +/* + * On architectures which have enabled parallel bringup this invokes all BP + * prepare states for each of the to be onlined APs first. The last state + * sends the startup IPI to the APs. The APs proceed through the low level + * bringup code in parallel and then wait for the control CPU to release + * them one by one for the final onlining procedure. + * + * This avoids waiting for each AP to respond to the startup IPI in + * CPUHP_BRINGUP_CPU. + */ +static bool __init cpuhp_bringup_cpus_parallel(unsigned int ncpus) +{ + const struct cpumask *mask =3D cpu_present_mask; + + if (__cpuhp_parallel_bringup) + __cpuhp_parallel_bringup =3D arch_cpuhp_init_parallel_bringup(); + if (!__cpuhp_parallel_bringup) + return false; + + if (cpuhp_smt_aware()) { + const struct cpumask *pmask =3D cpuhp_get_primary_thread_mask(); + static struct cpumask tmp_mask __initdata; + + /* + * X86 requires to prevent that SMT siblings stopped while + * the primary thread does a microcode update for various + * reasons. Bring the primary threads up first. + */ + cpumask_and(&tmp_mask, mask, pmask); + cpuhp_bringup_mask(&tmp_mask, ncpus, CPUHP_BP_KICK_AP); + cpuhp_bringup_mask(&tmp_mask, ncpus, CPUHP_ONLINE); + /* Account for the online CPUs */ + ncpus -=3D num_online_cpus(); + if (!ncpus) + return true; + /* Create the mask for secondary CPUs */ + cpumask_andnot(&tmp_mask, mask, pmask); + mask =3D &tmp_mask; } + + /* Bring the not-yet started CPUs up */ + cpuhp_bringup_mask(mask, ncpus, CPUHP_BP_KICK_AP); + cpuhp_bringup_mask(mask, ncpus, CPUHP_ONLINE); + return true; +} +#else +static inline bool cpuhp_bringup_cpus_parallel(unsigned int ncpus) { retur= n false; } +#endif /* CONFIG_HOTPLUG_PARALLEL */ + +void __init bringup_nonboot_cpus(unsigned int setup_max_cpus) +{ + /* Try parallel bringup optimization if enabled */ + if (cpuhp_bringup_cpus_parallel(setup_max_cpus)) + return; + + /* Full per CPU serialized bringup */ + cpuhp_bringup_mask(cpu_present_mask, setup_max_cpus, CPUHP_ONLINE); } =20 #ifdef CONFIG_PM_SLEEP_SMP From nobody Fri Nov 1 00:09:59 2024 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 B3957C77B71 for ; Fri, 14 Apr 2023 23:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230390AbjDNXqs (ORCPT ); Fri, 14 Apr 2023 19:46:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230377AbjDNXqI (ORCPT ); Fri, 14 Apr 2023 19:46:08 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B0FFA5E6; Fri, 14 Apr 2023 16:45:25 -0700 (PDT) Message-ID: <20230414232311.254849089@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515907; 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=qlj4H3ejL+vBUDG3NY1lMMcGFIiTzrSNA2aqLKlihDE=; b=1GQ0vgasLWqRcJWgIXPbXDmKUvXohkJnXHYow4+Gk18ZVkMCsGTyrDjPv1CmK6RbyQU3xy sZOnCBi1gUZHMhyRrfBhTMtqyNFDPJ6vIKz6V9GUUqs40cNvVEv7vD+CBHvRT0wd1gUl1d 6b2tSiphU+RGH9LMrzC1SBAlXe4ncrHHHmvCSojPNfdfYrCZOS3cqdN5dvg1mrwkF+zHKS ZggDxsStwqH0PgeAnVkNUSmrn0NxE/MFHr8xTSF8rH/8cE10sWA0KKqw6/zjLrvWcuBEms WRc4LjINHUoNtUJjSQE1O0a6vHatkwkifR+Lal+9Qf7z5SXlNpUbZu7h4WPnRg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515907; 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=qlj4H3ejL+vBUDG3NY1lMMcGFIiTzrSNA2aqLKlihDE=; b=QX/aw2ZRTXXvpaXqpLyn2DL7d4KHZGqZGPQ3AUK084YoY4i+oS2d15EjnpvV8yHLp9Q5Sc 902bNwcd/YuBSyBA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 33/37] x86/topology: Store extended topology leaf information References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:07 +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" Save the extended topology leaf number if it exists and is valid in preparation of parallel CPU bringup. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/topology.h | 1 + arch/x86/kernel/cpu/topology.c | 3 +++ 2 files changed, 4 insertions(+) --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -121,6 +121,7 @@ extern unsigned int __max_die_per_packag #define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu)) #define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu)) =20 +extern unsigned int topology_extended_leaf; extern unsigned int __max_logical_packages; #define topology_max_packages() (__max_logical_packages) =20 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -29,6 +29,8 @@ unsigned int __max_die_per_package __rea EXPORT_SYMBOL(__max_die_per_package); =20 #ifdef CONFIG_SMP +unsigned int topology_extended_leaf __read_mostly; + /* * Check if given CPUID extended topology "leaf" is implemented */ @@ -72,6 +74,7 @@ int detect_extended_topology_early(struc if (leaf < 0) return -1; =20 + topology_extended_leaf =3D leaf; set_cpu_cap(c, X86_FEATURE_XTOPOLOGY); =20 cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx); From nobody Fri Nov 1 00:09:59 2024 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 54CA6C77B71 for ; Fri, 14 Apr 2023 23:48:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231176AbjDNXse (ORCPT ); Fri, 14 Apr 2023 19:48:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230392AbjDNXsK (ORCPT ); Fri, 14 Apr 2023 19:48:10 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61211A249; Fri, 14 Apr 2023 16:46:55 -0700 (PDT) Message-ID: <20230414232311.316352541@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515909; 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=2PTnDdSuwes/9NjD8Pm7hXlACOxFTN9vJCNjWOfgGXM=; b=Jh6ZM0Us9GGh285BMnb5fEm77rslh++J6j/QuRkHBnu0IJ3u2WPmnGe/3gdgkhs+Itn6YC EYm2JHM+HCoiKXud+mnLR3pzE3sn62xS6OTtxoSRYTybybUo7HLhqrcnKqV1RwxPAi5wc5 OBp150tG8AHyoMw6+86zMyjFChURpnILiUkhTuUlpHCRtOIbCa3VMT62a8kcqkB8R+gKQ4 U9tfXpB5IVu1MhpvFCVN68arP6yea+vniJ2RVD3n3fNQwQKszlDZIcpnpbeZf4M7nBLa8W ZFeGomntJTFI5LAn96fL2tniH8jRiNy2rM7ZxO27HO46gpoe/qq365pH/j/4pA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515909; 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=2PTnDdSuwes/9NjD8Pm7hXlACOxFTN9vJCNjWOfgGXM=; b=JDEmTRQRnlWI2RxVIaPHzb6Y3x+BSeHE+/1j/fasD5aAeXT8ZfKeZ96xHuB6wXG5qxyGWZ eqmeypWBVFC7DyAA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 34/37] x86/cpu/amd; Invoke detect_extended_topology_early() on boot CPU References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:08 +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" The early detection stores the extended topology leaf number which is required for parallel hotplug. Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/kernel/cpu/amd.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -692,6 +692,8 @@ static void early_init_amd(struct cpuinf } } =20 + detect_extended_topology_early(c); + if (cpu_has(c, X86_FEATURE_TOPOEXT)) smp_num_siblings =3D ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1; } From nobody Fri Nov 1 00:09:59 2024 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 6D2FBC77B7C for ; Fri, 14 Apr 2023 23:47:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230509AbjDNXrD (ORCPT ); Fri, 14 Apr 2023 19:47:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230466AbjDNXqd (ORCPT ); Fri, 14 Apr 2023 19:46:33 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85A4B975E; Fri, 14 Apr 2023 16:45:36 -0700 (PDT) Message-ID: <20230414232311.379210081@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515911; 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=30gAYfFq7D/rpiAsDZ0VJ8Kl0fjNcwxtQrZfJqj5x1Q=; b=slTd10Pp/4TGmD/zlEb43Gb2WKRTlAppsSoSOu/T/E5JWpZy7hpKytp5/flV3pXvlf98mG aFkvnauiXOzF9rU2jFxo9JDlLYJmNHG16yPTZ65k9zIeEDhe+RYXJnZZEJKz1jMvqGBqWY BrJbQ+/W6kvjZFEcMJnDOmBoB+wtMm7S1uu0QlhCDKdWnqg0/vW+4HXD1l1CY7ixM7tgU3 5PYqnW+jK7Z+hTrrlILf1oeW7ukViva1urpMPLhbmq0i0D+n8MofDLQxKVm+wNnRvv0a2W OS0dI9HKv3OCVLtAiJE196l54a2e8MLBX7ZcLL6pY36gkjwA0CwNz7FRv3fQXg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515911; 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=30gAYfFq7D/rpiAsDZ0VJ8Kl0fjNcwxtQrZfJqj5x1Q=; b=fpHp/7lpP4jb7NBZQJ1STRnv+01MPSKMiVut7RE9SWvxHshH6nA9x03/g2I1cMS+hCTLAP Z5dLyPS0dXp2guCA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 35/37] x86/smpboot: Support parallel startup of secondary CPUs References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:10 +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" From: David Woodhouse Rework the real-mode startup code to allow for APs to be brought up in parallel. This is in two parts: 1. Introduce a bit-spinlock to prevent them from all using the real mode stack at the same time. 2. Avoid needing to use the global smpboot_control variable to pass each AP its CPU number. To achieve the latter, export the cpuid_to_apicid[] array so that each AP can find its own CPU number by searching therein based on its APIC ID. Introduce flags in the top bits of smpboot_control which indicate methods by which an AP should find its CPU number. For a serialized bringup, the CPU number is explicitly passed in the low bits of smpboot_control as before. For parallel mode there are flags directing the AP to find its APIC ID in CPUID leaf 0x0b or 1x1f (for X2APIC mode) or CPUID leaf 0x01 where 8 bits are sufficient, then perform the cpuid_to_apicid[] lookup with that. Aside from the fact that APs will now look up their CPU number via the newly-exported cpuid_to_apicid[] table, there is no behavioural change intended, since the parallel bootup has not yet been enabled. [ tglx: Initial proof of concept patch with bitlock and APIC ID lookup ] [ dwmw2: Rework and testing, commit message, CPUID 0x1 and CPU0 support ] [ seanc: Fix stray override of initial_gs in common_cpu_up() ] [ Oleksandr Natalenko: reported suspend/resume issue fixed in x86_acpi_suspend_lowlevel ] Co-developed-by: Thomas Gleixner Signed-off-by: Thomas Gleixner Co-developed-by: Brian Gerst Signed-off-by: Brian Gerst Signed-off-by: David Woodhouse Signed-off-by: Usama Arif Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/apic.h | 2=20 arch/x86/include/asm/realmode.h | 3 + arch/x86/include/asm/smp.h | 8 +++ arch/x86/kernel/acpi/sleep.c | 9 +++ arch/x86/kernel/apic/apic.c | 2=20 arch/x86/kernel/head_64.S | 79 ++++++++++++++++++++++++++++++= ++++- arch/x86/kernel/smpboot.c | 5 -- arch/x86/realmode/init.c | 3 + arch/x86/realmode/rm/trampoline_64.S | 27 +++++++++-- 9 files changed, 125 insertions(+), 13 deletions(-) --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -55,6 +55,8 @@ extern int local_apic_timer_c2_ok; extern int disable_apic; extern unsigned int lapic_timer_period; =20 +extern int cpuid_to_apicid[]; + extern enum apic_intr_mode_id apic_intr_mode; enum apic_intr_mode_id { APIC_PIC, --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -52,6 +52,7 @@ struct trampoline_header { u64 efer; u32 cr4; u32 flags; + u32 lock; #endif }; =20 @@ -64,6 +65,8 @@ extern unsigned long initial_stack; extern unsigned long initial_vc_handler; #endif =20 +extern u32 *trampoline_lock; + extern unsigned char real_mode_blob[]; extern unsigned char real_mode_relocs[]; =20 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -198,4 +198,12 @@ extern unsigned int smpboot_control; =20 #endif /* !__ASSEMBLY__ */ =20 +/* Control bits for startup_64 */ +#define STARTUP_APICID_CPUID_1F 0x80000000 +#define STARTUP_APICID_CPUID_0B 0x40000000 +#define STARTUP_APICID_CPUID_01 0x20000000 + +/* Top 8 bits are reserved for control */ +#define STARTUP_PARALLEL_MASK 0xFF000000 + #endif /* _ASM_X86_SMP_H */ --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -16,6 +16,7 @@ #include #include #include +#include =20 #include #include "../../realmode/rm/wakeup.h" @@ -127,7 +128,13 @@ int x86_acpi_suspend_lowlevel(void) * value is in the actual %rsp register. */ current->thread.sp =3D (unsigned long)temp_stack + sizeof(temp_stack); - smpboot_control =3D smp_processor_id(); + /* + * Ensure the CPU knows which one it is when it comes back, if + * it isn't in parallel mode and expected to work that out for + * itself. + */ + if (!(smpboot_control & STARTUP_PARALLEL_MASK)) + smpboot_control =3D smp_processor_id(); #endif initial_code =3D (unsigned long)wakeup_long64; saved_magic =3D 0x123456789abcdef0L; --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2377,7 +2377,7 @@ static int nr_logical_cpuids =3D 1; /* * Used to store mapping between logical CPU IDs and APIC IDs. */ -static int cpuid_to_apicid[] =3D { +int cpuid_to_apicid[] =3D { [0 ... NR_CPUS - 1] =3D -1, }; =20 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -25,6 +25,7 @@ #include #include #include +#include =20 /* * We are not able to switch in one step to the final KERNEL ADDRESS SPACE @@ -234,8 +235,70 @@ SYM_INNER_LABEL(secondary_startup_64_no_ ANNOTATE_NOENDBR // above =20 #ifdef CONFIG_SMP + /* + * For parallel boot, the APIC ID is retrieved from CPUID, and then + * used to look up the CPU number. For booting a single CPU, the + * CPU number is encoded in smpboot_control. + * + * Bit 31 STARTUP_APICID_CPUID_1F flag (use CPUID 0x1f) + * Bit 30 STARTUP_APICID_CPUID_0B flag (use CPUID 0x0b) + * Bit 29 STARTUP_APICID_CPUID_01 flag (use CPUID 0x01) + * Bit 0-23 CPU# if STARTUP_APICID_CPUID_xx flags are not set + */ movl smpboot_control(%rip), %ecx + testl $STARTUP_APICID_CPUID_1F, %ecx + jnz .Luse_cpuid_1f + testl $STARTUP_APICID_CPUID_0B, %ecx + jnz .Luse_cpuid_0b + testl $STARTUP_APICID_CPUID_01, %ecx + jnz .Luse_cpuid_01 + andl $(~STARTUP_PARALLEL_MASK), %ecx + jmp .Lsetup_cpu + +.Luse_cpuid_01: + mov $0x01, %eax + cpuid + mov %ebx, %edx + shr $24, %edx + jmp .Lsetup_AP + +.Luse_cpuid_0b: + mov $0x0B, %eax + xorl %ecx, %ecx + cpuid + jmp .Lsetup_AP + +.Luse_cpuid_1f: + mov $0x1f, %eax + xorl %ecx, %ecx + cpuid =20 +.Lsetup_AP: + /* EDX contains the APIC ID of the current CPU */ + xorq %rcx, %rcx + leaq cpuid_to_apicid(%rip), %rbx + +.Lfind_cpunr: + cmpl (%rbx,%rcx,4), %edx + jz .Lsetup_cpu + inc %ecx +#ifdef CONFIG_FORCE_NR_CPUS + cmpl $NR_CPUS, %ecx +#else + cmpl nr_cpu_ids(%rip), %ecx +#endif + jb .Lfind_cpunr + + /* APIC ID not found in the table. Drop the trampoline lock and bail. */ + movq trampoline_lock(%rip), %rax + lock + btrl $0, (%rax) + +1: cli + hlt + jmp 1b + +.Lsetup_cpu: /* Get the per cpu offset for the given CPU# which is in ECX */ movq __per_cpu_offset(,%rcx,8), %rdx #else @@ -248,10 +311,20 @@ SYM_INNER_LABEL(secondary_startup_64_no_ * * RDX contains the per-cpu offset */ - movq pcpu_hot + X86_current_task(%rdx), %rax - movq TASK_threadsp(%rax), %rsp + movq pcpu_hot + X86_top_of_stack(%rdx), %rsp =20 /* + * Now that this CPU is running on its own stack, drop the realmode + * protection. For the boot CPU the pointer is NULL! + */ + movq trampoline_lock(%rip), %rax + testq %rax, %rax + jz .Lsetup_gdt + lock + btrl $0, (%rax) + +.Lsetup_gdt: + /* * We must switch to a new descriptor in kernel space for the GDT * because soon the kernel won't have access anymore to the userspace * addresses where we're currently running on. We have to do that here @@ -435,6 +508,8 @@ SYM_DATA(initial_code, .quad x86_64_star #ifdef CONFIG_AMD_MEM_ENCRYPT SYM_DATA(initial_vc_handler, .quad handle_vc_boot_ghcb) #endif + +SYM_DATA(trampoline_lock, .quad 0); __FINITDATA =20 __INIT --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -985,10 +985,7 @@ int common_cpu_up(unsigned int cpu, stru if (ret) return ret; =20 -#ifdef CONFIG_X86_32 - /* Stack for startup_32 can be just as for start_secondary onwards */ per_cpu(pcpu_hot.top_of_stack, cpu) =3D task_top_of_stack(idle); -#endif return 0; } =20 @@ -1014,7 +1011,7 @@ static int do_boot_cpu(int apicid, int c if (IS_ENABLED(CONFIG_X86_32)) { early_gdt_descr.address =3D (unsigned long)get_cpu_gdt_rw(cpu); initial_stack =3D idle->thread.sp; - } else { + } else if (!(smpboot_control & STARTUP_PARALLEL_MASK)) { smpboot_control =3D cpu; } =20 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -154,6 +154,9 @@ static void __init setup_real_mode(void) =20 trampoline_header->flags =3D 0; =20 + trampoline_lock =3D &trampoline_header->lock; + *trampoline_lock =3D 0; + trampoline_pgd =3D (u64 *) __va(real_mode_header->trampoline_pgd); =20 /* Map the real mode stub as virtual =3D=3D physical */ --- a/arch/x86/realmode/rm/trampoline_64.S +++ b/arch/x86/realmode/rm/trampoline_64.S @@ -37,6 +37,24 @@ .text .code16 =20 +.macro LOAD_REALMODE_ESP + /* + * Make sure only one CPU fiddles with the realmode stack + */ +.Llock_rm\@: + btl $0, tr_lock + jnc 2f + pause + jmp .Llock_rm\@ +2: + lock + btsl $0, tr_lock + jc .Llock_rm\@ + + # Setup stack + movl $rm_stack_end, %esp +.endm + .balign PAGE_SIZE SYM_CODE_START(trampoline_start) cli # We should be safe anyway @@ -49,8 +67,7 @@ SYM_CODE_START(trampoline_start) mov %ax, %es mov %ax, %ss =20 - # Setup stack - movl $rm_stack_end, %esp + LOAD_REALMODE_ESP =20 call verify_cpu # Verify the cpu supports long mode testl %eax, %eax # Check for return code @@ -93,8 +110,7 @@ SYM_CODE_START(sev_es_trampoline_start) mov %ax, %es mov %ax, %ss =20 - # Setup stack - movl $rm_stack_end, %esp + LOAD_REALMODE_ESP =20 jmp .Lswitch_to_protected SYM_CODE_END(sev_es_trampoline_start) @@ -177,7 +193,7 @@ SYM_CODE_START(pa_trampoline_compat) * In compatibility mode. Prep ESP and DX for startup_32, then disable * paging and complete the switch to legacy 32-bit mode. */ - movl $rm_stack_end, %esp + LOAD_REALMODE_ESP movw $__KERNEL_DS, %dx =20 movl $(CR0_STATE & ~X86_CR0_PG), %eax @@ -241,6 +257,7 @@ SYM_DATA_START(trampoline_header) SYM_DATA(tr_efer, .space 8) SYM_DATA(tr_cr4, .space 4) SYM_DATA(tr_flags, .space 4) + SYM_DATA(tr_lock, .space 4) SYM_DATA_END(trampoline_header) =20 #include "trampoline_common.S" From nobody Fri Nov 1 00:09:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=linutronix.de ARC-Seal: i=1; a=rsa-sha256; t=1681516159; cv=none; d=zohomail.com; s=zohoarc; b=bmrOePuygLv754FLvZfe42xHcfCcQgnJNacEUkgKL9F1bJX8HBPn4TYjuHkEcPtZeP0/AkeI4HoUBfMFC/tTwyZUrIr/GOX9SOsCWQd5erwEiFi55bBF5FaWQlF+KFqmtjrNgCurzW6TUeXXaHW5SAJBmgzWAz4o/ei0T0JYa8g= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1681516159; h=Content-Type:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=6cGHgynMBCaHRwYTrISGgGUY8IfBttwd4gSW6/8ncwo=; b=aEA8/JQrG8L07/RTPlhQEXOu66DvZ4OsGxZDq4BMTpBEZ0XVxB6uxLNzeuwePIeaU27orIyFWcWJ9K6C2EObayqFAPhJAJGyUIY6hCD1dC0mZHZnaKGbexe1PKxndinwWs77PPS62C3BQWd1mIZSEKFl59J1LgVMFe/P4N0DX2k= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1681516159342838.4808385276208; Fri, 14 Apr 2023 16:49:19 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.521288.809905 (Exim 4.92) (envelope-from ) id 1pnTA1-0002kx-NL; Fri, 14 Apr 2023 23:48:57 +0000 Received: by outflank-mailman (output) from mailman id 521288.809905; Fri, 14 Apr 2023 23:48:57 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnTA1-0002kq-KZ; Fri, 14 Apr 2023 23:48:57 +0000 Received: by outflank-mailman (input) for mailman id 521288; Fri, 14 Apr 2023 23:48:57 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pnT6Q-0000zb-Oh for xen-devel@lists.xenproject.org; Fri, 14 Apr 2023 23:45:14 +0000 Received: from galois.linutronix.de (galois.linutronix.de [193.142.43.55]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 6639473e-db1e-11ed-8611-37d641c3527e; Sat, 15 Apr 2023 01:45:13 +0200 (CEST) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 6639473e-db1e-11ed-8611-37d641c3527e Message-ID: <20230414232311.441918776@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515912; 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=6cGHgynMBCaHRwYTrISGgGUY8IfBttwd4gSW6/8ncwo=; b=Y6MvVoIRD+b308pDJWowuLkJP8xTk8BgVllbAchtET5SCLxH3pPaTbpOYvBSvJgt29AjQn ezcDEAwpvw4go5HJCn0jDdZCGPT9MLW24qpZKb8kz2KJNNnr6JcyXOPyaUGlM/ANv9N+fq tuEJRuRxzNty3GrkhGsgHYpRhP/0DX3AEiMTFdAHD/hkrve/Z/OGirQHyoZehUi+ZLj2of nh0+zW/XB9E47Zv4MWfj7UgDu31M48dyxxMexXPIhf0Fh2Xfz56PypK/Z4RNZ1QuLpDfkl MzM4X40h1quxb59BK38sroOGy3J6fRyyYS1Nn/XWNH7x+1QZ0XFumeRWVGSB2A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515912; 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=6cGHgynMBCaHRwYTrISGgGUY8IfBttwd4gSW6/8ncwo=; b=62z6QxHlYDjrTs4WKqbuHCfVc8G+x+AUIAn0i55mZeGFgkDCFd3an/Sr2oboSn6ZUcOcEh Lf1/KZWBw97ffRDQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland , Sabin Rapan Subject: [patch 36/37] x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:12 +0200 (CEST) X-ZohoMail-DKIM: pass (identity @linutronix.de) X-ZM-MESSAGEID: 1681516159941100001 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Implement the validation function which tells the core code whether parallel bringup is possible: 1) Valid CPUID leaf for APIC ID retrieval. For non x2APIC systmms leaf 0x1 is sufficient, otherwise leaf 0xb or 0x1f must be available. 2) Prevent parallel bringup on encrypted guests as this requires a different handling of the CPUID leaf retrieval via a call into the trusted firmware module. This is what the #VC trap handler does later on, which is not available during the very early startup. Originally-by: David Woodhouse Signed-off-by: Thomas Gleixner Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/Kconfig | 3 +- arch/x86/kernel/cpu/common.c | 6 ----- arch/x86/kernel/smpboot.c | 49 ++++++++++++++++++++++++++++++++++++++= +++-- 3 files changed, 50 insertions(+), 8 deletions(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -272,8 +272,9 @@ config X86 select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER select HAVE_GENERIC_VDSO + select HOTPLUG_PARALLEL if SMP && X86_64 select HOTPLUG_SMT if SMP - select HOTPLUG_SPLIT_STARTUP if SMP + select HOTPLUG_SPLIT_STARTUP if SMP && X86_32 select IRQ_FORCED_THREADING select NEED_PER_CPU_EMBED_FIRST_CHUNK select NEED_PER_CPU_PAGE_FIRST_CHUNK --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2127,11 +2127,7 @@ static inline void setup_getcpu(int cpu) } =20 #ifdef CONFIG_X86_64 -static inline void ucode_cpu_init(int cpu) -{ - if (cpu) - load_ucode_ap(); -} +static inline void ucode_cpu_init(int cpu) { } =20 static inline void tss_setup_ist(struct tss_struct *tss) { --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -58,6 +58,7 @@ #include #include #include +#include =20 #include #include @@ -75,7 +76,7 @@ #include #include #include -#include +#include #include #include #include @@ -128,7 +129,6 @@ int arch_update_cpu_topology(void) return retval; } =20 - static unsigned int smpboot_warm_reset_vector_count; =20 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip) @@ -247,6 +247,8 @@ static void notrace start_secondary(void #endif cpu_init_exception_handling(); =20 + load_ucode_ap(); + /* * Sync point with the hotplug core. Sets the sync state to ALIVE * and waits for the control CPU to release it. @@ -1251,6 +1253,49 @@ void __init smp_prepare_cpus_common(void set_cpu_sibling_map(0); } =20 +#ifdef CONFIG_X86_64 +/* Establish whether parallel bringup can be supported. */ +bool __init arch_cpuhp_init_parallel_bringup(void) +{ + unsigned int ctrl; + + if (boot_cpu_data.cpuid_level < 0x01) { + pr_info("Parallel CPU startup disabled due to lack of CPUID\n"); + return false; + } + + /* Encrypted guests require special CPUID handling. */ + if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) { + pr_info("Parallel CPU startup disabled due to guest state encryption\n"); + return false; + } + + switch (topology_extended_leaf) { + case 0x0b: + ctrl =3D STARTUP_APICID_CPUID_0B; + break; + case 0x1f: + ctrl =3D STARTUP_APICID_CPUID_1F; + break; + case 0x00: + /* For !x2APIC mode 8 bits from leaf 0x01 are sufficient. */ + if (!x2apic_mode) { + ctrl =3D STARTUP_APICID_CPUID_01; + break; + } + fallthrough; + default: + pr_info("Parallel CPU startup disabled. Unsupported topology leaf %u\n", + topology_extended_leaf); + return false; + } + + pr_debug("Parallel CPU startup enabled: 0x%08x\n", ctrl); + smpboot_control =3D ctrl; + return true; +} +#endif + /* * Prepare for SMP bootup. * @max_cpus: configured maximum number of CPUs, It is a legacy parameter From nobody Fri Nov 1 00:09:59 2024 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 5F301C77B77 for ; Fri, 14 Apr 2023 23:47:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230440AbjDNXrZ (ORCPT ); Fri, 14 Apr 2023 19:47:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230413AbjDNXq4 (ORCPT ); Fri, 14 Apr 2023 19:46:56 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2932EBB96; Fri, 14 Apr 2023 16:45:53 -0700 (PDT) Message-ID: <20230414232311.505152290@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1681515914; 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=nUZSh5064m2aKoxr+KQn5JPMu6mMKtsaGAC9NSZVNms=; b=tXdZ+JNXwmoFAj/D4wiLzLK3B9Tdjf372IqdJt5Tv46gv42xMEL/Nl0g5kdyiZHT7x9AOz mlFylzsIhnrXORGzmbDeoOd0v4PWWxn8r5JfaFvKB5y4Myd0UBCMyCyRl33Zi088uSB2Ir SvONUInWoGIX09mANT0wqHnMa8plhV/+A02oVVT5ueBVnLW3psXBgZVX1wGuoSRuwDa/iV WCxZeGiReQ8KfEt87/havCjKqbuogL4jZdqFqdulIebLR5I3xNrYIQ3tyIgS/ypjvwLm3u ZY0rsKukGMk7diouGwNhACQ22cLpXT7hOtDVbk+HLvlFHbrtTgmHuHYua/2ZDA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1681515914; 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=nUZSh5064m2aKoxr+KQn5JPMu6mMKtsaGAC9NSZVNms=; b=pkIQhDhWjPpGLy6aH5XoCk5G1NoyA94urqDixfl4xi4JgoGh52mUmdlWbRdLMez3lvqnCR cNwc4JXhAqWj08Aw== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, David Woodhouse , Andrew Cooper , Brian Gerst , "Arjan van de Veen" , Paolo Bonzini , Paul McKenney , Tom Lendacky , Sean Christopherson , Oleksandr Natalenko , Paul Menzel , "Guilherme G. Piccoli" , Piotr Gorski , Sabin Rapan , David Woodhouse , Usama Arif , Juergen Gross , Boris Ostrovsky , xen-devel@lists.xenproject.org, Russell King , Arnd Bergmann , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Guo Ren , linux-csky@vger.kernel.org, Thomas Bogendoerfer , linux-mips@vger.kernel.org, "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Mark Rutland Subject: [patch 37/37] x86/smpboot: Allow parallel bringup for SEV-ES References: <20230414225551.858160935@linutronix.de> MIME-Version: 1.0 Date: Sat, 15 Apr 2023 01:45:13 +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" From: David Woodhouse Enable parallel bringup for SEV-ES guests. The APs can't actually execute the CPUID instruction directly during early startup, but they can make the GHCB call directly instead, just as the #VC trap handler would do. Thanks to Sabin for talking me through the way this works. Suggested-by: Sabin Rapan Signed-off-by: David Woodhouse Signed-off-by: Usama Arif Signed-off-by: Thomas Gleixner Reviewed-by: Tom Lendacky Tested-by: Juergen Gross Tested-by: Michael Kelley --- arch/x86/include/asm/sev-common.h | 3 +++ arch/x86/include/asm/smp.h | 1 + arch/x86/kernel/head_64.S | 30 ++++++++++++++++++++++++++++++ arch/x86/kernel/smpboot.c | 14 ++++++++++++-- 4 files changed, 46 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/sev-common.h +++ b/arch/x86/include/asm/sev-common.h @@ -70,6 +70,7 @@ /* GHCBData[63:12] */ \ (((u64)(v) & GENMASK_ULL(63, 12)) >> 12) =20 +#ifndef __ASSEMBLY__ /* * SNP Page State Change Operation * @@ -161,6 +162,8 @@ struct snp_psc_desc { =20 #define GHCB_RESP_CODE(v) ((v) & GHCB_MSR_INFO_MASK) =20 +#endif /* __ASSEMBLY__ */ + /* * Error codes related to GHCB input that can be communicated back to the = guest * by setting the lower 32-bits of the GHCB SW_EXITINFO1 field to 2. --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -202,6 +202,7 @@ extern unsigned int smpboot_control; #define STARTUP_APICID_CPUID_1F 0x80000000 #define STARTUP_APICID_CPUID_0B 0x40000000 #define STARTUP_APICID_CPUID_01 0x20000000 +#define STARTUP_APICID_SEV_ES 0x10000000 =20 /* Top 8 bits are reserved for control */ #define STARTUP_PARALLEL_MASK 0xFF000000 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -26,6 +26,7 @@ #include #include #include +#include =20 /* * We are not able to switch in one step to the final KERNEL ADDRESS SPACE @@ -243,9 +244,14 @@ SYM_INNER_LABEL(secondary_startup_64_no_ * Bit 31 STARTUP_APICID_CPUID_1F flag (use CPUID 0x1f) * Bit 30 STARTUP_APICID_CPUID_0B flag (use CPUID 0x0b) * Bit 29 STARTUP_APICID_CPUID_01 flag (use CPUID 0x01) + * Bit 28 STARTUP_APICID_SEV_ES flag (CPUID 0x0b via GHCB MSR) * Bit 0-23 CPU# if STARTUP_APICID_CPUID_xx flags are not set */ movl smpboot_control(%rip), %ecx +#ifdef CONFIG_AMD_MEM_ENCRYPT + testl $STARTUP_APICID_SEV_ES, %ecx + jnz .Luse_sev_cpuid_0b +#endif testl $STARTUP_APICID_CPUID_1F, %ecx jnz .Luse_cpuid_1f testl $STARTUP_APICID_CPUID_0B, %ecx @@ -262,6 +268,30 @@ SYM_INNER_LABEL(secondary_startup_64_no_ shr $24, %edx jmp .Lsetup_AP =20 +#ifdef CONFIG_AMD_MEM_ENCRYPT +.Luse_sev_cpuid_0b: + /* Set the GHCB MSR to request CPUID 0x0B_EDX */ + movl $MSR_AMD64_SEV_ES_GHCB, %ecx + movl $(GHCB_CPUID_REQ_EDX << 30) | GHCB_MSR_CPUID_REQ, %eax + movl $0x0b, %edx + wrmsr + + /* Perform GHCB MSR protocol */ + rep; vmmcall /* vmgexit */ + + /* + * Get the result. After the RDMSR: + * EAX should be 0xc0000005 + * EDX should have the CPUID register value and since EDX + * is the target register, no need to move the result. + */ + rdmsr + andl $GHCB_MSR_INFO_MASK, %eax + cmpl $GHCB_MSR_CPUID_RESP, %eax + jne 1f + jmp .Lsetup_AP +#endif + .Luse_cpuid_0b: mov $0x0B, %eax xorl %ecx, %ecx --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -86,6 +86,7 @@ #include #include #include +#include =20 /* representing HT siblings of each logical CPU */ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map); @@ -1266,8 +1267,16 @@ bool __init arch_cpuhp_init_parallel_bri =20 /* Encrypted guests require special CPUID handling. */ if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) { - pr_info("Parallel CPU startup disabled due to guest state encryption\n"); - return false; + switch (cc_get_vendor()) { + case CC_VENDOR_AMD: + ctrl =3D STARTUP_APICID_SEV_ES; + if (topology_extended_leaf =3D=3D 0x0b) + goto setup; + fallthrough; + default: + pr_info("Parallel CPU startup disabled due to guest state encryption\n"= ); + return false; + } } =20 switch (topology_extended_leaf) { @@ -1290,6 +1299,7 @@ bool __init arch_cpuhp_init_parallel_bri return false; } =20 +setup: pr_debug("Parallel CPU startup enabled: 0x%08x\n", ctrl); smpboot_control =3D ctrl; return true;