From nobody Thu Apr 9 04:41:32 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2A69C433FE for ; Wed, 2 Nov 2022 07:49:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231127AbiKBHtI (ORCPT ); Wed, 2 Nov 2022 03:49:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230502AbiKBHsi (ORCPT ); Wed, 2 Nov 2022 03:48:38 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6CB2D275E7 for ; Wed, 2 Nov 2022 00:48:36 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 236111F8D0; Wed, 2 Nov 2022 07:48:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1667375315; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8mPWpLwJy7yzhex6eU7j5tLklymwcAzwe+PPdkowDuM=; b=jK+xtRHuGxgvIkpvOFSz7r4XQb0A4BZmX2KszjLMCulWag7FTQL5eJPNj8vloNmCtmUGAR VD6ozlxoai+mtixWWex89re4ODBn3w+t6Si82LwdfzTxwfv9MLOyQuOKiL0IJmCbI0saFh neFoGFASCrsQr0TiitJCiVMjDmtHjd8= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id CDD681376E; Wed, 2 Nov 2022 07:48:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id VZ/XMNIgYmNIcwAAMHmgww (envelope-from ); Wed, 02 Nov 2022 07:48:34 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Juergen Gross , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Subject: [PATCH v5 14/16] x86: switch cache_ap_init() to hotplug callback Date: Wed, 2 Nov 2022 08:47:11 +0100 Message-Id: <20221102074713.21493-15-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20221102074713.21493-1-jgross@suse.com> References: <20221102074713.21493-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Instead of explicitly calling cache_ap_init() in identify_secondary_cpu() use a CPU hotplug callback instead. By registering the callback only after having started the non-boot CPUs and initializing cache_aps_delayed_init with "true", calling set_cache_aps_delayed_init() at boot time can be dropped. It should be noted that this change results in cache_ap_init() being called a little bit later when hotplugging CPUs. By using a new hotplug slot right at the start of the low level bringup this is not problematic, as no operations requiring a specific caching mode are performed that early in CPU initialization. Suggested-by: Borislav Petkov Signed-off-by: Juergen Gross --- V4: - new patch --- arch/x86/include/asm/cacheinfo.h | 1 - arch/x86/kernel/cpu/cacheinfo.c | 18 +++++++++++++++--- arch/x86/kernel/cpu/common.c | 1 - arch/x86/kernel/smpboot.c | 2 -- include/linux/cpuhotplug.h | 1 + 5 files changed, 16 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/cacheinfo.h b/arch/x86/include/asm/cachei= nfo.h index a0ef46e9f453..ce9685fc78d8 100644 --- a/arch/x86/include/asm/cacheinfo.h +++ b/arch/x86/include/asm/cacheinfo.h @@ -16,7 +16,6 @@ void set_cache_aps_delayed_init(bool val); bool get_cache_aps_delayed_init(void); void cache_bp_init(void); void cache_bp_restore(void); -void cache_ap_init(void); void cache_aps_init(void); =20 #endif /* _ASM_X86_CACHEINFO_H */ diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinf= o.c index 1aaf830254df..231cf1ff0641 100644 --- a/arch/x86/kernel/cpu/cacheinfo.c +++ b/arch/x86/kernel/cpu/cacheinfo.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -1139,7 +1140,7 @@ static void cache_cpu_init(void) local_irq_restore(flags); } =20 -static bool cache_aps_delayed_init; +static bool cache_aps_delayed_init =3D true; =20 void set_cache_aps_delayed_init(bool val) { @@ -1174,10 +1175,10 @@ void cache_bp_restore(void) cache_cpu_init(); } =20 -void cache_ap_init(void) +static int cache_ap_init(unsigned int cpu) { if (!memory_caching_control || get_cache_aps_delayed_init()) - return; + return 0; =20 /* * Ideally we should hold mtrr_mutex here to avoid MTRR entries @@ -1194,6 +1195,8 @@ void cache_ap_init(void) */ stop_machine_from_inactive_cpu(cache_rendezvous_handler, NULL, cpu_callout_mask); + + return 0; } =20 /* @@ -1207,3 +1210,12 @@ void cache_aps_init(void) stop_machine(cache_rendezvous_handler, NULL, cpu_online_mask); set_cache_aps_delayed_init(false); } + +static int __init cache_ap_register(void) +{ + cpuhp_setup_state_nocalls(CPUHP_AP_CACHECTRL_STARTING, + "x86/cachectrl:starting", + cache_ap_init, NULL); + return 0; +} +core_initcall(cache_ap_register); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index fd058b547f8d..bf4ac1cb93d7 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1949,7 +1949,6 @@ void identify_secondary_cpu(struct cpuinfo_x86 *c) #ifdef CONFIG_X86_32 enable_sep_cpu(); #endif - cache_ap_init(); validate_apic_and_package_id(c); x86_spec_ctrl_setup_ap(); update_srbds_msr(); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 1b61a480c966..82b311c718bc 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1429,8 +1429,6 @@ void __init native_smp_prepare_cpus(unsigned int max_= cpus) =20 uv_system_init(); =20 - set_cache_aps_delayed_init(true); - smp_quirk_init_udelay(); =20 speculative_store_bypass_ht_init(); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index f61447913db9..0d277b4b025a 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -140,6 +140,7 @@ enum cpuhp_state { */ CPUHP_AP_IDLE_DEAD, CPUHP_AP_OFFLINE, + CPUHP_AP_CACHECTRL_STARTING, CPUHP_AP_SCHED_STARTING, CPUHP_AP_RCUTREE_DYING, CPUHP_AP_CPU_PM_STARTING, --=20 2.35.3