From nobody Mon Feb 9 05:58:27 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 B6F50C001DE for ; Thu, 10 Aug 2023 18:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235899AbjHJSjZ (ORCPT ); Thu, 10 Aug 2023 14:39:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235627AbjHJSi7 (ORCPT ); Thu, 10 Aug 2023 14:38:59 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECBBE3A99 for ; Thu, 10 Aug 2023 11:38:24 -0700 (PDT) Message-ID: <20230810160806.335674426@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1691692682; 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=tBiZyVFg2RByesw9s33ESky6BK8jMzTV8d/B5WDIvI8=; b=cHjg8QthTSVTOfwEITGEyETVFB0t1CwQJ8m9sRkLw3T0b5maZiQYdXwp/dsj3Cl1BeZ9P3 1ikXUGnv+05gnoPkWsv5Y29ANYnNwSQBVJCp2xBofhgsuX9/DCUZZJ0CLAffFUNluClZBZ NqDK/iswRgJXk8UJEXHU5gJZv3+zbCHw1+BVc9WQ2MeHOFqHz71pssJEMi/AkdaV5xz5nJ vVAemGsuepKo0WRfEX6iqWu3K9x1/6sK5zl8ChZ6HDS4OMKAnK5OD4WPI4lAspR2W8cePQ KcqhikfHHetaGgpaDhWrre9S8HugJu8H4wfcFOodJFHdh63NSmvhU63u+R7tTA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1691692682; 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=tBiZyVFg2RByesw9s33ESky6BK8jMzTV8d/B5WDIvI8=; b=5MIJrm3DvfbIko5yI4LNpL2PwBahiCjQIRi28+gWAdks7ZhE2sBoozIuCcxzAj8/3/UjXi lsBpuEXO0lA81+AQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Borislav Petkov , Ashok Raj , Arjan van de Ven Subject: [patch 24/30] x86/microcode: Replace the all in one rendevouz handler References: <20230810153317.850017756@linutronix.de> MIME-Version: 1.0 Date: Thu, 10 Aug 2023 20:38:01 +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: Thomas Gleixner with a new handler which just separates the control flow of primary and secondary CPUs. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/microcode/core.c | 51 ++++++------------------------= ----- 1 file changed, 9 insertions(+), 42 deletions(-) --- --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -337,7 +337,7 @@ struct ucode_ctrl { }; =20 static DEFINE_PER_CPU(struct ucode_ctrl, ucode_ctrl); -static atomic_t late_cpus_in, late_cpus_out; +static atomic_t late_cpus_in; =20 static bool wait_for_cpus(atomic_t *cnt) { @@ -371,7 +371,7 @@ static bool wait_for_ctrl(void) return false; } =20 -static __maybe_unused void ucode_load_secondary(unsigned int cpu) +static void ucode_load_secondary(unsigned int cpu) { unsigned int ctrl_cpu =3D this_cpu_read(ucode_ctrl.ctrl_cpu); enum ucode_state ret; @@ -407,7 +407,7 @@ static __maybe_unused void ucode_load_se this_cpu_write(ucode_ctrl.ctrl, SCTRL_DONE); } =20 -static __maybe_unused void ucode_load_primary(unsigned int cpu) +static void ucode_load_primary(unsigned int cpu) { struct cpumask *secondaries =3D topology_sibling_cpumask(cpu); enum sibling_ctrl ctrl; @@ -445,46 +445,14 @@ static __maybe_unused void ucode_load_pr =20 static int ucode_load_cpus_stopped(void *unused) { - int cpu =3D smp_processor_id(); - enum ucode_state ret; - - /* - * Wait for all CPUs to arrive. A load will not be attempted unless all - * CPUs show up. - * */ - if (!wait_for_cpus(&late_cpus_in)) { - this_cpu_write(ucode_ctrl.result, UCODE_TIMEOUT); - return 0; - } - - /* - * On an SMT system, it suffices to load the microcode on one sibling of - * the core because the microcode engine is shared between the threads. - * Synchronization still needs to take place so that no concurrent - * loading attempts happen on multiple threads of an SMT core. See - * below. - */ - if (cpumask_first(topology_sibling_cpumask(cpu)) !=3D cpu) - goto wait_for_siblings; + unsigned int cpu =3D smp_processor_id(); =20 - ret =3D microcode_ops->apply_microcode(cpu); - this_cpu_write(ucode_ctrl.result, ret); - -wait_for_siblings: - if (!wait_for_cpus(&late_cpus_out)) - panic("Timeout during microcode update!\n"); - - /* - * At least one thread has completed update on each core. - * For others, simply call the update to make sure the - * per-cpu cpuinfo can be updated with right microcode - * revision. - */ - if (cpumask_first(topology_sibling_cpumask(cpu)) =3D=3D cpu) - return 0; + if (this_cpu_read(ucode_ctrl.ctrl_cpu) =3D=3D cpu) + ucode_load_primary(cpu); + else + ucode_load_secondary(cpu); =20 - ret =3D microcode_ops->apply_microcode(cpu); - this_cpu_write(ucode_ctrl.result, ret); + /* No point to wait here. The CPUs will all wait in stop_machine(). */ return 0; } =20 @@ -498,7 +466,6 @@ static int ucode_load_late_stop_cpus(voi pr_err("You should switch to early loading, if possible.\n"); =20 atomic_set(&late_cpus_in, num_online_cpus()); - atomic_set(&late_cpus_out, num_online_cpus()); =20 /* * Take a snapshot before the microcode update in order to compare and