From mboxrd@z Thu Jan 1 00:00:00 1970 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 3889FCDB474 for ; Tue, 17 Oct 2023 21:26:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344262AbjJQV0g (ORCPT ); Tue, 17 Oct 2023 17:26:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344321AbjJQVZw (ORCPT ); Tue, 17 Oct 2023 17:25:52 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 595E4131 for ; Tue, 17 Oct 2023 14:24:08 -0700 (PDT) Message-ID: <20231017211723.688807375@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1697577846; 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=L9m8W4bdzDuhhTI4cJap7V+acmOzj+yrZ+giYWgienc=; b=eMFbUfbn//zHbW26T91mEuzFJyURdXE/G8WGZCvGYbFkFo+qqd593s20T6Snrj6q3AycWZ B7nZvUFiWljt6c3NFH4eQ1O00dGHhGGiGYouDw1AQJOO5oFvnvRNHmq4QFo1nN1uRLsxFM 8P9BohzMx7nqp2DhXCVBobMnJdYUy7Zw+vuns9KY1GN1WsvfId31285yuFQHwfcyQWbApb NYpWKdsbJl3qELKhQvtMpR4LlVqdp4ZlbS8jiuwjUuMr77uaNAj7uO61iwWbwTBZGGi2p/ DTI9Quu/hd32N0oqqCEo6rLZzft/t84zWaFdxhBkAfCAQY4xHmK+6Luinjqe9g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1697577846; 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=L9m8W4bdzDuhhTI4cJap7V+acmOzj+yrZ+giYWgienc=; b=Hir2o4x4E6IN7gYByVkLrAKiDLDgzKdmWcbf61iXoqbeDyulOsd/AmdNOQlSK0fyDd2Ryn s04lVl9+idPIAmBA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Borislav Petkov Subject: [patch V5 31/39] x86/microcode: Add per CPU control field References: <20231017200758.877560658@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Tue, 17 Oct 2023 23:24:06 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner Add a per CPU control field to ucode_ctrl and define constants for it which are going to be used to control the loading state machine. In theory this could be a global control field, but a global control does not cover the following case: 15 primary CPUs load microcode successfully 1 primary CPU fails and returns with an error code With global control the sibling of the failed CPU would either try again or the whole operation would be aborted with the consequence that the 15 siblings do not invoke the apply path and end up with inconsistent software state. The result in dmesg would be inconsistent too. There are two additional fields added and initialized: ctrl_cpu and secondaries. ctrl_cpu is the CPU number of the primary thread for now, but with the upcoming uniform loading at package or system scope this will be one CPU per package or just one CPU. Secondaries hands the control CPU a CPU mask which will be required to release the secondary CPUs out of the wait loop. Preparatory change for implementing a properly split control flow for primary and secondary CPUs. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/microcode/core.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) --- --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -252,8 +252,19 @@ static struct platform_device *microcode * requirement can be relaxed in the future. Right now, this is conservative * and good. */ +enum sibling_ctrl { + /* Spinwait with timeout */ + SCTRL_WAIT, + /* Invoke the microcode_apply() callback */ + SCTRL_APPLY, + /* Proceed without invoking the microcode_apply() callback */ + SCTRL_DONE, +}; + struct microcode_ctrl { + enum sibling_ctrl ctrl; enum ucode_state result; + unsigned int ctrl_cpu; }; static DEFINE_PER_CPU(struct microcode_ctrl, ucode_ctrl); @@ -398,7 +409,7 @@ static int load_late_stop_cpus(void) */ static bool setup_cpus(void) { - struct microcode_ctrl ctrl = { .result = -1, }; + struct microcode_ctrl ctrl = { .ctrl = SCTRL_WAIT, .result = -1, }; unsigned int cpu; for_each_cpu_and(cpu, cpu_present_mask, &cpus_booted_once_mask) { @@ -408,7 +419,12 @@ static bool setup_cpus(void) return false; } } - /* Initialize the per CPU state */ + + /* + * Initialize the per CPU state. This is core scope for now, + * but prepared to take package or system scope into account. + */ + ctrl.ctrl_cpu = cpumask_first(topology_sibling_cpumask(cpu)); per_cpu(ucode_ctrl, cpu) = ctrl; } return true;