From patchwork Wed Apr 27 06:08:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Bityutskiy X-Patchwork-Id: 12828314 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 C39F0C433FE for ; Wed, 27 Apr 2022 06:09:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232859AbiD0GMJ (ORCPT ); Wed, 27 Apr 2022 02:12:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232750AbiD0GMH (ORCPT ); Wed, 27 Apr 2022 02:12:07 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2616966F88 for ; Tue, 26 Apr 2022 23:08:58 -0700 (PDT) X-IronPort-AV: E=McAfee;i="6400,9594,10329"; a="245749366" X-IronPort-AV: E=Sophos;i="5.90,292,1643702400"; d="scan'208";a="245749366" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2022 23:08:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,292,1643702400"; d="scan'208";a="807873514" Received: from powerlab.fi.intel.com ([10.237.71.25]) by fmsmga006.fm.intel.com with ESMTP; 26 Apr 2022 23:08:56 -0700 From: Artem Bityutskiy To: "Rafael J. Wysocki" Cc: Linux PM Mailing List , Rui Zhang , Jan Beulich , Artem Bityutskiy Subject: [PATCH 1/2] intel_idle: fix the 'preferred_cstates' module parameter Date: Wed, 27 Apr 2022 09:08:52 +0300 Message-Id: <20220427060853.3975453-2-dedekind1@gmail.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220427060853.3975453-1-dedekind1@gmail.com> References: <20220427060853.3975453-1-dedekind1@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Artem Bityutskiy This patch is a fix for the following 5.18-rc1 commit: da0e58c038e6 intel_idle: add 'preferred_cstates' module argument Problem description. When user boots kernel up with the 'intel_idle.preferred_cstates=4' option, we enable C1E and disable C1 states on Sapphire Rapids Xeon (SPR). In order for C1E to work on SPR, we have to enable the C1E promotion bit on all CPUs. However, we enable it only on one CPU. Fix description. The 'intel_idle' driver already has the infrastructure for disabling C1E promotion on every CPU. This patch uses the same infrastructure for enabling C1E promotion on every CPU. It changes the boolean 'disable_promotion_to_c1e' variable to a tri-state 'c1e_promotion' variable. Tested on a 2-socket SPR system. I verified the following combinations: * C1E promotion enabled and disabled in BIOS. * Booted with and without the 'intel_idle.preferred_cstates=4' kernel argument. In all 4 cases C1E promotion was correctly set on all CPUs. Also tested on an old Broadwell system, just to make sure it does not cause a regression. C1E promotion was correctly disabled on that system, both C1 and C1E were exposed (as expected). Reported-by: Jan Beulich Signed-off-by: Artem Bityutskiy --- drivers/idle/intel_idle.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index b7640cfe0020..cf5ed4c1d02c 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -69,7 +69,12 @@ static unsigned int preferred_states_mask; static struct cpuidle_device __percpu *intel_idle_cpuidle_devices; static unsigned long auto_demotion_disable_flags; -static bool disable_promotion_to_c1e; + +static enum { + C1E_PROMOTION_PRESERVE, + C1E_PROMOTION_ENABLE, + C1E_PROMOTION_DISABLE +} c1e_promotion = C1E_PROMOTION_PRESERVE; struct idle_cpu { struct cpuidle_state *state_table; @@ -1398,8 +1403,6 @@ static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { } static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; } #endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */ -static void c1e_promotion_enable(void); - /** * ivt_idle_state_table_update - Tune the idle states table for Ivy Town. * @@ -1587,8 +1590,7 @@ static void __init spr_idle_state_table_update(void) spr_cstates[1].flags &= ~CPUIDLE_FLAG_UNUSABLE; /* Enable C1E using the "C1E promotion" bit. */ - c1e_promotion_enable(); - disable_promotion_to_c1e = false; + c1e_promotion = C1E_PROMOTION_ENABLE; } /* @@ -1754,7 +1756,9 @@ static int intel_idle_cpu_init(unsigned int cpu) if (auto_demotion_disable_flags) auto_demotion_disable(); - if (disable_promotion_to_c1e) + if (c1e_promotion == C1E_PROMOTION_ENABLE) + c1e_promotion_enable(); + else if (c1e_promotion == C1E_PROMOTION_DISABLE) c1e_promotion_disable(); return 0; @@ -1833,7 +1837,8 @@ static int __init intel_idle_init(void) if (icpu) { cpuidle_state_table = icpu->state_table; auto_demotion_disable_flags = icpu->auto_demotion_disable_flags; - disable_promotion_to_c1e = icpu->disable_promotion_to_c1e; + if (icpu->disable_promotion_to_c1e) + c1e_promotion = C1E_PROMOTION_DISABLE; if (icpu->use_acpi || force_use_acpi) intel_idle_acpi_cst_extract(); } else if (!intel_idle_acpi_cst_extract()) {