From patchwork Fri Mar 25 02:22:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Chang S. Bae" X-Patchwork-Id: 12791227 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 9D3D0C433EF for ; Fri, 25 Mar 2022 02:30:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242818AbiCYCcL (ORCPT ); Thu, 24 Mar 2022 22:32:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357737AbiCYCcK (ORCPT ); Thu, 24 Mar 2022 22:32:10 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CEC3B6E45; Thu, 24 Mar 2022 19:30:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648175438; x=1679711438; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=yQjfEUUI7oVHVPerk9SvpBNm5Nl0BnDkY26G7WSlbXw=; b=NAh4pJT+zpDF5T81V4rXFYEKlrC+cyXZUdHEu4vZf2yWqwdvJ3kRORi4 BtX1iJEEs4Ig7NfYZ3hrevAuL1c9WlUibEDC4NuDx6hP/va00lzmDVxVb aIsA5QAaMgIL2gfnlm6l1T05vL0dNr2hiRdfG7vn4v8K+zZYMmcDb9xo2 cCyhexQudwaLPRTZeXsT0IEGnM0kbizc76PNs2o8uqcuMl8NFN2iUqP7E fVJpF8jdQL1Yyij886LvPD1J3q86v51FdIZPxsMBXuaJSESU88NnRbwlw TZl+Xrpk5h3vRdUDASPdyHDFo8wZ6tOlIsYBqK5/QQQugwOLmPbJ8X5gq w==; X-IronPort-AV: E=McAfee;i="6200,9189,10296"; a="321733684" X-IronPort-AV: E=Sophos;i="5.90,209,1643702400"; d="scan'208";a="321733684" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2022 19:30:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,209,1643702400"; d="scan'208";a="693531285" Received: from chang-linux-3.sc.intel.com ([172.25.112.114]) by fmsmga001.fm.intel.com with ESMTP; 24 Mar 2022 19:30:35 -0700 From: "Chang S. Bae" To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-pm@vger.kernel.org Cc: tglx@linutronix.de, dave.hansen@linux.intel.com, peterz@infradead.org, bp@alien8.de, rafael@kernel.org, ravi.v.shankar@intel.com, chang.seok.bae@intel.com, Artem Bityutskiy Subject: [PATCH v3 3/3] intel_idle: Add a new flag to initialize the AMX state Date: Thu, 24 Mar 2022 19:22:19 -0700 Message-Id: <20220325022219.829-4-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220325022219.829-1-chang.seok.bae@intel.com> References: <20220325022219.829-1-chang.seok.bae@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The non-initialized AMX state can be the cause of C-state demotion from C6 to C1E. This low-power idle state may improve power savings and thus result in a higher available turbo frequency budget. This behavior is implementation-specific. Initialize the state for the C6 entrance of Sapphire Rapids as needed. Suggested-by: Peter Zijlstra (Intel) Signed-off-by: Chang S. Bae Tested-by : Zhang Rui Cc: Artem Bityutskiy Cc: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org Acked-by: Rafael J. Wysocki --- Changes from v2: * Remove an unnecessary backslash (Rafael Wysocki). Changes from v1: * Simplify the code with a new flag (Rui). * Rebase on Artem's patches for SPR intel_idle. * Massage the changelog. --- drivers/idle/intel_idle.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index b7640cfe0020..d35790890a3f 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -54,6 +54,7 @@ #include #include #include +#include #define INTEL_IDLE_VERSION "0.5.1" @@ -100,6 +101,11 @@ static unsigned int mwait_substates __initdata; */ #define CPUIDLE_FLAG_ALWAYS_ENABLE BIT(15) +/* + * Initialize large xstate for the C6-state entrance. + */ +#define CPUIDLE_FLAG_INIT_XSTATE BIT(16) + /* * MWAIT takes an 8-bit "hint" in EAX "suggesting" * the C-state (top nibble) and sub-state (bottom nibble) @@ -134,6 +140,9 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev, if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE) local_irq_enable(); + if (state->flags & CPUIDLE_FLAG_INIT_XSTATE) + fpu_idle_fpregs(); + mwait_idle_with_hints(eax, ecx); return index; @@ -154,8 +163,12 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev, static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { - unsigned long eax = flg2MWAIT(drv->states[index].flags); unsigned long ecx = 1; /* break on interrupt flag */ + struct cpuidle_state *state = &drv->states[index]; + unsigned long eax = flg2MWAIT(state->flags); + + if (state->flags & CPUIDLE_FLAG_INIT_XSTATE) + fpu_idle_fpregs(); mwait_idle_with_hints(eax, ecx); @@ -790,7 +803,8 @@ static struct cpuidle_state spr_cstates[] __initdata = { { .name = "C6", .desc = "MWAIT 0x20", - .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED, + .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED | + CPUIDLE_FLAG_INIT_XSTATE, .exit_latency = 290, .target_residency = 800, .enter = &intel_idle,