Received: by 2002:a25:c205:0:0:0:0:0 with SMTP id s5csp189768ybf; Wed, 26 Feb 2020 11:12:23 -0800 (PST) X-Google-Smtp-Source: APXvYqyazftv1UUyQ5Xhq22eVeBvVLdkfx4O9GB+yC65vTZKRJT2DGwN7SPEIvDQbQRGmS8vslVe X-Received: by 2002:aca:c4c4:: with SMTP id u187mr428569oif.120.1582744343308; Wed, 26 Feb 2020 11:12:23 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1582744343; cv=none; d=google.com; s=arc-20160816; b=Yw5x5ZcH3cVLU3MclQa28211n/pl3WP//+e6oEc9j1JTom1ExJIujv7GJnRzxgOzaP 9ib7EaVktsap5IygYQGZQXFb2lNaRXFStCLtKBck2ZqYEPzcjBuvNUyLV2+ZHCThVh3y na9rOJftmi/yCgob/8yhU2xPhzROi9ua6qSk+6mikYMwdyhLeO7fDBpqs9YxkSBt1R/a UvpcDuoZLkVOmsNkY7gZmPoZKaFcnJTpZyZuDBmQR/YJSy3jKq8H8gRnMdfeddtGWA9c nLJoH6LPvr2U9Hhd3hVwoy1bZoBq3tJKfOK5hfFLgduQhBddv0KNYoG1wrWE5pifyf06 1FQA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:date:subject:cc:to:from; bh=BMQI2/S4tGeEGmeSFX/6B8pSObSeuuqsOT37pqh4OQQ=; b=J0XIAHPyt0dDxruKYow/16zLNJ1FAu7YOl7q4i9+iScT5kppQO+VUyjjky6ZCDd1uh wBQtDylpO6ceHetxtMy434qeN1EUKlCWJVz4aYPpyw7Zt6slbdkf2tSA54wQotqqgKXk 5Hn3bCjZUbptDAu7+RqU6JeQEPty4XAXtpCon5buPutBHyWB4NSZ17T4NbnbcTZo/qYx VhB21qs5OrZ5GGGb5FlqsZD+TNPE7KTnRYGZu+vRhkS31ZanDrOTWi02PoZ9H1JsaPz0 QiPXs2vewpKF1BdyFsZ++Zs+3hv+9BBs9CLDBCRCQx3opxW88ep7nGi3N/WlFf36OoZE s2Sw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d199si86372oib.135.2020.02.26.11.12.11; Wed, 26 Feb 2020 11:12:23 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727242AbgBZTLl (ORCPT + 99 others); Wed, 26 Feb 2020 14:11:41 -0500 Received: from mga11.intel.com ([192.55.52.93]:20002 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726996AbgBZTLl (ORCPT ); Wed, 26 Feb 2020 14:11:41 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Feb 2020 11:11:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,489,1574150400"; d="scan'208";a="285072246" Received: from kmp-skylake-client-platform.sc.intel.com ([172.25.112.108]) by FMSMGA003.fm.intel.com with ESMTP; 26 Feb 2020 11:11:40 -0800 From: Kyung Min Park To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, gregkh@linuxfoundation.org, ak@linux.intel.com, tony.luck@intel.com, ashok.raj@intel.com, ravi.v.shankar@intel.com, fenghua.yu@intel.com Subject: [PATCH 0/2] x86/delay: Introduce TPAUSE instruction Date: Wed, 26 Feb 2020 11:10:56 -0800 Message-Id: <1582744258-42744-1-git-send-email-kyung.min.park@intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Intel processors that support the WAITPKG feature implement the TPAUSE instruction that suspends execution in a lower power state until the TSC (Time Stamp Counter) exceeds a certain value. Update the udelay() function to use TPAUSE on systems where it is available. Note that we hard code the deeper (C0.2) sleep state because exit latency is small compared to the "microseconds" that usleep() will delay. Kyung Min Park (2): x86/asm: Define a few helpers in delay_waitx() x86/asm/delay: Introduce TPAUSE delay arch/x86/include/asm/mwait.h | 17 +++++++++ arch/x86/lib/delay.c | 82 ++++++++++++++++++++++++++++++++------------ 2 files changed, 78 insertions(+), 21 deletions(-) -- 2.7.4