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 X-Spam-Level: X-Spam-Status: No, score=-8.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA094C04A6B for ; Mon, 6 May 2019 17:22:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C640A20830 for ; Mon, 6 May 2019 17:22:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727136AbfEFRWm (ORCPT ); Mon, 6 May 2019 13:22:42 -0400 Received: from mga07.intel.com ([134.134.136.100]:31139 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726407AbfEFRWR (ORCPT ); Mon, 6 May 2019 13:22:17 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 May 2019 10:22:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,438,1549958400"; d="scan'208";a="230014475" Received: from skuppusw-desk.jf.intel.com ([10.54.74.33]) by orsmga001.jf.intel.com with ESMTP; 06 May 2019 10:22:15 -0700 From: sathyanarayanan.kuppuswamy@linux.intel.com To: bhelgaas@google.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, keith.busch@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: [PATCH v2 4/5] PCI/ATS: Disable PF/VF ATS service independently Date: Mon, 6 May 2019 10:20:06 -0700 Message-Id: X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuppuswamy Sathyanarayanan Currently all VF's needs to be disable their ATS service before disabling the ATS service in corresponding PF device. But this logic is incorrect and does not align with the spec. Also it might lead to some power and performance impact in the system. As per PCIe spec r4.0, sec 9.3.7.8, ATS Capabilities in VFs and their associated PFs may be enabled/disabled independently. So remove this dependency logic in enable/disable code. Cc: Ashok Raj Cc: Keith Busch Suggested-by: Ashok Raj Signed-off-by: Kuppuswamy Sathyanarayanan --- drivers/pci/ats.c | 11 ----------- include/linux/pci.h | 1 - 2 files changed, 12 deletions(-) diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 718e6f414680..977f5a1ace40 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -72,8 +72,6 @@ int pci_enable_ats(struct pci_dev *dev, int ps) pdev = pci_physfn(dev); if (pdev->ats_stu != ps) return -EINVAL; - - atomic_inc(&pdev->ats_ref_cnt); /* count enabled VFs */ } else { dev->ats_stu = ps; ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU); @@ -91,20 +89,11 @@ EXPORT_SYMBOL_GPL(pci_enable_ats); */ void pci_disable_ats(struct pci_dev *dev) { - struct pci_dev *pdev; u16 ctrl; if (WARN_ON(!dev->ats_enabled)) return; - if (atomic_read(&dev->ats_ref_cnt)) - return; /* VFs still enabled */ - - if (dev->is_virtfn) { - pdev = pci_physfn(dev); - atomic_dec(&pdev->ats_ref_cnt); - } - pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl); ctrl &= ~PCI_ATS_CTRL_ENABLE; pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl); diff --git a/include/linux/pci.h b/include/linux/pci.h index 2a761ea63f8d..c38cbf8fa03b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -446,7 +446,6 @@ struct pci_dev { }; u16 ats_cap; /* ATS Capability offset */ u8 ats_stu; /* ATS Smallest Translation Unit */ - atomic_t ats_ref_cnt; /* Number of VFs with ATS enabled */ #endif #ifdef CONFIG_PCI_PRI u32 pri_reqs_alloc; /* Number of PRI requests allocated */ -- 2.20.1