From patchwork Wed Jul 3 20:46:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuppuswamy Sathyanarayanan X-Patchwork-Id: 11030301 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0E9A81398 for ; Wed, 3 Jul 2019 20:49:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F2F74289E8 for ; Wed, 3 Jul 2019 20:48:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E736A28A15; Wed, 3 Jul 2019 20:48:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8D42C289E8 for ; Wed, 3 Jul 2019 20:48:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727327AbfGCUsu (ORCPT ); Wed, 3 Jul 2019 16:48:50 -0400 Received: from mga05.intel.com ([192.55.52.43]:7207 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727359AbfGCUsj (ORCPT ); Wed, 3 Jul 2019 16:48:39 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jul 2019 13:48:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,448,1557212400"; d="scan'208";a="172258098" Received: from skuppusw-desk.jf.intel.com ([10.54.74.33]) by FMSMGA003.fm.intel.com with ESMTP; 03 Jul 2019 13:48:38 -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 v4 6/7] PCI/ATS: Disable PF/VF ATS service independently Date: Wed, 3 Jul 2019 13:46:23 -0700 Message-Id: <9a3027e646f202606ca63c351baeb14a04b13886.1562172836.git.sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 d2ee9ee56636..c3e3cbfe9a99 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -140,8 +140,6 @@ 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); @@ -159,20 +157,11 @@ 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 a317c3115d69..442ced0d2dd1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -449,7 +449,6 @@ 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 struct mutex pri_lock; /* PRI enable lock */