From patchwork Wed Aug 28 22:14:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuppuswamy Sathyanarayanan X-Patchwork-Id: 11120033 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 24BC818B7 for ; Wed, 28 Aug 2019 22:18:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DF3422DA7 for ; Wed, 28 Aug 2019 22:18:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727063AbfH1WSK (ORCPT ); Wed, 28 Aug 2019 18:18:10 -0400 Received: from mga17.intel.com ([192.55.52.151]:11611 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727109AbfH1WSJ (ORCPT ); Wed, 28 Aug 2019 18:18:09 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Aug 2019 15:18:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,442,1559545200"; d="scan'208";a="197662425" Received: from skuppusw-desk.jf.intel.com ([10.54.74.33]) by fmsmga001.fm.intel.com with ESMTP; 28 Aug 2019 15:18:06 -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 v7 6/7] PCI/ATS: Disable PF/VF ATS service independently Date: Wed, 28 Aug 2019 15:14:06 -0700 Message-Id: <8163ab8fa66afd2cba514ae95d29ab12104781aa.1567029860.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 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 893674520bbf..e7db42128176 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -108,8 +108,6 @@ 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); @@ -127,20 +125,11 @@ 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 782bca667010..2428414b2b9c 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -452,7 +452,6 @@ 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 u16 pri_cap; /* PRI Capability offset */