From patchwork Tue Jul 27 03:36:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vinicius Costa Gomes X-Patchwork-Id: 12401393 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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 670C3C4320A for ; Tue, 27 Jul 2021 03:37:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C10661078 for ; Tue, 27 Jul 2021 03:37:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235128AbhG0C4v (ORCPT ); Mon, 26 Jul 2021 22:56:51 -0400 Received: from mga12.intel.com ([192.55.52.136]:45171 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234990AbhG0C4u (ORCPT ); Mon, 26 Jul 2021 22:56:50 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10057"; a="191955827" X-IronPort-AV: E=Sophos;i="5.84,272,1620716400"; d="scan'208";a="191955827" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jul 2021 20:37:18 -0700 X-IronPort-AV: E=Sophos;i="5.84,272,1620716400"; d="scan'208";a="474230278" Received: from nmanikan-mobl1.amr.corp.intel.com (HELO localhost.localdomain) ([10.209.99.32]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jul 2021 20:37:17 -0700 From: Vinicius Costa Gomes To: intel-wired-lan@lists.osuosl.org Cc: Vinicius Costa Gomes , sasha.neftin@intel.com, anthony.l.nguyen@intel.com, linux-pci@vger.kernel.org, bhelgaas@google.com, netdev@vger.kernel.org, mlichvar@redhat.com, richardcochran@gmail.com, hch@infradead.org, helgaas@kernel.org, pmenzel@molgen.mpg.de Subject: [PATCH next-queue v6 0/4] igc: Add support for PCIe PTM Date: Mon, 26 Jul 2021 20:36:53 -0700 Message-Id: <20210727033657.39885-1-vinicius.gomes@intel.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, Changes from v5: - Improved commit messages (Paul Menzel); - Clearer loop for PCIe PTM timestamps retrieval (Paul Menzel); Changes from v4: - Improved commit messages (Bjorn Helgaas); Changes from v3: - More descriptive commit messages and comments (Bjorn Helgaas); - Added a pcie_ptm_enabled() helper (Bjorn Helgaas); Changes from v2: - Now the PTM timestamps are retrieved synchronously with the ioctl(); - Fixed some typos in constants; - The IGC_PTM_STAT register is write-1-to-clear, document this more clearly; Changes from v1: - This now should cross compile better, convert_art_ns_to_tsc() will only be used if CONFIG_X86_TSC is enabled; - PCIe PTM errors reported by the NIC are logged and PTM cycles are restarted in case an error is detected; Original cover letter (lightly edited): This adds support for PCIe PTM (Precision Time Measurement) to the igc driver. PCIe PTM allows the NIC and Host clocks to be compared more precisely, improving the clock synchronization accuracy. Patch 1/4 reverts a commit that made pci_enable_ptm() private to the PCI subsystem, reverting makes it possible for it to be called from the drivers. Patch 2/4 adds the pcie_ptm_enabled() helper. Patch 3/4 calls pci_enable_ptm() from the igc driver. Patch 4/4 implements the PCIe PTM support. Exposing it via the .getcrosststamp() API implies that the time measurements are made synchronously with the ioctl(). The hardware was implemented so the most convenient way to retrieve that information would be asynchronously. So, to follow the expectations of the ioctl() we have to use less convenient ways, triggering an PCIe PTM dialog every time a ioctl() is received. Some questions are raised (also pointed out in the commit message): 1. Using convert_art_ns_to_tsc() is too x86 specific, there should be a common way to create a 'system_counterval_t' from a timestamp. 2. convert_art_ns_to_tsc() says that it should only be used when X86_FEATURE_TSC_KNOWN_FREQ is true, but during tests it works even when it returns false. Should that check be done? Cheers, Vinicius Costa Gomes (4): Revert "PCI: Make pci_enable_ptm() private" PCI: Add pcie_ptm_enabled() igc: Enable PCIe PTM igc: Add support for PTP getcrosststamp() drivers/net/ethernet/intel/igc/igc.h | 1 + drivers/net/ethernet/intel/igc/igc_defines.h | 31 ++++ drivers/net/ethernet/intel/igc/igc_main.c | 6 + drivers/net/ethernet/intel/igc/igc_ptp.c | 179 +++++++++++++++++++ drivers/net/ethernet/intel/igc/igc_regs.h | 23 +++ drivers/pci/pci.h | 3 - drivers/pci/pcie/ptm.c | 9 + include/linux/pci.h | 10 ++ 8 files changed, 259 insertions(+), 3 deletions(-)