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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 088A9C433E4 for ; Mon, 27 Jul 2020 10:24:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB4752075A for ; Mon, 27 Jul 2020 10:24:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dhEUeIQw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727978AbgG0KYA (ORCPT ); Mon, 27 Jul 2020 06:24:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726196AbgG0KX7 (ORCPT ); Mon, 27 Jul 2020 06:23:59 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF8B6C061794; Mon, 27 Jul 2020 03:23:59 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id lw1so1061886pjb.1; Mon, 27 Jul 2020 03:23:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ZAJGKAnga8wUpgRoEi+tan8Djz516wktbKcW6mwyua8=; b=dhEUeIQw+3R4YXV12HUzPFXyzG8dBLIVThgI+T020YJw5GYKkIcQqV4JDX604Yfeii Wx5WwhV3rYUOz9E3FyvYVL1KCuCJ8EUxTYPfToYrUAmKh40P/V1niKtPsDwtJspf0Jar L813Dza1IGBUbxuUQiPvRub5sFclmP/orXtWqQHmdxztu59/cWrNqvm8i0QkLYXPerKm Y9iuVPZtvdgPiypRfmr1KScp8x9F4zsxu2w5PY73Bn7F7LHwZHbAhPF0E7TZYVeESAvW WMXVJMEVc27RRHZRV+4WiP6CZLyoJebsb1AVAv2Qzfe6vaRZ5d9EktUoteIt8usPmsh2 t8Tw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZAJGKAnga8wUpgRoEi+tan8Djz516wktbKcW6mwyua8=; b=r9k1iILusgDWFOE2ICoph67hNyJE3P42qzf94Wv6zDbm79mBVJvjfbp36V3jOvWjdk 0hKsS/tBlocdVSnJwqq0VkbB3Ugx7ASgyFY5ke3M7aZWSlkrzB06VNSo+fxZbfH6U3j4 LFzFEKynAR59OwDkyGYP9T+WunB5PUPZ71+TkiSYExJUBwtD7tduIhE5S7t+wVNZ/DwI fWc7f7oM3/VhdlTnIje3oIFB/sB2by1a+vhR8JlgQDfrQd/VSP/japwtwNl0gN0hgo7w KXQhk2vE/hqfvhDvNgDQJlTyBVqoqSpO2TAz95HPavwocQ4Bv9ykxGPSKQ36Ni4S635y rP/A== X-Gm-Message-State: AOAM531qIzyQlMbppIl1g+O9VTqxT8RWw6jK1xQH6ElNjnNBVPnQ/kX6 GNVGSbjqp4UbBUeqN7cPEJKFS3rh16HvZBpicLujlRkf X-Google-Smtp-Source: ABdhPJzH5cBHaWc793+UJPfg3Pf+4+gPEASjJ7Pi4ebUrJ8ymiJ0sAYKFnLBWG/8i+tmrgphKhSIvyHPPcXsch+sPMQ= X-Received: by 2002:a17:90a:a393:: with SMTP id x19mr15795672pjp.228.1595845439142; Mon, 27 Jul 2020 03:23:59 -0700 (PDT) MIME-Version: 1.0 References: <20200714062323.19990-1-david.e.box@linux.intel.com> <20200717190620.29821-1-david.e.box@linux.intel.com> In-Reply-To: <20200717190620.29821-1-david.e.box@linux.intel.com> From: Andy Shevchenko Date: Mon, 27 Jul 2020 13:23:44 +0300 Message-ID: Subject: Re: [PATCH V4 0/3] Intel Platform Monitoring Technology To: "David E. Box" Cc: Lee Jones , Darren Hart , Andy Shevchenko , Bjorn Helgaas , Alexander Duyck , Linux Kernel Mailing List , Platform Driver , linux-pci Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 17, 2020 at 10:05 PM David E. Box wrote: > > Intel Platform Monitoring Technology (PMT) is an architecture for > enumerating and accessing hardware monitoring capabilities on a device. > With customers increasingly asking for hardware telemetry, engineers not > only have to figure out how to measure and collect data, but also how to > deliver it and make it discoverable. The latter may be through some device > specific method requiring device specific tools to collect the data. This > in turn requires customers to manage a suite of different tools in order to > collect the differing assortment of monitoring data on their systems. Even > when such information can be provided in kernel drivers, they may require > constant maintenance to update register mappings as they change with > firmware updates and new versions of hardware. PMT provides a solution for > discovering and reading telemetry from a device through a hardware agnostic > framework that allows for updates to systems without requiring patches to > the kernel or software tools. > > PMT defines several capabilities to support collecting monitoring data from > hardware. All are discoverable as separate instances of the PCIE Designated > Vendor extended capability (DVSEC) with the Intel vendor code. The DVSEC ID > field uniquely identifies the capability. Each DVSEC also provides a BAR > offset to a header that defines capability-specific attributes, including > GUID, feature type, offset and length, as well as configuration settings > where applicable. The GUID uniquely identifies the register space of any > monitor data exposed by the capability. The GUID is associated with an XML > file from the vendor that describes the mapping of the register space along > with properties of the monitor data. This allows vendors to perform > firmware updates that can change the mapping (e.g. add new metrics) without > requiring any changes to drivers or software tools. The new mapping is > confirmed by an updated GUID, read from the hardware, which software uses > with a new XML. > > The current capabilities defined by PMT are Telemetry, Watcher, and > Crashlog. The Telemetry capability provides access to a continuous block > of read only data. The Watcher capability provides access to hardware > sampling and tracing features. Crashlog provides access to device crash > dumps. While there is some relationship between capabilities (Watcher can > be configured to sample from the Telemetry data set) each exists as stand > alone features with no dependency on any other. The design therefore splits > them into individual, capability specific drivers. MFD is used to create > platform devices for each capability so that they may be managed by their > own driver. The PMT architecture is (for the most part) agnostic to the > type of device it can collect from. Devices nodes are consequently generic > in naming, e.g. /dev/telem and /dev/smplr. Each capability driver > creates a class to manage the list of devices supporting it. Software can > determine which devices support a PMT feature by searching through each > device node entry in the sysfs class folder. It can additionally determine > if a particular device supports a PMT feature by checking for a PMT class > folder in the device folder. > > This patch set provides support for the PMT framework, along with support > for Telemetry on Tiger Lake. > I assume this goes thru MFD tree. > Changes from V3: > - Write out full acronym for DVSEC in PCI patch commit message and > add 'Designated' to comments > - remove unused variable caught by kernel test robot > - Add required Co-developed-by signoffs, noted by Andy > - Allow access using new CAP_PERFMON capability as suggested by > Alexey Bundankov > - Fix spacing in Kconfig, noted by Randy > - Other style changes and fixups suggested by Andy > > Changes from V2: > - In order to handle certain HW bugs from the telemetry capability > driver, create a single platform device per capability instead of > a device per entry. Add the entry data as device resources and > let the capability driver manage them as a set allowing for > cleaner HW bug resolution. > - Handle discovery table offset bug in intel_pmt.c > - Handle overlapping regions in intel_pmt_telemetry.c > - Add description of sysfs class to testing ABI. > - Don't check size and count until confirming support for the PMT > capability to avoid bailing out when we need to skip it. > - Remove unneeded header file. Move code to the intel_pmt.c, the > only place where it's needed. > - Remove now unused platform data. > - Add missing header files types.h, bits.h. > - Rename file name and build options from telem to telemetry. > - Code cleanup suggested by Andy S. > - x86 mailing list added. > > Changes from V1: > - In the telemetry driver, set the device in device_create() to > the parent PCI device (the monitoring device) for clear > association in sysfs. Was set before to the platform device > created by the PCI parent. > - Move telem struct into driver and delete unneeded header file. > - Start telem device numbering from 0 instead of 1. 1 was used > due to anticipated changes, no longer needed. > - Use helper macros suggested by Andy S. > - Rename class to pmt_telemetry, spelling out full name > - Move monitor device name defines to common header > - Coding style, spelling, and Makefile/MAINTAINERS ordering fixes > > David E. Box (3): > PCI: Add defines for Designated Vendor-Specific Extended Capability > mfd: Intel Platform Monitoring Technology support > platform/x86: Intel PMT Telemetry capability driver > > .../ABI/testing/sysfs-class-pmt_telemetry | 46 ++ > MAINTAINERS | 6 + > drivers/mfd/Kconfig | 10 + > drivers/mfd/Makefile | 1 + > drivers/mfd/intel_pmt.c | 215 +++++++++ > drivers/platform/x86/Kconfig | 10 + > drivers/platform/x86/Makefile | 1 + > drivers/platform/x86/intel_pmt_telemetry.c | 448 ++++++++++++++++++ > include/uapi/linux/pci_regs.h | 5 + > 9 files changed, 742 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_telemetry > create mode 100644 drivers/mfd/intel_pmt.c > create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c > > -- > 2.20.1 > -- With Best Regards, Andy Shevchenko