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, URIBL_BLOCKED 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 C627FC433E1 for ; Mon, 10 Aug 2020 14:42:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 988F520771 for ; Mon, 10 Aug 2020 14:42:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ROIr5aS0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727098AbgHJOmW (ORCPT ); Mon, 10 Aug 2020 10:42:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726111AbgHJOmV (ORCPT ); Mon, 10 Aug 2020 10:42:21 -0400 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 116C4C061756; Mon, 10 Aug 2020 07:42:21 -0700 (PDT) Received: by mail-lj1-x243.google.com with SMTP id g6so9825200ljn.11; Mon, 10 Aug 2020 07:42:20 -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=fWkEs1WmcVZE4cGDA+geI3RJmT88csh7VsEAZzHbrIo=; b=ROIr5aS0jcS+gqUwH/5SfvTlBgYX0g3JsYtZ7N2j1H+/WfBBmzMGg9b33QhoS5UIPJ b2lmsQKNLnR0KZ5UuajkL5uqIn/eZKsO2GedKjiPdISeocYIuZr38Px/yL942R41Gk4f 0eAVJIQrTiaq5GDvI1i4ZsrWV3A7FO1GnfIBR2vwGlxMwB4b4TSzNyDBJBXw25MxUYI4 JRknYSXTV9YJhStxcSoYbOeo4aF/+Fa/lkQHEMxVSyG/Uv3qXBlfseuNQqA5JmQ0sykg UuW2WT+Lm0/cRIMGohJeUXX9faFiJvwR5YNYkfZYDwNWnmD3Jj4/42T8JxQSXIZ3JC4K WDZQ== 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=fWkEs1WmcVZE4cGDA+geI3RJmT88csh7VsEAZzHbrIo=; b=lks1o7ItW/C+MwVIgrPJnY0H81toMWybq8D8ftnNuOnJMgfhFEqYRKHkFQ0FoZBYi6 5zxCR6QyleorL7TKLYViFY/73blANBaNfPTrb2oazzsExl4NgoRPhZJIS9zipbBkDm/f KX530tSroqdcvQQTjhhk3XAE4LcL0Sbs5sS5QRk3ytsIOnb1lO6xDogx+W2Bhu30lIPF GDFxOYxS9aFEPdQdfybDM2Qvj719red52vgF89LCekmK5gd+GL3o/glkNSUVAQ705oRH pn397jbfUketflJWHjXIZBGx0Bvdce7+AU2q6Hn0jmrfdVSpIPY9XwuxDIT/bM73dyrs WiJA== X-Gm-Message-State: AOAM532Q8THohpTfhEZ1VmtgpX9Mql7ugudEgjhNZw2wR9znUhzy6b/k gJKRheXlRtabLiFU6L8m1VOCYvSeRCCK5fnmoG8= X-Google-Smtp-Source: ABdhPJwN5hdXTAKIS+I6qaQJnbbB6NkAGRxJdotRt/2F9CSS+WpcAMsFTp28SCk9dvaDpPx8lYzCs8wObjrLyLui1kY= X-Received: by 2002:a2e:808f:: with SMTP id i15mr789540ljg.151.1597070538926; Mon, 10 Aug 2020 07:42:18 -0700 (PDT) MIME-Version: 1.0 References: <20200717190620.29821-1-david.e.box@linux.intel.com> <20200729213719.17795-1-david.e.box@linux.intel.com> <74c03fe9fea12f4b056bf694a0d03d5200244231.camel@linux.intel.com> In-Reply-To: <74c03fe9fea12f4b056bf694a0d03d5200244231.camel@linux.intel.com> From: Umesh A Date: Mon, 10 Aug 2020 20:12:07 +0530 Message-ID: Subject: Re: [PATCH V5 0/3] Intel Platform Monitoring Technology To: david.e.box@linux.intel.com Cc: lee.jones@linaro.org, dvhart@infradead.org, andy@infradead.org, bhelgaas@google.com, alexander.h.duyck@linux.intel.com, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-pci@vger.kernel.org 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 MCTP and PLDM are the latest in Platform management Technology. Sw application and drivers can be implemented on the PCIe platform. Previously I spent some time on this. On Mon, Aug 10, 2020 at 7:49 PM David E. Box wrote: > > Friendly ping. > > On Wed, 2020-07-29 at 14:37 -0700, 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. > > > > Changes from V4: > > - Replace MFD with PMT in driver title > > - Fix commit tags in chronological order > > - Fix includes in alphabetical order > > - Use 'raw' string instead of defines for device names > > - Add an error message when returning an error code for > > unrecognized capability id > > - Use dev_err instead of dev_warn for messages when returning > > an error > > - Change while loop to call pci_find_next_ext_capability once > > - Add missing continue in while loop > > - Keep PCI platform defines using PCI_DEVICE_DATA magic tied to > > the pci_device_id table > > - Comment and kernel message cleanup > > > > 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 < > > lkp@intel.com> > > - 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 | 220 +++++++++ > > 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, 747 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 > > >