lkml.org 
[lkml]   [2020]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH V4 0/3] Intel Platform Monitoring Technology
    On Fri, Jul 17, 2020 at 10:05 PM David E. Box
    <david.e.box@linux.intel.com> 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<n> and /dev/smplr<n>. 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 <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 | 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

    \
     
     \ /
      Last update: 2020-07-27 12:25    [W:2.782 / U:0.064 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site