linux-stable/Documentation/ABI/testing/sysfs-class-intel_pmt

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platform/x86: Intel PMT class driver Intel Platform Monitoring Technology is meant to provide a common way to access telemetry and system metrics. Register mappings are not provided by the driver. Instead, a GUID is read from a header for each endpoint. The GUID identifies the device and is to be used with an XML, provided by the vendor, to discover the available set of metrics and their register mapping. This allows firmware updates to modify the register space without needing to update the driver every time with new mappings. Firmware writes a new GUID in this case to specify the new mapping. Software tools with access to the associated XML file can then interpret the changes. The module manages access to all Intel PMT endpoints on a system, independent of the device exporting them. It creates an intel_pmt class to manage the devices. For each telemetry endpoint, sysfs files provide GUID and size information as well as a pointer to the parent device the telemetry came from. Software may discover the association between endpoints and devices by iterating through the list in sysfs, or by looking for the existence of the class folder under the device of interest. A binary sysfs attribute of the same name allows software to then read or map the telemetry space for direct access. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: David E. Box <david.e.box@linux.intel.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-10-29 01:55:34 +00:00
What: /sys/class/intel_pmt/
Date: October 2020
KernelVersion: 5.10
Contact: David Box <david.e.box@linux.intel.com>
Description:
The intel_pmt/ class directory contains information for
devices that expose hardware telemetry using Intel Platform
Monitoring Technology (PMT)
What: /sys/class/intel_pmt/telem<x>
Date: October 2020
KernelVersion: 5.10
Contact: David Box <david.e.box@linux.intel.com>
Description:
The telem<x> directory contains files describing an instance of
a PMT telemetry device that exposes hardware telemetry. Each
telem<x> directory has an associated telem file. This file
may be opened and mapped or read to access the telemetry space
of the device. The register layout of the telemetry space is
determined from an XML file that matches the PCI device id and
GUID for the device.
What: /sys/class/intel_pmt/telem<x>/telem
Date: October 2020
KernelVersion: 5.10
Contact: David Box <david.e.box@linux.intel.com>
Description:
(RO) The telemetry data for this telemetry device. This file
may be mapped or read to obtain the data.
What: /sys/class/intel_pmt/telem<x>/guid
Date: October 2020
KernelVersion: 5.10
Contact: David Box <david.e.box@linux.intel.com>
Description:
(RO) The GUID for this telemetry device. The GUID identifies
the version of the XML file for the parent device that is to
be used to get the register layout.
What: /sys/class/intel_pmt/telem<x>/size
Date: October 2020
KernelVersion: 5.10
Contact: David Box <david.e.box@linux.intel.com>
Description:
(RO) The size of telemetry region in bytes that corresponds to
the mapping size for the telem file.
What: /sys/class/intel_pmt/telem<x>/offset
Date: October 2020
KernelVersion: 5.10
Contact: David Box <david.e.box@linux.intel.com>
Description:
(RO) The offset of telemetry region in bytes that corresponds to
the mapping for the telem file.
What: /sys/class/intel_pmt/crashlog<x>
Date: October 2020
KernelVersion: 5.10
Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Description:
The crashlog<x> directory contains files for configuring an
instance of a PMT crashlog device that can perform crash data
recording. Each crashlog<x> device has an associated crashlog
file. This file can be opened and mapped or read to access the
resulting crashlog buffer. The register layout for the buffer
can be determined from an XML file of specified GUID for the
parent device.
What: /sys/class/intel_pmt/crashlog<x>/crashlog
Date: October 2020
KernelVersion: 5.10
Contact: David Box <david.e.box@linux.intel.com>
Description:
(RO) The crashlog buffer for this crashlog device. This file
may be mapped or read to obtain the data.
What: /sys/class/intel_pmt/crashlog<x>/guid
Date: October 2020
KernelVersion: 5.10
Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Description:
(RO) The GUID for this crashlog device. The GUID identifies the
version of the XML file for the parent device that should be
used to determine the register layout.
What: /sys/class/intel_pmt/crashlog<x>/size
Date: October 2020
KernelVersion: 5.10
Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Description:
(RO) The length of the result buffer in bytes that corresponds
to the size for the crashlog buffer.
What: /sys/class/intel_pmt/crashlog<x>/offset
Date: October 2020
KernelVersion: 5.10
Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Description:
(RO) The offset of the buffer in bytes that corresponds
to the mapping for the crashlog device.
What: /sys/class/intel_pmt/crashlog<x>/enable
Date: October 2020
KernelVersion: 5.10
Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Description:
(RW) Boolean value controlling if the crashlog functionality
is enabled for the crashlog device.
What: /sys/class/intel_pmt/crashlog<x>/trigger
Date: October 2020
KernelVersion: 5.10
Contact: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Description:
(RW) Boolean value controlling the triggering of the crashlog
device node. When read it provides data on if the crashlog has
been triggered. When written to it can be used to either clear
the current trigger by writing false, or to trigger a new
event if the trigger is not currently set.