| commit | 3f6bc73197d94e075a64c355fe11123ca1b59e76 | [log] [tgz] |
|---|---|---|
| author | Harshit Aghera <haghera@nvidia.com> | Wed Jul 23 14:22:01 2025 +0530 |
| committer | Ed Tanous <ed@tanous.net> | Fri Oct 24 23:19:51 2025 +0000 |
| tree | 7c66bf705d1c134b75708d78955a3663465dc42e | |
| parent | d9065a092b02d7f5fd6b56f597c3f8b45afb4d8c [diff] |
nvidia-gpu: add TLimit sensor properties Add support for DMTF Redfish properties ReadingBasis and Implementation for GPU TLimit sensor [1]. Property Implementation for TLimit is set to Synthesized because the GPU incorporates intelligent logic that determines the temperature delta from the first thermal management software slowdown event. TLimit is derived from other reported GPU sensors, such as HBM, Tavg, and others. DBus Interface definition - https://gerrit.openbmc.org/c/openbmc/phosphor-dbus-interfaces/+/81658 Tested: Build an image for gb200nvl-obmc machine with the following patches cherry picked. This patches are needed to enable the mctp stack. https://gerrit.openbmc.org/c/openbmc/openbmc/+/79422 ``` > curl -s -k -u 'root:0penBmc' https://10.137.203.137/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_1 { "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/temperature_NVIDIA_GB200_GPU_0_TEMP_1", "@odata.type": "#Sensor.v1_2_0.Sensor", "Description": "Thermal Limit(TLIMIT) Temperature is the distance in deg C from the GPU temperature to the first throttle limit.", "Id": "temperature_NVIDIA_GB200_GPU_0_TEMP_1", "Implementation": "Synthesized", "Name": "NVIDIA GB200 GPU 0 TEMP 1", "Reading": 56.59375, "ReadingBasis": "Headroom", "ReadingRangeMax": 127.0, "ReadingRangeMin": -128.0, "ReadingType": "Temperature", "ReadingUnits": "Cel", "Status": { "Health": "OK", "State": "Enabled" } }% root@gb200nvl-obmc:~# busctl introspect xyz.openbmc_project.GpuSensor /xyz/openbmc_project/sensors/temperature/NVIDIA_GB200_GPU_0_TEMP_1 NAME TYPE SIGNATURE RESULT/VALUE FLAGS org.freedesktop.DBus.Introspectable interface - - - .Introspect method - s - org.freedesktop.DBus.Peer interface - - - .GetMachineId method - s - .Ping method - - - org.freedesktop.DBus.Properties interface - - - .Get method ss v - .GetAll method s a{sv} - .Set method ssv - - .PropertiesChanged signal sa{sv}as - - xyz.openbmc_project.Association.Definitions interface - - - .Associations property a(sss) 1 "chassis" "all_sensors" "/xyz/openb... emits-change xyz.openbmc_project.Inventory.Item interface - - - .PrettyName property s "Thermal Limit(TLIMIT) Temperature is... emits-change xyz.openbmc_project.Sensor.Type interface - - - .Implementation property s "xyz.openbmc_project.Sensor.Type.Impl... emits-change .ReadingBasis property s "xyz.openbmc_project.Sensor.Type.Read... emits-change xyz.openbmc_project.Sensor.Value interface - - - .MaxValue property d 127 emits-change .MinValue property d -128 emits-change .Unit property s "xyz.openbmc_project.Sensor.Value.Uni... emits-change .Value property d 56.6836 emits-change writable xyz.openbmc_project.Sensor.ValueMutability interface - - - .Mutable property b true emits-change xyz.openbmc_project.State.Decorator.Availability interface - - - .Available property b true emits-change writable xyz.openbmc_project.State.Decorator.OperationalStatus interface - - - .Functional property b true emits-change ``` [1] : https://redfish.dmtf.org/schemas/v1/Sensor.v1_11_0.yaml Change-Id: I1a16ced44c563794d561d26232a5e5fba041b875 Signed-off-by: Harshit Aghera <haghera@nvidia.com>
dbus-sensors is a collection of sensor applications that provide the xyz.openbmc_project.Sensor collection of interfaces. They read sensor values from hwmon, d-bus, or direct driver access to provide readings. Some advance non-sensor features such as fan presence, pwm control, and automatic cpu detection (x86) are also supported.
runtime re-configurable from d-bus (entity-manager or the like)
isolated: each sensor type is isolated into its own daemon, so a bug in one sensor is unlikely to affect another, and single sensor modifications are possible
async single-threaded: uses sdbusplus/asio bindings
multiple data inputs: hwmon, d-bus, direct driver access
A typical dbus-sensors object support the following dbus interfaces:
Path /xyz/openbmc_project/sensors/<type>/<sensor_name> Interfaces xyz.openbmc_project.Sensor.Value xyz.openbmc_project.Sensor.Threshold.Critical xyz.openbmc_project.Sensor.Threshold.Warning xyz.openbmc_project.State.Decorator.Availability xyz.openbmc_project.State.Decorator.OperationalStatus xyz.openbmc_project.Association.Definitions
Sensor interfaces collection are described in phosphor-dbus-interfaces.
Consumer examples of these interfaces are Redfish, Phosphor-Pid-Control, IPMI SDR.
dbus-sensor daemons are reactors that dynamically create and update sensors configuration when system configuration gets updated.
Using asio timers and async calls, dbus-sensor daemons read sensor values and check thresholds periodically. PropertiesChanged signals will be broadcasted for other services to consume when value or threshold status change. OperationStatus is set to false if the sensor is determined to be faulty.
A simple sensor example can be found in entity-manager examples.
Sensor devices are described using Exposes records in configuration file. Name and Type fields are required. Different sensor types have different fields. Refer to entity manager schema for complete list.
ADC sensors are sensors based on an Analog to Digital Converter. They are read via the Linux kernel Industrial I/O subsystem (IIO).
One of the more common use cases within OpenBMC is for reading these sensors from the ADC on the Aspeed ASTXX cards.
To utilize ADC sensors feature within OpenBMC you must first define and enable it within the kernel device tree.
When using a common OpenBMC device like the AST2600 you will find a "adc0" and "adc1" section in the aspeed-g6.dtsi file. These are disabled by default so in your system-specific dts you would enable and configure what you want with something like this:
iio-hwmon { compatible = "iio-hwmon"; io-channels = <&adc0 0>; ... } &adc0 { status = "okay"; ... }; &adc1 { status = "okay"; ... };
Note that this is not meant to be an exhaustive list on the nuances of configuring a device tree but really to point users in the general direction.
You will then create an entity-manager configuration file that is of type "ADC" A very simple example would like look this:
"Index": 0, "Name": "P12V", "PowerState": "Always", "ScaleFactor": 1.0, "Type": "ADC"
When your system is booted, a "in0_input" file will be created within the hwmon subsystem (/sys/class/hwmon/hwmonX). The adcsensor application will scan d-bus for any ADC entity-manager objects, look up their "Index" value, and try to match that with the hwmon inY_input files. When it finds a match it will create a d-bus sensor under the xyz.openbmc_project.ADCSensor service. The sensor will be periodically updated based on readings from the hwmon file.