| Date: | 09-02-2024 |
|---|---|
| Title: | TPMI |
Contents
TPMI stands for Topology Aware Register and PM Capsule Interface and it is a memory-mapped interface for reading and writing processor's registers related to power management features on Intel CPUs.
TPMI registers are exposed by the processor via PCIe VSEC (Vendor-Specific Extended Capabilities), and the registers are grouped into TPMI features. For example, the "uncore" TPMI feature includes processor registers related to uncore frequency scaling. The "rapl" TPMI feature includes processor registers related to processor's Running Average Power Limit (RAPL). The "sst" feature includes processor registers related to Intel Speed Select Technology (SST).
In order for the 'pepc' tool to decode TPMI features, the spec file is required. The spec file describes the register names, bits, and offsets in the memory-mapped PCIe address space. If there is no spec file for a feature, it cannot be decoded.
The 'pepc' project comes with some standard pepc files, which will be searched for in the following locations and in the following order.
- './tpmi', in the directory of the running program
- '$PEPC_DATA_PATH/tpmi'
- '$HOME/.local/share/pepc/tpmi'
- '/usr/local/share/pepc/tpmi'
- '/usr/share/pepc/tpmi'
In addition to this, users can provide custom/private spec files by placing them to a directory and specifying the directory path via the 'PEPC_TPMI_DATA_PATH' environment variable.
- -h
- Show a short help message and exit.
- -q
- Be quiet.
- -d
- Print debugging information.
- --version
- Print version and exit.
- -H HOSTNAME, --host HOSTNAME
- Name of the host to run the command on.
- -U USERNAME, --username USERNAME
- Name of the user to use for logging into the remote host over SSH. The default user name is 'root'.
- -K PRIVKEY, --priv-key PRIVKEY
- Path to the private SSH key that should be used for logging into the remote host. By default the key is automatically found from standard paths like '$HOME/.ssh'.
- -T TIMEOUT, --timeout TIMEOUT
- SSH connection timeout in seconds, default is 8.
- -D DATASET, --dataset DATASET
This option is for debugging and testing purposes only, it defines the dataset that will be used to emulate a host for running the command on. This option is typically used when running 'pepc' from the source code directory, which includes datasets for many different systems.
The argument can be the dataset path, 'all' to specify all available dataset or name in which case the following locations will be searched for.
- './tests/data', in the directory of the running program
- '$PEPC_DATA_PATH/tests/data'
- '$HOME/.local/share/pepc/tests/data'
- '/usr/local/share/pepc/tests/data'
- '/usr/share/pepc/tests/data'
- --force-color
- Force coloring of the text output.
List supported TPMI features.
- -l, --long
- Provide additional information, such as TPMI device PCI addresses and TPMI instance numbers.
- --all
- Also print IDs of TPMI features supported by the processor, but for which there are no spec files, so they cannot be decoded.
Read one or multiple TPMI registers.
- -F FEATURES, --features FEATURES
- Comma-separated list of TPMI feature names to read the register(s) for. Read for all supported features by default.
- -a ADDRS, --addresses ADDRS
- Comma-separated list of TPMI device PCI addresses to read the registers from. Read from all devices by default.
- --packages PACKAGES
- Comma-separated list of integer package numbers to read TPMI registers for (all packages by default).
- -i INSTANCES, --instances INSTANCES
- Comma-separated list of integer TPMI instance numbers to read the registers from (all instances by default).
- -R REGISTERS, --registers REGISTERS
- Comma-separated list of TPMI registers names to read (all registers by default).
- -b BFNAMES, --bitfields BFNAMES
- Comma-separated list of TPMI register bit field names to read (all bit fields by default).
- --yaml
- Print information in YAML format.
Write to a TPMI register.
- -F FEATURE, --feature FEATURE
- Name of the TPMI feature the register belongs to.
- -a ADDRS, --addresses ADDRS
- Comma-separated list of TPMI device PCI addresses to write to.
- --packages PACKAGES
- Comma-separated list of package numbers to write the TPMI register for (all packages by default).
- -i INSTANCES, --instances INSTANCES
- Comma-separated list of integer TPMI instance numbers to write to (all instances by default).
- -R REGNAME, --register REGNAME
- Name of the TPMI register to write to.
- -b BITFIELD, --bitfield BITFIELD
- Name of the TPMI register bitfield to write to. If not specified, write to the register, not a bit field of the register.
- -V VALUE, --value VALUE
- The value to write to the TPMI register or its bit field.