1bbf21555SRichard Lowe.\" 2bbf21555SRichard Lowe.\" This file and its contents are supplied under the terms of the 3bbf21555SRichard Lowe.\" Common Development and Distribution License ("CDDL"), version 1.0. 4bbf21555SRichard Lowe.\" You may only use this file in accordance with the terms of version 5bbf21555SRichard Lowe.\" 1.0 of the CDDL. 6bbf21555SRichard Lowe.\" 7bbf21555SRichard Lowe.\" A full copy of the text of the CDDL should have accompanied this 8bbf21555SRichard Lowe.\" source. A copy of the CDDL is also available via the Internet at 9bbf21555SRichard Lowe.\" http://www.illumos.org/license/CDDL. 10bbf21555SRichard Lowe.\" 11bbf21555SRichard Lowe.\" 12bbf21555SRichard Lowe.\" Copyright 2019, Joyent, Inc. 13*71536d92SRobert Mustacchi.\" Copyright 2024 Oxide Computer Company 14bbf21555SRichard Lowe.\" 15*71536d92SRobert Mustacchi.Dd May 22, 2024 16bbf21555SRichard Lowe.Dt SMNTEMP 4D 17bbf21555SRichard Lowe.Os 18bbf21555SRichard Lowe.Sh NAME 19bbf21555SRichard Lowe.Nm smntemp 20bbf21555SRichard Lowe.Nd AMD SMN Temperature Sensor Driver 21bbf21555SRichard Lowe.Sh SYNOPSIS 22bbf21555SRichard Lowe.Pa /dev/sensors/temperature/cpu/* 23bbf21555SRichard Lowe.Sh DESCRIPTION 24bbf21555SRichard LoweThe 25bbf21555SRichard Lowe.Nm 26*71536d92SRobert Mustacchidriver provides the system access to the temperature and control sensors found 27*71536d92SRobert Mustacchiin the AMD System Management Network 28bbf21555SRichard Lowe.Pq SMN 29*71536d92SRobert Mustacchion Zen 1-5 processors 30*71536d92SRobert Mustacchi.Pq AMD Family 17h, 19h, and 1ah . 31bbf21555SRichard Lowe.Pp 32*71536d92SRobert MustacchiEach CCD, core complex die, present in the SoC exposes its own temperature in 33*71536d92SRobert Mustacchidegrees Celsius. 34*71536d92SRobert MustacchiThis covers the temperature of the CCD as a whole and could be thought of as a 35*71536d92SRobert Mustacchitemperature sensor for all the cores and caches in the die. 36*71536d92SRobert MustacchiThere is no per-core temperature sensor available. 37*71536d92SRobert Mustacchi.Pp 38*71536d92SRobert MustacchiIn addition, a control temperature is exposed for each I/O die, Zen 2 and newer, 39*71536d92SRobert Mustacchior each Zeppelin die, Zen 1. 40*71536d92SRobert MustacchiThe control temperature is a unitless measure derived from the temperature that 41*71536d92SRobert Mustacchiindicates to cooling infrastructure what action to take and can take any value 42*71536d92SRobert Mustacchion the range 0 to 100. 43*71536d92SRobert MustacchiA value of 95 indicates that thermal throttling should be occurring and a value 44*71536d92SRobert Mustacchiof 100 indicates that the chip will hit its thermal limit and shut down if no 45*71536d92SRobert Mustacchiaction is taken. 46*71536d92SRobert MustacchiCritically, the control temperature is not truly a measure of degrees! 47bbf21555SRichard Lowe.Pp 48bbf21555SRichard LoweTemperature information is available to the system via the fault 49bbf21555SRichard Lowemanagement architecture 50bbf21555SRichard Lowe.Pq FMA . 51bbf21555SRichard LoweThe file system location and programming interface to the 52bbf21555SRichard Lowe.Nm 53bbf21555SRichard Lowedriver are considered 54bbf21555SRichard Lowe.Sy Volatile , 55bbf21555SRichard Lowesubject to change without notice, and should not be used directly. 56bbf21555SRichard LoweRaw temperature information can be dumped through the FMA developer 57bbf21555SRichard Loweutility fmtopo. 58bbf21555SRichard Lowe.Sh SEE ALSO 59bbf21555SRichard Lowe.Xr amdnbtemp 4D , 60bbf21555SRichard Lowe.Xr amdzen 4D , 61bbf21555SRichard Lowe.Xr fmadm 8 62bbf21555SRichard Lowe.Rs 63bbf21555SRichard Lowe.%A AMD 64bbf21555SRichard Lowe.%B Open-Source Register Reference For AMD Family 17h Processors Models 00h-2Fh 65bbf21555SRichard Lowe.%D July, 2018 66bbf21555SRichard Lowe.Re 67