This patch adds the description to explain the TDP reporting mechanism and accumulated power algorithm. Signed-off-by: Huang Rui <ray.huang@xxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> --- Documentation/hwmon/fam15h_power | 57 +++++++++++++++++++++++++++++++++++++++- drivers/hwmon/fam15h_power.c | 2 +- 2 files changed, 57 insertions(+), 2 deletions(-) diff --git a/Documentation/hwmon/fam15h_power b/Documentation/hwmon/fam15h_power index e2b1b69..2c4fbee 100644 --- a/Documentation/hwmon/fam15h_power +++ b/Documentation/hwmon/fam15h_power @@ -10,14 +10,22 @@ Supported chips: Datasheets: BIOS and Kernel Developer's Guide (BKDG) For AMD Family 15h Processors BIOS and Kernel Developer's Guide (BKDG) For AMD Family 16h Processors + AMD64 Architecture Programmer's Manual Volume 2: System Programming Author: Andreas Herrmann <herrmann.der.user@xxxxxxxxxxxxxx> Description ----------- +1) Processor TDP (Thermal design power) + +Given a fixed frequency and voltage, the power consumption of a +processor varies based on the workload being executed. Derated power +is the power consumed when running a specific application. Thermal +design power (TDP) is an example of derated power. + This driver permits reading of registers providing power information -of AMD Family 15h and 16h processors. +of AMD Family 15h and 16h processors via TDP algorithm. For AMD Family 15h and 16h processors the following power values can be calculated using different processor northbridge function @@ -37,3 +45,50 @@ This driver provides ProcessorPwrWatts and CurrPwrWatts: On multi-node processors the calculated value is for the entire package and not for a single node. Thus the driver creates sysfs attributes only for internal node0 of a multi-node processor. + +2) Accumulated Power Mechanism + +This driver also introduces an algorithm that should be used to +calculate the average power consumed by a processor during a +measurement interval Tm. The feature of accumulated power mechanism is +indicated by CPUID Fn8000_0007_EDX[12]. + +* Tsample: compute unit power accumulator sample period +* Tref: the PTSC counter period +* PTSC: performance timestamp counter +* N: the ratio of compute unit power accumulator sample period to the + PTSC period +* Jmax: max compute unit accumulated power which is indicated by + MaxCpuSwPwrAcc MSR C001007b +* Jx/Jy: compute unit accumulated power which is indicated by + CpuSwPwrAcc MSR C001007a +* Tx/Ty: the value of performance timestamp counter which is indicated + by CU_PTSC MSR C0010280 +* PwrCPUave: CPU average power + +i. Determine the ratio of Tsample to Tref by executing CPUID Fn8000_0007. + N = value of CPUID Fn8000_0007_ECX[CpuPwrSampleTimeRatio[15:0]]. + +ii. Read the full range of the cumulative energy value from the new +MSR MaxCpuSwPwrAcc. + Jmax = value returned. +iii. At time x, SW reads CpuSwPwrAcc MSR and samples the PTSC. + Jx = value read from CpuSwPwrAcc and Tx = value read from +PTSC. + +iv. At time y, SW reads CpuSwPwrAcc MSR and samples the PTSC. + Jy = value read from CpuSwPwrAcc and Ty = value read from +PTSC. + +v. Calculate the average power consumption for a compute unit over +time period (y-x). Unit of result is uWatt. + if (Jy < Jx) // Rollover has occurred + Jdelta = (Jy + Jmax) - Jx + else + Jdelta = Jy - Jx + PwrCPUave = N * Jdelta * 1000 / (Ty - Tx) + +This driver provides PwrCPUave and interval(default is 10 millisecond +and maximum is 1 second): +* power1_average (PwrCPUave) +* power1_average_interval (Interval) diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c index 46cbca0..35800cd 100644 --- a/drivers/hwmon/fam15h_power.c +++ b/drivers/hwmon/fam15h_power.c @@ -1,7 +1,7 @@ /* * fam15h_power.c - AMD Family 15h processor power monitoring * - * Copyright (c) 2011 Advanced Micro Devices, Inc. + * Copyright (c) 2011-2016 Advanced Micro Devices, Inc. * Author: Andreas Herrmann <herrmann.der.user@xxxxxxxxxxxxxx> * * -- 1.9.1 _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
