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diff --git a/Documentation/hwmon/amd_energy.rst b/Documentation/hwmon/amd_energy.rst deleted file mode 100644 index 9d58cd5ee3da..000000000000 --- a/Documentation/hwmon/amd_energy.rst +++ /dev/null @@ -1,119 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -Kernel driver amd_energy -========================== - -Supported chips: - -* AMD Family 17h Processors: Model 30h - -* AMD Family 19h Processors: Model 01h - - Prefix: 'amd_energy' - - Addresses used: RAPL MSRs - - Datasheets: - - - Processor Programming Reference (PPR) for AMD Family 17h Model 01h, Revision B1 Processors - - https://developer.amd.com/wp-content/resources/55570-B1_PUB.zip - - - Preliminary Processor Programming Reference (PPR) for AMD Family 17h Model 31h, Revision B0 Processors - - https://developer.amd.com/wp-content/resources/56176_ppr_Family_17h_Model_71h_B0_pub_Rev_3.06.zip - -Author: Naveen Krishna Chatradhi <nchatrad@amd.com> - -Description ------------ - -The Energy driver exposes the energy counters that are -reported via the Running Average Power Limit (RAPL) -Model-specific Registers (MSRs) via the hardware monitor -(HWMON) sysfs interface. - -1. Power, Energy and Time Units - MSR_RAPL_POWER_UNIT/ C001_0299: - shared with all cores in the socket - -2. Energy consumed by each Core - MSR_CORE_ENERGY_STATUS/ C001_029A: - 32-bitRO, Accumulator, core-level power reporting - -3. Energy consumed by Socket - MSR_PACKAGE_ENERGY_STATUS/ C001_029B: - 32-bitRO, Accumulator, socket-level power reporting, - shared with all cores in socket - -These registers are updated every 1ms and cleared on -reset of the system. - -Note: If SMT is enabled, Linux enumerates all threads as cpus. -Since, the energy status registers are accessed at core level, -reading those registers from the sibling threads would result -in duplicate values. Hence, energy counter entries are not -populated for the siblings. - -Energy Caluclation ------------------- - -Energy information (in Joules) is based on the multiplier, -1/2^ESU; where ESU is an unsigned integer read from -MSR_RAPL_POWER_UNIT register. Default value is 10000b, -indicating energy status unit is 15.3 micro-Joules increment. - -Reported values are scaled as per the formula - -scaled value = ((1/2^ESU) * (Raw value) * 1000000UL) in uJoules - -Users calculate power for a given domain by calculating - dEnergy/dTime for that domain. - -Energy accumulation --------------------------- - -Current, Socket energy status register is 32bit, assuming a 240W -2P system, the register would wrap around in - - 2^32*15.3 e-6/240 * 2 = 547.60833024 secs to wrap(~9 mins) - -The Core energy register may wrap around after several days. - -To improve the wrap around time, a kernel thread is implemented -to accumulate the socket energy counters and one core energy counter -per run to a respective 64-bit counter. The kernel thread starts -running during probe, wakes up every 100secs and stops running -when driver is removed. - -Frequency of the accumulator thread is set during the probe -based on the chosen energy unit resolution. For example -A. fine grain (1.625 micro J) -B. course grain (0.125 milli J) - -A socket and core energy read would return the current register -value added to the respective energy accumulator. - -Sysfs attributes ----------------- - -=============== ======== ===================================== -Attribute Label Description -=============== ======== ===================================== - -* For index N between [1] and [nr_cpus] - -=============== ======== ====================================== -energy[N]_input EcoreX Core Energy X = [0] to [nr_cpus - 1] - Measured input core energy -=============== ======== ====================================== - -* For N between [nr_cpus] and [nr_cpus + nr_socks] - -=============== ======== ====================================== -energy[N]_input EsocketX Socket Energy X = [0] to [nr_socks -1] - Measured input socket energy -=============== ======== ====================================== - -Note: To address CVE-2020-12912, the visibility of the energy[N]_input -attributes is restricted to owner and groups only. |