|  | # SPDX-License-Identifier: GPL-2.0-only | 
|  | menuconfig RAS | 
|  | bool "Reliability, Availability and Serviceability (RAS) features" | 
|  | help | 
|  | Reliability, availability and serviceability (RAS) is a computer | 
|  | hardware engineering term. Computers designed with higher levels | 
|  | of RAS have a multitude of features that protect data integrity | 
|  | and help them stay available for long periods of time without | 
|  | failure. | 
|  |  | 
|  | Reliability can be defined as the probability that the system will | 
|  | produce correct outputs up to some given time. Reliability is | 
|  | enhanced by features that help to avoid, detect and repair hardware | 
|  | faults. | 
|  |  | 
|  | Availability is the probability a system is operational at a given | 
|  | time, i.e. the amount of time a device is actually operating as the | 
|  | percentage of total time it should be operating. | 
|  |  | 
|  | Serviceability or maintainability is the simplicity and speed with | 
|  | which a system can be repaired or maintained; if the time to repair | 
|  | a failed system increases, then availability will decrease. | 
|  |  | 
|  | Note that Reliability and Availability are distinct concepts: | 
|  | Reliability is a measure of the ability of a system to function | 
|  | correctly, including avoiding data corruption, whereas Availability | 
|  | measures how often it is available for use, even though it may not | 
|  | be functioning correctly. For example, a server may run forever and | 
|  | so have ideal availability, but may be unreliable, with frequent | 
|  | data corruption. | 
|  |  | 
|  | if RAS | 
|  |  | 
|  | source "arch/x86/ras/Kconfig" | 
|  | source "drivers/ras/amd/atl/Kconfig" | 
|  |  | 
|  | config RAS_FMPM | 
|  | tristate "FRU Memory Poison Manager" | 
|  | default m | 
|  | depends on AMD_ATL && ACPI_APEI | 
|  | help | 
|  | Support saving and restoring memory error information across reboot | 
|  | using ACPI ERST as persistent storage. Error information is saved with | 
|  | the UEFI CPER "FRU Memory Poison" section format. | 
|  |  | 
|  | Memory will be retired during boot time and run time depending on | 
|  | platform-specific policies. | 
|  |  | 
|  | endif |