Suspend to RAM and standby

modulename: pm.ko

and/or

suspend.ko

configname: CONFIG_SUSPEND

Linux Kernel Configuration
└─>Power management and ACPI options
└─>Suspend to RAM and standby
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Allow the system to enter sleep states in which main memory is
powered and thus its contents are preserved, such as the
suspend-to-RAM state (e.g. the ACPI S3 state).

source code:
/arch/mips/loongson64/pm.c