Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Device (NVDR) // Root device
{
Name (_HID, “ACPI0012”)
Method (_STA) {…}
Method (_FIT) {…}
Method (_DSM, …) {
…
}
Device (NVD1) // NVDIMM1
{
Name(_ADR, h1) //where h1 is NFIT Device Handle for this NVDIMM1
Method (_DSM, …) {
…
}
}
}
Device (NVD2) // NVDIMM2
{
Name(_ADR, h2) //where h2 is NFIT Device Handle for this NVDIMM2
Method (_DSM, …) {
…
}
}
Device (MEM0) // Memory module
{
Name (_HID, EISAID (“PNP0C80”))
Method (_STA) {…}
Method (_CRS) {…}
}
Scope (\_GPE)
{
Method (_L00) {
Notify (\_SB.NVDR, 0x80) // Notify to NVDIMM root device
Notify (\_SB.MEM0, 1) // Device Check to Memory Module
}
}
Hot Plugged memory is indicated to OS using ACPI Name Space device with PNPID of PNP0C80.
The NFIT entries created by the hot plug NVDIMM are communicated by the ACPI Name Space
device with ACPI0012.
NVDIMM hot add flow:
1. Prior to hot add of the NVDIMM, the corresponding ACPI Name Space devices, NVD1, NVD2
return an address from _ADR object (NFIT Device handle) which does not match any entries
present in NFIT (either the static or from _FIT) indicating that the corresponding NVDIMM is
not present. Further ACPI Name Space Device MEM0 returns _STA status of 0 indicating that
the devices are not present, not enabled and not functioning.
2. On hot add
a Send Notify 0x80 to NVDR to cause NVDIMM bus driver to enumerate all the devices
under the root hierarchy
558 April, 2015 Version 6.0