Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
to the NVDIMM region to be flushed out of the intervening platform buffers 1 to the targeted
NVDIMM (to achieve durability).
Table 5-135 Flush Hint Address Structure
Field
Byte Byte Offset Description
Length
Type 2 0 6 Flush Hint Address Structure
Length 2 2 Length in bytes for entire structure.
NFIT Device Handle 4 4 Indicates the NVDIMM supported by the Flush
Hint Addresses in this structure.
Number of Flush Hint
Addresses in this structure
(m)
2 8 Number of Flush Hint Addresses in this structure.
Reserved 6 10 Reserved
Flush Hint Address 1 8 16 64-bit system physical address that needs to be
written to cause durability flush. Software is
allowed to write up to a cache line of data. The
content of the data is not relevant to the
functioning of flush hint mechanism.
… 8 24
Flush Hint Address m 8 16+ ((m-
1)*8)
64-bit system physical address that needs to be
written to cause durability flush. Software is
allowed to write up to a cache line of data. The
content of the data is not relevant to the
functioning of flush hint mechanism.
5.3 ACPI Namespace
For all Definition Blocks, the system maintains a single hierarchical namespace that it uses to refer
to objects. All Definition Blocks load into the same namespace. Although this allows one Definition
Block to reference objects and data from another (thus enabling interaction), it also means that
OEMs must take care to avoid any naming collisions 2 . Only an unload operation of a Definition
Block can remove names from the namespace, so a name collision in an attempt to load a Definition
Block is considered fatal. The contents of the namespace changes only on a load or unload operation.
The namespace is hierarchical in nature, with each name allowing a collection of names “below” it.
The following naming conventions apply to all names:
1. Note that the platform buffers do not include processor cache(s)! Processors typically include ISA to flush
data out of processor caches.
2. For the most part, since the name space is hierarchical, typically the bulk of a dynamic definition file will
load into a different part of the hierarchy. The root of the name space and certain locations where interaction is being
designed are the areas in which extra care must be taken.
212 April, 2015 Version 6.0