# SPDX-License-Identifier: GPL-2.0-only
|
config DAX_DRIVER
|
select DAX
|
bool
|
|
menuconfig DAX
|
tristate "DAX: direct access to differentiated memory"
|
select SRCU
|
default m if NVDIMM_DAX
|
|
if DAX
|
|
config DEV_DAX
|
tristate "Device DAX: direct access mapping device"
|
depends on TRANSPARENT_HUGEPAGE
|
help
|
Support raw access to differentiated (persistence, bandwidth,
|
latency...) memory via an mmap(2) capable character
|
device. Platform firmware or a device driver may identify a
|
platform memory resource that is differentiated from the
|
baseline memory pool. Mappings of a /dev/daxX.Y device impose
|
restrictions that make the mapping behavior deterministic.
|
|
config DEV_DAX_PMEM
|
tristate "PMEM DAX: direct access to persistent memory"
|
depends on LIBNVDIMM && NVDIMM_DAX && DEV_DAX
|
default DEV_DAX
|
help
|
Support raw access to persistent memory. Note that this
|
driver consumes memory ranges allocated and exported by the
|
libnvdimm sub-system.
|
|
Say M if unsure
|
|
config DEV_DAX_HMEM
|
tristate "HMEM DAX: direct access to 'specific purpose' memory"
|
depends on EFI_SOFT_RESERVE
|
select NUMA_KEEP_MEMINFO if (NUMA && X86)
|
default DEV_DAX
|
help
|
EFI 2.8 platforms, and others, may advertise 'specific purpose'
|
memory. For example, a high bandwidth memory pool. The
|
indication from platform firmware is meant to reserve the
|
memory from typical usage by default. This driver creates
|
device-dax instances for these memory ranges, and that also
|
enables the possibility to assign them to the DEV_DAX_KMEM
|
driver to override the reservation and add them to kernel
|
"System RAM" pool.
|
|
Say M if unsure.
|
|
config DEV_DAX_HMEM_DEVICES
|
depends on DEV_DAX_HMEM && DAX=y
|
def_bool y
|
|
config DEV_DAX_KMEM
|
tristate "KMEM DAX: volatile-use of persistent memory"
|
default DEV_DAX
|
depends on DEV_DAX
|
depends on MEMORY_HOTPLUG # for add_memory() and friends
|
help
|
Support access to persistent, or other performance
|
differentiated memory as if it were System RAM. This allows
|
easier use of persistent memory by unmodified applications, or
|
adds core kernel memory services to heterogeneous memory types
|
(HMEM) marked "reserved" by platform firmware.
|
|
To use this feature, a DAX device must be unbound from the
|
device_dax driver and bound to this kmem driver on each boot.
|
|
Say N if unsure.
|
|
config DEV_DAX_PMEM_COMPAT
|
tristate "PMEM DAX: support the deprecated /sys/class/dax interface"
|
depends on m && DEV_DAX_PMEM=m
|
default DEV_DAX_PMEM
|
help
|
Older versions of the libdaxctl library expect to find all
|
device-dax instances under /sys/class/dax. If libdaxctl in
|
your distribution is older than v58 say M, otherwise say N.
|
|
endif
|
