1# SPDX-License-Identifier: GPL-2.0-only 2config DAX_DRIVER 3 select DAX 4 bool 5 6menuconfig DAX 7 tristate "DAX: direct access to differentiated memory" 8 select SRCU 9 default m if NVDIMM_DAX 10 11if DAX 12 13config DEV_DAX 14 tristate "Device DAX: direct access mapping device" 15 depends on TRANSPARENT_HUGEPAGE 16 help 17 Support raw access to differentiated (persistence, bandwidth, 18 latency...) memory via an mmap(2) capable character 19 device. Platform firmware or a device driver may identify a 20 platform memory resource that is differentiated from the 21 baseline memory pool. Mappings of a /dev/daxX.Y device impose 22 restrictions that make the mapping behavior deterministic. 23 24config DEV_DAX_PMEM 25 tristate "PMEM DAX: direct access to persistent memory" 26 depends on LIBNVDIMM && NVDIMM_DAX && DEV_DAX 27 default DEV_DAX 28 help 29 Support raw access to persistent memory. Note that this 30 driver consumes memory ranges allocated and exported by the 31 libnvdimm sub-system. 32 33 Say M if unsure 34 35config DEV_DAX_KMEM 36 tristate "KMEM DAX: volatile-use of persistent memory" 37 default DEV_DAX 38 depends on DEV_DAX 39 depends on MEMORY_HOTPLUG # for add_memory() and friends 40 help 41 Support access to persistent memory as if it were RAM. This 42 allows easier use of persistent memory by unmodified 43 applications. 44 45 To use this feature, a DAX device must be unbound from the 46 device_dax driver (PMEM DAX) and bound to this kmem driver 47 on each boot. 48 49 Say N if unsure. 50 51config DEV_DAX_PMEM_COMPAT 52 tristate "PMEM DAX: support the deprecated /sys/class/dax interface" 53 depends on m && DEV_DAX_PMEM=m 54 default DEV_DAX_PMEM 55 help 56 Older versions of the libdaxctl library expect to find all 57 device-dax instances under /sys/class/dax. If libdaxctl in 58 your distribution is older than v58 say M, otherwise say N. 59 60endif 61