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Diffstat (limited to 'drivers/dax/Kconfig')
| -rw-r--r-- | drivers/dax/Kconfig | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig new file mode 100644 index 000000000..a88744244 --- /dev/null +++ b/drivers/dax/Kconfig @@ -0,0 +1,81 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig DAX + tristate "DAX: direct access to differentiated memory" + 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_CXL + tristate "CXL DAX: direct access to CXL RAM regions" + depends on CXL_BUS && CXL_REGION && DEV_DAX + default CXL_REGION && DEV_DAX + help + CXL RAM regions are either mapped by platform-firmware + and published in the initial system-memory map as "System RAM", mapped + by platform-firmware as "Soft Reserved", or dynamically provisioned + after boot by the CXL driver. In the latter two cases a device-dax + instance is created to access that unmapped-by-default address range. + Per usual it can remain as dedicated access via a device interface, or + converted to "System RAM" via the dax_kmem facility. + +config DEV_DAX_HMEM_DEVICES + depends on DEV_DAX_HMEM && DAX + def_bool y + +config DEV_DAX_KMEM + tristate "KMEM DAX: map dax-devices as System-RAM" + 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. + +endif |