menuconfig LIBNVDIMM tristate "NVDIMM (Non-Volatile Memory Device) Support" depends on PHYS_ADDR_T_64BIT depends on HAS_IOMEM depends on BLK_DEV help Generic support for non-volatile memory devices including ACPI-6-NFIT defined resources. On platforms that define an NFIT, or otherwise can discover NVDIMM resources, a libnvdimm bus is registered to advertise PMEM (persistent memory) namespaces (/dev/pmemX) and BLK (sliding mmio window(s)) namespaces (/dev/ndblkX.Y). A PMEM namespace refers to a memory resource that may span multiple DIMMs and support DAX (see CONFIG_DAX). A BLK namespace refers to an NVDIMM control region which exposes an mmio register set for windowed access mode to non-volatile memory. if LIBNVDIMM config BLK_DEV_PMEM tristate "PMEM: Persistent memory block device support" default LIBNVDIMM select DAX select ND_BTT if BTT select ND_PFN if NVDIMM_PFN help Memory ranges for PMEM are described by either an NFIT (NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a non-standard OEM-specific E820 memory type (type-12, see CONFIG_X86_PMEM_LEGACY), or it is manually specified by the 'memmap=nn[KMG]!ss[KMG]' kernel command line (see Documentation/admin-guide/kernel-parameters.rst). This driver converts these persistent memory ranges into block devices that are capable of DAX (direct-access) file system mappings. See Documentation/nvdimm/nvdimm.txt for more details. Say Y if you want to use an NVDIMM config ND_BLK tristate "BLK: Block data window (aperture) device support" default LIBNVDIMM select ND_BTT if BTT help Support NVDIMMs, or other devices, that implement a BLK-mode access capability. BLK-mode access uses memory-mapped-i/o apertures to access persistent media. Say Y if your platform firmware emits an ACPI.NFIT table (CONFIG_ACPI_NFIT), or otherwise exposes BLK-mode capabilities. config ND_CLAIM bool config ND_BTT tristate config BTT bool "BTT: Block Translation Table (atomic sector updates)" default y if LIBNVDIMM select ND_CLAIM help The Block Translation Table (BTT) provides atomic sector update semantics for persistent memory devices, so that applications that rely on sector writes not being torn (a guarantee that typical disks provide) can continue to do so. The BTT manifests itself as an alternate personality for an NVDIMM namespace, i.e. a namespace can be in raw mode (pmemX, ndblkX.Y, etc...), or 'sectored' mode, (pmemXs, ndblkX.Ys, etc...). Select Y if unsure config ND_PFN tristate config NVDIMM_PFN bool "PFN: Map persistent (device) memory" default LIBNVDIMM depends on ZONE_DEVICE select ND_CLAIM help Map persistent memory, i.e. advertise it to the memory management sub-system. By default persistent memory does not support direct I/O, RDMA, or any other usage that requires a 'struct page' to mediate an I/O request. This driver allocates and initializes the infrastructure needed to support those use cases. Select Y if unsure config NVDIMM_DAX bool "NVDIMM DAX: Raw access to persistent memory" default LIBNVDIMM depends on NVDIMM_PFN help Support raw device dax access to a persistent memory namespace. For environments that want to hard partition peristent memory, this capability provides a mechanism to sub-divide a namespace into character devices that can only be accessed via DAX (mmap(2)). Select Y if unsure config OF_PMEM tristate "Device-tree support for persistent memory regions" depends on OF default LIBNVDIMM help Allows regions of persistent memory to be described in the device-tree. Select Y if unsure. endif