xref: /openbmc/linux/drivers/nvdimm/Kconfig (revision f5005f78)
1menuconfig LIBNVDIMM
2	tristate "NVDIMM (Non-Volatile Memory Device) Support"
3	depends on PHYS_ADDR_T_64BIT
4	depends on BLK_DEV
5	help
6	  Generic support for non-volatile memory devices including
7	  ACPI-6-NFIT defined resources.  On platforms that define an
8	  NFIT, or otherwise can discover NVDIMM resources, a libnvdimm
9	  bus is registered to advertise PMEM (persistent memory)
10	  namespaces (/dev/pmemX) and BLK (sliding mmio window(s))
11	  namespaces (/dev/ndblkX.Y). A PMEM namespace refers to a
12	  memory resource that may span multiple DIMMs and support DAX
13	  (see CONFIG_DAX).  A BLK namespace refers to an NVDIMM control
14	  region which exposes an mmio register set for windowed access
15	  mode to non-volatile memory.
16
17if LIBNVDIMM
18
19config BLK_DEV_PMEM
20	tristate "PMEM: Persistent memory block device support"
21	default LIBNVDIMM
22	depends on HAS_IOMEM
23	select ND_BTT if BTT
24	help
25	  Memory ranges for PMEM are described by either an NFIT
26	  (NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a
27	  non-standard OEM-specific E820 memory type (type-12, see
28	  CONFIG_X86_PMEM_LEGACY), or it is manually specified by the
29	  'memmap=nn[KMG]!ss[KMG]' kernel command line (see
30	  Documentation/kernel-parameters.txt).  This driver converts
31	  these persistent memory ranges into block devices that are
32	  capable of DAX (direct-access) file system mappings.  See
33	  Documentation/nvdimm/nvdimm.txt for more details.
34
35	  Say Y if you want to use an NVDIMM
36
37config ND_BLK
38	tristate "BLK: Block data window (aperture) device support"
39	default LIBNVDIMM
40	select ND_BTT if BTT
41	help
42	  Support NVDIMMs, or other devices, that implement a BLK-mode
43	  access capability.  BLK-mode access uses memory-mapped-i/o
44	  apertures to access persistent media.
45
46	  Say Y if your platform firmware emits an ACPI.NFIT table
47	  (CONFIG_ACPI_NFIT), or otherwise exposes BLK-mode
48	  capabilities.
49
50config ND_BTT
51	tristate
52
53config BTT
54	bool "BTT: Block Translation Table (atomic sector updates)"
55	default y if LIBNVDIMM
56	help
57	  The Block Translation Table (BTT) provides atomic sector
58	  update semantics for persistent memory devices, so that
59	  applications that rely on sector writes not being torn (a
60	  guarantee that typical disks provide) can continue to do so.
61	  The BTT manifests itself as an alternate personality for an
62	  NVDIMM namespace, i.e. a namespace can be in raw mode (pmemX,
63	  ndblkX.Y, etc...), or 'sectored' mode, (pmemXs, ndblkX.Ys,
64	  etc...).
65
66	  Select Y if unsure
67
68endif
69