xref: /openbmc/linux/drivers/nvdimm/Kconfig (revision 74ce1896)
1menuconfig LIBNVDIMM
2	tristate "NVDIMM (Non-Volatile Memory Device) Support"
3	depends on PHYS_ADDR_T_64BIT
4	depends on HAS_IOMEM
5	depends on BLK_DEV
6	help
7	  Generic support for non-volatile memory devices including
8	  ACPI-6-NFIT defined resources.  On platforms that define an
9	  NFIT, or otherwise can discover NVDIMM resources, a libnvdimm
10	  bus is registered to advertise PMEM (persistent memory)
11	  namespaces (/dev/pmemX) and BLK (sliding mmio window(s))
12	  namespaces (/dev/ndblkX.Y). A PMEM namespace refers to a
13	  memory resource that may span multiple DIMMs and support DAX
14	  (see CONFIG_DAX).  A BLK namespace refers to an NVDIMM control
15	  region which exposes an mmio register set for windowed access
16	  mode to non-volatile memory.
17
18if LIBNVDIMM
19
20config BLK_DEV_PMEM
21	tristate "PMEM: Persistent memory block device support"
22	default LIBNVDIMM
23	select DAX
24	select ND_BTT if BTT
25	select ND_PFN if NVDIMM_PFN
26	help
27	  Memory ranges for PMEM are described by either an NFIT
28	  (NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a
29	  non-standard OEM-specific E820 memory type (type-12, see
30	  CONFIG_X86_PMEM_LEGACY), or it is manually specified by the
31	  'memmap=nn[KMG]!ss[KMG]' kernel command line (see
32	  Documentation/admin-guide/kernel-parameters.rst).  This driver converts
33	  these persistent memory ranges into block devices that are
34	  capable of DAX (direct-access) file system mappings.  See
35	  Documentation/nvdimm/nvdimm.txt for more details.
36
37	  Say Y if you want to use an NVDIMM
38
39config ND_BLK
40	tristate "BLK: Block data window (aperture) device support"
41	default LIBNVDIMM
42	select ND_BTT if BTT
43	help
44	  Support NVDIMMs, or other devices, that implement a BLK-mode
45	  access capability.  BLK-mode access uses memory-mapped-i/o
46	  apertures to access persistent media.
47
48	  Say Y if your platform firmware emits an ACPI.NFIT table
49	  (CONFIG_ACPI_NFIT), or otherwise exposes BLK-mode
50	  capabilities.
51
52config ND_CLAIM
53	bool
54
55config ND_BTT
56	tristate
57
58config BTT
59	bool "BTT: Block Translation Table (atomic sector updates)"
60	default y if LIBNVDIMM
61	select ND_CLAIM
62	help
63	  The Block Translation Table (BTT) provides atomic sector
64	  update semantics for persistent memory devices, so that
65	  applications that rely on sector writes not being torn (a
66	  guarantee that typical disks provide) can continue to do so.
67	  The BTT manifests itself as an alternate personality for an
68	  NVDIMM namespace, i.e. a namespace can be in raw mode (pmemX,
69	  ndblkX.Y, etc...), or 'sectored' mode, (pmemXs, ndblkX.Ys,
70	  etc...).
71
72	  Select Y if unsure
73
74config ND_PFN
75	tristate
76
77config NVDIMM_PFN
78	bool "PFN: Map persistent (device) memory"
79	default LIBNVDIMM
80	depends on ZONE_DEVICE
81	select ND_CLAIM
82	help
83	  Map persistent memory, i.e. advertise it to the memory
84	  management sub-system.  By default persistent memory does
85	  not support direct I/O, RDMA, or any other usage that
86	  requires a 'struct page' to mediate an I/O request.  This
87	  driver allocates and initializes the infrastructure needed
88	  to support those use cases.
89
90	  Select Y if unsure
91
92config NVDIMM_DAX
93	bool "NVDIMM DAX: Raw access to persistent memory"
94	default LIBNVDIMM
95	depends on NVDIMM_PFN
96	help
97	  Support raw device dax access to a persistent memory
98	  namespace.  For environments that want to hard partition
99	  peristent memory, this capability provides a mechanism to
100	  sub-divide a namespace into character devices that can only be
101	  accessed via DAX (mmap(2)).
102
103	  Select Y if unsure
104
105endif
106