1# SPDX-License-Identifier: GPL-2.0-only
  2menuconfig LIBNVDIMM
  3	tristate "NVDIMM (Non-Volatile Memory Device) Support"
  4	depends on PHYS_ADDR_T_64BIT
  5	depends on HAS_IOMEM
  6	depends on BLK_DEV
  7	select MEMREGION
  8	help
  9	  Generic support for non-volatile memory devices including
 10	  ACPI-6-NFIT defined resources.  On platforms that define an
 11	  NFIT, or otherwise can discover NVDIMM resources, a libnvdimm
 12	  bus is registered to advertise PMEM (persistent memory)
 13	  namespaces (/dev/pmemX). A PMEM namespace refers to a
 14	  memory resource that may span multiple DIMMs and support DAX
 15	  (see CONFIG_DAX).
 16
 17if LIBNVDIMM
 18
 19config BLK_DEV_PMEM
 20	tristate "PMEM: Persistent memory block device support"
 21	default LIBNVDIMM
 22	select DAX
 23	select ND_BTT if BTT
 24	select ND_PFN if NVDIMM_PFN
 25	help
 26	  Memory ranges for PMEM are described by either an NFIT
 27	  (NVDIMM Firmware Interface Table, see CONFIG_ACPI_NFIT), a
 28	  non-standard OEM-specific E820 memory type (type-12, see
 29	  CONFIG_X86_PMEM_LEGACY), or it is manually specified by the
 30	  'memmap=nn[KMG]!ss[KMG]' kernel command line (see
 31	  Documentation/admin-guide/kernel-parameters.rst).  This driver converts
 32	  these persistent memory ranges into block devices that are
 33	  capable of DAX (direct-access) file system mappings.  See
 34	  Documentation/driver-api/nvdimm/nvdimm.rst for more details.
 35
 36	  Say Y if you want to use an NVDIMM
 37
 38config ND_CLAIM
 39	bool
 40
 41config ND_BTT
 42	tristate
 43
 44config BTT
 45	bool "BTT: Block Translation Table (atomic sector updates)"
 46	default y if LIBNVDIMM
 47	select ND_CLAIM
 48	help
 49	  The Block Translation Table (BTT) provides atomic sector
 50	  update semantics for persistent memory devices, so that
 51	  applications that rely on sector writes not being torn (a
 52	  guarantee that typical disks provide) can continue to do so.
 53	  The BTT manifests itself as an alternate personality for an
 54	  NVDIMM namespace, i.e. a namespace can be in raw mode pmemX,
 55	  or 'sectored' mode.
 56
 57	  Select Y if unsure
 58
 59config ND_PFN
 60	tristate
 61
 62config NVDIMM_PFN
 63	bool "PFN: Map persistent (device) memory"
 64	default LIBNVDIMM
 65	depends on ZONE_DEVICE
 66	select ND_CLAIM
 67	help
 68	  Map persistent memory, i.e. advertise it to the memory
 69	  management sub-system.  By default persistent memory does
 70	  not support direct I/O, RDMA, or any other usage that
 71	  requires a 'struct page' to mediate an I/O request.  This
 72	  driver allocates and initializes the infrastructure needed
 73	  to support those use cases.
 74
 75	  Select Y if unsure
 76
 77config NVDIMM_DAX
 78	bool "NVDIMM DAX: Raw access to persistent memory"
 79	default LIBNVDIMM
 80	depends on NVDIMM_PFN
 81	help
 82	  Support raw device dax access to a persistent memory
 83	  namespace.  For environments that want to hard partition
 84	  persistent memory, this capability provides a mechanism to
 85	  sub-divide a namespace into character devices that can only be
 86	  accessed via DAX (mmap(2)).
 87
 88	  Select Y if unsure
 89
 90config OF_PMEM
 91	tristate "Device-tree support for persistent memory regions"
 92	depends on OF
 93	default LIBNVDIMM
 94	help
 95	  Allows regions of persistent memory to be described in the
 96	  device-tree.
 97
 98	  Select Y if unsure.
 99
100config NVDIMM_KEYS
101	def_bool y
102	depends on ENCRYPTED_KEYS
103	depends on (LIBNVDIMM=ENCRYPTED_KEYS) || LIBNVDIMM=m
104
105config NVDIMM_KMSAN
106	bool
107	depends on KMSAN
108	help
109	  KMSAN, and other memory debug facilities, increase the size of
110	  'struct page' to contain extra metadata. This collides with
111	  the NVDIMM capability to store a potentially
112	  larger-than-"System RAM" size 'struct page' array in a
113	  reservation of persistent memory rather than limited /
114	  precious DRAM. However, that reservation needs to persist for
115	  the life of the given NVDIMM namespace. If you are using KMSAN
116	  to debug an issue unrelated to NVDIMMs or DAX then say N to this
117	  option. Otherwise, say Y but understand that any namespaces
118	  (with the page array stored pmem) created with this build of
119	  the kernel will permanently reserve and strand excess
120	  capacity compared to the CONFIG_KMSAN=n case.
121
122	  Select N if unsure.
123
124config NVDIMM_TEST_BUILD
125	tristate "Build the unit test core"
126	depends on m
127	depends on COMPILE_TEST && X86_64
128	default m if COMPILE_TEST
129	help
130	  Build the core of the unit test infrastructure. The result of
131	  this build is non-functional for unit test execution, but it
132	  otherwise helps catch build errors induced by changes to the
133	  core devm_memremap_pages() implementation and other
134	  infrastructure.
135
136config NVDIMM_SECURITY_TEST
137	bool "Enable NVDIMM security unit tests"
138	depends on NVDIMM_KEYS
139	help
140	  The NVDIMM and CXL subsystems support unit testing of their device
141	  security state machines. The NVDIMM_SECURITY_TEST option disables CPU
142	  cache maintenance operations around events like secure erase and
143	  overwrite.  Also, when enabled, the NVDIMM subsystem core helps the unit
144	  test implement a mock state machine.
145
146	  Select N if unsure.
147
148endif