Kconfig

  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 RAMDAX
101	tristate "Support persistent memory interfaces on RAM carveouts"
102	depends on X86_PMEM_LEGACY || OF || COMPILE_TEST
103	default LIBNVDIMM
104	help
105	  Allows creation of DAX devices on RAM carveouts.
106
107	  Memory ranges that are manually specified by the
108	  'memmap=nn[KMG]!ss[KMG]' kernel command line or defined by dummy
109	  pmem-region device tree nodes would be managed by this driver as DIMM
110	  devices with support for dynamic layout of namespaces.
111	  The driver steals 128K in the end of the memmap range for the
112	  namespace management. This allows supporting up to 509 namespaces
113	  (see 'ndctl create-namespace --help').
114	  The driver should be force bound to e820_pmem or pmem-region platform
115	  devices using 'driver_override' device attribute.
116
117	  Select N if unsure.
118
119config NVDIMM_KEYS
120	def_bool y
121	depends on ENCRYPTED_KEYS
122	depends on (LIBNVDIMM=ENCRYPTED_KEYS) || LIBNVDIMM=m
123
124config NVDIMM_KMSAN
125	bool
126	depends on KMSAN
127	help
128	  KMSAN, and other memory debug facilities, increase the size of
129	  'struct page' to contain extra metadata. This collides with
130	  the NVDIMM capability to store a potentially
131	  larger-than-"System RAM" size 'struct page' array in a
132	  reservation of persistent memory rather than limited /
133	  precious DRAM. However, that reservation needs to persist for
134	  the life of the given NVDIMM namespace. If you are using KMSAN
135	  to debug an issue unrelated to NVDIMMs or DAX then say N to this
136	  option. Otherwise, say Y but understand that any namespaces
137	  (with the page array stored pmem) created with this build of
138	  the kernel will permanently reserve and strand excess
139	  capacity compared to the CONFIG_KMSAN=n case.
140
141	  Select N if unsure.
142
143config NVDIMM_TEST_BUILD
144	tristate "Build the unit test core"
145	depends on m
146	depends on COMPILE_TEST && X86_64
147	default m if COMPILE_TEST
148	help
149	  Build the core of the unit test infrastructure. The result of
150	  this build is non-functional for unit test execution, but it
151	  otherwise helps catch build errors induced by changes to the
152	  core devm_memremap_pages() implementation and other
153	  infrastructure.
154
155config NVDIMM_SECURITY_TEST
156	bool "Enable NVDIMM security unit tests"
157	depends on NVDIMM_KEYS
158	help
159	  The NVDIMM and CXL subsystems support unit testing of their device
160	  security state machines. The NVDIMM_SECURITY_TEST option disables CPU
161	  cache maintenance operations around events like secure erase and
162	  overwrite.  Also, when enabled, the NVDIMM subsystem core helps the unit
163	  test implement a mock state machine.
164
165	  Select N if unsure.
166
167endif