1 # SPDX-License-Identifier: GPL-2.0-only 2 menuconfig 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 17 if LIBNVDIMM 18 19 config 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 38 config ND_CLAIM 39 bool 40 41 config ND_BTT 42 tristate 43 44 config 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 59 config ND_PFN 60 tristate 61 62 config 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 77 config 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 90 config 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. 99 100 config NVDIMM_KEYS 101 def_bool y 102 depends on ENCRYPTED_KEYS 103 depends on (LIBNVDIMM=ENCRYPTED_KEYS) || LIBNVDIMM=m 104 105 config 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. 123 124 config 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. 135 136 config 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. 147 148 endif 149