32ab0a3f51
Enable the pmem driver to handle PFN device instances. Attaching a pmem namespace to a pfn device triggers the driver to allocate and initialize struct page entries for pmem. Memory capacity for this allocation comes exclusively from RAM for now which is suitable for low PMEM to RAM ratios. This mechanism will be expanded later for setting an "allocate from PMEM" policy. Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
91 lines
3 KiB
Text
91 lines
3 KiB
Text
menuconfig LIBNVDIMM
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tristate "NVDIMM (Non-Volatile Memory Device) Support"
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depends on PHYS_ADDR_T_64BIT
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depends on BLK_DEV
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help
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Generic support for non-volatile memory devices including
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ACPI-6-NFIT defined resources. On platforms that define an
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NFIT, or otherwise can discover NVDIMM resources, a libnvdimm
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bus is registered to advertise PMEM (persistent memory)
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namespaces (/dev/pmemX) and BLK (sliding mmio window(s))
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namespaces (/dev/ndblkX.Y). A PMEM namespace refers to a
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memory resource that may span multiple DIMMs and support DAX
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(see CONFIG_DAX). A BLK namespace refers to an NVDIMM control
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region which exposes an mmio register set for windowed access
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mode to non-volatile memory.
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if LIBNVDIMM
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config BLK_DEV_PMEM
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tristate "PMEM: Persistent memory block device support"
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default LIBNVDIMM
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depends on HAS_IOMEM
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select ND_BTT if BTT
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select ND_PFN if NVDIMM_PFN
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help
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Memory ranges for PMEM are described by either an NFIT
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(NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a
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non-standard OEM-specific E820 memory type (type-12, see
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CONFIG_X86_PMEM_LEGACY), or it is manually specified by the
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'memmap=nn[KMG]!ss[KMG]' kernel command line (see
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Documentation/kernel-parameters.txt). This driver converts
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these persistent memory ranges into block devices that are
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capable of DAX (direct-access) file system mappings. See
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Documentation/nvdimm/nvdimm.txt for more details.
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Say Y if you want to use an NVDIMM
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config ND_BLK
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tristate "BLK: Block data window (aperture) device support"
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default LIBNVDIMM
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select ND_BTT if BTT
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help
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Support NVDIMMs, or other devices, that implement a BLK-mode
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access capability. BLK-mode access uses memory-mapped-i/o
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apertures to access persistent media.
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Say Y if your platform firmware emits an ACPI.NFIT table
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(CONFIG_ACPI_NFIT), or otherwise exposes BLK-mode
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capabilities.
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config ND_CLAIM
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bool
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config ND_BTT
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tristate
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config BTT
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bool "BTT: Block Translation Table (atomic sector updates)"
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default y if LIBNVDIMM
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select ND_CLAIM
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help
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The Block Translation Table (BTT) provides atomic sector
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update semantics for persistent memory devices, so that
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applications that rely on sector writes not being torn (a
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guarantee that typical disks provide) can continue to do so.
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The BTT manifests itself as an alternate personality for an
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NVDIMM namespace, i.e. a namespace can be in raw mode (pmemX,
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ndblkX.Y, etc...), or 'sectored' mode, (pmemXs, ndblkX.Ys,
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etc...).
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Select Y if unsure
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config ND_PFN
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tristate
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config NVDIMM_PFN
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bool "PFN: Map persistent (device) memory"
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default LIBNVDIMM
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depends on ZONE_DEVICE
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select ND_CLAIM
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help
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Map persistent memory, i.e. advertise it to the memory
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management sub-system. By default persistent memory does
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not support direct I/O, RDMA, or any other usage that
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requires a 'struct page' to mediate an I/O request. This
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driver allocates and initializes the infrastructure needed
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to support those use cases.
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Select Y if unsure
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endif
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