047fc8a1f9
The libnvdimm implementation handles allocating dimm address space (DPA) between PMEM and BLK mode interfaces. After DPA has been allocated from a BLK-region to a BLK-namespace the nd_blk driver attaches to handle I/O as a struct bio based block device. Unlike PMEM, BLK is required to handle platform specific details like mmio register formats and memory controller interleave. For this reason the libnvdimm generic nd_blk driver calls back into the bus provider to carry out the I/O. This initial implementation handles the BLK interface defined by the ACPI 6 NFIT [1] and the NVDIMM DSM Interface Example [2] composed from DCR (dimm control region), BDW (block data window), IDT (interleave descriptor) NFIT structures and the hardware register format. [1]: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf [2]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jens Axboe <axboe@fb.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
68 lines
2.4 KiB
Text
68 lines
2.4 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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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_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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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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endif
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