BMC/Intel-BMC/linux.git/drivers/nvdimm/Makefile, branch dev-4.6

libnvdimm, pfn: 'struct page' provider infrastructure

2015-08-29T03:39:36+00:00

Implement the base infrastructure for libnvdimm PFN devices. Similar to BTT devices they take a namespace as a backing device and layer functionality on top. In this case the functionality is reserving space for an array of 'struct page' entries to be handed out through pfn_to_page(). For now this is just the basic libnvdimm-device-model for configuring the base PFN device. As the namespace claiming mechanism for PFN devices is mostly identical to BTT devices drivers/nvdimm/claim.c is created to house the common bits. Cc: Ross Zwisler Signed-off-by: Dan Williams

libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option

2015-08-19T04:34:34+00:00

We currently register a platform device for e820 type-12 memory and register a nvdimm bus beneath it. Registering the platform device triggers the device-core machinery to probe for a driver, but that search currently comes up empty. Building the nvdimm-bus registration into the e820_pmem platform device registration in this way forces libnvdimm to be built-in. Instead, convert the built-in portion of CONFIG_X86_PMEM_LEGACY to simply register a platform device and move the rest of the logic to the driver for e820_pmem, for the following reasons: 1/ Letting e820_pmem support be a module allows building and testing libnvdimm.ko changes without rebooting 2/ All the normal policy around modules can be applied to e820_pmem (unbind to disable and/or blacklisting the module from loading by default) 3/ Moving the driver to a generic location and converting it to scan "iomem_resource" rather than "e820.map" means any other architecture can take advantage of this simple nvdimm resource discovery mechanism by registering a resource named "Persistent Memory (legacy)" Cc: Christoph Hellwig Signed-off-by: Dan Williams

libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory

2015-06-26T15:23:38+00:00

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 Cc: Boaz Harrosh Cc: H. Peter Anvin Cc: Jens Axboe Cc: Ingo Molnar Cc: Christoph Hellwig Signed-off-by: Ross Zwisler Acked-by: Rafael J. Wysocki Signed-off-by: Dan Williams

nd_btt: atomic sector updates

2015-06-26T15:23:38+00:00

BTT stands for Block Translation Table, and is a way to provide power fail sector atomicity semantics for block devices that have the ability to perform byte granularity IO. It relies on the capability of libnvdimm namespace devices to do byte aligned IO. The BTT works as a stacked blocked device, and reserves a chunk of space from the backing device for its accounting metadata. It is a bio-based driver because all IO is done synchronously, and there is no queuing or asynchronous completions at either the device or the driver level. The BTT uses 'lanes' to index into various 'on-disk' data structures, and lanes also act as a synchronization mechanism in case there are more CPUs than available lanes. We did a comparison between two lane lock strategies - first where we kept an atomic counter around that tracked which was the last lane that was used, and 'our' lane was determined by atomically incrementing that. That way, for the nr_cpus > nr_lanes case, theoretically, no CPU would be blocked waiting for a lane. The other strategy was to use the cpu number we're scheduled on to and hash it to a lane number. Theoretically, this could block an IO that could've otherwise run using a different, free lane. But some fio workloads showed that the direct cpu -> lane hash performed faster than tracking 'last lane' - my reasoning is the cache thrash caused by moving the atomic variable made that approach slower than simply waiting out the in-progress IO. This supports the conclusion that the driver can be a very simple bio-based one that does synchronous IOs instead of queuing. Cc: Andy Lutomirski Cc: Boaz Harrosh Cc: H. Peter Anvin Cc: Jens Axboe Cc: Ingo Molnar Cc: Christoph Hellwig Cc: Neil Brown Cc: Jeff Moyer Cc: Dave Chinner Cc: Greg KH [jmoyer: fix nmi watchdog timeout in btt_map_init] [jmoyer: move btt initialization to module load path] [jmoyer: fix memory leak in the btt initialization path] [jmoyer: Don't overwrite corrupted arenas] Signed-off-by: Vishal Verma Signed-off-by: Dan Williams

libnvdimm: infrastructure for btt devices

2015-06-25T08:20:04+00:00

NVDIMM namespaces, in addition to accepting "struct bio" based requests, also have the capability to perform byte-aligned accesses. By default only the bio/block interface is used. However, if another driver can make effective use of the byte-aligned capability it can claim namespace interface and use the byte-aligned ->rw_bytes() interface. The BTT driver is the initial first consumer of this mechanism to allow adding atomic sector update semantics to a pmem or blk namespace. This patch is the sysfs infrastructure to allow configuring a BTT instance for a namespace. Enabling that BTT and performing i/o is in a subsequent patch. Cc: Greg KH Cc: Neil Brown Signed-off-by: Dan Williams

libnvdimm: namespace indices: read and validate

2015-06-25T01:24:10+00:00

This on media label format [1] consists of two index blocks followed by an array of labels. None of these structures are ever updated in place. A sequence number tracks the current active index and the next one to write, while labels are written to free slots. +------------+ | | | nsindex0 | | | +------------+ | | | nsindex1 | | | +------------+ | label0 | +------------+ | label1 | +------------+ | | ....nslot... | | +------------+ | labelN | +------------+ After reading valid labels, store the dpa ranges they claim into per-dimm resource trees. [1]: http://pmem.io/documents/NVDIMM_Namespace_Spec.pdf Cc: Neil Brown Acked-by: Christoph Hellwig Signed-off-by: Dan Williams

libnvdimm, pmem: move pmem to drivers/nvdimm/

2015-06-25T01:24:10+00:00

Prepare the pmem driver to consume PMEM namespaces emitted by regions of an nvdimm_bus instance. No functional change. Acked-by: Christoph Hellwig Tested-by: Toshi Kani Signed-off-by: Dan Williams

libnvdimm: support for legacy (non-aliasing) nvdimms

2015-06-25T01:24:10+00:00

The libnvdimm region driver is an intermediary driver that translates non-volatile "region"s into "namespace" sub-devices that are surfaced by persistent memory block-device drivers (PMEM and BLK). ACPI 6 introduces the concept that a given nvdimm may simultaneously offer multiple access modes to its media through direct PMEM load/store access, or windowed BLK mode. Existing nvdimms mostly implement a PMEM interface, some offer a BLK-like mode, but never both as ACPI 6 defines. If an nvdimm is single interfaced, then there is no need for dimm metadata labels. For these devices we can take the region boundaries directly to create a child namespace device (nd_namespace_io). Acked-by: Christoph Hellwig Tested-by: Toshi Kani Signed-off-by: Dan Williams

libnvdimm, nfit: regions (block-data-window, persistent memory, volatile memory)

2015-06-25T01:24:10+00:00

A "region" device represents the maximum capacity of a BLK range (mmio block-data-window(s)), or a PMEM range (DAX-capable persistent memory or volatile memory), without regard for aliasing. Aliasing, in the dimm-local address space (DPA), is resolved by metadata on a dimm to designate which exclusive interface will access the aliased DPA ranges. Support for the per-dimm metadata/label arrvies is in a subsequent patch. The name format of "region" devices is "regionN" where, like dimms, N is a global ida index assigned at discovery time. This id is not reliable across reboots nor in the presence of hotplug. Look to attributes of the region or static id-data of the sub-namespace to generate a persistent name. However, if the platform configuration does not change it is reasonable to expect the same region id to be assigned at the next boot. "region"s have 2 generic attributes "size", and "mapping"s where: - size: the BLK accessible capacity or the span of the system physical address range in the case of PMEM. - mappingN: a tuple describing a dimm's contribution to the region's capacity in the format (,,). For a PMEM-region there will be at least one mapping per dimm in the interleave set. For a BLK-region there is only "mapping0" listing the starting DPA of the BLK-region and the available DPA capacity of that space (matches "size" above). The max number of mappings per "region" is hard coded per the constraints of sysfs attribute groups. That said the number of mappings per region should never exceed the maximum number of possible dimms in the system. If the current number turns out to not be enough then the "mappings" attribute clarifies how many there are supposed to be. "32 should be enough for anybody...". Cc: Neil Brown Cc: Cc: Greg KH Cc: Robert Moore Cc: Rafael J. Wysocki Acked-by: Christoph Hellwig Acked-by: Rafael J. Wysocki Tested-by: Toshi Kani Signed-off-by: Dan Williams

libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver infrastructure

2015-06-25T01:24:10+00:00

* Implement the device-model infrastructure for loading modules and attaching drivers to nvdimm devices. This is a simple association of a nd-device-type number with a driver that has a bitmask of supported device types. To facilitate userspace bind/unbind operations 'modalias' and 'devtype', that also appear in the uevent, are added as generic sysfs attributes for all nvdimm devices. The reason for the device-type number is to support sub-types within a given parent devtype, be it a vendor-specific sub-type or otherwise. * The first consumer of this infrastructure is the driver for dimm devices. It simply uses control messages to retrieve and store the configuration-data image (label set) from each dimm. Note: nd_device_register() arranges for asynchronous registration of nvdimm bus devices by default. Cc: Greg KH Cc: Neil Brown Acked-by: Christoph Hellwig Tested-by: Toshi Kani Signed-off-by: Dan Williams