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path: root/drivers/nvdimm/namespace_devs.c
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2017-07-04Merge branch 'for-4.13/dax' into libnvdimm-for-nextDan Williams1-9/+5
2017-06-29libnvdimm, btt: BTT updates for UEFI 2.7 formatVishal Verma1-2/+59
The UEFI 2.7 specification defines an updated BTT metadata format, bumping the revision to 2.0. Add support for the new format, while retaining compatibility for the old 1.1 format. Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Linda Knippers <linda.knippers@hpe.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-28libnvdimm, nfit: enable support for volatile rangesDan Williams1-4/+4
Allow volatile nfit ranges to participate in all the same infrastructure provided for persistent memory regions. A resulting resulting namespace device will still be called "pmem", but the parent region type will be "nd_volatile". This is in preparation for disabling the dax ->flush() operation in the pmem driver when it is hosted on a volatile range. Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-28x86, libnvdimm, pmem: remove global pmem apiDan Williams1-5/+1
Now that all callers of the pmem api have been converted to dax helpers that call back to the pmem driver, we can remove include/linux/pmem.h and asm/pmem.h. Cc: <x86@kernel.org> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-16libnvdimm, label: add address abstraction identifiersDan Williams1-0/+74
Starting with v1.2 labels, 'address abstractions' can be hinted via an address abstraction id that implies an info-block format. The standard address abstraction in the specification is the v2 format of the Block-Translation-Table (BTT). Support for that is saved for a later patch, for now we add support for the Linux supported address abstractions BTT (v1), PFN, and DAX. The new 'holder_class' attribute for namespace devices is added for tooling to specify the 'abstraction_guid' to store in the namespace label. For v1.1 labels this field is undefined and any setting of 'holder_class' away from the default 'none' value will only have effect until the driver is unloaded. Setting 'holder_class' requires that whatever device tries to claim the namespace must be of the specified class. Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-16libnvdimm, label: populate 'isetcookie' for blk-aperture namespacesDan Williams1-6/+14
Starting with the v1.2 definition of namespace labels, the isetcookie field is populated and validated for blk-aperture namespaces. This adds some safety against inadvertent copying of namespace labels from one DIMM-device to another. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-16libnvdimm, label: populate the type_guid property for v1.2 namespacesDan Williams1-19/+38
The type_guid refers to the "Address Range Type GUID" for the region backing a namespace as defined the ACPI NFIT (NVDIMM Firmware Interface Table). This 'type' identifier specifies an access mechanism for the given namespace. This capability replaces the confusing usage of the 'NSLABEL_FLAG_LOCAL' flag to indicate a block-aperture-mode namespace. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-16libnvdimm, label: honor the lba size specified in v1.2 labelsDan Williams1-12/+53
Previously we only honored the lba size for blk-aperture mode namespaces. For pmem namespaces the lba size was just assumed to be 512. With the new v1.2 label definition and compatibility with other operating environments, the ->lbasize property is now respected for pmem namespaces. Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-16libnvdimm, label: add v1.2 interleave-set-cookie algorithmDan Williams1-2/+7
The interleave-set-cookie algorithm is extended to incorporate all the same components that are used to generate an nvdimm unique-id. For backwards compatibility we still maintain the old v1.1 definition. Reported-by: Nicholas Moulin <nicholas.w.moulin@intel.com> Reported-by: Kaushik Kanetkar <kaushik.a.kanetkar@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-05libnvdimm: handle locked label storage areasDan Williams1-5/+12
Per the latest version of the "NVDIMM DSM Interface Example" [1], the label data retrieval routine can report a "locked" status. In this case all regions associated with that DIMM are disabled until the label area is unlocked. Provide generic libnvdimm enabling for NVDIMMs with label data area locking capabilities. [1]: http://pmem.io/documents/ Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-05libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKEDDan Williams1-1/+1
This is a preparation patch for handling locked nvdimm label regions, a new concept as introduced by the latest DSM document on pmem.io [1]. A future patch will leverage nvdimm_set_locked() at DIMM probe time to flag regions that can not be enabled. There should be no functional difference resulting from this change. [1]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example-V1.3.pdf Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-03-01nfit, libnvdimm: fix interleave set cookie calculationDan Williams1-4/+14
The interleave-set cookie is a sum that sanity checks the composition of an interleave set has not changed from when the namespace was initially created. The checksum is calculated by sorting the DIMMs by their location in the interleave-set. The comparison for the sort must be 64-bit wide, not byte-by-byte as performed by memcmp() in the broken case. Fix the implementation to accept correct cookie values in addition to the Linux "memcmp" order cookies, but only allow correct cookies to be generated going forward. It does mean that namespaces created by third-party-tooling, or created by newer kernels with this fix, will not validate on older kernels. However, there are a couple mitigating conditions: 1/ platforms with namespace-label capable NVDIMMs are not widely available. 2/ interleave-sets with a single-dimm are by definition not affected (nothing to sort). This covers the QEMU-KVM NVDIMM emulation case. The cookie stored in the namespace label will be fixed by any write the namespace label, the most straightforward way to achieve this is to write to the "alt_name" attribute of a namespace in sysfs. Cc: <stable@vger.kernel.org> Fixes: eaf961536e16 ("libnvdimm, nfit: add interleave-set state-tracking infrastructure") Reported-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com> Tested-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-02-01libnvdimm, namespace: do not delete namespace-id 0Dan Williams1-4/+7
Given that the naming of pmem devices changes from the pmemX form to the pmemX.Y form when namespace id is greater than 0, arrange for namespaces with id-0 to be exempt from deletion. Otherwise a simple reconfiguration of an existing namespace to a new mode results in a name change of the resulting block device: # ndctl list --namespace=namespace1.0 { "dev":"namespace1.0", "mode":"raw", "size":2147483648, "uuid":"3dadf3dc-89b9-4b24-b20e-abc8a4707ce3", "blockdev":"pmem1" } # ndctl create-namespace --reconfig=namespace1.0 --mode=memory --force { "dev":"namespace1.1", "mode":"memory", "size":2111832064, "uuid":"7b4a6341-7318-4219-a02c-fb57c0bbf613", "blockdev":"pmem1.1" } This change does require tooling changes to explicitly look for namespaceX.0 if the seed has already advanced to another namespace. Cc: <stable@vger.kernel.org> Fixes: 98a29c39dc68 ("libnvdimm, namespace: allow creation of multiple pmem-namespaces per region") Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-02-01nvdimm: constify device_type structuresBhumika Goyal1-3/+3
Declare device_type structure as const as it is only stored in the type field of a device structure. This field is of type const, so add const to declaration of device_type structure. File size before: text data bss dec hex filename 19278 3199 16 22493 57dd nvdimm/namespace_devs.o File size after: text data bss dec hex filename 19929 3160 16 23105 5a41 nvdimm/namespace_devs.o Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-01-13libnvdimm, namespace: fix pmem namespace leak, delete when size set to zeroDan Williams1-13/+10
Commit 98a29c39dc68 ("libnvdimm, namespace: allow creation of multiple pmem-namespaces per region") added support for establishing additional pmem namespace beyond the seed device, similar to blk namespaces. However, it neglected to delete the namespace when the size is set to zero. Fixes: 98a29c39dc68 ("libnvdimm, namespace: allow creation of multiple pmem-namespaces per region") Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-12-18Merge branch 'for-4.10/libnvdimm' into libnvdimm-for-nextDan Williams1-4/+4
2016-12-16libnvdimm: replace mutex_is_locked() warnings with lockdep_assert_heldDan Williams1-1/+1
For warnings that should only ever trigger during development and testing replace WARN statements with lockdep_assert_held. The lockdep pattern is prevalent, and these paths are are well covered by libnvdimm unit tests. Reported-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-12-04libnvdimm, namespace: use octal for permissionsFabian Frederick1-2/+2
According to commit f90774e1fd27 ("checkpatch: look for symbolic permissions and suggest octal instead") Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-11-29libnvdimm, namespace: fix the type of name variableNicolas Iooss1-1/+1
In create_namespace_blk(), the local variable "name" is defined as an array of NSLABEL_NAME_LEN pointers: char *name[NSLABEL_NAME_LEN]; This variable is then used in calls to memcpy() and kmemdup() as if it were char[NSLABEL_NAME_LEN]. Remove the star in the variable definition to makes it look right. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-19libnvdimm, namespace: potential NULL deref on allocation errorDan Carpenter1-6/+8
If the kcalloc() fails then "devs" can be NULL and we dereference it checking "devs[i]". Fixes: 1b40e09a1232 ('libnvdimm: blk labels and namespace instantiation') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07libnvdimm, namespace: allow creation of multiple pmem-namespaces per regionDan Williams1-3/+45
Similar to BLK regions, publish new seed namespace devices to allow unused PMEM region capacity to be consumed by additional namespaces. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07libnvdimm, namespace: lift single pmem limit in scan_labels()Dan Williams1-3/+0
Now that the rest of the infrastructure has been converted to handle multi-pmem configurations, lift the artificial barrier at scan time. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07libnvdimm, namespace: filter out of range labels in scan_labels()Dan Williams1-2/+7
Short-circuit doomed-to-fail label validation attempts by skipping labels that are outside the given region. For example a DIMM that has multiple PMEM regions will waste time attempting to create namespaces only to find that the interleave-set-cookie does not validate, e.g.: nd_region region6: invalid cookie in label: 73e608dc-47b9-4b2a-b5c7-2d55a32e0c2 Similar to how we skip BLK labels when performing PMEM validation we can skip out-of-range labels early. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07libnvdimm, namespace: enable allocation of multiple pmem namespacesDan Williams1-38/+90
Now that we have nd_region_available_dpa() able to handle the presence of multiple PMEM allocations in aliased PMEM regions, reuse that same infrastructure to track allocations from free space. In particular handle allocating from an aliased PMEM region in the case where there are dis-contiguous holes. The allocation for BLK and PMEM are documented in the space_valid() helper: BLK-space is valid as long as it does not precede a PMEM allocation in a given region. PMEM-space must be contiguous and adjacent to an existing existing allocation (if one exists). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07libnvdimm, namespace: expand pmem device naming scheme for multi-pmemDan Williams1-1/+15
pmem devices are currently named /dev/pmem<region-index>. Preserve the naming of the 0th device, but add a ".<namespace-index>" for other devices. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07libnvdimm, namespace: sort namespaces by dpa at initDan Williams1-3/+32
Add more determinism to initial namespace device-name assignments by sorting the namespaces by starting dpa. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-07libnvdimm, namespace: allow multiple pmem-namespaces per region at scan timeDan Williams1-12/+72
If label scanning finds multiple valid pmem namespaces allow them to be surfaced rather than fail namespace scanning. Support for creating multiple namespaces per region is saved for a later patch. Note that this adds some new error messages to clarify which of the pmem namespaces in the set are potentially impacted by invalid labels. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-06libnvdimm, namespace: unify blk and pmem label scanningDan Williams1-178/+207
In preparation for allowing multiple namespace per pmem region, unify blk and pmem label scanning. Given that blk regions already support multiple namespaces, teaching that path how to do pmem namespace scanning is an incremental step towards multiple pmem namespace support. This should be functionally equivalent to the previous state in that stops after finding the first valid pmem label set. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-06libnvdimm, namespace: refactor uuid_show() into a namespace_to_uuid() helperDan Williams1-7/+12
The ability to translate a generic struct device pointer into a namespace uuid is a useful utility as we go to unify the blk and pmem label scanning paths. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-01libnvdimm, label: convert label tracking to a linked listDan Williams1-53/+120
In preparation for enabling multiple namespaces per pmem region, convert the label tracking to use a linked list. In particular this will allow select_pmem_id() to move labels from the unvalidated state to the validated state. Currently we only track one validated set per-region. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-09-21libnvdimm, namespace: debug invalid interleave-set-cookie valuesDan Williams1-1/+3
If platform firmware fails to populate unique / non-zero serial number data for each nvdimm in an interleave-set it may cause pmem region initialization to fail. Add a debug message for this case. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-09-02nvdimm: Spelling s/unacknoweldged/unacknowledged/Geert Uytterhoeven1-1/+1
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-10libnvdimm, dax: introduce device-dax infrastructureDan Williams1-1/+18
Device DAX is the device-centric analogue of Filesystem DAX (CONFIG_FS_DAX). It allows persistent memory ranges to be allocated and mapped without need of an intervening file system. This initial infrastructure arranges for a libnvdimm pfn-device to be represented as a different device-type so that it can be attached to a driver other than the pmem driver. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-04-22libnvdimm: cleanup nvdimm_namespace_common_probe(), kill 'host'Dan Williams1-12/+7
The 'host' variable can be killed as it is always the same as the passed in device. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-03-05libnvdimm, pmem: adjust for section collisions with 'System RAM'Dan Williams1-0/+7
On a platform where 'Persistent Memory' and 'System RAM' are mixed within a given sparsemem section, trim the namespace and notify about the sub-optimal alignment. Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-26libnvdimm: fix mode determination for e820 devicesDan Williams1-3/+5
Correctly display "safe" mode when a btt is established on a e820/memmap defined pmem namespace. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-06libnvdimm: fix namespace object confusion in is_uuid_busy()Dan Williams1-0/+53
When btt devices were re-worked to be child devices of regions this routine was overlooked. It mistakenly attempts to_nd_namespace_pmem() or to_nd_namespace_blk() conversions on btt and pfn devices. By luck to date we have happened to be hitting valid memory leading to a uuid miscompare, but a recent change to struct nd_namespace_common causes: BUG: unable to handle kernel NULL pointer dereference at 0000000000000001 IP: [<ffffffff814610dc>] memcmp+0xc/0x40 [..] Call Trace: [<ffffffffa0028631>] is_uuid_busy+0xc1/0x2a0 [libnvdimm] [<ffffffffa0028570>] ? to_nd_blk_region+0x50/0x50 [libnvdimm] [<ffffffff8158c9c0>] device_for_each_child+0x50/0x90 Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-12-24libnvdimm, pfn: move 'memory mode' indication to sysfsDan Williams1-13/+28
'Memory mode' is defined as the capability of a DAX mapping to be the source/target of DMA and other "direct I/O" scenarios. While it currently requires allocating 'struct page' for each page frame of persistent memory in the namespace it will not always be the case. Work continues on reducing the kernel's dependency on 'struct page'. Let's not maintain a suffix that is expected to lose meaning over time. In other words a future 'raw mode' pmem namespace may be as capable as today's 'memory mode' namespace. Undo the encoding of the mode in the device name and leave it to other tooling to determine the mode of the namespace from its attributes. Reported-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-12-13libnvdimm, pfn: fix pfn seed creationDan Williams1-0/+12
Similar to btt, plant a new pfn seed when the existing one is activated. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-12-09nvdimm: improve diagnosibility of namespacesDmitry Krivenok1-4/+22
In order to bind namespace to the driver user must first set all mandatory attributes in the following order: - uuid - size - sector_size (for blk namespace only) If the order is wrong, then user either won't be able to set the attribute or bind the namespace. This simple patch improves diagnosibility of common operations with namespaces by printing some details about the error instead of failing silently. Below are examples of error messages (assuming dyndbg is enabled for nvdimms): [/]# echo 4194304 > /sys/bus/nd/devices/region5/namespace5.0/size [ 288.372612] nd namespace5.0: __size_store: uuid not set [ 288.374839] nd namespace5.0: size_store: 400000 fail (-6) sh: write error: No such device or address [/]# [/]# echo namespace5.0 > /sys/bus/nd/drivers/nd_blk/bind [ 554.671648] nd_blk namespace5.0: nvdimm_namespace_common_probe: sector size not set [ 554.674688] ndbus1: nd_blk.probe(namespace5.0) = -19 sh: write error: No such device [/]# Signed-off-by: Dmitry V. Krivenok <krivenok.dmitry@gmail.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-29libnvdimm, pmem: direct map legacy pmem by defaultDan Williams1-5/+30
The expectation is that the legacy / non-standard pmem discovery method (e820 type-12) will only ever be used to describe small quantities of persistent memory. Larger capacities will be described via the ACPI NFIT. When "allocate struct page from pmem" support is added this default policy can be overridden by assigning a legacy pmem namespace to a pfn device, however this would be only be necessary if a platform used the legacy mechanism to define a very large range. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-29libnvdimm, pfn: 'struct page' provider infrastructureDan Williams1-8/+26
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 <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-14libnvdimm, btt: write and validate parent_uuidVishal Verma1-0/+20
When a BTT is instantiated on a namespace it must validate the namespace uuid matches the 'parent_uuid' stored in the btt superblock. This property enforces that changing the namespace UUID invalidates all former BTT instances on that storage. For "IO namespaces" that don't have a label or UUID, the parent_uuid is set to zero, and this validation is skipped. For such cases, old BTTs have to be invalidated by forcing the namespace to raw mode, and overwriting the BTT info blocks. Based on a patch by Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm: Add sysfs numa_node to NVDIMM devicesToshi Kani1-0/+1
Add support of sysfs 'numa_node' to I/O-related NVDIMM devices under /sys/bus/nd/devices, regionN, namespaceN.0, and bttN.x. An example of numa_node values on a 2-socket system with a single NVDIMM range on each socket is shown below. /sys/bus/nd/devices |-- btt0.0/numa_node:0 |-- btt1.0/numa_node:1 |-- btt1.1/numa_node:1 |-- namespace0.0/numa_node:0 |-- namespace1.0/numa_node:1 |-- region0/numa_node:0 |-- region1/numa_node:1 These numa_node files are then linked under the block class of their device names. /sys/class/block/pmem0/device/numa_node:0 /sys/class/block/pmem1s/device/numa_node:1 This enables numactl(8) to accept 'block:' and 'file:' paths of pmem and btt devices as shown in the examples below. numactl --preferred block:pmem0 --show numactl --preferred file:/dev/pmem1s --show Signed-off-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, blk: add support for blk integrityVishal Verma1-1/+2
Support multiple block sizes (sector + metadata) for nd_blk in the same way as done for the BTT. Add the idea of an 'internal' lbasize, which is properly aligned and padded, and store metadata in this space. Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memoryRoss Zwisler1-1/+64
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>
2015-06-26nd_btt: atomic sector updatesVishal Verma1-0/+24
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 <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> Cc: Neil Brown <neilb@suse.de> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg KH <gregkh@linuxfoundation.org> [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 <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-25libnvdimm: infrastructure for btt devicesDan Williams1-34/+170
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 <gregkh@linuxfoundation.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-25libnvdimm: write blk label setDan Williams1-4/+53
After 'uuid', 'size', 'sector_size', and optionally 'alt_name' have been set to valid values the labels on the dimm can be updated. The difference with the pmem case is that blk namespaces are limited to one dimm and can cover discontiguous ranges in dpa space. Also, after allocating label slots, it is useful for userspace to know how many slots are left. Export this information in sysfs. Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Neil Brown <neilb@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-25libnvdimm: write pmem label setDan Williams1-11/+72
After 'uuid', 'size', and optionally 'alt_name' have been set to valid values the labels on the dimms can be updated. Write procedure is: 1/ Allocate and write new labels in the "next" index 2/ Free the old labels in the working copy 3/ Write the bitmap and the label space on the dimm 4/ Write the index to make the update valid Label ranges directly mirror the dpa resource values for the given label_id of the namespace. Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Neil Brown <neilb@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>