aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/nvdimm/btt.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2015-09-08Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimmLinus Torvalds1-37/+13
Pull libnvdimm updates from Dan Williams: "This update has successfully completed a 0day-kbuild run and has appeared in a linux-next release. The changes outside of the typical drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and the introduction of ZONE_DEVICE + devm_memremap_pages(). Summary: - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic mechanism for adding device-driver-discovered memory regions to the kernel's direct map. This facility is used by the pmem driver to enable pfn_to_page() operations on the page frames returned by DAX ('direct_access' in 'struct block_device_operations'). For now, the 'memmap' allocation for these "device" pages comes from "System RAM". Support for allocating the memmap from device memory will arrive in a later kernel. - Introduce memremap() to replace usages of ioremap_cache() and ioremap_wt(). memremap() drops the __iomem annotation for these mappings to memory that do not have i/o side effects. The replacement of ioremap_cache() with memremap() is limited to the pmem driver to ease merging the api change in v4.3. Completion of the conversion is targeted for v4.4. - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem driver, update the VFS DAX implementation and PMEM api to provide persistence guarantees for kernel operations on a DAX mapping. - Convert the ACPI NFIT 'BLK' driver to map the block apertures as cacheable to improve performance. - Miscellaneous updates and fixes to libnvdimm including support for issuing "address range scrub" commands, clarifying the optimal 'sector size' of pmem devices, a clarification of the usage of the ACPI '_STA' (status) property for DIMM devices, and other minor fixes" * tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits) libnvdimm, pmem: direct map legacy pmem by default libnvdimm, pmem: 'struct page' for pmem libnvdimm, pfn: 'struct page' provider infrastructure x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB add devm_memremap_pages mm: ZONE_DEVICE for "device memory" mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h dax: drop size parameter to ->direct_access() nd_blk: change aperture mapping from WC to WB nvdimm: change to use generic kvfree() pmem, dax: have direct_access use __pmem annotation dax: update I/O path to do proper PMEM flushing pmem: add copy_from_iter_pmem() and clear_pmem() pmem, x86: clean up conditional pmem includes pmem: remove layer when calling arch_has_wmb_pmem() pmem, x86: move x86 PMEM API to new pmem.h header libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option pmem: switch to devm_ allocations devres: add devm_memremap libnvdimm, btt: write and validate parent_uuid ...
2015-08-28libnvdimm, pfn: 'struct page' provider infrastructureDan Williams1-3/+3
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/+2
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>
2015-08-14libnvdimm, btt: consolidate arena validationVishal Verma1-27/+1
Use arena_is_valid as a common routine for checking the validity of an info block from both discover_arenas, and nd_btt_probe. As a result, don't check for validity of the BTT's UUID, and lbasize. The checksum in the BTT info block guarantees self-consistency, and when we're called from nd_btt_probe, we don't have a valid uuid or lbasize available to check against. Also cleanup to return a bool instead of an int. Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-14libnvdimm, btt: clean up internal interfacesVishal Verma1-10/+9
Consolidate the parameters passed to arena_is_valid into just nd_btt, and an info block to increase re-usability. Similarly, btt_arena_write_layout doesn't need to be passed a uuid, as it can be obtained from arena->nd_btt. Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig1-2/+3
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-27libnvdimm, btt: sparse fixDan Williams1-2/+3
Fix: drivers/nvdimm/btt.c:635:29: warning: restricted __le64 degrades to integer Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, nfit: handle unarmed dimms, mark namespaces read-onlyDan Williams1-2/+8
Upon detection of an unarmed dimm in a region, arrange for descendant BTT, PMEM, or BLK instances to be read-only. A dimm is primarily marked "unarmed" via flags passed by platform firmware (NFIT). The flags in the NFIT memory device sub-structure indicate the state of the data on the nvdimm relative to its energy source or last "flush to persistence". For the most part there is nothing the driver can do but advertise the state of these flags in sysfs and emit a message if firmware indicates that the contents of the device may be corrupted. However, for the case of ACPI_NFIT_MEM_ARMED, the driver can arrange for the block devices incorporating that nvdimm to be marked read-only. This is a safe default as the data is still available and new writes are held off until the administrator either forces read-write mode, or the energy source becomes armed. A 'read_only' attribute is added to REGION devices to allow for overriding the default read-only policy of all descendant block devices. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm: enable iostatDan Williams1-1/+6
This is disabled by default as the overhead is prohibitive, but if the user takes the action to turn it on we'll oblige. Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, btt: add support for blk integrityVishal Verma1-16/+113
Support multiple block sizes (sector + metadata) using the blk integrity framework. This registers a new integrity template that defines the protection information tuple size based on the configured metadata size, and simply acts as a passthrough for protection information generated by another layer. The metadata is written to the storage as-is, and read back with each sector. Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26nd_btt: atomic sector updatesVishal Verma1-0/+1371
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>