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>
Prepare the pmem driver to consume PMEM namespaces emitted by regions of
an nvdimm_bus instance. No functional change.
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
A struct nvdimm_bus is the anchor device for registering nvdimm
resources and interfaces, for example, a character control device,
nvdimm devices, and I/O region devices. The ACPI NFIT (NVDIMM Firmware
Interface Table) is one possible platform description for such
non-volatile memory resources in a system. The nfit.ko driver attaches
to the "ACPI0012" device that indicates the presence of the NFIT and
parses the table to register a struct nvdimm_bus instance.
Cc: <linux-acpi@vger.kernel.org>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
