With the arrival of the device-dax facility in 4.7 a pmem namespace can
now be configured into a total of four distinct modes: 'raw', 'sector',
'memory', and 'dax'. Where raw, sector, and memory are block device
modes and dax supports the device-dax character device. With that degree
of freedom in the use cases it is overly restrictive to continue the
current limit of only one pmem namespace per-region, or "interleave-set"
in ACPI 6+ terminology.
This series adds support for reading and writing configurations that
describe multiple pmem allocations within a region. The new rules for
allocating / validating the available capacity when blk and pmem regions
alias are (quoting space_valid()):
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).
Where "adjacent" allocations grow an existing namespace. Note that
growing a namespace is potentially destructive if free space is consumed
from a location preceding the current allocation. There is no support
for dis-continuity within a given namespace allocation.
Previously, since there was only one namespace per-region, the resulting
pmem device would be named after the region. Now, subsequent namespaces
after the first are named with the region index and a
".<namespace-index>" suffix. For example:
/dev/pmem0.1
---
Dan Williams (14):
libnvdimm, region: move region-mapping input-paramters to nd_mapping_desc
libnvdimm, label: convert label tracking to a linked list
libnvdimm, namespace: refactor uuid_show() into a namespace_to_uuid()
helper
libnvdimm, namespace: unify blk and pmem label scanning
tools/testing/nvdimm: support for sub-dividing a pmem region
libnvdimm, namespace: allow multiple pmem-namespaces per region at scan
time
libnvdimm, namespace: sort namespaces by dpa at init
libnvdimm, region: update nd_region_available_dpa() for multi-pmem support
libnvdimm, namespace: expand pmem device naming scheme for multi-pmem
libnvdimm, namespace: update label implementation for multi-pmem
libnvdimm, namespace: enable allocation of multiple pmem namespaces
libnvdimm, namespace: filter out of range labels in scan_labels()
libnvdimm, namespace: lift single pmem limit in scan_labels()
libnvdimm, namespace: allow creation of multiple pmem-namespaces per
region
drivers/acpi/nfit/core.c | 30 +
drivers/nvdimm/dimm_devs.c | 192 ++++++--
drivers/nvdimm/label.c | 192 +++++---
drivers/nvdimm/namespace_devs.c | 786 +++++++++++++++++++++++----------
drivers/nvdimm/nd-core.h | 23 +
drivers/nvdimm/nd.h | 28 +
drivers/nvdimm/region_devs.c | 58 ++
include/linux/libnvdimm.h | 25 -
include/linux/nd.h | 8
tools/testing/nvdimm/test/iomap.c | 134 ++++--
tools/testing/nvdimm/test/nfit.c | 21 -
tools/testing/nvdimm/test/nfit_test.h | 12 -
12 files changed, 1055 insertions(+), 454 deletions(-)
