From 1f7df6f88b9245a7f2d0f8ecbc97dc88c8d0d8e1 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 9 Jun 2015 20:13:14 -0400 Subject: libnvdimm, nfit: regions (block-data-window, persistent memory, volatile memory) 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 --- drivers/nvdimm/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/nvdimm/Makefile') diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile index d44b5c1fcd3b..88afd0d849c3 100644 --- a/drivers/nvdimm/Makefile +++ b/drivers/nvdimm/Makefile @@ -4,3 +4,4 @@ libnvdimm-y := core.o libnvdimm-y += bus.o libnvdimm-y += dimm_devs.o libnvdimm-y += dimm.o +libnvdimm-y += region_devs.o -- cgit v1.2.3