On Thu, Apr 5, 2018 at 12:21 AM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > On Wed, Apr 4, 2018 at 7:04 AM, Oliver <oohall@xxxxxxxxx> wrote: >> On Wed, Apr 4, 2018 at 10:07 PM, Balbir Singh <bsingharora@xxxxxxxxx> wrote: >>> On Tue, 3 Apr 2018 10:37:51 -0700 >>> Dan Williams <dan.j.williams@xxxxxxxxx> wrote: >>> >>>> On Tue, Apr 3, 2018 at 7:24 AM, Oliver O'Halloran <oohall@xxxxxxxxx> wrote: >>>> > Add device-tree binding documentation for the nvdimm region driver. >>>> > >>>> > Cc: devicetree@xxxxxxxxxxxxxxx >>>> > Signed-off-by: Oliver O'Halloran <oohall@xxxxxxxxx> >>>> > --- >>>> > v2: Changed name from nvdimm-region to pmem-region. >>>> > Cleaned up the example binding and fixed the overlapping regions. >>>> > Added support for multiple regions in a single reg. >>>> > --- >>>> > .../devicetree/bindings/pmem/pmem-region.txt | 80 ++++++++++++++++++++++ >>>> > MAINTAINERS | 1 + >>>> > 2 files changed, 81 insertions(+) >>>> > create mode 100644 Documentation/devicetree/bindings/pmem/pmem-region.txt >>>> >>>> Device-tree folks, does this look, ok? >>>> >>>> Oliver, is there any concept of a management interface to the >>>> device(s) backing these regions? libnvdimm calls these "nmem" devices >>>> and support operations like health status and namespace label >>>> management. >> >> It's something I'm planning on implementing as soon as someone gives >> me some hardware that isn't hacked up lab crap. I'm posting this >> version with just regions since people have been asking for something >> in upstream even if it's not fully featured. >> >> Grumbling aside, the plan is to have separate drivers for the DIMM >> type. Discovering DIMM devices happens via the normal discovery >> mechanisms (e.g. an NVDIMM supporting the JEDEC interface is an I2C >> device) and when binding to a specific DIMM device it registers a DIMM >> descriptor structure and a ndctl implementation for that DIMM type >> with of_pmem. When of_pmem binds to a region it can plug everything >> into the region specific bus. There's a few details to work out, but I >> think it's a reasonable approach. > > Yeah, that sounds reasonable. It would mean that your management > interface would need to understand that nmems on different buses could > potentially move to another bus after a reconfiguration, but that's > not too much different than the ACPI case where nmems can join and > leave regions after a reset / reconfig. > >>> We would need a way to have nmem and pmem-regions find each other. Since we >>> don't have the ACPI abstractions, the nmem region would need to add the >>> ability for a driver to have a phandle to the interleaving and nmem properties. >>> >>> I guess that would be a separate driver, that would manage the nmem devices >>> and there would be a way to relate the pmem and nmems. Oliver? >> >> Yes, that's the plan. > > So Balbir, is that enough for an Acked-by for this device-tree proposal? For context Balbir is working with me on some of the pmem stuff. You probably want an Ack from Rob rather than one of us. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
