From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757992AbbFQVhx (ORCPT ); Wed, 17 Jun 2015 17:37:53 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:47262 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755379AbbFQVhv (ORCPT ); Wed, 17 Jun 2015 17:37:51 -0400 From: "Rafael J. Wysocki" To: Dan Williams Cc: linux-nvdimm@ml01.01.org, mingo@kernel.org, sfr@canb.auug.org.au, rafael@kernel.org, neilb@suse.de, gregkh@linuxfoundation.org, "Rafael J. Wysocki" , Robert Moore , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, jmoyer@redhat.com, axboe@kernel.dk, linux-api@vger.kernel.org, akpm@linux-foundation.org, hch@lst.de Subject: Re: [PATCH v6 07/21] libnvdimm, nfit: regions (block-data-window, persistent memory, volatile memory) Date: Thu, 18 Jun 2015 00:03:50 +0200 Message-ID: <2337285.ixNCaGxhrS@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.1.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <20150611201047.25175.43773.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20150611183830.25175.51256.stgit@dwillia2-desk3.amr.corp.intel.com> <20150611201047.25175.43773.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, June 11, 2015 04:10:47 PM Dan Williams wrote: > 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 > Signed-off-by: Dan Williams For the ACPI part: Acked-by: Rafael J. Wysocki