From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964816AbbDUUv3 (ORCPT ); Tue, 21 Apr 2015 16:51:29 -0400 Received: from g4t3427.houston.hp.com ([15.201.208.55]:40628 "EHLO g4t3427.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933039AbbDUUvZ (ORCPT ); Tue, 21 Apr 2015 16:51:25 -0400 Message-ID: <1429648353.17259.40.camel@misato.fc.hp.com> Subject: Re: [Linux-nvdimm] [PATCH 04/21] nd: create an 'nd_bus' from an 'nfit_desc' From: Toshi Kani To: Dan Williams Cc: "linux-nvdimm@lists.01.org" , "linux-kernel@vger.kernel.org" Date: Tue, 21 Apr 2015 14:32:33 -0600 In-Reply-To: References: <20150418013256.25237.96403.stgit@dwillia2-desk3.amr.corp.intel.com> <20150418013535.25237.4770.stgit@dwillia2-desk3.amr.corp.intel.com> <1429644912.17259.31.camel@misato.fc.hp.com> <1429646156.17259.39.camel@misato.fc.hp.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-4.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2015-04-21 at 13:35 -0700, Dan Williams wrote: > On Tue, Apr 21, 2015 at 12:55 PM, Toshi Kani wrote: > > On Tue, 2015-04-21 at 12:58 -0700, Dan Williams wrote: > >> On Tue, Apr 21, 2015 at 12:35 PM, Toshi Kani wrote: > >> > On Fri, 2015-04-17 at 21:35 -0400, Dan Williams wrote: > >> > : > >> >> + > >> >> +static int nd_mem_init(struct nd_bus *nd_bus) > >> >> +{ > >> >> + struct nd_spa *nd_spa; > >> >> + > >> >> + /* > >> >> + * For each SPA-DCR address range find its corresponding > >> >> + * MEMDEV(s). From each MEMDEV find the corresponding DCR. > >> >> + * Then, try to find a SPA-BDW and a corresponding BDW that > >> >> + * references the DCR. Throw it all into an nd_mem object. > >> >> + * Note, that BDWs are optional. > >> >> + */ > >> >> + list_for_each_entry(nd_spa, &nd_bus->spas, list) { > >> >> + u16 spa_index = readw(&nd_spa->nfit_spa->spa_index); > >> >> + int type = nfit_spa_type(nd_spa->nfit_spa); > >> >> + struct nd_mem *nd_mem, *found; > >> >> + struct nd_memdev *nd_memdev; > >> >> + u16 dcr_index; > >> >> + > >> >> + if (type != NFIT_SPA_DCR) > >> >> + continue; > >> > > >> > This function requires NFIT_SPA_DCR, SPA Range Structure with NVDIMM > >> > Control Region GUID, for initializing an nd_mem object. However, > >> > battery-backed DIMMs do not have such control region SPA. IIUC, the > >> > NFIT spec does not require NFIT_SPA_DCR. > >> > > >> > Can you change this function to work with NFIT_SPA_PM as well? > >> > >> NFIT_SPA_PM ranges are handled separately from nd_mem_init(). See > >> nd_region_create() in patch 10. > > > > If nd_mem_init() does not initialize nd_mem objects, nd_bus_probe() in > > core.c fails in nd_bus_init_interleave_sets() and skips all subsequent > > nd_bus_xxx() calls. So, nd_region_create() won't be called. > > > > nd_bus_init_interleave_sets() fails because init_interleave_set() > > returns -ENODEV if (!nd_mem). > > Ah, ok your test case is specifying PMEM backed by memory device > info. We have a test case for simple ranges (nfit_test1_setup()), but > it doesn't hit this bug because it does not specify any memory-device > tables. > > Thanks, will fix this in v2 of the patch set. > > > BTW, there are two nd_bus_probe() in bus.c and core.c, which is > > confusing. > > Ok, will fix this as well in the v2 posting. Cool! Thanks Dan! -Toshi