From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B360C169C4 for ; Wed, 6 Feb 2019 16:06:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01B9E217F9 for ; Wed, 6 Feb 2019 16:06:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730683AbfBFQGr (ORCPT ); Wed, 6 Feb 2019 11:06:47 -0500 Received: from mga05.intel.com ([192.55.52.43]:6386 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726270AbfBFQGq (ORCPT ); Wed, 6 Feb 2019 11:06:46 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Feb 2019 08:06:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,340,1544515200"; d="scan'208";a="142077354" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by fmsmga004.fm.intel.com with ESMTP; 06 Feb 2019 08:06:44 -0800 Date: Wed, 6 Feb 2019 09:06:14 -0700 From: Keith Busch To: Jonathan Cameron Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, Greg Kroah-Hartman , Rafael Wysocki , Dave Hansen , Dan Williams Subject: Re: [PATCHv5 03/10] acpi/hmat: Parse and report heterogeneous memory Message-ID: <20190206160613.GG28064@localhost.localdomain> References: <20190124230724.10022-1-keith.busch@intel.com> <20190124230724.10022-4-keith.busch@intel.com> <20190206122814.00000127@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190206122814.00000127@huawei.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 06, 2019 at 12:28:14PM +0000, Jonathan Cameron wrote: > On Thu, 24 Jan 2019 16:07:17 -0700 > Keith Busch wrote: > > > + pr_info("HMAT: Locality: Flags:%02x Type:%s Initiator Domains:%d Target Domains:%d Base:%lld\n", > > + hmat_loc->flags, hmat_data_type(type), ipds, tpds, > > + hmat_loc->entry_base_unit); > > + > > + inits = (u32 *)(hmat_loc + 1); > > + targs = &inits[ipds]; > > This line is a bit of an oddity as it's indexing off the end of the data. > targs = inits + ipds; > would be nicer to my mind as doesn't even hint that we are in inits still. > > > > + entries = (u16 *)(&targs[tpds]); Sure, I can change these to addition rather than indexing. I have no preference either way. > As above I'd prefer we did the pointer arithmetic explicitly rather > than used an index off the end of the array. > > > + for (init = 0; init < ipds; init++) { > > + for (targ = 0; targ < tpds; targ++) { > > + value = entries[init * tpds + targ]; > > + value = (value * hmat_loc->entry_base_unit) / 10; > > + pr_info(" Initiator-Target[%d-%d]:%d%s\n", > > + inits[init], targs[targ], value, > > + hmat_data_type_suffix(type)); > > Worth checking at this early stage that the domains exist in SRAT? > + screaming if they don't. Sure, I think it should be sufficient to check pxm_to_node() for a valid value to validate the table is okay.. > > + } > > + } > > + > > + return 0; > > +} > > + > > +static __init int hmat_parse_cache(union acpi_subtable_headers *header, > > + const unsigned long end) > > +{ > > + struct acpi_hmat_cache *cache = (void *)header; > > + u32 attrs; > > + > > + if (cache->header.length < sizeof(*cache)) { > > + pr_debug("HMAT: Unexpected cache header length: %d\n", > > + cache->header.length); > > + return -EINVAL; > > + } > > + > > + attrs = cache->cache_attributes; > > + pr_info("HMAT: Cache: Domain:%d Size:%llu Attrs:%08x SMBIOS Handles:%d\n", > > + cache->memory_PD, cache->cache_size, attrs, > > + cache->number_of_SMBIOShandles); > > Can we sanity check those smbios handles actually match anything? Will do. > > + > > + return 0; > > +} > > + > > +static int __init hmat_parse_address_range(union acpi_subtable_headers *header, > > + const unsigned long end) > > +{ > > + struct acpi_hmat_address_range *spa = (void *)header; > > + > > + if (spa->header.length != sizeof(*spa)) { > > + pr_debug("HMAT: Unexpected address range header length: %d\n", > > + spa->header.length); > > My gut feeling is that it's much more useful to make this always print rather > than debug. Same with other error paths above. Given the number of times > broken ACPI tables show up, it's nice to complain really loudly! > > Perhaps others prefer to not do so though so I'll defer to subsystem norms. Yeah, I demoted these to debug based on earlier feedback. We should still be operational even with broken HMAT, so I don't want to create unnecessary panic if its broken, but I agree something should be immediately noticable if the firmware tables are incorrect. Maybe like what bad_srat() provides.