From patchwork Wed Apr 6 09:44:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharata B Rao X-Patchwork-Id: 606912 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qg17s2xMpz9t5g for ; Wed, 6 Apr 2016 19:46:17 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3qg17s1zcyzDqMY for ; Wed, 6 Apr 2016 19:46:17 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [125.16.236.5]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qg16c4zsDzDq6B for ; Wed, 6 Apr 2016 19:45:11 +1000 (AEST) Received: from localhost by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 6 Apr 2016 15:15:05 +0530 X-IBM-Helo: d28relay03.in.ibm.com X-IBM-MailFrom: bharata@linux.vnet.ibm.com X-IBM-RcptTo: linuxppc-dev@lists.ozlabs.org Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay03.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u369j4HK50987258 for ; Wed, 6 Apr 2016 15:15:04 +0530 Received: from d28av03.in.ibm.com (localhost [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u369iuea001978 for ; Wed, 6 Apr 2016 15:15:00 +0530 Received: from bharata.in.ibm.com ([9.79.183.243]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u369ikdY001245; Wed, 6 Apr 2016 15:14:47 +0530 From: Bharata B Rao To: linuxppc-dev@lists.ozlabs.org Subject: [RFC FIX PATCH v0] powerpc,numa: Fix memory_hotplug_max() Date: Wed, 6 Apr 2016 15:14:43 +0530 Message-Id: <1459935883-29445-1-git-send-email-bharata@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 X-TM-AS-MML: disable x-cbid: 16040609-0017-0000-0000-00001DC785CE X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bharata B Rao , nfonteno@us.ibm.com, aik@au1.ibm.com, mdroth@linux.vnet.ibm.com, david@gibson.dropbear.id.au MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" memory_hotplug_max() uses hot_add_drconf_memory_max() to get maxmimum addressable memory by referring to ibm,dyanamic-memory property. There are three problems with the current approach: 1 hot_add_drconf_memory_max() assumes that ibm,dynamic-memory includes all the LMBs of the guest, but that is not true for PowerKVM which populates only DR LMBs (LMBs that can be hotplugged/removed) in that property. 2 hot_add_drconf_memory_max() multiplies lmb-size with lmb-count to arrive at the max possible address. Since ibm,dynamic-memory doesn't include RMA LMBs, the address thus obtained will be less than the actual max address. For example, if max possible memory size is 32G, with lmb-size of 256MB there can be 127 LMBs in ibm,dynamic-memory (1 LMB for RMA which won't be present here). hot_add_drconf_memory_max() would then return the max addressable memory as 127 * 256MB = 31.75GB, the max address should have been 32G which is what ibm,lrdr-capacity shows. 3 In PowerKVM, there can be a gap between the end of boot time RAM and beginning of hotplug RAM area. So just multiplying lmb-count with lmb-size will not provide the correct max possible address for PowerKVM. This patch fixes 1 by using ibm,lrdr-capacity property to return the max addressable memory whenever the property is present. Then it fixes 2 & 3 by fetching the address of the last LMB in ibm,dynamic-memory property. NOTE: There are some unnecessary changes in the patch because of converting spaces to tabs w/o which checkpatch.pl complains. Signed-off-by: Bharata B Rao --- arch/powerpc/mm/numa.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 669a15e..57d5877 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1164,17 +1164,32 @@ int hot_add_scn_to_nid(unsigned long scn_addr) static u64 hot_add_drconf_memory_max(void) { struct device_node *memory = NULL; - unsigned int drconf_cell_cnt = 0; - u64 lmb_size = 0; + struct device_node *dn = NULL; + unsigned int drconf_cell_cnt = 0; + u64 lmb_size = 0; const __be32 *dm = NULL; + const __be64 *lrdr = NULL; + struct of_drconf_cell drmem; + + dn = of_find_node_by_path("/rtas"); + if (dn) { + lrdr = of_get_property(dn, "ibm,lrdr-capacity", NULL); + of_node_put(dn); + if (lrdr) + return be64_to_cpup(lrdr); + } memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory"); if (memory) { - drconf_cell_cnt = of_get_drconf_memory(memory, &dm); - lmb_size = of_get_lmb_size(memory); - of_node_put(memory); - } - return lmb_size * drconf_cell_cnt; + drconf_cell_cnt = of_get_drconf_memory(memory, &dm); + lmb_size = of_get_lmb_size(memory); + + /* Advance to the last cell, each cell has 6 32 bit integers */ + dm += (drconf_cell_cnt - 1) * 6; + read_drconf_cell(&drmem, &dm); + of_node_put(memory); + } + return drmem.base_addr + lmb_size; } /*