From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3r5DXF5JWhzDqZQ for ; Thu, 12 May 2016 23:35:57 +1000 (AEST) Received: from localhost by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 12 May 2016 23:35:55 +1000 Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id CB4CF2CE805F for ; Thu, 12 May 2016 23:35:47 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u4CDZYd88192324 for ; Thu, 12 May 2016 23:35:42 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u4CDYt4t014439 for ; Thu, 12 May 2016 23:34:56 +1000 From: Bharata B Rao To: linuxppc-dev@lists.ozlabs.org Cc: david@gibson.dropbear.id.au, nfont@linux.vnet.ibm.com, aik@au1.ibm.com, mpe@ellerman.id.au, Bharata B Rao Subject: [FIX PATCH v2 2/2] powerpc,numa: Fix memory_hotplug_max() Date: Thu, 12 May 2016 19:04:15 +0530 Message-Id: <1463060055-24158-3-git-send-email-bharata@linux.vnet.ibm.com> In-Reply-To: <1463060055-24158-1-git-send-email-bharata@linux.vnet.ibm.com> References: <1463060055-24158-1-git-send-email-bharata@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. Signed-off-by: Bharata B Rao --- arch/powerpc/mm/numa.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 4a87ccb..f8b1da7 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1164,17 +1164,33 @@ int hot_add_scn_to_nid(unsigned long scn_addr) static u64 hot_add_drconf_memory_max(void) { struct device_node *memory = NULL; + 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); + + /* 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; } - return lmb_size * drconf_cell_cnt; + return 0; } /* -- 2.1.0