From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rv75R021TzDqN8 for ; Wed, 20 Jul 2016 03:56:26 +1000 (AEST) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u6JHsW2O062378 for ; Tue, 19 Jul 2016 13:56:24 -0400 Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) by mx0a-001b2d01.pphosted.com with ESMTP id 2495r85h55-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 19 Jul 2016 13:56:24 -0400 Received: from localhost by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 19 Jul 2016 11:56:23 -0600 Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 627883E40067 for ; Tue, 19 Jul 2016 11:56:20 -0600 (MDT) Subject: Re: [PATCH v2 2/2] powerpc/pseries: Implemented indexed-count hotplug memory remove To: Sahil Mehta , linuxppc-dev@lists.ozlabs.org References: <43770dca-871a-8f6c-6dbf-cdf842b6b442@linux.vnet.ibm.com> From: Nathan Fontenot Date: Tue, 19 Jul 2016 12:56:19 -0500 MIME-Version: 1.0 In-Reply-To: <43770dca-871a-8f6c-6dbf-cdf842b6b442@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Message-Id: <578E69C3.4050309@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 07/18/2016 10:08 AM, Sahil Mehta wrote: > Indexed-count remove for memory hotplug guarantees that a contiguous block > of lmbs beginning at a specified will be unassigned (NOT > that lmbs will be removed). Because of Qemu's per-DIMM memory > management, the removal of a contiguous block of memory currently > requires a series of individual calls. Indexed-count remove reduces > this series into a single call. > > Signed-off-by: Sahil Mehta Reviewed-by: Nathan Fontenot > --- > v2: -use u32s drc_index and count instead of u32 ic[] > in dlpar_memory > > arch/powerpc/platforms/pseries/hotplug-memory.c | 84 +++++++++++++++++++++++ > 1 file changed, 84 insertions(+) > > diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c > index d7942ca..244e1a8 100644 > --- a/arch/powerpc/platforms/pseries/hotplug-memory.c > +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c > @@ -503,6 +503,86 @@ static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop) > return rc; > } > > +static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index, > + struct property *prop) > +{ > + struct of_drconf_cell *lmbs; > + u32 num_lmbs, *p; > + int i, rc; > + int lmbs_available = 0, start_index = 0, end_index; > + > + pr_info("Attempting to hot-remove %u LMB(s) at %x\n", > + lmbs_to_remove, drc_index); > + > + if (lmbs_to_remove == 0) > + return -EINVAL; > + > + p = prop->value; > + num_lmbs = *p++; > + lmbs = (struct of_drconf_cell *)p; > + > + /* Navigate to drc_index */ > + while (start_index < num_lmbs) { > + if (lmbs[start_index].drc_index == drc_index) > + break; > + > + start_index++; > + } > + > + end_index = start_index + lmbs_to_remove; > + > + /* Validate that there are enough LMBs to satisfy the request */ > + for (i = start_index; i < end_index; i++) { > + if (lmbs[i].flags & DRCONF_MEM_RESERVED) > + break; > + > + lmbs_available++; > + } > + > + if (lmbs_available < lmbs_to_remove) > + return -EINVAL; > + > + for (i = 0; i < end_index; i++) { > + if (!(lmbs[i].flags & DRCONF_MEM_ASSIGNED)) > + continue; > + > + rc = dlpar_remove_lmb(&lmbs[i]); > + if (rc) > + break; > + > + lmbs[i].reserved = 1; > + } > + > + if (rc) { > + pr_err("Memory indexed-count-remove failed, adding any removed LMBs\n"); > + > + for (i = start_index; i < end_index; i++) { > + if (!lmbs[i].reserved) > + continue; > + > + rc = dlpar_add_lmb(&lmbs[i]); > + if (rc) > + pr_err("Failed to add LMB, drc index %x\n", > + be32_to_cpu(lmbs[i].drc_index)); > + > + lmbs[i].reserved = 0; > + } > + rc = -EINVAL; > + } else { > + for (i = start_index; i < end_index; i++) { > + if (!lmbs[i].reserved) > + continue; > + > + pr_info("Memory at %llx (drc index %x) was hot-removed\n", > + lmbs[i].base_addr, lmbs[i].drc_index); > + > + lmbs[i].reserved = 0; > + } > + } > + > + return rc; > +} > + > #else > static inline int pseries_remove_memblock(unsigned long base, > unsigned int memblock_size) > @@ -821,6 +901,10 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog) > } else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) { > drc_index = hp_elog->_drc_u.drc_index; > rc = dlpar_memory_remove_by_index(drc_index, prop); > + } else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_IC) { > + count = hp_elog->_drc_u.indexed_count[0]; > + drc_index = hp_elog->_drc_u.indexed_count[1]; > + rc = dlpar_memory_remove_by_ic(count, drc_index, prop); > } else > rc = -EINVAL; > break; > > On 07/18/2016 10:04 AM, Sahil Mehta wrote: >> Indexed-count memory management allows addition and removal of contiguous >> lmb blocks with a single command. When compared to the series of calls >> previously required to manage contiguous blocks, indexed-count decreases >> command frequency and reduces risk of buffer overflow. >> >> Changes in v2: >> -------------- >> -[PATCH 1/2]: -remove potential memory leak when parsing command >> -use u32s drc_index and count instead of u32 ic[] >> in dlpar_memory >> -[PATCH 2/2]: -use u32s drc_index and count instead of u32 ic[] >> in dlpar_memory >> >> -Sahil Mehta >> --- >> include/asm/rtas.h | 2 >> platforms/pseries/dlpar.c | 34 ++++++ >> platforms/pseries/hotplug-memory.c | 184 +++++++++++++++++++++++++++++++++++-- >> 3 files changed, 208 insertions(+), 12 deletions(-) >> >> _______________________________________________ >> Linuxppc-dev mailing list >> Linuxppc-dev@lists.ozlabs.org >> https://lists.ozlabs.org/listinfo/linuxppc-dev >> > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev >