From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752811AbdKWLPC (ORCPT ); Thu, 23 Nov 2017 06:15:02 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46112 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752708AbdKWLPB (ORCPT ); Thu, 23 Nov 2017 06:15:01 -0500 Date: Thu, 23 Nov 2017 11:14:52 +0000 From: Andrea Reale To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, m.bielski@virtualopensystems.com, arunks@qti.qualcomm.com, mark.rutland@arm.com, scott.branden@broadcom.com, will.deacon@arm.com, qiuxishi@huawei.com, catalin.marinas@arm.com, mhocko@suse.com, realean2@ie.ibm.com Subject: [PATCH v2 4/5] mm: memory_hotplug: Add memory hotremove probe device References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 17112311-0012-0000-0000-00000590C65E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17112311-0013-0000-0000-0000190B9D87 Message-Id: <22d34fe30df0fbacbfceeb47e20cb1184af73585.1511433386.git.ar@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-11-23_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1711230157 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adding a "remove" sysfs handle that can be used to trigger memory hotremove manually, exactly simmetrically with what happens with the "probe" device for hot-add. This is usueful for architecture that do not rely on ACPI for memory hot-remove. Signed-off-by: Andrea Reale Signed-off-by: Maciej Bielski --- drivers/base/memory.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 1d60b58..8ccb67c 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -530,7 +530,36 @@ memory_probe_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store); -#endif + +#ifdef CONFIG_MEMORY_HOTREMOVE +static ssize_t +memory_remove_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + u64 phys_addr; + int nid, ret; + unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block; + + ret = kstrtoull(buf, 0, &phys_addr); + if (ret) + return ret; + + if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1)) + return -EINVAL; + + nid = memory_add_physaddr_to_nid(phys_addr); + ret = lock_device_hotplug_sysfs(); + if (ret) + return ret; + + remove_memory(nid, phys_addr, + MIN_MEMORY_BLOCK_SIZE * sections_per_block); + unlock_device_hotplug(); + return count; +} +static DEVICE_ATTR(remove, S_IWUSR, NULL, memory_remove_store); +#endif /* CONFIG_MEMORY_HOTREMOVE */ +#endif /* CONFIG_ARCH_MEMORY_PROBE */ #ifdef CONFIG_MEMORY_FAILURE /* @@ -790,6 +819,9 @@ bool is_memblock_offlined(struct memory_block *mem) static struct attribute *memory_root_attrs[] = { #ifdef CONFIG_ARCH_MEMORY_PROBE &dev_attr_probe.attr, +#ifdef CONFIG_MEMORY_HOTREMOVE + &dev_attr_remove.attr, +#endif #endif #ifdef CONFIG_MEMORY_FAILURE -- 2.7.4