From patchwork Thu Nov 8 11:04:47 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 1714971 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 2C1BCE0010 for ; Thu, 8 Nov 2012 10:59:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753491Ab2KHK7T (ORCPT ); Thu, 8 Nov 2012 05:59:19 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:55605 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751465Ab2KHK7B (ORCPT ); Thu, 8 Nov 2012 05:59:01 -0500 X-IronPort-AV: E=Sophos;i="4.80,737,1344182400"; d="scan'208";a="6161802" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 08 Nov 2012 18:57:19 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id qA8AwspG006481; Thu, 8 Nov 2012 18:58:54 +0800 Received: from ghost.fnst.cn.fujitsu.com ([10.167.225.226]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012110818585952-1025733 ; Thu, 8 Nov 2012 18:58:59 +0800 From: Wen Congyang To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org, Len Brown Cc: "Rafael J. Wysocki" , Andrew Morton , Yasuaki Ishimatsu , Lai Jiangshan , Jiang Liu , KOSAKI Motohiro , Minchan Kim , Mel Gorman , David Rientjes , Konrad Rzeszutek Wilk , Toshi Kani , Wen Congyang , Jiang Liu , Benjamin Herrenschmidt , Paul Mackerras , Christoph Lameter Subject: [Patch v4 1/7] acpi, memory-hotplug: introduce a mutex lock to protect the list in acpi_memory_device Date: Thu, 8 Nov 2012 19:04:47 +0800 Message-Id: <1352372693-32411-2-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 1.8.0 In-Reply-To: <1352372693-32411-1-git-send-email-wency@cn.fujitsu.com> References: <1352372693-32411-1-git-send-email-wency@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/08 18:58:59, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/08 18:59:00, Serialize complete at 2012/11/08 18:59:00 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org The memory device can be removed by 2 ways: 1. send eject request by SCI 2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject This 2 events may happen at the same time, so we may touch acpi_memory_device.res_list at the same time. This patch introduce a lock to protect this list. CC: David Rientjes CC: Jiang Liu CC: Len Brown CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro CC: Yasuaki Ishimatsu CC: Rafael J. Wysocki CC: Konrad Rzeszutek Wilk Signed-off-by: Wen Congyang --- The commit in pm tree is 85fcb375 drivers/acpi/acpi_memhotplug.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 1e90e8f..4c18ee3 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -83,7 +83,8 @@ struct acpi_memory_info { struct acpi_memory_device { struct acpi_device * device; unsigned int state; /* State of the memory device */ - struct list_head res_list; + struct mutex list_lock; + struct list_head res_list; /* protected by list_lock */ }; static int acpi_hotmem_initialized; @@ -101,19 +102,23 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) (address64.resource_type != ACPI_MEMORY_RANGE)) return AE_OK; + mutex_lock(&mem_device->list_lock); list_for_each_entry(info, &mem_device->res_list, list) { /* Can we combine the resource range information? */ if ((info->caching == address64.info.mem.caching) && (info->write_protect == address64.info.mem.write_protect) && (info->start_addr + info->length == address64.minimum)) { info->length += address64.address_length; + mutex_unlock(&mem_device->list_lock); return AE_OK; } } new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL); - if (!new) + if (!new) { + mutex_unlock(&mem_device->list_lock); return AE_ERROR; + } INIT_LIST_HEAD(&new->list); new->caching = address64.info.mem.caching; @@ -121,6 +126,7 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) new->start_addr = address64.minimum; new->length = address64.address_length; list_add_tail(&new->list, &mem_device->res_list); + mutex_unlock(&mem_device->list_lock); return AE_OK; } @@ -138,9 +144,11 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS, acpi_memory_get_resource, mem_device); if (ACPI_FAILURE(status)) { + mutex_lock(&mem_device->list_lock); list_for_each_entry_safe(info, n, &mem_device->res_list, list) kfree(info); INIT_LIST_HEAD(&mem_device->res_list); + mutex_unlock(&mem_device->list_lock); return -EINVAL; } @@ -236,6 +244,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) * We don't have memory-hot-add rollback function,now. * (i.e. memory-hot-remove function) */ + mutex_lock(&mem_device->list_lock); list_for_each_entry(info, &mem_device->res_list, list) { if (info->enabled) { /* just sanity check...*/ num_enabled++; @@ -256,6 +265,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) info->enabled = 1; num_enabled++; } + mutex_unlock(&mem_device->list_lock); if (!num_enabled) { printk(KERN_ERR PREFIX "add_memory failed\n"); mem_device->state = MEMORY_INVALID_STATE; @@ -316,14 +326,18 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) * Ask the VM to offline this memory range. * Note: Assume that this function returns zero on success */ + mutex_lock(&mem_device->list_lock); list_for_each_entry_safe(info, n, &mem_device->res_list, list) { if (info->enabled) { result = remove_memory(info->start_addr, info->length); - if (result) + if (result) { + mutex_unlock(&mem_device->list_lock); return result; + } } kfree(info); } + mutex_unlock(&mem_device->list_lock); /* Power-off and eject the device */ result = acpi_memory_powerdown_device(mem_device); @@ -438,6 +452,7 @@ static int acpi_memory_device_add(struct acpi_device *device) mem_device->device = device; sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); + mutex_init(&mem_device->list_lock); device->driver_data = mem_device; /* Get the range from the _CRS */