From patchwork Wed Sep 5 09:25:42 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 1407341 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 DAE6DDF264 for ; Wed, 5 Sep 2012 09:23:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758366Ab2IEJUk (ORCPT ); Wed, 5 Sep 2012 05:20:40 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:59180 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1758305Ab2IEJUf (ORCPT ); Wed, 5 Sep 2012 05:20:35 -0400 X-IronPort-AV: E=Sophos;i="4.80,373,1344182400"; d="scan'208";a="5789090" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 05 Sep 2012 17:19:15 +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 q859KPBD030003; Wed, 5 Sep 2012 17:20:25 +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 2012090517200226-640084 ; Wed, 5 Sep 2012 17:20:02 +0800 From: wency@cn.fujitsu.com To: x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, sparclinux@vger.kernel.org Cc: rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, Wen Congyang Subject: [RFC v9 PATCH 08/21] memory-hotplug: remove /sys/firmware/memmap/X sysfs Date: Wed, 5 Sep 2012 17:25:42 +0800 Message-Id: <1346837155-534-9-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1346837155-534-1-git-send-email-wency@cn.fujitsu.com> References: <1346837155-534-1-git-send-email-wency@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/09/05 17:20:02, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/09/05 17:20:03, Serialize complete at 2012/09/05 17:20:03 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org From: Yasuaki Ishimatsu When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type} sysfs files are created. But there is no code to remove these files. The patch implements the function to remove them. Note : The code does not free firmware_map_entry since there is no way to free memory which is allocated by bootmem. 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 Signed-off-by: Yasuaki Ishimatsu Signed-off-by: Wen Congyang --- drivers/firmware/memmap.c | 98 +++++++++++++++++++++++++++++++++++++++++- include/linux/firmware-map.h | 6 +++ mm/memory_hotplug.c | 9 +++- 3 files changed, 109 insertions(+), 4 deletions(-) diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c index c1cdc92..6740d26 100644 --- a/drivers/firmware/memmap.c +++ b/drivers/firmware/memmap.c @@ -21,6 +21,7 @@ #include #include #include +#include /* * Data types ------------------------------------------------------------------ @@ -41,6 +42,7 @@ struct firmware_map_entry { const char *type; /* type of the memory range */ struct list_head list; /* entry for the linked list */ struct kobject kobj; /* kobject for each entry */ + unsigned int bootmem:1; /* allocated from bootmem */ }; /* @@ -79,7 +81,26 @@ static const struct sysfs_ops memmap_attr_ops = { .show = memmap_attr_show, }; + +static inline struct firmware_map_entry * +to_memmap_entry(struct kobject *kobj) +{ + return container_of(kobj, struct firmware_map_entry, kobj); +} + +static void release_firmware_map_entry(struct kobject *kobj) +{ + struct firmware_map_entry *entry = to_memmap_entry(kobj); + + if (entry->bootmem) + /* There is no way to free memory allocated from bootmem */ + return; + + kfree(entry); +} + static struct kobj_type memmap_ktype = { + .release = release_firmware_map_entry, .sysfs_ops = &memmap_attr_ops, .default_attrs = def_attrs, }; @@ -94,6 +115,7 @@ static struct kobj_type memmap_ktype = { * in firmware initialisation code in one single thread of execution. */ static LIST_HEAD(map_entries); +static DEFINE_SPINLOCK(map_entries_lock); /** * firmware_map_add_entry() - Does the real work to add a firmware memmap entry. @@ -118,11 +140,25 @@ static int firmware_map_add_entry(u64 start, u64 end, INIT_LIST_HEAD(&entry->list); kobject_init(&entry->kobj, &memmap_ktype); + spin_lock(&map_entries_lock); list_add_tail(&entry->list, &map_entries); + spin_unlock(&map_entries_lock); return 0; } +/** + * firmware_map_remove_entry() - Does the real work to remove a firmware + * memmap entry. + * @entry: removed entry. + **/ +static inline void firmware_map_remove_entry(struct firmware_map_entry *entry) +{ + spin_lock(&map_entries_lock); + list_del(&entry->list); + spin_unlock(&map_entries_lock); +} + /* * Add memmap entry on sysfs */ @@ -144,6 +180,35 @@ static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry) return 0; } +/* + * Remove memmap entry on sysfs + */ +static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry) +{ + kobject_put(&entry->kobj); +} + +/* + * Search memmap entry + */ + +static struct firmware_map_entry * __meminit +firmware_map_find_entry(u64 start, u64 end, const char *type) +{ + struct firmware_map_entry *entry; + + spin_lock(&map_entries_lock); + list_for_each_entry(entry, &map_entries, list) + if ((entry->start == start) && (entry->end == end) && + (!strcmp(entry->type, type))) { + spin_unlock(&map_entries_lock); + return entry; + } + + spin_unlock(&map_entries_lock); + return NULL; +} + /** * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do * memory hotplug. @@ -193,9 +258,36 @@ int __init firmware_map_add_early(u64 start, u64 end, const char *type) if (WARN_ON(!entry)) return -ENOMEM; + entry->bootmem = 1; return firmware_map_add_entry(start, end, type, entry); } +/** + * firmware_map_remove() - remove a firmware mapping entry + * @start: Start of the memory range. + * @end: End of the memory range. + * @type: Type of the memory range. + * + * removes a firmware mapping entry. + * + * Returns 0 on success, or -EINVAL if no entry. + **/ +int __meminit firmware_map_remove(u64 start, u64 end, const char *type) +{ + struct firmware_map_entry *entry; + + entry = firmware_map_find_entry(start, end - 1, type); + if (!entry) + return -EINVAL; + + firmware_map_remove_entry(entry); + + /* remove the memmap entry */ + remove_sysfs_fw_map_entry(entry); + + return 0; +} + /* * Sysfs functions ------------------------------------------------------------- */ @@ -217,8 +309,10 @@ static ssize_t type_show(struct firmware_map_entry *entry, char *buf) return snprintf(buf, PAGE_SIZE, "%s\n", entry->type); } -#define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) -#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) +static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr) +{ + return container_of(attr, struct memmap_attribute, attr); +} static ssize_t memmap_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) diff --git a/include/linux/firmware-map.h b/include/linux/firmware-map.h index 43fe52f..71d4fa7 100644 --- a/include/linux/firmware-map.h +++ b/include/linux/firmware-map.h @@ -25,6 +25,7 @@ int firmware_map_add_early(u64 start, u64 end, const char *type); int firmware_map_add_hotplug(u64 start, u64 end, const char *type); +int firmware_map_remove(u64 start, u64 end, const char *type); #else /* CONFIG_FIRMWARE_MEMMAP */ @@ -38,6 +39,11 @@ static inline int firmware_map_add_hotplug(u64 start, u64 end, const char *type) return 0; } +static inline int firmware_map_remove(u64 start, u64 end, const char *type) +{ + return 0; +} + #endif /* CONFIG_FIRMWARE_MEMMAP */ #endif /* _LINUX_FIRMWARE_MAP_H */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 299747d..e74a01d 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1052,9 +1052,9 @@ int offline_memory(u64 start, u64 size) return 0; } -int remove_memory(int nid, u64 start, u64 size) +int __ref remove_memory(int nid, u64 start, u64 size) { - int ret = -EBUSY; + int ret = 0; lock_memory_hotplug(); /* * The memory might become online by other task, even if you offine it. @@ -1065,8 +1065,13 @@ int remove_memory(int nid, u64 start, u64 size) "because the memmory range is online\n", start, start + size); ret = -EAGAIN; + goto out; } + /* remove memmap entry */ + firmware_map_remove(start, start + size, "System RAM"); + +out: unlock_memory_hotplug(); return ret;