From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx141.postini.com [74.125.245.141]) by kanga.kvack.org (Postfix) with SMTP id E00AC6B0036 for ; Wed, 24 Jul 2013 16:51:43 -0400 (EDT) From: "K. Y. Srinivasan" Subject: [PATCH 1/2] Drivers: base: memory: Export functionality for "in kernel" onlining of memory Date: Wed, 24 Jul 2013 14:29:58 -0700 Message-Id: <1374701399-30842-1-git-send-email-kys@microsoft.com> In-Reply-To: <1374701355-30799-1-git-send-email-kys@microsoft.com> References: <1374701355-30799-1-git-send-email-kys@microsoft.com> Sender: owner-linux-mm@kvack.org List-ID: To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, andi@firstfloor.org, akpm@linux-foundation.org, linux-mm@kvack.org, kamezawa.hiroyuki@gmail.com, mhocko@suse.cz, hannes@cmpxchg.org, yinghan@google.com, dave@sr71.net Cc: "K. Y. Srinivasan" The current machinery for hot-adding memory requires having user level to bring the memory segments online. Export the necessary functionality to bring the memory segment online without involving user space code. Signed-off-by: K. Y. Srinivasan --- drivers/base/memory.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/memory.h | 5 +++++ 2 files changed, 40 insertions(+), 0 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 2b7813e..a7140b3 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -541,6 +541,41 @@ struct memory_block *find_memory_block(struct mem_section *section) return find_memory_block_hinted(section, NULL); } +/* + * Given the start pfn of a memory block; bring the memory + * block online. This API would be useful for drivers that may + * want to bring "online" the memory that has been hot-added. + */ + +int online_memory_block(unsigned long start_pfn) +{ + struct mem_section *cur_section; + struct memory_block *cur_memory_block; + int ret_val = -EINVAL; + + cur_section = __pfn_to_section(start_pfn); + + if (!valid_section(cur_section)) + return ret_val; + + mutex_lock(&mem_sysfs_mutex); + cur_memory_block = find_memory_block(cur_section); + + if (!cur_memory_block) { + mutex_unlock(&mem_sysfs_mutex); + return ret_val; + } + + lock_device_hotplug(); + ret_val = memory_block_change_state(cur_memory_block, MEM_ONLINE, + MEM_OFFLINE, ONLINE_KEEP); + unlock_device_hotplug(); + mutex_unlock(&mem_sysfs_mutex); + + return ret_val; +} +EXPORT_SYMBOL_GPL(online_memory_block); + static struct attribute *memory_memblk_attrs[] = { &dev_attr_phys_index.attr, &dev_attr_end_phys_index.attr, diff --git a/include/linux/memory.h b/include/linux/memory.h index 85c31a8..7d0d2a6 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -109,12 +109,17 @@ static inline int memory_isolate_notify(unsigned long val, void *v) { return 0; } +static inline int online_memory_block(unsigned long start_pfn) +{ + return 0; +} #else extern int register_memory_notifier(struct notifier_block *nb); extern void unregister_memory_notifier(struct notifier_block *nb); extern int register_memory_isolate_notifier(struct notifier_block *nb); extern void unregister_memory_isolate_notifier(struct notifier_block *nb); extern int register_new_memory(int, struct mem_section *); +extern int online_memory_block(unsigned long start_pfn); #ifdef CONFIG_MEMORY_HOTREMOVE extern int unregister_memory_section(struct mem_section *); #endif -- 1.7.4.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org