memory-hotplug: remove memmap of sparse-vmemmap

Introduce a new API vmemmap_free() to free and remove vmemmap
pagetables.  Since pagetable implements are different, each architecture
has to provide its own version of vmemmap_free(), just like
vmemmap_populate().

Note: vmemmap_free() is not implemented for ia64, ppc, s390, and sparc.

[mhocko@suse.cz: fix implicit declaration of remove_pagetable]
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 4e58b83e6b2e..474e28f10815 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1011,6 +1011,14 @@ remove_pagetable(unsigned long start, unsigned long end, bool direct)
         flush_tlb_all();
 }
 
+void __ref vmemmap_free(struct page *memmap, unsigned long nr_pages)
+{
+        unsigned long start = (unsigned long)memmap;
+        unsigned long end = (unsigned long)(memmap + nr_pages);
+
+        remove_pagetable(start, end, false);
+}
+
 static void __meminit
 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
 {