[S390] Add support for memory hot-remove.

This patch enables memory hot-remove on s390.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 15 insertions, 1 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 2ed88122be93..8d41908e2513 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -317,6 +317,9 @@ config ARCH_ENABLE_MEMORY_HOTPLUG
         def_bool y
         depends on SPARSEMEM
 
+config ARCH_ENABLE_MEMORY_HOTREMOVE
+        def_bool y
+
 source "mm/Kconfig"
 
 comment "I/O subsystem configuration"
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 4993b0f594eb..1169130a97ef 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -179,7 +179,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
         int rc;
 
         pgdat = NODE_DATA(nid);
-        zone = pgdat->node_zones + ZONE_NORMAL;
+        zone = pgdat->node_zones + ZONE_MOVABLE;
         rc = vmem_add_mapping(start, size);
         if (rc)
                 return rc;
@@ -189,3 +189,14 @@ int arch_add_memory(int nid, u64 start, u64 size)
         return rc;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int remove_memory(u64 start, u64 size)
+{
+        unsigned long start_pfn, end_pfn;
+
+        start_pfn = PFN_DOWN(start);
+        end_pfn = start_pfn + PFN_DOWN(size);
+        return offline_pages(start_pfn, end_pfn, 120 * HZ);
+}
+#endif /* CONFIG_MEMORY_HOTREMOVE */