sh: Add support for memory hot-remove.

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/mm/Kconfig

@@ -134,6 +134,10 @@ config ARCH_ENABLE_MEMORY_HOTPLUG
 	def_bool y
 	depends on SPARSEMEM
 
+config ARCH_ENABLE_MEMORY_HOTREMOVE
+	def_bool y
+	depends on SPARSEMEM
+
 config ARCH_MEMORY_PROBE
 	def_bool y
 	depends on MEMORY_HOTPLUG

arch/sh/mm/init.c

@@ -292,4 +292,21 @@ int memory_add_physaddr_to_nid(u64 addr)
 }
 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int remove_memory(u64 start, u64 size)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT);
+	int ret;
+
+	ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
+	if (unlikely(ret))
+		printk("%s: Failed, offline_pages() == %d\n", __func__, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(remove_memory);
 #endif
+
+#endif /* CONFIG_MEMORY_HOTPLUG */