3 files changed, 37 insertions, 10 deletions

diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index cd15df6c63cd..5e781d824e6d 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -301,6 +301,8 @@ static inline int unregister_pm_notifier(struct notifier_block *nb)
 #define pm_notifier(fn, pri)    do { (void)(fn); } while (0)
 #endif /* !CONFIG_PM_SLEEP */
 
+extern struct mutex pm_mutex;
+
 #ifndef CONFIG_HIBERNATION
 static inline void register_nosave_region(unsigned long b, unsigned long e)
 {
@@ -308,8 +310,23 @@ static inline void register_nosave_region(unsigned long b, unsigned long e)
 static inline void register_nosave_region_late(unsigned long b, unsigned long e)
 {
 }
-#endif
 
-extern struct mutex pm_mutex;
+static inline void lock_system_sleep(void) {}
+static inline void unlock_system_sleep(void) {}
+
+#else
+
+/* Let some subsystems like memory hotadd exclude hibernation */
+
+static inline void lock_system_sleep(void)
+{
+        mutex_lock(&pm_mutex);
+}
+
+static inline void unlock_system_sleep(void)
+{
+        mutex_unlock(&pm_mutex);
+}
+#endif
 
 #endif /* _LINUX_SUSPEND_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index fd3386242cf0..44cf6f0a3a6d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -128,12 +128,9 @@ config SPARSEMEM_VMEMMAP
 config MEMORY_HOTPLUG
         bool "Allow for memory hot-add"
         depends on SPARSEMEM || X86_64_ACPI_NUMA
-        depends on HOTPLUG && !(HIBERNATION && !S390) && ARCH_ENABLE_MEMORY_HOTPLUG
+        depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG
         depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390)
 
-comment "Memory hotplug is currently incompatible with Software Suspend"
-        depends on SPARSEMEM && HOTPLUG && HIBERNATION && !S390
-
 config MEMORY_HOTPLUG_SPARSE
         def_bool y
         depends on SPARSEMEM && MEMORY_HOTPLUG
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 380aef45c2cf..2047465cd27c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -26,6 +26,7 @@
 #include <linux/migrate.h>
 #include <linux/page-isolation.h>
 #include <linux/pfn.h>
+#include <linux/suspend.h>
 
 #include <asm/tlbflush.h>
 
@@ -485,14 +486,18 @@ int __ref add_memory(int nid, u64 start, u64 size)
         struct resource *res;
         int ret;
 
+        lock_system_sleep();
+
         res = register_memory_resource(start, size);
+        ret = -EEXIST;
         if (!res)
-                return -EEXIST;
+                goto out;
 
         if (!node_online(nid)) {
                 pgdat = hotadd_new_pgdat(nid, start);
+                ret = -ENOMEM;
                 if (!pgdat)
-                        return -ENOMEM;
+                        goto out;
                 new_pgdat = 1;
         }
 
@@ -515,7 +520,8 @@ int __ref add_memory(int nid, u64 start, u64 size)
                 BUG_ON(ret);
         }
 
-        return ret;
+        goto out;
+
 error:
         /* rollback pgdat allocation and others */
         if (new_pgdat)
@@ -523,6 +529,8 @@ error:
         if (res)
                 release_memory_resource(res);
 
+out:
+        unlock_system_sleep();
         return ret;
 }
 EXPORT_SYMBOL_GPL(add_memory);
@@ -759,6 +767,8 @@ int offline_pages(unsigned long start_pfn,
         if (!test_pages_in_a_zone(start_pfn, end_pfn))
                 return -EINVAL;
 
+        lock_system_sleep();
+
         zone = page_zone(pfn_to_page(start_pfn));
         node = zone_to_nid(zone);
         nr_pages = end_pfn - start_pfn;
@@ -766,7 +776,7 @@ int offline_pages(unsigned long start_pfn,
         /* set above range as isolated */
         ret = start_isolate_page_range(start_pfn, end_pfn);
         if (ret)
-                return ret;
+                goto out;
 
         arg.start_pfn = start_pfn;
         arg.nr_pages = nr_pages;
@@ -844,6 +854,7 @@ repeat:
         writeback_set_ratelimit();
 
         memory_notify(MEM_OFFLINE, &arg);
+        unlock_system_sleep();
         return 0;
 
 failed_removal:
@@ -853,6 +864,8 @@ failed_removal:
         /* pushback to free area */
         undo_isolate_page_range(start_pfn, end_pfn);
 
+out:
+        unlock_system_sleep();
         return ret;
 }